JPWO2008139996A1 - Film-like circuit connection material and circuit member connection structure - Google Patents

Abstract

A first circuit member having a first circuit electrode formed on the main surface of the first circuit board, and a second circuit member having a second circuit electrode formed on the main surface of the second circuit board Is a film-like circuit connecting material for electrically connecting the first and second circuit electrodes facing each other, and generates free radicals by heating with a film-forming material, a radical polymerizable compound, and heating. A radical polymerization initiator and an isocyanate group-containing compound, and the content ratio of the isocyanate group-containing compound is 0.09 to 5 parts by mass with respect to 100 parts by mass in total of the film-forming material and the radical polymerizable compound. A film-like circuit connection material.

Description

  The present invention relates to a film-like circuit connection material and a circuit member connection structure.

  In recent years, various adhesive materials have been used for fixing electronic components and making circuit connections in fields such as semiconductors and liquid crystal displays. In these applications, higher density and higher definition are required, and high adhesive strength and reliability are required for adhesives.

  In particular, an anisotropic conductive adhesive in which conductive particles are dispersed in an adhesive is used as a circuit connection material for connection between a liquid crystal display and TCP, connection between an FPC and TCP, or connection between an FPC and a printed wiring board. in use. Recently, even when a semiconductor silicon chip is mounted on a substrate, so-called flip chip mounting, in which the semiconductor silicon chip is directly mounted on the substrate face down, is being used instead of the conventional wire bond. Application of a conductive adhesive has been started.

  Furthermore, in recent years, in the field of precision electronic equipment, the density of circuits has been increasing, and the electrode width and electrode interval have become extremely narrow. For this reason, under the connection conditions of the circuit connection material using a conventional epoxy resin system, the wiring is easily dropped, peeled off, and misaligned.

In addition, shortening of the connection time is desired in order to improve production efficiency, and a circuit connection material that can be connected in 10 seconds or less is demanded. Therefore, an electric / electronic circuit connection material that is excellent in low-temperature fast-curing property and has a long pot life has been developed (see, for example, Patent Document 1).
JP-A-11-97825

  However, the adhesive strength of the circuit connecting material varies depending on the material of the circuit member to be connected. In particular, when the surface of the circuit member is coated with silicon nitride, silicone resin, or polyimide resin, or when these resins are attached to the surface of the circuit member, the adhesive strength tends to decrease. Therefore, there is a demand for a circuit connecting material that is excellent in adhesiveness regardless of the material of the circuit member and has a sufficiently long pot life.

  The present invention has been made in view of the above circumstances, and uses a film-like circuit connection material that exhibits sufficiently high adhesiveness regardless of the material of the circuit member and has a sufficiently long pot life, and the same. It aims at providing the connection structure of a circuit member.

  The present invention provides a first circuit member in which a first circuit electrode is formed on a main surface of a first circuit board, and a second circuit electrode in which a second circuit electrode is formed on a main surface of a second circuit board. 2 is a film-like circuit connecting material for electrically connecting the circuit member 2 with the first and second circuit electrodes facing each other, and the film forming material, the radical polymerizable compound, and heating It contains a radical polymerization initiator that generates free radicals and an isocyanate group-containing compound, and the content ratio of the isocyanate group-containing compound is 0.09 to 100 parts by mass with respect to a total of 100 parts by mass of the film-forming material and the radical polymerizable compound. A film-like circuit connecting material having 5 parts by mass is provided.

  By providing the said structure, the film-form circuit connection material of this invention shows sufficiently high adhesiveness irrespective of the material of a circuit member, and has a sufficiently long pot life. The reason why such an effect can be manifested is not clear, but the present inventors presume as follows.

  Usually, in order to lengthen the pot life of the circuit connecting material, it is necessary to control the reactivity of the circuit connecting material. However, if the reactivity of the circuit connecting material is controlled, depending on the type of adherend, there is a tendency that sufficient adhesion cannot be exhibited. On the other hand, although the said isocyanate group containing compound is excellent in the reactivity under the temperature conditions at the time of circuit connection, it is thought that it is stable under the temperature lower than it. Therefore, the film-like circuit connecting material of the present invention can achieve both good adhesiveness and a sufficiently long pot life by containing a predetermined amount of the isocyanate group-containing compound together with the other components described above, Conceivable.

  The film-like circuit connecting material preferably contains a fluorine-containing organic compound. Such a film-like circuit connecting material has an effect that adhesiveness is further improved and transferability is also excellent.

  Moreover, it is preferable that the film-form circuit connection material of this invention contains the organic compound which has a urethane bond of a weight average molecular weight 10,000 or more as a film formation material. Thereby, the softness | flexibility of a film-form circuit connection material improves and the effect of this invention that it is excellent in adhesiveness with various circuit members can be exhibited more effectively.

  The circuit connection material of the present invention preferably further contains conductive particles. As a result, the circuit connecting material itself can easily have conductivity. Therefore, this circuit connecting material can be used as a conductive adhesive in the fields of electric industry and electronic industry such as circuit electrodes and semiconductors. Furthermore, in this case, since the circuit connection material has conductivity, the connection resistance after curing can be further reduced.

  According to the present invention, a first circuit member having a first circuit electrode formed on the main surface of the first circuit board, a second circuit electrode formed on the main surface of the second circuit board, A second circuit member disposed so that the two circuit electrodes are opposed to the first circuit electrode, and the first circuit board and the second circuit board. A circuit member connection structure comprising: a circuit connection portion that connects the first circuit member and the second circuit member so that the circuit electrodes of the first and second circuit members are electrically connected to each other. Provided is a circuit member connection structure formed of a cured product of a film-like circuit connection material.

  Such a circuit member connection structure is formed by a cured product of the film-like circuit connection material of the present invention, in which the circuit connection portion is sufficiently excellent in adhesiveness and has a sufficiently long pot life. The resistance value between the circuit electrodes facing each other can be reduced while maintaining the insulation between the adjacent circuit electrodes.

  In the circuit member connection structure of the present invention, at least one of the first and second circuit electrodes has at least a surface selected from the group consisting of gold, silver, tin, a platinum group metal, and indium-tin oxide. It is preferable to consist of the material containing 1 type. In such a circuit member connection structure, the resistance value between the facing circuit electrodes can be further reduced while maintaining the insulation between the adjacent circuit electrodes on the same circuit member.

  In the circuit member connection structure of the present invention, at least one of the first and second circuit boards is at least selected from the group consisting of polyethylene terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin, and glass. A substrate made of a material including one kind is preferable. When the circuit connection material of the present invention is cured to form a circuit connection portion, it can exhibit higher adhesion with a substrate made of these specific materials.

  Furthermore, in the connection structure of the circuit member, the member is selected from the group consisting of silicon nitride, silicone resin, polyimide resin, and acrylic resin between at least one of the first and second circuit members and the circuit connection portion. It is preferable that a layer containing at least one material is formed. Thereby, compared with the thing in which the said layer is not formed, the adhesiveness of a circuit member and a circuit connection part improves further.

