JP2006249415A - Adhesive composition for semiconductor device, adhesive sheet for the semiconductor device given by using the same, substrate for connecting semiconductor, and the semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for a semiconductor device, excellent in resistance to heat at a high temperature for a long period, reflow resistance, thermal cycling properties, to provide an adhesive sheet for the semiconductor device, given by using the same, to provide a substrate for connecting a semiconductor, and to provide the semiconductor device. <P>SOLUTION: This adhesive composition for the semiconductor device has a reaction rate of 70-100%, when measured by DSC (differential scanning calorimetry) after heating, and further has at least one softening point in a temperature range of ≥200°C, after heating. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pattern processing tape of a tape automated bonding (TAB) method, a semiconductor connection substrate such as an interposer for a ball grid array (BGA) package, a lead frame fixing tape, and a LOC, which are used when mounting a semiconductor integrated circuit. Die bonding materials, heat spreaders, reinforcing plates, adhesives for shield materials, solder resists, anisotropic conductivity, used for bonding of fixing tapes, electronic components such as semiconductor elements, and support members such as lead frames and insulating support substrates The present invention relates to an adhesive composition suitable for producing a film, a copper-clad laminate, a coverlay, a semiconductor encapsulant, an insulating layer, and the like, an adhesive sheet using the same, a semiconductor connection substrate, and a semiconductor device.

  A method using a metal lead frame is most often used for mounting a semiconductor integrated circuit (IC). In recent years, a conductive pattern for IC connection is formed on an organic insulating film such as glass epoxy or polyimide. An increasing number of systems are provided via a semiconductor connection substrate called an interposer.

  As a package form, a package form such as a dual in-line package (DIP), a small outline package (SOP), a quad flat package (QFP) has 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 (chip scale package) in which connection terminals are arranged on the back surface of the package have been used.

  Examples of the connection method of the substrate for semiconductor connection include a tape automated bonding (TAB) method, a wire bonding method, a flip chip method, and the like, and a tape with an adhesive for TAB can be used.

  Of course, the TAB method is advantageous for the connection method having the inner leads, but the BGA method is particularly suitable for the process of laminating the copper foil after mechanically punching the holes for solder balls and the device holes for IC. Is suitable. On the other hand, in the case of wire bonding and flip chip connection without an inner lead, it is possible to use not only a tape with an adhesive for TAB, but also a copper-clad laminate already laminated with copper foil and heat-cured adhesive. is there.

  FIG. 1 shows an example of a BGA type semiconductor device. The BGA system is characterized in that it has solder balls (6) on the grid (grid array) corresponding to the number of pins of the IC as an external connection portion of the semiconductor integrated circuit connection substrate to which the semiconductor integrated circuit (1) is connected. Yes. Connection to the printed circuit board is performed by placing the solder ball surface so as to coincide with the conductor pattern of the printed circuit board on which the solder has already been printed, and melting the solder by reflow. The biggest feature is that since the surface of the interposer can be used, many terminals can be arranged in a small space as compared with a package such as QFP that can use only the peripheral side. The chip scale package (CSP) is a further advancement of this miniaturization function, and includes micro BGA (μ-BGA), fine pitch BGA (FP-BGA), memory BGA (m-BGA), and board on chip (BOC). ) Etc. have been proposed. The μ-BGA is characterized in that a beam lead is taken out from the interposer and connected to the IC. In the m-BGA, BOC, and FP-BGA, the IC and the interposer are wire-bonded by a bonding wire (5). The wire bonding connection is difficult to deal with a fine pitch, but does not require complicated beam lead processing, and a conventional wire bonder for a lead frame can be used, which is advantageous in terms of cost. The adhesive layer (2), that is, the die bonding material is also used when bonding the IC of the package having these structures and the interposer.

  In addition, the semiconductor connection board may be laminated with components such as a reinforcing plate (stiffener) for imparting rigidity and flatness or a heat radiating plate (heat spreader) for heat dissipation. Is used. In addition, an adhesive is also used for a sealant and an insulating layer.

  Since these adhesives often remain in the package in the end, it is required to satisfy various properties such as adhesiveness, heat resistance and thermal cycleability.

  Recently, particularly in the field of power devices, SiC (silicon carbide) having better electrical characteristics is being used in place of conventional silicone (Si) wafers used as semiconductor chips. Since this SiC has excellent electrical characteristics, the voltage applied to the unit area becomes higher than that of Si, and accordingly, the temperature applied to the unit area also increases. Therefore, the temperature applied to the adhesive is also extremely high, and heat resistance exceeding 150 ° C. to 200 ° C. and further exceeding 200 ° C. is required, and furthermore, heat resistance that can endure for a long time (up to about 1000 hours) at those temperatures. Is required. Further, in the above-described solder reflow process, the lead contained in the solder has an adverse effect on the environment, so that a solder containing no lead is often used. Therefore, the melting temperature of the solder, which has been about 230 ° C. in the past, has become 250 ° C. or higher, and accordingly, the temperature applied to the adhesive in the solder reflow process also increases.

