JPWO2012157615A1 - Method for manufacturing adhesive sheet and electronic component - Google Patents

Abstract

Providing a photocurable pressure-sensitive adhesive sheet in which softening of the pressure-sensitive adhesive layer due to heating hardly occurs. A pressure-sensitive adhesive sheet formed by laminating a photocurable pressure-sensitive adhesive layer on a base material, and the photocurable pressure-sensitive adhesive forming the photocurable pressure-sensitive adhesive layer comprises a (meth) acrylate copolymer and a photopolymerizable compound And a polyfunctional isocyanate curing agent and a photopolymerization initiator, and a pressure-sensitive adhesive sheet containing no tackifying resin. Since this pressure-sensitive adhesive sheet does not contain a tackifier resin, the pressure-sensitive adhesive layer does not soften even when heated.

Description

  The present invention relates to an adhesive sheet and a method for producing an electronic component using the adhesive sheet.

  For semiconductor wafers, the adhesive sheet is pasted after the circuit is formed, then cutting into element pieces (dicing), washing, drying, stretching of the adhesive sheet (expanding), peeling of the element pieces from the adhesive sheet (pickup) ), Distributed to each process such as mounting. The pressure-sensitive adhesive sheet (dicing tape) used in these processes has sufficient adhesive force against the cut element chips (chips) from the dicing process to the drying process, but has no adhesive residue during the pick-up process. It is desired that the adhesive strength is reduced to a certain extent.

  As the pressure-sensitive adhesive sheet, there is one in which a pressure-sensitive adhesive layer that undergoes a polymerization and curing reaction by ultraviolet light or the like is coated on a base material that is transparent to active rays such as ultraviolet rays and / or electron beams. In this pressure-sensitive adhesive sheet, 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 pressure-sensitive adhesive force, and then a cut chip is picked up.

  As such a pressure-sensitive adhesive sheet, Patent Document 1 and Patent Document 2 disclose a compound having a photopolymerizable unsaturated double bond in its molecule (polyfunctional) that can be three-dimensionally reticulated on the substrate surface by, for example, actinic rays. An adhesive sheet coated with an adhesive containing an oligomer) is disclosed.

  Patent Document 3 discloses a semiconductor processing pressure-sensitive adhesive sheet obtained by applying a pressure-sensitive adhesive layer comprising a base polymer, a radiation polymerizable compound, and a radiation polymerizable polymerization initiator on a substrate surface.

JP-A-60-196956 JP 60-223139 A JP 2002-285134 A

  In the semiconductor wafer processing step, when the performance of a semiconductor wafer on which a circuit is formed is tested to select a good product and a defective product, the semiconductor wafer may be heated. The semiconductor wafer is also heated when removing the cutting water in the dicing process.

  When such a semiconductor wafer is heated, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is softened by the heating, and the pressure-sensitive adhesive sheet may be excessively adhered to the semiconductor wafer. If the adhesive sheet is too close to the semiconductor wafer, even if the adhesive layer is cured by irradiating ultraviolet rays etc., the adhesive strength of the adhesive layer does not decrease sufficiently, making pick-up difficult and defects such as adhesive residue. Cause it to occur.

  Therefore, the main object of the present invention is to provide a pressure-sensitive adhesive sheet in which softening of the pressure-sensitive adhesive layer due to heating hardly occurs.

