KR20170106982A - Dicing tape - Google Patents

Abstract

The present invention also provides a dicing tape which can suppress scattering and chipping of a chip in a dicing step even in small and thin electronic components, can easily perform pick-up, and is free from residual adhesive residue. According to the present invention, there is provided a dicing tape comprising a substrate film laminated with a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive composition comprises 100 parts by mass of a (meth) acrylic acid ester copolymer, 5 to 250 parts by mass of a photopolymerizable compound, (Meth) acrylate unit is contained in an amount of 35 to 85% by mass and a 2-ethylhexyl (meth) acrylate unit is contained in an amount of 0.1 to 20 parts by mass and a photopolymerization initiator in an amount of 0.1 to 20 parts by mass, Wherein the photopolymerizable compound has a weight average molecular weight of 4,000 to 8,000 and an unsaturated double bond functional group is contained in an amount of 10 to 60% by mass, 0.5 to 10% by mass of a monomer unit having a carboxyl group and 0.05 to 5% by mass of a monomer unit having a hydroxyl group, Wherein the pressure-sensitive adhesive layer is a urethane acrylate oligomer having a number of 10 to 15, and the thickness of the pressure-sensitive adhesive layer is 3 to 7 占 퐉.

Description

Dicing tape

The present invention relates to a dicing tape used in a manufacturing process of an electronic component.

The semiconductor wafer or the substrate is subjected to various processes such as cutting (dicing) into a device piece after the dicing tape is bonded, stretching of the dicing tape (expansion), peeling of the device piece from the dicing tape . It is expected that the dicing tape used in such a process has a sufficient adhesive force to the cut pieces (chips) in the dicing step, and the adhesive force is reduced to such an extent that there is no adhesive residue during the pick-up process.

As the dicing tape, there has been coated a pressure-sensitive adhesive layer which undergoes polymerization curing reaction with ultraviolet rays or the like on a base film having transparency to an active ray such as ultraviolet rays and / or electron rays. This dicing tape employs a method of irradiating ultraviolet rays or the like to the pressure-sensitive adhesive layer after the dicing process and polymerizing and curing the pressure-sensitive adhesive layer to lower the adhesive force, and then picking up the cut chips.

As such a dicing tape, Patent Documents 1 and 2 include a compound (polyfunctional oligomer) having a photopolymerizable unsaturated double bond in a molecule, which can be three-dimensionally retreated by an actinic ray, for example, A dicing tape coated with a pressure-sensitive adhesive is disclosed.

Japanese Patent Application Laid-Open No. 2006-049509 Japanese Patent Application Laid-Open No. 2007-246633

In recent years, along with the miniaturization and thinning of electronic components, chip scattering and chipping (chip defects) are likely to occur in the dicing process of a semiconductor wafer or substrate, leading to a decrease in yield .

Therefore, it is an object of the present invention to provide a dicing tape which can suppress scattering and chipping of a chip in a dicing step even in small-sized and thin electronic components, can easily perform pick-up, The purpose.

According to the present invention, there is provided a dicing tape comprising a substrate film laminated with a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive composition comprises 100 parts by mass of a (meth) acrylic acid ester copolymer, 5 to 250 parts by mass of a photopolymerizable compound, (Meth) acrylate unit is contained in an amount of 35 to 85% by mass and a 2-ethylhexyl (meth) acrylate unit is contained in an amount of 0.1 to 20 parts by mass and a photopolymerization initiator in an amount of 0.1 to 20 parts by mass, Wherein the photopolymerizable compound has a weight average molecular weight of 4,000 to 8,000, and the content of the monomer unit having a hydroxyl group is 0.05 to 5% by mass, the content of the monomer unit is 10 to 60% by mass, the content of the monomer unit having a carboxyl group is 0.5 to 10% Wherein the pressure-sensitive adhesive layer is a urethane acrylate oligomer having a number of functional groups of 10 to 15, and the thickness of the pressure-sensitive adhesive layer is 3 to 7 占 퐉.

In general, if the thickness of the pressure-sensitive adhesive layer is made small, chipping does not easily occur, but the adhesive force becomes small, and chip scattering tends to occur. Further, if the composition of the pressure-sensitive adhesive is adjusted in order to suppress the generation of scattering of the chips, chipping easily occurs, the pick-up property becomes worse, or the problem that the pressure-sensitive adhesive residue tends to be generated easily. Therefore, conventionally, it has been very difficult to effectively improve the pickup performance while effectively suppressing chipping, chip scattering, and adhesive residue.

