Preparation method of semiconductor gas sensor
By replacing gold and ruthenium oxide with graphite slurry and resin solutions, sensitive material treatment with silica aerogel and polyethylene glycol, the high cost, short life and high power consumption of planar semiconductor semiconductor gas sensors is solved. , improves material consistency and responsiveness.
Patent Information
- Application Number
- CN202411176210.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2024-12-13
AI Technical Summary
The high cost, short service life, large power consumption and sensitive material settlement problems of existing planar semiconductor semiconductor gas sensors lead to poor consistency and response characteristics.
Graphite slurry and resin solution instead of gold and ruthenium oxide as electrodes and heating resistors, silica aerogel is used to prevent resistance loss, and slurry mixed with metal oxide and polyethylene glycol and other components are used as sensitive materials, through Sintering treatment improves material uniformity.
It significantly reduces product costs, extends service life, reduces power consumption, and improves uniformity and responsive characteristics of sensitive materials.
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Abstract
Description
Technical Field
[0001] The invention belongs to the field of gas sensors, and in particular relates to a method for preparing a semiconductor gas sensor. Background Art
[0002] Semiconductor gas sensors use semiconductor materials as sensitive gas sensors and require high temperatures to maintain response when working. There are two common semiconductor gas sensor structures on the market: ceramic tube side-heating type and planar semiconductor type. Due to structural and process problems, ceramic tube side-heating type semiconductor gas sensors cannot be miniaturized and power consumption cannot be reduced. Therefore, most planar semiconductor type semiconductor gas sensors are used to reduce power consumption.
[0003] The existing planar semiconductor type semiconductor gas sensor chip uses a 0.25mm thick ceramic substrate. First, gold (AU) is used to make electrodes on both sides of the ceramic substrate, and then ruthenium oxide is printed on one side of the ceramic substrate as a heating resistor. The sensitive material made of metal oxide is coated on the electrode (generally nano-tin dioxide is used as the main material, and the sensitivity and response characteristics of the sensitive material are improved by doping metal oxides. Its working principle is based on the change in the resistance value of the oxide caused by the oxidation / reduction reaction of the gas to be measured on the surface of the semiconductor metal oxide at a certain working temperature). Figure 1 and Figure 2 As shown, two sides of the ceramic substrate are shown respectively, where a represents the ceramic substrate, b represents the electrode, and c represents the heating resistor.
[0004] However, the electrodes in the existing planar semiconductor-type semiconductor gas sensor chip are made of gold, and the heating resistor is made of ruthenium oxide. Since the value of gold and ruthenium oxide is relatively high, the production cost is relatively high; the heating resistor in the existing planar semiconductor-type semiconductor gas sensor is exposed to the air for a long time and is easily damaged, which affects the service life. At the same time, the operating temperature of the planar semiconductor-type semiconductor gas sensor is generally above 200 degrees, so the power consumption of the sensor is large; in addition, metal oxide is used as a sensitive material for coating. Since the metal oxide in the sensitive material has a sedimentation problem after long-term storage, the uniformity of the material is deteriorated. When coated on the semiconductor gas sensor, the thickness and concentration of the sensitive material are uneven, resulting in poor consistency and response characteristics of the semiconductor gas sensor. Summary of the invention
[0005] The purpose of the present invention is to solve the problems raised in the background technology and to provide a method for preparing a semiconductor gas sensor.
