Acid and alkali resistant UV viscosity-reducing glue and its preparation method, adhesive tape, and application

Abstract

This invention provides an acid and alkali resistant UV-curing adhesive, its preparation method, tape, and applications. The adhesive comprises polyurethane resin, a tack-reducing resin, and an isocyanate curing agent, with a mass ratio of polyurethane resin: tack-reducing resin: isocyanate curing agent of 80-95: 5-20: 1-5. The acrylate functionality of the tack-reducing resin is not less than 3, and the isocyanate functionality of the isocyanate curing agent is not less than 2. The raw materials for preparing the polyurethane resin include hydroxyl monomers, isocyanate monomers, and epoxy resin. The hydroxyl monomers include polyester polyols and / or polyether polyols, and the mass ratio of hydroxyl monomers to isocyanate monomers is 4-10:1. This acid and alkali resistant UV-curing adhesive can form an adhesive layer with excellent acid and alkali resistance. Even in strongly acidic or alkaline environments, this adhesive layer exhibits good adhesion to the bonded surfaces.

Description

Technical Field

[0001] This invention relates to the field of adhesives, specifically to an acid and alkali resistant UV-resistant adhesive, its preparation method, tape, and applications. Background Technology

[0002] In recent years, the rapid advancements in the optoelectronics and microelectronics industries have been leading numerous fields, including aerospace, aviation, machinery, light industry, and chemicals, toward a trend of high integration and miniaturization. With the surge in complexity and functional sophistication of integrated circuits, higher demands have been placed on their packaging density and size, making the pursuit of ultimate compactness and miniaturization a consensus.

[0003] Wafer dicing, an indispensable part of semiconductor chip manufacturing, is crucial. Due to the thinness of wafers, direct cutting and transfer of single-layer wafers is difficult. Therefore, adhesive tape is used to adhere to the wafer surface to facilitate these operations. Industry technicians commonly use UV-resistant tape to protect wafers. This tape exhibits high adhesion and good bonding before UV irradiation, but its adhesion significantly decreases after UV irradiation, making it easy to peel off the wafer surface. However, wafer manufacturing processes include operations involving strong acids and alkalis, such as etching, pickling, and rinsing. Current UV-resistant tapes lack sufficient resistance to these acidic and alkaline environments. During wafer processing, commercially available UV-resistant tapes easily detach from the wafer surface, affecting processing efficiency and yield.

[0004] Therefore, developing a UV-resistant wafer tape with good resistance for protection during wafer fabrication is of valuable and significant purpose. Summary of the Invention

[0005] The purpose of this invention is to provide an acid and alkali resistant UV anti-tack adhesive, its preparation method, tape, and application. This acid and alkali resistant UV anti-tack adhesive can form an adhesive layer with excellent acid and alkali resistance.

[0006] According to one aspect of the present invention, an acid and alkali resistant UV-resistant adhesive is provided, comprising a polyurethane resin, a tack-reducing resin, and an isocyanate curing agent, wherein the mass ratio of polyurethane resin: tack-reducing resin: isocyanate curing agent is 80-95: 5-20: 1-5; the acrylate functionality of the tack-reducing resin is not less than 3; the isocyanate functionality of the isocyanate curing agent is not less than 2; the raw materials for preparing the polyurethane resin include hydroxyl monomers and isocyanate monomers, wherein the hydroxyl monomers include polyester polyols and / or polyether polyols, and the mass ratio of hydroxyl monomers to isocyanate monomers is 4-10:1.