The present inventors have found that the softening of the tackifying resin contained in the pressure-sensitive adhesive causes the softening of the pressure-sensitive adhesive layer by heating.
Based on this knowledge, the present invention is a pressure-sensitive adhesive sheet obtained by laminating a photocurable pressure-sensitive adhesive layer on a substrate, and the photocurable pressure-sensitive adhesive forming the photocurable pressure-sensitive adhesive layer is (meth) acrylic acid. There is provided a pressure-sensitive adhesive sheet comprising an ester copolymer, a photopolymerizable compound, a polyfunctional isocyanate curing agent, and a photopolymerization initiator, and not including a tackifier resin. Since this pressure-sensitive adhesive sheet does not contain a tackifier resin, the pressure-sensitive adhesive layer does not soften even when heated.
In this pressure-sensitive adhesive sheet, the photocurable pressure-sensitive adhesive preferably contains a silicone-based graft copolymer, and the polyfunctional isocyanate curing agent preferably has three or more isocyanate groups. The photopolymerization initiator preferably has a temperature at which the mass reduction rate is 10% when the temperature is increased from 23 ° C. to 500 ° C. at a rate of temperature increase of 10 ° C./min. Further, the base material is preferably formed of a propylene-based copolymer, particularly a copolymer of propylene, 1-butene and ethylene.
This pressure-sensitive adhesive sheet is suitably used by being attached to the electronic component in the inspection process of the electronic component.
Further, the present invention is an adhesive for forming an adhesive layer of an adhesive sheet used by being attached to the electronic component in an inspection process of the electronic component, the (meth) acrylic acid ester copolymer and photopolymerization There is also provided a pressure-sensitive adhesive comprising a functional compound, a polyfunctional isocyanate curing agent, and a photopolymerization initiator and not including a tackifying resin.

Furthermore, this invention includes the heating process which heats the electronic component which affixed the adhesive sheet at 60-150 degreeC, The adhesive sheet formed by laminating | stacking a photocurable adhesive layer on a base material as said adhesive sheet The photocurable pressure-sensitive adhesive that is formed of a propylene-based copolymer and forms the photocurable pressure-sensitive adhesive layer comprises a (meth) acrylic acid ester copolymer and a photopolymerizable compound. There is also provided a method for producing an electronic component, characterized in that a pressure-sensitive adhesive sheet containing a polyfunctional isocyanate curing agent and a photopolymerization initiator and not containing a tackifying resin is used.
In this electronic component manufacturing method, the heating process for the performance test can be performed at least before or after the dicing process. That is, in this method of manufacturing an electronic component, a sticking step of sticking the adhesive sheet to a semiconductor wafer or substrate and a ring frame, and a semiconductor wafer or substrate to which the adhesive sheet is attached are placed on a stage at 60 to 150 ° C. The adhesive sheet is placed in contact with the stage, heated by adsorbing and fixing, a heating process for inspecting the semiconductor wafer or substrate, and the semiconductor wafer or substrate to which the adhesive sheet is attached is diced to obtain a semiconductor chip or semiconductor The dicing process to make parts, the light irradiation process to irradiate the photocurable adhesive layer of the adhesive sheet with actinic rays, the expanding process to stretch the adhesive sheet to widen the distance between semiconductor chips or semiconductor components, and the adhesive sheet to the semiconductor And a pickup process for picking up a chip or a semiconductor component. Kill. The electronic component manufacturing method includes an attaching step of attaching the adhesive sheet to a semiconductor wafer or substrate and a ring frame, and dicing the semiconductor wafer or substrate to which the adhesive sheet is attached to form a semiconductor chip or semiconductor component. The semiconductor chip or semiconductor component to which the adhesive sheet is attached is placed on the stage at 60 to 150 ° C. so that the adhesive sheet is in contact with the stage, and is heated by adsorbing and fixing the semiconductor chip or semiconductor. A heating process for inspecting parts, a light irradiation process for irradiating the photocurable adhesive layer of the pressure-sensitive adhesive sheet with actinic rays, an expanding process for expanding the pressure-sensitive adhesive sheet to widen the distance between semiconductor chips or semiconductor components, and a pressure-sensitive adhesive sheet Pickup process for picking up semiconductor chips or semiconductor components from It may be.

  Here, the “tackifying resin” is a resin that has been conventionally blended to increase the tackiness of an acrylic adhesive, such as a rosin resin, a terpene resin, an aliphatic petroleum resin, an aromatic petroleum resin. Hydrogenated petroleum resins, chroman indene resins, styrene resins, xylene resins, and mixtures of these resins.

  According to the present invention, a pressure-sensitive adhesive sheet is provided in which the pressure-sensitive adhesive layer is not easily softened by heating.

