Special stick glue for cutting ultrathin silicon wafer and preparation method thereof

Abstract

The invention relates to the field of adhesive rods, in particular to special adhesive rod glue for cutting ultrathin silicon wafers and a preparation method of the adhesive rod glue. The stick glue is prepared from the following raw materials: a component A and a component B, the component A is prepared from the following raw materials: novolac epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, a reactive diluent, a plasticizer, a defoaming agent A, a dispersing agent A, toner and filler A; the component B is prepared from the following raw materials: modified polymercaptan, a modified DDM liquid curing agent, an epoxy curing agent, a toughening agent, an accelerant, a defoaming agent B, a dispersing agent B, color paste and filler B; the modified polymercaptan is prepared from the following raw materials: polymercaptan, DMP-30, IPDI (isophorone diisocyanate) and benzyl alcohol; the modified DDM liquid curing agent is prepared from the following raw materials: DDM, DMP-30, salicylic acid and benzyl alcohol. The rod sticking glue prepared by the invention is excellent in heat resistance, can be suitable for cutting ultrathin silicon wafers, has the advantages of low wafer falling rate and low edge breakage rate, and is excellent in use effect.

Description

Technical Field

[0001] The invention relates to the field of adhesive sticks, in particular to an adhesive stick adhesive specially used for cutting ultra-thin silicon slices and a preparation method thereof. Background Art

[0002] The large-size and thin-film photovoltaic silicon wafers are important ways for photovoltaic material research and development companies to reduce costs and increase efficiency. Large-size silicon wafers can increase the production capacity of equipment, allowing more silicon wafers to be produced per unit time, thereby improving production efficiency; and thin-filming can significantly reduce the thickness of silicon wafers, thereby reducing silicon consumption. Therefore, large-size and thin-filming can effectively improve the working efficiency of components and reduce production and power generation costs.

[0003] Patent document CN115595099B discloses a high-performance diamond wire silicon slice stick adhesive, which is suitable for cutting silicon wafers with a size of 182 / 210mm and a thickness of 150μm; Patent document CN110437779B discloses a stick adhesive for thin-slice silicon slices, which is suitable for cutting silicon wafers with a size of 166mm and a thickness of 160-170μm. Due to the urgent need to reduce costs and increase efficiency, the silicon wafer cutting industry is actively adopting large-size silicon wafers and promoting thinning to 130μm thickness. However, with the changes in silicon wafer size and thickness, the industry is also facing new challenges. When cutting large-size, thin-slice silicon wafers, the technical solutions disclosed in existing patents are prone to frequent chipping of silicon wafers, and after cutting, silicon wafers are prone to fall off the plastic pad, causing losses. Mainly due to the brittle nature of elemental silicon, coupled with its non-deformability compared to glue and plastic pads, silicon wafers are more susceptible to damage during the cutting process. Especially when the silicon wafer is cut to a thinner size, the bonding area between it and the plastic pad is greatly reduced, and the bonding difficulty increases accordingly. In addition, the thinning leads to an increase in the number of silicon wafers, and the heat generated during the cutting process also increases accordingly. If the coolant does not dissipate heat in time, it is very easy to cause edge collapse and wafer drop, which seriously affects the yield of the slices.

[0004] In the automated production line, the gluing process also faces challenges. To ensure the gluing effect, the silicon rods must be transferred to storage for curing and maintenance only after the glue is dry. However, as slicing companies continue to improve their production capacity and efficiency, gluing automation has become a general trend. However, the curing and drying time of the glue in the existing technology is relatively long and can no longer meet current production needs. Although the drying time can be shortened by adding accelerators, this also accelerates the gel process, resulting in the inability of the glue to fully wet the bonding substrate and expel bubbles, which in turn causes empty glue and chip falling problems, which is also not conducive to slicing production.

[0005] Therefore, there is an urgent need for a special adhesive stick for ultra-thin silicon wafer cutting to enable photovoltaic companies to reduce production costs, increase production capacity, and enhance the market competitiveness of enterprises. Summary of the invention

[0006] In order to solve the above technical problems, the first aspect of the present invention provides a special adhesive stick for ultra-thin silicon wafer cutting, and its preparation raw materials include: component A and component B; wherein the preparation raw materials of component A include: epoxy resin, active diluent, plasticizer, defoamer A, dispersant A, color powder, filler A; the preparation raw materials of component B include: modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoamer B, dispersant B, color paste, filler B.

