CN107112221A - Dicing tape - Google Patents

Abstract

The present invention provides a dicing tape capable of suppressing chip flying and chipping during a dicing process even for small and thin electronic components, enabling easy pickup and less generation of adhesive residue. According to the present invention, there is provided a dicing tape in which an adhesive layer composed of an adhesive composition is laminated on a base film, wherein the adhesive composition contains (meth)acrylic acid 100 parts by mass of an 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, the (meth)acrylate copolymer containing methyl (meth)acrylate 35 to 85% by mass of ester units, 10 to 60% by mass of 2-ethylhexyl (meth)acrylate units, 0.5 to 10% by mass of monomer units having carboxyl groups, and 0.05 to 5% by mass of monomer units having hydroxyl groups , the photopolymerizable compound is a urethane acrylate oligomer with a weight average molecular weight of 4000-8000 and an unsaturated double bond functional group number of 10-15, and the thickness of the adhesive layer is 3-7 μm.

Description

cutting tape

【Technical field】

This invention relates to the dicing tape used in the manufacturing process of an electronic component.

【Background technique】

After the semiconductor wafer or substrate is bonded with dicing tape, it undergoes various processes such as division (dicing) into component pieces, extension (expansion) of the dicing tape, and peeling (pick up) of component pieces from the dicing tape. It is desired that the dicing tape used in these processes has sufficient adhesive force to the component chips (chips) formed in the dicing process, and at the same time reduce the adhesive force to such an extent that no adhesive residue occurs in the pick-up process.

As a dicing tape, there is a dicing tape in which an adhesive layer that is polymerized and cured by ultraviolet rays or the like is coated on a base film that is transparent to active rays such as ultraviolet rays and/or electron beams. In this dicing tape, after the dicing process, the adhesive layer is irradiated with ultraviolet light or the like to polymerize and cure the adhesive layer to reduce the adhesive force, and then the divided chips are picked up.

As such a dicing tape, Patent Document 1 and Patent Document 2 disclose a dicing tape in which a film containing, for example, a three-dimensionally reticulated, photopolymerizable polymer in the molecule is coated on the substrate film surface. Adhesives made of compounds with unsaturated double bonds (polyfunctional oligomers).

[Prior Art Literature]

【Patent Literature】

[Patent Document 1] Japanese Unexamined Patent Publication No. 2006-049509

[Patent Document 2] Japanese Unexamined Patent Publication No. 2007-246633

【Content of invention】

【Problems to be solved by the invention】

In recent years, along with miniaturization and thinning of electronic components, chip flying and chipping (chip chipping) are likely to occur during the dicing process of semiconductor wafers or substrates, which may become a factor of yield reduction.

Therefore, the main object of the present invention is to provide a dicing tape that can suppress chip flying and chipping during the dicing process even for small and thin electronic components, is easy to pick up, and does not easily generate adhesive residue.

【Technical means to solve the problem】

According to the present invention, there is provided a dicing tape in which an adhesive layer composed of an adhesive composition is laminated on a base film, wherein the adhesive composition contains (meth)acrylic acid 100 parts by mass of an 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, the (meth)acrylate copolymer containing (meth) 35 to 85 mass % of methyl acrylate units, 10 to 60 mass % of 2-ethylhexyl (meth)acrylate units, 0.5 to 10 mass % of monomer units having carboxyl groups, and 0.05 to 5 mass % of monomer units having hydroxyl groups % by mass, the photopolymerizable compound is a urethane acrylate oligomer with a weight average molecular weight of 4000-8000 and an unsaturated double bond functional group number of 10-15, and the thickness of the adhesive layer is 3-7 μm.

In general, when the thickness of the adhesive layer is reduced, cracking is less likely to occur, but the adhesive force becomes smaller and chip flying tends to occur. In addition, if the composition of the adhesive is adjusted in order to suppress the occurrence of chip fly, problems such as easy occurrence of cracking, deterioration of pick-up performance, or occurrence of adhesive residue tend to occur. Therefore, it has been difficult to achieve good pick-up performance while effectively suppressing chipping, chip flying, and adhesive residue.

