Special polishing pad for silicon substrate and preparation method thereof

Abstract

The invention relates to the technical field of polishing pads special for silicon substrates, in particular to a polishing pad special for a silicon substrate and a preparation method thereof.The polishing pad special for the silicon substrate is prepared from, by weight, 50-60 parts of polyurethane prepolymer, 30-50 parts of silane-terminated polyurethane prepolymer, 15-20 parts of filler, 1-3 parts of foaming agent, 0.5-1 part of curing agent and 3-4 parts of foam stabilizer; the prepared special polishing pad for the silicon substrate can better resist friction force and abrasive impact in the polishing process, and the surface abrasion speed is reduced. Meanwhile, the chemical corrosion resistance is enhanced, so that adverse reaction is not easy to occur when the polishing solution is in contact with various polishing solutions, and the risks of performance reduction and service life shortening caused by corrosion are reduced. Besides, by improving the thermal stability of the formula, the influence of temperature change in the polishing process on the performance of the polishing pad is resisted to a certain extent, so that the service life of the polishing pad is prolonged and can reach 100 h or above, the replacement frequency is reduced, and the polishing cost of the silicon substrate is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of special polishing pads for silicon substrates, and more specifically, to a special polishing pad for silicon substrates and a preparation method thereof. Background Art

[0002] Polyurethane polishing pads are made of polyurethane, with hardness, toughness, and elasticity adjustable according to different formulations and processes. They offer excellent chemical stability and corrosion resistance, are less likely to react adversely with polishing fluids, and are adaptable to a variety of polishing fluid systems. They maintain their shape and performance during the polishing process, offer high polishing rates, typically between 5-10 μm / h, and achieve excellent flatness and surface finish. They are a commonly used polishing pad specifically for silicon substrates.

[0003] However, despite their many advantages, polyurethane polishing pads still have certain limitations in their service life. In actual polishing applications, polyurethane polishing pads face many challenges. First, the friction effect during the polishing process cannot be ignored. The huge friction generated during the relative motion between the polishing pad and the workpiece surface will gradually wear down the surface material of the polishing pad, making the surface rough and even causing scratches and cracks, which in turn affects the polishing effect and precision. Secondly, abrasive impact is also a major factor causing polishing pad wear. Abrasive particles in the polishing liquid will exert a strong impact and grinding effect on the surface of the polishing pad during the polishing process, accelerating the wear of the polishing pad. As the polishing process continues, the hardness, elasticity and other properties of the polishing pad will gradually decrease, and the initial polishing effect cannot be maintained.

[0004] Furthermore, the corrosive effects of polishing fluids should not be underestimated. Although polyurethane inherently possesses a certain degree of chemical resistance, prolonged exposure to the polishing fluid can still cause corrosion to the polishing pad due to some of its active ingredients, damaging its internal structure and gradually deteriorating its performance. Furthermore, the heat generated during polishing increases the temperature of the polishing pad, and this temperature change further exacerbates pad aging and wear. High temperatures can alter the physical properties of the polishing pad, causing it to become softer and more brittle, leading to a decrease in its wear and corrosion resistance, ultimately shortening its service life. Currently, polyurethane polishing pads typically have a service life of only 45-75 hours, which undoubtedly increases production costs and the frequency of equipment maintenance. Summary of the Invention

[0005] In order to extend the service life of a polyurethane polishing pad, the present application provides a polishing pad dedicated to silicon substrates and a preparation method thereof.

[0006] In a first aspect, the present application provides a polishing pad specifically for silicon substrates, which adopts the following technical solution: A special polishing pad for silicon substrates is prepared from the following raw materials in parts by weight: 50-60 parts polyurethane prepolymer 30-50 parts of silane-terminated polyurethane prepolymer 15-20 parts of filler 1-3 parts of foaming agent 0.5-1 parts of curing agent 3-4 parts of foam leveling agent.

[0007] By adopting the above technical solution, the polishing pad specifically designed for silicon substrates can better withstand friction and abrasive impact during the polishing process, reducing surface wear. Furthermore, the enhanced chemical resistance makes it less susceptible to adverse reactions when exposed to various polishing fluids, reducing the risk of performance degradation and lifespan shortening due to corrosion. Furthermore, by improving the thermal stability of the formulation, the pad's performance is somewhat protected against temperature fluctuations during the polishing process, thereby extending the pad's service life to over 100 hours, reducing replacement frequency and lowering the cost of polishing silicon substrates.

