阅读说明：本技术 植入式的双面电极及其制备方法 (Implanted double-sided electrode and preparation method thereof ) 是由 王蕾 张永成 于 2020-03-31 设计创作，主要内容包括：本公开提出了一种植入式的双面电极,双面电极具有正面和与正面相反的背面,其包括：第一绝缘层,其具有多个第一窗口；第一导电层,其设置在第一绝缘层上并包括多个第一电极刺激点、多条第一连接线和多个第一焊点；第二绝缘层,其覆盖第一绝缘层和第一导电层；第二导电层,其设置在第二绝缘层上并包括多个第二电极刺激点、多条第二连接线和多个第二焊点；以及第三绝缘层,其覆盖第二导电层和第二绝缘层,并且具有多个第二窗口,其中,多个第一电极刺激点经多个第一窗口暴露而形成背面侧电极阵列,多个第二电极刺激点经多个第二窗口暴露而形成正面侧电极阵列。根据本公开能够提供一种工艺简单的植入式的双面电极及其制备方法。(The present disclosure proposes an implantable double-sided electrode having a front side and a back side opposite to the front side, comprising: a first insulating layer having a plurality of first windows; a first conductive layer disposed on the first insulating layer and including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first solder points; a second insulating layer covering the first insulating layer and the first conductive layer; a second conductive layer disposed on the second insulating layer and including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second pads; and a third insulating layer covering the second conductive layer and the second insulating layer and having a plurality of second windows, wherein the plurality of first electrode stimulation points are exposed through the plurality of first windows to form a back-side electrode array, and the plurality of second electrode stimulation points are exposed through the plurality of second windows to form a front-side electrode array. According to the present disclosure, an implantable double-sided electrode with a simple process and a preparation method thereof can be provided.)

1. An implantable double-sided electrode having a front side and a back side opposite the front side,

the method comprises the following steps:

a first insulating layer having a plurality of first windows that penetrate the first insulating layer;

a first conductive layer disposed on the first insulating layer and formed in a first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first pads connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively;

a second insulating layer formed on the first conductive layer and covering the first insulating layer and the first conductive layer;

a second conductive layer disposed on the second insulating layer and formed in a second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second pads connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively; and

a third insulating layer formed on the second conductive layer and covering the second conductive layer and the second insulating layer, and having a plurality of second windows penetrating the third insulating layer,

wherein the plurality of first electrode stimulation points correspond to the plurality of first windows such that the plurality of first electrode stimulation points are exposed to the outside through the plurality of first windows to form a back side electrode array, the plurality of second electrode stimulation points correspond to the plurality of second windows such that the plurality of second electrode stimulation points are exposed to the outside through the plurality of second windows to form a front side electrode array opposite to the back side electrode array,

the plurality of first welding points correspond to a plurality of first channels, the first channels penetrate through the second insulating layer and the third insulating layer, the plurality of second welding points correspond to a plurality of second channels, and the second channels penetrate through the third insulating layer,

the first pads are exposed to the outside through the first channels to form a first pad array, the second pads are exposed to the outside through the second channels to form a second pad array, and the first pad array and the second pad array are located on the same side as the front side electrode array.

2. The bi-facial stimulation electrode of claim 1,

the front side electrode array and the back side electrode array form virtual electrode arrays in the front orthographic projection mode, and the virtual electrode arrays are staggered with each other.

3. The bi-facial stimulation electrode of claim 1 or 2,

the front side electrode array and the back side electrode array are arranged in the same arrangement mode, the distances between the adjacent second electrode stimulation points in the front side electrode array are equal to each other, and the distances between the adjacent first electrode stimulation points in the back side electrode array are equal to each other.

4. The double-sided electrode according to claim 1,

the first insulating layer and the second insulating layer are fused to each other, the second insulating layer and the third insulating layer are fused to each other, and the first conductive layer and the second conductive layer are insulated from each other by the second insulating layer.

5. The double-sided electrode according to claim 1,

the distance between the front-side electrode array and the second pad array is smaller than the distance between the back-side electrode array and the first pad array.

6. The double-sided electrode according to claim 1,

the double-sided electrode comprises an implanting end, a connecting portion and a welding end connected with the implanting end through the connecting portion, the front-side electrode array and the back-side electrode array are located at the implanting end, and the second pad array and the first pad array are located at the welding end.

7. A preparation method of an implanted double-sided electrode is characterized in that,

the method comprises the following steps:

(a) preparing a substrate with a first dielectric film and a second dielectric film which are opposite to each other, forming a sacrificial layer on the first dielectric film, and forming a first insulating layer on the sacrificial layer;

(b) forming a first conductive layer in a first predetermined pattern on the first insulating layer, and then forming a second insulating layer on the first conductive layer and covering the first insulating layer and the first conductive layer, the first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first pads connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively;

(c) forming a second conductive layer in a second predetermined pattern on the second insulating layer, and then forming a third insulating layer on the second conductive layer and covering the second insulating layer and the second conductive layer, the second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second pads connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively;

(d) forming a patterned mask layer on the third insulating layer and etching according to the pattern on the mask layer to form a plurality of second windows, a plurality of second channels and a plurality of first channels; and is

(e) Patterning and etching the second dielectric film to form a plurality of first windows to obtain the double-sided electrode,

wherein the first window penetrates the first insulating layer, the first channel penetrates the second insulating layer and the third insulating layer, and the second window and the second channel respectively penetrate the third insulating layer,

the plurality of first electrode stimulation points correspond to the plurality of first windows so that the plurality of first electrode stimulation points are exposed to the outside through the plurality of first windows to form a back side electrode array, the plurality of second electrode stimulation points correspond to the plurality of second windows so that the plurality of second electrode stimulation points are exposed to the outside through the plurality of second windows to form a front side electrode array opposite to the back side electrode array,

the plurality of first welding spots correspond to the plurality of first channels, the plurality of first welding spots are exposed to the outside through the plurality of first channels to form a first pad array, the plurality of second welding spots correspond to the plurality of second channels, the plurality of second welding spots are exposed to the outside through the plurality of second channels to form a second pad array, and the first pad array and the second pad array are positioned on the same side as the front side electrode array.

8. The production method according to claim 7,

in the step (a), patterning the sacrificial layer and etching to form a groove for marking, wherein the position of the groove corresponds to the position of the first window.

9. The production method according to claim 7,

in the step (b), a patterned protection layer is formed on the first insulating layer, and the protection layer is removed after the first conductive layer is formed, so that the first conductive layer in a first predetermined pattern is formed.

10. The production method according to claim 7,

the first insulating layer, the second insulating layer and the third insulating layer are respectively made of flexible insulating materials, the flexible insulating materials are at least one of polyimide, polyethylene terephthalate, parylene, silicone resin, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol or polytetrafluoroethylene resin,

the first conductive layer and the second conductive layer are respectively made of metal materials, the metal materials are at least one of silver, platinum, gold, titanium, palladium, iridium and niobium,

the sacrificial layer is made of at least one of aluminum, silicon oxide, chromium and titanium.

Technical Field

The present disclosure relates to an implantable double-sided electrode and a method of making the same.

Background

Electrodes are widely used in biomedical engineering, for example, electrodes can be used to obtain bioelectric signals and to electrically stimulate nerves or myogenic tissue, etc. As an example of obtaining the bioelectrical signal, for example, it is possible to record an electrophysiological signal of a nerve cell and obtain a multidimensional weak signal such as an electrochemical signal of a neurotransmitter such as dopamine by implanting a microelectrode, and it is important to research a neural network. As an example of electrically stimulating the nerve or myogenic tissue, for example, the microelectrode implanted in the body acts on the target tissue to electrically stimulate the specific tissue, repair the specific function, such as artificial retina, convert the image into a stimulating electrical signal through an in vitro device, and the microelectrode transmits a stimulating current to the optic nerve to promote the blindness person to generate a certain visual experience.

For the electrode, in order to improve the quality of the acquired bioelectrical signal and the selectivity of the electrical stimulation, a double-sided electrode is often required, however, the current double-sided electrode preparation process is complex, and in order to reduce the damage to the biological tissue, the double-sided electrode often uses a flexible material as a substrate material, and the flexible material is used, so that the processing on the substrate is necessary, and the difficulty of the double-sided electrode preparation process is further increased.

Patent document (CN101172185A) provides a method for preparing an embedded double-sided flexible microarray electrode, in which a silicon wafer containing a sacrificial layer and having a front electrode is bonded to a patterned glass substrate by a bonding method through thermocompression bonding, a back electrode is formed after the silicon wafer containing the sacrificial layer is removed, and then the glass substrate is removed, so as to obtain a flexible electrode. However, in the manufacturing method disclosed in this patent document, bonding alignment is required, deviation is easily generated, and two kinds of substrates need to be processed, which increases the difficulty of the process.

Disclosure of Invention

The present disclosure has been made in view of the above-mentioned state of the art, and an object thereof is to provide an implantable double-sided electrode having a simple process and a method for manufacturing the same.

