TWI654234B - Adhesive sheet for semiconductor processing - Google Patents

Abstract

The adhesive sheet for semiconductor processing of the present invention has an adhesive layer on a substrate film, and the 5% modulus of the base film is 7.0 to 20.0 MPa, the base film is one layer, and styrene is contained in 100 parts by mass with respect to the base resin. The block copolymer is 5 to 39 parts by mass, and the styrene block copolymer is selected from the group consisting of styrene-hydrogenated isoprene-styrene block copolymer and styrene-isoprene-styrene block copolymer. a styrene-hydrogenated butadiene-styrene block copolymer and at least one resin of a styrene-hydrogenated isoprene/butadiene-styrene block copolymer, the base resin being selected from the group consisting of polypropylene, At least one of polyethylene and other specific resins.

Description

Adhesive sheet for semiconductor processing

The present invention relates to an adhesive sheet for semiconductor processing.

More specifically, the present invention relates to an adhesive tape for dicing which is suitable for use in a semiconductor wafer, such as a dicing adhesive tape for fixing and holding a semiconductor wafer, and a semiconductor package. In particular, it relates to a cutting adhesive tape suitable for use in high-density semiconductor package processing applications.

The dicing adhesive tape is used to protect and fix the wafer when the semiconductor wafer in which the circuit pattern is formed is separated into a wafer. After the semiconductor wafer is fixed to the adhesive tape, it is cut by a rotary blade called a dicing blade to form a semiconductor wafer that is separated into a wafer. The semiconductor wafer is held by the adhesive tape prior to the picking step.

Thereafter, when a plurality of semiconductor wafers are molded by a resin and individually separated to form respective semiconductor packages, they are attached to a dicing tape for fixing, and are cut by a rotary blade called a dicing blade. In the cutting step of the package which is once sealed by the resin, the load at the time of cutting is large, and the encapsulating resin contains a releasing agent and the surface of the resin also has a structure containing minute irregularities. Therefore, in order to firmly hold the package, the adhesive used for the adhesive tape for semiconductor processing does not cause the package to be caught and not scattered during dicing (hereinafter, referred to as "sealing" Use a soft adhesive to prevent problems such as flying.

However, due to the use of such a soft adhesive, there is a problem that the adhesive adheres to the side of the package or the laser marks are peeled off from the package due to the cutting.

In order to reduce the scattering of such packages, the industry has conducted research since.

For example, an adhesive tape using (meth) acrylate in the adhesive layer has been proposed (see Patent Document 1).

However, in recent years, the package has become more and more miniaturized, and the area of the package held on the adhesive tape has become smaller, and it is more likely to cause package scattering. Therefore, only improving the adhesive is not sufficient to suppress the package scattering.

In addition, in order to suppress the vibration of the semiconductor wafer, it is proposed to prevent chipping during dicing by inserting an elastic body on the surface of the substrate of the adhesive sheet (see Patent Document 2). In this manner, it is preferable that not only the adhesive is soft but also the base material side is soft, and the adhesion to the package can be improved. On the other hand, the small size of the package on the market is evolving, and the previous pick-up method using the pin-up has become very time consuming to pick up. Therefore, at present, the adhesive tape is bent by scratching the back surface of the adhesive tape with a tweezers or the like, and the package is instantaneously dropped (hereinafter, referred to as scraping), thereby picking up.

However, when an elastic body is placed on the surface of the base material of the adhesive sheet and the base material side is softened, there is a problem in that, even if the adhesive tape is bent by the scraping, the package is not dropped, so that the package is scraped off. Not smooth.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-100064

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-170886

The present invention has been made to solve the problems associated with the prior art as described above, and an object of the present invention is to provide a method for reducing the occurrence of package scattering which occurs during dicing and which can be quickly and surely peeled off from the adhesive tape even after picking by scraping or the like after cutting. Adhesive sheets for semiconductor processing.

The inventors of the present invention have conducted intensive studies on the content of the styrene-based copolymer relative to the base resin and the 5% modulus of the adhesive sheet, and found that the key is that the styrene-based copolymer has a small content and the loss coefficient. The value is low, thereby completing the present invention.

That is, the above problems of the present invention are solved by the following means.

