JP5210346B2 - Method for manufacturing adhesive sheet and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet having improved coating property on the surface of an adhesive of a dicing tape, and to provide a method for manufacturing electronic components by using the adhesive sheet. <P>SOLUTION: The adhesive sheet comprises a base film, an adhesive layer layered on one face of the base film, and a die-attach film layered on an exposed face of the adhesive layer. The adhesive in the adhesive layer comprises a (meth)acrylate ester polymer, a polyfunctional (meth)acrylate, a photopolymerization initiator and an isocyanate. Each of the (meth)acrylate ester polymer, the polyfunctional (meth)acrylate and the photopolymerization initiator has a hydroxy group. The isocyanate has at least three isocyanate groups. The molar quantity of isocyanate groups in the isocyanate is from 0.8 to 1.2 times of the molar quantity of hydroxy groups in all of the (meth)acrylate ester polymer, the polyfunctional (meth)acrylate and the photopolymerization initiator. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

The present invention relates to an adhesive sheet and an electronic component manufacturing method using the adhesive sheet.

As a method of manufacturing electronic components such as ICs, a circuit pattern is formed on a semiconductor wafer such as silicon or gallium arsenide or an insulating substrate to form an electronic component assembly, and this electronic component assembly is attached to an adhesive sheet, and a ring After fixing to the frame, dicing into individual chips. Thereafter, a method is widely used in which a pressure-sensitive adhesive sheet is stretched as necessary, a diced chip is picked up, an adhesive is applied to the picked-up chip, and is fixed to a lead frame or the like.

Here, in order to omit the step of applying the adhesive to the chip, a die attach film-integrated sheet that is a pressure-sensitive adhesive sheet having the function of an adhesive sheet for dicing and an adhesive for fixing the chip to a lead frame or the like is provided. A method of using it has been proposed. The die attach film integrated sheet is an adhesive sheet in which an adhesive sheet and a die attach film are integrated (see Patent Documents 1 to 3, etc.).

A radiation-polymerizable compound having two or more unsaturated bonds in a copolymer of (meth) acrylic acid ester and a hydroxyl group-containing polymerizable monomer as a pressure-sensitive adhesive for a pressure-sensitive adhesive sheet used when dicing an electronic component assembly A method of using is known (see Patent Document 4).

JP-A-2-24864 Japanese Patent Laid-Open No. 8-053655 JP 2004-186429 A Japanese Patent No. 3410202

When the pressure-sensitive adhesive component of the dicing tape is phase-separated, coating unevenness occurs on the surface of the pressure-sensitive adhesive, which is transferred to a die attach film, resulting in unstable quality.

This invention makes it a subject to provide the manufacturing method of the electronic component using the adhesive sheet which improved the applicability | paintability of the adhesive surface of a dicing tape, and an adhesive sheet.

The present invention comprises a base film, a pressure-sensitive adhesive layer laminated on one surface of the base film, and a die attach film laminated on the exposed surface of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer comprises: (Meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, photopolymerization initiator, and isocyanate-containing (meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, and light The polymerization initiator has a hydroxyl group, the isocyanate has three or more isocyanate groups, and the isocyanate group has a molar amount of “(meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, In addition, the pressure-sensitive adhesive sheet is 0.8 to 1.2 times the “hydroxyl mole amount of all hydroxyl groups in the photopolymerization initiator”.

The polyfunctional (meth) acrylate preferably has 3 or more (meth) acryloyl groups, and the photopolymerization initiator preferably has 2 or more hydroxyl groups.

In the above-mentioned pressure-sensitive adhesive, the blending ratio of the (meth) acrylic acid ester polymer is 100 parts by weight, the blending ratio of the polyfunctional (meth) acrylate is 20 parts by weight or more and 200 parts by weight or less, and the blending of the photopolymerization initiator. The ratio is preferably 0.05 parts by mass or more and 20 parts by mass or less.
Is preferred.

