JP2005281553A - Adhesive composition for semiconductor device and adhesive sheet for semiconductor device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide industrially a new adhesive composition for a semiconductor device which is excellent in adhesiveness, reflow heat resistance, and workability, and to provide an adhesive sheet for a semiconductor device using it. <P>SOLUTION: The adhesive composition for a semiconductor device is characterized in that it contains a thermoplastic resin and a thermosetting resin, in that the thermoplastic resin is an epoxy group-containing acrylic copolymer, and in that its epoxy equivalent is larger than 0 and not larger than 1,500 g/eq, and the adhesive sheet for a semiconductor device uses it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tape automated bonding (TAB) pattern processing tape used for mounting a semiconductor integrated circuit, a semiconductor connection substrate such as a ball grid array (BGA) package interposer, a lead frame fixing tape, a LOC The present invention relates to an adhesive composition used for bonding an electronic component such as a fixing tape or a semiconductor element and a support member such as a lead frame or an insulating support substrate, and an adhesive sheet using the same.

  For the mounting of semiconductor integrated circuits (ICs), there is an increasing number of systems through a semiconductor connection substrate called an interposer in which a conductive pattern for IC connection is formed on an organic insulating film such as glass epoxy or polyimide. .

  On the other hand, package forms such as a dual inline package (DIP), a small outline package (SOP), and a quad flat package (QFP) have been used. However, with the increase in the number of pins of ICs and the miniaturization of packages, the QFP that can increase the number of pins is approaching the limit. Therefore, BGA (ball grid array) and CSP (chips) that arrange connection terminals on the back surface of the package. Scale package) has been used.

  FIG. 1 shows an example of a BGA system represented by a board on chip (BOC). The BGA system has solder balls on the grid (grid array) that substantially correspond to the number of pins of the IC as an external connection portion of the semiconductor integrated circuit connection substrate to which the IC is connected. Connection to the wiring board 3 is performed by placing the solder ball 6 surface on the conductor portion 4 of the wiring board 3 on which solder has already been printed, and melting the solder by reflow. The biggest feature is that since the surface of the interposer (wiring board 3) can be used, many terminals can be arranged in a small space compared to a package such as QFP that can use only the surrounding sides. A chip scale package (CSP) is a further advancement of this miniaturization function. Micro BGA (μ-BGA), fine pitch BGA (FP-BGA), memory BGA (m-BGA), board on chip (BOC) ) Etc. The μ-BGA is characterized in that a beam lead is taken out from the interposer and connected to the IC. The m-BGA, BOC (FIG. 1), and FP-BGA are connected between the IC and the interposer by wire bonding. The wire bonding connection is difficult to cope with a fine pitch, but does not require complicated beam lead processing and can use a conventional wire bonder for a lead frame, which is advantageous in terms of cost. An adhesive, that is, a die bonding material is also used for bonding the IC and interposer of the package having these structures.

  In addition, components such as a reinforcing plate (stiffener) for imparting rigidity and flatness or a heat radiating plate (heat spreader) for heat radiation are also laminated on the semiconductor connection substrate, but in this case, bonding is also performed. Agent is used.

  As electronic devices become smaller and more dense, these adhesives often end up in the package, so they satisfy various properties such as adhesiveness, heat resistance, and thermal cycleability. Is required. For example, as an adhesive suitable for a CSP type semiconductor device, a system having an acrylic copolymer as an essential component has also been proposed (see Patent Document 1). In this case, the thermal expansion difference between the heat spreader and the semiconductor chip is proposed. Although it has excellent stress relaxation ability, electric corrosion resistance and moisture resistance to absorb water, the heat resistance is not sufficient.

Recently, in particular, attention has been focused on solders that are friendly to an environment that does not contain lead, and they are starting to be applied in practice. However, it is known that this lead-free solder generally has a high melting point (see Patent Document 2), and correspondingly, each semiconductor member is required to have high heat resistance.
JP 11-284114 A (6th paragraph) JP 2001-25891 A (3rd paragraph)

  In the adhesive composition using the conventional acrylic copolymer, sufficient characteristics were not necessarily obtained in the adhesive strength after curing and the reflow resistance.

