JP2008150597A - Electroconductive adhesive composition, substrate having electronic part mounted thereon and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroconductive adhesive composition which is sufficiently excellent in adhesion property and shelf stability without containing any halogen-based flux and is capable of forming a cured product sufficiently excellent in electrical conductivity. <P>SOLUTION: The conductive adhesive composition contains electroconductive particles and an adhesive component. Here, the electroconductive particle has a melting point of ≤260°C and contains a metal other than lead, and the adhesive component contains a thermosetting resin and an aliphatic dihydroxycarboxylic acid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a conductive adhesive composition, an electronic component mounting substrate, and a semiconductor device.

  In order to mount an electronic component on a circuit board or the like, a joining method using lead-containing solder is widely known. However, in recent years, with the growing awareness of environmental problems, lead-free solder and conductive adhesive compositions that do not contain lead have been attracting attention in place of solder. However, the Sn—Ag—Cu solder mainly used as lead-free solder has a problem that it cannot be used in some electronic components having a high connection temperature of 260 ° C. and high heat sensitivity. Further, Sn—Bi solder having a melting point of 138 ° C. is used as lead-free solder that can be connected at a lower temperature. However, when an electronic device to which the connection by Sn-Bi solder is applied is used in a high temperature environment, the composition of the metal in the Sn-Bi solder changes due to being left at a high temperature, and the solder joint becomes weak. There was a problem.

  In order to overcome these problems, a conductive adhesive has been proposed in which metal particles such as silver powder are dispersed in a thermosetting resin to form a paste (see Patent Document 1). Such a thermosetting conductive adhesive can suppress a decrease in strength of the cured body at a high temperature by using a thermosetting resin as a binder component. However, since the conductivity development mechanism in this adhesive is due to the contact between metal particles, it is necessary to increase the content of the conductive particles in order to ensure good conductivity. As a result, the adhesive strength of the adhesive decreases with a decrease in the binder component.

Then, the adhesive which aimed at coexistence of adhesiveness and electroconductivity by containing the metal particle and flux which fuse | melt at low temperature, such as lead-free solder, with a thermosetting resin is proposed (patent) References 2 and 3). The adhesives described in these patent documents can secure conductivity by metal bonding of solder and can secure adhesive force by thermosetting resin.
JP 2002-161259 A JP 2004-160508 A JP 2001-170797 A

  However, since the halogen-based flux disclosed in Patent Document 2 has problems such as environmental load and migration induction, an alternative flux is required. Further, the bifunctional carboxylic acid used as a flux in Patent Documents 2 and 3 needs to be contained in a large amount in the adhesive in order to form a metal bond. As a result, the storage stability of the adhesive is lowered or the adhesive strength is lowered.

  Therefore, the present invention has been made in view of the above circumstances, and is a cured product that is sufficiently excellent in adhesiveness and storage stability and sufficiently excellent in electrical conductivity even if it does not contain a halogen flux. It is an object of the present invention to provide a conductive adhesive composition capable of forming an object, and an electronic component mounting substrate and a semiconductor device in which each member is electrically connected using the conductive adhesive composition.

  In order to achieve the above object, the present invention includes a conductive particle having a melting point of 260 ° C. or less and containing a metal other than lead, and an adhesive component containing a thermosetting resin and an aliphatic dihydroxycarboxylic acid. A conductive adhesive composition is provided.

  Moreover, since the conductive adhesive composition of the present invention has excellent TCT resistance in addition to high temperature storage resistance, a cured product with good mounting reliability can be formed.

ここで、式（Ｉ）中、Ｒ^１は置換していてもよい炭素数１〜５のアルキル基を示し、ｎ及びｍはそれぞれ独立に０〜５の整数を示す。このような脂肪族ジヒドロキシカルボン酸を含有する導電性接着剤組成物は、接着性及び硬化物の導電性が更に高まると共に、硬化物の耐ＴＣＴ性が向上する。 In the conductive adhesive composition of the present invention, the aliphatic dihydroxycarboxylic acid is preferably a compound represented by the following general formula (I) or tartaric acid.

Here, in formula (I), R ¹ represents an optionally substituted alkyl group having 1 to 5 carbon atoms, and n and m each independently represent an integer of 0 to 5. In such a conductive adhesive composition containing an aliphatic dihydroxycarboxylic acid, the adhesiveness and the conductivity of the cured product are further increased, and the TCT resistance of the cured product is improved.

  In addition, from the viewpoint of obtaining better storage stability, electrical conductivity, and printability, the conductive adhesive composition of the present invention contains aliphatic dihydroxycarboxylic acid in an amount of 0.5 to 20 masses per 100 mass parts of the metal. It is preferable to include a part.