The inventors of the present invention conducted intensive studies to obtain a dicing tape excellent in these aspects, and as a result, found that when an adhesive layer having a thickness of 3 to 7 μm is formed using an adhesive of a specific composition, cracking can be effectively suppressed, The present invention has been accomplished by improving the pick-up performance while chip flying and adhesive residue are combined.

It is preferably characterized in that the above-mentioned curing agent is a polyfunctional isocyanate curing agent or a polyfunctional epoxy curing agent.

Preferably, the dicing tape has an adhesive force to a mirror surface of a silicon wafer measured in accordance with JIS Z0237 of 5.0 N/20 mm or more.

According to another aspect of the present invention, there is provided a method of manufacturing an electronic component, the method having the following steps: (a) attaching step, attaching a dicing tape to a semiconductor wafer or a substrate and a ring frame; (b) cutting step, dicing the above-mentioned semiconductor wafer or substrate to form semiconductor chips or semiconductor components; (c) a light irradiation process irradiating active light rays to the above-mentioned dicing tape; (d) an expanding process, in order to expand the interval between the above-mentioned semiconductor chips or semiconductor components, The tape is stretched; and (e) a pick-up step of picking up a semiconductor chip or a semiconductor component from the above-mentioned dicing tape, which is the above-mentioned dicing tape.

【Invention effect】

According to the present invention, it is possible to provide a dicing tape that can suppress chip flying and chipping during a dicing process, is easy to pick up, and hardly generates adhesive residue, even for small and thin electronic components.

【detailed description】

Hereinafter, preferred modes for carrying out the present invention will be described. In addition, the embodiment described below is an example of typical embodiment of this invention, and the scope of this invention should not be interpreted too narrowly accordingly.

<Adhesive composition>

The adhesive composition used for forming the adhesive layer of the dicing tape of the present invention contains 100 parts by mass of a (meth)acrylate copolymer, 5 to 250 parts by mass of a photopolymerizable compound, and 0.1 to 20 parts by mass of a curing agent. , and 0.1 to 20 parts by mass of a photopolymerization initiator.

((meth)acrylate copolymer)

The (meth)acrylate copolymer contains: 35 to 85% by mass (preferably 45 to 75% by mass, more preferably 50 to 70% by mass, still more preferably 55 to 65% by mass) of methyl (meth)acrylate units) 10 to 60% by mass (preferably 20 to 50% by mass, more preferably 25 to 45% by mass, still more preferably 30 to 40% by mass) of 2-ethylhexyl (meth)acrylate units, units having carboxyl groups 0.5 to 10% by mass (preferably 2 to 7% by mass, more preferably 3 to 6% by mass, further preferably 4 to 5% by mass) of monomeric units, 0.05 to 5% by mass (preferably 0.1% by mass) of monomeric units having hydroxyl groups to 3% by mass, more preferably 0.2 to 2% by mass, still more preferably 0.3 to 1% by mass, still more preferably 0.4 to 0.7% by mass). By making the (meth)acrylate copolymer consist of such monomer units, even if the thickness of the pressure-sensitive adhesive layer is as small as 3 to 7 μm, a dicing tape having sufficiently high adhesive force can be obtained. In addition, as for the adhesive force of a dicing tape, it is preferable that the adhesive force to the mirror surface of a silicon wafer measured based on JIS Z 0237 is 5.0 N/20mm or more.

Examples of monomers having a carboxyl group include (meth)acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, acrylamide N-glycolic acid, and cinnamic acid, among which (methyl) acrylic acid.

Examples of monomers with hydroxyl-containing functional groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate, preferably (meth) 2-Hydroxyethyl acrylate.