[0007] As an implementable case, the raw materials for preparing component A include, by weight: 40-75 parts of epoxy resin, 5-15 parts of active diluent, 1-5 parts of plasticizer, 0.1-1 parts of defoamer A, 0.5-2 parts of dispersant A, 1-5 parts of color powder, and 30-55 parts of filler A.

[0008] As an implementable case, the raw materials for preparing component B include, by mass, 35-65 parts of modified polythiol, 10-20 parts of modified DDM liquid curing agent, 5-15 parts of epoxy curing agent, 5-15 parts of toughening agent, 5-15 parts of accelerator, 0.1-1 parts of defoaming agent B, 0.5-2 parts of dispersant B, 0.5-1.5 parts of color paste, and 35-60 parts of filler B.

[0009] As an implementable example, the epoxy resin includes novolac epoxy resin, bisphenol A epoxy resin and bisphenol F epoxy resin.

[0010] Furthermore, the mass ratio of the phenolic epoxy resin, bisphenol A epoxy resin and bisphenol F epoxy resin is (5-15): (30-45): (5-15).

[0011] Furthermore, the brand of the phenolic epoxy resin is NPPN-638S, the brand of the bisphenol A epoxy resin is NPEL-128, and the brand of the bisphenol F epoxy resin is NPEF-170, all of which are purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd.

[0012] As an implementable case, the active diluent includes: one or more of acryloylmorpholine, alkoxylated acrylate monomers, acrylates, polyether acrylates, pentaerythritol tetraacrylate, pentaerythritol tetraglycidyl ether, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0013] Furthermore, the active diluent is pentaerythritol tetraglycidyl ether, which is purchased from Anhui Xinyuan Technology Co., Ltd.

[0014] As an implementable case, the plasticizer includes: one or more of dibutyl phthalate, dioctyl phthalate, dioctyl adipate, dioctyl sebacate, and triphenyl phosphate.

[0015] Furthermore, the plasticizer is dibutyl phthalate.

[0016] Pentaerythritol tetraglycidyl ether has four glycidyl ether groups, which can react chemically with phenolic epoxy resin, bisphenol A epoxy resin and bisphenol F epoxy resin in the system to form a three-dimensional cross-linked structure with strong resistance to chemical corrosion and mechanical impact, which can make the product have higher cross-linking density and reactivity, thereby improving the strength and hardness of the adhesive stick; in addition, the product of the three-dimensional cross-linked structure can effectively resist thermal decomposition and oxidation performance at high temperature, thereby improving the heat resistance of the adhesive stick, so the glue can still maintain stable performance in a high temperature environment and is not prone to deformation or failure. Dibutyl phthalate, as a plasticizer, can improve the flexibility and fluidity of the epoxy resin and pentaerythritol tetraglycidyl ether system; by interacting with the hydroxyl and amino groups in the epoxy resin, it forms cross-links of the polymer molecular chains, further increasing the plasticity and ductility of the molecular chains. In addition, dibutyl phthalate can also react with the epoxy groups in the epoxy resin to form a cross-linked structure, increase the cross-linking force between molecules, increase the viscosity and viscosity of the adhesive, improve the degumming situation, reduce the chip drop rate, and at the same time increase the sensitivity of the adhesive film to acid.

[0017] As an implementable case, the toner includes titanium dioxide, brand BLR-891, purchased from Longbai Group Co., Ltd.

[0018] As an implementable case, the dispersant A and dispersant B include: one of silicon dioxide, aluminum oxide, and calcium silicate.

[0019] Furthermore, the dispersant A and the dispersant B are both silicon dioxide.

[0020] Furthermore, the silicon dioxide is fumed silicon dioxide with a brand name of R972, purchased from Evonik Industries.

[0021] The present invention does not further limit the types of the defoamer A and the defoamer B. Any substance that can reduce the generation of foam during the preparation process can be used, including but not limited to the defoamer with the brand name Elementis Defom 6800.

[0022] As an implementable case, the filler A includes: one of calcium carbonate, calcium oxide, and aluminum hydroxide.

[0023] Furthermore, the filler A is calcium carbonate.

[0024] Furthermore, the calcium carbonate is light calcium carbonate with a mesh size of 1250, purchased from Guangxi Qi Chuang Biotechnology Co., Ltd.

[0025] As an implementable case, the filler B includes: one of calcium carbonate, calcium oxide, and aluminum hydroxide.

[0026] Furthermore, the filler B is aluminum hydroxide.

[0027] Furthermore, the aluminum hydroxide has a mesh size of 1000 mesh and is purchased from Aluminum Corporation of China.

