JP2005247953A - Adhesive composition for semiconductor and adhesive sheet for semiconductor using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for a semiconductor device, having high adhesiveness, high resistance to solder reflow, and excellent wire bonding processability. <P>SOLUTION: The adhesive composition for the semiconductor device comprises at least one kind of a thermoplastic resin selected from a copolymer containing butadiene as a copolymerizing component and a copolymer containing an acrylic ester and a methacrylic ester having 1-8C side chain as copolymerizing components, a thermoset resin, and inorganic particles having ≤10μm maximum particle diameter and >0.1 μm and ≤2 μm average particle diameter. The content of the inorganic particles is regulated so as to be ≥25 and ≤50 wt.% based on the whole amount of the composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an adhesive composition used for a semiconductor device constituting a semiconductor integrated circuit connection substrate (interposer) used when a semiconductor integrated circuit is mounted and packaged.

  LOC (lead on chip), which is a typical semiconductor package in recent years, has a structure as shown in FIG. 1, and an epoxy resin or a polyamide resin is used for bonding the semiconductor chip 1 and the inner lead of the lead frame 4. An adhesive 3 made of polyimide resin, polyamideimide resin or the like is used. This adhesive is required to have both adhesiveness and heat resistance that does not cause package cracks during solder reflow.

  Recently, some semiconductor packages belonging to LOC have a structure as shown in FIG. In this package, the lead frame 9 and the semiconductor chip 6 are not directly connected by wire bonding 7, but are connected by wire bonding from the lead frame 9 to the polyimide film substrate 10 and then connected from the polyimide film substrate 10 to the semiconductor chip by wire bonding. . The use of this semiconductor package is very useful from the viewpoint of cost because the degree of design freedom as a semiconductor package is greatly increased by changing the circuit pattern of the film substrate without changing the circuit design of the semiconductor chip. Examples of the polyimide film substrate used here include a TAB (Tape Automated Bonding) tape and a flexible printed circuit board. Specifically, a three-layer TAB tape in which a conductor pattern is formed on a polyimide film via an adhesive layer, And a two-layer TAB tape in which a copper layer is directly formed on the polyimide resin layer.

  The adhesive layer that bonds the lead frame and the polyimide film substrate in the semiconductor package as described above has high adhesion between the lead frame and the polyimide film substrate, and reflow resistance when the semiconductor package is mounted on the base substrate. Required. In particular, in a semiconductor package having a large number of pins, the operating temperature becomes a high temperature exceeding 100 ° C., and when a material having a different linear expansion coefficient, that is, a polyimide film substrate and a lead frame are bonded, so-called stress is relieved. Thermal cycle resistance is also required for the adhesive layer.

As an adhesive composition used for bonding a polyimide film substrate and a lead frame, many systems based on an acrylonitrile-butadiene copolymer have been proposed as a main component and have excellent reflow resistance. Examples thereof include an adhesive composed of an acrylonitrile-butadiene copolymer, an epoxy resin, and a curing agent (see, for example, Patent Document 1). In addition, an adhesive containing an epoxy resin, a thermoplastic resin, and silica powder has been proposed as one excellent in reflow resistance and thermal cycle resistance (see, for example, Patent Document 2). Furthermore, there is an adhesive composition having a high elastic modulus containing inorganic fine particles (see, for example, Patent Document 3).
JP-A-11-116924 (7-16 paragraphs) Japanese Patent Laid-Open No. 10-178067 (paragraphs 16 to 41) JP 2003-113320 A (8-90 paragraphs)

  However, when these adhesives are applied to a semiconductor package as shown in FIG. 2, they exhibit high adhesion and reflow resistance, but wire bonding is performed between the semiconductor chip and the polyimide film substrate and between the polyimide film substrate and the lead frame. At this time, the bonding pad on the polyimide film substrate is recessed, which causes a big problem that bonding cannot be performed. This is due to the fact that the adhesive layer that bonds the polyimide film substrate and the lead frame becomes soft near the normal bonding temperature of 150 ° C., and that the bonding pad portion is dented by deformation. Furthermore, if only inorganic fine particles are added, the reflow resistance is inferior although it exhibits a high elastic modulus.

  An object of the present invention is to solve the problems in wire bonding of the above-mentioned adhesive composition for semiconductors, has high adhesion, high reflow resistance, and has excellent wire bonding processability. Is to provide.

