JP2002256236A - Adhesive sheet, method for producing semiconductor device and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive sheet having good die-bonding functions and wafer fixing functions at the same time. SOLUTION: This adhesive sheet has an adhesive layer usable as a die- bonding layer on a radiation-polymerizable substrate. Thereby, the adhesive having both the wafer fixing functions and the die-bonding functions at the same time can be provided. The adhesive layer comprises (A) a polyimide resin prepared by reacting a tetracarboxylic dianhydride comprising a tetracarboxylic dianhydride represented by the following chemical formula (I) (wherein, n denotes an integer of 2-20) in an amount of >=70 mol% based on the whole acid dianhydride with a diamine, (B) an epoxy resin, (C) a phenol resin and (D) a curing accelerator as the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive sheet used for manufacturing a semiconductor device, and more particularly to an adhesive sheet for dicing and an adhesive function for fixing a chip on a wiring connection substrate such as a lead frame. It relates to an adhesive sheet having both.

[0002]

2. Description of the Related Art Processes for semiconductor devices such as silicon and gallium arsenide include a pre-process in which elements are formed in a large-diameter semiconductor wafer state, and a process in which a wafer is separated into element pieces (chips) and finished into a final product. Process.

In the subsequent process, first, the semiconductor wafer is cut and separated (diced) for each chip. At this time, the semiconductor wafer is diced, washed, dried, and adhered to the adhesive sheet in advance. (Expanding) and peeling (pickup) of the chip from the adhesive sheet. This is followed by a die bonding step of the chip on the lead frame.

An adhesive sheet used in a process from a dicing process of a semiconductor wafer to a pickup process is:
From the dicing step to the drying step, it is necessary to maintain a sufficient adhesive force to the chip, and it is desired that the chip has good releasability so that the adhesive does not adhere to the chip during pickup.

In order to die-bond the picked-up chip to a lead frame, a die bonding adhesive such as an epoxy bonding agent is used. Therefore, at the time of die bonding, it is necessary to apply an adhesive to the back surface of the chip. However, when the chip is very small, it is difficult to apply an appropriate amount of adhesive to the chip. When the adhesive protrudes from the IC chip or when the IC chip is large, the amount of the adhesive is insufficient. For example, it is not always easy to perform bonding so as to have an appropriate bonding force. In addition, such an operation of applying the die-bonding adhesive is complicated, and improvement is required to simplify the process.

[0006] MICROELECTRONIC MAN
UFACTURING AND TESTING (October 1985) reports a conductive adhesive film for die bonding in which a conductive filler is filled in a thermoplastic resin. Thus, if a film adhesive is used as the die bonding adhesive,
The adjustment of the amount of the adhesive becomes easy.

[0007] This conductive adhesive film raises the temperature to near the melting point of the thermoplastic resin, and is bonded by pressure.
In the conductive adhesive film reported in the above-mentioned magazine, if a thermoplastic resin having a low melting point is selected and used, the bonding temperature can be lowered, and damage to the chip such as oxidation of the lead frame can be reduced. However, in this case, since the adhesive strength at the time of heating is low, it cannot withstand heat treatment after die bonding, for example, a wire bonding and a sealing step. Conversely, if a thermoplastic resin having a high melting point is used so as to withstand such heat treatment, the temperature required for bonding increases, and the lead frame may be damaged by oxidation or the like.

On the other hand, recently, various types of pressure-sensitive adhesive sheets for attaching a wafer having both a wafer fixing function and a die bonding function have been proposed (for example, Japanese Patent Application Laid-Open Nos. Hei 2-32181 and Hei 3-268345, and Japanese Patent Publication No. Hei 3-268345). 3-348
No. 53, etc.).

JP-A-2-32181 discloses a composition comprising a (meth) acrylate copolymer, an epoxy resin, a photopolymerizable low-molecular compound, a heat-active latent epoxy resin curing agent and a photopolymerization initiator. An adhesive tape comprising an adhesive layer formed from a product and a substrate is disclosed. The adhesive layer has a function of fixing the wafer at the time of wafer dicing, and after the dicing is completed, is hardened by irradiating with an energy ray, and the adhesive strength between the substrate and the base material is reduced. Therefore, when the chip is picked up, the adhesive layer peels off together with the chip. I with adhesive layer
When the C chip is placed on the lead frame and heated, the adhesive layer develops an adhesive force, and the bonding between the IC chip and the lead frame is completed.