[0028] As an implementable case, the preparation method of component A includes: heating the phenolic epoxy resin to 40-45°C, putting it into a stirring kettle, adding an active diluent and a plasticizer, stirring at 400-600rpm for 10-20min, adding bisphenol A epoxy resin and bisphenol F epoxy resin, defoamer A and dispersant A, stirring at 30-45°C and 600-800rpm for 1-2h; adding color powder and filler A, and vacuum stirring at 35-45°C and 600-800rpm for 1-2h to obtain the product.

[0029] As an implementable case, the raw materials for preparing the modified DDM liquid curing agent include, by weight, 100 parts of DDM (diaminodiphenylmethane), 5-15 parts of DMP-30 (epoxy accelerator), 10-20 parts of salicylic acid, and 45-70 parts of benzyl alcohol.

[0030] As an implementable case, the preparation method of the DDM liquid curing agent includes: first adding DDM and salicylic acid to a reaction kettle, heating to 90-120°C, and stirring at 400-800rpm for 0.5-2.0h; after stirring evenly, cooling to 60-80°C, adding benzyl alcohol and DMP-30, and then vacuum stirring for 0.5-2.0h at a speed of 400-800rpm and a vacuum degree of -0.07 to -0.1MPa; after stirring evenly, cooling to 25-30°C to obtain the product.

[0031] As an implementable case, the raw materials for preparing the modified polythiol include, by weight, 100 parts of polythiol, 5-15 parts of DMP-30, 2-6 parts of isophorone diisocyanate (IPDI), and 5-20 parts of benzyl alcohol.

[0032] As an practicable example, the preparation method of the modified polythiol comprises:

[0033] First, add polythiol, benzyl alcohol and DMP-30 into the reaction kettle, heat to 60-80°C, and stir at 600-1000rpm for 0.5-1.5h; then add IPDI dropwise, and then continue stirring for 1-2.5h at 60-80°C, rotation speed 600-1000rpm, vacuum degree -0.07~-0.1MPa to obtain the product.

[0034] Furthermore, the Vicat softening point of the polythiol is 34.2° C., the brand is GPM-800, and it is purchased from Huntsman Corporation of the United States.

[0035] The raw material IPDI of the modified polythiol in the present invention is an alicyclic diisocyanate having two active isocyanate groups (-NCO) and can undergo addition reaction with the thiol group (-SH) in the polythiol to form a polyurethane structure; the polyurethane structure itself has excellent heat resistance and can withstand high temperatures without significant performance degradation; and DMP-30, as an efficient catalyst, can reduce the activation energy required for the reaction between polythiol and IPDI, thereby accelerating the reaction and efficiently preparing the modified polythiol.

[0036] The modified polythiol in the present invention can work together with the modified DDM liquid curing agent to further improve the heat resistance and bonding performance of the adhesive stick glue, and at the same time can also delay the operable time to avoid the situation of empty glue or silicon wafer falling due to factors such as too fast gelation, too short time for the adhesive stick glue to wet the bonding substrate, and too short time for degassing.

[0037] As an implementable case, the epoxy curing agent is a modified amine epoxy curing agent.

[0038] Furthermore, the modified amine epoxy curing agent is of the brand G-328, purchased from Mitsubishi Gas Chemical Co., Ltd. of Japan.

[0039] As an implementable example, the cross-linking agent includes pentaerythritol tetrakis(3-mercaptopropionate), which is purchased from Guangzhou Green New Materials Co., Ltd.

[0040] As an implementable case, the accelerator includes DMP-30 (2,4,6-tris(dimethylaminomethyl)phenol), which is purchased from Guangzhou Feisi Synthetic Materials Co., Ltd.

[0041] As an implementable case, the brand of the color paste includes NS-39, and the brand is Indonesia Motor.

[0042] As an implementable case, the preparation method of the B component includes: heating the stirring kettle to 35-45°C, adding modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoamer B, dispersant B and color paste, stirring at 600-800rpm for 1-2h, then adding filler B, stirring at 800-1000rpm for 1-2h; and then vacuuming for 1-2h to obtain.

[0043] The second aspect of the present invention provides a method for preparing a special adhesive stick for ultra-thin silicon wafer cutting, comprising: mixing component A and component B, and curing to obtain the adhesive stick.

[0044] Beneficial Effects

[0045] (i) The present invention has excellent fatigue resistance and impact resistance through the stick glue, and is resistant to high heat and coolant erosion, which can effectively prevent the glue layer from being damaged during the cutting process of the thin slice.

[0046] (ii) The adhesive stick provided by the present invention can be applied to the bonding of silicon wafer slices with a thickness of 130 μm. After bonding, the silicon wafer is not easy to break and fall off, which is a significant improvement compared with the prior art.

