阅读说明：本技术 一种电能转换器件及其制备方法 (Electric energy conversion device and preparation method thereof ) 是由 何强 聂京凯 耿进锋 崔建业 史昌明 龚文 肖伟民 于 2021-09-01 设计创作，主要内容包括：本发明提供一种电能转换器件及其制备方法,电能转换器件包括：微穿孔板；与所述微穿孔板相对设置的能量收集组件；支架,所述支架位于所述能量收集组件的边缘区域和所述微穿孔板的边缘区域之间；所述能量收集组件包括：压电膜层；位于所述压电膜层朝向所述微穿孔板一侧表面的第一电极层；位于所述压电膜层背向所述微穿孔板一侧表面的第二电极层；贯穿所述压电膜层和所述第一电极层的第一开口,且所述第一开口的底部暴露出部分所述第二电极层；位于所述第二电极层背向所述压电膜层一侧表面的接合层；位于所述接合层背向所述压电膜层一侧的支撑层。电能转换器件可以自发电,提高了电能转换器件的稳定性。(The invention provides an electric energy conversion device and a preparation method thereof, wherein the electric energy conversion device comprises: a micro-perforated plate; an energy collection assembly disposed opposite the microperforated panel; a support located between an edge region of the energy collection assembly and an edge region of the microperforated panel; the energy harvesting assembly includes: a piezoelectric film layer; the first electrode layer is positioned on the surface of one side, facing the micro-perforated plate, of the piezoelectric film layer; the second electrode layer is positioned on the surface of one side, back to the micro-perforated plate, of the piezoelectric film layer; a first opening penetrating through the piezoelectric film layer and the first electrode layer, and a part of the second electrode layer is exposed from the bottom of the first opening; the junction layer is positioned on one side surface, opposite to the piezoelectric film layer, of the second electrode layer; and the supporting layer is positioned on one side of the junction layer, which is opposite to the piezoelectric film layer. The electric energy conversion device can generate electricity, and the stability of the electric energy conversion device is improved.)

1. An electrical energy conversion device, comprising:

a micro-perforated plate;

an energy collection assembly disposed opposite the microperforated panel;

a support located between an edge region of the energy collection assembly and an edge region of the microperforated panel;

the energy harvesting assembly includes: a piezoelectric film layer; the first electrode layer is positioned on the surface of one side, facing the micro-perforated plate, of the piezoelectric film layer; the second electrode layer is positioned on the surface of one side, back to the micro-perforated plate, of the piezoelectric film layer; the junction layer is positioned on one side surface, opposite to the piezoelectric film layer, of the second electrode layer; the supporting layer is positioned on one side, opposite to the piezoelectric film layer, of the junction layer, a plurality of second openings penetrating through the supporting layer are formed in the supporting layer, and part of the junction layer is exposed out of the second openings.

2. The electrical energy conversion device of claim 1, wherein the energy harvesting assembly further comprises: the first opening penetrates through the piezoelectric film layer and the first electrode layer, and a part of the second electrode layer is exposed at the bottom of the first opening.

3. The electric energy conversion device according to claim 1, wherein the bonding layer includes a first sub-bonding film and a second sub-bonding film, the first sub-bonding film being located between the second sub-bonding film and the second electrode layer;

preferably, the material of the first sub-junction film includes silicon nitride, and the material of the second sub-junction film includes silicon dioxide;

preferably, the thickness of the first sub junction film is 150nm to 250 nm; the thickness of the second sub-junction film is 250nm to 350 nm.

4. An electrical energy conversion device according to claim 1, wherein the material of the support layer is a semiconductor material;

preferably, the semiconductor material comprises silicon;

preferably, the thickness of the support layer is 50 μm to 200 μm.

5. The electrical energy conversion device of claim 1, wherein a plurality of the second openings are arranged in an array;

preferably, the projection of the second opening on the surface of the piezoelectric film layer is square;

preferably, the width of the second opening is 3mm to 5 mm; the distance between the adjacent second openings is 1 mm-5 mm.

6. The device of claim 1, wherein the material of the piezoelectric film layer comprises lead zirconate titanate piezoelectric ceramic, polyvinylidene fluoride, aluminum nitride, or zinc oxide;

preferably, the thickness of the piezoelectric film layer is 100nm to 1000 nm.

7. The electric energy conversion device according to claim 1, wherein a plurality of through holes are formed at intervals in the thickness direction of the microperforated plate and penetrate through the microperforated plate; the micro-perforated plate includes: a microperforated body layer, the material of the microperforated body layer comprising a semiconductor material;

preferably, the micro-perforated plate further comprises: an adhesion layer on a side surface of the microperforated body layer facing the energy collection assembly;

preferably, the material of the adhesion layer comprises silicon nitride;

preferably, the diameter of the through holes is 100-200 μm, and the distance between the adjacent through holes is 200-400 μm;

preferably, the thickness of the micro perforated plate is 0.2mm to 2 mm.

8. The electrical energy conversion device of claim 1, wherein the support is fixedly connected to the microperforated panel by an adhesive, and the support is electrically connected to the first electrode layer by a conductive silver paste.

9. A method of fabricating an electrical energy conversion device, comprising:

forming a micro-perforated plate;

forming an energy harvesting assembly;

supporting an edge region of the energy collection assembly and an edge region of the microperforated panel with a support;

the method of forming the energy harvesting assembly comprises: providing an initial support layer; forming a bonding layer on one side surface of the initial support layer; forming a second electrode layer on the surface of one side, opposite to the initial support layer, of the bonding layer; forming a piezoelectric film layer on the surface of one side, facing away from the initial support layer, of the second electrode layer; forming a first electrode layer on the surface of one side, back to the second electrode layer, of the piezoelectric film layer; and forming a plurality of second openings penetrating through the initial supporting layer, wherein the second openings expose part of the bonding layer.