[0008] The combination of polyurethane prepolymer and silane-terminated polyurethane prepolymer imparts excellent elasticity and toughness to the polishing pad, enabling it to withstand high friction during the polishing process and reducing surface wear caused by friction. It also imparts excellent impact resistance, making it less susceptible to cracking or breakage when exposed to tiny bumps or hard particles on the workpiece surface. The use of fillers further enhances the polishing pad's wear and impact resistance, while also improving its adaptability to different workpiece materials. It effectively resists the impact and wear of abrasive particles, reduces scratches and wear on the pad surface, and thus extends its service life.

[0009] At the same time, the cross-linked network structure of the polyurethane prepolymer and the silane-terminated polyurethane prepolymer gives the polishing pad good thermal stability, which can maintain the physical properties of the polishing pad stable in a high temperature environment and prevent the polishing pad from deformation, softening or brittleness due to temperature changes.

[0010] Foaming agents and leveling agents create a uniform microporous structure within the polishing pad, improving its cushioning properties and elasticity. Curing agents promote cross-linking between the various components in the polishing pad, giving it greater hardness and strength while also improving its chemical resistance and thermal stability.

[0011] Preferably, the polyurethane prepolymer is prepared by the following method: After mixing the first polyisocyanate, polyester diol, terminal hydroxyl polybutadiene, and the first catalyst, the temperature is raised to 70-80°C, and the mixture is stirred and reacted for 2-3 hours. Then, the first chain extender and hydroxy acrylate are added, the temperature is raised to 90-100°C, and the mixture is stirred and reacted for 2-3 hours. The mixture is cooled to 80-90°C, and the mixture is stirred and reacted for 30-40 minutes. When the viscosity is 5000-10000 mPa.s, the temperature is lowered to stop the reaction to obtain a polyurethane prepolymer.

[0012] GM has employed this technical solution to enhance the overall performance of polishing pads through specific raw material ratios and reaction conditions. First, through the rational combination of raw materials such as the first polyisocyanate, polyester diol, and hydroxyl-terminated polybutadiene, and the staged control of reaction temperature and time, the mechanical strength and wear resistance of the polyurethane prepolymer are effectively improved, thereby extending the service life of the polishing pad. Second, the addition of hydroxy acrylate and the optimization of the reaction process further enhance the material's corrosion resistance and stability, making the polishing pad less susceptible to erosion by polishing fluids during long-term use.

[0013] Preferably, the weight parts of the raw materials used to prepare the polyurethane prepolymer are as follows: 20-30 parts of the first polyisocyanate 30-40 parts of polyester diol 10-15 parts of hydroxyl-terminated polybutadiene 0.1-0.5 parts of the first catalyst 1-2 parts of the first chain extender 3-5 parts of hydroxy acrylate.

[0014] By adopting the above technical solution, the raw material ratio of the polyurethane prepolymer is optimized, which can significantly improve the hardness and toughness of the polishing pad while ensuring its elastic properties, so that it can better adapt to the requirements of different workpiece surfaces during the polishing process; and further enhance the mechanical properties, chemical corrosion resistance and aging resistance of the polishing pad, thereby extending its service life.

[0015] Preferably, the silane-terminated polyurethane prepolymer is prepared by the following method: After mixing the second polyisocyanate, polyether diol, and the second catalyst, the temperature is raised to 70-80°C, and the reaction is stirred for 2-3 hours. Then, the second chain extender is added, the temperature is raised to 90-100°C, and the reaction is stirred for 1-2 hours. The silicone polyol is added to the reactor and stirred for 3-5 hours. The temperature is lowered to 80-90°C, and the second polyisocyanate is added. The mixture is vacuum-treated and stirred. When the -CNO content is less than 5% and the viscosity is 5000-10000 mPa.s, the temperature is lowered to stop the reaction to obtain a silane-terminated polyurethane prepolymer.