  According to the present invention, it is possible to provide a film-like circuit connection material that exhibits sufficiently high adhesiveness regardless of the material of the circuit member and has a sufficiently long pot life, and a circuit member connection structure using these. .

It is a schematic sectional drawing which shows one Embodiment of the connection structure of the circuit member which concerns on this invention. It is process drawing which shows an example of the manufacturing method of the connection structure of the circuit member shown in FIG. 1 with a schematic sectional drawing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Circuit connection structure of a circuit member, 5 ... Adhesive component, 7 ... Conductive particle, 10 ... Circuit connection part, 11 ... Hardened | cured material of an adhesive component, 20 ... 1st circuit member, 21 ... 1st circuit Substrate, 21a ... first circuit board main surface, 22 ... first circuit electrode, 30 ... second circuit member, 31 ... second circuit board, 31a ... second circuit board main surface, 32 ... second Circuit electrode, 40 ... film-like circuit connecting material.

  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. In the present specification, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto, “(Meth) acryloyl” means “acryloyl” and its corresponding “methacryloyl”.

(Film-like circuit connection material)
The film-like circuit connecting material (adhesive film for circuit connection) of the present invention includes a first circuit member in which a first circuit electrode is formed on a main surface of a first circuit board, and a main circuit board of a second circuit board. A second circuit member having a second circuit electrode formed on the surface is electrically connected with the first and second circuit electrodes facing each other. The film-like circuit connecting material of the present invention contains, as an adhesive component, a film-forming material, a radically polymerizable compound, a radical polymerization initiator that generates free radicals upon heating, and an isocyanate group-containing compound. The content rate of a containing compound is 0.09-5 mass parts with respect to a total of 100 mass parts of a film formation material and a radically polymerizable compound.

  The film-forming material is a material that solidifies a liquid material and forms a constituent composition into a film shape, so that the film is easy to handle and imparts mechanical properties that do not easily tear, crack, or stick. Yes, it can be handled as a film in a normal state. Examples of the film forming material include polyvinyl formal resin, polystyrene resin, polyvinyl butyral resin, polyester resin, polyester urethane resin, polyamide resin, polyurethane resin, polyamideimide resin, polyimide resin, xylene resin, and phenoxy resin. The film forming material may be modified with a radical polymerizable functional group.

  The film-like circuit connecting material of the present invention preferably contains an organic compound having a urethane bond (hereinafter sometimes referred to as “urethane compound”) as a film-forming material from the viewpoint that it is more excellent in adhesiveness. In addition, it is preferable that a urethane compound has a urethane bond in the principal chain, and it is more preferable to have an ester bond with a urethane bond.

  This urethane compound is obtained, for example, by a reaction between a polyester polyol and diisocyanate. The urethane compound obtained by this reaction is generally sometimes referred to as a polyester urethane resin.

  Diisocyanates include 2,4-tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and aromatic and alicyclic rings. An aliphatic or aliphatic diisocyanate is preferably used.

  The polyester polyol is obtained, for example, by a reaction between a dicarboxylic acid and a diol. As the dicarboxylic acid, aromatic or aliphatic dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, and sebacic acid are preferable. As the diol, glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, hexanediol, neopentyl glycol, diethylene glycol, and triethylene glycol are preferable.

  The urethane compound preferably has a weight average molecular weight of 10,000 or more. When the weight average molecular weight of the urethane compound is less than 10,000, the film formability tends to decrease. In addition, the upper limit of the weight average molecular weight of the urethane compound is not particularly limited, but if the weight average molecular weight is too high, the solubility in the solvent and the compatibility are reduced, and a coating liquid for molding into a film is obtained. Since it tends to be difficult to prepare, about 200,000 is preferable.

  The weight average molecular weight in this specification is measured by gel permeation chromatography (GPC) analysis according to the conditions shown in Table 1, and is determined by conversion using a standard polystyrene calibration curve. GPC condition 1 is a condition for measuring the weight average molecular weight of the polyimide resin, and GPC condition 2 is a condition for measuring the weight average molecular weight of an organic compound other than the polyimide resin.

  The radically polymerizable compound has a functional group capable of radical polymerization. As the radically polymerizable compound, for example, a (meth) acrylic acid compound, a maleimide compound or a styrene derivative is preferably used. These radically polymerizable compounds may be any of a polymerizable monomer and a polymerizable oligomer, and a polymerizable monomer and a polymerizable oligomer can be used in combination. Since the polymerizable oligomer generally has a high viscosity, when the polymerizable oligomer is used, it is preferable to adjust the viscosity by using a polymerizable monomer such as a polymerizable polyfunctional (meth) acrylate having a low viscosity.

  Examples of (meth) acrylic acid compounds include photopolymerizable oligomers such as epoxy (meth) acrylate oligomers, urethane (meth) acrylate oligomers, polyether (meth) acrylate oligomers, and polyester (meth) acrylate oligomers, and trimethylolpropane tri (Meth) acrylate, polyethylene glycol di (meth) acrylate, polyalkylene glycol di (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, isocyanuric acid modified bifunctional (meth) acrylate, isocyanuric acid modified trifunctional (meth) acrylate, 2,2'-di Polyfunctional (meth) acrylate compounds such as (meth) acryloyloxydiethyl phosphate and 2- (meth) acryloyloxyethyl acid phosphate, pentaerythritol (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyclohexyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (Meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) Acrylate, 2-phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, neopentyl glycol di (meth) acrylate, t-butylaminoethyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxy Ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, n-lauryl (meth) acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, and glycidyl ( And (meth) acrylate.

  A (meth) acrylic acid compound is used individually by 1 type or in combination of 2 or more types. In order to suppress the curing shrinkage of the circuit connecting material and to provide flexibility, it is preferable to add a urethane (meth) acrylate oligomer.

  As the maleimide compound, those containing two or more maleimide groups in the molecule are preferable. Specific examples thereof include 1-methyl-2,4-bismaleimide benzene, N, N′-m-phenylene bismaleimide, N, N′-p-phenylene bismaleimide, N, N′-m-toluylene bis. Maleimide, N, N′-4,4-biphenylenebismaleimide, N, N′-4,4- (3,3′-dimethyl-biphenylene) bismaleimide, N, N′-4,4- (3,3 '-Dimethyldiphenylmethane) bismaleimide, N, N'-4,4- (3,3'-diethyldiphenylmethane) bismaleimide, N, N'-4,4-diphenylmethane bismaleimide, N, N'-4,4 -Diphenylpropane bismaleimide, N, N'-4,4-diphenyl ether bismaleimide, N, N'-3,3'-diphenylsulfone bismaleimide, 2,2-bis [ -(4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl Decane, 4,4′-cyclohexylidene-bis [1- (4-maleimidophenoxy) -2-cyclohexylbenzene] and 2,2-bis [4- (4-maleimidophenoxy) phenyl] hexafluoropropane. It is done.

  A maleimide compound is used individually by 1 type or in combination of 2 or more types.

