Acid-resistant UV viscosity-reducing adhesive tape and preparation method thereof

Abstract

The invention provides an acid-resistant UV viscosity-reducing adhesive tape. The adhesive tape sequentially comprises a release film layer, an adhesive layer and a base material layer from top to bottom, the adhesive layer is an acrylate adhesive layer, the adhesive layer is obtained by coating an acrylate adhesive coating liquid and then curing, and the preparation raw materials of the acrylate adhesive coating liquid comprise the following components in parts by weight: 100 parts of an acrylate polymer, 0.1-2 parts of a cross-linking agent, 1-3 parts of a photoinitiator and 35-100 parts of ethyl acetate. By introducing the high-Tg hard monomer, a rigid molecular skeleton is provided for the adhesive layer, and the activity of a molecular chain segment is reduced, so that the compactness of the adhesive layer is improved, and permeation and diffusion of acid liquor are physically hindered. Meanwhile, by using the multifunctional acrylate cross-linking agent, a three-dimensional network structure with high cross-linking density is formed after UV curing, so that the cohesive strength and chemical stability of an adhesive layer are greatly improved, and the adhesive layer can keep a complete structure in an acid environment without swelling, softening or internal damage.

Description

Technical Field

[0001] This invention belongs to the field of UV anti-adhesion tape technology, and particularly relates to an acid-resistant UV anti-adhesion tape and its preparation method. Background Technology

[0002] Anti-adhesion films are an important auxiliary material in semiconductor manufacturing and precision machining of various electronic components. By providing robust adhesive protection during processing and enabling clean peeling after completion, they ensure the feasibility and efficiency of miniaturized and precision production.

[0003] Currently, most anti-adhesion protective films on the market are UV anti-adhesion films, which refer to films that have high adhesion before UV irradiation, but whose adhesion decreases significantly after UV irradiation, making them easy to peel off. In special processes such as glass cutting and thinning of monocrystalline silicon materials, acid and alkali solutions are often used for cleaning and etching, so the UV anti-adhesion tapes need to have acid and alkali resistance.

[0004] Currently, UV anti-adhesion tapes lack sufficient resistance to acid and alkali environments, and are prone to falling off the wafer surface during wafer processing, affecting the wafer processing yield.

[0005] Conventional UV anti-adhesion tapes show acid penetration at the edges after being immersed in a 50% sulfuric acid solution at high temperature for 1 hour. However, the present invention maintains excellent adhesive strength after immersion in acid solution, with no acid penetration at the edges.

[0006] Furthermore, conventional UV anti-adhesion tapes lack resistance to acidic environments, leaving adhesive residue on the surface of the object after debonding. In contrast, this invention achieves low peel strength and no adhesive residue on the surface of the object after UV irradiation. Summary of the Invention

[0007] The purpose of this invention is to provide an acid-resistant UV-resistant pressure-reducing tape and its preparation method. Compared with traditional tapes, this pressure-sensitive tape maintains excellent adhesive strength after being soaked in acid, and there is no penetration at the edges.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: an acid-resistant UV-resistant tape, wherein the tape comprises, from top to bottom, a release film layer, an adhesive layer, and a substrate layer;

[0009] The adhesive layer is an acrylic adhesive layer, which is obtained by coating an acrylic adhesive coating liquid and then curing it. The raw materials for preparing the acrylic adhesive coating liquid include the following components by weight: 100 parts of acrylic polymer, 0.1 to 2 parts of crosslinking agent, 1 to 3 parts of photoinitiator, and 35 to 100 parts of ethyl acetate.

[0010] The acrylate polymer is copolymerized from 60-70 parts of soft monomers, 30-40 parts of hard monomers, 5-10 parts of functional monomers, 0.1-1 parts of initiator, 0.05-0.2 parts of polymerization inhibitor, 1-7 parts of end-capping agent, and 100-200 parts of solvent.