The present inventors have conducted intensive studies to obtain excellent dicing tapes from all of them. As a result, it has been found that when a pressure sensitive adhesive layer having a thickness of 3 to 7 탆 is formed using a pressure sensitive adhesive having a specific composition, chipping, chip scattering, It is possible to improve the pick-up property while effectively suppressing the above-mentioned problems, thereby completing the present invention.

Preferably, the curing agent is a polyfunctional isocyanate curing agent or a polyfunctional epoxy curing agent.

Preferably, the adhesive force of the dicing tape to the mirror surface of the silicon wafer measured according to JIS Z0237 is 5.0 N / 20 mm or more.

According to another aspect of the present invention, there is provided a semiconductor device comprising: (a) a bonding step of bonding a dicing tape to a semiconductor wafer or a substrate and a ring frame; (b) dicing the semiconductor wafer or substrate to form a semiconductor chip or a semiconductor part; (C) exposing the dicing tape to an actinic ray; and (d) expanding the dicing tape to widen the distance between the semiconductor chips or the semiconductor components, and and a pickup step of picking up a semiconductor chip or a semiconductor component from the dicing tape, wherein the dicing tape is a dicing tape of the substrate.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to suppress scattering and chipping of a chip in a dicing step even in a small and thin electronic component, and to provide a dicing tape which can easily be picked up and hard to produce adhesive residue.

Hereinafter, preferred embodiments for carrying out the present invention will be described. On the other hand, the embodiment described below is an example of a representative embodiment of the present invention, and the scope of the present invention is not narrowly construed thereby.

≪ Pressure sensitive adhesive composition &

The pressure-sensitive adhesive composition for use in forming the pressure-sensitive adhesive layer of the dicing tape of the present invention comprises 100 parts by mass of a (meth) acrylic acid ester copolymer, 5 to 250 parts by mass of a photopolymerizable compound, 0.1 to 20 parts by mass of a curing agent, Mass part.

((Meth) acrylic acid ester copolymer)

The (meth) acrylic acid ester copolymer preferably contains 35 to 85% by mass (preferably 45 to 75% by mass, more preferably 50 to 70% by mass, and more preferably 55 to 65% by mass) of methyl (meth) (Preferably 20 to 50 mass%, more preferably 25 to 45 mass%, still more preferably 30 to 40 mass%) of 2-ethylhexyl (meth) (Preferably 2 to 7% by mass, more preferably 3 to 6% by mass, and more preferably 4 to 5% by mass) of a monomer unit having a carboxyl group, and a monomer unit having a hydroxyl group (Preferably 0.1 to 3 mass%, more preferably 0.2 to 2 mass%, still more preferably 0.3 to 1 mass%, and still more preferably 0.4 to 0.7 mass%). (Meth) acrylic acid ester copolymer is composed of such a monomer unit, a dicing tape having a sufficiently small adhesive force of 3 to 7 占 퐉 and a relatively small adhesive force can be obtained. On the other hand, it is preferable that the adhesive force of the dicing tape is 5.0 N / 20 mm or more in terms of the adhesive force to the mirror surface of the silicon wafer measured in accordance with JIS Z 0237.

Examples of the monomer having a carboxyl group include (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, acrylamido N-glycolic acid and cinnamic acid, and (meth) acrylic acid is preferable.

Examples of the functional group-containing monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 2-hydroxybutyl (meth) -Hydroxyethyl (meth) acrylate are preferable.

(Photopolymerizable compound)

The blending amount of the photopolymerizable compound is 5 to 250 parts by mass, preferably 40 to 200 parts by mass, per 100 parts by mass of the (meth) acrylic acid ester copolymer. When the compounding amount of the photopolymerizable compound is decreased, the peeling property of the dicing tape after irradiation with an actinic ray such as ultraviolet light is lowered, and the pickup failure of the semiconductor chip tends to occur easily. On the other hand, if the compounding amount of the photopolymerizable compound is increased, the adhesive force is excessively lowered by the light irradiation step, and the chip is loosened in the pick-up step, which causes a decrease in productivity.