10. The method of manufacturing a power conversion device according to claim 9, further comprising: forming a first opening in the first electrode layer and the piezoelectric film layer, wherein the bottom of the first opening exposes a part of the second electrode layer;

the step of forming the second opening includes: forming a plurality of second initial openings in the initial supporting layer with partial thickness through a first etching process; after the second electrode layer is formed, the second initial opening is positioned on one side, facing away from the second electrode layer, of the initial support layer; after the first opening is formed, etching the initial supporting layer at the bottom of the second initial opening through a second etching process to enable the initial supporting layer to form a supporting layer, wherein the supporting layer is provided with a second opening penetrating through the supporting layer;

preferably, the second preliminary opening is formed before the second electrode layer is formed;

preferably, the first etching process includes a wet etching process, and the second etching process includes a dry etching process.

11. The method of manufacturing a power conversion device according to claim 9, wherein the method of forming the microperforated panel comprises:

providing a first semiconductor substrate;

forming an adhesion material layer on one side surface of the first semiconductor substrate;

forming a first mask material layer on the surface of one side, back to the first semiconductor substrate, of the adhesion material layer;

patterning the first mask material layer to enable the first mask material layer to form a first mask layer, wherein the first mask layer is provided with a plurality of first mask through holes which are spaced and penetrate through the first mask layer;

etching the adhesion material layer at the bottom of the first mask through hole to form an adhesion layer on the adhesion material layer, wherein a first sub through hole penetrating through the adhesion layer is formed in the adhesion layer;

etching the first semiconductor substrate at the bottom of the first sub-through hole to enable the first semiconductor substrate to form a micro-perforated body layer, wherein a second sub-through hole penetrating through the micro-perforated body layer is formed in the micro-perforated body layer, and the second sub-through hole is communicated with the first sub-through hole to form the through hole;

after the through hole is formed, removing the first mask layer;

preferably, the material of the adhesion material layer comprises silicon nitride, and the material of the first mask material layer comprises aluminum.

12. The method of manufacturing a power conversion device according to claim 11, further comprising, after forming the adhesion material layer and before forming the first mask material layer: thinning the first semiconductor substrate by a third etching process;

preferably, the third etching process includes a wet etching process.

Technical Field

The invention relates to the technical field of sound-electricity energy conversion, in particular to an electric energy conversion device and a preparation method thereof.

Background

With the rapid development of the internet of things technology, the demand of people for the micro sensor is becoming stronger, however, the energy source problem of the micro sensor becomes one of the bottlenecks restricting the development, and people hope that the micro sensor can be provided with an energy collecting module, and can actively collect various forms of energy from the environment and store the energy for the micro sensor. The power consumption of the micro-sensor is greatly reduced due to the advancement of the MEMS (micro electro mechanical system) technology, and many micro-sensors with excellent performance and consuming energy in the mW scale (even lower) appear, so that the existing energy collection technology has the potential of supplying power to the micro-sensor, and thus, the related research fields have attracted great attention.

However, the stability of the current energy collection modules is insufficient and it is difficult to use them in a vibrating environment.

Disclosure of Invention

Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the stability of the energy collection module needs to be improved, thereby providing an electric energy conversion device and a method for manufacturing the same.

The present invention provides an electric energy conversion device comprising: a micro-perforated plate; an energy collection assembly disposed opposite the microperforated panel; a support located between an edge region of the energy collection assembly and an edge region of the microperforated panel; the energy harvesting assembly includes: a piezoelectric film layer; the first electrode layer is positioned on the surface of one side, facing the micro-perforated plate, of the piezoelectric film layer; the second electrode layer is positioned on the surface of one side, back to the micro-perforated plate, of the piezoelectric film layer; the junction layer is positioned on one side surface, opposite to the piezoelectric film layer, of the second electrode layer; the supporting layer is positioned on one side, opposite to the piezoelectric film layer, of the junction layer, a plurality of second openings penetrating through the supporting layer are formed in the supporting layer, and part of the junction layer is exposed out of the second openings.

Optionally, the energy harvesting assembly further comprises: the first opening penetrates through the piezoelectric film layer and the first electrode layer, and a part of the second electrode layer is exposed at the bottom of the first opening.

Alternatively, the bonding layer includes a first sub-bonding film and a second sub-bonding film, and the first sub-bonding film is located between the second sub-bonding film and the second electrode layer.

Optionally, the material of the first sub-junction film includes silicon nitride, and the material of the second sub-junction film includes silicon dioxide.

Optionally, the thickness of the first sub-junction film is 150nm to 250 nm; the thickness of the second sub-junction film is 250nm to 350 nm.

Optionally, the material of the support layer is a semiconductor material.

Optionally, the semiconductor material comprises silicon.

Optionally, the thickness of the support layer is 50 μm to 200 μm.

Optionally, a plurality of the second openings are arranged in an array.

Optionally, a projection of the second opening on the surface of the piezoelectric film layer is square.

Optionally, the width of the second opening is 3mm to 5 mm; the distance between the adjacent second openings is 1 mm-5 mm.

Optionally, the material of the piezoelectric film layer includes lead zirconate titanate piezoelectric ceramic, polyvinylidene fluoride, aluminum nitride, or zinc oxide.

Optionally, the thickness of the piezoelectric film layer is 100nm to 1000 nm.

Optionally, a plurality of through holes which are spaced and penetrate through the microperforated plate are formed in the thickness direction of the microperforated plate; the micro-perforated plate includes: a microperforated body layer, the material of the microperforated body layer comprising a semiconductor material.

Optionally, the micro-perforated plate further comprises: an adhesion layer on a side surface of the microperforated body layer facing the energy collection assembly;

optionally, the material of the adhesion layer includes silicon nitride.

Optionally, the diameter of each through hole is 100 μm to 200 μm, and the distance between adjacent through holes is 200 μm to 400 μm.

Optionally, the thickness of the micro-perforated plate is 0.2 mm-2 mm.

