A method for preparing a micro-curved surface conformal sensor

Abstract

The application discloses a preparation method of a micro-curved surface conformal sensor, which comprises the following steps: sequentially preparing an insulating layer and a sensitive layer on an irregular micro-curved surface space, taking polydimethylsiloxane (PDMS) as a mask, and adopting an electroblotting technology to precisely spray and pattern the PDMS on the sensitive layer; then, etching and removing the sensitive layer which is not covered by the mask, and keeping the mask layer as a protective layer of the sensor, so as to realize conformal manufacturing of a patterned structure of the sensor in a micro space. The application integrates the mask preparation and the protective layer preparation processes, improves the production efficiency, and can realize conformal manufacturing of the sensor in a non-flat micro-curved surface space, and has important practical production significance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensor manufacturing, in particular to a preparation method of a micro-small curved surface conformal sensor. BACKGROUND

[0002] In the prior art, the preparation of sensors is mostly used for flat surfaces. However, with the rapid development of microelectronic technology and micro-mechanical systems, the application demand of sensors in irregular micro-small spaces is gradually increasing.

[0003] However, the traditional preparation method is difficult to realize high-precision sensor patterning structure on a micro-small curved surface, which limits its application in actual production. Therefore, a new preparation method is needed to solve this problem. SUMMARY

[0004] The purpose of the present application is to solve the above-mentioned problems in the prior art, and to provide a preparation method of a micro-small curved surface conformal sensor. Through specific materials and process steps, high-precision and high-resolution sensor patterning structure is realized to meet the application demand on a micro-small curved surface.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A preparation method of a micro-small curved surface conformal sensor, comprising the following steps:

[0007] 1) An insulating layer is prepared on a micro-small curved surface to be prepared for a sensor by using a polyimide solution;

[0008] 2) A sensitive layer is sputtered on the insulating layer;

[0009] 3) Polydimethylsiloxane is used as a mask and a protective layer and is sprayed onto the sensitive layer by using an electrohydrodynamic printing technology;

[0010] 4) A wet etching method is used to remove the sensitive layer that is not covered by the mask to form a required sensor pattern; the line width of the pattern is below 10 μm.

[0011] In step 1), the polyimide solution is covered on the micro-small curved surface to be prepared for a sensor by first standing and pulling, and then blowing the surface thin by using an air gun to prepare an insulating layer.

[0012] In step 1), the solvent of the polyimide solution is polyamide acid, which is diluted by using dimethylacetamide, and the solution concentration is 15wt%-20wt%.

[0013] In step 2), the material of the sensitive layer is selected from copper.

[0014] In step 2), the sensitive layer with a thickness of 200-300 μm is deposited by using a magnetron sputtering method.

[0015] In step 3), the e-fluid jetting e-fluid jetting head is a glass needle head with a tip of 5 μm, the applied voltage is 0.9-1.3 kV, and the mask jetting line width is below 10 μm.

[0016] In step 3), n-hexane is used as a diluent of polydimethylsiloxane.

[0017] In step 4), the etching environment temperature of the wet etching is 20-40℃.

[0018] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0019] The method integrates the mask preparation and the protective layer preparation processes, improves the production efficiency, realizes high resolution with a line width below 10 μm, can prepare a strain sensor conformally on a non-flat micro-surface, and provides a new preparation method, which has important practical production significance. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The figure is a flowchart of the preparation method of the present application;

[0021] Figure 2 The figure is a schematic diagram of the sensor film layer structure of the present application;

[0022] Figure 3 The figure is a schematic diagram of the product of the present application.

[0023] The figure is a schematic diagram of the product of the present application. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical schemes and beneficial effects of the present application clearer and more apparent, the present application is further described in detail below with reference to the drawings and examples.

[0025] Referring to Figure 1 and Figure 2 The present application provides a preparation method of a micro-surface conformal sensor, which comprises a non-flat micro-surface as a substrate 1, an insulating layer 2 prepared on the substrate by first standing and then blowing the surface thin by using an air gun, a sensitive layer 3 attached on the surface of the insulating layer 2 by magnetic control sputtering, and a mask and a protective layer 4 deposited by e-fluid jetting.

