Fluorine-containing acrylate pressure-sensitive adhesive as well as preparation method and application thereof

Abstract

The invention provides a fluorine-containing acrylate pressure-sensitive adhesive as well as a preparation method and application thereof, and the fluorine-containing acrylate pressure-sensitive adhesive is prepared from the following raw materials in parts by weight: 30-70 parts of a soft monomer; 10 to 40 parts of a hard monomer; 1-40 parts of a fluorine-containing monomer; 1-10 parts of a functional monomer; 0.1 to 0.3 part of a thermal initiator; 100 to 300 parts of a solvent; the fluorine-containing monomer comprises any one or a combination of at least two of trifluoroethyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, hexafluoroisopropyl acrylate, octafluoroamyl acrylate, dodecafluoroheptyl acrylate, dodecafluoroheptyl methacrylate and tridecafluorooctyl methacrylate. The wafer cutting adhesive tape prepared from the fluorine-containing acrylate pressure-sensitive adhesive provided by the invention has relatively good stripping performance, high temperature resistance and hydrophobicity.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor wafer dicing tapes, and relates to a fluorine-containing acrylate pressure-sensitive adhesive and a preparation method and application thereof, and specifically relates to a fluorine-containing acrylate pressure-sensitive adhesive and a preparation method thereof, a wafer dicing tape and a preparation method and application thereof. Background Art

[0002] Wafer dicing tape is an important consumable required in the semiconductor back-end process. It protects and supports the wafer. The wafer dicing process requires this type of tape to have high adhesion to protect and fix the chip, and at the same time have a certain peel strength to ensure that there is no residual adhesive left on the wafer surface after peeling. The performance of wafer dicing tape is directly related to the yield and reliability of the chip.

[0003] With the development of advanced packaging technology, the requirements for large-size, ultra-thin wafer processing, and the emergence of new dicing processes, traditional acrylic pressure-sensitive adhesive (PSA)-based non-UV wafer dicing tapes have certain limitations in terms of heat resistance, radiation resistance, and solvent resistance. Therefore, it is necessary to functionalize traditional acrylic PSA to impart certain heat resistance and solvent resistance. At the same time, through modification, the adhesive properties of the PSA can be adjusted to better meet the challenges of advanced packaging technology. Summary of the Invention

[0004] In response to the shortcomings of the prior art, the present invention aims to provide a fluorinated acrylate pressure-sensitive adhesive, its preparation method, and its application. The present invention introduces fluorinated groups into the acrylate polymer molecular chain. Since these rigid groups effectively enhance the cohesive strength of the pressure-sensitive adhesive system, thereby improving the adhesive's thermal stability and solvent resistance, the fluorinated groups also possess extremely low surface free energy, enhancing the tape's hydrophobicity. Furthermore, the adhesive properties of the pressure-sensitive adhesive can be adjusted to meet the demands of wafer dicing applications.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a fluorinated acrylate pressure-sensitive adhesive. The raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive include the following components in parts by weight:

[0007]

[0008] The fluorine-containing monomer includes any one of trifluoroethyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, hexafluoroisopropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl acrylate, dodecafluoroheptyl methacrylate, and tridecafluorooctyl methacrylate, or a combination of at least two thereof.

[0009] The present invention introduces a specific type of fluorine-containing monomer into a traditional acrylate pressure-sensitive adhesive system to prepare a fluorine-containing acrylate pressure-sensitive adhesive, which is used in wafer dicing tape, effectively improving the cohesive strength of the adhesive layer, thereby improving the thermal stability and solvent resistance of the adhesive layer, reducing the surface free energy of the tape, improving the hydrophobicity of the tape surface, and improving the bonding performance with the wafer surface.

[0010] In the present invention, the raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive are calculated by weight, and the amount of the soft monomer can be 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, etc.

[0011] In the present invention, the raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive are calculated by weight, and the amount of the hard monomer used can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, etc.

[0012] In the present invention, the raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive are calculated in parts by weight, and the amount of the fluorinated monomer can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, etc.

[0013] In the present invention, the raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive are calculated by weight, and the amount of the functional monomer can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0014] In the present invention, the raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive are calculated by weight, and the amount of the thermal initiator used can be 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, etc.

[0015] In the present invention, the raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive are calculated by weight, and the amount of the solvent used can be 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, 150 parts, 160 parts, 170 parts, 180 parts, 190 parts, 200 parts, 210 parts, 220 parts, 230 parts, 240 parts, 250 parts, 260 parts, 270 parts, 280 parts, 290 parts, 300 parts, etc.