ここで、ｎは１〜３の整数を示す。The film-like circuit connecting material of the present invention preferably contains a phosphate ester type (meth) acrylate as a radically polymerizable compound for the purpose of improving adhesiveness. By containing the phosphoric ester type (meth) acrylate, the film-like circuit connecting material is improved particularly in adhesion to an inorganic material such as a metal. As the phosphate ester type (meth) acrylate, known ones can be used without particular limitation. Specific examples thereof include compounds represented by the following general formula (2).

Here, n shows the integer of 1-3.

  Generally, phosphoric ester type (meth) acrylate is obtained as a reaction product of phosphoric anhydride and 2-hydroxyethyl (meth) acrylate. Specific examples of the phosphate ester type (meth) acrylate include mono (2-methacryloyloxyethyl) acid phosphate and di (2-methacryloyloxyethyl) acid phosphate. These are used singly or in combination of two or more.

  The film-like circuit connecting material of the present invention can contain allyl (meth) acrylate from the viewpoint of being more excellent in adhesiveness. The mixing ratio of allyl (meth) acrylate is preferably 0.1 to 10 parts by mass, and 0.5 to 5 parts by mass with respect to 100 parts by mass in total of the film forming material and the radical polymerizable compound. It is more preferable.

  Moreover, as a radical polymerization initiator that generates free radicals upon heating, conventionally known peroxide compounds (organic peroxides) and azo compounds are used.

  Organic peroxides and azo compounds generate free radicals mainly by heating. When these compounds are used as radical polymerization initiators, one or more organic peroxides and / or azo compounds are used as the desired connection temperature, connection time, pot life (hereinafter referred to as “pot life”). Etc.).

  The organic peroxide is preferably an organic peroxide having a 10-hour half-life temperature of 40 ° C. or higher and a 1-minute half-life temperature of 180 ° C. or lower from the viewpoint of achieving both high reactivity and a long pot life. An organic peroxide having a 10-hour half-life temperature of 60 ° C. or higher and a 1-minute half-life temperature of 170 ° C. or lower is more preferable. The organic peroxide preferably has a chlorine ion or organic acid content of 5000 ppm by mass or less in order to prevent corrosion of the circuit electrode (connection terminal) of the circuit member. Further, the organic peroxide is more preferably one that generates less organic acid after thermal decomposition.

  Specifically, the organic peroxide is one or more selected from the group consisting of diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide and silyl peroxide. Organic peroxides are preferred. Among these, from the viewpoint of achieving both high storage stability during storage and high reactivity during use, it is selected from the group consisting of peroxyesters, peroxyketals, dialkyl peroxides, hydroperoxides, and silyl peroxides. One or more organic peroxides are more preferred. Furthermore, the organic peroxide is more preferably a peroxyester and / or a peroxyketal in that higher reactivity can be obtained.

  Examples of the diacyl peroxide include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, and succinic peroxide. , Benzoylperoxytoluene and benzoyl peroxide. These are used singly or in combination of two or more.

  Examples of the dialkyl peroxide include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and t. -Butyl cumyl peroxide is mentioned. These are used singly or in combination of two or more.

  Examples of peroxydicarbonate include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, Bis (2-ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate and bis (3-methyl-3-methoxybutylperoxy) dicarbonate are mentioned. These are used singly or in combination of two or more.

  Examples of peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t -Hexylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis ( 2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethyl Hexanoate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclo Xane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis (m- Toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, t-butylperoxyacetate and bis (t-butylperoxy) Hexahydroterephthalate is mentioned. These are used singly or in combination of two or more.

  Examples of peroxyketals include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis ( t-Butylperoxy) -3,3,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane and 2,2-bis (t-butylperoxy) decane. These are used singly or in combination of two or more.

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide. These are used singly or in combination of two or more.

  Examples of the silyl peroxide include t-butyltrimethylsilyl peroxide, bis (t-butyl) dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis (t-butyl) divinylsilyl peroxide, tris (t- Butyl) vinylsilyl peroxide, t-butyltriallylsilyl peroxide, bis (t-butyl) diallylsilyl peroxide, and tris (t-butyl) allylsilyl peroxide. These are used singly or in combination of two or more.

  When these organic peroxides are used, a combination of a decomposition accelerator, an inhibitor and the like may be used. Further, these organic peroxides are preferably microencapsulated by being coated with a polyurethane-based or polyester-based polymer substance because the pot life is extended.

  Examples of the azo compound include 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (1-acetoxy-1-phenylethane), and 2,2′-azobisisobutyrate. Ronitrile, 2,2′-azobis (2-methylbutyronitrile), dimethyl-2,2′-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid) and 1,1′- Azobis (1-cyclohexanecarbonitrile) is mentioned. These are used singly or in combination of two or more.

  Usually, it is preferable that the mixture ratio of a radical polymerization initiator is 0.05-20 mass parts with respect to a total of 100 mass parts of a film formation material and a radically polymerizable compound, and is 0.1-10 mass parts. It is more preferable. When the blending ratio of the radical polymerization initiator is less than 0.05 parts by mass, the reaction rate decreases, so that the film-like circuit connecting material tends to be hard to be cured. When the blending ratio of the radical polymerization initiator exceeds 20 parts by mass, the pot life tends to be shortened. In addition, the mixture ratio of a radical polymerization initiator can be suitably set with the target connection temperature, connection time, pot life, etc. For example, when the connection time is 25 seconds or less, in order to obtain a sufficient reaction rate, the blending ratio of the radical polymerization initiator is 2 to 2 parts by mass with respect to a total of 100 parts by mass of the film forming material and the radical polymerizable compound. The amount is preferably 10 parts by mass, and more preferably 4 to 8 parts by mass.

  The isocyanate group-containing compound is not particularly limited as long as it is a compound having an isocyanate group in the molecule. Examples of the isocyanate group-containing compound include monoisocyanate compounds such as p-toluenesulfonyl isocyanate, octadecyl isocyanate, (meth) acryloyl isocyanate, and γ-triisocyanatopropyltriethoxysilane, 2,4-tolylene diisocyanate, 2,6- Diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane-4,4-diisocyanate, various polyether polyols, polyester polyols, polyamides, etc. The compound which has is mentioned. As a diisocyanate compound, it can obtain as a commercial item, for example, the brand names "Coronate L", "Millionate MR", "Coronate EH", and "Coronate HL" by Nippon Polyurethane Industry can be used. From the viewpoint of further improving the adhesion to the adherend, it is preferable that the isocyanate group-containing compound has a highly reactive polar group such as a hydroxyl group, a nitrile group, or a carboxyl group at the terminal. Furthermore, when the isocyanate group-containing compound has an alkoxysilyl group such as a trimethoxysilyl group or a triethoxysilyl group, these groups form a chemical bond with the adsorbed water on the adherend surface and can be firmly bonded. Therefore, it is more preferable.

  The content ratio of the isocyanate group-containing compound is 0.09 to 5 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass in total of the film-forming material and the radical polymerizable compound. More preferably, it is 0.5-3 mass parts. When the content ratio of the isocyanate group-containing compound is less than 0.09 parts by mass, sufficient adhesiveness is hardly obtained, and when it exceeds 5 parts by mass, the pot life tends to be shortened.

