JP2002235055A - Dicing pressure-sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dicing pressure-sensitive adhesive sheet using a polyvinyl chloride film as a substrate film, having a good yield of a material to be cut such as a semiconductor wafer and further good adhesion of an adhesive mass layer to the polyvinyl chloride film and capable of ensuring a sufficient chip element interval in an expanding step without causing peeling of the adhesive mass layer from the substrate film during dicing, pickup, or the like. SOLUTION: This dicing pressure-sensitive adhesive sheet is characterized in that the substrate film is the polyvinyl chloride film, the thickness of a primer layer is 0.5-10 μm and the storage modulus of the adhesive mass layer at 0-10 deg.C is within the range of 3×105 to 1×109 N/m2 in the dicing pressure-sensitive adhesive sheet provided with the adhesive mass layer through the primer layer on the substrate film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure-sensitive adhesive sheet for dicing. The pressure-sensitive adhesive sheet for dicing of the present invention,
When dicing various substrates such as semiconductor wafers into patterns one by one and dividing them into semiconductor elements, and further dividing the semiconductor elements into various semiconductor packages including the semiconductor elements therein, the semiconductor wafers and the like are used. It is particularly useful as an adhesive sheet for dicing a semiconductor wafer used to fix an object to be cut. For example, the pressure-sensitive adhesive sheet for dicing of the present invention can be used as a pressure-sensitive adhesive sheet for silicon semiconductor dicing, a pressure-sensitive adhesive sheet for compound semiconductor wafer dicing, a pressure-sensitive adhesive sheet for semiconductor package dicing, a pressure-sensitive adhesive sheet for glass dicing, and the like.

[0002]

2. Description of the Related Art A semiconductor wafer on which a predetermined circuit pattern such as an IC is formed is polished on the back surface to a thickness of, for example, 0.1.
After the thickness is reduced to about 0.4 mm as much as possible, the wafer is diced to a predetermined chip size by a rotating blade such as a method of rotating a blade in which metal particles are dispersed, and the process is further moved to a mounting process. At this time, a dicing step, a cleaning step, an expanding step, a pickup step, and a mounting step are performed while the semiconductor wafer is attached and held on the adhesive sheet.

As the dicing pressure-sensitive adhesive sheet, a sheet obtained by applying an acrylic pressure-sensitive adhesive or the like on a base material made of a plastic film is generally used. Various types of plastic films are used. For example, a polyvinyl chloride film has been awarded. In a polyvinyl chloride-based film, a sufficient chip element interval can be obtained in an expanding step of stretching an adhesive sheet as compared with a polyolefin-based film.

In the dicing process, the semiconductor wafer is cut by a circular blade that moves while rotating. At this time, the semiconductor wafer is cut to a part (about 5 to 20 μm) of the thickness of the dicing adhesive sheet for holding the semiconductor wafer. A cutting method called full cutting for cutting is becoming mainstream. However, in recent years, thinning of the semiconductor wafer and metal processing on the wafer surface have been frequently used. When cutting the semiconductor wafer by full cutting, a conventional acrylic adhesive or the like is used as an adhesive sheet for dicing. In the case of using an adhesive sheet as an agent layer, the application of the cut side to the back side (several μm to several mm) is a problem, which causes a decrease in the yield of semiconductor wafers.

Therefore, Japanese Patent Application Laid-Open No. H10-242086 proposes to use a pressure-sensitive adhesive sheet having a specific storage elastic modulus as a pressure-sensitive adhesive layer as a dicing pressure-sensitive adhesive sheet capable of reducing chipping. JP-A-10-24
According to Japanese Patent No. 2086, it is possible to improve the problem of chipping and to reduce the yield of semiconductor wafers. But,
The pressure-sensitive adhesive layer having a specific storage modulus described in JP-A-10-242086 has a higher storage modulus than a commonly used pressure-sensitive adhesive layer, and thus has poor adhesion to a polyvinyl chloride film. When a polyvinyl chloride-based film is also used as the base film, there is a problem that the adhesive is peeled off from the base film (polyvinyl chloride film) during dicing. In particular, when picking up diced small chips, there is a problem that the adhesive layer falls off the base film and adheres to the small chips. In addition, although the above-mentioned problem regarding adhesion can be avoided by using a polyolefin-based film or the like surface-modified by corona treatment or the like as a base film, a polyolefin-based film or the like has a sufficient chip in the expanding step of stretching the pressure-sensitive adhesive sheet as described above. There is a problem that the element spacing cannot be obtained.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an adhesive sheet for dicing using a polyvinyl chloride film as a base film, which has a good yield of an object to be cut such as a semiconductor wafer and has an adhesive layer and a polyvinyl chloride. To provide an adhesive film having good adhesion to a base film, not causing peeling of an adhesive layer from a base film at the time of dicing, pick-up, etc., and ensuring a sufficient chip element interval in an expanding step. Aim.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the dicing pressure-sensitive adhesive sheet shown below, and have completed the present invention. Was.

