A kind of heat-reducing adhesive tape for semiconductor cutting and preparation method thereof

Abstract

The present invention relates to the technical field of new tape materials, and in particular to a heat-reducing adhesive tape for semiconductor cutting, which comprises a substrate layer and a heat-reducing adhesive layer, wherein the heat-reducing adhesive layer comprises a polyacrylate copolymer resin, a thermoplastic resin, a polyisocyanate curing agent, a carboxyl crosslinking agent, a surface-modified heat-expandable microsphere and an organic solvent. The present invention functionalizes the surface of the heat-expandable microsphere by using a heat-expandable microsphere surface treatment technology, and matches the polyacrylate copolymer resin that participates in the crosslinking reaction with the heat-expandable microsphere and the thermoplastic resin that improves the heat-reducing adhesive tape, thereby improving the comprehensive performance of the heat-reducing adhesive tape.

Description

Technical Field

[0001] The invention relates to the technical field of new adhesive tape materials, and in particular to a heat-reducing adhesive tape for semiconductor cutting and a preparation method thereof. Background Art

[0002] The semiconductor chip manufacturing process mainly includes chip design, wafer integrated circuit embedding, wafer grinding, wafer dicing, packaging, package sawing, testing and other processes. In the package cutting process, the dicing tape mainly plays the role of protecting and fixing the package. The dicing tape must meet the following requirements: initial high adhesion to ensure that the package is fixed during the cutting process, even small-sized semiconductor devices will not be displaced or fall off. At the same time, the adhesion can be reduced after the cutting is completed, ensuring that even large-sized semiconductor devices can be easily picked up or separated correctly, and there is no pollution and residual adhesive on the surface of the semiconductor device.

[0003] Package cutting tapes are mainly divided into UV viscosity-reducing tapes and thermal viscosity-reducing tapes. Both can provide high viscosity at the beginning, which can effectively fix the package during the cutting process. After that, the viscosity of the tape can be reduced by illumination and heating, respectively, so that the semiconductor device can be easily peeled off the tape. With the thinning and multifunctionalization of electronic products, semiconductor chips and their packaging technology are developing towards high density, high pin position, thinness and miniaturization, and the proportion of small-sized semiconductor chip devices has increased accordingly. When using UV viscosity-reducing tape to cut the package into small-sized devices, the smaller the size of the semiconductor device, the larger the specific surface area of ​​the device. Therefore, the contact area between the adhesive layer fixing the semiconductor device and the air increases. In the process of reducing the viscosity of the tape by illumination, oxygen inhibition is easy to occur. Oxygen inhibition leads to insufficient curing reaction of the UV viscosity-reducing adhesive layer and the problem of residual adhesive. In addition, since the UV viscosity-reducing tape will have a high residual adhesive force after illumination, additional processes are required to separate the semiconductor device from the tape. The separated semiconductor devices also need to be cleaned to remove the residual adhesive, which seriously reduces production efficiency and product yield. Thermal detackifying tape, when used in the cutting process of small-sized semiconductor devices, can automatically separate the device from the tape by appropriate heating, without the problem of oxygen inhibition. However, in the existing thermal detackifying tape technology, due to the technical defects adopted, the heat-expandable microspheres used are only physically mixed with the matrix resin. During the thermal debonding process, the heat-expandable microspheres are easily separated from the main resin of the pressure-sensitive adhesive, causing the problem of residual adhesive. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a thermal debonding tape for semiconductor dicing and a preparation method thereof, which can effectively solve the above-mentioned problems of the prior art.

[0005] Technical Solution

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The invention provides a heat-reducing adhesive tape for semiconductor cutting, which comprises a substrate layer and a heat-reducing adhesive layer. The heat-reducing adhesive layer comprises polyacrylate copolymer resin, thermoplastic resin, polyisocyanate curing agent, carboxyl crosslinking agent, surface-modified thermal expansion microspheres and organic solvent.

[0008] Furthermore, as a preferred embodiment of the above technical solution, the components of the heat-reducing adhesive layer include 10-50 parts by weight of polyacrylate copolymer resin, 2-20 parts of thermoplastic resin, 0.2-1.0 parts of polyisocyanate curing agent, 0.1-0.5 parts of carboxyl crosslinking agent, 1-5 parts of surface-modified heat-expandable microspheres and 50-80 parts of organic solvent.

[0009] Furthermore, the glass transition temperature of the polyacrylate copolymer resin is between -55°C and -20°C, the weight average molecular weight Mw is between 100,000 and 1,000,000, the molecular weight distribution is ≤1.3, and the polyacrylate copolymer resin contains carboxyl groups and hydroxyl groups.

