TWI666295B - Adhesive sheet - Google Patents

Abstract

The adhesive sheet 1 of the present invention is an adhesive sheet having an adhesive layer 12 on a base film 11. The adhesive layer 12 contains an energy ray-curable polymer and a cross-linking agent. It is obtained by copolymerizing a cyano monomer, and the aforementioned crosslinking agent is a metal chelate compound.

Description

Adhesive sheet

The present invention relates to an adhesive sheet having solvent resistance and plating resistance.

This application claims priority based on Japanese Patent Application No. 2014-157580 filed in Japan on August 1, 2014, and the contents are incorporated herein by reference.

Regarding a semiconductor wafer, after the circuit is formed on the surface, the back surface is ground to adjust the thickness, and then the semiconductor wafer is fixed on a dicing sheet and singulated into a specific wafer size. A semiconductor wafer singulated into a wafer size is picked up from a dicing wafer and transferred to the next step.

With the popularity of IC (integrated circuit) cards in recent years, semiconductor wafers are becoming thinner. In order to obtain such a semiconductor wafer, a thin wafer is extremely easy to break, so it may be damaged in a grinding step on the back surface, a subsequent processing step, and a conveying step. Therefore, in these steps, the wafer is held on a rigid support such as glass. After the steps are completed, the wafer is transferred from the hard support to the dicing sheet. On the (adhesive sheet), after the outer periphery of the dicing sheet is fixed with a ring frame, the wafer is cut (diced) for each circuit to become a wafer, and the wafer is picked up from the dicing sheet. In this process, an adhesive or a decomposition product thereof may remain on the surface of the wafer after peeling off the hard support. Therefore, in order to remove these adhesives or their decomposition products, the wafer fixed on the dicing sheet is cleaned with a polar organic solvent.

In addition, as for a semiconductor wafer with a gold film for a power device, a wafer that has been peeled from a hard support and fixed to a dicing sheet as described above is usually immersed in a plating solution to form a gold film, and then diced. As an adhesive sheet having plating resistance assuming that a plating solution is used in this manner, for example, a person having a specific tensile elastic modulus and tear strength is disclosed (for example, refer to Patent Document 1).

[Prior technical literature]

[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2005-68420

However, led by those described in Patent Document 1, although conventional adhesive sheets have plating resistance, there is a problem that the resistance is insufficient for the solvent cleaning for removing the adhesive or its decomposition product as described above.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an adhesive sheet having solvent resistance and plating resistance.

In order to solve the above problems, the present invention provides an adhesive sheet comprising an adhesive layer on a base film, the adhesive layer containing an energy ray-curable polymer and a cross-linking agent, and the energy ray-curable polymer having a cyanide It is obtained by copolymerizing a monomer of a basic group, and the aforementioned crosslinking agent is a metal chelate compound.

In the adhesive sheet of the present invention, the monomer having a cyano group is preferably acrylonitrile.

In the adhesive sheet of the present invention, it is preferable that the aforementioned crosslinking agent is an aluminum chelate compound or a titanium chelate compound.

In the pressure-sensitive adhesive sheet of the present invention, when the energy ray-curable polymer is prepared by polymerizing the monomer, the ratio of the amount of the cyano-containing monomer to the total amount of the monomer is 0.2% by mass ~ 30% by mass.

In the pressure-sensitive adhesive sheet of the present invention, the content of the crosslinking agent in the pressure-sensitive adhesive layer is preferably 0.2 to 10 parts by mass relative to 100 parts by mass of the content of the energy ray-curable polymer.

In the pressure-sensitive adhesive sheet of the present invention, the energy ray-curable polymer is preferably a (meth) acrylate copolymer having a hydroxyl group and a polymerizable group in a side chain via a urethane bond.

According to the present invention, an adhesive sheet having solvent resistance and plating resistance can be provided.

1‧‧‧ adhesive sheet

11‧‧‧ substrate film

11a‧‧‧ Surface of substrate film

12‧‧‧ Adhesive layer

FIG. 1 is a cross-sectional view schematically showing an adhesive sheet of the present invention.

<< adhesive sheet >>

The adhesive sheet of the present invention is provided with an adhesive layer on a base film. The adhesive layer contains an energy ray-curable polymer and a crosslinking agent. The energy ray-curable polymer is obtained by copolymerizing a monomer having a cyano group. The aforementioned crosslinking agent is a metal chelate compound. As such an adhesive sheet, the adhesive sheet 1 which has the adhesive layer 12 on the surface 11a of the base film 11 as shown in FIG. 1 is illustrated, for example.

The adhesive sheet is provided with an adhesive layer, and the adhesive layer contains an energy ray-curable polymer obtained by copolymerizing a monomer having a cyano group, and a cross-linking agent as a metal chelate compound, thereby having solvent resistance. And plating resistance.

The aforementioned adhesive sheet is suitable for use as a dicing sheet used in a series of steps of transducing and cutting a semiconductor wafer held on a rigid support into a semiconductor wafer. The aforementioned adhesive sheet is solvent-resistant, so even if the semiconductor wafer adhered to the adhesive is washed with a polar organic solvent, The adhesive on the round surface or its decomposition product can also stably maintain the laminated structure of the adhesive layer and the semiconductor wafer. In addition, since the aforementioned adhesive sheet has plating resistance, even if a metal film is formed by dipping in a plating solution in a state where the semiconductor wafer has been adhered, the laminated structure of the adhesive layer and the semiconductor wafer can be stably maintained. . During the above-mentioned plating, the semiconductor wafer to which the adhesive sheet is attached is sequentially immersed in, for example, the following chemical solutions (1) to (9). During this period, the adhesive layer does not deteriorate and can be stably maintained. Laminated structure of adhesive layer and semiconductor wafer.

(1) Degreasing solution (pH 10 ~ 12, room temperature ~ 50 ° C, containing surfactant).

(2) Strong acid cleaning solution (sulfuric acid, nitric acid, pH value is 1 ~ 4, room temperature ~ 50 ℃).

(3) Adjust the solution (pH is close to 7 neutral, about room temperature, containing a surfactant).

(4) Zincate solution (first time) (pH is 10-12, about room temperature).

(5) Strong acid (sulfuric acid, nitric acid, pH 1 ~ 4, about room temperature).

(6) Zincate solution (second time) (pH 10 ~ 12, about room temperature).

(7) Nickel plating solution (pH 2 ~ 5, 70 ℃ ~ 90 ℃)

(8) Palladium plating solution (pH 2 ~ 5, 70 ℃ ~ 90 ℃)

(9) Gold plating solution (pH 2 ~ 5, 70 ℃ ~ 90 ℃)

The aforementioned adhesive sheet is suitable for the steps of contacting with a polar organic solvent and a plating solution in a state in which a semiconductor wafer is fixed as described above, such as a manufacturing step of a semiconductor wafer with a gold film for power components, and also suitable for Manufacturing steps or processing steps for various electronic parts having the same steps.