  The present invention includes an electronic component comprising a substrate, an electronic component, and a conductive layer that bonds and electrically connects the substrate and the electronic component, and the conductive layer is a cured product of the conductive adhesive composition described above. Provide mounting board. The present invention also includes a support substrate for mounting a semiconductor, a semiconductor element, and a conductive layer that adheres and electrically connects the support substrate and the semiconductor element, and the conductive layer is the conductive bond described above. Provided is a semiconductor device which is a cured product of an agent composition.

  Since the conductive layer in the electronic component mounting substrate and the semiconductor device of the present invention is a cured product of the conductive adhesive composition, it can exhibit sufficiently excellent conductivity and adhesiveness. Furthermore, since the conductive layer exhibits good TCT resistance and high temperature resistance, these electronic component mounting substrates and semiconductor devices have high reliability.

  According to the present invention, a conductive adhesive composition that is sufficiently excellent in adhesiveness and storage stability and can form a cured product that is sufficiently excellent in electrical conductivity without containing a halogen flux. And the electronic component mounting board | substrate and semiconductor device with which each member was electrically connected using the conductive adhesive composition can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

  Since the conductive adhesive composition of the present invention has the same degree of conductivity as solder and is excellent in adhesive strength (fixing force), it can be widely used as an alternative material for parts where solder has been used in the past. it can. It can also be used in fields where adhesiveness is not so required. In other words, electronic parts such as passive parts and LSI packages, plastic films such as polyimide resins and epoxy resins, and substrates such as glass nonwoven fabrics impregnated and cured with plastics such as polyimide resins, epoxy resins, and BT resins, alumina It can be used for bonding with a substrate such as ceramics.

  Specifically, as shown in FIGS. 1 and 2, the conductive adhesive composition of the present invention was connected with passive components that were conventionally connected with solder, or with solder or an anisotropic conductive film. It can also be applied to the connection of electronic components such as semiconductor elements. In particular, since the conductive adhesive composition of the present invention can be connected at a low temperature as compared with solder, it is suitably used for connecting components having poor heat resistance such as a CCD module. Conventionally, when a semiconductor element and a substrate are connected by solder, an underfill material is injected between the element and the substrate in order to relieve stress generated due to a difference in thermal expansion coefficient between the semiconductor element and the substrate. There was a need to do. On the other hand, when connecting with the conductive adhesive composition of the present invention, since the resin component has a stress relaxation action, an underfill material is not required and the process can be simplified.

  Moreover, as shown in FIG. 3, the conductive adhesive composition of the present invention can be used in combination with solder to connect a semiconductor element and a substrate. Furthermore, as shown in FIG. 4, the conductive adhesive composition of the present invention is used when a substrate as an interposer on which the passive component shown in FIGS. 1 and 2 is mounted on another substrate such as a motherboard. Can also be used.

  The conductive adhesive composition of the present invention (hereinafter simply referred to as “adhesive composition”) used for such applications contains (A) conductive particles and (B) an adhesive component. is there. Hereinafter, each component will be described in detail.

<(A) Conductive particles>
The electroconductive particle which concerns on this invention will not be specifically limited if melting | fusing point is 260 degrees C or less, and contains metals other than lead. Examples of such a metal include one metal selected from the group consisting of Sn, Ag, Cu, Bi, In, and Zn, or an alloy of two or more metals selected from the above group. More specifically, Sn42-Bi58 solder, Sn96.5-Ag3-Cu0.5 solder, etc. are mentioned. These are used singly or in combination of two or more.

  The average particle diameter of the conductive particles is not particularly limited, but is preferably 0.1 to 100 μm. When the average particle size is less than 0.1 μm, the viscosity of the adhesive composition tends to increase and workability tends to decrease. Moreover, when the aliphatic dihydroxycarboxylic acid mentioned later is contained in a large amount adhesive composition in order to improve the meltability of electroconductive particle, the storage stability and adhesive force tend to be lowered. On the other hand, when the average particle diameter of the conductive particles exceeds 100 μm, the printability or connection reliability tends to decrease. From the viewpoint of further improving the printability or workability of the adhesive composition, the average particle size is more preferably 1.0 to 50 μm. Furthermore, from the viewpoint of improving the storage stability of the adhesive composition and the mounting reliability of the cured product, the average particle size is particularly preferably 5.0 to 30 μm.

  The conductive particles according to the present invention may be conductive particles in which the surface of particles made of a solid material other than a metal such as a ceramic material or a resin material is coated with a metal film, in addition to those composed only of a metal, A mixture thereof may also be used.