  That is, the present invention is at least one selected from a copolymer having butadiene as a copolymer component, or a copolymer having an acrylic acid ester and a methacrylic acid ester having a side chain having 1 to 8 carbon atoms as a copolymer component. Thermoplastic resin, thermoplastic resin, inorganic particles having a maximum particle size of 10 μm or less and an average particle size of more than 0.1 μm and 2 μm or less, and the content of inorganic particles is 25% by weight or more and 50% by weight with respect to the total amount of the composition % Of the adhesive composition for a semiconductor device.

  ADVANTAGE OF THE INVENTION According to this invention, it has high adhesiveness and high reflow resistance, and can obtain the adhesive composition for semiconductor devices which is excellent in wire bonding workability.

  The semiconductor adhesive composition in the present invention is an interlayer adhesive for semiconductor elements, lead frames, and wiring boards (interposers), and the shape and material of these adherends are not particularly limited.

  The adhesive composition constituting the adhesive layer of the present invention preferably contains at least one kind of thermoplastic resin and thermosetting resin. The thermoplastic resin has functions such as adhesion, flexibility, relaxation of thermal stress, and improvement of insulation due to low water absorption.

  The thermoplastic resin has a copolymer containing butadiene as a copolymer component or a side chain having 1 to 8 carbon atoms from the viewpoint of adhesion to the lead frame metal material, flexibility, and relaxation effect of thermal stress. At least one selected from copolymers having acrylic acid esters and methacrylic acid esters as copolymerization components may be used, or one or more may be used. These thermoplastic resins may have a functional group capable of reacting with a thermosetting resin described later. Specific examples include an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a methylol group, an isocyanate group, a vinyl group, and a silanol group. These functional groups are preferable because the bond with the thermosetting resin becomes stronger and the heat resistance is improved.

  More preferable thermoplastic resins include acrylonitrile-butadiene copolymer (NBR), styrene-butadiene-ethylene resin (SEBS), and styrene-butadiene resin (SBS) from the viewpoints of adhesion to metal and chemical resistance. ) And the like. Further, copolymers having butadiene as an essential copolymer component and having a carboxyl group are more preferable, and examples thereof include NBR (NBR-C), SEBS (SEBS-C), and SBS (SBS-C). Here, “C” means having a carboxyl group. Examples of NBR-C include those obtained by carboxylating terminal groups of a copolymer rubber obtained by copolymerizing acrylonitrile and butadiene at a molar ratio of about 10/90 to 50/50, or acrylonitrile, butadiene and acrylic acid, maleic acid, etc. And terpolymer rubbers of carboxyl group-containing polymerizable monomers. Specifically, PNR-1H (manufactured by Nippon Synthetic Rubber Co., Ltd.), “Nipole” 1072J, “Nipol” DN612, “Nipol” DN631 (manufactured by Nippon Zeon Co., Ltd.), “Hiker” CTBN (BF Goodrich) Etc.). Moreover, MX-073 (made by Asahi Kasei Co., Ltd.) can be illustrated as SEBS-C, and D1300X (made by Shell Japan Co., Ltd.) can be exemplified as SBS-C.

  The thermosetting resin is necessary to realize a balance of heat resistance, insulation at high temperature, chemical resistance, strength of the adhesive layer, and the like. Examples of the thermosetting resin include known resins such as epoxy resins, phenol resins, melamine resins, xylene resins, furan resins, and cyanate ester resins. In particular, an epoxy resin and a phenol resin are preferable because of excellent insulation.

  The epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule, but diglycidyl ether such as bisphenol F, bisphenol A, bisphenol S, resorcinol, dihydroxynaphthalene, dicyclopentadiene diphenol, and epoxidation Examples include phenol novolak, epoxidized cresol novolak, epoxidized trisphenylol methane, epoxidized tetraphenylol ethane, epoxidized metaxylene diamine, cyclohexane epoxide, and the like. Specifically, YD-128 (manufactured by Toto Kasei Co., Ltd.), “Epicoat” 828, “Epicoat” 180 (manufactured by Yuka Shell Epoxy Co., Ltd.) and the like can be exemplified. Furthermore, it is also effective to use a halogenated epoxy resin, particularly a brominated epoxy resin, for imparting flame retardancy. At this time, although it is possible to impart flame retardancy with a brominated epoxy resin alone, it is more effective to use a mixed system with a non-brominated epoxy resin because the heat resistance of the adhesive is greatly reduced. Examples of brominated epoxy resins include copolymerized epoxy resins of tetrabromobisphenol A and bisphenol A, or brominated phenol novolac type epoxy resins such as “BREN” -S (manufactured by Nippon Kayaku Co., Ltd.). . Two or more kinds of these brominated epoxy resins may be mixed in consideration of bromine content and epoxy equivalent.

