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

Abstract

The invention provides acid and alkali resistant UV viscosity-reducing glue, a preparation method, an adhesive tape and application, the acid and alkali resistant UV viscosity-reducing glue comprises polyurethane resin, viscosity-reducing resin and an isocyanate curing agent, and the mass ratio of the polyurethane resin to the viscosity-reducing resin to the isocyanate curing agent is (80-95): (5-20): (1-5); the acrylate functionality of the visbreaking resin is not lower than 3, and the isocyanate functionality of the isocyanate curing agent is not lower than 2; the preparation raw materials of the polyurethane resin comprise a hydroxyl monomer, an isocyanate monomer and epoxy resin, the hydroxyl monomer comprises polyester polyol and / or polyether polyol, and the mass ratio of the hydroxyl monomer to the isocyanate monomer is (4-10): 1. The acid and alkali resistant UV viscosity-reducing glue can form an adhesive layer with excellent acid and alkali resistance, and the adhesive layer has a good bonding effect on a bonded object even in a strong acid and strong alkali environment.

Description

Technical Field

[0001] The invention relates to the field of adhesives, and in particular to an acid- and alkali-resistant UV viscosity-reducing glue, a preparation method, an adhesive tape, and applications. Background Art

[0002] In recent years, the rapid progress of optoelectronics and microelectronics industries is leading many fields such as aerospace, aviation, machinery, light industry and chemical industry to move towards a trend of high integration and miniaturization. With the surge in the complexity of integrated circuits and the improvement of their functions, higher requirements are placed on their packaging density and size, and the pursuit of extreme compactness and miniaturization has become a consensus.

[0003] Wafer cutting process is an indispensable part of the semiconductor chip manufacturing process. During the wafer processing, due to the thinness of the wafer, it is difficult to directly cut and transfer the single-layer wafer. Therefore, it is necessary to use tape to stick to the surface of the wafer to facilitate wafer transfer, cutting and other operations. Technical personnel in this industry often use UV anti-sticking tape to protect the wafer. UV anti-sticking tape refers to a tape with high adhesion and good adhesion before UV irradiation, and the adhesion is significantly reduced after UV irradiation, and it is easy to peel off from the surface of the wafer. However, in the process of wafer manufacturing, there are still operations such as etching, pickling and washing that will use strong acids and alkalis. However, the current UV anti-sticking tape lacks sufficient tolerance to these acid and alkali environments. During the wafer processing, the commercially available UV anti-sticking tape is easy to fall off from the surface of the wafer, affecting the processing efficiency and yield of the wafer.

[0004] Therefore, it is of beneficial value and significance to develop a UV-resistant wafer tape with good tolerance for wafer processing protection. Summary of the invention

[0005] The purpose of the present invention is to provide an acid- and alkali-resistant UV viscosity-reducing glue, a preparation method, an adhesive tape, and an application. The acid- and alkali-resistant UV viscosity-reducing glue can form an adhesive layer with excellent acid- and alkali-resistant properties.

[0006] According to one aspect of the present invention, there is provided an acid-base resistant UV viscosity-reducing glue, comprising a polyurethane resin, a viscosity-reducing resin and an isocyanate curing agent, wherein the mass ratio of the polyurethane resin: the viscosity-reducing resin: the isocyanate curing agent is 80-95:5-20:1-5; the acrylate functionality of the viscosity-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 comprise a hydroxyl monomer and an isocyanate monomer, the hydroxyl monomer comprises a polyester polyol and / or a polyether polyol, and the mass ratio of the hydroxyl monomer to the isocyanate monomer is 4-10:1.