  Moreover, it is preferable that the film-form circuit connection material of this invention contains a fluorine-containing organic compound as an adhesive agent component. As a fluorine-containing organic compound, what is necessary is just a compound which has a fluorine in a molecule | numerator, a well-known thing may be sufficient, and the film forming material or radical polymerizable compound mentioned above may have a fluorine atom. Specifically, for example, fluorine-containing polyvinyl butyral resin, fluorine-containing polyvinyl formal resin, fluorine-containing polyimide resin, fluorine-containing polyamide resin, fluorine-containing polyamideimide resin, fluorine-containing polyester resin, fluorine-containing phenol resin, fluorine-containing epoxy resin, Fluorine-containing phenoxy resin, fluorine-containing polyurethane resin, fluorine-containing polyester urethane resin, fluorine-containing polyarylate resin, fluorine-containing styrene resin, fluorine-containing silicone resin, fluorine-containing acrylic rubber, fluorine-containing nitrile rubber, fluorine-containing NBR, and fluorine-containing SBS Can be mentioned. These are used individually or in mixture of 2 or more types. When the film-like circuit connecting material contains these fluorine-containing organic compounds, better adhesiveness is exhibited regardless of the material of the circuit member, the change in transferability with time is suppressed, and transferability is excellent.

  The weight average molecular weight of the fluorine-containing organic compound is preferably from 5,000 to 1,000,000, more preferably from 20,000 to 200,000, from the viewpoint of excellent stress relaxation during curing and further improved adhesiveness. When the weight average molecular weight of the fluorine-containing organic compound is less than 5,000, the film formability tends to be insufficient, and when the weight average molecular weight exceeds 1,000,000, the compatibility with other components tends to be poor.

  Furthermore, the film-like circuit connecting material of the present invention can contain acrylic rubber in order to be excellent in stress relaxation. As the acrylic rubber, a polymer or copolymer obtained by polymerizing at least one acrylic monomer of acrylic acid, (meth) acrylic acid ester or acrylonitrile is used. The acrylic rubber may be a copolymer of the above monomer and glycidyl (meth) acrylate having a glycidyl ether group. The weight average molecular weight of the acrylic rubber is preferably 200000 or more from the viewpoint of increasing the cohesive strength of the film-like circuit connecting material.

  In addition to the above-described materials, another material may be added to the film-like circuit connecting material of the present invention as an adhesive component depending on the purpose of use. For example, an adhesion assistant such as a coupling agent, an adhesion improver, and a leveling agent may be appropriately added to the film-like circuit connecting material. As a result, it is possible to impart even better adhesiveness and handleability.

  As the coupling agent, a ketimine, vinyl group, acrylic group, amino group, epoxy group and isocyanate group-containing material can be preferably used from the viewpoint of improving adhesiveness. Specifically, as a silane coupling agent having an acrylic group, (3-methacryloxypropyl) trimethoxysilane, (3-acryloxypropyl) trimethoxysilane, (3-methacryloxypropyl) dimethoxymethylsilane, (3 -Acryloxypropyl) dimethoxymethylsilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ as a silane coupling agent having an amino group -Aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane. Examples of the silane coupling agent having ketimine include those obtained by reacting the above silane coupling agent having an amino group with a ketone compound such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Moreover, as a silane coupling agent having an epoxy group, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, γ-glycidyloxypropyl-methyldimethoxysilane, γ-glycidyloxypropyl-methyldiethoxysilane Is mentioned.

  As for the mixture ratio of a coupling agent, 0.1-20 mass parts is preferable with respect to a total of 100 mass parts of the other compound in a circuit connection material. When the blending ratio of the coupling agent is less than 0.1 parts by mass, there is a tendency that a substantial addition effect cannot be obtained. Moreover, when the compounding ratio of the coupling agent exceeds 20 parts by mass, the film formability of the adhesive layer when the adhesive layer made of the circuit connecting material is formed on the supporting base material tends to decrease, and the film thickness strength tends to decrease. is there.

  Even if the film-like circuit connecting material of the present invention does not contain conductive particles, connection can be obtained by direct contact between circuit electrodes facing each other at the time of connection. However, it is preferable that the film-like circuit connecting material contains conductive particles because a more stable connection between circuit electrodes can be obtained.

  In the present invention, the conductive particles included as necessary are not particularly limited as long as they have electrical conductivity capable of obtaining electrical connection. Examples of the conductive particles include metal particles such as Au, Ag, Ni, Cu, and solder, and carbon. Further, the conductive particles may be one in which the core particles are covered with one layer or two or more layers, and the outermost layer has conductivity. In this case, from the viewpoint of obtaining a superior pot life, the outermost layer is preferably composed mainly of a noble metal such as Au, Ag and / or a platinum group metal rather than a transition metal such as Ni or Cu. More preferably, it consists of at least one kind of noble metal. Of these noble metals, Au is most preferable.

  The conductive particles are formed by coating the surface of a particle mainly composed of transition metal as a nucleus or a layer mainly composed of transition metal covering the nucleus with a layer mainly composed of noble metal. Also good. In addition, the conductive particles have insulating particles mainly composed of non-conductive glass, ceramics, plastics, etc. as the core, and the surface of the core is coated with a layer mainly composed of the metal or carbon. May be.

  In the case where the conductive particles are formed by coating nuclei that are insulating particles with a conductive layer, the insulating particles are mainly composed of plastic, and the outermost layer is composed mainly of a noble metal. And preferred. Thereby, the electroconductive particle in a film-form circuit connection material can deform | transform favorably with respect to a heating and pressurization. In addition, the contact area between the conductive particles and the circuit electrodes and connection terminals increases when connecting the circuit and the like. Therefore, the connection reliability of the film-like circuit connection material can be further improved. From the same point of view, the conductive particles are preferably particles containing as a main component a metal that is melted by the heating.

  In the case where the conductive particles are formed by covering nuclei that are insulating particles with a conductive layer, the thickness of the conductive layer is preferably 100 mm (10 nm) or more in order to obtain better conductivity. Further, the conductive particles are formed by coating the surface of a layer mainly composed of a transition metal as a nucleus or a layer mainly composed of a transition metal covering the nucleus with a layer mainly composed of a noble metal. In some cases, the thickness of the outermost layer mainly composed of the noble metal is preferably 300 mm (30 nm) or more. When this thickness is less than 300 mm, the outermost layer is easily broken. As a result, the exposed transition metal comes into contact with the adhesive component, and free radicals are easily generated due to the redox action of the transition metal, so that the pot life tends to be easily reduced. On the other hand, since the effect is saturated when the thickness of the conductive layer is increased, the thickness is preferably 1 μm or less.