The photopolymerizable compound usable in the present invention is a urethane acrylate oligomer having a weight average molecular weight of 4,000 to 8,000 and an unsaturated double bond functional group number of 10 to 15. If the weight average molecular weight is small, the pressure sensitive adhesive tends to be chipped because of the softening of the pressure sensitive adhesive. If the weight average molecular weight is large, the adhesiveness to the adherend is lowered and the chip tends to be scattered. If the number of the unsaturated double bond functional groups is small, the curing property of the pressure-sensitive adhesive after irradiation with light such as ultraviolet rays is lowered, and the pickup failure tends to occur. If the number of unsaturated double bond functional groups is large, curing of the pressure- In addition, when a urethane acrylate oligomer is used, adhesion and flexibility with the base film are excellent, which makes it difficult for the pressure-sensitive adhesive to remain at the time of picking up.

The urethane acrylate oligomer can be obtained by reacting a (meth) acrylate having a hydroxy group with a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound such as a polyester type or a polyether type with a polyisocyanate compound.

As the polyol compound, for example, ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, pentanediol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, do. Examples of the polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, Diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like. Examples of the (meth) acrylate having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol (meth) acrylate, pentaerythritol tri Acrylate, glycidol di (meth) acrylate, dipentaerythritol monohydroxypentaacrylate, and the like.

(Hardener)

The blending amount of the curing agent is preferably 0.1 part by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the (meth) acrylic acid ester copolymer. If the blending amount of the curing agent is decreased, the adhesive residue tends to be generated. On the other hand, if the blending amount of the curing agent is increased, the adhesive force is insufficient and the chips are dispersed, which leads to a decrease in productivity.

Examples of the curing agent include a polyfunctional isocyanate curing agent, a polyfunctional epoxy curing agent, an azine compound, and a melamine compound, and a polyfunctional isocyanate curing agent and a polyfunctional epoxy curing agent are preferable. By using a polyfunctional epoxy curing agent or a polyfunctional isocyanate curing agent as at least a part of the curing agent, the functional group-containing monomer having a carboxyl group can be selectively reacted and eliminated, so that the amount of the functional group-containing monomer having a carboxyl group after curing can be controlled.

As the polyfunctional isocyanate curing agent, there are, for example, aromatic polyisocyanate curing agents, aliphatic polyisocyanate curing agents and fatty aliphatic polyisocyanate curing agents.

The aromatic polyisocyanate is not particularly limited and examples thereof include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate , 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, Diene diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, ω'-diisocyanate-1,3-dimethylbenzene, ω, Isocyanate-1,4-dimethylbenzene, ω, ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate .

The aliphatic polyisocyanate is not particularly limited and includes, for example, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, , 3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

The alicyclic polyisocyanate is not particularly limited, and examples thereof include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4 Cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanate methyl) Cyclohexane and 1,4-bis (isocyanatomethyl) cyclohexane.

Among the polyisocyanates, 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- Isocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, and hexamethylene diisocyanate can be preferably used.

The polyfunctional epoxy curing agent refers to a compound having at least two epoxy groups and at least one tertiary nitrogen atom and includes N · N-glycidyl aniline, N · N-glycidyl toluidine, mN · N-gly N, N ', N'-tetraglycidyldiaminodiphenylmethane, N, N'N'-N'-tetraglycidylaminophenylglycidyl ether, pN.N-glycidylaminophenylglycidyl ether, triglycidylisocyanurate, , N · N · N '· N'-tetraglycidyl-m-xylylenediamine, N · N · N' · N '· N' '- pentaglycidyldiethylenetriamine and the like.

(Photopolymerization initiator)

The blending amount of the photopolymerization initiator is preferably 0.1 part by mass or more and 20 parts by mass or less, more preferably 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the (meth) acrylic acid ester polymer. If the blending amount is too small, the peeling property from the dicing tape after the light irradiation is lowered, and the pickup failure of the semiconductor chip tends to occur easily. On the other hand, if the blending amount is too large, the photopolymerization initiator bleeds out to the surface of the pressure-sensitive adhesive and becomes a cause of contamination.

As the photopolymerization initiator, benzoin, benzoin alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones and the like can be used.

Examples of the benzoin include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether and the like.