  The present invention solves such problems, and provides an adhesive composition for a semiconductor device having excellent adhesive force and reflow resistance, and further having easy workability, and an adhesive sheet for a semiconductor device using the same. With the goal.

  That is, the present invention is an epoxy group-containing acrylic copolymer containing a thermoplastic resin and a thermosetting resin and having an epoxy equivalent of more than 0 and 1500 g / eq or less. A composition and an adhesive sheet for a semiconductor device using the composition.

  According to the present invention, it is possible to obtain an adhesive composition and an adhesive sheet having improved reflow heat resistance and adhesive strength, and having easy workability.

  Hereinafter, the configuration of the present invention will be described in detail. In the present invention, by controlling the epoxy equivalent of the acrylic copolymer, it is possible to obtain an adhesive composition for a semiconductor device excellent in adhesive strength, reflow resistance and easy workability.

  The adhesive composition for a semiconductor device of the present invention (hereinafter referred to as an adhesive composition) preferably contains at least one thermoplastic resin and one thermosetting resin. Thermoplastic resins have functions such as adhesion, flexibility, relaxation of thermal stress, and improvement of insulation due to low water absorption, and thermosetting resins have heat resistance, insulation at high temperatures, chemical resistance, adhesion It is necessary to realize a balance of physical properties such as strength when forming the agent layer.

  In this adhesive, the thermoplastic resin used is an epoxy group-containing acrylic copolymer, and the epoxy equivalent is more than 0 and 1500 g / eq or less, preferably more than 0 and 700 g / eq or less. When the epoxy equivalent exceeds 1500 g / eq, the adhesive strength of the adhesive becomes insufficient. Here, the method for measuring the epoxy equivalent is as follows. First, a well-prepared sample (about 3 g) is collected in a flask, 20 ml of methyl ethyl ketone (MEK) is added and dissolved therein, and then 25 ml of 0.2 N hydrochloric acid (MEK solution) is added. After leaving this for 1 hour, 40 ml of MEK is added and another 10 ml of water is added with stirring. This solution was titrated with 0.5 N potassium hydroxide (ethanol solution), and the titration that turned red for 1 minute or more was taken as the end point. The epoxy equivalent is calculated by the following formula:

  Epoxy equivalent (unit: g / eq) = [m × NV / (BA) × 0.5 × F] × 1000.

  Here, m is the weight (g) of the sample, NV is the solid content ratio, B is the titration amount of the blank (ml), A is the titration amount of the sample, and F is the factor of 0.5 N potassium hydroxide.

  The weight average molecular weight is suitably 400,000 to 1,000,000, preferably 500,000 to 800,000. When the weight average molecular weight is less than 400,000, the tackiness of the adhesive is increased and the handleability is deteriorated. In addition, the film strength is insufficient, so that the reflow heat resistance is lowered. If it exceeds 1 million, the film strength at the B stage (semi-cured state) becomes too high, and the adhesive strength is reduced. The weight average molecular weight is determined in terms of polystyrene using a liquid chromatograph. For example, it is injected at a sample concentration of 30 mg / ml into a column having a tetrahydrofuran reagent grade 1 as the mobile phase, a mobile phase flow rate of 2 ml / min, and a temperature maintained at 35-40 ° C.

The adhesive composition preferably has an adhesive force after being completely cured, preferably 5 Ncm ⁻¹ or more, more preferably 10 Ncm ⁻¹ or more. When the adhesive force after complete curing is lower than 5 Ncm ⁻¹ , it is not preferable because peeling occurs during handling of the package or reflow heat resistance is lowered.

