阅读说明：本技术 一种离子束溅射薄膜高温应变片及其制备方法 (Ion beam sputtering film high-temperature strain gauge and preparation method thereof ) 是由 戚云娟 潘婷 高波 薛晓婷 蔺露 李莹 于 2020-11-25 设计创作，主要内容包括：本发明公开了一种离子束溅射薄膜高温应变片及其制备方法,该离子束溅射薄膜高温应变片包括镍基合金基底、绝缘薄膜层、镍铬丝栅薄膜层、保护薄膜层以及电极薄膜；镍基合金基底、绝缘薄膜层、以及镍铬丝栅薄膜层从下到上依次层叠设置；电极薄膜和保护薄膜层均通过离子束溅射镀膜工艺沉积于镍铬丝栅薄膜层的顶部,电极薄膜和保护薄膜层同层设置；镍铬丝栅薄膜层由通过离子束溅射镀膜工艺沉积于绝缘薄膜层的镍铬薄膜层经过刻蚀形成；电极薄膜用于连接耐高温导线。上述离子束溅射薄膜高温应变片能够在高温下进行稳定的测量工作。(The invention discloses an ion beam sputtering film high-temperature strain gauge and a preparation method thereof, wherein the ion beam sputtering film high-temperature strain gauge comprises a nickel-based alloy substrate, an insulating film layer, a nickel-chromium wire grid film layer, a protective film layer and an electrode film; the nickel-based alloy substrate, the insulating film layer and the nickel-chromium wire grid film layer are sequentially stacked from bottom to top; the electrode film and the protective film layer are deposited on the top of the nickel-chromium wire grid film layer through an ion beam sputtering coating process, and the electrode film and the protective film layer are arranged on the same layer; the nickel-chromium wire grid thin film layer is formed by etching a nickel-chromium thin film layer deposited on the insulating thin film layer by an ion beam sputtering coating process; the electrode film is used for connecting a high-temperature-resistant lead. The ion beam sputtering film high-temperature strain gauge can perform stable measurement work at high temperature.)

1. The high-temperature strain gauge of the ion beam sputtering film is characterized by comprising a nickel-based alloy substrate, an insulating film layer, a nickel-chromium wire grid film layer, a protective film layer and an electrode film; the nickel-based alloy substrate, the insulating film layer and the nickel-chromium wire grid film layer are sequentially stacked from bottom to top;

the electrode film and the protective film layer are deposited on the top of the nickel-chromium wire grid film layer through an ion beam sputtering coating process, and the electrode film and the protective film layer are arranged on the same layer;

the nickel-chromium wire grid thin film layer is formed by etching a nickel-chromium thin film layer deposited on the insulating thin film layer through an ion beam sputtering coating process;

the electrode film is used for connecting a high-temperature-resistant lead;

the protective film layer is used for protecting the nickel-chromium wire grid film layer.

2. The ion beam sputtered thin film high temperature strain gage of claim 1, wherein the insulating thin film layer is SiO₂/Si₃N₄The thickness of the composite insulating film layer is 1.5 mu m.

3. The ion beam sputtered thin film high temperature strain gage of claim 1 in which the protective thin film layer is Si₃N₄A protective film was formed to a thickness of 0.3. mu.m.

4. The ion beam sputtering thin film high temperature strain gauge of claim 1, wherein the electrode thin film is a Ni/Au composite thin film having a thickness of 0.5 μm.

5. The ion beam sputtered thin film high temperature strain gage of claim 1 wherein the thickness of the nickel base alloy substrate is 10 μm;

the thickness of the nickel-chromium wire grid film layer is 0.6 mu m.

6. The preparation method of the ion beam sputtering film high-temperature strain gauge is characterized by comprising the following steps of:

depositing an insulating film layer on the nickel-based alloy substrate by adopting a plasma chemical vapor deposition process;

depositing a nickel-chromium film layer on the surface of the insulating film layer by an ion beam sputtering coating process;

carrying out ion beam etching on the nickel-chromium thin film layer to form a nickel-chromium wire grid thin film layer;

protecting the electrode pad by adopting positive photoresist, and depositing a protective film layer in the region outside the electrode pad by adopting an ion beam sputtering coating process;

and adopting positive photoresist to protect the region outside the electrode pad, and depositing an electrode film on the electrode pad by an ion beam sputtering coating process.