Examples of the acetophenones include benzoin alkyl ethers, acetophenone, 2,2-dimethoxy-2-acetophenone, 2,2-diethoxy-2-acetophenone, 1,1-dichloroacetophenone and the like have.

Examples of the anthraquinones include 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-tertiary butyl anthraquinone, 1-chloro anthraquinone, and the like.

The thioxanthones include, for example, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone.

Examples of the ketalization include acetophenone dimethyl ketal, benzyldimethyl metal, benzyldiphenylsulfide, tetramethylthioureasulfide, azobisisobutyronitrile, dibenzyl, diacetyl,? -Chloroanthraquinone, and the like .

The photopolymerization initiator may be used in combination with one or more kinds of conventionally known photopolymerization accelerators, if necessary. As the photopolymerization accelerator, a benzoic acid or a tertiary amine can be used. Examples of tertiary amines include triethylamine, tetraethylpentanamine, dimethylaminoethyl and the like.

(Tackifier resin)

A tackifier resin may be added to the pressure-sensitive adhesive composition. As the tackifier resin, terpene phenol resin is completely or partially hydrogenated terpene phenol resin.

The terpene phenol resin can be produced, for example, by reacting 1 mole of a terpene compound with 0.1 to 50 of a phenol.

Examples of the terpene compound include myrcene, alloocimene, ocimene,? -Pinene,? -Pinene, dipentene, limonene,? -Perlandrene,? -Terpinene,? -Terpinene, Phenanols, 1,8-cineol, 1,4-cineol,? -Terpineol,? -Terpineol,? -Terpineol, And the like. Among these compounds,? -Pinene,? -Pinene, limonene, myrcene, allocyanene and? -Terpinene are particularly preferably used in the present invention.

Examples of phenols include, but are not limited to, phenol, cresol, xylenol, catechol, resorcin, hydroquinone, bisphenol A and the like.

The ratio of the phenols of the terpene phenol resin is about 25 to 50 mol%, but is not limited thereto.

The hydroxyl value of the completely or partially hydrogenated terpene phenol resin is preferably 50 to 250. When the hydroxyl group value is less than 50, the reaction with the isocyanate curing agent becomes insufficient and causes bleeding-out on the surface of the pressure-sensitive adhesive to cause contamination. When the hydroxyl value is more than 250, the viscosity increases and mixing unevenness with the (meth) And the pickup characteristic is not stable.

The method of hydrogenation is not particularly limited, and examples thereof include a method in which a noble metal such as palladium, ruthenium, or rhodium is supported on a carrier such as activated carbon, activated alumina or diatomaceous earth as a catalyst, The hydrotreating rate can be measured by measuring the bromine value, measuring the iodine value, and the like.

The hydrogenation rate of the completely or partially hydrogenated terpene phenol resin is preferably 30 mol% or more, and more preferably 70 mol% or more. When the content is less than 30 mol%, the adhesion of the photopolymerizable compound is not sufficiently lowered due to the reaction of the photopolymerizable compound with the irradiation of the actinic ray, resulting in deterioration of the pick-up property.

The blending ratio of the completely or partially hydrogenated terpene phenol resin is preferably 0.5 parts by mass or more and 100 parts by mass or less, more preferably 1.0 parts by mass or more and 50 parts by mass or less, based on 100 parts by mass of the (meth) acrylic acid ester copolymer. If the amount of the completely or partially hydrogenated terpene phenol resin is 0.5 parts by mass or more, the adhesive strength is not too low. Therefore, the durability of the semiconductor chip is maintained at the time of dicing, and if it is 100 parts by mass or less,

(Such as additives)

Various additives such as a softening agent, an anti-aging agent, a filler, a conductive agent, an ultraviolet absorber, and a light stabilizer may be added to the pressure-sensitive adhesive composition.

The thickness of the pressure-sensitive adhesive layer is 3 to 7 占 퐉, preferably 4 to 6 占 퐉. If the pressure-sensitive adhesive layer is too thick, chipping tends to occur. In addition, if the pressure-sensitive adhesive layer is too thin, the adhesive force becomes too low, so that the chip retention at the time of dicing is lowered, and scattering of the chip occurs, or peeling may occur between the ring frame and the sheet.