  The epoxy group-containing acrylic copolymer used in the present invention is obtained by copolymerizing glycidyl acrylate, acrylonitrile, alkyl acrylate and the like. If an acrylic ester containing a carboxyl group or a hydroxyl group is used here, the adhesive coating tends to gel because the crosslinking reaction is likely to occur, and the B-stage adhesive strength over time when the adhesive sheet is formed. Since deterioration is accelerated, it is not preferable. Here, as the polymerization method, any method such as suspension polymerization and solution polymerization can be selected. The content of the epoxy group-containing acrylic copolymer in the adhesive composition of the present invention is preferably 2 to 80% by weight, more preferably 5 to 70% by weight, and still more preferably 10 to 60% by weight. If it is less than 2% by weight, flexibility cannot be obtained, and if it exceeds 80% by weight, the heat resistance is insufficient.

  As the thermosetting resin, an epoxy resin and a phenol resin are particularly preferable because they are excellent in insulation. To control the softening point characteristics, it is necessary to control the compatibility. However, it is an effective method to appropriately select the structure and molecular weight of these thermosetting resins.

  The epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule, but bisphenol F, bisphenol A, bisphenol S, resorcinol, dihydroxynaphthalene, dicyclopentadiene diphenol, dicyclopentadienedixylenol, etc. Alicyclic epoxies such as diglycidyl ether, epoxidized phenol novolak, epoxidized cresol novolak, epoxidized trisphenylol methane, epoxidized tetraphenylol ethane, epoxidized metaxylene diamine, and cyclohexane epoxide. Furthermore, it is effective to use a halogenated epoxy resin, particularly a brominated epoxy resin, for imparting flame retardancy. At this time, although the flame retardancy can be imparted only by the brominated epoxy resin, 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.). . These brominated epoxy resins may be used in combination of two or more 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.

  Content of a thermosetting resin is 5-400 weight part with respect to 100 weight part of thermoplastic resins, Preferably it is 20-200 weight part. When the content of the thermosetting resin is less than 5 parts by weight, the modulus of elasticity at high temperatures is significantly reduced, and the semiconductor integrated circuit connecting substrate is deformed during use of the device mounted with the semiconductor device. The handling workability is lacking. When the addition amount of the thermosetting resin exceeds 400 parts by weight, the elastic modulus is high, the linear expansion coefficient is small, and the effect of relaxing the thermal stress is small.

  The addition of a curing agent and a curing accelerator to the adhesive composition of the present invention is not limited at all. For example, 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'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'- Aromatic polyamines such as diaminobenzophenone, 3,4,4'-triaminodiphenylsulfone, boron trifluoride triethylamine Boron trifluoride amine complexes such as complexes, imidazole derivatives such as 2-alkyl-4-methylimidazole and 2-phenyl-4-alkylimidazole, organic acids such as phthalic anhydride and trimellitic anhydride, dicyandiamide, triphenyl A phosphine or the like can be used. You may use these individually or in mixture of 2 or more types. The addition amount is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the adhesive composition.

  In the present invention, by adding an inorganic filler to the adhesive layer, processability such as reflow resistance and punchability, thermal conductivity, and flame retardancy can be further improved. The inorganic filler is not particularly limited as long as it does not impair the properties of the adhesive, but inorganic hydroxides such as aluminum hydroxide are not suitable because they decompose at high temperatures. In particular, silica, aluminum oxide, silicon nitride, and silicon carbide are preferable, and at least one of these is preferably used. Here, the silica may be either amorphous or crystalline, and it is not limited that the silica can be properly used according to the characteristics of each.