Regarding heat-resistant adhesives, adhesives using polyimide, polyamide, polyamideimide, and polynadiimide have been proposed (see, for example, Patent Documents 1 and 2). However, these patent documents do not mention long-term high-temperature heat resistance.
Japanese Patent Laid-Open No. 7-252459 Japanese Patent Laid-Open No. 8-245942

  The present invention solves such problems, has an excellent long-term high-temperature heat resistance, and further has excellent reflow resistance and thermal cycle properties, an adhesive composition for semiconductor devices, an adhesive sheet for semiconductor devices using the same, and a semiconductor It is an object to provide a connection substrate and a semiconductor device.

  That is, the present invention provides an adhesive composition for a semiconductor device having a DSC reaction rate of 70 to 100% after heating and having at least one softening point in a temperature region of 200 ° C. or higher after heating. There are an adhesive sheet for a semiconductor device, a substrate for semiconductor connection and a semiconductor device using the same.

  The adhesive composition of the present invention provides an effect that is excellent in long-term high-temperature heat resistance, reflow resistance, and thermal cycle properties. Furthermore, the reliability of a semiconductor device can be improved by the adhesive composition for a semiconductor device of the present invention.

  Hereinafter, the configuration of the present invention will be described in detail.

  The adhesive composition for a semiconductor device and the adhesive sheet for a semiconductor device of the present invention are tape automated used when mounting the above-described stiffener, heat spreader, semiconductor integrated circuit for a semiconductor element or a wiring board (interposer). Bonding (TAB) pattern processing tape, semiconductor connection substrates such as ball grid array (BGA) package interposers, lead frame fixing tapes, LOC fixing tapes, electronic components such as semiconductor elements, lead frames and insulating support substrates Suitable for manufacturing die bonding materials, heat spreaders, reinforcing plates, shield material adhesives, solder resists, anisotropic conductive films, copper-clad laminates, coverlays, etc. Adhesive composition and adhesive sheet using the same Ri, shape and material thereof adherend is not particularly limited. Moreover, it can be used also for the use as a sealing agent which seals a semiconductor, and the use as an insulating layer, and a use is not specifically limited. Among them, the adhesive composition of the present invention is used as a circuit adhesive or an insulating layer in a power device. After an element is formed on a semiconductor substrate such as silicone, the semiconductor integrated is separated as shown in FIG. The circuit (bare chip) (1) is bonded to the wiring board layer composed of the insulator layer (3) and the conductor pattern (4) with the adhesive layer (2) of the present invention, and the semiconductor integrated circuit (1) and the wiring board This is effective for use as a semiconductor device having a structure in which layers are connected by bonding wires (5).

  The adhesive composition for a semiconductor device of the present invention has a reaction rate of 70 to 100% in DSC after heating, and has at least one softening point in a temperature region of 200 ° C. or higher after heating.

  In the present invention, the reaction rate in DSC after heating is measured by the calorific value Q1 (mJ / mg) of the sample before heating and the calorific value Q2 (mJ / mg) of the sample after heating at 150 ° C. for 2 hours, The reaction rate (%) = value obtained as ((Q1-Q2) / Q1) × 100. The calorific value is DSC6200 manufactured by Seiko Instruments Inc. (currently SII Nanotechnology Co., Ltd.), temperature 25 ° C. to 350 ° C., heating rate 10 ° C./min, sample amount about 10 mg, Al open pan used, nitrogen gas flow 40 ml / It can be measured in min.

  The softening point in the present invention is defined by the peak temperature of tan δ (= E ″ / E ′) in the dynamic viscoelasticity measurement. E ′ (storage elastic modulus) and E ″ (loss elastic modulus) are measured at a frequency of 1 to 35 Hz and a heating rate of 2 to 5 ° C./min.

  The adhesive composition of the present invention has a DSC reaction rate of 70 to 100%, more preferably 80 to 100%, and still more preferably 90 to 100% after heating. By setting it in this range, the physical properties (particularly heat resistance and toughness) after heat curing can be improved. In order to achieve such a reaction rate, the heating temperature and the heating time may be appropriately adjusted in each composition system. Further, it has at least one softening point in a temperature region of 200 ° C. or higher after heating, more preferably 230 ° C. or higher, and further preferably at least one softening point at 250 ° C. or higher. When the softening point is less than 200 ° C., the thermal cycle property is lowered. Furthermore, it is preferable that the adhesive composition after heating has at least one softening point in a temperature region of −65 ° C. or more and 50 ° C. or less and a temperature region of 200 ° C. or more and 300 ° C. or less, respectively, It is more preferable to have at least one softening point at 230 ° C. to 280 ° C., respectively, and long-term high-temperature heat resistance and thermal cycle performance can be improved. This is considered to be because the change in elastic modulus is performed stepwise by increasing the high temperature side softening point, and the stress change during the thermal cycle can be absorbed stepwise. On the other hand, when the low-temperature side softening point is −65 ° C. or higher, it is easy to maintain the shape as a solid, and when it is 50 ° C. or lower, the thermal cycle property is excellent.