To this end, the present disclosure provides, in one aspect, an implantable double-sided electrode having a front side and a back side opposite the front side, comprising: a first insulating layer having a plurality of first windows that penetrate the first insulating layer; a first conductive layer disposed on the first insulating layer and formed in a first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first pads connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively; a second insulating layer formed on the first conductive layer and covering the first insulating layer and the first conductive layer; a second conductive layer disposed on the second insulating layer and formed in a second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection parts, and a plurality of second pads connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively; and a third insulating layer formed on the second conductive layer and covering the second conductive layer and the second insulating layer, and having a plurality of second windows penetrating the third insulating layer, wherein the plurality of first electrode stimulation points correspond to the plurality of first windows such that the plurality of first electrode stimulation points are exposed to the outside through the plurality of first windows to form a back side electrode array, the plurality of second electrode stimulation points correspond to the plurality of second windows such that the plurality of second electrode stimulation points are exposed to the outside through the plurality of second windows to form a front side electrode array opposite to the back side electrode array, the plurality of first pads correspond to a plurality of first channels penetrating the second insulating layer and the third insulating layer, and the plurality of second pads correspond to the plurality of second channels, the second channel penetrates through the third insulating layer, the first welding spots are exposed to the outside through the first channels to form a first welding pad array, the second welding spots are exposed to the outside through the second channels to form a second welding pad array, and the first welding pad array and the second welding pad array are located on the same side with the front side electrode array. In an aspect of the present disclosure, a double-layered electrode structure is employed, a first window exposes a first electrode stimulation point of a first conductive layer from a back side direction, a second window exposes a second electrode stimulation point of a second conductive layer from a front side direction, and both a first pad and a second pad are exposed in the front side direction, whereby the double-layered electrode structure can be simply manufactured.

In addition, in the double-sided electrode according to the aspect of the present disclosure, it is preferable that virtual electrode arrays formed by orthographic projections of the front-side electrode array and the back-side electrode array on the front surface intersect with each other. This can contribute to reducing the mutual interference between the front-side electrode array and the back-side electrode array.

In addition, in the double-sided electrode according to the aspect of the present disclosure, optionally, the front-side electrode array and the back-side electrode array are arranged in the same arrangement, distances between the adjacent second electrode stimulation points in the front-side electrode array are equal to each other, and distances between the adjacent first electrode stimulation points in the back-side electrode array are equal to each other. Thus, the front-side electrode array and the back-side electrode array can be easily produced.

In addition, in the double-sided electrode according to the aspect of the present disclosure, optionally, the first insulating layer and the second insulating layer are merged with each other, the second insulating layer and the third insulating layer are merged with each other, and the first conductive layer and the second conductive layer are insulated from each other by the second insulating layer. Therefore, the first insulating layer, the second insulating layer and the third insulating layer can be fused into a whole, and mutual interference between the first conductive layer and the second conductive layer can be further reduced.

In addition, in the double-sided electrode according to the aspect of the present disclosure, optionally, a distance between the front-side electrode array and the second pad array is smaller than a distance between the back-side electrode array and the first pad array. This can facilitate the same-side arrangement of the first pad array and the second pad array.

In addition, in the double-sided electrode according to the aspect of the present disclosure, optionally, the double-sided electrode includes an implanting end, a connecting portion, and a welding end connected to the implanting end via the connecting portion, the front-side electrode array and the back-side electrode array are located at the implanting end, and the second pad array and the first pad array are located at the welding end. Thereby, the front-side electrode array and the back-side electrode array can be easily arranged at one end, and the second pad array and the first pad array can be arranged at the other end.

Another aspect of the present disclosure provides a method for preparing an implantable double-sided electrode, comprising the steps of: (a) preparing a substrate with a first dielectric film and a second dielectric film which are opposite to each other, forming a sacrificial layer on the first dielectric film, and forming a first insulating layer on the sacrificial layer; (b) forming a first conductive layer in a first predetermined pattern on the first insulating layer, and then forming a second insulating layer on the first conductive layer and covering the first insulating layer and the first conductive layer, the first predetermined pattern including a plurality of first electrode stimulation points, a plurality of first connection lines, and a plurality of first pads connected to the plurality of first electrode stimulation points via the plurality of first connection lines, respectively; (c) forming a second conductive layer in a second predetermined pattern on the second insulating layer, and then forming a third insulating layer on the second conductive layer and covering the second insulating layer and the second conductive layer, the second predetermined pattern including a plurality of second electrode stimulation points, a plurality of second connection lines, and a plurality of second pads connected to the plurality of second electrode stimulation points via the plurality of second connection lines, respectively; (d) forming a patterned mask layer on the third insulating layer and etching according to the pattern on the mask layer to form a plurality of second windows, a plurality of second channels and a plurality of first channels; and (e) patterning and etching the second dielectric film to form a plurality of first windows, so as to obtain the double-sided electrodes, wherein the first windows penetrate through the first insulating layer, the first channels penetrate through the second insulating layer and the third insulating layer, the second windows and the second channels respectively penetrate through the third insulating layer, a plurality of first electrode stimulation points correspond to the plurality of first windows, so that the plurality of first electrode stimulation points are exposed to the outside through the plurality of first windows to form a back-side electrode array, a plurality of second electrode stimulation points correspond to the plurality of second windows, so that the plurality of second electrode stimulation points are exposed to the outside through the plurality of second windows to form a front-side electrode array opposite to the back-side electrode array, and a plurality of first welding points correspond to the plurality of first channels, the first welding spots are exposed to the outside through the first channels to form a first welding pad array, the second welding spots correspond to the second channels, the second welding spots are exposed to the outside through the second channels to form a second welding pad array, and the first welding pad array and the second welding pad array are located on the same side with the front side electrode array. Therefore, the double-sided electrode can be simply prepared, and the yield and the repeatability of the double-sided electrode preparation process are improved.

In addition, in the double-sided electrode according to another aspect of the present disclosure, optionally, in the step (a), the method further includes performing patterning processing on the sacrificial layer and etching to form a groove for marking, where a position of the groove corresponds to a position of the first window. Therefore, the first window can be facilitated to be etched later.

In addition, in the double-sided electrode according to another aspect of the present disclosure, optionally, in the step (b), a patterned protection layer is formed on the first insulating layer, and the protection layer is removed after the first conductive layer is formed, so that the first conductive layer in a first predetermined pattern is formed. Thus, the first conductive layer can be easily prepared.

In addition, in the double-sided electrode according to another aspect of the present disclosure, optionally, the first insulating layer, the second insulating layer, and the third insulating layer are each made of a flexible insulating material, the flexible insulating material is at least one of polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethyl methacrylate, polyethylene glycol, or polytetrafluoroethylene resin, the first conductive layer and the second conductive layer are each made of a metal material, the metal material is at least one of silver, platinum, gold, titanium, palladium, iridium, and niobium, and the sacrificial layer is at least one selected from aluminum, silicon oxide, chromium, and titanium. Thus, a double-sided electrode having biocompatibility and good electrical conductivity can be prepared.

According to the present disclosure, an implantable double-sided electrode with a simple process and a preparation method thereof can be provided.

Drawings

The disclosure will now be explained in further detail by way of example only with reference to the accompanying drawings, in which:

fig. 1 is a schematic diagram illustrating the structure of an implantable double-sided electrode according to an example of the present disclosure.

Fig. 2 shows a top view of an implantable, double-sided electrode according to examples of the present disclosure.

Fig. 3 shows a partial view of an implantable double-sided electrode according to an example of the present disclosure.

Fig. 4 illustrates an orthographic view of first and second electrode stimulation points on a front side of an implantable, bifacial electrode according to another example of the present disclosure.

Fig. 5 shows a flow chart of a method of making an implantable, double-sided electrode according to examples of the present disclosure.

Fig. 6 shows a schematic process diagram of a method for manufacturing an implantable double-sided electrode according to an example of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic and the ratio of the dimensions of the components and the shapes of the components may be different from the actual ones.

In the present disclosure, the implanted double-sided electrode 1 may be simply referred to as "double-sided electrode 1", and the method for manufacturing the implanted double-sided electrode 1 may be simply referred to as "manufacturing method". In addition, the implantable double-sided electrode 1 according to the present disclosure can be applied to, for example, an artificial retina to transmit a stimulation current to a optic nerve or the like. Furthermore, the implantable double-sided electrode 1 may have a front side 1A and a back side 1B opposite the front side 1A.

In the present embodiment, the double-sided electrode 1 may include an implanting end 1a, a connecting portion 1b, and a welding end 1 c. Wherein the implanting end 1a can be connected with the welding end 1c through the connecting portion 1 b. In some examples, the implantation end 1a may have a stimulation portion that releases an electrical stimulation signal, for example, when the bifacial electrode 1 according to the present embodiment is used to stimulate nerves or tissues, the implantation end 1a may be implanted into a living body (e.g., eyeball, brain, cochlea, etc.), and the stimulation portion may release an electrical stimulation signal into which a specific signal (e.g., a visual signal) is converted at a designated position (e.g., retina) to repair a specific function (e.g., vision). In some examples, the welding tip 1c may be electrically connected with an external structure that converts a specific signal into an electrical stimulation signal to receive the electrical stimulation signal. Examples of the present disclosure are not limited thereto, and in some examples, the double-sided electrode 1 may acquire a bioelectric signal.

Fig. 1 is a schematic diagram showing the structure of an implantable double-sided electrode 1 according to an example of the present disclosure. Fig. 2 shows a top view of an implantable double-sided electrode 1 according to an example of the present disclosure.