In Japanese Patent Publication No. 3-34853,
A dicing film comprising a polymer support film having a surface substantially free of a release layer and a conductive adhesive is taught. This conductive adhesive has substantially the same function as the above-mentioned adhesive layer.

In Japanese Patent Application Laid-Open No. 3-268345, an adhesive layer for bonding a die is provided on a heat-foamable adhesive layer provided on a supporting base material. There is taught a die-bonding sheet having a function of supporting a semiconductor wafer at the time of dividing the semiconductor wafer so that the heat-foamable pressure-sensitive adhesive layer can be peeled off.

If the pressure-sensitive adhesive sheet for attaching a wafer having both the wafer fixing function and the die bonding function as described above is used, so-called direct die bonding can be performed, and the step of applying the die bonding adhesive can be omitted. Become like Since there is no need to newly apply an adhesive for the die bonding step, the process can be simplified.

[0013]

However, even in the pressure-sensitive adhesive sheet for attaching a wafer having both the wafer fixing function and the die bonding function as described above, the reliability of the die bonding function cannot be said to be sufficient. There is room for improvement.

In the manufacturing process of a semiconductor device, high-temperature processing steps such as a wire bonding step and a sealing step follow as necessary after die bonding depending on the desired package form. After packaging, for example, when mounting on a printed circuit board, a solder reflow process at 210 ° C. to 260 ° C. is required. Therefore, it is desired that the adhesive for die bonding can maintain sufficient adhesiveness even under such high temperature conditions.

An object of the present invention is to provide an adhesive sheet having both a good wafer fixing function in a dicing step and a good die bonding function in a die bonding step, and a good adhesive sheet in the steps after the die bonding. An object of the present invention is to provide an adhesive sheet having an adhesive layer that can maintain adhesion reliability.

[0016]

Means for Solving the Problems The adhesive sheet of the present invention comprises:
A radiation-polymerizable base material and an adhesive layer provided on the base material and containing a polyimide resin (A), an epoxy resin (B), a phenol resin (C), and a curing accelerator (D) It is characterized by having.

Further, a method of manufacturing a semiconductor device according to the present invention
A step of attaching the adhesive sheet of the present invention to a semiconductor wafer with the adhesive layer as an adhesive surface, a step of dicing the semiconductor wafer, and irradiating the radiation polymerizable substrate of the adhesive sheet with radiation from the substrate side. A step of peeling the semiconductor chip with the adhesive layer adhered from the base material of the adhesive sheet, and a step of bonding the peeled semiconductor chip to a wiring connection substrate such as a lead frame via an adhesive layer. It is characterized by having.

Since the adhesive sheet of the present invention has a radiation-polymerizable substrate, the substrate can be polymerized and cured by irradiation with radiation, and the adhesiveness between the substrate and the adhesive layer can be adjusted. Therefore, the adhesive sheet of the present invention can be used as an adhesive sheet for fixing a wafer at the time of dicing in the process of manufacturing a semiconductor device, and after the dicing step, the base material is irradiated with radiation to obtain a base material. The adhesiveness between the material and the adhesive layer is reduced, and the chip with the adhesive layer adhered can be easily separated from the substrate. Thereafter, the separated chip can be adhered to a wiring connection substrate such as a lead frame via an adhesive layer.

The adhesive layer of the present invention can have good strength and adhesiveness at high temperature by adding a thermosetting epoxy resin and a phenol resin to a polyimide resin. Good adhesiveness can be maintained with respect to the subsequent wire bonding and encapsulation steps involving high temperatures.

In particular, as the polyimide resin (A) of the adhesive layer of the present invention, the following chemical formula (I) (where n = 2 to 2)
Indicates an integer of 20. In the case where a tetracarboxylic dianhydride represented by the formula (1) is selected by reacting the dicarboxylic acid with a tetracarboxylic dianhydride contained in an amount of 70 mol% or more based on the total acid dianhydride, more reliable In addition, since it exhibits good adhesive strength to high temperatures, sufficient adhesiveness can be maintained even in a process involving high temperatures after die bonding. Also, since the amount of tetracarboxylic dianhydride is adjusted, die bonding can be performed at a relatively low temperature without oxidizing a wiring connection substrate such as a lead frame.

