JP2006137816A - Adhesive sheet for semiconductor member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet which is used for semiconductor members, does not cause the scatter of chips and the pulling-up of a paste, when diced, and does not scatter the chips on the periphery, when irradiated with radiations and then picked up with a pick-up pin. <P>SOLUTION: This adhesive sheet for the semiconductor members, having a filmy substrate and a radiation-curable adhesive layer formed on at least one side of the substrate is characterized in that the radiation-curable adhesive layer comprises 100 pts.mass of an acrylic adhesive, 40 to 200 pts.mass of a radiation-polymerizable compound having two or more unsaturated bonds, and 0.03 to 20 pts.mass of a curing agent; the acrylic adhesive is produced by copolymerizing a (meth)acrylate, a carboxyl group-containing polymerizing monomer, and a hydroxyl group-containing polymerizable monomer; and 5 to 90 mass% of the radiation-polymerizable compound having two or more unsaturated bonds has four unsaturated bonds; the hydroxyl group-containing polymerizable monomer is contained in an amount of 0.2 to 10 mass% based on the acrylic adhesive; and the carboxyl group-containing polymerizing monomer is contained in an amount of 0.2 to 15 mass% based on the acrylic adhesive. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive sheet for a semiconductor member, and in particular, even if a semiconductor member affixed to a pressure-sensitive adhesive sheet is diced into chips, the semiconductor member is not scattered excessively and does not cause the glue to be scraped up during dicing. Furthermore, the present invention relates to a pressure-sensitive adhesive sheet for a semiconductor member that can be picked up without separating peripheral chips when picking up a semiconductor member formed into chips after dicing.

  Patent Document 1 is known as a pressure-sensitive adhesive sheet used when dicing a semiconductor member and a method for manufacturing a semiconductor device using the same.

Japanese Patent No. 3410202

  The pressure-sensitive adhesive sheet for wafer sticking described in Patent Document 1 and the method for producing a semiconductor device using the same are obtained by copolymerizing an acrylic ester with an OH group-containing polymerizable monomer and having a specific number of unsaturated bonds. A compound is added. In this technique, the release of the sealing resin and the generation of package cracks are suppressed by incorporating a radiation polymerizable compound having a specific number of unsaturated bonds.

  However, this technique is suitable for dicing with a chip size of about 10 mm □. However, if the dicing of the recently requested miniaturization with a chip size of about 5 mm □ is performed, chip jumping or scraping of glue occurs during dicing. There was a problem that peripheral chips were scattered at the time of picking up with a push-up pin after irradiation.

  It is an object of the present invention to provide a pressure-sensitive adhesive sheet for a semiconductor member that does not cause chip fly or glue scraping during dicing and does not disperse peripheral chips during pick-up work with a push-up pin after irradiation.

  The invention according to claim 1 is a pressure-sensitive adhesive sheet for a semiconductor member having a film-shaped substrate and a radiation-curable pressure-sensitive adhesive layer formed on at least one surface of the substrate. Formed of a resin composition having 100 parts by weight of an agent, 40 to 200 parts by weight of a radiation polymerizable compound having two or more unsaturated bonds, and 0.03 to 20 parts by weight of a curing agent, and an acrylic pressure-sensitive adhesive is (meth) acrylic An acid ester, a carboxyl group-containing polymerizable monomer, and a hydroxyl group-containing polymerizable monomer are copolymerized, and 5 to 90% by mass of the radiation-polymerizable compound having two or more unsaturated bonds is unsaturated bonds. 4 or more, the hydroxyl group-containing polymerizable monomer is contained in an amount of 0.2 to 10% by mass of the acrylic adhesive, and the carboxyl group-containing polymerizable monomer is contained in an amount of 0.2 to 15% by mass of the acrylic adhesive. The And it has a pressure-sensitive adhesive sheet for semiconductor member.

  The invention according to claim 2 is the pressure-sensitive adhesive sheet for semiconductor members according to claim 1, wherein the curing agent is an isocyanate compound.

