Porous epoxy polyurethane polishing pad base material, preparation method and application

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a novel chemical mechanical polishing pad which is used for polishing at least one substrate selected from a magnetic substrate, an optical substrate and a semiconductor substrate. The method aims at solving the problems that in the prior art, due to the fact that bubbles of a base material in the grinding and polishing field are not uniform in volume and not uniform in distribution, the microstructure of the base material is not stable, the performance of the base material in the grinding and polishing field is reduced, and the abrasion attenuation frequency is increased. The invention relates to a porous epoxy polyurethane polishing pad base material as well as a preparation method and application of the porous epoxy polyurethane polishing pad base material. A polyurethane prepolymer is terminated through an epoxy modifier, and an epoxy group replaces a traditional NCO group to participate in a curing reaction; the problem that large pores are formed in the polishing pad due to the fact that NCO groups react with moisture in air to generate COgas is fundamentally avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor manufacturing, and relates to a preparation method of a polishing pad substrate, in particular to a porous epoxy polyurethane polishing pad substrate, a preparation method and uses thereof. Background Art

[0002] In the integrated circuit manufacturing process, a chemical mechanical polishing (CMP) system usually includes three precision polishing processes, and its core process parameters (including polishing pressure, polishing pad material selection, structural configuration and hardness control) need to be precisely adjusted according to the differentiated objectives of each process. As the core consumable of the CMP process, the physical and chemical properties of the polishing pad directly determine the surface planarization quality of the wafer.

[0003] The technical standard configuration of traditional CMP includes a polishing head assembly, a rotating table and a fluid delivery system. Among them, the polishing head fixes the wafer substrate by adsorption or other methods, so that its polishing surface contacts the polishing layer of the polishing pad arranged on the table and maintains a preset contact pressure. During the process, the polishing liquid is evenly distributed on the surface of the polishing pad through a precision dispensing system and penetrates into the wafer-polishing layer interface area under the action of centrifugal force. By driving the relative rotational movement of the wafer and the polishing pad, an annular polishing track is formed on the surface of the wafer, and the precise control of the surface microtopography is achieved by the synergistic action of the chemical corrosion and mechanical grinding of the polishing medium.

[0004] U.S. Patent No. US20060442076A discloses a polyurethane polishing pad, which includes a polymer matrix having an upper polishing surface; the top polishing surface has polymeric polishing abrasive grains or forms polymeric polishing abrasive grains after abrasive conditioning. The polymeric polishing abrasive grains extend from the polymer matrix and represent the part that can contact the top polishing surface of the substrate during polishing. The polymeric polishing particles are from a polymeric material, and its overall tensile strength is at least 6500 psi (44.8 MPa), and the overall tear strength is at least 250 lb / in.

[0005] However, the existing polyurethane polishing pad manufacturing technology still has the following technical problems: Defects in cell structure control: The side reaction of isocyanate (NCO) groups in the prepolymer system with residual moisture in the system or environmental moisture will cause abnormal gas release, forming abnormal cell structures with oversized dimensions. Such structural defects will cause multiple negative effects: a) Local abrasive aggregation leads to a significant increase in the risk of surface scratching; b) Uneven pressure distribution causes an abnormal increase in surface waviness.

[0006] Curing process instability: The high reactivity of NCO groups makes it difficult to control the reaction kinetics during the high-temperature curing stage, specifically manifested as differences in local crosslinking density, uneven distribution of residual stress, and excessive dispersion of mechanical properties. These defects directly lead to a decline in the polishing performance of the polishing pad and difficulty in ensuring the performance consistency between batches.

[0007] Microscopic texture decay: The surface groove structure formed by traditional processes undergoes plastic deformation under continuous mechanical stress, severely restricting process stability.