[0011] The following is a further improvement to the above technical solution:

[0012] 1. In the above scheme, the soft monomer is one or more of methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, glycidyl acrylate, isobutyl acrylate, and isooctyl acrylate.

[0013] 2. In the above scheme, the Tg temperature of the hard monomer is greater than -30℃, specifically one or more of methacrylic acid, methyl methacrylate, styrene, acrylonitrile, hydroxyethyl acrylate, alkyl methacrylate, and methacrylic acid-modified bisphenol A epoxy resin.

[0014] 3. In the above scheme, the functional monomer is a monomer with cross-linking functional groups, specifically one or more of acrylamide, acrylic acid, maleic anhydride, epoxy acrylate, 1,6-hexanediol diacrylate, bispentaerythritol hexaacrylate, and pentaerythritol triacrylate.

[0015] 4. In the above scheme, the crosslinking agent is an isocyanate curing agent from Covestro. N3800 N 3300 N 3900 XP 2763 XP2838 XP 2489 XP 2847 At least one of XP2617 and Toyo Ink Co., Ltd.'s BHS-8515.

[0016] 5. In the above scheme, the initiator is at least one of benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), dilauroyl peroxide (LPO), tert-amyl peroxide-2-ethylhexanoate (TAPO), tert-amyl peroxide-2-ethylhexanoate (TAPO), and dihydroxycyclohexane peroxide (BHCP);

[0017] 6. In the above scheme, the polymerization inhibitor is at least one of 2,6-di-tert-butyl-p-methylphenol, 4-tert-butyl-2-phenylphenol, and p-hydroxyanisole;

[0018] 7. In the above scheme, the capping agent is at least one of isooctanoic acid, 4-phenylethynylaniline, and methyl ethyl ketone oxime;

[0019] 8. In the above scheme, the solvent is at least one selected from toluene, methylcyclohexane, cyclohexanone, methyl isobutyl ketone, butanone, ethyl acetate, butyl acetate, and n-heptane.

[0020] 9. In the above scheme, the preparation method of the acrylate polymer includes the following steps:

[0021] 60–80 wt% soft monomer, 60–80 wt% hard monomer, 70–90 wt% functional monomer and 60–80 wt% solvent are added to a reaction vessel. Nitrogen gas is purged under stirring at 60°C for 20–40 minutes. Under nitrogen atmosphere, part of the initiator and the remaining soft monomer, remaining hard monomer and remaining functional monomer are added dropwise to the reaction vessel. The addition is completed in two hours. The reaction is then carried out for another 4 hours. The remaining initiator is added and the reaction is maintained for 4–8 hours to obtain the first mixture.

[0022] Air was introduced into the first mixture for half an hour, then the polymerization inhibitor and the remaining first solvent were added, and the reaction was allowed to proceed for 1 hour. Then, the end-capping agent was added and the reaction was continued at 60°C for another hour to obtain the acrylate polymer.

[0023] 10. In the above scheme, the release layer is PET with a thickness of 25-75 μm;

[0024] 11. In the above scheme, the substrate layer is one or more of PET and PO films, with a thickness of 25-100 μm;

[0025] 12. In the above scheme, the thickness of the adhesive layer is 15-40 μm.

[0026] A method for preparing an acid-resistant UV-resistant adhesive tape, the method comprising the following steps:

[0027] S1. By weight, mix 100 parts of acrylate polymer, 0.1-2 parts of isocyanate curing agent, 1-3 parts of photoinitiator, and 35-100 parts of solvent evenly to obtain an acrylate adhesive coating liquid.

[0028] S2. Apply the adhesive layer to the substrate using a comma-shaped coating head, and remove the solvent in an oven at 110℃~125℃ for 2-3 minutes to obtain the adhesive layer.

[0029] S3. Lay the release layer onto the adhesive layer, cure at 45°C for 3 days, and then roll up to obtain the finished product.

[0030] 1. In the above scheme, the adhesive layer in step S2 is 20-40 μm thick.