[1] An adhesive sheet for semiconductor processing, comprising an adhesive layer on a base film, wherein a 5% modulus of the base film is 7.0 to 20.0 MPa, and the base film is one layer, and The styrene block copolymer is selected from the group consisting of styrene-hydrogenated isoprene-styrene block copolymer and styrene in an amount of 5 to 39 parts by mass based on 100 parts by mass of the base resin. - at least 1 in the isoprene-styrene block copolymer, the styrene-hydrogenated butadiene-styrene block copolymer and the styrene-hydrogenated isoprene/butadiene-styrene block copolymer The resin is selected from the group consisting of polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer sulfide, Polybutene, polybutadiene, polymethylpentene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl (meth) acrylate copolymer, ethylene-(methyl ) Ethyl acrylate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamine, ionic polymer, nitrile rubber, At least one resin of butyl rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber, and its hydride or modified product.

[2] The adhesive sheet for semiconductor processing according to [1], wherein the base resin is polypropylene.

[3] The adhesive sheet for semiconductor processing according to [1], wherein the adhesive forming the adhesive layer is an acrylic adhesive.

The adhesive sheet for semiconductor processing according to any one of the above aspects, wherein the styrene block copolymer is 10 to 35 parts by mass based on 100 parts by mass of the base resin.

[5] The adhesive sheet for semiconductor processing according to any one of [1] to [4], which is used for cutting a semiconductor package.

In the present invention, the case of the acrylic system also includes a methacrylic acid system.

Further, in order to make the acrylic system more specific, as in the case of (meth)acrylic acid, the "(meth)" bracket portion means that the portion may or may not be used. For example, (meth)acrylic acid is acrylic or methyl. Acrylic or may be included.

According to the present invention, it is possible to provide an adhesive sheet for semiconductor processing which can reduce the occurrence of package scattering during dicing and which can be quickly and surely peeled off from the adhesive tape even after picking up by squeegee or the like after dicing.

The above and other features and advantages of the present invention will be further clarified by reference to the appended drawings.

1‧‧‧Base film

2‧‧‧Adhesive layer

11‧‧‧Retainer

12‧‧‧Adhesive sheets for semiconductor processing

13‧‧‧Semiconductor wafer

14‧‧‧Semiconductor wafer

15‧‧‧solid arrow direction

16‧‧‧Expander

17‧‧‧Dash arrow direction

Fig. 1 is a cross-sectional view showing an embodiment of an adhesive sheet for semiconductor processing of the present invention.

2 is a cross-sectional view illustrating a cutting step and a picking step of a semiconductor wafer.

3 is a cross-sectional view illustrating a cutting step and a picking step of a semiconductor wafer.

4 is a cross-sectional view illustrating a cutting step and a picking step of a semiconductor wafer.

Fig. 5 is a cross-sectional view for explaining a cutting step and a picking step of a semiconductor wafer.

Hereinafter, the adhesive sheet for semiconductor processing of the present invention will be described in detail.

<<Adhesive film for semiconductor processing>>

The adhesive sheet 12 for semiconductor processing of the present invention has an adhesive layer 2 on at least one side of the base film 1 as in the schematic cross-sectional view schematically shown in FIG.

First, the substrate film will be described in order.

<Substrate film>

In the present invention, the base film is not a laminated body in which a plurality of resin films are laminated, but is composed of one layer, that is, a single resin film.

The resin constituting the substrate film is not a single resin but is composed of a base resin and at least a styrene block copolymer.

(styrene block copolymer)

The styrenic block copolymer is an elastomer, which is also called a styrene-based thermoplastic elastomer or a styrene-based elastomer.

The styrene block copolymer is preferably a styrene block copolymer composed of a hard segment of a hard segment and a soft segment, and examples of the soft segment include polybutylene. Diene, polyisobutylene, polyisoprene, hydrogenated polybutadiene (ie ethylene/propylene), hydrogenated polyisobutylene (ie ethylene/butene), hydrogenated isoprene/butadiene (ie ethylene-ethylene/ Propylene), butadiene rubber, epoxidized polybutadiene, and the like.

By using a styrene block copolymer, the base film becomes soft, and adhesion to a semiconductor package can be improved. Moreover, it becomes easy to extend.

Wherein, in the present invention, a styrene-hydrogenated isoprene-styrene block copolymer (SEPS), a styrene-isoprene-styrene copolymer (SIS), a styrene-hydrogenated butyl group is used. At least one resin in a diene-styrene copolymer (SEBS) and a styrene-hydrogenated isoprene/butadiene-styrene copolymer (SEEPS).

Here, in the styrene block copolymer, "-" means that it is connected in block units (one block), and "/" means that it is one repeating unit and it becomes a block unit (one inlay) segment).