<Substrate film>

The material of the substrate film is preferably various resins. Specific examples include polyethylene (low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene). (HDPE, high density polyethylene, etc.), polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polyterephthalate Butyl formate, polyimide, ethylene-vinyl acetate copolymer, ionic polymer resin, polystyrene, polycarbonate, fluororesin, ethylene- (meth) acrylic copolymer, ethylene- (meth) Acrylate copolymers, hydrides, modifiers, crosslinkers, or copolymers of any of these resins.

Among these, the material of the base film is preferably polypropylene.

The base film may be formed of one layer (single layer), or may include a plurality of layers. In addition, when the base film includes a plurality of layers, the materials of the respective layers may be the same or different, or may be the same only partially.

The thickness of the substrate film can be appropriately selected according to the purpose, and is preferably 50 μm to 300 μm, and more preferably 60 μm to 100 μm.

In order to improve the adhesion between the base film and the adhesive layer provided thereon, the surface may be subjected to a roughening treatment by sandblasting, a solvent treatment, or the like, or a corona discharge treatment, an electron beam irradiation treatment, or a plasma. Treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or oxidation treatment such as hot air treatment. Moreover, the base film may be one whose surface has been subjected to a primer treatment.

Among these, as the base film, from the viewpoint of suppressing chipping of the base film due to friction of the blade during cutting, it is particularly preferred that the surface is subjected to an electron beam irradiation treatment.

<Adhesive layer>

The adhesive layer contains an energy ray-curable polymer and a cross-linking agent, and the adhesive force becomes low after curing. When attached to a semiconductor wafer, the adhesive layer has high pick-up property for a semiconductor wafer obtained by dicing.

The thickness of the adhesive layer can be appropriately selected according to the purpose, and is preferably 1 μm to 100 μm, more preferably 1 μm to 60 μm, and even more preferably 1 μm to 30 μm.

The adhesive layer is formed using an adhesive composition containing a target component. That is, the adhesive layer system uses an energy ray-curable polymer and a crosslink The adhesive composition of the adhesive is formed, and the content ratio of the non-volatile components of the adhesive composition to each other is also the same in the adhesive layer.

[Energy ray hardening polymer]

The aforementioned energy ray-curable polymer in the adhesive layer is hardened (polymerized) by irradiation with energy rays such as ultraviolet rays, and is obtained by copolymerizing a monomer having a cyano group (-CN). That is, the energy ray-curable polymer has a structural unit derived from the monomer having a cyano group.

Examples of the monomer having a cyano group include those having a cyano group and a polymerizable unsaturated bond (-C = C-, etc.), and more specifically, acrylonitrile (CH ₂ = CH-CN), methacrylic acid, etc. Nitrile (CH ₂ = C (CH ₃ ) -CN), 2-vinylbenzonitrile (CH ₂ = CH- (C ₆ H ₄ ) -CN), 3-vinylbenzonitrile, 4-vinylbenzene Nitrile.

Except for the structural unit derived from the aforementioned monomer having a cyano group, the structural unit possessed by the aforementioned energy ray-curable polymer is not particularly limited, and can be arbitrarily selected according to the purpose.

When the energy ray-curable polymer is prepared by polymerization of its monomer, the ratio of the blending amount of the cyano-containing monomer to the total blending amount of the monomer is preferably 0.2% to 30% by mass. It is more preferably 0.4% to 20% by mass, and even more preferably 0.6% to 15% by mass.

The energy ray-curable polymer is preferably a (meth) acrylate copolymer, and more preferably a (meth) acrylate copolymer having a hydroxyl group and a polymerizable group in a side chain via a urethane bond. Such a (meth) acrylate copolymer having a hydroxyl group and a polymerizable group is crosslinked by reacting the hydroxyl group with the aforementioned crosslinking agent. In addition, as compared with the case where, for example, a low-molecular-weight energy-ray-curable compound is used and a curing (polymerization) reaction is performed by irradiation with energy rays, such a (meth) acrylate copolymer system having a hydroxyl group and a polymerizable group By having a polymerizable group in the side chain, the adhesiveness of the adhesive layer is reduced after the hardening reaction, and the peelability from the adherend is improved. With this improvement in peelability, for example, the ease of picking up a semiconductor wafer is improved. In addition, since it is not necessary to separately use a low molecular weight energy ray polymerizable compound, for example, migration of the energy ray polymerizable compound from the adhesive layer containing the energy ray polymerizable compound to the object to be attached can be suppressed. In addition, when such a (meth) acrylic acid ester copolymer having a hydroxyl group and a polymerizable group is in contact with a plating solution to be described later, dissolution into the plating solution can be significantly suppressed.

The term "(meth) acrylic acid" as used herein refers to a concept including both "acrylic acid" and "methacrylic acid".

((Meth) acrylate copolymer)

The (meth) acrylic acid ester copolymer is obtained, for example, by using a composition prepared by blending a (meth) acrylic acid ester, a hydroxyl-containing monomer, and the monomer having a cyano group, and polymerizing to obtain polymerization. And react the hydroxyl group of the polymer with the isocyanate group of the compound having an isocyanate group and a polymerizable group.

Preferred examples of the (meth) acrylate copolymer include the following: (hydroxy) -free (meth) acrylate, hydroxy-containing (meth) acrylate, and the aforementioned cyano-containing monomer A monomer is required, and an acrylic copolymer is obtained by copolymerizing these monomers. The acrylic copolymer is obtained by reacting a hydroxyl group of the acrylic copolymer with an isocyanate group of a compound having an isocyanate group and a polymerizable group.

Examples of the hydroxyl-free (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (formyl) (Pentyl) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, (meth) acrylic acid Isononyl ester, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), tridecyl (meth) acrylate , Tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, cetyl (meth) acrylate (palmityl (meth) acrylate), Heptadecyl (meth) acrylate, stearyl (meth) acrylate (stearyl (meth) acrylate), isostearyl (meth) acrylate (isostearyl (meth) acrylate) ) And other alkyl groups constituting alkyl esters are alkyl (meth) acrylates having a chain structure of 1 to 18 carbon atoms (hereinafter, referred to as "C1-18 alkyl (meth) acrylates"); (meth) acrylic acid Isoamyl ester, dicyclopentyl (meth) acrylate, etc. ( Yl) acrylate, cycloalkyl acrylate; (meth) acrylate Aryl (meth) acrylates such as benzyl acid; cyclo (meth) acrylates such as dicyclopentenyl (meth) acrylate; dicyclopentenyloxyethyl (meth) acrylates (methyl Cycloalkenyloxyalkyl acrylate; (meth) acrylamidoimine; glycidyl (meth) acrylate-containing (meth) acrylate and the like.

Among the above, as the (meth) acrylic acid ester having no hydroxyl group, an alkyl (meth) acrylic acid ester (hereinafter referred to as "(formaldehyde) Base) C8-18 alkyl acrylate "), the acrylic copolymer is preferably one obtained by copolymerizing C8-18 alkyl (meth) acrylate as an essential monomer. By using an acrylic copolymer obtained by copolymerizing C8-18 alkyl (meth) acrylate, the solvent resistance of the adhesive layer is more excellent.

Examples of the hydroxyl-containing (meth) acrylate include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate.