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.

1. Adhesive sheet (1) Photocurable adhesive (1-1) Tackifying resin (1-2) (Meth) acrylic acid ester copolymer (1-3) Photopolymerizable compound (1-4) Multifunctional isocyanate curing Agent (1-5) Photopolymerization initiator (2) Base material Manufacturing method of electronic parts (1) Sticking step (2) Heating step (3) Dicing step (4) Light (ultraviolet) irradiation step (5) Expanding / pickup step

1. Pressure-sensitive adhesive sheet The pressure-sensitive adhesive sheet according to the present invention is formed by laminating a photocurable pressure-sensitive adhesive layer (hereinafter also simply referred to as “pressure-sensitive adhesive layer”) on a base material, and does not contain a tackifying resin in the pressure-sensitive adhesive layer. And Since the pressure-sensitive adhesive sheet according to the present invention does not cause softening of the pressure-sensitive adhesive layer due to softening of the tackifying resin even when heated, it does not excessively adhere to a semiconductor wafer or the like. Therefore, in the pressure-sensitive adhesive sheet according to the present invention, a sufficient decrease in the adhesive strength of the pressure-sensitive adhesive layer can be obtained by irradiation with ultraviolet rays or the like, and pickup failure and adhesive residue can be prevented.

(1) Photocurable adhesive The photocurable adhesive forming the adhesive layer of the adhesive sheet according to the present invention is a (meth) acrylic acid ester copolymer, a photopolymerizable compound, a polyfunctional isocyanate curing agent, and light. It contains a polymerization initiator and does not contain a tackifier resin.

(1-1) Tackifying resin Although it does not specifically limit as tackifying resin which causes softening of the adhesive layer by heating, It is rosin resin, terpene resin, aliphatic petroleum resin, aromatic petroleum resin, hydrogenation. Examples include petroleum resins, chroman indene resins, styrene resins, xylene resins, and mixtures of these resins.

  As long as the tackifier does not contain a tackifier resin, various additives such as a peel imparting agent, an anti-aging agent, a filler, an ultraviolet absorber, and a light stabilizer may be added. For example, a silicone-based graft polymer can be used as the release imparting agent.

(1-2) (meth) acrylic acid ester copolymer (meth) acrylic acid ester copolymer is a polymer of (meth) acrylic acid ester monomer only, or (meth) acrylic acid ester monomer And a vinyl compound monomer. In addition, (meth) acrylate is a general term for acrylate and methacrylate. Similarly, a compound containing (meth) such as (meth) acrylic acid is a general term for a compound having “meta” in the name and a compound not having “meta”.

  Examples of the (meth) acrylic acid ester monomer include butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, octyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, tridecyl (meth) acrylate, myristyl ( (Meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl (meth) Acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxymethyl (meth) acrylate and ethoxy-n-propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate 4-hydroxybutyl (meth) acrylate.

  Examples of the vinyl compound monomer copolymerizable with the (meth) acrylic acid ester monomer include, for example, a carboxyl group, an epoxy group, an amide group, an amino group, a methylol group, a sulfonic acid group, a sulfamic acid group, or (sub) Examples thereof include a functional group-containing monomer having one or more functional groups such as a phosphate group.

Examples of the monomer having a carboxyl group include (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide N-glycolic acid and cinnamic acid.
Examples of the monomer having an epoxy group include allyl glycidyl ether and (meth) acrylic acid glycidyl ether.
Examples of the monomer having an amide group include (meth) acrylamide.
Examples of the monomer having an amino group include N, N-dimethylaminoethyl (meth) acrylate.
Examples of the monomer having a methylol group include N-methylolacrylamide.

(1-3) Photopolymerizable compound Examples of the photopolymerizable compound include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, and dipenta. Erythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, cyanuric acid triethyl acrylate, commercially available oligoester acrylate, and the like are used.

  As the photopolymerizable compound, a urethane acrylate oligomer can be used in addition to the acrylate compound. The urethane acrylate oligomer is 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 polyvalent isocyanate compound.