[0010] Furthermore, the thermoplastic resin is a polymer that does not contain hydroxyl groups and carboxyl groups, the softening point of the thermoplastic resin is 50° C. to 90° C., and the thermoplastic resin can be dissolved in toluene, ethyl acetate, butanone or a mixed solvent thereof.

[0011] Furthermore, the thermoplastic resin is one or both of ethylene-vinyl acetate copolymer (EVA) and polyacrylate resin.

[0012] Furthermore, the polyisocyanate curing agent is a compound containing two or more isocyanate groups in one molecule, and is one of aromatic polyisocyanate or aliphatic polyisocyanate.

[0013] Furthermore, the carboxyl crosslinking agent is a mixture of one or both of a multifunctional aziridine (trimethylolpropane-tris[3-(2-methylaziridinyl)propionate], SC-100) and a tetrafunctional epoxy resin (N,N,N',N'-tetraglycidyl-m-xylene diamine, GA-240).

[0014] Furthermore, the shell of the surface-modified heat-expandable microsphere is a polyacrylonitrile copolymer, the particle size is 10 to 30 μm, preferably 10 to 20 μm, and the expansion temperature is 90 to 130° C.; there are carboxyl groups on the surface of the shell of the surface-modified heat-expandable microsphere;

[0015] The preparation steps of the surface modified thermally expandable microspheres are as follows:

[0016] Heat-expandable microspheres with a particle size of 10 to 20 μm, an expansion temperature of 90 to 130° C., and a shell of a polyacrylonitrile copolymer are added to a 0.1 to 0.8 mol / L potassium hydroxide aqueous solution, heated to 30 to 80° C., and stirred for reaction for 1 to 5 hours. After the reaction is completed, the pH of the reaction solution is adjusted to 5 to 7 with an HCl aqueous solution, and a white powder is obtained by filtration. The white powder is rinsed with pure water and dried to obtain surface-modified heat-expandable microspheres.

[0017] Furthermore, the organic solvent is toluene, ethyl acetate, butanone or a mixture of several thereof.

[0018] Furthermore, the substrate is one of PET (polyethylene terephthalate), PO / PP / PE (polyolefin film), PI (polyimide film), and PEN (polyethylene naphthalate).

[0019] A method for preparing a heat-reducing adhesive tape for semiconductor dicing comprises the following steps:

[0020] (1) Preparation of surface modified thermally expandable microspheres:

[0021] Add heat-expandable microspheres with a particle size of 10 to 20 μm, an expansion temperature of 90 to 130° C., and a shell of a polyacrylonitrile copolymer into a 0.5 mol / L potassium hydroxide aqueous solution, heat to 50° C., and react with stirring for 1 to 5 hours. After the reaction is completed, adjust the pH of the reaction solution to 6 with an HCl aqueous solution, filter to obtain a white powder, and rinse the white powder with pure water and dry to obtain a surface-modified heat-expandable microsphere.

[0022] (2) adding the surface-modified heat-expandable microspheres, polyacrylate copolymer resin, and thermoplastic resin into an organic solvent, stirring to obtain a mixed solution, dissolving a polyisocyanate curing agent and a carboxyl crosslinking agent in the organic solvent respectively, and sequentially adding the two into the mixed solution, stirring to obtain a heat-reduced viscosity adhesive;

[0023] (3) The heat-reducing adhesive obtained in step (2) is applied to a substrate with a thickness of 12 μm to 200 μm by blade coating, and after heating, drying and curing, a heat-reducing adhesive tape is obtained. The temperature of the heating, drying and curing is between 50 and 80° C., and the thickness of the heat-reducing layer obtained after drying is 30 μm to 100 μm, preferably 30 μm to 50 μm.

[0024] Beneficial Effects

[0025] Compared with the known public technology, the technical solution provided by the present invention has the following beneficial effects:

[0026] (1) The present invention functionalizes the surface of heat-expandable microspheres through the surface treatment technology of heat-expandable microspheres, and combines them with polyacrylate copolymer resins that participate in the cross-linking reaction and thermoplastic resins that enhance the thermal viscosity-reducing effect, thereby improving the comprehensive performance of the heat-reducing adhesive tape. In the present invention, the polyacrylate copolymer resin and the surface-modified heat-expandable microspheres are directly chemically bonded through a cross-linking reaction, thereby solving the problem of residual adhesive in the prior art. Among them, the added thermoplastic resin increases the fluidity of the adhesive layer during the heating process, reduces the peeling force between the adhesive layer and the semiconductor device, thereby enhancing the viscosity-reducing effect and achieving automatic separation between the semiconductor device and the tape during the heating process.