In addition to the above-mentioned essential monomers, the acrylic copolymer may be made of (meth) acrylic acid; itaconic acid; non- (meth) acrylic monomers such as vinyl acetate, styrene, and N-methylmethacrylamide Wait for any monomer to copolymerize.

The acrylic copolymer is preferably an acrylic copolymer obtained by copolymerizing the hydroxyl-containing (meth) acrylic acid C1-18 alkyl ester, the hydroxyl-containing (meth) acrylate, acrylonitrile, and (meth) acrylic acid.物 (A ').

The acrylic copolymer (A ') used for the preparation of the aforementioned hydroxyl-free (meth) acrylic acid C1-18 alkyl ester, hydroxyl-containing (meth) acrylate, and (meth) acrylic acid may be used in only one kind. , Or two or more.

When the acrylic copolymer (A ') is prepared by polymerizing the monomers, the ratio of the compounded amount of the C1-18 alkyl (meth) acrylic acid without hydroxyl groups to the total compounded amount of the monomers is relatively small. It is preferably 50% to 89.5% by mass, and more preferably 60% to 84% by mass.

In addition, when the acrylic copolymer (A ') is prepared by polymerization of its monomer, the ratio of the blending amount of the hydroxyl-containing (meth) acrylate to the total blending amount of the monomer is preferably 10 Mass% to 30% by mass, more preferably 15% to 25% by mass.

In addition, when the aforementioned acrylic copolymer (A ') is prepared by polymerization of its monomers, the ratio of the amount of acrylonitrile to the total amount of monomers is preferably 0.3% to 15% by mass, more It is preferably 0.7% to 12% by mass.

In addition, when the acrylic copolymer (A ') is prepared by polymerization of its monomer, the ratio of the (meth) acrylic acid blending amount to the total blending amount of the monomer is preferably 0.2% by mass to 5% by mass. %, More preferably 0.3% to 3% by mass.

When the aforementioned acrylic copolymer (A ') is prepared by polymerization of its monomers, it is preferred that the above-mentioned (meth) acrylic acid C1 to 18 alkyl esters are blended with respect to the total blending amount of the monomers. The ratio of the amount is 50% to 89.5% by mass. The ratio of the above-mentioned hydroxyl-containing (meth) acrylate is 10% to 30% by mass. The ratio of the amount of acrylonitrile is 0.3% to 15% by mass. %, And the ratio of the (meth) acrylic acid compounding amount is 0.2 mass% to 5 mass%.

In addition, when the acrylic copolymer (A ') is prepared by polymerization of its monomers, it is more preferable that the aforementioned (meth) acrylic acid C1-18 alkyl esters do not contain hydroxyl groups relative to the total blending amount of the monomers. The ratio of the blending amount is 60% to 84% by mass. The ratio of the blending amount of the aforementioned hydroxyl-containing (meth) acrylate is 15% to 25% by mass. The ratio of the blending amount of acrylonitrile is 0.7% by mass. 12 mass%, and the ratio of the (meth) acrylic acid compounding amount is 0.3 mass% to 3 mass%.

When the acrylic copolymer (A ') is prepared by polymerization of the monomers, the blending amount of the C8-18 alkyl (meth) acrylate without hydroxyl group is relative to the (meth) group without hydroxyl group. The ratio of the total blended amount of C1-18 alkyl acrylate is preferably 40% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, and also 100% by mass. By using such an acrylic copolymer (A ') having a large blending ratio of (hydroxy) -containing (meth) acrylic acid C8 to 18 alkyl esters, the solvent resistance of the adhesive layer is more excellent.

Examples of the compound having an isocyanate group and a polymerizable group include an isocyanate group-containing alkyl (meth) acrylate such as 2-methacryloxyethyl isocyanate.

When the acrylic copolymer (A ') is reacted with the isocyanate group and the polymerizable group to obtain the (meth) acrylate copolymer, the amount of the compound having the isocyanate group and the polymerizable group is relatively large. The amount is preferably 40 mol% to 100 mol%, and more preferably 50 mol% relative to the structural unit derived from the (meth) acrylate containing a hydroxyl group in the acrylic copolymer (A '). ~ 90 mol%. By setting the aforementioned amount of the compound having an isocyanate group and a polymerizable group within this range, it is possible to further suppress the (meth) acrylate copolymer from dissolving in the plating solution when the adhesive sheet described later contacts the plating solution, and The characteristics of the adhesive layer become better.

The compound having the isocyanate group and the polymerizable group used in the preparation of the (meth) acrylate copolymer may be only one kind, or two or more kinds.

So far, the (meth) acrylic acid ester copolymer is described as being obtained by reacting the aforementioned hydroxyl group of a polymer having a hydroxyl group with the aforementioned isocyanate group of a compound having an isocyanate group and a polymerizable group. However, the aforementioned (meth) acrylate copolymer of the present invention is not limited to this, For example, a polymer having a hydroxyl group and a functional group other than a hydroxyl group may be used instead of the polymer having a hydroxyl group, and a compound having an isocyanate group and a polymerizable group may be used instead of a polymer having a reactivity with the functional group. A compound of a reactive group and a polymerizable group obtained by reacting the functional group with the reactive group. Here, the "polymerizable group" in the compound having a reactive group and a polymerizable group is the same as the "polymerizable group" in the compound having an isocyanate group and a polymerizable group.

Examples of the functional group other than the hydroxyl group include a carboxyl group, an amine group in which one hydrogen atom can be substituted with a substituent such as an alkyl group, an epoxy group, and the like, and a monomer having such a functional group can be copolymerized to obtain a functional group. The aforementioned polymer.

The reactive group may be selected according to the type of the functional group other than the hydroxyl group, and examples thereof include a hydroxyl group, a carboxyl group, an amine group in which one hydrogen atom can be substituted with a substituent such as an alkyl group, and an epoxy group.

The polymer having a functional group other than a hydroxyl group and the compound having a reactive group and a polymerizable group used in the preparation of the (meth) acrylate copolymer may be only one type or two types, respectively. the above.

The weight average molecular weight of the energy ray-curable polymer is preferably 100,000 to 2,000,000, and more preferably 400,000 to 1,000,000. In addition, the weight average molecular weight described in this specification can be measured using a gel permeation chromatography (GPC method: Gel Permeation Chromatography).

The energy ray-curable polymer contained in the adhesive composition may be only one kind, or two or more kinds.

The content of the energy ray-curable polymer of the adhesive composition is preferably 80% by mass or more, and more preferably 90% by mass or more, relative to the total amount of all the contained components other than the solvent in the adhesive composition. The content of the energy ray-curable polymer in the adhesive composition is preferably 99% by mass or less, and more preferably 97.5% by mass or less, based on the total amount of all the components contained in the adhesive composition except for the solvent. That is, the content of the energy ray-curable polymer of the adhesive composition is preferably in a range of 80% to 99% by mass with respect to the total amount of all the components contained in the adhesive composition except for the solvent. The range is from 90% by mass to 97.5% by mass.

[Crosslinking agent]

The aforementioned crosslinking agent is a metal chelate compound. In the present specification, the "crosslinking agent" means a crosslinker of the metal chelate compound unless otherwise specified.