[0007] The acid-base resistant UV viscosity-reducing glue provided in this scheme can form an adhesive layer with excellent acid-base resistance, which is not easily corroded by strong acidic and alkaline liquids, and can maintain a good bonding effect even in a strong acidic and alkaline environment; and the adhesive layer formed by the UV viscosity-reducing glue has excellent bonding performance before UV irradiation, but the viscosity decreases after UV irradiation, which is conducive to peeling from the surface of the adhered object and reducing residual glue. On the one hand, by using polyester polyols and / or polyether polyols as hydroxyl monomers, and adjusting the feed mass ratio of hydroxyl monomers and isocyanate monomers to the above range, the polyurethane resin has a large number of hydroxyl reactive groups. Then, the polyurethane prepolymer obtained by the reaction of hydroxyl monomers and isocyanate monomers is epoxy-modified with epoxy resin. Compared with unmodified polyurethane resins, epoxy vinyl resins have higher molecular weights and more long carbon chains, thereby further improving the compactness and penetration resistance of the adhesive layer formed by the acid-base resistant UV viscosity-reducing glue. Further, the polyurethane resin is combined with a viscosity-reducing resin having an acrylate functionality of not less than 3 and an isocyanate curing agent having an isocyanate functionality of not less than 2 according to the above mass ratio, and the reactive groups and reactivity of the raw materials are regulated, so that the originally independent linear molecules are connected to each other, and finally a complex three-dimensional network structure is constructed, which significantly improves the bonding performance and compactness of the adhesive layer. By forming this three-dimensional network structure, the intermolecular bonding can be made tighter, and the compactness of the adhesive layer can be improved, which directly leads to the enhanced resistance of the adhesive layer to liquid penetration, and at the same time, the acid and alkali corrosion resistance of the adhesive layer can be improved. Among them, the acrylate functionality refers to the number of the functional group of the acrylate group in the viscosity-reducing resin, and the isocyanate functionality refers to the number of the functional group of the isocyanate group in the isocyanate curing agent. For example, a multifunctional acrylate with a functionality of 3 describes a molecule with 3 acrylate groups. On the other hand, during the wafer processing process, strong acid or strong alkaline solutions are needed to clean and etch the wafers bonded with tape. Using the above-mentioned acid- and alkali-resistant UV viscosity-reducing glue tape to bond and protect the wafers can effectively reduce the possibility of penetration and corrosion by strong acid or strong alkaline solutions, and avoid the adhesive layer falling off from the wafer surface during the processing process, which helps to improve wafer processing efficiency and yield.

[0008] Preferably, calculated by weight, the acid-base resistant UV viscosity-reducing glue comprises 80 to 95 parts of polyurethane resin, 5 to 20 parts of viscosity-reducing resin, and 1 to 5 parts of isocyanate curing agent.

[0009] Preferably, the isocyanate curing agent comprises 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 viscosity-reducing glue further comprises a photoinitiator and a solvent.

[0013] Preferably, calculated by weight, the acid-base resistant UV viscosity-reducing glue includes 1 to 5 parts of photoinitiator.

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

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

[0016] Preferably, calculated by weight, the acid-base resistant UV viscosity-reducing glue includes 40 to 60 parts of solvent.

[0017] Preferably, the solvent comprises ethyl acetate.

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

[0019] Preferably, the viscosity-reducing resin includes at least one of dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, and ethoxylated trimethylolpropane triacrylate. The above-mentioned viscosity-reducing resin can not only effectively regulate the acrylate functionality of the viscosity-reducing resin, which is beneficial to improving the acid and alkali resistance of the adhesive layer formed by the UV viscosity-reducing glue, but also can greatly reduce the glass strength between the adhesive layer and the bonded object after the adhesive layer formed by the UV viscosity-reducing glue is irradiated by UV. Thus, the residual glue and the damage to the wafer during the tape stripping stage can be reduced, and the wafer preparation yield rate can be improved.

[0020] Preferably, the hydroxyl monomer includes polyester polyol and polyether polyol, and the mass of polyester polyol is not less than that of polyether polyol; the molecular weight of polyether polyol is 1000 to 3000. By regulating the molecular weight of polyether polyol and the feeding mass of polyether polyol and polyester polyol, it is beneficial to improve the viscoelasticity of acid-base resistant UV viscosity-reducing glue, thereby improving the toughness and bonding performance of the adhesive layer formed by the UV viscosity-reducing glue.

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

[0022] Preferably, 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, phthalic anhydride polyester polyol, and aromatic-aliphatic copolyester polyol. Among them, castor oil polyoxyethylene ether is obtained by ring-opening etherification reaction of castor oil and ethylene oxide; trimethylolpropane polyoxyethylene ether is obtained by ring-opening etherification reaction of trimethylolpropane and ethylene oxide; polyoxypropylene glycerol ether is obtained by ring-opening etherification reaction of glycerol and propylene oxide; pentaerythritol polyoxypropylene ether is obtained by ring-opening etherification reaction of pentaerythritol and propylene oxide; sorbitol polyoxypropylene ether is obtained by ring-opening etherification reaction of sorbitol and propylene oxide.