[0016] By employing the above-mentioned technical solution and controlling the reaction conditions and steps for preparing the silane-terminated polyurethane prepolymer, the flexibility and wear resistance of the polishing pad can be effectively improved, thereby extending its service life. The reaction product of the second polyisocyanate and the polyether diol enhances the hardness and wear resistance of the polishing pad, resulting in a longer service life in the face of abrasive impact and friction. The use of a second chain extender further improves the elasticity and toughness of the polishing pad, enabling it to better adapt to changes in the workpiece surface during the polishing process. The introduction of the organosilicon polyol significantly enhances the chemical resistance and high-temperature stability of the polishing pad, reducing the impact of polishing fluid and temperature changes on the polishing pad's performance. The subsequent addition of the polyisocyanate is precisely controlled to a ratio of 5-10% of the previous amount, ensuring the final product has moderate viscosity and a stable structure, providing excellent mechanical strength to the polishing pad.

[0017] Preferably, the weight parts of the raw materials used to prepare the silane-terminated polyurethane prepolymer are as follows: 20-30 parts of the second polyisocyanate 30-40 parts of polyether diol 0.1-0.5 parts of the second catalyst 1-2 parts of the second chain extender 10-15 parts of silicone polyol.

[0018] By employing this technical solution and optimizing the specific raw material ratio used in the preparation of silane-terminated polyurethane prepolymers, the polishing pad's hardness and wear resistance are further enhanced, resulting in a longer service life when subjected to abrasive impact and friction. Furthermore, the polishing pad's chemical resistance and thermal stability are improved, reducing erosion by polishing fluids and minimizing performance degradation in high and low temperature environments.

[0019] Preferably, the filler is pretreated by the following method: grinding the filler to 50-100 nm, stirring with ethanol, adding a hydroxy silane coupling agent, ultrasonicating for 30-60 minutes, filtering, collecting the filter residue, and drying to obtain the pretreated filler.

[0020] Preferably, the weight ratio of the filler to the hydroxysilane coupling agent is 10:(3-5).

[0021] After pretreatment, the filler's particle size is reduced to 50-100 nm, significantly improving its uniformity of dispersion within the polishing pad matrix, thereby enhancing the pad's mechanical properties and wear resistance. Furthermore, surface modification through stirring with ethanol and adding a hydroxysilane coupling agent improves the compatibility between the filler and the polyurethane matrix, further enhancing the pad's overall performance. Ultrasonic treatment enhances the filler's surface activity, contributing to a more stable composite structure and resulting in improved corrosion resistance and a longer service life.

[0022] Preferably, the blowing agent comprises at least one of hydrochlorofluorocarbons, hydrofluorocarbons, alkanes or liquid carbon dioxide.

[0023] By adopting the above technical solution, the type of foaming agent is optimized, so that the polishing pad can form a uniform foam structure during the preparation process, thereby improving the elasticity and cushioning performance of the polishing pad, helping to reduce surface wear during the polishing process, extending the service life of the polishing pad, and improving the consistency and stability of the polishing effect.

[0024] Preferably, the foam leveling agent is a polyether-modified silicone surfactant.

[0025] The above technical solution significantly improves foam stability during polishing pad preparation. Specifically, the polyether-modified silicone surfactant exhibits excellent surface activity and dispersibility, effectively reducing liquid surface tension during mixing and promoting uniform distribution of bubbles. This prevents internal structural defects in the polishing pad caused by uneven foaming, enhances the pad's compactness and uniformity, and further improves its mechanical properties and service life.

[0026] Preferably, the curing agent is one of 3,3′-dichloro-4,4′-diaminodiphenylmethane, dimethylthiotoluenediamine or diethyltoluenediamine.

[0027] By adopting the above technical solution and optimizing the type of curing agent, the overall performance of the polishing pad can be effectively improved. This type of curing agent can efficiently cross-link with the polyurethane prepolymer and the silane-terminated polyurethane prepolymer, forming a denser network structure, thereby improving the hardness and wear resistance of the polishing pad. Furthermore, the resulting cross-linked structure enhances the heat resistance and chemical stability of the polishing pad, reducing the risk of aging caused by temperature fluctuations and chemical corrosion during the polishing process, and extending the service life of the polishing pad.

[0028] In a second aspect, the present application provides a method for preparing a polishing pad specifically for silicon substrates, which adopts the following technical solution: A method for preparing a polishing pad specifically for silicon substrates, comprising the following preparation steps: S1, uniformly mixing a polyurethane prepolymer, a silane-terminated polyurethane prepolymer, a filler, a foaming agent, a curing agent and a foam leveling agent to obtain a mixture; S2. Pour the mixture into a mold, place it at a temperature of 100-110° C., cure it for 120-180 minutes, demold it, and mature it at 70-90° C. for 20-30 hours to obtain a polishing pad specifically for silicon substrates.

