JP2012212732A - Adhesive tape for processing radiation curable semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape for processing a radiation curable semiconductor which exhibits good antistatic properties in semiconductor processing, can significantly reduce generation of fibrous cut waste in a dicing process, allows little slack of the tape by irradiation and hardly allows an adhesive to remain on an adherend in pickup.SOLUTION: In an adhesive tape for processing a radiation curable semiconductor in which a particular adhesive layer is formed on a base material resin film, the base material resin film consists of at least of two layers, a layer contacting with the adhesive layer of the base material resin film is a resin composition having ethylene-vinyl acetate copolymer (a1) and a resin (a2) in which carboxyl group of a copolymer containing at least of ethylene composition and (meta) acrylic acid composition as a component, is crosslinked by way of potassium ions, and a layer other than the layer contacting with the adhesive layer is a resin composition containing high density polyethylene or polypropylene.

Description

  The present invention relates to a radiation-curable adhesive tape for processing a semiconductor used when processing a semiconductor used for an electrical component or an electronic component.

Conventionally, when processing semiconductors used in electrical and electronic components, adhesive tapes for semiconductor processing intended for fixing and protecting components in the dicing process for obtaining semiconductor chips from semiconductor wafers and other processes Is used.
In the semiconductor dicing process, the separator is peeled off from the semiconductor processing adhesive tape, the semiconductor wafer is diced in a state where the adhesive tape is bonded, the cutting powder is washed with ultrapure water having high electrical insulation, The semiconductor chip that has been cut and separated is picked up. In these steps, static electricity is generated on an adherend such as a substrate (wafer) or a resin-sealed package. When the substrate of a component that forms a circuit is an insulating material such as ceramics or glass, static electricity is not quickly leaked, and there is a case where discharge of the circuit due to a short circuit or adhesion of foreign matters such as dust may occur.

In recent years, high integration of circuits has been accelerated with the thinning of wafers, and it has become a big issue to prevent circuit breakdown due to static electricity. Static electricity removing devices such as ionizers are used to prevent static electricity damage, but sufficient antistatic effects have not been obtained, and there is an increasing demand for adhesive tapes for semiconductor processing having antistatic properties.
Then, the adhesive tape for semiconductor fixation which provided the antistatic layer containing conductive polymers, such as polythiophene and polypyrrole, on the single side | surface or both surfaces of the base resin film is disclosed (for example, patent document 1 and patent document 2 are disclosed). reference.). In this adhesive tape, since the antistatic layer is divided by dicing, it is difficult to maintain the antistatic performance after dicing.

  Further, in the dicing process, a dicing blade that is a rotary blade is cut into a part of the base resin film of the semiconductor fixing adhesive tape. For this reason, in addition to semiconductor device wafers and semiconductor device package cutting waste, thread-like beard-like cutting waste is generated by melting and stretching the base resin film of the adhesive tape during cutting. It often remains on the uneven surface. In particular, when dicing a package that is collectively sealed, a dicing blade with a thickness of about 0.1 to 0.5 mm is used, so that the dicing blade has a thickness of about 0.02 to 0.1 mm. Compared with the case of dicing a semiconductor device wafer that uses swarf, beard-like cutting waste is particularly likely to occur. This cutting waste contaminates the semiconductor wafer, the resin-encapsulated package, and the like and lowers the yield, so it is necessary to reduce it as much as possible.

  When picking up an adherend such as a semiconductor element or a resin-sealed package from an adhesive tape, it is preferable to reduce the adhesive force of the adhesive layer in contact with the adherend. As a method therefor, there is known a radiation-curable pressure-sensitive adhesive tape using a pressure-sensitive adhesive layer that can reduce the adhesive strength by irradiation. However, since this radiation contains not a little infrared light, the adhesive tape may be heated by radiation irradiation, and the adhesive tape may be stretched or partially loosened. The slack of the tape causes trouble in storing the adherend in the carrier cassette used for transfer between processing steps, and also causes variation in element gaps in the pick-up process of the adherend, causing defective pick-up of the element. It can also be a cause. Tape slack may also occur due to cutting heat during dicing.

  In addition, adherends such as semiconductor wafers and resin-encapsulated packages may have unevenness on the adhesive tape bonding surface, or may have markings (concave portions) commonly referred to as laser marks. is there. Since there is a limit to the followability of the adhesive with respect to the uneven portion, there may be a gap that is not in close contact between the adhesive layer and the adherend. Since this gap portion is in contact with air, the adhesive force is greatly reduced by radiation irradiation as an adhesive layer, and in the pick-up process after dicing, it is easy to pick up the semiconductor chip obtained by cutting. In some cases, the radiation curing reaction of the pressure-sensitive adhesive is inhibited by oxygen in the air, and adhesive residue may be generated in the concave portion of the adherend.

JP 2008-255345 A JP 2008-280520 A

  The present invention exhibits an excellent antistatic property in a semiconductor processing process, can significantly reduce the generation of shaving-like cutting waste in a dicing process, has less tape slack due to irradiation, and has an adhesive on an adherend during pick-up. It is an object of the present invention to provide a radiation-curable adhesive tape for semiconductor processing that is difficult to remain.

The present inventors have intensively studied to achieve the above object. As a result, a pressure-sensitive adhesive layer containing the polymer (B) in which the radiation-curable carbon-carbon double bond-containing group was bonded to the repeating unit of the main chain (pendant) was formed on the base resin film. A radiation curable adhesive tape for semiconductor processing, wherein the base resin film comprises at least two layers,
The layer in contact with the pressure-sensitive adhesive layer of the base resin film has an ethylene-vinyl acetate copolymer (a1) and a carboxyl group of a copolymer having at least an ethylene component and a (meth) acrylic acid component as constituent components. A resin composition containing the resin (a2) crosslinked at a specific ratio,
The layer other than the layer in contact with the pressure-sensitive adhesive layer is a resin composition containing high-density polyethylene or polypropylene, the radiation-curable pressure-sensitive adhesive tape for semiconductor processing exhibits excellent antistatic properties in the semiconductor processing step, and in the dicing step It has been found that the generation of beard-like cutting scraps can be remarkably reduced, the tape is not loosened by irradiation, and the adhesive does not easily remain on the adherend during pick-up. The present invention has been made based on these findings.