[0006] To achieve the above object, the technical solution adopted by the present invention is: The present invention provides a method for preparing a semiconductor gas sensor, comprising: S1. preparing a first mixed graphite slurry and a first mixed resin solution respectively; S2, stirring and mixing the prepared first mixed graphite slurry and the first mixed resin solution at a ratio of 1:0.5-3 at room temperature for 30-90 minutes to obtain an electrode slurry; S3, printing the electrode slurry onto the ceramic substrate, and then curing it at 280-350° C. for 60-90 min, at which time the electrode slurry forms an electrode to obtain a ceramic substrate with an electrode; S4, preparing a second mixed graphite slurry and a second mixed resin solution respectively; S5, stirring and mixing the prepared second mixed graphite slurry and the second mixed resin solution at a ratio of 1:0.5-3 at room temperature for 30-90 minutes to obtain a heating coating slurry; S6, printing the heating coating slurry onto one side of the ceramic substrate obtained in S3, and then placing it at room temperature for 30 to 60 minutes, and then curing it at 280 to 350° C. for 60 to 90 minutes, at which time the heating coating slurry forms a heating resistor, thereby obtaining a ceramic substrate with electrodes and a heating resistor; S7, evenly coating the silica aerogel on the heating resistor prepared in S6, leaving it at room temperature for 30 to 60 minutes, and then placing it in an environment of 120 to 200° C. for 15 to 30 minutes, to obtain a ceramic substrate with electrodes and a low-power consumption heating resistor; S8. Prepare a third mixed slurry, print the prepared third mixed slurry onto the surface of the electrode, and the printing thickness is 0.3~0.5mm, then place the ceramic substrate with the electrode and the low-power heating resistor in a muffle furnace, increase the temperature to 550℃~650℃ at a heating rate of 20~30℃ / min, and then sinter for 120~180min.
[0007] Preferably, the preparation of the first mixed graphite slurry comprises: 15-50% of graphite powder, 5-30% of graphene, 20-78% of deionized water, 1% of silane coupling agent and 1% of aqueous defoaming agent are mixed at room temperature for 20-40 minutes, heated to 90-120°C and kept mixed for 40-60 minutes, then cooled to room temperature and ball milled for 24-48 hours to obtain a first mixed graphite slurry.
[0008] Preferably, the preparing the first mixed resin solution comprises: 20-75% of aqueous polyimide resin, 24-79% of deionized water and 1% of aqueous defoaming agent are mixed in a stirrer at 1000 r / min for 10-40 minutes to obtain a first mixed resin solution.
[0009] Preferably, the preparation of the second mixed graphite slurry comprises: 33-66% of graphite powder, 33-66% of deionized water, 3-6% of silane coupling agent and 3-6% of aqueous defoaming agent are mixed at room temperature for 15-30 minutes, and then 15-35% of graphene is added, and the mixture is heated to 50-80°C and mixed for 15-30 minutes, and then cooled to room temperature and ball-milled for 24-48 hours to obtain a first mixed graphite slurry.
[0010] Preferably, the preparing the second mixed resin solution comprises: 50-80% of aqueous polyimide resin and 20-50% of deionized water are mixed at 60-90° C. for 15-30 minutes, then cooled to room temperature and mixed in a stirrer at 1000 r / min for 30-90 minutes to obtain a second mixed resin solution.
[0011] Preferably, the preparing the third mixed slurry comprises: 16-22% of tin dioxide, 0.5-1% of palladium chloride, 0.8-1.5% of metal group oxide, 13-20% of dispersion medium, 12-18% of hydrophilic dispersant, 20.7-40% of surfactant and 10-15% of polyethylene glycol are placed in an agate mortar and ground and mixed at room temperature for 30-60 minutes, then raised to 60-90° C. and continued to grind and mix for 30-60 minutes to obtain a third mixed slurry.
[0012] Preferably, the metal oxide is vanadium pentoxide, antimony pentoxide or antimony trioxide, the dispersion medium is deionized water, ethanol, ethylene glycol or isopropanol, the hydrophilic dispersant is a silane coupling agent or hexadecyl ammonium bromide, and the surfactant is citric acid, malic acid or acetic acid.