[0016] Preferably, the soft monomer includes any one of isooctyl acrylate, butyl acrylate, lauryl acrylate, isononyl acrylate, and ethyl acrylate, or a combination of at least two thereof.

[0017] Preferably, the hard monomer includes any one of methyl acrylate, methyl methacrylate, isobornyl methacrylate, vinyl acetate, styrene, acrylonitrile, and acrylamide, or a combination of at least two thereof.

[0018] Preferably, the functional monomer includes any one or a combination of at least two of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid, and acrylamide.

[0019] Preferably, the thermal initiator includes any one of azobisisobutyronitrile, azobisisoheptanenitrile, and dibenzoyl peroxide, or a combination of at least two thereof.

[0020] Preferably, the solvent includes any one of ethyl acetate, toluene, methanol, and ethanol, or a combination of at least two thereof.

[0021] In a second aspect, the present invention provides a method for preparing the fluorinated acrylate pressure-sensitive adhesive as described in the first aspect, the preparation method comprising the following steps:

[0022] The soft monomer, the hard monomer, the fluorine-containing monomer, the functional monomer, the thermal initiator and the solvent are mixed, and the fluorine-containing acrylate pressure-sensitive adhesive is synthesized by adopting a thermally initiated free radical polymerization process.

[0023] As a preferred technical solution of the present invention, the preparation method of the fluorinated acrylate pressure-sensitive adhesive specifically comprises the following steps:

[0024] (1) adding part of the soft monomer, part of the hard monomer, part of the functional monomer, part of the fluorine-containing monomer, and part of the solvent into a reaction vessel as a base material, and heating;

[0025] (2) After the base material is heated up, the remaining soft monomer, the remaining hard monomer, the remaining functional monomer, the remaining fluorine-containing monomer, part of the solvent, and part of the thermal initiator are added to the reaction vessel and kept warm for reaction;

[0026] (3) heating the reaction system, adding part of the solvent and part of the thermal initiator, and maintaining the temperature for reaction;

[0027] (4) heating the reaction system, adding the remaining solvent and the remaining thermal initiator, and then maintaining the temperature to react to obtain the fluorinated acrylate pressure-sensitive adhesive.

[0028] As a preferred technical solution of the present invention, in the preparation method of the fluorinated acrylate pressure-sensitive adhesive, the free radical polymerization reaction adopts a semi-continuous dropwise polymerization process to improve the conversion rate and prevent the gel effect.

[0029] Preferably, the total amount of the part of the soft monomers, part of the hard monomers, part of the functional monomers, and part of the fluorine-containing monomers in step (1) accounts for 30 wt.% to 40 wt.% of the total amount of all reactive monomers (i.e., the total amount of soft monomers, hard monomers, functional monomers, and fluorine-containing monomers), for example, 30 wt.%, 32 wt.%, 34 wt.%, 35 wt.%, 36 wt.%, 38 wt.%, 40 wt.%, etc.

[0030] Preferably, the amount of the partial solvent in step (1) accounts for 35wt.% to 45wt.% of the total solvent amount, for example, 35wt.%, 36wt.%, 38wt.%, 40wt.%, 42wt.%, 43wt.%, 45wt.%, etc.

[0031] Preferably, the temperature in step (1) is raised to 65-70°C, such as 65°C, 66°C, 68°C, 70°C, etc.

[0032] Preferably, the amount of the partial solvent used in step (2) accounts for 15wt.% to 25wt.% of the total solvent amount, for example, 15wt.%, 16wt.%, 18wt.%, 20wt.%, 22wt.%, 23wt.%, 25wt.%, etc.

[0033] Preferably, the amount of the partial thermal initiator in step (2) accounts for 45wt.% to 55wt.% of the total amount of thermal initiator, for example, 45wt.%, 46wt.%, 48wt.%, 50wt.%, 52wt.%, 53wt.%, 55wt.%, etc.

[0034] Preferably, the adding in step (2) includes dropwise addition, and the addition is completed within 1 to 2 hours (e.g., 1 hour, 1.5 hours, 2 hours, etc.). For example, a small peristaltic pump can be used for slow dropwise addition.

[0035] Preferably, the temperature of the insulation reaction in step (2) is 65-70°C (e.g., 65°C, 66°C, 68°C, 70°C, etc.), and the insulation reaction time is 2-4 hours, e.g., 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, etc.

[0036] Preferably, the temperature in step (3) is raised to 71-76°C, such as 71°C, 72°C, 73°C, 75°C, 76°C, etc.

[0037] Preferably, the amount of the partial solvent in step (3) accounts for 15wt.% to 25wt.% of the total solvent amount, for example, 15wt.%, 16wt.%, 18wt.%, 20wt.%, 22wt.%, 23wt.%, 25wt.%, etc.

