KR102355077B1 - Adhesive sheet for semiconductor processing - Google Patents

Abstract

It has a pressure-sensitive adhesive layer on the base film, the loss coefficient at a frequency of 0.01 to 10 Hz is 0.08 or more and less than 0.15, the base film is one layer, and contains 5 to 39 parts by mass of a styrenic block copolymer with respect to 100 parts by mass of the base resin and the styrenic block copolymer is a styrene-hydrogenated isoprene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-hydrogenated butadiene-styrene block copolymer, and a styrene-hydrogenated isoprene/butadiene-styrene block It is at least 1 type of resin chosen from copolymer, The adhesive sheet for semiconductor processing whose base resin is at least 1 type of resin chosen from specific resins, such as polypropylene and polyethylene.

Description

Adhesive sheet for semiconductor processing

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

More specifically, it relates to an adhesive tape for dicing suitable for fixing and holding a semiconductor wafer when dicing a semiconductor wafer into chips and the like, and an adhesive tape for dicing used for processing a semiconductor package. In particular, it relates to an adhesive tape for dicing suitable for processing a high-density packaging semiconductor package.

The adhesive tape for dicing protects and fixes a wafer during a dicing process of separating a semiconductor wafer on which a circuit pattern is formed into a chip shape. A semiconductor wafer is diced by a rotating blade called a dicing blade after being fixed to an adhesive tape, and becomes a semiconductor chip separated into chip shape. The semiconductor chip is held by the adhesive tape until the pick-up process.

After that, a plurality of semiconductor chips are collectively molded with resin, and individually separated to form individual semiconductor packages, the semiconductor chips are pasted and fixed to a dicing tape, and dicing is performed with a rotating blade called a dicing blade. do Thus, in the dicing process of the package sealed with resin, the load at the time of cutting is large, and while the package resin contains a mold release agent, the resin surface also has a structure which has minute unevenness|corrugation. For this reason, the adhesive used for the tape for semiconductor processing can hold the package firmly, and the flexible adhesive so that a problem such as scattering (hereinafter referred to as "package fly") does not occur without holding the package at the time of dicing. is being used

However, by using such a flexible adhesive, the adhesive adhesion to the package side by dicing and the problem that the laser mark stamped on the package peels has arisen.

In order to reduce such a package fly, examination is performed conventionally.

For example, an adhesive tape using (meth)alkyl acid ester for the pressure-sensitive adhesive layer has been proposed (see Patent Document 1).

However, with the further miniaturization of the package in recent years, the area in which the package is held by the adhesive tape becomes smaller, and the package fly is more likely to occur. For this reason, only improving an adhesive was insufficient for suppressing a package fly.

Moreover, in order to suppress the vibration of a semiconductor wafer, suppressing the chipping at the time of dicing by putting an elastomer in the base material surface of an adhesive sheet is proposed (refer patent document 2). Thus, by making not only an adhesive but the base material side flexible, since adhesiveness with a package can be improved, it is preferable. On the other hand, in the market, the size reduction of the package is progressing, and in the conventional pickup method by pushing up with a pin, the pickup takes a very long time. Therefore, the tape was bent by rubbing the back surface of the tape with tweezers or the like, and the package was peeled off at once (hereinafter referred to as rubbing) to perform pickup.

However, when an elastomer is put on the base surface of the pressure-sensitive adhesive sheet to make the base material flexible, since it is flexible, even if the tape is bent by rubbing it in reverse, a package does not occur, so there is a problem that the rubbing is difficult.

Japanese Laid-Open Patent Publication No. 2007-100064 Japanese Patent Application Laid-Open No. 2009-170886

The present invention is to solve the problems accompanying the prior art as described above, while reducing the occurrence of package plies that occur during dicing, and quickly and reliably It makes it a subject to provide the adhesive sheet for semiconductor processing which can peel.