Examples of the crosslinking agent include those in which a ligand as an organic group is coordinated to a metal atom or a metal ion.

The aforementioned crosslinking agent (metal chelate compound) is preferably an aluminum chelate compound whose metal species is aluminum, a titanium chelate compound whose metal species is titanium, or a zirconium chelate compound whose metal species is zirconium, and more preferably aluminum chelate Compound or titanium chelate compound.

Examples of the aluminum chelate compound include aluminum acetoacetone (aluminum acetoacetone), aluminum tris (ethylacetoacetate), aluminum acetoacetate diisopropoxide, (3-ethoxycarbonyl-2 -Propylene-2-yloxy aluminum diisopropoxide) and the like.

Examples of the titanium chelate compound include titanium (2,4-pentanedione) titanium.

Examples of the zirconium chelate compound include tetra (2,4-pentanedione) zirconium.

The cross-linking agent contained in the adhesive composition may be only one kind, or two or more kinds.

The content of the cross-linking agent in the adhesive composition (adhesive layer) is 100 parts by mass relative to the content of the energy ray-curable polymer, preferably 0.2 to 10 parts by mass, and more preferably 0.3 to parts by mass. 7 parts by mass, particularly preferably 0.4 to 5 parts by mass.

[Photopolymerization initiator]

The adhesive composition preferably contains a photopolymerization initiator in addition to the energy ray-curable polymer and the crosslinking agent.

The aforementioned photopolymerization initiator may be a known one, and specific examples thereof include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α'- Α-keto alcohol compounds such as dimethylacetophenone, 2-methyl-2-hydroxyphenylacetone, and 1-hydroxycyclohexylphenyl ketone; methoxyacetophenone, 2,2-dimethoxy- 2- Phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinylpropane-1 and other acetophenones Compounds; benzoin ether compounds such as benzoin diethyl ether, benzoin isopropyl ether, anisole methyl ether; ketal compounds such as benzoin dimethyl ketal; aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride ; 1-benzophenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime and other photoactive oxime compounds; benzophenone, benzamidinebenzoic acid, 3,3'-dimethyl- Benzophenone compounds such as 4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, Thiothanone compounds such as isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone; camphorquinone; halogen Ketones; fluorenyl phosphine oxide; fluorenyl phosphonate; oligo [2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) acetone] and the like.

Among these, the photopolymerization initiator is preferably one having a molecular weight of 400 or more, and more preferably one having a molecular weight of 600 or more. Such a relatively large molecular weight photopolymerization initiator can significantly inhibit dissolution into the plating solution when the adhesive sheet is in contact with a plating solution described later. As a result, the hardening (polymerization) of the energy ray-curable polymer by energy ray irradiation proceeds well, and the adhesiveness of the adhesive layer is reduced after the hardening reaction, thereby improving the peelability from the adherend, and For example, the ease of picking up a semiconductor wafer is improved.

The content of the photopolymerization initiator of the adhesive composition is 100 parts by mass with respect to the content of the (meth) acrylate copolymer, and preferably 0.05 to 20 parts by mass. By setting the aforementioned content of the photopolymerization initiator to be above the aforementioned lower limit, the effect of using the photopolymerization initiator can be sufficiently obtained. fruit. In addition, by setting the content of the photopolymerization initiator to be equal to or smaller than the upper limit value, it is possible to suppress generation of by-products from the excess photopolymerization initiator, and harden the adhesive layer more favorably.

(Solvent)

The adhesive composition preferably contains a solvent in addition to the energy ray-curable polymer and the crosslinking agent.

The aforementioned solvent is not particularly limited, and preferred examples include hydrocarbons such as toluene and xylene; methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-1-ol), 1-butanol, and the like Alcohols; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; fluorenamines (compounds having fluorenamine bonds) such as dimethylformamide and N-methylpyrrolidone; and the like.

The solvent contained in the adhesive composition may be only one kind, or two or more kinds.

The content of the solvent of the adhesive composition is preferably 20% to 85% by mass, and more preferably 30% to 65% by mass relative to the total amount of the adhesive composition.

(Other ingredients)

The adhesive composition may contain other components in addition to the energy ray-curable polymer, the cross-linking agent, the photopolymerization initiator, and the solvent as long as the effect of the present invention is not impaired.

The other components contained in the adhesive composition may be only one kind, or two or more kinds.

The aforementioned other components may be known and may be arbitrarily selected according to the purpose, and are not particularly limited. Preferred examples include dyes, pigments, anti-degradants, antistatic agents, flame retardants, polysiloxanes, and chain transfer agents. And other additives.

As the other component, a cross-linking agent other than the aforementioned cross-linking agent (metal chelate compound) (hereinafter referred to as "other cross-linking agent") may be used.

The other cross-linking agent is not particularly limited, and may be a known one. Preferred examples include isocyanate-based cross-linking agents (organic polyisocyanate compounds), epoxy-based cross-linking agents (organic poly-epoxide compounds), and imine-based compounds. Cross-linking agent (organic polyimide compound) and the like.

The isocyanate-based crosslinking agent is not particularly limited as long as it is a crosslinking agent having an isocyanate group (-N = C = O). Preferred examples include 2,4-toluene diisocyanate and 2,6-toluene. Diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiisocyanate Phenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, p-trimethylol All or other polyols such as propane A compound obtained by adding a part of hydroxyl groups to toluene diisocyanate or hexamethylene diisocyanate, and a diamine diisocyanate.

Examples of the epoxy-based crosslinking agent include bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, 1,3-bis (N, N-diglycidylaminomethyl) toluene, and N, N, N ', N'-tetraglycidyl-4,4-diaminodiphenylmethane and the like.

Examples of the imine-based crosslinking agent include N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxyamidoamine), and trimethylolpropane-tri-β-aziridine. Pyridinyl propionate, tetramethylol methane-tri-β-aziridinyl propionate, N, N'-toluene-2,4-bis (1-aziridinylcarbamidine) triethyl Melamine and so on.

In the said adhesive composition, content of the said other crosslinking agent with respect to content of the said crosslinking agent (metal chelate compound) is 1 mass part, Preferably it is 0.1 mass part or less, More preferably, it is 0.05 mass part or less.

In the said adhesive composition, content of the said other component other than the said other crosslinking agent can be arbitrarily adjusted according to the objective.

The said adhesive composition is obtained by mix | blending the said energy ray hardening polymer, a crosslinking agent, and components other than these as needed.

The order of adding each component is not particularly limited, and two or more components may be added simultaneously.

The method of mixing the components during the preparation is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by applying an ultrasonic wave.

The temperature and time during addition and mixing of each component are not particularly limited as long as they do not deteriorate each of the prepared components, and may be appropriately adjusted, and the temperature is preferably 15 ° C to 30 ° C.

When a solvent is used, the solvent can be used by mixing the solvent with any formulation component other than the solvent and diluting the formulation component in advance, or by not diluting any formulation component other than the solvent in advance, The ingredients are mixed and used.

Furthermore, in the adhesive sheet of this embodiment, the elastic modulus of the adhesive layer formed from the aforementioned adhesive composition before UV irradiation is preferably 0.02 MPa to 0.12 MPa.