  When the film-like circuit connecting material contains conductive particles, the blending ratio of the conductive particles is not particularly limited, but is 0.1 to 30 parts by volume with respect to 100 parts by volume of the adhesive component in the film-like circuit connecting material. It is preferable that it is a volume part, and it is more preferable that it is 0.1-10 volume part. If this value is less than 0.1 part by volume, good conductivity tends to be difficult to obtain, and if it exceeds 30 parts by volume, short circuits such as circuits tend to occur. In addition, the mixture ratio (volume part) of electroconductive particle is determined based on the volume of each component before hardening the film-form circuit connection material in 23 degreeC. The volume of each component is a method of converting from weight to volume using specific gravity, or a female containing an appropriate solvent (water, alcohol, etc.) that does not dissolve or swell the component but wets the component well The component can be obtained by charging the component into a container such as a cylinder and calculating from the increased volume. Further, when the film-like circuit connecting material is divided into two or more layers and divided into a layer containing a radical polymerization initiator and a layer containing conductive particles, an improvement in pot life can be obtained.

  The film-like circuit connecting material according to the present invention may contain rubber. As a result, stress can be relaxed and adhesion can be improved. The rubber fine particles have an average particle size of not more than twice the average particle size of the conductive particles to be blended, and the storage elastic modulus at room temperature (25 ° C.) at the room temperature of the conductive particles and the circuit connecting material. What is necessary is just to be 1/2 or less of storage elastic modulus. In particular, it is preferable that the fine particles whose material of the rubber fine particles is silicone, acrylic emulsion, SBR, NBR, or polybutadiene rubber are used alone or in admixture of two or more. These three-dimensionally crosslinked rubber fine particles have excellent solvent resistance and are easily dispersed in the film-like circuit connecting material.

  The film-like circuit connection material composed of the above-mentioned components is one in which the adhesive component in the circuit connection material melts and flows at the time of connection of the circuit member, and after being connected to the opposite circuit member, it is cured to maintain the connection. It is. For this reason, the fluidity of the film-like circuit connecting material is an important factor.

  For example, when a circuit connecting material having a thickness of 35 μm and a thickness of 5 mm × 5 mm is sandwiched between a glass plate having a thickness of 0.7 mm and 15 mm × 15 mm, and heated and pressed at 150 ° C. and 2 MPa for 10 seconds, the initial area (A ) And the area (B) after heating and pressurization, the value of fluidity (B) / (A) is preferably 1.3 to 3.0, and 1.5 to 2. 5 is more preferable. When the value of (B) / (A) is less than 1.3, there is a tendency that good circuit member connection cannot be obtained due to poor fluidity. On the other hand, when the value of (B) / (A) exceeds 3.0, bubbles are likely to be generated and connection reliability tends to be inferior.

  The elastic modulus at 40 ° C. after curing of the film-like circuit connecting material is preferably 100 to 3000 MPa, and preferably 500 to 2000 MPa from the viewpoint of stabilization of connection resistance and maintaining connection reliability at high temperature and high humidity. Is more preferable.

  Furthermore, a stabilizer can be added to the film-like circuit connecting material in order to control the curing rate and to provide storage stability. Furthermore, a filler, a softening agent, an accelerator, an anti-aging agent, a colorant, a flame retardant, a thixotropic agent, a phenol resin, a melamine resin, and the like may be blended in the film-like circuit connecting material.

  The film-like circuit connecting material is preferable when it contains a filler (filler) because it improves connection reliability and the like. The filler can be used if it has insulating properties and its maximum diameter is less than the average particle diameter of the conductive particles. The blending ratio of the filler is preferably 5 to 60 parts by volume with respect to 100 parts by volume of the adhesive component. When the blending ratio of the filler exceeds 60 parts by volume, the effect of improving the reliability tends to be saturated, and when it is less than 5 parts by volume, the effect of adding the filler tends to be small.

  The film-like circuit connecting material of the present invention is obtained by forming a circuit connecting material containing the above-described components into a film shape. This film-like circuit connecting material is placed on a supporting substrate by applying a mixed solution obtained by adding a solvent or the like to the circuit connecting material on a supporting substrate, or impregnating the mixed solution into a substrate such as a nonwoven fabric. It can be obtained by removing the solvent and the like.

  As the supporting substrate used, a sheet-like or film-like one is preferable. Further, the support substrate may have a shape in which two or more layers are laminated. Examples of the supporting substrate include a polyethylene terephthalate (PET) film, an oriented polypropylene (OPP) film, a polyethylene (PE) film, and a polyimide film. Among these, PET film is preferable from the viewpoint of improvement in dimensional accuracy and cost reduction.

  The above-mentioned film-like circuit connecting material can also be used as a circuit connecting material for different types of adherends having different thermal expansion coefficients. Specifically, in addition to film-like circuit connection materials represented by anisotropic conductive adhesive films, silver films, etc., semiconductor device adhesive materials represented by CSP elastomers, CSP underfill materials, LOC tapes, etc. Can be used.

(Circuit member connection structure)
FIG. 1 is a schematic sectional view showing an embodiment of a circuit member connection structure according to the present invention. The circuit member connection structure 1 shown in FIG. 1 includes a first circuit member 20 and a second circuit member 30 that face each other, and is between the first circuit member 20 and the second circuit member 30. Are provided with a circuit connecting portion 10 for connecting them.

  The first circuit member 20 includes a first circuit board 21 and a first circuit electrode 22 formed on the main surface 21 a of the first circuit board 21. The second circuit member 30 includes a second circuit board 31 and a second circuit electrode 32 formed on the main surface 31 a of the second circuit board 31. An insulating layer (not shown) may be formed on the main surface 21 a of the first circuit board 21 and / or the main surface 31 a of the second circuit board 31 in some cases. That is, the insulating layer is formed between at least one of the first circuit member 20 and the second circuit member 30 and the circuit connection portion 10.

  Examples of the first and second circuit boards 21 and 31 include semiconductors, glass, ceramics and other inorganic materials, TCP, FPC, COF, polyimide base, polycarbonate, polyethylene terephthalate, polyethersulfone, epoxy resin, acrylic Examples thereof include substrates made of organic materials such as resins, and materials obtained by combining these inorganic materials and organic materials. From the viewpoint of further improving the adhesiveness with the circuit connection portion 10, at least one of the first and second circuit boards is selected from the group consisting of polyethylene terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin, and glass. It is preferable that the substrate is made of a material containing at least one of the above.

  In the case where an insulating layer is formed, the insulating layer is preferably a layer containing at least one selected from the group consisting of silicon nitride, silicone resin, polyimide resin, and acrylic resin. Thereby, the adhesiveness of the 1st circuit board 21 and / or the 2nd circuit board 31 and the circuit connection part 10 improves further compared with the thing in which the said layer is not formed.

  At least one of the first circuit electrode 22 and the second circuit electrode 32 is made of a material whose surface includes at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide. It is preferable to become. Thereby, the resistance value between the circuit electrodes 22 and 33 which oppose can be reduced further, maintaining insulation between the circuit electrodes 22 or 32 adjacent on the same circuit member 20 or 30. FIG.