Optionally, the support is fixedly connected with the micro-perforated plate through an adhesive, and the support is electrically connected with the first electrode layer through conductive silver paste.

The invention also provides a preparation method of the electric energy conversion device, which comprises the following steps: forming a micro-perforated plate; forming an energy harvesting assembly; supporting an edge region of the energy collection assembly and an edge region of the microperforated panel with a support; the method of forming the energy harvesting assembly comprises: providing an initial support layer; forming a bonding layer on one side surface of the initial support layer; forming a second electrode layer on the surface of one side, opposite to the initial support layer, of the bonding layer; forming a piezoelectric film layer on the surface of one side, facing away from the initial support layer, of the second electrode layer; forming a first electrode layer on the surface of one side, back to the second electrode layer, of the piezoelectric film layer; and forming a plurality of second openings penetrating through the initial supporting layer, wherein the second openings expose part of the bonding layer.

Optionally, the method further includes: forming a first opening in the first electrode layer and the piezoelectric film layer, wherein the bottom of the first opening exposes a part of the second electrode layer; the step of forming the second opening includes: forming a plurality of second initial openings in the initial supporting layer with partial thickness through a first etching process; after the second electrode layer is formed, the second initial opening is positioned on one side, facing away from the second electrode layer, of the initial support layer; and after the first opening is formed, etching the initial support layer at the bottom of the second initial opening by a second etching process to enable the initial support layer to form a support layer, wherein the support layer is provided with a second opening penetrating through the support layer.

Optionally, the second preliminary opening is formed before forming the second electrode layer.

Optionally, the first etching process includes a wet etching process, and the second etching process includes a dry etching process.

Optionally, the method of forming the microperforated panel includes: providing a first semiconductor substrate; forming an adhesion material layer on one side surface of the first semiconductor substrate; forming a first mask material layer on the surface of one side, back to the first semiconductor substrate, of the adhesion material layer; patterning the first mask material layer to enable the first mask material layer to form a first mask layer, wherein the first mask layer is provided with a plurality of first mask through holes which are spaced and penetrate through the first mask layer; etching the adhesion material layer at the bottom of the first mask through hole to form an adhesion layer on the adhesion material layer, wherein a first sub through hole penetrating through the adhesion layer is formed in the adhesion layer; etching the first semiconductor substrate at the bottom of the first sub-through hole to enable the first semiconductor substrate to form a micro-perforated body layer, wherein a second sub-through hole penetrating through the micro-perforated body layer is formed in the micro-perforated body layer, and the second sub-through hole is communicated with the first sub-through hole to form the through hole; and removing the first mask layer after the through hole is formed.

Optionally, the material of the adhesion material layer includes silicon nitride, and the material of the first mask material layer includes aluminum.

Optionally, after forming the adhesion material layer and before forming the first mask material layer, the method further includes: and thinning the first semiconductor substrate through a third etching process.

Optionally, the third etching process includes a wet etching process.

The technical scheme of the invention has the following beneficial effects:

1. the micro-perforated plate, the support and the energy collecting component jointly form a Helmholtz resonant cavity, the micro-perforated plate plays a role in absorbing sound wave energy, when sound waves pass through the micro-perforated plate, the energy of the sound waves causes the vibration of the micro-perforated plate, the vibration of the micro-perforated plate is transmitted to the energy collecting component through the support, due to the piezoelectric property of a piezoelectric film layer in the energy collecting component, the mechanical energy of the vibration is converted into electric energy, the collected electric energy is transmitted to an electric energy storage circuit through a first electrode layer and a second electrode layer to complete the conversion from the sound energy to the electric energy, and the electric energy can be subsequently utilized. Secondly, the supporting layer is positioned on one side, back to the piezoelectric film layer, of the second electrode layer, and due to the supporting of the supporting layer, the area of the piezoelectric film layer is larger, and meanwhile, the thickness of the piezoelectric film layer can be thinner, so that the sensitivity of the piezoelectric film layer is higher, and the electric energy collection efficiency of the energy collection assembly is improved; the bonding layer is positioned between the second electrode layer and the supporting layer, so that the bonding force between the second electrode layer and the supporting layer is improved, and the structure of the electric energy conversion device is more stable.

2. Furthermore, the first opening penetrates through the piezoelectric film layer and the first electrode layer, part of the second electrode layer is exposed at the bottom of the first opening, and the second electrode layer can be led out from the first opening through a wire, so that the connection stability of the second electrode layer is improved.

3. Further, the first bonding layer includes a first sub-bonding film and a second sub-bonding film, the material of the first sub-bonding film includes silicon nitride, and the material of the second sub-bonding film includes silicon dioxide, so that the second electrode layer and the support layer are bonded more tightly.

4. Furthermore, the thickness of the piezoelectric film layer is 100 nm-1000 nm, and the thickness of the piezoelectric film layer is thin, so that the sensitivity of the energy collecting assembly is high, and the energy collecting assembly can generate polarization charges even if weak vibration occurs.

5. The invention provides a preparation method of an electric energy conversion device, a micro-perforated plate, a conductive bracket and an energy collecting component jointly form a Helmholtz resonant cavity, the micro-perforated plate plays a role in absorbing sound wave energy, when sound waves pass through the micro-perforated plate, the energy of the sound wave causes the micro-perforated plate to vibrate, the vibration of the micro-perforated plate is transmitted to the energy collecting component through the conductive bracket, the piezoelectric film layer in the energy collection component converts the mechanical energy of vibration into electric energy due to the piezoelectric property of the piezoelectric film layer, the collected electric energy is transferred to the electric energy storage circuit through the first electrode layer and the second electrode layer to complete the conversion of the acoustic energy into the electric energy, and the electric energy can be subsequently utilized, therefore, the electric energy conversion device can generate electricity, can be applied to a noise monitoring device, and realizes self-powered monitoring of a transformer noise system. Secondly, the supporting layer is positioned on one side, back to the piezoelectric film layer, of the second electrode layer, and due to the supporting of the supporting layer, the area of the piezoelectric film layer is larger, and meanwhile, the thickness of the piezoelectric film layer can be thinner, so that the sensitivity of the piezoelectric film layer is higher, and the electric energy collection efficiency of the energy collection assembly is improved; the bonding layer is positioned between the second electrode layer and the supporting layer, so that the bonding force between the second electrode layer and the supporting layer is improved, and the structure of the electric energy conversion device is more stable. The first opening penetrates through the piezoelectric film layer and the first electrode layer, part of the second electrode layer is exposed at the bottom of the first opening, and the second electrode layer can be led out from the first opening through a wire, so that the connection stability of the second electrode layer is improved. Therefore, the stability and the electric energy collection efficiency of the electric energy conversion device are improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 to 8 are schematic structural diagrams in a process of manufacturing a micro-perforated plate according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a micro-perforated plate according to an embodiment of the present invention;

