JP2003282489A - Adhesive sheet used for processing semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet used for processing semiconductors having the capability of preventing electrostatic charges from being generated in a semiconductor manufacturing process and semiconductor devices from breaking down and degrading in their properties due to the electrostatic charges. <P>SOLUTION: The adhesive sheet used for processing the semiconductors in which an adhesive agent layer comprising a base polymer, a radiation polymerizable chemical agent and a radiation polymerization starting agent is applied to a substrate surface pervious with respect to an ultraviolet ray and/or an electron beam, wherein an antistatic effect is obtained and an electrostatic-charged voltage does not exceed 200 V in the adhesive surface of the sheet when a film for exfoliation has been exfoliated. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pressure-sensitive adhesive sheet for semiconductor processing, which has a base material and a pressure-sensitive adhesive layer and has an antistatic effect.

[0002]

2. Description of the Related Art Conventionally, a semiconductor wafer and a package that have been collectively sealed are attached to each other, dicing, expanding, etc. are performed, and then they are mounted at the same time as mounting (in the case of a package, they are stored in a tray).
As a semiconductor processing sheet used at this time, a pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer that undergoes a polymerization and curing reaction by ultraviolet rays and / or electron beams is applied on a base material that is transparent to ultraviolet rays and / or electron beams is used for dicing. There is known a method of subsequently irradiating the pressure-sensitive adhesive layer with ultraviolet rays and / or electron beams to polymerize and cure the pressure-sensitive adhesive layer to reduce the pressure-sensitive adhesive force and pick up a semiconductor wafer or a cut package. For example, in JP-A-60-196956 and JP-A-60-223139, trimethylolpropane triacrylate, pentaerythritol triacrylate, polyethylene glycol diacrylate are used as photopolymerizable initiators constituting the adhesive layer. It has been proposed to use an acrylic resin-based compound having at least two UV- and / or electron-beam polymerizable carbon-carbon double bonds in the molecule, such as oligoester acrylate.

However, in recent years, with the high integration of semiconductor devices, circuits have become more detailed, and problems such as product destruction due to electrification and operational problems have arisen. Charges that are a concern during the process include charging by peeling when peeling the sheet from the release film, charging by friction between the blade and the sheet during dicing, peeling charge when removing the sheet from the adsorption table after dicing, and high-pressure discharge during cleaning. There are charging due to friction between the cleaning liquid and the sheet, charging generated by rotating the table at a high speed during cleaning and drying, charging due to peeling when picking up the chip and the package. These electrifications cause problems such as destruction of semiconductor devices and deterioration of performance, and problems in subsequent operations.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above problems and prevent the occurrence of electrification during the semiconductor manufacturing process, especially the electrification that occurs when the substrate is peeled from the release film, Another object of the present invention is to provide a pressure-sensitive adhesive sheet for semiconductor processing, which can prevent the destruction of semiconductor devices and the deterioration of products due to the above.

[0005]

The present invention provides (1) a pressure-sensitive adhesive comprising a base material having transparency to ultraviolet rays and / or electron beams, a base polymer, a radiation-polymerizable compound, and a radiation-polymerizable polymerization initiator. In the pressure-sensitive adhesive sheet for semiconductor processing, which comprises a layer and a peeling film, the pressure-sensitive adhesive layer has a thickness of 10 to 40 μm, and the pressure-sensitive adhesive sheet for semiconductor processing has an antistatic effect, and is a sheet when the peeling film is peeled off. A semiconductor processing pressure-sensitive adhesive sheet having a charging voltage of 200 V or less to the pressure-sensitive adhesive surface, (2) The semiconductor processing pressure-sensitive adhesive sheet according to item (1), wherein the base material has been subjected to antistatic treatment. is there.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the present invention, the adhesive sheet for semiconductor processing has a voltage applied to the adhesive surface of the sheet of 200 when the release film is peeled off.
It is set to be V or less. When the charged voltage is 200 V or more, there arises a problem that the semiconductor device may be broken or a work problem may occur during the assembly process.

The base material used in the present invention is preferably subjected to an antistatic treatment. If the treatment is not performed, the electric charge generated due to some cause during the assembling process such as peeling off the release film cannot be transferred, so that the film is charged. The antistatic treatment method is not particularly limited, and kneading of an antistatic agent, anchor treatment at the interface between the pressure-sensitive adhesive layer and the base material, coating treatment at the surface opposite to the surface having the pressure-sensitive adhesive on the base material , Or a combination of these. Examples of the antistatic agent used in these treatments include anionic surfactants represented by alpha olefin sulfonates, alkyl sulfate ester salts, methyl taurates, alkylbenzene sulfonates, ether carboxylates, etc. There are cationic surfactants typified by primary ammonium and amine salts, nonylphenol-based, higher alcohol-based, fatty acid ester-based, nonionic surfactants typified by alkylamine ethylene oxide adducts, and the like. Alternatively, these may be used in combination. In addition, a π-electron conjugated system such as polypyrrole type, polyaniline type, polythiophene type or the like, a conductive polymer doped with a metal ion, tin oxide, indium oxide, zinc oxide, titanium oxide, carbon black, or a silicon type organic compound can be used. Even if these are used alone, the effect can be obtained, but they may be used in combination of two or more kinds. In addition, a conductive filler such as a complex of polyalkylene glycol and a perchlorate such as lithium perchlorate, or a conductive filler doped with antimony or the like to improve antistatic property may be used.
Further, the above surfactant, metal oxide, and conductive polymer may be used in combination.