  Specific examples of the first and second circuit members 20 and 30 include a glass substrate or a plastic substrate on which circuit electrodes are formed of ITO or the like, a printed wiring board, a ceramic wiring board, a flexible, used for a liquid crystal display. A wiring board, a semiconductor silicon chip, etc. are mentioned. These are used in combination as necessary.

  The circuit connection part 10 is formed from the hardened | cured material of the said film-form circuit connection material containing electroconductive particle. The circuit connection part 10 is comprised from the hardened | cured material 11 of the adhesive agent component contained in a circuit connection material, and the electroconductive particle 7 currently disperse | distributed in the hardened | cured material 11 of an adhesive agent component. The conductive particles 7 in the circuit connection part 10 are arranged not only between the first circuit electrode 22 and the second circuit electrode 32 facing each other but also between the main surfaces 21a and 31a. In the circuit member connection structure 1, the conductive particles 7 are in direct contact with both the first and second circuit electrodes 22 and 32. Thereby, the first and second circuit electrodes 22 and 32 are electrically connected via the conductive particles 7. For this reason, the connection resistance between the 1st circuit electrode 22 and the 2nd circuit electrode 32 is fully reduced, maintaining the insulation between the circuit electrodes which adjoin on the same circuit member. Therefore, the flow of current between the first and second circuit electrodes 22 and 32 can be made smooth, and the functions of the circuit can be fully exhibited. In addition, when the circuit connection part 10 does not contain the electroconductive particle 7, the 1st circuit electrode 22 and the 2nd circuit electrode 32 are electrically connected by contacting directly.

  Since the circuit connection portion 10 is made of a cured product of the film-like circuit connection material as will be described later, the adhesive force of the circuit connection portion 10 to the first circuit member 20 and the second circuit member 30 is sufficient. Very expensive.

(Method for manufacturing circuit member connection structure)
FIG. 2 is a process diagram schematically showing a cross-sectional view of an embodiment of a method for manufacturing a circuit member connection structure according to the present invention.

  In this embodiment, first, the first circuit member 20 and the film-like circuit connecting material 40 described above are prepared. The film-like circuit connecting material 40 comprises an adhesive component 5 and conductive particles 7 containing a film forming material, a radical polymerizable compound, a radical polymerization initiator that generates free radicals upon heating, and an isocyanate group-containing compound. Including.

  A circuit connecting material that does not contain the conductive particles 7 can also be used. In this case, the circuit connection material may be called NCP (Non Conductive Paste). On the other hand, the circuit connection material containing the conductive particles 7 may be called ACP (Anisotropic Conductive Paste).

  The thickness of the film-like circuit connecting material 40 is preferably 5 to 50 μm. If the thickness of the film-like circuit connecting material 40 is less than 5 μm, the film-like circuit connecting material 40 tends to be insufficiently filled between the first and second circuit electrodes 22 and 32. On the other hand, when it exceeds 50 μm, it tends to be difficult to ensure conduction between the first and second circuit electrodes 22 and 32.

  Next, the film-like circuit connecting material 40 is placed on the surface of the first circuit member 20 on which the circuit electrodes 22 are formed. And the film-form circuit connection material 40 is pressurized to the arrow A and B direction of Fig.2 (a), and the film-form circuit connection material 40 is temporarily connected to the 1st circuit member 20 (FIG.2 (b)).

  Although the pressure at this time will not be restrict | limited especially if it is a range which does not damage a circuit member, Generally it is preferable to set it as 0.1-30 Mpa. Moreover, you may pressurize, heating, and let heating temperature be the temperature which the film-form circuit connection material 40 does not harden | cure substantially. In general, the heating temperature is preferably 50 to 190 ° C. These heating and pressurization are preferably performed in the range of 0.5 to 120 seconds.

  Next, as shown in FIG. 2C, the second circuit member 30 is placed on the film-like circuit connection material 40 so that the second circuit electrode 32 faces the first circuit member 20 side. When the film-like circuit connection material 40 is provided in close contact with a support base (not shown), the second circuit member 30 is removed from the support base after the second base member 30 is peeled off. 40. And the whole is pressurized in the arrow A and B direction of FIG.2 (c), heating the film-form circuit connection material 40. FIG. In addition, the film-like circuit connecting material 40 has a sufficiently long pot life even when left on the support base material, and maintains sufficiently high adhesion to the circuit member. .

  The heating temperature is, for example, 90 to 200 ° C., and the connection time is, for example, 1 second to 10 minutes. These conditions are appropriately selected depending on the intended use, the film-like circuit connecting material, and the circuit member, and may be post-cured as necessary. For example, the heating temperature when the film-like circuit connecting material contains a radically polymerizable compound is a temperature at which the radical polymerization initiator can generate radicals. As a result, radicals are generated in the radical polymerization initiator, and polymerization of the radical polymerizable compound is started.

  By heating the film-like circuit connecting material 40, the film-like circuit connecting material 40 is cured in a state where the distance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently small, and the first circuit The member 20 and the second circuit member 30 are firmly connected via the circuit connection portion 10.

  The circuit connection portion 10 is formed by curing the film-like circuit connection material 40, and a circuit member connection structure 1 as shown in FIG. 1 is obtained. The connection conditions are appropriately selected depending on the application to be used, the film-like circuit connection material, and the circuit member.

  According to the present embodiment, in the obtained circuit member connection structure 1, the conductive particles 7 can be brought into contact with both the first and second circuit electrodes 22 and 32 facing each other, and on the same circuit member. The connection resistance between the first and second circuit electrodes 22 and 32 facing each other can be sufficiently reduced while maintaining insulation between adjacent circuit electrodes. And since the circuit connection part 10 is comprised with the hardened | cured material of the said film-form circuit connection material, the adhesive force of the circuit connection part 10 with respect to the 1st and 2nd circuit member 20 or 30 will become a thing high enough. .

  As mentioned above, although preferred embodiment of this invention was described, this invention is not restrict | limited to this. The present invention can be variously modified without departing from the gist thereof.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

(Preparation of conductive particles)
A layer made of nickel having a thickness of 0.2 μm was provided on the surface of the polystyrene particles, and a layer made of gold having a thickness of 0.04 μm was further provided on the surface of the layer made of nickel. Thus, conductive particles having an average particle diameter of 10 μm were obtained.

(Adjustment of urethane acrylate)
400 parts by mass of polycaprolactone diol having a weight average molecular weight of 800, 131 parts by mass of 2-hydroxypropyl acrylate, 0.5 parts by mass of dibutyltin dilaurate as a catalyst and 1.0 part by mass of hydroquinone monomethyl ether as a polymerization inhibitor The mixture was stirred while heating. Next, 222 parts by mass of isophorone diisocyanate was added dropwise, and the temperature was raised to 80 ° C. while stirring to advance the urethanization reaction. After confirming that the reaction rate of the isocyanate group was 99% or more, the temperature was lowered to obtain urethane acrylate.