[0029] By employing this technical solution, the various raw materials are thoroughly mixed and uniformly mixed, resulting in a structurally stable polishing pad. This ensures the polishing pad's wear, impact, and corrosion resistance, while also allowing it to withstand certain temperature fluctuations and resist softening, deformation, or performance degradation due to high temperatures. During the curing and maturation process, chemical reactions occur between the various components, forming a stable cross-linked network structure that increases the hardness and strength of the polishing pad, making it less susceptible to wear from abrasive impact and friction, extending its service life, and reducing replacement frequency.

[0030] In summary, this application has the following beneficial effects: 1. The present application enhances the wear resistance, impact resistance, corrosion resistance and hardness of the polishing pad by mixing polyurethane prepolymer, silane-terminated polyurethane prepolymer, filler, foaming agent, curing agent and foam leveling agent. At the same time, it can maintain the physical properties of the polishing pad stable in a high temperature environment, prevent the polishing pad from deformation, softening or embrittlement due to temperature changes, and greatly improve the service life of the polishing pad. DETAILED DESCRIPTION

[0031] Preparation Example Polybutylene adipate was purchased from Shanghai Jieshikai Reagent Co., Ltd. with the model number KA640173-100g.

[0032] Hydroxyl-terminated polybutadiene was purchased from Hubei Xinhongli Chemical Co., Ltd. with the model number XHL0554.

[0033] Bis(hydroxyethyl)-terminated polydimethylsiloxane was purchased from Hubei Kewode Chemical Co., Ltd. under the brand Kanos.

[0034] Polytetramethylenetetrahydrofuran diol was purchased from Hubei Yongkuo Technology Co., Ltd., model number YK0106.

[0035] Preparation Example 1 A polyurethane prepolymer is prepared by the following method: After mixing 200 g of the first polyisocyanate (2,4-toluene diisocyanate), 300 g of polyester diol (polybutylene adipate), 100 g of terminal hydroxyl polybutadiene, and 1 g of the first catalyst (dibutyltin dilaurate), the temperature was raised to 70°C, and the reaction was stirred for 2 hours. Then, 10 g of the first chain extender (1,3-propylene glycol) and 30 g of hydroxy acrylate (hydroxyethyl acrylate) were added, the temperature was raised to 90°C, and the reaction was stirred for 2 hours. The temperature was lowered to 80°C, and the reaction was stirred for 30 minutes. When the viscosity reached 5000 mPa.s, the temperature was lowered to stop the reaction to obtain a polyurethane prepolymer.

[0036] Preparation Example 2-3 differs from Preparation Example 1 in that the types of raw materials, amounts used, and experimental parameters used to prepare the polyurethane prepolymer are different. The specific differences are shown in Table 1: Table 1 Types of raw materials, amounts and experimental parameters for preparing polyurethane prepolymers in Preparation Examples 1-3 Preparation Example a A silane-terminated polyurethane prepolymer is prepared by the following method: After mixing 180 g of the second polyisocyanate (2,4-toluene diisocyanate), 300 g of polyether diol (polytetrahydrofuran diol), and 1 g of the second catalyst (dibutyltin dilaurate), the temperature was raised to 70°C and stirred for reaction for 2 hours. Then, 10 g of the second chain extender (1,3-propylene glycol) was added, the temperature was raised to 90°C, and the reaction was stirred for 1 hour. Silicone polyol was added to the reactor and stirred for 3 hours. The temperature was lowered to 80°C, and 20 g of polyisocyanate (2,4-toluene diisocyanate) was added. The mixture was vacuum-stirred and stirred. When the -CNO content was less than 0.5% and the viscosity was 5000 mPa.s, the temperature was lowered to stop the reaction to obtain a silane-terminated polyurethane prepolymer.

[0037] Preparation Examples ac and a are different in the types of raw materials, amounts, and experimental parameters used to prepare the polyurethane prepolymer. The specific differences are shown in Table 2: Table 2 Types of raw materials, amounts and experimental parameters for preparing polyurethane prepolymers in Preparation Examples ac Example

[0038] Polyether modified silicone surfactant was purchased from Shandong Dayi Chemical Co., Ltd., model number DY-ET129.