[0008] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, although the inventors studied a large number of documents and patents when making this invention, due to space limitations, all details and contents are not listed in detail. However, this does not mean that this invention does not possess the features of these prior arts. On the contrary, this invention already possesses all the features of the prior arts, and the applicant reserves the right to add relevant prior arts in the background art. Summary of the Invention

[0009] Based on the above technical problems, the present invention relates to a novel chemical mechanical polishing pad, which is used for polishing at least one of substrates selected from magnetic substrates, optical substrates, and semiconductor substrates. The present invention aims to solve the problems of unstable microstructure of substrates in the prior art in the fields of grinding and polishing caused by uneven bubble volume and distribution of substrates, thereby causing a decline in the performance of substrates in the fields of grinding and polishing and an increase in the wear attenuation frequency.

[0010] One of the objectives of the present invention is to provide a porous epoxy polyurethane polishing pad substrate, the components of which are selected from the following groups: 1 to 30 parts by weight of diol, 2 to 25 parts by weight of diisocyanate compounds, 1 to 5 parts by weight of epoxy modifiers, 0.4 to 3.0 parts by weight of chain extenders, 0.0001 to 0.05 parts by weight of dibutyltin dilaurate; 1 to 30 parts by weight of polyol, 2 to 25 parts by weight of diisocyanate compounds, 1 to 5 parts by weight of epoxy modifiers, 0.4 to 3.0 parts by weight of chain extenders, 0.0001 to 0.05 parts by weight of dibutyltin dilaurate.

[0011] According to a preferred embodiment, the diisocyanate compounds are selected from one or more of the following components: 1,6 - hexamethylene diisocyanate, isophorone diisocyanate, p - cyclohexyl isocyanate, toluene diisocyanate, diphenylmethane diisocyanate, tea diisocyanate, benzidine diisocyanate, 3,3'-bitolylene diisocyanate, diphenyl - 4,4 - diisocyanate, tetramethylxylylene diisocyanate, p - phenylene diisocyanate, xylylene diisocyanate; The diol is selected from one of the following components: Polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, polyester diol; The epoxy modifier is selected from one or more of the following components: Glycidol, 1,3-diglycidyl ether glycerol, propylene glycol diglycidyl ester, 1-[4-(2-hydroxyethyl)phenoxy]-2,3-epoxypropane, oxetane-3-methanol, 3-hydroxytetrahydrofuran, 2-(tetrahydro-2H-pyran-2-yl)ethanol; The chain extender is selected from one or more of the following components: Tetraethylenepentamine, triethylenediamine, 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), diethyltoluenediamine, dimethylthiotoluenediamine, 4,4-(sec-butylamino)diphenylmethane, 1,3-propanediol bis(4-aminobenzoate), 4,4-methylenedi-(2,6-diethylaniline), 4,4-methylenedi-(2,6-diisopropylaniline), 4,4-methylenedi-(2-isopropyl-6-methylaniline), 2-[2-(2-aminophenyl)thioalkyl ethylthio]aniline, 4,4'-methylenedi-(2-chloroaniline), 4,4-methylenedi(N-sec-butylaniline).

[0012] According to a preferred embodiment, the molar ratio of the NCO group of the diisocyanate compound to the hydroxyl group is 1.5 to 3.0. Preferably, the molar ratio of the NCO group of the diisocyanate compound to the hydroxyl group is 1.5. The molar ratio of the NCO group of the diisocyanate compound to the hydroxyl group is 3.0.

[0013] According to a preferred embodiment, the porous epoxy polyurethane polishing pad substrate components are selected from the following group: 3.4 parts of diphenylmethane diisocyanate, 13.5 parts of polypropylene glycol (molecular weight 1000), 1 part of glycidol, 0.01 part of dibutyltin dilaurate and 1.6 parts of tetraethylenepentamine by weight.

[0014] According to a preferred embodiment, the porous epoxy polyurethane polishing pad substrate components are selected from the following group: 7.2 parts of toluene diisocyanate, 13.2 parts of polytetrahydrofuran ether glycol (650), 3 parts of glycidol, 0.03 part of dibutyltin dilaurate and 4.8 parts of tetraethylenepentamine by weight.

[0015] According to a preferred embodiment, the porous epoxy polyurethane polishing pad substrate components further comprise not more than 5 parts of thermally expandable microspheres by weight.

[0016] One of the objects of the present invention is to provide the use of the porous epoxy polyurethane polishing pad substrate involved in the present invention in grinding or polishing.

