Hyperbranched carboxyl-terminated polyesters, liquid waxes containing the same and methods of making and using the same

Abstract

The application provides a hyperbranched carboxyl-terminated polyester, a liquid wax containing the polyester, and a preparation method and application thereof. The hyperbranched carboxyl-terminated polyester is obtained by esterification of a binary acid and an alcohol amine, and then esterification with adipic acid, and the terminal functional groups are all carboxyl groups. The liquid wax comprises 20-60 parts of the hyperbranched carboxyl-terminated polyester, 5-20 parts of a bonding resin, 10-60 parts of a polar solvent, 0.1-1 parts of a leveling agent, and 0.2-1 parts of modified polydimethylsiloxane by mass. The hyperbranched carboxyl-terminated polyester is rich in carboxyl groups at the terminal, and is easily hydrolyzed under alkaline conditions, so that the liquid wax can be quickly and completely cleaned by an alkaline aqueous solution. Meanwhile, the acrylate modified polydimethylsiloxane endows the liquid wax with good coating performance and anti-sticking performance, effectively preventing material back-staining in the cleaning process. The liquid wax has the advantages of short cleaning time, no residue, and good process adaptability in wafer thinning and other temporary bonding processes.

Description

Technical Field

[0001] This invention relates to liquid wax technology, and more particularly to a hyperbranched end-carboxyl polyester, a liquid wax containing the polyester, and its preparation method and application. Background Technology

[0002] As the performance of global integrated circuit products continues to improve and their internal physical linewidths shrink, temporary bonding technology has received increasing attention as a key process in advanced manufacturing and packaging. Temporary bonding processes include bonding and debonding. Based on different debonding methods, they can be categorized into mechanical debonding, chemical debonding, thermal slip debonding, and laser debonding. Among these, thermal slip debonding and ultraviolet laser debonding are the two most widely used temporary bonding material system solutions.

[0003] The United States began developing temporary bonding materials in the early 20th century, possessing a wide range of thermoplastic adhesives and complementary mechanical and laser-released layer products suitable for various application conditions and substrate types. Its temporary bonding adhesives primarily operate in three temperature ranges: high temperature (HT, 175°C-225°C), ultra-high temperature (VHT, 225°C-350°C), and ultra-high temperature (UHT, 350°C-400°C and above). However, the bonding process for these adhesives is complex, requiring significant equipment investment and sophisticated bonding and debonding techniques. The adhesives need to be compatible with the equipment, resulting in limited versatility. With the development of temporary bonding adhesive technology in China, domestic temporary bonding materials and laser-emitting materials exhibit excellent thermal stability. Temporary bonding adhesives can withstand process temperatures above 300℃ and can be verified through thinning and various back-side processes, such as wafer thinning (below 50μm), high-temperature high-vacuum, dry etching, PVD, and PECVD, demonstrating high process reliability. However, the bonding adhesive requires special cleaning agents, resulting in significant residue after debonding and making cleaning difficult. Therefore, developing liquid waxes that possess high-temperature resistance, corrosion resistance, and residue-free cleaning capabilities is a crucial consideration in liquid wax development.

[0004] Patent CN120737764A discloses a corrosion-resistant and heat-resistant temporary bonding adhesive. It uses a mixed solvent system of low-polarity solvent and non-polar solvent, compounded with low molecular weight resin and medium molecular weight resin. Through the principle of similar compatibility, it effectively increases the solubility of the resin, increases the solid content of the bonding adhesive, and maintains a low viscosity. At the same time, the surface tension is lower after mixing, and it has lower flow resistance in spin coating, ensuring that the bonding adhesive is evenly spread and penetrated on the wafer surface. In addition, due to the presence of low molecular weight resin, the bonding adhesive can be quickly dissolved in non-polar solvent after debonding, thereby achieving dissolution and detachment at room temperature and improving the cleaning efficiency of the wafer after debonding. However, ultrasonic immersion cleaning in xylene is required during cleaning. Yang Chunming et al. pointed out in the article "A Review of Wafer Dewaxing Technology" [J]. Tianjin Science and Technology, 2008, 35(3):74-75. that the mainstream liquid wax cleaning agent is a water-soluble special dewaxing liquid. Mixing this special dewaxing liquid with water in a certain proportion and ultrasonic cleaning can achieve the purpose of dewaxing the wafer. However, current ultrasonic cleaning for dewaxing is time-consuming and suffers from some wafer re-adhesion. It is evident that existing liquid waxes generally suffer from problems such as difficult cleaning after debonding, long cleaning times, easy residue buildup, and the need for special cleaning agents or organic solvents. Summary of the Invention

