A modified SU-8 photoelastic sensor for adapting an insulating space-charge ellipsometry detection system and a preparation method thereof

Abstract

The application discloses a modified SU-8 glue type photoelastic sensor suitable for an insulating space charge ellipsometric detection system and a preparation method thereof. The photoelastic sensor prepared by the method has good thermodynamic stability and can provide technical support for insulating charge ellipsometric measurement in a variable temperature range. The preparation method comprises the following steps: (1) placing a silicon wafer in a muffle furnace for thermal oxidation to generate a dense silicon dioxide layer on the surface of the silicon wafer; (2) adding carboxylated carbon nanotubes into an SU-8 glue solution, uniformly mixing the carboxylated carbon nanotubes by ultrasonic treatment, preparing a modified SU-8 glue solution, and dropping the mixed solution on the silicon wafer to obtain a modified SU-8 glue layer; (3) setting ultraviolet exposure energy, adjusting a mask, and realizing the transfer of the sensor structure to the SU-8 glue layer; and (4) placing the sample after exposure into a developing solution, removing the unexposed part, and performing post-baking treatment to remove the developing solution and moisture, so as to obtain the modified SU-8 glue type photoelastic sensor.

Description

Technical Field

[0001] This invention relates to the field of insulating space charge ellipsometric measurement, and more specifically to a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system and its preparation method. Background Technology

[0002] Compared to traditional electrical equipment, power electronic equipment operates under more complex and severe conditions. In addition to being subjected to general AC and DC stresses, it also has to endure the transient PWM switching pulse stress generated by the transformation of power electronic devices. Therefore, in order to clarify the mechanism of space charge accumulation at high frequencies and support the insulation assessment and optimization design of power electronic equipment, it is urgent to develop a space charge ellipsometric measurement method with high spatiotemporal resolution.

[0003] However, the insulation operating temperature range of new energy power system equipment under high-frequency transient electrical stress is generally 25-60℃, which has a large temperature span. Therefore, the development of an elastic-optical sensor with high thermodynamic stability adapted to the insulation space charge ellipsometric detection system has become a prerequisite for achieving highly reliable charge measurement. Summary of the Invention

[0004] One of the objectives of this invention is to provide a method for preparing a modified SU-8 gel-type elastic-optical sensor adapted to an insulating space charge ellipsometric detection system. The elastic-optical sensor prepared by this method has good thermodynamic stability and can provide technical support for measuring the insulating charge ellipsometrics in a variable temperature range.

[0005] Another objective of this invention is to provide a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, which is prepared using the above-described method.

[0006] To achieve the above objectives, the present invention provides a method for fabricating a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, comprising the following steps:

[0007] (1) Place the silicon wafer in a muffle furnace for thermal oxidation, set the thermal oxidation temperature to 1100℃ and the time to 2 hours, and generate a dense silicon dioxide layer on its surface.

[0008] (2) Carboxylated carbon nanotubes were incorporated into SU-8 adhesive solution and sonicated for 2 hours to make them uniformly mixed, thus preparing a modified SU-8 adhesive solution. The mixed solution was dropped onto a silicon wafer, and the homogenization speed was set to 500 rpm and the homogenization time was 30 seconds to obtain a modified SU-8 adhesive layer.

[0009] (3) Set the UV exposure energy to 300 mJ / cm 2 Adjust the mask to achieve the transfer of a 1 cm diameter circular sensor structure to the SU-8 adhesive layer;

[0010] (4) After exposure, the sample is placed in the developer to remove the unexposed part and then baked to remove the developer and water, thus obtaining the modified SU-8 gel-type photosensitive sensor.

[0011] Furthermore, the silicon wafer mentioned in step (1) is a P-type, 110-oriented monocrystalline silicon wafer with a thickness of 300 micrometers and a diameter of 50.8 millimeters.

[0012] Further, in step (2), the mass ratio of carboxylated carbon nanotubes to SU-8 photoresist solution is 0.005:1, wherein the SU-8 photoresist solution is SU-8 2000.5 photoresist solution generated by MicroChem.

[0013] Compared with the prior art, in the modified SU-8 photoresist photosensitive sensor preparation method for the insulating space charge ellipsometric detection system provided by the present invention, the SU-8 photoresist is first modified by doping a certain proportion of carboxylated carbon nanotubes to improve the thermodynamic stability of the material, thereby providing a highly reliable photosensitive basis for insulating space charge ellipsometric detection.

[0014] Furthermore, the present invention also provides a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, which is prepared by the above method. Attached Figure Description

[0015] Figure 1 A schematic diagram of the fabrication process of the modified SU-8 gel-type photoelastic sensor adapted to the insulating space charge ellipsometric detection system.

