JPWO2016111283A1 - Dicing tape - Google Patents

Abstract

Provided is a dicing tape which can suppress chip jumping and chipping in a dicing process even in a small and thin electronic component, can be easily picked up, and hardly causes adhesive residue. According to the present invention, it is a dicing tape formed by laminating a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive composition on a base film, and the pressure-sensitive adhesive composition comprises 100 parts by weight 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, and the (meth) acrylic acid ester copolymer is methyl (meth) Monomers having 35 to 85% by mass of acrylate units, 10 to 60% by mass of 2-ethylhexyl (meth) acrylate units, 0.5 to 10% by mass of monomer units having a carboxyl group, and monomers having a hydroxyl group A unit containing 0.05 to 5% by mass, 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, Dicing tape thickness of the serial pressure-sensitive adhesive layer, characterized in that a 3~7μm is provided.

Description

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

  The semiconductor wafer or substrate is applied to each process, such as cutting a dicing tape (dicing), stretching the dicing tape (expanding), and peeling the dicing tape from the dicing tape (pickup). Is done. The dicing tape used in these processes has sufficient adhesive strength to the cut element chips (chips) in the dicing process, but the adhesive strength is reduced to the extent that no adhesive remains during the pick-up process. It is hoped that

  As a dicing tape, there is one in which a pressure-sensitive adhesive layer that undergoes a polymerization and curing reaction by ultraviolet rays or the like is applied 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 step, ultraviolet light or the like is irradiated to the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is polymerized and cured to reduce the adhesive force, and then a cut chip is picked up.

  As such a dicing tape, Patent Document 1 and Patent Document 2 disclose a compound (polyfunctional) having a photopolymerizable unsaturated double bond in a molecule, which can be three-dimensionally reticulated on the base film surface by, for example, active light. A dicing tape coated with a pressure-sensitive adhesive containing a functional oligomer) is disclosed.

JP 2006-049509 A JP 2007-246633 A

  In recent years, along with the downsizing and thinning of electronic components, chip jumping and chipping (chip chipping) are likely to occur in the dicing process of a semiconductor wafer or substrate, which may cause a decrease in yield.

  Accordingly, the present invention mainly aims to provide a dicing tape that can suppress chip jumping and chipping in a dicing process even in a small and thin electronic component, can be easily picked up, and is less likely to have adhesive residue. .

  According to the present invention, it is a dicing tape formed by laminating a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive composition on a base film, and the pressure-sensitive adhesive composition comprises 100 parts by weight 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, and the (meth) acrylic acid ester copolymer is methyl (meth) Monomers having 35 to 85% by mass of acrylate units, 10 to 60% by mass of 2-ethylhexyl (meth) acrylate units, 0.5 to 10% by mass of monomer units having a carboxyl group, and monomers having a hydroxyl group A unit containing 0.05 to 5% by mass, 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, Dicing tape thickness of the serial pressure-sensitive adhesive layer, characterized in that a 3~7μm is provided.

  In general, when the thickness of the pressure-sensitive adhesive layer is reduced, chipping is less likely to occur, but the adhesive force is reduced and chip fly is likely to occur. Further, when the composition of the pressure-sensitive adhesive is adjusted in order to suppress the occurrence of chip jumping, problems such as chipping are likely to occur, pick-up properties are deteriorated, and adhesive residue is likely to occur. For this reason, it has been extremely difficult to improve the pick-up property while effectively suppressing chipping, chip jump, and adhesive residue.

  As a result of intensive studies to obtain a dicing tape excellent in all of these, the inventor found that when an adhesive layer having a thickness of 3 to 7 μm was formed using an adhesive having a specific composition, chipping and chip jumping were performed. The inventors have found that it is possible to improve the pick-up property while effectively suppressing adhesive residue, and have completed the present invention.

Preferably, the curing agent is a polyfunctional isocyanate curing agent or a polyfunctional epoxy curing agent.
Preferably, the adhesive force with respect to the mirror surface of the silicon wafer measured according to JISZ0237 of the dicing tape is 5.0 N / 20 mm or more.
According to another aspect of the present invention, (a) an attaching step of attaching a dicing tape to a semiconductor wafer or substrate and a ring frame, and (b) dicing the semiconductor wafer or substrate into a semiconductor chip or a semiconductor component. A dicing step, (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 interval between the semiconductor chips or semiconductor components, and (e) the above There is provided a method for manufacturing an electronic component, including a pickup step of picking up a semiconductor chip or a semiconductor component from a dicing tape, wherein the dicing tape is the dicing tape described above.