The styrene block copolymer may be used singly or in combination of several kinds.

The styrene-based block copolymer is used in combination with the base resin. In the present invention, it is contained in an amount of 5 to 39 parts by mass, preferably 10 to 35 parts by mass, per 100 parts by mass of the base resin.

When the content of the styrene block copolymer is less than 5 parts by mass, the base film becomes rigid and the adhesion to the semiconductor package cannot be improved. On the other hand, when it exceeds 39 mass parts, even if the semiconductor processing adhesive sheet is bent by scraping, the package does not fall, and the scraping is not smooth.

(base resin)

In the present invention, the base resin is a resin other than the styrene block copolymer.

As the base resin, a thermoplastic resin is preferred, and water resistance and heat resistance of the base film are more preferred. Excellent, especially for synthetic resin film.

Examples of the thermoplastic resin include polyolefin resin, polyamide resin, polyether amide resin, thermoplastic polyimide resin, thermoplastic polyamide amide resin, polyurethane resin, urea resin, polyester resin, and liquid crystal polymerization. Ester resin, polyacetal resin, polycarbonate resin, polyphenylene ether (including modified polyphenylene ether) resin, polyfluorene resin, polyether oxime resin, polyphenylene sulfide resin, polyetheretherketone ( The invention comprises a modified polyetheretherketone resin, a polyether ketone resin, a polyaryl ether ketone resin, a polyarylate resin, a fluorine resin, a polyphenylene oxide resin, a polylactic acid, a phenol resin, a melamine resin, Epoxy resin, phenoxy resin, enamel resin, and the like.

Among the thermoplastic resins, a polyolefin resin is particularly preferred.

Further, the thermoplastic resin may be modified by acid modification or the like, and may be amorphous or amorphous.

Wherein, in the present invention, a selected from the group consisting of polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer sulfide , polybutene, polybutadiene, polymethylpentene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl (meth) acrylate copolymer, ethylene-(A Ethyl acrylate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamide, ionic polymer, nitrile rubber, butyl At least one resin of base rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber, and its hydride or modified product.

(polyolefin resin)

The polyolefin resin is a polyolefin resin obtained by polymerizing at least one type of olefin, and may be a homopolymer or a copolymer.

Examples of such an olefin include ethylene, propylene, isobutylene, and isobutylene (1- Butene) A-olefin having 4 to 12 carbon atoms, butadiene, isoprene, (meth) acrylate, (meth)acrylic acid, (meth) acrylamide, vinyl alcohol, vinyl acetate Ester, vinyl chloride, styrene, acrylonitrile, and the like.

Further, examples of the α-olefin having 4 to 12 carbon atoms include 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, and 3-methyl-1-. Butene, 1-hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene , 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1 -pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1- Hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-oxime Alkene, 1-decene, 1-undecene, 1-dodecene, and the like.

Examples of the polyolefin resin include a polyethylene resin, a polypropylene resin, a polyisobutylene resin, a polyisobutylene resin, a polyisoprene resin, a polybutadiene resin, and a (meth)acrylic resin (so-called allylic resin). ), vinyl resin such as polyvinyl chloride resin, poly(meth)acrylamide resin, polystyrene resin, acrylonitrile/butadiene/styrene copolymer resin (ABS resin), ethylene/(meth)acrylic acid Ester copolymer, ethylene/vinyl acetate copolymer, and the like.

Among these resins, a polyethylene resin, a polypropylene resin, an acrylonitrile/butadiene/styrene copolymer resin (ABS resin), and a polyethylene resin or a polypropylene resin are preferable.

Examples of the polyethylene resin include an ethylene homopolymer and an ethylene-α-olefin copolymer. As the α-olefin, 1-butene, 1-pentene, 1-hexene, and 1-octene are preferable.

Examples of the ethylene-α-olefin copolymer include an ethylene-1-butene copolymer, an ethylene-1-pentene copolymer, an ethylene-1-hexene copolymer, and an ethylene-1-octene copolymer. Polymer, etc.

Furthermore, in the case of classification by density or shape, it may be high density polyethylene (HDPE), low density polyethylene (LDPE), ultra low density polyethylene (VLDPE), linear low density polyethylene (LLDPE). ), any of ultra high molecular weight polyethylene (UHMW-PE).

