JP6615223B2 - Adhesive sheet for semiconductor processing - Google Patents

Description

The present invention relates to an adhesive sheet for semiconductor processing.
More specifically, the present invention relates to a dicing adhesive tape suitable for fixing and holding a semiconductor wafer when dicing the semiconductor wafer into chips and a dicing adhesive tape used for semiconductor package processing. In particular, the present invention relates to a dicing adhesive tape suitable for high-density mounting semiconductor package processing.

  The dicing adhesive tape protects and fixes a wafer during a dicing process in which a semiconductor wafer on which a circuit pattern is formed is separated into chips. After the semiconductor wafer is fixed to the adhesive tape, it is diced with a rotary blade called a dicing blade to form semiconductor chips separated into chips. The semiconductor chip is held by the adhesive tape until the pickup process.

Thereafter, when a plurality of semiconductor chips are collectively molded with a resin and separated into individual semiconductor packages to form individual semiconductor packages, they are affixed to a dicing tape and fixed, and dicing is performed with a rotary blade called a dicing blade. Thus, in the dicing process of the package collectively sealed with the resin, the load at the time of cutting is large, and the package resin contains a release agent and the resin surface has a structure with minute irregularities. For this reason, the adhesive used in the semiconductor processing tape can hold the package firmly, and the package does not hold when dicing and is not scattered (hereinafter referred to as “package fly”). So flexible adhesive is used.
However, the use of such a flexible pressure-sensitive adhesive causes problems such as adhesion of the pressure-sensitive adhesive to the side surface of the package by dicing and peeling of the laser mark printed on the package.

In order to reduce such package fly, studies have been made conventionally.
For example, an adhesive tape using a (meth) alkyl acid ester for an adhesive layer has been proposed (see Patent Document 1).
However, with the recent miniaturization of the package, the area where the package is held on the adhesive tape becomes smaller and package fly is more likely to occur. For this reason, simply improving the pressure-sensitive adhesive is insufficient to suppress package fly.
Moreover, in order to suppress the vibration of the semiconductor wafer, it has been proposed to suppress chipping during dicing by putting an elastomer on the base material surface of the pressure-sensitive adhesive sheet (see Patent Document 2). In this way, not only the pressure-sensitive adhesive but also the base material side is made flexible so that the adhesiveness with the package can be increased, which is preferable. On the other hand, the size of the package has been reduced in the market, and the pick-up method using the conventional pin push-up has become very time consuming. Therefore, picking up has been performed by bending the tape by rubbing the back surface of the tape with tweezers or the like and dropping the package at a stroke (hereinafter referred to as scraping).
However, if an elastomer is put on the base material surface of the adhesive sheet to make the base material side flexible, the problem is that the package will not stand up even if the tape is bent by rubbing, and the scrub will not work well. there were.

JP 2007-100064 A JP 2009-170886 A

  The present invention is intended to solve the problems associated with the prior art as described above, and while reducing the occurrence of package fly that occurs during dicing, it can be quickly and reliably picked up by scraping after dicing. It aims at providing the adhesive sheet for semiconductor processing which can be peeled from an adhesive tape.

As a result of diligent study, the present inventors have studied in detail the content of the styrene-based copolymer with respect to the base resin and the loss coefficient of the pressure-sensitive adhesive sheet. As a result, the content of the styrene-based copolymer is small and the value of the loss coefficient Has been found to be important, and the present invention has been achieved.
That is, the said subject of this invention is solved by the following means.

[1] A semiconductor processing pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on a substrate film,
Using a test piece obtained by processing the pressure-sensitive adhesive sheet for semiconductor processing to a width of 5 mm, a loss factor measured in a film shape by a dynamic viscoelasticity measuring apparatus is 0.08 or more and less than 0.15 when the frequency is 0.01 to 10 Hz. And
The base film is a single layer, and includes 5 to 39 parts by mass of a styrenic block copolymer with respect to 100 parts by mass of the base resin.
The styrenic block copolymer is 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 selected from styrene block copolymers;
The base resin is polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene / propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer vulcanizate, polybutene, polybutadiene, poly Methylpentene, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid methyl copolymer, ethylene- (meth) acrylic acid ethyl copolymer, polyvinyl chloride, Vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamide, ionomer, nitrile rubber, butyl rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber and its water additives or modifications Selected from things Adhesive sheet for semiconductor processing, wherein the at least one resin.
[2] The adhesive sheet for semiconductor processing according to [1], wherein the base resin is polypropylene.
[3] The pressure-sensitive adhesive sheet for semiconductor processing according to [1] or [2], wherein the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive.
[4] The semiconductor processing device as described in any one of [1] to [3], wherein the styrene block copolymer is 10 to 35 parts by mass with respect to 100 parts by mass of the base resin. Adhesive sheet.
[5] The adhesive sheet for semiconductor processing according to any one of [1] to [4], which is used for dicing a semiconductor package.