  As for content of the electroconductive particle in the adhesive composition of this invention, it is preferable that content of the metal which comprises the electroconductive particle is 5-95 mass% with respect to the whole quantity of an adhesive composition. When content of the said metal is less than 5 mass%, it exists in the tendency for the electroconductivity of the hardened | cured material of adhesive composition to fall. On the other hand, when the content of the metal exceeds 95% by mass, the viscosity of the adhesive composition is increased and workability tends to be lowered. Moreover, since the adhesive component in the adhesive composition is relatively reduced, the mounting reliability of the cured product tends to be lowered. The content of the metal adhesive composition with respect to the total amount is more preferably 10 to 90% by mass from the viewpoint of improving workability or conductivity, and from the viewpoint of increasing the mounting reliability of the cured product. It is especially preferable that it is 85 mass%.

<(B) Adhesive component>
The adhesive component according to the present invention has an action of adhering the adherend, and also acts as a binder component that binds the conductive particles in the adhesive composition and the filler added as necessary. The adhesive component is not particularly limited as long as it contains a thermosetting resin and an aliphatic dihydroxycarboxylic acid.

  Examples of the thermosetting resin include thermosetting organic polymer compounds such as epoxy resins, acrylic resins, maleimide resins, and cyanate resins, and precursors thereof. In these, the compound which has the carbon-carbon double bond which can be polymerized in a molecule | numerator represented by the acrylic resin and the maleimide resin, or an epoxy resin is preferable. These preferable thermosetting resins are excellent in heat resistance and adhesiveness, and also can be handled in a liquid state if dissolved or dispersed in an organic solvent as required, so that they are excellent in workability. The above-mentioned thermosetting resins are used singly or in combination of two or more.

  Examples of the compound having a polymerizable carbon-carbon double bond in the molecule include a monoacrylate compound, a monomethacrylate compound, a diacrylate compound, and a dimethacrylate compound.

  Examples of the monoacrylate compound include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2- Ethylhexyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, tridecyl acrylate, hexadecyl acrylate, stearyl acrylate, isostearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, diethylene glycol acrylate, polyethylene glycol acrylate, polypropylene Acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, dicyclopentenyloxyethyl acrylate, 2-phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate 2-benzoyloxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, γ-acryloxyethyl trimethoxysilane, glycidyl acrylate, tetrahydrofurfuryl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl A Examples include acrylate, acryloxyethyl phosphate, and acryloxyethyl phenyl acid phosphate.

  Examples of the monomethacrylate compound include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2- Ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, hexadecyl methacrylate, stearyl methacrylate, isostearyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, diethylene glycol methacrylate Polyethylene glycol methacrylate, polypropylene methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, dicyclopentenyloxyethyl methacrylate, 2-phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate , Phenoxypolyethylene glycol methacrylate, 2-benzoyloxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, benzyl methacrylate, 2-cyanoethyl methacrylate, γ-methacryloxyethyltrimethoxysilane, glycidyl methacrylate, tetrahy Examples include drofurfuryl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methacryloxyethyl phosphate, and methacryloxyethyl phenyl acid phosphate.

  Examples of the diacrylate compound include ethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,3-butanediol diacrylate, neo Pentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, bisphenol A, bisphenol F or bisphenol AD 1 mole and glycidyl acrylate 2 Mole reactant, polyethylene of bisphenol A, bisphenol F or bisphenol AD It includes dimethylsiloxane copolymers - diacrylate adduct, bisphenol A, diacrylate of a polypropylene oxide adduct of bisphenol F or bisphenol AD, bis (acryloxypropyl) polydimethylsiloxane, bis (acryloxypropyl) methylsiloxane.

  Examples of the dimethacrylate compound include ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,3-butanediol dimethacrylate, neodymium. Pentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, bisphenol A, bisphenol F or bisphenol AD 1 mole and glycidyl methacrylate 2 Molar reactants, bisphenol A, bisphenol F or bi It includes dimethylsiloxane copolymer - dimethacrylate of a polyethylene oxide adduct of phenol AD, polypropylene oxide adduct of bisphenol F or bisphenol AD, bis (methacryloxypropyl) polydimethylsiloxane, bis (methacryloxypropyl) methylsiloxane.

  These compounds having a polymerizable carbon-carbon double bond in the molecule are used singly or in combination of two or more.

  When the adhesive component contains a compound having a polymerizable carbon-carbon double bond in the molecule as a thermosetting resin, it is preferable to further contain a radical polymerization initiator. The radical polymerization initiator is preferably an organic peroxide from the viewpoint of effectively suppressing voids. Further, from the viewpoint of improving the curability and viscosity stability of the adhesive component, the organic peroxide preferably has a decomposition temperature of 70 to 170 ° C.

  Examples of the radical polymerization initiator include 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis ( t-butylperoxy) cyclododecane, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) 3-hexyne, cumene hydroperoxide. These are used singly or in combination of two or more.

  The blending ratio of the radical polymerization initiator is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and 0.5 to 5% by mass with respect to the total amount of the adhesive component. More preferably.