[0027] (2) Compared with the UV adhesive tape for semiconductor cutting, the thermal adhesive tape for semiconductor cutting made by the present invention does not leave residual adhesive when cutting small-sized semiconductor devices, and the adhesiveness after thermal adhesive removal is low. The semiconductor devices after cutting can be automatically separated from the tape by heating. However, the UV adhesive tape has a higher residual adhesiveness and cannot automatically separate the device from the tape after cutting.

[0028] (3) The heat-expandable microspheres of the semiconductor cutting heat-reducing tape made by the present invention are chemically modified and have carboxyl groups on the surface. The microspheres react chemically with the main resin (polyacrylate copolymer) in the heat-reducing layer through a carboxyl cross-linking agent to produce chemical cross-linking, thereby avoiding the generation of residual adhesive during the thermal expansion process.

[0029] (4) The heat-reducing adhesive tape for semiconductor cutting made by the present invention has a thermoplastic resin with a softening point of 50°C to 90°C added to the heat-reducing adhesive layer, which can reduce the interaction between the heat-reducing adhesive tape and the semiconductor device during the heating process, improve the heat-reducing adhesive effect, and realize the automatic separation of the device and the tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 This is a schematic diagram of a process flow for preparing a heat-reducing adhesive tape for semiconductor dicing according to the present invention;

[0032] Figure 2 This is a schematic diagram of automatic separation and residual glue evaluation. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention will be further described below in conjunction with the embodiments.

[0035] A heat-reducing adhesive tape for semiconductor cutting comprises a substrate layer and a heat-reducing adhesive layer, wherein the heat-reducing adhesive layer comprises polyacrylate copolymer resin, thermoplastic resin, polyisocyanate curing agent, carboxyl crosslinking agent, surface-modified heat-expandable microspheres and an organic solvent.

[0036] As a preferred embodiment of the above technical solution, the components of the heat-reducing adhesive layer include 10-50 parts by weight of polyacrylate copolymer resin, 2-20 parts of thermoplastic resin, 0.2-1.0 parts of polyisocyanate curing agent, 0.1-0.5 parts of carboxyl crosslinking agent, 1-5 parts of surface-modified heat-expandable microspheres and 50-80 parts of organic solvent.

[0037] As a preferred embodiment of the above technical solution, the components of the heat-reducing adhesive layer include 30 parts of polyacrylate copolymer resin, 5 parts of thermoplastic resin, 0.5 parts of polyisocyanate curing agent, 0.2 parts of carboxyl crosslinking agent, 3 parts of surface-modified thermally expandable microspheres and 66.3 parts of organic solvent in parts by weight.

[0038] As a preferred embodiment of the above technical solution, the glass transition temperature of the polyacrylate copolymer resin is between -55°C and -20°C, the weight average molecular weight Mw is between 100,000 and 1,000,000, the molecular weight distribution is ≤1.3, and the polyacrylate copolymer resin contains carboxyl groups and hydroxyl groups.

[0039] As a preferred embodiment of the above technical solution, the thermoplastic resin is a polymer free of hydroxyl and carboxyl groups, the softening point of the thermoplastic resin is 50° C. to 90° C., and the thermoplastic resin is soluble in toluene, ethyl acetate, butanone or a mixed solvent thereof.

[0040] As a preferred embodiment of the above technical solution, the thermoplastic resin is one or both of ethylene-vinyl acetate copolymer (EVA) and polyacrylate resin.

[0041] As a preferred embodiment of the above technical solution, the polyisocyanate curing agent is a compound containing two or more isocyanate groups in one molecule, and is one of aromatic polyisocyanate or aliphatic polyisocyanate.

[0042] As a preferred embodiment of the above technical solution, the carboxyl crosslinking agent is a mixture of one or both of a multifunctional aziridine (trimethylolpropane-tris[3-(2-methylaziridinyl) propionate], SC-100) and a tetrafunctional epoxy resin (N,N,N',N'-tetraglycidyl-m-xylene diamine, GA-240).