  A method for obtaining such softening point characteristics is not particularly limited. In order to impart such a softening point property to the adhesive composition itself, there is a method of using a plurality of thermoplastic resins or thermosetting resins having different softening points and selecting those having appropriate compatibility with each other. It is done.

  The adhesive composition of the present invention has a softening point A after heating at 150 ° C. for 2 hours and a softening point B after heating at 150 ° C. for 2 hours and further at 200 ° C. for 168 hours, B / A ≦ 1. 5, more preferably 0.8 ≦ B / A ≦ 1.5. B / A ≦ 1.5 is preferable because it is excellent in long-term high-temperature heat resistance and thermal cycle performance.

The storage elastic modulus E ′ of the adhesive composition at 150 ° C. to 250 ° C. is preferably 1 MPa ≦ E ′ ≦ 500 MPa, more preferably 5 MPa ≦ E ′ ≦ 100 MPa. If it is 1 MPa <= E '<= 500MPa, since it is excellent in wire-bonding property, reflow resistance, and thermal cycle property, it is preferable. Moreover, the change rate of the storage elastic modulus E1 ′ after heating at 150 ° C. for 2 hours and the storage elastic modulus E2 ′ after further heating at 200 ° C. for 168 hours is 6 × 10 ⁻³ (h ⁻¹ ) or less. Preferably there is. Here, the rate of change of E ′ is E ′ after heating at 150 ° C. for 2 hours, that is, E1 ′, and E ′ after heating at 150 ° C. for 2 hours and then at 200 ° C. for 168 hours, that is, E2 ′. , E ′ change rate = (LogE2′−LogE1 ′) / 168. E ′ was read at 200 ° C. An adhesive composition having such an elastic modulus can be obtained by combining a thermosetting resin and a thermoplastic resin. For example, a combination with a polyfunctional epoxy resin and a thermoplastic resin having a low glass transition temperature described later is effective.

Further, the adhesive composition of the present invention preferably has an adhesive strength after heating of 5 Ncm ⁻¹ or more, more preferably 10 Ncm ⁻¹ or more. It is preferable that the adhesive strength after heating is 5 Ncm ⁻¹ or more because peeling is unlikely to occur during handling and reflow of the package.

  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 adhesive composition of the present invention preferably contains at least one kind of thermoplastic resin and thermosetting resin, but the kind is not particularly limited. 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 There is an effect of realizing a balance of physical properties such as the strength of the agent layer.

  Examples of thermoplastic resins include acrylonitrile-butadiene copolymer (NBR), acrylonitrile-butadiene rubber-styrene resin (ABS), polybutadiene, styrene-butadiene-ethylene resin (SEBS), and acrylic having 1 to 8 carbon side chains. Examples include acid and / or methacrylic acid ester resin (acrylic rubber), polyvinyl butyral, polyamide, polyester, polyimide, polyamideimide, polyurethane and the like. Moreover, 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 hydroxyalkyl 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. The copolymer having acrylic acid and / or methacrylic acid ester having a side chain having 1 to 8 carbon atoms as an essential copolymerization component has a softening point in a temperature range of −65 to 50 ° C. in the adhesive composition after heating. In addition, since it is excellent in adhesiveness with a material such as a wiring board layer, flexibility, and thermal stress relaxation effect, it can be particularly preferably used. Moreover, these copolymers may also 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 hydroxyalkyl group, an isocyanate group, a vinyl group, and a silanol group. Further, in this case, it is more preferable to use a copolymer having a carboxyl group and / or a hydroxyl group as a functional group in combination with a copolymer having another functional group because the adhesiveness is improved. The functional group content is preferably 0.07 eq / kg or more and 0.7 eq / kg or less, more preferably 0.07 eq / kg or more and 0.45 eq / kg or less, and further preferably 0.07 eq / kg or more and 0.0. 14 eq / kg or less. Further, from the viewpoint of flexibility after heating for a long time, the weight average molecular weight (Mw) is preferably 300,000 or more, more preferably 500,000 or more, more preferably 1,000,000 or more, and still more preferably 1,200,000 or more. The glass transition temperature (Tg) is preferably 20 ° C. or lower, more preferably 0 ° C. or lower, more preferably −20 ° C., and still more preferably −40 ° C. or lower. By setting it within this range, a composition having excellent flexibility after heating for a long time can be obtained. When two or more kinds of thermoplastic resins are used, it is sufficient that at least one of them satisfies this range. The weight average molecular weight was measured by GPC (gel permeation chromatography) method and calculated in terms of polystyrene. Tg was calculated by the DSC method. In addition, polyamide resin is also preferably used because of its good deterioration at high temperatures and good electrical characteristics. Various known polyamide resins can be used. In particular, it is preferable that the adhesive layer has flexibility and a dicarboxylic acid (so-called dimer acid) having a low water absorption carbon number of 36 as an essential component. Polyamide resin containing dimer acid is obtained by polycondensation of dimer acid and diamine by a conventional method. At this time, dicarboxylic acid other than dimer acid, azelaic acid, sebacic acid and the like is contained as a copolymerization component. Also good. As the diamine, known ones such as ethylene diamine, hexamethylene diamine, and piperazine can be used, and two or more kinds may be mixed from the viewpoint of hygroscopicity and solubility.