[0021]

Embedded image

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the adhesive sheet for attaching a wafer according to the present invention will be described.

The adhesive sheet according to the embodiment of the present invention comprises:
It is composed of a radiation polymerizable substrate and a die bonding adhesive layer formed thereon. By irradiating the base material with radiation such as UV (ultraviolet light) or EB (electron beam), the adhesive strength between the base material and the die bonding adhesive layer is adjusted, so that the wafer fixing function and the die bonding function can be performed. Combine.

As the radiation polymerizable substrate, a resin film containing a component having a radiation polymerizable functional group in a resin film or a resin film having a resin having a radiation polymerizable functional group formed in a film shape can be used. .

The resins used for the radiation-polymerizable base material include thermoplastic resins such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, polyamide, polyethylene, and polysulfone; epoxy resins; A thermosetting resin such as a resin, a silicone resin, and a phenol resin, or an acrylic resin, a rubber-based polymer, a fluororubber-based polymer, a fluororesin, or the like can be used. A resin obtained by mixing a radiation-polymerizable component in these resins, or a modified resin obtained by adding a radiation-polymerizable functional group to these resin films can be used. Two or more of these may be used in combination.

As the radiation polymerizable functional group in the substrate, a compound having at least one carbon-carbon double bond in the molecule can be used.

If necessary, a reactive diluent may be added to the radiation-polymerizable substrate. As the reactive diluent, the molecular weight is about 100 to 3000, preferably 1
A polymerizable compound having a molecular weight of about 00 to 1500 and having at least one carbon-carbon double bond in the molecule is used. Specifically, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate,
Any one or a plurality of commercially available oligoester acrylates can be used. The reactive diluent is preferably used in an amount of 0 to 50 parts by weight, particularly preferably 0 to 30 parts by weight, based on 100 parts by weight of the resin.

Furthermore, by mixing a photoreaction initiator into the above-mentioned substrate having radiation polymerizability, the polymerization curing time by light irradiation and the amount of light irradiation can be reduced. As such a photoreaction initiator, specifically,
Benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl,
β-chloranthraquinone and the like. The photoreaction initiator is preferably used in an amount of 0.1 to 10 parts by weight, particularly 0.5 to 5 parts by weight, based on 100 parts by weight of the resin.

The adhesive for die bonding preferably contains a polyimide resin (A), an epoxy resin (B), a phenol resin (C), and a curing accelerator (D).

Particularly, as the polyimide resin (A),
Tetracarboxylic dianhydride in which the tetracarboxylic dianhydride represented by the following chemical formula (I) (where n is an integer of 2 to 20) is contained in an amount of 70 mol% or more based on the total acid dianhydride. It is preferable to use a polyimide resin obtained by reacting a diamine. This material allows bonding at relatively low temperatures due to its low glass transition point (Tg). In addition, since the composition is soluble in a solvent, an adhesive film can be easily prepared by dissolving the composition in a solvent to form a varnish, and coating the composition on a supporting substrate. Further, since the water absorption is low, the incorporation of moisture into the semiconductor device can be reduced, and the reliability of the semiconductor device can be improved.

[0031]

Embedded image Here, the tetracarboxylic dianhydride represented by the chemical formula (I) as a raw material of the polyimide resin (A) includes:
Ethylene bis trimellitate dianhydride, trimethylene bis trimellitate dianhydride, tetramethylene bis trimellitate dianhydride, pentamethylene bis trimellitate dianhydride, hexamethylene bis trimellitate dianhydride, heptamethylene bis trimellitate dianhydride Anhydride, octamethylene bis trimellitate dianhydride, nonamethylene bis trimellitate dianhydride, decamethylene bis trimellitate dianhydride, dodecamethylene bis trimellitate dianhydride, hexadecamethylene bis trimellitate dianhydride, octa Decamethylene bistrimellitate dianhydride and the like may be mentioned, and one or more of these may be used in combination.