[0047] (III) The raw materials of component A in the present invention include pentaerythritol tetraglycidyl ether, phenolic epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin and dibutyl phthalate, which can form a macromolecular polymer with a cross-linked network structure after compounding reaction. After the product is used, it not only reduces the chip drop rate, but also improves the heat resistance of the adhesive.

[0048] (IV) The raw materials for preparing the modified DDM liquid curing agent in the present invention include DDM, salicylic acid and accelerator DMP-30. Using salicylic acid to modify DDM and DMP-30 with amino groups can further improve the heat resistance of the product.

[0049] (V) The adhesive stick provided by the present invention is in line with adhesive automation, can improve the bonding efficiency, shorten the time for machine cutting, and can effectively help silicon wafer cutting companies reduce production costs, increase production capacity, improve the market competitiveness of enterprises, and promote the development of China's photovoltaic industry. DETAILED DESCRIPTION

[0050] In the following Examples 1-3, the manufacturers and brands of the raw materials used are as follows:

[0051] The brand of the phenolic epoxy resin is NPPN-638S, the brand of the bisphenol A epoxy resin is NPEL-128, and the brand of the bisphenol F epoxy resin is NPEF-170, all of which are purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd.

[0052] The pentaerythritol tetraglycidyl ether was purchased from Anhui Xinyuan Technology Co., Ltd.

[0053] The dibutyl phthalate was purchased from Shandong Chuangying Chemical Co., Ltd.

[0054] The defoamer with the brand name Elementis Defom 6800 was purchased from Shanghai Haimingshi Deqian Chemical Co., Ltd.

[0055] The grade of the fumed silica is R972, purchased from Evonik Industries.

[0056] The brand of the titanium dioxide is BLR-891, which was purchased from Longbai Group Co., Ltd.

[0057] The mesh number of the light calcium carbonate is 1250 mesh, which is purchased from Guangxi Qi Chuang Biotechnology Co., Ltd.

[0058] The Vicat softening point of the polythiol is 34.2° C., the grade is GPM-800, and it is purchased from Huntsman Corporation of the United States.

[0059] The benzyl alcohol was purchased from Hubei Green Home Materials Technology Co., Ltd.

[0060] The DMP-30 was purchased from Guangzhou Feisi Synthetic Materials Co., Ltd.

[0061] The IPDI was purchased from Wanhua Chemical Group.

[0062] The DDM was purchased from Tongchuang Chemical (Nanjing) Co., Ltd.

[0063] The salicylic acid was purchased from Langfang Pengcai Fine Chemical Co., Ltd.

[0064] The epoxy curing agent with the brand name of G-328 was purchased from Mitsubishi Gas Chemical Co., Ltd. of Japan.

[0065] The tetrakis(3-mercaptopropionic acid) pentaerythritol ester was purchased from Guangzhou Green New Materials Co., Ltd.

[0066] The color paste is NS-39 and the brand is Indonesian Motor.

[0067] The aluminum hydroxide has a mesh size of 1000 mesh and is purchased from Aluminum Corporation of China.

[0068] Example 1

[0069] In a first aspect, this example provides a special adhesive stick for ultra-thin silicon wafer cutting, and the raw materials for preparing the adhesive stick include: component A and component B.

[0070] The raw materials for preparing the component A include, by weight: 7 parts of phenolic epoxy resin, 45 parts of bisphenol A epoxy resin, 5 parts of bisphenol F epoxy resin, 10 parts of active diluent, 5 parts of plasticizer, 0.2 parts of defoamer A, 1 part of dispersant A, 2 parts of color powder, and 45 parts of filler A.

[0071] The active diluent is pentaerythritol tetraglycidyl ether.

[0072] The plasticizer is dibutyl phthalate.

[0073] The brand of the defoamer A is Elementis Defom 6800.

[0074] The accelerator is DMP-30.

[0075] The dispersant A is fumed silica.

[0076] The toner is titanium dioxide.

[0077] The filler A is aluminum hydroxide.

[0078] The preparation method of component A comprises: heating a phenolic epoxy resin to 45°C, putting the phenolic epoxy resin into a stirring kettle, adding an active diluent and a plasticizer, stirring at 600 rpm for 15 minutes, adding bisphenol A epoxy resin and bisphenol F epoxy resin, a defoamer A and a dispersant A, stirring at 45°C and 800 rpm for 2 hours; adding a color powder and a filler A, and vacuum stirring at 45°C and 800 rpm for 2 hours to obtain the component.