Another invention is a bonding step of bonding a silicon wafer to the die attach film surface of any one of the above-mentioned pressure-sensitive adhesive sheets, a dicing step of dicing the silicon wafer after the bonding step, and a dicing step This is a method for manufacturing an electronic component having a pickup step of picking up a silicon wafer and a die attach film later from an adhesive layer.

This invention can improve the applicability | paintability of the adhesive surface, when the adhesive component of a dicing tape suppresses phase separation.

It is sectional drawing which showed typically the manufacturing method of the electronic component using the adhesive sheet of this invention, and an adhesive sheet, and is the figure which showed the state after the bonding process. It is the figure which showed the state after the dicing process performed after the bonding process of FIG. It is the figure which showed the state at the time of the pick-up process performed after the dicing process of FIG. It is the figure which showed the state after a pick-up process.

DESCRIPTION OF SYMBOLS 1 Adhesive sheet 2 Base film 3 Adhesive layer 4 Die attach film 5 Silicon wafer 51 Die chip 6 Ring frame 7 Dicing blade 71 Notch 8 Lead frame

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Explanation of terms>
In the present specification, “parts” and “%” are based on mass unless otherwise specified, the (meth) acryloyl group is a general term for an acryloyl group and a methacryloyl group, and (meth) acrylic acid is A general term for acrylic acid and methacrylic acid.

<Outline of Embodiment>
1 to 4 are cross-sectional views schematically showing how to use the pressure-sensitive adhesive sheet of the present invention.
As shown in FIG. 1, the pressure-sensitive adhesive sheet of this embodiment includes a base film 2, a pressure-sensitive adhesive layer 3 laminated on one surface of the base film 2, and a diamond laminated on the exposed surface of the pressure-sensitive adhesive layer 3. The pressure-sensitive adhesive sheet 1 includes a touch film 4.

<Adhesive>
The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 3 contains a (meth) acrylic acid ester polymer, a polyfunctional (meth) acrylate, a photopolymerization initiator, and an isocyanate.

A (meth) acrylic acid ester polymer is a polymer obtained by polymerizing a (meth) acrylic acid ester monomer. The (meth) acrylic acid ester polymer may contain a vinyl compound monomer other than the (meth) acrylic acid ester monomer. The (meth) acrylic acid ester polymer needs to have a hydroxyl group.

As a monomer of (meth) acrylic acid ester, 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 Rate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxymethyl (meth) acrylate, and ethoxy-n-propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) There are acrylates and 2-hydroxybutyl (meth) acrylates. As other vinyl compound monomers, those having at least one functional group consisting of a hydroxyl group and a carboxyl group can be suitably used, and vinyl compound monomers having a hydroxyl group include vinyl alcohol. Examples of the vinyl compound 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.

A polyfunctional (meth) acrylate has a hydroxyl group and at least two (meth) acrylate groups. Polyfunctional (meth) acrylates containing a hydroxyl group and two or more (meth) acrylate groups include glycerol (meth) acrylate, pentaerythritol triacrylate, hydroxypropylated trimethylolpropane triacrylate, dipentaerythritol hydroxypentaacrylate, There are bis (pentaerythritol) tetraacrylate and tetramethylolmethane-triacrylate. The number of (meth) acrylate groups in the polyfunctional (meth) acrylate is preferably 3 or more, and more preferably 5 or more. By having three or more (meth) acrylate groups, the die attach film 4 and the pressure-sensitive adhesive layer 3 can be easily separated after irradiation, and the pick-up property of the die chip 51 can be improved. The upper limit of the number of (meth) acrylate groups is not particularly limited.

The blending ratio of the polyfunctional (meth) acrylate is preferably 20 parts by mass or more and 200 parts by mass or less, and particularly preferably 60 parts by mass or more and 100 parts by mass or less.

If the blending amount of the polyfunctional (meth) acrylate is too small, the peelability between the pressure-sensitive adhesive sheet and the die attach film in the pickup process described later tends to decrease, and if it is too large, the pressure-sensitive adhesive is scraped up during the dicing process. The adhesive that has been scraped tends to cause a decrease in accuracy in the pickup process.