  The present invention provides a dicing tape that can suppress chip skipping and chipping in a dicing process even in a small and thin electronic component, can be easily picked up, and hardly causes adhesive residue.

  Hereinafter, preferred embodiments for carrying out the present invention will be described. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<Adhesive composition>
The pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer of the dicing tape of the present invention is 100 parts by weight of a (meth) acrylic acid ester copolymer, 5 to 250 parts by weight of a photopolymerizable compound, and 0.1 to 20 parts by weight of a curing agent. Part and a photoinitiator 0.1-20 mass part.

((Meth) acrylic acid ester copolymer)
The (meth) acrylic acid ester copolymer has a methyl (meth) acrylate unit of 35 to 85% by mass (preferably 45 to 75% by mass, more preferably 50 to 70% by mass, more preferably 55 to 65% by mass). 2-ethylhexyl (meth) acrylate unit of 10 to 60% by mass (preferably 20 to 50% by mass, more preferably 25 to 45% by mass, more preferably 30 to 40% by mass), and a single unit having a carboxyl group. The monomer unit is 0.5 to 10% by mass (preferably 2 to 7% by mass, more preferably 3 to 6% by mass, and further preferably 4 to 5% by mass), and the monomer unit having a hydroxyl group is 0.00. 05-5 mass% (preferably 0.1-3 mass%, more preferably 0.2-2 mass%, more preferably 0.3-1 mass%, more preferably 0.4-0.7 mass%) The amount%) containing. Since the (meth) acrylic acid ester copolymer is composed of such monomer units, the adhesive strength is sufficiently high even though the thickness of the pressure-sensitive adhesive layer is relatively small of 3 to 7 μm. A dicing tape can be obtained. In addition, it is preferable that the adhesive force with respect to the mirror surface of the silicon wafer measured based on JISZ0237 shall be 5.0 N / 20mm or more about the adhesive force of a dicing tape.

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

(Photopolymerizable compound)
The compounding quantity of a photopolymerizable compound is 5-250 mass parts with respect to 100 mass parts of (meth) acrylic acid ester copolymers, and 40-200 mass parts is preferable. When the blending amount of the photopolymerizable compound is reduced, the peelability of the dicing tape after irradiation with actinic rays such as ultraviolet rays is lowered, and the pick-up failure of the semiconductor chip is likely to occur. On the other hand, when the blending amount of the photopolymerizable compound is increased, the adhesive strength is excessively reduced by the light irradiation process, and chip separation occurs in the pickup process, 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. When the weight average molecular weight is small, the pressure-sensitive adhesive becomes flexible, so that chipping is likely to occur. When the weight average molecular weight is large, the adhesion to the adherend is lowered, and chip fly tends to occur. When the number of unsaturated double bond functional groups is small, the curability of the adhesive after light irradiation such as ultraviolet rays is reduced, and pickup failure tends to occur. When the number of unsaturated double bond functional groups is large, light irradiation such as ultraviolet rays is performed. Excessive curing of the adhesive causes chip chipping. Moreover, when a urethane acrylate oligomer is used, since it is excellent in adhesiveness and a softness | flexibility with a base film, there exists an advantage that it is hard to remain glue at the time of pick-up.

  The urethane acrylate oligomer is obtained by reacting a (meth) acrylate having a hydroxyl group with a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound such as polyester type or polyether type with a polyvalent isocyanate compound.

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

(Curing agent)
The compounding amount of the curing agent is 0.1 part by mass or more and 20 parts by mass or less, and preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer. If the amount of the curing agent is reduced, adhesive residue is likely to occur. On the other hand, when the compounding amount of the curing agent is increased, insufficient adhesive strength or chip dispersion occurs, which causes a decrease in productivity.

Examples of the curing agent include a polyfunctional isocyanate curing agent, a polyfunctional epoxy curing agent, an azirine 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 above curing agent, it is possible to selectively cause a functional group-containing monomer having a carboxyl group to react and disappear. It is possible to adjust the amount of the functional group-containing monomer having a carboxyl group after curing.