  The thermoplastic resin content 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 this range, since flexibility and heat resistance can be maintained, it is preferable.

  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. Although control of compatibility is necessary for controlling the softening point characteristics, it is an effective method to appropriately select the structure 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. Among them, those having three or more epoxy groups in one molecule are preferably used in order to increase the crosslinking density of the adhesive composition and increase the softening point after heating. As these polyfunctional epoxy resins, orthocresol novolak type: specifically, E180H65 manufactured by JER (Japan Epoxy Resin Co., Ltd.), ESCN195 manufactured by Sumitomo Chemical Co., Ltd., EOCN1020 manufactured by Nippon Kayaku Co., Ltd., EOCN102S, 103S, 104S, etc., DPP novolak type: specifically, J157 E157S65, etc., trishydroxyphenylmethane type: specifically Nippon Kayaku Co., Ltd. EPPN501H, JER E1032, etc., tetraphenylolethane type: specifically E1031S made by JER, dicyclopentadienephenol type: Specifically, HP7200 made by DIC (Dainippon Ink Chemical Co., Ltd.), other polyfunctional epoxy resins having a naphthalene structure, ESN made by Nippon Steel Chemical Co., Ltd. , YL6241 made by JER with special skeleton, etc. Epoxy resins have been sales. Two or more of these epoxy resins may be used in combination. In particular, it is preferable to mix a trifunctional epoxy resin and a tetrafunctional epoxy resin because the control of the softening point is easier and the change in the softening point after standing at high temperature for a long time can be suppressed. Furthermore, it is effective to use a halogenated epoxy resin, particularly a brominated epoxy resin, for imparting flame retardancy. At this time, it is effective to use a mixed system with a non-brominated epoxy resin because the brominated epoxy resin alone can impart flame retardancy, but the heat resistance of the adhesive decreases greatly. 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. However, brominated epoxies and the like contain bromine, which is a barogen, and may have an adverse effect on the environment. Recently, epoxy resins that do not contain barogen, specifically phosphorous epoxy Many resins and nitrogen-containing epoxy resins are also used. These epoxy resins may be used for imparting flame retardancy.

  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, p-t-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.

  As for content of a thermosetting resin, 5-400 weight part is preferable with respect to 100 weight part of thermoplastic resins, More preferably, it is 20-200 weight part. If the content of the thermosetting resin is 5 parts by weight or more, the elastic modulus at a high temperature can be maintained, the semiconductor integrated circuit connection substrate is not deformed during use of the device mounted with the semiconductor device, and the processing step It is preferable because it is easy to handle. If the content of the thermosetting resin is 400 parts by weight or less, it is preferable because the elastic modulus does not increase too much and the linear expansion coefficient does not decrease.

  It is not limited at all that the adhesive layer of the present invention contains a curing agent and a curing accelerator of epoxy resin and phenol resin. 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 Known materials such as phosphine can be used. You may use these individually or in mixture of 2 or more types. The content 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 containing an inorganic filler in 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. Specific examples thereof include silica, aluminum oxide, silicon nitride, aluminum hydroxide, gold, silver, copper, iron, nickel, silicon carbide, Examples thereof include aluminum nitride, titanium nitride, and titanium carbide. Of these, silica, aluminum oxide, silicon nitride, silicon carbide, and aluminum hydroxide are 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 surface treatment using a silane coupling agent or the like for the purpose of improving heat resistance, adhesiveness and the like. The following silane coupling agents can be used. 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, and a crushing system is preferably used. As used herein, crushing refers to a non-spherical (not rounded) shape. The particle size of the inorganic filler is not particularly limited, but those having an average particle size of 3 μm or less and a maximum particle size of 10 μm or less are preferably used from the viewpoint of reliability such as dispersibility and coatability, reflow resistance, thermal cycle property, and the like. . From the viewpoint of fluidity and dispersibility, it is more effective to use inorganic fillers having different average particle diameters in combination. The particle size can be measured with a Horiba LA500 laser diffraction particle size distribution meter. The average particle diameter here is defined by a particle diameter (median diameter) corresponding to 50% when a particle size distribution is measured with reference to a sphere equivalent volume and the cumulative distribution is expressed in percent (%). The particle size distribution referred to here is such that the particle size display is a 56-segment piece logarithm display (0.1 to 200 μm) on a volume basis. The maximum particle size is defined by a particle size corresponding to 100% when the cumulative distribution is expressed in percent (%) in the particle size distribution defined by the average particle size. In addition, the measurement sample is obtained by putting particles in ion-exchanged water so as to become cloudy and performing ultrasonic dispersion for 10 minutes. In addition, the refractive index is 1.1 and the light transmittance is measured according to a reference value (about 70%, which is already set in the apparatus). The blending amount is preferably 2 to 60% by weight, more preferably 5 to 50% by weight, based on the entire adhesive composition.

