KR20170023740A - Conductive adhesive composition - Google Patents

Abstract

A polyurethane polyurea resin (F) obtained by reacting a urethane prepolymer (D) obtained by reacting a polyol compound (A), a diisocyanate compound (B) and a carboxyl group-containing diol compound (C) with a polyamino compound (E) A polyurethane polyurea resin (F) having at least an epoxy resin (G) having at least two epoxy groups and an electrically conductive filler (H), a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / Is 18 to 30 mgKOH / g. The conductive adhesive composition according to claim 1, wherein the polyurethane resin (F-2) is a polyurethane resin.

Description

CONDUCTIVE ADHESIVE COMPOSITION [0002]

TECHNICAL FIELD The present invention relates to a conductive adhesive composition, a conductive adhesive film using the conductive adhesive composition, and an electromagnetic wave shielding film.

BACKGROUND ART [0002] Conventionally, conductive adhesives composed of conductive fillers and resin compositions are used for printed wiring boards, conductive adhesive films, and electromagnetic shielding films. Such a conductive adhesive is required to have high heat resistance capable of enduring the reflow process, high adhesion property to maintain high connection resistance or low connection resistance value even when exposed to a high temperature and high humidity environment, and an embedding property capable of filling the opening provided in the printed board with a conductive adhesive . In addition, in a printed circuit board on which electronic components are mounted, if the printed circuit board is bent at the time of use, deformation may occur in the area where the electronic components are mounted and the electronic components may be damaged. For this reason, a reinforcing plate made of stainless steel or the like may be provided at a position opposite to a portion where electronic components are mounted on such a printed board. The reinforcing plate is fixed to the printed circuit board after punching the conductive plate with a conductive adhesive film in a predetermined shape. Here, the conductive adhesive film is required to have a tackiness with a metal reinforcing plate when punched into a predetermined shape, and an adhesion property after being fixed to a printed board (also referred to as adhesiveness after adhesion).

As such a conductive adhesive composition, Patent Document 1 discloses a conductive resin composition containing a polyurethane polyurea resin and an epoxy resin. Patent Documents 2 and 3 disclose an adhesive composition containing a polyurethane polyurea resin and an epoxy resin.

Patent Document 1: JP-A-2010-143981 Patent Document 2: International Publication No. 2007/032463 Patent Document 3: JP-A-2005-298812

The conductive resin compositions described in Patent Documents 1 to 3 can be improved to some extent with respect to heat resistance and adhesiveness after being exposed to a high temperature and high humidity environment. However, the adhesiveness between the adherend and the printed substrate after hot pressing (adhesiveness after adhesion) Heat resistance could not be satisfied at all.

Therefore, an object of the present invention is to provide a conductive adhesive excellent in both heat resistance, adhesiveness, adhesiveness after bonding, and adhesion to a base material, a conductive adhesive sheet using the same, and an electromagnetic wave shielding film.

The present inventors have focused on using a plurality of polyurethane polyurea resins contained in the conductive adhesive.

It has been found that the combination of a resin having a low acid value and a resin having a high acid value as the polyurethane polyurea resin provides excellent adhesion to the base material, adhesion, adhesion after the main adhesion, Completed.

[1] Polyurethane polyurea resin obtained by reacting a urethane prepolymer (D) obtained by reacting a polyol compound (A), a diisocyanate compound (B) and a carboxyl group-containing diol compound (C) with a polyamino compound (E) F),

An epoxy resin (G) having two or more epoxy groups,

And at least a conductive filler (H)

Wherein the polyurethane polyurea resin (F) is a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / .

[2] The conductive adhesive composition according to [1], wherein the amount of the polyurethane polyurea resin (F-2) relative to 100 parts by mass of the polyurethane polyurea resin (F-1) is 30 to 300 parts by mass.

[3] The conductive adhesive composition according to [1] or [2], wherein the epoxy resin (G) is contained in an amount of 50 to 500 parts by mass per 100 parts by mass of the polyurethane polyurea resin (F).

[4] A conductive adhesive film having a releasable base material and an adhesive layer comprising the conductive adhesive composition according to any one of [1] to [3].

[5] An electromagnetic shielding film having at least an insulating layer and a conductive adhesive layer, wherein the conductive adhesive layer comprises the conductive adhesive composition according to any one of [1] to [3].

[6] A semiconductor device comprising: a base member having a ground wiring pattern on at least one surface;

A cover ray covering the ground wiring pattern and provided with an opening so that a part of the ground wiring pattern is exposed,

A conductive reinforcing plate disposed opposite to the ground wiring pattern,

A conductive adhesive layer for bonding the ground wiring pattern of the base member and the conductive reinforcing plate in a conductive state,

And an electronic component disposed on the other surface of the base member at a position corresponding to the conductive reinforcing plate,

Wherein the conductive adhesive layer has the conductive adhesive composition according to any one of [1] to [3].

According to the present invention, it is possible to obtain a conductive adhesive composition which is excellent in heat resistance, adhesion to a base material, adhesiveness, and adhesiveness after the main adhesion, and a conductive adhesive film and an electromagnetic shielding film using the same.

1 is a schematic view of a printed wiring board to which an electromagnetic wave shielding film and a conductive adhesive are adhered.
2 is a schematic view of a circuit board using an electromagnetic wave shielding film having a metal layer.
3 is a schematic view of a first circuit board to which a reinforcing plate is adhered by a conductive adhesive film.
4 is a schematic view of a second circuit board on which a reinforcing plate is bonded by a conductive adhesive film.
Fig. 5 is a diagram showing an outline when measuring the affixing property. Fig.
Fig. 6 is a diagram schematically showing the measurement of adhesion after the adhesion. Fig.
7 is a view schematically showing measurement of adhesion to a polyimide film.
8 is a view schematically showing the measurement of the adhesion with the gold-plated copper foil.

Hereinafter, the present invention will be described in detail.