fig. 10 to 17 are schematic structural views illustrating a manufacturing process of an energy collecting module according to an embodiment of the present invention;

FIG. 18 is a schematic structural view of an energy harvesting assembly according to an embodiment of the present invention;

FIG. 19 is a schematic top view of an energy harvesting assembly according to one embodiment of the present invention;

fig. 20 is a schematic structural diagram of an electrical energy conversion device according to an embodiment of the present invention.

Detailed Description

Taking a power transformer as an example, the power transformer is an important component for normal operation of the whole power system, however, under the condition of actual operation of the power transformer, sudden noise is generated along with a series of reasons such as increase of service life, change of loading working condition and the like, and in recent years, the occurrence frequency of the condition that noise of the power transformer disturbs people also increases year by year, and the interference and harm brought by the noise are increased day by day. The continuous pursuit of the people for quiet and good working and living conditions is contradictory, which provides new requirements and challenges for the real-time monitoring capability of the noise of the power transformer. The noise source of the power transformer is mainly the vibration of the iron core and the winding, and the main reasons for the vibration of the iron core and the winding can be summarized as the uneven stress distribution among the silicon steel sheets caused by the magnetostriction of the silicon steel sheets and the distortion of magnetic lines of force at the seam of the iron core. The frequency range of noise generated by the power transformer is usually low frequency line spectrum such as 50Hz, 100Hz, 200Hz, etc., and the noise monitoring for the power transformer mainly faces practical problems such as long duration, wide monitoring range, long monitoring distance, etc. Most of the conventional noise monitoring systems need power lines and data transmission lines, and the noise monitoring requirements generally have the defects of complex cable arrangement, high manpower and material resource consumption, poor system robustness and the like. Meanwhile, the power transformer is usually required to be in a working state for real-time noise monitoring of the power transformer, and the power transformer is in a safe distance, so that frequent entering of workers to a station for maintaining equipment is not allowed in order to prevent safety production accidents, an electric energy conversion device is provided for this purpose, a Helmholtz resonant cavity is formed by a micro-perforated plate, a support and an energy collection assembly, and the energy collection assembly converts mechanical energy of vibration into electric energy to realize self-energy supply.

However, the above-described electric energy conversion device has insufficient stability and is difficult to be used in a vibration environment.

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

An embodiment of the present invention provides an electric energy conversion device, please refer to fig. 9, 18, 19 and 20, which includes:

a micro-perforated plate 1;

an energy collection member 2 disposed opposite to the microperforated panel 1;

a support 3, said support 3 being located between an edge region of said energy collecting assembly 2 and an edge region of said microperforated panel 1;

the energy harvesting assembly 2 comprises: a piezoelectric film layer 201; a first electrode layer 202 positioned on the surface of the piezoelectric film layer 201 facing the micro-perforated plate 1; the second electrode layer 203 is positioned on the surface of one side, opposite to the micro-perforated plate 1, of the piezoelectric film layer 201; a first opening 2a penetrating through the piezoelectric film layer 201 and the first electrode layer 202, and a portion of the second electrode layer 203 is exposed at the bottom of the first opening 2 a; a bonding layer 205 positioned on the surface of the second electrode layer 203 on the side opposite to the piezoelectric film layer 201; and the support layer 204 is positioned on the side, opposite to the piezoelectric film layer 201, of the bonding layer 205.

It should be noted that fig. 20 is only for illustrating the relative positional relationship among the micro-perforated plate 1, the energy collecting module 2, and the holder 3, and a part of the structure is not shown.

In one embodiment, the second electrode layer 203 may be connected to the external charge collection circuit by gold wire ball bonding.

The supporting layer 204 is provided with a plurality of second openings 2b penetrating through the supporting layer 204, the second openings 2b expose a portion of the bonding layer 205, that is, the piezoelectric film layer 201 on a side of the bonding layer 205 opposite to the supporting layer 204 is not shielded by the supporting layer 204, so that the sensitivity of the piezoelectric film layer 201 is high, which is beneficial to improving the power generation efficiency of the electric energy conversion device.

In this embodiment, the support 3 is a conductive support, the support 3 is electrically connected to the second electrode layer 203, the support 3 is electrically connected to an external charge collecting circuit, and the support 3 leads an electrical signal on the second electrode layer 203 to the external charge collecting circuit.

In one embodiment, the material of the support layer 204 is a semiconductor material, so that the second openings 2b are easily formed by a semiconductor process, and especially when the density and the openings of the second openings 2b are small, the second openings 2b are easily formed by an etching process.

In this embodiment, the semiconductor material comprises silicon, for example, monocrystalline silicon.

In the present embodiment, the thickness of the support layer 204 is 50 μm to 200 μm, for example, 50 μm, 100 μm, 150 μm or 200 μm, and the area of the support layer 204 is 700mm²～8000mm²E.g. 700mm²、1000mm²、3000mm²、5000mm²、7000mm²Or 8000mm². The area of the piezoelectric film layer 201 is 700mm²～8000mm²E.g. 700mm²、1000mm²、3000mm²、5000mm²、7000mm²Or 8000mm². If the thickness of the support layer 204 is too thick, the difficulty in preparing the second opening 2b is increased, and if the thickness of the support layer 204 is too thin, the support effect of the support layer 204 on the piezoelectric film layer 201 is not good, so that it is difficult to make the piezoelectric film layer 201 thin and large, which is not beneficial to improving the sensitivity of the piezoelectric film layer 201.

