A kind of UV anti-adhesive tape and preparation method thereof

Abstract

The present invention relates to a UV anti-viscosity tape and a preparation method thereof, and belongs to the technical field of adhesive tapes. The UV anti-viscosity tape comprises a first anti-viscosity adhesive layer and a second anti-viscosity adhesive layer, wherein the first anti-viscosity adhesive layer comprises 20-70 parts of an acrylic resin containing a carbon-carbon double bond, 0.4-2 parts of a photoinitiator, 0.01-0.1 parts of a thermosetting agent, and 50-100 parts of an organic solvent in parts by mass; the second anti-viscosity adhesive layer comprises 0.1-3 parts of an active diluent containing a carbon-carbon double bond, 20-70 parts of an acrylic resin containing a carbon-carbon double bond, 0.4-2 parts of a photoinitiator, 0.01-0.1 parts of a thermosetting agent, and 50-100 parts of an organic solvent in parts by mass; the weight average molecular weight of the acrylic resin containing a carbon-carbon double bond is 300,000-700,000; the glass transition temperature is ‑50°C to ‑10°C; and the carbon-carbon double bond content is 0.1-0.3 mmol / g. The anti-viscosity tape not only meets the requirement of convenient chip picking, but also solves the problem of chip contamination caused by separation of the anti-viscosity adhesive layer and the substrate.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesive tapes, and in particular relates to a UV anti-viscosity adhesive tape and a preparation method thereof. Background Art

[0002] At present, in the process of semiconductor chip manufacturing, there are two important processes, wafer grinding and chip cutting. As the cut chips become smaller and smaller, if the viscosity is insufficient during the cutting process, it will cause the chip to split. After the cutting is completed, the viscosity needs to be reduced when picking up the chip to facilitate picking up. When cutting the wafer, the wafer is often fixed on a substrate with a high viscosity and coated with an adhesive. When the film is expanded and picked up, after UV irradiation, the adhesive on the substrate loses its viscosity, which is very convenient to pick up. The applied adhesive is called UV viscosity-reducing adhesive.

[0003] To facilitate film expansion, the substrate commonly used to fix the wafer is a PO film or PVC film with a large elongation at break. The applied UV viscosity-reducing adhesive loses its viscosity after UV irradiation. At the same time, the cross-linking of internal double bonds will cause volume shrinkage, leading to stratification from the substrate, thereby causing contamination of the chip.

[0004] The most commonly used UV anti-viscosity tape in current chip cutting is made of UV anti-viscosity adhesive. However, the UV anti-viscosity tape made of UV anti-viscosity adhesive has the phenomenon of delamination between the adhesive layer and the substrate layer after UV irradiation. This is because the UV adhesive's viscosity decreases rapidly after UV energy irradiation, and the adhesion to the substrate is significantly reduced.

[0005] There are two main types of UV viscosity-reducing adhesives on the market. One is based on acrylate polymer adhesives, and then mixed with multifunctional active diluents, photoinitiators and curing agents. The other is to graft carbon-carbon double bonds on the adhesive chain. In order to achieve a significant reduction in viscosity after UV irradiation, both introduce a large amount of carbon-carbon double bonds, which leads to a significant reduction in the viscosity of the adhesive after UV irradiation and a significant shrinkage in volume, which reduces the adhesion to the substrate. When the chip is picked up, the adhesive adheres to the chip, causing chip contamination. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a UV anti-viscosity tape and a preparation method thereof. The UV anti-viscosity tape comprises a substrate layer, a first anti-viscosity adhesive layer, a second anti-viscosity adhesive layer and a release layer. Since the first anti-viscosity adhesive layer has a low double bond content, it will not cause a large volume shrinkage after UV irradiation and will not be delaminated from the substrate layer. Since the second anti-viscosity adhesive layer contains double bond molecules, it will cause a large volume shrinkage of the anti-viscosity adhesive after UV irradiation, and the viscosity will decrease significantly, and the anti-viscosity effect is good, thereby ensuring the effect of UV anti-viscosity and solving the delamination problem of the anti-viscosity adhesive and the substrate layer.