≪ Conductive adhesive composition >

The conductive adhesive composition of the present invention is a polyurethane resin obtained by reacting a urethane prepolymer (D) obtained by reacting a polyol compound (A), a diisocyanate compound (B) and a carboxyl group-containing diol compound (C) (F), an epoxy resin (G) having two or more epoxy groups and an electrically conductive filler (H), wherein the polyurethane polyurea resin (F) is a polyurethane polyurea resin having an acid value of 1 to 6 mgKOH / g (F-1) having an acid value of 18 to 30 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / g.

The polyurethane polyurea resin (F) contained in the conductive adhesive composition of the present invention comprises a urethane prepolymer (D) obtained by reacting a polyol compound (A), a diisocyanate compound (B) and a diol compound (C) Can be obtained by reacting an amino compound (E).

(Polyol compound (A))

The polyol compound in the present invention is not particularly limited, and a known polyol used for urethane synthesis can be used. Examples of such polyols include polyester polyols, polyether polyols, polycarbonate polyols, and other polyols.

Examples of the polyester polyol include aliphatic dicarboxylic acids (e.g. succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.) and / or aromatic dicarboxylic acids (e.g., isophthalic acid, terephthalic acid, (Such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol, 1,4- Cyclohexane, cyclohexane, and the like).

Specific examples of such polyester polyols include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene / butylene adipate diol, polyneopentyl / hexyl adipate diol, Poly-3-methylpentane adipate diol, polybutylene isophthalate diol, polycaprolactone diol, and poly-3-methylvalerolactone diol.

Specific examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and random / block copolymers thereof. Specific examples of the polycarbonate polyol include polytetramethylene carbonate diol, polypentamethylene carbonate diol, poly neopentyl carbonate diol, polyhexamethylene carbonate diol, poly (1,4-cyclohexanedimethylene carbonate) diol, and random / And the like.

Specific examples of other polyols include dimer diols, polybutadiene polyols and hydrogenated products thereof, polyisoprene polyols and hydrogenated products thereof, acrylic polyols, epoxy polyols, polyether ester polyols, siloxane modified polyols, α, ω-polymethyl methacrylate diols ,?,? - polybutyl methacrylate diol, and the like.

The number-average molecular weight (Mn, determined by the amount of the terminal functional group) of the polyol compound (A) is not particularly limited, but is preferably 500 to 3,000. When the number average molecular weight (Mn) of the polyol compound (A) is less than 500, the cohesive force of the urethane bond is difficult to manifest and the mechanical properties tend to be lowered. In addition, the crystalline polyol having a number average molecular weight of more than 3,000 may cause whitening when it is formed into a film. The polyol compound (A) may be used alone or in combination of two or more.

It is also preferable to use a short-chain diol component and / or a diamine component as necessary as a reaction component for obtaining the urethane prepolymer (D). This makes it easy to control the hardness, viscosity and the like of the polyurethane polyurea resin (F). Specific examples of the short chain diol component include aliphatic glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol and neopentyl glycol, Oxide adduct having a number-average molecular weight of less than 500 as determined by terminal functional groups; Alicyclic glycols such as 1,4-bis hydroxymethylcyclohexane and 2-methyl-1,1-cyclohexanedimethanol, and alkylene oxide adducts thereof (number average molecular weight less than 500, as above); Aromatic glycols such as xylylene glycol and their alkylene oxide adducts (number average molecular weight less than 500, as above); Bisphenols such as bisphenol A, thiobisphenol, and sulfone bisphenol, and alkylene oxide adducts thereof (number average molecular weight less than 500, as above); Alkyl diethanol amines such as C1-C18 alkyl diethanol amines, and the like.

Specific examples of the diamine compound include short chain aliphatic diamine compounds such as methylene diamine, ethylenediamine, trimethylenediamine, hexamethylenediamine and octamethylenediamine; Phenylenediamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4'-methylenebis (phenylamine), 4,4'-diaminodiphenyl ether, Aromatic diamine compounds such as diaminodiphenylsulfone; And alicyclic diamine compounds such as cyclopentyldiamine, cyclohexyldiamine, 4,4'-diaminodicyclohexylmethane, 1,4-diaminocyclohexane and isophoronediamine. Furthermore, hydrazines such as hydrazine, carbodihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and phthalic acid dihydrazide can be used as a diamine compound. Also, long chain alkylene diamines, polyoxyalkylene diamines, terminal amine polyamides, siloxane-modified polyamines, and the like can be given as the long chain. These diamine compounds may be used singly or in combination of two or more.

(Diisocyanate compound (B))

The diisocyanate compound (B) in the present invention is not particularly limited, but conventionally known diisocyanate compounds used in the production of polyurethane can be used. Specific examples of the diisocyanate compound (B) include toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, Dienes such as 1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4'- methylene bis (phenylene isocyanate) Aromatic diesters such as benzene diisocyanate, norbornene diisocyanate, norbornene diisocyanate, norbornene diisocyanate, norbornene diisocyanate, norbornene diisocyanate, norbornene diisocyanate, Isocyanate; Aliphatic diisocyanates such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate and 1,10-decamethylene diisocyanate; Alicyclic diisocyanates such as 1,4-cyclohexylene diisocyanate, methylene bis (4-cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI and hydrogenated XDI; And polyurethane prepolymers obtained by reacting these diisocyanates with low molecular weight polyols or polyamines so that the ends thereof become isocyanates.

(Diol compound (C) having a carboxyl group)

The diol compound (C) having a carboxyl group in the present invention is not particularly limited, and examples thereof include dimethyrolalkanoic acid such as dimethyolpropanoic acid and dimethyolbutanoic acid; Alkylene oxide adduct of dimethyrolalkanoic acid (number-average molecular weight less than 500 as determined by terminal functional group); ? -Caprolactone adduct of dimethyrolalkanoic acid (number-average molecular weight less than 500 by quantitative determination of terminal functional group); Half esters derived from acid anhydrides of dimethyrol alkanoic acid and glycerin; A compound obtained by free radical reaction of a monomer having an unsaturated bond and a monomer having a carboxyl group and an unsaturated bond, and the like. Among them, dimethyrolalkanoic acid such as dimethyrolpropanoic acid and dimethyolbutanoic acid is suitable from the viewpoints of availability and easiness of adjustment of acid value.