  As the phenol resin, any known phenol resin such as novolak type phenol resin and resol type phenol resin can be used. For example, alkyl-substituted phenols such as phenol, cresol, pt-butylphenol, nonylphenol, p-phenylphenol, cyclic alkyl-modified phenols such as terpene and dicyclopentadiene, hetero groups such as nitro groups, halogen groups, cyano groups, and amino groups Examples thereof include those having functional groups containing atoms, those having a skeleton such as naphthalene and anthracene, and resins composed of polyfunctional phenols such as bisphenol F, bisphenol A, bisphenol S, resorcinol, and pyrogallol.

  The addition amount of the thermosetting resin is 5 to 400 parts by weight, preferably 50 to 200 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If the amount of the thermosetting resin added is less than 5 parts by weight, the elastic modulus will decrease significantly at high temperatures, and the semiconductor integrated circuit connection substrate will be deformed during use of the device mounted with the semiconductor device and handled in the processing process. This is not preferable because of lack of workability. If the addition amount of the thermosetting resin exceeds 400 parts by weight, the elastic modulus is high, the thermal expansion coefficient is small, and the thermal stress relaxation effect is small, which is not preferable.

  Addition of an epoxy resin and phenolic resin curing agent and curing accelerator to the adhesive layer of the present invention is not limited. For example, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol and 1,8-diazabicyclo (5,4,0) Tertiary amine compounds such as undecene-7, 3,3′5,5′-tetramethyl-4,4′-diaminodiphenylmethane, 3,3′5,5′-tetraethyl-4,4′-diaminodiphenylmethane, 3, , 3′-dimethyl-5,5′-diethyl-4,4′-diaminodiphenylmethane, 3,3′-dichloro-4,4′-diaminodiphenylmethane, 2,2′3,3′-tetrachloro-4, 4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminobenzophenone Aromatics such as 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminobenzophenone, 3,4,4′-triaminodiphenyl sulfone Boron trifluoride amine complexes such as polyamine, boron trifluoride triethylamine complex, imidazole derivatives such as 2-alkyl-4-methylimidazole and 2-phenyl-4-alkylimidazole, phthalic anhydride, trimellitic anhydride, etc. Organic phosphine compounds such as organic acid, dicyandiamide, triphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine and tri (nonylphenyl) phosphine can be used. These may be used alone or in combination of two or more. The addition amount is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the adhesive composition.

  Moreover, a silane coupling agent can also be used together as a hardening | curing agent. The silane coupling agent has a structure in which silicon has an organic functional group capable of binding or binding to an organic matrix and a hydrolyzable group capable of binding to an inorganic material. Examples of the organic functional group include an alkyl group, a phenyl group, an amino group, an epoxy group, a vinyl group, a methacryloxy group, a mercaptooxy group, and generally bonded to a silicon atom via an alkylene group having 1 to 6 carbon atoms. doing. Moreover, what has an epoxy group and an amino group as an organic functional group has good reactivity, and is excellent in the reflow resistance of an adhesive agent, and preferable. Specifically, when the organic functional group is an amino group, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltris (β-methoxy-ethoxy-ethoxy) silane, N-methyl -Γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, triaminopropyltrimethoxysilane, Examples thereof include N-phenyl-γ-aminopropyltrimethoxysilane and γ-4,5 dihydroxyimidazolepropyltriethoxysilane. When the organic functional group is an epoxy group, β-3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyl Diethoxysilane is mentioned.