[0007] The acid and alkali resistant UV-curing adhesive provided in this solution can form an adhesive layer with excellent acid and alkali resistance. This adhesive layer is not easily corroded by strong acid and alkali liquids and can maintain good adhesion even in strongly acidic and alkaline environments. Furthermore, the adhesive layer formed by this UV-curing adhesive has excellent adhesion before UV irradiation, but its tackiness decreases after UV irradiation, facilitating peeling from the surface of the bonded object and reducing adhesive residue. On one hand, by using polyester polyols and / or polyether polyols as hydroxyl monomers and adjusting the mass ratio of hydroxyl monomers to isocyanate monomers to the aforementioned range, the polyurethane resin is endowed with a large number of hydroxyl reactive groups. Then, the polyurethane prepolymer obtained by reacting the hydroxyl monomers and isocyanate monomers with epoxy resin is epoxy modified. Compared to unmodified polyurethane resin, the epoxy vinyl resin has a higher molecular weight and more long carbon chains, thereby further improving the density and impermeability of the adhesive layer formed by the acid and alkali resistant UV-curing adhesive. Furthermore, the polyurethane resin is combined with an acrylate-based anti-tack resin with a functionality of not less than 3 and an isocyanate curing agent with a functionality of not less than 2 in the aforementioned mass ratio. This allows for the control of the reactive bonding groups and reactivity of the raw materials, thereby connecting the originally independent linear molecules to form a complex three-dimensional network structure. This significantly improves the adhesion and density of the adhesive layer. The formation of this three-dimensional network structure enables tighter intermolecular bonding, enhancing the density of the adhesive layer. This directly leads to increased resistance to liquid penetration and improved acid and alkali corrosion resistance. Here, acrylate functionality refers to the number of acrylate functional groups in the anti-tack resin, and isocyanate functionality refers to the number of isocyanate functional groups in the isocyanate curing agent. For example, a multifunctional acrylate with a functionality of 3 describes a molecule with three acrylate groups. On the other hand, during wafer processing, strong acid or alkaline solutions are needed to clean and etch the wafers with adhesive tape. Applying adhesive tape with the aforementioned acid and alkali resistant UV anti-tack adhesive to the wafers can effectively reduce the possibility of penetration and corrosion by strong acid or alkaline solutions, and prevent the adhesive layer from falling off the wafer surface during processing, which helps to improve wafer processing efficiency and yield.

[0008] Preferably, the acid and alkali resistant UV anti-tack adhesive comprises 80-95 parts polyurethane resin, 5-20 parts anti-tack resin, and 1-5 parts isocyanate curing agent, calculated by weight.

[0009] Preferably, the isocyanate curing agent includes an aromatic isocyanate curing agent.

[0010] Preferably, the aromatic isocyanate curing agent includes at least one of polymethylene polyphenyl polyisocyanate (PAPI), toluene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI).

[0011] Preferably, the isocyanate monomer includes at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymethylene polyphenyl polyisocyanate (PAPI).

[0012] Preferably, the acid and alkali resistant UV anti-tack adhesive also includes a photoinitiator and a solvent.

[0013] Preferably, the acid and alkali resistant UV adhesive comprises 1 to 5 parts by weight of photoinitiator.

[0014] Preferably, the photoinitiator includes a free radical photoinitiator.

[0015] Preferably, the free radical photoinitiator includes at least one of diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride (TPO) and 2-hydroxy-2-methylacetophenone.

[0016] Preferably, the acid and alkali resistant UV adhesive comprises 40 to 60 parts by weight of solvent.

[0017] Preferably, the solvent includes ethyl acetate.

[0018] Preferably, the acrylate functionality of the tack-reducing resin is 3 to 6.

[0019] Preferably, the anti-tack resin includes at least one of pentaerythritol hexaacrylate, bis(trimethylolpropane)tetraacrylate, pentaerythritol tetraacrylate, and ethoxylated trimethylolpropane triacrylate. Using the above-mentioned anti-tack resins not only effectively controls the acrylate functionality of the anti-tack resin, which is beneficial for improving the acid and alkali resistance of the adhesive layer formed by the UV anti-tack adhesive, but also significantly reduces the glass strength between the adhesive layer and the substrate after UV irradiation. This reduces residual adhesive and damage to the wafer during the tape peeling stage, thereby improving the wafer yield.

[0020] Preferably, the hydroxyl monomers include polyester polyols and polyether polyols, and the mass of the polyester polyol is not less than the mass of the polyether polyol; the molecular weight of the polyether polyol is 1000-3000. By controlling the molecular weight of the polyether polyol and the mass of the polyether polyol and polyester polyol, it is beneficial to improve the viscoelasticity of the acid and alkali resistant UV anti-tack adhesive, thereby improving the toughness and bonding performance of the adhesive layer formed by the UV anti-tack adhesive.

[0021] Preferably, the polyether polyol is prepared by ring-opening etherification reaction of polyol with ethylene oxide and / or propylene oxide.