[0008] That is, the present invention provides a method for printing on a base film.
For dicing with pressure-sensitive adhesive layer provided through a rimer layer
In the adhesive sheet, the base film is made of polyvinyl chloride
System film, the thickness of the primer layer is 0.5 μm
-10 μm, and storage of the pressure-sensitive adhesive layer at 0-10 ° C.
The elastic modulus is 3 × 10^Five ~ 1 × 10⁹ N / m ^Two In the range
Pressure-sensitive adhesive sheet for dicing,
You.

In the pressure-sensitive adhesive sheet for dicing of the present invention, the pressure-sensitive adhesive layer has a storage elastic modulus at 0 to 10 ° C. of 3 × 10 ⁵ to
Since it is in the range of 1 × 10 ⁹ N / m ² , chipping of the cut surface during dicing can be prevented, and the chip yield is good. The pressure-sensitive adhesive layer is preferably such that the storage elastic modulus is higher from the viewpoint of preventing chipping of the chip cut surface, and the storage elastic modulus of the pressure-sensitive adhesive layer is higher from the viewpoint of prevention of chipping of chip cutting surface and compatibility with fixed holding of the wafer. 4 × 10 ⁵ N / m ² or more, especially 1
It is preferably from × 10 ⁶ to 1 × 10 ⁹ N / m ² . The lower the storage elastic modulus at 20 ° C. or higher is, the more preferable it is from the viewpoint of fixing and holding the wafer such as adhesive strength. The storage modulus at 20 ° C. or more is 3 × 10 N / m ² or less, particularly 1 × 10 ^{5 to} 3 ×.
Those having 10 ⁵ N / m ² are preferred.

In the pressure-sensitive adhesive sheet for dicing of the present invention, a polyvinyl chloride film is used as a substrate film, but the pressure-sensitive adhesive layer is laminated on the substrate film via a primer layer. It improves the adhesion between the film and the pressure-sensitive adhesive layer. Therefore, the adhesive does not fall off from the base film at the time of dicing or pick-up. Moreover, the thickness of the primer layer is 0.5 μm to 10 μm
Is adjusted to the range. In the present invention, by using a polyvinyl chloride-based film as the base film, sufficient expandability of the chip element interval can be realized in the expanding step of stretching the pressure-sensitive adhesive sheet, but the primer layer generally has a cut portion of the pressure-sensitive adhesive sheet. The thickness of the primer layer is set to 10 μm or less, because when the thickness increases, the expandability of the pressure-sensitive adhesive sheet decreases, since the amount of deformation during dicing is reduced. are doing. The thickness of the primer layer is preferably 5 μm or less. When the thickness of the primer layer is larger than 10 μm, the expandability (width of the chip interval) is reduced by 20%. On the other hand, the thickness of the primer layer is 0.5 μm or more in order to ensure adhesion between the base film and the pressure-sensitive adhesive layer. 1 μm
It is preferable to make the above.

In the holding sheet for dicing, the material for forming the primer layer preferably has a glass transition point of 20 ° C. or higher. As a material for forming the primer layer,
A glass transition point of 20 ° C. or higher, more preferably 20 to 120 ° C., which reduces the amount of deformation of the cut portion of the adhesive sheet and reduces the amount of deformation at the time of dicing, is preferred.