In this embodiment, as shown in fig. 1, the implantable double-sided electrode 1 may include an insulating substrate 10 and a metal electrode 20. Among them, the insulating substrate 10 may include a first insulating layer 11, a second insulating layer 12, and a third insulating layer 13, and the metal electrode 20 may include a first conductive layer 21 and a second conductive layer 22. In addition, as shown in fig. 1, a first conductive layer 21 may be disposed on the first insulating layer 11, a second insulating layer 12 may be formed on the first conductive layer 21 and cover the first insulating layer 11 and the first conductive layer 21, and a third insulating layer 13 may be formed on the second conductive layer 22 and cover the second conductive layer 22 and the second insulating layer 12.

In some examples, the first conductive layer 21 may be formed in a first predetermined pattern including a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first pads 213 connected to the plurality of first electrode stimulation points 211 via the plurality of first connection lines 212, respectively (refer to fig. 2). In other examples, the second conductive layer 22 may be formed in a second predetermined pattern T including a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second pads 223 connected to the plurality of second electrode stimulation points 221 via the plurality of second connection lines 222, respectively.

In some examples, the first insulating layer 11 may have a plurality of first windows 111, and the plurality of first windows 111 may penetrate the first insulating layer 11. In addition, in some examples, as shown in fig. 1, the third insulating layer 13 may have a plurality of second windows 131, and the plurality of second windows 131 may penetrate the third insulating layer 13.

In some examples, optionally, the plurality of first electrode stimulation points 211 correspond to the plurality of first windows 111 such that the plurality of first electrode stimulation points 211 are exposed to the outside through the plurality of first windows 111 to form a back-side electrode array, and the plurality of second electrode stimulation points 221 correspond to the plurality of second windows 131 such that the plurality of second electrode stimulation points 221 are exposed to the outside through the plurality of second windows 131 to form a front-side electrode array P. In addition, the front-side electrode array P may be opposite to the back-side electrode array.

In some examples, the plurality of first pads 213 may correspond to the plurality of first channels 133, wherein the first channels 133 may penetrate the second insulating layer 12 and the third insulating layer 13 (refer to fig. 1). In other examples, the plurality of second pads 223 may correspond to the plurality of second channels 132, wherein the second channels 132 may penetrate the third insulation layer 13 (refer to fig. 1).

In some examples, the plurality of first pads 213 may be exposed to the outside through the plurality of first channels 133 to form a first pad array R, and the plurality of second pads 223 may be exposed to the outside through the plurality of second channels 132 to form a second pad array Q, respectively. In addition, as shown in fig. 2, the first pad array R and the second pad array Q may be located on the same side as the front-side electrode array P.

In the double-sided electrode 1 according to the present embodiment, the double-layered electrode structure is adopted, and the first window 111 exposes the first electrode stimulation point 211 of the first conductive layer 21 from the back side direction, the second window 131 exposes the second electrode stimulation point 221 of the second conductive layer 22 from the front side direction, and the first pad 213 and the second pad 223 are both exposed in the front side direction, so that the double-layered electrode structure can be easily manufactured, the mutual interference between the first conductive layer 21 and the second conductive layer 22 can be reduced, the electrical performance can be improved, and the electrical connection of the first pad 213 and the electrical connection of the second pad 223 can be facilitated.

In some examples, the insulating substrate 10 may be composed of a flexible insulating material. In addition, the insulating substrate 10 may have biocompatibility. In other examples, the flexible insulating material may be at least one selected from polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethylmethacrylate, polyethylene glycol, or polytetrafluoroethylene resin.

In some examples, the insulating substrate 10 may be composed of a first insulating layer 11, a second insulating layer 12, and a third insulating layer 13. In addition, in some examples, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 may be respectively composed of a flexible insulating material. Thus, a double-sided electrode having biocompatibility can be formed. In other examples, the first, second, and third insulating layers 11, 12, and 13 may be constructed of the same or different flexible insulating materials.

In some examples, the first insulating layer 11 may have a plurality of first windows 111, and each of the first windows 111 may penetrate the first insulating layer 11. In some examples, the first window 111 may be located at the implanted end 1a of the double-sided electrode 1.

In some examples, the thickness of the first insulating layer 11 may be 4 μm to 7 μm. For example, the thickness of the first insulating layer 11 may be 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, or 7.0 μm. In addition, the thickness of the first insulating layer 11 of the present disclosure is not limited thereto.

In some examples, the aperture of the first window 111 may be 100 μm to 500 μm. For example, the aperture of the first window 111 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the aperture of the first window 111 of the present disclosure is not limited thereto.

In some examples, the aperture of the first window 111 may also be selected according to the number of first windows 111. In other examples, the aperture of each first window 111 may be the same or different, depending on practical requirements.

In some examples, the shape of the first window 111 is not particularly limited. For example, the first window 111 may have a regular shape such as a cylinder cube, an elliptical cylinder, a triangular cylinder, or the like, or may have an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shapes of the respective first windows 111 may be the same or different.

In some examples, the number of the first windows 111 is not particularly limited, for example, the number of the first windows 111 may be 2, 10, 20, 40, 64, or the like, and may also be 1.

In some examples, the spacing between the respective first windows 111 may be 100 μm to 1500 μm. For example, the pitch between the respective first windows 111 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the spacing between the first windows 111 is selected depending on the application and the layout of the first electrode stimulation points 211. Further, the interval between the respective first windows 111 of the present disclosure is not limited thereto.

In some examples, as shown in fig. 1, the central axis direction of the first window 111 may be substantially perpendicular to the front surface 1A and the back surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the first window 111 may form an oblique angle with the front surface 1A and the back surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis directions of the respective first windows 111 may be the same or different.

In some examples, in the second insulating layer 12, the front surface may be covered by the third insulating layer 13 and the second conductive layer 22, and the rear surface may cover the first insulating layer 11 and the first conductive layer 21. In addition, the second insulating layer 12 may have a plurality of vias forming the first channel 133, and each of the vias may penetrate the second insulating layer 12.

In some examples, the thickness of the second insulating layer 12 may be 4 μm to 7 μm. For example, the thickness of the second insulating layer 12 may be 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, or 7.0 μm. In addition, the thickness of the second insulating layer 12 of the present disclosure is not limited thereto.

In some examples, the aperture of the via on the second insulating layer 12 may be 100 μm to 200 μm. For example, the aperture of the via on the second insulating layer 12 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the aperture of the via on the second insulating layer 12 of the present disclosure is not limited thereto.

In some examples, the pitch between the respective vias on the second insulating layer 12 may be 100 μm to 500 μm. For example, the pitch between the respective vias on the second insulating layer 12 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the pitch between the respective vias on the second insulating layer 12 of the present disclosure is not limited thereto. In addition, the spacing between the vias on the second insulating layer 12 may be equal or different.

In some examples, the shape of the via on the second insulating layer 12 is not particularly limited. For example, the shape of the via on the second insulating layer 12 may be a cylindrical cube, an elliptical cylinder, a triangular cylinder, or the like. In other examples, the number of vias on the second insulating layer 12 is not particularly limited. For example, the number of vias on the second insulating layer 12 may be the same as the number of first windows 111.

In some examples, the third insulating layer 13 may have a plurality of second windows 131 and a plurality of second channels 132. In other examples, each second window 131 may extend through the third insulating layer 13, and each second channel 132 may extend through the third insulating layer 13. In addition, the second window 131 may be located at the implantation end 1a of the double-sided electrode 1, and the second channel 132 may be located at the welding end 1c of the double-sided electrode 1.

In some examples, the third insulating layer 13 may include a plurality of perforations forming the first channel 133. In other examples, the perforations of the third insulating layer 13 may cooperate with the passages of the second insulating layer 12 to form the first channels 133. In addition, the first channel 133 may be located at the welding end 1c of the double-sided electrode 1.

In some examples, the thickness of the third insulating layer 13 may be 4 μm to 7 μm. For example, the thickness of the third insulating layer 13 may be 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, or 7.0 μm. In addition, the thickness of the third insulating layer 13 of the present disclosure is not limited thereto.

In some examples, the aperture of the second window 131 may be 100 μm to 500 μm. For example, the aperture of the second window 131 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the aperture of the second window 131 of the present disclosure is not limited thereto. In addition, the aperture of the second window 131 may be the same as or different from the aperture of the first window 111.

In some examples, the aperture of the second window 131 may also be selected according to the number of second windows 131. In some examples, the aperture of each second window 131 may be the same. In other examples, the aperture of each second window 131 may be different according to actual requirements.

In some examples, the shape of the second window 131 is not particularly limited. For example, the second window 131 may have a regular shape such as a cylinder cube, an elliptical cylinder, a triangular cylinder, or the like, or may have an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shapes of the respective second windows 131 may be the same or different.

In some examples, the number of the second windows 131 is not particularly limited, for example, the number of the second windows 131 may be 2, 10, 20, 40, 64, or the like, and may also be 1. In addition, the number of the second windows 131 may be the same as or different from the number of the first windows 111.

In some examples, the spacing between the respective second windows 131 may be 100 μm to 1500 μm. For example, the pitch between the respective second windows 131 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the interval between the respective second windows 131 of the present disclosure is not limited thereto. In addition, the spacing between the second windows 131 is selected depending on the application, the layout of the second electrode stimulation points 221.