[0079] The raw materials for preparing the B component include, by weight: 35 parts of modified polythiol, 20 parts of modified DDM liquid curing agent, 10 parts of epoxy curing agent, 10 parts of toughening agent, 12 parts of accelerator, 0.2 parts of defoamer B, 1 part of dispersant B, 0.5 parts of color paste, and 50 parts of filler B.

[0080] The raw materials for preparing the modified polythiol include, by weight, 100 parts of polythiol, 10 parts of benzyl alcohol, 10 parts of DMP-30 and 5 parts of IPDI.

[0081] The preparation method of the modified polythiol comprises:

[0082] First, add polythiol, benzyl alcohol and DMP-30 into the reaction kettle, heat to 80°C, and stir at 600rpm for 1h; then add IPDI dropwise while keeping the temperature, and then continue stirring at 80°C, 600rpm, and vacuum degree -0.08MPa for 2h, and then cool to 25°C to obtain the product.

[0083] The raw materials for preparing the modified DDM liquid curing agent include, by weight, 100 parts of DDM (diaminodiphenylmethane), 5 parts of DMP-30, 15 parts of salicylic acid, and 45 parts of benzyl alcohol.

[0084] The preparation method of the DDM liquid curing agent comprises: firstly adding DDM and salicylic acid into a reaction kettle, heating to 120°C, and stirring at 800 rpm for 1.5 hours; after stirring evenly, cooling to 80°C, adding benzyl alcohol and DMP-30, and then vacuum stirring for 2.0 hours at a speed of 800 rpm and a vacuum degree of -0.08 MPa; after stirring evenly, cooling to 25°C to obtain the product.

[0085] The brand of the epoxy curing agent is G-328.

[0086] The toughening agent is pentaerythritol tetrakis (3-mercaptopropionic acid) ester.

[0087] The accelerator is DMP-30.

[0088] The brand of the defoamer B is Elementis Defom 6800.

[0089] The filler B is light calcium carbonate.

[0090] The preparation method of the B component comprises: heating the stirring kettle to 45° C., adding modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoamer B, dispersant B and color paste, stirring at 800 rpm for 2 hours, then adding filler B, stirring at 1000 rpm for 2 hours; and then vacuuming for 1 hour to obtain the product.

[0091] The second aspect of this example provides a method for preparing a special adhesive for ultra-thin silicon wafer cutting, comprising: mixing component A and component B in a volume ratio of 1:1, bonding a silicon rod to a pad, and curing for 2 hours.

[0092] Example 2

[0093] In a first aspect, this example provides a special adhesive stick for ultra-thin silicon wafer cutting, and the raw materials for preparing the adhesive stick include: component A and component B.

[0094] The raw materials for preparing the component A include, by weight: 10 parts of phenolic epoxy resin, 45 parts of bisphenol A epoxy resin, 5 parts of bisphenol F epoxy resin, 15 parts of active diluent, 5 parts of plasticizer, 0.2 parts of defoamer A, 1 part of dispersant A, 2 parts of color powder, and 45 parts of filler A.

[0095] The active diluent is pentaerythritol tetraglycidyl ether.

[0096] The plasticizer is dibutyl phthalate.

[0097] The brand of the defoamer A is Elementis Defom 6800.

[0098] The accelerator is DMP-30.

[0099] The dispersant A is fumed silica.

[0100] The toner is titanium dioxide.

[0101] The filler A is aluminum hydroxide.

[0102] The preparation method of component A comprises: heating a phenolic epoxy resin to 45°C, putting the phenolic epoxy resin into a stirring kettle, adding an active diluent and a plasticizer, stirring at 600 rpm for 15 minutes, adding bisphenol A epoxy resin and bisphenol F epoxy resin, a defoamer A and a dispersant A, stirring at 45°C and 800 rpm for 2 hours; adding a color powder and a filler A, and vacuum stirring at 45°C and 800 rpm for 2 hours to obtain the component.

[0103] The raw materials for preparing the B component include, by weight: 60 parts of modified polythiol, 15 parts of modified DDM liquid curing agent, 15 parts of epoxy curing agent, 10 parts of toughening agent, 10 parts of accelerator, 0.2 parts of defoamer B, 1 part of dispersant B, 0.5 parts of color paste, and 50 parts of filler B.

[0104] The raw materials for preparing the modified polythiol include, by weight, 100 parts of polythiol, 10 parts of benzyl alcohol, 10 parts of DMP-30 and 5 parts of IPDI.