[0012] Further, in the holding sheet for dicing, it is preferable that a material for forming a primer layer contains an acrylic resin as a main component. As a material for forming the primer layer, an acrylic resin having good adhesion between the base film and the pressure-sensitive adhesive layer is preferably used. In particular, those having an amino group, an amine, an amide group or the like in the side chain are preferable in view of adhesion to a polyvinyl chloride film.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a dicing pressure-sensitive adhesive sheet of the present invention will be described in detail with reference to FIG. As shown in FIG. 1, in the pressure-sensitive adhesive sheet for dicing of the present invention, a pressure-sensitive adhesive layer 13 is provided on a base film (polyvinyl chloride film) 11 via a primer layer 12. Further, a separator 14 is provided on the pressure-sensitive adhesive layer 13 as necessary. In FIG. 1, an adhesive layer is provided on one side of the base film, but an adhesive layer may be formed on both sides of the base film. The dicing pressure-sensitive adhesive sheet may be wound into a tape to form a tape.

As the polyvinyl chloride film used as the base film 11, various kinds of conventionally known films can be used without particular limitation. For example, polyvinyl chloride containing a plasticizer is widely used as a flexible polyvinyl chloride film. In addition, as the polyvinyl chloride film, a vinyl chloride-vinylidene chloride copolymer resin containing a plasticizer, a vinyl chloride-vinyl acetate copolymer resin, a polyvinylidene chloride, and the like are preferably used. The thickness of the polyvinyl chloride film is usually 10 to
It is about 300 μm, preferably about 30 to 200 μm.

As a material for forming the primer layer 12, for example, a urethane (polyisocyanate) resin,
Examples include polyester resin, acrylic resin, polyamide resin, melamine resin, olefin resin, polystyrene resin, epoxy resin, phenol resin, isocyanurate resin, polyvinyl acetate resin, and the like. Further, the resin used for the primer layer is cross-linked and cured,
What has reactivity, such as superposition | polymerization and condensation, and expresses the said physical property by making it react may be sufficient. A crosslinking agent can be appropriately added for crosslinking and curing. Further, a functional additive such as an antistatic agent may be added to the undercoat layer to provide other functions. The material for forming these primer layers is a glass transition point of 20 ° C. or higher,
Those having a temperature of 20 ° C. are preferably used.

As a material for forming the primer layer, an acrylic resin is preferable. As the acrylic resin, for example, methyl methacrylate as a main component,
For this, a copolymer obtained by copolymerizing an alkyl (meth) acrylate other than methyl methacrylate or a copolymerizable monomer is used. In addition, (meth) acrylic acid ester means acrylic acid ester and / or methacrylic acid ester, and (meth) in the present invention has the same meaning.

Examples of the alkyl ester of the (meth) acrylic acid alkyl ester include methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, and s-ester.
Butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, Examples thereof include linear or branched alkyl esters having 1 to 30 carbon atoms, particularly 4 to 18 carbon atoms, of alkyl groups such as tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, and eicosyl ester. .

As the copolymerizable monomer, for example,
(Meth) acrylic acid, carboxyethyl acrylate,
Carboxypentyl acrylate, carboxyl group-containing monomers such as itaconic acid and maleic acid, fumaric acid and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; 2-hydroxyethyl (meth) acrylate and (meth) acrylic acid 2-hydroxypropyl acid, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8- (meth) acrylic acid
Hydroxyl group-containing monomers such as hydroxyoctyl, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) -methyl acrylate, and N-hydroxymethyl amide (meth) acrylate Sulfonic acids such as styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate and (meth) acryloyloxynaphthalenesulfonic acid; A group-containing monomer; a phosphoric group-containing monomer such as 2-hydroxyethyl acryloyl phosphate; dimethylaminoethyl methacrylate;
Amino group-containing monomers such as t-butylaminoethyl methacrylate; epoxy group-containing monomers such as glycidyl (meth) acrylate; and other (meth) acrylamide, vinyl acetate, styrene, and acrylonitrile. The amount of the alkyl (meth) acrylate or copolymerizable monomer to be copolymerized with the methyl methacrylate is preferably 50% by weight or less of the total monomer components.

The acrylic resin used as a material for forming the primer layer may be butyl glycidyl ether, phenyl glycidyl ether or nonylphenyl glycidyl when a carboxyl group-containing monomer or an acid anhydride monomer is used as the copolymerizable monomer. Modified with epoxy compounds such as ether, monomethylamine,
Amidated with a primary or secondary amine such as dimethylamine, monoethylamine and diethylamine can also be used. Further, a graft of polyethyleneimine can be obtained by grafting ethyleneimine or the like.