The substrate used in the present invention is
There is no particular limitation as long as it is transparent to ultraviolet rays and / or electron beams, and examples thereof include vinyl chloride, polyethylene terephthalate, polyethylene, polypropylene,
Polyurethane, ethylene vinyl acetate copolymer, ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-propylene-butene copolymer and the like are used. These may be subjected to a surface treatment for increasing the adhesiveness with the pressure-sensitive adhesive layer or a surface treatment such as non-slipperiness on the side not contacting the pressure-sensitive adhesive layer.

The base polymer used in the present invention is not particularly limited, and examples thereof include a polymer composed of acrylic acid, methacrylic acid and their esters, and copolymerizable with acrylic acid, methacrylic acid and their esters. Unsaturated monomers such as vinyl acetate,
A copolymer with styrene, acrylonitrile or the like is used. The pressure-sensitive adhesive of the present invention includes a rosin resin, a terpene resin, a coumarone resin, a phenol resin, a styrene resin, an aliphatic petroleum resin, an aromatic petroleum resin, and an aliphatic aromatic copolymer petroleum petroleum in order to enhance cohesive force. A tackifier such as a resin may be added.

The radiation-polymerizable compound used in the present invention is not particularly limited and, for example, urethane acrylate, acrylic monomer and the like are used.

The urethane acrylate is a urethane acrylate having 2 to 4 acryloyl groups in the molecule and is a compound synthesized by diisocyanate, polyol and hydroxy (meth) acrylate, and preferably 2 acryloyl groups. It is a urethane acrylate that has. As the above-mentioned isocyanate,
For example, toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, dicyclohexylmethane diisocyanate, xylene diisocyanate, tetramethyl xylene diisocyanate, naphthalene diisocyanate and the like can be mentioned. Examples of the polyol include ethylene glycol, propylene glycol, butanediol, hexanediol and the like. Examples of the hydroxy (meth) acrylate include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

Examples of the acrylate monomer include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetrachloride, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate and the like.

The radiation-polymerizable polymerization initiator used in the present invention is not particularly limited, and examples thereof include 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxy-cyclohexyl-phenyl ketone and 2-methyl. -1- [4- (methylthio) phenyl]
2-Monfonyl propane or the like is used. The mixing ratio of the radiation-polymerizable compound and the radiation-polymerizable polymerization initiator is
The radiation-polymerizable compound is 50 to 200 parts by weight, and the radiation-polymerizable polymerization initiator is 0.03 to 22.5 parts by weight with respect to 100 parts by weight of the base polymer. If the proportion of the radiation-polymerizable compound is less than 50 parts by weight, the adhesive strength after curing will not be sufficiently reduced, making it difficult to pick up the device, and if it exceeds 200 parts by weight, the cohesive strength of the adhesive layer will be insufficient, which is not preferable. . If the proportion of the radiation-polymerizable polymerization initiator is less than 0.03 part by weight, the curing reaction of the radiation-polymerizable compound upon irradiation with ultraviolet rays and / or electron beams becomes poor, and the adhesive strength is insufficiently reduced, which is not preferable. If it exceeds the weight part, the stability under heat or under a fluorescent lamp is deteriorated, which is not preferable.

In the present invention, the thickness of the adhesive layer is 1
About 0 to 40 μm is preferable. Thickness of adhesive layer is 10μ
When the thickness is less than m, the pressure-sensitive adhesive layer having high fluidity is thin and the peeled state becomes unsmooth when the peeling film is peeled off, and a mechanical external force is applied, resulting in a large amount of electrification. On the other hand, when the thickness of the pressure-sensitive adhesive layer is thicker than 40 μm, the distance between the peeled surface of the pressure-sensitive adhesive and the base material subjected to the charging treatment becomes large, which hinders the movement of the generated charges, resulting in a large charge amount.

In the present invention, the pressure-sensitive adhesive layer is formed on the base material to produce a pressure-sensitive adhesive paper for semiconductor wafer processing, in which the components constituting the pressure-sensitive adhesive layer are used as they are or in a solution with a suitable organic solvent. It can be obtained by subjecting it to a coating, spraying, or the like to apply it to a substrate, and then drying it by heating, for example, at 80 to 100 ° C. for about 30 seconds to 10 minutes.