[0022] Preferably, the polyether polyol includes at least one selected from castor oil polyoxyethylene ether, trimethylolpropane polyoxyethylene ether, polyoxypropylene glycerol ether, pentaerythritol polyoxypropylene ether, and sorbitol polyoxypropylene ether; and / or, the polyester polyol includes at least one selected from phthalic anhydride polyester polyol, trimellitic anhydride polyester polyol, and aromatic-aliphatic copolyester polyol. Specifically, castor oil polyoxyethylene ether is obtained by a ring-opening etherification reaction of castor oil and ethylene oxide; trimethylolpropane polyoxyethylene ether is obtained by a ring-opening etherification reaction of trimethylolpropane and ethylene oxide; polyoxypropylene glycerol ether is obtained by a ring-opening etherification reaction of glycerol and propylene oxide; pentaerythritol polyoxypropylene ether is obtained by a ring-opening etherification reaction of pentaerythritol and propylene oxide; and sorbitol polyoxypropylene ether is obtained by a ring-opening etherification reaction of sorbitol and propylene oxide.

[0023] Preferably, the epoxy resin includes epoxy vinyl ester resin. By using epoxy vinyl ester resin to perform epoxy modification on polyurethane resin, the flexibility and impact resistance of the adhesive layer formed by the acid and alkali resistant UV anti-tack adhesive can be improved, and the density and acid and alkali resistance of the network crosslinking structure can also be improved.

[0024] Preferably, the epoxy vinyl resin includes a urethane-modified epoxy vinyl resin. The urethane-modified epoxy vinyl resin possesses excellent corrosion resistance, flexibility, and processability, and can also improve the compatibility of the epoxy resin with the polyurethane resin. Modifying the polyurethane resin with a urethane-modified epoxy vinyl resin can improve the penetration resistance and mechanical properties of the adhesive layer formed by the UV anti-tack adhesive. Furthermore, wafer processing involves operations such as wafer dicing and die expansion. When a urethane-modified epoxy vinyl resin is used to prepare the UV anti-tack adhesive, the resulting tape exhibits excellent adhesion and mechanical properties, effectively preventing wafer damage during processing and further reducing the wafer defect rate.

[0025] Preferably, the urethane-modified epoxy resin includes at least one of E51 epoxy resin and E44 epoxy resin.

[0026] Preferably, the raw materials for preparing polyurethane resin, calculated by weight, include 15 to 40 parts polyester polyol, 5 to 15 parts polyether polyol, and 5 to 15 parts isocyanate monomer.

[0027] Preferably, the raw materials for preparing polyurethane resin include 1 to 8 parts of epoxy resin, calculated by weight.

[0028] Preferably, the raw materials for preparing polyurethane resin also include additives and solvents.

[0029] Preferably, the additives include at least one of chain extenders, catalysts, curing agents, anti-aging agents, and leveling agents.

[0030] Preferably, the raw materials for preparing polyurethane resin include 0.5 to 2 parts by weight of chain extender, 0.01 to 0.1 parts by catalyst, and 50 to 80 parts by solvent.

[0031] Preferably, the chain extender includes trimethylolpropane.

[0032] Preferably, the catalyst includes an organotin catalyst.

[0033] Preferably, the preparation method of polyurethane resin includes the following operations: S1. Mixing hydroxyl monomers, isocyanate monomers, additives, and solvents, and then reacting the reaction system at 70-90°C for 2-4 hours to obtain a polyurethane prepolymer; S2. Lowering the temperature of the reaction system to below 60°C, and then mixing the polyurethane prepolymer, epoxy resin, and additives, stirring until the solid content of the reaction system is 30-50%, thereby obtaining the polyurethane resin.

[0034] Preferably, the hydroxyl monomer is dehydrated so that the water content of the hydroxyl monomer is not higher than 5000 ppm.

[0035] Preferably, when the additives include chain extenders and / or catalysts, the chain extenders and catalysts are added in step S1.

[0036] According to another aspect of the present invention, a method for preparing the above-mentioned acid and alkali resistant UV anti-tack adhesive is provided, comprising the following operations: mixing polyurethane resin, anti-tack resin, isocyanate curing agent and solvent to obtain a first mixture, and mixing the first mixture with a photoinitiator to obtain the acid and alkali resistant UV anti-tack adhesive.