In addition, the gel fraction of the adhesive layer measured by a method described later in detail before ultraviolet irradiation is preferably in the range of 5.6 to 20.1 (%).

In addition, the adhesive sheet of this embodiment is immersed in each solution of a nickel plating solution, warm water, an alkaline aqueous solution, and a sulfuric acid solution under specific conditions, which are measured by a detailed method described below, in a state of being attached to a silicon wafer. The change rate of the peeling force when peeling the adhesive sheet from the silicon wafer is preferably -5% or more.

<< Manufacturing method of adhesive sheet >>

The adhesive sheet of the present invention can be produced by using the aforementioned adhesive composition to form an adhesive layer on a substrate film.

The adhesive layer can be formed by applying an adhesive composition on the surface of the substrate film, removing the solvent and drying it. In the adhesive sheet 1 illustrated in FIG. 1, an adhesive layer 12 is formed on the surface 11 a of the base film 11. At this time, it is also possible to perform cross-linking by heating the applied adhesive composition if necessary. The heating condition may be, for example, 0.5 minutes to 5 minutes at 100 ° C to 130 ° C, but is not limited thereto. In addition, an adhesive layer can also be formed by coating the surface of the release layer of the release material with an adhesive composition and drying it to form an adhesive layer, and bonding the aforementioned adhesive layer to the base film Surface and remove the aforementioned release material. The conditions for forming the adhesive layer on the surface of the release layer of the release material may be the same as the conditions for forming the adhesive layer on the surface of the substrate film.

The application of the adhesive composition to the substrate film surface or the release layer surface of the release material may be performed by a known method, and examples thereof include an air knife coater, a knife coater, a bar coater, and a gravure coater. , Roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, wire rod coater, contact coater, etc. How to distribute the machine.

[Example]

Hereinafter, the present invention will be described in more detail through specific examples. However, the present invention is not limited to the examples shown below.

[Example 1]

<Manufacture of Adhesive Sheet>

(Manufacturing of adhesive composition)

An energy ray-curable polymer (600,000 weight average molecular weight) (100 parts by mass), a photopolymerization initiator ("ESACURE KIP 150" manufactured by DKSH Corporation), and an oligo [2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) acetone]) (3 parts by mass) and a cross-linking agent ("MA-5" manufactured by Soken Chemical Co., Ltd., an aluminum chelate compound) (0.6 parts by mass) in formazan The ethyl ethyl ketone (77 mass parts) was mixed at 23 degreeC, and the adhesive composition was obtained.

The energy ray-curable polymer is a (meth) acrylate copolymer made of lauryl acrylate (hereinafter referred to as "LA") (68 parts by mass), and methyl methacrylate (hereinafter referred to as "MMA") (10 parts by mass), 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") (20 parts by mass), acrylonitrile (hereinafter referred to as "AN") (1 part by mass), and acrylic acid (hereinafter referred to as "AA" ") (1 part by mass) was copolymerized to obtain an acrylic copolymer (A'-1), and the acrylic copolymer (A'-1) (100 parts by mass) and 2-methacrylic acid isocyanate Ethyl ester (hereinafter abbreviated as "MOI") (21.4 parts by mass, obtained by reacting with an amount of 80 mol% with respect to the structural unit derived from HEA in the acrylic copolymer (A'-1)). The blending amount of each component is shown in Table 1 below. In addition, in the following Table 1, the mark of "-" in the column of a compounded ingredient means that the ingredient is not compounded. This is also the same in Tables 2 and 3 below.

(Manufacturing of adhesive sheet)

The adhesive composition obtained above was coated on the release surface of a release film ("SP-PET381031" manufactured by LINTEC), and dried at 120 ° C for 1 minute to form an adhesive layer having a thickness of 10 μm. . Next, a polypropylene film with a thickness of 80 μm was laminated on the surface of the adhesive layer, thereby obtaining an adhesive sheet.

<Evaluation of Adhesive Sheet>

(Plating resistance)

The adhesive sheet is attached to the mirror-polished surface of a silicon wafer (6 inches in diameter and 150 μm in thickness) that has been mirror-polished on one side through its adhesive layer. The attaching conditions at this time were set to a temperature of 23 ° C., an attaching pressure of 0.3 MPa, and an attaching speed of 5 mm / sec. Next, the outer periphery of the adhered adhesive sheet was attached to a resin-made ring frame (RF) under the same conditions to obtain a laminate.

Then, the obtained laminate was immersed in a nickel plating solution ("EPITHAS NPR-18" manufactured by Uemura Industrial Co., Ltd.) under conditions of 80 minutes, 20 minutes, 40 minutes, and 60 minutes, and then visually observed. The appearance state confirms the penetration of liquid and generation of bubbles between the wafer and the adhesive sheet. The results are shown in Tables 1 to 3 below.

(Adhesion change rate)

The adhesive sheet was attached to the mirror-polished surface of a silicon wafer by the same method as in the above-mentioned evaluation of plating resistance.

Next, the silicon wafer to which the adhesive sheet is attached (hereinafter referred to as "silicon wafer with adhesive sheet") is immersed in each liquid under any of the following conditions, which are (i) nickel-plated Solution ("EPITHAS NPR-18" manufactured by Kamuramura Corporation) was immersed at 80 ° C for 60 minutes; (ii) immersed in warm water at 80 ° C for 60 minutes; (iii) in an alkaline aqueous solution (a degreasing solution manufactured by Kamuramura Corporation) "MCL-16") for 30 minutes at 50 ° C; and (iv) for 60 minutes at 80 ° C in a sulfuric acid solution.

Then, for an area of 25 mm × 25 cm in the aforementioned silicon wafer with an adhesive sheet after immersion, the self-adhesive sheet was measured at a peeling angle of 180 ° and a peeling speed of 300 mm / minute. The peeling force when the wafer is peeled is set as the adhesive force of the adhesive sheet. In addition, for the silicon wafer with the adhesive sheet attached before the dipping, the adhesive force of the adhesive sheet was also measured under the same conditions in advance, and the change rate of the adhesive force of the adhesive sheet was calculated from the following formula (1). The results are shown in Tables 1 to 3 below. In addition, in the following Tables 1 to 3, the change rate of the adhesive force in each liquid is set to "no problem" when the value is -5% or more, and "problematic" when the value is less than -5%.

Adhesive force change rate (%) = (adhesive force of the adhesive sheet after being immersed in the liquid / adhesive force of the adhesive sheet before being immersed in the liquid) × 100-100‧‧‧‧‧ (1)

(Solvent resistance)

The adhesive sheet is attached to the mirror-polished surface of a silicon wafer (8 inches in diameter and 50 μm in thickness) that has been mirror-polished on one side through its adhesive layer. The attaching conditions at this time were set to a temperature of 23 ° C, an attaching pressure of 0.3 MPa, and an attaching condition. Speed is 5mm / sec. Next, the outer periphery of the adhered adhesive sheet was attached to a resin-made ring frame (RF) under the same conditions to obtain a laminate.