  Examples of the polyfunctional isocyanate curing agent include an aromatic polyisocyanate curing agent, an aliphatic polyisocyanate curing agent, and an alicyclic polyisocyanate curing agent.

  The aromatic polyisocyanate is not particularly limited, and for example, 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, 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 and the like.

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

  The alicyclic polyisocyanate is not particularly limited. For example, 3-isocyanate methyl-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 (isocyanatomethyl) cyclohexane, and 1,4-bis (isocyanatomethyl) cyclohexane There is.

  Among polyisocyanates, 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 and hexamethylene diisocyanate are preferably used.

  The polyfunctional epoxy curing agent mainly refers to a compound having two or more epoxy groups and one or more tertiary nitrogen atoms, such as N.N-glycidylaniline, N.N-glycidyltoluidine, mN.N-N-. Glycidylaminophenyl glycidyl ether, pN · N-glycidylaminophenyl glycidyl ether, triglycidyl isocyanurate, N · N · N '· N'-tetraglycidyldiaminodiphenylmethane, N · N · N' · N'-tetraglycidyl -M-xylylenediamine, N · N · N ′ · N ′ · N ″ -pentaglycidyldiethylenetriamine and the like.

(Photopolymerization initiator)
The compounding quantity of a photoinitiator is 0.1 mass part or more and 20 mass parts or less with respect to 100 mass parts of (meth) acrylic acid ester polymers, and 1 mass part or more and 10 mass parts or less are preferable. When the blending amount is too small, the peelability from the dicing tape after light irradiation is lowered, and the pick-up failure of the semiconductor chip is likely to occur. On the other hand, if the amount is too large, the photopolymerization initiator bleeds out to the pressure-sensitive adhesive surface, causing contamination.

  As the photopolymerization initiator, benzoin, benzoin alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones or xanthones 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, and the like.
Anthraquinones include 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 1-chloroanthraquinone and the like.
Examples of thioxanthones include 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.
Examples of ketals include acetophenone dimethyl ketal, benzyldimethylmethal, benzyldiphenylsulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloranthraquinone, and the like.

  In the photopolymerization initiator, conventionally known photopolymerization accelerators may be used alone or in combination of two or more as required. A benzoic acid type | system | group, a tertiary amine, etc. can be used for a photoinitiator. Examples of the tertiary amine include triethylamine, tetraethylpentamine, dimethylamino ether and the like.

(Tackifying resin)
You may mix | blend tackifier resin with an adhesive composition. The tackifier resin is a terpene phenol resin that is completely or partially hydrogenated with a terpene phenol resin.

  A terpene phenol resin can be manufactured by making 1 mol of terpene compounds and phenols 0.1-50 react, for example.

  As the terpene compound, myrcene, alloocimene, ocimene, α-pinene, β-pinene, dipentene, limonene, α-ferrandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, Examples include α-terpineol, β-terpineol, γ-terpineol, camphene, tricyclene, sabinene, paramentadienes, and carenes. 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, but are not limited to, phenol, cresol, xylenol, catechol, resorcin, hydroquinone, bisphenol A, and the like.

  Although the ratio of the phenols of a terpene phenol resin is about 25-50 mol%, it is not limited to these.

  The hydroxyl value of the completely or partially hydrogenated terpene phenol resin is preferably 50 to 250. When the hydroxyl value is less than 50, the reaction with the isocyanate curing agent is not sufficient, bleeds out to the surface of the pressure-sensitive adhesive, causing contamination, and when it exceeds 250, the viscosity increases and the (meth) acrylic acid ester This is because uneven mixing with a polymer or the like occurs and the pickup characteristics are not stable.

  The hydrogenation method is not particularly limited, and for example, a noble metal such as palladium, ruthenium, rhodium or the like supported on a carrier such as activated carbon, activated alumina, or diatomaceous earth is used as a catalyst. The hydrogenation rate can be measured by bromine number measurement, iodine number measurement or the like.

  The hydrogenation rate of the completely or partially hydrogenated terpene phenol resin is preferably 30 mol% or more, more preferably 70 mol% or more. When the amount is less than 30 mol%, the adhesive force is not sufficiently lowered due to the reaction inhibition of the photopolymerizable compound by irradiation with actinic rays, and the pickup property is lowered.