  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.

  As the photopolymerizable compound, a urethane acrylate oligomer having 4 or more vinyl groups is preferable in that the adhesive is cured well after irradiation with ultraviolet rays or the like.

  It is preferable that the compounding quantity of a photopolymerizable compound shall be 5 to 200 mass parts with respect to 100 mass parts of (meth) acrylic acid ester copolymers. If the blending amount of the photopolymerizable compound is reduced, the peelability of the pressure-sensitive adhesive sheet after irradiation is reduced, 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, pick-up failure is likely to occur due to the glue being picked up during dicing, and a minute adhesive residue due to a reaction residue is generated, which causes contamination.

(1-4) Polyfunctional isocyanate curing agent The polyfunctional isocyanate curing agent has two or more isocyanate groups. For example, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, and dimers thereof. Body, trimer, adduct body, etc. are used.

  Examples of the aromatic polyisocyanate 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, 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 It is 1,4-tetramethylxylylene diisocyanate and 1,3-tetramethylxylylene diisocyanate.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate and 2 4,4-trimethylhexamethylene diisocyanate.

  Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2, There are 4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylene bis (cyclohexyl isocyanate), 1,4-bis (isocyanate methyl) cyclohexane and 1,4-bis (isocyanate methyl) cyclohexane.

  Examples of the dimer, trimer and adduct include diphenylmethane diisocyanate dimer, hexamethylene diisocyanate trimer, trimethylolpropane and tolylene diisocyanate adduct, trimethylolpropane and hexamethylene diisocyanate. There is an adduct body.

  Among the above-mentioned polyisocyanates, those having three or more isocyanate groups are preferable, and in particular, a trimer of hexamethylene diisocyanate, an adduct of trimethylolpropane and tolylene diisocyanate, an adduct of trimethylolpropane and hexamethylene diisocyanate. Is preferred.

  The blending ratio of the polyfunctional isocyanate curing agent is preferably 0.5 parts by mass or more and 20 parts by mass or less, and more preferably 1.0 parts 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. preferable. If the polyfunctional isocyanate curing agent is 0.5 parts by mass or more, since the adhesive strength is not too strong, the occurrence of pickup failure can be suppressed. If a polyfunctional isocyanate hardening | curing agent is 20 mass parts or less, adhesive force will not fall and the retainability of a semiconductor chip will be maintained at the time of dicing.

(1-5) Photopolymerization initiator 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.

  The photopolymerization initiator preferably has a temperature of 250 ° C. or higher when the temperature is increased from 23 ° C. to 500 ° C. at a rate of temperature increase of 10 ° C./min and the mass reduction rate becomes 10%. When the pressure-sensitive adhesive sheet affixed to a wafer or the like is heated at 60 to 150 ° C. in the heating step described later, if the photopolymerization initiator volatilizes or deteriorates, the pressure-sensitive adhesive layer is not cured in the subsequent light irradiation step. This is sufficient, and a sufficient decrease in adhesive strength cannot be obtained, causing a pickup failure in the subsequent pickup process. For this reason, it is preferable to use a photopolymerization initiator which has the above properties and hardly volatilizes or deteriorates due to heating.

  Examples of the photopolymerization initiator having a temperature of 250 ° C. or higher include etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime). ) (Manufactured by BASF Japan, product name IRGACURE OXE02), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by BASF Japan, product name LUCIRIN TPO), and 2-hydroxy-1- {4- [ 4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (manufactured by BASF Japan, product name IRGACURE 127), 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl) -butanone-1 (manufactured by BASF Japan, product name IRGA URE369), 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (manufactured by BASF Japan, product name IRGACURE379), bis (2 , 4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by BASF Japan, product name IRGACURE819).

  Of these, particularly, the above-mentioned temperature is 270 ° C. or higher, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) ( BASF Japan, product name IRGACURE OXE02), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (BASF Japan, product name LUCIRIN TPO), and 2-hydroxy-1- {4- [4- (2-Hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (manufactured by BASF Japan, product name IRGACURE127) is preferred.