The bonding layer 205 includes a first sub-bonding film 2051 and a second sub-bonding film 2052, the first sub-bonding film 2051 being located between the second sub-bonding film 2052 and the second electrode layer 203.

In this embodiment, the material of the first sub-junction film 2051 comprises silicon nitride, and the material of the second sub-junction film 2052 comprises silicon dioxide. Because the material of the support layer 204 is silicon, the second sub-junction film 2052 is more easily and tightly combined with the support layer 204, and because the first sub-junction film 2051 is more easily combined with the second electrode layer 203, the first sub-junction film 2051 is further arranged on the basis of the second sub-junction film 2052, so that the second electrode layer 203 is more tightly combined with the support layer 204, the stability of the energy collection assembly 2 is improved, and even if the electric energy conversion device is attached to the surface of a vibration mechanism such as a transformer, the piezoelectric film layer 201 is not separated from the support layer 204 due to vibration.

In the present embodiment, the thickness of the first sub junction film 2051 is 150nm to 250nm, for example, 150nm, 200nm, or 250nm, preferably 200 nm; the thickness of the second sub junction film 2052 is 250nm to 350nm, for example, 250nm, 300nm, or 350nm, preferably 300 nm. Due to the thickness setting, the piezoelectric film layer 201 can have a good flexibility requirement and a good deformation capacity, and meanwhile, the requirement for improving the combination capacity of the second electrode layer 203 and the support layer 204 can be met.

The plurality of second openings 2b are arranged in an array.

In this embodiment, the projection of the second opening 2b on the surface of the piezoelectric film 201 is square; in other embodiments, the projection of the second opening 2b on the surface of the piezoelectric film layer 201 is triangular or circular.

Preferably, the width of the second opening 2b is 3mm to 5mm, for example, 3mm, 4mm or 5 mm; the distance between adjacent second openings 2b is 1mm to 5mm, for example, 1mm, 2mm, 3mm, 4mm, or 5 mm. If the width of the second opening 2b is too small, the deformation of the piezoelectric film 201 is small and the generated polarization charge is small under the action of vibration, and if the width of the second opening 2b is too large, the flatness of the piezoelectric film 201 is not sufficient, resulting in poor sensitivity of the piezoelectric film 201.

The material of the piezoelectric film layer 201 includes lead zirconate titanate piezoelectric ceramic, polyvinylidene fluoride, aluminum nitride, or zinc oxide.

In the present embodiment, the thickness of the piezoelectric film layer 201 is 100nm to 1000nm, for example, 100nm, 300nm, 500nm, 700nm, 900nm, or 1000 nm. The thickness of the piezoelectric film 201 is thin, so that the sensitivity of the energy collection assembly 2 is high, and even a weak vibration can cause the energy collection assembly 2 to generate polarization charges.

A plurality of through holes 7 which are spaced and penetrate through the micro-perforated plate 1 are arranged in the thickness direction of the micro-perforated plate 1; the micro-perforated plate 1 includes: a microperforated body layer 101, the material of the microperforated body layer 101 comprising a semiconductor material. In this embodiment, the material of the microperforated body layer 101 is single crystal silicon.

Preferably, the through holes 7 are periodically arranged in the micro-perforated plate 1 in an array manner, the aperture sizes of the through holes 7 are consistent, and the intervals are uniform.

In this embodiment, the microperforated panel 1 further includes: an adhesion layer 102, the adhesion layer 102 being located on a side surface of the microperforated body layer 101 facing the energy collection assembly 2.

In this embodiment, the material of the adhesion layer 102 comprises silicon nitride, which can make the micro-perforated plate 1 and the holder 3 more tightly combined.

In the present embodiment, the diameter of the through holes 7 is 100 μm to 200 μm, for example, 100 μm, 150 μm, or 200 μm, and the pitch between adjacent through holes 7 is 200 μm to 400 μm, for example, 200 μm, 300 μm, or 400 μm.

In the present embodiment, the microperforated panel 1 has a thickness of 0.2mm to 2mm, for example, 0.2mm, 0.5mm, 1mm, 1.5mm, or 2 mm.

The support 3 is fixedly connected with the micro-perforated plate 1 through an adhesive, and the support 3 is electrically connected with the first electrode layer 202 through conductive silver paste.

The material of the holder 3 comprises a metal, e.g. copper, the holder 3 has a certain strength, and the holder 3 functions to electrically connect the first electrode layer 202 and also functions to support the micro-perforated plate 1 and the energy collecting member 2.

In the electric energy conversion device provided by this embodiment, the micro-perforated plate 1, the bracket 3 and the energy collecting assembly 2 together form a helmholtz resonant cavity, the micro-perforated plate 1 plays a role of absorbing sound wave energy, when sound waves pass through the micro-perforated plate 1, the energy of the sound wave causes the micro-perforated plate 1 to vibrate, the vibration of the micro-perforated plate 1 is transmitted to the energy collecting component 2 through the bracket 3, due to the piezoelectric property of the piezoelectric film layer 201 itself in the energy collection module 2, the mechanical energy of the vibration is converted into electric energy, and the collected electric energy is transferred to an electric energy storage circuit through the first electrode layer 202 and the second electrode layer 203 to complete the conversion of the acoustic energy into electric energy, and the electric energy can be used subsequently, therefore, the electric energy conversion device can generate electricity, can be applied to a noise monitoring device, and realizes self-powered monitoring of a transformer noise system. Secondly, the support layer 204 is located on the side of the second electrode layer 203, which faces away from the piezoelectric film layer 201, and due to the support of the support layer 204, the area of the piezoelectric film layer 201 can be larger, and the thickness of the piezoelectric film layer 201 can also be thinner, so that the sensitivity of the piezoelectric film layer 201 is higher, and the electric energy collection efficiency of the energy collection assembly 2 is improved; since the bonding layer 205 is located between the second electrode layer 203 and the support layer 204, a bonding force between the second electrode layer 203 and the support layer 204 is improved, so that the structure of the electric energy conversion device is more stable. The first opening 2a penetrates through the piezoelectric film layer 201 and the first electrode layer 202, a part of the second electrode layer 203 is exposed at the bottom of the first opening 2a, and the second electrode layer 203 can be led out from the first opening 2a through a wire, which is beneficial to improving the connection stability of the second electrode layer 203. Therefore, the stability and the electric energy collection efficiency of the electric energy conversion device are improved.