In the present invention, the term “acrylic” includes methacrylic.
In order to make the acrylic system clearer, the parenthesis part of “(meth)” means that it may or may not be present as in the case of (meth) acrylic system. For example, (meth) acrylic system May be acrylic, methacrylic, or any of these.

According to the present invention, it is possible to provide an adhesive sheet for semiconductor processing that can reduce the occurrence of package fly that occurs at the time of dicing and can be quickly and reliably peeled off from the adhesive tape even by pick-up by scraping or the like after dicing. .
The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the pressure-sensitive adhesive sheet for semiconductor processing of the present invention. FIG. 2 is a cross-sectional view illustrating a semiconductor wafer dicing step and a pickup step. FIG. 3 is a cross-sectional view illustrating a semiconductor wafer dicing step and a pickup step. FIG. 4 is a cross-sectional view illustrating a semiconductor wafer dicing step and a pickup step. FIG. 5 is a cross-sectional view illustrating a semiconductor wafer dicing step and a pickup step.

  Below, the adhesive sheet for semiconductor processing of this invention is demonstrated in detail.

<< Semiconductor processing adhesive sheet >>
The adhesive sheet 12 for semiconductor processing of this invention has the adhesive layer 2 on the at least one surface on the base film 1 like the schematic sectional drawing typically shown in FIG.
First, it demonstrates in order from a base film.

<Base film>
In the present invention, the base film is not a laminate in which a plurality of resin films are laminated, but consists of one layer, that is, a single resin film.
The resin constituting the base film is not a single resin but a base resin and at least a styrene block copolymer.

(Styrene block copolymer)
The styrene block copolymer is an elastomer and is also referred to as a styrene thermoplastic elastomer or a styrene elastomer.
The styrenic block copolymer is preferably a styrene block copolymer composed of a hard segment polystyrene and a soft segment. Examples of the soft segment include polybutadiene, polyisobutylene, polyisoprene, and hydrogenated polybutadiene (that is, ethylene / propylene). , Hydrogenated polyisobutylene (ie, ethylene / butylene), hydrogenated isoprene / butadiene (ie, ethylene-ethylene / propylene), butadiene rubber, epoxidized polybutadiene, and the like.

  By using the styrene block copolymer, the base film becomes flexible and the adhesion to the semiconductor package can be increased. Also, the expansion can be easily performed.

  Of these, in the present invention, styrene-hydrogenated isoprene-styrene block copolymer (SEPS), styrene-isoprene-styrene copolymer ((SIS), styrene-hydrogenated butadiene-styrene copolymer (SEBS), and styrene. Use at least one resin selected from hydrogenated isoprene / butadiene-styrene copolymer (SEEPS).

  Here, in the styrenic block copolymer, “−” means to be connected in block units (one block), and “/” is one repeating unit, which is a block unit (one block). Means that

  One or more styrenic block copolymers may be used in combination.

The styrenic block copolymer is used together with the base resin. In the present invention, the styrenic block copolymer is contained in an amount of 5 to 39 parts by mass with respect to 100 parts by mass of the base resin.
When the content of the styrenic 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, if the amount exceeds 39 parts by mass, the package does not stand even if the adhesive sheet for semiconductor processing is bent by rubbing off.

(Base resin)
In the present invention, the base resin is a resin other than the styrenic block copolymer.
As the base resin, a thermoplastic resin is preferable, a base film having excellent water resistance and heat resistance is more preferable, and a synthetic resin film is particularly preferable.

Thermoplastic resins include polyolefin resin, polyamide resin, polyetheramide resin, thermoplastic polyimide resin, thermoplastic polyamideimide resin, polyurethane resin, urea resin, polyester resin, liquid crystal polyester resin, polyacetal resin, polycarbonate resin, polyphenylene ether ( (Including modified polyphenylene ether) resin, polysulfone resin, polyether sulfone resin, polyphenylene sulfide resin, polyether ether ketone (including modified polyether ether ketone) resin, polyether ketone resin, polyaryl ether ketone resin, polyarylate resin, Fluorine resin, polyphenylene oxide resin, polylactic acid, phenol resin, melamine resin, epoxy resin, phenoxy resin, silicon resin, etc. That.
Of the thermoplastic resins, polyolefin resin is particularly preferable.
The thermoplastic resin may be modified by acid modification or the like, and may be crystalline or amorphous.