  As for the compounding quantity of a photoinitiator, 0.1 to 20 mass parts is preferable with respect to 100 mass parts of (meth) acrylic acid ester polymers. If the blending amount is too small, the peelability of the pressure-sensitive adhesive sheet after 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.

  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.

  The thickness of the pressure-sensitive adhesive layer is preferably 3 μm or more and 100 μm, particularly preferably 5 μm or more and 20 μm or less. If the pressure-sensitive adhesive layer is too thick, the pressure-sensitive adhesive strength becomes too high and the pick-up property is lowered. On the other hand, if the pressure-sensitive adhesive layer is too thin, the pressure-sensitive adhesive force becomes too low, chip retention during dicing is lowered, and peeling may occur between the ring frame and the sheet.

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

  A propylene-based copolymer is preferably used as the base material. Propylene-based copolymer with excellent heat resistance and extensibility is used as a material, so it will not soften or melt even when heated, it will not shrink, and it can be fully stretched in the expansion / pickup process. A pressure-sensitive adhesive sheet is obtained.

  Examples of the propylene-based copolymer include a random copolymer of propylene and other components, a block copolymer of propylene and other components, and an alternating copolymer of propylene and other components. Examples of other components include α-olefins such as ethylene, 1-butene, 1-pentene, 1-hexene and 1-heptene, copolymers composed of at least two kinds of α-olefins, and styrene-diene copolymers. is there.

  Among the propylene-based copolymers, a copolymer of propylene, 1-butene and ethylene is particularly preferable. Since a copolymer of propylene, 1-butene and ethylene has flexibility in addition to heat resistance, a pressure-sensitive adhesive sheet with good expandability can be obtained by using this copolymer.

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

  The base material is preferably subjected to an antistatic treatment. Examples of the antistatic treatment include a treatment for adding an antistatic agent to the substrate, a treatment for applying the antistatic agent to the substrate surface, 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.

2. Manufacturing method of electronic component The manufacturing method of the electronic component which concerns on this invention includes the process of heating the electronic component which affixed the above-mentioned adhesive sheet at 60-150 degreeC. Hereinafter, specific steps of the manufacturing method will be described in order. In the present invention, “electronic component” refers to, for example, a semiconductor wafer, a substrate, a semiconductor chip, a semiconductor component, and the like.

(1) Affixing process First, in an affixing process, an adhesive sheet is affixed on a semiconductor wafer (or substrate) and a ring frame. The 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.

(2) Heating step When testing a circuit formed on a wafer or the like, the wafer or the like is heated at about 60 to 150 ° C for about 15 minutes to 5 hours after the attaching step. Specifically, the semiconductor wafer or substrate on which the adhesive sheet is affixed is placed on a stage at 60 to 150 ° C. so that the adhesive sheet is in contact with the stage, and is heated by adsorbing and fixing the semiconductor wafer or substrate. inspect. In addition, when a circuit test is performed after obtaining a semiconductor chip or a semiconductor component, a heating process is performed in the same manner after a dicing process described below. That is, a semiconductor chip or a semiconductor component with an adhesive sheet attached is placed on a stage at 60 to 150 ° C. so that the adhesive sheet is in contact with the stage, and is heated by adsorbing and fixing, thereby inspecting the semiconductor chip or semiconductor component. To do. Furthermore, the heating step is also performed for the purpose of removing cutting water after the dicing step, and similarly, the semiconductor chip or the like is heated at about 60 to 150 ° C. for about 15 minutes to 5 hours.

  Since the pressure-sensitive adhesive sheet according to the present invention does not cause softening of the pressure-sensitive adhesive layer due to softening of the tackifying resin even when heated, it does not excessively adhere to a semiconductor wafer or the like. Therefore, in the method for manufacturing an electronic component according to the present invention, in the ultraviolet ray irradiation step and the pickup step described later, the adhesive force of the pressure-sensitive adhesive layer can be sufficiently lowered by irradiation with ultraviolet rays and the like, and pickup defects and adhesive residue can be prevented.