[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The semiconductor gas sensor preparation method greatly reduces the cost of the product by using the first graphite slurry and the first mixed resin solution instead of gold as electrodes, and using the second mixed graphite slurry and the second mixed resin solution instead of ruthenium oxide as heating resistors; 2. The semiconductor gas sensor preparation method effectively prevents the loss of the heating resistor and reduces power consumption by coating the silicon dioxide aerogel on the heating resistor; 3. The semiconductor gas sensor preparation method adopts the method of coating the third mixed slurry as the sensitive material on the surface of the electrode, and the third mixed slurry is mixed with dispersion medium and polyethylene glycol and other components, so that the metal oxide in the sensitive material is not easy to settle and is in a suspended state for a long time, thereby solving the problem of sedimentation of metal oxides after long-term storage of sensitive materials in the prior art, resulting in deterioration of material uniformity, and the problem that coating on the semiconductor gas sensor will lead to deterioration of consistency and response characteristics of the semiconductor gas sensor due to uneven thickness and concentration of the sensitive material. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a first-view schematic diagram of a ceramic substrate of a semiconductor gas sensor in the prior art; Figure 2 It is a schematic diagram of a ceramic substrate of a semiconductor gas sensor in the prior art from a second viewing angle. DETAILED DESCRIPTION
[0015] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0016] It should be noted that when a component is referred to as being "connected" to another component, it may be directly connected to the other component or there may be an intermediate component. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0017] In one embodiment, a method for preparing a semiconductor gas sensor is disclosed, comprising: S1. preparing a first mixed graphite slurry and a first mixed resin solution respectively; Wherein: preparing the first mixed graphite slurry comprises: 15-50% of graphite powder, 5-30% of graphene, 20-78% of deionized water, 1% of silane coupling agent and 1% of aqueous defoaming agent (e.g., graphite powder accounts for 40%, graphene accounts for 20%, and deionized water accounts for 38%) are mixed at room temperature for 20-40 minutes (e.g., 30 minutes), the temperature is raised to 90-120° C. (e.g., 105° C.) and the mixture is kept warm for 40-60 minutes (e.g., 50 minutes), then the mixture is cooled to room temperature and ball milled for 24-48 hours (e.g., 36 hours) to obtain a first mixed graphite slurry.
[0018] Preparing a first mixed resin solution includes: Mix 20-75% of water-based polyimide resin, 24-79% of deionized water and 1% of water-based defoaming agent (e.g., water-based polyimide resin accounts for 60% and deionized water accounts for 39%) in a stirrer at 1000 r / min for 10-40 minutes (e.g., 30 minutes) to obtain a first mixed resin solution.
[0019] S2, stirring and mixing the prepared first mixed graphite slurry and the first mixed resin solution at a ratio of 1:0.5-3 at room temperature for 30-90 minutes (for example, mixing at a ratio of 1:1, using a stirrer at 1500 r / min for 60 minutes), to obtain an electrode slurry; S3, printing the electrode slurry onto the ceramic substrate (specifically, printing the electrode slurry onto both sides of the ceramic substrate of the semiconductor gas sensor by screen printing, specifically, where the electrodes should be located on the ceramic substrate, for example Figure 1 and Figure 2 The electrode a is located in the region), and then cured at 280-350°C for 60-90 minutes (e.g., cured and dried at 300°C for 60 minutes), at which time the electrode slurry forms an electrode to obtain a ceramic substrate with an electrode; S4, preparing a second mixed graphite slurry and a second mixed resin solution respectively; Wherein: preparing the second mixed graphite slurry comprises: 33-66% of graphite powder, 33-66% of deionized water, 3-6% of silane coupling agent and 3-6% of aqueous defoamer (e.g., graphite powder accounts for 50%, deionized water accounts for 40%, silane coupling agent accounts for 5%, and aqueous defoamer accounts for 5%) are mixed at room temperature for 15-30 minutes (e.g., 20 minutes), and then 15-35% of graphene is added (e.g., graphene accounts for 20%), and the temperature is raised to 50-80°C and mixed for 15-30 minutes (e.g., raised to 65°C and mixed for 20 minutes), and then the temperature is lowered to room temperature and ball milled for 24-48 hours (e.g., ball milled for 36 hours) to obtain a first mixed graphite slurry.
[0020] Preparing the second mixed resin solution includes: Mix 50-80% of water-based polyimide resin and 20-50% of deionized water (e.g., the water-based polyimide resin accounts for 66% and the deionized water accounts for 34%) at 60-90°C for 15-30 minutes (e.g., at 75°C for 20 minutes), then cool to room temperature and mix in a stirrer at 1000 r / min for 30-90 minutes (e.g., 60 minutes) to obtain a second mixed resin solution.