[0005] The purpose of this invention is to address the problem of difficult cleaning of traditional liquid waxes after debonding, and to propose a hyperbranched terminal carboxyl polyester, whose terminal functional groups are all carboxyl groups, which are easily hydrolyzed under alkaline conditions, so that liquid waxes containing this polyester can be thoroughly cleaned by alkaline aqueous solution in a short time with almost no residue.

[0006] It should be noted that, in this invention, unless otherwise specified, the specific meaning of "comprising" in relation to composition and description includes both open-ended meanings such as "comprising," "including," etc., and closed-ended meanings such as "composed of," "consisting of," etc., and similar meanings.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a hyperbranched end-carboxyl polyester, which is obtained by esterification of a dicarboxylic acid and an alkanolamine followed by esterification with adipic acid.

[0008] Furthermore, the hyperbranched carboxyl-terminated polyester is obtained by esterifying a dicarboxylic acid containing heteroatoms or carbon-carbon double bonds with an alkanolamine containing at least two hydroxyl groups, followed by esterification with adipic acid.

[0009] Furthermore, the molar ratio of the dicarboxylic acid, the alcohol amine, and the adipic acid is (1.7~3):(1~2):(1.5~2).

[0010] Furthermore, the preferred molar ratio of the dicarboxylic acid, the alcohol amine, and the adipic acid is 2:1:1.5.

[0011] Furthermore, the dicarboxylic acid is selected from iminodiacetic acid and / or maleic acid.

[0012] Furthermore, the alkanolamine is selected from one or more of triethanolamine, diethanolamine, triisopropanolamine, and diisopropanolamine. Another objective of the invention is to disclose the application of a hyperbranched end-carboxyl polyester in the field of wafer thinning. Another object of the present invention discloses a method for preparing a hyperbranched carboxyl-terminated polyester, comprising the following steps: Dicarboxylic acid and alcoholamine are dissolved in a solvent by stirring. The mixture is heated to 110-150°C and reacted for 2-6 hours under an inert atmosphere. Then, adipic acid is added and the reaction is continued at 110-150°C for another 2-6 hours. The mixture is then evaporated and concentrated, and dried under vacuum at 100-140°C to prepare hyperbranched carboxyl-terminated polyester.

[0013] Furthermore, the solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0014] Furthermore, the amount of solvent used is 30%-80% of the total mass of the reactants, and the reactants include diacids, alkanolamines, and adipic acid.

[0015] Furthermore, the inert atmosphere is nitrogen. Another objective of the invention is to disclose the application of the hyperbranched carboxyl-terminated polyester prepared by the above method in the field of wafer thinning. Another object of the present invention discloses a liquid wax comprising, by weight, the following components: 20-60 parts of hyperbranched carboxyl-terminated polyester; 5-20 parts of bonding resin; 10-60 parts polar solvent; 0.1 to 1 part leveling agent; 0.2 to 1 part of modified polydimethylsiloxane.

[0016] Furthermore, the hyperbranched end-carboxyl polyester comprises 20 to 40 parts.

[0017] Furthermore, the bonding resin is selected from one or more of modified petroleum resin, modified terpene resin, terpene phenol resin and modified rosin resin.

[0018] Furthermore, the modified petroleum resin is selected from one or more of the Arakawa Chemical p-series, Mitsui Chemicals 6000 series, and Zero series.

[0019] Furthermore, the amount of the adhesive resin is 5 to 15 parts.

[0020] Furthermore, the polar solvent is selected from one or more of dodecene, D-limonene, dipentene, cyclododecene, butyl acetate, isopropyl acetate, n-butyl propionate, cyclopentanone, diethylene glycol butyl ether, dipropylene glycol methyl ether, ethylene glycol ethyl ether acetate, and diethylene glycol ethyl ether.

[0021] Furthermore, the polar solvent is 20 to 60 parts.