[0037] Preferably, the solid content of the first mixture is 20-30%.

[0038] According to another aspect of the present invention, a tape is provided, comprising a substrate and an adhesive layer, the adhesive layer being made using the aforementioned acid and alkali resistant UV-resistant adhesive.

[0039] Preferably, the substrate includes at least one of polyurethane (PU), polyolefin (PO), and polyethylene terephthalate (PET).

[0040] According to another aspect of the present invention, the application of the above-mentioned acid and alkali resistant UV anti-tack adhesive or the above-mentioned tape in the fields of wafer processing or chip manufacturing is provided. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0042] Example 1

[0043] This embodiment provides an acid and alkali resistant UV-resistant adhesive.

[0044] (1) The composition of the acid and alkali resistant UV anti-tack adhesive is shown in Table 1.

[0045] Table 1. Composition of Acid and Alkali Resistant UV Anti-Tack Adhesive

[0046]

[0047]

[0048] The preparation method of acid and alkali resistant UV anti-tack adhesive includes the following steps:

[0049] Polyurethane resin, anti-tack resin, isocyanate curing agent and solvent are mixed to obtain a first mixture with a solid content of 30-50%. The first mixture is then mixed with a photoinitiator to obtain an acid and alkali resistant UV anti-tack adhesive.

[0050] Table 2. Composition of polyurethane resin

[0051]

[0052] The molecular weight of the polyether polyol is 2000±100. E44 epoxy resin is an epoxy vinyl resin modified with urethane. From Table 2, the mass ratio of hydroxyl monomer to isocyanate monomer is 40:5 = 8:1.

[0053] The preparation method of polyurethane resin includes the following steps:

[0054] S1. First, the hydroxyl monomer is dehydrated so that the water content of the hydroxyl monomer is not higher than 5000ppm. Then, the hydroxyl monomer, isocyanate monomer, chain extender, catalyst and solvent are mixed. The reaction system is then reacted at 80±2℃ for 3 hours to obtain polyurethane prepolymer.

[0055] S2. Reduce the temperature of the reaction system to below 60°C, then mix the polyurethane prepolymer, epoxy resin, curing agent, anti-aging agent, and leveling agent, and stir until the solid content of the reaction system is 40±5%, thereby obtaining polyurethane resin.

[0056] In other embodiments, the types and amounts of the tack-reducing resin, isocyanate curing agent, photoinitiator, solvent, polyester polyol, polyether polyol, isocyanate monomer, epoxy resin, chain extender, catalyst, curing agent, anti-aging agent, and leveling agent can be adjusted according to actual application requirements. For example, the isocyanate curing agent can be at least one of polymethylene polyphenyl polyisocyanate (PAPI), toluene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI); the photoinitiator can be at least one of diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride (TPO) and 2-hydroxy-2-methylacetophenone. For example, polyester polyols can be selected from at least one of castor oil polyoxyethylene ether, trimethylolpropane polyoxyethylene ether, polyoxypropylene glycerol ether, pentaerythritol polyoxypropylene ether, and sorbitol polyoxypropylene ether; polyether polyols can be selected from at least one of phthalic anhydride polyester polyol, trimellitic anhydride polyester polyol, and aromatic-aliphatic copolyester polyol; isocyanate monomers can be selected from at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymethylene polyphenyl polyisocyanate (PAPI); epoxy resins can be selected from at least one of E51 epoxy resin and E44 epoxy resin.

[0057] (2) Adhesive tape

[0058] The tape includes an adhesive layer and a substrate. The adhesive layer is made of the aforementioned acid and alkali resistant UV-resistant adhesive, and the substrate is a polyurethane (PU) film.