The photopolymerization initiator has at least one hydroxyl group. As photopolymerization initiators having one hydroxyl group, 2-hydroxy-methyl-1-phenyl-propan-1-one (Darocur 1173 (registered trademark) manufactured by Ciba Japan), 1-hydroxy-cyclohexyl-phenyl-ketone ( As a photopolymerization initiator having two or more hydroxyl groups, 1- [4- (hydroxyethoxy) -phenyl] -2-hydroxy-2methyl-1-propane is available. -1-one (Irgacure 2959 (registered trademark) manufactured by Ciba Japan), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl -Propan-1-one (Irgacure 127 (registered trademark) manufactured by Ciba Japan). The number of hydroxyl groups in the photopolymerization initiator is preferably 2 or more. By having two or more, the photoinitiator cleaved after irradiation can be taken into the reaction system of the acryloyl group of the (meth) acrylate monomer, and migration to the die attach film 4 can be suppressed. . The upper limit of the number of hydroxyl groups is not particularly limited.

If the amount of the photopolymerization initiator is too small, the peelability between the pressure-sensitive adhesive sheet and the die attach film in the pickup process tends to decrease. Since it tends to cause adhesive residue on the body, it is preferably 0.05 parts by mass or more and 20 parts by mass or less, particularly preferably 0.5 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer. Or less.

The isocyanate needs to have a hydroxyl group and needs to have three or more isocyanate groups. Such isocyanate includes aromatic diisocyanate, alicyclic diisocyanate, and aliphatic diisocyanate, and aromatic isocyanate or alicyclic isocyanate is preferable. As a form of an isocyanate compound, there are a monomer, a dimer, and a trimer, and a trimer is preferable.

Examples of the aromatic diisocyanate include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and xylylene diisocyanate, and examples of the alicyclic diisocyanate include isophorone diisocyanate and methylene bis (4-cyclohexyl isocyanate).

Aliphatic diisocyanates include hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

As the diisocyanate, a trimethylolpropane adduct, a burette reacted with water, a trimer having an isocyanurate ring, and the like can be suitably used.

The blending amount of isocyanate is not determined according to “all blending ratios of (meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, and photopolymerization initiator” but based on the molar amount. If the molar amount of the isocyanate group is too small compared to “the molar amount of all hydroxyl groups of the (meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, and photopolymerization initiator”, the component having an unreacted hydroxyl group is didia. It may shift to touch film and cause deterioration of the characteristics of the die attach film.If it is too much, it will change with time when stored as a tape, and this may cause problems in quality stability. The amount is 0.8 to 1.2 times the “(meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, and all hydroxyl groups in the photopolymerization initiator”.

Additives such as a tackifier, a release agent, a softener, an anti-aging agent, a filler, an ultraviolet absorber, or a light stabilizer are added to the pressure-sensitive adhesive as long as the effects of the invention are not adversely affected. be able to.

If the lower limit of the thickness of the pressure-sensitive adhesive layer is too thin, chip retention during dicing tends to decrease due to a decrease in adhesive force, and peeling between the ring frame and the pressure-sensitive adhesive sheet tends not to occur. Preferably it is 1 micrometer, More preferably, it is 2 micrometers. The upper limit of the thickness of the pressure-sensitive adhesive layer is preferably 100 μm, more preferably 40 μm, because if it is too thick, the adhesive force tends to be too high and pickup failure tends to occur.

<Adhesive sheet>
As shown in FIG. 1, the pressure-sensitive adhesive sheet 1 includes a base film 2, a pressure-sensitive adhesive layer 3 formed of the above-mentioned pressure-sensitive adhesive applied on the base film 2, and a diamond laminated on the pressure-sensitive adhesive layer 3. It is formed by the touch film 4.

The material of the base film 2 is, for example, polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylate film, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, ethylene-acrylic acid. Copolymers and ionomer resins formed by crosslinking an ethylene- (meth) acrylic acid copolymer, an ethylene- (meth) acrylic acid- (meth) acrylic acid ester copolymer, etc. with metal ions, or these There are mixtures of resins and copolymers, as well as multilayers of these materials.