[0021] S5, stirring and mixing the prepared second mixed graphite slurry and the second mixed resin solution at a ratio of 1:0.5-3 at room temperature for 30-90 minutes (for example, mixing at a ratio of 1:1 with a stirrer at 1500 r / min for 60 minutes) to obtain a heating coating slurry; S6, printing the heating coating slurry onto one side of the ceramic substrate obtained in S3 (specifically, printing it on the ceramic substrate by screen printing, specifically, the position where the heating resistor should be located on the ceramic substrate, for example Figure 2 The heating resistor c is located in the area shown in the figure), and then it is placed at room temperature for 30 to 60 minutes (such as 45 minutes), and then placed in a 280 to 350 ° C environment for curing for 60 to 90 minutes (such as curing and drying at 300 ° C for 60 minutes). At this time, the coating slurry is heated to form a heating resistor, and a ceramic substrate with electrodes and heating resistors is obtained; S7, evenly coating the silica aerogel on the heating resistor prepared in S6 (the silica aerogel can be directly purchased on the market), leaving it at room temperature for 30 to 60 minutes (such as leaving it at room temperature for 45 minutes), and then placing it at 120 to 200°C for 15 to 30 minutes (such as placing it at 150°C for 20 minutes), to obtain a ceramic substrate with electrodes and a low-power consumption heating resistor; S8. Prepare a third mixed slurry (as a sensitive material), print the prepared third mixed slurry on the surface of the electrode (screen printing can be used for uniform printing), and the printing thickness is 0.3~0.5mm (such as 0.4mm), and then place the ceramic substrate with the electrode and the low-power heating resistor in a muffle furnace, and heat the temperature to 550℃~650℃ at a heating rate of 20~30℃ / min (such as heating to 600℃ at a heating rate of 25℃ / min), and then sinter for 120~180min (such as 150min), so that the electrode surface is wrapped by the third mixed slurry; finally, install the obtained ceramic substrate with the electrode and the low-power heating resistor (the ceramic substrate with the electrode and the low-power heating resistor is the chip) into the base of the semiconductor gas sensor, thereby obtaining a low-cost, low-power semiconductor gas sensor.
[0022] Wherein: preparing the third mixed slurry comprises: 16-22% of tin dioxide, 0.5-1% of palladium chloride, 0.8-1.5% of metal group oxide, 13-20% of dispersion medium, 12-18% of hydrophilic dispersant, 20.7-40% of surfactant and 10-15% of polyethylene glycol (e.g., 20% of tin dioxide, 0.8% of palladium chloride, 1.2% of metal group oxide, 18% of dispersion medium, 16% of hydrophilic dispersant, 32% of surfactant and 12% of polyethylene glycol) are placed in an agate mortar and ground and mixed at room temperature for 30-60 minutes (e.g., 45 minutes), then raised to 60-90° C. (e.g., 75° C.), and continued to grind and mix for 30-60 minutes (e.g., 45 minutes) to obtain a third mixed slurry.
[0023] The metal oxide is vanadium pentoxide, antimony pentoxide or antimony trioxide, the dispersion medium is deionized water, ethanol, ethylene glycol or isopropanol, the hydrophilic dispersant is a silane coupling agent or hexadecyl ammonium bromide, and the surfactant is citric acid, malic acid or acetic acid (for example, the metal oxide is vanadium pentoxide, the dispersion medium is ethanol, the hydrophilic dispersant is a silane coupling agent, and the surfactant is citric acid).
[0024] The mixing in the semiconductor gas sensor preparation method can be performed by stirring and mixing with a stirrer, or by other mixing methods.
