JP4861081B2 - A pressure-sensitive adhesive sheet for fixing a semiconductor member and an electronic component manufacturing method using the same. - Google Patents

Description

The present invention relates to an adhesive sheet for fixing a semiconductor member and an electronic component manufacturing method using the same.

In manufacturing various electronic components, an electronic component assembly formed by forming a circuit pattern on a semiconductor wafer or the like is fixed to an adhesive sheet, diced with a dicing blade equipped with abrasive grains such as diamond, and a chip-shaped electronic component. The method of doing is known (refer patent documents 1-4 etc.).

Examples of the electronic component assembly include a semiconductor wafer or a circuit pattern formed by a method such as photolithography.

A radiation-polymerizable compound having two or more unsaturated bonds in a copolymer of (meth) acrylic acid ester and a hydroxyl group-containing polymerizable monomer as a pressure-sensitive adhesive for a pressure-sensitive adhesive sheet used when dicing an electronic component assembly A method using this is known (see Patent Document 5).

As acrylic pressure-sensitive adhesives, those containing acrylic compounds and urethane acrylate oligomers having various functional groups having a weight average molecular weight of 200,000 or more and a Tg (glass transition temperature) of −60 to −30 ° C. are known ( (See Patent Document 6).

In recent years, with the spread of small electronic devices such as PDAs, mobile phones, and flash memories, the chip size tends to be miniaturized. As a means for improving the adhesive strength, a method of adding a tackifying resin is known. When tackifying resin is used for the pressure-sensitive adhesive, the adhesiveness between the base material and the pressure-sensitive adhesive is deteriorated when the chip-shaped electronic component is recovered, and the pressure-sensitive adhesive may be transferred to the adherend.

JP 09-328663 A JP 2003-007654 A JP 2003-257893 A JP 2005-229040 A Japanese Patent No. 3410202 JP 11-293201 A

The present invention provides an adhesive sheet for fixing a semiconductor member and an electronic component manufacturing method using the same.

The present invention comprises a laminate of a pressure-sensitive adhesive and a base material, the pressure-sensitive adhesive contains a base polymer and a tackifying resin, the tackifying resin has a hydroxyl group, and the hydroxyl value of the tackifying resin by JIS K0070 neutralization titration method. Is a pressure-sensitive adhesive sheet for fixing a semiconductor member having a thickness of 170 to 250 KOH mg / g, and an electronic component manufacturing method using the same.

The adhesive sheet for fixing a semiconductor member of the present invention is a dicing electronic component assembly attached to an adhesive sheet for fixing a semiconductor member, and as a chip-shaped electronic component, while suppressing scattering of the electronic component during dicing, There are effects that the amount of the adhesive remaining on the adherend surface after peeling can be reduced.

In this specification, (meth) acrylate is a general term for acrylate and methacrylate. Similarly, a compound containing (meth) such as (meth) acrylic acid is a general term for a compound having “meta” in the name and a compound not having “meta”. A monomer unit means a structural unit derived from a monomer. Unless otherwise indicated, parts and% in this specification are based on mass.

The pressure-sensitive adhesive contains a base polymer and a tackifier resin, the tackifier resin has a hydroxyl group, and the hydroxyl value of the tackifier resin by a JIS K0070 neutralization titration method is 170 to 250 KOHmg / g.

(Base polymer)
The base polymer is not particularly limited, and acrylic, epoxy, silicone, and the like can be used, but acrylic and easily available (especially (meth) acrylic acid ester polymers) are preferably used.

((Meth) acrylic acid ester polymer)
The (meth) acrylic acid ester polymer is a vinyl polymer having a monomer unit derived from a (meth) acrylic acid alkyl ester monomer.

Examples of the (meth) acrylic acid ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, Heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl ( Examples include (meth) acrylic acid alkyl esters such as meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate. The alkyl group of the (meth) acrylic acid alkyl ester may have a straight chain structure, and may have a branched structure, a double bond, an ether bond, or the like.

The (meth) acrylic acid ester polymer is selected from the group consisting of hydroxyl group, carboxyl group, epoxy group, amide group, amino group, methylol group, sulfonic acid group, sulfamic acid group, and (sub) phosphate group. It preferably contains a functional group-containing monomer unit having one or more functional groups.