  Among these, in the present invention, polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene / propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer vulcanizate, polybutene, polybutadiene , Polymethylpentene, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) methyl acrylate copolymer, ethylene- (meth) ethyl acrylate copolymer, polychlorinated Vinyl, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamide, ionomer, nitrile rubber, butyl rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber and its water additives Or choose from denatured products It is the use of at least one resin.

(Polyolefin resin)
The polyolefin resin is a polyolefin resin obtained by polymerizing at least one olefin, and may be a homopolymer or a copolymer.
Examples of such olefins include α-olefins having 4 to 12 carbon atoms including ethylene, propylene, isobutylene, isobutene (1-butene), butadiene, isoprene, (meth) acrylic acid ester, and (meth) acrylic acid. , (Meth) acrylamide, vinyl alcohol, vinyl acetate, vinyl chloride, styrene, acrylonitrile and the like.

  Examples of the α-olefin having 4 to 12 carbon atoms include 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, 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-none , 1-decene, 1-undecene, and 1-dodecene, and the like.

  Examples of the polyolefin resin include polyethylene resins, polypropylene resins, polyisobutylene resins, polyisobutene resins, polyisoprene resins, polybutadiene resins, (meth) acrylic resins (so-called allyl resins), vinyl resins such as polyvinyl chloride resins, and poly (meta ) Acrylamide resin, polystyrene resin, acrylonitrile / butadiene / styrene copolymer resin (ABS resin), ethylene / (meth) acrylate copolymer, ethylene / vinyl acetate copolymer, and the like.

  Among these resins, polyethylene resins, polypropylene resins, and acrylonitrile / butadiene / styrene copolymer resins (ABS resins) are preferable, and polyethylene resins and polypropylene resins are particularly 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. Can be mentioned.

  When classified by density or shape, high density polyethylene (HDPE), low density polyethylene (LDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), ultra high molecular weight polyethylene (UHMW-PE) )

  Examples of the polypropylene resin include propylene homopolymer, propylene-ethylene random copolymer, propylene-α-olefin random copolymer, propylene-ethylene-α-olefin copolymer, propylene block copolymer (propylene homopolymer component) Or a copolymer component mainly composed of propylene and a copolymer obtained by copolymerizing at least one monomer selected from ethylene and α-olefin and propylene). These polypropylene resins may be used alone 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, 1-butene, 1-hexene, 1- Octene is more preferred.

  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 propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, and the like. It is done.

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

  Of these polypropylene resins, propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-ethylene-1-butene copolymer, and propylene block copolymer are preferable.

The crystallinity of the polypropylene resin is determined by the melting temperature (melting point) and stereoregularity, depending on the quality required for the polyolefin resin composition of the present invention and the quality required for the molded product obtained by molding it, adjust.
The stereoregularity is referred to as an isotactic index and a syndiotactic index.

The isotactic index is determined by the ¹³ C-NMR method described in Macromolecules, Vol. 8, page 687 (1975). Specifically, the isotactic index of the polypropylene resin is determined as the area fraction of the mmmm peak in the total absorption peak of the methyl group carbon region in the ¹³ C-NMR spectrum.
Those having a high isotactic index have high crystallinity, preferably 0.96 or more, more preferably 0.97 or more, and even more preferably 0.98 or more.

  On the other hand, the syndiotactic index is J.H. Am. Chem. Soc. 110, 6255 (1988) and Angew. Chem. Int. Ed. Engl. , 1955, 34, 1143-1170, and those having a high syndiotactic index have high crystallinity.

  Examples of vinyl resins include vinyl chloride resins [vinyl chloride monomer homopolymers (polyvinyl chloride resin, etc.), copolymers of vinyl chloride monomers and other monomers (vinyl chloride-vinyl acetate copolymer). And the like, etc.], vinyl alcohol resins (such as homopolymers such as polyvinyl alcohol, copolymers such as ethylene-vinyl alcohol copolymer), polyvinyl formal, etc. A polyvinyl acetal resin etc. are mentioned. These vinyl resins can be used singly or in combination of two or more.