[0025] In another embodiment, a sensor prepared by the present method and a commercially available metal oxide type methane gas sensor are selected, and a standard material with a methane gas volume fraction of 0.5% in nitrogen and a standard gas with a relative expanded uncertainty of no more than 1% (k = 2) is used. By controlling the gas concentration, flow rate, interfering gas, and temperature and humidity environment inside the chamber, the sensor detection experiment is carried out as follows:
[0026] (1) Changes in reference voltage with gas flow rate The reference voltage refers to the voltage value of the sensor when it is not affected by any gas. It is a reference for the sensor output signal. In general, the reference voltage is determined by the characteristics of the sensor itself and is not affected by external factors. When using the sensor to detect gas concentration, the information of the gas concentration can be obtained by measuring the difference between the sensor output signal and the reference voltage. Therefore, the accuracy and stability of the reference voltage have an important influence on the measurement accuracy and stability of the sensor. The test results are shown in Table 1 below. The experimental results show that gases with different flow rates have an impact on the reference voltage value of the same sensor. As the gas flow rate increases, the reference voltage value shows a downward trend, but when the flow rate exceeds 500ml / min, the impact tends to stabilize. Among them, the reference voltage value of the commercially available sensor varies greatly. When the flow rate is 50ml / min, the reference voltage is 0.669V. When the flow rate increases to 1000ml / min, the reference voltage drops to 0.375V, and the variation range is 43.95%. However, the reference voltage of the sensor of the present invention varies less. When the flow rate is 50ml / min, the reference voltage is 0.494V. When the flow rate increases to 1000ml / min, the reference voltage only drops to 0.429V, and the variation range is 13.16%.
[0027] The reference voltage is an important indicator for measuring the detection of target gas by gas sensors. A stable reference voltage value can improve the measurement accuracy of methane gas sensors. The results in Table 1 show that the greater the flow rate, the higher the sensitivity, the smaller the reference voltage, and the drift of the sensor of the present invention is the smallest, indicating that it has better stability.
[0028] Table 1 Reference voltage of the sensor at different flow rates (V) Sensor flow rate (ml / min) 50 100 300 500 800 1000 The reference voltage of the sensor for this method (V) 0.494 0.463 0.446 0.444 0.438 0.429 Reference voltage of commercially available sensors (V) 0.669 0.621 0.576 0.407 0.369 0.375 (2) Changes of steady-state voltage with gas flow rate The steady-state voltage of the gas sensor in the target gas environment reflects, to a certain extent, the sensor's response capability to the target gas. Table 2 lists the response voltages of the sensor prepared by this method to 50 ppm methane gas at different flow rates.
[0029] The sensor shows that its steady-state voltage is inversely proportional to the gas flow rate. When the gas flow rate increases, the time for the gas to react with the sensor decreases, resulting in a decrease in the steady-state voltage. Among them, the steady-state voltage value of the commercially available sensor varies greatly. When the flow rate is 50ml / min, the steady-state voltage is 1.557V. When the flow rate increases to 1000ml / min, the steady-state voltage drops to 1.101V, with a change of 29.29%; while the steady-state voltage of the sensor of the present invention changes less. When the flow rate is 50ml / min, the steady-state voltage is 1.346V. When the flow rate increases to 1000ml / min, the steady-state voltage only drops to 1.197V, with a change of 11.07%.
[0030] Table 2 Steady-state voltage of the sensor at different flow rates (V) Sensor flow rate (ml / min) 50 100 300 500 800 1000 Steady-state voltage of the sensor of this method (V) 1.346 1.325 1.304 1.262 1.214 1.197 Steady-state voltage of commercially available sensors (V) 1.557 1.502 1.426 1.332 1.183 1.101 Steady-state voltage is also an important indicator for measuring the detection of target gas by gas sensors. A stable steady-state voltage value can improve the measurement accuracy of methane gas sensors. The results in Table 2 show that the greater the flow rate, the higher the sensitivity, and the smaller the steady-state voltage, but the change amplitude is not obvious. However, the drift of the sensor prepared by this method is small, indicating that it has better stability and stronger consistency.
[0031] (3) Changes in response sensitivity with gas flow rate The sensitivity of the sensor is the basis for detecting the target gas. Table 3 lists the sensitivity of the sensor prepared by this method and the commercially available sensor to methane gas at different flow rates. The sensitivity of the sensor increases with the increase of the gas flow rate.