[0038] Preferably, the amount of the partial thermal initiator in step (3) accounts for 25wt.% to 35wt.% of the total amount of thermal initiator, for example, 25wt.%, 26wt.%, 28wt.%, 30wt.%, 32wt.%, 33wt.%, 35wt.%, etc.

[0039] Preferably, the adding method in step (3) includes dropwise addition, and the dropwise addition is controlled to be completed within 20 to 40 minutes (for example, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.).

[0040] Preferably, the temperature of the insulation reaction in step (3) is 71-76°C (e.g., 71°C, 72°C, 73°C, 75°C, 76°C, etc.), and the insulation reaction time is 1-2 hours, e.g., 1 hour, 1.5 hours, 2 hours, etc.

[0041] Preferably, the temperature in step (4) is raised to 77-80°C, such as 77°C, 78°C, 79°C, 80°C, etc.

[0042] Preferably, the adding method in step (4) includes dropwise addition, and the dropwise addition is controlled to be completed within 20 to 40 minutes (for example, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.).

[0043] Preferably, the temperature of the insulation reaction in step (4) is 77-80°C (e.g., 77°C, 78°C, 79°C, 80°C, etc.), and the insulation reaction time is 1-2 hours, e.g., 1 hour, 1.5 hours, 2 hours, etc.

[0044] Preferably, steps (1) to (4) are all carried out in an inert atmosphere.

[0045] Preferably, the inert atmosphere comprises a nitrogen atmosphere.

[0046] Preferably, the heat preservation reactions in steps (2) to (4) are all carried out under stirring conditions, for example, a cantilever stirrer can be used for stirring.

[0047] Preferably, the stirring speed is 50-200 rpm, for example, 50 rpm, 100 rpm, 150 rpm, 200 rpm, etc., preferably 150 rpm. If the viscosity of the polymer is too high and climbing occurs during the reaction, the speed can be appropriately reduced to 50-100 rpm.

[0048] Preferably, the solid content of the fluorine-containing acrylate pressure-sensitive adhesive is 30% to 35%, for example, 30%, 32%, 33%, 35%, etc.

[0049] The synthesis mechanism of the fluorinated acrylate pressure-sensitive adhesive provided by the present invention is as follows:

[0050]

[0051] In a third aspect, the present invention provides a wafer dicing tape, comprising a release film layer, a fluorinated acrylate pressure-sensitive adhesive layer, and a substrate film layer stacked in sequence;

[0052] The fluorine-containing acrylate pressure-sensitive adhesive layer is prepared from the fluorine-containing acrylate pressure-sensitive adhesive described in the first aspect.

[0053] In a fourth aspect, the present invention provides a method for preparing the wafer dicing tape according to the third aspect, the preparation method comprising the following steps:

[0054] The fluorine-containing acrylate pressure-sensitive adhesive, solvent, and curing agent are mixed to obtain a mixed solution, which is coated on a release film and pre-baked, and then a base film is attached to the adhesive layer and cured to obtain the wafer dicing tape.

[0055] Preferably, the solvent comprises ethyl acetate.

[0056] Preferably, the curing agent includes any one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate, or a combination of at least two thereof.

[0057] Preferably, the mass ratio of the solid content to the curing agent in the fluorinated acrylate pressure-sensitive adhesive is (30-80):1, for example, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, etc.

[0058] Preferably, the mixing step further includes a standing step to eliminate bubbles.

[0059] Preferably, the release film is made of polyethylene terephthalate (PET).

[0060] Preferably, the pre-baking temperature is 80-100°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, etc., and the pre-baking time is 100-150s, for example, 100s, 110s, 120s, 130s, 140s, 150s, etc.

[0061] Preferably, the material of the substrate film includes any one of polyethylene, polypropylene, polybutylene, and polyvinyl chloride, or a combination of at least two thereof.

[0062] Preferably, the thickness of the adhesive layer is 10 to 30 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc.

[0063] Preferably, the curing temperature is 30-50°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C, etc., and the curing time is 48-72h, for example, 48h, 55h, 60h, 65h, 70h, 72h, etc.

[0064] In a fifth aspect, the present invention provides a use of the fluorinated acrylate pressure-sensitive adhesive as described in the first aspect or the wafer dicing tape as described in the third aspect in wafer dicing.