7. The method of claim 6, further comprising, prior to the step of depositing the insulating thin film layer on the nickel-based alloy substrate using a plasma chemical vapor deposition process:

manufacturing a nickel-chromium wire grid film layer, a protective film layer and a mask plate required by an electrode film;

and carrying out surface treatment on the nickel-based alloy substrate by a grinding and polishing process to ensure that the surface roughness of the nickel-based alloy substrate is less than 5 nm.

8. The method according to claim 6, wherein the step of performing ion beam etching on the nickel-chromium thin film layer to form the nickel-chromium wire grid thin film layer specifically comprises:

transferring the strain strip wire grid pattern on the mask to the surface of the insulating film layer by glue homogenizing, ultraviolet exposure and developing processes on the surface of the nickel-chromium film layer;

carrying out ion beam etching on the nickel-chromium film layer;

carrying out ultrasonic cleaning on the nickel-chromium thin film layer, and cleaning off the redundant nickel-chromium metal thin film outside the strain strip-shaped wire grid pattern to form the nickel-chromium wire grid thin film layer;

carrying out pattern inspection on the nickel-chromium wire grid thin film layer under a microscope;

and correcting the resistance value of the qualified nickel-chromium wire grid thin film layer by adopting an ion beam etching process.

9. The method of claim 6, further comprising, between depositing the protective thin film layer and depositing the electrode thin film:

and (3) carrying out vacuum heat treatment on the nickel-based alloy substrate formed with the insulating film layer, the nickel-chromium wire grid film layer and the protective film layer for 2.5 hours at 400 ℃ by adopting a vacuum annealing furnace.

10. The method of claim 6, further comprising, after the step of depositing the electrode thin film:

and welding a high-temperature-resistant lead on the electrode film.

Technical Field

The invention relates to the technical field of sensors, in particular to an ion beam sputtering film high-temperature strain gauge and a preparation method thereof.

Background

The aero-engine mostly adopts a turbine engine as a power source, and the blade is one of the most critical parts on the turbine engine, and the blade can be influenced by high temperature, high pressure and high vibration during working, and can cause engine faults after long-time working, so that the sensor is used for accurately measuring the working state of the aero-engine in a high-temperature environment, and the health monitoring technology of the aero-engine is very important all the time. In addition, with the high performance of machinery and equipment in each industrial sector, the working temperature is increasing, so strain measurement at high temperature has become a more urgent problem in engineering. Although there are many methods for measuring high temperature stress, up to now, the measurement using strain gauge is still the most important and practical test means for measuring high temperature stress.

The traditional strain gauge is usually adhered to a test piece by using an adhesive, and the adhesive layer formed by the adhesive plays a very important role in strain measurement and is required to accurately transmit the strain of the test piece to the wire grid; the presence of the adhesive not only affects the operating characteristics of the strain gauge, such as creep, hysteresis, null shift, sensitivity coefficient, linearity, but also risks reducing the reliability of the strain gauge, such as adhesive denaturation failure, at high temperatures.

Disclosure of Invention

In view of this, the invention provides an ion beam sputtering thin film high-temperature strain gauge and a preparation method thereof, which can perform stable measurement operation at high temperature.

The invention adopts the following specific technical scheme:

an ion beam sputtering film high-temperature strain gauge comprises a nickel-based alloy substrate, an insulating film layer, a nickel-chromium wire grid film layer, a protective film layer and an electrode film; the nickel-based alloy substrate, the insulating film layer and the nickel-chromium wire grid film layer are sequentially stacked from bottom to top;

the electrode film and the protective film layer are deposited on the top of the nickel-chromium wire grid film layer through an ion beam sputtering coating process, and the electrode film and the protective film layer are arranged on the same layer;

the nickel-chromium wire grid thin film layer is formed by etching a nickel-chromium thin film layer deposited on the insulating thin film layer through an ion beam sputtering coating process;

the electrode film is used for connecting a high-temperature-resistant lead;

the protective film layer is used for protecting the nickel-chromium wire grid film layer.

Furthermore, the insulating film layer is SiO₂/Si₃N₄The thickness of the composite insulating film layer is 1.5 mu m.

Further, Si is adopted as the protective film layer₃N₄A protective film was formed to a thickness of 0.3. mu.m.

Further, the electrode thin film is a Ni/Au composite thin film with a thickness of 0.5 μm.

Further, the thickness of the nickel-based alloy substrate is 10 μm;

the thickness of the nickel-chromium wire grid film layer is 0.6 mu m.