[0032] The basic sensitivity of the sensor prepared by this method is higher than that of the commercially available sensor, which is about 1.85-2.60 times higher. At the same time, the sensitivity increase of the sensor of the present invention increased from 13.693 to 15.337, an increase of 12.01%, and the commercially available sensor increased from 5.268 to 8.301, an increase of 57.57%, which is a large increase. This shows that although the sensitivity increase of the commercially available sensor is large, the stability is not strong, and the overall sensitivity is lower than that of the sensor of the present invention.
[0033] Table 3 Sensitivity of the sensor at different flow rates Sensor flow rate (ml / min) 50 100 300 500 800 1000 The sensitivity of the sensor in this method 13.693 13.998 14.949 14.951 15.163 15.337 Sensitivity of commercially available sensors 5.268 5.972 6.824 7.858 8.168 8.301 (4) Alarm test When a high concentration of gas is introduced into the target gas environment, the gas sensor will have an obvious voltage difference change, thereby triggering a high concentration alarm, which can also reflect the sensor's responsiveness to the target gas to a certain extent. As shown in Tables 4 and 5, the alarm voltage and response difference of the sensor of the present invention and the commercially available sensor under the 4000ppm high concentration methane gas test are listed.
[0034] According to the results in the table, the response difference of the sensor prepared by this method is smaller than that of the commercially available sensor. It can be seen that the alarm speed is faster and can accurately help users. Secondly, the alarm voltage of the sensor of the present invention is more stable and consistent than that of the commercially available sensor.
[0035] Table 4 4000ppm high concentration methane test of the sensor of the present invention Serial number Zero voltage 4000ppm alarm voltage Response Difference 1 0.45 2.99 2.54 2 0.50 3.01 2.51 3 0.41 3.05 2.64 4 0.41 3.00 2.59 5 0.43 3.08 2.65 6 0.45 3.06 2.61 7 0.45 3.00 2.55 8 0.45 3.08 2.63 9 0.49 3.10 2.61 10 0.40 3.11 2.71 average 0.49 3.08 2.59 Table 5 4000ppm high concentration methane test of commercially available sensors Serial number Zero voltage 4000ppm alarm voltage Response Difference 1 0.37 4.96 4.59 2 0.34 4.78 4.44 3 0.31 4.64 4.33 4 0.36 5.24 4.88 5 0.37 4.75 4.38 6 0.39 4.32 3.93 7 0.32 4.98 4.66 8 0.36 5.05 4.69 9 0.36 5.12 4.76 10 0.33 4.69 4.36 average 0.351 4.853 4.502 (5) Actual power consumption measurement The sensor prepared by this method and the commercially available sensor were heated, and the heating resistance required by the two was compared, thereby comparing the energy consumption of the two. The results are shown in Table 6: Table 6 Power consumption test sensor Heating resistance (ohm) Sensors for this method 85 Commercially available sensors 60 The actual measurement shows that for the same heating temperature of 230 degrees, the heating resistor without aerogel coating needs 60 ohms, while the heating resistor after aerogel coating only needs 85 ohms to reach 230 degrees. Calculated based on the heating voltage of 5V, the coating of silica aerogel reduces the heating voltage by 30%, which shows that the sensor of the present invention can reduce a lot of energy consumption.
[0036] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0037] The above-described embodiments only express the more specific and detailed embodiments described in this application, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of this application, which all belong to the protection scope of this application. Therefore, the protection scope of the patent application shall be based on the attached claims.
