阅读说明：本技术 一种全金属微惯性系统器件及其加工方法 (All-metal micro-inertia system device and processing method thereof ) 是由 李以贵 金敏慧 于 2019-10-10 设计创作，主要内容包括：本发明涉及一种全金属微惯性系统器件的加工方法,包括以下步骤：提供硅基板,在硅基板电镀一层Cr/Au金属层,将PMMA光刻胶层覆盖到Cr/Au金属层表面；将掩模板与硅基板对准后,采用X射线照射PMMA光刻胶层,显影得到光刻胶微结构,并在光刻胶微结构的缝隙中显露出Cr/Au金属层；在显露的Cr/Au金属层表面电镀Ni/Cu金属层；打磨将Ni/Cu金属层的厚度处理为100～1000um；分离硅基板,去除PMMA光刻胶层和Cr/Au金属层得到全金属微惯性系统器件。与现有技术相比,本发明具有工艺步骤少、成本低、加工过程简单、成品抗冲击力强等优点。(The invention relates to a processing method of an all-metal micro-inertia system device, which comprises the following steps: providing a silicon substrate, electroplating a Cr/Au metal layer on the silicon substrate, and covering a PMMA photoresist layer on the surface of the Cr/Au metal layer; after aligning the mask plate with the silicon substrate, irradiating the PMMA photoresist layer by adopting X rays, developing to obtain a photoresist microstructure, and exposing a Cr/Au metal layer in a gap of the photoresist microstructure; electroplating a Ni/Cu metal layer on the surface of the exposed Cr/Au metal layer; polishing to enable the thickness of the Ni/Cu metal layer to be 100-1000 um; and separating the silicon substrate, and removing the PMMA photoresist layer and the Cr/Au metal layer to obtain the all-metal micro-inertia system device. Compared with the prior art, the invention has the advantages of less process steps, low cost, simple processing process, strong impact resistance of the finished product and the like.)

1. A processing method of an all-metal micro-inertia system device is characterized by comprising the following steps:

providing a silicon substrate (6), electroplating a Cr/Au metal layer (7) on the silicon substrate (6), and covering a PMMA photoresist layer (8) on the surface of the Cr/Au metal layer (7);

after aligning a mask plate with a silicon substrate (6), irradiating the PMMA photoresist layer (8) by adopting X rays, developing to obtain a photoresist microstructure (9), and exposing a Cr/Au metal layer (7) in a gap of the photoresist microstructure (9);

electroplating a Ni/Cu metal layer (10) on the surface of the exposed Cr/Au metal layer (7);

polishing to enable the thickness of the Ni/Cu metal layer (10) to be 100-1000 um;

and separating the silicon substrate (6), and removing the PMMA photoresist layer (8) and the Cr/Au metal layer (7) to obtain the all-metal micro-inertial system device.

2. The method of claim 1, wherein the X-ray photon energy is greater than 1.3 kev.

3. The method for processing the all-metal micro inertial system device according to claim 2, wherein the X-ray irradiation method is to obtain an X-ray beam through a kempton window, and then the X-ray beam passes through a mask plate, irradiates the PMMA photoresist layer (8) for exposure, and transfers the pattern of the mask plate onto the photoresist.

4. A method for manufacturing an all-metal micro inertial system device according to claim 3, wherein the size of the all-metal micro inertial system device is larger than the size of the kepton window, and the PMMA photoresist layer (8) is subjected to moving lithography.

5. A method of fabricating an all-metal micro inertial system device according to claim 3, wherein the kepton window has a size of 5 x 30 mm.

6. The method for fabricating an all-metal micro inertial system device according to claim 4, wherein the time for irradiating the PMMA photoresist layer (8) with X-rays is 5min to 60 min.

7. The method for manufacturing an all-metal micro inertial system device according to claim 1, wherein the thickness of the PMMA photoresist layer (8) is 1um to 1 mm.

8. The method as claimed in claim 1, wherein the mask plate has a plurality of product patterns with the same or different sizes.

9. An all-metal micro-inertial device obtained by the machining method according to claim 1, comprising a mass (3), a spring (2) connected to the mass (3) and an anchor point (1) connected to the spring (2); the anchor point (1) is connected to the strap measuring means.

10. An all-metal micro-inertial device obtained by the method of claim 1, further comprising a guide portion (4) connected to the mass (3), the guide portion (4) having a cavity (5) for housing the spring (2).

Technical Field

The invention relates to the field of micro-machining, in particular to an all-metal micro-inertia system device and a machining method thereof.

Background

Photolithography is one of the key technologies that have been used to advance the manufacturing industry of micro-machines. With the advent of new technology revolution, the development of optical lithography technology is gradually perfected. X-ray lithography has matured substantially over the last thirty years. Compared with other common optical lithography technologies, the X-ray lithography has the advantages of strong penetrability, high resolution, high depth-to-width ratio, simple process and the like.

In the preparation of the traditional micro inertial system device, a single mask plate is usually adopted for photoetching, and only micro devices with the same size and dimension can be obtained each time. For the mass production of all-metal micro-inertia systems with different sizes, the method has the defects of complicated and time-consuming steps, greatly improves the mask cost and is not suitable for mass production.

Taking an existing all-metal micro-inertial system device as an example, see patent "an all-metal capacitor plate micro-acceleration sensor" (patent number CN104020313A), which generates a capacitance difference by the displacement of a mass block, thereby obtaining a feedback voltage to measure the magnitude of acceleration. By adopting the capacitive polar plate, the size of the capacitor is easily interfered by the surrounding environment. And because the distance relation between the capacitance of the capacitive sensor and the upper and lower polar plates is nonlinear, a compensation circuit needs to be additionally connected, and after the circuit is connected, the distribution of cables is easy to influence the capacitance.