[0007] The first object of the present invention is to provide a UV anti-viscosity adhesive tape, comprising a substrate layer, a release layer arranged on the substrate layer, and an adhesive layer arranged between the substrate layer and the release layer, wherein the adhesive layer comprises a first anti-viscosity adhesive layer and a second anti-viscosity adhesive layer, wherein the first anti-viscosity adhesive layer is adjacent to the substrate layer; and the second anti-viscosity adhesive layer is adjacent to the release layer;

[0008] The first viscosity-reducing adhesive layer comprises, by weight, 20-70 parts of an acrylic resin containing a carbon-carbon double bond, 0.4-2 parts of a photoinitiator, 0.01-0.1 parts of a thermal curing agent, and 50-100 parts of an organic solvent;

[0009] The second viscosity-reducing adhesive layer comprises, by weight, 0.1-3 parts of a reactive diluent containing a carbon-carbon double bond, 20-70 parts of an acrylic resin containing a carbon-carbon double bond, 0.4-2 parts of a photoinitiator, 0.01-0.1 parts of a thermal curing agent, and 50-100 parts of an organic solvent;

[0010] The weight average molecular weight of the acrylic resin containing carbon-carbon double bonds is 300,000-700,000; the glass transition temperature is -50°C to -10°C; and the carbon-carbon double bond content is 0.1-0.3 mmol / g.

[0011] In one embodiment of the present invention, the acrylic resin containing carbon-carbon double bonds is a branched polymer containing carbon-carbon double bonds on the side chains.

[0012] In one embodiment of the present invention, the method for preparing the acrylic resin containing carbon-carbon double bonds comprises the following steps:

[0013] S1. Under an inert atmosphere, the soft monomer, the hard monomer, the functional monomer and the functional monomer containing active hydroxyl groups are dissolved in part of the solvent, the temperature is raised to 60-80° C. under stirring, the initiator is added stepwise and the temperature is kept for 4-8 hours, and then the temperature is lowered to 50-60° C. to obtain a reaction solution;

[0014] S2. Add a catalyst to the reaction solution described in step S1, and dropwise add a mixture of isocyanate containing a carbon-carbon double bond and the remaining solvent under stirring, and react for 3-5 hours. Finally, cool the reaction solution to room temperature to obtain the acrylic resin containing a carbon-carbon double bond, and the dropping time is 0.1-1 hour.

[0015] In one embodiment of the present invention, in S1, the soft monomer is an alkyl acrylate, and the number of carbon atoms of the alkyl group is an integer of 1-12;

[0016] The hard monomer is alkyl methacrylate, and the carbon number of the alkyl group is an integer of 1-6;

[0017] The functional monomer is one or more of acrylic acid, methacrylic acid, N-hydroxymethyl acrylamide, glycidyl methacrylate, N,N-dimethylacrylamide and isobornyl methacrylate;

[0018] The functional monomer containing active hydroxyl groups is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and diethylene glycol monoacrylate;

[0019] The initiator is one or more of benzoyl peroxide, azobisisobutyronitrile, di-tert-butyl hydroperoxide and tert-butyl peroxy-2-ethylhexanoic acid;

[0020] The solvent is one or more of ethyl acetate, toluene, butanone and heptane.

[0021] In one embodiment of the present invention, in S1, the soft monomer is one or more of ethyl acrylate, butyl acrylate, isooctyl acrylate and lauryl acrylate;

[0022] The hard monomer is methyl methacrylate and / or cyclohexyl methacrylate.

[0023] In one embodiment of the present invention, in S1, the weight ratio of the soft monomer, the hard monomer, the functional monomer and the functional monomer containing active hydroxyl groups is 30-70: 1-10: 1-10: 1.4-7.

[0024] In one embodiment of the present invention, in S2, the catalyst is one or more of dioctyltin dilaurate, dibutyltin dilaurate and zirconium acetylacetonate;

[0025] The isocyanate containing a carbon-carbon double bond is isocyanate ethyl acrylate and / or isocyanate ethyl methacrylate; the amount of the isocyanate containing a carbon-carbon double bond and the functional monomer containing an active hydroxyl group added is the same.

[0026] In one embodiment of the present invention, the photoinitiator is one or more of benzil dimethyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4-p-phenylmercaptobenzophenone, 4-methylbenzophenone, isopropylthioxanthene and 2-ethylanthraquinone;

[0027] The thermal curing agent is one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate;

[0028] The organic solvent is one or more of ethyl acetate, toluene, butanone and heptane.

