Preparation process of special adsorption pad for repairing silicon carbide substrate and product thereof

Abstract

The invention relates to the technical field of silicon carbide substrate adsorption pads, in particular to a preparation process of a special adsorption pad for repairing a silicon carbide substrate and a product thereof, and the preparation process comprises the following preparation steps: S1, dissolving polyurethane 1 and polyurethane 2 in DMF (Dimethyl Formamide) to obtain a polyurethane mixture; s2, non-woven fabric is soaked in the polyurethane mixture, after the non-woven fabric is soaked, the non-woven fabric is placed in a coagulating tank to be coagulated, and a semi-finished product is obtained; s3, blade-coating a polyurethane mixture on the surface of the semi-finished product, putting the semi-finished product in a coagulating tank for solidification, washing with water, and drying at the temperature of 150-160 DEG C to obtain the special adsorption pad for repairing the silicon carbide substrate; wherein the modulus of the polyurethane 1 is 25 to 35 MPa, and the modulus of the polyurethane 2 is 55 to 65 MPa; the non-woven fabric is produced from polyester fibers and viscose fibers through a non-woven fabric needling process, the adsorption capacity, the compression ratio and the rebound resilience of the non-woven fabric are improved by optimizing the combination process of the polyurethane mixture and the non-woven fabric, the production cost can be effectively reduced, and the substrate repairing quality can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of silicon carbide substrate adsorption pads, and more specifically, to a preparation process and product of a special adsorption pad for repairing silicon carbide substrates. Background Art

[0002] Silicon carbide substrates, as representatives of third-generation semiconductor materials, exhibit broad application prospects in fields such as high-frequency and high-power electronic devices, new energy vehicles, and smart power grids due to their excellent properties such as wide bandgap, high saturated electron drift rate, high critical breakdown electric field, and high thermal conductivity. However, during the preparation and processing of silicon carbide substrates, especially in the precision polishing process, crystallization defects or structural defects, as well as surface scratches, pits, and other defects may occur. These defects will seriously affect the use performance of the substrates, so rework and repair are required.

[0003] During the repair process, various methods can be used to repair silicon carbide substrates, including chemical mechanical polishing, electrochemical polishing, and tribochemical polishing. Chemical mechanical polishing is a process that removes the material surface through the combined action of chemical and mechanical effects, and can effectively improve the flatness of the substrate surface and reduce surface defects. Electrochemical polishing uses an electrochemical reaction to remove the material surface. This method can repair surface defects to a certain extent and improve the surface quality of the substrate. Tribochemical polishing combines friction and chemical reactions to achieve the effect of repairing and smoothing the surface.

[0004] During the above repair process, the silicon carbide substrate needs to be adsorbed on a special adsorption pad to ensure the adsorption and fixation of the substrate during the polishing process. Existing adsorption pads usually include at least three-layer structures, namely a porous adsorption layer, a bonding layer, and a base layer. Although this multi-layer structure provides good adsorption effect, bending problems are likely to occur during cutting and installation. When the cut edges are uneven or there are creases, the surface of the adsorption pad will be uneven, affecting the adsorption effect. In addition, the process of the multi-layer structure adsorption pad in the masking project is relatively complex, increasing the production cost and operation difficulty. Summary of the Invention

[0005] To solve the problems that existing adsorption pads will have creases or unevenness during use and the preparation process is complex, the present application provides a preparation process and product of a special adsorption pad for repairing silicon carbide substrates.

[0006] In the first aspect, the present application provides a preparation process of a special adsorption pad for repairing silicon carbide substrates, adopting the following technical solutions: A preparation process of a special adsorption pad for repairing silicon carbide substrates includes the following preparation steps: S1. Dissolve polyurethane 1 and polyurethane 2 in DMF to obtain a polyurethane mixture; S2. Immerse the non-woven fabric in the polyurethane mixture. Wait until the non-woven fabric is fully soaked, and then place it in a coagulation tank for coagulation to obtain a semi-finished product. S3. Scraping the polyurethane mixture on the surface of the semi-finished product, then placing it in a coagulation tank for coagulation, followed by water washing, and then drying at a temperature of 150 - 160 °C to obtain an adsorption pad dedicated to the repair of silicon carbide substrates. Among them, the modulus of polyurethane 1 is 25 - 35 MPa, and the modulus of polyurethane 2 is 55 - 65 MPa. The non-woven fabric is produced by the needle-punched non-woven fabric process from polyester fibers and viscose fibers.