(Substrate film)

Examples of the material of the base film include polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylic acid ester film, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, , An ethylene-acrylic acid copolymer, and an ionomer resin obtained by crosslinking an ethylene- (meth) acrylic acid copolymer or an ethylene- (meth) acrylic acid- (meth) acrylic acid ester copolymer with a metal ion. The base film may be a mixture or a copolymer of these resins, or a laminate of films or sheets of these resins.

It is preferable to use an ionomer resin as a material of the base film. Among the ionomer resins, the use of ionomer resins obtained by crosslinking a copolymer having an ethylene unit, a methacrylic acid unit and a (meth) acrylic acid alkyl ester unit with metal ions such as Na ⁺ , K ⁺ , Zn ²⁺ or the like can be used to suppress cutting debris The effect is remarkable and is preferably used.

The base film may be a single layer or a multilayer film or sheet made of the above-described material, or a laminate of films made of other materials or the like. The thickness of the base film is 50 to 200 占 퐉, preferably 70 to 150 占 퐉.

It is preferable that the base film is subjected to an antistatic treatment. As the antistatic treatment, there are a treatment for adding an antistatic agent to a base film, a treatment for applying an antistatic agent to the surface of the base film, and a treatment for corona discharge.

As the antistatic agent, for example, quaternary amine salt monomers and the like can be used. Examples of the quaternary amine salt monomer include dimethylaminoethyl (meth) acrylate quaternary chloride, diethylaminoethyl (meth) acrylate quaternary chloride, methylethylaminoethyl (meth) acrylate quaternary chloride, p- Dimethylaminostyrene quaternary chloride and p-diethylaminostyrene quaternary chloride. Of these, dimethylaminoethyl methacrylate quaternary chloride is preferable.

The method of using the lubricant and the antistatic agent is not particularly limited. For example, a lubricant and / or an antistatic agent may be applied to the back surface of the base film and a lubricant and / The resin may be kneaded and put into a sheet.

An adhesive may be laminated on one surface of the base film and the other surface may be an embossed surface having an average surface roughness (Ra) of 0.3 to 1.5 탆. By providing the embossed surface on the machine table side of the expanded device, the base film can be easily expanded in the exposing step after dicing.

(slush)

In order to improve the expandability after dicing, a lubricant may be added to the non-contact surface of the pressure-sensitive adhesive of the base film, or a lubricant may be kneaded into the base film.

The lubricant is not particularly limited as long as it is a material that lowers the friction coefficient of the dicing tape and the expanding device. For example, a silicone compound such as silicone resin or (modified) silicone oil, a fluorine resin, hexagonal boron nitride, Black and molybdenum disulfide. Such a friction modifier may be a mixture of a plurality of components. Since the manufacture of electronic components is performed in a clean room, it is preferable to use a silicone compound or a fluororesin. Among the silicone compounds, copolymers having silicon macromonomer units in particular are preferably used because they have good compatibility with the antistatic layer and balance antistatic properties and expansibility.

The specific steps of the method of manufacturing an electronic component according to the present invention will be described in order.

(1) Adhesive process

First, in the attaching step, the dicing tape is stuck to the semiconductor wafer or the substrate and the ring frame. The semiconductor wafer may be a conventional wafer such as a silicon wafer, a gallium nitride wafer, a silicon carbide wafer, or a sapphire wafer. The substrate may be a general-purpose substrate such as a package substrate in which a chip is sealed with a resin, an LED package substrate, or a ceramic substrate.

(2) Dicing process

In the dicing step, a semiconductor wafer or a substrate is diced into a semiconductor chip or a semiconductor component.

(3) Light irradiation process

In the light irradiation step, the dicing tape is irradiated with an actinic ray such as ultraviolet ray or electron ray. The active ray is preferably irradiated from the base film side. As a light source of ultraviolet rays, a low pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, and a metal halide lamp can be used. Alternatively, an electron beam may be used in place of the ultraviolet ray, and?,?, And? Rays may be used as a light source of the electron beam.

By the irradiation of light, the pressure-sensitive adhesive layer is three-dimensionally networked and hardened, and the adhesive force of the pressure-sensitive adhesive layer is lowered. In this case, as described above, since the dicing tape according to the present invention is not excessively adhered to the semiconductor wafer or the substrate even when it is warmed, a sufficient decrease in the adhesive force can be obtained by irradiation with ultraviolet rays or the like.