  In the present invention, by including a silane coupling agent in the adhesive layer, it is possible to improve the adhesive force with various metals including copper and rigid substrates such as a glass epoxy substrate. The silane coupling agent is represented by the following formula (1).

X's may be the same or different and each has 1 to 1 carbon atoms substituted with a vinyl group, an epoxy group, a styryl group, an acryloxy group, an amino group, a methacryl group, a mercapto group, an isocyanate group and at least one functional group thereof. Selected from 6 alkyl groups. Among them, those containing an amino group or an epoxy group are preferable from the viewpoint of adhesiveness. R is selected from CH ₃ , C ₂ H ₅ , and CH ₃ OC ₂ H ₄ , and among them, a methyl group and an ethyl group are preferable.

  In addition to the above components, it is not limited at all to contain organic and inorganic components such as antioxidants and ion scavengers as long as the properties of the adhesive are not impaired. Fine inorganic components include metal hydroxides such as magnesium hydroxide, calcium aluminate hydrate, zirconium oxide, zinc oxide, antimony trioxide, antimony pentoxide, magnesium oxide, titanium oxide, iron oxide, cobalt oxide Metal oxides such as chromium oxide and talc, inorganic salts such as calcium carbonate, metal fine particles such as aluminum, carbon black, and glass. Organic components include styrene, NBR rubber, acrylic rubber, polyamide, polyimide, and silicone. And the like. In addition, inorganic ion exchangers are often used as ion scavengers. Inorganic ion exchangers (1) have high ion selectivity, can separate specific ions from a system in which two or more ions coexist, (2) have excellent heat resistance, (3) organic solvents and resins (4) Since it is excellent in oxidation resistance, it is effective in trapping ionic impurities by containing it in the material, suppressing the decrease in insulation resistance, preventing corrosion of aluminum wiring, and preventing electromigration. Prevention of the occurrence can be expected. There are many types, a) aluminosilicate (natural zeolite, synthetic zeolite, etc.), b) hydroxide or hydrous oxide (hydrous titanium oxide, hydrous bismuth oxide etc.), c) acid salt (zirconium phosphate, phosphorus Titanium oxide, etc.), d) basic salts, complex hydrous oxides (hydrotalcite, etc.), e) heteropolyacids (ammonium molybdate, etc.), f) hexacyanoiron (III) salts, etc. (hexacyanozinc, etc.), g ) Can be classified as other. Product names include IXE-100, IXE-300, IXE-500, IXE-530, IXE-550, IXE-600, IXE-633, IXE-700, IXE-700F, IXE-800 from Toa Gosei Co., Ltd. Etc. There are cation exchangers, anion exchangers, and both ion exchangers, but both ion exchangers are preferred because both positive and negative ionic impurities are present in the adhesive composition. By using these, when used for an insulating layer, it is possible to prevent migration of wiring and suppress a decrease in insulation resistance.

  In the present invention, the use of an antioxidant is effective. The antioxidant is not particularly limited as long as it imparts an antioxidant function. Known antioxidants such as a phenol-based antioxidant, a thioether-based antioxidant, a phosphorus-based antioxidant, and an amine-based antioxidant are used. An inhibitor can be used. This is because, for example, in the case of a resin containing a double bond such as NBR rubber, when left for a long time at a high temperature, the crosslinking of the double bond part gradually proceeds and the adhesive film tends to become brittle, but an antioxidant is used. This is because these reactions can be suppressed. These organic and inorganic components may be used alone or in combination of two or more. In view of dispersion stability, the average particle size of the fine particle component is preferably 0.2 to 5 μm. Moreover, 0.1 to 50 weight% of the whole adhesive composition is suitable for content.