Then, the obtained laminate was immersed in each liquid under any one of the conditions described below (v) on propylene glycol-1-monomethyl ether-2-acetate (hereinafter referred to as "PGMEA") Soak for 5 minutes at 50 ° C or (vi) immerse in N-methylpyrrolidone (hereinafter simply referred to as "NMP") at room temperature for 60 minutes.

Next, by visually observing the appearance state, it was confirmed that liquid infiltration between the wafer and the adhesive sheet, peeling of the adhesive sheet from the wafer, peeling of the adhesive layer in the adhesive sheet from the substrate, and the like. The results are shown in Tables 1 to 3 below.

(Comprehensive plating resistance / solvent resistance)

When the above three items (plating resistance, solvent resistance, and adhesive force change rate) are all normal (all pass), the evaluation is ○, and when one item is abnormal (one item fails), the evaluation is △, When there are abnormalities in two or more items (failure of two or more items), the evaluation is ×. The results are shown in Tables 1 to 3 below.

(Cutability)

The adhesive sheet was evaluated for "water penetration / wafer release", "debris", "extensibility", and "pickability" shown below. The results are shown in Tables 1 to 3 below. The evaluation results shown in Tables 1 to 3 below As a result, when there are no problems in all four items, it is recorded as "no problem", and when any item has problems, the content of the item is recorded.

Water infiltration / wafer detachment: The aforementioned adhesive sheet is attached to a mirror-polished surface of a silicon wafer (6 inches in diameter and 150 μm in thickness) which has been mirror-polished on one side through its adhesive layer. The attaching conditions at this time were set to a temperature of 23 ° C., an attaching pressure of 0.3 MPa, and an attaching speed of 5 mm / sec.

Next, the structure formed by attaching an adhesive sheet to a silicon wafer is sequentially immersed in the chemical solutions (1) to (3) below. In addition, during the immersion, washing with pure water was performed for at least 1 minute between each step. The impregnation of these chemical liquids is selected assuming the steps of plating the aforementioned structures.

(1) Immerse in a degreasing solution (pH 10 ~ 12, room temperature ~ 50 ° C, containing a surfactant) for 10 minutes.

(2) Immerse in a strong acid cleaning solution (sulfuric acid, nitric acid, pH 1 ~ 4, room temperature ~ 50 ° C) for 40 minutes.

(3) Immersion in a nickel plating solution (pH 2 to 5, 70 ° C to 90 ° C) for 40 minutes.

Then, the silicon wafer was cut into a size of 2 mm × 2 mm to form a wafer. The situation where the diced square wafer was peeled from the adhesive sheet was set as "problematic". Evaluation was performed on all wafers.

Debrisability: Using the same method as in the case of "water penetration / chip detachment" described above, the structure formed by attaching an adhesive sheet to a silicon wafer is sequentially immersed in the above-mentioned (1) ~ (3) medicinal solution.

Next, a silicon wafer was cut into a size of 8 mm × 8 mm to form a wafer, and the number of wafers with chips (notches, etc.) having a size of 30 μm or more from the cutting line inside was set to “no problem”. , Set one or more cases as "problematic". The evaluation was performed on 5 vertical lines and 5 horizontal lines.

Extensibility: First, using the same method as in the above-mentioned evaluation of chipping property, proceed to a step of cutting a silicon wafer into a size of 8 mm × 8 mm to become a wafer. After that, the structure obtained by attaching the adhesive sheet to the wafer is fixed to the extension device ("SE-100" manufactured by JCM Corporation), and only the ring frame is pulled down by 10mm, 20mm. At this time, for the In the case of an adhesive sheet, the case where the number of adhesive sheets having a crack in the base film is 0 is set to "no problem", and the case where more than one sheet is set to "problem".

Pickability: The same method as in the case of "water infiltration / chip detachment" and "debris" described above is used to sequentially impregnate the structure formed by attaching an adhesive sheet to a silicon wafer in the above (1) to (3) In the liquid medicine.

Next, the silicon wafer was cut into a size of 10 mm × 10 mm to form a wafer. Next, a UV (ultraviolet) irradiation device ("RAD-2000m / 12" manufactured by Lindec) was used to irradiate ultraviolet rays under the conditions of an illuminance of 200 mW / cm ² and a light amount of 200 mJ / cm ² , followed by 5 mm stretching. And 4 pins are applied for top-up. At this time, the case where there is no residue on the wafer and no wafer crack is set to "no problem", and the case where there is at least one of the residue and the wafer crack is set to "problem".

(Elastic modulus before UV irradiation of the adhesive layer)

A release sheet (Lintec) was prepared by forming a silicone-based release agent layer (thickness: 0.1 μm) on one of the main surfaces of a polyethylene terephthalate base film (thickness: 38 μm). Manufactured "SPET382120"). Then, the thickness of the finally obtained adhesive layer was 40 μm, and the adhesive composition obtained above was applied to the surface of the release agent layer of the release sheet by a knife coater to form a coating film. Together with the release sheet, the obtained coating film was allowed to pass in an environment of 100 ° C. for 1 minute, thereby drying the coating film to form an adhesive layer, and producing a plurality of laminated bodies having an adhesive layer on a base film.

Then, using the plurality of laminates, after peeling off the above-mentioned base film, the adhesive layer was bonded until the total thickness became 1 mm, and the laminate of the obtained adhesive layer was punched into a circular shape with a diameter of 10 mm. A sample for measuring viscoelasticity was obtained.

Next, using a viscoelasticity measuring device ("ARES" manufactured by TA Instruments), a strain having a frequency of 1 Hz was applied to the sample obtained above, and a storage modulus of -50 ° C to 150 ° C was measured. The value of the storage modulus was set as the elastic modulus before ultraviolet irradiation of the adhesive layer. The results are shown in Tables 1 to 3 below. In addition, in the following Tables 1 to 3, the elastic modulus before the ultraviolet irradiation of the adhesive layer is set to "no problem" in the case of 0.02 MPa to 0.12 MPa, and "problematic" in other cases .

(Gel fraction before UV irradiation of the adhesive layer)

An adhesive layer was formed by the same method as that in the case of measuring the elastic modulus before the ultraviolet irradiation except that the thickness was set to 20 μm instead of 40 μm.

Next, the adhesive layer was cut into a size of 50 mm × 100 mm, and the obtained adhesive layer was covered with a 100 mm × 150 mm nylon mesh (mesh size: 200), and the mass of only the adhesive layer was measured with a precision balance. Let the mass at this time be M1. Then, the adhesive layer covered with the nylon mesh was immersed in ethyl acetate (100 mL) at 25 ° C for 24 hours, and then taken out, dried at 120 ° C for 1 hour, and further, at 23 ° C and 50% relative humidity. Allow to stand for 1 hour under these conditions to adjust the humidity. Then, the mass of only the adhesive layer is measured with a precision balance. Let the mass at this time be M2. Then, the gel fraction before the ultraviolet irradiation of the adhesive layer was calculated by the following formula (2). The results are shown in Tables 1 to 3 below.