In some examples, as shown in fig. 1, the central axis direction of the second window 131 may be substantially perpendicular to the front surface 1A and the back surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the second window 131 may form an oblique angle with the front surface 1A and the back surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis directions of the respective second windows 131 may be the same or different.

In some examples, the pore size of the second channel 132 may be 100 μm to 200 μm. For example, the pore size of the second channel 132 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the aperture of the second channel 132 of the present disclosure is not limited thereto.

In other examples, the spacing between the second channels 132 may be 100 μm to 500 μm. For example, the pitch between the respective second channels 132 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the interval between the respective second channels 132 of the present disclosure is not limited thereto. Further, the spacing between the respective second channels 132 may be equal or unequal.

In some examples, the shape of the second channel 132 is not particularly limited. For example, the second window 131 may have a regular shape such as a cylinder cube, an elliptical cylinder, a triangular cylinder, or the like, or may have an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shape of each second channel 132 may be the same or different.

In some examples, the number of second channels 132 is not particularly limited. For example, the number of second channels 132 may be the same as or different from the number of second windows 131.

In some examples, as shown in fig. 1, the central axis direction of the second channel 132 may be substantially perpendicular to the front surface 1A and the back surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the second channel 132 may form an oblique angle with the front surface 1A and the back surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis directions of the respective second channels 132 may be the same or different.

In some examples, the aperture of the perforations on the third insulating layer 13 may be 100 μm to 200 μm. For example, the aperture of the through-holes on the third insulating layer 13 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the aperture of the perforations on the third insulating layer 13 of the present disclosure is not limited thereto.

In some examples, the pitch between the respective through holes on the third insulation layer 13 may be 100 μm to 500 μm. For example, the pitch between the respective through holes on the third insulating layer 13 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the interval between the respective through holes on the third insulation layer 13 of the present disclosure is not limited thereto. In addition, the spacing between the perforations in the third insulating layer 13 may be equal or different.

In some examples, the shape of the perforations on the third insulating layer 13 is not particularly limited. For example, the shape of the through hole on the third insulating layer 13 may be a cylindrical cube, an elliptical cylinder, a triangular cylinder, or the like. In other examples, the number of perforations in the third insulating layer 13 is not particularly limited. For example, the number of perforations in the third insulating layer 13 may be the same as the number of first windows 111, and the number of perforations in the third insulating layer 13 may be the same as the number of vias in the second insulating layer 12.

In some examples, as shown in fig. 1, the first channel 133 may be composed of a perforation of the third insulating layer 13 and a passage of the second insulating layer 12, which have the same shape and aperture. In other examples, the through holes of the third insulating layer 13 and the through holes of the second insulating layer 12 are aligned.

In some examples, the aperture of the first channel 133 may be 100 μm to 200 μm. In addition, the aperture of the first channel 133 of the present disclosure is not limited thereto. In addition, the aperture of the first channel 133 may be the same as or different from the aperture of the second channel 132.

In some examples, the pitch between the respective first channels 133 may be 100 μm to 500 μm. In addition, the interval between the respective first channels 133 of the present disclosure is not limited thereto. Further, the spacing between the respective first channels 133 may be equal or unequal.

In some examples, the shape of the first channel 133 is not particularly limited. For example, the second window 131 may have a regular shape or an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the shape of each first channel 133 may be the same or different.

In some examples, the number of first channels 133 is not particularly limited. For example, the number of the first channels 133 may be the same as or different from the number of the first windows 111.

In some examples, the central axis direction of the first channel 133 may be substantially perpendicular to the front surface 1A and the back surface 1B of the double-sided electrode 1. In other examples, the central axis direction of the first channel 133 may form an oblique angle with the front surface 1A and the back surface 1B of the double-sided electrode 1. In addition, in some examples, the central axis directions of the respective first channels 133 may be the same or different.

In some examples, the first insulating layer 11 and the second insulating layer 12 may be fused to each other, and the second insulating layer 12 and the third insulating layer 13 may be fused to each other. Thereby, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 can be integrated. That is, there may be no distinct boundary between the first insulating layer 11 and the second insulating layer 12, and there may be no distinct boundary between the second insulating layer 12 and the third insulating layer 13. In other words, the insulating substrate 10 may be integrally molded. This can reduce the possibility of delamination after implantation.

In some examples, the metal electrode 20 may be composed of a conductive metal material. In addition, the metal electrode 20 may have biocompatibility. In other examples, the metal electrode 20 may be composed of at least one selected from silver, platinum, gold, titanium, palladium, iridium, and niobium.

In some examples, the metal electrode 20 may include a first conductive layer 21 and a second conductive layer 22. In some examples, the first conductive layer 21 and the second conductive layer 22 may be respectively composed of a metal material. In some examples, the metal material may be at least one selected from silver, platinum, gold, titanium, palladium, iridium, niobium. Thus, a double-sided electrode having good conductive properties can be formed. In other examples, the first conductive layer 21 and the second conductive layer 22 may be composed of the same material.

In some examples, first conductive layer 21 and second conductive layer 22 may be composite metal layers, such as a titanium-platinum-titanium structure, a titanium-gold-titanium structure, a niobium-gold-niobium structure, or the like. Thus, the conductive sheet has good conductive performance.

In some examples, the thickness of the first conductive layer 21 may be 400nm to 600 nm. For example, the thickness of the first conductive layer 21 may be 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, or 700 nm.

In some examples, the thickness of the second conductive layer 22 may be 400nm to 600 nm. For example, the thickness of the second conductive layer 22 may be 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, or 700 nm. In addition, the thickness of the first conductive layer 21 may be the same as or different from the thickness of the second conductive layer 22.

In some examples, the thickness of the upper metal layer may be 30nm to 100nm, the thickness of the middle metal layer may be 100nm to 300nm, and the thickness of the lower metal layer may be 30nm to 100nm in the composite metal layer. For example, in the titanium-platinum-titanium structure, the thickness of the titanium metal layer may be 30nm to 100nm, the thickness of the platinum metal layer may be 100nm to 300nm, and the thickness of the titanium metal layer may be 30nm to 100 nm.

In some examples, as shown in fig. 1, an end of the first conductive layer 21 at the implanted end 1a may be aligned with an end of the second conductive layer 22 at the implanted end 1 a. In addition, the first conductive layer 21 and the second conductive layer 22 may not be aligned at both ends.

In some examples, as shown in fig. 2, the first conductive layer 21 is formed in a first predetermined pattern on the first insulating layer 11. In other examples, as shown in fig. 2, the first conductive layer 21 may include a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first pads 213.

In some examples, as shown in fig. 2, the first predetermined pattern may be composed of a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first pads 213 connected to the plurality of first electrode stimulation points 211 via the plurality of first connection lines 212, respectively.

In some examples, the shape of the first electrode stimulation points 211 is not particularly limited, for example, the first electrode stimulation points 211 may have a regular shape, such as a circle, a square, a diamond, a triangle, etc., or may have an irregular shape (including a shape in which a regular shape and an irregular shape are combined). In addition, the shape of each first electrode stimulation point 211 may be the same or different.

In some examples, the number of the first electrode stimulation points 211 is not particularly limited, for example, the number of the first electrode stimulation points 211 may be 2, 10, 20, 40, 64, and the like, and may also be 1. In addition, the number of first electrode stimulation points 211 may be the same as or different from the number of first windows 111.

In some examples, the arrangement shape of the first electrode stimulation points 211 is not particularly limited. In some examples, the first electrode stimulation points 211 may be arranged in a regular shape such as an octagonal array, a square, a circle, and so forth. In other examples, the first electrode stimulation points 211 may also be arranged in irregular shapes (including a combination of regular and irregular shapes). In addition, the arrangement of the first windows 111 may be the same as the arrangement of the first electrode stimulation points 211.

In some examples, the outer diameter of the first electrode stimulation spot 211 may be 100 μm to 500 μm. For example, the outer diameter of the first stimulation spot may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the outer diameter of the first stimulation point may be equal to or different from the aperture of the first window 111.

In some examples, the outer diameter of the first electrode stimulation points 211 may also be selected according to the number of first electrode stimulation points 211. In other examples, the outer diameter of each first electrode stimulation point 211 may be the same or different according to actual needs.

In some examples, the spacing between the individual first electrode stimulation points 211 may be 100 μm to 1500 μm. For example, the spacing between the individual first electrode stimulation points 211 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the spacing between the individual first electrode stimulation points 211 is selected depending on the application and layout.

In some examples, the shape of the first welding points 213 is not particularly limited, for example, the first welding points 213 may have a ring shape, such as a circular ring, a square ring elliptical ring, a circular square hole, a square circular hole, and the like. Thereby, the first pads 213 can be advantageously electrically connected. In addition, in some examples, the first connection line 212 may be elongated, such as a string.

In some examples, the first solder joint 213 may have an outer diameter of 100 μm to 200 μm. For example, the first solder joint 213 may have an outer diameter of 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the outer diameter of the first welding spots 213 may be equal to or different from the aperture of the first channel 133.

In some examples, the pitch between the respective first welding points 213 may be 100 μm to 500 μm. For example, the pitch between the respective first pads 213 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the intervals between the respective first pads 213 may be equal or different.