[0007] The adsorption pad dedicated to the repair of silicon carbide substrates significantly improves the durability and performance by optimizing the bonding process of the polyurethane mixture and the non-woven fabric. Its high adsorption force, chemical corrosion resistance, good compression ratio and resilience, as well as reusability, make it perform excellently in the repair process of silicon carbide substrates, effectively reducing production costs and improving the quality of substrate repair.

[0008] By dissolving polyurethane 1 and polyurethane 2 in DMF and combining the non-woven fabric as the substrate, the prepared adsorption pad has better adsorption performance, can evenly disperse external forces, avoid substrate cracking caused by excessive local stress, can fix the silicon carbide substrate more firmly, and ensure the stability of the substrate during the polishing process.

[0009] By mixing polyurethanes with different moduli, the optimization of mechanical properties can be achieved. The modulus of polyurethane 1 is 25 - 35 MPa, and the modulus of polyurethane 2 is 55 - 65 MPa. This mixing method can form a gradient structure in the material, making the adsorption pad have both good flexibility (from the low-modulus polyurethane) and sufficient strength (from the high-modulus polyurethane), so as to better fix the silicon carbide substrate during the polishing process and reduce the damage of the substrate during the processing.

[0010] In this application, polyester fibers and viscose fibers are used to prepare the non-woven fabric, making the non-woven fabric have the characteristics of light weight, softness, fluffiness, easy cutting, etc. Moreover, the non-woven fabric produced by the needle-punched process has good air permeability and porous structure, and can evenly adsorb the polyurethane mixture. Polyester fibers have high strength and wear resistance, while viscose fibers increase the flexibility and hydrophilicity of the adsorption pad. This combination can provide better adsorption performance and mechanical stability. The combination of the polyurethane mixture and the non-woven fabric can form a uniform adsorption surface, provide stable adsorption force, and reduce the displacement and damage of the substrate during the polishing process.

[0011] The traditional multi-layer structure adsorption pad has a complex process in the shielding project, increasing the production cost and operation difficulty. This technical solution simplifies the structure of the adsorption pad, reduces the process steps, lowers the production cost, and improves the operation convenience at the same time.

[0012] Preferably, the weight ratio of the polyurethane 1 to the polyurethane 2 is (60 - 70):(30 - 40).

[0013] By adopting the above technical solution, the dosages of the polyurethane 1 and the polyurethane are optimized, the stress is further effectively dispersed, the fatigue damage caused by local stress concentration is reduced, and thus the service life of the adsorption pad is prolonged. At the same time, the mixed use of the polyurethane 1 and the polyurethane 2 can form a more uniform adsorption surface, reduce the uneven distribution of the adsorption force, thus better fixing the silicon carbide substrate and reducing the displacement of the substrate during the polishing process. Moreover, the surface flatness of the adsorption pad is improved, and the scratches and damages of the substrate during the adsorption and polishing processes can be reduced.

[0014] Preferably, the weight ratio of the polyester fiber to the viscose fiber is (85 - 95):10.

[0015] By adopting the above technical solution, the dosages of the polyester fiber and the viscose fiber are optimized, the mechanical strength of the adsorption pad is further improved, so that it can withstand the external force during the polishing process, and at the same time, the softness of the adsorption pad can be increased, so that it is not easy to break during the processing, and at the same time, a certain elasticity is maintained.

[0016] Preferably, in steps S2 and S3, the coagulation tank is filled with a coagulation liquid, and the coagulation liquid is obtained by mixing water, sodium bicarbonate and a coagulant according to a weight ratio of 15:(0.5 - 1):(1 - 2).

[0017] By adopting the above technical solution, the curing process of the polyurethane mixture can be significantly accelerated, and the strength after curing can be improved.

[0018] Among them, sodium bicarbonate will release an alkaline environment after being dissolved in water, which helps to accelerate the curing reaction of the polyurethane mixture. The addition of the coagulant further promotes the curing process of the polyurethane molecules to be more rapid and uniform. At the same time, the calcium carbonate particles generated by the decomposition of sodium bicarbonate during the curing process can be filled in the polyurethane network to enhance the mechanical strength of the material. This enhancement helps the adsorption pad to better fix the silicon carbide substrate during the polishing process, reduce the displacement and damage of the substrate, and thus improve the repair quality. The decomposition reaction of sodium bicarbonate can generate tiny pores, and these pores form a uniformly distributed microporous structure in the polyurethane network, which helps to improve the air permeability and moisture absorption of the adsorption pad. This optimized microstructure not only improves the adsorption performance of the adsorption pad, but also reduces the scratches of the substrate during the adsorption and polishing processes. The weak alkaline environment of sodium bicarbonate can promote the chemical reaction on the surface of the polyurethane, making the surface more uniform and smooth.