A preparation method of an ion beam sputtering film high-temperature strain gauge comprises the following steps:

depositing an insulating film layer on the nickel-based alloy substrate by adopting a plasma chemical vapor deposition process;

depositing a nickel-chromium film layer on the surface of the insulating film layer by an ion beam sputtering coating process;

carrying out ion beam etching on the nickel-chromium thin film layer to form a nickel-chromium wire grid thin film layer;

protecting the electrode pad by adopting positive photoresist, and depositing a protective film layer in the region outside the electrode pad by adopting an ion beam sputtering coating process;

and adopting positive photoresist to protect the region outside the electrode pad, and depositing an electrode film on the electrode pad by an ion beam sputtering coating process.

Further, before the step of depositing the insulating thin film layer on the nickel-based alloy substrate by using the plasma chemical vapor deposition process, the method further comprises the following steps:

manufacturing a nickel-chromium wire grid film layer, a protective film layer and a mask plate required by an electrode film;

and carrying out surface treatment on the nickel-based alloy substrate by a grinding and polishing process to ensure that the surface roughness of the nickel-based alloy substrate is less than 5 nm.

Further, the step of performing ion beam etching on the nickel-chromium thin film layer to form the nickel-chromium wire grid thin film layer specifically comprises the following steps:

transferring the strain strip wire grid pattern on the mask to the surface of the insulating film layer by glue homogenizing, ultraviolet exposure and developing processes on the surface of the nickel-chromium film layer;

carrying out ion beam etching on the nickel-chromium film layer;

carrying out ultrasonic cleaning on the nickel-chromium thin film layer, and cleaning off the redundant nickel-chromium metal thin film outside the strain strip-shaped wire grid pattern to form the nickel-chromium wire grid thin film layer;

carrying out pattern inspection on the nickel-chromium wire grid thin film layer under a microscope;

and correcting the resistance value of the qualified nickel-chromium wire grid thin film layer by adopting an ion beam etching process.

Further, between depositing the protective film layer and depositing the electrode film, it also includes:

and (3) carrying out vacuum heat treatment on the nickel-based alloy substrate formed with the insulating film layer, the nickel-chromium wire grid film layer and the protective film layer for 2.5 hours at 400 ℃ by adopting a vacuum annealing furnace.

Further, after the step of depositing the electrode film, the method further comprises the following steps:

and welding a high-temperature-resistant lead on the electrode film.

Has the advantages that:

compared with the prior art, the ion beam sputtering film high-temperature strain gauge adopts the nickel-based alloy substrate to replace the existing polyimide substrate, and the nickel-based alloy substrate has good high temperature resistance, high pressure resistance and corrosion resistance, so that the nickel-based alloy substrate is an ideal strain material, the strain test of high-temperature components of an aeroengine can be realized by using the strain material to prepare the film strain gauge, the use temperature range is increased from 300 ℃ to over 1000 ℃, the use temperature range is obviously increased, and the nickel-based alloy substrate can be used in severe environment; the thickness of the nickel-chromium wire grid thin film layer can reach micron level, so that the electrical property of the nickel-chromium wire grid thin film layer is close to that of a block material, the high-temperature performance is stable, and the ion beam sputtering thin film high-temperature strain gauge can perform stable measurement work at high temperature; in addition, in the process of preparing the ion beam sputtering thin film high-temperature strain gauge, the ion beam sputtering coating process is adopted to replace the existing vacuum evaporation process to prepare the nickel-chromium thin film layer, and the ion beam sputtering coating process is adopted to replace the existing printing method to coat the protective glue to prepare the protective thin film layer, so that the resistance value dispersion degree, the compactness and the reliability of the thin film strain gauge are improved, and the binding force of the protective thin film layer is improved.

Compared with the traditional strain gauge, the ion beam sputtering film high-temperature strain gauge has the advantages of high temperature and high pressure resistance, oxidation resistance and the like, the thickness of the strain gauge is in the micron order, the structure of an aircraft engine blade cannot be damaged, and the ion beam sputtering film high-temperature strain gauge has the advantages of small disturbance to the airflow of an engine, high response speed, high sensitivity, high temperature, high pressure and airflow scouring resistance and the like.

Drawings

FIG. 1 is a schematic top view of an ion beam sputtered thin film high temperature strain gage of the present invention;

FIG. 2 is a schematic side view of the ion beam sputtered thin film high temperature strain gage of FIG. 1;

FIG. 3 is a process flow chart of the method for preparing the ion beam sputtering thin film high-temperature strain gauge of the present invention.