  In addition to the above components, an inorganic particle component is added for the purpose of suppressing deformation of the adhesive composition during wire bonding and improving the film strength. The particle size of the inorganic particle component is preferably a maximum particle size of 10 μm or less, more preferably a maximum particle size of 5 μm or less, from the viewpoints of dispersibility, coating properties, reflow resistance and the like. The average particle size is preferably more than 0.1 μm and not more than 2 μm, more preferably more than the average particle size of 0.1 μm and not more than 1 μm. If the average particle diameter exceeds 2 μm, the dispersion of the particles in the adhesive composition will be inferior and the effect of improving the film strength will be low, so that the required characteristics will not be satisfied. On the other hand, when the maximum particle size exceeds 10 μm, the embedding of the adhesive into the adherend is worsened, and the adhesive strength and reflow resistance are lowered. If the average particle size is 0.1 μm or less, the particles are likely to aggregate in the adhesive coating during the adhesive manufacturing process, making it difficult to achieve a uniform dispersion state, and the intended effect cannot be obtained. The average particle size and the maximum particle size can be measured using a laser diffraction / scattering particle size distribution measuring device, a dynamic light scattering particle size distribution measuring device, or the like. Moreover, the particle diameter contained in an adhesive bond layer can also be investigated by TEM (transmission electron microscope) observation of the adhesive bond cross section after hardening.

  In particular, from the viewpoint of reflow resistance, those that do not decompose at a temperature of 250 to 260 ° C. during solder reflow, specific examples include silica, alumina, zirconium oxide, zinc oxide, antimony trioxide, antimony pentoxide, Examples thereof include metal oxides such as magnesium oxide, titanium oxide, iron oxide, cobalt oxide, chromium oxide and talc, fine metal particles such as aluminum, gold, silver, nickel and iron, carbon black and glass. You may use these individually or in mixture of 2 or more types.

  Of these, silica is particularly preferable because the thermal decomposition temperature greatly exceeds 300 ° C., the fluidity of the adhesive sheet is easily adjusted, and the particle size is stable. The particle shape and crystallinity are not particularly limited, and crushing systems, spheres, scales, etc. are used. Good dispersibility in paints, excellent adhesive strength and film strength of the adhesive composition, and thermal expansion. Fused spherical silica, which has a large coefficient reduction effect, is preferably used. The fused silica here means amorphous silica having a true specific gravity of 2.3. The production of the fused silica does not necessarily need to go through a molten state, and examples thereof include a method of melting crystalline silica and a method of synthesizing from various raw materials.

  The blending amount of the inorganic particles is preferably 25% by weight to 50% by weight and more preferably 30% by weight to 45% by weight of the entire adhesive composition. If it is less than 25% by weight, the resin flow of the target heat-cured adhesive becomes large, which is not preferable. On the other hand, if it exceeds 50 parts by weight, the resin flow becomes small, but the adhesion strength to the adherend is lowered.

  In order to improve reliability after mounting, it is preferable that the purity of the particles exceeds 99%, preferably exceeds 99.8%, and more preferably exceeds 99.9%. When the purity is 99% or less, a soft error of the semiconductor element is likely to occur due to α rays emitted by radiation impurities such as uranium and thorium. These inorganic particles may be subjected to surface treatment using a silane coupling agent or the like in order to improve heat resistance, adhesive strength and the like.

The adhesive sheet for a semiconductor device of the present invention is prepared from the adhesive composition for a semiconductor device of the present invention, and the thermally cured adhesive composition has a pressing temperature of 150 ° C., a pressing pressure of 35 MPa, and a pressing time of 5 minutes. In the resin flow measurement in the pressure bonding, the resin flow is preferably 120% or less, more preferably 110% or less. If the resin flow exceeds 120%, the adhesive layer that bonds the TAB tape and the lead frame becomes soft and deforms easily at the normal bonding temperature of 150 ° C when processing semiconductor packages. This causes a problem that bonding cannot be performed, which is not preferable. The resin flow of the heat-cured adhesive was determined by the following method. After laminating an adhesive single film having a diameter of 6 mm and a thickness of 100 μm so as to have a glass plate / adhesive / copper plate configuration, post-cure is performed. Next, this sample is pressure bonded under the conditions of a pressure bonding temperature of 150 ° C., a pressure bonding pressure of 35 MPa, and a pressure bonding time of 5 minutes. Since the adhesive single film is deformed by pressure bonding, the amount of deformation is calculated from the diameter after pressure bonding with respect to the diameter of 6 mm before pressure bonding using the following formula, and this is defined as resin flow [%].
Resin flow (%) = (diameter after crimping / diameter 6 mm before crimping) × 100.