[0043] As a preferred embodiment of the above technical solution, the shell of the surface-modified heat-expandable microsphere is a polyacrylonitrile copolymer, with a particle size of 10 to 30 μm, preferably 10 to 20 μm, and an expansion temperature of 90 to 130° C.; there are carboxyl groups on the surface of the shell of the surface-modified heat-expandable microsphere;

[0044] The preparation steps of the surface modified thermally expandable microspheres are as follows:

[0045] Heat-expandable microspheres with a particle size of 10 to 20 μm, an expansion temperature of 90 to 130° C., and a shell of a polyacrylonitrile copolymer are added to a 0.1 to 0.8 mol / L potassium hydroxide aqueous solution, heated to 30 to 80° C., and stirred for reaction for 1 to 5 hours. After the reaction is completed, the pH of the reaction solution is adjusted to 5 to 7 with an HCl aqueous solution, and a white powder is obtained by filtration. The white powder is rinsed with pure water and dried to obtain surface-modified heat-expandable microspheres.

[0046] As a preferred embodiment of the above technical solution, the organic solvent is toluene, ethyl acetate, butanone or a mixture of several thereof.

[0047] As a preferred embodiment of the above technical solution, the substrate is one of PET (polyethylene terephthalate), PO / PP / PE (polyolefin film), PI (polyimide film), and PEN (polyethylene naphthalate).

[0048] like Figure 1 As shown, a method for preparing a heat-reducing adhesive tape for semiconductor dicing comprises the following steps:

[0049] (1) Preparation of surface modified thermally expandable microspheres:

[0050] Add heat-expandable microspheres with a particle size of 10 to 20 μm, an expansion temperature of 90 to 130° C., and a shell of a polyacrylonitrile copolymer into a 0.5 mol / L potassium hydroxide aqueous solution, heat to 50° C., and react with stirring for 1 to 5 hours. After the reaction is completed, adjust the pH of the reaction solution to 6 with an HCl aqueous solution, filter to obtain a white powder, and rinse the white powder with pure water and dry to obtain a surface-modified heat-expandable microsphere.

[0051] (2) adding the surface-modified heat-expandable microspheres, polyacrylate copolymer resin, and thermoplastic resin into an organic solvent, stirring to obtain a mixed solution, dissolving a polyisocyanate curing agent and a carboxyl crosslinking agent in the organic solvent respectively, and sequentially adding the two into the mixed solution, stirring to obtain a heat-reduced viscosity adhesive;

[0052] (3) The heat-reducing adhesive obtained in step (2) is applied to a substrate with a thickness of 12 μm to 200 μm by blade coating, and heated, dried and cured to obtain a heat-reducing adhesive tape. The temperature of the heating, drying and curing is between 50 and 80° C., and the thickness of the heat-reducing adhesive layer obtained after drying is 30 μm to 100 μm, preferably 30 μm to 50 μm.

[0053] (I) Preparation of thermal anti-viscosity protective film

[0054] Embodiment 1:

[0055] By weight, 30 parts of expanded microspheres with polyacrylonitrile copolymer shells (particle size 10-20 μm, expansion temperature 90-130° C.) were added to 2000 parts of 0.5 mol / L potassium hydroxide aqueous solution, heated to 50° C., stirred for reaction for 3 hours, HCl aqueous solution was added to adjust the pH of the reaction solution to 6, and white powder was obtained by vacuum filtration. The powder was washed three times with 2000 parts of pure water and dried to obtain surface-modified thermally expandable microspheres.

[0056] Weigh 30 parts of polyacrylate copolymer (Tg = -40 ° C, Mw = 500,000, molecular weight distribution PDI = 1.3, hydroxyl value = 10 mgKOH / g, carboxyl value = 58 mgKOH / g), 5 parts by weight of ethylene-vinyl acetate copolymer levamelt 686 (the brand is Alan Xinke's levamelt 686, molecular weight of about 80,000, softening point of about 70 ° C), 3 parts by weight of surface-modified heat-expandable microspheres, 50 parts of ethyl acetate, and stir to obtain mixed solution A. Weigh 0.5 parts of polyisocyanate curing agent (Desmodur L 75, NCO content = 13.3%) and 10 parts of ethyl acetate, stir to add to mixed solution A, and obtain mixed solution B. Weigh 0.2 parts of carboxyl crosslinking agent (GA-240) and 6.3 parts of ethyl acetate, stir to add to mixed solution B, and obtain mixed solution C. Mixed solution C is fully stirred and filtered to obtain a heat-reduced adhesive. The obtained heat-reduced adhesive was coated on a 50 μm thick transparent PET film by a doctor blade coating process, and the coating amount of the coating liquid was 150 g / m 2 , dried at 80°C for 3 min, and post-cured at 40°C for 48 h to obtain a heat-reducing adhesive tape.