  These inorganic fillers may be subjected to a surface treatment using a silane coupling agent or the like for the purpose of improving heat resistance, adhesion and the like. Further, the shape of the inorganic filler is not particularly limited, and a crushing system, a spherical shape, a scale shape, and the like are used. From the viewpoint of dispersibility in the paint, a spherical shape is preferably used. Further, the particle size of the inorganic filler is not particularly limited, but an average particle size of 3 μm or less and a maximum particle size of 10 μm or less are preferred from the viewpoint of reliability such as dispersibility and coatability, reflow resistance, thermal cycleability, etc. Has an average particle size of 1 μm or less, a maximum particle size of 6 μm or less, more preferably an average particle size of 0.7 μm or less and a maximum particle size of 2 μm or less. The average particle size and the maximum particle size here are those measured with a Horiba LA500 laser diffraction particle size distribution meter. Further, in order to improve the reliability after mounting, the purity of the particles exceeds 99%, preferably exceeds 99.8%, and more preferably exceeds 99.9%. If it is 99% or less, soft errors of the semiconductor element are likely to occur due to α rays emitted from radioactive impurities such as uranium and thorium. Further, the content is preferably 2 to 60 parts by weight, more preferably 5 to 50 parts by weight of the entire adhesive composition.

  In addition to the above components, addition of organic and inorganic components such as antioxidants and ion scavengers is not limited as long as the properties of the adhesive are not impaired. Fine inorganic components include zirconium oxide, zinc oxide, antimony trioxide, antimony pentoxide, magnesium oxide, titanium oxide, iron oxide, cobalt oxide, chromium oxide, talc and other metal oxides, and inorganic salts such as calcium carbonate. Examples of the organic component include cross-linked polymers such as styrene, NBR rubber, acrylic rubber, polyamide, polyimide, and silicone.

  The adhesive sheet for a semiconductor device of the present invention (hereinafter referred to as an adhesive sheet) is composed of the adhesive composition for a semiconductor device of the present invention as an adhesive layer and having one or more peelable protective film layers. Say things. For example, a two-layer structure of protective film layer / adhesive layer or a three-layer structure of protective film layer 8 / adhesive layer 9 / protective film layer 8 corresponds to this (FIG. 2). The adhesive layer includes a composite structure in which an insulating film such as polyimide is laminated in addition to a single film of the adhesive composition. The adhesive sheet may be adjusted in degree of curing by heat treatment. The adjustment of the curing degree has an effect of preventing excessive flow of the adhesive when adhering the adhesive sheet to the wiring board or IC, and preventing foaming due to moisture during heat curing. The degree of cure can be defined by, for example, the minimum viscosity (flow tester method) at the bonding processing temperature specified in JIS-K7210. The flow tester method requires conditions to be defined, but as an example, if the temperature is 120 ° C., the die size is 2 × 5 mm, and the test pressure is 9.8 MPa, 3000 to 60000 Pa · s, preferably 6000 to 30000 Pa · s is suitable. .

  Although the thickness of an adhesive bond layer can be suitably selected by the relationship with an elasticity modulus and a linear expansion coefficient, 2-500 micrometers is preferable, More preferably, it is 20-200 micrometers.

  The protective film layer as used herein refers to an adhesive before bonding an adhesive layer to a wiring board layer (TAB tape or the like) composed of an insulator layer and a conductor pattern or a layer (stiffener or the like) where no conductor pattern is formed. Although it will not specifically limit if it can peel without impairing the form and function of a layer, For example, polyester, polyolefin, polyphenylene sulfide, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyvinyl butyral, polyvinyl acetate, polyvinyl alcohol , Polycarbonate, polyamide, polyimide, polymethylmethacrylate, and other plastic films, films coated with a release agent such as silicone or fluorine compound, and these films are laminated. Sorted paper, paper or the like impregnated or coated with a releasing property of a certain resin. More preferably, the protective film layer is colored. Since it can be confirmed visually whether the protective film has been peeled off, forgetting to peel off can be prevented.

When there are protective film layers on both sides of the adhesive layer, F ₁ -F ₂ is preferably when the peel strength of each protective film layer to the adhesive layer is F ₁ , F ₂ (F ₁ > F ₂ ). 5 Nm ⁻¹ or more, more preferably 15 Nm ⁻¹ or more is required. When F ₁ -F ₂ is smaller than 5 Nm ⁻¹ , which protective film layer side the release surface is on is not stable, which is a serious problem in use. The peeling forces F ₁ and F ₂ are preferably ¹ to 200 Nm ⁻¹ , more preferably 3 to 100 Nm ⁻¹ . When it is lower than ¹ Nm ⁻¹ , the protective film layer falls off, and when it exceeds 200 Nm ⁻¹ , peeling is unstable and the adhesive layer may be damaged.