As a result of earnest examination, the present inventors have studied in detail the content of the styrenic copolymer with respect to the base resin and the loss coefficient of the adhesive sheet. Found and came to the present invention.

That is, the said subject of this invention is solved by the following means.

[1] A pressure-sensitive adhesive sheet for semiconductor processing having a pressure-sensitive adhesive layer on a base film,

The loss coefficient measured in a film shape by a dynamic viscoelasticity measuring device using a test piece processed by processing the adhesive sheet for semiconductor processing to a width of 5 mm is 0.08 or more and less than 0.15 when the frequency is 0.01 to 10 Hz,

The base film is one layer, and contains 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 a styrene-hydrogenated isoprene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-hydrogenated butadiene-styrene block copolymer, and a styrene-hydrogenated isoprene/butadiene-styrene block copolymer. At least one resin selected from coalescing,

The base resin is polypropylene, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene/propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer vulcanized product, polybutene, polybutadiene, polymethylpentene, ethylene- Vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)methyl acrylate copolymer, ethylene-(meth)ethyl acrylate 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 at least one resin selected from hydrogenated substances or modified products thereof An adhesive sheet for semiconductor processing.

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

[3] The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive, the pressure-sensitive adhesive sheet for semiconductor processing according to [1] or [2].

[4] The pressure-sensitive adhesive sheet for semiconductor processing according to any one of [1] to [3], wherein the styrenic 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 dicing a semiconductor package.

In this invention, when calling an acryl type, a methacrylic type is also encompassed.

In addition, in order to make the acrylic system clearer, like the (meth)acrylic type, the parenthesis part of "(meth)" means that it may be present or not. Or in any case in which these are included.

Advantageous Effects of Invention According to the present invention, it is possible to provide an adhesive sheet for semiconductor processing that can be quickly and reliably peeled from the adhesive tape even after dicing by pick-up such as rubbing after dicing while reducing the occurrence of package plies generated during dicing. did it

The above and other characteristics and advantages of the present invention will become more apparent from the following description with reference to the accompanying drawings as appropriate.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows one Embodiment of the adhesive sheet for semiconductor processing of this invention.
2 : is sectional drawing explaining the dicing process of a semiconductor wafer, and a pick-up process.
3 : is sectional drawing explaining the dicing process of a semiconductor wafer, and a pick-up process.
4 : is sectional drawing explaining the dicing process and a pick-up process of a semiconductor wafer.
5 : is sectional drawing explaining the dicing process of a semiconductor wafer, and a pick-up process.

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

《Adhesive sheet for semiconductor processing》

The adhesive sheet 12 for a semiconductor process 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, the base film will be sequentially described.

<base film>

In the present invention, the base film is not a laminate 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 base film is not a single resin, but a base resin and at least a styrenic block copolymer.

(Styrenic block copolymer)

A styrenic block copolymer is an elastomer, and is also called a styrenic thermoplastic elastomer or a styrenic elastomer.

The styrenic block copolymer is preferably a styrene block copolymer composed of a hard segment polystyrene and a soft segment, and as the soft segment, for example, polybutadiene, polyisobutylene, polyisoprene, hydrogenated polybutadiene (that is, ethylene/propylene), hydrogenated polyisobutylene (ie, ethylene/butylene), hydrogenated isoprene/butadiene (ie, ethylene-ethylene/propylene), butadiene rubber, and epoxidized polybutadiene.

By using a styrenic block copolymer, a base film becomes flexible and adhesiveness with a semiconductor package becomes high. In addition, it is possible to easily expand.

Among them, in the present invention, styrene-hydrogenated isoprene-styrene block copolymer (SEPS), styrene-isoprene-styrene copolymer (SIS), styrene-hydrogenated butadiene-styrene copolymer (SEBS) and styrene-hydrogenated isoprene At least one kind of resin selected from /butadiene-styrene copolymer (SEEPS) is used.