Of the above-mentioned resins, it is preferable to use an ionomer resin as the material of the base film 2. Among ionomer resins, it is possible to suppress the generation of shaving-like cutting scraps. “Copolymers having an ethylene unit, a (meth) acrylic acid unit, and a (meth) acrylic acid alkyl ester unit are Na ⁺ , K ⁺ , Zn ^2+, etc. An ionomer resin cross-linked with a metal ion is more preferable.

The base film 2 is subjected to an antistatic treatment on both or both of the contact surface and the non-contact surface of the die attach film 4 of the base film 2, or an antistatic agent is added to the synthetic resin constituting the base film. Thus, charging at the time of peeling of the die attach film 4 can be prevented.

Antistatic agents include quaternary amine salt monomers. Examples of the quaternary amine salt monomer include dimethylaminoethyl (meth) acrylate quaternary chloride, diethylaminoethyl (meth) acrylate quaternary chloride, methylethylaminoethyl (meth) acrylate quaternary chloride, p- There are dimethylaminostyrene quaternary chloride and p-diethylaminostyrene quaternary chloride, and among these, dimethylaminoethyl methacrylate quaternary chloride is preferred.

In the base film 2, the expandability after the dicing process is improved by laminating a lubricant on the non-contact surface of the die attach film 4 of the base film 2 or by blending the lubricant with a synthetic resin constituting the base film. Can be made.

The lubricant is a substance that lowers the coefficient of friction between the pressure-sensitive adhesive sheet 1 and the expanding device (not shown). For example, a silicone compound such as silicone resin or (modified) silicone oil, fluororesin, hexagonal boron nitride, carbon black, or In addition, there is a simple substance or a mixture of molybdenum disulfide, and a silicone compound or a fluororesin is preferable. Among silicone compounds, a copolymer having a silicone macromonomer unit is preferable. When a copolymer having a silicone macromonomer unit is used, the compatibility with the antistatic layer is good, and the balance between antistatic properties and expandability can be achieved.

It is preferable that the base film 2 has an embossed surface having an average surface roughness (Ra) of 0.3 μm or more and 1.5 μm or less on the surface opposite to the laminated side of the pressure-sensitive adhesive layer 3. By making it an embossed surface, the base film 2 can be easily expanded in the expanding step.

The thickness of the base film 2 is preferably 30 μm or more and 300 μm or less, more preferably 60 μm or more and 200 μm or less.

The method of forming the pressure-sensitive adhesive layer 3 on the base film 2 includes a method of directly applying the pressure-sensitive adhesive on the base film 2 with a coater such as a gravure coater, comma coater, bar coater, knife coater, or roll coater. is there. The adhesive may be printed on the base film 2 by letterpress printing, intaglio printing, planographic printing, flexographic printing, offset printing, screen printing, or the like.

<Die attach film>
The die attach film 4 is an adhesive sheet obtained by forming an adhesive or an adhesive into a film shape. The material of the die attach film 4 is, for example, epoxy resin, polyamide resin, acrylic resin, polyimide resin, vinyl acetate resin, ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, polysulfone, polyamic acid, silicone, There are a phenol resin, a rubber polymer, a fluororubber polymer, or a simple substance of a fluororesin, a mixture thereof, a copolymer thereof, or a laminate thereof, and among these, an epoxy resin and a polyimide resin are preferable. Furthermore, it is preferable to mix these synthetic resins with additives such as a photopolymerization initiator, an antistatic agent, and a crosslinking accelerator.

<Method for manufacturing electronic parts>
An electronic component manufacturing method according to another invention will be described in detail with reference to the drawings.
The present invention includes a bonding step of bonding a silicon wafer 5 to the surface of a die attach film 4 of any one of the above-described pressure-sensitive adhesive sheets 1, and a dicing step of dicing the silicon wafer 5 after the bonding step. And the manufacturing method of the electronic component which has the pick-up process which picks up from the adhesive layer 3 together with the silicon wafer 5 and the die attach film 4 after a dicing process.