Examples of the polypropylene resin include a propylene homopolymer, a propylene-ethylene random copolymer, a propylene-α-olefin random copolymer, a propylene-ethylene-α-olefin copolymer, and a propylene block copolymer (from propylene). A polymer component or a copolymer component mainly composed of propylene, and a copolymer obtained by copolymerizing at least one of a monomer selected from ethylene and an α-olefin with propylene). These polypropylene resins may be used singly or in combination of two or more.

The α-olefin used for the polypropylene resin is preferably 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, more preferably 1-butene, 1-hexene, 1-octene.

Examples of the propylene-α-olefin random copolymer include a propylene-1-butene random copolymer, a propylene-1-hexene random copolymer, and a propylene-1-octene random copolymer.

Examples of the propylene-ethylene-α-olefin copolymer include a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, and a propylene-ethylene-1-octene copolymer.

Examples of the propylene block copolymer include (propylene)-(propylene-ethylene) copolymer, (propylene)-(propylene-ethylene-1-butene) copolymer, and (propylene)-(propylene-ethylene-1). -hexene) copolymer, (propylene)-(propylene-1-butene) copolymer, (propylene)-(propylene-1-hexene) copolymer, (propylene-ethylene)-(propylene-ethylene) copolymer , (propylene-ethylene)-(propylene-ethylene -1-butene) copolymer, (propylene-ethylene)-(propylene-ethylene-1-hexene) copolymer, (propylene-ethylene)-(propylene-1-butene) copolymer, (propylene-ethylene) -(propylene-1-hexene) copolymer, (propylene-1-butene)-(propylene-ethylene) copolymer, (propylene-1-butene)-(propylene-ethylene-1-butene) copolymer , (propylene-1-butene)-(propylene-ethylene-1-hexene) copolymer, (propylene-1-butene)-(propylene-1-butene) copolymer, (propylene-1-butene) )-(propylene-1-hexene) copolymer or the like.

Among these polypropylene resins, preferred are propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-ethylene-1-butene copolymer, and propylene block copolymerization. Things.

The crystallinity of the polypropylene resin is required in terms of melting temperature (melting point) or stereoregularity, and is required according to the quality required for the polyolefin resin composition of the present invention or the molded article obtained by molding it. Adjust accordingly.

Furthermore, stereoregularity is called the isotactic index and the syndiotactic index.

The same row index is obtained by ¹³ C-NMR method described in Macromolecules, Vol. 8, p. 687 (1975). Specifically, the same-row index of the polypropylene resin was determined in the form of the area fraction of the mmmm peak in the total absorption peak of the carbon region of the methyl group in the ¹³ C-NMR spectrum.

The crystallinity of the higher rank index is higher, preferably 0.96 or more, more preferably 0.97 or more, and still more preferably 0.98 or more.

On the other hand, the index is obtained by the method described in J. Am. Chem. Soc., 110, 6255 (1988) or Angew. Chem. Int. Ed. Engl., 1955, 34, 1143-1170. The crystallity of the higher index is higher.

Examples of the vinyl resin include a vinyl chloride resin [a homopolymer of a vinyl chloride monomer (such as a polyvinyl chloride resin), a copolymer of a vinyl chloride monomer and another monomer (a vinyl chloride-vinyl acetate copolymer, a vinyl chloride resin (such as a vinyl chloride-(meth)acrylate copolymer), a vinyl alcohol resin (a homopolymer such as polyvinyl alcohol or a copolymer such as an ethylene-vinyl alcohol copolymer), or a polyvinyl acetal resin such as polyethylene formaldehyde. . These vinyl resins may be used singly or in combination of two or more.

The melt flow rate (MFR) of the polyolefin resin is usually from 0.01 to 400 g/10 min, and is preferably from 1 to 400 g/10 min, more preferably from 1 to 100 g/10 min, from the viewpoint of improving mechanical strength or production stability. It is preferably 1 to 50 g/10 min.

Further, in the present invention, the melt flow rate (MFR) is the mass (g/10 min) of the polymer which flows out every 10 minutes at 190 ° C under a load of 2.16 kg according to JIS K7210.

In the present invention, the base resin is particularly preferably polypropylene.

The surface of the substrate film that is in contact with the adhesive layer may be subjected to corona treatment or other layers such as an undercoat layer may be provided to improve adhesion.

The thickness of the substrate film is not particularly limited, but is preferably 70 to 300 μm, more preferably 100 to 200 μm, still more preferably 100 to 250 μm, still more preferably 100 to 150 μm.