[0023] Preferably, the epoxy resin includes epoxy vinyl resin. By selecting epoxy vinyl resin to epoxy-modify the polyurethane resin, the flexibility and impact resistance of the adhesive layer formed by the acid- and alkali-resistant UV viscosity-reducing glue can be improved, and the compactness and acid- and alkali-resistant performance of the network cross-linked structure can be improved.

[0024] Preferably, the epoxy vinyl resin includes an epoxy vinyl resin modified by carbamate. The epoxy vinyl resin modified by carbamate has excellent corrosion resistance, flexibility and processing performance, and can improve the compatibility of epoxy resin in polyurethane resin. The polyurethane resin is modified by the epoxy vinyl resin modified by carbamate, which can improve the permeability resistance and mechanical properties of the adhesive layer formed by the UV viscosity-reducing glue. In addition, the wafer processing process involves operations such as wafer cutting and wafer expansion. When the UV viscosity-reducing glue is prepared by the epoxy vinyl resin modified by carbamate, the tape formed by the UV viscosity-reducing glue has excellent bonding properties and mechanical properties, which can effectively avoid damage to the wafer during processing and further reduce the wafer processing defect rate.

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

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

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

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

[0029] Preferably, the auxiliary agent includes at least one of a chain extender, a catalyst, a curing agent, an anti-aging agent, and a leveling agent.

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

[0031] Preferably, the chain extender comprises trimethylolpropane.

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

[0033] Preferably, the preparation method of the polyurethane resin includes the following operations: S1. mixing a hydroxyl monomer, an isocyanate monomer, an auxiliary agent and a solvent, and then reacting the reaction system at 70 to 90° C. for 2 to 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 the auxiliary agent, and stirring until the solid content of the reaction system is 30 to 50%, thereby obtaining a polyurethane resin.

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

[0035] Preferably, when the auxiliary agent includes a chain extender and / or a catalyst, the chain extender and the catalyst 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 viscosity-reducing glue is provided, comprising the following operations: mixing a polyurethane resin, a viscosity-reducing resin, an isocyanate curing agent and a solvent to obtain a first mixture, and mixing the first mixture with a photoinitiator to obtain the acid- and alkali-resistant UV viscosity-reducing glue.

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

[0038] According to another aspect of the present invention, there is provided an adhesive tape comprising a substrate and an adhesive layer, wherein the adhesive layer is made of the above-mentioned acid- and alkali-resistant UV viscosity-reducing glue.

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

[0040] According to another aspect of the present invention, there is provided application of the acid- and alkali-resistant UV viscosity-reducing glue or the adhesive tape in the field of wafer processing or chip manufacturing. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0042] Example 1

[0043] This embodiment provides an acid and alkali resistant UV viscosity reducing glue.

[0044] (1) The components of the acid and alkali resistant UV viscosity reducing glue are shown in Table 1.

[0045] Table 1. Components of acid and alkali resistant UV viscosity reducing glue

[0046]

[0047]

[0048] The preparation method of acid and alkali resistant UV viscosity reducing glue includes the following operations:

[0049] The polyurethane resin, the viscosity-reducing resin, the isocyanate curing agent and the solvent are mixed to obtain a first mixture with a solid content of 30-50%, and the first mixture is mixed with a photoinitiator to obtain an acid- and alkali-resistant UV viscosity-reducing glue.

[0050] Table 2. Components of polyurethane resin

[0051]

[0052] Among them, the molecular weight of the polyether polyol is 2000±100, and the E44 epoxy resin is an epoxy vinyl resin modified by carbamate. It can be calculated from Table 2 that the mass ratio of the hydroxyl monomer to the isocyanate monomer is 40:5=8:1.