  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, and 100 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer. Less than the mass part is more preferable. If the completely or partially hydrogenated terpene phenol resin is 0.5 parts by mass or more, the adhesive strength is not too low, so the retention of the semiconductor chip is maintained during dicing, and if it is 100 parts by mass or less, the pickup is poor. Can be suppressed.

(Additives, etc.)
You may add various additives, such as a softening agent, anti-aging agent, a filler, a electrically conductive agent, a ultraviolet absorber, and a light stabilizer, to an adhesive composition.

  The thickness of the pressure-sensitive adhesive layer is 3 to 7 μm, preferably 4 to 6 μm. If the pressure-sensitive adhesive layer is too thick, chipping tends to occur. On the other hand, if the pressure-sensitive adhesive layer is too thin, the adhesive strength becomes too low, chip retention during dicing is reduced, and chip fly may occur, or peeling may occur between the ring frame and the sheet.

(Base film)
Examples of the material for the base film include polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylic ester film, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, and propylene-based copolymer. Polymers, ethylene-acrylic acid copolymers, and ionomer resins obtained by cross-linking ethylene- (meth) acrylic acid copolymers, ethylene- (meth) acrylic acid- (meth) acrylic acid ester copolymers, etc. with metal ions Etc. The base film may be a mixture or copolymer of these resins, and may be a laminate of films or sheets made of these resins.

It is preferable to use an ionomer resin as a material for the base film. Among ionomer resins, if an ionomer resin obtained by crosslinking a copolymer having an ethylene unit, a methacrylic acid unit, and a (meth) acrylic acid alkyl ester unit with a metal ion such as Na ⁺ , K ⁺ , or Zn ²⁺ is used, cutting is performed. The dust suppressing 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 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.

  The base film is preferably subjected to an antistatic treatment. As the antistatic treatment, there are a treatment of adding an antistatic agent to the base film, a treatment of applying the antistatic agent to the surface of the base film, and a treatment by corona discharge.

  As the antistatic agent, for example, a quaternary amine salt monomer 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-dimethyl. Examples include aminostyrene quaternary chloride and p-diethylaminostyrene quaternary chloride. Of these, dimethylaminoethyl methacrylate quaternary chloride is preferred.

  The method of using the slip agent and the antistatic agent is not particularly limited. For example, the adhesive may be applied to one side of the base film, and the slip agent and / or the antistatic agent may be applied to the back side thereof. Alternatively, an antistatic agent may be kneaded into the resin of the base film to form a sheet.

  An adhesive can be laminated on one side of the base film, and the other side can be an embossed surface with an average surface roughness (Ra) of 0.3 to 1.5 μm. By installing the embossed surface on the machine table side of the expanding device, the base film can be easily expanded in the expanding process after dicing.

(Slip agent)
In order to improve the expandability after dicing, a slipping agent can be applied to the adhesive non-contact surface of the base film, or a slipping agent can be kneaded into the base film.

  The slip agent is not particularly limited as long as it is a substance that lowers the coefficient of friction between the dicing tape and the expanding device. For example, silicone compounds such as silicone resin and (modified) silicone oil, fluororesin, hexagonal boron nitride, carbon black, And molybdenum disulfide. These friction reducing agents may mix a plurality of components. Since manufacture of an electronic component is performed in a clean room, it is preferable to use a silicone compound or a fluororesin. Among silicone compounds, a copolymer having a silicone macromonomer unit is particularly preferred because it has good compatibility with the antistatic layer and can achieve a balance between antistatic properties and expandability.

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

(1) Affixing process First, in an affixing process, a dicing tape is affixed on a semiconductor wafer or a substrate and a ring frame. The semiconductor wafer may be a conventional general-purpose wafer such as a silicon wafer and 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 process, the semiconductor wafer or substrate is diced into semiconductor chips or semiconductor components.

(3) Light irradiation step In the light irradiation step, the dicing tape is irradiated with actinic rays such as ultraviolet rays and electron beams. The actinic ray is preferably irradiated from the base film side. As the ultraviolet light source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or a metal halide lamp can be used. In addition, an electron beam may be used instead of ultraviolet rays, and α-rays, β-rays, and γ-rays can be used as a light source for the electron beams.