Further, in the present invention, it is preferably more than 100 μm, and in this case, it is preferably more than 100 μm and 300 μm or less, more preferably 110 to 300 μm, still more preferably 110 to 250 μm, and particularly preferably 110 to 200 μm. .

<5% modulus of substrate film>

In the present invention, the 5% modulus of the substrate film is 7.0 to 20.0 MPa.

The 5% modulus of the substrate film is preferably 7.0 to 15.0 MPa, more preferably 7.0 MPa and 15.0. MPa or less is more preferably 8.0 MPa and 15.0 MPa or less, still more preferably 8.5 to 15.0 MPa, and most preferably 10.0 to 15.0 MPa.

When the 5% modulus of the base film is less than 7.0 MPa, since the base film is soft, the force is not transmitted during the scraping of the wafer, and the wafer remains on the adhesive sheet for semiconductor processing. If it exceeds 20.0 MPa, the base is used. The film is too rigid, so the adhesion to the semiconductor package is deteriorated, and the package is scattered during the cutting.

The 5% modulus was obtained by measuring the stress at 5% strain in accordance with JIS K 7127/2/300.

In the present invention, each of the MD direction and the TD direction is measured five times, and the value obtained by averaging all of the measured values is set to a value of 5% modulus.

In order to set the 5% modulus to the above range, it can be adjusted depending on the type of the base resin and the styrene block copolymer and the blending amount.

<Adhesive, Adhesive Layer>

The adhesive layer can be formed by various adhesives previously known. The adhesive is not limited, and for example, an adhesive such as a rubber-based, acrylic-based, polyoxy-oxygen-based or polyvinyl ether-based adhesive can be used.

In the present invention, an acrylic adhesive is preferred.

In order to add cohesive force to the base polymers, a crosslinking agent may be blended.

Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a metal chelate crosslinking agent, an aziridine crosslinking agent, and an amine resin. Further, various additives may be contained in the adhesive as needed within the scope of the object of the present invention.

Further, a radiation hardening type or a heat foaming type adhesive can also be used.

As the radiation-curable adhesive, an adhesive which is cured by ultraviolet rays, an electron beam or the like and which is easily peeled off during peeling can be used. Further, as the heat-expandable pressure-sensitive adhesive, an adhesive which is easily peeled off by heating and a foaming agent or a swelling agent can be used. Further, as the adhesive, an adhesive capable of both dicing and die-bonding may be used. For example, the radiation-curing type adhesive is preferably used in the Japanese Patent Publication No. Hei 1-56612, Japanese Patent Application Laid-Open No. Hei No. Hei No. Hei. In the present invention, it is preferred to use an ultraviolet curable adhesive. In this case, it is sufficient to have a property of being hardened by radiation and three-dimensionally reticulating, for example, using at least 2 lights in a blend of a usual rubber-based or acrylic-based pressure-sensitive base resin (polymer). A polymerizable carbon-carbon double bond low molecular weight compound (hereinafter referred to as a photopolymerizable compound) and a photopolymerization initiator are used.

The rubber-based or acrylic base resin is a rubber-based polymer such as natural rubber or various synthetic rubbers, or a polyalkyl (meth)acrylate, an alkyl (meth)acrylate, or an alkyl (meth)acrylate. An acrylic polymer such as a copolymer of another unsaturated monomer copolymerizable therewith.

Further, by mixing the isocyanate-based curing agent with the above-mentioned adhesive, the initial adhesive force can be set to an arbitrary value. As such a hardener, specifically, a polyvalent isocyanate compound such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-benzenedimethyl diisocyanate or 1,4-dimethylbenzene is used. Isocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, Dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, isocyanuric acid isocyanate, and the like.

In the case of an ultraviolet curing adhesive, by mixing light in the adhesive The initiator can reduce the polymerization hardening time and ultraviolet radiation amount by ultraviolet irradiation.

Specific examples of such a photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, and tetramethylthiuram monosulfide. , azobisisobutyronitrile, bibenzyl, diethyl hydrazine, β-chloro-anthraquinone, and the like.

The mass average molecular weight of the base polymer of the acrylic pressure-sensitive adhesive is preferably 100,000 or more, more preferably 200,000 or more, further preferably 250,000 or more, particularly preferably 300,000 or more, and most preferably 400,000 or more. The upper limit of the mass average molecular weight is preferably 2,000,000 or less, more preferably 1.5,000,000 or less, further preferably 1,000,000 or less, and particularly preferably 800,000 or less.