[0022] Furthermore, the leveling agent is selected from one or more of polyester-modified polysiloxane leveling agents, polyether-modified polysiloxane leveling agents, aralkyl-modified polymethylalkylsiloxane leveling agents, and polyether-modified polymethylalkylsiloxane leveling agents.

[0023] Furthermore, the leveling agent is 0.2 to 0.8 parts.

[0024] Furthermore, the modified polydimethylsiloxane is acrylate-modified polydimethylsiloxane.

[0025] Furthermore, the acrylate-modified polydimethylsiloxane is prepared by reacting acrylate compounds with siloxane compounds.

[0026] Furthermore, the molar ratio of the acrylate compound to the siloxane compound is 1:1 to 1:2.

[0027] Furthermore, the acrylate compound is selected from one or more of allyl methacrylate, methyl methacrylate, ethyl methacrylate, and butyl acrylate.

[0028] Furthermore, the siloxane compound is selected from one or more of polymethylhydrosiloxane (CAS: 63148-57-2), tetramethyldisiloxane, hexamethylcyclotrisiloxane, and 3-mercaptopropylmethyldimethoxysilane.

[0029] Furthermore, the preparation method of the acrylate-modified polydimethylsiloxane includes the following steps: Acrylate-modified polydimethylsiloxane was prepared by adding acrylate compounds, benzene compounds, polymerization inhibitors and catalysts into a reactor under N2 protection, and adding siloxane compounds dropwise at 50-85°C for 6-10 hours.

[0030] Furthermore, the acrylate compound is selected from one or more of allyl methacrylate, methyl methacrylate, ethyl methacrylate, and butyl acrylate.

[0031] Furthermore, the benzene compounds are selected from one or more of toluene, xylene, and styrene.

[0032] Furthermore, the amount of benzene is 2 to 10% of the molar amount of the acrylate compound.

[0033] Furthermore, the polymerization inhibitor is selected from p-methoxyphenol and / or 3-methyl-3-trimethylsiloxy-1-butyne.

[0034] Furthermore, the amount of the polymerization inhibitor is 1% to 5% of the molar amount of the acrylate compound.

[0035] Furthermore, the catalyst is selected from triphenylphosphine rhodium chloride and / or H2PtCl6·6H2O.

[0036] Furthermore, the amount of catalyst used is 0.02 to 0.06 times the molar amount of the acrylate compound, preferably 0.04 times.

[0037] Furthermore, the reaction temperature is preferably 60~70℃.

[0038] Furthermore, the modified polydimethylsiloxane is present in amounts of 0.2 to 0.8 parts.

[0039] This invention provides a liquid wax that is easily cleaned with an alkaline aqueous solution. It comprises a hyperbranched carboxyl-terminated polyester, wherein the terminal functional groups of the hyperbranched carboxyl-terminated polyester are all carboxyl groups. Under alkaline conditions, the carboxyl and ester groups in the hyperbranched carboxyl-terminated polyester react with the hydroxyl groups in the cleaning solution, resulting in rapid hydrolysis. Furthermore, this liquid wax also contains acrylate-modified polydimethylsiloxane, making it easy to apply while exhibiting a large water contact angle and low surface energy, thus demonstrating good anti-stick properties. Another object of the present invention is to disclose the application of the above-mentioned liquid wax in the field of wafer thinning. Another object of the present invention discloses a method for preparing liquid wax, comprising the following steps: Step (1) Mix the polar solvent, leveling agent and modified polydimethylsiloxane evenly according to the formula; Step (2) Heat the mixture from step (1) to 30~70°C, add the bonding resin and hyperbranched carboxyl-terminated polyester while stirring, and stir until a clear and transparent liquid is formed; Step (3) Cool and filter the clear and transparent liquid obtained in step (2) to obtain the liquid wax.

[0040] Furthermore, the stirring speed for mixing in step (1) is 100~300 rpm.