  The adhesive sheet for a semiconductor device of the present invention refers to a sheet having an adhesive layer made of the adhesive composition for a semiconductor device of the present invention and at least one peelable protective film layer. For example, a two-layer structure of a protective film layer / adhesive layer or a three-layer structure of a protective film layer / adhesive layer / protective film layer 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. Adjustment of the degree of cure has the 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 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, silicone rubber, and other plastic films, films coated with a release agent such as silicone or fluorine compounds, and films Paper laminated with arm, paper and 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 the protective film layers are provided on both surfaces of the adhesive layer, when the peeling force of each protective film layer to the adhesive layer is F ₁ and F ₂ (F ₁ > F ₂ ), F ₁ -F ₂ is preferably 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. Further, 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.

  As shown in FIG. 1, the substrate for semiconductor connection of the present invention is a layer having a conductor pattern for connecting an electrode pad of a bare chip and the outside of a package (printed circuit board, TAB tape, etc.), and an insulator layer (3 ) Is provided with a conductor pattern (4) on one or both sides. 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. Via holes may be formed in the wiring board layer thus produced, if necessary, and the conductive patterns formed on both sides by plating may be connected by plating.

  The adhesive layer is an adhesive layer mainly used for bonding the insulating substrate and the wiring board layer composed of the conductor pattern and the semiconductor integrated circuit. However, it is not limited at all to be used for adhesion between the wiring board layer and other members (for example, IC and a heat sink), and it is not limited at all to be used for other purposes (for example, an insulating layer). 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, an example of an adhesive sheet for a semiconductor device using the adhesive composition of the present invention and a method for manufacturing the semiconductor device will be described.

(1) Adhesive sheet for semiconductor device (a) A paint obtained by dissolving the adhesive composition of the present invention in a solvent is applied onto 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 methyl ethyl ketone and methyl isobutyl ketone, and aprotic polar solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone alone or a mixture are preferred. It is.

  (B) An adhesive sheet for a semiconductor device according to the present invention, wherein the film of (a) is laminated with a polyester or polyolefin-based protective film layer having a releasability lower than that of the polyester film having the releasability. Get. In order to further increase the adhesive thickness, the adhesive sheet for a semiconductor device may be laminated a plurality of times. When manufacturing a composite structure in which an insulating film such as polyimide is laminated in addition to a single film, the adhesive sheet for a semiconductor device is laminated on the insulating film as described above, or directly coated on both sides of the insulating film. May be produced. In this case, the thickness of the insulating film is preferably 3 to 125 μm. After lamination, for example, the degree of curing may be adjusted by heat treatment at 30 to 70 ° C. for about 20 to 200 hours.

(2) Semiconductor device (a) 12-35 μm electrolytic copper foil is laminated on a tape with an adhesive for TAB under the conditions of 130-170 ° C., 0.1-0.5 MPa, and then 80- A TAB tape with a copper foil is produced by sequentially heating and curing at 170 ° C. Photoresist film formation, etching, resist stripping, electrolytic nickel plating, electrolytic gold plating, and solder resist film fabrication are performed on the copper foil surface of the obtained TAB tape with copper foil by a conventional method to fabricate a wiring board.

  (B) The adhesive sheet for a semiconductor device obtained in (1) is thermocompression bonded to the wiring board of (a), and the IC is further thermocompression bonded to the opposite surface of the adhesive sheet. In this state, heat curing at 120 to 180 ° C. is performed.

  (C) After the IC and the wiring board are connected by wire bonding under conditions of about 150 to 250 ° C. and about 100 to 150 kHz, they are sealed with resin.

  (D) Finally, solder balls are mounted by reflow to obtain the semiconductor device of the present invention.

  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.

  (1) Preparation of evaluation pattern tape: TAB adhesive tape (# 7100, (type 31N0-00FS), manufactured by Toray Industries, Inc.) is laminated with an electrolytic copper foil of 18 μm under conditions of 140 ° C. and 0.1 MPa. did. Subsequently, using an air oven, a heat curing treatment was sequentially performed at 80 ° C. for 3 hours, at 100 ° C. for 5 hours, and at 150 ° C. for 5 hours to produce a TAB tape with copper foil. A photoresist film was formed on the copper foil surface of the obtained TAB tape with copper foil by a conventional method, and etching, resist stripping, electrolytic nickel plating, and electrolytic gold plating were performed to prepare a pattern tape sample for evaluation. The nickel plating thickness was 3 μm, and the gold plating thickness was 1 μm.

  (2) Reflow resistance: After laminating the adhesive sheet for semiconductor devices (thickness 50 μm) of the present invention on the back surface of the evaluation pattern tape of (1) under the conditions of 130 ° C. and 0.1 MPa, an aluminum electrode pad An evaluation semiconductor device having the structure shown in FIG. The adhesive was cured at 150 ° C. for 2 hours. Twenty 30 mm square samples prepared by this method were prepared for each level, and after conditioning for 192 hours in an atmosphere of 30 ° C. and 70% RH, two infrared reflow ovens with a maximum temperature of 265 ° C. and 15 seconds were immediately performed. It was allowed to pass through, and swelling and peeling were confirmed, and the number of peeled pieces out of 20 pieces was examined.