<Bonding process>
The bonding step is a step of bonding the silicon wafer 5 to the surface of the die attach film 4 of any one of the above-described pressure-sensitive adhesive sheets 1. Specifically, the silicon wafer 5 is bonded to the pressure-sensitive adhesive sheet 1. And fixing the pressure-sensitive adhesive sheet 1 to the ring frame 6. In FIG. 1, the state after a bonding process is shown.

<Dicing process>
The dicing process is for dicing the silicon wafer 5 after the bonding process, and the state after the dicing process is shown in FIG. In dicing, the silicon wafer 5 is diced with a dicing blade 7. Reference numeral 71 in FIG. 2 is a notch.

<Pickup process>
The pick-up process is a process of picking up the silicon wafer 5 and the die attach film 4 together from the pressure-sensitive adhesive layer 3 after the dicing process, and the state in the pick-up process is shown in FIG. FIG. 4 shows the state of the die chip 51 after the pickup process. Specifically, the pickup process is the following process.

After irradiating one or both of ultraviolet rays or radiation from the base film 2 side of the pressure-sensitive adhesive sheet 1 and then expanding the pressure-sensitive adhesive sheet 1 radially to increase the distance between the die chips 51, the die chip 51 is moved with a needle or the like (not shown). Push up. Thereafter, the die chip 51 is adsorbed by a vacuum collet or air tweezers (not shown), peeled between the adhesive sheet 1 and the die attach film 4, and the die chip 51 to which the die attach film 4 is attached is picked up.

The picked up die chip 51 is mounted on the lead frame 8 together with the die attach film 4. In this mounting, it is stably fixed by the adhesive force of the die attach film 4. After mounting, the die attach film 4 is heated, and the die chip 51 and the lead frame 8 are heat bonded. Finally, the die chip 51 mounted on the lead frame 8 is molded with resin (not shown).

Even if the manufacturing method having the above-described steps is performed, since the coating property of the pressure-sensitive adhesive has been improved, the transfer of the pressure-sensitive adhesive component to the die attach film 4 is suppressed. An overall excellent manufacturing method of the above could be obtained.

Although the lead frame 8 is shown in FIG. 4, a circuit board on which a circuit pattern is formed instead of the lead frame 8 may be used.

The irradiation with one or both of ultraviolet rays and radiation is to reduce the adhesive force of the pressure-sensitive adhesive layer 3 by making the vinyl groups in the compound molecules constituting the pressure-sensitive adhesive layer 3 three-dimensionally reticulated. Thereby, before irradiation, excellent chip retention is given by the pressure-sensitive adhesive layer 3 having a high initial pressure-sensitive adhesive force, and the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer 3 is reduced by irradiation, and the die attach film 4 and the pressure-sensitive adhesive layer 3 The die chip 51 can be easily picked up and the die chip 51 can be picked up.

Ultraviolet light sources include low-pressure mercury lamps, high-pressure mercury lamps, ultrahigh-pressure mercury lamps, and metal halide lamps. Radiation light sources include electron beams, α rays, β rays, and γ rays.

According to the pressure-sensitive adhesive sheet of the present invention, since there is little migration of the pressure-sensitive adhesive component to the die attach film 4, the die chip 51 to which the die attach film 4 is attached is mounted on the lead frame 8 and heated as shown in FIG. Even when bonded, the occurrence of poor adhesion due to contamination is small.

<Silicon wafer>
The method for manufacturing an electronic component of the present invention is directed to a silicon wafer, but other wafers such as a gallium nitride wafer, a silicon carbide wafer, and a sapphire wafer may be used.

Hereinafter, the present invention will be described with reference to Table 1. The present invention is not limited to these. Table 1 summarizes the composition of the adhesive and its evaluation.