  As the epoxy resin, a compound having two or more epoxy groups in one molecule is preferable. Examples of such an epoxy resin include epoxy resins derived from bisphenol A, bisphenol F, bisphenol AD, and the like and epichlorohydridone.

  Such epoxy resins are commercially available. Specific examples thereof include AER-X8501 (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.), R-301 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), YL-980 (Oka Chemical Shell Epoxy Co., Ltd.), which are bisphenol A type epoxy resins. Product name), YDF-170 (trade name, manufactured by Tohto Kasei Co., Ltd.), a bisphenol F type epoxy resin, R-1710 (trade name, manufactured by Mitsui Petrochemical Co., Ltd.), a phenol novolac, bisphenol AD type epoxy resin Type epoxy resin N-730S (manufactured by Dainippon Ink and Chemicals, trade name), Quatrex-2010 (manufactured by Dow Chemical Co., trade name), YDCN-702S (made by Toto Kasei Co., Ltd.), a cresol novolac type epoxy resin ), EOCN-100 (manufactured by Nippon Kayaku Co., Ltd., trade name), EPPN-50 which is a polyfunctional epoxy resin (Nippon Kayaku Co., Ltd., trade name), TACTIX-742 (Dow Chemical Co., trade name), VG-3010 (Mitsui Petrochemical Co., Ltd., trade name), 1032S (Okasei Shell Epoxy, trade name) Name), HP-4032 (manufactured by Dainippon Ink & Chemicals, Inc., product name) which is an epoxy resin having a naphthalene skeleton, EHPE-3150 and CEL-3000 (both manufactured by Daicel Chemical Industries, Ltd., products) Name), DME-100 (trade name, manufactured by Shin Nippon Chemical Co., Ltd.), EX-216L (product name, manufactured by Nagase Kasei Kogyo Co., Ltd.), W-100 (Shin Nihon Chemical Company, trade name) which is an aliphatic epoxy resin, ELM-100 (trade name) manufactured by Sumitomo Chemical Co., Ltd., YH-434L (trade name, manufactured by Tohto Kasei Co., Ltd.), TETRAD-X, TETRAC-C (both Mitsubishi) Sena Chemical Co., Ltd., trade name), Denacol EX-201 (trade name, manufactured by Nagase Kasei Kogyo Co., Ltd.) which is a resorcinol type epoxy resin, Denacol EX-211 (trade name, produced by Nagase Kasei Kogyo Co., Ltd.), a neopentyl glycol type epoxy resin ), Denacol EX-212 (trade name) manufactured by Nagase Kasei Kogyo Co., Ltd., which is a hexane dinel glycol type epoxy resin, and Denacol EX series (EX-810, 811, 850, 851, 821) which are ethylene / propylene glycol type epoxy resins. , 830, 832, 841, 861 (all manufactured by Nagase Kasei Kogyo Co., Ltd., trade name)), epoxy resins E-XL-24 and E-XL-3L represented by the following general formula (1) (both Mitsui Toatsu) Chemical name, product name).

ここで、式（１）中、ｋは１〜５の整数を示す。

Here, in Formula (1), k shows the integer of 1-5.

  The above-mentioned epoxy resins are used singly or in combination of two or more.

  Moreover, when an adhesive agent component contains the above-mentioned epoxy resin as a thermosetting resin, you may further contain the epoxy compound which has only one epoxy group in 1 molecule as a reactive diluent. Such epoxy compounds are commercially available, and specific examples thereof include, for example, PGE (trade name, manufactured by Nippon Kayaku Co., Ltd.), PP-101 (trade name, manufactured by Tohto Kasei Co., Ltd.), ED-502, ED-509, ED-509S (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), YED-122 (manufactured by Yuka Shell Epoxy Co., Ltd., trade name), KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), TSL-8350 , TSL-8355, TSL-9905 (manufactured by Toshiba Silicone Co., Ltd., trade names). These are used singly or in combination of two or more.

  The mixing ratio of the reactive diluent may be in a range that does not hinder the effect of the present invention, and is preferably 0 to 30% by mass with respect to the total amount of the epoxy resin.

  When the adhesive component contains an epoxy resin as a thermosetting resin, it is preferable to further contain the curing agent, and it is more preferable to contain a curing accelerator for improving the curability in addition to that. is there.

  As a hardening | curing agent, if it is conventionally used, it will not specifically limit, A commercially available thing is available. Commercially available curing agents include, for example, phenol novolac resin H-1 (Maywa Kasei Co., Ltd., trade name), VR-9300 (Mitsui Toatsu Chemical Co., trade name), and phenol aralkyl resin XL-225. (Trade name) manufactured by Mitsui Toatsu Chemical Co., Ltd., MTPC (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) which is a p-cresol novolak resin represented by the following general formula (II), and AL- which is an allylated phenol novolac resin VR-9300 (trade name, manufactured by Mitsui Toatsu Chemical Co., Ltd.) and PP-700-300 (trade name, manufactured by Nippon Petrochemical Co., Ltd.), which is a special phenol resin represented by the following general formula (III).