(Urethane prepolymer (D))

The urethane prepolymer (D) of the present invention can be obtained by reacting a polyol compound (A), a diisocyanate compound (B) and a diol compound (C) having a carboxyl group.

In the reaction, the equivalent ratio of the polyol compound (A) to the diisocyanate compound (B) relative to the hydroxyl group of the diol compound (C) having a carboxyl group is preferably 1.1 to 2.5. Within the above range, a conductive adhesive composition having high heat resistance and mechanical strength can be obtained. The reaction temperature is not particularly limited, but may be a form carried out at 60 to 100 占 폚.

(Reaction terminator)

When the urethane prepolymer (D) is obtained by reacting the polyol compound (A), the diisocyanate compound (B) and the diol compound (C) having a carboxyl group, for the purpose of adjusting the molecular weight of the urethane prepolymer, Can be used. As the reaction terminator, monoalcohol compounds, monoamine compounds, alkanolamine compounds and the like can be used. As the monoalcohol, for example, methanol, ethanol, butanol, isopropanol and the like can be used. As the monoamine compound, butylamine, dibutylamine and the like can be used. As the alkanolamine, monoethanolamine, diethanolamine and the like can be used.

(Polyamino compound (E))

The polyamino compound (E) in the present invention is not particularly limited, but conventionally known polyamino compounds used in the production of polyurea resins can be used. Specific examples of the polyamino compound (E) include ethylenediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, - diamines such as dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine and 1,2-propanediamine; And aminoalkylalkanolamines such as aminoethylethanolamine, aminopropylethanolamine, aminohexylethanolamine, aminoethylpropanolamine, aminopropylpropanolamine, aminohexylpropanolamine, and the like.

(Polyurethane polyurea resin (F))

The polyurethane polyurea resin (F) in the present invention is obtained by reacting a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / . The acid value of the polyurethane polyurea resin (F-1) is more preferably less than 1 to 3 mg KOH / g, and still more preferably 1 to 2.5 mg KOH / g. The acid value of the polyurethane polyurea resin (F-2) is more preferably from 25 mgKOH / g to 30 mgKOH / g, and more preferably from 26 to 30 mgKOH / g.

If the acid value of the polyurethane polyurea resin (F-1) is 1 to 6 mgKOH / g, the adhesion between the conductive adhesive film and the printed wiring board is improved.

It is more preferable that the acid value of the polyurethane polyurea resin (F-1) is less than 3 from the viewpoint of excellent adherence and adhesion to the gold-plated copper foil.

When the acid value of the polyurethane polyurea resin (F-2) is 18 to 30 mgKOH / g, the adhesion property of the conductive adhesive film is improved.

It is more preferable that the polyurethane polyurea resin (F-2) has an acid value of more than 25 from the viewpoint of excellent adhesiveness to the adherend or gold-plated copper foil.

Further, by using the polyurethane polyurea resins (F-1) and (F-2) having an acid value in the above specific range, the flowability (heat resistance) of the conductive adhesive film obtained using the conductive adhesive composition of the present invention is enhanced . Further, by using the polyurethane polyurea resins (F-1) and (F-2) having an acid value in the above-specified range, both of the adhesiveness and the adhesiveness after the main adhesion are contributed.

The combination of the polyurethane polyurea resins (F-1) and (F-2) constituting the polyurethane polyurea resin (F) is not particularly limited as long as it is within the above specified range. Such a combination is a combination of a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / g, (F-1) having an acid value of 1 to 2.5 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / g are used in combination, a polyurethane polyurea A combination of the resin (F-1) and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / g, a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / (F-1) having an acid value of less than 1 to 3 mg KOH / g and a polyurethane polyurea resin (F-1) having an acid value of more than 25 mg KOH / g (F-1) having an acid value of 1 to 2.5 mgKOH / g and an acid value of more than 25 mgKOH / g to 30 mgKOH / g (F-2) In pole A polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 26 mgKOH / g to 30 mgKOH / g, -2), a polyurethane polyurea resin (F-1) having an acid value of less than 1 to 3 mg KOH / g and a polyurethane polyurea resin (F-2) having an acid value of 26 mg KOH / g to 30 mg KOH / (F-1) having an acid value of 1 to 2.5 mg KOH / g and a polyurethane polyurea resin (F-2) having an acid value of 26 mg KOH / g to 30 mg KOH / g are used in combination have.

Further, it is preferable to use a combination in which the acid value of the polyurethane polyurea resin (F-1) is less than 3 mgKOH / g and the acid value of the polyurethane polyurea resin (F-2) is more than 25 mgKOH / g, More preferable.

The polyurethane polyurea resins (F-1) and (F-2) may be used by mixing two or more kinds thereof so long as they satisfy the respective acid value.

The acid value of the polyurethane polyurea resin in the present invention is measured in accordance with the neutralization titration method of JIS K 0070.

The weight average molecular weight of the polyurethane polyurea resins (F-1) and (F-2) is usually 50,000 to 100,000.

In addition, the conductive adhesive film using the conductive adhesive of the present invention is excellent in adhesiveness to the base material, and the adhesion to the base material is favorable to the adhesion to a resin plate such as a polyimide film and the adhesion of a gold plated copper foil or a conductive reinforcing plate And two types of adhesion to the same metal material.

In the present invention, the term "platability" refers to the adhesion between the conductive adhesive film and the reinforcing plate when the reinforcing plate and the conductive adhesive film are adhered to each other and then punched into a predetermined shape or the releasable base material is peeled off.