  Further, if the tackiness (adhesive strength) of the adhesive is strong as handleability, there is a problem that bubbles are likely to enter when adhering to the substrate. On the other hand, if it is too weak, the adhesion to the substrate is insufficient and the function as an adhesive is not achieved. In a production line, when you take a process of stacking several sheets of adhesive sheets with a single-sided protective film cut into individual pieces, picking them up one by one and sticking them to the substrate There is. In this case, generally, if there is an adhesive strength exceeding 2N, pick-up may be difficult, and it is desirable to control the adhesive strength to be preferably 1.5N or less and at least 0.5N or more.

  The adhesive composition for a semiconductor device and the adhesive sheet for a semiconductor device in the present invention are a TAB pattern used when mounting a semiconductor integrated circuit for a stiffener, a heat spreader, a semiconductor element, or a wiring board (interposer). Bonding of processing parts, semiconductor connection substrates such as BGA package interposers, lead frame fixing tapes, LOC fixing tapes, semiconductor elements and other electronic components and support members such as lead frames and insulating support substrates, that is, die bonding materials, An adhesive composition suitable for producing a heat spreader, a reinforcing plate, an adhesive for a shielding material, a solder resist, and the like, and an adhesive sheet using the same, and the shape and material of the adherend are not particularly limited. . In particular, the adhesive composition according to the present invention is applied to a wiring substrate layer in which a semiconductor integrated circuit (bare chip) separated after an element is formed on a semiconductor substrate such as silicon is formed of an insulator layer and a conductor pattern. This is effective for a semiconductor device having a structure in which a semiconductor integrated circuit and a wiring board layer are connected by wire bonding. The wiring board layer is a layer having a conductor pattern for connecting the electrode pad of the bare chip and the outside of the package (printed board, TAB tape, etc.), and the conductor pattern is formed on one side or both sides of the insulator layer. is there.

  The insulator layer here 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. A ceramic substrate such as an insulating film having a flexibility of 125 μm, alumina, zirconia, soda glass, and quartz glass is suitable, and a plurality of layers selected from these may be laminated. If necessary, the insulator layer can be subjected to surface treatment such as hydrolysis, corona discharge, low-temperature plasma, physical roughening, and easy adhesion coating treatment.

  The conductor pattern is generally formed by either the subtractive method or the additive method, but any of them may be used in the present invention. In the subtractive method, a metal plate such as a copper foil is bonded to the insulator layer with an insulating adhesive (the adhesive composition of the present invention can also be used), or the insulator layer is bonded to the metal plate. A pattern is formed by etching a material prepared by a method in which precursors are stacked and an insulator layer is formed by heat treatment or the like by chemical treatment. Specific examples of the material herein include a rigid or copper-clad material for a flexible printed circuit board and a TAB tape. On the other hand, in the additive method, a conductor pattern is directly formed on the insulator layer by electroless plating, electrolytic plating, sputtering, or the like. In either case, the formed conductor may be plated with a metal having high corrosion resistance to prevent corrosion. The wiring board layer (A) thus produced may be provided with via holes as necessary, and the conductive patterns formed on both surfaces by plating may be connected by plating.

  The adhesive layer is an adhesive layer mainly used for bonding the wiring board layer and the semiconductor substrate. However, it is not limited at all to be used for adhesion between the wiring board layer and other members (for example, an IC and a heat sink). This adhesive layer is usually laminated in a semi-cured state on a substrate for connecting a semiconductor integrated circuit. A pre-curing reaction is carried out at a temperature of 30 to 200 ° C. for an appropriate time before or after the lamination to increase the degree of curing. Can be adjusted.