In some examples, the number of the first welding points 213 is not particularly limited. For example, the number of the first welding points 213 may be the same as or different from the number of the first stimulation points. In addition, the number of the first pads 213 may be the same as or different from the number of the first channels 133. In addition, the number of the first welding points 213 may be the same as or different from the number of the first stimulation points.

In some examples, the arrangement shape of the first welding points 213 is not particularly limited. In some examples, the first pads 213 may be arranged in a regular shape such as an octagonal array, a square, a circle, and the like. In other examples, the first welding points 213 may also be arranged in irregular shapes (including a combination of regular shapes and irregular shapes). In addition, the arrangement of the first channels 133 may be the same as the arrangement of the first pads 213.

In some examples, as shown in fig. 1, the first electrode stimulation point 211 may correspond to the first window 111. In other examples, the first electrode stimulation point 211 may be exposed to the outside via the first window 111.

In some examples, the plurality of first electrode stimulation points 211 may correspond to the plurality of first windows 111, respectively. In other words, each first electrode stimulation point 211 may correspond to one first window 111, respectively.

In some examples, the plurality of first electrode stimulation points 211 may be exposed to the outside through the plurality of first windows 111, respectively, to form a back-side electrode array (refer to fig. 2). In other words, each of the first electrode stimulation points 211 may be exposed to the outside through one of the first windows 111 and arranged in the back-side electrode array, respectively.

In some examples, the arrangement of the back-side electrode array is not particularly limited. In some examples, the array of backside electrodes may be arranged in a regular shape such as an octagonal array, a square, a circle, or the like. In other examples, the back-side electrode array may be arranged in an irregular shape (including a combination of a regular shape and an irregular shape). In addition, the distances between the adjacent first electrode stimulation points 211 in the back-side electrode array may be equal to each other. This makes it possible to easily produce the rear-side electrode array.

In some examples, as shown in fig. 1, the first pads 213 may correspond to the first channels 133. In other examples, the first solder 213 may be exposed to the outside through the first channel 133.

In some examples, the plurality of first pads 213 may correspond to the plurality of first channels 133, respectively. In other words, each of the first pads 213 may correspond to one of the first channels 133, respectively.

In some examples, the plurality of first pads 213 may be exposed to the outside through the plurality of first channels 133, respectively, to form a first pad array R (refer to fig. 2). In other words, the first pads 213 may be exposed to the outside through the first vias 133 and arranged in the first pad array R.

In some examples, the arrangement of the first pad array R is not particularly limited. In some examples, the first pad array R may be arranged in a regular shape such as an octagonal array, a square, a circle, and the like. In other examples, the first pad array R may be arranged in an irregular shape (including a combination of a regular shape and an irregular shape). In addition, distances between the adjacent first pads 213 in the first pad array R may be equal to each other.

In some examples, as shown in fig. 2, in the first conductive layer 21, the plurality of first electrode stimulation points 211 may be connected with the plurality of first pads 213 via the plurality of first connection lines 212, respectively. In other words, the plurality of first electrode stimulation points 211 may be connected to the plurality of first pads 213 via the plurality of first connection lines 212 in a one-to-one correspondence. That is, each of the first electrode stimulation points 211 may be connected with one of the first pads 213 via one of the first connection lines 212. In addition, the first connection lines 212 may not contact each other.

In some examples, in the first conductive layer 21, two or more first electrode stimulation points 211 may be connected with one first pad 213 via at least one first connection line 212. For example, two first electrode stimulation points 211 may be connected to one first pad 213 via one first connection line 212, two first electrode stimulation points 211 may be connected to one first pad 213 via two first connection lines 212, and so on.

In some examples, the second conductive layer 22 is formed in a second predetermined pattern T on the second insulating layer 12. In other examples, the second conductive layer 22 may include a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second pads 223.

In some examples, the second predetermined pattern T may be composed of a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second pads 223 connected to the plurality of second electrode stimulation points 221 via the plurality of second connection lines 222, respectively.

In some examples, the shape of the second electrode stimulation points 221 is not particularly limited, for example, the second electrode stimulation points 221 may have a regular shape, such as a circle, a square, a diamond, a triangle, etc., or may have an irregular shape (including a shape in which a regular shape and an irregular shape are combined). In addition, the shape of each second electrode stimulation point 221 may be the same or different.

In some examples, the number of the second electrode stimulation points 221 is not particularly limited, for example, the number of the second electrode stimulation points 221 may be 2, 10, 20, 40, 64, and the like, and may also be 1. In addition, the number of second electrode stimulation points 221 may be the same as or different from the number of second windows 131. Further, the number of second electrode stimulation points 221 may be the same as or different from the number of first electrode stimulation points 211.

In some examples, the arrangement shape of the second electrode stimulation points 221 is not particularly limited. In some examples, the second electrode stimulation points 221 may be arranged in a regular shape such as an octagonal array, a square, a circle, and the like. In other examples, the second electrode stimulation points 221 may also be arranged in irregular shapes (including a combination of regular and irregular shapes). In addition, the arrangement of the second windows 131 may be the same as the arrangement of the second electrode stimulation points 221. In addition, the arrangement of the second electrode stimulation points 221 may be the same as the arrangement of the first electrode stimulation points 211.

In some examples, the outer diameter of the second electrode stimulation point 221 may be 100 μm to 500 μm. For example, the outer diameter of the second stimulation spot may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. In addition, the outer diameter of the second stimulation point may be equal to or different from the aperture of the second window 131. Furthermore, the outer diameter of the second stimulation point may be the same as or different from the outer diameter of the first stimulation point.

In some examples, the outer diameter of the second electrode stimulation points 221 may also be selected according to the number of second electrode stimulation points 221. In other examples, the outer diameter of each second electrode stimulation point 221 may be the same or different according to actual needs.

In some examples, the spacing between the individual second electrode stimulation points 221 may be 100 μm to 1500 μm. For example, the spacing between the individual second electrode stimulation points 221 may be 100 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1200 μm, or 1500 μm. In addition, the spacing between the individual second electrode stimulation points 221 is selected depending on the application and layout.

Fig. 3 shows a partial view of an implanted double-sided electrode 1 according to an example of the present disclosure. Fig. 3(a) shows a schematic structural diagram of the second solder joint 223 of the implanted double-sided electrode 1 according to an example of the present disclosure, and fig. 3(b) shows a top view of the second solder joint 223 of the implanted double-sided electrode 1 according to an example of the present disclosure.

In some examples, the shape of the second welding spot 223 is not particularly limited, for example, the second welding spot 223 may have a ring shape, such as a circular ring (refer to fig. 3), a square ring elliptical ring, a circular square hole, a square circular hole, or the like. This can facilitate electrical connection of second pad 223. In addition, in some examples, the second connection line 222 may have an elongated shape, such as a string shape.

In some examples, the outer diameter of the second solder joint 223 may be 100 μm to 200 μm. For example, the outer diameter of the second solder bump 223 may be 100 μm, 110 μm, 120 μm, 150 μm, 170 μm, or 200 μm. In addition, the outer diameter of the second solder joint 223 may be equal to or different from the aperture of the second channel 132. In addition, the outer diameter of the second welding spot 223 may be the same as or different from the outer diameter of the first welding spot 213.

In some examples, the interval between the respective second welding points 223 may be 100 μm to 500 μm. For example, the pitch between the respective second solder bumps 223 may be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. In addition, the intervals between the respective second welding spots 223 may be equal or different.

In some examples, the number of the second welding spots 223 is not particularly limited. For example, the number of second welding spots 223 may be the same as or different from the number of second stimulation spots. In addition, the number of the second welding spots 223 may be the same as or different from the number of the second channels 132. In addition, the number of the second welding spots 223 may be the same as or different from the number of the second stimulation spots.

In some examples, the arrangement shape of the second welding spots 223 is not particularly limited. In some examples, the second solder joints 223 may be arranged in a regular shape such as an octagonal array, a square, a circle, and the like. In other examples, the second welding spots 223 may also be arranged in irregular shapes (including a combination of regular shapes and irregular shapes). In addition, the arrangement of the second channels 132 may be the same as the arrangement of the second pads 223.

In some examples, as shown in fig. 1, the second electrode stimulation point 221 may correspond to the second window 131. In other examples, the second electrode stimulation point 221 may be exposed to the outside via the second window 131.

In some examples, the plurality of second electrode stimulation points 221 may correspond to the plurality of second windows 131, respectively. In other words, each second electrode stimulation point 221 may correspond to one second window 131.

In some examples, the plurality of second electrode stimulation points 221 may be exposed to the outside through the plurality of second windows 131 to form the front-side electrode array P, respectively. In other words, each of the second electrode stimulation points 221 may be exposed to the outside through one of the second windows 131 and arranged as the front side electrode array P.

In some examples, the arrangement of the front side electrode array P is not particularly limited. In some examples, the front side electrode array P may be arranged in a regular shape such as an octagonal array, a square, a circle, or the like. In other examples, the front-side electrode array P may be arranged in an irregular shape (including a combination of a regular shape and an irregular shape). In addition, distances between adjacent second electrode stimulation points 221 in the front side electrode array P may be equal to each other. This enables the front electrode array P to be easily produced.

In some examples, the front-side electrode array P and the back-side electrode array may be arranged in the same arrangement. In other examples, the front-side electrode array P and the back-side electrode array may be arranged in different arrangements.