The electric energy conversion device provided by the embodiment can be attached to the surface of a vibration mechanism such as a transformer, mechanical energy is converted into electric energy by using vibration of the vibration mechanism, the electric energy conversion device can simultaneously convert the mechanical energy of the vibration and the sound energy of noise into electric energy, and the electric energy conversion device is high in power generation efficiency.

Another embodiment of the present invention further provides a method for manufacturing an electric energy conversion device, including:

forming a micro-perforated plate 1;

forming an energy harvesting assembly 2;

supporting the edge region of the energy collection module 2 and the edge region of the microperforated panel 1 with a support 3;

the method of forming the energy harvesting assembly 2 includes: providing an initial support layer 204 a; forming a bonding layer 205 on one side surface of the preliminary support layer 204 a; forming a second electrode layer 203 on a surface of the bonding layer 205 on a side opposite to the preliminary support layer 204 a; forming a piezoelectric film layer 201 on the surface of the second electrode layer 203, which faces away from the initial support layer 204 a; forming a first electrode layer 202 on the surface of the piezoelectric film layer 201, which faces away from the second electrode layer 203; a first opening 2a is formed in the first electrode layer 202 and the piezoelectric film layer 201, and a portion of the second electrode layer 203 is exposed at the bottom of the first opening 2 a.

The method for manufacturing the electric energy conversion device further includes: forming a plurality of second openings 2b penetrating the initial support layer 204a, the second openings 2b being opposite to a portion of the piezoelectric film layer 201; the step of forming the second opening 2b includes: forming a plurality of second initial openings 2c in the initial support layer 204a with partial thickness by a first etching process; after the second electrode layer 203 is formed, the second initial opening 2c is located on a side of the initial support layer 204a facing away from the second electrode layer 203; after the first opening 2a is formed, the initial support layer 204a at the bottom of the second initial opening 2c is etched by a second etching process, so that the initial support layer 204a forms a support layer 204, and the support layer 204 has a second opening 2b penetrating through the support layer 204.

In the present embodiment, the second preliminary opening 2c is formed before the second electrode layer 203 is formed.

In this embodiment, the first etching process includes a wet etching process, and the second etching process includes a dry etching process.

The method of forming the microperforated panel 1 includes:

providing a first semiconductor substrate 101 a;

forming an adhesive material layer 102a on one side surface of the first semiconductor substrate 101 a;

forming a first mask material layer 6a on the surface of the adhesion material layer 102a opposite to the first semiconductor substrate 101 a;

patterning the first mask material layer 6a to enable the first mask material layer 6a to form a first mask layer 6b, wherein the first mask layer 6b is provided with a plurality of first mask through holes 6c which are spaced and penetrate through the first mask layer 6 b;

etching the adhesion material layer 102a at the bottom of the first mask through hole 6c to form an adhesion layer 102 on the adhesion material layer 102a, wherein a first sub through hole 102b penetrating through the adhesion layer 102 is formed in the adhesion layer 102;

etching the first semiconductor substrate 101a at the bottom of the first sub-via 102b, so that the first semiconductor substrate 101a forms a micro-perforated body layer 101, wherein the micro-perforated body layer 101 has a second sub-via 102c penetrating through the micro-perforated body layer 101, and the second sub-via 102c penetrates through the first sub-via 102b and forms the via 7;

after the through hole 7 is formed, removing the first mask layer 6 b;

preferably, the material of the adhesion material layer 102a includes silicon nitride, and the material of the first mask material layer 6a includes aluminum.

After forming the adhesion material layer 102a and before forming the first mask material layer 6a, the method further comprises: the first semiconductor substrate 101a is thinned by a third etching process.

In this embodiment, the third etching process includes a wet etching process.

Referring to fig. 1 to 9, the formation steps of the micro-perforated plate 1 will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, a first semiconductor substrate 101a is provided and the first semiconductor substrate 101a is cleaned using a standard cleaning process.

Specifically, the standard cleaning process comprises the following steps:

placing the first semiconductor substrate 101a in an acetone solvent and cleaning for 5 minutes using ultrasound; then, the first semiconductor substrate 101a is placed in an ethanol solvent, and ultrasonic cleaning is performed for 5 minutes to remove organic matter on the surface of the first semiconductor substrate 101 a; then, the first semiconductor substrate 101a is rinsed with deionized water to remove acetone and ethanol remained on the surface of the first semiconductor substrate 101 a; then, the first semiconductor substrate 101a is placed in concentrated sulfuric acid and heated to boiling, and after cooling, the surface of the first semiconductor substrate 101a is repeatedly washed with deionized water; then, the first semiconductor substrate 101a is placed into deionized water several times to boil, so as to remove sulfuric acid on the surface of the first semiconductor substrate 101 a; thereafter, the surface of the first semiconductor substrate 101a is rinsed with deionized water; after that, the first semiconductor substrate 101a is dried.

The first semiconductor substrate 101a is put into a mixed solution of HCL: H2O2: H2O at a concentration ratio of 1:2:5 and boiled to remove metal ions on the surface of the first semiconductor substrate 101 a.