[0105] The preparation method of the modified polythiol comprises:

[0106] First, add polythiol, benzyl alcohol and DMP-30 into the reaction kettle, heat to 80°C, and stir at 600rpm for 1h; then add IPDI dropwise while keeping the temperature, and then continue stirring at 80°C, 600rpm, and vacuum degree -0.08MPa for 2h, and then cool to 25°C to obtain the product.

[0107] The raw materials for preparing the modified DDM liquid curing agent include, by weight, 100 parts of DDM, 5 parts of DMP-30, 15 parts of salicylic acid, and 45 parts of benzyl alcohol.

[0108] The preparation method of the DDM liquid curing agent comprises: firstly adding DDM and salicylic acid into a reaction kettle, heating to 120°C, and stirring at 800 rpm for 1.5 hours; after stirring evenly, cooling to 80°C, adding benzyl alcohol and DMP-30, and then vacuum stirring for 2.0 hours at a speed of 800 rpm and a vacuum degree of -0.08 MPa; after stirring evenly, cooling to 25°C to obtain the product.

[0109] The brand of the epoxy curing agent is G-328.

[0110] The toughening agent is pentaerythritol tetrakis (3-mercaptopropionic acid) ester.

[0111] The accelerator is DMP-30.

[0112] The brand of the defoamer B is Elementis Defom 6800.

[0113] The filler B is light calcium carbonate.

[0114] The preparation method of the B component comprises: heating the stirring kettle to 45° C., adding modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoamer B, dispersant B and color paste, stirring at 800 rpm for 2 hours, then adding filler B, stirring at 1000 rpm for 2 hours; and then vacuuming for 1 hour to obtain the product.

[0115] The second aspect of this example provides a method for preparing a special adhesive for ultra-thin silicon wafer cutting, comprising: mixing component A and component B in a volume ratio of 1:1, bonding a silicon rod to a pad, and curing for 2 hours.

[0116] Example 3

[0117] In a first aspect, this example provides a special adhesive stick for ultra-thin silicon wafer cutting, and the raw materials for preparing the adhesive stick include: component A and component B.

[0118] The raw materials for preparing the A component include, by weight: 10 parts of phenolic epoxy resin, 40 parts of bisphenol A epoxy resin, 15 parts of bisphenol F epoxy resin, 5 parts of active diluent, 5 parts of plasticizer, 0.2 parts of defoamer A, 1 part of dispersant A, 2 parts of color powder, and 50 parts of filler A.

[0119] The active diluent is pentaerythritol tetraglycidyl ether.

[0120] The plasticizer is dibutyl phthalate.

[0121] The brand of the defoamer A is Elementis Defom 6800.

[0122] The accelerator is DMP-30.

[0123] The dispersant A is fumed silica.

[0124] The toner is titanium dioxide.

[0125] The filler A is aluminum hydroxide.

[0126] The preparation method of component A comprises: heating a phenolic epoxy resin to 45°C, putting the phenolic epoxy resin into a stirring kettle, adding an active diluent and a plasticizer, stirring at 600 rpm for 15 minutes, adding bisphenol A epoxy resin and bisphenol F epoxy resin, a defoamer A and a dispersant A, stirring at 45°C and 800 rpm for 2 hours; adding a color powder and a filler A, and vacuum stirring at 45°C and 800 rpm for 2 hours to obtain the component.

[0127] The raw materials for preparing the B component include, by weight: 50 parts of modified polythiol, 20 parts of modified DDM liquid curing agent, 5 parts of epoxy curing agent, 15 parts of toughening agent, 15 parts of accelerator, 0.2 parts of defoamer B, 1 part of dispersant B, 0.5 parts of color paste, and 50 parts of filler B.

[0128] The raw materials for preparing the modified polythiol include, by weight, 100 parts of polythiol, 5 parts of benzyl alcohol, 15 parts of DMP-30 and 2 parts of IPDI.

[0129] The preparation method of the modified polythiol comprises:

[0130] First, add polythiol, benzyl alcohol and DMP-30 into the reaction kettle, heat to 80°C, and stir at 600rpm for 1h; then add IPDI dropwise while keeping the temperature, and then continue stirring at 80°C, 600rpm, and vacuum degree -0.08MPa for 2h, and then cool to 25°C to obtain the product.

[0131] The raw materials for preparing the modified DDM liquid curing agent include, by weight, 100 parts of DDM, 15 parts of DMP-30, 15 parts of salicylic acid, and 70 parts of benzyl alcohol.