[0019] Preferably, the curing temperature in step S2 is 40 - 50°C, and the curing pressure is 0.1 - 0.5 MPa.

[0020] By adopting the above technical solution, the porosity inside the cured polyurethane can be controlled so that the polyurethane forms a uniform microporous structure during the curing process, which not only helps to improve the air permeability and moisture absorption of the adsorption pad, but also reduces scratches on the substrate during adsorption and polishing.

[0021] Appropriate external pressure can make the polyurethane mixture more evenly distributed in the non-woven fabric, reducing defects such as pores and voids caused by uneven solvent volatilization. At the same time, pressure can promote the bonding between polyurethane and non-woven fibers, improving the overall strength and stability of the adsorption pad. The above curing conditions help maintain the flexibility of polyurethane, so that it can better adapt to the shape changes of the silicon carbide substrate in the adsorption pad, reduce damage caused by mechanical stress, and promote the cross-linking of polyurethane molecular chains to form a denser network structure, thereby improving the tensile strength and wear resistance of the adsorption pad.

[0022] Preferably, the curing temperature of step S3 is 30-40° C., and the curing pressure is 1-2 MPa.

[0023] By adopting the above technical solution, the curing speed of the polyurethane on the surface of the adsorption pad is further improved, and a polyurethane layer with better flexibility is formed, so that it can better adapt to the shape changes of the silicon carbide substrate in the adsorption pad and reduce damage caused by mechanical stress. At the same time, it can promote the cross-linking of polyurethane molecular chains to form a denser network structure, thereby improving the tensile strength and wear resistance of the adsorption pad. And the polyurethane forms a uniform microporous structure during the curing process, which not only helps to improve the air permeability and hygroscopicity of the adsorption pad, but also reduces scratches on the substrate during adsorption and polishing.

[0024] Preferably, the coating amount of the polyurethane mixture in step S3 is 15-25 g / m 2 .

[0025] By adopting the above technical solution, the polyurethane mixture can form a uniform coating on the surface of the semi-finished product, avoiding excessive coating thickness due to excessive coating or discontinuous coating due to insufficient coating. The uniform coating thickness helps to improve the flatness and consistency of the adsorption pad, thereby better fixing the silicon carbide substrate during the polishing process and reducing the displacement and shaking of the substrate. In addition, the appropriate amount of polyurethane mixture can provide sufficient strength and flexibility, so that the adsorption pad can withstand external forces during the polishing process without being easily damaged.

[0026] Preferably, the needle punching density of the nonwoven fabric is 150-200 needles / ㎡.

[0027] By adopting the above technical solutions, the mechanical strength and stability of the non-woven fabric can be significantly improved. The needling process can reduce the surface roughness of the non-woven fabric by increasing the entanglement degree between fibers, making it smoother, enabling it to better fit the surface of the substrate, reducing scratches and damage during the polishing process, and enabling the non-woven fabric to withstand higher external forces without being easily damaged during the polishing process. At the same time, increasing the fiber density of the non-woven fabric can enhance its adsorption capacity.

[0028] In a second aspect, the present application provides a special adsorption pad for repairing a silicon carbide substrate, adopting the following technical solutions: A special adsorption pad for repairing a silicon carbide substrate is prepared by the preparation process of the special adsorption pad for repairing a silicon carbide substrate described in the first aspect.

[0029] The above adsorption pad has a good adsorption effect on the silicon carbide substrate, can ensure the stability of the silicon carbide substrate during processing, avoid displacement and shaking, and at the same time can evenly disperse external forces, prevent local overstress, and effectively avoid the cracking of the silicon carbide substrate caused by unstable adsorption. Moreover, the non-woven fabric used in the adsorption pad is produced by the needling process of polyester fiber and viscose fiber, and the surface is impregnated with polyurethane, having high flatness and good resilience. This characteristic enables the adsorption pad to better fit the surface of the substrate during the polishing process, reducing scratches and damage.