[0059] Example 2

[0060] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV anti-tack adhesive and tape. The difference between this embodiment and Example 1 is that the composition of the acid and alkali resistant UV anti-tack adhesive is adjusted so that the polyurethane resin is 80 parts by weight, the anti-tack resin is 20 parts by weight, and the isocyanate curing agent is 1 part by weight. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0061] Example 3

[0062] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV anti-tack adhesive and tape. The difference between this embodiment and Example 1 is that in the preparation of the acid and alkali resistant UV anti-tack adhesive, the polyurethane resin is 95 parts by weight, the anti-tack resin is 5 parts by weight, and the isocyanate curing agent is 5 parts by weight. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0063] Example 4

[0064] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV anti-tack adhesive and tape. The difference between this embodiment and Example 1 is that an equal mass of ethoxylated trimethylolpropane triacrylate is used instead of the anti-tack resin in Example 1, wherein the acrylate functionality of the ethoxylated trimethylolpropane triacrylate is 3. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0065] Example 5

[0066] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV anti-tack adhesive and tape. The difference between this embodiment and Example 1 is that an equal mass of bis(trimethylolpropane)tetraacrylate is used instead of the anti-tack resin in Example 1, wherein the acrylate functionality of bis(trimethylolpropane)tetraacrylate is 4. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0067] Example 6

[0068] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV anti-adhesive adhesive and tape. The difference between this embodiment and Example 1 is that in the process of preparing polyurethane resin, the isocyanate monomer is adjusted to 10 parts by weight, thereby calculating the mass ratio of hydroxyl monomer to isocyanate monomer to be 4:1. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0069] Example 7

[0070] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV anti-adhesive adhesive and tape. The difference between this embodiment and Example 1 is that in the preparation of polyurethane resin, the hydroxyl monomer is adjusted to 50 parts by weight and the isocyanate monomer is adjusted to 5 parts by weight, thus the mass ratio of hydroxyl monomer to isocyanate monomer is calculated to be 10:1. In addition, the mass ratio of polyester polyol to polyether polyol in the hydroxyl monomer is consistent with that in Example 1. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0071] Example 8

[0072] This embodiment refers to the preparation method provided in Example 1 to prepare an acid and alkali resistant UV-resistant adhesive and tape. The difference between this embodiment and Example 1 is that in the preparation of the polyurethane resin, an equal mass of bisphenol A epoxy vinyl ester resin is used instead of the epoxy resin in Example 1. This bisphenol A epoxy vinyl ester resin is not modified with urethane. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0073] Comparative Example 1

[0074] This comparative example uses 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 composition of the acid and alkali resistant UV anti-tack adhesive is adjusted so that the polyurethane resin is 75 parts by weight, the anti-tack resin is 25 parts by weight, and the isocyanate curing agent is 1 part by weight. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0075] Comparative Example 2

[0076] This comparative example uses 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 preparation of the acid and alkali resistant UV anti-tack adhesive, the polyurethane resin is 100 parts by weight, the anti-tack resin is 3 parts by weight, and the isocyanate curing agent is 7 parts by weight. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0077] Comparative Example 3

[0078] This comparative example uses the preparation method provided in Example 1 to prepare an adhesive and tape. The difference between this comparative example and Example 1 is that an equal mass of tripropylene glycol diacrylate is used instead of the anti-tack resin in Example 1, wherein the acrylate functionality of the tripropylene glycol diacrylate is 2. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0079] Comparative Example 4

[0080] This comparative example uses 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 isocyanate monomer is adjusted to 15 parts by weight during the preparation of the polyurethane resin, resulting in a mass ratio of hydroxyl monomer to isocyanate monomer of 2.67:1. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0081] Comparative Example 5

[0082] This comparative example uses 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 isocyanate monomer is adjusted to 3 parts by weight during the preparation of the polyurethane resin, thus the mass ratio of hydroxyl monomer to isocyanate monomer is calculated to be 13.3:1. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0083] Comparative Example 6

[0084] This comparative example uses the preparation method provided in Example 1 to prepare an adhesive and tape. The difference between this comparative example and Example 1 is that an equal mass of solvent is used instead of the epoxy resin in Example 1 during the preparation of the polyurethane resin. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0085] Test Case

[0086] Test subjects: the tapes provided in Examples 1-8 and Comparative Examples 1-6.

[0087] Test items and test methods:

[0088] (1) Peel strength before UV irradiation: Referring to the test method in GB / T 2792-2014 Test method for peel strength of adhesive tape, the test object was cut into a size of 24mm*150mm, and the release layer of the test object was peeled off. The adhesive layer was then attached to the steel plate, and the object was rolled back and forth three times with a 1kg rubber roller. The object was then placed in an environment of 23±1℃ and 50±5%RH for 20min. Then, the test object was peeled off from the steel plate at a peeling speed of 300mm / min and a peeling angle of 180°. The peel strength of the test object before UV irradiation was recorded.