(3) Dicing process In the dicing process, a silicon wafer or the like is diced into semiconductor chips or semiconductor components. After the dicing process, the above heating process may be performed for the purpose of removing cutting water.

(4) Light irradiation process In a light irradiation process, actinic rays, such as an ultraviolet-ray, are irradiated to a photocurable adhesive layer from the base material 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-dimensionally reticulated and cured by light irradiation, and the adhesive strength of the pressure-sensitive adhesive layer is reduced. At this time, as described above, since the pressure-sensitive adhesive sheet according to the present invention does not excessively adhere to a wafer or the like even when heated, a sufficient decrease in adhesive force can be obtained by irradiation with ultraviolet rays or the like.

(5) Expanding and Picking Up Step In the expanding and picking up step, the adhesive sheet is stretched to widen the gap 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 adhesive sheet and picked up. At this time, in the pressure-sensitive adhesive sheet 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 becomes easy, and good pick-up properties are obtained. And no defects such as glue residue occur.

  After the pick-up process, the picked-up chip or component is mounted on the lead frame via a die attach paste. After mounting, the die attach paste is heated, and the chip or component and the lead frame are heat bonded. Thereafter, the chip or component mounted on the lead frame is molded with resin.

<Example 1>
A photocurable pressure-sensitive adhesive was prepared according to the formulation shown in “Table 1”. The photocurable pressure-sensitive adhesive was applied onto a polyethylene terephthalate separator film, and coated so that the thickness of the pressure-sensitive adhesive layer after drying was 10 μm. This pressure-sensitive adhesive layer was laminated on a base film and aged at 40 ° C. for 7 days to obtain a pressure-sensitive adhesive sheet. As the base film (K-1), a propylene-based copolymer (product number: X500F) manufactured by Sun Allomer Co., Ltd. was used to form a film having a thickness of 80 μm by T-die extrusion.

[Base film]
K-1: Propylene copolymer (product number: X500F) manufactured by Sun Allomer Co., which contains propylene, 1-butene and ethylene as polymerization components, MFR (melt flow rate) value is 7.5 g / 10 min, density is 0.89 g / Cm ³ .
K-2: Propylene copolymer (product number: Q300F) manufactured by Sun Allomer Co., which contains propylene and ethylene as polymerization components, MFR value 0.9 g / 10 min, density 0.89 g / cm ³ .
K-3: ethylene copolymer manufactured by Tosoh Corporation (product number: Ultracene 537), vinyl acetate content 6%, MFR value 8.5 g / 10 min, density 0.93 g / cm ³ .
K-4: Low density polyethylene (product number: Petrocene 170) manufactured by Tosoh Corporation, MFR value 1.0 g / 10 min, density 0.92 g / cm ³ .

[Photo-curing adhesive]
[(Meth) acrylic acid ester copolymer]
A-1: Acrylic rubber AR53L manufactured by Nippon Zeon Co., Ltd .; a copolymer of ethyl acrylate 54%, butyl acrylate 19%, methoxyethyl acrylate 24%, obtained by emulsion polymerization.
A-2: SK dyne 1496 manufactured by Soken Chemical Co., Ltd .; a copolymer of 96% 2-ethylhexyl acrylate and 4% 2-hydroxyethyl acrylate, obtained by solution polymerization.
[Photopolymerizable compound]
B-1: UN-905 manufactured by Negami Kogyo Co., Ltd. A trimer of isophorone diisocyanate was reacted with an acrylate containing dipetaerythritol pentaacrylate as a main component, and the number of vinyl groups was 15.
B-2: Shin-Nakamura Chemical A-TMPT; trimethylolpropane triacrylate, the number of vinyl groups is three.
[Multifunctional isocyanate curing agent]
C-1: Coronate L-45E manufactured by Nippon Polyurethane Co .; Trimethylolpropane adduct of 2,4-tolylene diisocyanate.
C-2: trimethylene diisocyanate.
(Photopolymerization initiator)
D-1: IRSFACURE OXE02 manufactured by BASF Japan Ltd .; ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime), mass decreased The temperature is 320 ° C. when the rate is 10%.
D-2: LUSFIRIN TPO manufactured by BASF Japan; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, temperature 270 ° C. when mass reduction rate is 10%.
D-3: IRGACURE127 manufactured by BASF Japan; 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one, Temperature 275 ° C. when mass reduction rate is 10%.
D-4: IRSFACURE 651 manufactured by BASF Japan; benzyl dimethyl ketal, temperature 185 ° C. when mass reduction rate is 10%.
[Silicone-based graft copolymer]
E-1: UTMM-LS2 manufactured by Soken Chemical Co., Ltd .; a silicone graft copolymer obtained by polymerizing a silicone oligomer unit having a (meth) acryloyl group at the end of a silicone molecular chain and an acrylic vinyl unit comprising methyl methacrylate Polymer.
[Tackifying resin]
F-1: YS Polystar S145 manufactured by Yasuhara Chemical; terpene phenol-based tackifier resin, softening point 145 ° C.