Claims
1. A method for preparing a semiconductor gas sensor, characterized in that: The semiconductor gas sensor preparation method comprises: S1. preparing a first mixed graphite slurry and a first mixed resin solution respectively; S2, stirring and mixing the prepared first mixed graphite slurry and the first mixed resin solution at a ratio of 1:0.5-3 at room temperature for 30-90 minutes to obtain an electrode slurry; S3, printing the electrode slurry onto the ceramic substrate, and then curing it at 280-350° C. for 60-90 min, at which time the electrode slurry forms an electrode to obtain a ceramic substrate with an electrode; S4, preparing a second mixed graphite slurry and a second mixed resin solution respectively; S5, stirring and mixing the prepared second mixed graphite slurry and the second mixed resin solution at a ratio of 1:0.5-3 at room temperature for 30-90 minutes to obtain a heating coating slurry; S6, printing the heating coating slurry onto one side of the ceramic substrate obtained in S3, and then placing it at room temperature for 30 to 60 minutes, and then curing it at 280 to 350° C. for 60 to 90 minutes, at which time the heating coating slurry forms a heating resistor, thereby obtaining a ceramic substrate with electrodes and a heating resistor; S7, evenly coating the silica aerogel on the heating resistor prepared in S6, leaving it at room temperature for 30 to 60 minutes, and then placing it in an environment of 120 to 200° C. for 15 to 30 minutes, to obtain a ceramic substrate with electrodes and a low-power consumption heating resistor; S8. Prepare a third mixed slurry, print the prepared third mixed slurry onto the surface of the electrode, and the printing thickness is 0.3~0.5mm, then place the ceramic substrate with the electrode and the low-power heating resistor in a muffle furnace, increase the temperature to 550℃~650℃ at a heating rate of 20~30℃ / min, and then sinter for 120~180min.
2. The method for preparing a semiconductor gas sensor according to claim 1, characterized in that: The preparation of the first mixed graphite slurry comprises: 15-50% of graphite powder, 5-30% of graphene, 20-78% of deionized water, 1% of silane coupling agent and 1% of aqueous defoaming agent are mixed at room temperature for 20-40 minutes, heated to 90-120°C and kept mixed for 40-60 minutes, then cooled to room temperature and ball milled for 24-48 hours to obtain a first mixed graphite slurry.
3. The method for preparing a semiconductor gas sensor according to claim 1, wherein: The preparation of the first mixed resin solution comprises: 20-75% of aqueous polyimide resin, 24-79% of deionized water and 1% of aqueous defoaming agent are mixed in a stirrer at 1000 r / min for 10-40 minutes to obtain a first mixed resin solution.
4. The method for preparing a semiconductor gas sensor according to claim 1, wherein: The preparation of the second mixed graphite slurry comprises: 33-66% of graphite powder, 33-66% of deionized water, 3-6% of silane coupling agent and 3-6% of aqueous defoaming agent are mixed at room temperature for 15-30 minutes, and then 15-35% of graphene is added, and the mixture is heated to 50-80°C and mixed for 15-30 minutes, and then cooled to room temperature and ball-milled for 24-48 hours to obtain a first mixed graphite slurry.
5. The method for preparing a semiconductor gas sensor according to claim 1, wherein: The preparation of the second mixed resin solution comprises: 50-80% of aqueous polyimide resin and 20-50% of deionized water are mixed at 60-90° C. for 15-30 minutes, then cooled to room temperature and mixed in a stirrer at 1000 r / min for 30-90 minutes to obtain a second mixed resin solution.
6. The method for preparing a semiconductor gas sensor according to claim 1, wherein: The preparing the third mixed slurry comprises: 16-22% of tin dioxide, 0.5-1% of palladium chloride, 0.8-1.5% of metal group oxide, 13-20% of dispersion medium, 12-18% of hydrophilic dispersant, 20.7-40% of surfactant and 10-15% of polyethylene glycol are placed in an agate mortar and ground and mixed at room temperature for 30-60 minutes, then raised to 60-90° C. and continued to grind and mix for 30-60 minutes to obtain a third mixed slurry.
7. The method for preparing a semiconductor gas sensor according to claim 6, characterized in that: The metal oxide is vanadium pentoxide, antimony pentoxide or antimony trioxide, the dispersion medium is deionized water, ethanol, ethylene glycol or isopropanol, the hydrophilic dispersant is a silane coupling agent or hexadecyl ammonium bromide, and the surfactant is citric acid, malic acid or acetic acid.