[0029] In one embodiment of the present invention, the carbon-carbon double bond-containing active diluent is one or more of allyl acrylate, tetraethylene glycol diacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate and dipentaerythritol hexaacrylate.

[0030] In one embodiment of the present invention, the material of the substrate layer is a PO film with a thickness of 90-150 μm;

[0031] The thickness of the first and second anti-viscosity adhesive layers are both 10-30 μm;

[0032] The release layer is made of a silicon release film with a thickness of 25-50 μm.

[0033] The second object of the present invention is to provide a method for preparing the UV adhesive tape, comprising the following steps:

[0034] (1) mixing an acrylic resin containing a carbon-carbon double bond, a photoinitiator, a thermal curing agent and an organic solvent, and allowing the mixture to stand for defoaming to obtain a first viscosity-reducing adhesive;

[0035] (2) mixing a reactive diluent containing a carbon-carbon double bond, an acrylic resin containing a carbon-carbon double bond, a photoinitiator, a thermal curing agent, and an organic solvent, and allowing the mixture to stand for defoaming to obtain a second viscosity-reducing adhesive;

[0036] (3) coating the first viscosity-reducing adhesive described in step (1) on the surface of the substrate layer and drying to form a first viscosity-reducing adhesive layer; coating the second viscosity-reducing adhesive described in step (2) on the surface of the first viscosity-reducing adhesive layer and drying to form a second viscosity-reducing adhesive layer; and compounding a release layer on the surface of the second viscosity-reducing adhesive layer and aging to obtain the UV viscosity-reducing adhesive tape.

[0037] The technical solution of the present invention has the following advantages over the prior art:

[0038] (1) The structure of the UV anti-viscosity tape of the present invention is substrate layer / first anti-viscosity adhesive layer / second anti-viscosity adhesive layer / release layer. The first anti-viscosity adhesive layer has a small amount of carbon-carbon double bonds. After UV irradiation, it will not cause a sharp shrinkage in volume and will not cause separation from the substrate PO film. The second anti-viscosity adhesive layer contains a relatively large amount of carbon-carbon double bonds due to the addition of an active diluent containing carbon-carbon double bonds. After UV irradiation, it will cause a significant decrease in viscosity, resulting in a good anti-viscosity effect, which is convenient for separation from the chip and is conducive to picking up. At the same time, the first anti-viscosity adhesive and the second anti-viscosity adhesive have similar components, which overcomes the separation of the adhesive layers.

[0039] (2) The UV anti-viscosity tape of the present invention comprises a first anti-viscosity adhesive layer and a second anti-viscosity adhesive layer, and the two anti-viscosity adhesive layers only require one synthesis reaction. The anti-viscosity tape prepared by this method not only satisfies the convenience of picking up the chip, but also solves the problem of separation of the anti-viscosity adhesive layer and the substrate, which causes chip contamination.

[0040] (3) The UV anti-viscosity tape of the present invention can significantly reduce the viscosity after UV irradiation and overcome the separation of the anti-viscosity adhesive layer and the substrate. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0042] In the present invention, unless otherwise specified, the "parts" described in the examples are all parts by weight.

[0043] In the present invention, unless otherwise specified, the PO membranes in the examples are purchased from ZAPOL, model number ZAPOL150T.

[0044] In the present invention, unless otherwise specified, the silicon release film in the embodiments is produced by Jiangyin Huamei Optoelectronics Technology Co., Ltd., and the model number is HM36T10.

[0045] Example 1

[0046] A UV anti-viscosity tape, which comprises, from bottom to top, a substrate layer, a first anti-viscosity layer, a second anti-viscosity layer and a release layer; wherein the substrate layer is a 150 μm PO film; the thickness of the first anti-viscosity layer and the second anti-viscosity layer are both 10 μm; and the release layer is a 36 μm silicone release film;

[0047] The preparation of the above-mentioned UV anti-viscosity tape specifically comprises the following steps:

[0048] A. Preparation of acrylic resin containing carbon-carbon double bonds

[0049] (1) 30 parts of isooctyl acrylate, 30 parts of butyl acrylate, 5 parts of methyl methacrylate, 5 parts of hydroxyethyl acrylate, 10 parts of N,N-dimethylacrylamide and 120 parts of ethyl acetate were mixed uniformly, stirred under a nitrogen atmosphere, heated to 75° C., 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 2 hours, and then 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 3 hours, and the temperature was lowered to 50° C. to obtain a reaction solution;