  The obtained adhesive sheet was bonded to a silicon wafer having a diameter of 8 inches and a thickness of 0.1 mm on which a dummy circuit pattern was formed and a ring frame, and diced. The silicon wafer was placed on a hot plate so that the surface opposite to the surface to which the adhesive sheet was applied was in contact, heated at 120 ° C. for 1 hour, and then subjected to light irradiation and expand / pickup processes.

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 rate: 50 mm / sec. Dicing size: 10 mm square cut depth: 15 μm
Cutting water temperature: 25 ° C
Cutting water volume: 1.0 l / min

The conditions of the light irradiation process were as follows.
UV irradiation: 150 mJ / cm ² with a high-pressure mercury lamp

The conditions for the expanding and picking up process were as follows.
Pickup device: CAP-300II manufactured by Canon Machinery
Expanding amount: 8mm
Needle pin shape: 250μmR
Number of needle pins: 5 Needle pin push-up height: 0.3 mm

The following evaluations were performed in the dicing process and the expand pickup process.
(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 adhesive sheet after the dicing step.
Excellent: Chip skipping is less than 5% Good: Chip skipping is 5% or more and less than 10% Impossibility: Chip skipping is 10% or more

(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% Impossibility: Chip pickup success rate is less than 80%

  The evaluation results are shown in “Table 1”. In the pressure-sensitive adhesive sheet according to Example 1, both the chip holding property and the pickup property were evaluated as excellent.

<Examples 2 to 11>
Table 1 shows the types of base film materials, (meth) acrylic acid ester copolymers and photopolymerizable compounds, polyfunctional isocyanate curing agents, photopolymerization initiators, and silicone-based graft copolymers. A pressure-sensitive adhesive sheet was produced and evaluated in the same manner as in Example 1 except for the above changes. The results are shown in “Table 1”.

<Examples 12 to 20>
The adhesive sheet obtained in the same manner as in Example 1 was bonded to a silicon wafer having a diameter of 8 inches and a thickness of 0.1 mm on which a dummy circuit pattern was formed, and a ring frame, followed by dicing. A silicon wafer is placed on a hot plate so that the surface opposite to the surface to which the adhesive sheet is attached is heated and heated under the conditions shown in “Table 1”. 1 and under the same conditions. The results are shown in “Table 1”.

<Comparative Example 1>
A pressure-sensitive adhesive sheet was produced and evaluated in the same manner as in Example 1 except that the silicone-based graft copolymer was not added and a tackifier resin was added. The results are shown in “Table 1”.

  In Examples 2 to 20, good chip retention and pickup properties were confirmed. On the other hand, in Comparative Example 1, the pick-up property was poor and the adhesive residue was remarkable.

The pressure-sensitive adhesive sheet according to the present invention does not cause softening of the pressure-sensitive adhesive layer even when heated, and does not excessively adhere to a semiconductor wafer or the like. And good pick-up properties can be obtained. Therefore, the pressure-sensitive adhesive sheet according to the present invention is suitable when a semiconductor wafer processing process includes a heating process for the purpose of performance testing of a semiconductor wafer or the like on which a circuit is formed or cutting water removal in a dicing process. Can be used.