(photopolymerizable compound)

The compounding quantity of a photopolymerizable compound is 5-250 mass parts with respect to 100 mass parts of (meth)acrylate copolymers, Preferably it is 40-200 mass parts. When the compounding quantity of a photopolymerizable compound is reduced, the peelability of the dicing tape after irradiating active light rays, such as an ultraviolet-ray, will fall, and the pick-up defect of a semiconductor chip will become easy to generate|occur|produce. On the other hand, if the compounding amount of the photopolymerizable compound is increased, the adhesive force will be excessively reduced by the light irradiation process, chip looseness will occur in the pick-up process, and this will become a factor of 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 10 to 15 unsaturated double bond functional groups. If the weight-average molecular weight is small, the side of the adhesive is soft, so chipping is likely to occur, and when the weight-average molecular weight is large, the adhesiveness with the adherend is reduced, and chip flying is likely to occur. If the number of unsaturated double bond functional groups is small, the curability of the adhesive after irradiation with ultraviolet light or the like is reduced, and pick-up failures are likely to occur. If the number of unsaturated double bond functional groups is large, the curing of the adhesive after irradiation with ultraviolet light, etc. Chip loosening occurs. Moreover, when using a urethane acrylate oligomer, since it has excellent adhesiveness with a base film, and flexibility, there exists an advantage that adhesive residue does not generate|occur|produce easily at the time of picking up.

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

As the polyol compound, for example, ethylene glycol, propylene glycol, butylene glycol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, pentylene glycol, glycerin, trimethylolpropane, trihydroxy Methylethane, pentaerythritol, etc. As polyvalent isocyanate compounds, for example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, Diisocyanate, diphenylmethane 4,4-diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate Sour fat, etc. In addition, examples of (meth)acrylates having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, Pentaerythritol triacrylate, glycidyl di(meth)acrylate, dipentaerythritol monohydroxypentaacrylate, and the like.

(Hardener)

The compounding quantity of a hardening|curing agent is 0.1-20 mass parts with respect to 100 mass parts of (meth)acrylate copolymers, Preferably it is 1-10 mass parts. If the mixing amount of curing agent is reduced, adhesive residue will easily occur. On the other hand, if the mixing amount of the curing agent is increased, insufficient adhesive force or chip loosening will occur, which will be a factor of lowering productivity.

As the curing agent, there are polyfunctional isocyanate curing agents, polyfunctional epoxy curing agents, aziridine compounds, melamine compounds, etc., preferably polyfunctional isocyanate curing agents and polyfunctional epoxy curing agents. By using a polyfunctional epoxy curing agent or a polyfunctional isocyanate curing agent as at least a part of the above-mentioned curing agents, it is possible to selectively react the functional group-containing monomers having carboxyl groups to reduce them, thereby adjusting the cured Amount of monomers having carboxyl-containing functional groups.

Examples of polyfunctional isocyanate curing agents include aromatic polyisocyanate curing agents, aliphatic polyisocyanate curing agents, and alicyclic polyisocyanate curing agents.

The aromatic polyisocyanate is not particularly limited, and examples include 1,3-phenylene diisocyanate, 4,4'-diphenylene diisocyanate, 1,4-phenylene diisocyanate , 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-toluene diisocyanate , 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate , 4,4',4"-triphenylmethane triisocyanate, ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate- 1,4-Dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3 - Tetramethylxylylene diisocyanate, etc.

The aliphatic polyisocyanate is not particularly limited, and examples thereof include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, and pentamethylene diisocyanate. Cyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate Grease, and 2,4,4-trimethylhexamethylene diisocyanate, etc.

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

Among polyisocyanates, 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'- Diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-toluene diisocyanate, hexamethylene diisocyanate isocyanate.

Multifunctional epoxy curing agents mainly refer to compounds with more than 2 epoxy groups and more than 1 tertiary nitrogen atom, such as N N-glycidyl aniline, N N-glycidyl toluidine, m- N·N-glycidylaminophenyl glycidyl ether, p－N·N-glycidylaminophenyl glycidyl ether, triglycidyl isocyanurate, N·N·N'·N'－ Tetraglycidyl diaminodiphenylmethane, N·N·N'·N'-tetraglycidyl-m-xylylenediamine, N·N·N'·N'·N”-pentahydric Glyceryl diethylene triamine, etc.