Here, in the styrenic block copolymer, "-" means connecting by a block unit (one block), and "/" means one repeating unit, which means that it becomes a block unit (one block). do.

A styrenic block copolymer may use two or more types together, and it is not cared about.

A styrenic block copolymer is used with a base resin, and although 5-39 mass parts is contained with respect to 100 mass parts of base resins in this invention, 10-35 mass parts is preferable.

When content of a styrenic block copolymer is less than 5 mass parts, a base film becomes rigid and it becomes impossible to improve adhesiveness with a semiconductor package. Conversely, when it exceeds 39 mass parts, even if it bends the adhesive sheet for a semiconductor process by rubbing, since a package does not arise, it is difficult to rub off.

(Base resin)

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

The base resin is preferably a thermoplastic resin, more preferably a base film having excellent water resistance and heat resistance, and particularly preferably a synthetic resin film.

Examples of the thermoplastic resin include polyolefin resins, polyamide resins, polyetheramide resins, thermoplastic polyimide resins, thermoplastic polyamideimide resins, polyurethane resins, urea resins, polyester resins, liquid crystal polyester resins, polyacetal resins, and polycarbonate resins. , 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. are mentioned.

Among the thermoplastic resins, polyolefin resins are particularly preferable.

In addition, the thermoplastic resin may be modified|denatured, such as acid modification, and it does not matter whether it is crystalline or non-crystalline.

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 vulcanized product, polybutene, polybutadiene, polymethylpentene, Ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)methyl acrylate copolymer, ethylene-(meth)acrylate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene- At least one resin selected from vinyl chloride-vinyl acetate copolymer, polystyrene, polyurethane, polyamide, ionomer, nitrile rubber, butyl rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber, and hydrogenated substances or modified products thereof use.

(polyolefin resin)

Polyolefin resin is a polyolefin resin formed by superposing|polymerizing at least 1 type of olefin, and a homopolymer or a copolymer may be sufficient as it.

Examples of the olefin include ethylene, propylene, isobutylene, α-olefin having 4 to 12 carbon atoms including isobutene (1-butene), butadiene, isoprene, (meth)acrylic acid ester, (meth) Acrylic acid, (meth)acrylamide, vinyl alcohol, vinyl acetate, vinyl chloride, styrene, acrylonitrile, etc. are mentioned.

On the other hand, 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, and 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-nonene, 1-decene, 1-undecene, 1-dodecene, etc. are mentioned.

Examples of the polyolefin resin include polyethylene resin, polypropylene resin, polyisobutylene resin, polyisobutene resin, polyisoprene resin, polybutadiene resin, (meth)acrylic resin (so-called allyl resin), polyvinyl chloride resin, etc. of vinyl resin, poly(meth)acrylamide resin, polystyrene resin, acrylonitrile/butadiene/styrene copolymer resin (ABS resin), ethylene/(meth)acrylic acid ester copolymer, ethylene/vinyl acetate copolymer, etc. are mentioned. .

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

On the other hand, when classified by density or shape, any of high-density polyethylene (HDPE), low-density polyethylene (LDPE), ultra-low-density polyethylene (VLDPE), linear low-density polyethylene (LLDPE), and ultra-high molecular weight polyethylene (UHMW-PE) none.

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 (a propylene homopolymer component or a copolymer mainly composed of propylene). It consists of a copolymer obtained by copolymerizing propylene with at least 1 sort(s) of a monomer chosen from a coalescing component and ethylene and alpha-olefin) etc. are mentioned. These polypropylene resins may be used independently or may use 2 or more types together.

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

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 propyleneethylene-α-olefin copolymer include a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, and a propylene-ethylene-1-octene copolymer.

As the propylene block copolymer, for example, (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, (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, etc. are mentioned.

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

Crystallinity of polypropylene resin can be calculated|required by melting temperature (melting point) or stereoregularity, and it adjusts according to the quality requested|required of the polyolefin resin composition of this invention, and the quality requested|required of the molded article obtained by shape|molding it.