  The invention according to claim 3 is the pressure-sensitive adhesive sheet for semiconductor members according to claim 1 or 2, wherein the radiation polymerizable compound having 4 or more unsaturated bonds is a urethane acrylate oligomer.

  The effect of the present invention is that chip skipping and glue scraping do not occur during dicing, and peripheral chips do not separate during pick-up work with a push-up pin after irradiation.

  As an acrylic pressure-sensitive adhesive, a (meth) acrylic acid ester, a carboxyl group-containing polymerizable monomer, and a hydroxyl group-containing polymerizable monomer were copolymerized. By copolymerizing two kinds of polymerizable monomers with an acrylate ester, the carboxyl group component improves the adhesion due to the interaction with the adherend (semiconductor member), and the semiconductor member can be diced into chips. This is because the semiconductor component is not scattered unnecessarily, and the hydroxyl group component acts as a cross-linking point by reaction with the curing agent to improve the cohesiveness of the adhesive itself and prevent the glue from being scraped up during dicing.

  Examples of polymerizable monomers for (meth) acrylic acid esters include butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, and octyl (meth) acrylate. , 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, and mixtures of two or more thereof.

  Examples of the carboxyl group-containing polymerizable monomer include (meth) acrylic acid, β-carboxyethyl (meth) acrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid, 3- (meth) acryloylpropionic acid, and the like. Is mentioned. Of these, preferred is (meth) acrylic acid.

  The proportion of the carboxyl group-containing polymerizable monomer is 0.2 to 15% by mass, preferably 0.5 to 11% by mass. If the value is lower than 0.2% by mass, the desired adhesiveness cannot be obtained and chip skipping occurs during dicing. If the value is higher than 15% by mass, the adhesive itself becomes too hard and chip skipping occurs during dicing. appear.

  Examples of the hydroxyl group-containing polymerizable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and the like. Among these, 2-hydroxyethyl (meth) acrylate is preferable.

  The ratio of the hydroxyl group-containing polymerizable monomer is 0.2 to 10% by mass, preferably 0.5 to 8% by mass, based on the acrylic pressure-sensitive adhesive. When the content is lower than 0.2% by mass, the crosslinking reaction with the curing agent is not sufficiently obtained, and the glue is scraped up. When the content is higher than 10% by mass, the pressure-sensitive adhesive itself becomes too hard and chip fly occurs during dicing.

  The (meth) acrylic acid ester copolymer obtained by polymerizing these polymerizable monomers has a weight average molecular weight of 100,000 to 1,600,000, preferably 150,000 to 1,000,000.

  Other copolymerization components of the acrylic pressure-sensitive adhesive include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) Acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, styrene, vinyl toluene, allyl acetate, (meth) acrylonitrile, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl versatate, vinyl ethyl ether , Vinyl propyl ether, vinyl isobutyl ether and the like.

  “Radiation polymerizable compound having two or more unsaturated bonds” blended in radiation curable pressure-sensitive adhesive has two or more unsaturated bonds (carbon-carbon double bonds) in the molecule when irradiated with radiation. Adopted to reduce the adhesive strength of the adhesive itself by making it into a three-dimensional network. When the blending amount of the “radiation polymerizable compound having two or more unsaturated bonds” is less than 40 parts by mass, the curability due to radiation irradiation becomes insufficient and the pick-up property is deteriorated. Is reduced to cause glue scraping and chip separation during pick-up, so that the amount is 40 to 200 parts by mass, preferably 50 to 180 parts by mass.

  The “radiation-polymerizable compound having two or more unsaturated bonds” is sufficient in curability by radiation irradiation if the content of the “radiation-polymerizable compound having four or more unsaturated bonds” in the composition is less than 5% by mass. When the amount exceeds 90% by mass, the curability due to radiation irradiation becomes too high and chip dispersion occurs at the time of picking up. Therefore, the blending ratio of “radiation polymerizable compound having 4 or more unsaturated bonds” is 5 It is -90 mass%, Preferably it is 10-80 mass%.

  Examples of radiation polymerizable compounds having two or more unsaturated bonds include acrylate compounds, polyester acrylate oligomers, epoxy acrylate oligomers, and urethane acrylate oligomers. Examples of the acrylate compound include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, There are 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, and cyanuric acid triethyl acrylate.