Wherein, 1-nickel base alloy substrate, 2-insulating film layer, 3-nickel chromium wire grid film layer, 4-protective film layer and 5-electrode film layer

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

Example one

Referring to fig. 1 and 2, an embodiment of the invention provides an ion beam sputtered film high-temperature strain gauge which can be used for blade strain parameter measurement of an aircraft engine; the ion beam sputtering film high-temperature strain gauge comprises a nickel-based alloy substrate 1, an insulating film layer 2, a nickel-chromium wire grid film layer 3, a protective film layer 4 and an electrode film 5; the nickel-based alloy substrate 1, the insulating film layer 2 and the nickel-chromium wire grid film layer 3 are sequentially stacked from bottom to top; the electrode film 5 and the protective film layer 4 are arranged on the same layer and are both arranged on the top of the nickel-chromium wire grid film layer 3;

the nickel base alloy substrate 1 is used as the basis of the whole strain gauge; the thickness of the nickel-base alloy substrate 1 may be 10 μm; the insulating film layer 2 may be SiO₂/Si₃N₄The thickness of the composite insulating film layer can be 1.5 mu m;

the nickel-chromium wire grid thin film layer 3 is formed by etching a nickel-chromium thin film layer deposited on the insulating thin film layer 2 by an ion beam sputtering coating process; the nickel-chromium film layer is used as a strain layer and is deposited on the insulating film layer 2 through an ion beam sputtering coating process; the nickel-chromium wire grid thin film layer 3 is formed by etching the nickel-chromium thin film layer deposited on the insulating thin film layer 2; the nickel-chromium wire grid thin film layer 3 is formed by a plurality of grid-shaped resistance strips formed by etching; the thickness of the nickel-chromium wire grid thin film layer 3 can be 600 nm;

as shown in the structure of fig. 2, the electrode thin film 5 and the protective thin film layer 4 are both deposited on the top of the nickel-chromium wire grid thin film layer 3 by an ion beam sputtering coating process; the electrode thin film 5 and the protective thin film layer 4 completely cover the top of the nickel-chromium wire grid thin film layer 3, but the electrode thin film 5 and the protective thin film layer 4 are not overlapped;

the electrode film 5 is used for connecting a high-temperature-resistant lead; the electrode film 5 can be a Ni/Au composite film, and the thickness can be 500 nm;

the protective film layer 4 is used for protecting the nickel-chromium wire grid film layer 3 and preventing grid shapeThe resistor strips are oxidized and polluted; the protective film layer 4 is made of Si₃N₄The protective film is formed to a thickness of 300 nm.

The ion beam sputtering film high-temperature strain gauge adopts a nickel-based alloy substrate 1 to replace the existing polyimide substrate, and adopts a nickel-chromium wire grid thin film layer 3 formed by etching a nickel-chromium thin film layer as a strain layer, wherein the nickel-chromium thin film layer is deposited on an insulating thin film layer 2 through an ion beam sputtering coating process, and an electrode thin film 5 and a protective thin film layer 4 are both deposited on the top of the nickel-chromium wire grid thin film layer 3 through the ion beam sputtering coating process; the nickel-based alloy substrate 1 has good high temperature resistance, high pressure resistance and corrosion resistance, and is an ideal strain material, the strain test of high-temperature parts of an aeroengine can be realized by using the strain material to prepare the film strain gauge, the use temperature range is increased from 300 ℃ to over 1000 ℃, the use temperature range is obviously increased, and the film strain gauge can be used in severe environment; the thickness of the nickel-chromium wire grid thin film layer 3 can reach micron level, so that the electrical property of the nickel-chromium wire grid thin film layer 3 is close to that of a block material, the high-temperature performance is stable, and the ion beam sputtering thin film high-temperature strain gauge can perform stable measurement work at high temperature; the ion beam sputtering coating process is adopted to deposit to replace the existing vacuum evaporation process to prepare the nickel-chromium thin film layer, the ion beam sputtering coating process is adopted to deposit to replace the existing printing method to coat the protective glue to prepare the protective thin film layer 4, so that the resistance value dispersion degree, the compactness and the reliability of the thin film strain gauge are improved, and the binding force of the protective thin film layer 4 is improved; therefore, the ion beam sputtering film high-temperature strain gauge has the advantages of high temperature and high pressure resistance, oxidation resistance and the like, the thickness of the strain gauge is in the micron order, the structure of an aero-engine blade cannot be damaged, and the ion beam sputtering film high-temperature strain gauge has the advantages of small disturbance to engine airflow, high response speed, high sensitivity, high temperature, high pressure and airflow scouring resistance and the like.