[0017] One of the objectives of the present invention is to provide a method for preparing a porous epoxy polyurethane polishing pad substrate, which comprises the following steps: At 80°C, mix 2-25 parts by weight of a diisocyanate compound with 1-30 parts of a polyol, or mix 2-25 parts by weight of a diisocyanate compound with 1-30 parts of a diol; Add 1-5 parts of an epoxy modifier; Add 0.0001-0.05 part of dibutyltin dilaurate and 0.4-3.0 parts of a chain extender; Mix at a set rotation speed of 1000 rpm for 1-2 min; Cure by thermal cycle heating.

[0018] One of the objectives of the present invention is to provide a porous epoxy polyurethane polishing pad prepared using the porous epoxy polyurethane polishing pad substrate involved in the present invention.

[0019] According to a preferred embodiment, the thermal cycle heating cure includes: The first stage: heat at 110°C and hold for 12 h; The second stage: adjust the temperature to 90°C and hold for 6 h.

[0020] According to a preferred embodiment, at 80°C, mix 3.4 parts by weight of a diisocyanate compound which is toluene diisocyanate with 13.5 parts of polypropylene glycol, and then add 0.01 part of dibutyltin dilaurate and 1.6 parts of a chain extender which is tetraethylenepentamine. Preferably, in this step, 1 part of glycidol is also added.

[0021] According to a preferred embodiment, at 80°C, mix 7.2 parts by weight of a diisocyanate compound which is toluene diisocyanate with 13.2 parts of polytetrahydrofuran ether glycol (650), and then add 0.03 part of dibutyltin dilaurate and 4.8 parts of a chain extender which is tetraethylenepentamine. Preferably, in this step, 3 parts of glycidol are also added.

[0022] According to a preferred embodiment, mix at a set rotation speed of 1000 rpm for 1 min.

[0023] One of the objectives of the present invention is to provide a substrate for preparing a polishing pad, and the density of the substrate is not less than 0.63 g / cm 3 .

[0024] The present invention relates to a method for preparing a novel chemical mechanical polishing pad or a polishing pad substrate, which caps the polyurethane prepolymer with an epoxy modifier to replace the traditional NCO group with an epoxy group to participate in the curing reaction, fundamentally avoiding the problem of the formation of large pores inside the polishing pad due to the reaction of the NCO group with moisture in the air to generate CO2 gas. Specifically, the beneficial effects of this technical solution are as follows: 1. Eliminate the side reaction of the NCO group and improve the pore uniformity (Reaction formula: R-NCO + H2O → R-NH2 + CO2↑) The curing of the current polyurethane polishing pad depends on the reaction of the unreacted NCO group in the prepolymer with a chain extender (such as an amine) or environmental moisture, and the reaction of the NCO group with moisture will generate CO2 gas. The currently used polyurethane polishing pad matrix generally contains a large number of pores, and these pores have different sizes and uneven distributions, affecting the density and stiffness of the polishing pad, resulting in changes in the height of the rough peaks on the surface of the polishing pad and causing surface topography measurement errors (Research Progress of Chemical Mechanical Polishing Pads) http: / / wap.qikanzj.com )

[0025] The present invention caps the polypropylene glycol prepolymer capped with tolylene diisocyanate with glycidol to convert the NCO group at the end of the prepolymer into an epoxy group (Reaction formula: R-NCO + HO-CH2-CH(O)-CH2-OH → R-O-CH2-CH(O)-CH2-O- + NH3↑), making the curing reaction completely dependent on the addition reaction of the epoxy group with an amine chain extender (Reaction formula: epoxy group + NH2-R → crosslinked network). Since the epoxy group is insensitive to moisture, the prepolymer after capping basically does not generate CO2 gas in the chain extension reaction, thus avoiding the formation of large pores and significantly improving the uniformity of the pores inside the polishing pad.