[0057] Embodiment 2:

[0058] The difference between this embodiment and embodiment 1 is that the weight portion of ethylene-vinyl acetate copolymer levamelt 686 in this embodiment is 10 parts.

[0059] Example 3

[0060] The difference between this embodiment and Example 1 is that the weight portion of the ethylene-vinyl acetate copolymer levamelt 686 elastomer in this embodiment is 15 parts.

[0061] Example 4

[0062] The difference between this embodiment and Example 1 is that 0.2 parts of the carboxyl crosslinking agent (GA-240) is replaced by 0.2 parts of the carboxyl crosslinking agent trimethylolpropane-tris[3-(2-methylaziridinyl)propionate] (SC-100).

[0063] Example 5

[0064] The difference between this embodiment and Example 1 is that the thermoplastic resin in this embodiment is polyacrylate copolymer Kuraray LA4285 (Japanese Kuraray, softening point is 50° C.).

[0065] Comparative Example 1:

[0066] The difference between this embodiment and embodiment 1 is that the thermal expansion particles are not chemically modified.

[0067] Comparative Example 2:

[0068] The difference from Example 1 is that the polyacrylate copolymer (Tg = -40°C, Mw = 500,000, molecular weight distribution PDI = 1.3, hydroxyl value = 10 mgKOH / g, carboxyl value = 58 mgKOH / g) is 30 parts, and no thermoplastic resin is added.

[0069] Comparative Example 3:

[0070] The difference between this embodiment and Example 1 is that no carboxyl cross-linking agent is added.

[0071] (II) Performance test

[0072] Evaluation Methodology:

[0073] 1. Initial 180° peeling force to SUS 304 standard steel plate, GB / T 2792-2014;

[0074] 2. 180° peel strength test after heat-removal: The heat-removal tape is treated at high temperature of 120°C for 3 minutes, and the heat-treated tape is applied to a standard steel plate (SUS 304) for peel strength test, and the 180° peel strength is tested according to GB / T 2792-2014;

[0075] 3. Automatic separation and residual glue evaluation: Figure 2 As shown, a heat-reducing adhesive tape (300mm*300mm) is attached to a semiconductor chip package (epoxy resin package, size 100mm*200mm), and the semiconductor chip package is cut into semiconductor devices of 0.8mm*1.6mm with a cutter wheel. After cutting, the sample is placed in a heating oven with the adhesive surface of the attached device facing down, and the sample is heat treated at 120℃ for 3min to observe whether the semiconductor device after cutting can be completely separated from the heat-reducing adhesive tape, and the percentage of automatic separation is counted. At the same time, the residual adhesive on the surface of the semiconductor device is observed, and the proportion of residual adhesive devices is counted.

[0076]

[0077] Based on the above experimental data, it can be known that the present invention obtains heat-expandable microspheres with carboxyl groups on the surface by surface modification of commercially available heat-expandable microspheres with polyacrylonitrile copolymer as the shell. The heat-expandable microspheres can undergo cross-linking reaction with the carboxyl functional groups of the polyacrylate copolymer resin through a carboxyl cross-linking agent, thereby realizing chemical bonding between the heat-expandable microspheres and the polyacrylic acid copolymer resin. During the application of the heat-reducing adhesive tape, the expansion process of the heat-expandable microspheres will not cause direct physical separation of the expanded microspheres and the polyacrylic acid copolymer resin, thereby avoiding the generation of residual adhesive.

[0078] In addition, by adding some thermoplastic resin with a softening point of 50°C to 90°C into the formula of the heat-reducing adhesive, it can start to work before the heat-expanding microspheres start to expand, reducing the force between the heat-reducing tape and the semiconductor package, thereby improving the heat-reducing effect.