[0065] Compared with the prior art, the present invention has at least the following beneficial effects:

[0066] The present invention introduces a specific type of fluorine-containing monomer into a traditional acrylate pressure-sensitive adhesive system to prepare a fluorine-containing acrylate pressure-sensitive adhesive, which is used in wafer dicing tape, effectively improving the cohesive strength of the adhesive layer, thereby improving the thermal stability and solvent resistance of the adhesive layer, reducing the surface free energy of the tape, improving the hydrophobicity of the tape surface, and improving the bonding performance with the wafer surface. DETAILED DESCRIPTION

[0067] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0068] Example 1

[0069] In this embodiment, a fluorinated acrylate pressure-sensitive adhesive is provided, and a preparation method thereof comprises the following steps:

[0070] (1) Set up the experimental apparatus, introduce nitrogen for 1 h to expel the air from the apparatus, weigh 12.42 g of butyl acrylate, 10.8 g of methyl acrylate, 1.08 g of 2-hydroxyethyl acrylate, 2.7 g of trifluoroethyl acrylate, and 84 g of ethyl acetate, mix them, and add them to a five-necked flask as a base material. Heat the base material to 70°C.

[0071] (2) Weigh 28.98 g of butyl acrylate, 25.2 g of methyl acrylate, 2.52 g of 2-hydroxyethyl acrylate, 6.3 g of trifluoroethyl acrylate, 42 g of ethyl acetate, and 0.09 g of azobisisobutyronitrile, mix them, and add the mixture to a five-necked flask using a peristaltic pump. Control the addition rate to ensure that the addition is complete within 90 min, and keep the mixture at 70°C for 3 h.

[0072] (3) The reaction system was then heated to 76°C, 42 g of ethyl acetate and 0.054 g of azobisisobutyronitrile were weighed and mixed, and the mixture was added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 76°C for 1.5 h.

[0073] (4) Finally, the reaction system was heated to 78° C., 42 g of ethyl acetate and 0.036 g of azobisisobutyronitrile were weighed and added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 78° C. for 1.5 h. After cooling to room temperature, the mixture was taken out and sealed for storage to obtain the fluorinated acrylate pressure-sensitive adhesive (solid content 30%).

[0074] The entire synthesis reaction was carried out under a nitrogen atmosphere and stirring with a cantilever stirrer, and the speed of the cantilever stirrer was controlled to be 150 rpm.

[0075] In this embodiment, a wafer dicing tape is also provided, and a preparation method thereof includes the following steps:

[0076] Weigh 20g of the above-mentioned fluorinated acrylate pressure-sensitive adhesive with a solid content of 30%, mix it with 10g of ethyl acetate and 0.24g of toluene diisocyanate solution (solid content of 45%, solvent is ethyl acetate), use a magnetic stirrer to mix at 300rpm for 20min until uniform, let it stand for 20min after mixing to eliminate bubbles, and obtain a fluorinated acrylate glue solution. Use a 100μm four-sided coating rod on a small vacuum adsorption coating machine to evenly apply the fluorinated acrylate glue solution to the surface of the PET release film, put the PET film with the adhesive layer on the surface into an 80℃ oven for pre-bake for 2min to evaporate and remove the solvent in the adhesive layer. Use a film laminating machine to laminate the polyvinyl chloride (PVC) substrate film to the surface of the adhesive layer, measure the thickness of the adhesive layer to be 15μm, then put it into a 50℃ oven for curing for 72h, cool to room temperature, and obtain the wafer dicing tape.

[0077] Example 2

[0078] In this embodiment, a fluorinated acrylate pressure-sensitive adhesive is provided, and a preparation method thereof comprises the following steps:

[0079] (1) Set up the experimental apparatus, introduce nitrogen for 1 h to expel the air from the apparatus, weigh 12.42 g of butyl acrylate, 10.8 g of methyl acrylate, 1.08 g of 2-hydroxyethyl acrylate, 2.7 g of hexafluorobutyl acrylate, and 84 g of ethyl acetate, mix them, and add them to a five-necked flask as a base material. Heat the base material to 70°C.

[0080] (2) Weigh 28.98 g of butyl acrylate, 25.2 g of methyl acrylate, 2.52 g of 2-hydroxyethyl acrylate, 6.3 g of hexafluorobutyl acrylate, 42 g of ethyl acetate, and 0.09 g of azobisisobutyronitrile, mix them, and add the mixture into a five-necked flask using a peristaltic pump. Control the addition rate to ensure that the addition is completed within 90 min, and keep the mixture at 70°C for 3 h.

[0081] (3) The reaction system was then heated to 76°C, 42 g of ethyl acetate and 0.054 g of azobisisobutyronitrile were weighed and mixed, and the mixture was added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 76°C for 1.5 h.