That is, the present invention
<1> A radiation curable semiconductor in which a pressure-sensitive adhesive layer containing a polymer (B) having a radiation curable carbon-carbon double bond-containing group bonded to a repeating unit of a main chain is formed on a base resin film. An adhesive tape for processing, wherein the base resin film comprises at least two layers;
The layer of the base resin film in contact with the pressure-sensitive adhesive layer is an ethylene-vinyl acetate copolymer (a1) 90 to 70% by mass and a copolymer having at least an ethylene component and a (meth) acrylic acid component as constituent components. It is a resin composition containing 10 to 30% by mass of a resin (a2) obtained by crosslinking a carboxyl group with potassium ions,
A layer other than the layer in contact with the pressure-sensitive adhesive layer is a resin composition containing high-density polyethylene or polypropylene, a radiation-curable pressure-sensitive adhesive tape for semiconductor processing,
<2> The base resin film is composed of three or more layers, and the intermediate layer X1 sandwiched between the layer 1 in contact with the pressure-sensitive adhesive layer and the outermost layer X2 is a resin composition containing high-density polyethylene or polypropylene. <1> The radiation-curable adhesive tape for semiconductor processing according to <1>,
<3> The radiation-curable adhesive tape for semiconductor processing according to <1> or <2>, wherein the ethylene-vinyl acetate copolymer has a vinyl acetate component content of 5 to 25% by mass,
<4> A polymer (B) in which a radiation-curable carbon-carbon double bond-containing group is bonded to a repeating unit of the main chain is 65 to 87% by mass of a 2-ethylhexyl acrylate component as a component (b1). <1>-<3> The radiation-curable adhesive tape for semiconductor processing according to any one of <1> to <3>, and <5> the glass transition start temperature of the adhesive layer before radiation curing is − The adhesive tape for radiation-curable semiconductor processing according to any one of <1> to <4>, wherein the adhesive tape is 65 to -45 ° C.
Is to provide.

  The present invention exhibits an excellent antistatic property in a semiconductor processing process, can significantly reduce the generation of shaving-like cutting waste in a dicing process, has less tape slack due to irradiation, and has an adhesive on an adherend during pick-up. It is possible to provide a radiation-curable adhesive tape for semiconductor processing that is less likely to remain.

It is sectional drawing which shows typically one Embodiment of the adhesive tape for radiation-curable semiconductor processing of this invention. It is sectional drawing which shows typically other one Embodiment of the adhesive tape for radiation-curable semiconductor processing of this invention.

The present invention will be described with reference to the drawings. FIG. 1 schematically shows a preferred embodiment of the radiation-curable semiconductor processing pressure-sensitive adhesive tape of the present invention. In the radiation curable adhesive tape 100 for semiconductor processing, the base resin film 10 includes a layer 1 in contact with the adhesive layer and a layer 2 other than the layer in contact with the adhesive layer. An adhesive layer 20 is formed on the layer 1 in contact with the layer.
FIG. 2 schematically shows another preferred embodiment of the pressure-sensitive adhesive tape for processing semiconductors according to the present invention. In the radiation curable adhesive tape for semiconductor processing 200, the base resin film 10 is composed of a layer 1 in contact with the adhesive layer and a layer 2 other than the layer in contact with the adhesive layer, and other than the layer in contact with the adhesive layer. Layer 2 consists of intermediate layer X1 and outermost layer X2 of the base resin film.

1. Base resin film The base resin film of the radiation curable semiconductor processing pressure-sensitive adhesive tape of the present invention comprises two or more layers as shown in FIGS. 1 and 2, and the layer 1 in contact with the pressure-sensitive adhesive layer has antistatic properties. ing. The layer 1 in contact with the pressure-sensitive adhesive layer is composed of an ethylene-vinyl acetate copolymer (a1) 90 to 70% by mass and a carboxyl group of a copolymer having at least an ethylene component and a (meth) acrylic acid component as constituents. It is comprised with the resin composition containing 10-30 mass% of resin (a2) bridge | crosslinked by. In the present invention, to crosslink the carboxyl group of the copolymer with potassium ion means to crosslink at least 0.5 mmol / g of the carboxyl group, preferably 1.5 mmol / g or more.

(Layer in contact with the adhesive layer)
(1) Resin (a2) obtained by crosslinking a carboxyl group of a copolymer having at least an ethylene component and a (meth) acrylic acid component as constituent components with potassium ions
The resin (a2) obtained by crosslinking a carboxyl group of a copolymer having at least an ethylene component and a (meth) acrylic acid component as constituent components with potassium ions includes an ethylene component and a (meth) acrylic acid component as the copolymer component. , A resin in which the carboxyl group of the (meth) acrylic acid component is crosslinked with potassium ions. In the present specification, the ethylene- (meth) acrylic acid copolymer includes both an ethylene-acrylic acid copolymer and an ethylene-methacrylic acid copolymer. Resin (a2) may be a binary copolymer containing an ethylene component and a (meth) acrylic acid component, or may be a ternary or higher copolymer containing other components. Examples of other components include (meth) acrylic acid esters. Examples of the (meth) acrylic acid ester include ethyl acrylate and butyl methacrylate. Examples of the other components include vinyl acetate, acrylonitrile, acrylic amide, styrene, itaconic acid, acrylic amide, methylol acrylic amide, maleic anhydride and the like.

  The resin (a2) needs to be crosslinked with potassium ions as metal ion species. Since the saturated moisture content is high due to crosslinking with potassium ions, excellent antistatic properties can be achieved. Other metal ions such as sodium ion, zinc ion, and magnesium ion have a low saturated water content and do not provide sufficient antistatic properties.

  When the resin film is composed of a resin composition containing the resin (a2) and the ethylene-vinyl acetate copolymer (a1), the resin (a2) is an ethylene-vinyl acetate copolymer, as will be described later. In order to make it easier to form a phase-separated structure that is more linearly oriented, in addition to a strong shearing force, the melt flow rate (MFR) of the base resin (190 ° C. in accordance with JIS K 7210, 2.16 kg load condition) Is preferably lower, and the range is 0.5 to 4.0, more preferably 1.0 to 3.0. When MFR is too high, a streaky antistatic phase is not formed, and when it is too low, film formation cannot be performed.