  (3) Thermal cycle performance: 30 samples of 30 mm square semiconductor devices for evaluation prepared by the method of (2) above were prepared for each level, and in a thermal cycle tester (PL-3 type, manufactured by Tabay Espec Co., Ltd.) Then, the film was processed at -65 ° C. to 150 ° C. at the minimum and maximum temperatures for 30 minutes, and the occurrence of peeling was evaluated. Samples were taken out at the end of each of 100 cycles, 300 cycles, 500 cycles, and 800 cycles, and the occurrence of peeling was evaluated. If it is confirmed that at least one of 30 pieces is peeled off, N. G. It was.

  (4) Softening point (° C.), storage elastic modulus (E ′ (PMa)), softening point ratio (B / A), E ′ change rate: dynamic viscoelasticity measuring device (Seiko Instruments Inc. (currently SAI Using DMS6100) manufactured by I-Nanotechnology Co., Ltd., temperature -70 ° C to 300 ° C, frequency 1 Hz, heating rate 5 ° C / min, tensile mode, sample size: length 5 mm, width 10 mm Storage elastic modulus E ′, loss elastic modulus E ″, and tan δ (= E ″ / E ′) were measured. As the softening point, a peak temperature of tan δ was adopted. A sample having a thickness of 25 μm heated at 150 ° C. for 2 hours was used. B / A was determined from the softening point A after heating at 150 ° C. for 2 hours and the softening point B after heating at 150 ° C. for 2 hours and then standing at 200 ° C. for 168 hours. The rate of change of E ′ is the change in E ′ using E ′ after heating at 150 ° C. for 2 hours, ie E1 ′, E ′ after heating for 2 hours at 150 ° C. and then 168 hours at 200 ° C., ie E2 ′. It calculated | required as a ratio = (LogE2'-LogE1 ') / 168. E 'was read at 200 ° C.

  (5) Adhesive strength: After laminating the adhesive sheet for a semiconductor device of the present invention on the back surface of the pattern tape for evaluation of (1) above at 130 ° C. and 0.1 MPa, the silicon wafer was placed at 160 ° C., 0. It heat-pressed to the adhesive sheet for semiconductor devices on the conditions of 3 MPa. Subsequently, heat treatment was performed at 150 ° C. for 2 hours in an air oven. The obtained pattern tape of the sample was cut so as to have a width of 5 mm, peeled in the 90 ° direction at a speed of 50 mm / min, and the adhesive force at that time was measured.

  (6) Insulation reliability: an adhesive layer having a thickness of 50 μm made of an adhesive composition on a conductor pattern surface of a comb shape evaluation sample having a conductor width of 50 μm and a distance between conductors of 50 μm of the evaluation pattern tape of (1) Then, a pure copper plate with a thickness of 0.1 mm was laminated under conditions of 130 ° C. and 0.1 MPa, and then heat-treated in an air oven at 150 ° C. for 2 hours. Using the obtained sample, resistance values immediately after measurement and after 400 hours were measured in a state where a voltage of 100 V was continuously applied in a constant temperature and humidity chamber at 85 ° C. and 85% RH.

  (7) Long-term high-temperature heat resistance: A 25 μm thick adhesive sheet for semiconductor devices is applied to a glossy surface of electrolytic copper foil (1/2 ounce) cleaned according to the standard procedure for cleaning the copper surface of JPCA-BM02 at 130 ° C. And heated at 150 ° C. for 2 hours. They were placed in an air oven at 180 ° C. and a long-term standing test was conducted. If the adhesive peels off during the process, G. It was.

  (8) Reaction rate: The calorific value Q1 (mJ / mg) of the sample before heating and the calorific value Q2 (mJ / mg) of the sample after heating at 150 ° C. for 2 hours were measured, and the reaction rate (%) = (( It calculated | required as Q1-Q2) / Q1) * 100. The measurement conditions were DSC6200 manufactured by Seiko Instruments Inc. (currently SII Nanotechnology Co., Ltd.), temperature 25 ° C. to 350 ° C., heating rate 10 ° C./min, sample amount about 10 mg, Al open pan used, nitrogen gas flow 40 ml / Measured in min.

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 was mixed in an approximately equal range, and an antifoaming agent and a phosphoric acid catalyst were added in an amount of 1% by weight to the previous mixture, A reactant was prepared. The reactant was stirred and heated at 140 ° C. for 1 hour, then heated to 205 ° C. and stirred for about 1.5 hours. The temperature was lowered under a vacuum of about 2 kPa for 0.5 hours. Finally, an antioxidant was added, and a polyamide resin having a weight average molecular weight of 20000 and an acid value of 10 was taken out.

  Table 1 shows details of each material used in Examples and Comparative Examples.