The primer layer can be formed by pressing a film made of the above-mentioned primer layer forming material onto the polyvinyl chloride film, applying a melt of the forming material and cooling the solution, or a solution of the forming material. Can be formed by a method of applying and drying. The coating method can be appropriately selected, but the thickness accuracy is 0.5 μm to 1 μm.
To adjust the thickness to 0 μm, gravure coating, reverse roll coating, spray coating and the like are preferably used.

As long as the pressure-sensitive adhesive layer 13 satisfies the above storage modulus, the pressure-sensitive adhesive is not limited at all. For example, various pressure-sensitive adhesives such as rubber, acrylic, silicone, and polyvinyl ether can be used. Is used. Above all, from the viewpoint of adhesiveness to semiconductor wafers, cleaning and cleaning properties of wafers after peeling with an appropriate organic solvent such as ultrapure water or alcohol, acrylic adhesives based on acrylic polymers, etc. Agents are preferred.

Examples of the acrylic polymer used in the pressure-sensitive adhesive layer include a polymer of an alkyl (meth) acrylate or a copolymer of an alkyl (meth) acrylate and a copolymerizable monomer. For example,
A polymer of an alkyl (meth) acrylate or a copolymer of an alkyl (meth) acrylate and a copolymerizable monomer is used.

Examples of the alkyl ester of the alkyl (meth) acrylate include, for example, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester and isobutyl ester. Pentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, tridecyl ester, tetradecyl ester, hexadecyl ester, C1-C1 alkyl groups such as octadecyl ester and eicosyl ester
30, particularly a linear or branched alkyl ester having 4 to 18 carbon atoms. One or more of these (meth) acrylic acid alkyl esters are used.

Examples of the copolymerizable monomer include (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, carboxyl group-containing monomers such as itaconic acid and maleic acid, fumaric acid and crotonic acid; and maleic anhydride and itaconic anhydride. Acid anhydride monomers such as acids; 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, (meth)
4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4- (Hydroxymethylcyclohexyl) -methyl acrylate, hydroxyl group-containing monomers such as (meth) acrylic acid N-hydroxymethylamide; styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) Acrylamide propane sulfonic acid, sulfopropyl (meth)
Sulfonic acid group-containing monomers such as acrylate and (meth) acryloyloxynaphthalene sulfonic acid; phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate; dimethylaminoethyl methacrylate;
Examples include amino group-containing monomers such as butylaminoethyl methacrylate; epoxy group-containing monomers such as glycidyl (meth) acrylate, and other (meth) acrylamide, vinyl acetate, styrene, and acrylonitrile. One or more of these copolymerizable monomers can be used. The use amount of these copolymerizable monomers is preferably 50% by weight or less of all monomer components. Further, the acrylic polymer may include a polyfunctional monomer or the like as a monomer component for copolymerization, if necessary, for crosslinking.

Further, the acrylic polymer may include a polyfunctional monomer or the like as a copolymerizable monomer, if necessary, for crosslinking. Such polyfunctional monomers include, for example, hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate
Acrylate, dipentaerythritol hexa (meth)
Examples include acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, and urethane (meth) acrylate. One or more of these polyfunctional monomers can be used. The amount of the polyfunctional monomer to be used is preferably 30% by weight or less of the total monomer components from the viewpoint of adhesive properties and the like.

The acrylic polymer is obtained by subjecting a single monomer or a mixture of two or more monomers to polymerization. The polymerization can be performed by any method such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization and the like. The acrylic polymer of the pressure-sensitive adhesive layer preferably has a low content of a low molecular weight substance from the viewpoint of preventing contamination of a semiconductor wafer or the like. In this respect, the number average molecular weight of the acrylic polymer is preferably 300,000 or more, and more preferably 400,000 to
It is about 3 million.

Further, a crosslinking agent may be appropriately added to the pressure-sensitive adhesive in order to increase the number average molecular weight of an acrylic polymer or the like as a base polymer. Specific examples of the crosslinking agent include vulcanizing agents such as polyisocyanate compounds, epoxy compounds, aziridine compounds, melamine compounds, metal salt compounds, metal chelate compounds, amino resin compounds, and peroxides. When a crosslinking agent is used, the amount of the crosslinking agent used is determined in consideration of the crosslinking density of the pressure-sensitive adhesive layer. Generally, it is preferable to add about 0.01 to 20 parts by weight to 100 parts by weight of the base polymer.

Further, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer includes:
If necessary, conventional additives such as conventionally known various tackifiers, antioxidants, fillers, antioxidants, and coloring agents can be contained.