(2) Ethylene-vinyl acetate copolymer (a1)
The resin composition constituting the base resin film contains an ethylene-vinyl acetate copolymer (a1). In the resin composition containing the ethylene-vinyl acetate copolymer and the resin (a2), the vinyl acetate component in the ethylene-vinyl acetate copolymer (a1) is a carboxyl of the ethylene- (meth) acrylic acid copolymer. It interacts with the potassium ion of the resin whose group is crosslinked with potassium ion. As a result, it is easy to form a phase-separated structure in which the resin phase in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer is crosslinked with potassium ions is finely dispersed in the ethylene-vinyl acetate copolymer. Thereby, a conduction path is formed, and excellent antistatic properties can be achieved.

When the resin (a2) is blended, the adhesion between the base resin film and the pressure-sensitive adhesive layer is weakened, but by using an ethylene-vinyl acetate copolymer, the base resin film and the pressure-sensitive adhesive layer High adhesion can be maintained. The vinyl acetate component content in the ethylene-vinyl acetate copolymer is preferably 5 to 25% by mass. When there is too little vinyl acetate component content, the adhesiveness between a base resin film and an adhesive layer will deteriorate, and when too large, since stickiness will become large, manufacturability will deteriorate. For example, when a base resin film is produced by extrusion molding, sticking of the base resin film to a cooling roll may occur.
On the other hand, when an ethylene- (meth) acrylic acid copolymer is used instead of the ethylene-vinyl acetate copolymer (a1), the adhesion between the base resin film and the adhesive layer is good. However, since (a2) a phase separation structure with the resin cannot be formed, it is difficult to obtain sufficient antistatic properties.

  The resin composition constituting the base resin film of the layer in contact with the pressure-sensitive adhesive layer is a copolymer having 90 to 70% by mass of an ethylene-vinyl acetate copolymer and at least an ethylene component and a (meth) acrylic acid component as constituent components. 10-30 mass% of resin (a2) which bridge | crosslinked the carboxyl group of the coalescence with potassium ion is contained. Thereby, generation | occurrence | production of a beard-like cutting waste can be reduced significantly. (A2) If there is too much resin, the adhesion between the base resin film and the pressure-sensitive adhesive layer is low, so that delamination occurs between the base resin film and the pressure-sensitive adhesive layer in the pick-up process, and laser marks and the like are deposited Adhesive residue is generated in the concave portion of the body surface layer. On the other hand, if the amount of (a2) resin is too small, sufficient antistatic properties cannot be achieved.

  (A2) Since the resin has a strong shearing force during film formation, it becomes easy to form a phase-separated structure in the base resin in the form of a streak in the molding direction. It is preferable to mold the base resin film by a molding method in which a strong shearing force is applied. Since compression force acts in compression molding, the antistatic resin is difficult to disperse in a streak form, and in cast molding, a sufficient shearing force cannot be obtained. The layer constituting the base resin film in contact with the pressure-sensitive adhesive layer may be subjected to a corona treatment or a treatment such as a primer in order to further improve the adhesion.

(Layers other than the layer in contact with the adhesive layer)
Layers other than the layer in contact with the pressure-sensitive adhesive layer in the base resin film are resin compositions containing high-density polyethylene or polypropylene. Since high-density polyethylene and polypropylene are excellent in heat resistance, it is possible to prevent looseness of the adhesive tape by heat generated during radiation irradiation. Here, polypropylene is a homopolymer of propylene (homopolypropylene), an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, propylene and another small amount of α-olefin (for example, 1-butene, 1-hexene). , 4-methyl-1-pentene, etc.), polypropylene containing atactic propylene as a constituent, and a block copolymer of propylene and ethylene copolymer rubber. In the present specification, the polypropylene resin refers to a copolymer having a propylene component of 85% by mass or more among copolymers having a propylene component and an ethylene component as constituent components in addition to a propylene homopolymer.
As shown in FIG. 3, it is preferable that the base layer resin film has three or more layers by having the intermediate layer X1, and the intermediate layer X1 is made of a resin composition containing high-density polyethylene or polypropylene. With this configuration, the dicing blade can easily enter during dicing, and the generation of whiskers can be suppressed.

  The thickness of the high density polyethylene or polypropylene layer is preferably 20 to 70% of the total thickness of the base resin film. If the high-density polyethylene or polypropylene layer is too thick, it will be easy to prevent tape slack and adhesion of whiskers will be suppressed, but the base resin film will be hard and difficult to manufacture, and will follow the adherend. Since it becomes difficult, an adherend will spread easily at the time of dicing. On the other hand, if the high-density polyethylene or polypropylene layer is too thin, the adherend can be prevented from scattering during dicing, but tape slack and whiskers adhere.

Since the blade outer peripheral section used at the time of dicing has an R shape, a dicing tape is used more smoothly when a blade having a thicker blade is used to smooth the cutting surface of the dicing blade, which is the side of the semiconductor device. It is necessary to cut deeply. For this reason, it is necessary to increase the thickness of the base resin film as the blade blade thickness is increased. Therefore, the thickness of the base resin film is preferably at least 30% of the thickness of the blade used for dicing. On the other hand, if the base resin film becomes too thick, the rigidity of the antistatic semiconductor processing pressure-sensitive adhesive tape increases, and workability may deteriorate.
Since a blade with a blade thickness of about 50 to 400 μm is used as a blade for mold resin batch sealing package dicing, the thickness of the base resin film of the adhesive tape for antistatic semiconductor processing of the present invention is preferably 30. It is -300 micrometers, More preferably, it is 50-250 micrometers.

2. The pressure-sensitive adhesive layer The pressure-sensitive adhesive for the radiation-curable semiconductor processing pressure-sensitive adhesive tape of the present invention contains a polymer in which a radiation-curable carbon-carbon double bond-containing group is bonded to a repeating unit of the main chain. Have sex. In the present invention, “a polymer in which a radiation-curable carbon-carbon double bond-containing group is bonded to a repeating unit of a main chain” means that a radiation-curable unsaturated carbon-carbon double bond-containing group is present in the molecule. A bonded (ie, pendant) polymer. Adhesives composed of a polymer having no radiation curable carbon-carbon double bond and a resin composition containing an oligomer having a radiation curable carbon-carbon double bond have sufficient adhesive strength before radiation curing. In order to ensure a good pick-up property, it is necessary to greatly reduce the adhesive strength by irradiation with radiation. The pressure-sensitive adhesive having such high radiation curability has a large curing shrinkage at the time of radiation curing, and the pressure-sensitive adhesive tends to bite into the concave portion of the adherend surface layer that is in contact with the pressure-sensitive adhesive layer such as a laser mark. When the pressure-sensitive adhesive bites into the concave portion of the adherend surface layer, delamination is likely to occur between the base resin film and the pressure-sensitive adhesive layer at the time of pickup, and adhesive residue is likely to occur in the concave portion. Furthermore, when the resin composition containing (a2) resin is used for the base resin film, the adhesiveness between the base resin film and the pressure-sensitive adhesive layer is lowered, and adhesive residue is likely to be generated due to the recesses.