The melt flow rate (MFR) of the polyolefin resin is usually 0.01 to 400 g / 10 minutes, and preferably 1 to 400 g / 10 minutes, more preferably from the viewpoint of improving mechanical strength and production stability. Is 1 to 100 g / 10 min, and more preferably 1 to 50 g / 10 min.
In the present invention, the melt flow rate (MFR) is a mass (g / 10 minutes) of a polymer flowing out per 10 minutes under a load of 190 ° C. and 2.16 kg in accordance with JIS K7210.

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

In order to improve the adhesion, the surface of the base film in contact with the pressure-sensitive adhesive layer may be subjected to corona treatment or may be provided with other layers such as a primer.
The thickness of the base film is not particularly limited, but is preferably 30 to 300 μm, more preferably 30 to 200 μm, and still more preferably 50 to 150 μm.
Moreover, in this invention, what exceeds 100 micrometers is also preferable, In this case, it exceeds 100 micrometers and is 300 micrometers or less, 110-300 micrometers is more preferable, 110-250 micrometers is more preferable, 110-200 micrometers is especially preferable.

<Adhesive, adhesive layer>
The pressure-sensitive adhesive layer can be formed of various conventionally known pressure-sensitive adhesives. Such a pressure-sensitive adhesive is not limited at all, but for example, a pressure-sensitive adhesive based on rubber, acrylic, silicone, polyvinyl ether or the like is used.
In the present invention, an acrylic pressure-sensitive adhesive is preferred.

In order to add cohesion to these base polymers, a crosslinking agent can be blended.
Examples of the crosslinking agent include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a metal chelate-based crosslinking agent, an aziridine-based crosslinking agent, and an amine resin corresponding to the base polymer. Further, the pressure-sensitive adhesive can contain various additive components as desired within the range in which the object of the present invention is not impaired.

A radiation-curing type or heat-foaming type pressure-sensitive adhesive can also be used.
As the radiation-curable pressure-sensitive adhesive, a pressure-sensitive adhesive that is cured by ultraviolet rays, an electron beam, or the like and easily peels at the time of peeling can be used. Moreover, as a heat foaming type adhesive, the adhesive which becomes easy to peel with a foaming agent or an expansion agent by heating can be used. Furthermore, the adhesive may be an adhesive that can be used for dicing and dyne bonding. As the radiation curable adhesive, for example, those described in JP-B-1-56112, JP-A-7-135189 and the like are preferably used, but are not limited thereto. In the present invention, it is preferable to use an ultraviolet curable adhesive. In that case, it is only necessary to have a property of being cured by radiation to form a three-dimensional network. For example, at least two photopolymerizations in a molecule relative to a normal rubber-based or acrylic pressure-sensitive base resin (polymer). A compound comprising a low molecular weight compound having a reactive carbon-carbon double bond (hereinafter referred to as a photopolymerizable compound) and a photopolymerization initiator is used.

  The above rubber-based or acrylic base resins are natural rubber, rubber polymers such as various synthetic rubbers, or poly (meth) acrylic acid alkyl esters, (meth) acrylic acid alkyl esters, (meth) acrylic acid alkyl esters. And an acrylic polymer such as a copolymer of the above and other unsaturated monomer copolymerizable therewith.

  Moreover, an initial stage adhesive force can be set to arbitrary values by mixing an isocyanate type hardening | curing agent in said adhesive. Specific examples of such curing agents include polyvalent isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, and diphenylmethane. -4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, Lysine isocyanate and the like are used.

In the case of an ultraviolet curable pressure-sensitive adhesive, by mixing a photopolymerization initiator in the pressure-sensitive adhesive, it is possible to reduce the polymerization curing time and the amount of ultraviolet irradiation by ultraviolet irradiation.
Specific examples of such a photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloranthraquinone and the like can be mentioned.

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 million or less, more preferably 1.5 million or less, further preferably 1 million or less, and particularly preferably 800,000 or less.
In this invention, 100,000-2 million is mentioned as a preferable range, for example, 250,000-2 million is mentioned as a more preferable range. If another range example is shown, the range of 200,000 to 1.5 million is also mentioned, for example.
The weight average molecular weight is obtained by standard polystyrene conversion by gel permeation chromatography (GPC).

  Although the thickness in particular of an adhesive layer is not restrict | limited, Preferably it is 4-30 micrometers, Most preferably, it is 5-25 micrometers.