[0082] (4) Finally, the reaction system was heated to 78° C., 42 g of ethyl acetate and 0.036 g of azobisisobutyronitrile were weighed and added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 78° C. for 1.5 h. After cooling to room temperature, the mixture was taken out and sealed for storage to obtain the fluorinated acrylate pressure-sensitive adhesive (solid content 30%).

[0083] The entire synthesis reaction was carried out under a nitrogen atmosphere and stirring with a cantilever stirrer, and the speed of the cantilever stirrer was controlled to be 150 rpm.

[0084] In this embodiment, a wafer dicing tape is also provided, and a preparation method thereof includes the following steps:

[0085] Weigh 20g of the above-mentioned fluorinated acrylate pressure-sensitive adhesive with a solid content of 30%, mix it with 10g of ethyl acetate and 0.24g of toluene diisocyanate solution (solid content of 45%, solvent is ethyl acetate), use a magnetic stirrer to mix at 300rpm for 20min until uniform, let it stand for 20min after mixing to eliminate bubbles, and obtain fluorinated acrylate glue. Use a 100μm four-sided coating rod on a small vacuum adsorption coating machine to evenly apply the fluorinated acrylate glue to the surface of the PET release film, put the PET film with the adhesive layer on the surface into an 80℃ oven for pre-bake for 2min to evaporate and remove the solvent in the adhesive layer. Use a film laminating machine to laminate the PVC base film to the surface of the adhesive layer, measure the thickness of the adhesive layer to be 13μm, then put it into a 50℃ oven for curing for 72h, cool to room temperature, and obtain the wafer dicing tape.

[0086] Example 3

[0087] In this embodiment, a fluorinated acrylate pressure-sensitive adhesive is provided, and a preparation method thereof comprises the following steps:

[0088] (1) Set up the experimental apparatus, introduce nitrogen for 1 h to expel the air from the apparatus, weigh 15.12 g of butyl acrylate, 5.4 g of methyl acrylate, 1.08 g of 2-hydroxyethyl acrylate, 5.4 g of trifluoroethyl acrylate, and 84 g of ethyl acetate, mix them, and add them to a five-necked flask as a base material. Heat the base material to 70°C.

[0089] (2) Weigh 35.28 g of butyl acrylate, 12.6 g of methyl acrylate, 2.52 g of 2-hydroxyethyl acrylate, 12.6 g of trifluoroethyl acrylate, 42 g of ethyl acetate, and 0.09 g of azobisisobutyronitrile, mix them, and add the mixture to a five-necked flask using a peristaltic pump. Control the addition rate to ensure that the addition is complete within 90 min, and keep the mixture at 70°C for 3 h.

[0090] (3) The reaction system was then heated to 76°C, 42 g of ethyl acetate and 0.054 g of azobisisobutyronitrile were weighed and mixed, and the mixture was added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 76°C for 1.5 h.

[0091] (4) Finally, the reaction system was heated to 78° C., 42 g of ethyl acetate and 0.036 g of azobisisobutyronitrile were weighed and added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 78° C. for 1.5 h. After cooling to room temperature, the mixture was taken out and sealed for storage to obtain the fluorinated acrylate pressure-sensitive adhesive (solid content 30%).

[0092] The entire synthesis reaction was carried out under a nitrogen atmosphere and stirring with a cantilever stirrer, and the speed of the cantilever stirrer was controlled to be 150 rpm.

[0093] In this embodiment, a wafer dicing tape is also provided, and a preparation method thereof includes the following steps:

[0094] Weigh 20g of the above-mentioned fluorinated acrylate pressure-sensitive adhesive with a solid content of 30%, mix it with 10g of ethyl acetate and 0.24g of toluene diisocyanate solution (solid content of 45%, solvent is ethyl acetate), use a magnetic stirrer to mix at 300rpm for 20min until uniform, let it stand for 20min after mixing to eliminate bubbles, and obtain fluorinated acrylate glue. Use a 100μm four-sided coating rod on a small vacuum adsorption coating machine to evenly apply the fluorinated acrylate glue to the surface of the PET release film, put the PET film with the adhesive layer on the surface into an 80℃ oven for pre-bake for 2min to evaporate and remove the solvent in the adhesive layer. Use a film laminating machine to laminate the PVC base film to the surface of the adhesive layer, measure the thickness of the adhesive layer to be 15μm, then put it into a 50℃ oven for curing for 72h, cool to room temperature, and obtain the wafer dicing tape.