These tetracarboxylic dianhydrides can be synthesized from trimellitic anhydride monochloride and the corresponding diol. The content of the above tetracarboxylic dianhydride is 7 to the total tetracarboxylic dianhydride.
It is preferable to be 0 mol% or more. If the content is less than 70 mol%, the temperature required for bonding at the time of die bonding becomes too high. Therefore, when a substrate having low heat resistance is used, when the substrate is bonded to the substrate, wrinkles may occur on the substrate. Or
Sometimes lamination does not work well.

Examples of the tetracarboxylic anhydride which can be used together with the tetracarboxylic dianhydride of the formula (I) include pyromellitic dianhydride, 3,3 ', 4,4'-
Diphenyltetracarboxylic dianhydride, 2,2 ', 3
3'-diphenyltetracarboxylic dianhydride, 2,2-
Bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride Anhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-
Dicarboxyphenyl) methane dianhydride, bis (3,4
-Dicarboxyphenyl) methane dianhydride, bis (3,
4-dicarboxyphenyl) sulfone dianhydride, 3,
4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 3,4 3 ', 4'-benzophenonetetracarboxylic dianhydride, 2,3,2', 3-benzophenonetetracarboxylic dianhydride, 2,3,3 ', 4'-benzophenonetetracarboxylic dianhydride, , 2,5,6-
Naphthalenetetracarboxylic dianhydride, 2,3,6,7
-Naphthalenetetracarboxylic dianhydride, 1,2,4
5-naphthalene-tetracarboxylic dianhydride, 1,4
5,8-Naphthalene-tetracarboxylic dianhydride can be used.

Further, 2,6-dichloronaphthalene-1,
4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-
1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, thiophene -2,3,4,5-tetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,4,3', 4'-biphenyltetracarboxylic dianhydride Product, 2,3,2 ', 3'-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3,4
-Dicarboxyphenyl) methylphenylsilane dianhydride, bis (3,4-dicarboxyphenyl) diphenylsilane dianhydride, 1,4-bis (3,4-dicarboxyphenyldimethylsilyl) benzene dianhydride, , 3-
Bis (3,4-dicarboxyphenyl) -1,1,3
3-Tetramethyldicyclohexane dianhydride and p-phenylbis (trimellitic acid monoester acid anhydride) may be used.

Further, ethylene tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 8-dimethyl-1,2,3,
5,6,7-hexahydronaphthalene-1,2,5,6
Tetracarboxylic dianhydride, cyclopentane-1,
2,3,4-tetracarboxylic dianhydride, pyrrolidine-
2,3,4,5-tetracarboxylic dianhydride, 1,2,2
3,4-cyclobutanetetracarboxylic dianhydride, bis (exo-bicyclo [2,2,1] heptane-2,3-
Dicarboxylic anhydride) sulfone, bicyclo- (2,2,
2) -Octo (7) -ene 2,3,5,6-tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,2-
Bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 1,4-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride), 1,3-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride), 5- (2,5-dioxo) Tetrahydrofuryl)-
3-Methyl-3-cyclohexene-1,2-dicarboxylic anhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride and the like may be used. Two or more of these may be used in combination.

The diamines used for producing the polyimide resin by reacting with tetracarboxylic dianhydride include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, and 1,4-diaminobutane. 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12 Aliphatic diamines such as diaminododecane, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,
3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenyldifluoromethane,
3,4'-diaminodiphenyldifluoromethane, 4,
4'-diaminodiphenyldifluoromethane, 3,3 '
-Diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfide, 3,
4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylketone, 3,4'-diaminodiphenylketone,
4,4'-diaminodiphenyl ketone, 2,2-bis (3-aminophenyl) propane, 2,2 '-(3
4'-diaminodiphenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-
Aminophenyl) hexafluoropropane, 2,2-
(3,4'-diaminodiphenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy)
Benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,3 '-(1,4-phenylenebis (1-methylethylidene)) bisaniline, , 4 '-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 4,4'-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 2,2-bis (4- ( 3
-Aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (3-aminophenoxy) phenyl) hexafluoropropane, 2,2- Screw (4-
(4-aminophenoxy) phenyl) hexafluoropropane, bis (4- (3-aminophenoxy) phenyl) sulfide, bis (4- (4-aminophenoxy)
Phenyl) sulfide, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 4,4 '-Methylene-bis (2,6-diethylaniline), o-tolidinesulfone, 1,4-bis (4-aminophenoxy) benzene, 4,4-methylene-bis (2,6-diisopropylaniline), 4, 4'-bis (4-aminophenoxy)
Examples include aromatic diamines such as biphenyl, 1,1-bis (4- (4-aminophenoxy) phenyl) cyclohexane, and 1,3-bis (3-aminopropyl) tetramethyldisiloxane.