(photopolymerization initiator)

The compounding quantity of a photoinitiator is 0.1-20 mass parts with respect to 100 mass parts of (meth)acrylate polymers, Preferably it is 1-10 mass parts. When the mixing amount is too small, the peelability from the dicing tape after light irradiation will fall, and the pick-up defect of a semiconductor chip will become easy to generate|occur|produce. On the other hand, if the blending amount is too large, the photopolymerization initiator will ooze out on the surface of the adhesive, causing contamination.

As the photopolymerization initiator, benzoin, benzoin alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones, or the like are used.

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

Examples of acetophenones include benzoin alkyl ethers, acetophenone, 2,2-dimethoxy-2-acetophenone, 2,2-diethoxy-2-acetophenone, 1,1-dichloroacetophenone, etc.

Examples of the anthraquinones include 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and the like.

Examples of thioxanthones include 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, etc. .

Examples of ketals include acetophenone dimethyl ketal, benzyl diketal, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, bibenzyl, Diacetyl, β-chloroanthraquinone, etc.

The photopolymerization initiator can be used in combination of 1 type or 2 or more types of conventionally well-known photopolymerization accelerators as needed. As a photopolymerization accelerator, a benzoic acid system, a tertiary amine, etc. can be used. Triethylamine, tetraethylpentamine, dimethylaminoether, etc. are mentioned as a tertiary amine.

(adhesion imparting resin)

An adhesion-imparting resin may be blended in the adhesive composition. The tackifier resin is a terpene phenol resin obtained by completely or partially hydrogenating a terpene phenol resin.

The terpene phenol resin can be produced by making 1 mol of a terpene compound react with 0.1-50 phenols, for example.

Examples of terpene compounds include myrcene, alloocimene, ocimene, α-pinene, β-pinene, dipentene, limonene, α-phellandrene, α-terpinene, and γ-pine oil Terpinene, Terpinene, 1,8-Cineole, 1,4-Cineole, α-Terpineol, β-Terpineol, γ-Terpineol, Camphene, Tricyclene, Sabinene , p-menthadiene, carene, etc. Among these compounds, α-pinene, β-pinene, limonene, myrcene, alloocimene, and α-terpinene are particularly preferably used in the present invention.

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

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

The hydroxyl value of the fully or partially hydrogenated terpene phenol resin is preferably 50-250. When the hydroxyl value is less than 50, the reaction with the isocyanate-based curing agent is insufficient and oozes out to the surface of the adhesive, causing contamination. If it is greater than 250, the viscosity increases and copolymerization with (meth)acrylate occurs. Inhomogeneous mixing of objects, etc., unstable pickup characteristics.

The hydrogenation method is not particularly limited, and examples include the following method: using as a catalyst a noble metal such as palladium, ruthenium, rhodium, or a carrier such as activated carbon, activated alumina, or diatomaceous earth. Method, the hydrogenation rate can be determined by bromine value measurement, iodine value measurement, etc.

The hydrogenation rate of the fully or partially hydrogenated terpene phenol resin is preferably 30 mol % or more, more preferably 70 mol % or more. When it is less than 30 mol%, since the reaction inhibition of the photopolymerizable compound by irradiation of actinic light rays cannot fully reduce adhesive force, pick-up property will fall.

The compounding ratio of the fully or partially hydrogenated terpene phenol resin is preferably 0.5 to 100 parts by mass with respect to 100 parts by mass of the (meth)acrylate copolymer, more preferably 1.0 to 50 parts by mass. When the amount of fully or partially hydrogenated terpene phenol resin is 0.5 parts by mass or more, the adhesive force will not be too low, and the holding property of the semiconductor chip during dicing is maintained, and if it is 100 parts by mass or less, the occurrence of pick-up failure can be suppressed.

(additives, etc.)

Various additives such as softeners, anti-aging agents, fillers, conductive agents, ultraviolet absorbers, and light stabilizers can be added to the adhesive composition, for example.