  The pressure-sensitive adhesive layer is three-dimensional networked and cured by light irradiation, and the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer is reduced. At this time, as described above, since the dicing tape according to the present invention does not excessively adhere to the semiconductor wafer or the substrate even when heated, a sufficient decrease in adhesive force can be obtained by irradiation with ultraviolet rays or the like.

(4) Expanding and Picking Up Step In the expanding and picking up step, the dicing tape is stretched to widen the distance between the semiconductor chips or semiconductor components, and the chip or components are pushed up with a needle pin or the like. Thereafter, the chip or component is adsorbed by a vacuum collet or air tweezers, peeled off from the adhesive layer of the dicing tape, and picked up. At this time, in the dicing tape according to the present invention, a sufficient decrease in the adhesive strength is obtained by irradiation with ultraviolet rays or the like, so that peeling between the chip or component and the pressure-sensitive adhesive layer is facilitated, and good pick-up properties are obtained. And no defects such as glue residue occur.

<Manufacture of dicing tape>
As a method of forming a pressure-sensitive adhesive layer on a substrate film to obtain a dicing tape, for example, a method of directly applying a pressure-sensitive adhesive on a substrate film with a coater such as a gravure coater, comma coater, bar coater, knife coater or roll coater Alternatively, there is a method in which a pressure-sensitive adhesive is applied to a release film and bonded to a base film after drying. The adhesive may be printed on the base film by convex plate printing, concave plate printing, flat plate printing, flexographic printing, offset printing, screen printing, or the like.

The dicing tape of the present invention is suitably used for attaching an electronic component assembly called a workpiece in a dicing step and a back grinding step, which are electronic component manufacturing steps.

  The adhesive composition and dicing tape which concern on an Example and a comparative example were manufactured with the following prescription. Tables 1 to 3 show the main formulations and the results of each experimental example.

  The numerical value about the composition in Table 1-Table 3 represents a mass part. The numerical value about a photopolymerizable compound, a hardening | curing agent, and a photoinitiator represents a mass part when a (meth) acrylic acid ester copolymer is 100 parts. Details of the base film, photopolymerizable compound, curing agent, and photopolymerization initiator are as follows.

In addition, a weight average molecular weight is the value measured as a weight average molecular weight of polystyrene conversion by the gel permeation chromatography method (GPC). Specifically, it is as follows.
Apparatus: GPC-8020 SEC system (manufactured by Tosoh Corporation)
Column: TSK Guard HZ-L + HZM-N 6.0 × 150 mm × 3
Flow rate: 0.5ml / min
Detector: RI-8020
Concentration: 0.2wt / Vol%
Injection volume: 20 μL
Column temperature: 40 ° C
System temperature: 40 ° C
Solvent: THF
Calibration curve: Prepared using standard polystyrene (manufactured by PL), and the weight average molecular weight (Mw) was expressed in terms of polystyrene.

<Base film>
Resin film A: Mainly composed of an ionomer resin film having a thickness of 80 μm and a Zn salt of ethylene-methacrylic acid-acrylic acid 2-methylpropyl copolymer. MFR 2.8 g / 10 min (JIS K7210 method, 210 ° C.), manufactured by Mitsui DuPont Polychemical Co., Ltd. (commercial product).

<Photopolymerizable compound>
Photopolymerizable compound A: a compound obtained by reacting an isocyanate of hexamethylene diisocyanate with a hydroxyl group-containing acrylate containing dipetaerythritol pentaacrylate as a main component, a weight average molecular weight of 7,500, and an unsaturated double bond Urethane acrylate oligomer (synthetic product) having 10 functional groups.
Photopolymerizable compound B: Urethane acrylate oligomer with a weight average molecular weight of 4,200 and unsaturated double bond functional group number 10 (synthesized product) synthesized by the same production method as photopolymerizable compound A
Photopolymerizable compound C: urethane acrylate oligomer (synthetic product) having a weight average molecular weight of 2,100 and an unsaturated double bond functional group of 10 synthesized by the same production method as photopolymerizable compound A
Photopolymerizable compound D: Urethane acrylate oligomer having a weight average molecular weight of 10,300 and an unsaturated double bond functional group of 10 synthesized by the same production method as that of photopolymerizable compound A (synthetic product)
Photopolymerizable compound E: a compound obtained by reacting an isocyanate of isophorone diisocyanate with a hydroxyl group-containing acrylate containing dipetaerythritol pentaacrylate as a main component, having a weight average molecular weight of 4,900, and unsaturated. Urethane acrylate oligomer (synthetic product) having 15 double bond functional groups.
The photopolymerization compound was prepared by a known method described in JP-A No. 61-42529.