[0089] (2) Peel strength after UV irradiation: Referring to the test method in GB / T 2792-2014 Test Method for Peel Strength of Adhesive Tapes, the test object was cut into 24mm*150mm pieces, and the release layer was peeled off. The adhesive layer was then adhered to the steel plate, and the object was rolled back and forth three times with a 1kg rubber roller. After being placed in an environment of 23±1℃ and 50±5%RH for 20 minutes, it was irradiated with 250mJ / cm2 UV light for 30 minutes. Then, the test object was peeled off from the steel plate at a peeling speed of 300mm / min and a peeling angle of 180°. The peel strength of the test object after UV irradiation was recorded. In this test example, a peel strength of 0.5N / 25mm or less after UV irradiation was considered qualified.

[0090] (3) Acid and alkali resistance test method ①: Refer to the test method in GB / T 9274-1988 Determination of resistance to liquid media for paints and varnishes. In an environment of 23±2℃ and 65±5%RH, laminate 50mm wide tape with 50-micron thick PI film on both sides. After placing it in the environment of 23±2℃ and 65±5%RH for 20min, immerse it in a solution of HF:HCl = 1:4 for 1h. Remove it and observe whether there is liquid penetration and corrosion of the substrate surface. If liquid penetration and / or corrosion of the substrate surface occur, mark it with ×; otherwise, mark it with ○.

[0091] (4) Acid and alkali resistance test ②: In an environment of 23±2℃ and 65±5%RH, a 50mm wide tape is laminated with a 50-micron thick PI film on both sides. After being placed in the environment of 23±2℃ and 65±5%RH for 20 minutes, it is then subjected to (1% NaCO3 immersion for 24 hours → 5% NaCl immersion for 24 hours → 3% NaOH immersion for 24 hours). After removal, observe whether there is any liquid penetration. If liquid penetration and / or corrosion of the substrate surface occur, mark it with ×; otherwise, mark it with ○.

[0092] (5) Wafer defect rate: The test object is attached to the wafer surface, cut and expanded, and then irradiated with 250mJ / cm2 UV light for 30min to obtain a wafer sample. 10,000 wafer samples are prepared in a repeating process. If the wafer sample has cracks, scratches, breaks or residual adhesive on the surface, it is considered a defective product.

[0093] Test results: The test results are shown in Table 3.

[0094] Table 3. Test results of the participants

[0095]

[0096] Results analysis:

[0097] Comparing the test results of Examples 1-8 with those of Comparative Examples 1-6, it can be seen that the tapes provided in Examples 1-8 exhibit better acid and alkali resistance than those provided in Comparative Examples 1-6, and the wafer defect rate is lower when the tapes are applied to wafer fabrication. This demonstrates that the adhesive layer formed by the acid and alkali resistant UV anti-tack adhesive provided in this application can form an adhesive layer with excellent acid and alkali resistance, which is not easily corroded by strong acid or alkali liquids.

[0098] Comparing the test results of Examples 1-3 and Comparative Examples 1-2 in Table 3, it can be seen that when the mass ratio of polyurethane resin, tack-reducing resin, and isocyanate curing agent in the acid- and alkali-resistant UV tack-reducing adhesive is 80-95:5-20:1-5, the adhesive layer formed by this UV tack-reducing adhesive has excellent bonding performance before UV irradiation, but the tack decreases and the peel force is small after UV irradiation, which is conducive to peeling from the surface of the bonded object and reducing residual adhesive. Among them, the adhesive layer formed by the adhesive provided in Comparative Example 1 has weak bonding performance and poor acid resistance before UV irradiation, so the wafer defect rate is 0.56%. The adhesive layer formed by the adhesive provided in Comparative Example 2 has high peel force after UV irradiation, which easily leaves a lot of residual adhesive on the wafer surface, affecting the wafer fabrication efficiency.

[0099] Comparing the test results of Examples 1, 4-5 and Comparative Example 3 in Table 3, it can be seen that when the acrylate functionality of the anti-tack resin is not less than 3, the acid and alkali resistant UV anti-tack adhesive has more reactive bonding groups and higher reactivity, which is reflected in the better density and acid and alkali resistance of the adhesive layer. When applied to wafer processing, the wafer defect rate is lower.