Fig. 4 shows a front projection view of first electrode stimulation point 211 and second electrode stimulation point 221 of implantable double-sided electrode 1 on front side 1A according to another example of the present disclosure.

In some examples, as shown in fig. 4, imaginary electrode arrays formed by orthographic projections of the front-side electrode array P and the back-side electrode array on the front surface 1A may be staggered with each other. This can contribute to reducing the mutual interference between the front-side electrode array P and the back-side electrode array. In other examples, the front-side electrode array P and the back-side electrode array may overlap or intersect with an imaginary electrode array formed by orthographic projection of the front surface 1A.

In some examples, as shown in fig. 1, the second solder joint 223 may correspond to the second channel 132. In other examples, the second solder joint 223 may be exposed to the outside through the second channel 132.

In some examples, the plurality of second welding spots 223 may correspond to the plurality of second channels 132, respectively. In other words, each of the second pads 223 may correspond to one of the second channels 132, respectively.

In some examples, the plurality of second pads 223 may be exposed to the outside through the plurality of second vias 132, respectively, to form a second pad array Q (refer to fig. 2). In other words, the respective second pads 223 may be exposed to the outside through one second via 132 and arranged into the second pad array Q, respectively.

In some examples, the arrangement of the second pad array Q is not particularly limited. In some examples, the second pad array Q may be arranged in a regular shape such as an octagonal array, a square, a circle, and the like. In other examples, the second pad array Q may be arranged in an irregular shape (including a combination of a regular shape and an irregular shape). In addition, distances between adjacent second pads 223 in the second pad array Q may be equal to each other.

In some examples, the distance between the front-side electrode array P and the second pad array Q may be smaller than the distance between the back-side electrode array and the first pad array R. This can facilitate the same-side arrangement of the first pad array R and the second pad array Q. In addition, the distance between the front-side electrode array P and the second pad array Q may be greater than or equal to the distance between the back-side electrode array and the first pad array R.

In some examples, as shown in fig. 2, the same side arrangement of the first pad array R and the second pad array Q can facilitate electrical connection of the double-sided electrode 1 (e.g., with a feed-through ceramic).

In some examples, the front-side electrode array P and the back-side electrode array may be located at the implant end 1a, and the second pad array Q and the first pad array R may be located at the bonding end 1 c. Thereby, the front-side electrode array P and the back-side electrode array can be easily arranged at one end, and the second pad array Q and the first pad array R can be arranged at the other end.

In some examples, in the second conductive layer 22, the plurality of second electrode stimulation points 221 may be connected with the plurality of second pads 223 via the plurality of second connection lines 222, respectively. In other words, the plurality of second electrode stimulation points 221 may be connected with the plurality of second pads 223 in a one-to-one correspondence via the plurality of second connection lines 222. That is, each second electrode stimulation point 221 may be connected with one second welding point 223 via one second connection line 222. In addition, the second connection lines 222 may not contact each other.

In some examples, in the second conductive layer 22, two or more second electrode stimulation points 221 may be connected with one second pad 223 via at least one second connection line 222. For example, two second electrode stimulation points 221 may be connected with one second welding point 223 via one second connection line 222, two second electrode stimulation points 221 may be connected with one second welding point 223 via two second connection lines 222, and so on.

In some examples, the first connection line 212 and the second connection line 222 may be located at the connection part 1 b. This allows the first electrode stimulation point 211 and the first pad 213, and the second electrode stimulation point 221 and the second pad 223 to be easily connected.

In some examples, the width of the connection portion 1b may be smaller than the width of the implantation end 1a and the welding end 1 c. Thereby, implantation of the double-sided electrode 1 can be facilitated. In other examples, the length of the connecting portion 1b may be greater than the length of the implanting end 1a and the welding end 1 c. Thereby, the implantation depth of the double-sided electrode 1 can be advantageously increased.

In some examples, the surfaces of the first electrode stimulation points 211 and the second electrode stimulation points 221 may be disposed with analyte-responsive sensitive substances that specifically react with the target analytes. Thereby, the concentration of the target analyte can be sensed by the reaction. In this case, chemical information during the reaction process can be converted by the double-sided electrode 1 into a measurable signal, such as an electrical signal, where the double-sided electrode 1 can be used for real-time continuous monitoring of parameters of target analytes in the living body. For example, the double-sided electrode 1 may be uric acid monitoring, cholesterol monitoring, blood glucose monitoring, etc., and the sensitive substance responding to the analyte may be different according to actual needs.

In some examples, the implantation end 1a may be arranged with a biocompatible coating, whereby the implantation end 1a can have a high biocompatibility. In addition, the biocompatible coating can prevent non-target analytes in the body from contacting sensitive substances of the double-sided electrode 1 responding to the analytes, and has the function of resisting interference. Examples of the present disclosure are not limited thereto, and in some examples, the biocompatible coating may cover the entire double-sided electrode 1.

In some examples, the biocompatible coating may be made of a plant material. The plant material may be at least one selected from sodium alginate, tragacanth gum, pectin, acacia gum, xanthan gum, guar gum, agar, etc., and natural material derivatives. The natural material derivative may include a starch derivative or a cellulose derivative, among others.

Fig. 5 is a flowchart illustrating a method of manufacturing the implantable double-sided electrode 1 according to an example of the present disclosure. Fig. 6 is a schematic diagram illustrating a manufacturing process of the implantable double-sided electrode 1 according to an example of the present disclosure.

Hereinafter, a method for manufacturing the implantable double-sided electrode 1 according to the example of the present disclosure will be described in detail with reference to fig. 5 and 6. In addition, specific descriptions regarding the first conductive layer 21, the second conductive layer 22, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 in the manufacturing method may refer to the corresponding descriptions in the above-described double-sided electrode 1. In addition, the implantable double-sided electrode 1 obtained by the preparation method according to the present embodiment may specifically refer to the above description.

In this embodiment, as shown in fig. 5, the method for manufacturing the implanted double-sided electrode 1 may include preparing a substrate 2 having a first dielectric film 3a and a second dielectric film 3b opposite to each other, forming a sacrificial layer 4 on the first dielectric film 3a, and forming a first insulating layer 11 on the sacrificial layer 4 (step S10); forming a first conductive layer 21 in a first predetermined pattern on the first insulating layer 11, and then forming a second insulating layer 12 on the first conductive layer 21 and covering the first insulating layer 11 and the first conductive layer 21 (step S20); forming a second conductive layer 22 in a second predetermined pattern T on the second insulating layer 12, and then forming a third insulating layer 13 on the second conductive layer 22 and covering the second insulating layer 12 and the second conductive layer 22 (step S30); forming a patterned mask layer 5 on the third insulating layer 13 and etching according to the pattern on the mask layer 5, thereby forming a plurality of second windows 131, a plurality of second vias 132, and a plurality of first vias 133 (step S40); the second dielectric film 3b is subjected to patterning processing and etching, thereby forming a plurality of first windows 111 to obtain the double-sided electrodes 1 (step S50).

In the method for manufacturing the implanted double-sided electrode 1 according to the present embodiment, the double-sided electrode 1 is manufactured and obtained on a single substrate by using simple and highly repeatable processes such as double-sided etching and deep trench etching, so that the double-sided electrode 1 can be simply manufactured and the yield and the repeatability of the manufacturing process of the double-sided electrode 1 can be improved.

In some examples, in step S10, the substrate 2 may have a front side and a back side opposite the front side, as shown in fig. 6 a. In addition, in some examples, the first dielectric film 3a and the second dielectric film 3b may be formed on the front surface and the back surface of the substrate 2, respectively. For example, the first dielectric film 3a may be formed on the front surface of the substrate 2, and the second dielectric film 3b may be formed on the back surface of the substrate 2. In this case, the first dielectric film 3a and the second dielectric film 3b can reduce damage caused by a subsequent etching process, thereby being capable of contributing to improvement of process accuracy.

In some examples, a cleaning step may be performed before the first dielectric film 3a and the second dielectric film 3b are formed on the substrate 2 in step S10. Thereby, the oxide layer on the surface of the substrate 2 can be removed. For example, the substrate 2 may be cleaned using an FSI cleaner to remove an oxide layer from the surface of the substrate 2.

In some examples, in step S10, the substrate 2 may be double-polished, so that the first dielectric film 3a and the second dielectric film 3b can be formed on the front and back surfaces of the substrate 2, respectively. In other examples, in step S10, the substrate 2 may be selected from one of glass, silicon dioxide, and silicon nitride.

In some examples, the first dielectric film 3a may be composed of at least one of a silicon oxide layer and a silicon nitride layer. In other examples, the first dielectric film 3a may be a composite dielectric film in which a silicon dioxide layer and a silicon nitride layer are laminated.

In some examples, the second dielectric film 3b may be composed of at least one of a silicon oxide layer and a silicon nitride layer. In other examples, the second dielectric film 3b may be a composite dielectric film formed by laminating a silicon dioxide layer and a silicon nitride layer. In addition, the first dielectric film 3a and the second dielectric film 3b may be the same or different.

In some examples, the silicon dioxide layer may not exceed 3 μm and the silicon nitride layer may not exceed 2 μm in the composite dielectric film. For example, in a composite dielectric film, the silicon dioxide layer may be 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, or 3 μm, and the silicon nitride layer may not exceed 0.2, 0.5 μm, 1 μm, 1.5 μm, or 2 μm.