(Preparation of polyester urethane resin)
Polyester polyol was obtained by reaction of terephthalic acid as digalbonic acid and propylene glycol as diol. This polyester polyol was dissolved in methyl ethyl ketone (MEK) to obtain a solution. The obtained solution was put into a stainless steel autoclave equipped with a heater equipped with a stirrer, a thermometer, a condenser, a vacuum generator, and a nitrogen gas introduction tube. Next, a predetermined amount of 4,4′-diphenylmethane diisocyanate is added as an isocyanate to the autoclave, and dibutyltin laurate is added as a catalyst in an amount of 0.02 parts by mass with respect to 100 parts by mass of the polyester polyol. After reacting for 10 hours, the mixture was cooled to 40 ° C. Further, piperazine was added and reacted for 30 minutes to extend the chain, and then neutralized with triethylamine.

  When the solution after the reaction was dropped into pure water, the solvent and the catalyst were dissolved in water, and the polyester urethane resin was precipitated. And the precipitated polyester urethane resin was dried with the vacuum dryer. It was 27000 when the weight molecular weight of the polyester urethane resin was measured by GPC analysis. In preparing the polyester urethane resin, the blending molar ratio of terephthalic acid / propylene glycol / 4,4′-diphenylmethane diisocyanate was 1.0 / 1.3 / 0.25.

(Adjustment of phenoxy resin)
50 g of phenoxy resin (trade name “PKHC”, manufactured by Union Carbide Corporation, weight average molecular weight: 45000) in terms of mass ratio is toluene (boiling point 110.6 ° C., SP value 8.90) / ethyl acetate (boiling point 77.1 ° C., It was dissolved in a mixed solvent of SP value 9.10) = 50/50 to obtain a solution having a solid content of 40% by mass.

(Preparation of fluorine-containing polyimide resin)
A 1000 mL separable flask equipped with a Dean-Stark reflux condenser, a thermometer, and a stirrer was prepared. There, 15.0 mmol of polyoxypropylenediamine as a diamine compound, 105.0 mmol of 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, and 287 g of N-methyl-2-pyrrolidone as an aprotic polar solvent And stirred at room temperature (25 ° C.) for 30 minutes. Next, 180 g of toluene is added as an aromatic hydrocarbon-based organic solvent azeotropic with water, and 114.0 mmol of 4,4′-hexafluoropropylidenebisphthalic dianhydride is added as a tetracarboxylic dianhydride, up to 50 ° C. The temperature was raised and the mixture was stirred at that temperature for 1 hour, and further heated to 160 ° C. and refluxed for 3 hours. After confirming that the theoretical amount of water has accumulated in the moisture determination receiver and that no water has flowed out, remove the water and toluene in the moisture determination receiver, and raise the temperature to 180 ° C. Then, an NMP solution of polyimide resin was obtained.

  The NMP solution of the polyimide resin was put into methanol, and the precipitate was collected, then pulverized and dried to obtain a fluorine-containing polyimide resin. The obtained fluorine-containing polyimide resin also had a weight average molecular weight of 112,000. The fluorine-containing polyimide resin was dissolved in methyl ethyl ketone so as to be 40% by mass.

  The circuit connection materials of Examples and Comparative Examples were adjusted at the blending ratios (parts by mass: solid content conversion) shown in Tables 2 and 3 below, and film-like circuit connection materials were produced.

Example 1
60 parts by mass of a polyester urethane resin as a film-forming material, 40 parts by mass of the urethane acrylate as a radical polymerizable compound, and 1 part by mass of a phosphate ester acrylate (manufactured by Kyoeisha Yushi Co., Ltd., trade name “P2M”), methacryloyl as an isocyanate group-containing compound 0.5 parts by mass of isocyanate and 5 parts by mass of t-hexylperoxy-2-ethylhexanoate as a radical polymerization initiator were mixed. Next, 3% by volume of the conductive particles were mixed and dispersed with respect to 100 parts by volume of the component to prepare a circuit connecting material. Next, this circuit connecting material was applied to a PET film having a surface treated on one side having a thickness of 80 μm using a coating apparatus to obtain a coating film. Next, the coating film was dried with hot air at 70 ° C. for 10 minutes to obtain a film-like circuit connecting material having a thickness of 20 μm.

(Example 2)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 0.5 part by mass of hexamethylene diisocyanate was used instead of 0.5 part by mass of methacryloyl isocyanate.

(Example 3)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 0.5 part by mass of γ-isocyanatopropyltriethoxysilane was used instead of 0.5 part by mass of methacryloyl isocyanate.

Example 4
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 0.1 part by mass of γ-isocyanatopropyltriethoxysilane was used instead of 0.5 part by mass of methacryloyl isocyanate.

(Example 5)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 3 parts by mass of γ-isocyanatopropyltriethoxysilane was used instead of 0.5 parts by mass of methacryloyl isocyanate.

(Example 6)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 5 parts by mass of γ-isocyanatopropyltriethoxysilane was used instead of 0.5 parts by mass of methacryloyl isocyanate.

(Example 7)
A film-like circuit connecting material was obtained in the same manner as in Example 5 except that 60 parts by mass of the phenoxy resin was used instead of 60 parts by mass of the polyester urethane resin.

(Example 8)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 55 parts by mass of polyester urethane resin and 5 parts by mass of fluorine-containing polyimide resin were used instead of 60 parts by mass of polyester urethane resin.

(Comparative Example 1)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that methacryloyl isocyanate was not used.

(Comparative Example 2)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 0.05 part by mass of γ-isocyanatopropyltriethoxysilane was used instead of 0.5 part by mass of methacryloyl isocyanate.

(Comparative Example 3)
A film-like circuit connecting material was obtained in the same manner as in Example 1 except that 7.5 parts by mass of γ-isocyanatopropyltriethoxysilane was used instead of 0.5 parts by mass of methacryloyl isocyanate.

<Production of circuit member connection structure>
A three-layer flexible substrate in which 500 copper circuit wiring lines having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm are formed on a polyimide film A (Ube Industries, trade name “UPILEX”, thickness of 75 μm) via an adhesive layer. 1 (FPC board 1) was prepared. In addition, a two-layer flexible substrate 2 (FPC substrate 2) in which 500 copper circuit wires having a line width of 50 μm, a pitch of 100 μm, and a thickness of 8 μm are directly formed on a polyimide film B (trade name “UPILEX”, thickness 25 μm, manufactured by Ube Industries). ) Was prepared. Furthermore, a glass substrate was prepared in which 500 chrome circuit wires having a line width of 50 μm, a pitch of 100 μm, and a thickness of 0.4 μm were directly formed on glass (product name “# 1737” manufactured by Corning).

  Subsequently, the film-like circuit connecting material obtained as described above was disposed between each of the FPC substrates and the glass substrate. Then, using a thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.), heating and pressurization were performed for 10 seconds in the stacking direction under the conditions of 160 ° C. and 3 MPa. Thus, a circuit member connection structure in which the FPC substrate and the glass substrate were electrically connected with a cured product of the circuit connection material over a width of 2 mm was produced. The circuit member connection structure thus produced was used as an initial characteristic evaluation sample.