[0050] (2) Add 0.02 parts of dibutyltin dilaurate as a catalyst to the reaction solution obtained in step (1), stop passing nitrogen, and add 6.08 parts of a mixture of ethyl isocyanate acrylate and 9.12 parts of ethyl acetate dropwise over 0.5 h under stirring conditions, keep the mixture warm for 5 h, cool it down and discharge it to obtain an acrylic resin liquid 1 containing carbon-carbon double bonds (the carbon-carbon double bond content of the acrylic resin liquid 1 is about 0.2 mmol / g, the glass transition temperature is about -30°C, and the Mw is about 480,000).

[0051] B. Preparation of UV adhesive tape

[0052] (1) 50 parts of an acrylic resin liquid containing a carbon-carbon double bond 1, 0.4 parts of a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.05 parts of a thermal curing agent dicyclohexylmethane diisocyanate, and 50 parts of ethyl acetate were mixed evenly, and allowed to stand for 30 minutes to defoam, thereby obtaining a first viscosity-reducing adhesive;

[0053] (2) is basically the same as step (1), except that 1 part of tetraethylene glycol diacrylate is further added to obtain a second viscosity-reducing adhesive;

[0054] (3) coating a first viscosity-reducing adhesive on the surface of the substrate layer and drying to form a first viscosity-reducing adhesive layer; coating a second viscosity-reducing adhesive on the surface of the first viscosity-reducing adhesive layer and drying to form a second viscosity-reducing adhesive layer; compounding a release layer on the surface of the second viscosity-reducing adhesive layer, protecting from light, and aging at 45° C. for 3 days to obtain a UV viscosity-reducing adhesive tape.

[0055] Example 2

[0056] A UV anti-viscosity tape, which comprises, from bottom to top, a substrate layer, a first anti-viscosity layer, a second anti-viscosity layer and a release layer; wherein the substrate layer is a 150 μm PO film; the thickness of the first anti-viscosity layer and the second anti-viscosity layer are both 10 μm; and the release layer is a 36 μm silicone release film;

[0057] The preparation of the above-mentioned UV anti-viscosity tape specifically comprises the following steps:

[0058] A. Preparation of acrylic resin containing carbon-carbon double bonds

[0059] (1) 30 parts of isooctyl acrylate, 30 parts of butyl acrylate, 5 parts of cyclohexyl methacrylate, 2 parts of acrylic acid, 5 parts of diethylene glycol monoacrylate, 8 parts of N,N-dimethylacrylamide and 120 parts of ethyl acetate were mixed uniformly, stirred under a nitrogen atmosphere, heated to 75° C., 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 2 hours, and then 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 3 hours, and the temperature was lowered to 50° C. to obtain a reaction solution;

[0060] (2) Add 0.02 parts of dibutyltin dilaurate as a catalyst to the reaction solution obtained in step (1), stop passing nitrogen, and add 4.4 parts of a mixture of ethyl isocyanate acrylate and 6.6 parts of ethyl acetate dropwise over 0.5 h under stirring, keep the mixture warm for 5 h, cool and discharge the mixture to obtain an acrylic resin liquid 2 containing carbon-carbon double bonds (the carbon-carbon double bond content of the acrylic resin liquid 2 is about 0.15 mmol / g, the glass transition temperature is about -35°C, and the Mw is about 530,000).

[0061] B. Preparation of UV adhesive tape

[0062] (1) is basically the same as Example 1, except that the acrylic resin liquid 1 containing carbon-carbon double bonds is replaced by the acrylic resin liquid 2 containing carbon-carbon double bonds to obtain a first viscosity-reducing adhesive;

[0063] (2) is basically the same as Example 1, except that 1 part of trimethylolpropane triacrylate is further added to obtain a second viscosity-reducing adhesive;

[0064] (3) Same as Example 1.