(4) Expansion and Pickup Process

In the expanded / pick-up process, the dicing tape is stretched to widen the distance between the semiconductor chips or the semiconductor components, and the chips or parts are pushed up to the needle pins or the like. Thereafter, the chip or the component is adsorbed by a vacuum collet, an air force or the like, peeled from the pressure-sensitive adhesive layer of the dicing tape and picked up. In this case, since the dicing tape according to the present invention can attain a sufficient reduction of the adhesive force by irradiation with ultraviolet rays or the like, peeling between the chip or the component and the pressure-sensitive adhesive layer is facilitated, There is no defect such as adhesive residue.

≪ Preparation of dicing tape &

Examples of the method of forming a pressure-sensitive adhesive layer on a base film to form a dicing tape include a gravure coater, a comma coater, a bar coater, a knife coater, A method of directly applying a pressure-sensitive adhesive on a base film with a coater such as a roll coater, or a method of applying a pressure-sensitive adhesive on a release film / drying and then bonding the pressure-sensitive adhesive to a base film. The pressure-sensitive adhesive may be printed on the base film by iron plate printing, intaglio printing, flat plate printing, flexo printing, offset printing, or screen printing.

The dicing tape of the present invention is preferably used in the dicing step or the back grind step, which is a manufacturing process of an electronic part, to be an application of a bundle of electronic parts called a work.

The pressure-sensitive adhesive composition and dicing tape of Examples and Comparative Examples were prepared by the following prescription. Table 1 to Table 3 show the main formulation and the results of each experimental example.

The numerical values relating to the compositions in Tables 1 to 3 indicate mass parts. The numerical values of the photopolymerizable compound, the curing agent and the photopolymerization initiator indicate the parts by mass when 100 parts of the (meth) acrylic acid ester copolymer is used. Details of the base film, the photopolymerizable compound, the curing agent and the photopolymerization initiator are as follows.

On the other hand, the weight average molecular weight is a value measured as a weight average molecular weight in terms of polystyrene by gel permeation chromatography (GPC). Specifically, it is as follows.

Apparatus: GPC-8020 SEC system (manufactured by Tosoh Corporation)

Column: TSK Guard HZ-L + HZM-N 6.0 × 150mm × 3

Flow rate: 0.5 ml / min

Detector: RI-8020

Concentration: 0.2wt / Vol%

Injection volume: 20 μL

Column temperature: 40 DEG C

System temperature: 40 ℃

Solvent: THF

Calibration curve: Prepared using standard polystyrene (manufactured by PL), and weight average molecular weight (Mw) expressed in terms of polystyrene.

<Base film>

Resin film A: A film made of an ionomer resin having a thickness of 80 μm, and a Zn salt of an ethylene-methacrylic acid-2-methylpropyl acrylate copolymer. MFR 2.8 g / 10 min (JIS K7210 method, 210 캜), manufactured by Mitsui DuPont Chemicals, Inc. (commercially available).

&Lt; Photopolymerizable compound >

Photopolymerizable compound A: A reaction product of an isocyanate of hexamethylene diisocyanate with a hydroxyl group-containing acrylate containing dipentaerythritol pentaacrylate as a main component and having a weight average molecular weight of 7,500 and a urethane acrylate having an unsaturated double bond functional group of 10 Oligomers (synthetic).

Photopolymerizable compound B: A urethane acrylate oligomer (synthetic product) having a weight average molecular weight of 4,200 and a number of unsaturated double bond functional groups synthesized by the same production method as that of the photopolymerizable compound A,

Photopolymerizable compound C: A urethane acrylate oligomer (synthetic product) synthesized by the same production method as the photopolymerizable compound A and having a weight average molecular weight of 2,100 and an unsaturated double bond functional group of 10,

Photopolymerizable compound D: A urethane acrylate oligomer (synthetic product) synthesized by the same production method as the photopolymerizable compound A and having a weight average molecular weight of 10,300 and an unsaturated double bond functional group of 10,

Photopolymerizable compound E: isocyanate of isophorone diisocyanate trimer is reacted with hydroxyl group-containing acrylate containing dipentaerythritol pentaacrylate as a main component, and has a weight average molecular weight of 4,900 and an unsaturated double bond functional group of 15 Urethane acrylate oligomer (synthetic).

On the other hand, the photopolymerizable compound was prepared by a known method described in JP-A-61-42529.