[0132] The preparation method of the DDM liquid curing agent comprises: firstly adding DDM and salicylic acid into a reaction kettle, heating to 120°C, and stirring at 800 rpm for 1.5 hours; after stirring evenly, cooling to 80°C, adding benzyl alcohol and DMP-30, and then vacuum stirring for 2.0 hours at a speed of 800 rpm and a vacuum degree of -0.08 MPa; after stirring evenly, cooling to 25°C to obtain the product.

[0133] The brand of the epoxy curing agent is G-328.

[0134] The toughening agent is pentaerythritol tetrakis (3-mercaptopropionic acid) ester.

[0135] The accelerator is DMP-30.

[0136] The brand of the defoamer B is Elementis Defom 6800.

[0137] The filler B is light calcium carbonate.

[0138] The preparation method of the B component comprises: heating the stirring kettle to 45° C., adding modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoamer B, dispersant B and color paste, stirring at 800 rpm for 2 hours, then adding filler B, stirring at 1000 rpm for 2 hours; and then vacuuming for 1 hour to obtain the product.

[0139] The second aspect of this example provides a method for preparing a special adhesive for ultra-thin silicon wafer cutting, comprising: mixing component A and component B in a volume ratio of 1:1, bonding a silicon rod to a pad, and curing for 2 hours.

[0140] Comparative Example 1

[0141] The stick glue was prepared according to the technical scheme of Example 4 involved in Chinese patent CN110437779B.

[0142] Specifically, the stick glue comprises component A and component B.

[0143] Component A comprises the following raw materials in mass fractions: 10% of glycidyl ester epoxy resin, 35% of bisphenol A epoxy resin, 10% of hydrogenated bisphenol A epoxy resin, 3% of organosilicon defoamer, 5% of fumed silica, 3% of KH-570 and 34% of talc.

[0144] Component B comprises the following raw materials in mass fractions: 50% of polythiol, 1% of m-xylylenediamine, 3.99% of accelerator, 40% of barium sulfate, 0.01% of hydrogenated castor oil, and 5% of fumed silica.

[0145] The mass ratio of component A to component B is 1:1.

[0146] Comparative Example 2

[0147] The stick glue was prepared according to the technical scheme involved in Example 1 of Chinese patent CN115595099B.

[0148] Specifically, the raw materials of the adhesive stick include component A and component B.

[0149] Among them: Component A, in parts by weight, includes the following raw materials: bisphenol A epoxy resin E-51: 25 parts, bisphenol A epoxy resin E-44: 10 parts, hydrogenated bisphenol A epoxy resin 30 parts, dodecyl glycidyl ether: 5 parts, dibutyl phthalate: 5 parts, defoamer: 0.5 parts, anti-settling agent: 1.5 parts, thixotropic agent: 1 part, coupling agent: 1.3 parts, diluent: 0.5 parts, titanium dioxide: 5 parts, and silicon micropowder 40 parts.

[0150] Component B, in parts by weight, includes the following raw materials: modified polythiol: 60 parts, modified quick-drying polythiol: 30 parts, pentaerythritol tetrakis(3-mercaptopropionic acid): 10 parts, modified polyetheramine: 1 part, modified alicyclic amine: 8 parts, meta-xylylenediamine: 2 parts, diluent: 10 parts, defoamer: 0.6 parts, anti-settling agent: 2 parts, and calcium carbonate: 45 parts.

[0151] The modified polythiol brand is GPM830CB, the modified quick-drying polythiol brand is QE-340M; the coupling agent is silane coupling agent KH-560; the A component diluent is benzyl alcohol; the B component diluent (accelerator) is DMP-30; the defoaming agent is defoaming agent BYK-054; the anti-settling agent is anti-settling agent BYK-410 and fumed silica; the weight ratio of anti-settling agent BYK-410 to fumed silica is 2:3.

[0152] Performance Evaluation

[0153] The products prepared in Examples 1-3 and Comparative Examples 1-2 were ultrasonically immersed in Derby coolant NB168 at 45°C and 1.5% mass concentration for 2 hours, and then the shear strength, gel time, surface dry time and Vicat softening point were tested. At the same time, data of bonding 182 / 210mm silicon rods and cutting 130μm thick silicon wafers during actual field applications were collected for comparison, and specific chip drop rate and edge collapse rate were tested. The experimental test data are detailed in Table 1.

[0154] Table 1

[0155]

[0156] The above experimental results show that the products prepared in Examples 1-3 have excellent heat resistance and coolant resistance. After ultrasonic immersion in coolant, the shear strength remains above 15MPa, and the chip drop rate is significantly reduced. The separation of the silicon wafer and the adhesive layer after cutting was observed on site at the slicing end. There was almost no separation in Examples 1-3, while the silicon wafer and the adhesive were separated to varying degrees or seriously dropped in Comparative Examples 1-2, resulting in large losses.