  In the adhesive composition of the present invention, the heat-cured adhesive composition preferably has a storage elastic modulus at 150 ° C. of 3 MPa or more, more preferably 5 MPa or more. If it is less than 3 MPa, the film strength of the adhesive is low, and deformation of the adhesive at high temperatures becomes large, which is not preferable for wire bonding. For wire bonding, a larger storage elastic modulus is preferable, but it is preferably 100 MPa or less from the viewpoint of adhesive strength, reflow resistance, and stress relaxation effect. The storage elastic modulus is measured with a tensile mode dynamic viscoelasticity measuring device at a frequency of 1 Hz, a heating rate of 5 ° C./min, and a temperature measurement range of −70 to 300 ° C.

  The thickness of the adhesive layer of the present invention can be appropriately selected depending on the relationship between adhesive strength, resin flow, and storage elastic modulus, but is preferably 10 μm or more and 250 μm or less, and more preferably 12 μm or more and 150 μm or less.

  The adhesive sheet for a semiconductor device of the present invention may be any sheet as long as the adhesive layer made of the composition of the present invention is formed on at least one surface of the organic insulating film. The aspect which has a film is also included. The organic insulating film to be used is roughly divided into two types, and the following materials can be mentioned depending on whether they are used as a base material or a protective layer.

  The case where an organic insulating film is used as a base material is shown below. When a metal plate such as a copper foil is bonded to an organic insulating film with the adhesive layer of the present invention and the copper foil is etched to form a pattern, it can be used as a wiring board. The organic insulating film at this time is made of a composite material such as polyimide, polyester, polyphenylene sulfide, polyethersulfone, polyetheretherketone, aramid, polycarbonate, polyarylate, or a plastic or epoxy resin-impregnated glass cloth. An insulating film having flexibility of ˜125 μm is used.

  Next, the case where an organic insulating film is used as a role of an adhesive protective layer (hereinafter also referred to as a protective film) will be described below. The adhesive sheet for a semiconductor device of the present invention may have a protective layer on at least one side and, if necessary, on both sides in order to protect the adhesive layer. The material of the protective layer is a wiring board layer (TAB tape or the like) composed of an insulator layer and a conductor pattern, or a layer where a conductor pattern is not formed (lead frame, heat spreader, etc.) It will not specifically limit if the form and function of an adhesive bond layer are not impaired and it can peel as needed. Specific examples are polyester, polyolefin, polyphenylene sulfide, polyvinyl chloride, polytetrafluoroethylene, polyvinyl fluoride, polyvinyl butyral, polyvinyl acetate, polyvinyl alcohol, polycarbonate, polyamide, polyimide, polymethyl methacrylate, and other plastic films. Films that have been coated with a release agent such as silicone, alkyd resin, polyolefin resin, or fluorine-containing compound, paper laminated with these films, laminates of these films, or impregnated with releasable resins Examples thereof include coated paper. Moreover, a sand mat processed film is also mentioned. This is a film with fine irregularities formed by spraying fine particles on the film surface, and the releasability can be adjusted by the irregularity level. Among these protective films, those particularly preferably used in the present invention are films which have been subjected to a release treatment such as silicone or a fluorine-containing compound, which are excellent in controlling the release properties. More preferably, the polyester film subjected to the above-described mold release treatment is excellent in terms of heat resistance.

  In particular, when protective films are provided on both sides of the adhesive layer as shown in FIG. 3, F1-F2 is preferable when the peel strength of each protective film to the adhesive layer is F1, F2 (F1> F2). Needs 5 N / m or more, more preferably 10 N / m or more. When F1-F2 is less than 5 N / m, it is not preferable which side of the protective film the release surface is on, which is not stable because it causes a problem in use. The peeling forces F1 and F2 are both 1 to 200 N / m, preferably 3 to 150 N / m, and more preferably 3 to 100 N / m. If it is less than 1 N / m, the protective film will drop off, and if it exceeds 200 N / m, peeling becomes difficult, which is not preferable.

  The protective film may be colored with a pigment so as to have good visibility during processing. Thereby, since the protective film of the side which peels previously can be recognized easily, misuse can be avoided.