On the other hand, stereoregularity is called an isotactic index and a syndiotactic index.

The isotactic index can be obtained by ¹³ C-NMR method described in Macromolecules, vol. 8, page 687 (1975). Specifically, the isotactic index of the polypropylene resin is obtained as the area fraction of the mmmm peak among the total absorption peaks in the carbon region of the methyl group in the ^{13 C-NMR spectrum.}

A thing with a high isotactic index has high crystallinity, 0.96 or more are preferable, 0.97 or more are more preferable, and 0.98 or more are still more preferable.

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

As the vinyl resin, for example, a vinyl chloride resin [homopolymer of a vinyl chloride monomer (polyvinyl chloride resin, etc.), a copolymer of a vinyl chloride monomer and another monomer (vinyl chloride-vinyl acetate copolymer, vinyl chloride- (meth ) acrylic acid ester copolymer, etc.), vinyl alcohol resin (homopolymer such as polyvinyl alcohol, copolymer such as ethylene-vinyl alcohol copolymer, etc.), polyvinyl acetal resin such as polyvinyl formal . These vinyl resins can be used individually or in combination of 2 or more types.

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

In addition, in this invention, melt flow rate (MFR) is the mass (g/10min) of polymer flowing out per 10 minutes under 190 degreeC and 2.16 kg load, based on JIS K7210.

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

In order to improve adhesiveness, you may corona-treat on the surface which contact|connects the adhesive layer of a base film, or you may form other layers, such as a primer.

Although the thickness in particular of a base film is not restrict|limited, 30-300 micrometers is preferable, 30-200 micrometers is more preferable, 50-150 micrometers is still more preferable.

Moreover, in this invention, it is also preferable that it exceeds 100 micrometers, In this case, more than 100 micrometers and 300 micrometers or less are preferable, 110-300 micrometers is more preferable, 110-250 micrometers is still more preferable, 110-200 micrometers μm is particularly preferred.

<Adhesive, adhesive layer>

The pressure-sensitive adhesive layer can be formed by conventionally known various pressure-sensitive adhesives. Although it does not specifically limit as such an adhesive, For example, the adhesive which used rubber type, acrylic type, silicone type, polyvinyl ether type, etc. as a base polymer is used.

In this invention, an acrylic adhesive is preferable.

A crosslinking agent may be blended in order to add cohesive force to these base polymers.

As a crosslinking agent, it respond|corresponds to a base polymer, For example, an isocyanate type crosslinking agent, an epoxy type crosslinking agent, a metal chelate type crosslinking agent, an aziridine type crosslinking agent, an amine resin, etc. are mentioned. In addition, the pressure-sensitive adhesive may contain various additional components, if necessary, within a range that does not impair the object of the present invention.

Moreover, a radiation-curing type or heat foaming type adhesive can also be used.

As the radiation-curing pressure-sensitive adhesive, an adhesive that is cured with ultraviolet rays, electron beams, or the like and is easily peeled off can be used. Moreover, as a heat-foaming type adhesive, the adhesive which becomes easy to peel with a foaming agent or an expanding agent by heating can be used. Moreover, as an adhesive, the adhesive agent which can use both dicing and die-bonding may be sufficient. As the radiation-curable pressure-sensitive adhesive, for example, those described in Japanese Patent Application Laid-Open No. Hei 1-56112 and Japanese Unexamined Patent Application Laid-Open No. Hei 7-135189 are preferably used, but are not limited thereto. In this invention, it is preferable to use an ultraviolet curable adhesive. In that case, what is necessary is just to have the property of hardening by radiation to form a three-dimensional network, for example, at least two photopolymerizable carbons in a molecule|numerator with respect to an ordinary rubber-based or acrylic pressure-sensitive base resin (polymer). - A compound formed by blending a low molecular weight compound having a carbon double bond (hereinafter referred to as a photopolymerizable compound) and a photopolymerization initiator is used.