<Curing agent>

Curing agent A: Trimethylol propane adduct of 2,4-tolylene diisocyanate (commercially available)

Curing agent B: Trimethylol propane adduct of hexamethylene diisocyanate (commercially available)

Curing agent C: N, N, N ', N'-tetraglycidyl-m-xylylenediamine (commercially available)

<Photopolymerization initiator>

Photopolymerization initiator A: 1-Hydroxycyclohexyl phenyl ketone (commercially available)

Photopolymerization initiator B: Benzyl dimethyl ketal (commercially available)

(1) Adhesion

(Manufactured by A & D Co., RTG-1210) in accordance with JIS Z 0237, 2009. The dicing tape was stuck to the mirror surface of a silicon wafer for 20 minutes, and subjected to 180 ° peeling method at 23 ° C and 50% The adhesive force was measured. The tensile speed was 300 mm / min, and the size of the dicing tape was 250 mm x 20 mm. On the other hand, a mirror surface of a silicon wafer manufactured by JIS H 0614 was used.

(2) Evaluation of chip retainability, pick-up property and chipping

The obtained dicing tape was bonded to a ring wafer with a silicon wafer having a diameter of 8 inches by a thickness of 0.15 mm on which a dummy circuit pattern was formed. 20 minutes after the lamination, ultraviolet rays were irradiated at 150 mJ / cm ² with a high-pressure mercury lamp, and dicing and pickup were performed.

The conditions of the dicing step were as follows.

Dicing device: DAD341 manufactured by DISCO

Dicing blade: manufactured by DISCO NBC-ZH205O-27HEEE

Dicing blade shape: outer diameter 55.56 mm, knife width 35 m, inner diameter 19.05 mm

Rotation speed of dicing blade: 40,000 rpm

Dicing blade feed rate: 100 mm / sec

Dicing size: 1.0mm square

Depth for dicing tape: 30μm

Cutting temperature: 25 degrees

Cutting water amount: 1.0 liter / min

The conditions of the pickup process were as follows.

Pick-up device: CAP-300II manufactured by Canon Machinery Inc.

Expanded amount: 8mm

Needle pin shape: 70 mR

Number of needle pins: 1

Needle pin push-up height: 0.3mm

The following evaluations were carried out in the dicing step and the pick-up step.

(2-1) Chip retention

Chip retention was evaluated based on the remaining ratio of the semiconductor chips held by the dicing tape after the dicing step according to the following criteria.

◎ (excellent): chip scattering less than 5%

○ (Good): chip scattering is 5% or more and less than 10%

× (not applicable): chip scattering of 10% or more

(2-2) Pickup property

The pick-up performance was evaluated based on the following criteria based on the ratio at which the semiconductor chips were picked up in the pickup process.

◎ (excellent): Chip pickup success rate is over 95%

○ (Good): Chip pickup success rate is over 80% and less than 95%

× (not applicable): Chip pickup success rate less than 80%

(2-3) Chipping

Chipping picked up 50 randomly selected chips, and observed four sides of the back surface of the chip with a 500-fold microscope. The size of the largest defect in the center direction was evaluated according to the following criteria.

◎ (Excellent): Size of defect is less than 25μm

(Good): The size of the defect is not less than 25 占 퐉 and less than 50 占 퐉

× (not allowed): The size of the defect is 50 μm or more

(3) Contamination

The dicing tape was attached to the mirror surface of the silicon wafer. After 20 minutes, ultraviolet rays were irradiated at 150 mJ / cm ² with a high-pressure mercury lamp, and the dicing tape was peeled off. The number of particles of 0.28 탆 or more remained on the mirror surface (adhesive surface) of the silicon wafer was measured with a particle counter.

◎ (Excellent): No more than 500 particles

○ (Good): More than 501 particles and less than 2000 particles

× (Not applicable): More than 2000 particles

(4) Dispersion of chips

The chip dispersion was evaluated according to the following criteria based on the rate at which adjacent semiconductor chips of the semiconductor chip to be picked up in the pick-up process were dispersed by the impact of the push-up of the pins.