The thickness of the adhesive layer is 3 to 7 μm, preferably 4 to 6 μm. If the adhesive layer is too thick, it will easily crack. In addition, if the adhesive layer is too thin, the adhesive force will be too low, and the chip holding property at the time of dicing may be lowered to cause chips to fly, or peelability may occur between the ring frame and the sheet.

(substrate film)

As the material of the base film, for example, an ionomer resin obtained by cross-linking the following substances with metal ions, etc.: polyvinyl chloride, polyethylene terephthalate, acetic acid-vinyl acetate copolymer, Ethylene-acrylic acid-acrylate film, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, propylene-based copolymer, ethylene-acrylic acid copolymer, and ethylene-(meth)acrylic acid copolymer or ethylene-(meth)acrylic acid copolymer Acrylic acid-(meth)acrylate copolymer, etc. The base film may be a mixture or a copolymer of these resins, or may be a laminate of films or sheets made of these resins.

As a material of the base film, ionomer resin is preferably used. As the ionomer resin, if a copolymer having ethylene units, methacrylic acid units and alkyl (meth)acrylate units is cross-linked with metal ions such as Na ⁺ , K ⁺ , Zn ²⁺ If the material resin is used, the cutting chip suppression effect is remarkable, so it is preferably used.

The base film may be a single-layer or multi-layer film or sheet made of the above materials, or may be a laminate of films made of different materials. The thickness of the base film is 50 to 200 μm, preferably 70 to 150 μm.

It is preferable to apply antistatic treatment to the base film. Examples of the antistatic treatment include a treatment in which an antistatic agent is incorporated into a base film, a treatment in which an antistatic agent is applied to the surface of a base film, and a treatment by corona discharge.

As an antistatic agent, a quaternary ammonium salt monomer etc. can be used, for example. Examples of quaternary ammonium salt monomers include (meth)acrylate dimethylaminoethyl chloride quaternary salt, (meth)acrylate diethylaminoethyl chloride quaternary salt, (meth)acrylate methyl Ethylaminoethyl ester quaternary chloride, p-dimethylaminostyrene chlorinated quaternary salt, and p-diethylaminostyrene chlorinated quaternary salt. Among them, dimethylaminoethyl methacrylate chloride quaternary salt is preferred.

The usage method of slipping agent and antistatic agent is not particularly limited, for example, adhesive agent can be coated on one side of substrate film, slipping agent and/or antistatic agent can be coated on its back side, also can slip agent and/or antistatic agent The electrostatic agent is mixed into the resin of the base film to form a sheet.

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

(slip agent)

In order to improve the spreadability after dicing, a slip agent may be applied to the adhesive non-contact surface of the base film, or a slip agent may be mixed into the base film.

The sliding agent is not particularly limited as long as it is a substance that lowers the coefficient of friction between the dicing tape and the expansion device, and examples thereof include silicone compounds such as silicone resins or (modified) silicone oils, fluororesins, hexagonal boron nitride, and carbon black. and molybdenum disulfide. These friction reducers may also be mixed with various components. For the production of electronic components in a clean room, it is preferable to use a silicone compound or a fluororesin. Among organosilicon compounds, especially copolymers having organosilicon macromonomer units are preferably used because they have good compatibility with the antistatic layer and can achieve a balance between antistatic properties and expansibility.

The specific process of the manufacturing method of the electronic component which concerns on this invention is demonstrated sequentially.

(1) Attachment process

First, in the attaching process, the dicing tape is attached to the semiconductor wafer or substrate and the ring frame. The semiconductor wafer may be a silicon wafer, a gallium nitride wafer, a silicon carbide wafer, a sapphire wafer, or other conventionally used wafers. The substrate may be a general-purpose substrate such as a package substrate in which chips are sealed with resin, an LED package substrate, or a ceramic substrate.

(2) Cutting process

In the dicing process, a semiconductor wafer or substrate is diced to form semiconductor chips or semiconductor components.

