JP4676297B2 - An adhesive, an adhesive sheet using the adhesive, and an electronic component manufacturing method using the adhesive sheet. - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet using the pressure-sensitive adhesive, and an electronic component manufacturing method using the pressure-sensitive adhesive sheet.

As a pressure-sensitive adhesive sheet used when dicing an electronic component assembly such as a BGA (ball grid array) substrate, a glass substrate, an epoxy substrate, or a vector substrate into a chip-shaped electronic component, the semiconductors described in Patent Documents 1 to 3 There is a wafer fixing sheet.

The conventional adhesive sheet for fixing a semiconductor wafer has few chip jumps in the dicing process, but since the chip jump occurs due to the recent miniaturization of the chip size, further adhesive force has been required.

In the conventional adhesive sheet for fixing a semiconductor wafer, the defective rate of the semiconductor member may be increased due to static electricity generated at the time of peeling at the time of picking up after dicing the electronic component assembly.

Therefore, the present invention does not scatter the semiconductor member even if the semiconductor member affixed to the adhesive sheet is diced into chips, and has a great effect of suppressing static electricity when picking up the semiconductor member formed into chips after dicing. There was a need for adhesives and adhesive sheets.

JP 9-328663 A Japanese Patent No. 3035179 Japanese Patent No. 3410202

An adhesive and an adhesive sheet are provided.

The present invention relates to a pressure-sensitive adhesive for pressure-sensitive adhesive sheets used when dicing an electronic component assembly, and an elastomer having at least one chlorine-containing polymerizable monomer unit : 100 parts by mass and an amino group-containing silane coupling Agent : A pressure-sensitive adhesive containing 0.01 to 20 parts by mass and containing 0.1 to 55% by mass of a chlorine-containing polymerizable monomer unit in the elastomer and a pressure-sensitive adhesive sheet using the same.

By using the pressure-sensitive adhesive and pressure-sensitive adhesive sheet of the present invention, high adhesive strength is exhibited when dicing an electronic component assembly. The pressure-sensitive adhesive sheet has a great effect of suppressing chip jump at the time of dicing, and has an effect such as a large effect of suppressing static electricity when the adherend and the pressure-sensitive adhesive sheet are peeled off after completion of dicing.

The present invention has 100 parts by mass of an elastomer and 0.01 to 20 parts by mass of an amino group-containing silane coupling agent, and the elastomer has at least one halogen-containing polymerizable monomer unit. It is a pressure-sensitive adhesive having a monomer unit content of 0.1 to 55% by mass relative to the elastomer.

Examples of the halogen component of the halogen-containing polymerizable monomer include chlorine, fluorine, bromine and iodine, which are light in molecular weight, preferably fluorine and chlorine, and more preferably chlorine.

The reason why the content of the halogen-containing polymerizable monomer unit is set to 0.1 to 55% by mass of the entire elastomer is that the surface resistance value of the pressure-sensitive adhesive tends to increase when the content is less than 0.1% by mass. If the amount exceeds 55% by mass, the adhesive strength is lowered and the halogen component tends to move to the adherend. The minimum with preferable content rate is 1 mass%, and a preferable upper limit is 30 mass%.

The elastomer satisfying the requirements of the present invention contains a halogen-containing monomer unit and may be a copolymer of a halogen-containing monomer and a halogen-free monomer. Specific examples of the elastomer include an epihalohydrin rubber, a fluororubber, a copolymer of a halogen-containing monomer and a (meth) acrylic acid ester monomer, or a mixture of these, particularly preferably adhesive to a semiconductor member. From the height, a copolymer of a halogen-containing monomer and a (meth) acrylic acid ester monomer is preferable.

Epihalohydrin is a halogen-containing monomer of epihalohydrin rubber. Examples of the epihalohydrin include epichlorohydrin, epibromohydrin, epiiodohydrin, and β-methylepichlorohydrin. Examples of the halogen-free monomer of the epihalohydrin rubber include alkylene oxide and unsaturated epoxide.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, 1,2-epoxybutane, 1,2-epoxy-iso-butane, 2,3-epoxybutane, 1,2-epoxyhexane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, 1,2-epoxyoctadecane, 1,2-epoxyeicosane, 1,2-epoxycyclopentane, 1,2-epoxycyclohexane There are hexane, 1,2-epoxycyclododecane, 1,2-epoxy-isobutane, 2,3-epoxy-isobutane, 2,3-epoxy-3-chloropentane.