[0041] Furthermore, the stirring time in step (2) is 30~90 min. Another object of the present invention is to disclose the application of the liquid wax prepared by the above method in the field of wafer thinning. The present invention relates to a hyperbranched carboxyl-terminated polyester, a liquid wax containing the polyester, a method for preparing the wax, and its applications. Compared with the prior art, the present invention has the following advantages: 1) The terminal functional groups of the hyperbranched carboxyl-terminated polyester of this invention are all carboxyl groups, which readily react with hydroxyl groups in alkaline cleaning solutions to form soluble carboxylates, thus leading to rapid hydrolysis. Performance tests and comparisons are provided in the attached examples. Figure 1 As shown in the cleaning effect diagram, after ultrasonic cleaning in an alkaline cleaning solution at 60°C for 5 minutes, there is no wax residue on the surface of the silicon wafer.

[0042] 2) The liquid wax of this invention contains acrylate-modified polydimethylsiloxane, which has low surface tension and a large contact angle with water, making the liquid wax easy to apply and having a good anti-stick effect in subsequent processes, which helps to prevent material back-sticking during the cleaning process.

[0043] 3) The synergistic effect of the hyperbranched carboxyl-terminated polyester and acrylate-modified polydimethylsiloxane in this invention enables the liquid wax to achieve the effect of "short time, easy cleaning, and almost no residue". After cleaning for 5 minutes, there is no wax residue on the silicon wafer. Compared with the existing technology, which may require special cleaning agents, long-term ultrasonic cleaning, or have difficult-to-remove residues, this can effectively reduce the cleaning cost and time consumption in mass production and improve production efficiency.

[0044] In summary, the liquid wax of this invention has good application prospects and potential for large-scale industrialization in the field of thinning the back side of thin wafers. Attached Figure Description

[0045] Figure 1 Comparative images of cleaning a 4-inch sapphire crystal with liquid wax from Example 12 and Comparative Example 7 for 5 minutes are shown. The left image shows liquid wax from Comparative Example 7, and the right image shows liquid wax from Example 12.

[0046] Figure 2 The image shows the FTIR spectrum of the hyperbranched carboxyl-terminated polyester in Example 1. Detailed Implementation

[0047] The present invention will be further described below with reference to embodiments. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that: Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0048] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0049] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0050] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0051] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0052] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 15-25℃.

[0053] Unless otherwise specified, all reagents or instruments used in this instruction manual are commercially available products. Examples 1-6 Examples 1-6 disclose various hyperbranched carboxyl-terminated polyesters, prepared as follows: A dicarboxylic acid and an alkanolamine are weighed and dissolved in a solvent by stirring. The solution is then transferred to a three-necked flask equipped with a mechanical stirrer and a condenser. Under N2 protection, the mixture is heated to 120°C and reacted for 4 hours. Adipic acid is then added to the flask, and the reaction continues for another 4 hours. The sample is then concentrated using a rotary evaporator and finally dried under vacuum at 120°C to obtain the hyperbranched carboxyl-terminated polyester. The raw materials and formulations used in this method are shown in Table 1. Comparative Examples 1-3 Comparative Examples 1-3 disclose various polyesters. Their preparation methods are the same as those in Example 1, and the raw materials and formulations used are shown in Table 1.

[0054] Table 1. Raw materials and proportions for Examples 1-6 and Comparative Examples 1-3

[0055] Examples 7-11 Examples 7-11 disclose various modified polydimethylsiloxanes, prepared by the following method: acrylate compounds, benzene compounds, polymerization inhibitors, and catalysts are added to a four-necked flask equipped with a temperature controller, stirrer, condenser, feed tube, and N2 protection device. Siloxane compounds are added dropwise at 60°C, and the reaction is completed after 8 hours to obtain modified polydimethylsiloxanes. The raw materials and formulations used in this method are shown in Table 2. Comparative Example 4-5 Comparative Examples 4-5 disclose various modified polydimethylsiloxanes. Their preparation methods are the same as in Example 7, and the raw materials and formulations used are shown in Table 2.

[0056] Table 2. Raw materials and proportions for Examples 7-11 and Comparative Examples 4-5

[0057] Examples 12-17 Examples 12-17 disclose various liquid waxes, the preparation methods of which are as follows: Step (1) Add polar solvent, leveling agent and modified polydimethylsiloxane to the kettle according to the ratio and stir and mix evenly at 300 rpm; Step (2) Heat the solution from step (1) to 40°C, add the bonding resin and hyperbranched carboxyl-terminated polyester while stirring continuously, and stir for 90 minutes until a clear and transparent liquid is formed.