[0095] Example 4

[0096] In this embodiment, a fluorinated acrylate pressure-sensitive adhesive is provided, and a preparation method thereof comprises the following steps:

[0097] (1) Set up the experimental apparatus, introduce nitrogen for 1 h to expel the air from the apparatus, weigh 9.0306 g of butyl acrylate, 6.4494 g of methyl acrylate, 0.72 g of 2-hydroxyethyl acrylate, 1.8 g of dodecafluoroheptyl methacrylate, and 56 g of ethyl acetate, mix them, and add them to a five-necked flask as a base material. Heat the base material to 70°C.

[0098] (2) Weigh 21.0714 g of butyl acrylate, 15.0486 g of methyl acrylate, 1.68 g of 2-hydroxyethyl acrylate, 4.2 g of dodecafluoroheptyl methacrylate, 28 g of ethyl acetate, and 0.06 g of azobisisobutyronitrile, mix them, and add the mixture to a five-necked flask using a peristaltic pump. Control the addition rate to ensure that the addition is completed within 90 min, and keep the mixture at 70°C for 3 h.

[0099] (3) The reaction system was then heated to 76°C, 28 g of ethyl acetate and 0.036 g of azobisisobutyronitrile were weighed and mixed, and the mixture was added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 76°C for 1.5 h.

[0100] (4) Finally, the reaction system was heated to 78° C., 28 g of ethyl acetate and 0.024 g of azobisisobutyronitrile were weighed and added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 78° C. for 1.5 h. After cooling to room temperature, the mixture was taken out and sealed for storage to obtain the fluorinated acrylate pressure-sensitive adhesive (solid content 30%).

[0101] The entire synthesis reaction was carried out under a nitrogen atmosphere and stirring with a cantilever stirrer, and the speed of the cantilever stirrer was controlled to be 150 rpm.

[0102] In this embodiment, a wafer dicing tape is also provided, and a preparation method thereof includes the following steps:

[0103] Weigh 20g of the above-mentioned fluorinated acrylate pressure-sensitive adhesive with a solid content of 30%, mix it with 10g of ethyl acetate and 0.24g of toluene diisocyanate solution (solid content of 45%, solvent is ethyl acetate), use a magnetic stirrer to mix at 300rpm for 20min until uniform, let it stand for 20min after mixing to eliminate bubbles, and obtain fluorinated acrylate glue. Use a 100μm four-sided coating rod on a small vacuum adsorption coating machine to evenly apply the fluorinated acrylate glue to the surface of the PET release film, put the PET film with the adhesive layer on the surface into an 80℃ oven for pre-bake for 2min to evaporate and remove the solvent in the adhesive layer. Use a film laminating machine to laminate the PVC base film to the surface of the adhesive layer, measure the thickness of the adhesive layer to be 13μm, then put it into a 50℃ oven for curing for 72h, cool to room temperature, and obtain the wafer dicing tape.

[0104] Comparative Example 1

[0105] In this comparative example, a basic acrylic pressure-sensitive adhesive is provided, and the preparation method comprises the following steps:

[0106] (1) Set up the experimental apparatus, introduce nitrogen for 1 h to expel the air from the apparatus, weigh 15.12 g of butyl acrylate, 10.8 g of methyl acrylate, 1.08 g of 2-hydroxyethyl acrylate, and 84 g of ethyl acetate, mix them, and add them to a five-necked flask as a base material. Heat the base material to 70°C.

[0107] (2) Weigh 35.28 g of butyl acrylate, 25.2 g of methyl acrylate, 2.52 g of 2-hydroxyethyl acrylate, 42 g of ethyl acetate, and 0.09 g of azobisisobutyronitrile, mix them, and add the mixture to a five-necked flask using a peristaltic pump. Control the addition rate to ensure that the addition is complete within 90 min, and keep the mixture at 70°C for 3 h.

[0108] (3) The reaction system was then heated to 76°C, 42 g of ethyl acetate and 0.054 g of azobisisobutyronitrile were weighed and mixed, and the mixture was added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 76°C for 1.5 h.

[0109] (4) Finally, the reaction system was heated to 78° C., 42 g of ethyl acetate and 0.036 g of azobisisobutyronitrile were weighed and added dropwise to a five-necked flask via a peristaltic pump over 30 min. After the addition was complete, the mixture was kept at 78° C. for 1.5 h. After cooling to room temperature, the mixture was taken out and sealed for storage to obtain the base acrylic pressure-sensitive adhesive (solid content 30%).

[0110] The entire synthesis reaction was carried out under a nitrogen atmosphere and stirring with a cantilever stirrer, and the speed of the cantilever stirrer was controlled to be 150 rpm.