In the present invention, the adhesion after the present adhesion means the adhesion between the printed substrate and the conductive adhesive film after the conductive adhesive film or the like is fixed (originally adhered) to the printed substrate. It is also referred to as adhesiveness and workability. The adhesiveness after the main adhesion is also referred to as the main adhesion.

The adhesiveness and the adhesion measurement method after the main adhesion will be described in detail in Examples.

The ratio of the polyurethane polyurea resin (F-1) to the polyurethane polyurea resin (F-2) was such that the ratio of the polyurethane polyurea resin (F-2) to the polyurethane polyurea resin (F- It is preferably 30 to 300 parts by mass. If the ratio of the polyurethane polyurea resin (F-1) and the polyurethane polyurea resin (F-2) is within the above range, the adhesion property, adhesiveness and filling property of the conductive adhesive film and the printed wiring board are improved.

(Epoxy resin (G))

The epoxy resin (G) in the present invention is not particularly limited, but a known epoxy resin having two or more epoxy groups per molecule can be used. Examples of such epoxy resins include bisphenol-type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins and bisphenol S type epoxy resins, spirocyclic epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, Glycidyl ether type epoxy resins such as tris (glycidyloxyphenyl) methane, tetrakis (glycidyloxyphenyl) ethane and the like, glycidylamine type epoxy resins such as tetraglycidyldiaminodiphenylmethane and the like , Novolak type epoxy resins such as tetrabromo bisphenol A type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin,? -Naphthol novolak type epoxy resin and brominated phenol novolak type epoxy resin, rubber modified epoxy Resin or the like can be used. These may be used alone or in combination of two or more.

When two or more kinds of epoxy resins are used in combination, it is preferable to use them in combination of an epoxy equivalent weight of 800 to 10000 (epoxy resin (G1)) and an epoxy equivalent of 90 to 300 (epoxy resin (G2)). In this case, the epoxy resin (G1) and the epoxy resin (G2) may be of the same kind or may have different chemical structures.

As the epoxy resin (G1), an epoxy equivalent weight of 800 to 10,000 is preferably used. This is preferable in that the adhesion with the reinforcing plate is further improved. The lower limit of the epoxy equivalent is more preferably 1000, and still more preferably 1500. The upper limit of the epoxy equivalent is more preferably 5000, and still more preferably 3000. As the epoxy resin (G1), it is preferable to use a solid at room temperature. A solid at room temperature means a solid state at 25 ° C with no solvent in a non-solvent state.

Examples of commercially available epoxy resins that can be used as the epoxy resin (G1) include EPICLON 4050, 7050, HM-091, HM-101 (trade names, products of DIC Co.), jER1003F, 1004, 1004AF, 1004FS, 1005F, 1006FS, 1007, 1007FS, 1009, 1009F, 1010, 1055, 1256, 4250, 4275, 4004P, 4005P, 4007P, 4010P (trade name, product of Mitsubishi Chemical Corporation).

The epoxy resin (G2) preferably has an epoxy equivalent of 90 to 300.

Thus, the effect of increasing the heat resistance of the resin can be obtained. The lower limit of the epoxy equivalent is more preferably 150, and still more preferably 170. The upper limit of the epoxy equivalent is more preferably 250, and still more preferably 230. As the epoxy resin (G2), it is preferable to use a solid at room temperature.

The epoxy resin (G2) is more preferably a novolak type epoxy resin. Although the novolak type epoxy resin has a high density of epoxy resin, it has good compatibility with other epoxy resins, and the difference in reactivity between epoxy groups is small, so that the entire coating film can be made uniformly high in cross-link density.

The novolak type epoxy resin is not particularly limited and examples thereof include cresol novolak type epoxy resins, phenol novolak type epoxy resins,? -Naphthol novolak type epoxy resins, and brominated phenol novolak type epoxy resins.

Examples of commercially available epoxy resins usable as the epoxy resin (G2) as described above include EPICLON N-660, N-665, N-670, N-673, N-680, N-695, N-655- N-665-EXP, N-665-EXP-S, N-672-EXP, N-670-EXP-S, (Trade name, manufactured by DIC Co., Ltd.), N-680-75M, N-690-75M, N-740, N-770, N-775, N-740-80M, N-770-70M, N-865 and N-865-80M 700, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700, YDCN-700-2, YDCN- 700-10, YDCN-704, and YDCN-700-A (trade name, manufactured by Shinnitetsu Chemical Co., Ltd.).

When a novolak type epoxy resin is used as the epoxy resin (G2), it is preferable to use an epoxy resin other than the novolak type epoxy resin which is solid at room temperature. If the adhesive layer is composed only of a novolak type epoxy resin, there is a problem in that the adhesiveness is not sufficient. Therefore, it is preferable to use an epoxy resin (G1) other than the novolak type epoxy resin.

In the present invention, the ratio of the polyurethane polyurea resin (F) to the epoxy resin (G) is preferably 50 to 500 parts by mass of the epoxy resin (G) relative to 100 parts by mass of the polyurethane polyurea resin (F) More preferably from 50 to 300 parts by mass, and more preferably from 50 to 200 parts by mass considering the adhesiveness after the main bonding. By setting the ratio within the above range, the degree of crosslinking with the polyurethane polyurea resin is appropriately adjusted, so that the flexibility of the conductive adhesive composition or the electromagnetic shielding film, the adhesion with the printed wiring board, the adhesiveness and the filling property are improved. Particularly, since the epoxy resin (G) is 50 parts by mass or more based on 100 parts by mass of the polyurethane polyurea resin (F), the flowability, adhesiveness after the main adhesion and adhesion with the resin plate are improved, The adhesiveness to the metal material such as the plating resistance and the gold plating is improved.