As a monomer which has a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, etc. are mentioned, for example.

Examples of the monomer having a carboxyl group include (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide N-glycolic acid, and cinnamic acid.

Examples of the monomer having an epoxy group include allyl glycidyl ether and (meth) acrylic acid glycidyl ether. Examples of the monomer having an amide group include (meth) acrylamide. Examples of the monomer having an amino group include N, N-dimethylaminoethyl (meth) acrylate. Examples of the monomer having a methylol group include N-methylolacrylamide.

Monomers other than those mentioned above may be used for the (meth) acrylic acid ester polymer, for example, ethylene, styrene, vinyl toluene, allyl acetate, vinyl propionate, vinyl butyrate, vinyl versatate, vinyl ethyl ether, vinyl propyl. Examples thereof include vinyl compounds such as ether, (meth) acrylonitrile, and vinyl isobutyl ether.

The number average molecular weight of the (meth) acrylic acid ester polymer is not particularly limited, but is preferably 100,000 to 1,000,000. If the number average molecular weight is low, the amount of the adhesive remaining on the adherend surface after peeling may increase, and if the number average molecular weight is high, the electronic components may be easily scattered during dicing.

Among (meth) acrylic acid ester polymers, polymers having monomer units derived from methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate are readily available, and after peeling The amount of the adhesive remaining on the adherend surface is small and preferable.

(Tackifying resin)
As the tackifier resin, a compound having a hydroxyl group is used. Examples of such tackifier resins include terpene phenol resins, rosin phenol resins, and alkylphenol resins.

The tackifier resin has a hydroxyl value of 170 to 250 KOHmg / g, preferably 180 to 230 KOHmg / g, derived by JIS K0070-1992, neutralization titration. If the hydroxyl value is small, the adhesion between the substrate and the pressure-sensitive adhesive may be insufficient, and if the hydroxyl value is large, the pressure-sensitive adhesive component may be phase-separated to reduce the pressure-sensitive adhesiveness.

Examples of the terpene phenol resin include α-pinene / phenol resin, β-pinene / phenol resin, dipentene / phenol resin, and terpene bisphenol resin. It is preferable to use a terpene phenol resin as the tackifier resin because of its high compatibility with various base polymers.

1-50 mass parts is preferable with respect to 100 mass parts of base polymers of an adhesive, and, as for the compounding quantity of tackifying resin, 3-20 mass parts is more preferable. In some cases, the amount of the tackifying resin is small or the amount of the tackifying resin is insufficient.

Although the pressure-sensitive adhesive can be a pressure-sensitive pressure-sensitive adhesive mainly composed of a base polymer and a tackifying resin, an acrylate oligomer, a curing agent, a photopolymerization initiator, etc. are used in addition to the base polymer and the tackifying resin. It can be used as a radiation polymerization pressure-sensitive adhesive.

(Acrylate oligomer)
The acrylate oligomer is not particularly limited except that it is an oligomer having an acroyl group as a terminal, and a urethane acrylate oligomer having a urethane bond in the molecule is easily available and is preferably used.

The number average molecular weight of the acrylate oligomer is not particularly limited, but the number average molecular weight is preferably 3000 or less. If the number average molecular weight of the acrylate oligomer is high, the adhesive strength of the adhesive may be insufficient.

(Curing agent)
Although it will not specifically limit if a hardening | curing agent can be used as a hardening | curing agent for adhesives, When a base polymer is made into a (meth) acrylic acid ester polymer, an isocyanate type hardening | curing agent is used suitably. Examples of the isocyanate curing agent include aromatic isocyanate, alicyclic isocyanate, and aliphatic isocyanate.

Examples of the aromatic diisocyanate include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and xylylene diisocyanate.

Examples of the alicyclic diisocyanate include isophorone diisocyanate and methylene bis (4-cyclohexyl isocyanate).

Examples of the aliphatic diisocyanate include hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

In these isocyanate curing agents, the dimer or trimer of the isocyanate compound may be used, or an adduct may be used.