  As a polymer in which a radiation-curable carbon-carbon double bond-containing group is bonded to a repeating unit of the main chain, an acrylic type having at least one radiation-curable carbon-carbon double bond-containing group to the main chain Examples thereof include a polymer containing a monomer as a constituent unit (hereinafter referred to as “acrylic copolymer (B)”). The acrylic copolymer (B) is, for example, a carbon chain of a copolymer (B1) composed of (meth) acrylic acid ester, hydroxyl group-containing unsaturated compound, carboxyl group-containing unsaturated compound, etc. as the component (b1). Can be obtained by addition reaction of a functional group capable of undergoing addition reaction with respect to the functional group of the copolymer and a compound (b2) having a radiation-curable unsaturated carbon bond.

  As the (meth) acrylic ester of the component (b1) constituting the copolymer (B1), hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate having 6 to 12 carbon atoms, Examples thereof include decyl acrylate, pentyl acrylate having 5 or less carbon atoms, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, and methacrylates similar to these. Since the glass transition temperature of the copolymer decreases as the carbon number of the (meth) acrylic acid ester increases, the copolymer having a desired glass transition temperature can be obtained by using a (meth) acrylic acid ester having a specific carbon number. A polymer can be made. In addition, in order to impart properties such as a desired glass transition temperature and compatibility, a low molecular compound having an unsaturated carbon bond such as vinyl acetate, styrene, acrylonitrile or the like is blended as a copolymerization component to obtain the copolymer. You can also. The blending amount of the low molecular weight compound having an unsaturated carbon bond is preferably 5% by mass or less.

  It is preferable that the said copolymer (B1) contains 2-ethylhexyl acrylate as a structural component (b1). It is more preferable that 2-ethylhexyl acrylate is a main component (that is, more than 50% by mass) in the copolymer, and the amount of 2-ethylhexyl acrylate in the constituent component in the copolymer (B1) is 65 to 87% by mass. % Is particularly preferred. Since 2-ethylhexyl acrylate has a low glass transition temperature, if 2-ethylhexyl acrylate is the main component of (meth) acrylic acid ester, the acrylic copolymer (B) prepared from the copolymer (B1) is flexible. It is possible to secure sufficient adhesion between the base resin film and the pressure-sensitive adhesive layer. However, when the amount of 2-ethylhexyl acrylate is too small, the adhesion between the base resin film and the pressure-sensitive adhesive layer is weakened, and delamination occurs between the antistatic layer and the pressure-sensitive adhesive layer when the adherend is picked up. Adhesive residue is generated in the recesses of the adherend surface layer such as marks. On the other hand, if the amount of 2-ethylhexyl acrylate is too large, the amount of the functional group possessed by the copolymer (B1) that undergoes an addition reaction with the functional group possessed by the compound (b2) having a radiation curable unsaturated carbon bond is decreased. It becomes impossible to carry out addition reaction of the compound (b2) having a radiation-curable unsaturated carbon bond in an amount of.

  Examples of the hydroxyl group-containing unsaturated compound as the component (b1) include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate and the like. Examples of the carboxyl group-containing unsaturated compound as the component (b1) include acrylic acid and methacrylic acid.

  As the functional group capable of undergoing an addition reaction with respect to the functional group of the copolymer (B1) having the component (b1), the functional group of the copolymer (B1) is a carboxyl group or a cyclic acid anhydride group. In this case, a hydroxyl group, an epoxy group, an isocyanate group and the like can be mentioned. When the functional group that the copolymer (B1) has is a hydroxyl group, a cyclic acid anhydride group, an isocyanate group, and the like can be given. When the functional group of the copolymer (B1) is an amino group, an isocyanate group can be exemplified. Specific examples of the compound (b2) include acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycol monoacrylates, glycol monoacrylate. Methacrylates, N-methylolacrylamide, N-methylolmethacrylamide, allyl alcohol, N-alkylaminoethyl acrylates, N-alkylaminoethyl methacrylates, acrylamides, methacrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride Radiation curable with some hydroxyl groups or carboxyl groups of acid, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, polyisocyanate compounds It is possible to enumerate such as those urethanization a monomer having a saturated carbon bonds.

  In the synthesis of the acrylic copolymer (B), examples of the organic solvent in the case where the copolymerization is carried out by solution polymerization include ketone-based, ester-based, alcohol-based, and aromatic-based organic solvents. A good solvent for acrylic polymers such as ethyl, isopropyl alcohol, benzene methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, and the like, and preferably a solvent having a boiling point of 60 to 120 ° C. The polymerization initiator is α, α′-azobis. A radical generator such as an azobis type such as isobutyl nitrile or an organic peroxide type such as benzobel peroxide is usually used. At this time, if necessary, a catalyst and a polymerization inhibitor can be used in combination, the polymerization temperature and the polymerization time are adjusted, and then an addition reaction at a functional group is performed, whereby an acrylic copolymer (B) having a desired molecular weight is obtained. Can be obtained. In terms of adjusting the molecular weight, it is preferable to use a mercaptan or carbon tetrachloride solvent. The copolymerization is not limited to solution polymerization, and other methods such as bulk polymerization and suspension polymerization may be used.

Furthermore, the acrylic copolymer (B) may be copolymerized with monomers such as acrylonitrile and vinyl acetate for the purpose of controlling adhesiveness and cohesion. The weight average molecular weight of the acrylic copolymer (A) obtained by polymerizing these monomers is preferably 5 × 10 ⁴ to 2 × 10 ⁶ , and preferably 1 × 10 ⁵ to 1 × 10 ^6. Is more preferable.

  It is preferable that the acrylic copolymer (B) has a hydroxyl value of 5 to 100 because the risk of pick-up mistakes can be further reduced by reducing the adhesive strength after radiation irradiation. Moreover, it is preferable that the acid value of the said acrylic copolymer (B) will be 0.5-30. Here, the hydroxyl value is a value measured by the pyridine-acetyl chloride method described in JIS K 0070, and the acid value is a value measured by the neutralization titration method described in JIS K 0070. By setting the hydroxyl value of the acrylic copolymer (B) within an appropriate range, the fluidity of the pressure-sensitive adhesive layer after irradiation can be set within an appropriate range, and the adhesive strength after irradiation can be increased. It can be lowered sufficiently. In addition, by setting the acid value of the acrylic copolymer (B) within an appropriate range, the fluidity of the pressure-sensitive adhesive layer after irradiation can be set within an appropriate range, and the tape recoverability is satisfied. Can be made.