[0111] In this comparative example, a wafer dicing tape is also provided, and a preparation method thereof comprises the following steps:

[0112] Weigh 20g of the above-mentioned basic acrylic pressure-sensitive adhesive with a solid content of 30%, mix it with 10g of ethyl acetate and 0.24g of toluene diisocyanate solution (solid content of 45%, solvent is ethyl acetate), use a magnetic stirrer to mix at 300rpm for 20min until uniform, let it stand for 20min after mixing to eliminate bubbles, and obtain a basic acrylic adhesive. Use a 100μm four-sided coating rod on a small vacuum adsorption coating machine to evenly apply the basic acrylic adhesive to the surface of the PET release film, put the PET film with the adhesive layer on the surface into an 80℃ oven for pre-bake for 2min to evaporate and remove the solvent in the adhesive layer. Use a film laminating machine to laminate the PVC base film to the surface of the adhesive layer, measure the thickness of the adhesive layer to be 15μm, then put it into a 50℃ oven for curing for 72h, cool to room temperature, and obtain the wafer dicing tape.

[0113] Comparative Example 2

[0114] The difference between this comparative example and Example 1 is that in the preparation process of the fluorinated acrylate pressure-sensitive adhesive, trifluoroethyl acrylate in step (1) and step (2) is replaced by trifluoroethyl methacrylate.

[0115] The performance tests were conducted on the fluorine-containing wafer dicing tapes provided in Examples 1-4 and Comparative Example 2, and the basic system wafer dicing tape provided in Comparative Example 1. The test methods are as follows:

[0116] (1) 90° peel strength: tested according to GB / T 2792-2014, with the surface to be tested being a silicon wafer;

[0117] (2) Thermal stability: The 10% thermal weight loss temperature of the adhesive layer is measured using a thermogravimetric analyzer to characterize the performance;

[0118] (3) Hydrophobicity: The static water contact angle of the tape surface is measured by a fully automatic contact angle instrument to characterize the hydrophobicity.

[0119] (4) Surface free energy: Calculated by testing the contact angles of the tape surface with pure water and diiodomethane using the OWRK model.

[0120] The performance test results are shown in Table 1.

[0121] Table 1

[0122]

[0123] As can be seen from Table 1, the wafer dicing tape prepared from the fluorinated acrylate pressure-sensitive adhesive provided by the present invention has excellent peel strength (98.29-221.93 gF, preferably 121.98-221.93 gF) with the wafer surface, while improving thermal stability (10% weight loss temperature: 364.45-368.98°C) and surface hydrophobicity (static water contact angle: 92.74°-108.15°), and also reduces the surface free energy to a certain extent (22.18-32.07 mJ / m 2 ).

[0124] Compared with Example 1, the peeling performance, heat resistance, and hydrophobicity of the basic wafer dicing tape provided in Comparative Example 1 are all reduced, while the surface free energy is increased; although the fluorine-containing wafer dicing tape provided in Comparative Example 2 performs well in thermal stability and hydrophobicity, its adhesion performance to the wafer surface is poor, which does not meet the basic performance requirements of the wafer dicing process for dicing tape.

[0125] The applicant declares that while the above-described embodiments illustrate the fluorinated acrylate pressure-sensitive adhesive, its preparation method, and its application, the present invention is not limited to these embodiments, nor does it necessarily rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials in the present invention, addition of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A fluorinated acrylate pressure-sensitive adhesive, characterized in that: The raw materials for preparing the fluorinated acrylate pressure-sensitive adhesive include the following components in parts by weight: The fluorine-containing monomer includes any one of trifluoroethyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, hexafluoroisopropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl acrylate, dodecafluoroheptyl methacrylate, and tridecafluorooctyl methacrylate, or a combination of at least two thereof.

2. The fluorinated acrylate pressure-sensitive adhesive according to claim 1, characterized in that: The soft monomer includes any one or a combination of at least two of isooctyl acrylate, butyl acrylate, lauryl acrylate, isononyl acrylate, and ethyl acrylate; Preferably, the hard monomer includes any one of methyl acrylate, methyl methacrylate, isobornyl methacrylate, vinyl acetate, styrene, acrylonitrile, and acrylamide, or a combination of at least two thereof.

3. The fluorinated acrylate pressure-sensitive adhesive according to claim 1 or 2, characterized in that: The functional monomers include any one or a combination of at least two of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid, and acrylamide; Preferably, the thermal initiator comprises any one of azobisisobutyronitrile, azobisisoheptanenitrile, and dibenzoyl peroxide, or a combination of at least two thereof; Preferably, the solvent includes any one of ethyl acetate, toluene, methanol, and ethanol, or a combination of at least two thereof.

4. A method for preparing the fluorinated acrylate pressure-sensitive adhesive according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: The soft monomer, the hard monomer, the fluorine-containing monomer, the functional monomer, the thermal initiator and the solvent are mixed, and the fluorine-containing acrylate pressure-sensitive adhesive is synthesized by adopting a thermally initiated free radical polymerization process.