The addition amount of the isocyanate curing agent is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the base polymer. If the amount of the isocyanate curing agent is small, the adhesive may be scraped up during dicing or the laser mark may disappear. If the isocyanate curing agent is excessive, the pressure-sensitive adhesive becomes hard and chip skipping may occur during dicing.

Various additives such as a photopolymerization initiator, a thermal polymerization inhibitor, a softening agent, an antiaging agent, a filler, an ultraviolet absorber, and a light stabilizer may be added to the adhesive.

(Base material)
The thickness and type of the substrate are not particularly limited and can be appropriately selected depending on the application. Specific examples include polyvinyl chloride, polyethylene, polypropylene, polyester, ethylene vinyl alcohol, and ionomer resin.

A friction reducing agent or an antistatic agent may be applied to the substrate or kneaded.

(Friction reducing agent)
The friction reducing agent is not particularly limited as long as it is a substance that lowers the coefficient of friction between the adhesive sheet for fixing a semiconductor member and the expanding apparatus. Examples thereof include nitride, carbon black, and molybdenum disulfide. These friction reducing agents may mix a plurality of components. The friction reducing agent is preferable because when the friction reducing agent is kneaded in an amount of 0.1 to 30 parts by mass in 100 parts by mass of the base material, the blocking suppression effect and the adhesion between the base material layer and the pressure-sensitive adhesive layer are good. .

Since electronic parts are manufactured in a clean room, it is preferable to use a silicone compound or a fluororesin. Among silicone compounds, a copolymer having a silicone graft compound as a monomer (hereinafter referred to as “silicone graft copolymer”) has good compatibility with the antistatic layer, and has antistatic properties and expandability. Since balance can be achieved, it is preferably used.

The silicone graft copolymer includes a monomer having a vinyl group such as a (meth) acryloyl group or a styryl group at the end of the silicone molecular chain (hereinafter referred to as “silicone monomer”), (meth) acrylic. And vinyl polymers obtained by polymerizing monomers having a vinyl group such as ethylene and styrene (see, for example, JP 2000-080135 A).

(Antistatic agent)
The antistatic agent is not particularly limited, and examples thereof include a quaternary amine salt monomer.

Examples of the quaternary amine salt monomer include dimethylaminoethyl (meth) acrylate quaternary chloride, diethylaminoethyl (meth) acrylate quaternary chloride, methylethylaminoethyl (meth) acrylate quaternary chloride, p- Examples thereof include dimethylaminostyrene quaternary chloride and p-diethylaminostyrene quaternary chloride, and dimethylaminoethyl methacrylate quaternary chloride is preferably used.

(Electronic component manufacturing method)
The adherend of the adhesive sheet for fixing a semiconductor member is not particularly limited as long as it is a member containing a semiconductor. For example, an electronic component assembly formed by forming a plurality of electronic circuits on the surface of a semiconductor wafer is suitably used as the adherend. be able to.

(Dicing)
The method of manufacturing an electronic component by dicing using a pressure-sensitive adhesive sheet for fixing a semiconductor member is not particularly limited. For example, the adhesive component is attached to an electronic component assembly and fixed, and then the electronic component is diced with a rotating round blade. The method of (chip) is preferably used.

The method for collecting the electronic components after dicing is not particularly limited, and examples thereof include a method of irradiating with radiation. Examples of a method for recovering electronic components by irradiating radiation include the following procedures.
(1) Irradiate ultraviolet rays and / or radiation from the substrate side of the adhesive sheet for fixing a semiconductor member.
(2) Expanding (enlarging) the adhesive sheet for fixing semiconductor members radially, expanding the element pieces (electronic parts) at regular intervals, and then pushing the element pieces (electronic parts) with a needle or the like
(3) A method of picking up an element piece by a method such as suction using a vacuum collector, air tweezers, etc., and then fixing the element piece on a lead frame and mounting it.

The light source of ultraviolet rays and / or radiation when the adhesive sheet for fixing a semiconductor member is a radiation curable type is not particularly limited, and known ones can be used. Examples of the ultraviolet ray source include a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, and a metal halide lamp, and examples of the radiation source include an electron beam. Examples of the radiation light source include radioisotopes (such as Co ⁶⁰ ) that emit α rays, β rays, and γ rays.