[0030] In summary, the present application has the following beneficial effects: 1. Simplify the multi-layer structure: Traditional adsorption pads usually adopt a multi-layer structure, which is prone to problems such as bending, uneven cut edges or creases during cutting and installation. However, this process simplifies the structure of the adsorption pad by directly coating the mixture of polyurethane 1 and polyurethane 2 on the non-woven fabric, reducing the complexity brought by the multi-layer structure.

[0031] 2. Optimize mechanical properties: The moduli of polyurethane 1 and polyurethane 2 are 25 - 35 MPa and 55 - 65 MPa respectively. The mixed polyurethane material can combine the advantages of the two polyurethanes to form a gradient structure. This structure not only ensures the flexibility of the adsorption pad but also provides sufficient strength, thus better fixing the silicon carbide substrate during the polishing process.

[0032] 3. Uniform adsorption force: The non-woven fabric as the base material can uniformly adsorb the polyurethane mixture to form a stable adsorption surface. This uniform adsorption force helps to reduce the displacement and shaking of the substrate during processing, thereby improving the uniformity of polishing and the repair quality of the substrate.

[0033] 4. Reduce substrate damage: The high wear resistance and good surface flatness of the polyurethane material can reduce scratches and damage to the substrate during adsorption and polishing, further improving the overall quality of the substrate. Specific embodiments Examples

[0034] The polyester fiber was purchased from Hangzhou Yongxing Chemical Fiber Co., Ltd. with a fineness of 500D.

[0035] The viscose fiber was purchased from Dezhou Caishihe Textile Co., Ltd. with a fineness of 1000D.

[0036] Polyurethane 1 and Polyurethane 2 are from BASF in Germany.

[0037] Example 1 A special adsorption pad for repairing silicon carbide substrates is prepared by the following method: S1. Dissolve Polyurethane 1 and Polyurethane 2 in DMF to obtain a polyurethane mixture. S2. Immerse the non-woven fabric in the polyurethane mixture. After the non-woven fabric is soaked, place it in a coagulation bath for coagulation to obtain a semi-finished product. The curing temperature is 40°C and the curing time is 15 minutes. S3. Scrape and coat the polyurethane mixture on the surface of the semi-finished product with a coating amount of 10 g / m 2 , then place it in a coagulation bath for coagulation. The curing temperature is 40°C and the curing time is 60 minutes. Then wash it with water and place it at a temperature of 150 - 160°C for drying to obtain a special adsorption pad for repairing silicon carbide substrates. Among them, the modulus of Polyurethane 1 is 25 MPa and the dosage is 500 g. The modulus of Polyurethane 2 is 55 MPa and the dosage is 200 g. The non-woven fabric is produced by the needle-punched non-woven fabric process from polyester fiber and viscose fiber. Among them, the weight ratio of polyester fiber to viscose fiber is 70:10, the gram weight of the non-woven fabric is 100 g / m 2 , and the needle punching density is 100 punches / ㎡.

[0038] The coagulating liquid in the coagulation bath is pure water.

[0039] The differences between Example 2 - 3 and Example 1 are that the types, dosages, and parameters of the raw materials for preparing the special adsorption pad for repairing silicon carbide substrates are different. The specific differences are shown in Table 1: Table 1 Types, Dosages, and Parameters of Raw Materials for Preparing the Special Adsorption Pad for Repairing Silicon Carbide Substrates in Examples 1 - 3 Example 4 A special adsorption pad for repairing silicon carbide substrates. The difference between this example and Example 1 is that the weight ratio of Polyurethane 1 to Polyurethane 2 is 60:30.

[0040] Example 5 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that the weight ratio of polyurethane 1 to polyurethane 2 is 70:40.

[0041] Embodiment 6 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that the weight ratio of polyester fiber to viscose fiber is 85:10.

[0042] Embodiment 7 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 4 is that the weight ratio of polyester fiber to viscose fiber is 95:10.

[0043] Embodiment 8 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that in steps S2 and S3, the coagulation tank is filled with a coagulation liquid, which is obtained by mixing water, sodium bicarbonate, and a coagulant (ethylenediamine) in a weight ratio of 15:0.5:1.

[0044] Embodiment 9 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 7 is that in steps S2 and S3, the coagulation tank is filled with a coagulation liquid, which is obtained by mixing water, sodium bicarbonate, and a coagulant (triethylamine) in a weight ratio of 15:1:2.