  Urethane acrylate oligomers are polyol compounds such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, pentanediol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol and many others. Divalent isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane 4,4-diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate , Terminal isocyanate urethane prepolymers obtained by reacting isophorone diisocyanate, etc. (Meth) acrylate having a hydroxy group, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol (meth) acrylate, pentaerythritol triacrylate, glycidol di (meth) acrylate, It can be obtained by reacting dipentaerythritol monohydroxypentaacrylate.

  Examples of the acrylate compound as the radiation polymerizable compound having 4 or more unsaturated bonds include pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol hydroxypentaacrylate, ditrimethylolpropane tetra There are acrylate and pentaerythritol ethoxytetraacrylate.

  Urethane acrylate oligomers as radiation polymerizable compounds having 4 or more unsaturated bonds include polyol compounds such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, pentanediol, glycerin. , Trimethylolpropane, trimethylolethane, pentaerythritol and the like, and polyvalent isocyanate compounds such as 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 The terminal isocyanate urethane prepolymer obtained by reacting, for example, is reacted with a polyvalent (meth) acrylate having a hydroxy group, such as pentaerythritol triacrylate, glycidol di (meth) acrylate, dipentaerythritol monohydroxypentaacrylate, etc. The resulting compound is raised.

  A hardening | curing agent is employ | adopted in order to improve the cohesiveness of an adhesive composition, and the compounding quantity is 0.03-20 mass parts, Preferably it is 0.05-16 mass parts. Specifically, there are a simple substance or a mixture of an isocyanate compound, an epoxy compound, a methylol compound, a chelate compound, and an aziridine compound, and among these, an isocyanate curing agent is preferable. The reason why the isocyanate curing agent is preferable is that the reactivity of the hydroxyl group-containing polymerizable monomer with the hydroxyl group is high, thereby shortening the aging period of the pressure-sensitive adhesive sheet for electronic members.

  As isocyanate compounds, 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 those adduct types. Epoxy compounds include neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, phthalic acid diglycidyl ester, dimer acid diglycidyl ether, triglycidyl isocyanurate, diglycerol tris Glycidyl ether, sorbitol tetraglycidyl ether, N, N, N ′, N′-tetraglycidyl m-xylenediamine, 1′3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N There is' -tetraglycidyldiaminodiphenylmethane. Examples of methylol compounds include melamine and phenol.

  In the pressure-sensitive adhesive composition of the present invention, conventionally known additives such as a radiation polymerization initiator, a tackifier, a softening agent, an anti-aging agent, a filler, and a radiation absorber are within the range in which the object of the present invention is not impaired. In addition, a light stabilizer may be appropriately selected and added.

  As a film-like base material, a conventionally known synthetic resin can be appropriately selected and used according to the use, and specifically, there are polyvinyl chloride, polyethylene, polypropylene, polyester, ethylene vinyl alcohol, and the thickness thereof is used. The film can be appropriately selected depending on the sheet shape, and can include not only a sheet shape but also a film shape.

  Radiation includes ultraviolet rays and electron beams, and electron beams include α rays, β rays, γ rays, and neutron rays.

  The semiconductor member which is an example of the adherend of the pressure-sensitive adhesive sheet according to the present invention includes a BGA (ball grid array) substrate, a silicon wafer, gallium arsenide, glass, an epoxy substrate, and a vector substrate.

  Hereinafter, examples of the present invention will be described with reference to Table 1 in comparison with comparative examples.

  The dicing properties shown in Table 1 indicate that the adhesive sheets according to the examples and comparative examples are pasted so that air bubbles do not enter the semiconductor member molded with the mold resin for package molding, and are diced to 5 mm □ after being left for 10 minutes. Is the number (chip skipping number) obtained by converting the number of chips skipped when the process is repeated five times. In terms of work, this value is better as the numerical value is smaller, and 0 is preferable.