◎ (excellent): chip dispersion less than 1%

○ (Good): Chip dispersion is 1% or more and less than 3%

× (not applicable): chip dispersion of 3% or more

(Review)

As shown in Examples and Comparative Examples of Tables 1 to 3, in all the examples in which the pressure-sensitive adhesive layer having a thickness of 3 to 7 占 퐉 was formed using the pressure-sensitive adhesive of a specific composition, the overall judgment was? Or?. On the other hand, in all comparative examples in which the composition of the pressure-sensitive adhesive or the thickness of the pressure-sensitive adhesive layer was outside the specified range, the overall judgment was negative. These results demonstrate that the use of the dicing tape of the present invention makes it possible to improve pick-up properties while effectively suppressing chipping, chip scattering, and adhesive residue.

More detailed analysis is as follows.

In Comparative Example 1, the stainability deteriorated because the methyl (meth) acrylate unit was too small.

In Comparative Example 2, since the methyl (meth) acrylate unit was too large, chip retention deteriorated and chips were liable to be dispersed.

In Comparative Example 3, since the number of monomer units having a carboxyl group was too small, chip retention deteriorated.

In Comparative Example 4, since the number of monomer units having a carboxyl group was too large, the pickup property and the staining property were deteriorated.

In Comparative Example 5, since the number of monomer units having a hydroxyl group was too small, the staining property deteriorated.

In Comparative Example 6, since the number of monomer units having a hydroxyl group was too large, chip dispersion tended to occur easily.

In Comparative Example 7, since the photopolymerizable compound was too small, the chip retention property and the pick-up property deteriorated.

In Comparative Example 8, since the photopolymerizable compound was too much, the staining property deteriorated and chips were liable to be dispersed.

In Comparative Example 9, since the weight average molecular weight of the photopolymerizable compound was too small, chipping occurred easily.

In Comparative Example 10, since the weight average molecular weight of the photopolymerizable compound was too large, chip retention deteriorated.

In Comparative Example 11, the stainability deteriorated because the amount of the curing agent was too small.

In Comparative Example 12, since the amount of the curing agent was too large, the chip retainability and staining property deteriorated and chips were liable to be dispersed.

In Comparative Example 13, since the photopolymerization initiator was too small, the pickupability deteriorated.

In Comparative Example 14, since the photopolymerization initiator was too much, the staining property deteriorated and the chips were liable to be dispersed.

In Comparative Example 15, since the pressure-sensitive adhesive layer was too thin, chip retention deteriorated and chips were liable to be dispersed.

In Comparative Example 16, since the pressure-sensitive adhesive layer was too thick, chipping occurred easily and the pickup property deteriorated.

Claims (4)

A dicing tape comprising a base film laminated with a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition,
Wherein the pressure-sensitive adhesive composition comprises 100 parts by mass of a (meth) acrylic acid ester copolymer, 5 to 250 parts by mass of a photopolymerizable compound, 0.1 to 20 parts by mass of a curing agent, and 0.1 to 20 parts by mass of a photopolymerization initiator,
Wherein the (meth) acrylic acid ester copolymer contains 35 to 85 mass% of a methyl (meth) acrylate unit, 10 to 60 mass% of a 2-ethylhexyl (meth) acrylate unit, 0.5 to 10 By mass and 0.05 to 5% by mass of a monomer unit having a hydroxyl group,
The photopolymerizable compound is a urethane acrylate oligomer having a weight average molecular weight of 4,000 to 8,000 and an unsaturated double bond functional group number of 10 to 15,
Wherein the pressure-sensitive adhesive layer has a thickness of 3 to 7 占 퐉. The method according to claim 1,
Wherein the curing agent is a polyfunctional isocyanate curing agent or a polyfunctional epoxy curing agent. 3. The method according to claim 1 or 2,
Wherein the adhesive force of the dicing tape to the mirror surface of the silicon wafer measured according to JIS Z 0237 is 5.0 N / 20 mm or more. (a) an attaching step of attaching a dicing tape to a semiconductor wafer or a substrate and a ring frame,
(b) a dicing step of dicing the semiconductor wafer or substrate into semiconductor chips or semiconductor parts,
(c) a light irradiation step of irradiating the dicing tape with an actinic ray,
(d) an expanding step of stretching the dicing tape to widen the gap between the semiconductor chips or the semiconductor components,
(e) picking up a semiconductor chip or a semiconductor component from the dicing tape
/ RTI &gt;
Wherein the dicing tape is the dicing tape according to any one of claims 1 to 3.