[0058] Step (3) After cooling the clarified liquid obtained in step (2), filter it to complete the preparation of liquid wax.

[0059] The raw materials and formulations used in this method are shown in Table 3.

[0060] Table 3. Raw materials and proportions of liquid waxes in Examples 12-17

[0061] Comparative Examples 6-13 Comparative Examples 6-13 disclose various liquid waxes. Their preparation methods are the same as those in Example 12, and the raw materials and formulations used are shown in Table 4.

[0062] Table 4 Comparative Example 6-13 Liquid Wax Raw Materials and Proportions of Liquid Wax

[0063] The liquid waxes of Examples 12-17 and Comparative Examples 6-13 were tested respectively. The test methods and results are as follows: Table 5 Performance Tests

[0064] As can be seen from the table above, the liquid wax of the present invention containing hyperbranched carboxyl-terminated polyester and modified polydimethylsiloxane can clean better and leave no wax residue. However, due to the molar ratio of diacid, alkanolamine and adipic acid of 2:3:1 in Example 17, the hydroxyl group is excessive, which results in the inability to clean completely within 5 minutes and the presence of a small amount of residue. Comparative Example 6, due to the absence of adipic acid, resulted in polyesters with hydroxyl ends, leading to a low reaction rate with alkaline cleaning agents. Consequently, the cleaning process could not be completed within 5 minutes, leaving a large amount of dirt residue. Comparative Example 7 prepared polyester by reacting iminodiacetic acid, neopentyl glycol and adipic acid. This reaction is an esterification reaction of multiple acids and alcohols. The resulting polyester has some hydroxyl groups at the end, which makes it difficult to clean in a short time. In Comparative Example 8, since no iminodiacetic acid was added, the polyester ends were all hydroxyl groups, which also made the resin difficult to clean in a short time. Comparative Example 9 uses carboxyl-terminated butadiene-acrylonitrile rubber as the polyester component. Its molecular structure is relatively complex, and the chain-breaking reaction with the alkaline cleaning agent is incomplete, resulting in the inability to thoroughly clean in a short time. Comparative Example 10 uses polyurethane acrylate as the polyester component. Its molecular structure contains double bonds, which are more difficult to break than single bonds, increasing the difficulty of cleaning. Comparative Example 11 did not add allyl methacrylate when preparing modified polydimethylsiloxane, and the resulting product had low surface tension and poor anti-sticking effect. In Comparative Example 12, isocyanate was used instead of allyl methacrylate in the preparation of modified polydimethylsiloxane. Isocyanate has low reactivity with methyl hydrogen silicone oil, resulting in a higher surface tension of the product. Comparative Example 13 did not contain modified polydimethylsiloxane, therefore it could not achieve the corresponding modification effect.

[0065] Figure 1 Comparative images show the cleaning process of a 4-inch sapphire crystal using liquid wax from Example 12 and Comparative Example 7 for 5 minutes. It is evident that after cleaning with alkaline solution for 5 minutes, Comparative Example 7 (left) left obvious white dot-like wax residue on the sapphire surface, making it difficult to clean. In contrast, the liquid wax from Example 12 (right) left no wax residue under the same conditions, demonstrating that the liquid wax of this invention is easier to clean.

[0066] Figure 2 This is the FTIR spectrum of the hyperbranched carboxyl-terminated polyester in Example 1. It can be seen that at 1757 cm⁻¹... -1 The strong characteristic peak appearing at 1136 cm⁻¹ is the characteristic absorption peak of C=O, indicating that there are a large number of ester groups in the product, and the peak at 1136 cm⁻¹ is a characteristic absorption peak of C=O. -1 The characteristic peak appearing at 3445 cm⁻¹ belongs to the stretching vibration peak of CN, which proves that triethanolamine has successfully reacted with iminodiacetic acid. Additionally, at 3445 cm⁻¹... -1 There is a fairly strong resonance peak at that point, which is the -OH functional group in the carboxyl group. in: The test method for performance 1 cleaning residue is as follows: Taking a 4-inch sapphire wafer as an example, liquid wax was used for cleaning verification. The 4-inch sapphire wafer after spin coating was placed in an alkaline cleaning solution at 60℃, ultrasonically cleaned for 5 minutes, then immersed in water for 5 minutes, and after drying, the surface phenomenon was observed.