  Next, the example of the manufacturing method of the adhesive sheet for semiconductor devices using the adhesive composition of this invention is demonstrated.

  (A) A paint obtained by dissolving the adhesive composition of the present invention in a solvent is applied on a polyester film having releasability and dried. 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 methylethylketone and methylisobutylketone, and aprotic polar solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone alone or a mixture are preferred. It is.

  (B) The adhesive sheet of the present invention is obtained by laminating a polyester or polyolefin-based protective film layer having a releasability with a lower peel strength than the above to the film of (a). When the adhesive thickness is further increased, the adhesive sheet may be laminated a plurality of times. After lamination, for example, the degree of curing may be adjusted by heat treatment at 40 to 70 ° C. for about 20 to 200 hours.

  The present invention is an adhesive composition suitable for producing a die bonding material, a heat spreader, a reinforcing plate, an adhesive for a shield material, a solder resist, and the like, and an adhesive sheet using the same.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The evaluation method will be described before the description of the examples.

Evaluation method (1) Reflow heat resistance: After peeling off one protective film of a 50 μm-thick adhesive sheet die-cut to 30 mm square, and having a protective film only on one side of the adhesive layer, 50 sheets are stacked, room temperature Leave for 1 hour. Thereafter, the sheets are lifted one by one from the top and placed on a 30 mm square 0.25 mm thick SUS304. If the sheets are attached to each other, remove the part that is attached by hand. After roll laminating under conditions of 60 ° C., 1 MPa, 1 m / min, a 30 mm square semiconductor connection substrate in which a simulated pattern with a conductor width of 100 μm and a distance between conductors of 100 μm is formed on an adhesive sheet is 150 ° C., 5 MPa, Roll lamination was performed under conditions of 1 m / min. Then, it hardened | cured on the conditions of 100 degreeC, 1 hour, 170 degreeC, and 2 hours, and produced the sample for reflow heat resistance evaluation. An ultrasonic flaw detector was used to detect whether or not swell occurred after 20 samples of 30 mm square were moisture-absorbed for 168 hours under conditions of 30 ° C./70% RH and then immediately passed through an infrared reflow oven with temperature set. Observed. The maximum temperature of the infrared reflow furnace is 260 ° C., 270 ° C., and 280 ° C., and the holding time is 10 seconds each. The number of samples in which swelling occurred in 20 evaluation samples was counted.

  (2) Adhesive strength: An adhesive sheet having a thickness of 40 μm was laminated on SUS304 having a thickness of 0.35 mm under the conditions of 130 ° C. and 1 MPa. Thereafter, a polyimide film (75 μm: “UPILEX 75S” manufactured by Ube Industries, Ltd.) was further laminated on the adhesive sheet surface laminated on the previous SUS under the conditions of 130 ° C. and 1 MPa, and then in an air oven at 100 ° C. A sample for evaluation was prepared by sequentially performing heat treatment for 1 hour at 170 ° C. for 2 hours. 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.

  (3) Tackiness (adhesive strength): The cover film bonded to both surfaces of an adhesive sheet having a thickness of 50 μm die-cut to 20 mm square is peeled off. The sample is set in a tacking tester (using TAC-II manufactured by Resuka Co., Ltd.). The tip of the probe is pressed against the adherend surface of the sample with an applied pressure of 50 g, and then the tip of the probe is separated from the adherend surface at a separation speed of 120 mm / min. The peak value of the stress at this time was taken as the tack value.

  (4) Epoxy equivalent: First, a well-sampled sample (about 3 g) is collected in a flask, 20 ml of methyl ethyl ketone (MEK) is added and dissolved therein, and then 25 ml of 0.2 N hydrochloric acid (MEK solution) is added. After leaving this for 1 hour, 40 ml of MEK is added and another 10 ml of water is added with stirring. This solution was titrated with 0.5 N potassium hydroxide (ethanol solution), and the titration that turned red for 1 minute or more was taken as the end point. The epoxy equivalent is calculated by the following formula:

  Epoxy equivalent (unit: g / eq) = [m × NV / (BA) × 0.5 × F] × 1000.