式（ＩＩ）中、Ｒ^２は、それぞれ独立に１価の炭化水素基、好ましくはメチル基又はアリル基を示し、ｑは１〜５の整数を示す。また、式（ＩＩＩ）中、Ｒ^３はアルキル基、好ましくはメチル基又はエチル基を示し、Ｒ^４は水素原子又は１価の炭化水素基を示し、ｐは２〜４の整数を示す。

In formula (II), each R ² independently represents a monovalent hydrocarbon group, preferably a methyl group or an allyl group, and q represents an integer of 1 to 5. In formula (III), R ³ represents an alkyl group, preferably a methyl group or an ethyl group, R ⁴ represents a hydrogen atom or a monovalent hydrocarbon group, and p represents an integer of 2 to 4.

  The blending ratio of the curing agent is preferably such that the total amount of reactive groups in the curing agent is 0.3 to 1.2 equivalents with respect to 1.0 equivalent of epoxy groups of the epoxy resin, 0.4 The ratio is more preferably -1.0 equivalent, and still more preferably 0.5-1.0 equivalent. When the reactive group is less than 0.2 equivalent, the reflow crack resistance of the adhesive component tends to decrease, and when it exceeds 1.2 equivalent, the viscosity of the adhesive component increases and workability tends to decrease. There is. The reactive group is a substituent having a reactive activity with an epoxy resin, and examples thereof include a phenolic hydroxyl group.

  The curing accelerator is not particularly limited as long as it is conventionally used as a curing accelerator, such as dicyandiamide, and a commercially available product is available. Commercially available products include, for example, ADH, PDH, and SDH (both trade names manufactured by Nippon Hydrazine Kogyo Co., Ltd.), which are dibasic acid dihydrazides represented by the following general formula (IV), and a reaction product of an epoxy resin and an amine compound. Novacure (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.), which is a microcapsule-type curing agent comprising: These curing accelerators are used alone or in combination of two or more.

式（ＩＶ）中、Ｒ^５は２価の芳香族基又は炭素数１〜１２の直鎖若しくは分岐鎖のアルキレン基、好ましくはｍ−フェニレン基又はｐ−フェニレン基を示す。

In the formula (IV), R ⁵ represents a divalent aromatic group or a linear or branched alkylene group having 1 to 12 carbon atoms, preferably an m-phenylene group or a p-phenylene group.

  The blending ratio of the curing accelerator is preferably 0.01 to 90 parts by mass and more preferably 0.1 to 50 parts by mass with respect to 100 parts by mass of the epoxy resin. If the blending ratio of this curing accelerator is less than 0.01 parts by mass, the curability tends to decrease, and if it exceeds 90 parts by mass, the viscosity increases and the workability when handling the adhesive component tends to decrease. There is.

  Further, as a commercially available curing accelerator, in addition to / in place of the above, for example, an organic boron salt compound EMZ · K, TPPK (both manufactured by Hokuko Chemical Co., Ltd., trade name), tertiary amines or the like DBU, which is a salt, U-CAT102, 106, 830, 840, 5002 (both manufactured by Sun Apro, trade name), Cureazole, which is an imidazole, 2PZ-CN, 2P4MHZ, C17Z, 2PZ-OK (both Shikoku Chemicals ( (Trade name), etc. may be used.

  The blending ratio of these curing accelerators is preferably 20 parts by mass or less with respect to 100 parts by mass of the epoxy resin.

  Moreover, you may use a hardening | curing agent and a hardening accelerator individually by 1 type or in combination of 2 or more types, respectively.

  The aliphatic dihydroxycarboxylic acid contained in the adhesive component in the present invention acts as a flux component and a curing agent. This aliphatic dihydroxycarboxylic acid has two hydroxyl groups and one or more carboxyl groups bonded directly to the aliphatic main chain skeleton, or two hydroxyl groups and one or more via an aliphatic side chain. It is preferable that the compound has a carboxyl group bonded thereto. Such a compound is not particularly limited as long as the main chain is an aliphatic skeleton and has two hydroxyl groups and one or more carboxyl groups. For example, the compound is represented by the general formula (I). A compound or tartaric acid is preferred.

Here, in the formula (I), R ¹ represents an optionally substituted alkyl group having 1 to 5 carbon atoms, and from the viewpoint of more effectively exerting the above-described effects of the present invention, a propyl group, a butyl group, or A pentyl group is preferred. N and m each independently represent an integer of 0 to 5, and from the viewpoint of more effectively exhibiting the above-described effects of the present invention, n is 0 and m is 1, or both n and m are 1 It is preferable that both n and m are 1.