[0039] Example 1 A special polishing pad for silicon substrates is prepared by the following method: S1. 500 g of the polyurethane prepolymer from Preparation Example 1, 300 g of the silane-terminated polyurethane prepolymer from Preparation Example a, 150 g of a filler (silicon dioxide), 10 g of a blowing agent (chlorodifluoromethane), 5 g of a curing agent (3,3′-dichloro-4,4′-diaminodiphenylmethane), and 30 g of a foaming agent (polyether-modified silicone surfactant) were mixed to obtain a mixture; S2. Pour the mixture into a mold, place it at a temperature of 100° C., cure it for 120 minutes, demould it, place it at 70° C., and mature it for 20 hours to obtain a polishing pad specifically for silicon substrates.

[0040] The difference between Example 2-3 and Example 1 is that the raw material types, amounts and test parameters for preparing the polishing pad for silicon substrates are different. The specific differences are shown in Table 3: Table 3 Types of raw materials, amounts and test parameters for preparing polishing pads for silicon substrates in Examples 1-3 Example 4 A polishing pad specifically for silicon substrates. This embodiment differs from embodiment 1 in that the filler is pretreated by the following method: 150 g of filler (silicon dioxide) is ground to 50 nm, then stirred with 200 g of ethanol, 45 g of a hydroxysilane coupling agent (3-hydroxypropylmethyldimethoxysilane) is added, ultrasonicated for 30 minutes, filtered, and the filter residue is collected and dried to obtain a pretreated filler.

[0041] Example 5 A polishing pad specifically for silicon substrates. This embodiment differs from Example 1 in that the filler is pretreated by the following method: 150 g of filler (silicon dioxide) is ground to 100 nm, then stirred with 300 g of ethanol, 75 g of a hydroxysilane coupling agent (3-hydroxypropyltrimethoxysilane) is added, ultrasonicated for 60 minutes, filtered, and the filter residue is collected and dried to obtain a pretreated filler.

[0042] Comparative Example Comparative Example 1 A polishing pad specially used for silicon substrates. The difference between this comparative example and the embodiment is that epoxy resin is used instead of polyurethane prepolymer.

[0043] The epoxy resin was purchased from Nantong Xingchen Synthetic Materials Co., Ltd. and its model is E-44 epoxy resin.

[0044] Comparative Example 2 A polishing pad specially used for silicon substrates. The difference between this comparative example and the embodiment is that polyurethane prepolymer is used instead of silane-terminated polyurethane prepolymer.

[0045] Polyurethane prepolymer was purchased from Shanghai Hecheng Polymer Technology Co., Ltd., model number 6295.

[0046] Detection method / test method Tensile strength and elongation at break: tested according to ASTM D638-14.

[0047] Wear resistance test: The wear resistance of the sample was measured using a Taber abrader. An H-18 ceramic grinding wheel with a load of 1.5 kg was used for abrasion. The weight loss was measured after 500 rotations at 75 rpm.

[0048] Hardness: Tested according to ISO 7619-1.

[0049] Corrosion resistance test: prepare an alkaline potassium permanganate solution (mass fraction 5.2% pH = 9), soak the polishing pad in the alkaline potassium permanganate solution for 24 hours, take out the polishing pad and ultrasonically clean it in clean water twice, each time for 10 minutes, then ultrasonically clean it in 2.5% oxalic acid solution for 10 minutes, and then ultrasonically clean it in clean water for 10 minutes to obtain the sample to be tested, and then test its wear resistance.

[0050] Temperature resistance: The silicon substrate polishing pad was placed in a 60°C environment for 3 hours, and then placed in a 30°C environment for 3 hours. This constituted one cycle. After 50 cycles, the sample was obtained and its wear resistance was tested. The experimental data is shown in Table 4: Table 4 Experimental data of Examples 1-5 and Comparative Examples 1-2 It can be seen from the experimental data of Example 1 and Comparative Examples 1-2 that by using polyurethane prepolymer and silane-terminated polyurethane prepolymer in combination, the mechanical strength, wear resistance, hardness, corrosion resistance and temperature resistance of the polishing pad for silicon substrates can be further improved, thereby greatly extending the life of the polishing pad for silicon substrates.