The epoxy resin (B) contains at least two epoxy groups in the molecule, and a phenol glycidyl ether type epoxy resin is preferably used from the viewpoint of curability and cured product characteristics. As such a resin,
Examples include bisphenol A, bisphenol AD, bisphenol S, bisphenol F or condensates of halogenated bisphenol A and epichlorohydrin, glycidyl ether of phenol novolak resin, glycidyl ether of cresol novolak resin, and glycidyl ether of bisphenol A novolak resin. The amount of the epoxy resin is 1 to 100 parts by weight of the polyimide resin.
When the amount is less than 200 parts by weight, preferably 5 to 100 parts by weight, the adhesiveness is poor, and when it is more than this, the film formability is poor.

The phenolic resin (C) has at least two phenolic hydroxyl groups in the molecule. Examples of such a resin include a phenol novolak resin,
Cresol novolak resin, bisphenol A novolak resin, poly-p-vinylphenol, phenol aralkyl resin and the like can be mentioned. The amount of the phenolic resin is in the range of 2 to 150 parts by weight, preferably 50 to 120 parts by weight, based on 100 parts by weight of the epoxy resin.

The curing accelerator (D) is not particularly limited as long as it is used for curing the epoxy resin.
Examples of such a compound include imidazoles, dicyandiamide derivatives, dicarboxylic dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole-tetraphenylborate, 1,8-diazabicyclo (5, (4,0) Undecene-7-tetraphenyl borate and the like are used. These may be used in combination of two or more. The curing accelerator is used in an amount of 0.01 to 50 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the epoxy resin. Worse.

Further, a silane coupling agent, a titanium-based coupling agent,
A nonionic surfactant, a fluorine-based surfactant, a silicone-based additive, or the like may be appropriately added.

Further, for the purpose of imparting conductivity, gold, silver, copper, nickel, aluminum, stainless steel, carbon, ceramic,
Alternatively, a conductive filler such as nickel or aluminum coated with silver may be added, and for the purpose of providing thermal conductivity, gold, silver, copper, nickel, aluminum, stainless steel, silicon, germanium, etc. A heat conductive substance such as a metal material or an alloy thereof may be added. These additives may be blended in an amount of about 10 to 400 parts by weight based on 100 parts by weight of the die bonding adhesive.

In the method for producing the adhesive sheet of the present embodiment, the adhesive layer and the radiation-polymerizable base material are applied to a film-like support member, dried, and then the adhesive layer and the radiation-polymerizable material are applied. A method can be used in which the substrates are bonded at room temperature, and in some cases, while heating and pressing. Note that either the adhesive layer or the base material may be used as a support member. For example, when a base material is used as a support member, an adhesive layer is directly formed on the base material as the support member.

The support member may be peeled off after being attached to the back surface of the wafer, but may be attached as a protective material before use. Further, it is possible to polymerize by irradiation of radiation before or after the adhesive layer formation of each surface layer opposite to the adhesive layer forming surface of the radiation polymerizable substrate,
It is preferable from the viewpoint of workability.

The shape of the adhesive sheet can be any shape such as a tape shape and a label shape.

When the adhesive sheet for attaching a wafer of the present embodiment described above is irradiated with radiation, the adhesive strength of the substrate is greatly reduced after the irradiation, and the adhesive is easily peeled off at the interface between the die bonding adhesive and the substrate. become able to. That is, the chip can be picked up from the base material of the adhesive sheet while the adhesive for die bonding is adhered to the back surface of the semiconductor chip.

Hereinafter, a method of using the adhesive sheet according to the present embodiment will be described. A semiconductor wafer to be diced is pressure-bonded to the die-bonding adhesive layer of the adhesive sheet at room temperature or with heating, and the steps of dicing, washing, and drying the wafer are performed. At this time, the wafer chip is sufficiently bonded and held to the adhesive sheet substrate by the die bonding adhesive layer, so that the wafer chip does not fall off during each of the above steps. The base material of the adhesive sheet is irradiated with radiation such as a line (EB) to polymerize and cure the base material having radiation polymerizability. As a result, the adhesive force between the radiation-polymerizable substrate and the die-bonding adhesive layer is
Reduced to the point where chips can be picked up, and expanding the adhesive sheet expands the chip spacing,
This is a condition under which the chip can be easily picked up.