  Here, m is the weight (g) of the sample, NV is the solid content ratio, B is the titration amount of the blank (ml), A is the titration amount of the sample, and F is the factor of 0.5 N potassium hydroxide.

  (5) Weight average molecular weight: A high performance liquid chromatograph 655A type manufactured by Hitachi, Ltd. was used here. It was injected at a sample concentration of 30 mg / ml into a column having a tetrahydrofuran reagent grade 1 as the mobile phase, a mobile phase flow rate of 2 ml / min and a temperature of 35-40 ° C., and a weight average molecular weight was calculated using polystyrene gel as a calibration curve.

Examples 1-5, Comparative Examples 1-2
(Adhesive composition and method for producing adhesive sheet)
As an inorganic filler, silica or aluminum hydroxide 22% by weight shown in the following examples was mixed with toluene so as to have a concentration of 20% by weight, followed by sand mill treatment to prepare a dispersion. In this dispersion, 55% by weight of the epoxy group-containing acrylic copolymer shown in the following examples, 20% by weight of the bisphenol A type epoxy resin shown in the following examples as a thermosetting resin, and 4,4% as a curing agent. Methyl ethyl ketone was added so that 4'-diaminodiphenylsulfone was 1.5 wt%, 2-heptadecylimidazole was 0.1 wt%, and the total solid content was 20 wt%, and the mixture was stirred and mixed at 30 ° C. Thus, an adhesive solution was prepared. This adhesive solution was applied with a bar coater to a 38 μm thick polyethylene terephthalate film with a silicone release agent (“Film Vina” GT manufactured by Fujimori Kogyo Co., Ltd.) to a dry thickness of about 50 μm, and at 120 ° C. It dried for 5 minutes, the protective film shown in the following Example was bonded together, and the adhesive agent sheet for semiconductor devices of this invention was produced.

Example 1
43 parts of butyl acrylate, 33 parts of acrylonitrile and 24 parts of glycidyl methacrylate were polymerized by a suspension polymerization method in a weight ratio to obtain an epoxy group-containing acrylic copolymer A. This copolymer had an epoxy equivalent of 700 g / eq and a weight average molecular weight of 673,000. The obtained epoxy group-containing acrylic copolymer, bisphenol A type epoxy resin (trade name, “Epicoat 1001”, epoxy equivalent 450, manufactured by Japan Epoxy Resins Co., Ltd.), 4,4′-diaminodiphenylsulfone (as a curing agent) Trade name, “SUMICURE S”, manufactured by Sumitomo Chemical Co., Ltd.) and 2-heptadecylimidazole (trade name, “CURAZOLE C17Z”, manufactured by Shikoku Kasei Kogyo Co., Ltd.), silica as a mineral filler (trade name, “ SO-E1 ″ (manufactured by Admatechs Co., Ltd.) was used to prepare an adhesive composition and an adhesive sheet by blending at the above composition ratio.

Example 2
By weight, 50 parts of butyl acrylate, 39 parts of acrylonitrile, and 11 parts of glycidyl methacrylate were polymerized by suspension polymerization to obtain an epoxy group-containing acrylic copolymer B. This copolymer had an epoxy equivalent of 1500 g / eq and a weight average molecular weight of 645,000. An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1 except that the epoxy group-containing acrylic copolymer A was changed to the epoxy group-containing acrylic copolymer B in Example 1.

Example 3
43 parts of butyl acrylate, 33 parts of acrylonitrile and 24 parts of glycidyl methacrylate were polymerized by a suspension polymerization method in a weight ratio to obtain an epoxy group-containing acrylic copolymer C. The epoxy equivalent of this copolymer was 700 g / eq, and the weight average molecular weight was 454000. An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1 except that the epoxy group-containing acrylic copolymer A in Example 1 was changed to the epoxy group-containing acrylic copolymer C.