[0031] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0032] 1. The acrylic adhesive system of the present invention contains hard monomers (such as bisphenol A type epoxy resin) with high glass transition temperature, which increases the rigidity and density of the adhesive layer and hinders the diffusion of acid molecules.

[0033] 2. The adhesive layer of the present invention contains multifunctional acrylate monomers, which can provide crosslinking points, promote crosslinking of polymerized monomers, form a high crosslinking density network, and the high degree of crosslinking gives the adhesive layer extremely high cohesive strength, making it less prone to internal damage in acidic environments.

[0034] 3. By using a multifunctional acrylate crosslinking agent, a three-dimensional network structure with high crosslinking density is formed after UV curing. This greatly improves the cohesive strength and chemical stability of the adhesive layer, enabling it to maintain structural integrity in acidic environments without swelling, softening, or internal damage. Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments:

[0036] Example 1

[0037] The preparation method of acrylate polymers includes the following steps:

[0038] 60 wt% soft monomer, 60 wt% hard monomer, 70 wt% functional monomer and 60 wt% solvent were added to a reaction vessel and stirred at 60°C with nitrogen gas for 30 minutes. Under nitrogen atmosphere, part of the initiator and the remaining soft monomer, the remaining hard monomer and the remaining functional monomer were added dropwise to the reaction vessel. The addition was completed in two hours. The reaction was then carried out for another 4 hours. The remaining initiator was added and the reaction was maintained for 6 hours to obtain the first mixture.

[0039] Air was introduced into the first mixture for half an hour, then the polymerization inhibitor and the remaining first solvent were added, and the reaction was carried out for 1 hour. Then, the end-capping agent was added and the reaction was continued at 60°C for another hour to obtain the acrylate polymer.

[0040] A method for preparing an acid-resistant UV-resistant adhesive tape, the method comprising the following steps:

[0041] S1. By weight, the acrylate polymer, isocyanate curing agent, photoinitiator and solvent are mixed evenly to obtain an acrylate adhesive coating liquid.

[0042] S2. Apply the adhesive layer to the substrate using a comma-shaped coating head, and remove the solvent in an oven at 110℃~125℃ for 2-3 minutes to obtain the adhesive layer.

[0043] S3. Lay the release layer onto the adhesive layer, cure at 45°C for 3 days, and then roll up to obtain the finished product.

[0044] The specific formulation components of Examples 2 and 3 are shown in Table 1.

[0045] Comparative Example 1: This comparative example refers to the preparation method provided in Example 1 to prepare an adhesive and tape. The difference between this comparative example and Example 1 is that no functional monomers are added during the synthesis of the acrylate polymer.

[0046] Comparative Example 2: This comparative example refers to the preparation method provided in Example 1 to prepare an adhesive and tape. The difference between this comparative example and Example 1 is that in the process of preparing the acrylate polymer, an equal mass of epoxy resin is used instead of the methacrylic acid modified bisphenol A type epoxy resin in Example 1. This resin is not modified with methacrylic acid.

[0047] Comparative Example 3: This comparative example refers to the preparation method provided in Example 1 to prepare an adhesive and tape. The difference between this comparative example and Example 1 is that the crosslinking agent NE-100C is used when preparing the acrylic adhesive coating liquid.

[0048] Examples 2-3 and Comparative Examples 1-3 used the same preparation method as Example 1, and the specific components are as follows:

[0049] The formulation of the acrylate polymers is shown in Table 1:

[0050] Table 1. Proportions of acrylate polymers

[0051]

[0052]

[0053] The formulation of acrylic adhesive coating liquid is as follows:

[0054]

[0055] In Examples 1-3 and Comparative Examples 1-3, the thicknesses of the substrate layer and the adhesive layer are respectively:

[0056]

[0057] Test methods and results

[0058] The above embodiments and comparative examples were subjected to performance tests, including peel strength before 180° UV exposure, peel strength after 180° UV exposure, acid resistance test, and residual adhesive test. The test results are shown in Table 1. The specific test methods are as follows:

[0059] 180° UV peel force: The sample width is 25mm. The sample is attached to the SUS steel plate / wafer with a 2kg roller at a speed of 300mm / min. The sample is rolled back and forth three times. The sample is left to stand at room temperature for 20min. Tensile testing parameters: tensile speed is 300mm / min, and distance is 150mm.