[0053] The preparation method of polyurethane resin comprises the following operations:

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

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

[0056] In other embodiments, the types and addition amounts of the viscosity-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 selected from at least one of polymethylene polyphenyl polyisocyanate (PAPI), toluene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI); for example, the photoinitiator can be selected from at least one of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) and 2-hydroxy-2-methylacetophenone. For example, the polyester polyol 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; the polyether polyol can be selected from at least one of phthalic anhydride polyester polyol, phthalic anhydride polyester polyol, and aromatic-aliphatic copolyester polyol; the isocyanate monomer can be selected from at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymethylene polyphenyl polyisocyanate (PAPI); the epoxy resin can be selected from at least one of E51 epoxy resin and E44 epoxy resin.

[0057] (2) Adhesive tape

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

[0059] Example 2

[0060] This embodiment refers to the preparation method provided in Example 1 to prepare an acid-base resistant UV viscosity-reducing glue and tape. The difference between this embodiment and Example 1 is that the components of the acid-base resistant UV viscosity-reducing glue are adjusted to make the polyurethane resin 80 parts by weight, the viscosity-reducing resin 20 parts by weight, and the isocyanate curing agent 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 example refers to the preparation method provided in Example 1 to prepare an acid-base resistant UV viscosity-reducing glue and tape. The difference between this example and Example 1 is that in the process of preparing the acid-base resistant UV viscosity-reducing glue, the polyurethane resin is 95 parts by weight, the viscosity-reducing 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 example refers to the preparation method provided in Example 1 to prepare an acid-base resistant UV viscosity-reducing glue and tape. The difference between this example and Example 1 is that an equal mass of ethoxylated trimethylolpropane triacrylate is used to replace the viscosity-reducing resin in Example 1, wherein the acrylate functionality of the ethoxylated trimethylolpropane triacrylate is 3. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0065] Example 5

[0066] This example refers to the preparation method provided in Example 1 to prepare an acid-base resistant UV viscosity-reducing glue and tape. The difference between this example and Example 1 is that an equal mass of ditrimethylolpropane tetraacrylate is used to replace the viscosity-reducing resin in Example 1, wherein the acrylate functionality of ditrimethylolpropane tetraacrylate is 4. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0067] Example 6

[0068] This example refers to the preparation method provided in Example 1 to prepare an acid-base resistant UV viscosity-reducing glue and tape. The difference between this example and Example 1 is that in the process of preparing the polyurethane resin, the isocyanate monomer is adjusted to 10 parts by weight, thereby calculating the mass ratio of the hydroxyl monomer to the isocyanate monomer to be 4:1. The rest of the 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-base resistant UV viscosity-reducing glue and tape. The difference between this embodiment and Example 1 is that in the process of preparing the polyurethane resin, the hydroxyl monomer is adjusted to 50 parts and the isocyanate monomer is adjusted to 5 parts by weight, so that the mass ratio of the hydroxyl monomer to the isocyanate monomer is 10:1, and in the hydroxyl monomer, the mass ratio of the polyester polyol to the polyether polyol is consistent with that in Example 1. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0071] Example 8

[0072] This example refers to the preparation method provided in Example 1 to prepare an acid-base resistant UV viscosity-reducing glue and tape. The difference between this example and Example 1 is that in the process of preparing the polyurethane resin, an equal mass of bisphenol A epoxy vinyl ester resin is used to replace the epoxy resin in Example 1, and the bisphenol A epoxy vinyl ester resin is not modified by urethane. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0073] Comparative Example 1

[0074] This comparative example refers to the preparation method provided in Example 1 to prepare a glue and an adhesive tape. The difference between this comparative example and Example 1 is that the component composition of the acid-base resistant UV viscosity-reducing glue is adjusted to make the polyurethane resin 75 parts by weight, the viscosity-reducing resin 25 parts by weight, and the isocyanate curing agent 1 part by weight. The remaining raw material ratios and preparation methods are strictly consistent with Example 1.

[0075] Comparative Example 2

[0076] This comparative example refers to the preparation method provided in Example 1 to prepare a glue and an adhesive tape. The difference between this comparative example and Example 1 is that in the process of preparing the acid-base resistant UV viscosity-reducing glue, the polyurethane resin is 100 parts by weight, the viscosity-reducing 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 refers to the preparation method provided in Example 1 to prepare a glue and an adhesive tape. The difference between this comparative example and Example 1 is that an equal mass of tripropylene glycol diacrylate is used to replace the viscosity-reducing resin in Example 1, wherein the acrylate functionality of the tripropylene glycol diacrylate is 2. The rest of the raw material ratios and the preparation method are strictly consistent with those in Example 1.