The first semiconductor substrate 101a is put into a mixed solution of NH4: H2O2: H2O at a concentration ratio of 1:2:8 and boiled to remove the complex on the surface of the first semiconductor substrate 101 a.

Referring to fig. 2, an adhesion material layer 102a is formed on a side surface of a first semiconductor substrate 101 a.

The process of forming the adhesion material layer 102a includes a deposition process, such as low pressure chemical vapor deposition.

Referring to fig. 3, the first semiconductor substrate 101a is thinned.

The process of thinning the first semiconductor substrate 101a includes a wet etching process, and the adhesion material layer 102a serves as a mask layer of the wet etching process to protect a side surface of the first semiconductor substrate 101 a.

The method of the wet etching process comprises the following steps: placing the first semiconductor substrate 101a in a KOH solution, wherein the content of KOH is 33%, the wet etching time is 55 minutes, and the thickness of the thinned first semiconductor substrate 101a is 0.2mm to 2mm, for example, 0.2mm, 0.5mm, 1mm, 1.5mm or 2 mm; then, the first semiconductor substrate 101a is rinsed with deionized water; thereafter, the first semiconductor substrate 101a is dried; thereafter, the first semiconductor substrate 101a is cleaned with O2 plasma for 3 minutes to remove contaminants from the surface of the adhesion material layer 102 a.

Referring to fig. 4, a first mask material layer 6a is formed on a surface of the adhesion material layer 102a opposite to the first semiconductor substrate 101 a.

The process of forming the first mask material layer 6a includes an evaporation process.

Referring to fig. 5, a patterned first photoresist layer 6d is formed on a surface of the first mask material layer 6a opposite to the adhesion material layer 102 a.

Referring to fig. 6, the first mask material layer 6a is etched using the first photoresist layer 6d as a mask, so that the first mask material layer 6a forms a first mask layer 6b, and the first mask layer 6b has a plurality of first mask through holes 6c spaced apart from each other and penetrating through the first mask layer 6 b.

The method of forming the first mask via hole 6c is: placing the first semiconductor substrate 101a in a phosphoric acid solution to remove the first masking material layer 6a not covered by the first photoresist layer 6d, the concentration of the phosphoric acid solution being analytically pure; thereafter, the first semiconductor substrate 101a is taken out and repeatedly rinsed with deionized water to remove the residual phosphoric acid on the surface of the first semiconductor substrate 101 a.

Referring to fig. 7, the adhesion material layer 102a is etched by using the first mask layer 6b as a mask, so that the adhesion material layer 102a forms an adhesion layer 102, and the adhesion layer 102 has a plurality of first sub-vias 102b spaced apart from each other and penetrating through the adhesion layer 102.

The method for forming the first sub-via 102b is as follows: the first sub-via 102b is formed using a plasma etching process using an etching gas including sulfur hexafluoride, carbon tetrafluoride, nitrogen trifluoride, hexafluoroethane, perfluoropropane, or trifluoromethane.

Referring to fig. 8, the first semiconductor substrate 101a is etched using the first mask layer 6b as a mask to remove the first semiconductor substrate 101a not covered by the first mask layer 6b, so that the first semiconductor substrate 101a forms a micro-perforated body layer 101, and the micro-perforated body layer 101 has a plurality of second sub-vias 102c spaced apart from each other and penetrating through the micro-perforated body layer 101.

The process of forming the second sub-via 102c includes a Deep Reactive Ion Etching (DRIE) process.

Referring to fig. 9, the first photoresist layer 6d and the first mask layer 6b are removed.

Specifically, the first semiconductor substrate 101a is placed in an acetone solution, and the first photoresist layer 6d on the surface of the first semiconductor substrate 101a is removed; then, the first semiconductor substrate 101a is placed in a phosphoric acid solution to remove the first mask layer 6b on the surface of the first semiconductor substrate 101a, and the concentration of the phosphoric acid solution is analytically pure.

In this embodiment, the microperforation body layer 101 and the adhesion layer 102 constitute the microperforation panel 1, and in other embodiments, the adhesion layer 102 may be eliminated, and the microperforation panel 1 is constituted by only the microperforation body layer 101.

Referring to fig. 10 to 18, the steps for forming the energy collecting assembly 2 will be described in detail with reference to the accompanying drawings.

Referring to fig. 10, a preliminary support layer 204a is provided and the preliminary support layer 204a is cleaned using a standard cleaning process.

The method of labeling the cleaning process is described with reference to the related description.

Referring to fig. 11, a second sub-bonding film 2052, a fourth initial sub-bonding film 2052a, a first sub-bonding film 2051, and a third initial sub-bonding film 2051a are formed on both side surfaces of the initial support layer 204 a.

Specifically, the second sub-junction film 2052 and the fourth initial sub-junction film 2052a are formed on both side surfaces of the initial support layer 204a by Low Pressure Chemical Vapor Deposition (LPCVD); thereafter, a first sub-junction film 2051 is formed on a surface of the second sub-junction film 2052 on a side facing away from the preliminary support layer 204a, and a third preliminary sub-junction film 2051a is formed on a surface of the fourth preliminary sub-junction film 2052a on a side facing away from the preliminary support layer 204a, again by a low pressure chemical vapor deposition method.

Referring to fig. 12, a second photoresist layer 6e is formed on a surface of the third preliminary sub-junction film 2051a opposite to the preliminary support layer 204 a.

The process of forming the second photoresist layer 6e includes a photolithography process.

Specifically, the process references of the photolithography process include: the surface of the third initial sub-junction film 2051a is coated with a positive photoresist by a spin coating method, the spin coating speed of the spin coating method is 1000rpm, the coating time is 60 seconds, the prebaking time is 30 minutes, the prebaking temperature is 80 ℃, the exposure illumination wavelength is 350 nm-450 nm, the exposure time is 23 seconds, the alignment accuracy of exposure is 1 micron, the alkaline substance in the developing solution is NaOH, wherein the concentration of NaOH is 0.6%, the developing time is 30 seconds, the postbaking time of the photolithography process is 30 minutes, and the postbaking temperature is 80 ℃.