The compounds described in Table 1 are as follows.
(Meth) acrylic acid ester polymer (A) A1: A commercial product (product name SK, manufactured by Soken Chemical Co., Ltd.) made of a copolymer of 95% 2-ethylhexyl acrylate and 5% 2-hydroxyethyl acrylate. Dyne 1496).
(Meth) acrylic acid ester polymer (A) A2: An in-house polymerized product comprising a copolymer of 95% 2-ethylhexyl acrylate and 5% 2-hydroxyethyl methacrylate and obtained by solution polymerization.
(Meth) acrylic acid ester polymer (A) A3: In-house polymerized product consisting of 100% 2-ethylhexyl acrylate and obtained by solution polymerization.
Multifunctional acrylate (B) B1: Monohydroxydipentaerythritol pentaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name NK-A-9550)
Multifunctional acrylate (B) B2: Monohydroxypentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name NK ester-A-TMM-3LM-N).
Multifunctional acrylate (B) B3: Monohydroxydiglycerol (meth) acrylate Multifunctional acrylate (B) B4: Monohydroxydipentaerythritol pentamethacrylate Multifunctional acrylate (B) B5: Dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) Product name NK Ester A-DPH)
Photopolymerization initiator (C) C1: 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (Ciba・ Product made in Japan, product name Irgacure 127)
Photopolymerization initiator (C) C2: 1-hydroxy-cyclohexyl-phenyl-ketone (product name Irgacure 184, manufactured by Ciba Japan)
Photopolymerization initiator (C) C3: benzyldimethyl ketal (Ciba Japan, product name Irgacure 651)
Isocyanate (D): Trimethylolpropane adduct of tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name Coronate L-45E)
Urethane acrylate oligomer (E): a terminal acrylate oligomer obtained by reacting hexamethylene diisocyanate (aliphatic diisocyanate) with dipetaerythritol pentaacrylate, an urethane having an average molecular weight (Mw) of 4,900 and 10 acrylate functional groups A commercial product of acrylate oligomer (manufactured by Negami Kogyo Co., Ltd., product name UN-904M).

Table 1 shows the main components of the pressure-sensitive adhesive corresponding to each of the examples and comparative examples, and the blending amounts thereof. In preparing each pressure-sensitive adhesive, these are added to the components shown in Table 1. For example, as shown in Table 1, the amount of the isocyanate of Example 1 is such that (D) —NCO group mol amount is 1 with respect to (A) + (B) + (C) —OH group mol amount. Doubled.

Next, the obtained pressure-sensitive adhesive was applied onto a PET separator film, coated so that the thickness of the pressure-sensitive adhesive layer after drying was 10 μm, and laminated on a 100 μm base film to obtain a pressure-sensitive adhesive sheet. A die attach film having a thickness of 30 μm was laminated on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet to obtain a pressure-sensitive adhesive sheet.

The base film is made of an ionomer resin mainly composed of a Zn salt of an ethylene-methacrylic acid-methacrylic acid alkyl ester copolymer, and has a melt flow rate (MFR) of 1.5 g / 10 minutes (JIS K7210, 210 ° C.). ), A melting point of 96 ° C., and a film containing Zn ²⁺ ions (Mitsui / DuPont Polychemical Co., Ltd., product name High Milan 1650) was used.

2. The following were prepared as die attach films.
Die attach film: A film having a thickness of 30 μm, and its composition is an epoxy adhesive.

3. The following electronic component assemblies were prepared.
For the manufacture of the electronic component, a silicon wafer having a diameter of 8 inches and a thickness of 0.1 mm formed with a dummy circuit pattern was used.

<Dicing process>
The amount of cut into the adhesive sheet was 30 μm. Dicing was performed with a chip size of 10 mm × 10 mm.
A DAD341 manufactured by DISCO was used as the dicing apparatus. The dicing blade used was NBC-ZH205O-27HEEE manufactured 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: 80 mm / sec.
Cutting water temperature: 25 ° C.
Cutting water amount: 1.0 L / min.