[0065] Example 3

[0066] A UV anti-viscosity tape, which comprises, from bottom to top, a substrate layer, a first anti-viscosity layer, a second anti-viscosity layer and a release layer; wherein the substrate layer is a 150 μm PO film; the thickness of the first anti-viscosity layer and the second anti-viscosity layer are both 10 μm; and the release layer is a 36 μm silicone release film;

[0067] The preparation of the above-mentioned UV anti-viscosity tape specifically comprises the following steps:

[0068] A. Preparation of acrylic resin containing carbon-carbon double bonds

[0069] (1) 60 parts of isooctyl acrylate, 3 parts of cyclohexyl methacrylate, 10 parts of glycidyl methacrylate, 7 parts of hydroxyethyl acrylate and 120 parts of ethyl acetate were mixed uniformly, stirred under a nitrogen atmosphere, heated to 75° C., 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 2 hours, and then 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 3 hours, and the temperature was lowered to 50° C. to obtain a reaction solution;

[0070] (2) Add 0.02 parts of dibutyltin dilaurate as a catalyst to the reaction solution obtained in step (1), stop passing nitrogen, and add 8.5 parts of a mixed solution of ethyl isocyanate acrylate and 12.75 parts of ethyl acetate dropwise over 0.5 h under stirring conditions, keep the mixture warm for 4 h, cool and discharge the mixture to obtain an acrylic resin liquid 3 containing carbon-carbon double bonds (the carbon-carbon double bond content of the acrylic resin liquid 3 is about 0.27 mmol / g, the glass transition temperature is about -42°C, and the Mw is about 420,000).

[0071] B. Preparation of UV adhesive tape

[0072] (1) is basically the same as Example 1, except that the acrylic resin liquid 1 containing carbon-carbon double bonds is replaced by the acrylic resin liquid 3 containing carbon-carbon double bonds to obtain a first viscosity-reducing adhesive;

[0073] (2) is basically the same as Example 1, except that 1 part of trimethylolpropane tetraacrylate is further added to obtain a second viscosity-reducing adhesive;

[0074] (3) Same as Example 1.

[0075] Example 4

[0076] A UV anti-viscosity tape, which comprises, from bottom to top, a substrate layer, a first anti-viscosity layer, a second anti-viscosity layer and a release layer; wherein the substrate layer is a 150 μm PO film; the thickness of the first anti-viscosity layer and the second anti-viscosity layer are both 10 μm; and the release layer is a 36 μm silicone release film;

[0077] The preparation of the above-mentioned UV anti-viscosity tape specifically comprises the following steps:

[0078] A. Preparation of acrylic resin containing carbon-carbon double bonds

[0079] (1) 40 parts of isooctyl acrylate, 25 parts of lauryl acrylate, 5 parts of methyl methacrylate, 8 parts of N,N-dimethylacrylamide, 2.4 parts of hydroxyethyl acrylate and 120 parts of ethyl acetate were mixed uniformly, stirred under a nitrogen atmosphere, heated to 75° C., 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 2 hours, and then 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 3 hours, and the temperature was lowered to 50° C. to obtain a reaction solution;

[0080] (2) Add 0.02 parts of dibutyltin dilaurate as a catalyst to the reaction solution obtained in step (1), stop the nitrogen flow, and add 2.92 parts of ethyl isocyanate acrylate and 4.38 parts of ethyl acetate dropwise for 0.5 h under stirring, keep the mixture warm for 4 h, cool and discharge the mixture to obtain an acrylic resin liquid 4 containing carbon-carbon double bonds (the carbon-carbon double bond content of the acrylic resin liquid 4 is about 0.1 mmol / g, the glass transition temperature is about -45°C, and the Mw is about 410,000).

[0081] B. Preparation of UV adhesive tape

[0082] (1) is basically the same as Example 1, except that the acrylic resin liquid 1 containing carbon-carbon double bonds is replaced by the acrylic resin liquid 4 containing carbon-carbon double bonds to obtain a first viscosity-reducing adhesive;

[0083] (2) is basically the same as Example 1, except that 1 part of dipentaerythritol hexaacrylate is further added to obtain a second viscosity-reducing adhesive;

[0084] (3) Same as Example 1.