[0045] Embodiment 10 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that the curing temperature in step S2 is 40°C and the curing pressure is 0.1 MPa.

[0046] Embodiment 11 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 9 is that the curing temperature in step S2 is 50°C and the curing pressure is 0.5 MPa.

[0047] Embodiment 12 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that the curing temperature in step S3 is 30°C and the curing pressure is 1 MPa.

[0048] Embodiment 13 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 11 is that the curing temperature in step S3 is 40°C and the curing pressure is 2 MPa.

[0049] Embodiment 14 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that: the coating amount of the polyurethane mixture in step S3 is 15 g / m 2 .

[0050] Embodiment 15 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that: the coating amount of the polyurethane mixture in step S3 is 25 g / m 2 .

[0051] Embodiment 16 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that: the needling density of the non-woven fabric is 150 needles per square meter.

[0052] Embodiment 17 A special adsorption pad for repairing silicon carbide substrates. The difference between this embodiment and Embodiment 1 is that: the needling density of the non-woven fabric is 200 needles per square meter.

[0053] Comparative example Comparative example 1 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative example 1 is that the polyurethane is polyurethane 1 in both cases.

[0054] Comparative example 2 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative example 1 is that the polyurethane is polyurethane 2 in both cases.

[0055] Comparative example 3 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative example 1 is that the modulus of polyurethane 1 is 10 MPa.

[0056] Comparative example 4 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative example 1 is that the modulus of polyurethane 2 is 65 MPa.

[0057] Comparative example 5 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative example 1 is that the non-woven fabric is produced by the needling non-woven fabric process from polyester fibers.

[0058] Comparative example 6 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative example 1 is that the non-woven fabric is produced by the needling non-woven fabric process from viscose fibers.

[0059] Comparative example 7 A special adsorption pad for repairing silicon carbide substrates. The difference between this comparative example and Comparative Example 1 is that the step of scraping and coating the polyurethane mixture on the surface of the semi-finished product and then placing it in the solidification tank for solidification is omitted.

[0060] Detection method / Test method Adsorption force: Fix the adsorption pad on the silicon carbide substrate, apply a certain external force, and use a tensiometer to gradually increase the pulling force until the adsorption pad is separated from the silicon carbide substrate, and record the required pulling force value.

[0061] Adsorption speed: Bring the adsorption pad into contact with the silicon carbide substrate and record the time from the start of contact to the adsorption force reaching stability.

[0062] Place the specimen on the workbench, measure the initial height (h0) with a thickness gauge, place weight A (2 kg) on the specimen, remove it after 30 seconds, repeat three times, and measure the height of the specimen again (h1). Compression ratio P1 = (h0 - h1) / h0 * 100%.

[0063] Place weight B (4 kg) on the specimen, measure the compressed height (h2) after 30 seconds, and the compression recovery rate = compression ratio P2 = (h2 - h1) / (h0 - h1) * 100%.

[0064] Service life of the adsorption pad: Attach the adsorption pad flatly to the polishing machine disk, clean the surface of the adsorption pad, then install the material to be polished on the surface of the adsorption pad and perform polishing, and record the service life (153 h). The experimental data is shown in Table 2: Table 2 Experimental data of Examples 1 - 17 and Comparative Examples 1 - 7 Comparing Example 1 with Comparative Examples 1 - 2, the adsorption force and adsorption speed of Comparative Examples 1 - 2 are lower than those of Example 1, the service life of Comparative Example 1 is lower than that of Example 1, and the compression ratio and compression resilience rate in Comparative Example 2 are both lower than those of Example 1. This shows that by using polyurethane 1 and polyurethane 2 in combination, the adsorption pad has good adsorption force, adsorption speed, elasticity, and service life.

[0065] Comparing Example 1 with Comparative Examples 3 - 4, the adsorption force, adsorption speed, compression ratio, compression resilience rate, and service life of Comparative Examples 3 - 4 are all lower than those of Example 1. This shows that by using polyurethane 1 with a specific modulus and polyurethane 2 with a specific modulus together, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad are further improved.

[0066] Comparing Example 1 with Comparative Examples 5 - 6, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Comparative Examples 5 - 6 are slightly lower than those of Example 1, indicating that by using polyester fiber and viscose fiber together, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad can be improved.

[0067] Comparing Example 1 with Comparative Example 7, the adsorption force and adsorption speed of Comparative Example 7 are lower than those of Example 1, indicating that by coating with a polyurethane mixture, the adsorption force and adsorption speed of the adsorption pad can be improved.