After picking up the pickup with a needle pin, the chip was adsorbed with a vacuum collet and peeled between the adhesive sheet and the die attach film to obtain a chip with the die attach film attached thereto. As a pickup device, CAP-300 B manufactured by Canon Machinery Co., Ltd. was used.
Needle pin shape: 250μmR
Number of needle pins: 5
Needle pin push-up height: 0.5mm
Expanding amount: 8mm

<Evaluation of experimental results>
1. Coating property: The coating lines on the pressure-sensitive adhesive sheet surface per 1 m ² were visually evaluated.
◎ (excellent): No coating streaks with a length of 10 mm or more ○ (good): 1 to 5 coating streaks with a length of 10 mm or more were observed x (impossible): Coating streaks with a length of 10 mm or more More than 6 places were observed

2. Chip retention: When the silicon wafer was diced under the above conditions, the number of chips held on the adhesive sheet was evaluated.
◎ (excellent): 95% or more of the chip held on the adhesive sheet ○ (good): 90% or more of the chip held on the adhesive sheet is less than 95% × (impossible): chip held on the adhesive sheet Is less than 90%

3. Pickup property: After the silicon wafer was diced under the above conditions, the number of chips that could be picked up with the die attach film attached was evaluated as shown in FIG.
◎ (excellent): 95% or more of chips could be picked up ○ (good): 80% or more and less than 95% of chips could be picked up x (impossible): less than 80% of chips could be picked up

4). Contamination prevention: Adhesive surface of the adhesive sheet is attached to the die attach film, stored for 1 week, irradiated with 500 mJ / cm ² of ultraviolet light with a high pressure mercury lamp, stored for 1 week, or stored for 4 weeks. It peeled. The peeled die attach film was subjected to GC-MS analysis, and a peak derived from the photopolymerizable initiator was confirmed.
◎ (excellent): After irradiation with ultraviolet rays, after 1 week storage, and after 4 weeks storage, there is no peak derived from the photopolymerization initiator from the die attach film from which the adhesive sheet was peeled. ○ (good): After irradiation with ultraviolet rays, No peak derived from the photopolymerizable initiator from the die attach film from which the adhesive sheet was peeled after storage for 1 week. And there is a peak derived from a photopolymerization initiator from the die attach film from which the pressure-sensitive adhesive sheet was peeled after storage for 4 weeks after irradiation with ultraviolet rays.
X (Not possible): After irradiation with ultraviolet rays, there was a peak derived from a photopolymerizable initiator from the die attach film from which the pressure-sensitive adhesive sheet was peeled off after being stored for 1 week and after being stored for 4 weeks.

The pressure-sensitive adhesive sheet used in the present invention is excellent in holding a chip during dicing, can be easily peeled off during pick-up work, and has a low anti-contamination property due to a small amount of adhesive residue. It is preferably used in a method of manufacturing an electronic component that is picked up with a film layer attached, mounted on a lead frame or the like, and bonded.

Claims (5)

A base film, a pressure-sensitive adhesive layer laminated on one surface of the base film, and a die attach film laminated on the exposed surface of the pressure-sensitive adhesive layer,
The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer contains (meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, photopolymerization initiator, and isocyanate,
Each of the (meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, and photopolymerization initiator has a hydroxyl group,
The isocyanate has three or more isocyanate groups,
Isocyanate group mol amount of isocyanate is 0.8 to 1.2 times of “all hydroxyl group mol amount of (meth) acrylic acid ester polymer, polyfunctional (meth) acrylate, and photopolymerization initiator”. Adhesive sheet. The pressure-sensitive adhesive sheet according to claim 1, wherein the polyfunctional (meth) acrylate has 3 or more (meth) acryloyl groups. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the photopolymerization initiator has two or more hydroxyl groups. The compounding ratio of the (meth) acrylic acid ester polymer in the pressure-sensitive adhesive according to any one of claims 1 to 3, is 100 parts by mass, and the compounding ratio of the polyfunctional (meth) acrylate is 20 parts by mass or more and 200 parts by mass or less. The adhesive sheet whose compounding ratio of a photoinitiator is 0.05 mass part or more and 20 mass parts or less. A bonding step of bonding a silicon wafer to the die attach film surface of the pressure-sensitive adhesive sheet according to any one of claims 1 to 4, a dicing step of dicing the silicon wafer after the bonding step, and a silicon wafer after the dicing step And the manufacturing method of the electronic component which has the pick-up process picked up from an adhesive layer together with a die attach film.

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