  In addition, the adhesive sheet in the present invention is not preferable if air bubbles are bitten into an adherend such as a copper foil or a reinforcing plate at the time of reflow. Therefore, in order to reduce the adhesiveness of the adhesive itself, one side of the adhesive layer, and if necessary, both sides may be roughened. According to this method, even if the adhesive layer itself has high tackiness, the surface is roughened, and the contacts to the object to be bonded are dispersed, thereby reducing the tackiness. The method for roughening the adhesive is not particularly limited, but the following examples can be given. When a coating liquid in which the adhesive composition is dissolved is applied onto a film and dried to produce a semi-cured adhesive sheet, if the surface shape of the film to which the adhesive composition is applied is uneven, Unevenness can be transferred to the surface of the adhesive sheet and roughened. For example, any film that has been embossed or sand-matted may be used. Moreover, if a film with unevenness is used for the protective film of the produced adhesive sheet and laminated, the unevenness is similarly transferred to the surface of the adhesive sheet. However, since the adhesive is embedded in the unevenness of the film surface, it may be difficult to peel off the film in actual use. For this reason, the film preferably used in the present invention is a film which has been subjected to mold release treatment such as silicone or a fluorine-containing compound. In addition, the adhesive sheet can be roughened with an uneven rubber roll.

  Moreover, it can also be set as a low-adhesive adhesive sheet by combining the technique which lowers | sticks adhesiveness and the roughening by laminating | stacking a low-adhesive adhesive layer thinly to the adhesive layer of this invention. Specific examples of the low-adhesive adhesive layer include an adhesive having a composition in which the amount of inorganic particles is increased, or an adhesive layer whose adhesiveness is controlled by subjecting a thin adhesive sheet to heat aging.

Next, an example of an adhesive sheet for a semiconductor device, a method for manufacturing a substrate for connecting a semiconductor integrated circuit using the same, and a method for manufacturing a semiconductor device will be described.
(1) Preparation of an adhesive sheet for a semiconductor device: A paint obtained by dissolving the adhesive composition of the present invention in a solvent is applied onto a polyester film which has been subjected to a release treatment on both sides, and is semi-cured, that is, B A staged adhesive is obtained. It is preferable to apply so that the thickness of the adhesive layer is 10 to 100 μm. Drying conditions are 100 to 200 ° C. and 1 to 5 minutes. Solvents are not particularly limited, but aromatics such as toluene, xylene and chlorobenzene, ketones such as methyl ethyl ketone and methyl ethyl isobutyl ketone (MIBK), aprotic such as dimethylformamide (DMF), dimethylacetamide and N-methylpyrodoline A polar system solvent alone or a mixture is preferred.

  A polyester or polyolefin protective film having higher releasability is laminated on the coated and dried adhesive layer to obtain the adhesive sheet of the present invention. Further, when the thickness of the adhesive is increased, the adhesive sheet may be laminated a plurality of times. In some cases, the degree of curing may be adjusted by, for example, aging at 40 to 100 ° C. for about 1 to 200 hours after lamination. FIG. 3 illustrates the shape of the adhesive sheet for a semiconductor device obtained in the present invention. The protective film 13 is provided on both surfaces of the adhesive layer 14.

  (2) Preparation of TAB tape with adhesive: A TAB tape having a three-layer structure in which an adhesive layer and a protective film layer are laminated on a polyimide film is processed by the following steps (a) to (d). (A) Drilling of sprockets and device holes, (b) Thermal lamination with copper foil, (c) Tin or gold plating treatment. As described above, a patterned TAB tape is obtained. The protective film on one side of the adhesive sheet for a semiconductor device prepared in (1) above is peeled off and laminated on the polyimide film surface on the back surface of the TAB tape. The bonding conditions are preferably a temperature of 20 to 200 ° C. and a pressure of 0.1 to 5 MPa. Further, depending on the shape of the semiconductor device, punching and cutting are appropriately performed.

  (3) Production of semiconductor device: The protective film is peeled off from the part (TAB tape with adhesive) obtained in (2), and is bonded to an appropriately molded lead frame. As the metal used for the lead frame, 42 alloy and copper are suitable, and the thickness is usually 0.05 to 0.5 mm. The bonding conditions are preferably a temperature of 20 to 200 ° C. and a pressure of 0.1 to 5 MPa. Finally, post-curing is performed at 80 to 200 ° C. for about 15 to 180 minutes in order to heat and cure the adhesive layer in a hot air oven.

  FIG. 2 shows a cross-sectional view of one embodiment of a semiconductor device in which the adhesive composition of the present invention is used. After the post cure, the semiconductor chip 6 is die-bonded on the lead frame 9, and the wire bonding 7 is performed between the semiconductor chip and the TAB tape 10 and between the TAB tape and the lead frame. Next, a semiconductor device is formed through a sealing process using the sealing resin 12.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited at all by these Examples. First, evaluation methods used in Examples and Comparative Examples will be described.