<Loss coefficient of adhesive sheet for semiconductor processing>
Using a test piece obtained by processing a semiconductor processing pressure-sensitive adhesive sheet to a width of 5 mm, a loss factor (tan δ) measured in a film form by a dynamic viscoelasticity measuring device in a method based on JISK7244 has a frequency of 0.01 to 10 Hz. Sometimes it is 0.08 or more and less than 0.15.
In the present invention, the loss factor (tan δ) is preferably 0.1 to 0.13.
The loss coefficient (tan δ) is expressed by tan δ = loss elastic modulus E ″ / storage elastic modulus E ′, and the larger the number, the softer the material.

  When the loss factor (tan δ) is less than 0.08, the risk of package fly increases. When the loss coefficient (tan δ) is 39 or more, the risk of chips remaining on the semiconductor processing pressure-sensitive adhesive sheet by the scraping pickup increases.

The loss factor can be measured with a dynamic viscoelasticity measuring apparatus (for example, Rhegel-E4000 manufactured by UBM).
In the present invention, a test piece having a width of 5 mm and a length of 10 mm is cut out from a pressure-sensitive adhesive sheet for semiconductor processing, and the test piece is fixed to a dynamic viscoelasticity measuring apparatus with a supporting jig, at a temperature of 23 ° C. and a frequency of 0.01 to 10 Hz. It is the value obtained by measuring with.

  In order to make the loss coefficient within the above range, it can be adjusted by the types and blending amounts of the base resin, the styrene block copolymer and the pressure-sensitive adhesive.

  A semiconductor wafer is bonded to the semiconductor processing pressure-sensitive adhesive sheet of the present invention, and the wafer can be diced and picked up as shown in FIGS. In the semiconductor wafer processing method using the adhesive sheet for semiconductor processing according to the present invention, not cutting the base film reduces the cutting resistance of the dicing blade, smoothes the semiconductor wafer cutting, and reduces chipping. Therefore, it is preferable. In order to prevent the cutting from reaching the base film, for example, the setting of the cutting depth of the dicing apparatus 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 conventionally used bare wafers.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to this.

<Manufacture of base film>
1) Base 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 Industries, Ltd. Manufactured] was mixed at a blending ratio shown in Table 1 below, and processed by film extrusion at about 200 ° C. with a biaxial kneader to produce a substrate film A having a thickness of 150 μm.

2) Base film B
Styrene-isoprene-styrene copolymer (SIS) [trade name: HIBLER 5127, manufactured by Kuraray Co., Ltd.] and homopropylene (PP) [trade name: J-105G, manufactured by Ube Industries, Ltd.] The mixture was mixed at a blending ratio shown in FIG. 1 and processed by film extrusion at about 200 ° C. with a twin-screw kneader to produce a substrate film B having a thickness of 150 μm.

3) Base 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.] It mixed by the compounding ratio shown in following Table 1, and it processed by the film extrusion molding at about 200 degreeC with the biaxial kneader, and manufactured the base film C with a thickness of 150 micrometers.

4) Base film D
Tylene-hydrogenated isoprene / butadiene-styrene copolymer (SEEPS) [trade name: Septon Septon 4033, manufactured by Kuraray Co., Ltd.] and homopropylene (PP) [trade name: J-105G, Ube Industries, Ltd. Manufactured] was mixed at a blending ratio shown in Table 1 below, and processed by film extrusion at about 200 ° C. with a twin-screw kneader to produce a substrate film D having a thickness of 150 μm.

<Preparation of adhesive>
Polyisocyanate compound [trade name: Coronate] on 100 parts by mass of acrylic base polymer (copolymer comprising 2-ethylhexyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, mass average molecular weight 400,000, glass transition temperature: -35 ° C.) L, manufactured by Nippon Polyurethane Industry Co., Ltd.] 3 parts by mass, 50 parts by mass of tetramethylolmethane tetraacrylate as a compound having a photopolymerizable carbon-carbon double bond, and 1 part by mass of α-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator Part was added and mixed.

Examples 1 to 3 and Comparative Example 1
On one surface of the base film A, the pressure-sensitive adhesive is coated to a thickness of 20 μm to form a pressure-sensitive adhesive layer, and the respective semiconductor processing pressure-sensitive adhesive sheets of Examples 1 to 3 and Comparative Example 1 are manufactured. did.

Example 4
A pressure-sensitive adhesive sheet for semiconductor processing was produced in the same manner as in Example 1 except that the base film B was used.

Example 5
A pressure-sensitive adhesive sheet for semiconductor processing was produced in the same manner as in Example 1 except that the base film C was used.