(Conductive filler)

The conductive adhesive film of the present invention contains the conductive filler (H). The conductive filler (H) is not particularly limited, and for example, a metal filler, a metal-coated resin filler, a carbon filler, and a mixture thereof can be used. Examples of the metal filler include copper powder, silver powder, nickel powder, silver coat copper powder, gold coat copper powder, silver nickel powder and gold coat nickel powder. These metal powders can be prepared by an electrolytic method, an atomization method and a reduction method.

Moreover, in order to easily obtain contact between the fillers, it is preferable to set the average particle diameter of the conductive filler to 3 to 50 mu m. Examples of the shape of the conductive filler include a spherical shape, a flake shape, a resin shape, and a fiber shape.

The conductive filler (H) is preferably at least one selected from the group consisting of silver powder, silver copper powder and copper powder from the viewpoint of connection resistance and cost.

The conductive filler (H) is preferably contained in a proportion of 40 to 90% by weight based on the total amount of the conductive adhesive composition.

In addition, a silane coupling agent, an antioxidant, a pigment, a dye, a tackifier resin, a plasticizer, an ultraviolet absorber, a defoaming agent, a leveling regulator, a filler, a flame retardant, etc. may be added to the conductive adhesive film within a range not deteriorating the solder reflow resistance .

≪ Conductive adhesive film &

The conductive adhesive film of the present invention can be produced by coating a releasable base material (release film) with a conductive adhesive composition. The coating method is not particularly limited, and known coating apparatus typified by die coat, lip coat, comma coat and the like can be used.

As the release film, a silicone-based or non-silicone-based release agent may be applied on a base film such as polyethylene terephthalate or polyethylene naphthalate coated on the surface of the side where the conductive adhesive layer is formed. The thickness of the release film is not particularly limited and is determined in consideration of the ease of use.

The conditions for coating the release film with the conductive adhesive composition may be appropriately set. The thickness of the obtained conductive adhesive layer is preferably 15 to 100 mu m. When the thickness is smaller than 15 탆, the filling property becomes insufficient, and when it is thicker than 100 탆, it is disadvantageous in terms of cost, so that it can not meet the demand for thinning. With such a thickness, it is preferable that the base material is deformed into a shape such as to fill the concave portion by flowing appropriately when there is unevenness in the base material, so that adhesion with high adhesiveness can be performed.

<Anisotropic Conductive Adhesive Layer, Isotropic Conductive Adhesive Layer>

The conductive adhesive composition of the present invention can be used as an anisotropic conductive adhesive layer or an isotropic conductive adhesive layer depending on the purpose of use. For example, when the conductive adhesive composition of the present invention is used as the conductive adhesive film for adhesion to the electromagnetic shielding film or the reinforcing plate which does not have the metal layer described above, it can be used as an isotropic conductive adhesive layer.

In the case of an electromagnetic wave shielding film having a metal layer, it may be used as an isotropic conductive adhesive layer or an anisotropic conductive adhesive layer, but it is preferably used as an anisotropic conductive adhesive layer.

These may be any one of them depending on the blending amount of the conductive filler (H). In order to form the anisotropic conductive adhesive layer, it is preferable that the conductive filler is contained in an amount of 5 wt% or more and less than 40 wt% in the total solid content of the conductive adhesive composition. In order to form an isotropic conductive adhesive layer, it is preferable that the conductive filler (H) is 40 wt% or more and 90 wt% or less in the total solid content of the conductive adhesive composition.

(Electromagnetic wave shielding film)

The electromagnetic shielding film using the conductive adhesive composition of the present invention preferably has a conductive adhesive layer and a protective layer. The protective layer is not particularly limited as long as it is an insulating resin composition, and any known layer can be used. As the protective layer, a resin component (except for the conductive filler) used in the above-described conductive adhesive layer may be used. The protective layer may be formed of two or more layers having different compositions and hardnesses. If necessary, the protective layer may contain a curing accelerator, a tackifier, an antioxidant, a pigment, a dye, a plasticizer, an ultraviolet absorber, a defoaming agent, a leveling agent, a filler, a flame retardant, a viscosity adjusting agent and an antiblocking agent.

It is preferable that the thickness of the conductive adhesive layer in the electromagnetic wave shielding film is in the range of 3 to 30 mu m. If the thickness is less than 3 mu m, sufficient connection with the ground circuit may not be obtained. When the thickness exceeds 30 mu m, it is not preferable because it can not meet the demand for thinning.

Next, a specific form of the method for producing an electromagnetic wave shielding film of the present invention will be described.

For example, a method of coating and drying a resin composition for a protective layer on one side of a peelable film to form a protective layer, coating and drying the conductive adhesive composition on the protective layer to form a conductive adhesive layer, and the like .

A laminated electromagnetic shielding film of a conductive adhesive layer / a protective layer / a peelable film can be obtained by the manufacturing method as illustrated.

The conductive adhesive layer and the protective layer may be formed by a known coating method such as a gravure coat method, a kiss coat method, a die coat method, a lip coat method, a comma coat method, a blade coat method, a roll coat method, A spray coat method, a bar coat method, a spin coat method, a dip coat method, or the like.

The electromagnetic wave shielding film can be adhered to the printed wiring board by a hot press. The conductive adhesive layer of the electromagnetic wave shielding layer is softened by heating and flows into the ground portion provided on the printed wiring board by pressurization. As a result, the ground circuit and the conductive adhesive are electrically connected to each other to enhance the shielding effect.

A schematic view of a printed wiring board to which an electromagnetic wave shielding film and a conductive adhesive are adhered is shown in Fig. 1, the conductive adhesive layer 4 is formed so as to be in contact with the ground portion 5. Since the conductive adhesive layer 4 of the present invention has an appropriate fluidity, the filling property is good and good electrical connection can be made in the ground portion 5. [

(Electromagnetic wave shielding film having a metal layer)

The electromagnetic wave shielding film of the present invention may have a metal layer. By having a metal layer, more excellent electromagnetic shielding performance can be obtained.