(3) Light irradiation process

In the photoirradiation step, the dicing tape is irradiated with active rays such as ultraviolet rays or electron beams. Actinic light is preferably irradiated from the base film side. As a light source of ultraviolet light, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, or a metal halide lamp can be used. In addition, electron beams may be used instead of ultraviolet rays, and α-rays, β-rays, and γ-rays may be used as electron beam light sources.

Light irradiation causes the adhesive layer to form a three-dimensional network and is cured, reducing the adhesive force of the adhesive layer. At this time, as described above, the dicing tape according to the present invention does not adhere excessively to the semiconductor wafer or the substrate even when heated, and thus sufficiently low adhesive force can be obtained by irradiation of ultraviolet rays or the like.

(4) Expansion and pick-up process

In the expanding/pick-up process, the dicing tape is stretched to expand the space between semiconductor chips or semiconductor parts, and the chips or parts are pushed up with pins, etc. Thereafter, chips or parts are attracted by vacuum chucks or pneumatic chucks, and the chips or parts are picked up by peeling them off the adhesive layer of the dicing tape. At this time, since the adhesive force of the dicing tape according to the present invention can be sufficiently reduced by irradiation of ultraviolet rays or the like, the peeling between the chip or the component and the adhesive layer becomes easy, and good pick-up performance is obtained, and there is no There are adverse phenomena such as residual glue.

<Manufacturing of dicing tape>

As a method of forming an adhesive layer on a base film to obtain a dicing tape, for example, there is a method of using a gravure coater, a comma coater, a rod coater, a knife coater, or a roll coater. A method in which the adhesive is directly coated on the substrate film by a coating machine; or a method in which the adhesive is applied to a release film and dried and bonded to the substrate film. The adhesive may also be printed on the substrate film using letterpress printing, gravure printing, offset printing, flexographic printing, offset printing, or screen printing, among others.

The dicing tape of the present invention is preferably used for adhering an assembly of electronic components called a workpiece in a dicing process and a back grinding process in the manufacturing process of electronic components.

【Example】

The adhesive compositions and dicing tapes related to Examples and Comparative Examples were produced according to the following formulations. The main compounding components and the result of each experiment example are shown in Table 1-Table 3.

The numerical values of the compositions in Tables 1 to 3 represent parts by mass. The numerical value of a photopolymerizable compound, a hardening|curing agent, and a photoinitiator shows the mass part when the (meth)acrylate copolymer was 100 parts. Details of the base film, photopolymerizable compound, curing agent, and photopolymerization initiator are as follows.

In addition, the weight average molecular weight is the value measured as the polystyrene conversion weight average molecular weight by gel permeation chromatography (GPC). Specifically, it is as follows.

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

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

Flow rate: 0.5ml/min

Detector: RI－8020

Concentration: 0.2wt/Vol%

Injection volume: 20μL

Living temperature: 40℃

System temperature: 40℃

Solvent: THF

Calibration curve: prepared using standard polystyrene (manufactured by PL Co., Ltd.), and the weight-average molecular weight (Mw) is expressed in terms of polystyrene.

<Base film>

· Resin film A: an ionomer resin film having a thickness of 80 μm, mainly composed of Zn salt of an ethylene-methacrylic acid-2-methylpropyl acrylate copolymer. MFR 2.8g/10min (JIS K7210 method, 210 degreeC), the Mitsui DuPont Polychemicals Co., Ltd. make (commercial item).

<Photopolymerizable compound>

Photopolymerizable compound A: a compound obtained by reacting the isocyanate of hexamethylene diisocyanate with the hydroxyl-containing acrylate mainly composed of dipentaerythritol pentaacrylate, the weight average molecular weight is 7500, And urethane acrylate oligomer (synthetic product) with 10 unsaturated double bond functional groups.