  The adhesive can further contain a curing agent, whereby the adhesive force and cohesive force can be set to desired values. Examples of such curing agents include polyvalent isocyanate compounds, polyvalent epoxy compounds, polyvalent aziridine compounds, chelate compounds and the like. Specific examples of the polyvalent isocyanate compound include toluylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and those adduct types. Specific examples of the polyvalent epoxy compound include ethylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, and the like. Specific examples of the polyvalent aziridine compound include tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, tris [1- (2-methyl) -aziridinyl] phosphine oxide, hexa [1 -(2-Methyl) -aziridinyl] triphosphatriazine and the like are used. Specific examples of the chelate compound include ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  The pressure-sensitive adhesive can further contain a radiation polymerization initiator, which makes it possible to polymerize and cure in a short time with a small amount of radiation. Specific examples of such radiation polymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chlore. And anthraquinone. The radiation polymerization initiator is usually blended in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the acrylic polymer (B).

  The glass transition temperature of the pressure-sensitive adhesive layer before radiation curing is preferably −65 to −45 ° C. In addition, a glass transition temperature is calculated | required by DSC method based on JISK7121, and the glass transition temperature said here is an extrapolation glass transition start temperature. If the glass transition temperature is too high, the adhesive layer has low flexibility, so the adhesion between the base resin film and the adhesive layer is weakened, and the substrate resin film and the adhesive layer are not picked up when the adherend is picked up. In this case, delamination occurs, and adhesive residue is generated in the concave portion of the adherend surface layer such as a laser mark. On the other hand, if it is too low, the amount of the functional group possessed by the copolymer (B1) that undergoes an addition reaction with the functional group possessed by the compound (b2) having a radiation curable unsaturated carbon bond is reduced, so that a desired amount of radiation curable property is obtained. The addition reaction of the compound (b2) having an unsaturated carbon bond becomes impossible.

  The pressure-sensitive adhesive layer included in the radiation-curable semiconductor processing pressure-sensitive adhesive tape of the present invention has a structure as described above, so that it has a sufficient adhesive force to the adherend before radiation irradiation, and after radiation irradiation. The adhesive strength is significantly reduced. Therefore, the tape of the present invention can adhere the adherend with sufficient adhesive force before irradiation, and can securely fix the adherend, and can be easily peeled off from the adherend after irradiation. can do. There is no restriction | limiting in particular in the thickness of the adhesive layer in the tape of this invention, Although it can set suitably by the to-be-adhered body to apply, Preferably it is 4-100 micrometers, Most preferably, it is 5-40 micrometers. Although the thickness of the pressure-sensitive adhesive layer depends on the composition, if the thickness is too thin, the adhesiveness to the semiconductor device package will be insufficient, the yield will decrease due to die fly during dicing, and the scattered die will hit the blade. Blade damage may occur. If the thickness of the pressure-sensitive adhesive layer is too thin, the pressure-sensitive adhesive layer is lifted up by rotating the blade during dicing, and peeling failure from the semiconductor device may occur in the pickup process.

The surface resistivity of the pressure-sensitive adhesive layer side and the tape back side in the radiation-curable semiconductor processing pressure-sensitive adhesive tape of the present invention is preferably 1 × 10 ¹³ Ω / □ or less. Preferably it is 5 × 10 ¹² Ω / □ or less, more preferably 1 × 10 ¹² Ω / □ or less. If the surface resistivity is low, excellent antistatic properties can be exhibited, but if the surface low efficiency is too high, the semiconductor may be destroyed by charged static electricity.

  As mentioned above, although preferred embodiment of the adhesive tape concerning this invention was described, this invention is not limited to the example which concerns.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples. In addition, the adhesive composition and base-material-constituting resin used in Examples and Comparative Examples are as follows. Table 1 shows the base resin film resin composition, and Table 2 shows the adhesive resin composition.

<Resin composition constituting base resin film>
As a base resin film, it is set as each resin mixture using the following base resin film resin mixture A1-A7, B1-B3, C1, D1, E1, F1, G1, and G2, and the resin composition manufactured from these is used. Using. The melt flow rate of the resin constituting the base resin film is determined according to JIS K 7210, and the carboxyl groups of the ethylene-vinyl acetate copolymer resin and the ethylene- (meth) acrylic acid copolymer are crosslinked with potassium ions. Resin, ethylene-methacrylic acid copolymer resin, high-density polyethylene, low-density polyethylene, and ethylene- (meth) acrylic acid copolymer carboxyl group cross-linked with zinc ion and ethylene- (meth) acrylic acid copolymer The resin in which the carboxyl group of the coalescence was cross-linked with sodium ions was measured under a load condition of 190 ° C. and 2.16 kg, and the polypropylene was measured under a load condition of 230 ° C. and 2.16 kg. The vinyl acetate content of the ethylene-vinyl acetate copolymer was determined according to JIS K 6730.

(Base resin film resin mixture A1)
Ethylene-vinyl acetate copolymer (trade name: NUC-8451, manufactured by Nippon Unicar Co., Ltd., melt flow rate 1.5 g / 10 min) having a vinyl acetate content of 14% by mass and ethylene- (meth) acrylic A resin obtained by dry blending 20% by mass of a resin obtained by crosslinking a carboxyl group of an acid copolymer with potassium ions (trade name: ENTILA MK400, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 1.0 g / 10 min) Film resin mixture A1 was obtained.

(Base resin film resin mixture A2)
Resin in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer of the base resin film resin mixture A1 is crosslinked with potassium ions (trade name: ENTILA MK400, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 1.0 g / 10 min), and the base resin is the same as the base resin film resin mixture A1, except that the amount of the ethylene-vinyl acetate copolymer in the resin composition A1 is 88% by weight. Film resin mixture A2 was obtained.

(Base resin film resin mixture A3)
Resin in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer of the base resin film resin mixture A1 is crosslinked with potassium ions (trade name: ENTILA MK400, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 1.0 g / 10 min) in the same manner as the base resin film resin mixture A1, except that the blending amount is 25% by weight and the blending amount of the ethylene-vinyl acetate copolymer in the base resin film resin mixture A1 is 75% by weight. A base resin film resin mixture A3 was obtained.