Examples of the metal material for forming the metal layer include nickel, copper, silver, tin, gold, palladium, aluminum, chromium, titanium, zinc and alloys containing any one or more of these materials. The metal material and thickness of the metal layer may be suitably selected in accordance with the required electromagnetic shielding effect and repeated flexural and sliding resistance. However, the thickness of the metal layer may be about 0.1 to 8 占 퐉. Examples of the metal layer forming method include an electrolytic plating method, an electroless plating method, a sputtering method, an electron beam evaporation method, a vacuum evaporation method, a CVD method, and a metal organic method. The metal layer may be a metal foil or metal nanoparticles.

The electromagnetic wave shielding film having such a metal layer can be produced by the same method as the above-described electromagnetic wave shielding film, and is preferably composed of a conductive adhesive layer / metal layer / protective layer / peelable film.

A circuit board using an electromagnetic wave shielding film having a metal layer is shown in Fig. In Fig. 2, the metal layer 3 is electrically connected to the ground portion 5 through the conductive adhesive layer 4 to obtain electromagnetic shielding performance. At this time, since the conductive adhesive layer 4 has appropriate fluidity, the filling property is good, and good electrical connection can be made in the ground portion 5. [

As an adherend capable of adhering the electromagnetic shielding film of the present invention, for example, a flexible substrate which undergoes repeated bending can be cited as a representative example. It is of course also applicable to rigid printed wiring boards. Furthermore, the present invention is not limited to the one-sided shield, but includes the two-sided shield.

The electromagnetic wave shielding film can be adhered to the substrate by heating and pressing. The hot pressing under such heating and pressurization can be carried out under ordinary conditions, and can be performed under the conditions of, for example, 1 to 5 MPa, 140 to 190 DEG C, and 15 to 90 minutes.

<Bonding method>

Next, a method of using the conductive adhesive film of the present invention will be described. The use of the conductive adhesive film is not particularly limited, but it is used for bonding a reinforcing plate to a circuit board, for example. In particular, when the reinforcing plate is conductive, it is used not only to bond the conductive reinforcing plate but also to electrically connect the conductive reinforcing plate with the ground electrode in the circuit board main body.

The material of the circuit board main body may be any material that has insulating properties and can form an insulating layer, and examples thereof include polyimide resins.

It is preferable to use a metal plate as the conductive reinforcing plate, and a stainless steel plate, an iron plate, a copper plate, an aluminum plate, or the like can be used as the metal plate. Of these, stainless steel plates are more preferable. By using a stainless steel plate, even a thin plate thickness has sufficient strength to support the electronic component. The thickness of the conductive reinforcing plate is not particularly limited, but is preferably 0.025 to 2 mm, more preferably 0.1 to 0.5 mm. When the conductive reinforcing plate is within this range, the circuit board to which the conductive reinforcing plate is adhered can be easily accommodated in a small appliance and has sufficient strength to support the mounted electronic component. A metal layer of Ni or the like may be formed on the surface of the reinforcing plate by plating or the like. The surface of the metal reinforcing plate may be provided with a concavo-convex shape by sandblasting, etching, or the like.

As the electronic components referred to herein, chip components such as resistors and capacitors in addition to connectors and ICs can be mentioned.

In the bonding method using the conductive adhesive film of the present invention, the above-mentioned conductive adhesive film is adhered onto the adherend base material X which is a reinforcing plate or a flexible substrate by the steps (1) and (1) And a step (2) of laminating the adhesive base material (Y), which is a flexible board or a reinforcing plate, to the adherend base material (X)

The above-described conductive adhesive film can be suitably used particularly for bonding a flexible substrate and a reinforcing plate in a flexible circuit board. That is, a metal plate or the like that is electrically conductive as a reinforcing plate is used, and the conductive plate is adhered to the flexible circuit board to obtain electromagnetic shielding ability by the reinforcing plate.

The conductive adhesive film of the present invention has a particularly excellent effect in that good adhesion performance is obtained when the reinforcing plate is adhered by such a method. That is, the adhesive base material X having the conductive adhesive film obtained by the step (1) and the step (1) of adhering the conductive adhesive film on the adherend base material X as the reinforcing plate or the flexible substrate is provided with a flexible The conductive adhesive of the present invention exhibits excellent adhesion and durability in a high-temperature environment in both the step (2) of overlapping the substrate (Y) to be adhered as a substrate or a reinforcing plate and hot pressing.

In the bonding method of the present invention, first, the conductive adhesive film is adhered onto the base material X to be adhered. The adhesion base material X may be a reinforcing plate or a flexible substrate, but it is preferably a reinforcing plate. The conditions for the adhesion are not particularly limited, and the adhesive may be any material as long as the conductive adhesive film is fixed on the base material to be adhered without being shifted. That is, it is preferable that adhesion is performed on the entire adhesive surface.

The bonding can be performed by a press machine, and the bonding conditions can be appropriately set. For example, the conditions include temperature: 120 DEG C, time: 5 seconds, and pressure: 0.5 MPa.

Step (2) is a step of superposing a bonded substrate material (Y), which is a flexible substrate or a reinforcing plate, on the adherend base material (X) having the conductive adhesive film obtained by the step (1) and thermally pressing.

One of the adhesion base material X and the adhesion base material Y is a reinforcing plate and the other is a flexible substrate.

The conditions for hot pressing can be set appropriately, but can be performed under the conditions of, for example, 1 to 5 MPa, 140 to 190 DEG C, and 15 to 90 minutes.