Example 6
A pressure-sensitive adhesive sheet for semiconductor processing was produced in the same manner as in Example 1 except that the base film D was used.

  The loss factor (tan δ), package fly, and pickup success rate were evaluated for each of these semiconductor processing adhesive sheets as follows.

(Loss factor)
A test piece having a width of 5 mm and a length of 10 mm was cut out from the adhesive sheet for semiconductor processing.
The test piece was fixed to a dynamic viscoelasticity measuring apparatus (UBE Co., Rheogel-E4000) with a supporting jig by a method based on JISK7244, and measured at a temperature of 23 ° C. and a frequency of 0.01 to 10 Hz. A loss coefficient (tan δ = loss elastic modulus E ″ / storage elastic modulus E ′) within this frequency range was obtained.

(Package fly)
A QFN package (60 mm × 150 mm, thickness 0.95 mm) was bonded to each semiconductor processing adhesive sheet. Dicing was performed with a dicer (DFD6340 manufactured by DISCO Corporation) at a blade rotation speed of 20000 rpm, a cutting speed of 30 mm / min, and a cutting depth of 60 μm into the pressure-sensitive adhesive sheet so as to obtain a chip size of 1 mm × 1 mm.
After dicing, the following evaluation criteria were used for evaluation.

Evaluation criteria ○: All chips remain on the adhesive sheet for semiconductor processing ×: One or more chips flew

(Pickup success rate)
Evaluation was performed by the following scrubbing method.
After dicing, ultraviolet irradiation (200 mJ / cm ² ) was performed, the back surface of the semiconductor processing adhesive sheet was rubbed with tweezers, and the chip was dropped.

The obtained results are summarized in Table 1 below.
In the table, a blank means unused.

From Table 1 above, each of the adhesive sheets for semiconductor processing of Examples 1 to 6 has a loss coefficient value of 0.08 or more and less than 0.15, and no package fly is generated, and the pick-up is also scraped off. It was good.
In contrast, the semiconductor processing pressure-sensitive adhesive sheet of Comparative Example 1 had a large amount of elastomer component and a high loss factor. As a result, package fly did not occur. Since all packages did not stand up even if the board was bent, chips that could not be scraped off remained on the adhesive sheet for semiconductor processing.
On the other hand, the pressure-sensitive adhesive sheet for semiconductor processing of Comparative Example 2 had a small elastomer component and a low loss factor. As a result, the pressure-sensitive adhesive sheet for semiconductor processing could not absorb the vibration during dicing, and package fly occurred.

  While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

  This application claims the priority based on Japanese Patent Application No. 2006-073263 for which it applied for a patent in Japan on March 31, 2016, and this is referred to here for the contents of this specification. Capture as part.

DESCRIPTION OF SYMBOLS 1 Base film 2 Adhesive layer 11 Holder 12 Adhesive sheet for semiconductor processing 13 Semiconductor wafer 14 Semiconductor chip 15 Solid arrow direction 16 Expander 17 Dotted arrow direction

Claims (5)

A pressure-sensitive adhesive sheet for semiconductor processing having a pressure-sensitive adhesive layer on a base film,
Using a test piece obtained by processing the pressure-sensitive adhesive sheet for semiconductor processing to a width of 5 mm, a loss factor measured in a film shape by a dynamic viscoelasticity measuring apparatus is 0.08 or more and less than 0.15 when the frequency is 0.01 to 10 Hz. And
The base film is a single layer, and includes 5 to 39 parts by mass of a styrenic block copolymer with respect to 100 parts by mass of the base resin.
The styrenic block copolymer is 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 selected from styrene block copolymers;
The base resin is polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene / propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer vulcanizate, polybutene, polybutadiene, poly Methylpentene, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid methyl copolymer, ethylene- (meth) acrylic acid ethyl copolymer, polyvinyl chloride, Vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamide, ionomer, nitrile rubber, butyl rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber and its water additives or modifications Selected from things Adhesive sheet for semiconductor processing, wherein the at least one resin.   The adhesive sheet for semiconductor processing according to claim 1, wherein the base resin is polypropylene.   The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1 or 2, wherein the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive.   The pressure-sensitive adhesive sheet for semiconductor processing according to any one of claims 1 to 3, wherein the styrenic block copolymer is 10 to 35 parts by mass with respect to 100 parts by mass of the base resin.   It is used for the dicing of a semiconductor package, The adhesive sheet for semiconductor processing of any one of Claims 1-4 characterized by the above-mentioned.

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