[0051] It can be seen from the experimental data of Example 1 and Implementations 4-5 that by adding pretreated fillers, the mechanical strength, wear resistance, hardness, corrosion resistance and temperature resistance of the silicon substrate polishing pad can be further improved, thereby greatly extending the life of the silicon substrate polishing pad.

[0052] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A polishing pad for silicon substrates, characterized in that: Prepared from the following raw materials in parts by weight: 50-60 parts polyurethane prepolymer 30-50 parts of silane-terminated polyurethane prepolymer 15-20 parts of filler 1-3 parts foaming agent 0.5-1 part of curing agent 3-4 parts of foam leveling agent.

2. The special polishing pad for silicon substrates according to claim 1, characterized in that: The polyurethane prepolymer is prepared by the following method: After mixing the first polyisocyanate, polyester diol, terminal hydroxyl polybutadiene, and the first catalyst, the temperature is raised to 70-80°C, and the mixture is stirred and reacted for 2-3 hours. Then, the first chain extender and hydroxy acrylate are added, the temperature is raised to 90-100°C, and the mixture is stirred and reacted for 2-3 hours. The mixture is cooled to 80-90°C, and the mixture is stirred and reacted for 30-40 minutes. When the viscosity reaches 5000-10000 mPa.s, the temperature is lowered to stop the reaction to obtain a polyurethane prepolymer.

3. The special polishing pad for silicon substrates according to claim 2, characterized in that: The weight parts of the raw materials used to prepare the polyurethane prepolymer are as follows: 20-30 parts of the first polyisocyanate 30-40 parts of polyester diol 10-15 parts of hydroxyl-terminated polybutadiene 0.1-0.5 parts of the first catalyst 1-2 parts of the first chain extender 3-5 parts of hydroxy acrylate.

4. The special polishing pad for silicon substrates according to claim 1, characterized in that: The silane-terminated polyurethane prepolymer is prepared by the following method: After mixing the second polyisocyanate, polyether diol, and second catalyst, the temperature is raised to 70-80°C, stirred and reacted for 2-3 hours, and then the second chain extender is added. The temperature is raised to 90-100°C, stirred and reacted for 1-2 hours. The organosilicon polyol is added to the reactor and stirred for 3-5 hours. The temperature is lowered to 80-90°C, and the second polyisocyanate is added. The mixture is vacuum-treated and stirred. When the -CNO content is less than 5% and the viscosity is 5000-10000 mPa.s, the temperature is lowered to stop the reaction to obtain a silane-terminated polyurethane prepolymer.

5. The special polishing pad for silicon substrates according to claim 4, characterized in that: The weight parts of the raw materials used to prepare the silane-terminated polyurethane prepolymer are as follows: 20-30 parts of the second polyisocyanate 30-40 parts of polyether diol 0.1-0.5 parts of the second catalyst 1-2 parts of the second chain extender 10-15 parts of silicone polyol.

6. The dedicated polishing pad for silicon substrates according to claim 1, characterized in that: The filler is pretreated by the following method: The filler is ground to 50-100 nm, stirred with ethanol, and a hydroxy silane coupling agent is added. The process is ultrasonicated for 30-60 minutes, filtered, and the filter residue is collected and dried to obtain a pretreated filler.

7. The polishing pad for silicon substrates according to claim 1, wherein: The foaming agent includes at least one of hydrochlorofluorocarbons, hydrofluorocarbons, alkanes or liquid carbon dioxide.

8. The polishing pad for silicon substrates according to claim 1, wherein: The curing agent is one of 3,3′-dichloro-4,4′-diaminodiphenylmethane, dimethylthiotoluenediamine or diethyltoluenediamine.

9. The dedicated polishing pad for silicon substrates according to claim 1, characterized in that: The foam leveling agent is a polyether-modified organic silicon surfactant.

10. A method for preparing a polishing pad specifically for silicon substrates according to any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: S1, uniformly mixing a polyurethane prepolymer, a silane-terminated polyurethane prepolymer, a filler, a foaming agent, a curing agent and a foam leveling agent to obtain a mixture; S2. Pour the mixture into a mold, place it at a temperature of 100-110° C., cure it for 120-180 minutes, demold it, and mature it at 70-90° C. for 20-30 hours to obtain a polishing pad specifically for silicon substrates.

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