Chinese patent CN1778505A discloses a method for manufacturing an extremely long and special-shaped micro electrode for electric spark machining, which comprises the following steps of 1, coating photoresist on a conductive substrate; step 2, aligning the mask plate with the conductive substrate, exposing, and developing to obtain a photoresist microstructure; step 3, electroforming metal in the gaps of the photoresist microstructure; step 4, repeating the steps 1-3; and 5: and removing the photoresist and the conductive substrate to obtain the required metal electrode. However, ultraviolet light is adopted in the patent technology, and for all-metal micro-inertia system devices, the surface roughness and the structural strength of the devices need to be ensured, so that the thickness requirement of the devices is high, and the ultraviolet light cannot meet the requirement.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide an all-metal micro-inertial system device with high processing efficiency, simple processing technology and accurate measurement and a processing method thereof.

The purpose of the invention can be realized by the following technical scheme:

a processing method of an all-metal micro-inertia system device comprises the following steps:

(1) providing a silicon substrate, electroplating a Cr/Au metal layer on the silicon substrate, and covering a PMMA photoresist layer on the surface of the Cr/Au metal layer;

(2) after aligning a mask plate with a silicon substrate, irradiating the PMMA photoresist layer by adopting X rays, developing to obtain a photoresist microstructure, and exposing a Cr/Au metal layer in a gap of the photoresist microstructure;

(3) electroplating a Ni/Cu metal layer on the surface of the exposed Cr/Au metal layer;

(4) polishing to enable the thickness of the Ni/Cu metal layer to be 100-1000 um;

(5) and separating the silicon substrate, and removing the PMMA photoresist layer and the Cr/Au metal layer to obtain the all-metal micro-inertia system device.

The photon energy of the X-ray is greater than 1.3 kev.

The X-ray irradiation method comprises the steps of obtaining an X-ray beam by using a Kempton window, irradiating the PMMA photoresist layer by the X-ray beam through a mask plate for exposure, and transferring the pattern of the mask plate to the photoresist.

And the size of the all-metal micro-inertia system device is larger than that of the Kepton window, and the PMMA photoresist layer is subjected to mobile photoetching.

The time for irradiating the PMMA photoresist layer by the X-ray is changed according to the size of a device to be processed and can be changed within the range of 5 min-60 min.

The PMMA photoresist layer has the highest thickness of 1mm and the thickness of the PMMA photoresist layer changes in a floating mode within the range of 1 um-1 mm.

Compared with the prior art, the surface roughness of the component obtained under the X-ray exposure condition is small, the thickness of the component can reach 1mm at most, the shock resistance is strong, and all-metal micro-inertia system devices with different sizes can be obtained on the same silicon wafer only by changing the size of a mask pattern and only needing one-time X-exposure, so that the mass production can be realized.

Among the manufacturing processes, the most critical process is X-ray exposure. Selecting different exposure times according to the thickness of the all-metal device to be prepared, wherein the exposure times are different from 5min to 60min, and if the photoetching time is too short, the photoresist microstructure with the corresponding depth on the PMMA photoresist layer cannot be ensured, so that the thickness and the structure of a final product cannot be ensured; the etching time is too long, other structures which do not need to be etched are easy to damage, and the transitional etching causes unnecessary waste to the light source in consideration of the high use cost of the X light source. When the size of the all-metal device is larger than the size of the X-ray window, the processing device needs to be subjected to moving exposure.

The mask plate is provided with a plurality of product patterns with the same or different sizes.

All-metal micro-inertia system devices with different sizes can be obtained on the same silicon chip by changing the size of the mask pattern, and only one-time X-ray exposure is needed, so that the mass production can be realized, and the defects of time consumption and high cost in the prior art are overcome.

The all-metal micro-inertia device obtained by the processing method comprises a mass block, a spring connected with the mass block and an anchor point connected with the spring; the anchor point is connected to the belt measuring member.

The all-metal micro-inertia device further comprises a guide part connected to the mass block, and a cavity for placing the spring is arranged in the guide part.

The working principle of the all-metal micro-inertia device provided by the invention is as follows:

when the device spring is connected to the substrate through the anchor point, when the acceleration along the horizontal direction of the device acts on the member, the mass block is deflected towards the right due to the inertia force, and meanwhile, the spring is stretched towards the left, and under the condition of not counting friction, the magnitude of the acceleration can be obtained through the deformation quantity of the spring by the Newton's second law F-ma and the Hooke's law F-kx.

Compared with the prior art, the invention has the following advantages:

(1) the process of the invention adopts the combination of the X-ray photoetching process and the electroplating process, the surface roughness of the produced all-metal micro-inertia system device is small, the thickness of the component can reach 1mm at most, the impact resistance is strong, and the requirements of the micro-sensor are met;

(2) all-metal micro-inertia system devices with different sizes can be obtained on the same silicon wafer only through one-time X exposure, mass production can be achieved, production efficiency is high, and cost is low.

Drawings

FIG. 1 is a schematic structural diagram of an all-metal micro-inertial device according to the present invention;

FIG. 2 is a schematic view of the working principle of the all-metal micro-inertia device according to the present invention;

FIG. 3 is a flow chart of a process for fabricating an all-metal micro-inertial device according to the present invention;

FIG. 4 is a schematic structural diagram of a mask plate employed in the present invention;

in the figure, 1 is an anchor point, 2 is a spring, 3 is a mass block, 4 is a guide part, 5 is a cavity, 6 is a silicon substrate, 7 is a Cr/Au metal layer, 8 is a PMMA photoresist layer, 9 is a photoresist microstructure, and 10 is a Ni/Cu metal layer.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.