<1> Adhesive strength An adhesive sheet having a thickness of 50 μm was laminated on a pure copper plate having a thickness of 0.35 mm under the conditions of 130 ° C. and 1 MPa. Thereafter, the polyimide film (75 μm: “UPILEX 75S” manufactured by Ube Industries Co., Ltd.) was further laminated on the surface of the adhesive sheet laminated on the pure copper plate at 130 ° C. and 1 MPa, and then in an air oven, 100 A post-cure was sequentially performed at 1 ° C. for 1 hour, 150 ° C. for 1 hour, and an evaluation sample was prepared. After slitting the polyimide film to a width of 5 mm, the polyimide film having a width of 5 mm was peeled at a rate of 50 mm / min in the 90 ° direction, and the adhesive force at that time was measured. The adhesive strength is preferably 10 N / cm or more from the viewpoint of processability, handling properties, and reliability of the semiconductor device.

<2> Reflow resistance Ten pieces prepared by cutting the post-cured sample prepared by the above method <1> into 30 mm squares are prepared. The sample was heat-dried at 125 ° C. for 12 hours, and then moisture-absorbed for 168 hours under conditions of 30 ° C. and 70% RH, and then immediately subjected to IR reflow at a maximum temperature of 260 ° C. for 10 seconds. Observation was performed with a sonic short wound machine. In this test, it was examined how many samples were peeled off in 10 pieces.

<3> Resin Flow After laminating a B-stage adhesive having a diameter of 6 mm and a thickness of 100 μm under the conditions of 130 ° C. and 1 MPa so as to form a glass plate / adhesive / copper plate, Post-cure for 1 hour at 150 ° C. Next, this sample is pressure bonded under the conditions of a pressure bonding temperature of 150 ° C., a pressure bonding pressure of 35 MPa, and a pressure bonding time of 5 minutes. The resin flow was calculated based on the following formula.
Resin flow (%) = (diameter after crimping / diameter 6 mm before crimping) × 100.

<4> Storage elastic modulus measurement A B-stage adhesive single film having a thickness of 100 μm was post-cured at 100 ° C., 1 hour, 150 ° C., 1 hour. This sample was subjected to a tensile mode dynamic viscoelasticity measurement apparatus (RHEOVIBRON-DDV-II / III-EA, manufactured by Orientec Co., Ltd.) at a frequency of 1 Hz, a temperature increase rate of 5 ° C./min, and a temperature measurement range of -70 to 300. Measurements were made at ° C.

<5> Wire bonding processability A TAB tape is prepared in which a simulated pattern having a polyimide film thickness of 25 μm, a copper foil thickness of 12 μm, a conductor width of 50 μm, and a distance between conductors of 50 μm is prepared. Laminate the adhesive composition under the conditions of 130 ° C. and 1 MPa so that the thickness is 50 μm after drying on the pattern back side of the TAB tape, that is, the polyimide film side, and then on the pure copper plate of 0.35 mm thickness, Lamination was further performed under the conditions of 130 ° C. and 1 MPa so as to obtain an adhesive / pure copper plate configuration. Finally, post-cure was performed at 100 ° C. for 1 hour, 150 ° C. for 1 hour in an air oven to obtain a sample for evaluation. Bonding was performed on the conductor pattern of the TAB tape with a gold wire, and the feasibility was examined. Bonding conditions were as follows: gold wire diameter 25 μm, gold wire capillary hole diameter 35 μm, outer diameter 140 μm, bonding temperature 150 ° C., ultrasonic power output 2.0 W, ultrasonic wave application time 0.1 seconds, bond weight 0.5 N. It was.

Reference Example 1 (Synthesis of polyamide resin)
Using dimer acid PRIPOL 1009 (manufactured by Unikema) and adipic acid as the acid, the acid / amine ratio is equal, and the acid / amine reactant, antifoaming agent and 1% or less phosphoric acid catalyst are added, 140 ° C. for 1 hour The mixture was stirred and heated at 205 ° C. for 1.5 hours. Under a vacuum of 2 KPa, it was kept for 0.5 hours and allowed to cool. Finally, an antioxidant was added to obtain a polyamide resin having a weight average molecular weight of 20000 and an acid value of 10.