Claims (11)

A pressure-sensitive adhesive sheet formed by laminating a photocurable pressure-sensitive adhesive layer on a substrate,
The photocurable pressure-sensitive adhesive forming the photocurable pressure-sensitive adhesive layer comprises a (meth) acrylic acid ester copolymer, a photopolymerizable compound, a polyfunctional isocyanate curing agent, and a photopolymerization initiator, and a tackifying resin. An adhesive sheet characterized by not containing.   The pressure-sensitive adhesive sheet according to claim 1, wherein the photocurable pressure-sensitive adhesive contains a silicone-based graft copolymer.   The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the polyfunctional isocyanate curing agent has three or more isocyanate groups.   The temperature at which the photopolymerization initiator has a mass reduction rate of 10% when heated from 23 ° C to 500 ° C at a rate of temperature increase of 10 ° C / min is 250 ° C or higher. The pressure-sensitive adhesive sheet according to item.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the base material is formed of a propylene-based copolymer.   The pressure-sensitive adhesive sheet according to claim 5, wherein the propylene-based copolymer is a copolymer of propylene, 1-butene and ethylene.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive sheet is used by being attached to the electronic component in an inspection process of the electronic component.   A pressure-sensitive adhesive for forming a pressure-sensitive adhesive layer of a pressure-sensitive adhesive sheet used by being attached to an electronic component in an inspection process of the electronic component, comprising a (meth) acrylate copolymer, a photopolymerizable compound, and a polyfunctional isocyanate A pressure-sensitive adhesive comprising a curing agent and a photopolymerization initiator and not including a tackifying resin. Including a heating step of heating the electronic component with the adhesive sheet pasted at 60 to 150 ° C.,
The pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet obtained by laminating a photocurable pressure-sensitive adhesive layer on a base material, and the base material is formed of a propylene-based copolymer to form the light-curable pressure-sensitive adhesive layer. The curable pressure-sensitive adhesive comprises a (meth) acrylic acid ester copolymer, a photopolymerizable compound, a polyfunctional isocyanate curing agent, and a photopolymerization initiator, and uses a pressure-sensitive adhesive sheet that does not contain a tackifying resin. Manufacturing method of electronic components. An attaching step of attaching the adhesive sheet to a semiconductor wafer or substrate and a ring frame;
The semiconductor wafer or substrate to which the pressure-sensitive adhesive sheet is attached is placed on a stage at 60 to 150 ° C. so that the pressure-sensitive adhesive sheet is in contact with the stage, heated by suction fixing, and the semiconductor wafer or substrate is inspected. The heating step;
A dicing step of dicing the semiconductor wafer or substrate to which the adhesive sheet is affixed into a semiconductor chip or a semiconductor component;
A light irradiation step of irradiating the photocurable pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet with actinic rays;
An expanding step of stretching the adhesive sheet to widen the gap between the semiconductor chips or semiconductor components;
The manufacturing method of the electronic component of Claim 9 including the pick-up process which picks up the said semiconductor chip or semiconductor component from the said adhesive sheet. An attaching step of attaching the adhesive sheet to a semiconductor wafer or substrate and a ring frame;
A dicing step of dicing the semiconductor wafer or substrate to which the adhesive sheet is affixed into a semiconductor chip or a semiconductor component;
The semiconductor chip or semiconductor component to which the adhesive sheet is attached is placed on a stage at 60 to 150 ° C. so that the adhesive sheet is in contact with the stage, and is heated by adsorbing and fixing the semiconductor chip or semiconductor component. The heating step to
A light irradiation step of irradiating the photocurable pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet with actinic rays;
An expanding step of stretching the adhesive sheet to widen the gap between the semiconductor chips or semiconductor components;
The manufacturing method of the electronic component of Claim 9 including the pick-up process which picks up the said semiconductor chip or semiconductor component from the said adhesive sheet.