  Examples of the compound represented by the general formula (I) include 2,2-bishydroxymethylpropionic acid, 2,2-bishydroxymethylbutanoic acid, and 2,2-bishydroxymethylpentanoic acid.

  The content of the aliphatic dihydroxycarboxylic acid is 0.5 to less than the above melting point of 260 ° C. and 100 parts by mass of the total amount of metals other than lead, from the viewpoint of more effectively exhibiting the above-described effects of the present invention. It is preferably 20 parts by mass. Furthermore, it is more preferable that it is 1.0-10 mass parts from a storage stability and electroconductive viewpoint. When the content of the aliphatic dihydroxycarboxylic acid is less than 0.5 parts by mass, the meltability of the metal tends to decrease and the conductivity tends to decrease. When the content exceeds 20 parts by mass, the storage stability and printability are increased. There is a tendency to decrease.

  In addition to the above-described components, the adhesive component according to the present invention includes, as necessary, a flexible agent for stress relaxation, a diluent for improving workability, an adhesive strength improver, a wettability improver, and a dissipator. One or more additives selected from the group consisting of foaming agents may be included. In addition to these components, various additives may be included within a range that does not impair the effects of the present invention.

  For example, the adhesive component of the present invention may include a flexible agent for the purpose of relieving the stress generated by adhering the semiconductor element and the lead frame. As a flexible agent, liquid polybutadiene (Ube Industries, product name "CTBN-1300x31", "CTBN-1300x9", Nippon Soda Co., Ltd. product name "NISSO-PB-C-2000") etc. Is mentioned. The content of the flexible agent is usually preferably 0 to 500 parts by mass with respect to 100 parts by mass of the total amount of the thermosetting organic polymer compound and its precursor.

  The adhesive component in the present invention may contain a coupling agent such as a silane coupling agent or a titanium coupling agent for the purpose of improving the adhesive strength. Examples of the silane coupling agent include trade name “KBM-573” manufactured by Shin-Etsu Chemical Co., Ltd. Further, for the purpose of improving wettability, an anionic surfactant or a fluorosurfactant may be contained in the adhesive component. Furthermore, the adhesive component may contain silicone oil or the like as an antifoaming agent. The said adhesive force improver, wettability improver, and antifoamer are used individually by 1 type or in combination of 2 or more types, respectively. It is preferable that 0.1-10 mass% of these are contained with respect to the whole quantity of an adhesive composition.

  Moreover, in order to make the workability | operativity at the time of preparation of a paste composition and the application | coating workability | operativity at the time of use more favorable, a diluent can be added to the adhesive component of this invention as needed. As such a diluent, an organic solvent having a relatively high boiling point such as butyl cellosolve, carbitol, butyl cellosolve, carbitol acetate, dipropylene glycol monomethyl ether, ethylene glycol diethyl ether, and α-terpineol is preferable. This diluent is preferably contained in an amount of 0.1 to 30% by mass with respect to the total amount of the adhesive composition.

  The adhesive composition of the present invention may contain a filler. Examples of the filler include polymer particles such as acrylic rubber and polystyrene, inorganic particles other than metals such as diamond, boron nitride, aluminum nitride, and alumina, metal particles such as gold, platinum, silver, copper, nickel, aluminum, and palladium, Alternatively, coated particles obtained by plating gold, platinum, silver, copper, nickel, aluminum, and palladium on polymer particles, inorganic particles, or metal particles can be used. You may use a filler individually by 1 type or in mixture of 2 or more types.

  In the present invention, from the viewpoint of more effectively exhibiting the above effects, the blending ratio of the adhesive component to the conductive particles (adhesive component / conductive particles) is a solid content ratio (mass ratio) in the adhesive composition. It is preferable that it is 5 / 95-50 / 50. Furthermore, from the viewpoint of adhesiveness, conductivity, and workability, the blending ratio is more preferably 10/90 to 30/70. When the blending ratio is less than 5/95, the viscosity of the adhesive composition becomes high, and it becomes difficult to ensure workability, or the adhesive force tends to decrease. When this blending ratio is less than 50/50, the conductivity tends to decrease.

  In the present invention, the components described above may be combined with any of those exemplified above.

  In the above-mentioned adhesive composition of the present invention, each component described above is divided into one or more times and heated as necessary, and each component is uniformly dispersed by mixing, dissolving, pulverizing kneading or dispersing. Obtained as a paste. Examples of the dispersing / dissolving device used in this case include a known stirrer, a leaker, a three roll, a planetary mixer and the like.

  The adhesive composition of the present invention thus obtained is used as an electronic component, a circuit wiring material, an electrode material, a conductive bonding material, a conductive adhesive, or a die bonding material.