Irradiation of the adhesive sheet with radiation is preferably performed from the back side of the substrate having radiopolymerizability. When ultraviolet light (UV) is used as the radiation, it is preferable that the base material is a transparent material having light transmittance of a certain level or more with respect to the irradiation wavelength, but the electron beam (EB) is used as the radiation.
When is used, the substrate does not necessarily need to be a transparent material.

After the expanding step, the chip is picked up together with the adhesive layer and die-bonded to the lead frame via the adhesive layer. At the time of die bonding, the chip may be pressure-bonded to the lead frame at room temperature or while heating, or may be bonded and fixed to the lead frame by heating after pressure bonding.

The die bonding adhesive develops an adhesive force that can withstand reliability and completes the bonding between the chip and the lead frame.

As described above, the adhesive sheet of the present invention
It is composed of a two-layer structure of a base material and an adhesive layer. Since the structure is simple, the film needs to be bonded only once, and the manufacturing process is simple. Further, the adhesive sheet of the present invention can be peeled off by irradiation of radiation because the base material has radiopolymerizability, but the radioactive polymerizability is given only to the base material, and the adhesive layer remaining on the back surface of the semiconductor chip has Since no radioactive polymerizing agent is added, the adhesive layer can be composed of a composition intended for a pure adhesive function. Therefore, by forming an adhesive layer having the above-described composition, the adhesive layer can have sufficient adhesive strength. Therefore, the manufacturing method of the semiconductor device using the adhesive sheet of the present invention, while the manufacturing process is simple,
A semiconductor device with high bonding reliability can be provided.

[0051]

Embodiments of the present invention will be described below.

<Preparation of Adhesive Layer for Die Attachment> As shown in the composition table of Table 2 in FIG. 1, seven kinds of varnishes were prepared. Among them, sample No. 1 to 5 are examples of the present invention, and sample Nos. 6 to 7 correspond to comparative examples.

In Table 1, "Polyimide A" is composed of ethylene bis trimellitate dianhydride (1 mol%)
2-bis (4- (4-aminophenoxy) phenyl) propane (1 mol%) and “polyimide B” are tetramethylene bis trimellitate dianhydride (1 mol%) and 4,4′-methylene-bis (2, 6-diisopropylaniline) (0.9 mol%) and 1,3-bis (3-aminopropyl) tetramethyldisiloxane (0.1 mol
1%), "Polyimide C" is composed of decamethylene bistrimellitate dianhydride (0.8 mol%) and benzophenonetetracarboxylic dianhydride (0.2 mol%)
2-bis (4-aminophenoxyphenyl) propane (0.8 mol%) and 3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane (0.2 m
ol%).

These seven types of varnishes were coated on a polypropylene film as a support to a thickness of 30 to 50 μm,
Heating was performed at 0 ° C. for 10 minutes and then at 120 ° C. for 30 minutes to obtain an adhesive film.

Next, the adhesive strength of the adhesive layer formed on the film was tested. The adhesive film was cut into a size of 4 mm × 4 mm, which was sandwiched between a 4 mm × 4 mm silicon chip and a 42 alloy lead frame with silver plating.
After applying a load of 00 g and pressure bonding at 260 ° C. for 3 seconds, the adhesive force was measured at room temperature and after heating at 350 ° C. for 20 seconds using a push-pull gauge. The measurement results are shown in Table 2 of FIG.

As shown in Table 2, the sample No. according to the embodiment of the present invention has the following characteristics. 1 to No. 5 is 350 ° C.
Although the adhesive strength was maintained even at the temperature of Sample No. 3, the adhesive layer did not contain a polyimide resin. In the case of the adhesive layer of No. 6, since the adhesive layer was brittle and could not be formed into a film,
The adhesion could not be measured. In addition, Sample No. containing no epoxy resin or phenol resin as a thermosetting resin. In the case of the adhesive layer No. 7, the adhesive strength was 2 at room temperature, but was insufficient at 350 ° C.