[0016] Figure 2 This is a schematic diagram of an evaluation platform for the ellipsometry sensor ellipsometry measurement performance, used to evaluate the accuracy of the measurement performance of the fabricated elastic-optical sensor.

[0017] Figure 3 The image shows the measurement response of the fabricated photoelastic sensor under nanosecond pulse width elastic waves.

[0018] Figure 4 The measurement response diagram of the fabricated photoelastic sensor at a kilohertz repetition frequency is shown. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited to the described parts. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0020] This invention provides a method for fabricating a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, such as... Figure 1As shown, it includes the following steps:

[0021] (1) Place the silicon wafer in a muffle furnace for thermal oxidation, set the thermal oxidation temperature to 1100℃ and the time to 2 hours, and generate a dense silicon dioxide layer on its surface.

[0022] (2) Carboxylated carbon nanotubes were incorporated into SU-8 adhesive solution and sonicated for 2 hours to make them uniformly mixed, thus preparing a modified SU-8 adhesive solution. The mixed solution was dropped onto a silicon wafer, and the homogenization speed was set to 500 rpm and the homogenization time was 30 seconds to obtain a modified SU-8 adhesive layer.

[0023] (3) Set the UV exposure energy to 300 mJ / cm 2 Adjust the mask to achieve the transfer of a 1 cm diameter circular sensor structure to the SU-8 adhesive layer;

[0024] (4) After exposure, the sample is placed in the developer to remove the unexposed part and then baked to remove the developer and water, thus obtaining the modified SU-8 gel-type photosensitive sensor.

[0025] Furthermore, the silicon wafer mentioned in step (1) is a P-type, 110-oriented monocrystalline silicon wafer with a thickness of 300 micrometers and a diameter of 50.8 millimeters.

[0026] Further, in step (2), the mass ratio of carboxylated carbon nanotubes to SU-8 photoresist solution is 0.005:1, wherein the SU-8 photoresist solution is SU-8 2000.5 photoresist solution generated by MicroChem.

[0027] Furthermore, the present invention also provides a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, which is prepared by the above method.

[0028] Furthermore, a performance evaluation platform for ellipsometric measurement of the elastic-optical sensor was constructed, the principle of which is as follows: Figure 2 As shown, elastic pulses with repetition frequencies of kilohertz and pulse widths of nanoseconds were applied to the fabricated elastic-optical sensor, and the sensor's measured response was as follows. Figure 3 and Figure 4 As shown, the experimental results demonstrate that the prepared elastic-optical sensor can achieve real-time response to elastic waves with kilohertz repetition frequency and nanosecond pulse width, providing a technical basis for the detection of weak stress in varying temperature ranges.

Claims

1. A method for fabricating a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, characterized in that... The elastic-optical sensor can be applied to the detection of insulated space charge ellipsometrics, and includes the following preparation steps: (1) A silicon wafer is placed in a muffle furnace for thermal oxidation to produce a dense silicon dioxide layer on its surface; wherein the silicon wafer is a P-type, 110 crystal orientation single crystal silicon wafer with a thickness of 300 micrometers and a diameter of 50.8 millimeters; (2) Carboxylated carbon nanotubes are incorporated into SU-8 photoresist solution and ultrasonically mixed to obtain a modified SU-8 photoresist solution. The mixed solution is then dropped onto a silicon wafer and homogenized to obtain a modified SU-8 photoresist layer. The mass ratio of carboxylated carbon nanotubes to SU-8 photoresist solution is 0.005:

1. The SU-8 photoresist solution is SU-8 2000.5 photoresist solution produced by MicroChem. (3) Set the ultraviolet exposure energy and adjust the mask to realize the transfer of the sensor structure to the SU-8 adhesive layer; (4) After exposure, the sample is placed in the developer to remove the unexposed part and then baked to remove the developer and water, thus obtaining the modified SU-8 gel-type photosensitive sensor.

2. The method for fabricating a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system according to claim 1, characterized in that, The thermal oxidation temperature in step (1) is 1100℃ and the time is 2 hours.

3. The method for fabricating a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system according to claim 1, characterized in that, The homogenization speed in step (2) is 500 rpm and the homogenization time is 30 seconds.

4. The method for fabricating a modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system according to claim 1, characterized in that, The ultraviolet exposure energy in step (3) is 300 mJ / cm2, and the sensor structure is a circle with a diameter of 1 cm.

5. A modified SU-8 gel-type photoelastic sensor adapted to an insulating space charge ellipsometric detection system, characterized in that, The modified SU-8 gel-type photoelastic sensor was prepared using the method described in any one of claims 1-4.

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