[Evaluation of adhesion]
As shown below, the adhesiveness is measured by measuring the connection resistance and adhesive strength between circuits in the circuit member connection structure produced as described above, and observing the connection appearance in the circuit member connection structure. evaluated. In addition, as for the sample for initial characteristic evaluation, a sample having excellent connection resistance, adhesive strength, and connection appearance is sufficiently excellent in adhesiveness.

<Measurement of connection resistance>
The connection resistance was measured with a multimeter (trade name: TR6848, manufactured by Advantest Corporation), and indicated as an average (x + 3σ) of 150 resistances between adjacent circuits. The results are shown in Tables 4 and 5. Here, Table 4 shows the evaluation results of the FPC1 / glass substrate connection sample, and Table 5 shows the evaluation results of the FPC2 / glass substrate connection sample.

<Measurement of adhesive strength>
The adhesive strength was measured by a 90-degree peeling method according to JIS-Z0237. Tensilon UTM-4 (peeling speed 50 mm / min, 25 ° C., manufactured by Toyo Baldwin Co., Ltd.) was used as an adhesive strength measuring device. The results are shown in Tables 4 and 5.

<Observation of connection appearance>
The circuit member connection structure was placed in a constant temperature and humidity test apparatus at 85 ° C. and a relative humidity of 85% RH for 250 hours to perform a moisture resistance test. And the external appearance immediately after adhesion | attachment and a moisture resistance test was observed with the microscope from the glass substrate side. When peeling occurred between the circuit connection portion and the inter-circuit space interface, the insulation between the circuits was significantly deteriorated, so that it was determined as NG. The results are shown in Tables 4 and 5.

[Evaluation of pot life]
Each of the film-like circuit connection materials obtained in the examples and comparative examples is housed in a vacuum packaging material and left to stand at 40 ° C. for 5 days. Then, a circuit member connection structure is prepared in the same manner as described above, and the pot life is evaluated. A sample was used. And the adhesiveness was also evaluated in the same manner as described above for the sample for evaluating the pot life. The results are shown in Tables 4 and 5. In the evaluation of adhesiveness, it was determined that the pot life was long when each characteristic of the sample for pot life evaluation was smaller than the characteristics of the sample for initial characteristic evaluation and the initial characteristics were maintained.

  As can be seen from Tables 4 and 5, the initial connection resistance was about 1Ω in both the examples and the comparative examples. Moreover, the initial adhesive strength was 7 N / cm or more in both Examples and Comparative Examples. Particularly in Examples 5 and 6, the adhesive strength increased with an increase in the amount of the isocyanate group-containing compound. In Example 8, the adhesive strength of the FPC2 / glass substrate connection sample was improved by using fluorine-containing polyimide.

  When the film-like circuit connecting materials obtained in Examples 1 to 3 and 5 to 8 and Comparative Example 3 were used, no peeling was observed. In addition, since the film-like circuit connecting material obtained in Example 4 has a small amount of isocyanate group-containing compound, a slight amount of peeling was observed in the FPC1 / glass substrate connecting sample after the moisture resistance test, but there was a problem in use. There was no level. On the other hand, in Comparative Example 1 that does not contain an isocyanate group-containing compound and Comparative Example 2 in which the blending amount of the isocyanate group-containing compound is further small, peeling occurred after the moisture resistance test.

  As described above, it was confirmed that Examples 1 to 8 and Comparative Example 3 had good initial characteristics in terms of adhesive strength, connection resistance, and connection appearance, and exhibited sufficiently high adhesiveness.

  Moreover, when using the film-like circuit connection material after being left at 40 ° C. for 5 days, in Examples 1 to 8 and Comparative Examples 1 and 2, the adhesive properties equivalent to the initial characteristics are maintained, and the pot life is Was confirmed to be long. On the other hand, in Comparative Example 3 in which the compounding amount of the isocyanate group-containing compound is 7.5 parts by mass, the connection resistance after standing at 40 ° C. for 5 days increases to more than twice the initial connection resistance, and the pot life is short. all right.

  As mentioned above, it turns out that the film circuit-shaped connection material of Examples 1-8 shows sufficiently high adhesiveness compared with the film circuit-shaped connection material of Comparative Examples 1-3, and has a sufficiently long pot life. It was. From this, it was confirmed that the film-like circuit connecting material of the present invention showed sufficiently high adhesiveness regardless of the material of the circuit member and had a sufficiently long pot life.

  Further, the film-like circuit connecting material of the present invention has a sufficiently long pot life, and in particular, the circuit board supporting the circuit electrode is selected from polyethylene terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin and glass. Good adhesion to a circuit member made of a material containing at least one kind and a circuit member whose surface is coated or adhered with at least one kind of material selected from silicon nitride, silicone resin, polyimide resin and acrylic resin I also found it.

  According to the present invention, it is possible to provide a film-like circuit connecting material that exhibits sufficiently high adhesiveness regardless of the material of the circuit member and has a sufficiently long pot life, and a circuit member connecting structure using these. .

Claims (8)

A first circuit member having a first circuit electrode formed on the main surface of the first circuit board, and a second circuit member having a second circuit electrode formed on the main surface of the second circuit board A film-like circuit connecting material for electrically connecting the first and second circuit electrodes in a state of facing each other,
A film-forming material, a radical polymerizable compound, a radical polymerization initiator that generates free radicals upon heating, and an isocyanate group-containing compound,
The film-form circuit connection material whose content rate of the said isocyanate group containing compound is 0.09-5 mass parts with respect to a total of 100 mass parts of the said film formation material and the said radically polymerizable compound.   The film-like circuit connection material according to claim 1, further comprising a fluorine-containing organic compound.   The film-form circuit connection material of Claim 1 or 2 in which the said film formation material contains the organic compound which has a urethane bond of the weight average molecular weight 10,000 or more.   The film-form circuit connection material as described in any one of Claims 1-3 which further contains electroconductive particle. A first circuit member having a first circuit electrode formed on the main surface of the first circuit board;
A second circuit member formed on the main surface of the second circuit board, wherein the second circuit electrode is disposed so that the second circuit electrode is opposed to the first circuit electrode;
The first circuit member and the second circuit board are provided between the first circuit board and the second circuit board so that the first and second circuit electrodes are electrically connected to each other. A circuit connection for connecting the circuit members;
A circuit member connection structure comprising:
The connection structure of the circuit member whose said circuit connection part is the hardened | cured material of the film-form circuit connection material as described in any one of Claims 1-4.   At least one of the first and second circuit electrodes is made of a material containing at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide. Item 6. A circuit member connection structure according to Item 5. Wherein at least one of the first and the second circuit board is a substrate made of a material containing at least one selected polyethylene terephthalate, polyether sulfone, epoxy resin, acrylic resin, from the group consisting of polyimide resins and glass The connection structure for a circuit member according to claim 5 or 6.   A layer containing at least one material selected from the group consisting of silicon nitride, silicone resin, polyimide resin, and acrylic resin is formed between at least one of the first and second circuit members and the circuit connection portion. The circuit member connection structure according to claim 5, wherein the circuit member connection structure is provided.

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