In some examples, a silicon dioxide layer in the composite dielectric film may be formed on the surface of the substrate 2, and a silicon nitride layer may be formed on the silicon dioxide layer. In other examples, the silicon dioxide layer may be formed by thermal oxidation, and the silicon nitride layer may be formed by plating, spin coating, evaporation, printing, or extrusion.

In some examples, in step S10, as shown in fig. 6a, the sacrificial layer 4 may be formed on the first dielectric film 3 a. In addition, in some examples, the sacrificial layer 4 may be made of at least one selected from aluminum, silicon oxide, chromium, and titanium. In other examples, the sacrificial layer 4 may be formed on the first dielectric film 3a by sputtering or evaporation. For example, aluminum may be evaporated or sputtered to form a sacrificial aluminum film as the sacrificial layer 4 on the first dielectric film 3 a.

In some examples, in step S10, patterning the sacrificial layer 4 and etching to form a groove 4a for a mark may be further included, and a position of the groove 4a may correspond to a position of the first window 111. This can facilitate subsequent etching of the first window 111. In addition, a plurality of grooves 4a may be formed on the sacrificial layer 4, and one groove 4a may correspond to one first window 111. Further, the groove 4a may penetrate the sacrificial layer 4.

In some examples, the patterning process of the sacrificial layer 4 may employ a photolithography process. Specifically, a photoresist may be spin-coated on the surface of the sacrificial layer 4, exposed by using a mask plate with a predetermined pattern, etched after development (for example, etched by an etching solution or a metal etcher) and removed by photoresist (for example, wet photoresist removal), and then the patterned sacrificial layer 4 is obtained. However, examples of the present disclosure are not limited thereto, and in other examples, the patterning process of the sacrificial layer 4 may be patterned using other patterning methods such as surface modification or printing.

In some examples, optionally, a photoresist is spin-coated on the sacrificial layer 4 at a spin-coating speed of 3000rmp to 4000rmp for 30s to 60s, then pre-baked at 90 ℃ to 100 ℃ for 1min to 2min, then exposed through a mask plate with a specified pattern for 5s to 10s (ultraviolet light, 365nm to 406nm), developed, then placed at 100 ℃ to 110 ℃ for hard-film baking for 1min to 2min, then etched by using an etching solution (e.g., an aluminum etching solution) or a metal etcher to form a groove 4a, and then wet-stripped, and finally the patterned sacrificial layer 4 is obtained.

In some examples, in step S10, as shown in fig. 6b, a first insulating layer 11 may be formed on the patterned sacrificial layer 4. In other words, the first insulating layer 11 may cover the sacrificial layer 4. In addition, the first insulating layer 11 may also fill the groove 4a on the sacrificial layer 4.

In addition, in some examples, the first insulating layer 11 is optionally formed on the patterned sacrificial layer 4 in a manner of plating, spin coating, evaporation, printing, or extrusion. In other examples, the first insulating layer 11 may be formed by curing under an inert gas or nitrogen gas shield (such as a vacuum nitrogen gas shield).

In some examples, in step S10, the thickness of the first insulating layer 11 may be 4 μm to 7 μm. In other examples, the first insulating layer 11 may be composed of a flexible insulating material. This can reduce damage to the living body.

In some examples, the flexible insulating material may be at least one of polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethylmethacrylate, polyethylene glycol, or polytetrafluoroethylene resin. Thereby, the double-sided electrode 1 having biocompatibility can be prepared.

In some examples, in step S10, a flexible insulating material (e.g., polyimide) may be spin-coated on the patterned sacrificial layer 4 for 30S to 40S (e.g., 35S) at a spin-coating speed of 3000rmp to 4000rmp, and then placed in a vacuum nitrogen oven for curing, forming a first insulating layer 11 of 5 μm to 6 μm.

In some examples, in step S20, as shown in fig. 6b, the first conductive layer 21 may be formed on the first insulating layer 11, and the first conductive layer 21 may be formed in a first predetermined pattern.

In some examples, in step S20, forming a patterned protection layer on the first insulating layer 11 and removing the protection layer after forming the first conductive layer 21 may be further included, so as to form the first conductive layer 21 in a first predetermined pattern. Thereby, the first conductive layer 21 in the first predetermined pattern can be prepared.

In some examples, a patterned photoresist layer may be formed on the first insulating layer 11. Specifically, a photoresist may be first spin-coated on the first insulating layer 11 (e.g., a 30s to 60s positive, negative, inversion or bilayer photoresist may be spin-coated at a spin-coating speed of 3000rmp to 4000 rmp), and then the photoresist layer may be exposed to light (e.g., 365nm to 406nm ultraviolet light, exposure 5s to 10s) using a reticle having a first predetermined pattern, developed, and a first predetermined pattern may be formed on the photoresist layer.

In some examples, the first conductive layer 21 may be formed on the surface of the photoresist layer having the first predetermined pattern by evaporation, sputtering, plating, or the like, and then the photoresist layer may be stripped to obtain the first conductive layer 21 having the first predetermined pattern. In addition, the residual metal on the photoresist layer outside the first predetermined pattern may be removed by stripping the photoresist layer.

In some examples, the first conductive layer 21 may be composed of a metal material. Additionally, in some examples, the metallic material may be selected from at least one of silver, platinum, gold, titanium, palladium, iridium, niobium. Thereby, the double-sided electrode 1 having biocompatibility can be prepared.

In some examples, the first conductive layer 21 may be a composite metal layer, and the composite metal layer may be formed of at least two metal materials, such as a titanium-platinum-titanium structure, a titanium-gold-titanium structure, a niobium-gold-niobium structure, and the like. In addition, in some examples, the composite metal layer may be formed by evaporation, sputtering, or plating using various metal materials in sequence, for example, titanium, platinum, titanium may be sputtered in sequence to form a titanium-platinum-titanium structure.

In some examples, the thickness of the first conductive layer 21 may be 400nm to 600 nm. In other examples, the thickness of the upper metal layer, the middle metal layer and the lower metal layer in the composite metal layer may be 30nm to 100nm, 100nm to 300nm, and 30nm to 100nm, respectively. For example, in the titanium-platinum-titanium structure, the thickness of the titanium metal layer may be 30nm to 100nm, the thickness of the platinum metal layer may be 100nm to 300nm, and the thickness of the titanium metal layer may be 30nm to 100 nm.

In some examples, the first predetermined pattern may include a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213. In addition, the plurality of first electrode stimulation points 211 may be connected with the plurality of first pads 213 via a plurality of first connection lines 212, respectively.

In some examples, the first predetermined pattern may be composed of a plurality of first electrode stimulation points 211, a plurality of first connection lines 212, and a plurality of first welding points 213 connected to the plurality of first electrode stimulation points 211 via the plurality of first connection lines 212, respectively.

In some examples, in step S20, as shown in fig. 6c, a second insulating layer 12 may be formed on the first insulating layer 11 and the first conductive layer 21. This enables covering the first insulating layer 11 and the first conductive layer 21. In addition, in some examples, the second insulating layer 12 may be formed on the first insulating layer 11 and the first conductive layer 21 in a plating, spin coating, evaporation, printing, or extrusion manner. In other examples, the second insulating layer 12 may be formed by curing under an inert gas shield (such as a vacuum nitrogen shield).

In some examples, in step S20, the thickness of the second insulating layer 12 may be 4 μm to 7 μm. In other examples, the second insulating layer 12 may be composed of a flexible insulating material. This can reduce damage to the living body. In addition, the first insulating layer 11 and the second insulating layer 12 may be made of the same or different flexible insulating materials.

In some examples, in step S20, a flexible insulating material (e.g., polyimide) may be spin-coated for 30S to 40S (e.g., 35S) at a spin-coating speed of 3000rmp to 4000rmp, and then placed in a vacuum nitrogen oven to be cured, forming the second insulating layer 12 of 5 μm to 6 μm.

In some examples, in step S30, as shown in fig. 6c, the second conductive layer 22 may be formed on the second insulating layer 12, and the second conductive layer 22 may be formed in the second predetermined pattern T.

In some examples, step S30 may further include forming a patterned masking layer on the second insulating layer 12, and removing the masking layer after forming the second conductive layer 22, thereby forming the second conductive layer 22 in the second predetermined pattern T. Thereby, the second conductive layer 22 in the second predetermined pattern T can be simply prepared.

In some examples, a patterned photoresist layer may be formed on the second insulating layer 12. Specifically, a photoresist may be first spin-coated on the second insulating layer 12 (e.g., a 30s to 60s positive, negative, inversion or bilayer photoresist may be spin-coated at a spin-coating speed of 3000rmp to 4000 rmp), and then the photoresist layer may be exposed to light (e.g., 365nm to 406nm ultraviolet light, exposure for 5s to 10s) using a reticle having a second predetermined pattern T, developed, and the second predetermined pattern T may be formed on the photoresist layer.

In some examples, the second conductive layer 22 may be formed on the surface of the photoresist layer having the second predetermined pattern T by evaporation, sputtering, plating, or the like, and then the photoresist layer may be stripped to obtain the second conductive layer 22 having the second predetermined pattern T. In addition, the residual metal on the photoresist layer outside the second predetermined pattern T may be removed by peeling the photoresist layer.