Photopolymerizable compound B: a polyurethane acrylate oligomer (synthetic product) with a weight average molecular weight of 4200 and an unsaturated double bond functional group number of 10 synthesized by the same method as photopolymerizable compound A

Photopolymerizable compound C: a polyurethane acrylate oligomer (synthetic product) with a weight average molecular weight of 2100 and an unsaturated double bond functional group number of 10 synthesized by the same method as photopolymerizable compound A

Photopolymerizable compound D: a polyurethane acrylate oligomer (synthetic product) with a weight average molecular weight of 10300 and a number of unsaturated double bond functional groups of 10 synthesized by the same method as photopolymerizable compound A

・Photopolymerizable compound E: a compound obtained by reacting an isophorone diisocyanate trimer isocyanate with a hydroxyl-containing acrylate mainly composed of dipentaerythritol pentaacrylate, weight average molecular weight The polyurethane acrylate oligomer (synthetic product) is 4900 and has 15 unsaturated double bond functional groups.

In addition, the photopolymerizable compound was prepared by the well-known method described in Unexamined-Japanese-Patent No. 61-42529 etc.,.

<curing agent>

・Curing agent A: trimethylolpropane adduct of 2,4-toluene diisocyanate (commercially available)

· Curing agent B: trimethylolpropane 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)

【Table 1】

【Table 2】

【table 3】

(1) Adhesion

According to JIS Z 0237; 2009, using a tensile tester (manufactured by A&D Corporation, RTG-1210), measure the dicing tape attached to the mirror surface of a silicon wafer by the 180° peeling method after 20 minutes at 23°C and a relative humidity of 50 Adhesion under %. The stretching speed is 300 mm/min, and the size of the dicing tape is 250 mm×20 mm. In addition, the mirror surface of a silicon wafer used the mirror surface manufactured based on JISH0614.

(2) Evaluation of chip retention, pick-up and cracking

The obtained dicing tape was bonded to a silicon wafer having a diameter of 8 inches x a thickness of 0.15 mm and a ring frame on which a dummy circuit pattern was formed. After bonding for 20 minutes, irradiate 150mJ/cm ² of ultraviolet rays with a high-pressure mercury lamp, and then perform cutting and picking processes.

The conditions of the cutting process are as follows.

Cutting device: DAD341 manufactured by DISCO

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

Cutting blade shape: outer diameter 55.56mm, blade width 35μm, inner diameter 19.05mm

Cutting blade speed: 40000rpm

Cutting blade feed speed: 100mm/sec

Cutting size: 1.0mm square

Cutting amount in dicing tape: 30μm

Cutting water temperature: 25℃

Cutting water volume: 1.0 L/min

The conditions of the picking up process are as follows.

Pickup device: CAP-300II manufactured by Canon Machinery

Expansion: 8mm

Pin shape: 70μmR

Number of pins: 1

Pin push-up height: 0.3mm

In the dicing process and the picking-up process, the following evaluations were performed.

(2－1) Chip retention

Chip retention was evaluated on the basis of the following criteria based on the residual ratio of semiconductor chips held by the dicing tape after the dicing process.

◎(Excellent): Chip scattering is less than 5%

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

× (impossible): Chip scattering is 10% or more

(2－2) Pickup

Pickup performance was evaluated on the basis of the following criteria based on the ratio of semiconductor chips that can be picked up in the pick-up process.

◎(Excellent): The chip picking success rate is over 95%

○ (Good): The chip picking success rate is above 80% and below 95%

× (Not allowed): The chip picking success rate is less than 80%

(2－3)Chipping

For chipping, 50 picked-up chips were randomly selected, and the four sides on the back of the chip were observed with a microscope at magnification of 500, and the size of the largest defect in the center direction was evaluated according to the following criteria.

◎(Excellent): The defect size is less than 25μm

○ (good): The size of the defect is 25 μm or more and less than 50 μm

× (impossible): The size of the defect is 50 μm or more

(3) Pollution

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

◎(Excellent): Less than 500 particles

○ (good): 501 or more particles and less than 2,000 particles.

× (impossible): 2000 or more particles.

(4) The chip is loose

Chip looseness was evaluated on the basis of the following criteria based on the ratio of semiconductor chips adjacent to the semiconductor chip to be picked up in the pick-up process loosened by the impact of the pins.