<Preparation of Radiation-Polymerizable Substrate> An acrylic ester having a copolymerization ratio of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid of 55/8/15/22 by weight is used. Polymer (acid value 143.3, glass transition point 66.
3 ° C., weight average molecular weight 80,000) 100 parts by weight, a mixture 60 of trimethylolpropane triacrylate / polyethylene glycol dimethacrylate in a weight ratio of 20/10 // 60.
A composition comprising 5 parts by weight of benzophenone and 5 parts by weight of benzophenone was applied on a support, and dried in an oven at 100 ° C. for 3 minutes to obtain a radiation-polymerizable substrate.

<Preparation of Adhesive Sheet> Adhesive layers of 1 to 5 were bonded together, and 10 mJ / c using a high-pressure mercury lamp from the back side of the substrate.
m ² was irradiated. The support material at the time of forming the base material was peeled off to obtain an adhesive sheet.

<Preparation of Semiconductor Device> A silicon wafer was thermocompression-bonded to the obtained adhesive sheet at 100 ° C. and 1 kg.
Until the adhesive layer is diced into 10 mm × 10 mm, followed by irradiation 500 mJ / cm ² in an adhesive sheet ultraviolet (UV) from the substrate side using a high pressure mercury lamp. After the UV irradiation, the diced silicon wafer could be easily picked up from the base material of the adhesive sheet together with the adhesive layer.
The silicon chip to which the adhesive was adhered was directly mounted on the lead frame as it was, and was cured by heating, so that the lead frame and the chip could be strongly die-bonded.

[0060]

As described above, since the adhesive sheet of the present invention has an adhesive layer which can be used as a die bonding agent on a radioactive polymerizable substrate, it has a wafer fixing function and a die bonding function. Can be provided at the same time. Therefore, in the manufacturing process of the semiconductor device,
The step of bonding the die bonding adhesive can be omitted.

The adhesive sheet of the present invention can provide a highly reliable semiconductor device because the adhesive layer can maintain good adhesiveness and strength at high temperatures.

[Brief description of the drawings]

FIG. 1 is a composition table of a varnish of an adhesive layer according to an example of the present invention.

FIG. 2 shows a measurement result of an adhesive force of an adhesive layer according to an example of the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/52 H01L 21/52 C 21/301 21/78 M (72) Inventor Katsuhide Aichi Tsukuba, Ibaraki Ichiwadai 48 Hitachi Chemical Co., Ltd. Research Laboratory (72) Inventor Takashi Masuko 48 Tsukaba, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd. Research Laboratory F-term (reference) 5F047 AA11 BA21 BA24 BA34 BA35 BA37 BB03 FA90

Claims (7)

[Claims] 1. A radiation-polymerizable substrate, and a polyimide resin (A), an epoxy resin (B), a phenol resin (C), and a curing accelerator (D) provided on the substrate.
An adhesive sheet having an adhesive layer containing: 2. A polyimide resin (A) for the adhesive layer.
Is a tetracarboxylic acid in which a tetracarboxylic dianhydride represented by the following chemical formula (I) (where n is an integer of 2 to 20) is contained in an amount of 70 mol% or more based on the total acid dianhydride. The adhesive sheet according to claim 1, wherein the adhesive sheet is obtained by reacting a dianhydride with a diamine. Embedded image 3. The radiation-polymerizable base material includes a carbon double bond (C) as a radiation-polymerizable substance in the base material.
＝ C) or a compound having at least one carbon double bond (C ＝ C) added to the substrate.
Or the adhesive sheet according to claim 2. 4. A step of attaching the adhesive sheet according to claim 1 to a semiconductor wafer using the adhesive layer as an adhesive surface; a step of dicing the semiconductor wafer; Irradiating the base material of the adhesive sheet with radiation; removing the semiconductor chip with the adhesive layer adhered from the base material; and placing the peeled semiconductor chip on a wiring connection board with the adhesive layer. Bonding the semiconductor device via the semiconductor device. 5. The method of manufacturing a semiconductor device according to claim 4, further comprising the step of electrically connecting said semiconductor chip and said wiring connection substrate. 6. The method according to claim 5, further comprising the step of sealing the semiconductor chip with a resin. 7. A semiconductor device manufactured by the method of manufacturing a semiconductor device according to claim 4.