As the halogen-containing monomer of the fluororubber, there is a fluorine monomer. Examples of the fluorine monomer include vinylidene fluoride, hexafluoropropylene, pentafluoropropylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, vinyl fluoride, perfluoromethyl vinyl ether, and perfluoropropyl vinylidene. Examples of the fluorine-free monomer of fluororubber include acrylic acid ester, propylene, ethylene, and diene. Specific examples of the fluororubber include tetrafluoroethylene / propylene and hexafluoropropylene / ethylene copolymer.

Examples of the halogen-containing monomer when a copolymer of a halogen-containing monomer and a (meth) acrylic acid ester monomer is used as the elastomer include haloalkyl (meth) acrylates, haloacyloxyalkyl (meth) acrylates, halogen-containing (meta ) Acrylates, unsaturated carboxylic acid haloalkyls, halogen-containing unsaturated nitriles, halogen-containing unsaturated amides, halogen-containing saturated carboxylic acid unsaturated alcohol esters, halogen-containing unsaturated ethers, haloalkylalkenyl ketones, halogen Examples thereof include aromatic vinyl compounds, halogenated olefins, halogen-containing dienes, and compounds containing a polymerizable unsaturated group and a halogen atom. These halogen-containing monomers may be used alone or in combination of two or more.

Examples of haloalkyl (meth) acrylates include chloromethyl (meth) acrylate, 1-chloroethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 1,2-dichloroethyl (meth) acrylate, 2-chloropropyl (meth) ) Acrylate, 3-chloropropyl (meth) acrylate, 2,3-dichloropropyl (meth) acrylate, 2-chlorobutyl (meth) acrylate, 3-chlorobutyl (meth) acrylate, 4-chlorobutyl (meth) acrylate, 3,4 -Dichlorobutyl (meth) acrylate etc. are mentioned.

Examples of haloacyloxyalkyl (meth) acrylates include chloroacetoxymethyl (meth) acrylate, 2- (chloroacetoxy) ethyl (meth) acrylate, 3- (chloroacetoxy) propyl (meth) acrylate, and 4- (chloroacetoxy). Examples include butyl (meth) acrylate.

Examples of halogen-containing (meth) acrylates include chloroacetylcarbamoyloxymethyl (meth) acrylate, 2- (chloroacetylcarbamoyloxy) ethyl (meth) acrylate, 3- (chloroacetylcarbamoyloxy) propyl (meth) acrylate, 3 -(Hydroxycyclohexylacetoxy) propyl (meth) acrylate, 4- (hydroxycyclohexylacetoxy) propyl (meth) acrylate, etc. are mentioned.

Examples of unsaturated carboxylic acid haloalkyls include 2-chloroethyl ethacrylate, 2-chloroethyl crotonic acid, 2-chloroethyl cinnamate, and the like.

Examples of the halogen-containing unsaturated nitriles include α-chloroacrylonitrile and α-chloromethylacrylonitrile.

Examples of halogen-containing unsaturated amides include N-chloromethylacrylamide, N-chloromethylmethacrylamide, chloroacetamidomethylacrylamide, chloroacetamidomethylmethacrylamide and the like.

Examples of the unsaturated alcohol ester of a halogen-containing saturated carboxylic acid include vinyl chloroacetate, vinyl 2-chloropropionate, allyl chloroacetate, vinylbenzyl chloroacetate and the like.

Examples of halogen-containing unsaturated ethers include chloromethyl vinyl ether, 2-chloroethyl vinyl ether, 3-chloropropyl vinyl ether, 2- (hydroxychloroacetoxy) ethyl vinyl ether, 3- (hydroxychloroacetoxy) propyl vinyl ether, chloromethyl allyl ether. 2-chloroethyl allyl ether, 3-chloropropyl allyl ether, 2- (hydroxychloroacetoxy) ethyl allyl ether, 3- (hydroxychloroacetoxy) propyl allyl ether, and the like.

Examples of haloalkyl alkenyl ketones include 2-chloroethyl vinyl ketone, 3-chloropropyl vinyl ketone, 4-chlorobutyl vinyl ketone, 2-chloroethyl allyl ketone, 3-chloropropyl allyl ketone, and 4-chlorobutyl allyl ketone. is there. Examples of the halogen-containing aromatic vinyl compound include α-chlorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-chloromethylstyrene, o-chloromethyl-methylstyrene, and p-chloromethyl-methyl. Examples thereof include styrene, o-di (chloromethyl) styrene, o-di (chloromethyl) styrene, vinylbenzyl chloride and the like.