Example two

The embodiment of the invention also provides a preparation method of the ion beam sputtering film high-temperature strain gauge, and with reference to fig. 3, the preparation method comprises the following specific steps:

step S11, making a mask plate required by the nickel-chromium wire grid film layer 3, the protective film layer 4 and the electrode film 5; before preparation, mask patterns required when the nickel-chromium wire grid thin film layer 3, the protective thin film layer 4 and the electrode thin film 5 are prepared need to be designed and manufactured, and corresponding mask plates are prepared according to the mask patterns;

step S12, performing surface treatment on the nickel-based alloy substrate 1 through a polishing process to enable the surface roughness of the nickel-based alloy substrate 1 to be less than 5 nm; in order to meet the requirements of a deposition process, the surface of the nickel-based alloy substrate 1 needs to be pretreated before deposition, the surface of the nickel-based alloy substrate 1 is treated by a grinding and polishing process, the surface roughness of the deposited insulating film layer 2 is smaller than 5nm, and the surface of the nickel-based alloy substrate 1 meets the coating requirements;

step S13, depositing an insulating film layer 2 on the nickel-based alloy substrate 1 by adopting a plasma chemical vapor deposition process; depositing an insulating film layer 2 with the thickness of 1.5 microns on the nickel-based alloy substrate 1 subjected to surface pretreatment by adopting a plasma chemical vapor deposition method;

step S14, depositing a nickel-chromium film layer on the surface of the insulating film layer 2 through an ion beam sputtering coating process; the method comprises the following steps of manufacturing a strain metal film, and depositing a nickel-chromium film layer with the thickness of 600nm on the surface of the insulating film layer 2 by an ion beam sputtering coating method;

step S15, performing ion beam etching on the nickel-chromium thin film layer to form a nickel-chromium wire grid thin film layer 3; the step of manufacturing the strain pattern may specifically include: transferring the strain strip wire grid pattern on the mask to the surface of the insulating film layer 2 by glue homogenizing, ultraviolet exposure and developing processes on the surface of the nickel-chromium film layer; carrying out ion beam etching on the nickel-chromium film layer; carrying out ultrasonic cleaning on the nickel-chromium thin film layer, and cleaning off the redundant nickel-chromium metal thin film outside the strain strip-shaped wire grid pattern to form a nickel-chromium wire grid thin film layer 3; carrying out pattern inspection on the nickel-chromium wire grid thin film layer 3 under a microscope, wherein in the inspection process, pattern defects can comprise incompleteness, short grids, overlapping, obvious burrs, sawteeth and the like of the nickel-chromium wire grid thin film layer 3; correcting the resistance value of the qualified nickel-chromium wire grid thin film layer 3 by adopting an ion beam etching process; the qualified strain gauge can be tested according to the resistance value and the insulation requirement;

step S16, protecting the electrode pad by using positive photoresist through a photoetching method, and depositing a protective film layer 4 in the region outside the electrode pad by using an ion beam sputtering coating process; the protective thin film layer 4 may be Si with a thickness of 300nm₃N₄A protective film for protecting the strain pattern thereof by a protective film layer 4;

step S17, carrying out vacuum heat treatment on the nickel-based alloy substrate 1 formed with the insulating film layer 2, the nickel-chromium wire grid film layer 3 and the protective film layer 4 by using a vacuum annealing furnace, wherein the temperature of the vacuum annealing furnace can be 400 ℃ in the heat treatment process, and the annealing time is 2.5 hours; the strain gauge plated with the protective film layer 4 is placed in a vacuum annealing furnace for vacuum heat treatment, so that the stress of the film can be fully released, and the stability of the film is improved;

step S18, protecting the region outside the electrode pad by adopting positive photoresist through a photoetching method, and depositing an electrode film 5 on the electrode pad through an ion beam sputtering coating process; the electrode film 5 can be a Ni/Au composite electrode film 5 with the thickness of 500nm and is used for welding a lead;

in step S19, a high-temperature-resistant wire is welded to the electrode film 5.

In the preparation process, the preparation method can also comprise a resistance insulation test step, after the lead welding machine is connected, resistance and insulation resistance value tests are carried out, the resistance value is within (120 +/-5) omega, and the insulation resistance value is greater than 5000M omega.