[0026] Referring to Figure 3 According to the product schematic diagram of the micro-surface conformal sensor of the present application, it can be seen that the sensor is prepared on a micro-tooth groove, and the sensitive layer has high resolution with a line width below 10 μm.

[0027] In the present application, the specific technical solutions are as follows:

[0028] The first step, preparing an insulating layer on an irregular micro-surface substrate: on the micro-surface substrate to be prepared into a sensor, a polyimide (PI) solution is covered on the surface by the method of first standing and then blowing the surface thin with an air gun, to prepare a PI insulating layer;

[0029] In the preparation of the PI insulating layer, the solvent of the PI solution is polyamide acid, which is diluted with dimethylacetamide (DMAC), and the solution concentration is 16wt%.

[0030] The PI insulating layer is dried and cured to ensure that it uniformly covers the entire micro-surface.

[0031] The second step, depositing a sensitive layer on the insulating layer: a cupronickel (CuNi) sensitive layer is deposited on the PI insulating layer by the method of magnetron sputtering.

[0032] In the sputtering of 200-300 μm of cupronickel alloy, the sensitive layer is ensured to have good conductivity and strain-sensitive characteristics.

[0033] The third step, precisely spraying a polydimethylsiloxane (PDMS) mask onto the sensitive layer using electrohydrodynamic printing technology: using electrohydrodynamic printing technology, the PDMS mask is precisely sprayed onto the surface of the cupronickel sensitive layer to form a patterned mask and protective layer. After electrohydrodynamic printing, the mask and protective layer are cured by heating at 120°C to ensure the stability and durability of the sensor.

[0034] In the electrohydrodynamic printing, the electrohydrodynamic nozzle is a glass needle with a tip of 5 μm, and the applied voltage is 1.05 kV.

[0035] In the electrohydrodynamic printing, PDMS is used as the material of the mask and protective layer, and n-hexane is used as the diluent of PDMS.

[0036] In the electrohydrodynamic printing, a high resolution of less than 10 μm is achieved for the line width of the mask and protective layer.

[0037] The fourth step, etching to remove the sensitive layer not covered by the mask: wet etching is performed on the cupronickel sensitive layer not covered by the mask using a cupronickel etching solution to remove these parts, so that the cupronickel sensitive layer forms a predetermined pattern structure.

[0038] In the wet etching, a high cerium ammonium nitrate etching solution is used, and the etching environment temperature is 40°C.

[0039] The method of the present application integrates the mask preparation and protective layer preparation processes, improves the production efficiency, achieves a high resolution of less than 10 μm for the line width, can conformally prepare a strain sensor in a non-flat micro-surface, and provides a new preparation method, which has important practical production significance.

Claims

1. A method of fabricating a micro-curved conformal sensor, comprising: The method comprises the following steps: 1) covering polyimide solution on the micro-curved surface to be prepared into a sensor by the method of first static pull and then blowing the surface thin with an air gun to prepare an insulation layer; the solvent of the polyimide solution is polyamide acid diluted with dimethylacetamide, and the solution concentration is 15wt%-20wt%; 2) depositing a 200-300μm sensitive layer on the insulation layer by the way of magnetron sputtering, and the material of the sensitive layer is selected from constantan; 3) using the electrospray printing technology to print polydimethylsiloxane as a mask and a protective layer on the sensitive layer; the electrospray printing fluid nozzle is a glass needle with a tip of 5μm, the applied voltage is 0.9-1.3kV, and the mask printing line width is below 10μm; wherein, n-hexane is used as the diluent of polydimethylsiloxane; 4) using the wet etching method to remove the sensitive layer not covered by the mask to form the required sensor pattern; the line width of the pattern is below 10μm; and the etching environment temperature of the wet etching is 20-40℃.

2. A micro-curved conformal sensor, characterized by: The sensor is prepared by the preparation method of claim 1.

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