The above-mentioned rubber-based or acrylic-based base resin is a rubber-based polymer such as natural rubber or various synthetic rubbers, or poly(meth)acrylic acid alkyl ester, (meth)acrylic acid alkyl ester, (meth)acrylic acid alkyl ester and other unsaturated copolymerizable therewith. Acrylic polymers, such as a copolymer with a monomer, are used.

Moreover, the initial adhesive force can be set to arbitrary values by mixing an isocyanate type hardening|curing agent in said adhesive. Specific examples of the curing agent include polyhydric isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1, 3-xylylene diisocyanate, 1, 4-xylene diisocyanate, 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, etc. are used.

In the case of an ultraviolet curable adhesive, the polymerization hardening time and ultraviolet irradiation amount by ultraviolet irradiation can be decreased by mixing a photoinitiator in an adhesive.

Specific examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloro anthraquinone, and the like.

100,000 or more are preferable, as for the mass average molecular weight of the base polymer of an acrylic adhesive, 200,000 or more are more preferable, 250,000 or more are more preferable, 300,000 or more are especially preferable, and 400,000 or more are the most preferable. 2 million or less are preferable, as for the upper limit of a mass average molecular weight, 1.5 million or less are more preferable, 1 million or less are still more preferable, 800,000 or less are especially preferable.

In this invention, for example, 100,000-2 million can be mentioned as a preferable range, and 250,000-2 million can be mentioned as a more preferable range. If another example of a range is shown, the range of 200,000-1.5 million is also mentioned, for example.

The mass average molecular weight was obtained in terms of standard polystyrene by gel permeation chromatography (GPC).

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

<Loss factor of adhesive sheet for semiconductor processing>

A loss factor (tanδ) measured in a film shape by a dynamic viscoelasticity measuring device by a method based on JISK7244 using a test piece processed into a width of 5 mm of an adhesive sheet for semiconductor processing is 0.08 or more at a frequency of 0.01 to 10 Hz less than 0.15.

In the present invention, the loss coefficient (tan?) is preferably 0.1 to 0.13.

On the other hand, the loss modulus (tanδ) is expressed as tanδ=loss modulus E″/storage modulus E′, and the larger the number, the softer the material.

When the loss factor (tanδ) is less than 0.08, the risk of package ply increases, and when it is 39 or more, the risk that the chip remains on the adhesive sheet for semiconductor processing by scraping pickup increases.

The loss coefficient can be measured with a dynamic viscoelasticity measuring device (for example, Rheogel-E4000, manufactured by UBM).

In the present invention, a test piece having a width of 5 mm x a length of 10 mm is cut out from the pressure-sensitive adhesive sheet for semiconductor processing, the test piece is fixed to a dynamic viscoelasticity measuring device with a support jig, and the value obtained by measuring at a temperature of 23° C. and a frequency of 0.01 to 10 Hz to be.

In order to make a loss factor into the said range, it can adjust with the kind and compounding quantity of a base resin, a styrenic block copolymer, and an adhesive.

A semiconductor wafer is stuck to the adhesive sheet for semiconductor processing of this invention, and the dicing and pickup of the wafer shown in FIGS. 2-5 can be performed by a normal method. In the processing method of a semiconductor wafer using the adhesive sheet for semiconductor processing of this invention, since it reduces the cutting resistance of a dicing blade, makes semiconductor wafer cutting smooth, and reduces chipping, it is preferable not to cut to a base film. In order not to cut to a base film, what is necessary is just to change the setting of the cutting depth of the dicing apparatus to be used suitably according to a manual, for example.

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

Example

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

<Production of base film>

1) Base film A

Styrene-hydrogenated isoprene-styrene block copolymer (SEPS) [trade name: Sefton KF-2104, manufactured by KURARAY Corporation] and homopropylene (PP) [brand name: J-105g, Ubekosan ( Note) (manufactured by Ube Industries, Ltd.) was mixed at a compounding ratio shown in Table 1 below, and processed by film extrusion molding at about 200°C with a twin-screw kneader to prepare a base film A having a thickness of 150 µm.