[0068] Comparing Example 1 with Examples 4 - 5, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Examples 4 - 5 are higher than those of Example 1, indicating that by optimizing the dosages of polyurethane 1 and polyurethane 2, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad can be improved.

[0069] Comparing Example 1 with Example 6, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 6 are higher than those of Example 1; Comparing Example 4 with Example 7, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 7 are higher than those of Example 4; From the experimental data of Examples 1 and 6, 4 and 7, it can be seen that by optimizing the weights of polyester fiber and viscose fiber, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad can be improved.

[0070] Comparing Example 1 with Example 8, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 8 are slightly higher than those of Example 1, and the curing time in Steps S2 and S3 is greatly shortened; Comparing Example 7 with Example 9, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 9 are slightly higher than those of Example 7, and the curing time in Steps S2 and S3 is greatly shortened; From the experimental data of Examples 1 and 8, 7 and 9, it can be seen that by optimizing the type of solidifying liquid, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad can be improved, and the solidification time of polyurethane can be shortened.

[0071] Comparing Example 1 with Example 10, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 10 are higher than those of Example 1; Comparing Example 9 with Example 11, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 11 are higher than those of Example 9; From the experimental data of Examples 1 and 10, 9 and 11, it can be seen that by optimizing the curing temperature and pressure in Step S2, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad can be improved.

[0072] Comparing Example 1 with Example 12, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 12 are all higher than those of Example 1; Comparing Example 11 with Example 13, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Example 13 are all higher than those of Example 9; From the experimental data of Examples 1 and 12, and Examples 11 and 13, it can be seen that by optimizing the curing temperature and pressure in step S3, the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad can be improved. Comparing Example 1 with Examples 14 - 15, the adsorption force and adsorption speed of Examples 14 - 15 are both higher than those of Example 1, indicating that optimizing the coating amount of the polyurethane mixture in step S3 can improve the adsorption force and adsorption speed of the adsorption pad.

[0073] Comparing Example 1 with Examples 16 - 17, the adsorption force, adsorption speed, compression ratio, compression resilience ratio, and service life of Examples 16 - 17 are all higher than those of Example 1, indicating that optimizing the needling density of the non - woven fabric can improve the adsorption force, adsorption speed, elasticity, and service life of the adsorption pad.

[0074] This specific embodiment is only an interpretation of the present application, and it does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A process for preparing a special adsorption pad for repairing a silicon carbide substrate, characterized in that: The method comprises the following preparation steps: S1, dissolving polyurethane 1 and polyurethane 2 in DMF to obtain a polyurethane mixture; S2, soaking the non-woven fabric in the polyurethane mixture, and then placing the non-woven fabric in a coagulation tank for coagulation to obtain a semi-finished product; S3, applying the polyurethane mixture on the surface of the semi-finished product, placing it in a coagulation tank for coagulation, washing it with water, and then drying it at a temperature of 150-160° C. to obtain a special adsorption pad for repairing silicon carbide substrates; Among them, the modulus of polyurethane 1 is 25-35MPa, and the modulus of polyurethane 2 is 55-65MPa; Non-woven fabrics are produced by needle-punching polyester fibers and viscose fibers.

2. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: The weight ratio of the polyurethane 1 to the polyurethane 2 is (60-70):(30-40).

3. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: The weight ratio of the polyester fiber to the viscose fiber is (85-95):

10.

4. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: In steps S2 and S3, the coagulation tank is filled with a coagulation liquid, which is obtained by mixing water, sodium bicarbonate and a coagulant in a weight ratio of 15: (0.5-1): (1-2).

5. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: The curing temperature of step S2 is 40-50° C., and the curing pressure is 0.1-0.5 MPa.

6. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: The curing temperature of step S3 is 30-40° C., and the curing pressure is 1-2 MPa.

7. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: The coating amount of the polyurethane mixture in step S3 is 15-25g / m 2 .

8. The process for preparing a special adsorption pad for repairing a silicon carbide substrate according to claim 1, characterized in that: The needle punching density of the nonwoven fabric is 150-200 needles / ㎡.

9. A special adsorption pad for repairing silicon carbide substrates, characterized in that: The adsorption pad is prepared by the preparation process of the special adsorption pad for repairing silicon carbide substrates as described in any one of claims 1 to 8.

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