The pressure-sensitive adhesive may be a radiation-curable pressure-sensitive adhesive or a heat-foamable pressure-sensitive adhesive which is cured by ultraviolet rays, electron beams or the like. Further, the pressure-sensitive adhesive may be a pressure-sensitive adhesive that can be used for both dicing and die bonding. In the present invention, it is preferable to use a radiation-curable pressure-sensitive adhesive, particularly an ultraviolet-curable pressure-sensitive adhesive. When a radiation-curable pressure-sensitive adhesive is used as the pressure-sensitive adhesive, radiation is applied to the pressure-sensitive adhesive layer before or after the dicing step, so that the base film and the primer layer have sufficient radiation permeability. preferable.

As the radiation-curable pressure-sensitive adhesive, any one having at least two radiation-curable functional groups such as a carbon-carbon double bond and exhibiting tackiness can be used without particular limitation. As the radiation-curable pressure-sensitive adhesive, for example, radiation obtained by mixing a radiation-curable monomer component or oligomer component having at least two radiation-curable functional groups such as a carbon-carbon double bond with the acrylic pressure-sensitive adhesive or the like A curable adhesive can be exemplified.

As the radiation-curable monomer component, for example, urethane oligomer, urethane (meth)
Acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythol monohydroxypenta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth)
Acrylate and the like. Examples of the radiation-curable oligomer component include various oligomers such as urethane, polyether, polyester, polycarbonate, and polybutadiene, and have a molecular weight of 100 to 30.
A range of about 000 is suitable.

The amount of the radiation-curable monomer component or oligomer component is, for example, 5 to 100 parts by weight of a base polymer such as an acrylic polymer constituting the pressure-sensitive adhesive.
500 parts by weight, preferably about 70 to 150 parts by weight.

Further, as the radiation-curable pressure-sensitive adhesive, a base polymer having at least two carbon-carbon double bonds in the side chain of the polymer or in the main chain or at the terminal of the main chain may be used. As such a base polymer, a polymer having an acrylic polymer as a basic skeleton is preferable. In this case, it is not necessary to add a radiation-curable monomer component or oligomer component, and the use thereof is optional.

The radiation-curable pressure-sensitive adhesive contains a photopolymerization initiator when it is cured by ultraviolet rays or the like.
Examples of the photopolymerization initiator include benzoin alkyl ethers such as benzoin methyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzyl, benzoin,
Aromatic ketones such as benzophenone and α-hydroxycyclohexyl phenyl ketone; aromatic ketals such as benzyl dimethyl ketal; polyvinyl benzophenone;
And thioxanthone such as chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone and diethylthioxanthone. The amount of the photopolymerization initiator is, for example, 15 parts by weight or less, based on 100 parts by weight of a base polymer such as an acrylic polymer constituting the pressure-sensitive adhesive.
Preferably it is about 0.1 to 10 parts by weight.

The storage elastic modulus of the pressure-sensitive adhesive layer is adjusted by, for example, adding a cross-linking agent so that the pressure-sensitive adhesive layer forms a cross-linked structure, or by using a radiation-curable monomer in the case of a radiation cross-linkable pressure-sensitive adhesive. It is carried out by appropriately adjusting the crosslinking density.

The adhesive strength of the pressure-sensitive adhesive layer is usually the adhesive strength at normal temperature (90 ° peel value, peeling speed 300 mm / min) to the silicon wafer from the viewpoint of the wafer fixing and holding power and the recoverability of formed chips. , 20 N / 20 mm or less, 0.001 to 10 N / 20 mm, especially 0.01 to 8 N
/ 20 mm is preferred.

The thickness of the pressure-sensitive adhesive layer 13 may be determined as appropriate. However, the thickness is preferably 1 to 50 μm, more preferably 2 to 30 μm, in order to prevent chipping of the chip cut surface and to maintain compatibility with fixed holding of the wafer.
m, particularly preferably 2 to 15 μm.

Further, the pressure-sensitive adhesive sheet may have an antistatic function for the purpose of preventing static electricity from being generated at the time of bonding or peeling, and the circuit being broken by the charging of the semiconductor wafer due to the static electricity. Addition of antistatic ability
It is performed in an appropriate manner by providing a support sheet or a conductive layer made of a charge transfer complex, a metal film, or the like. For example, a method in which impurity ions which may deteriorate the semiconductor wafer are hardly generated is preferable.