  According to the conductive adhesive composition of the present embodiment described above, it is possible to achieve both a predetermined adhesive force and conductivity with short-time curing while having good storage stability. Therefore, when this conductive adhesive composition is used for a printed wiring board as a conductive adhesive for surface mounting electronic parts, it has excellent TCT resistance and high temperature storage resistance compared to conventional products. Thus, a highly reliable electronic component mounting substrate can be obtained.

  Next, the electronic component mounting substrate of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of an electronic component mounting board according to the present invention. As shown in FIG. 1, in the electronic component mounting substrate 1, a substrate connection terminal 14 formed on the substrate 12 and an electronic component connection terminal 18 connected to the electronic component 16 are joined to each other by a conductive member 10. And has an electrically connected structure. And the electrically-conductive member 10 hardens the adhesive composition of this invention mentioned above.

  In order to bond the electronic component 16 and the substrate 12 using the adhesive composition of the present invention, first, the adhesive composition is applied onto the substrate connection terminal 14 of the substrate 12 by a dispensing method, a screen printing method, a stamping method, or the like. To do. Next, the electronic component 16 having the electronic component connection terminals 18 is pressure-bonded to the substrate 12 so that the electronic component connection terminals 18 and the substrate connection terminals 14 are electrically connected via the adhesive composition, and then the oven or This can be done by heat-curing the adhesive composition using a heating device such as a reflow furnace.

  Moreover, the electronic component mounting substrate of this invention is not limited to the structure shown in FIG. 1, For example, you may have the structure shown in FIGS. The electronic component mounting substrate 2 shown in FIG. 2 is a conductive material in which a substrate connection terminal 14 formed on a substrate 12 and a lead 20 connected to the electronic component 16 are cured by curing the adhesive composition of the present invention. The structure is electrically connected by the member 10.

  Moreover, the electronic component mounting substrate 3 shown in FIG. 3 has a structure in which the substrate 12 and the electronic component 16 are connected by combining the adhesive composition of the present invention and solder. In the electronic component mounting substrate 3, electronic component connection terminals 18 are formed on the electronic components 16, and solder balls 22 are formed on the electronic component connection terminals 18. And this solder ball 22 and the board | substrate connection terminal 14 formed on the board | substrate 12 are electrically connected by the electrically-conductive member 10 which hardened the adhesive composition of this invention, and the electronic component mounting board 3 is formed. Has been.

Further, the electronic component mounting substrate 4 shown in FIG. 4 has a structure in which the substrate 12 on which the electronic component 16 shown in FIGS. 2 and 3 is mounted is further mounted on another substrate 24. Here, the connection between the electronic component 16 and the substrate 12 and the connection between the substrate 12 and the substrate 24 are performed by the conductive member 10 formed by curing the adhesive composition of the present invention.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof.

  For example, if the substrate in the above-described embodiment is replaced with a supporting substrate for mounting a semiconductor and the electronic component is replaced with a semiconductor element, the supporting substrate for mounting the semiconductor, the semiconductor element, and the supporting substrate and the semiconductor element are bonded. Thus, a semiconductor device of the present invention including a conductive layer electrically connected is formed. Here, the conductive layer is a cured product of the adhesive composition according to the present invention. Further, the supporting substrate and the semiconductor element for mounting the semiconductor may be conventional ones.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In addition, the material used by the Example and the comparative example was produced by the following method, or was obtained. An example of the preparation method is shown in Example 1, but the resin compositions and compounding ratios of other Examples and Comparative Examples are as shown in Tables 1 to 3, and the preparation method is the same as Example 1.

[Example 1]
25.2 parts by mass of YDF-170 (manufactured by Toto Kasei Co., Ltd., trade name of bisphenol F type epoxy resin, epoxy equivalent = 170) and 1.3 parts by mass of 2PZ-CN (trade name of imidazole compound, produced by Shikoku Kasei Co., Ltd.) And 3.5 parts by mass of BHPA (2,2-bishydroxymethylpropionic acid) were mixed, and an adhesive component was prepared by passing three rolls three times.

  Next, 70 parts by mass of Sn42-Bi58 particles (average particle diameter: 20 μm), which are conductive particles, was added to and mixed with 30 parts by mass of the adhesive component described above. Furthermore, after passing 3 rolls 3 times through those mixtures, the electrically conductive adhesive composition was obtained by performing a defoaming process for 10 minutes at 500 Pa or less using a vacuum stirrer.