[0060] 180° UV peel strength: The sample width is 25mm. Using a 2kg roller at a speed of 300mm / min, the sample is bonded to a SUS steel plate / wafer and rolled back and forth three times. It is then left to stand at room temperature for 20 minutes. Tensile testing parameters: Tensile speed 300mm / min, distance 150mm. Debonding parameters: Debonding using LED equipment, power 20%, time 5s, debonding energy 500mJ / cm².

[0061] Acid resistance test: The sample width is 25mm. The sample is attached to the wafer. The attached wafer is immersed in 50% sulfuric acid at high temperature (100℃) for 60 minutes. After taking it out, observe whether there is any seepage at the edge of the wafer.

[0062] Residual adhesive test: The sample width is 25mm. The sample is attached to the wafer. The attached wafer is immersed in 50% sulfuric acid at high temperature (100℃) for 60 minutes. After rinsing with clean water, it is dried at 100℃ for 60 minutes. After UV energy irradiation, it is peeled off by hand and the wafer surface is observed to see if there is any residual adhesive.

[0063] The test data is as follows:

[0064] Test Result 1

[0065]

[0066] Based on the above test results, it can be seen that, compared with Example 1 and Comparative Example 1, when functional monomers are added to prepare UV-resistant adhesive, the resulting tape exhibits excellent adhesive properties before UV irradiation. However, after UV irradiation, the adhesiveness decreases, the peel force is lower, which facilitates peeling from the surface of the adhered object without leaving any residue. Functional monomers can participate in the construction of cross-linking networks, improving cohesive strength and density, and preventing acid penetration.

[0067] Compared with Example 1 and Comparative Example 2 of the present invention, when bisphenol A type epoxy resin modified with methacrylic acid is used to prepare UV-resistant adhesive, the resulting tape has better density and acid and alkali resistance. After UV curing, it can achieve a significant reduction in tackiness and is less likely to leave residue.

[0068] Compared with Examples 1 and 2 of the present invention, increasing the proportion of crosslinking agent results in a higher degree of crosslinking, an increased density of physical entanglement points within the adhesive layer, and a decrease in tackiness before UV exposure. Compared with Examples 1 and 3, increasing the proportion of photoinitiator increases the number of free radicals, thereby initiating rapid polymerization of double bonds in the prepolymer and monomers, leading to a decrease in peel strength after UV exposure.

[0069] Compared with Example 1 and Comparative Example 3 of the present invention, when the aromatic crosslinking agent L-75 is used, the resulting tape has a large rigidity modulus, cannot have good wetting performance on the substrate, has low initial adhesion, and is prone to leakage after acid treatment.

[0070] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An acid-resistant UV-resistant adhesive tape, characterized in that, The tape consists of a release film layer, an adhesive layer, and a substrate layer from top to bottom. The adhesive layer is an acrylic adhesive layer, which is obtained by coating an acrylic adhesive coating liquid and then curing it. The raw materials for preparing the acrylic adhesive coating liquid include the following components by weight: 100 parts of acrylic polymer, 0.1 to 2 parts of crosslinking agent, 1 to 3 parts of photoinitiator, and 35 to 100 parts of ethyl acetate. The acrylate polymer is copolymerized from 60-70 parts of soft monomers, 30-40 parts of hard monomers, 5-10 parts of functional monomers, 0.1-1 parts of initiator, 0.05-0.2 parts of polymerization inhibitor, 1-7 parts of end-capping agent, and 100-200 parts of solvent.