The manufacturing method of the adhesive and the adhesive sheet for fixing a semiconductor member according to Experiment No. 1-1 is shown below. Other experimental examples are the same as those in Experiment No. 1-1 except for the matters described in Table 1.

(Materials used)
(Meth) acrylic acid ester polymer A: copolymer of 74% by mass of butyl acrylate, 20% by mass of methyl methacrylate, 1% by mass of 2-hydroxyethyl acrylate, and 5% by mass of acrylic acid. Glass transition temperature Tg = −28.8 ° C., weight average molecular weight 200,000, synthetic product.

Urethane acrylate oligomer A: A monomer of hexamethylene diisocyanate whose isocyanate component is an aliphatic diisocyanate, and a urethane acrylate oligomer whose acrylate component containing a hydroxyl group is dipetaerythritol pentaacrylate. Number average molecular weight (Mn) is 2,500, the number of vinyl groups is 10 per molecule, commercially available.

Tackifying resin A: terpene phenol resin, hydroxyl number 130.
Tackifying resin B: terpene phenol resin, hydroxyl number 175.
Tackifying resin C: terpene phenol resin, hydroxyl number 210.
Tackifying resin D: terpene phenol resin, hydroxyl number 260.
Photopolymerization initiator: 1-hydroxycyclohexyl phenyl ketone, commercially available product.
Isocyanate curing agent: Tolylene diisocyanate adduct of trimethylolpropane, synthetic product.
Base material: 150 μm thick polyethylene sheet, commercial product.

(Adhesive)
The pressure-sensitive adhesive is a blend of 100 parts by mass of a (meth) acrylic acid ester polymer, 100 parts by mass of a urethane acrylate oligomer, 3 parts by mass of a photopolymerization initiator, and 3 parts by mass of an isocyanate curing agent.

(Adhesive sheet)
An adhesive was applied to one side of the substrate to provide an adhesive layer having a thickness of 15 μm.

(Evaluation methods)
Dicing property (chip skipping): The pressure-sensitive adhesive sheet was attached to a semiconductor member molded with a mold resin for package molding, and diced to 4 mm □ after being left for 10 minutes. This is the ratio of chip skipping to the total number of 100 chips obtained by repeating this operation five times.

Adhesive adhesion to substrate: Adhesive sheet was irradiated with 150 mJ / cm ² using a high pressure mercury lamp lamp to cure the adhesive. An OPP tape (uniaxially stretched polypropylene tape) was bonded to the cured pressure-sensitive adhesive surface, and when the pressure-sensitive adhesive was peeled off, the pressure-sensitive adhesive was not peeled off from the base material.

Compatibility: When a pressure-sensitive adhesive was mixed, a cloudy product was not allowed, and a product that was not cloudy was considered good.

The pressure-sensitive adhesive sheet for fixing a semiconductor member of the present invention suppresses scattering of the electronic component and peels off when the electronic component assembly attached to the pressure-sensitive adhesive sheet for fixing a semiconductor member is diced into a chip-shaped electronic component. Since the effect of reducing the amount of the adhesive remaining on the adherend surface later can be obtained, it is suitably used for manufacturing electronic parts such as a dicing process.

Claims (5)

A pressure-sensitive adhesive and a base material are laminated, the pressure-sensitive adhesive contains a base polymer and a tackifier resin, the tackifier resin has a hydroxyl group, and the hydroxyl value of the tackifier resin by a JIS K0070 neutralization titration method is 175 to 175. 210 KOHmg / g der is,
A pressure-sensitive adhesive sheet for fixing a semiconductor member containing 1 to 50 parts by mass of a tackifier resin with respect to 100 parts by mass of a base polymer . The adhesive sheet for fixing a semiconductor member according to claim 1, comprising 3 to 20 parts by mass of a tackifier resin with respect to 100 parts by mass of the base polymer.   The adhesive sheet for fixing a semiconductor member according to claim 1 or 2, wherein the base polymer is a (meth) acrylic acid ester polymer.   The pressure-sensitive adhesive sheet for fixing a semiconductor member according to any one of claims 1 to 3, wherein the tackifier resin is a terpene phenol resin.   The electronic component manufacturing method using the adhesive sheet for semiconductor member fixation as described in any one of Claims 1 thru | or 4.