<Curing agent>
Curing agent A: 2,4-tolylene diisocyanate trimethylolpropane adduct (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 product)
Photopolymerization initiator B: benzyl dimethyl ketal (commercially available)

(1) Adhesive strength Based on JIS Z 0237; 2009, using a tensile tester (manufactured by A & D Co., Ltd., RTG-1210), it was affixed to the mirror surface of a silicon wafer and the dicing tape after 20 minutes had passed. The adhesive strength was measured by a 180 ° peeling method at 23 ° C. and 50% relative humidity. The tensile speed was 300 mm / min, and the dicing tape size was 250 mm × 20 mm. In addition, the mirror surface of the silicon wafer used what was manufactured by JIS H0614.

(2) Evaluation of Chip Retention Property, Pickup Property and Chipping The obtained dicing tape was bonded to a ring frame and a silicon wafer having a diameter of 8 inches × thickness of 0.15 mm on which a dummy circuit pattern was formed. 20 minutes after bonding, ultraviolet rays were irradiated at 150 mJ / cm ² with a high-pressure mercury lamp, and then dicing and pick-up processes were performed.

The conditions for the dicing process were as follows.
Dicing machine: DAD341 manufactured by DISCO
Dicing blade: NBC-ZH205O-27HEEE made by DISCO
Dicing blade shape: outer diameter 55.56 mm, blade width 35 μm, inner diameter 19.05 mm
Dicing blade rotation speed: 40,000 rpm
Dicing blade feed speed: 100 mm / sec. Dicing size: 1.0 mm square cutting depth: 30 μm
Cutting water temperature: 25 ° C
Cutting water volume: 1.0 l / min

The conditions for the pick-up process were as follows.
Pickup device: CAP-300II manufactured by Canon Machinery
Expanding amount: 8mm
Needle pin shape: 70μmR
Number of needle pins: 1 Needle pin push-up height: 0.3 mm

  The following evaluation was performed in the dicing process and the pickup process.

(2-1) Chip Retention The chip retention was evaluated according to the following criteria based on the remaining ratio of the semiconductor chips held on the dicing tape after the dicing process.
◎ (Excellent): Chip skipping is less than 5% ○ (Good): Chip skipping is 5% or more and less than 10% × (Not possible): Chip skipping is 10% or more

(2-2) Pickup property Pickup property was evaluated according to the following criteria based on the rate at which a semiconductor chip could be picked up in the pickup process.
◎ (Excellent): Chip pickup success rate is 95% or more ○ (Good): Chip pickup success rate is 80% or more and less than 95% × (Not possible): Chip pickup success rate is less than 80%

(2-3) Chipping Chipping is performed by randomly selecting 50 picked-up chips, observing the four sides of the back of the chip with a 500x microscope, and measuring the maximum chip size in the direction of the following. It was evaluated by.
◎ (excellent): chip size is less than 25 μm ○ (good): chip size is 25 μm or more and less than 50 μm × (impossible): chip size is 50 μm or more

(3) A fouling dicing tape was affixed to the mirror surface of the silicon wafer, and after 20 minutes, ultraviolet rays were irradiated at 150 mJ / cm ² with a high-pressure mercury lamp, and then the dicing tape was peeled off. The number of particles of 0.28 μm or more remaining on the mirror surface (bonding surface) of the silicon wafer was measured with a particle counter.
◎ (excellent): 500 or less particles ○ (good): 501 or more and less than 2000 particles.
X (impossible): 2000 or more particles.