Examples of halogenated olefins include vinyl chloride, vinylidene chloride, and 1,2-dichloroethylene.

Examples of the halogen-containing dienes include 2-chloro-1,3-butadiene, 1,2-dichloro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, and the like.

Examples of the compound containing a polymerizable unsaturated group and a halogen atom include compounds containing a polymerizable unsaturated group such as a vinyl group, a methacryl group, a methacryloyl group, an acryloyl group, a styryl group, and an allyl group and a halogen atom. is there.

Examples of the acrylic acid ester employed as the halogen-free monomer include a copolymer having a main monomer and a comonomer described below, and a polymer such as a monomer having a functional group.

Examples of the main monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, (meth) 3-methoxypropyl acrylate, 2-methoxybutyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, (meth) Examples include 4-ethoxybutyl acrylate.

Examples of the comonomer include acrylonitrile, acrylic amide, and styrene. Examples of the monomer having a functional group include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and an epoxy group-containing monomer.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, β-carboxyethyl (meth) acrylate, itaconic acid, crotonic acid, maleic acid, and fumaric acid. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

Examples of the epoxy group-containing monomer include (meth) acrylic acid glycidyl ether.

As described above, the amino group-containing silane coupling agent is used because the halogen group and the amino group of the amino group-containing silane coupling agent react to form an ammonium salt, thereby forming the adhesive itself. This is to reduce the surface resistivity, thereby increasing the adhesive strength as an adhesive and suppressing static electricity.

When the addition amount of the amino group-containing silane coupling agent is less than 0.01 parts by mass, there is a tendency that an improvement in adhesive force and a decrease in the adhesive surface resistivity cannot be expected. Since there exists a tendency to fall, it is 0.01-20 mass parts, a preferable minimum is 1 mass part and a preferable upper limit is 10 mass parts.

The chemical formula of the amino group-containing silane coupling agent is shown in Chemical Formula 1. X is an alkoxy group such as a methoxy group and an ethoxy group, and Y is an organic group containing an amino functional group.

Examples of amino group-containing silane coupling agents include N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3- Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-amino Examples thereof include propyltrimethoxysilane and hydrochloride of N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane.

In the pressure-sensitive adhesive of the present invention, conventionally known additives such as UV-polymerizable oligomers and / or monomers, polymerization initiators, tackifiers, curing agents, softeners, aging are used as long as the object of the present invention is not impaired. An inhibitor, a filler, an ultraviolet absorber and a light stabilizer can be appropriately selected and added.

The pressure-sensitive adhesive sheet of the present invention can be configured as a part of the pressure-sensitive adhesive sheet by forming a pressure-sensitive adhesive layer on one or both sides of the substrate.

The method of forming the pressure-sensitive adhesive layer on the substrate and forming the pressure-sensitive adhesive sheet is not particularly limited. For example, it is directly applied onto the substrate layer with a coater such as a gravure coater, comma coater, bar coater, knife coater, or roll coater. And a printing method such as convex printing, concave printing, flat printing, flexographic printing, offset printing, or screen printing. The thickness of the pressure-sensitive adhesive layer is not particularly limited, and a thickness of about 1 to 100 μm after drying is preferably used.

The thickness and material of the base material of an adhesive sheet can be suitably selected according to a use. Although the raw material of a base material is not specifically limited, For example, polyvinyl chloride, polyethylene, a polypropylene, polyester, ethylene vinyl alcohol etc. are mentioned.

The adherend of the adhesive sheet may be any, and examples of the semiconductor member include a BGA (ball grid array) substrate, a silicon wafer, gallium arsenide, a glass substrate, an epoxy substrate, and a vector substrate. Even if such a semiconductor member is diced, chip skipping hardly occurs and static electricity at the time of peeling can be reduced.

The dicing properties (chip skipping) shown in Table 1 are obtained by sticking the adhesive sheets according to the examples and comparative examples so that bubbles do not enter a semiconductor member having a length of 20 mm and a width of 25 mm molded with a packaging molding resin. 10 minutes This is the number of chips jumping with respect to a total of 100 chips when dicing to 5 mm □ after standing and dicing 5 semiconductor members. The smaller the value, the better.

For the adhesive strengths in Table 1, the adhesive sheets according to Examples and Comparative Examples were measured in accordance with JIS Z 0237 by adhering the semiconductor components molded with the packaging molding mold resin so that no air bubbles would enter. .

The surface resistivity shown in Table 1 is obtained by measuring the resistivity of the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet according to Examples and Comparative Examples using a surface resistance measuring instrument (Advantest R8340A) in an atmosphere at a temperature of 23 ° C. and a humidity of 55%. It is a thing.