[0067] Performance 2: The surface tension test method is as follows: A cleaned platinum plate with a known circumference is hung vertically on an electronic balance. After zeroing, the sample stage containing the test solution is slowly raised until the bottom of the plate just touches the liquid surface. The balance then measures the downward pulling force F of the liquid film and directly gives the surface tension according to γ=F / L (when fully wetted).

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hyperbranched carboxyl-terminated polyester, characterized in that, It is obtained by esterification of a dicarboxylic acid and an alcoholic amine, followed by esterification with adipic acid.

2. The hyperbranched carboxyl-terminated polyester according to claim 1, characterized in that, The molar ratio of the dicarboxylic acid, the alcohol amine, and the adipic acid is (1.7~3):(1~2):(1.5~2). And / or, the dicarboxylic acid is selected from iminodiacetic acid and / or maleic acid; And / or, the alkanolamine is selected from one or more of triethanolamine, diethanolamine, triisopropanolamine, and diisopropanolamine.

3. A method for preparing the hyperbranched carboxyl-terminated polyester according to claim 1 or 2, characterized in that, Includes the following steps: Dicarboxylic acid and alcoholamine are dissolved in a solvent by stirring. The mixture is heated to 110-150°C and reacted for 2-6 hours under an inert atmosphere. Then, adipic acid is added and the reaction is continued at 110-150°C for another 2-6 hours. The mixture is then evaporated and concentrated, and dried under vacuum at 100-140°C to prepare hyperbranched carboxyl-terminated polyester.

4. The method for preparing hyperbranched carboxyl-terminated polyester according to claim 3, characterized in that, The solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.

5. A liquid wax, characterized in that, Based on parts by weight, it includes the following components: 20 to 60 parts of the hyperbranched carboxyl-terminated polyester according to claim 1 or 2; 5-20 parts of bonding resin; 10-60 parts polar solvent; 0.1 to 1 part leveling agent; 0.2 to 1 part of modified polydimethylsiloxane.

6. The liquid wax according to claim 5, characterized in that, The bonding resin is selected from one or more of modified petroleum resin, modified terpene resin, terpene phenol resin and modified rosin resin; And / or, the polar solvent is selected from one or more of dodecene, D-limonene, dipentene, cyclododecene, butyl acetate, isopropyl acetate, n-butyl propionate, cyclopentanone, diethylene glycol butyl ether, dipropylene glycol methyl ether, ethylene glycol ethyl ether acetate, and diethylene glycol ethyl ether. And / or, the leveling agent is selected from one or more of polyester-modified polysiloxane leveling agents, polyether-modified polysiloxane leveling agents, aralkyl-modified polymethylalkylsiloxane leveling agents, and polyether-modified polymethylalkylsiloxane leveling agents; And / or, the modified polydimethylsiloxane is acrylate-modified polydimethylsiloxane.

7. The liquid wax according to claim 6, characterized in that, The acrylate-modified polydimethylsiloxane is prepared by reacting acrylate compounds with siloxane compounds.

8. The liquid wax according to claim 7, characterized in that, The molar ratio of the acrylate compound to the siloxane compound is 1:1 to 1:2; And / or, the acrylate compound is selected from one or more of allyl methacrylate, methyl methacrylate, ethyl methacrylate and butyl acrylate; And / or, the siloxane compound is selected from one or more of polymethylhydrosiloxane, tetramethyldisiloxane, hexamethylcyclotrisiloxane and 3-mercaptopropylmethyldimethoxysilane.

9. A method for preparing the liquid wax according to any one of claims 5-8, characterized in that, Includes the following steps: Step (1) Mix the polar solvent, leveling agent and modified polydimethylsiloxane evenly according to the formula; Step (2) Heat the mixture from step (1) to 30~70℃, add the bonding resin and hyperbranched carboxyl-terminated polyester while stirring, and stir until uniform; Step (3) Cool and filter the liquid obtained in step (2) to prepare the liquid wax.

10. The application of the hyperbranched carboxyl-terminated polyester of claim 1 or 2, or the liquid wax of any one of claims 5-8, in the field of wafer thinning.

Images