(4) Chip variation The chip variation was evaluated according to the following criteria based on the rate at which the semiconductor chip adjacent to the semiconductor chip to be picked up was scattered due to the impact of pin push-up in the pickup process.
◎ (excellent): chip variation is less than 1% ○ (good): chip variation is 1% or more and less than 3% × (impossible): chip variation is 3% or more

(Discussion)
As shown in the Examples and Comparative Examples in Tables 1 to 3, in all Examples in which a pressure-sensitive adhesive layer having a thickness of 3 to 7 μm was formed using a pressure-sensitive adhesive having a specific composition, the overall judgment was ○ or ◎. It was. On the other hand, in all the comparative examples in which the composition of the pressure-sensitive adhesive or the thickness of the pressure-sensitive adhesive layer was not specified, the overall judgment was x. From these results, it was proved that the pick-up property can be improved while the chipping, chip jump, and adhesive residue are effectively suppressed by using the dicing tape of the present invention.

A more detailed analysis is as follows.
In Comparative Example 1, the contamination was deteriorated because there were too few methyl (meth) acrylate units.
In Comparative Example 2, since there were too many methyl (meth) acrylate units, the chip retention was deteriorated, and chip scattering was likely to occur.
In Comparative Example 3, the chip retention was deteriorated because there were too few monomer units having a carboxyl group.
In Comparative Example 4, since there were too many monomer units having a carboxyl group, pick-up property and contamination were deteriorated.
In Comparative Example 5, since the monomer unit having a hydroxyl group was too small, the contamination was deteriorated.
In Comparative Example 6, since there were too many monomer units having a hydroxyl group, chip scattering was likely to occur.
In Comparative Example 7, since the amount of the photopolymerizable compound was too small, the chip holding property and the pickup property were deteriorated.
In Comparative Example 8, since there were too many photopolymerizable compounds, contamination | pollution property deteriorated and it became easy to produce chip dispersion | distribution.
In Comparative Example 9, since the weight average molecular weight of the photopolymerizable compound was too small, chipping was likely to occur.
In Comparative Example 10, the chip retention was deteriorated because the weight average molecular weight of the photopolymerizable compound was too large.
In Comparative Example 11, the contamination was deteriorated because the curing agent was too little.
In Comparative Example 12, since there were too many curing agents, chip retention and contamination were deteriorated, and chip scattering was likely to occur.
In Comparative Example 13, the pick-up property deteriorated because there was too little photopolymerization initiator.
In Comparative Example 14, since there were too many photopolymerization initiators, contamination | pollution property deteriorated and it became easy to produce chip dispersion | distribution.
In Comparative Example 15, since the pressure-sensitive adhesive layer was too thin, the chip retention was deteriorated, and the chip was easily broken.
In Comparative Example 16, since the pressure-sensitive adhesive layer was too thick, chipping was likely to occur, and the pick-up property was deteriorated.

Claims (4)

A dicing tape formed by laminating an adhesive layer made of an adhesive composition on a base film,
The pressure-sensitive adhesive composition comprises (meth) acrylic acid ester copolymer 100 parts by mass, photopolymerizable compound 5 to 250 parts by mass, curing agent 0.1 to 20 parts by mass, and photopolymerization initiator 0.1 to 20 parts by mass. Part
The (meth) acrylic acid ester copolymer is a monomer unit having a methyl (meth) acrylate unit of 35 to 85% by mass, a 2-ethylhexyl (meth) acrylate unit of 10 to 60% by mass, and a carboxyl group. 0.5 to 10% by mass, 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,
A dicing tape, wherein the pressure-sensitive adhesive layer has a thickness of 3 to 7 μm. The dicing tape according to claim 1, wherein the curing agent is a polyfunctional isocyanate curing agent or a polyfunctional epoxy curing agent. The dicing tape according to claim 1 or 2, wherein an adhesive force of the dicing tape to a mirror surface of a silicon wafer measured in accordance with 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 substrate and a ring frame;
(B) a dicing step of dicing the semiconductor wafer or substrate into a semiconductor chip or a semiconductor component;
(C) a light irradiation step of irradiating the dicing tape with actinic rays;
(D) an expanding step of stretching the dicing tape to widen the gap between the semiconductor chips or semiconductor components;
(E) including a pickup step of picking up a semiconductor chip or a semiconductor component from the dicing tape;
The said dicing tape is a manufacturing method of the electronic component which is a dicing tape as described in any one of Claims 1-3.