Gel fraction (%) = (M2 / M1) × 100‧‧‧‧‧ (2)

<Manufacturing and Evaluation of Adhesive Sheets>

[Example 2]

As shown in Table 1 below, instead of the acrylic copolymer (A'-1), 2-ethylhexyl acrylate (hereinafter referred to as "2-EHA") (68 parts by mass) and MMA (10 parts by mass) were used. Except for the acrylic copolymer (A'-2) obtained by copolymerizing HEA (20 parts by mass), AN (1 part by mass), and AA (1 part by mass), the same method as in Example 1 was used Manufacturing and evaluation of adhesive sheets. Obtained using an acrylic copolymer (A'-2) The weight average molecular weight of the energy ray-curable polymer is 600,000. The results are shown in Table 1 below.

[Example 3]

As shown in Table 1 below, instead of the acrylic copolymer (A'-1), isooctyl acrylate (hereinafter referred to as "iOA") (68 parts by mass), MMA (10 parts by mass), and HEA (20 Except for the acrylic copolymer (A'-3) obtained by copolymerization of AN) (1 part by mass) and AA (1 part by mass), an adhesive sheet was produced and evaluated by the same method as in Example 1. The weight-average molecular weight of the energy ray-curable polymer obtained using the acrylic copolymer (A'-3) was 600,000. The results are shown in Table 1 below.

[Example 4]

As shown in Table 1 below, instead of the acrylic copolymer (A'-1), isostearyl acrylate (hereinafter simply referred to as "iStA") (69 parts by mass), MMA (10 parts by mass), and HEA ( 20 parts by mass), an acrylic copolymer (A'-4) obtained by copolymerization of AN (1 part by mass) and AA (1 part by mass), except that an adhesive sheet was produced and evaluated by the same method as in Example 1. . The weight average molecular weight of the energy ray-curable polymer obtained by using the acrylic copolymer (A'-4) was 600,000. The results are shown in Table 1 below.

[Example 5]

As shown in Table 1 below, instead of the acrylic copolymer (A'-1), butyl acrylate (hereinafter referred to as "BA") (68 parts by mass), MMA (10 parts by mass), and HEA (20 parts by mass) were used. Except for the acrylic copolymer (A'-5) obtained by copolymerizing AN) (1 part by mass) and AA (1 part by mass), an adhesive sheet was produced and evaluated by the same method as in Example 1. The weight average molecular weight of the energy ray-curable polymer obtained by using the acrylic copolymer (A'-5) was 600,000. The results are shown in Table 1 below. In addition, in the evaluation of the adhesive sheet of Example 5, the "cutting property" was performed using an adhesive sheet that was not immersed in the above-mentioned chemical solution. As a result, "water penetration / chip release", "detritus", " There are no problems with all the items of "extendability" and "pickability".

[Example 6]

As shown in Table 1 below, instead of the acrylic copolymer (A'-1), LA (64 parts by mass), MMA (10 parts by mass), HEA (20 parts by mass), AN (5 parts by mass), and An acrylic copolymer (A'-6) obtained by copolymerizing AA (1 part by mass) was used to produce and evaluate an adhesive sheet by the same method as in Example 1. The weight average molecular weight of the energy ray-curable polymer obtained using the acrylic copolymer (A'-6) was 600,000. The results are shown in Table 1 below.

[Example 7]

As shown in Table 1 below, instead of the acrylic copolymer (A'-1), LA (58 parts by mass), MMA (10 parts by mass), and HEA (20 Except for the acrylic copolymer (A'-7) obtained by copolymerization of AN) (10 parts by mass) and AA (1 part by mass), an adhesive sheet was produced and evaluated by the same method as in Example 1. The weight-average molecular weight of the energy ray-curable polymer obtained using the acrylic copolymer (A'-7) was 600,000. The results are shown in Table 1 below.

[Example 8]

As shown in Table 2 below, instead of the acrylic copolymer (A'-1), LA (78 parts by mass), HEA (20 parts by mass), AN (1 part by mass), and AA (1 part by mass) were used for copolymerization. Except for the obtained acrylic copolymer (A'-8), an adhesive sheet was produced and evaluated by the same method as in Example 1. The weight-average molecular weight of the energy ray-curable polymer obtained using the acrylic copolymer (A'-8) was 600,000. The results are shown in Table 2 below.

[Example 9]

As shown in Table 2 below, instead of the aluminum chelate compound "MA-5" (0.6 parts by mass), a titanium chelate compound "TC-401" (Matsumoto Fine Chemicals) was used as a cross-linking agent in the production of the adhesive composition. (Matsumoto Fine Chemical), except that titanium tetraacetamidine acetone (0.8 parts by mass) was used, and an adhesive sheet was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Example 10]

As shown in Table 2 below, the compounding amount of the cross-linking agent (aluminum chelate compound "MA-5") at the time of producing the adhesive composition was set to 1 part by mass instead of 0.6 part by mass. An adhesive sheet was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Example 11]

As shown in Table 2 below, the compounding amount of the cross-linking agent (aluminum chelate compound "MA-5") at the time of producing the adhesive composition was set to 3 parts by mass instead of 0.6 part by mass. An adhesive sheet was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Example 12]

As shown in Table 2 below, in addition to the aluminum chelate compound "MA-5" (0.6 parts by mass), a toluene diisocyanate terpolymer of trimethylolpropane was used as a cross-linking agent when producing the adhesive composition. Adduct (hereinafter referred to as "TDI-TMP") "BHS-8515" (manufactured by Toyo Ink Manufacturing Co., Ltd.) (0.01 parts by mass), except that it was manufactured and evaluated by the same method as in Example 1. Adhesive sheet. The results are shown in Table 2 below.

[Reference Example 1]

As shown in Table 2 below, in addition to the aluminum chelate compound "MA-5" (0.6 parts by mass), TDI-TMP "BHS-8515" (0.1 parts by mass) was used as a cross-linking agent when manufacturing the adhesive composition. ), In addition, An adhesive sheet was produced and evaluated by the same method as in Example 1. The results are shown in Table 2 below.

[Reference Example 2]

As shown in Table 2 below, in addition to the aluminum chelate compound "MA-5" (0.6 parts by mass), TDI-TMP "BHS-8515" (1 part by mass) was used as a cross-linking agent when producing the adhesive composition. ), Except that an adhesive sheet was produced and evaluated by the same method as in Example 1. The results are shown in Table 2 below.

[Comparative Example 1]

As shown in Table 3 below, instead of the acrylic copolymer (A'-1), LA (69 parts by mass), MMA (10 parts by mass), HEA (20 parts by mass), and AA (1 part by mass) were used for copolymerization. The obtained acrylic copolymer (AR'-1) was used as a cross-linking agent in the production of the adhesive composition, and instead of the aluminum chelate compound "MA-5" (0.6 parts by mass), TDI-TMP " Except for BHS-8515 "(0.5 parts by mass), an adhesive sheet was produced and evaluated by the same method as in Example 1. The weight-average molecular weight of the energy ray-curable polymer obtained by using the acrylic copolymer (AR'-1) was 600,000. The results are shown in Table 3 below.