(Base resin film resin mixture A4)
The ethylene-vinyl acetate copolymer resin of the base resin film resin mixture A1 is an ethylene-vinyl acetate copolymer having a vinyl acetate content of 7.5% by mass (trade name: NUC-8430, manufactured by Nippon Unicar Co., Ltd., A base resin film resin mixture A4 was obtained in the same manner as the base resin film resin mixture A1 except that the melt flow rate was 2.3 g / 10 min.

(Base resin film resin mixture A5)
The ethylene-vinyl acetate copolymer of the base resin film resin mixture A1 is an ethylene-vinyl acetate copolymer having a vinyl acetate content of 20% by mass (trade name: Ultrasen 631 manufactured by Tosoh Corporation, melt flow rate 1 The base resin film resin mixture A5 was obtained in the same manner as the base resin film resin mixture A1 except that the amount was changed to 0.5 g / 10 min.

(Base resin film resin mixture A6)
The ethylene-vinyl acetate copolymer resin of the base resin film resin mixture A1 is an ethylene-vinyl acetate copolymer having a vinyl acetate content of 1.5% by mass (trade name: Novatec LV170, manufactured by Nippon Polyethylene Co., Ltd., melt A base resin film resin mixture A6 was obtained in the same manner as the base resin film resin mixture A1 except that the flow rate was 3.0 g / 10 min.

(Base resin film resin mixture A7)
The ethylene-vinyl acetate copolymer of the base resin film resin mixture A1 is an ethylene-vinyl acetate copolymer having a vinyl acetate content of 33% by mass (trade name: EVAFLEX EV170, manufactured by Mitsui DuPont Polychemical Co., Ltd., A base resin film resin mixture A7 was obtained in the same manner as the base resin film resin mixture A1 except that the melt flow rate was 1.0 g / 10 min.

(Base resin film resin B1)
An ethylene-vinyl acetate copolymer (trade name: NUC-8451, manufactured by Nippon Unicar Co., Ltd., melt flow rate 1.5 g / 10 min) having a vinyl acetate content of 14% by mass was used.

(Base resin film resin mixture B2)
Resin in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer of the base resin film resin mixture A1 is crosslinked with potassium ions (trade name: ENTILA MK400, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 1.0 g / 10 min), and the blending amount of the ethylene-vinyl acetate copolymer in the base resin film resin mixture A1 is 93% by weight, in the same manner as in the base resin film resin mixture A1. The base resin film resin mixture B2 was obtained.

(Base resin film resin composition B3)
Resin in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer of the base resin film resin mixture A1 is crosslinked with potassium ions (trade name: ENTILA MK400, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 1.0 g / 10 min), the base resin is the same as the base resin film resin mixture A1, except that the blending amount of the ethylene-vinyl acetate copolymer in the resin mixture A1 is 35% by weight and the blending amount is 65% by weight. Film resin mixture B3 was obtained.

(Base resin film resin composition C1)
The ethylene-vinyl acetate copolymer of the base resin film resin mixture A1 is changed to an ethylene-methacrylic acid copolymer resin (trade name: Nucrel N0903HC, Mitsui / DuPont Polychemical Co., Ltd., melt flow rate 3.0 g / 10 min). A base resin film resin mixture C1 was prepared in the same manner as the base resin film resin mixture A1, except that the base resin film resin mixture A1 was used.

(D1 for base resin film)
High-density polyethylene (trade name: Novatec HD HF560, manufactured by Nippon Polyethylene Co., Ltd., melt flow rate 7.0 g / 10 min) was used.

(Resin E1 for base resin film)
Polypropylene (trade name: Novatec PP FX4E manufactured by Nippon Polypro Co., Ltd., melt flow rate 5.3 g / 10 min) was used.

(Resin F1 for base resin film)
Low density polyethylene (trade name: Novatec LD LF640MA, manufactured by Nippon Polyethylene Co., Ltd., melt flow rate 5.0 g / 10 min) was used.

(Resin G1 for base resin film)
A resin (trade name: High Milan AM7316, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 1.1 g / 10 min) was used in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer was crosslinked with zinc ions.

(Resin G2 for base resin film)
A resin (trade name: High Milan 1707, manufactured by Mitsui DuPont Polychemical Co., Ltd., melt flow rate 0.9 g / 10 min) was used in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer was crosslinked with sodium ions.

<Adhesive>
The following α1 to α3, β1, γ1, and δ1 were used as the resin composition constituting the pressure-sensitive adhesive layer.

(Adhesive resin composition α1)
A copolymer was obtained by solution radical polymerization using 2-ethylhexyl acrylate (2-EHA) 80% by mass, 2-hydroxyethyl acrylate 19% by mass, and methacrylic acid 1% by mass as raw materials. Next, 2-methacryloyloxyethyl isocyanate (trade name: Karenz MOI, manufactured by Showa Denko KK) is dropped into this copolymer to cause a radiation-curable carbon-carbon double bond with respect to the repeating unit of the main chain. An acrylic polymer having a contained group bonded thereto was produced. By adjusting the dropping amount of 2-methacryloyloxyethyl isocyanate and the polymerization reaction time, the amount (concentration) of radiation curable unsaturated carbon bonds of the acrylic polymer was 0.6 meq / g. Moreover, the weight which computed the value which measured the value obtained by melt | dissolving the obtained acrylic polymer in tetrahydrofuran by the gel permeation chromatography (Brand name: 150-C ALC / GPC Waters) was converted into polystyrene. The average molecular weight was 800,000.
0.3 parts by mass of polyisocyanate compound (trade name: Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.) as a curing agent and α-as a radiation polymerization initiator with respect to 100 parts by mass of the acrylic polymer prepared above. 2 parts by mass of hydroxycyclohexyl phenyl ketone was blended to prepare an adhesive resin composition α1.

(Adhesive resin composition α2)
Adhesive except that the blending ratio of the monomers in the acrylic polymer of the adhesive resin composition a1 was changed to 70% by mass of 2-ethylhexyl acrylate (2-EHA), 29% by mass of 2-hydroxyethyl acrylate, and 1% by mass of acrylic acid. The adhesive resin composition α2 was prepared in the same manner as the adhesive resin composition α1.