5. The preparation method according to claim 4, characterized in that The preparation method specifically comprises the following steps: (1) adding part of the soft monomer, part of the hard monomer, part of the functional monomer, part of the fluorine-containing monomer, and part of the solvent into a reaction vessel as a base material, and heating; (2) After the base material is heated up, the remaining soft monomer, the remaining hard monomer, the remaining functional monomer, the remaining fluorine-containing monomer, part of the solvent, and part of the thermal initiator are added to the reaction vessel and kept warm for reaction; (3) heating the reaction system, adding part of the solvent and part of the thermal initiator, and maintaining the temperature for reaction; (4) heating the reaction system, adding the remaining solvent and the remaining thermal initiator, and then maintaining the temperature to react to obtain the fluorinated acrylate pressure-sensitive adhesive.

6. The preparation method according to claim 5, characterized in that The total amount of the soft monomer, hard monomer, functional monomer and fluorine-containing monomer in step (1) accounts for 30 wt.% to 40 wt.% of the total amount of all reaction monomers; Preferably, the amount of the partial solvent in step (1) accounts for 35 wt.% to 45 wt.% of the total amount of solvent; Preferably, the heating in step (1) is to 65-70°C; Preferably, the amount of the partial solvent in step (2) accounts for 15 wt.% to 25 wt.% of the total amount of solvent; Preferably, the amount of the partial thermal initiator in step (2) accounts for 45 wt.% to 55 wt.% of the total amount of thermal initiator; Preferably, the adding method in step (2) includes dropwise addition, and the dropwise addition is controlled to be completed within 1 to 2 hours; Preferably, the temperature of the insulation reaction in step (2) is 65-70° C., and the insulation reaction time is 2-4 hours; Preferably, the heating in step (3) is to 71-76°C; Preferably, the amount of the partial solvent in step (3) accounts for 15 wt.% to 25 wt.% of the total amount of solvent; Preferably, the amount of the partial thermal initiator in step (3) accounts for 25 wt.% to 35 wt.% of the total amount of thermal initiator; Preferably, the adding method in step (3) includes dropwise addition, and the dropwise addition is controlled to be completed within 20 to 40 minutes; Preferably, the temperature of the insulation reaction in step (3) is 71-76° C., and the insulation reaction time is 1-2 hours; Preferably, the heating in step (4) is to 77-80°C; Preferably, the adding method in step (4) includes dropwise addition, and the dropwise addition is controlled to be completed within 20 to 40 minutes; Preferably, the temperature of the insulation reaction in step (4) is 77-80° C., and the insulation reaction time is 1-2 hours; Preferably, steps (1) to (4) are all carried out in an inert atmosphere; Preferably, the insulation reactions in steps (2) to (4) are all carried out under stirring conditions; Preferably, the solid content of the fluorine-containing acrylate pressure-sensitive adhesive is 30% to 35%.

7. A wafer dicing tape, characterized in that: The wafer dicing tape comprises a release film layer, a fluorinated acrylate pressure-sensitive adhesive layer and a substrate film layer which are stacked in sequence; The fluorinated acrylate pressure-sensitive adhesive layer is prepared from the fluorinated acrylate pressure-sensitive adhesive according to any one of claims 1 to 3.

8. A method for preparing a wafer dicing tape according to claim 7, characterized in that: The preparation method comprises the following steps: The fluorine-containing acrylate pressure-sensitive adhesive, solvent, and curing agent are mixed to obtain a mixed solution, which is coated on a release film and pre-baked, and then a base film is attached to the adhesive layer and cured to obtain the wafer dicing tape.

9. The preparation method according to claim 8, characterized in that The solvent includes ethyl acetate; Preferably, the curing agent comprises any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate; Preferably, the ratio of the mass of the solid content to the mass of the curing agent in the fluorinated acrylate pressure-sensitive adhesive is (30-80):1; Preferably, the material of the release film includes polyethylene terephthalate; Preferably, the pre-baking temperature is 80-100° C., and the pre-baking time is 100-150 seconds; Preferably, the material of the substrate film includes any one of polyethylene, polypropylene, polybutylene, and polyvinyl chloride, or a combination of at least two thereof; Preferably, the thickness of the adhesive layer is 10 to 30 μm; Preferably, the curing temperature is 30-50° C., and the curing time is 48-72 hours.

10. Use of the fluorinated acrylate pressure-sensitive adhesive according to any one of claims 1 to 3 or the wafer dicing tape according to claim 7 in wafer dicing.

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