[0157] Since some silicon wafers were separated from the glue when cutting 182 / 210mm silicon rods and 130μm thick silicon wafers in Comparative Example 1-2, the adhesive surface of the silicon wafer was not protected by the glue layer when the steel wire was running, which caused the edge to break due to wear, resulting in degradation of the silicon wafer and reduced yield. In Example 1-3, there was no separation of the glue layer from the silicon wafer, which greatly reduced the occurrence of edge breakage and the edge breakage rate. At the same time, the surface drying time of the products in Example 1-3 was shorter, and the gel time was longer, which increased the bonding operation efficiency and extended the operable time of the slicing process.

Claims

1. A special adhesive for ultra-thin silicon wafer cutting, characterized in that: The preparation raw materials include: component A, component B; The raw materials for preparing the A component include: epoxy resin, reactive diluent, plasticizer, defoamer A, dispersant A, color powder, filler A; The epoxy resin includes novolac epoxy resin, bisphenol A epoxy resin and bisphenol F epoxy resin; The raw materials for preparing the B component include: modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoaming agent B, dispersant B, color paste and filler B.

2. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 1, characterized in that: The raw materials for preparing the component A include, by weight: 40-75 parts of epoxy resin, 5-15 parts of active diluent, 1-5 parts of plasticizer, 0.1-1 parts of defoamer A, 0.5-2 parts of dispersant A, 1-5 parts of color powder, and 30-55 parts of filler A.

3. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 1, characterized in that: The mass ratio of the phenolic epoxy resin, bisphenol A epoxy resin and bisphenol F epoxy resin is (5-15): (30-45): (5-15).

4. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 1, characterized in that: The preparation method of component A comprises: heating the phenolic epoxy resin to 40-45°C, putting it into a stirring kettle, adding a reactive diluent and a plasticizer, stirring at 400-600rpm for 10-20min, adding bisphenol A epoxy resin and bisphenol F epoxy resin, defoamer A and dispersant A, stirring at 30-45°C and 600-800rpm for 1-2h; adding color powder and filler A, stirring at 35-45°C and 600-800rpm for 1-2h, and obtaining the product.

5. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 1, characterized in that: The raw materials for preparing the modified DDM liquid curing agent include, by weight, 100 parts of DDM, 5-15 parts of DMP-30, 10-20 parts of salicylic acid, and 45-70 parts of benzyl alcohol.

6. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 5, characterized in that: The preparation method of the DDM liquid curing agent comprises: First, add DDM and salicylic acid into the reaction kettle, heat to 90-120°C, and stir at 400-800rpm for 0.5-2.0h; after stirring evenly, cool to 60-80°C, add benzyl alcohol and DMP-30, and then stir in vacuum at a speed of 400-800rpm and a vacuum degree of -0.07 to -0.1MPa for 0.5-2.0h; after stirring evenly, cool to 25-30°C to obtain the product.

7. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 1, characterized in that: The raw materials for preparing the modified polythiol include, by weight, 100 parts of polythiol, 5-15 parts of DMP-30, 2-6 parts of isophorone diisocyanate, and 5-20 parts of benzyl alcohol.

8. The special adhesive stick for ultra-thin silicon wafer cutting according to claim 7, characterized in that: The preparation method of the modified polythiol comprises: First, add polythiol, benzyl alcohol and DMP-30 into the reaction kettle, heat to 60-80°C, and stir at 600-1000rpm for 0.5-1.5h; then add isophorone diisocyanate dropwise, and then continue stirring for 1-2.5h at 60-80°C, rotation speed 600-1000rpm, vacuum degree -0.07~-0.1MPa to obtain the product.

9. The adhesive stick for ultra-thin silicon wafer cutting according to any one of claims 1 to 8, characterized in that: The preparation method of the B component comprises: heating the stirring kettle to 35-45° C., adding modified polythiol, modified DDM liquid curing agent, epoxy curing agent, toughening agent, accelerator, defoamer B, dispersant B and color paste, stirring at 600-800 rpm for 1-2 hours, then adding filler B, stirring at 800-1000 rpm for 1-2 hours; and then vacuuming for 1-2 hours to obtain the product.

10. A method for preparing a special adhesive stick for ultra-thin silicon wafer cutting according to any one of claims 1 to 9, characterized in that: include: Mix component A and component B and solidify to obtain the product.

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