[Comparative Example 2]

As shown in Table 3 below, the acrylic copolymer (AR'-1) was used in place of the acrylic copolymer (A'-1), and it was used for production adhesion. The cross-linking agent at the time of the agent composition was the same as that of Example 1 except that TDI-TMP "BHS-8515" (1 part by mass) was used instead of the aluminum chelate compound "MA-5" (0.6 part by mass). Method to make and evaluate the adhesive sheet. The results are shown in Table 3 below.

[Comparative Example 3]

As shown in Table 3 below, TDI-TMP "BHS-8515" (0.5 parts by mass) was used instead of the aluminum chelate compound "MA-5" (0.6 parts by mass) as a cross-linking agent when producing the adhesive composition. Other than that, an adhesive sheet was produced and evaluated by the same method as in Example 1. The results are shown in Table 3 below.

[Comparative Example 4]

As shown in Table 3 below, an epoxy compound "TC-5" (manufactured by Daisei Chemical Co., Ltd.) was used in place of the aluminum chelate compound "MA-5" (0.6 parts by mass) as a cross-linking agent in the production of the adhesive composition ) (0.5 part by mass), and an adhesive sheet was produced and evaluated by the same method as in Example 1. The results are shown in Table 3 below.

[Comparative Example 5]

As shown in Table 3 below, an adhesive sheet was produced and evaluated by the same method as in Example 1 except that a crosslinking agent was not used in the production of the adhesive composition. The results are shown in Table 3 below.

[Comparative Example 6]

As shown in Table 3 below, an adhesive sheet was produced and evaluated by the same method as in Example 1 except that the acrylic copolymer (AR'-1) was used instead of the acrylic copolymer (A'-1). The results are shown in Table 3 below.

[Comparative Example 7]

As shown in Table 3 below, instead of the acrylic copolymer (A'-1), an acrylic copolymer obtained by copolymerizing LA (79 parts by mass), HEA (20 parts by mass), and AA (1 part by mass) was used. (AR'-2), except that an adhesive sheet was produced and evaluated by the same method as in Example 1. The weight average molecular weight of the energy ray-curable polymer obtained by using the acrylic copolymer (AR'-2) was 600,000. The results are shown in Table 3 below.

According to the results shown in the above tables, it can be seen that the adhesive sheets of Examples 1 to 4, 6 to 12 have a composition in a specific range without compromising cutting properties, and have excellent solvent resistance and resistance. Plating property and adhesion change rate. The adhesive sheet of Example 5 also has an excellent plating resistance and a change rate of adhesive force by making the adhesive layer a composition in a specific range. Furthermore, in the adhesive sheet of Reference Example 1, in addition to the metal chelate compound, the adhesive layer also contains TDI-TMP which is not a metal chelate compound as a cross-linking agent, and the content (mixed amount) of TDI-TMP is too large. Therefore, when immersed in any one of a nickel plating solution, warm water, an alkaline aqueous solution, and a sulfuric acid solution, the rate of change in adhesion is poor. Compared with the adhesive sheet of Reference Example 1, the TDI-TMP content of the adhesive layer of the adhesive sheet of Reference Example 2 is more, and the generation of air bubbles can be seen due to its effect. The plating resistance is also poor, and the rate of change of adhesion Even worse.

In addition, the elastic modulus and gel fraction of the adhesive layer before ultraviolet irradiation were good in any of the examples.

On the other hand, the adhesive layer included in the adhesive sheet of Comparative Example 1 uses an acrylic copolymer (AR'-1) which is not copolymerized with a monomer having a cyano group, and uses a non-metal chelate compound as a crosslinking agent. , And the generation of air bubbles can be seen, and the plating resistance is poor. Moreover, when the adhesive sheet of Comparative Example 1 was immersed in any of a nickel plating solution, warm water, an alkaline aqueous solution, and a sulfuric acid solution, the change rate of adhesive force was inferior. In addition, in the adhesive sheet of Comparative Example 1, it was confirmed that water permeated at the time of cutting, and the cuttability was also poor.

Compared with the adhesive sheet of Comparative Example 1, the adhesive sheet of Comparative Example 2 increases the content of the cross-linking agent (mixing amount) of the adhesive layer. Due to its influence, not only the generation of air bubbles but also the penetration of liquid can be seen. Plating properties are worse, and the rate of change in adhesion is worse, making it impossible to measure.

The adhesive layer included in the adhesive sheet of Comparative Example 3 uses TDI-TMP, which is not a metal chelate compound, as a crosslinking agent, and is immersed in any of a nickel plating solution, warm water, an alkaline aqueous solution, and a sulfuric acid solution. , The rate of change of adhesion is poor.

As with the adhesive sheet of Comparative Example 3, the adhesive layer included in the adhesive sheet of Comparative Example 4 uses an epoxy compound that is not a metal chelate compound as a crosslinking agent, and is immersed in a nickel plating solution, warm water, and sulfuric acid, respectively. The rate of change in adhesion when in solution is poor.

The adhesive layer included in the adhesive sheet of Comparative Example 5 did not use a cross-linking agent, and the residue was confirmed on the wafer when picking up, the dicing property was poor, and it was not suitable for dicing.

The adhesive layer included in the adhesive sheet of Comparative Example 6 is an acrylic copolymer (AR'-1) in which a monomer having a cyano group is not copolymerized, and the rate of change in adhesion when immersed in an alkaline aqueous solution is poor.

As the adhesive layer included in the adhesive sheet of Comparative Example 7, an acrylic copolymer (AR'-2) in which a monomer having a cyano group was not copolymerized was used, and the adhesive sheet was immersed in an alkaline aqueous solution in the same manner as the adhesive sheet of Comparative Example 6. The rate of change in adhesion is poor at the time.

As described above, the adhesive sheets of Comparative Examples 1 to 7 cannot improve the solvent resistance, the plating resistance, and the rate of change in adhesion without impairing the cuttability.

[Industrial availability]

The present invention can be used in the manufacture or processing of electronic parts such as semiconductor wafers.

Claims (4)

An adhesive sheet is provided with an adhesive layer on a base film; the adhesive layer contains an energy ray-curable polymer and a cross-linking agent; the energy ray-curable polymer has a cyano group and has -C in the structure. = C- is obtained by copolymerizing a monomer having a polymerizable unsaturated bond; the aforementioned crosslinking agent is a metal chelate compound; the aforementioned energy ray-curable polymer has a hydroxyl group and has a side chain via a urethane bond. The content of the polymerizable group (meth) acrylate copolymer; the content of the cross-linking agent in the adhesive layer with respect to 100 parts by mass of the energy ray-curable polymer is 0.2 to 10 parts by mass. The adhesive sheet according to claim 1, wherein the monomer having a cyano group and a polymerizable unsaturated bond represented by -C = C- in the structure is acrylonitrile. The adhesive sheet according to claim 1 or 2, wherein the crosslinking agent is an aluminum chelate compound or a titanium chelate compound. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein when the energy ray-curable polymer is prepared by monomer polymerization, the polymer has a cyano group and a polymerizable unsaturated group represented by -C = C- in the structure. The ratio of the compounded amount of the bonded monomer to the total compounded amount of the monomer is 0.2% to 30% by mass.