2. The acid-resistant UV-resistant adhesive tape according to claim 1, characterized in that, The soft monomer is one or more of methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, glycidyl acrylate, isobutyl acrylate, and isooctyl acrylate.

3. The acid-resistant UV-resistant adhesive tape according to claim 1, characterized in that, The hard monomer has a Tg temperature greater than -30°C, and is specifically one or more of methacrylic acid, methyl methacrylate, styrene, acrylonitrile, hydroxyethyl acrylate, alkyl methacrylate, and methacrylic acid-modified bisphenol A epoxy resin.

4. The acid-resistant UV-resistant adhesive tape according to claim 1, characterized in that, The functional monomer is a monomer with cross-linking functional groups, specifically one or more of acrylamide, acrylic acid, maleic anhydride, epoxy acrylate, 1,6-hexanediol diacrylate, bispentaerythritol hexaacrylate, and pentaerythritol triacrylate.

5. The acid-resistant UV-resistant adhesive tape according to claim 1, characterized in that, The crosslinking agent is an isocyanate curing agent.

6. The acid-resistant UV-resistant adhesive tape according to claim 1, characterized in that, The initiator is at least one selected from benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), dilauroyl peroxide (LPO), tert-amyl peroxide-2-ethylhexanoate (TAPO), tert-amyl peroxide-2-ethylhexanoate (TAPO), and dihydroxycyclohexane peroxide (BHCP). The polymerization inhibitor is at least one of 2,6-di-tert-butyl-p-methylphenol, 4-tert-butyl-2-phenylphenol, and p-hydroxyanisole. The capping agent is at least one of isooctanoic acid, 4-phenylethynylaniline, and methyl ethyl ketone oxime; The solvent is at least one selected from toluene, methylcyclohexane, cyclohexanone, methyl isobutyl ketone, butanone, ethyl acetate, butyl acetate, and n-heptane.

7. The acid-resistant UV-resistant adhesive tape according to claim 1, characterized in that, The preparation method of the acrylate polymer includes the following steps: 60–80 wt% soft monomer, 60–80 wt% hard monomer, 70–90 wt% functional monomer and 60–80 wt% solvent are added to a reaction vessel. Nitrogen gas is purged under stirring at 60°C for 20–40 minutes. Under nitrogen atmosphere, part of the initiator and the remaining soft monomer, remaining hard monomer and remaining functional monomer are added dropwise to the reaction vessel. The addition is completed in two hours. The reaction is then carried out for another 4 hours. The remaining initiator is added and the reaction is maintained for 4–8 hours to obtain the first mixture. Air was introduced into the first mixture for half an hour, then the polymerization inhibitor and the remaining first solvent were added, and the reaction was allowed to proceed for 1 hour. Then, the end-capping agent was added and the reaction was continued at 60°C for another hour to obtain the acrylate polymer.

8. The acid-resistant UV-resistant adhesive tape according to claim 4, characterized in that, The release layer is PET with a thickness of 25–75 μm; The substrate layer is one or more of PET and PO films, with a thickness of 25-100 μm; The thickness of the adhesive layer is 15–40 μm.

9. A method for preparing an acid-resistant UV-resistant adhesive tape, characterized in that: The preparation method includes the following steps: S1. By weight, mix 100 parts of acrylate polymer, 0.1-2 parts of isocyanate curing agent, 1-3 parts of photoinitiator, and 35-100 parts of solvent evenly to obtain an acrylate adhesive coating liquid. S2. Apply the adhesive layer to the substrate using a comma-shaped coating head, and remove the solvent in an oven at 110℃~125℃ for 2-3 minutes to obtain the adhesive layer. S3. Lay the release layer onto the adhesive layer, cure at 45°C for 3 days, and then roll up to obtain the finished product.

10. The method for preparing an acid-resistant UV-resistant adhesive tape according to claim 9, characterized in that: The adhesive layer in step S2 is 20-40 μm thick.

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