[0085] Comparative Example 1

[0086] A viscosity-reducing tape, which comprises, from bottom to top, a substrate layer, a first viscosity-reducing adhesive layer, a second viscosity-reducing adhesive layer and a release layer; wherein the substrate layer is a 150 μm PO film; the thickness of the first viscosity-reducing adhesive layer and the second viscosity-reducing adhesive layer are both 10 μm; and the release layer is a 36 μm silicone release film;

[0087] The preparation of the above-mentioned adhesive tape specifically comprises the following steps:

[0088] A. Preparation of acrylic resin containing carbon-carbon double bonds

[0089] (1) 40 parts of isooctyl acrylate, 15 parts of lauryl acrylate, 5 parts of methyl methacrylate, 8 parts of N,N-dimethylacrylamide, 12 parts of hydroxyethyl acrylate and 120 parts of ethyl acetate were mixed uniformly, stirred under a nitrogen atmosphere, heated to 75° C., 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 2 hours, and then 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 3 hours, and the temperature was lowered to 50° C. to obtain a reaction solution;

[0090] (2) Add 0.02 parts of dibutyltin dilaurate as a catalyst to the reaction solution obtained in step (1), stop the nitrogen flow, and add 14.59 parts of a mixed solution of ethyl isocyanate acrylate and 21.88 parts of ethyl acetate dropwise over 0.5 h under stirring conditions, keep the mixture warm for 4 h, cool and discharge the mixture to obtain an acrylic resin liquid 5 containing carbon-carbon double bonds (the carbon-carbon double bond content of the acrylic resin liquid 5 is about 0.44 mmol / g, the glass transition temperature is about -27°C, and the Mw is about 410,000).

[0091] B. Preparation of anti-viscosity tape

[0092] (1) is basically the same as Example 1, except that the acrylic resin liquid 1 containing carbon-carbon double bonds is replaced with the acrylic resin liquid 5 containing carbon-carbon double bonds to obtain a first viscosity-reducing adhesive;

[0093] (2) is basically the same as Example 1, except that 1 part of dipentaerythritol hexaacrylate is further added to obtain a second viscosity-reducing adhesive;

[0094] (3) Same as Example 1.

[0095] Comparative Example 2

[0096] A viscosity-reducing tape, which comprises, from bottom to top, a substrate layer, a first viscosity-reducing adhesive layer, a second viscosity-reducing adhesive layer and a release layer; wherein the substrate layer is a 150 μm PO film; the thickness of the first viscosity-reducing adhesive layer and the second viscosity-reducing adhesive layer are both 10 μm; and the release layer is a 36 μm silicone release film;

[0097] The preparation of the above-mentioned adhesive tape specifically comprises the following steps:

[0098] A. Preparation of acrylic resin containing carbon-carbon double bonds

[0099] (1) 40 parts of isooctyl acrylate, 26.5 parts of lauryl acrylate, 5 parts of methyl methacrylate, 8 parts of N,N-dimethylacrylamide, 0.5 parts of hydroxyethyl acrylate and 120 parts of ethyl acetate were mixed uniformly, stirred under a nitrogen atmosphere, heated to 75° C., 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 2 hours, and then 0.01 parts of azobisisobutyronitrile as an initiator were added, and the temperature was kept for 3 hours, and the temperature was lowered to 50° C. to obtain a reaction solution;

[0100] (2) Add 0.01 part of dibutyltin dilaurate as a catalyst to the reaction solution obtained in step (1), stop passing nitrogen, and add 0.61 parts of a mixture of ethyl isocyanate acrylate and 0.91 parts of ethyl acetate dropwise over 0.5 h under stirring conditions, keep the mixture warm for 4 h, cool and discharge the mixture to obtain an acrylic resin liquid 6 containing carbon-carbon double bonds (the carbon-carbon double bond content of the acrylic resin liquid 6 is about 0.02 mmol / g, the glass transition temperature is about -47°C, and the Mw is about 510,000).

[0101] B. Preparation of anti-viscosity tape

[0102] (1) is basically the same as Example 1, except that the acrylic resin liquid 1 containing carbon-carbon double bonds is replaced with acrylic resin liquid 6 containing carbon-carbon double bonds to obtain a first viscosity-reducing adhesive;

[0103] (2) is basically the same as Example 1, except that 1 part of dipentaerythritol hexaacrylate is further added to obtain a second viscosity-reducing adhesive;

[0104] (3) Same as Example 1.

[0105] Comparative Example 3

[0106] Basically the same as Example 1, except that the first viscosity-reducing adhesive is the same as Comparative Example 1.

[0107] Comparative Example 4

[0108] The method is basically the same as Example 1, except that the second viscosity-reducing adhesive layer is not included.