(Adhesive resin composition α3)
Adhesive except that the blending ratio of the monomer in the acrylic polymer of the adhesive resin composition a1 was 85% by mass of 2-ethylhexyl acrylate (2-EHA), 14% by mass of 2-hydroxyethyl acrylate, and 1% by mass of acrylic acid. The adhesive resin composition α3 was prepared in the same manner as the adhesive resin composition α1.

(Adhesive resin composition β1)
Adhesive except that the blending ratio of the monomers in the acrylic polymer of the adhesive resin composition a1 was changed to 60% by mass of 2-ethylhexyl acrylate (2-EHA), 39% by mass of 2-hydroxyethyl acrylate, and 1% by mass of acrylic acid. The adhesive resin composition β1 was prepared in the same manner as the adhesive resin composition α1.

(Adhesive resin composition γ1)
The adhesive resin composition was the same as the adhesive resin composition α1 except that 2-ethylhexyl acrylate (2-EHA) in the acrylic polymer of the adhesive resin composition a1 was changed to n-butyl acrylate (n-BA). γ1 was prepared.

(Adhesive resin composition δ1)
An acrylic copolymer comprising 55% by mass of n-butyl acrylate, 17% by mass of methyl methacrylate, 2% by mass of methacrylic acid, and 26% by mass of 2-hydroxyethyl acrylate, and having a weight average molecular weight calculated by polystyrene conversion of 80,000. 100 parts by mass of radiation-curable oligomer (trade name: UN-3320HA manufactured by Negami Kogyo Co., Ltd.), which is hexafunctional and has a weight average molecular weight of 1,500, which is hexafunctional and calculated in terms of polystyrene, And 2 parts by mass of a polyisocyanate compound (trade name: Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.) as a curing agent and 3 parts by mass of α-hydroxycyclohexyl phenyl ketone as a radiation polymerization initiator, δ1 was prepared.

<Examples 1 to 15 and Comparative Examples 1 to 10>
As shown in Tables 3 and 4, the thickness of the layer 1 in contact with the pressure-sensitive adhesive layer shown in FIG. 2 using each resin composition obtained by charging the base resin film mixture into an extruder and melt-kneading. 55 μm, the thickness of the outermost layer X2 of the base resin film is 55 μm, the thickness of the intermediate layer X1 sandwiched between these base resin films is 40 μm, and the total thickness is 150 μm Manufactured.
Next, the adhesive resin composition was applied at a linear speed of 2 m / min to a polyethylene terephthalate film (thickness 25 μm) that had been subjected to silicon release treatment using a comma coater, and passed through a hot air drying oven set at 110 ° C. to a thickness of 20 μm. The pressure-sensitive adhesive layer was formed. Then, said adhesive was combined with the layer which contact | connects the adhesive layer of each base resin film obtained by said method as shown in Table 3, 4, and the radiation-curable semiconductor processing adhesive tape was manufactured.

About each obtained adhesive tape, the glass transition temperature of an adhesive layer, antistatic property, tape slack after ultraviolet curing, the adhesive residue to a laser mark, and beard adhesion were evaluated by the test shown below.

(1) Measurement of glass transition temperature of adhesive layer The glass transition temperature of the adhesive layer in each adhesive tape was measured by DSC method (based on JIS K7121). The state of the pressure-sensitive adhesive layer is the state before UV curing, and the glass transition temperature referred to here is the extrapolated glass transition start temperature. Note that Al ₂ O ₃ was used as a reference, and a sample piece of about 10 mg was rapidly cooled to −100 ° C., and the temperature was measured at 10 ° C./min in a nitrogen atmosphere at a flow rate of 40 ml / min. The results are shown in Tables 3 and 4.

(2) Evaluation of antistatic performance After holding each obtained adhesive tape in an environment of 23 ° C. and 50% RH for 3 days, a digital ultrahigh resistance / microammeter R8340 / 8340A and a resiliency chamber R12702A (both Apply a voltage of 500 V in an environment of 23 ° C. and 50% RH using the product manufactured by Advantest Co., Ltd., read the current value 60 seconds after the application, and the pressure-sensitive adhesive surface and the back surface of each obtained pressure-sensitive adhesive tape The surface resistivity was measured. The pressure-sensitive adhesive surface was measured after ultraviolet curing by irradiating with 500 mJ / cm ² ultraviolet rays using a high-pressure mercury lamp. The case where the surface resistivity of the pressure-sensitive adhesive surface and the back surface of the tape was 1 × 10 ¹³ Ω / □ or less was evaluated as “◯”, and the case where the surface resistivity was higher than “×” was evaluated. . The results are shown in Tables 3 and 4.

(3) Evaluation of adhesive residue on laser mark Using each of the obtained adhesive tape, the surface having the laser mark of the resin-encapsulated package having the laser mark and the adhesive tape are bonded together and diced under the conditions shown below. Went. Then, it picked up by ultraviolet-ray-curing by irradiating 500 mJ / cm < ² > of ultraviolet-rays using a black light, and picked up. The pickup conditions were a pin picker CAP-300II (manufactured by Canon Machinery Co., Ltd.), expanded by 2 mm, a tip having a tip diameter R of 150 μm, push-up speed: 50 mm / sec, and pin push-up height: 0.7 mm. The 200 chips that were picked up were observed, and the state of adhesion of the adhesive to the laser mark portion was observed. The ratio of chips to which at least one 10 μm square or more adhesive was attached to the laser mark portion per chip was defined as the adhesive adhesion rate. When the adhesive adhesion rate is less than 1%, “◯”, when it is 1% or more and less than 2%, “△”, when it is 2% or more, “×”, and “○” and “△” are accepted. . The results are shown in Tables 3 and 4.
Dicing conditions Dicing machine: DFD-6340 manufactured by DISCO Corporation
Blade: B1A801 SD320N100M42 manufactured by DISCO Corporation
Blade rotation speed: 20000 rpm
Cutting speed: 50 mm / s
Cutting water volume: 1L / min
Dicing size: 2mm square Blade height: 80μm

(4) Evaluation of beard-like cutting waste adhesion After the evaluation of the adhesive residue on the laser mark in (3), 200 chips were observed to observe the presence or absence of beard adhesion. The ratio of chips in which at least one beard-shaped cutting scrap of 100 μm or more remains per chip was defined as the residual ratio of the beard-shaped cutting scrap. When the residual rate of bearded cutting waste is less than 20%, it is “◯”, when it is 20% or more and less than 30%, “△”, when it is 30% or more, “×”, and “○” and “△” The case was accepted. The results are shown in Tables 3 and 4.