[0079] Comparative Example 4

[0080] This comparative example refers to the preparation method provided in Example 1 to prepare a glue and an adhesive tape. The difference between this comparative example and Example 1 is that in the process of preparing the polyurethane resin, the isocyanate monomer is adjusted to 15 parts by weight, and the mass ratio of the hydroxyl monomer to the isocyanate monomer is calculated to be 2.67:1. The rest of the raw material ratios and the preparation method are strictly consistent with Example 1.

[0081] Comparative Example 5

[0082] This comparative example refers to the preparation method provided in Example 1 to prepare a glue and an adhesive tape. The difference between this comparative example and Example 1 is that in the process of preparing the polyurethane resin, the isocyanate monomer is adjusted to 3 parts by weight, and the mass ratio of the hydroxyl monomer to the isocyanate monomer is calculated to be 13.3:1. The rest of the raw material ratios and the preparation method are strictly consistent with Example 1.

[0083] Comparative Example 6

[0084] This comparative example refers to the preparation method provided in Example 1 to prepare a glue and an adhesive tape. The difference between this comparative example and Example 1 is that in the process of preparing the polyurethane resin, an equal mass of solvent is used to replace the epoxy resin in Example 1. The rest of the raw material ratios and preparation methods are strictly consistent with Example 1.

[0085] Test Case

[0086] Test objects: the adhesive tapes provided in Examples 1 to 8 and Comparative Examples 1 to 6.

[0087] Test items and test methods:

[0088] (1) Peeling force before UV irradiation: Referring to the test method in GB / T 2792-2014 Test method for peeling 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, and the adhesive layer was attached to the steel plate, and rolled back and forth with a 1kg rubber roller three times, and 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°, and the peeling force of the test object before UV irradiation was recorded.

[0089] (2) Peeling force after UV irradiation: Refer to the test method in "GB / T 2792-2014 Test method for peeling strength of adhesive tape", cut the test object into a size of 24mm*150mm, peel off the release layer of the test object, and stick the adhesive layer on the steel plate. Roll it back and forth three times with a 1kg rubber roller. After placing it in an environment of 23±1℃ and 50±5%RH for 20 minutes, irradiate it with 250mJ / cm2 UV light and place it for 30 minutes. Then, peel the test object from the steel plate at a peeling speed of 300mm / min and a peeling angle of 180°, and record the peeling force of the test object after UV irradiation. In this test example, when the peeling force after UV irradiation is 0.5N / 25mm or less, it is considered qualified.

[0090] (3) Acid and alkali resistance test method ①: Refer to the test method in "GB / T 9274-1988 Determination of resistance of paints and varnishes to liquid media". In an environment of 23±2℃ and 65±5%RH, laminate both sides of a 50mm wide tape with a 50 micron thick PI film. Place it in an environment of 23±2℃ and 65±5%RH for 20 minutes, then soak it in a solution of HF:HCL=1:4 for 1 hour, take it out, and observe whether there is liquid penetration and corrosion on the substrate surface. If liquid penetration and / or corrosion on the substrate surface occurs, it is marked with ×, otherwise it is marked with ○.

[0091] (4) Acid and alkali resistance test ②: In an environment of 23±2℃, 65±5%RH, laminate the two sides of a 50mm wide tape with a 50μm thick PI film, place it in an environment of 23±2℃, 65±5%RH for 20min, and then soak it in (1% NaCO3 for 24h → 5% NaCL for 24h → 3% NaOH for 24h), take it out, and observe whether there is liquid penetration. If there is liquid penetration and / or corrosion on the substrate surface, it is marked with ×, otherwise it is marked 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 30 minutes to obtain a wafer sample. 10,000 wafer samples are prepared repeatedly. When a wafer sample has cracks, scratches, or breakage, 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 subjects

[0095]

[0096] Result analysis:

[0097] By comparing the test results of Examples 1 to 8 with those of Comparative Examples 1 to 6, it can be seen that the tapes provided in Examples 1 to 8 have better acid and alkali resistance than the tapes provided in Comparative Examples 1 to 6, and when the tapes are used in wafer preparation, the measured wafer defect rate is lower. This shows that the adhesive layer formed by the acid- and alkali-resistant UV viscosity-reducing glue provided in this application can form an adhesive layer with excellent acid and alkali resistance, and the adhesive layer is not easily corroded by strong acidic and alkaline liquids.