A known method can be used to use the pressure-sensitive adhesive sheet for semiconductors of the present invention. For example, after the pressure-sensitive adhesive sheet for semiconductor processing is attached and fixed to a semiconductor wafer, the semiconductor device is cut into small pieces by a rotary round blade. Disconnect. After that, ultraviolet rays and / or electron beams are irradiated from the base material side of the processing pressure-sensitive adhesive sheet, and then the processing pressure-sensitive adhesive sheet is radially expanded using a special jig to spread the chips at regular intervals, and then the device is It may be pushed up with a needle or the like and picked up by a method such as suction with a vacuum collet or air tweezers, and at the same time stored in a mounting or tray.

[0017]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. <Example 1> 50 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of butyl acrylate, 37 parts by weight of vinyl acetate, and 3 parts by weight of 2-hydroxyethyl methacrylate were used to obtain a weight average molecular weight of 500,000. 100 parts by weight of the copolymer, 100 parts by weight of dipentaerythritol monohydroxypentaacrylate as a radiation-polymerizable compound and 2,2-
A polyester solution having a thickness of 38 μm, which was prepared by peeling a resin solution which was an adhesive layer containing 8.3 parts by weight of dimethoxy-2-phenylacetophenone and 6 parts by weight of a polyisocyanate crosslinking agent (Coronate L [manufactured by Nippon Polyurethane]). The film was applied so that the thickness after drying would be 30 μm, and dried at 80 ° C. for 5 minutes. Then polypropylene 1
00 parts by weight and polyether / a polymeric antistatic agent
Polyolefin block polymer Pelestat 300
15 parts by weight (manufactured by Sanyo Kasei Co., Ltd.) were kneaded by a twin-screw kneader and then extruded by an extruder, and the sheet having a thickness of 150 μm was laminated to produce an adhesive sheet for semiconductor processing. The obtained adhesive sheet for semiconductor processing was matured at room temperature for 7 days or more, and then the electrification voltage was measured when the release film was peeled off.
In addition, a package was actually assembled using the sheet, and the presence or absence of the package breakage condition was evaluated. The results are shown in Table 1.

Example 2 A sample was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive layer had a thickness of 15 μm.
The same items as in Example 1 were tested. The results are shown in Table 1.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that a polypropylene sheet containing no antistatic agent was used as the substrate.
The same items as above were tested. The results are shown in Table 1. << Comparative Example 2 >> A sample was prepared in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer was 5 μm, and the same items as in Example 1 were tested. The results are shown in Table 1. Comparative Example 3 A sample was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive layer had a thickness of 50 μm, and the same items as in Example 1 were tested. The results are shown in Table 1.

[0020]

[Table 1]

The following evaluation methods were used to evaluate the examples and comparative examples.・ ELEC made by SIMCO JAPAN as a charging voltage measuring device for peeling electrification
15mm using TRO LOCATOR SS-2
100 mm / sec for the width sample. The electrification voltage on the surface of the pressure-sensitive adhesive when the peeling film was peeled off was measured.・ Package destruction test Using a tableted epoxy resin, low pressure transfer molding machine at 175 ℃, injection pressure 70kgf / cm
² , 80pQF semiconductor device under the condition of holding pressure 120 seconds
175 after molding to P (14 x 20 x 2.7 mm thickness)
After the semiconductor device obtained by post-curing at 8 ° C. for 8 hours is subjected to lead processing and exterior plating in a generally used process,
The operation of the device was confirmed. Good products were those in which all terminals worked without problems, and defective products in which terminals did not work properly.

[0022]

The semiconductor processing sheet of the present invention is characterized in that the voltage applied to the adhesive surface of the sheet when the peeling film is peeled off is 200 V or less, and the occurrence of electrification during the semiconductor manufacturing process. And the destruction of the semiconductor device and the deterioration of the product due to the charging can be prevented.

Continued front page    F-term (reference) 4J004 AA01 AA06 AA09 AA10 AA17                       AB01 AB06 AB07 CA03 CA04                       CA05 CA06 CA07 CA08 CC02                       CC03 CD01 DB02 FA05 FA08                 4J040 DB061 DE021 DF011 DF041                       DF051 DF081 EF181 EF281                       FA141 HA19 JA09 JB07                       JB08 JB09 KA13 KA26 LA09                       MB03 NA20 PA23 PA42

Claims (2)

[Claims] 1. A semiconductor processing comprising a substrate having transparency to ultraviolet rays and / or electron beams, an adhesive layer comprising a base polymer, a radiation-polymerizable compound and a radiation-polymerizable polymerization initiator, and a peeling film. In the adhesive sheet,
The pressure-sensitive adhesive layer has a thickness of 10 to 40 μm, the semiconductor processing pressure-sensitive adhesive sheet has an antistatic effect, and the electrification voltage to the pressure-sensitive adhesive surface of the sheet when the peeling film is peeled off is 200 V or less. Adhesive sheet for semiconductor processing. 2. The pressure-sensitive adhesive sheet for semiconductor processing according to claim 1, wherein the base material is subjected to an antistatic treatment.