2) Base film B

Styrene-isoprene-styrene copolymer (SIS) [trade name: Hybri 5127, manufactured by Kurare Co., Ltd.] and homopropylene (PP) [brand name: J-105 g, manufactured by Ubekosan Corporation] are shown in Table 1 below. It was mixed at the compounding ratio shown in, and it processed by film extrusion molding at about 200 degreeC with a twin-screw kneader, and the base film B with a thickness of 150 micrometers was manufactured.

3) Base film C

Styrene-hydrogenated butadiene-styrene copolymer (SEBS) [trade name: Sefton 8104, manufactured by Kurare Co., Ltd.] and homopropylene (PP) [brand name: J-105 g, manufactured by Ubekosan Corporation] were described below. It was mixed by the compounding ratio shown in Table 1, it processed by film extrusion molding at about 200 degreeC with a twin-screw kneader, and the 150-micrometer-thick base film C was manufactured.

4) base film D

Styrene hydrogenated isoprene/butadiene-styrene copolymer (SEEPS) [brand name: Sefton Sefton 4033, manufactured by Kuraray Corporation] and homopropylene (PP) [brand name: J-105 g, manufactured by Ubekosan Corporation] ] was mixed at the compounding ratio shown in Table 1 below, and processed by film extrusion molding at about 200°C with a twin-screw kneader to prepare a base film D having a thickness of 150 µm.

<Preparation of adhesive>

Polyisocyanate compound [brand name] 100 parts by mass of an acrylic base polymer (a copolymer composed of 2-ethylhexyl acrylate, methyl acrylate, and 2-hydroxyethyl acrylate, a mass average molecular weight of 400,000, glass transition temperature: -35°C) : Colonate L, Nippon Polyurethane Industry Co., Ltd. (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 1 mass part of (alpha)-hydroxycyclohexyl phenyl ketone was added as a photoinitiator, and it mixed, and obtained it.

Examples 1-3 and Comparative Example 1

On one surface of the said base film A, the said adhesive was coated to 20 micrometers in thickness, the adhesive layer was formed, and each adhesive sheet for a semiconductor process of Examples 1-3 and the comparative example 1 was manufactured.

Example 4

Except using the said base film B, it carried out similarly to Example 1, and manufactured the adhesive sheet for a semiconductor process.

Example 5

Except using the said base film C, it carried out similarly to Example 1, and manufactured the adhesive sheet for a semiconductor process.

Example 6

Except using the said base film D, it carried out similarly to Example 1, and manufactured the adhesive sheet for a semiconductor process.

About each of these adhesive sheets for a semiconductor process, it carried out as follows, and evaluated the loss coefficient (tan δ), the package fly, and the pick-up success rate.

(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.

By the method based on JISK7244, the test piece was fixed to the dynamic viscoelasticity measuring apparatus (The UBM company make, Rheogel-E4000) with the jig|tool for support, and it measured at the temperature of 23 degreeC, and the frequency of 0.01-10 Hz. A loss modulus (tan δ = loss modulus E"/ storage modulus E') within this frequency range was obtained.

(Package fly)

A QFN package (60 mm x 150 mm, thickness 0.95 mm) was stuck to each adhesive sheet for semiconductor processing. With a dicer (manufactured by DISCO Co., Ltd. DFD6340), dicing was carried out so as to have a chip size of 1 mm x 1 mm under the conditions of a blade rotation speed of 20000 rpm, a cutting speed of 30 mm/min, and a cutting amount of 60 µm with an adhesive sheet.

After dicing, the following evaluation criteria evaluated.

Evaluation standard

(circle): All the chips remain on the adhesive sheet for semiconductor processing.

x: One or more chips jumped out.