(5) Evaluation of looseness of adhesive tape after UV curing Using each of the obtained adhesive tapes, the surface having the laser mark of the resin-encapsulated package having a laser mark and the adhesive tape are bonded together (3) Dicing was performed under the same conditions. Ultraviolet curing was performed by irradiating with 500 mJ / cm ² of ultraviolet light using a high-pressure mercury lamp, and the appearance of the tape was observed. The case where there was no elongation or sag after UV irradiation was evaluated as “◯”, and the case where a partial wrinkle was generated due to a new elongation or sag was evaluated as “X”, and “◯” was accepted. The results are shown in Tables 3 and 4.

  The evaluation results of the examples are shown in Table 3. The pressure-sensitive adhesive tapes of Examples 1 to 13 included in the pressure-sensitive adhesive tape of the present invention are excellent in antistatic properties and have a low glass transition temperature of the pressure-sensitive adhesive layer. There was little tape slack after UV curing. In the tape of Example 11, since the layer made of the high-density polyethylene of the base resin film is the layer 3 on the back side of the tape, the adhesion of the shaving-like cutting chips is slightly inferior, but the antistatic property is good, and the laser mark There was little adhesive residue and tape slack after UV curing. Moreover, the resin composition of the adhesive layer in the tape of Example 12 is an acrylic copolymer with a small amount of 2-ethylhexyl acrylate, and the base polymer of the adhesive layer in the tape of Example 13 is n-butyl acrylate. Since it is an acrylic copolymer as a main component and both have a high glass transition temperature in the pressure-sensitive adhesive layer, the antistatic property is good although the adhesive residue on the laser mark is slightly inferior. Moreover, since the tape of Example 14 had a small vinyl acetate content in the ethylene-vinyl acetate copolymer, the adhesive residue on the laser mark was slightly inferior, but was at a satisfactory level. Further, since the tape of Example 15 has a large vinyl acetate content of the ethylene-vinyl acetate copolymer and a large stickiness, the base resin film is attached to the cooling roll when the base resin film is formed. The streaks entered the resin film, and the tape was slightly inferior in appearance and was slightly inferior in the beard adhesion, but it was at a satisfactory level.

  Table 4 shows the evaluation results of the comparative examples. The adhesive tapes of Comparative Examples 1 to 10 were inferior in antistatic properties, adhesive residue on the laser mark, beard adhesion, tape slack after UV curing, and manufacturability. In the tapes of Comparative Examples 1 and 2, since the amount of the resin obtained by crosslinking the carboxyl group of the ethylene- (meth) acrylic acid copolymer with potassium ions is small, the antistatic property is insufficient, and there is a slight amount of adhesion on the shaved cutting waste. It was inferior. Since the tape of Comparative Example 3 had a large amount of resin obtained by crosslinking the carboxyl group of the ethylene- (meth) acrylic acid copolymer with potassium ions, delamination occurred between the base resin film and the pressure-sensitive adhesive layer. Since the tape of Comparative Example 4 used an ethylene-methacrylic acid copolymer resin instead of the ethylene-vinyl acetate copolymer resin in the base resin film, a phase separation structure effective for conduction was not formed. The antistatic property was inferior. The tape of Comparative Example 5 was inferior in beard adhesion and tape slack after UV curing because the intermediate layer 2 in the base resin film was made of low density polyethylene. The tape of Comparative Example 6 was inferior in tape slack after UV curing because the base resin film had a single-layer structure, and was slightly inferior in beard adhesion. The tape of Comparative Example 7 was inferior in antistatic property on the pressure-sensitive adhesive surface side because the layer 1 in contact with the pressure-sensitive adhesive layer in the base resin film was made of high-density polyethylene. Further, the tape of Comparative Example 8 is a composition in which the pressure-sensitive adhesive layer has a composition in which an oligomer having a radiation curable unsaturated carbon bond is blended with a polymer having no radiation curable unsaturated carbon bond, and has a large curing shrinkage. It was inferior in the adhesive residue to Mark. The tapes of Comparative Examples 9 and 10 were inferior in antistatic performance because they used a resin in which the carboxyl group of the ethylene- (meth) acrylic acid copolymer was crosslinked with zinc ions or sodium ions.

DESCRIPTION OF SYMBOLS 1 Layer which touches an adhesive layer 2 Layers other than the layer which touches an adhesive layer 10 Base resin film 20 Adhesive layer 100,200 Radiation-curable adhesive tape for semiconductor processing X1 Intermediate layer of base resin film X2 Base resin film Outermost layer

Claims (5)

Radiation-curable adhesive for semiconductor processing in which a pressure-sensitive adhesive layer containing a polymer (B) in which a radiation-curable carbon-carbon double bond-containing group is bonded to a repeating unit of a main chain is formed on a base resin film A tape, wherein the base resin film comprises at least two layers,
The layer of the base resin film in contact with the pressure-sensitive adhesive layer is an ethylene-vinyl acetate copolymer (a1) 90 to 70% by mass and a copolymer having at least an ethylene component and a (meth) acrylic acid component as constituent components. It is a resin composition containing 10 to 30% by mass of a resin (a2) obtained by crosslinking a carboxyl group with potassium ions,
A layer other than the layer in contact with the pressure-sensitive adhesive layer is a resin composition containing high-density polyethylene or polypropylene.   The base resin film is composed of three or more layers, and the intermediate layer X1 sandwiched between the layer 1 in contact with the pressure-sensitive adhesive layer and the outermost layer X2 is a resin composition containing high-density polyethylene or polypropylene. The radiation-curable adhesive tape for semiconductor processing according to claim 1.   The radiation-curable adhesive tape for semiconductor processing according to claim 1 or 2, wherein the ethylene-vinyl acetate copolymer has a vinyl acetate component content of 5 to 25 mass%.   The polymer (B) in which a radiation-curable carbon-carbon double bond-containing group is bonded to the repeating unit of the main chain contains 65 to 87% by mass of a 2-ethylhexyl acrylate component as a component (b1). The pressure-sensitive adhesive tape for processing a radiation curable semiconductor according to any one of claims 1 to 3.   5. The radiation-curable adhesive tape for semiconductor processing according to claim 1, wherein the pressure-sensitive adhesive layer has a glass transition start temperature before radiation curing of −65 to −45 ° C. 6.

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