[0100] Comparing the test results of Examples 1, 6-7 and Comparative Examples 4-5 in Table 3, it can be seen that when the mass ratio of hydroxyl monomer to isocyanate monomer in the raw materials for preparing polyurethane resin is 4-10:1, the adhesive layer formed by the UV anti-tack adhesive has better acid and alkali resistance and adhesion. Specifically, the adhesive layer has low peel force and low wafer defect rate after UV irradiation.

[0101] Comparing the tapes provided in Examples 1, 8, and 6, it can be seen that when using epoxy-modified polyurethane resin to prepare the UV-resistant adhesive, the resulting tape exhibits better density and acid and alkali resistance. Furthermore, comparing the UV-resistant adhesives provided in Examples 1 and 8, it can be found that using urethane-modified epoxy vinyl resin in the polyurethane resin preparation process results in an adhesive layer with excellent bonding and mechanical properties.

[0102] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An acid and alkali resistant UV-resistant adhesive, characterized in that, The product comprises polyurethane resin, a non-tackifying resin, and an isocyanate curing agent, wherein the polyurethane resin : the non-tackifying resin : the isocyanate curing agent ratio is 80~95 : 5~20 : 1~5 by mass. The tack-reducing resin includes at least one of pentaerythritol hexaacrylate, bis(trimethylolpropane)tetraacrylate, pentaerythritol tetraacrylate, and ethoxylated trimethylolpropane triacrylate, and the isocyanate curing agent has an isocyanate functionality of not less than 2. The raw materials for preparing the polyurethane resin include hydroxyl monomers, isocyanate monomers, and epoxy resins, wherein the mass ratio of the hydroxyl monomers to the isocyanate monomers is 4~10:1; the hydroxyl monomers include polyester polyols and polyether polyols, and the mass of the polyester polyols is not less than the mass of the polyether polyols; the epoxy resins include epoxy vinyl resins.

2. The acid and alkali resistant UV anti-tack adhesive as described in claim 1, characterized in that, The molecular weight of the polyether polyol is 1000~3000.

3. The acid and alkali resistant UV anti-tack adhesive as described in claim 1, characterized in that, The polyether polyol includes at least one of castor oil polyoxyethylene ether, trimethylolpropane polyoxyethylene ether, polyoxypropylene glycerol ether, pentaerythritol polyoxypropylene ether, and sorbitol polyoxypropylene ether. And / or, the polyester polyol includes at least one of phthalic anhydride polyester polyol, trimellitic anhydride polyester polyol, and aromatic-aliphatic copolyol.

4. The acid and alkali resistant UV anti-tack adhesive as described in claim 1, characterized in that, The epoxy vinyl resin includes urethane-modified epoxy vinyl resin.

5. The acid and alkali resistant UV anti-tack adhesive as described in any one of claims 1 to 4, characterized in that, The preparation method of the polyurethane resin includes the following steps: S1. The hydroxyl monomer, isocyanate monomer, additives and solvent are mixed, and then the reaction system is reacted at 70~90℃ for 2~4 hours to obtain polyurethane prepolymer; S2. The temperature of the reaction system is lowered to below 60°C, and then the polyurethane prepolymer, the epoxy resin and the additives are mixed and stirred until the solid content of the reaction system is 30-50%, thereby obtaining the polyurethane resin.

6. A method for preparing an acid and alkali resistant UV-resistant adhesive as described in any one of claims 1 to 5, characterized in that, Includes the following operations: The polyurethane resin, the anti-tack resin, the isocyanate curing agent, and the solvent are mixed to obtain a first mixture. The first mixture is then mixed with a photoinitiator to obtain the acid and alkali resistant UV anti-tack adhesive.

7. A type of adhesive tape, characterized in that, It includes a substrate and an adhesive layer, wherein the adhesive layer is made of an acid and alkali resistant UV-resistant adhesive as described in any one of claims 1 to 5.

8. The application of the acid and alkali resistant UV anti-tack adhesive as described in any one of claims 1 to 5 or the tape as described in claim 7 in the field of wafer processing or chip manufacturing.

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