<Circuit board>

The circuit board using the conductive adhesive film of the present invention is a circuit board having at least a portion where a printed wiring board, a conductive adhesive film and a conductive reinforcing plate are stacked in this order. Such a circuit board may be bonded according to the above-described bonding method, or may be obtained by other bonding methods. Figs. 3 and 4 show a schematic view of such a circuit board. In Fig. 3, the circuit board and the reinforcing plate are bonded by the conductive adhesive film of the present invention and are electrically connected. In Fig. 4, the circuit board is composed of a coverlay, an insulating adhesive layer, and a wiring pattern composed of a copper foil whose surface is covered with a gold-plated layer and a base member in this order. In addition, the insulating adhesive layer may be omitted by performing CB treatment or the like. As the material constituting the coverlay and the base member, any material may be used as long as it has an insulating property and can form an insulating layer. Typical examples of the coverlay and the base member include a polyimide resin. Further, an opening is provided in a part of the coverlay, and a part of the ground circuit is exposed from the opening. The opening portion is filled with the conductive adhesive composition of the present invention. As a result, the ground circuit is electrically connected to the conductive reinforcing plate by the conductive adhesive composition of the present invention. Further, by connecting the reinforcing plate to the external ground member, the ground circuit can be grounded to the external ground through the reinforcing plate. An electronic component is disposed at a position corresponding to the conductive reinforcing plate on the other surface of the base member. With such a configuration, the conductive reinforcing member reinforces the mounting portion of the electronic component.

It is preferable that the conductive reinforcing plate exists only in a part of the circuit board in the circuit board. That is, it is preferable that the conductive reinforcing plate covers the portion having the electronic component in the circuit board.

In the circuit board using the conductive adhesive film of the present invention, it is preferable that at least a part of the surface of the reinforcing plate other than the surface coated with the circuit board is covered with the electromagnetic wave shielding film. That is, the electromagnetic shielding film may cover only a part of the surface of the reinforcing plate other than the surface covered with the circuit board, or may cover the entire surface except the surface covered with the circuit board. In this case, the electromagnetic shielding film may overlap with at least a part of the reinforcing plate. This is preferable in that a good electromagnetic shielding performance can be obtained over the entire surface of the circuit board.

In the prior art, there has been known an example in which only the adhesiveness between a resin reinforcing plate and a polyimide film or the like is focused on. However, if a conductive reinforcing plate such as a metal plate and a polyimide film are stitched together using a conventional adhesive composition, problems in workability and durability . That is, the resin reinforcing plate and the conductive reinforcing plate are common in that they are required to have adhesion with a resin base material (polyimide film or the like) after being fixed to a printed board. However, in addition to these features, the conductive reinforcing plate is required to have such characteristics that the conductive adhesive film is adhered to the reinforcing plate and punched into a predetermined shape, the floating property after the conductive adhesive film is filled in the opening of several mmΦ provided in the coverlay, Adhesion with a metal wiring pattern is also required. In conventional adhesive compositions known in the art, these characteristics can not all be satisfied, and the adhesiveness and underflow are insufficient. This is because when the resin reinforcing plate is used, there is no necessity of filling the adhesive composition into the opening provided in the cover lay, and therefore it is not necessary to satisfy the bottom flow property as in the present invention. It is necessary to sufficiently fill the openings of the order of several mmφ to sufficiently bond the conductive adhesive composition to the wiring pattern even after passing through the reflow process at about 265 ° C. and to have better physical properties than prior art adhesive compositions do.

Hereinafter, the present invention will be described concretely with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, &quot; part &quot; and &quot;% &quot; are based on mass unless otherwise specified.

(1) Production of polyurethane polyurea resin (F)

&Lt; Synthesis Example 1 &

A reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a manhole was prepared. After replacing the inside of the reaction vessel with nitrogen gas, 1.4 g of dimethyolpropionic acid (DMPA), 200.0 g of polyhexamethylene carbonate diol (trade name: Fraxel CD220, number average molecular weight of 2000 in terms of terminal functional group, And 83.5 g of dimethylformamide (DMF), and then 49.0 g of isophorone diisocyanate (IPDI) (2 equivalents of the NCO group with respect to the OH group) was added, and the mixture was heated to 90 ° C until NCO% reached 2.8% The reaction was carried out to obtain a urethane prepolymer. Next, 83.5 g of DMF was added and cooled to 40 캜 or lower.

Next, 17.5 g of isophoronediamine (IPDA) was diluted with 175 g of a mixed solvent obtained by mixing DMF / isopropyl alcohol (IPA) at a ratio of 7/3 parts by mass, and the diluted solution was added dropwise to react with the NCO group of the urethane prepolymer.

When the NCO group of the isophorone diamine and the urethane prepolymer is reacted, the reaction is continued until the absorption of 2,270 cm -1 by the free isocyanate group measured by infrared absorption spectroscopy disappears, and DMF / isopropyl alcohol (IPA) at a ratio of 7/3 parts by mass was added in an appropriate amount. Thus, a polyurethane polyurea resin (F-1-1) having an acid value of 2.2 mgKOH / g, a weight average molecular weight of 6.8 million, and a solid content of 30% (DMF / isopropyl alcohol = 80/20) was obtained.

&Lt; Synthesis Example 2 &

(DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), and dimethylformamide (DMF) / isopropyl alcohol were added in amounts as shown in Table 1, To obtain a polyurethane polyurea resin (F-2-1) having an acid value of 26.4 mgKOH / g, a weight average molecular weight of 650,000, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 3 &

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 To obtain a polyurethane resin (F-1-2) having an acid value of 1.0 mg KOH / g, a weight average molecular weight of 6.7 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 4 &

(DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), and dimethylformamide (DMF) / isopropyl alcohol were added in amounts as shown in Table 1, (F-1-3) having an acid value of 5.0 mgKOH / g, a weight average molecular weight of 6.7 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 5 &

(DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), and dimethylformamide (DMF) / isopropyl alcohol were added in amounts as shown in Table 1, To obtain a polyurethane polyurea resin (F-1-4) having an acid value of 6.0 mg KOH / g, a weight average molecular weight of 6.8 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 6 &

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 To obtain a polyurethane polyurea resin (F-2-2) having an acid value of 20.0 mgKOH / g, a weight average molecular weight of 6.9 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 7 &

(DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), and dimethylformamide (DMF) / isopropyl alcohol were added in amounts as shown in Table 1, (F-2-3) having an acid value of 28.0 mgKOH / g, a weight average molecular weight of 6.8 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 8 &

(DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), and dimethylformamide (DMF) / isopropyl alcohol were added in amounts as shown in Table 1, To obtain a polyurethane resin (F-1-5) having an acid value of 3.1 mg KOH / g, a weight average molecular weight of 6.9 million, and a solid content of 30% (DMF / isopropyl alcohol).