In the present invention, for example, 100,000 to 2,000,000 are cited as a preferred range, and 250,000 to 2,000,000 are listed as a better range. If other range examples are shown, for example, a range of 200,000 to 1,500,000 may be cited.

The mass average molecular weight is obtained by standard polystyrene conversion by gel permeation chromatography (GPC).

The thickness of the adhesive layer is not particularly limited, and is preferably 4 to 30 μm, particularly preferably 5 to 25 μm.

The semiconductor wafer can be bonded to the semiconductor processing adhesive sheet of the present invention, and the wafer can be cut and picked up as shown in FIGS. 2 to 5 by a conventional method. In the method of processing a semiconductor wafer using the adhesive sheet for semiconductor processing of the present invention, it is preferable that the substrate film is not cut into the substrate film, the cutting resistance of the dicing blade can be reduced, and the semiconductor wafer can be smoothly cut and debris can be reduced. In order not to allow the slit to reach the base film, for example, the setting of the cutting depth of the cutting device to be used may be appropriately changed according to the manual.

The bare wafer used in the present invention is not particularly limited and can be appropriately selected from any of the bare wafers previously used.

[Examples]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

<Manufacture of Substrate Film>

1) Substrate film A

Styrene-hydrogenated isoprene-styrene block copolymer (SEPS) (trade name: Septon KF-2104, manufactured by Kuraray Co., Ltd.) and homopropylene (PP) (trade name: J-105G, Ube Hiroshi) The product was produced by mixing at a blending ratio shown in the following Table 1, and was subjected to film extrusion molding at about 200 ° C by a biaxial kneading machine to produce a base film A having a thickness of 150 μm.

2) Substrate film B

Styrene-isoprene-styrene copolymer (SIS) (trade name: Hybrar 5127, manufactured by Kuraray Co., Ltd.) and homopropylene (PP) (trade name: J-105G, manufactured by Ube Industries Co., Ltd.) The mixture was mixed at a blending ratio shown in the following Table 1, and processed by film extrusion molding at about 200 ° C by a biaxial kneading machine to produce a base film B having a thickness of 150 μm.

3) Substrate film C

Styrene-hydrogenated butadiene-styrene copolymer (SEBS) (trade name: Septon 8104, manufactured by Kuraray Co., Ltd.) and homopropylene (PP) (trade name: J-105G, manufactured by Ube Industries, Ltd.) Mixing with the blending ratio shown in Table 1 below, and using biaxial kneading The film was processed by film extrusion molding at about 200 ° C to produce a substrate film C having a thickness of 150 μm.

4) Substrate film D

Styrene-hydrogenated isoprene/butadiene-styrene copolymer (SEEPS) (trade name: Septon 4033, manufactured by Kuraray Co., Ltd.) and homopolypropylene (PP) (trade name: J-105G, Ube Hiroshi) The product was produced by mixing at a blending ratio shown in the following Table 1, and was processed by film extrusion molding at about 200 ° C by a biaxial kneading machine to produce a substrate film D having a thickness of 150 μm.

<Preparation of Adhesives>

Addition of polyacrylic base polymer (copolymer composed of 2-ethylhexyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, mass average molecular weight: 400,000, glass transition temperature: -35 ° C) 3 parts by mass of an isocyanate compound (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), and 50 parts by mass of tetramethylol methane tetraacrylate as a compound having a photopolymerizable carbon-carbon double bond, as photopolymerization One part by mass of the α-hydroxycyclohexyl phenyl ketone of the starting agent was mixed to obtain an adhesive.

Examples 1 to 3 and Comparative Example 1

Each of the adhesive films was applied to one surface of the base film A to a thickness of 20 μm to form an adhesive layer, and each of the adhesive sheets for semiconductor processing of Examples 1 to 3 and Comparative Example 1 was produced.

Example 4

An adhesive sheet for semiconductor processing was produced in the same manner as in Example 1 except that the above-mentioned base film B was used.

Example 5

An adhesive sheet for semiconductor processing was produced in the same manner as in Example 1 except that the above-mentioned base film C was used.

Example 6

An adhesive sheet for semiconductor processing was produced in the same manner as in Example 1 except that the above-mentioned base film D was used.

Each of the semiconductor processing adhesive sheets was evaluated for 5% modulus, package scattering, and pick-up success rate as described below.