The adhesive strengths in Table 1 are as follows. Adhesive sheets according to Examples / Comparative Examples are pasted so that bubbles do not enter semiconductor components molded with a package molding mold resin, and before and after UV (ultraviolet) irradiation according to JIS Z 0237. Is measured. Before UV (ultraviolet) irradiation, it must be 5.0 N / 20 mm or more, and after UV irradiation, it must be 0.3 N / 20 mm or less. UV irradiation is irradiation with a light amount of 150 mJ / cm ² .

  For the glue scraping in Table 1, the adhesive sheets according to the examples and comparative examples are pasted so that no air bubbles enter the semiconductor member molded with the mold resin for package molding, and left for 10 minutes, and then diced to 5 mm □, With respect to 100 chips in total when this operation was repeated 5 times, adhesion of glue was confirmed on the side of the chip with a 1000 × microscope. The case where no adhesion of glue was confirmed on the side surface of the chip was marked with ◯, and the case where the glue was confirmed was marked with ×.

  The pick-up properties shown in Table 1 are as follows. The pressure-sensitive adhesive sheets according to Examples and Comparative Examples are pasted so that no air bubbles enter a semiconductor member molded with a mold resin for package molding, and left for 10 minutes and then diced to 5 mm □. Picking up was performed on 100 chips in total when 5 were repeated, and the number of chips that could not be picked up was measured. The case where there was no pick-up mistake was marked as ◯, and the case where there was even one pick-up was marked as x.

  The chip dispersion in Table 1 is obtained by attaching the pressure-sensitive adhesive sheet according to Example / Comparative Example so that bubbles do not enter the semiconductor member molded with the mold resin for package molding, dicing to 5 mm □ after leaving for 10 minutes, Pickup work was performed for 100 chips in total when the work was repeated 5 times, and the dispersion of peripheral chips was confirmed. The case where no chip variation was confirmed was marked with ○, and the case where even one chip was confirmed was marked with ×.

  The pressure-sensitive adhesive sheet of Example 1 according to the present invention is a polyethylene sheet having a thickness of 150 μm as a base material and a pressure-sensitive adhesive layer having a thickness of 25 μm on one surface of the base material. The composition of the pressure-sensitive adhesive layer is, as shown in the column of the pressure-sensitive adhesive composition in Table 1, 100 parts by mass of a (meth) acrylic acid ester copolymer and radiation polymerization having two or more unsaturated bonds as a radiation-polymerizable compound. 100 parts by mass of a functional compound, 3 parts by mass of diphenylmethane 4,4-diisocyanate as a curing agent, and 3 parts by mass of Ciba Geigy Irgacure 184 as an ultraviolet polymerization initiator out of the outside radiation polymerization initiator. When the (meth) acrylic acid ester copolymer is polymerized, 0.5% by mass of acrylic acid which is a carboxyl group-containing polymerizable monomer, 6% by mass of 2-hydroxyethyl acrylate which is a hydroxyl group-containing polymerizable monomer Are blended. The radiation-polymerizable compound was 50% by mass of a tetrafunctional urethane acrylate oligomer having 4 unsaturated bonds and 50% by mass of a bifunctional diethylene glycol diacrylate having 2 unsaturated bonds. Other examples and comparative examples which will be described later are the same as those of the present example except for the parts specifically mentioned.

  The pressure-sensitive adhesive sheet in Example 1 has good dicing properties (chip skipping: 0/100), the adhesive strength before and after UV irradiation is also appropriate, and there is no adhesive scraping and peripheral chip dispersion during pick-up. It was.

  In Example 2, acrylic acid which is a carboxyl group-containing polymerizable monomer of Example 1 is changed to 6% by mass, and 2-hydroxyethyl acrylate which is a hydroxyl group-containing polymerizable monomer is changed to 0.5% by mass. In Example 3, the acrylic acid of Example 1 was changed to 6% by mass, 2-hydroxyethyl acrylate was changed to 6% by mass, and the amount of the radiation polymerizable compound was changed to 70 parts by mass. In Example 4, the amount of the radiation polymerizable compound of Example 3 was changed to 170 parts by mass. In Example 5, the radiation polymerizable compound of Example 3 was changed to 100 parts by mass, and four unsaturated bonds were formed. The compound having the above was changed to 10% by mass, and Example 6 was obtained by changing the amount of the compound having 4 or more unsaturated bonds of Example 5 to 70% by mass. The curing agent of Example 1 is an epoxy compound N, N, N ′, N′-tetraglycidyl m-xylenediamine.