[0109] Comparative Example 5

[0110] The method is basically the same as Example 1, except that the first viscosity-reducing adhesive layer is not included.

[0111] Test Case

[0112] The performance of the adhesion-reducing tapes of Examples 1-4 and Comparative Examples 1-5 after the release films were removed was tested:

[0113] (1) 180° peel strength: refer to GB / T 2792-1998, electronic tensile testing machine, tape width 25 mm, peel rate 300 mm / min, adhered object is SUS304 steel plate, UV irradiation conditions are irradiation with UV lamp for 5 s, UV intensity 300 mJ / cm 2 ;

[0114] (2) Initial adhesion: refer to GB / T 4852-2002, rolling ball ramp stop test method, 30° inclination angle;

[0115] (3) Interlayer bonding: After film expansion, UV irradiation and viscosity reduction are performed and judged by visual method;

[0116] (4) Adhesion to the substrate: After film expansion, UV irradiation and adhesion reduction are performed and then visually inspected. If there is any adhesion reduction adhesive missing from the substrate, it is considered NG.

[0117] (5) Chip pick-up residual glue situation: After the chip is picked up, observe the chip surface under a 10x microscope. If residual glue is found, it is NG;

[0118] Table 1 shows the relevant parameters of the final measured materials:

[0119] Table 1

[0120]

[0121] It can be seen from Table 1 that the fewer carbon-carbon double bonds in the first viscosity-reducing adhesive layer of the UV viscosity-reducing tape of the embodiment will not cause a sharp shrinkage in volume after UV treatment, thereby causing a decrease in adhesion to the PO film. At the same time, an active diluent containing carbon-carbon double bonds is added to the second viscosity-reducing adhesive layer. After the double bonds are introduced again, the adhesive layer has a lower peeling force after UV treatment, which is convenient for picking up the chip without residual adhesive and the interlayer bonding force is not destroyed. In Comparative Example 1, the first viscosity-reducing adhesive layer has a relatively high carbon-carbon double bond content, which leads to the shrinkage of the adhesive layer after UV, resulting in a decrease in adhesion to the substrate; in Comparative Example 2, the second viscosity-reducing adhesive layer has a low carbon-carbon double bond content, resulting in a large peeling force after UV, which is not conducive to chip pickup; in Comparative Example 3, both the first and second viscosity-reducing adhesive layers contain a large amount of carbon-carbon double bonds, resulting in a decrease in the adhesion between the first viscosity-reducing adhesive layer and the substrate layer after UV. Although the peeling force of the second viscosity-reducing adhesive layer after UV is relatively low, and the chip is easy to pick up, the different compositions of the two adhesive layers result in a decrease in the interlayer bonding force, thereby causing residual glue on the chip surface; Comparative Example 4 only has the first viscosity-reducing adhesive layer, and the peeling force after UV is relatively large, making it difficult to pick up the chip, and the cohesive failure of the adhesive layer leads to the pickup of residual glue; Comparative Example 5 only has the second viscosity-reducing adhesive layer, and the relatively large carbon-carbon double bonds result in poor adhesion between the adhesive layer and the substrate after UV, and residual glue on the chip surface.