In the pressure-sensitive adhesive sheet for dicing of the present invention, for example, after a primer layer 12 is formed on the surface of a base film 11, a pressure-sensitive adhesive is further applied to the surface of the primer layer 12 and dried (as required). The pressure-sensitive adhesive layer 13 can be manufactured by forming a pressure-sensitive adhesive layer 13 and bonding a separator 14 to the surface of the pressure-sensitive adhesive layer 13 as necessary. In addition, after separately forming the pressure-sensitive adhesive layer 13 on the release liner 14, these are coated with the undercoat layer 1 on the base film 11.
2, a method of bonding together as shown in FIG. 1 or the like can be adopted. The pressure-sensitive adhesive sheet for dicing of the present invention can be used for the base film 1 even when the transfer coating method is employed.
1 and the pressure-sensitive adhesive layer 13 are favorable and advantageous.

The separator 14 is provided as necessary for label processing or for smoothing the adhesive before bonding to the semiconductor wafer in order to prevent contamination during storage or distribution. . Examples of a constituent material of the separator include paper, synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate. The surface of the separator may be subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, a fluorine treatment, or the like, as necessary, in order to enhance the releasability from the pressure-sensitive adhesive layer. Further, if necessary, an ultraviolet ray transmission preventing treatment or the like may be applied so that the adhesive sheet does not react with environmental ultraviolet rays. The thickness of the separator is usually 10 to
It is about 200 μm, preferably about 25 to 100 μm.

The pressure-sensitive adhesive sheet for dicing of the present invention is subjected to dicing according to a conventional method after being attached to a cut object such as a semiconductor component. In the dicing step, the blade is rotated at a high speed to cut the object to be cut into a predetermined size. For dicing, a cutting method called full-cut for cutting into the undercoat layer of the pressure-sensitive adhesive sheet and further to the inside of the substrate can be adopted. When a radiation-curable pressure-sensitive adhesive is used for the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is cured before or after dicing by radiation irradiation depending on the type of the pressure-sensitive adhesive to impart tackiness or reduce tackiness. Let it. By irradiation with radiation after dicing, the adhesiveness of the pressure-sensitive adhesive layer is reduced by curing, so that peeling can be facilitated. The means for irradiating the radiation is not particularly limited, but is performed by, for example, ultraviolet irradiation.

[0042]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In each example, parts are parts by weight.

Example 1 (Preparation of pressure-sensitive adhesive) An acrylic copolymer having a number average molecular weight of 800,000 obtained by copolymerizing 70 parts of methyl acrylate, 30 parts of butyl acrylate and 5 parts of acrylic acid in a conventional manner in toluene. In a solution containing a polymer, 100 parts of an acrylic copolymer was mixed with a urethane oligomer (trade name: UV-1700).
B, manufactured by Nippon Synthetic Chemical Co., Ltd.), 70 parts of a polyfunctional isocyanate compound (trade name "Coronate L", manufactured by Nippon Polyurethane) and 5 parts of a photopolymerization initiator (trade name: Irgacure 65)
1 ", Ciba Specialty Chemicals) (5 parts) to prepare an acrylic pressure-sensitive adhesive.

(Formation of Primer Layer) A grafted product of a methacrylic acid-methyl methacrylate copolymer and polyethyleneimine (glass transition point) was formed as a primer layer forming material on one side (glossy side) of a polyvinyl chloride film having a thickness of 70 μm. 40 ° C.) and heated at 100 ° C. for 2 minutes to prepare a film having a 1 μm-thick primer layer.

(Preparation of dicing pressure-sensitive adhesive sheet) The above pressure-sensitive adhesive was applied to a film having a primer layer,
The mixture was heated at a temperature of 3 ° C. for 3 minutes to obtain an adhesive sheet for dicing having an adhesive layer having a thickness of 15 μm. The storage elastic modulus of the pressure-sensitive adhesive layer is 1.99 × 10 ⁸ [N / m ² ] at 0 ° C.
At 73 ° C., it was 7.73 × 10 ⁶ [N / m ² ]. The storage elastic modulus was measured by a rheometric viscoelastic spectrometer (frequency: 1 Hz, sample thickness: 2 mm, compression load: 10
0 g) in the range of 0 ° C to 10 ° C.