[0026] 2. Optimize the curing process and enhance the stability of the crosslinked network The present invention adopts a staged temperature-rising curing process. Among them, in the first stage (heating to 110°C within 30 minutes and maintaining for 12 hours), high temperature promotes the rapid ring-opening reaction of the epoxy group with tetraethylenepentamine chain extender to form a preliminary crosslinked network; in the second stage (cooling to 90°C and maintaining for 6 hours), low temperature slowly releases the residual stress, reduces microcracks, and at the same time ensures that the chain extender fully penetrates to the end of the prepolymer chain segment to increase the crosslinking density.

[0027] 3. Precisely control the pore structure and improve the polishing performance By precisely controlling the amount of hollow microspheres and combining a curing system without CO2 gas interference, the present invention achieves a uniform distribution of pore sizes. Compared with traditional processes, the pore uniformity of this technical solution is significantly improved. The uniform pore structure can reduce local pressure fluctuations during the polishing process, thereby reducing the scratch rate on the substrate surface, and is particularly suitable for high-precision polishing scenarios such as magnetic substrates and optical substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the synthesis route of the epoxy polyurethane porous material of the present invention; Figure 2 is a stress-strain curve diagram of the epoxy polyurethane porous material with different microsphere contents of the present invention; Figure 3 is a density schematic diagram of the epoxy polyurethane porous material with different microsphere contents of the present invention; Figure 4 is a hardness schematic diagram of the epoxy polyurethane porous material with different microsphere contents of the present invention; Figure 5 is a compression rate schematic diagram of the epoxy polyurethane porous material with different microsphere contents of the present invention; Figure 6 is a SEM photograph of the epoxy polyurethane porous material with different microsphere contents of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] In the description of the present invention, the terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0030] Figure 1 Shows the synthesis route and preparation process of the substrate (epoxy polyurethane porous material) involved in the present invention. Specifically, polyether diol and isocyanate react to form an NCO group-terminated prepolymer-1, and then react to form an epoxy group-terminated prepolymer-2 under the action of an epoxy modifier (such as propylene oxide, etc.). The epoxy group-terminated prepolymer-2 is mixed with thermally expandable microspheres and tetraethylenepentamine respectively to form an epoxy polyurethane porous material. The material formed by the reaction becomes a polishing pad with a polishing layer after being processed by the casting and curing process steps.

[0031] Example 1 In this example, the following steps are used to prepare a polishing pad without a filled polishing layer: (1) At 80°C, 199.7 g of polytetrahydrofuran ether glycol prepolymer is mixed evenly with 29.6 g of glycidol, wherein the polytetrahydrofuran ether glycol prepolymer is terminated with toluene diisocyanate (TDI) with 8.4% by weight of unreacted NCO groups; (2) Add 0.23 g of dibutyltin dilaurate to the above mixture and continue to mix at 80 °C for 1 hour; (3) Add 15.14 g of tetraethylenepentamine (TETA) to the mixture and mix in a vortex mixer at a set speed of 1000 rpm for 1 minute; Inject the above mixture into a pre-prepared mold; Place the mold containing the mixture in an oven and cure it using thermally cycled air.

[0032] The curing process is divided into two stages: The first stage: Raise the curing temperature from room temperature to 110 °C within 30 minutes and hold for 12 hours; The second stage: Adjust the curing oven temperature to 90 °C and hold for 6 hours.

[0033] Example 2 In this example, a polishing pad filled with a polishing layer is prepared using the following steps: (1) At 80 °C, uniformly mix 199.7 g of polytetrahydrofuran ether glycol prepolymer with 29.6 g of glycidol, wherein the polytetrahydrofuran ether glycol prepolymer is capped with toluene diisocyanate (TDI) having 8.4% by weight of unreacted NCO groups; (2) Add 0.23 g of dibutyltin dilaurate to the above mixture and continue to mix at 80 °C for 1 hour; (3) Add 15.14 g of tetraethylenepentamine (TETA), and 2.45 g of hollow microspheres (AkzoNobel) to the mixture and mix in a vortex mixer at a set speed of 1000 rpm for 1.5 minutes; Inject the above mixture into a pre-prepared mold; Place the mold containing the mixture in an oven and cure it using thermally cycled air.

[0034] The curing process is divided into two stages: The first stage: Raise the curing temperature from room temperature to 110 °C within 30 minutes and hold for 12 hours; The second stage: Adjust the curing oven temperature to 90 °C and hold for 6 hours.