Examples 1-12, Comparative Examples 1-2
(Preparation of adhesive sheet for semiconductor devices)
Each inorganic filler listed in Tables 2-3 was mixed with toluene, and then ball milled to prepare a dispersion. To this dispersion, each thermoplastic resin, thermosetting resin, curing agent, curing accelerator, other additives, and an equal weight of methyl ethyl ketone to the dispersion were added so as to have the composition ratios shown in Tables 2 and 3, respectively. The mixture was stirred and mixed to prepare an adhesive solution. This adhesive solution was applied with a bar coater to a dry thickness required for a 38 μm-thick polyethylene terephthalate film with a silicone release agent (“Film Binner” GT manufactured by Fujimori Kogyo Co., Ltd.) It dried for minutes and bonded the protective film and produced the adhesive sheet for semiconductor devices of this invention. Each composition and characteristic are shown in Tables 2-3.

(Fabrication of semiconductor devices)
An 18 μm electrolytic copper foil was laminated on a tape with an adhesive for TAB (type # 7100, (31N0-00FS), manufactured by Toray Industries, Inc.) at 140 ° C. and 0.1 MPa. Subsequently, using an air oven, a heat curing treatment was sequentially performed at 80 ° C. for 3 hours, at 100 ° C. for 5 hours, and at 150 ° C. for 5 hours to produce a TAB tape with copper foil. A photoresist film was formed on the copper foil surface of the obtained TAB tape with copper foil by a conventional method, and etching, resist peeling, electrolytic nickel plating, electrolytic gold plating, and photo solder resist processing were performed to prepare a pattern tape. The nickel plating thickness was 3 μm, and the gold plating thickness was 1 μm. Subsequently, an adhesive sheet for a semiconductor device having each adhesive described in Tables 2 to 3 was laminated on the back surface of the pattern tape under conditions of 130 ° C. and 0.1 MPa, and then an IC having an aluminum electrode pad was 170. The adhesive sheet for semiconductor devices was thermocompression bonded under the conditions of ° C and 0.3 MPa. Next, heat treatment was performed at 150 ° C. for 2 hours in an air oven. Subsequently, a 25 μm gold wire was bonded to this at 180 ° C. and 110 kHz. Further, it was sealed with a liquid sealing resin (“Chip Coat” 8118, manufactured by NAMICS Co., Ltd.). Finally, a solder ball was mounted to manufacture a semiconductor device having the structure of FIG. The characteristics of the obtained semiconductor device are shown in Tables 2-3.

  From the Examples and Comparative Examples in Tables 2-3, it can be seen that the adhesive composition for semiconductor devices obtained by the present invention is excellent in adhesive strength, reflow resistance, and thermal cycle properties.

FIG. 14 is a cross-sectional view of one embodiment of a BGA semiconductor device. 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, 9 Adhesive layer 3 Insulator layer 4 Conductor pattern 5 Bonding wire 6 Solder ball 7 Sealing resin 8 Protective film layer

Claims (11)

An adhesive composition for a semiconductor device, having a DSC reaction rate of 70 to 100% after heating and having at least one softening point in a temperature region of 200 ° C. or higher after heating. The reaction rate in DSC after heating is 70 to 100%, and has at least one softening point in the temperature range of −65 ° C. or more and 50 ° C. or less and 200 ° C. or more and 300 ° C. or less after heating. The adhesive composition for a semiconductor device according to claim 1. The softening point A after heating at 150 ° C. for 2 hours and the softening point B after heating at 150 ° C. for 2 hours and further at 200 ° C. for 168 hours are B / A ≦ 1.5. Item 2. An adhesive composition for a semiconductor device according to Item 1. Acrylic acid ester and / or methacrylic acid ester having a side chain having 1 to 8 carbon atoms and at least one selected from an epoxy group, a hydroxyl group, a carboxyl group, an amino group, a hydroxyalkyl group, a vinyl group, a silanol group, and an isocyanate group The adhesive composition for a semiconductor device according to claim 1, comprising a thermoplastic resin having various functional groups. The adhesive composition for semiconductor devices according to claim 4, wherein the thermoplastic resin has a glass transition temperature of 20 ° C. or lower. The adhesive composition for a semiconductor device according to claim 1, comprising an epoxy resin and / or a phenol resin. The adhesive composition for a semiconductor device according to claim 1, further comprising an ion scavenger. 2. The adhesive composition for a semiconductor device according to claim 1, comprising at least one inorganic filler selected from silica, aluminum oxide, aluminum hydroxide, silicon nitride, and silicon carbide. An adhesive sheet for a semiconductor device comprising an adhesive layer comprising the adhesive composition for a semiconductor device according to claim 1 and at least one peelable protective film layer. The board | substrate for semiconductor connection using the adhesive composition for semiconductor devices in any one of Claims 1-8. A semiconductor device using the semiconductor connection substrate according to claim 10.

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