The ion beam sputtering film high-temperature strain gauge is prepared by the preparation method, the ion beam sputtering film coating process is adopted to replace the existing vacuum evaporation process to prepare the nickel-chromium film layer, the ion beam sputtering film coating process is adopted to replace the existing printing method to coat the protective glue to prepare the protective film layer 4, so that the resistance value dispersion degree, the compactness and the reliability of the film strain gauge are improved, and the binding force of the protective film layer 4 is improved.

The ion beam sputtering film high-temperature strain gauge is detected through tests, and the specific parameters are as follows:

the resistance value (including two end leads) of the strain gauge is between (120 +/-1) omega, and the dispersion degree of the resistance value is less than +/-5 percent; the strain gauge can realize stable measurement of structural strain in an environment below 800 ℃; at normal temperature, when the test voltage is 100V, the insulation resistance of the strain gauge is more than 1000 MOmega; the insulation resistance is more than 500M omega under the environment of 800 ℃; under the normal temperature environment, when the strain of the test piece is 1000u, the mechanical hysteresis of the strain gauge is less than 50 u.

The following is a specific process flow for preparing the ion beam sputtering film high-temperature strain gauge by adopting the preparation method:

mechanically polishing the nickel-based alloy substrate 1 with the thickness of 10 mu m to ensure that the surface roughness of the nickel-based alloy substrate reaches 5nm, ultrasonically cleaning the nickel-based alloy substrate for 20min by using an organic cleaning agent, finally washing the nickel-based alloy substrate by using clear water, drying the nickel-based alloy substrate by blowing, and waiting for coating;

loading the nickel base alloy substrate 1 with the treated surface into a plasma chemical vapor deposition device, and respectively passing 99.99 percent of laughing gas, silane and ammonia gas through a vacuum degree of 5 multiplied by 10^-3Loading radio frequency voltage to the vacuum chamber, controlling the film thickness to be 1.5 mu m by controlling the coating time, and alternately depositing 5 layers of SiO₂/Si₃N₄Compounding an insulating film layer to play an electric insulation and isolation role between the nickel-based alloy substrate 1 and the nickel-chromium wire grid film layer 3;

loading the substrate on which the insulating film is deposited into ion beam sputtering coating equipment, introducing ionized inert gas argon to bombard a nickel-chromium metal target material with the purity of 99.99%, and depositing a nickel-chromium film layer with the thickness of 3 mu m by controlling the process parameters such as ion energy, coating time and the like;

transferring the designed mask strain strip wire grid pattern to the surface of the insulating film by glue evening, ultraviolet exposure, development and ion beam etching methods on the surface of the deposited nickel-chromium film layer;

carrying out ultrasonic cleaning on the etched substrate, cleaning off the redundant nickel-chromium film layer except the strain pattern, and leaving the designed mask strain pattern;

carrying out pattern inspection on the manufactured strain gauge under a microscope, wherein pattern defects comprise incomplete wire grid films, short grids, overlapping, obvious burrs, sawteeth and the like on the edge of the wire grid; testing the qualified strain gauge according to the resistance value (120 +/-1) omega and the insulation requirement;

correcting and adjusting the resistance value of the strain gauge with the resistance value exceeding the range by adopting an ion beam etching method according to the resistance value requirement;

uniformly coating positive photoresist with the thickness of 0.3 mu m on the strain gauge with the resistance value corrected by adopting a mechanical rotation method, leaving the photoresist at the positions of two bonding pads through ultraviolet exposure and development, protecting the electrode bonding pads, and depositing Si with the thickness of 0.3 mu m on the region outside the electrode bonding pads by adopting an ion beam sputtering coating method₃N₄The protective film layer 4 is cleaned by ultrasonic after deposition is finished;

after the protective film layer 4 is manufactured, in order to improve the stability of the film and fully release the stress of the film, the strain gauge is placed in a vacuum annealing furnace and subjected to vacuum heat treatment for 2.5 hours at 400 ℃;

protecting the area outside the electrode pad by using positive photoresist through a photoetching method for the strain gauge subjected to vacuum heat treatment, and depositing a Ni/Au composite film with the thickness of 0.5 mu m through an ion beam sputtering coating method for welding as a lead;

welding a high-temperature-resistant wire on the Ni/Au composite film as a lead wire, and leading out from electrode pads at two ends of the strain gauge;

after the lead welding machine is connected, resistance and insulation resistance value tests are carried out, the resistance value of the strain gauge in the test process is within (120 +/-5) omega, and the insulation resistance value is greater than 5000M omega.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.