The preliminary support layer 204a was cleaned using an O2 plasma for 3 minutes to remove residual photoresist in the pattern after the development of the preliminary support layer 204 a.

Referring to fig. 13, the third initial sub-junction film 2051a and the fourth initial sub-junction film 2052a are etched using the second photoresist layer 6e as a mask, so that the third initial sub-junction film 2051a forms a third sub-junction film 2051b, and the fourth initial sub-junction film 2052a forms a fourth sub-junction film 2052 b. The third and fourth sub-bonding films 2051b and 2052b have third mask through holes 6f therein at intervals and penetrating the third and fourth sub-bonding films 2051b and 2052 b.

The process for forming the third mask through hole 6f includes a plasma etching process, the etching time of the plasma etching process is 5 minutes, and etching gas adopted by the plasma etching process includes sulfur hexafluoride, carbon tetrafluoride, nitrogen trifluoride, hexafluoroethane, perfluoropropane or trifluoromethane.

Referring to fig. 14, the preliminary support layer 204a is etched using the third sub-junction film 2051b and the fourth sub-junction film 2052b as masks, so that a second preliminary opening 2c is formed in the preliminary support layer 204.

The process for forming the second initial opening 2c includes a wet etching process, specifically, the initial support layer 204a is placed in a KOH etching solution with a concentration of 33% to be etched, the temperature of the etching solution is 80 ℃, the etching time is 250 minutes, and the depth of the second initial opening 2c is 100 micrometers; thereafter, the preliminary support layer 204a is washed with deionized water; thereafter, the initial support layer 204a is dried; thereafter, plasma cleaning was performed by O2 for 3 minutes to remove contaminants attached to the surface of the preliminary support layer 204a during wet etching.

Referring to fig. 15, a second electrode layer 203 is formed on a surface of the first sub-junction film 2051 opposite to the initial support layer 204 a.

The process of forming the second electrode layer 203 includes a sputtering process, and specifically, a chromium metal layer having a thickness of 50nm is sputtered on a surface of the first sub-junction film 2051 on a side facing away from the initial support layer 204a by a first sputtering process, and then a platinum metal layer having a thickness of 300nm is sputtered on a surface of the chromium metal layer on a side facing away from the initial support layer 204a by a second sputtering process, the chromium metal layer serving to increase adhesion of the first sub-junction film 2051 to the platinum metal layer.

Referring to fig. 16, a piezoelectric film 201 is formed on a surface of the second electrode layer 203 opposite to the initial support layer 204 a.

The process of forming the piezoelectric film layer 201 includes a sputtering process.

Referring to fig. 17, a first electrode layer 202 is formed on a surface of the piezoelectric film layer 201 opposite to the initial support layer 204a, and a first opening 2a is formed.

The method of forming the first electrode layer 202 is described with reference to the formation of the second electrode layer 203. The preliminary support layer 204a was soaked with acetone for 1 hour after the first electrode layer 202 was formed; thereafter, by sonication for 3 minutes; thereafter, the first opening 2a is formed by a metal lift-off process.

Referring to fig. 18, the initial support layer 204a is etched by using the third sub-junction film 2051b and the fourth sub-junction film 2052b as masks, so that the initial support layer 204a forms the support layer 204, and the support layer 204 has a plurality of second openings 2b spaced apart from each other and penetrating through the support layer 204.

The process of forming the second opening 2b includes a Deep Reactive Ion Etching (DRIE) process.

After the second opening 2b is formed, the support layer 204 is placed in an acetone solution to remove oil stains on the surface of the support layer 204; thereafter, the support layer 204 is rinsed multiple times with deionized water; thereafter, the support layer 204 is dried.

In the preparation method of the electric energy conversion device provided by this embodiment, the supporting layer 204 is located on the side of the second electrode layer 203, which faces away from the piezoelectric film layer 201, and due to the support of the supporting layer 204, the area of the piezoelectric film layer 201 is larger, and the thickness of the piezoelectric film layer 201 is also thinner, so that the sensitivity of the piezoelectric film layer 201 is higher, and the electric energy collection efficiency of the energy collection assembly 2 is improved. The first opening 2a penetrates through the piezoelectric film layer 201 and the first electrode layer 202, a part of the second electrode layer 203 is exposed at the bottom of the first opening 2a, and the second electrode layer 203 can be led out from the first opening 2a through a wire, which is beneficial to improving the connection stability of the second electrode layer 203. The support 3 is located between the edge region of the energy collecting component 2 and the edge region of the micro-perforated plate 1, the support 3 and the energy collecting component 2 together form a helmholtz resonant cavity, the micro-perforated plate 1 plays a role in absorbing sound wave energy, when sound waves pass through the micro-perforated plate 1, the energy of the sound waves causes the vibration of the micro-perforated plate 1, the vibration of the micro-perforated plate 1 is transmitted to the energy collecting component 2 through the support 3, due to the piezoelectric property of the piezoelectric film 201 in the energy collecting component 2, the mechanical energy of the vibration is converted into electric energy, the collected electric energy is transmitted to the electric energy storage circuit through the first electrode layer 202 and the second electrode layer 203, the conversion of the sound energy into the electric energy is completed, and the electric energy can be subsequently utilized, therefore, the electric energy conversion device can generate electricity and can be applied to a noise monitoring device, and self-powered monitoring of a transformer noise system is realized.

The electric energy conversion device provided by the embodiment can be attached to the surface of a vibration mechanism such as a transformer, mechanical energy is converted into electric energy by using vibration of the vibration mechanism, the electric energy conversion device can simultaneously convert the mechanical energy of the vibration and the sound energy of noise into electric energy, and the electric energy conversion device is high in power generation efficiency.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.