Example 1
The following thermoplastic resins, epoxy resins and other additives are blended so as to have the composition ratios shown in Table 1, respectively, and DMF (dimethylformamide) / monochlorobenzene / MIBK (methyl ethyl isobutyl) to a concentration of 28% by weight. The adhesive solution was prepared by stirring and dissolving in a ketone) mixed solvent at 40 ° C.
A. Thermosetting resin o-cresol novolac type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., “Epicoat” 180, epoxy equivalent: 200)
2. Bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., “Epicoat” 828, epoxy equivalent: 186)
B. Thermoplastic resin SEBS-C (Asahi Kasei Corporation, MX-073)
2. Dimer acid polyamide C.I. Inorganic particles Spherical silica with an average particle size of 1.6 μm and a maximum particle size of 7 μm (manufactured by Admatechs, SO-C5)
2. Spherical silica with an average particle size of 0.7 μm and a maximum particle size of 3 μm (SE-1 manufactured by Tokuyama Corporation)
3. Spherical silica with an average particle size of 0.2 μm and a maximum particle size of 1.5 μm (manufactured by Admatechs, SO-C1)
4). Spherical silica having an average particle size of 5 μm and a maximum particle size of 15 μm (Fuji Silysia Chemical Ltd., Silicia 740)
5). Spherical silica with an average particle size of 0.04 μm and a maximum particle size of 0.2 μm (manufactured by Nippon Aerosil Co., Ltd., OX50)
D. Phenol resin Phenol novolak resin (hydroxyl equivalent: 107, manufactured by Gunei Chemical Industry Co., Ltd., PSM4261)
E. Additive 1.4,4'-diaminodiphenylsulfone2. γ-aminopropyltriethoxysilane 3.2-heptadecylimidazole These adhesive solutions were applied to a 75 μm-thick polyester film (hereinafter referred to as polyester film 1) that had been subjected to silicone treatment on both sides with a dry thickness of 50 μm. And then dried at 100 ° C. for 1 minute and 150 ° C. for 5 minutes, and a polyester film having a lower peel strength than polyester film 1 (hereinafter referred to as polyester film 2) is laminated on the roll while being laminated. A B-staged adhesive sheet having a thickness of 50 μm was prepared. The obtained adhesive sheet has the structure shown in FIG.

Examples 2-6, Comparative Examples 1-5
It was produced in the same manner as in Example 1 with the composition shown in Table 1.

  As is apparent from the results of Examples and Comparative Examples in Table 1, the adhesive sheet for semiconductor devices obtained by the present invention is excellent in all of adhesive strength, reflow resistance, and wire bonding processability. I understand.

LOC (lead on chip) semiconductor device sectional view. Sectional drawing of the semiconductor device processed using the adhesive agent sheet for semiconductor devices of this invention. Sectional drawing of the one aspect | mode of the adhesive agent sheet for semiconductor devices of this invention.

Explanation of symbols

1, 6 Semiconductor integrated circuit (semiconductor chip)
2, 7 Bonding wire 3, 11 Adhesive film for semiconductor 4, 9 Lead frame 5, 12 Sealing resin 8, 14 Adhesive layer composed of the adhesive composition of the present invention 10 TAB tape (polyimide film substrate)
13 Protective film (protective layer)

Claims (4)

A thermoplastic resin selected from at least one selected from a copolymer having butadiene as a copolymer component, or a copolymer having an acrylic ester and a methacrylic ester having a side chain having 1 to 8 carbon atoms as a copolymer component, Curable resin, having inorganic particles with a maximum particle size of 10 μm or less and an average particle size of more than 0.1 μm and 2 μm or less, and the content of inorganic particles is 25% by weight or more and 50% by weight or less with respect to the total amount of the composition An adhesive composition for semiconductor devices. The adhesive composition for a semiconductor device according to claim 1, wherein the heat-cured adhesive has a resin flow of 120% or less in a resin flow measurement in a press bonding temperature of 150 ° C., a press bonding pressure of 35 MPa, and a press bonding time of 5 minutes. The adhesive composition for a semiconductor device according to claim 1, wherein the storage elastic modulus by dynamic viscoelasticity measurement at 150 ° C. is 3 MPa or more. An adhesive sheet for a semiconductor device having an adhesive layer on at least one surface of the organic insulating film, wherein the adhesive layer is the adhesive composition according to any one of claims 1 to 3. Sheet.

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