[0035] Example 3 In this example, a polishing pad filled with a polishing layer is prepared using the following steps: (1) At 80 °C, uniformly mix 199.7 g of polytetrahydrofuran ether glycol prepolymer with 29.6 g of glycidol, wherein the polytetrahydrofuran ether glycol prepolymer is capped with toluene diisocyanate (TDI) having 8.4% by weight of unreacted NCO groups; (2) Add 0.23 g of dibutyltin dilaurate to the above mixture and continue to mix at 80 °C for 1 hour; (3) Add 15.14 g of tetraethylenepentamine (TETA) and 6.12 g of hollow microspheres (AkzoNobel) to the mixture and mix in a vortex mixer at a set speed of 1000 rpm for 1.5 minutes; Inject the above mixture into a pre-prepared mold; Place the mold containing the mixture in an oven and cure it using thermally cycled air.

[0036] The curing process is divided into two stages: The first stage: Raise the curing temperature from room temperature to 110 °C within 30 minutes and hold for 12 hours; The second stage: Adjust the curing oven temperature to 90 °C and hold for 6 hours.

[0037] Example 4 The preparation method involved in this example is the same as that of Example 2 above, except for the different raw material ratios used.

[0038] (1) At 80 °C, mix 189.7 g of polypropylene glycol prepolymer with 29.6 g of glycidol evenly, where the polypropylene glycol prepolymer is capped with toluene diisocyanate containing 8.86% by weight of unreacted NCO groups; (2) Add 0.43 g of dibutyltin dilaurate to the above mixture and continue to mix at 80 °C for 1 hour; (3) Add 11.85 g of tetraethylenepentamine chain extender and 2.31 g of hollow microspheres (AkzoNobel) to the mixture and mix in a vortex mixer at a set speed of 1000 rpm for 1.5 minutes; Inject the above mixture into a pre-prepared mold; Place the mold containing the mixture in an oven and cure it using thermally cycled air.

[0039] The curing process is divided into two stages: The first stage: Raise the curing temperature from room temperature to 110 °C within 30 minutes and hold for 12 hours; The second stage: Adjust the curing oven temperature to 90 °C and hold for 6 hours.

[0040] Example 5 The preparation method involved in this example is the same as that of Example 2 above, except for the different raw material ratios used.

[0041] In this example, the following steps are used to prepare a polishing pad filled with a polishing layer: (1) At 80 °C, 269.7 g of polytetrahydrofuran ether glycol prepolymer was uniformly mixed with 29.6 g of glycidol. Among them, the polytetrahydrofuran ether glycol prepolymer was capped with toluene diisocyanate having 6.23% by weight of unreacted NCO groups; (2) 0.3 g of dibutyltin dilaurate was added to the above mixture, and the mixture was continuously mixed at 80 °C for 1 hour; (3) 15.14 g of tetraethylenepentamine chain extender and 7.86 g of hollow microspheres (AkzoNobel) were added to the mixture, and the mixture was mixed in a vortex mixer at a set rotation speed of 1000 rpm for 2 minutes; The above mixture was injected into a pre-prepared mold; The mold containing the mixture was placed in an oven and cured using hot circulating air.

[0042] The curing process was divided into two stages: The first stage: The curing temperature was raised from room temperature to 110 °C within 30 minutes and maintained for 12 hours; The second stage: The temperature of the curing oven was adjusted to 90 °C and maintained for 6 hours.

[0043] The stress, mechanical properties, density, Shore hardness, and compression ratio of the epoxy polyurethane porous materials with different microsphere contents in Example 2 (epoxy polyurethane porous material with 1% microsphere content) and Example 3 (epoxy polyurethane porous material with 2.5% microsphere content) were detected. The results Figures 2 - 5 and Table 1. EPPU-1% represents the sample in Example 2; EPPU-2.5% represents the sample in Example 3.