In some examples, the second conductive layer 22 may be composed of a metal material. In other examples, the second conductive layer 22 may be a composite metal layer. In addition, the first conductive layer 21 and the second conductive layer 22 may be made of the same or different metal materials.

In some examples, the thickness of the second conductive layer 22 may be 400nm to 600 nm. In addition, the thicknesses of the first conductive layer 21 and the second conductive layer 22 may be the same or different.

In some examples, the second predetermined pattern T may include a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of second welding points 223. In addition, the plurality of second electrode stimulation points 221 may be connected to the plurality of second pads 223 via a plurality of second connection lines 222, respectively.

In some examples, the second predetermined pattern T may be composed of a plurality of second electrode stimulation points 221, a plurality of second connection lines 222, and a plurality of first welding points 213 connected to the plurality of second electrode stimulation points 221 via the plurality of second connection lines 222, respectively.

In some examples, in step S30, as shown in fig. 6d, a third insulating layer 13 may be formed on the second insulating layer 12 and the second conductive layer 22. This can cover the second insulating layer 12 and the second conductive layer 22. In addition, in some examples, the third insulating layer 13 may be formed on the second insulating layer 12 and the second conductive layer 22 in a plating, spin coating, evaporation, printing, or extrusion manner. In other examples, the third insulating layer 13 may be formed by curing under an inert gas shield (such as a vacuum nitrogen shield).

In some examples, in step S30, the thickness of the third insulating layer 13 may be 4 μm to 7 μm. In other examples, the third insulating layer 13 may be composed of a flexible insulating material. This can reduce damage to the living body. In addition, the second insulating layer 12 and the third insulating layer 13 may be made of the same or different flexible insulating materials. Further, the first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 may be made of the same or different flexible insulating materials.

In some examples, in step S30, a flexible insulating material (e.g., polyimide) may be spin-coated for 30S to 40S (e.g., 35S) at a spin-coating speed of 3000rmp to 4000rmp, and then placed in a vacuum nitrogen oven to be cured, forming the third insulating layer 13 of 5 μm to 6 μm.

In some examples, as described above, the first, second, and third insulating layers 11, 12, and 13 may be respectively made of a flexible insulating material, which may be at least one of polyimide, polyethylene terephthalate, parylene, silicone, polydimethylsiloxane, polymethylmethacrylate, polyethylene glycol, or polytetrafluoroethylene resin, and the first and second conductive layers 21 and 22 may be respectively made of a metal material, which may be at least one of silver, platinum, gold, titanium, palladium, iridium, and niobium. Thereby, the double-sided electrode 1 having biocompatibility and good conductive properties can be prepared.

In some examples, in step S40, as shown in fig. 6d, the mask layer 5 may be formed on the third insulating layer 13 by evaporation or sputtering. In other examples, the mask layer 5 may be one selected from photoresist, aluminum, silicon oxide, chromium, and titanium. For example, aluminum may be evaporated or sputtered to form a hard aluminum layer on the third insulating layer 13 as the mask layer 5.

In some examples, the third insulating layer 13 may be subjected to a cleaning process before forming the mask layer 5. In addition, the third insulating layer 13 may also be subjected to plasma treatment, whereby the bonding between the third insulating layer 13 and the mask layer 5 can be enhanced.

In some examples, in step S40, the pattern of mask layer 5 may be formed via a photolithography process. Specifically, a photoresist may be first spin-coated on the surface of the mask layer 5 (for example, a 30s to 60s positive photoresist, a negative photoresist, a reverse photoresist, or a double-layer photoresist may be spin-coated at a spin-coating speed of 3000rmp to 4000 rmp), then exposure may be performed using a mask plate having a specific pattern (for example, 365nm to 406nm ultraviolet light, exposure for 5s to 10s), post-development etching (for example, metal etcher etching) and photoresist removal (for example, wet photoresist removal), and then the patterned mask layer 5 is obtained.

In some examples, as shown in fig. 6d, the pattern of the mask layer 5 may include a first engraved groove 5a for marking the second window 131, a second engraved groove 5b for marking the second channel 132, and a third engraved groove 5c for marking the first channel 133. In addition, the mask layer 5 may include a plurality of first trenches 5a, a plurality of second trenches 5b, and a plurality of third trenches 5 c. Furthermore, one first notch 5a may correspond to one second window 131, one second notch 5b may correspond to one second channel 132, and one third notch 5c may correspond to one first channel 133.

In some examples, in step S40, etching (e.g., reactive ion dry etcher etching) according to the pattern on the mask layer 5 may form the second window 131, the second channel 132, and the first channel 133. For example, as shown in fig. 6e, a second window 131, a second channel 132 and a first channel 133 may be etched according to the first trench 5a, the second trench 5b and the third trench 5c on the mask layer 5, respectively.

In some examples, the second window 131 may penetrate the third insulating layer 13. In addition, the plurality of second electrode stimulation points 221 may correspond to the plurality of second windows 131 such that the plurality of second electrode stimulation points 221 are exposed to the outside through the plurality of second windows 131 to form the front-side electrode array P.

In some examples, the second channel 132 may extend through the third insulating layer 13. In addition, the plurality of second pads 223 may correspond to the plurality of second channels 132 such that the plurality of second pads 223 are exposed to the outside through the plurality of second channels 132 to form a second pad 223 array.

In some examples, the first channel 133 may penetrate the second insulating layer 12 and the third insulating layer 13. In addition, the plurality of first pads 213 may correspond to the plurality of first vias 133 such that the plurality of first pads 213 are exposed to the outside through the plurality of first vias 133 to form the array of first pads 213. In addition, the first pad array R and the second pad array Q may be located on the same side as the front-side electrode array P.

In some examples, as shown in fig. 6d, the pattern of the mask layer 5 may further include a scribe line 5d for marking the shape, thereby being capable of facilitating the subsequent cutting to form the desired double-sided electrode 1.

In some examples, in step S50, the second dielectric film 3b may be patterned using a photolithography process. Specifically, a photoresist may be first spin-coated on the second dielectric film 3b (e.g., a 30s to 60s positive photoresist, a negative photoresist, an inverse photoresist, or a double-layer photoresist may be spin-coated at a spin-coating speed of 3000rmp to 4000 rmp), then exposed (e.g., 365nm to 406nm ultraviolet light, 5s to 10s exposure), developed and hardened (e.g., hardened at 100 ℃ to 110 ℃ for 1min to 2min), then etched (e.g., dry etching by inductively coupled plasma), to form a back deep trench etching opening, and then the photoresist is removed (e.g., dry photoresist removal), so as to obtain the patterned second dielectric film 3 b.

In some examples, in step S50, etching the substrate 2 according to the back side deep trench etching opening on the second dielectric film 3b may form a deep trench via. In other examples, the substrate 2 may be etched using a silicon deep trench etcher to form a deep trench via.

In some examples, in step S50, etching the first dielectric film 3a according to the deep trench via hole on the substrate 2 may form an etching opening, so that the groove 4a on the sacrificial layer 4 may be exposed. Thereby, the first insulating layer 11 filled in the groove 4a of the sacrificial layer 4 can be exposed. In addition, in some examples, the etch opening may expose all of the recesses 4a on the sacrificial layer 4.

In some examples, in step S50, etching the first insulating layer 11 exposed in the etching opening may form the first window 111. In other examples, the first window 111 is optionally formed by etching the first insulating layer 11 exposed in the etching opening using a reactive ion dry etcher.

In some examples, the first window 111 may penetrate the first insulating layer 11. In other examples, the plurality of first electrode stimulation points 211 may correspond to the plurality of first windows 111 such that the plurality of first electrode stimulation points 211 are exposed to the outside through the plurality of first windows 111 to form a back-side electrode array. In addition, the front-side electrode array P may be opposite to the back-side electrode array.

In some examples, in step S50, removing the sacrificial layer 4 and the mask layer 5 may be further included to obtain the double-sided electrode 1. For example, the sacrificial aluminum film and the hard aluminum layer may be etched away using an aluminum etchant to obtain the double-sided electrode 1. In addition, removal of the sacrificial layer 4 also removes the substrate 2.

In some examples, dicing may be performed using a dicing saw according to the dicing groove 5d of the mask layer 5 before the sacrificial layer 4 and the mask layer 5 are removed.

In some examples, a single substrate 2 may simultaneously prepare a plurality of prepared double-sided electrodes 1, and a single double-sided electrode 1 may be formed by dicing.

In some examples, if the first conductive layer 21 and the second conductive layer 22 are, for example, a titanium-platinum-titanium (Ti-Pt-Ti) structure, the double-sided electrode 1 after the substrate 2 is removed may be treated with hydrofluoric acid (HF) to etch away the titanium metal layer on the surface. Thereby, the conductive properties of the exposed first electrode stimulation point 211, second electrode stimulation point 221, first pad 213, and second pad 223 can be made better.

In the embodiment, the preparation method of the double-sided electrode 1 is compatible with the MEMS process, and the mature process with high repeatability and yield is adopted in the preparation method, which is beneficial to mass production.

According to the present disclosure, an implantable double-sided electrode 1 with a simple process and a preparation method thereof can be provided.

While the present disclosure has been described in detail in connection with the drawings and examples, it should be understood that the above description is not intended to limit the disclosure in any way. Those skilled in the art can make modifications and variations to the present disclosure as needed without departing from the true spirit and scope of the disclosure, which fall within the scope of the disclosure.