Example 2 (Preparation of pressure-sensitive adhesive) An acrylic copolymer having a number average molecular weight of 600,000 obtained by copolymerizing 90 parts of butyl acrylate, 5 parts of acrylonitrile and 5 parts of acrylic acid in a conventional manner in toluene. Acrylic copolymer 100 in a solution containing
Parts, urethane oligomer (trade name UV-1700)
B, manufactured by Nippon Gosei Kagaku Co., Ltd.), 50 parts of a polyfunctional isocyanate compound (trade name: “Coronate L”, manufactured by Nippon Polyurethane) and a photopolymerization initiator (trade name: Irgacure 65)
1 ", Ciba Specialty Chemicals) (5 parts) to prepare an acrylic pressure-sensitive adhesive.

(Formation of Primer Layer) A copolymer of methyl methacrylate-aminoethyl methacrylate (glass transition point 100 ° C.) was used as a primer layer forming material on one side (gloss side) of a polyvinyl chloride film having a thickness of 70 μm. It was coated and heated at 110 ° C. for 2 minutes to prepare a film having a 0.5 μm thick primer layer.

(Preparation of pressure-sensitive adhesive sheet for dicing) The above pressure-sensitive adhesive was applied to a film having a primer layer.
C. for 3 minutes to form a 10 μm thick adhesive layer,
It was left under a high-pressure mercury lamp of 80 W / cm ² for 60 seconds to be treated with ultraviolet rays to obtain a pressure-sensitive adhesive sheet for dicing. The storage elastic modulus of the pressure-sensitive adhesive layer was 4.05 × 10 ^{6 at} 0 ° C.
[N / m ² ] at 10 ° C. 1.06 × 10 ⁶ [N / m ² ]
m ² ].

Example 3 (Preparation of adhesive) Acrylic copolymer having a number average molecular weight of 500,000 obtained by copolymerizing 90 parts of butyl acrylate, 5 parts of acrylonitrile and 5 parts of acrylic acid in a conventional manner. Acrylic copolymer 100 in a solution containing
Parts, 10 parts of a polyfunctional acrylic monomer (dipentaerythritol hexaacrylate), 5 parts of a polyfunctional isocyanate compound (trade name “Coronate L”, manufactured by Nippon Polyurethane) and a photopolymerization initiator (trade name “Irgacure 65”)
1 ", Ciba Specialty Chemicals) (5 parts) to prepare an acrylic pressure-sensitive adhesive.

(Formation of Primer Layer) On one side (gloss side) of a polyvinyl chloride film having a thickness of 70 μm, acrylic acid / butyl methacrylate /
Ethyl methacrylate / methyl methacrylate = 10/25
/ 25/40 (weight ratio) copolymer (glass transition point 28
° C) and heated at 110 ° C for 2 minutes to a thickness of 2.5 µm
A film having a primer layer was prepared.

(Preparation of dicing pressure-sensitive adhesive sheet) The above pressure-sensitive adhesive was applied to a film having a primer layer, and
C. for 3 minutes to form a 15 μm thick adhesive layer,
It was left under a high-pressure mercury lamp of 80 W / cm ² for 60 seconds to be treated with ultraviolet rays to obtain a pressure-sensitive adhesive sheet for dicing. The storage elastic modulus of the pressure-sensitive adhesive layer is 6.90 × 10 ^{5 at} 0 ° C.
[N / m ² ] 4.00 × 10 ⁵ [N / m ² ] at 10 ° C.
m ² ].

Comparative Example 1 An adhesive sheet for dicing was obtained in the same manner as in Example 1 except that the adhesive layer was formed without providing a primer layer on the polyvinyl chloride film.

Comparative Example 2 An adhesive sheet for dicing was obtained in the same manner as in Example 2, except that an adhesive layer was formed without providing a primer layer on the polyvinyl chloride film.

Comparative Example 3 An adhesive sheet for dicing was obtained in the same manner as in Example 2 except that the thickness of the primer layer was changed to 15 μm.

Comparative Example 4 (Preparation of Pressure-Sensitive Adhesive) A solution containing an acrylic copolymer having a number average molecular weight of 300,000, obtained by copolymerizing 90 parts of butyl acrylate and 10 parts of acrylic acid in a conventional manner in toluene. And 100 parts of an acrylic copolymer, 30 parts of a plasticizer (dioctyl phthalate) and a polyfunctional isocyanate compound (trade name "Coronate L", manufactured by Nippon Polyurethane)
5 parts and a photopolymerization initiator (trade name “Irgacure 651”,
3 parts (Ciba Specialty Chemicals) was added to prepare an acrylic pressure-sensitive adhesive.