◎(Excellent): Chip looseness is less than 1%

○ (good): chip looseness is more than 1% and less than 3%

× (impossible): Chip looseness is more than 3%

(investigation)

As shown in Examples and Comparative Examples in Tables 1 to 3, in all Examples in which an adhesive layer having a thickness of 3 to 7 μm was formed using an adhesive of a specific composition, the overall judgment was ◯ or ⊚. On the other hand, in all comparative examples in which the composition of the adhesive and the thickness of the adhesive layer were out of specification, the overall judgment was x. From these results, it was confirmed that when the dicing tape of the present invention is used, chipping, chip flying, and adhesive residue can be effectively suppressed, and pick-up properties can be improved.

Further detailed analysis was performed as described below.

In Comparative Example 1, since there were too few methyl (meth)acrylate units, the contamination property was poor.

In Comparative Example 2, since there were too many methyl (meth)acrylate units, the chip holding property was poor, and the chip was easily loosened.

In Comparative Example 3, since there were too few monomer units having a carboxyl group, chip retention was poor.

In Comparative Example 4, since there were too many monomer units having a carboxyl group, the pick-up property and contamination property were poor.

In Comparative Example 5, since there were too few monomer units having a hydroxyl group, the contamination property was poor.

In Comparative Example 6, since there were too many monomer units having a hydroxyl group, the chip was easily loosened.

In Comparative Example 7, since the photopolymerizable compound was too small, the chip retention and pick-up properties were inferior.

In Comparative Example 8, since there was too much photopolymerizable compound, the contamination property was poor, and the chip was easily loosened.

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

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

In Comparative Example 11, since the curing agent was too small, the staining property was poor.

In Comparative Example 12, since there was too much curing agent, the chip retention and contamination properties were poor, and the chip was easily loosened.

In Comparative Example 13, since the photopolymerization initiator was too small, the pick-up property was poor.

In Comparative Example 14, since there was too much photopolymerization initiator, the contamination property was poor, and the chip was easily loosened.

In Comparative Example 15, since the adhesive layer was too thin, the chip holding property was poor, and the chip was easily loosened.

In Comparative Example 16, since the adhesive layer was too thick, cracking easily occurred and the pick-up property was poor.

Claims (4)

1. A dicing tape formed by laminating an adhesive layer composed of an adhesive composition on a base film, wherein: The adhesive composition contains 100 parts by mass of a (meth)acrylate 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, The (meth)acrylate copolymer contains 35 to 85% by mass of methyl (meth)acrylate units, 10 to 60% by mass of 2-ethylhexyl (meth)acrylate units, and 0.5% of monomer units having carboxyl groups. ~10% by mass, and 0.05 ~ 5% by mass of monomeric units having hydroxyl groups, The photopolymerizable compound is a polyurethane acrylate oligomer with a weight average molecular weight of 4000-8000 and an unsaturated double bond functional group of 10-15, The thickness of the adhesive layer is 3-7 μm. 2. The dicing tape according to claim 1, wherein the curing agent is a multifunctional isocyanate curing agent or a multifunctional epoxy curing agent. 3 . The dicing tape according to claim 1 , wherein the adhesive force of the dicing tape to the mirror surface of the silicon wafer measured in accordance with JIS Z 0237 is 5.0 N/20 mm or more. 4 . 4. A method of manufacturing an electronic component, characterized in that it has the following steps: (a) attaching process, attaching dicing tape on semiconductor wafer or substrate and ring frame; (b) cutting process, cutting the semiconductor wafer or substrate to form semiconductor chips or semiconductor components; (c) light irradiation process, irradiating active light to the dicing tape; (d) an expanding step of stretching the dicing tape in order to expand the interval between the semiconductor chips or semiconductor parts; and (e) a pick-up process of picking up a semiconductor chip or a semiconductor component from the dicing tape; The dicing tape is the dicing tape according to any one of claims 1-3.