(pickup success rate)

It evaluated by the method by the following rubbing off.

After dicing, ultraviolet irradiation (200 mJ/cm<2>) was carried out, the back surface of the adhesive sheet for semiconductor processing was rubbed with tweezers, and the chip|tip was peeled off.

The obtained result is put together in following Table 1, and is shown.

In addition, in a table|surface, a blank means an unused thing.

[Table 1]

In Table 1, all of the pressure-sensitive adhesive sheets for semiconductor processing of Examples 1 to 6 have loss coefficient values of 0.08 or more and less than 0.15, and package ply does not occur in any of them, and also good rubbing pickup.

On the other hand, the pressure-sensitive adhesive sheet for semiconductor processing of Comparative Example 1 had many elastomer components, and as a result of a high loss factor value, package fly did not occur, but even if the adhesive sheet for semiconductor processing was bent at the time of scraping pickup, all Since the packaging did not occur, chips that were difficult to scrape off remained on the adhesive sheet for semiconductor processing.

On the other hand, in the adhesive sheet for semiconductor processing of Comparative Example 2, there were few elastomer components, and as a result, the loss factor became low. As a result, the adhesive sheet for semiconductor processing did not fully absorb the vibration at the time of dicing, but package fly|flying has generate|occur|produced.

Although the present invention has been described along with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified, and interpret it broadly without going against the spirit and scope of the invention as set forth in the appended claims. I think it is natural to be

This application claims the priority based on Japanese Patent Application No. 2016-073263 for which the patent application was carried out in Japan on March 31, 2016, which takes in the content as a part of description of this specification with reference here.

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 (6)

A pressure-sensitive adhesive sheet for semiconductor processing used in a semiconductor processing method including a pickup step of picking up by rubbing,
Having an adhesive layer on the base film,
The loss coefficient measured in a film shape by a dynamic viscoelasticity measuring device using a test piece processed by processing the adhesive sheet for semiconductor processing to a width of 5 mm is 0.08 or more and less than 0.15 when the frequency is 0.01 to 10 Hz,
The base film is one layer, and contains 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 a styrene-hydrogenated isoprene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-hydrogenated butadiene-styrene block copolymer, and a styrene-hydrogenated isoprene/butadiene-styrene block copolymer. At least one resin selected from coalescing,
The base resin is polypropylene, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene/propylene copolymer, propylene copolymer, ethylene-propylene-diene copolymer vulcanized product, polybutene, polybutadiene, polymethylpentene, ethylene-acetic acid Vinyl copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)methyl acrylate copolymer, ethylene-(meth)ethyl acrylate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl chloride- At least one resin selected from vinyl acetate copolymer, polystyrene, polyurethane, polyamide, ionomer, nitrile rubber, butyl rubber, styrene isoprene rubber, styrene butadiene rubber, natural rubber, and hydrogenated substances or modified products thereof Adhesive sheet for semiconductor processing to do. The method of claim 1,
The said base resin is polypropylene, The adhesive sheet for semiconductor processing characterized by the above-mentioned. 3. The method according to claim 1 or 2,
The adhesive which forms the said adhesive layer is an acrylic adhesive, The adhesive sheet for semiconductor processing characterized by the above-mentioned. 3. The method according to claim 1 or 2,
The said styrenic block copolymer is 10-35 mass parts with respect to 100 mass parts of base resin, The adhesive sheet for semiconductor processing characterized by the above-mentioned. 3. The method according to claim 1 or 2,
It is used for dicing of a semiconductor package, The adhesive sheet for semiconductor processing characterized by the above-mentioned. 3. The method according to claim 1 or 2,
The styrenic block copolymer is 5 to 25 parts by mass based on 100 parts by mass of the base resin,
Said loss factor is 0.08 or more and 0.13 or less, The adhesive sheet for semiconductor processing characterized by the above-mentioned.

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