[0044] Table 1 Mechanical property parameters of epoxy polyurethane (EPPU) porous materials with different microsphere contents

[0045] According to Figure 2 It can be seen that the strain value of the EPPU-2.5% material reached the limit (225%) when the pressure was close to 3 Mpa, while the strain value of the EPPU-1% material reached the limit (300%) when the pressure was close to 5 Mpa. The above results show that the EPPU-1% material exhibited greater strain capacity (300%) at a higher pressure (5 MPa), indicating that its ductility is better than that of the EPPU-2.5% material.

[0046] According to Table 1, the tensile strength of the EPPU-2.5% material is 2.82 Mpa, the tensile strain is 213.3%, and the Young's modulus is 4.67 Mpa. The tensile strength of the EPPU-1% material is 5.11 Mpa, the tensile strain is 296.9%, and the Young's modulus is 5.01 Mpa. The tensile strength, tensile strain, and Young's modulus of the EPPU-1% material are all higher than those of the EPPU-2.5% material. The above results indicate that the EPPU-1% material has better tensile force resistance, ductility, and rigidity than the EPPU-2.5% material. This result is consistent with Figure 2 the results shown.

[0047] According to Figure 3 it can be seen that the density of the EPPU-2.5% material is 0.63 g / cm 3 . The density of the EPPU-1% material is 0.86 g / cm 3 . The above results show that the EPPU-1% material is denser and has higher strength.

[0048] According to Figure 4 it can be seen that the Shore hardness of the EPPU-2.5% material is 15.9 D. The Shore hardness of the EPPU-1% material is 21.2 D. The above results show that the EPPU-1% material performs better in terms of compressive and wear resistance than the EPPU-2.5% material.

[0049] According to Figure 5 it can be seen that the compression rate of the EPPU-2.5% material is 15.7%. The compression rate of the EPPU-1% material is 10.7%. The above results show that the EPPU-1% material deforms less when compressed than the EPPU-2.5% material.

[0050] According to Figure 6 the SEM of the materials shown, it can be seen that compared with the EPPU-2.5% material, the EPPU-1% material has fewer pores, improved pore size uniformity, and relatively uniform pore distribution.

[0051] The polishing pad substrate of the present invention realizes the synergistic optimization of wafer polishing performance by controlling the tensile strength within 3 - 15 MPa, regulating the elongation at break within 100 - 300%, optimizing the density to 0.60 - 0.90 g / cm³, and adjusting the hardness within the range of 20 - 60 D. Among them, the synergistic effect of tensile strength and elongation at break endows the substrate with excellent mechanical stability and anti-deformation ability, ensuring the lasting consistency of the cushion structure during the polishing process; the low-density characteristic is conducive to forming a uniformly distributed microporous structure, which plays roles such as storing and transporting the polishing liquid, discharging the removed substances, and ensuring the stability of the polishing process; the moderate hardness range reduces the risk of wafer scratching while ensuring the surface support strength. In particular, when the microsphere addition amount is 1%, the above performance parameters reach the best balance state, which can significantly improve the material removal rate of the wafer surface, obtain sub-nanometer surface roughness and ultra-high flatness, and at the same time effectively reduce the generation of micro-scratches and surface defects during the polishing process. Experiments on the material properties show that this parameter combination enables the polishing pad to have both high cutting efficiency and low damage characteristics, meeting the stringent requirements of advanced processes for the surface quality of wafers. The high hardness, high tensile strength, high tensile strain, low compression ratio, and high density of the EPPU-1% material indicate that this material is suitable for high-precision and high-load polishing tasks, especially in fields such as semiconductor wafers and optical lenses that have high requirements for the hardness, strength, and stability of the polishing pad.

[0052] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the description and drawings of the present invention are illustrative and do not constitute a limitation on the claims. The protection scope of the present invention is defined by the claims and their equivalents.

Claims

1. A porous epoxy polyurethane polishing pad substrate, characterized in that: Its components are selected from the following groups: According to weight, 1 to 30 parts of diol, 2 to 25 parts of diisocyanate compound, 1 to 5 parts of epoxy modifier, 0.4 to 3.0 parts of chain extender, 0.0001 to 0.05 parts of dibutyltin dilaurate; According to weight, 1 to 30 parts of polyol, 2 to 25 parts of diisocyanate compound, 1 to 5 parts of epoxy modifier, 0.4 to 3.0 parts of chain extender, and 0.0001 to 0.05 parts of dibutyltin dilaurate.