[0122] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A UV anti-adhesive tape, comprising a substrate layer, a release layer disposed on the substrate layer, and an adhesive layer disposed between the substrate layer and the release layer, It is characterized in that The adhesive layer includes a first viscosity-reducing adhesive layer and a second viscosity-reducing adhesive layer, wherein the first viscosity-reducing adhesive layer is adjacent to the substrate layer; the second viscosity-reducing adhesive layer is adjacent to the release layer; the first viscosity-reducing adhesive layer is adjacent to the second viscosity-reducing adhesive layer; The first viscosity-reducing adhesive layer comprises, by weight, 20-70 parts of an acrylic resin containing a carbon-carbon double bond, 0.4-2 parts of a photoinitiator, 0.01-0.1 parts of a thermal curing agent, and 50-100 parts of an organic solvent; The second viscosity-reducing adhesive layer comprises, by weight, 0.1-3 parts of a reactive diluent containing a carbon-carbon double bond, 20-70 parts of an acrylic resin containing a carbon-carbon double bond, 0.4-2 parts of a photoinitiator, 0.01-0.1 parts of a thermal curing agent, and 50-100 parts of an organic solvent; the reactive diluent containing a carbon-carbon double bond is one or more of tetraethylene glycol diacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, and dipentaerythritol hexaacrylate; The weight average molecular weight of the acrylic resin containing carbon-carbon double bonds is 300,000-700,000; the glass transition temperature is -50°C to -10°C; and the carbon-carbon double bond content is 0.1-0.3 mmol / g; The preparation method of the acrylic resin containing carbon-carbon double bonds comprises the following steps: S1. Under an inert atmosphere, the soft monomer, the hard monomer, the functional monomer and the functional monomer containing active hydroxyl groups are dissolved in part of the solvent, the temperature is raised to 60-80° C. under stirring, the initiator is added stepwise and the temperature is kept for 4-8 hours, and then the temperature is lowered to 50-60° C. to obtain a reaction solution; S2, adding a catalyst to the reaction solution described in step S1, adding dropwise a mixture of isocyanate containing a carbon-carbon double bond and the remaining solvent under stirring, reacting for 3-5 hours, and finally cooling the reaction solution to room temperature to obtain the acrylic resin containing a carbon-carbon double bond, wherein the dropping time is 0.1-1 hour; The soft monomer is one or more of ethyl acrylate, butyl acrylate, isooctyl acrylate and lauryl acrylate; The hard monomer is methyl methacrylate and / or cyclohexyl methacrylate; The functional monomer is one or more of acrylic acid, methacrylic acid, N-hydroxymethyl acrylamide, glycidyl methacrylate, N,N-dimethylacrylamide and isobornyl methacrylate; The functional monomer containing active hydroxyl groups is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and diethylene glycol monoacrylate; The weight ratio of the soft monomer, the hard monomer, the functional monomer and the functional monomer containing active hydroxyl groups is 30-70:1-10:1-10:1.4-7.

2. The UV adhesive tape according to claim 1, It is characterized in that In S1, the initiator is one or more of benzoyl peroxide, azobisisobutyronitrile, di-tert-butyl hydroperoxide and tert-butyl peroxy-2-ethylhexanoic acid; The solvent is one or more of ethyl acetate, toluene, butanone and heptane.

3. The UV adhesive tape according to claim 1, It is characterized in that In S2, the catalyst is one or more of dioctyltin dilaurate, dibutyltin dilaurate and zirconium acetylacetonate; The isocyanate containing a carbon-carbon double bond is isocyanate ethyl acrylate and / or isocyanate ethyl methacrylate; the amount of the isocyanate containing a carbon-carbon double bond and the functional monomer containing an active hydroxyl group added is the same.

4. The UV adhesive tape according to claim 1, It is characterized in that The photoinitiator is one or more of benzil dimethyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4-p-phenylmercaptobenzophenone, 4-methylbenzophenone, isopropylthioxanthene and 2-ethylanthraquinone; The thermal curing agent is one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate; The organic solvent is one or more of ethyl acetate, toluene, butanone and heptane.

5. The UV adhesive tape according to claim 1, It is characterized in that The material of the substrate layer is a PO film with a thickness of 90-150 μm; The thickness of the first and second anti-viscosity adhesive layers are both 10-30 μm; The release layer is made of a silicon release film with a thickness of 25-50 μm.

6. The method for preparing the UV adhesive tape according to any one of claims 1 to 5, It is characterized in that The following steps are included: (1) mixing an acrylic resin containing a carbon-carbon double bond, a photoinitiator, a thermal curing agent and an organic solvent, and allowing the mixture to stand for defoaming to obtain a first viscosity-reducing adhesive; (2) mixing a reactive diluent containing a carbon-carbon double bond, an acrylic resin containing a carbon-carbon double bond, a photoinitiator, a thermal curing agent, and an organic solvent, and allowing the mixture to stand for defoaming to obtain a second viscosity-reducing adhesive; (3) coating the first viscosity-reducing adhesive described in step (1) on the surface of the substrate layer and drying to form a first viscosity-reducing adhesive layer; coating the second viscosity-reducing adhesive described in step (2) on the surface of the first viscosity-reducing adhesive layer and drying to form a second viscosity-reducing adhesive layer; and compounding a release layer on the surface of the second viscosity-reducing adhesive layer and aging to obtain the UV viscosity-reducing adhesive tape.

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