[0079] The present invention functionalizes the surface of heat-expandable microspheres through the surface treatment technology of heat-expandable microspheres, and matches them with polyacrylate copolymer resins that participate in the cross-linking reaction and thermoplastic resins that enhance the heat-reducing effect, thereby improving the comprehensive performance of the heat-reducing adhesive tape. In the present invention, the polyacrylate copolymer resin and the surface-modified heat-expandable microspheres are directly chemically bonded through a cross-linking reaction, thereby solving the problem of residual adhesive in the prior art. Among them, the added thermoplastic resin increases the fluidity of the adhesive layer during the heating process, reduces the peeling force between the adhesive layer and the semiconductor device, thereby enhancing the viscosity-reducing effect, and achieving automatic separation between the semiconductor device and the tape during the heating process.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat-reducing adhesive tape for semiconductor dicing, characterized in that: It comprises a substrate layer and a heat-reducing adhesive layer, wherein the heat-reducing adhesive layer comprises a polyacrylate copolymer resin, a thermoplastic resin, a polyisocyanate curing agent, a carboxyl cross-linking agent, surface-modified heat-expandable microspheres and an organic solvent; The shell of the surface-modified heat-expandable microsphere is a polyacrylonitrile copolymer, the particle size is 10-30 μm, and the expansion temperature is 90-130° C.; there are carboxyl groups on the surface of the shell of the surface-modified heat-expandable microsphere; The preparation steps of the surface modified thermally expandable microspheres are as follows: Heat-expandable microspheres with a particle size of 10-20 μm, an expansion temperature of 90-130° C., and a shell of polyacrylonitrile copolymer are added to a 0.1-0.8 mol / L potassium hydroxide aqueous solution, heated to 30-80° C., and stirred for reaction for 1-5 hours. After the reaction, the pH of the reaction solution is adjusted to 5-7 with an HCl aqueous solution, and a white powder is obtained by filtration. The white powder is rinsed with pure water and dried to obtain surface-modified heat-expandable microspheres.

2. The semiconductor dicing heat-reducing adhesive tape according to claim 1, characterized in that: The polyacrylate copolymer resin has a glass transition temperature of -55°C to -20°C, a weight average molecular weight Mw of 100,000 to 1,000,000, and a molecular weight distribution of ≤1.

3. The polyacrylate copolymer resin contains a carboxyl group and a hydroxyl group.

3. The heat-reducing adhesive tape for semiconductor dicing according to claim 1, characterized in that: The thermoplastic resin is a polymer without hydroxyl and carboxyl groups, the softening point of the thermoplastic resin is 50° C. to 90° C., and the thermoplastic resin can be dissolved in toluene, ethyl acetate, butanone or a mixed solvent thereof.

4. The semiconductor dicing heat-reducing adhesive tape according to claim 3, characterized in that: The thermoplastic resin is one or both of ethylene-vinyl acetate copolymer and polyacrylate resin.

5. The semiconductor dicing heat-reducing adhesive tape according to claim 1, characterized in that: The polyisocyanate curing agent is a compound containing two or more isocyanate groups in one molecule, and is one of aromatic polyisocyanate or aliphatic polyisocyanate.

6. The heat-reducing adhesive tape for semiconductor dicing according to claim 1, characterized in that: The carboxyl crosslinking agent is a polyfunctional aziridine and a tetrafunctional epoxy resin or a mixture of the two.

7. The heat-reducing adhesive tape for semiconductor dicing according to claim 1, characterized in that: The organic solvent is toluene, ethyl acetate, butanone or a mixture of several thereof.

8. The semiconductor dicing heat-reducing adhesive tape according to claim 1, characterized in that: The substrate is one of PET, PO / PP / PE, PI and PEN.

9. A method for preparing a heat-reducing adhesive tape for semiconductor dicing as claimed in claim 1, characterized in that: It includes the following steps: (1) Preparation of surface modified thermally expandable microspheres: Add heat-expandable microspheres with a particle size of 10-20 μm, an expansion temperature of 90-130° C., and a shell of polyacrylonitrile copolymer into a 0.1-0.8 mol / L potassium hydroxide aqueous solution, heat to 30-80° C., stir and react for 1-5 hours, adjust the pH of the reaction solution to 5-7 with an HCl aqueous solution after the reaction, filter to obtain a white powder, rinse the white powder with pure water and dry it to obtain a surface-modified heat-expandable microsphere; (2) adding the surface-modified heat-expandable microspheres, polyacrylate copolymer resin and thermoplastic resin into an organic solvent, stirring them uniformly to obtain a mixed solution, dissolving a polyisocyanate curing agent and a carboxyl cross-linking agent in the organic solvent respectively and adding them into the mixed solution in sequence, stirring them uniformly to obtain a heat-reduced viscosity adhesive; (3) The heat-reducing adhesive obtained in step (2) is applied to a substrate with a thickness of 12 μm to 200 μm by blade coating, and after heating, drying and curing, a heat-reducing adhesive tape is obtained. The temperature of the heating, drying and curing is between 50 and 80° C., and the thickness of the heat-reducing adhesive layer obtained after drying is 30 μm to 100 μm.

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