  In these examples, good characteristic values were obtained.

  Next, a comparative example will be described. In Comparative Example 1, the amount of the radiation polymerizable compound in Example 1 was 35 parts by mass, and in Comparative Example 2, the amount of the radiation polymerizable compound in Example 1 was 220 parts by mass. In Comparative Example 3, the amount of the radiation polymerizable compound having 4 or more unsaturated bonds in Example 1 was 3% by mass, and in Comparative Example 4 the radiation polymerizable having 4 or more unsaturated bonds in Example 1 was used. The amount of the compound is 95% by mass. In Comparative Example 5, the curing agent of Example 1 was not blended, and in Comparative Example 6, 25 parts by mass of the curing agent of Example 1 was blended. In Comparative Example 7, the acrylic acid in Example 1 was 0.1% by mass, and in Comparative Example 8, the acrylic acid in Example 1 was 17% by mass. In Comparative Example 9, the amount of 2-hydroxyethyl acrylate in Example 1 was 0.1% by mass, and in Comparative Example 10, the amount of 2-hydroxyethyl acrylate in Example 1 was 17% by mass.

  As shown in Comparative Examples 1 and 2, when the amount of the radiation polymerizable compound was too small, all of the dicing property, the adhesive force and the pickup property were poor, and when too much, the glue was scraped up and the chips were scattered. As shown in Comparative Examples 3 and 4, if the “mass% of the radiation-polymerizable compound having 4 or more unsaturated bonds” is too small, the adhesive strength after UV irradiation is too high and the pick-up property is too bad and too much. As a result, chip breakage occurred. As shown in Comparative Examples 5 and 6, when the curing agent was not blended, the glue was scraped up, and when it was too blended, chip jumping and chip separation occurred. As Comparative Examples 7 and 8 show, the dicing property and the adhesive strength before UV irradiation were poor even if the mass% of the carboxyl group-containing monomer was too small or too large. As shown in Comparative Examples 9 and 10, when the mass% of the hydroxyl group-containing monomer was too small, the glue was scraped up, and when it was too large, the dicing property and the adhesive strength before UV irradiation were poor.

The pressure-sensitive adhesive sheet for a semiconductor member according to the present invention is attached to the back surface of the plate-shaped body when a plurality of semiconductor members formed on a single plate-shaped body are individually diced and picked up after dicing. Is.

Claims (3)

  In a pressure-sensitive adhesive sheet for a semiconductor member having a film-shaped base material and a radiation-curable pressure-sensitive adhesive layer formed on at least one surface of the base material, the radiation-curable pressure-sensitive adhesive comprises 100 parts by mass of an acrylic pressure-sensitive adhesive, and unsaturated. It is formed with a resin composition having 40 to 200 parts by mass of a radiation-polymerizable compound having two or more bonds and 0.03 to 20 parts by mass of a curing agent, and an acrylic adhesive is a (meth) acrylic acid ester and a carboxyl group-containing polymerizable compound. A monomer and a hydroxyl group-containing polymerizable monomer are copolymerized, and 5 to 90% by mass of the radiation-polymerizable compound having two or more unsaturated bonds has four or more unsaturated bonds, and a hydroxyl group. Adhesive for semiconductor member containing 0.2 to 10% by mass of polymerizable monomer in acrylic adhesive and 0.2 to 15% by mass of carboxyl-containing polymerizable monomer in acrylic adhesive Over door.   The pressure-sensitive adhesive sheet for a semiconductor member according to claim 1, wherein the curing agent is an isocyanate compound. The pressure-sensitive adhesive sheet for a semiconductor member according to claim 1 or 2, wherein the radiation polymerizable compound having 4 or more unsaturated bonds is a urethane acrylate oligomer.