(5% modulus)

A test piece was produced in accordance with JIS K7127/2/300 using each substrate film and a 5% modulus was measured. Each test piece was measured five times in the MD direction and the TD direction, and the values obtained by averaging all of the measured values were used as test results.

(package scattering)

A QFN package (60 mm × 150 mm, thickness: 0.95 mm) was bonded to each of the adhesive sheets for semiconductor processing. The cutting was performed so that the wafer size was 1 mm × 1 mm under the conditions of a blade rotation number of 20,000 rpm, a cutting speed of 30 mm/min, and a cutting amount of the adhesive sheet of 60 μm by a microtome (manufactured by DISCO Co., Ltd., DFD 6340).

After the cutting, the evaluation was performed according to the following evaluation criteria.

Evaluation basis

○: The wafer remains on the adhesive sheet for semiconductor processing.

×: One or more wafers are scattered

(pickup success rate)

The evaluation was carried out by the following two methods.

(1) Evaluation using scraping

After the dicing, ultraviolet irradiation (200 mJ/cm ² ) was performed, and the back surface of the adhesive sheet for semiconductor processing was scraped with tweezers to drop the wafer.

(2) Evaluation using ultrasonic waves

After the dicing, ultraviolet irradiation (200 mJ/cm ² ) was performed, and the back surface of the semiconductor processing adhesive sheet was brought into contact with the ultrasonic oscillation terminal to drop the wafer.

The results obtained are summarized in Table 1 below.

Furthermore, the blank in the table means unused.

According to the above Table 1, the adhesive sheets for semiconductor processing of Examples 1 to 6 have a value of 5% modulus in the range of 7.0 to 20.0 MPa, and no package scattering occurs, and the pick-up and ultrasonic oscillation terminals are used for picking up. good.

On the other hand, in the adhesive sheet for semiconductor processing of Comparative Example 1, the elastomer component was large, and the value of the 5% modulus was small. As a result, although the package scattering did not occur, the semiconductor was scratched particularly when picking up by scraping. The force of the adhesive sheet for processing is not well transmitted, causing the wafer to remain in the semiconductor processing Use adhesive on the piece.

On the other hand, in the adhesive sheet for semiconductor processing of Comparative Example 2, the elastomer component was small, and the value of the 5% modulus was small, and as a result, the loss coefficient was lowered, and as a result, the adhesion to the semiconductor package was deteriorated, resulting in package scattering. .

The present invention has been described in connection with the embodiments thereof, and it is not intended to limit the invention of the present invention to any of the details of the description, and the invention should not be inconsistent with the scope of the attached patent application. The spirit and scope of the invention as illustrated is broadly construed.

The present application claims priority to Japanese Patent Application No. 2016-073264, filed on Jan. 31,,,,,,,,,,,,,

Claims (5)

An adhesive sheet for semiconductor processing, which has an adhesive layer on a substrate film, wherein the semiconductor processing adhesive sheet is used for cutting a semiconductor package; and the 5% modulus of the base film is 7.0 to 20.0 MPa. The base film is one layer and contains 5 to 39 parts by mass of the styrene block copolymer with respect to 100 parts by mass of the base resin, and the styrene block copolymer is selected from styrene-hydrogenated isoprene. -styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-hydrogenated butadiene-styrene block copolymer and styrene-hydrogenated isoprene/butadiene - at least one resin in the styrene block copolymer, and the base resin is selected from the group consisting of polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-propylene copolymer, propylene copolymer, Ethylene-propylene-diene copolymer sulfide, polybutene, polybutadiene, polymethylpentene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(methyl) Methyl acrylate copolymer, ethylene-ethyl (meth) acrylate copolymer, poly Ethylene, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamidamine, ionic polymer, nitrile rubber, butyl rubber, styrene isoprene At least one resin of diene rubber, styrene butadiene rubber, natural rubber, and a hydride or modified product thereof. The adhesive sheet for semiconductor processing according to the first aspect of the invention, wherein the base resin is polypropylene. The adhesive sheet for semiconductor processing according to the first aspect of the patent application, wherein the adhesion is formed The adhesive of the agent layer is an acrylic adhesive. The adhesive sheet for semiconductor processing according to the second aspect of the invention, wherein the adhesive for forming the adhesive layer is an acrylic adhesive. The adhesive sheet for semiconductor processing according to any one of claims 1 to 4, wherein the styrene block copolymer is 10 to 35 parts by mass based on 100 parts by mass of the base resin.