2. The porous epoxy polyurethane polishing pad substrate according to claim 1, characterized in that: The diisocyanate compound is selected from one or more of the following components: 1,6-hexanediisocyanate, isophoronediisocyanate, p-cyclohexylisocyanate, toluenediisocyanate, diphenylmethanediisocyanate, teadiisocyanate, toluidinediisocyanate, 3,3'-ditolylenediisocyanate, diphenyl-4,4-diisocyanate, tetramethylxylenediisocyanate, p-phenylenediisocyanate, xylenediisocyanate; The diol is selected from one of the following components: Polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, polyester diol; The epoxy modifier is selected from one or more of the following components: Glycidol, 1,3-diglycidyl ether glycerol, propylene glycol diglycidyl ester, 1-[4-(2-hydroxyethyl)phenoxy]-2,3-epoxypropane, oxetane-3-methanol, 3-hydroxytetrahydrofuran, 2-(tetrahydro-2H-pyran-2-yl)ethanol; The chain extender is selected from one or more of the following components: Tetraethylenepentamine, triethylenediamine, 4,4'-methylenebis-(2-chloroaniline), 4,4'-methylenebis-(3-chloro-2,6-diethylaniline), diethyltoluenediamine, dimethylthiotoluenediamine, 4,4-(sec-butylamino)diphenylmethane, 1,3-propylene glycol di-(4-aminobenzoate), 4,4-methylene-bis-(2,6-diethylaniline), 4,4-methylene-bis-(2,6-diisopropylaniline), 4,4-methylene-bis-(2-isopropyl-6-methylaniline), 2-[2-(2-aminophenyl)sulfanylethylsulfanyl]aniline, 4,4'-methylene-bis-(2-chloroaniline), 4,4-methylenebis(N-sec-butylaniline).

3. The porous epoxy polyurethane polishing pad substrate according to claim 1, characterized in that: The molar ratio of the NCO group to the hydroxyl group of the diisocyanate compound is 1.5 to 3.

0.

4. The porous epoxy polyurethane polishing pad substrate according to claim 1, characterized in that: The porous epoxy polyurethane polishing pad substrate component is selected from the following group: 3.4 parts by weight of toluene diisocyanate, 13.5 parts of polypropylene glycol, 1 part of propylene oxide, 0.01 parts of dibutyltin dilaurate and 1.6 parts of tetraethylenepentamine.

5. The porous epoxy polyurethane polishing pad substrate according to claim 1, characterized in that: The porous epoxy polyurethane polishing pad substrate component further comprises no more than 5 parts by weight of heat-expandable microspheres.

6. Use of the porous epoxy polyurethane polishing pad substrate according to any one of claims 1 to 5 in grinding or polishing.

7. A method for preparing a porous epoxy polyurethane polishing pad substrate, characterized in that: The preparation method comprises the following steps: Under an environment of 80° C., 2 to 25 parts by weight of a diisocyanate compound is mixed with 1 to 30 parts by weight of a polyol, or 2 to 25 parts by weight of a diisocyanate compound is mixed with 1 to 30 parts by weight of a diol; Add 1 to 5 parts of epoxy modifier; Add 0.0001-0.05 parts of dibutyltin dilaurate and 0.4-3.0 parts of chain extender; Mix at a set speed of 1000 rpm for 1-2 min; Thermal cycle heating cure.

8. The preparation method according to claim 7, characterized in that: The thermal cycle heating curing comprises: Stage 1: heating at 110°C for 12 h; Stage 2: Adjust the temperature to 90°C and maintain for 6 h.

9. The preparation method according to claim 7 or 8, characterized in that: The molar ratio of the NCO group to the hydroxyl group of the diisocyanate compound is 1.5 to 3.

0.

10. A substrate for preparing a polishing pad, characterized in that: The density of the substrate prepared by the substrate according to any one of claims 1 to 5 or the preparation method according to claims 7 to 9 is not less than 0.63 g / cm 3 .

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