Example 4
48 parts of butyl acrylate, 37 parts of acrylonitrile and 15 parts of glycidyl methacrylate were polymerized by a suspension polymerization method in a weight ratio to obtain an epoxy group-containing acrylic copolymer E. The epoxy equivalent of this copolymer was 1100 g / eq, and the weight average molecular weight was 950000. An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1 except that the epoxy group-containing acrylic copolymer A was changed to the epoxy group-containing acrylic copolymer E in Example 1.

Example 5
Epoxy group-containing acrylic copolymer F was obtained by polymerizing 50 parts by weight of butyl acrylate, 39 parts of acrylonitrile, and 11 parts of glycidyl methacrylate by suspension polymerization. The epoxy equivalent of this copolymer was 1500 g / eq, and the weight average molecular weight was 661000. In Example 1, the epoxy group-containing acrylic copolymer A was changed to the epoxy group-containing acrylic copolymer F, and aluminum hydroxide (trade name, “Hijilite H-42I”, Showa Denko Co., Ltd.) was used as the inorganic filler. The adhesive composition and the adhesive sheet were produced in the same manner as in Example 1 except that the production was performed.

Comparative Example 1
52 parts of butyl acrylate, 39 parts of acrylonitrile, and 9 parts of glycidyl methacrylate were polymerized by a suspension polymerization method in a weight ratio to obtain an epoxy group-containing acrylic copolymer G. The epoxy equivalent of this copolymer was 1850 g / eq, and the weight average molecular weight was 303,000. An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1 except that the epoxy group-containing acrylic copolymer A was changed to the epoxy group-containing acrylic copolymer G in Example 1.

Comparative Example 2
52 parts of butyl acrylate, 40 parts of acrylonitrile, and 8 parts of glycidyl methacrylate were polymerized by a suspension polymerization method in a weight ratio to obtain an epoxy group-containing acrylic copolymer H. The epoxy equivalent of this copolymer was 2100 g / eq, and the weight average molecular weight was 1124000. An adhesive composition and an adhesive sheet were prepared in the same manner as in Example 1 except that the epoxy group-containing acrylic copolymer A in Example 1 was changed to the epoxy group-containing acrylic copolymer H.

  Table 1 shows the results of evaluating the reflow heat resistance, adhesive strength, and tackiness of the adhesive sheets prepared in Examples 1 to 5 and Comparative Examples 1 and 2.

Sectional drawing of the one aspect | mode of the BGA type semiconductor device (BOC) using the adhesive composition for semiconductor devices of this invention, and the adhesive agent sheet for semiconductor devices. Sectional drawing of the one aspect | mode of the adhesive agent sheet for semiconductor devices of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor integrated circuit 2 and 9 Adhesive layer 3 comprised from the adhesive composition of this invention Wiring board 4 Conductor part 5 for connecting a solder ball Bonding wire 6 Solder ball 7 Sealing resin 8 Adhesive sheet of this invention Constructing protective film layer

Claims (5)

An adhesive composition for a semiconductor device comprising a thermoplastic resin and a thermosetting resin, wherein the thermoplastic resin is an epoxy group-containing acrylic copolymer, and the epoxy equivalent exceeds 0 and is 1500 g / eq. The adhesive composition for semiconductor devices characterized by the following. The adhesive composition for a semiconductor device according to claim 1, wherein the epoxy group-containing acrylic copolymer has a weight average molecular weight in the range of 400,000 to 1,000,000. The adhesive composition for a semiconductor device according to claim 1, wherein the thermosetting resin is an epoxy resin and / or a phenol resin. 2. The adhesive composition for a semiconductor device according to claim 1, wherein the adhesive composition contains one or more inorganic fillers selected from silica, aluminum oxide, silicon nitride, and silicon carbide. The adhesive sheet for semiconductor devices which uses the adhesive composition for semiconductor devices in any one of Claims 1-4 as an adhesive layer, and has one or more peelable protective film layers.

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