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

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

[0100] By comparing the test results of Example 1, Examples 6 to 7 with Comparative Examples 4 to 5 in Table 3, it can be seen that when the mass ratio of the hydroxyl monomer to the isocyanate monomer in the preparation raw material of the polyurethane resin is 4 to 10:1, the adhesive layer formed by the UV viscosity-reducing glue has better acid and alkali resistance and bonding performance. Specifically, the adhesive layer has a small peeling force after UV irradiation and a low wafer defect rate.

[0101] By comparing the tapes provided in Example 1, Example 8, and Comparative Example 6, it can be seen that when the epoxy-modified polyurethane resin is used to prepare the UV viscosity-reducing glue, the obtained tape has better compactness and acid and alkali resistance. Further, by comparing the UV viscosity-reducing glues provided in Example 1 with those provided in Example 8, it can be found that in the process of preparing the polyurethane resin, the epoxy-vinyl resin modified by carbamate is used, and the adhesive layer formed by the UV viscosity-reducing glue has excellent bonding properties and mechanical properties.

[0102] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An acid and alkali resistant UV viscosity reducing glue, characterized in that: It comprises a polyurethane resin, a viscosity-reducing resin and an isocyanate curing agent, wherein the polyurethane resin: the viscosity-reducing resin: the isocyanate curing agent is calculated by mass ratio of 80-95:5-20:1-5; The acrylate functionality of the viscosity-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 monomer, isocyanate monomer and epoxy resin, the hydroxyl monomer includes polyester polyol and / or polyether polyol, and the mass ratio of the hydroxyl monomer to the isocyanate monomer is 4-10:

1.

2. The acid- and alkali-resistant UV viscosity-reducing glue according to claim 1, characterized in that: The viscosity-reducing resin includes at least one of dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, and ethoxylated trimethylolpropane triacrylate.

3. The acid- and alkali-resistant UV viscosity-reducing glue according to claim 1, characterized in that: The hydroxyl monomers include polyester polyols and polyether polyols, and the mass of the polyester polyols is not lower than that of the polyether polyols; the molecular weight of the polyether polyols is 1000-3000.

4. The acid- and alkali-resistant UV viscosity-reducing glue as claimed in claim 3, 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, metaphthalic anhydride polyester polyol, and aromatic-aliphatic copolyester polyol.

5. The acid- and alkali-resistant UV viscosity-reducing glue as claimed in claim 1, characterized in that: The epoxy resin includes epoxy vinyl resin.

6. The acid- and alkali-resistant UV viscosity-reducing glue as claimed in claim 5, characterized in that: The epoxy vinyl resin includes an epoxy vinyl resin modified by urethane.

7. The acid-alkali resistant UV viscosity-reducing glue according to any one of claims 1 to 6, characterized in that: The preparation method of the polyurethane resin comprises the following operations: S1. Mixing a hydroxyl monomer, an isocyanate monomer, an additive, and a solvent, and then reacting the reaction system at 70 to 90° C. for 2 to 4 hours to obtain a 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 additive are mixed and stirred until the solid content of the reaction system is 30 to 50%, thereby obtaining the polyurethane resin.

8. A method for preparing the acid- and alkali-resistant UV viscosity-reducing glue according to any one of claims 1 to 7, characterized in that: The following operations are included: The polyurethane resin, the viscosity-reducing resin, the isocyanate curing agent and a solvent are mixed to obtain a first mixture, and the first mixture is mixed with a photoinitiator to obtain the acid- and alkali-resistant UV viscosity-reducing glue.

9. An adhesive tape, characterized in that: The adhesive layer comprises a substrate and an adhesive layer, wherein the adhesive layer is made of the acid-base resistant UV viscosity-reducing glue as claimed in any one of claims 1 to 7.

10. Use of the acid- and alkali-resistant UV viscosity-reducing glue according to any one of claims 1 to 7 or the adhesive tape according to claim 9 in the field of wafer processing or chip manufacturing.

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