The halogen element extraction amounts in Table 1 are as follows. 100 cm ² of the pressure-sensitive adhesive sheets according to Examples and Comparative Examples are put into a conical beaker, immersed in 100 ml of ultrapure water, extracted at 100 ° C. for 2 hours using a hot plate, ion chromatography ( The analysis of the amount of halogen ions was performed by DIONEX DX-AQ).
○ (good): halogen extraction amount is less than 0.1 ppm.
X (Not possible): Halogen extraction amount is 0.1 ppm or more.

The pressure-sensitive adhesive sheet of Reference Example 1 is obtained by providing a pressure-sensitive adhesive layer having a thickness of 25 μm on one surface of a polyethylene sheet having a thickness of 150 μm as a base material.

(Materials used)
Elastomer: Epibromohydrin-ethylene oxide-allyl glycidyl ether copolymer.
Amino group-containing silane coupling agent: 3-aminopropyltriethoxysilane (manufactured by Shin-Etsu Silicone).
UV crosslinkable monomer: dipentaerythritol hexaacrylate (commercially available).
Photopolymerization initiator: 1-hydroxycyclohexyl phenyl ketone (commercially available product).
Polyisocyanate: TDI-based isocyanate-terminated prepolymer (commercially available).

(Adhesive)
100 parts by mass of an epibromohydrin-ethylene oxide-allyl glycidyl ether copolymer, 5 parts by mass of an amino group-containing silane coupling agent, 50 parts by mass of an ultraviolet-crosslinkable monomer, 3 parts by mass of a photopolymerization initiator, and 1 part by mass of a polyisocyanate. blend.

Reference examples, examples and comparative examples which will be described later are the same as reference example 1 except for the parts specifically mentioned.

The pressure-sensitive adhesive sheet in Reference Example 1 was good because it had no chip skip, a surface resistivity of 7.0 × 10 ¹¹ Ω / □, and a chlorine ion extraction amount of less than 0.1 ppm.

In Reference Example 2, the epibromohydrin-ethylene oxide-allyl glycidyl ether copolymer as the elastomer of the pressure-sensitive adhesive layer of Example 1 was changed to a vinylidene fluoride / hexafluoropropylene copolymer.

Example 1 is a monomer containing 5% by mass of a vinyl chloroacetate monomer containing no chlorine as an epibromohydrin-ethylene oxide-allyl glycidyl ether copolymer as an elastomer of the pressure-sensitive adhesive layer of Reference Example 1, and containing no halogen. The monomer is changed to an elastomer obtained by copolymerizing 90% by mass of butyl acrylate and 5% by mass of 2-hydroxyethyl acrylate.

Comparative Example 1: The amino group-containing silane coupling agent in Reference Example 1 was 0.005 part by mass.
Comparative Example 2: What made the amino group containing silane coupling agent in Reference Example 1 25 mass parts.
Comparative Example 3: The elastomer in Reference Example 1 did not contain “monomers having halogen”.
Comparative Example 4: The elastomer in Reference Example 1 having a halogen-containing monomer content of 0.05% by mass.
Comparative Example 5: The elastomer in Reference Example 1 having a halogen-containing monomer content of 60% by mass.

By using the pressure-sensitive adhesive and pressure-sensitive adhesive sheet of the present invention, high adhesive strength is exhibited when dicing an electronic component assembly. The adhesive sheet has a great effect of suppressing chip skipping during dicing, and after the completion of dicing, it has the effect of suppressing static electricity when the adherend and adhesive sheet are peeled off. It is preferably used when processing by grinding or dicing.

Claims (4)

A pressure-sensitive adhesive for a pressure-sensitive adhesive sheet used when dicing an electronic component assembly,
An elastomer having at least one chlorine-containing polymerizable monomer unit : 100 parts by weight;
An amino group-containing silane coupling agent : 0.01 to 20 parts by mass ,
The adhesive whose content rate of the chlorine-containing polymerizable monomer unit in the said elastomer is 0.1-55 mass%. The pressure-sensitive adhesive according to claim 1, wherein the elastomer has a halogen-containing polymerizable monomer unit and a halogen-free polymerizable monomer unit, and the halogen-free polymerizable monomer is a (meth) acrylic acid ester. A pressure-sensitive adhesive sheet for dicing using the pressure-sensitive adhesive according to claim 1. The electronic component manufacturing method using the adhesive sheet of Claim 3 .