(Preparation of pressure-sensitive adhesive sheet for dicing) The above pressure-sensitive adhesive was applied to one side (glossy surface) of a polyvinyl chloride film having a thickness of 70 μm on which no primer layer was formed.
The mixture was heated at 0 ° C. for 3 minutes to obtain an adhesive sheet for dicing having an adhesive layer having a thickness of 10 μm. The storage elastic modulus of the pressure-sensitive adhesive layer is 1.46 × 10 ⁵ [N / m ² ], 10
It was 1.02 × 10 ⁵ [N / m ² ] at ° C.

(Evaluation Test) The pressure-sensitive adhesive sheets for dicing obtained in Examples and Comparative Examples were subjected to the following tests. Table 1 shows the results.

[Evaluation of Dicing] A semiconductor wafer having a diameter of 4 inches on which a circuit pattern was formed was polished on the back surface to a thickness of 0.25 mm, and an adhesive sheet for dicing was adhered and fixed thereto. Dicing speed 80m / mi with Disco DFD-651)
n, dicing blade (2050HF, manufactured by Disco Corporation)
DD) 40,000 rpm. p. m. Full cut under the condition of cutting depth of adhesive sheet for dicing 30 μm, 1 mm
It was cut into a chip of × 1 mm. The surface of the pressure-sensitive adhesive layer of the cut pressure-sensitive adhesive sheet for dicing was observed, and the presence or absence of peeling of the pressure-sensitive adhesive was observed. Table 1 shows the number of locations where peeling occurred.

[Evaluation of Pickup Property] A 1 mm × 1 mm chip diced was placed in a die bonder (CPS-10).
0 (Nichiden Kikai)), needle thrust speed 10 mm /
When picked up in sec, the presence or absence of adhesion of the adhesive on the back surface of the chip was confirmed. In addition, Example 1, Comparative Example 1,
For 4, under a high pressure mercury lamp of 80 W / cm ²
The radiation-sensitive adhesive layer left for 2 seconds was cured, and then picked up. The glue adhesion occurrence rate was determined by (the number of adhesively attached chips / the total number of chips) × 100 (%).

[Expandability] Dicing ring: 2-6-1 (manufactured by Disco, inner diameter 1)
9.5 cm) Withdrawal amount: 10 mm Die bonder: Chip spacing was evaluated using CPS-100 (manufactured by NEC Machinery). A case of 80 μm or more was evaluated as ○.

[Yield] Observation of the back surface of the obtained chip was made, and it was judged that there was an adhering substance to be a defective product, and the other products were judged as non-defective products. (Number of non-defective chips / total number of chips) × 100 (%), The yield of non-defective products was examined.

[0062]

[Table 1] As shown in Table 1, in the examples, the pressure-sensitive adhesive layer has a predetermined storage modulus and a good yield. Also has a good adhesion between the base film and the adhesive layer having a predetermined thickness of the primer layer,
The adhesive layer does not peel off during dicing or pick-up, and the expandability is good. On the other hand, in Comparative Examples 1 and 2, since the primer layer was not provided, peeling of the adhesive layer occurred. Comparative Example 3 has a primer layer but has a poor expandability because the thickness exceeds a predetermined thickness. In Comparative Example 4, the yield was poor because the pressure-sensitive adhesive layer did not have a predetermined storage modulus.

[Brief description of the drawings]

FIG. 1 is a sectional view of an adhesive sheet for dicing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Base film 12 Primer layer 13 Adhesive layer 14 Separator

Claims (3)

[Claims] Claims: 1. A primer film is provided on a base film via a primer layer.
Adhesive sheet for dicing provided with adhesive layer
The base film is a polyvinyl chloride film, the thickness of the primer layer is 0.5 μm to 10 μm, and the storage elastic modulus of the pressure-sensitive adhesive layer at 0 to 10 ° C. is 3 × 10
^Five ~ 1 × 10⁹ N / m ^Two Characterized by the range
Adhesive sheet for dicing. 2. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the material for forming the primer layer has a glass transition point of 20 ° C. or higher. 3. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein a material for forming the primer layer contains an acrylic resin as a main component.