[Examples 2-9, Comparative Examples 1-6]
As described above, conductive adhesive compositions of Examples 2 to 9 and Comparative Examples 1 to 6 were obtained in the same manner as in Example 1 except that the compositions shown in Tables 1 and 2 were used. The details of the materials shown in Tables 1 and 2 are as follows. Moreover, the unit of the mixture ratio of each material in Table 1, 2 is a mass part.
BHBA: 2,2-bishydroxymethylbutanoic acid BHVA: 2,2-bishydroxymethylpentanoic acid TCG-1: silver powder, trade name, manufactured by Tokuru Chemical Laboratory

(Evaluation of adhesiveness, conductivity, TCT resistance, and high temperature storage resistance)
The characteristics of the conductive adhesive compositions according to Examples 1 to 9 and Comparative Examples 1 to 6 were measured by the following method. The results are summarized in Tables 1 and 2.

  (1) Adhesiveness (adhesive strength): About 0.5 mg of a conductive adhesive composition is applied on a silver-plated copper plate, and a rectangular plate-shaped tin-plated copper plate of 2 mm × 2 mm × 0.25 mm is formed thereon. A test piece was obtained by pressure bonding. Then, the heat history of 150 degreeC and 10 minutes was added with respect to the test piece which concerns on Examples 1-8 and Comparative Examples 1-5. For the test pieces of Example 9 and Comparative Example 6, the shear strength at 25 ° C. was measured with a bond tester (manufactured by DAGE, 2400) at a shear rate of 500 μm / sec and a clearance of 100 μm.

  (2) Conductivity (volume resistivity): 1 mm × 50 mm × 0.03 mm strip-shaped gold-plated copper plates are bonded to each other through the conductive adhesive composition so as to be orthogonal to each other. Got. This resulted in a 1 mm x 1 mm x 0.03 mm dimension of the adhesive layer at the orthogonal part. Subsequently, the same thermal history as in (1) above was added to the test piece. About the subsequent test piece, the volume resistivity was measured by the four probe method.

  (3) TCT resistance: A rectangular flat glass epoxy substrate of 100 mm × 50 mm × 1.0 mm provided with a copper foil land with silver plating of 1.7 mm × 1.4 mm was prepared. Next, the conductive adhesive composition was printed on the copper foil land using a metal mask (thickness: 100 μm, opening size: 1.0 mm × 1.6 mm), and chip resistance (3.2 mm × 1.6 mm) was mounted. . A thermal history similar to that of (1) above was added to this component mounting board to obtain a test board for TCT resistance evaluation. This test substrate was put into a thermal shock tester (1 cycle: held at -55 ° C for 30 minutes, raised to 125 ° C for 5 minutes, held at 125 ° C for 30 minutes, lowered to -55 ° C for 5 minutes), The connection resistance was measured. The TCT resistance was evaluated by the number of cycles that showed a resistance change rate within ± 10% with respect to the initial resistance.

  (4) Resistance to high-temperature storage: A test substrate prepared in the same manner as in (3) above was placed in a high-temperature bath at 125 ° C., and the connection resistance was measured. The evaluation of the high temperature storage resistance was performed in the storage time showing a resistance change rate within ± 10% with respect to the initial resistance.

1 is a schematic cross-sectional view showing a preferred embodiment of an electronic component mounting board according to the present invention. It is a schematic cross section which shows other suitable one Embodiment of the electronic component mounting board | substrate of this invention. It is a schematic cross section which shows other suitable one Embodiment of the electronic component mounting board | substrate of this invention. FIG. 10 is a schematic cross-sectional view showing still another preferred embodiment of the electronic component mounting board of the present invention.

Explanation of symbols

1, 2, 3, 4... Electronic component mounting board, 10... Conductive member, 12, 24 .. Board, 14 .. Board connection terminal, 16 .. Electronic component, 18 ... Electronic component connection terminal, 20. .

Claims (5)

An adhesive component having a melting point of 260 ° C. or less and containing a metal other than lead, and a thermosetting resin and an aliphatic dihydroxycarboxylic acid;
A conductive adhesive composition containing The conductive adhesive composition according to claim 1, wherein the aliphatic dihydroxycarboxylic acid is a compound represented by the following general formula (I) or tartaric acid.

(In formula (I), R ¹ represents an optionally substituted alkyl group having 1 to 5 carbon atoms, and n and m each independently represent an integer of 0 to 5)   The conductive adhesive composition according to claim 1 or 2, comprising 0.5 to 20 parts by mass of the aliphatic dihydroxycarboxylic acid with respect to 100 parts by mass of the metal. A substrate, an electronic component, and a conductive layer that bonds and electrically connects the substrate and the electronic component,
The electronic component mounting board | substrate whose said conductive layer is a hardened | cured material of the conductive adhesive composition as described in any one of Claims 1-3. A support substrate for mounting a semiconductor, a semiconductor element, and a conductive layer that bonds and electrically connects the support substrate and the semiconductor element,
The semiconductor device whose said conductive layer is a hardened | cured material of the conductive adhesive composition as described in any one of Claims 1-3.

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