<Comparative Synthesis Example 1>

(DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), and dimethylformamide (DMF) / isopropyl alcohol were added in amounts as shown in Table 1, To obtain a polyurethane polyurea resin (F-1-6) having an acid value of 10.4 mgKOH / g, a weight average molecular weight of 6.6 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 9 &

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 To obtain a polyurethane polyurea resin (F-2-4) having an acid value of 25.0 mgKOH / g, a weight average molecular weight of 650,000, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Synthesis Example 10 &

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 (F-2-5) having an acid value of 18.0 mgKOH / g, a weight average molecular weight of 6.7 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Comparative Synthesis Example 2 &

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 To obtain a polyurethane polyurea resin (F-2-6) having an acid value of 32.0 mgKOH / g, a weight average molecular weight of 6.8 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Comparative Synthesis Example 3 >

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 A polyurethane polyurea resin (F-1-7) having an acid value of 0.5 mg KOH / g, a weight average molecular weight of 6.7 million, and a solid content of 30% (DMF / isopropyl alcohol) was obtained.

&Lt; Comparative Synthesis Example 4 >

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 To obtain a polyurethane resin (F-1-8) having an acid value of 9.0 mg KOH / g, a weight average molecular weight of 6.7 million, and a solid content of 30% (DMF / isopropyl alcohol).

&Lt; Comparative Synthesis Example 5 >

The same procedure as in Synthesis Example 1 was carried out except that the amounts of dimethyrolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF) and dimethylformamide (DMF) / isopropyl alcohol were changed as shown in Table 1 (F-2-7) having an acid value of 15.0 mgKOH / g, a weight average molecular weight of 6.8 million, and a solid content of 30% (DMF / isopropyl alcohol).

The composition and the like of the polyurethane polyurea resin produced by the above procedure are shown in Tables 1 and 2.

(2) Production of conductive adhesive film

The conductive adhesive films of the respective examples and comparative examples will be described. To 55 parts by mass of the polyurethane polyurea resin (F) prepared above, 45 parts by mass of an epoxy resin was blended as shown in Table 3 to prepare a conductive adhesive composition. The composition of the epoxy resin was 20 parts by mass of a phenoxy type epoxy resin (trade name: jER4275, manufactured by Mitsubishi Chemical Corporation), 20 parts by mass of phenol novolak type epoxy resin (trade name jER152, manufactured by Mitsubishi Chemical Corporation) -4030, manufactured by Asahi Denka Co., Ltd.). This was hand-coated on a polyethylene terephthalate film subjected to release treatment using a doctor blade (plate-type spatula), and dried at 100 占 폚 for 3 minutes to prepare a conductive adhesive film. The doctor blade is suitably selected from 1 mil to 5 mil depending on the thickness of the conductive adhesive film to be manufactured. Further, 1 mil = 1/1000 inch = 25.4 占 퐉. In each of the Examples and Comparative Examples, the conductive adhesive film was formed so as to have a predetermined thickness. The thickness of the conductive adhesive film is measured by a micrometer.

The following conductive fillers were used.

Conductive filler: silver-coated copper powder (average particle size: 15 mu m, dendritic shape, manufactured by Fukuda Metal Powder Industry Co., Ltd.)

(3) Fabrication of circuit board with metal reinforcing plate

The conductive adhesive film (with the release agent of the polyethylene terephthalate product) prepared above and a metal reinforcing plate having a thickness of 200 탆 (Ni plating the surface of the SUS plate) were pressed at a temperature of 120 캜 for 5 seconds , And pressure: 0.5 MPa to prepare a conductive adhesive film having a metal reinforcing plate. Next, the polyethylene terephthalate film on the conductive adhesive film was peeled off, and a conductive adhesive film with a metal reinforcing plate was adhered to the flexible substrate under the same conditions as in the above-mentioned thermocompression bonding. Thereafter, a temperature of 170 ° C, Pressure: 3 MPa to prepare a circuit board having a metal reinforcing plate. 3, a copper foil 10 is formed on a polyimide film 1, and a coverlay 9 made of a polyimide film is formed thereon via an insulating adhesive layer 6 And a copper clad laminate in which an opening 11 simulating a ground connecting portion having a diameter of 1.0 mm was formed on the cover lay 9.

(4) Property evaluation

The obtained circuit boards having the metal reinforcing plate were evaluated based on the following evaluation criteria. The evaluation results are shown in Table 4.

(Low flow property)

And the flowability was evaluated. As a condition of reflow, assuming lead-free soldering, a temperature profile was set such that the temperature of the polyimide film on the circuit board with the metal reinforcing plate was exposed to 265 DEG C for 5 seconds. Specifically, the above circuit board with the metal reinforcing plate was passed through the hot air reflow five times, and the number of bulges in the opening 6 was visually observed. In addition, the number of the openings 6 was set to 90.

(Spoiled)

The adhesive strength after the metal reinforcing plate and the conductive adhesive film were laminated was measured by a 180 ° peeling test. Specifically, the metal reinforcing plate and the conductive adhesive film were plated using a press machine under the conditions of a temperature of 120 ° C, a time of 5 seconds, and a pressure of 0.5 MPa. Next, as shown in Fig. 5, the conductive adhesive film was peeled off at a tensile rate of 50 mm / min and a peeling angle of 180 占 with a tensile tester (product name: AGS-X50S, manufactured by Shimadzu Corporation) Respectively. If it is 0.6 N / cm or more, it can be used without any problem.

(Adhesiveness after the main bonding)

The adhesive strength after bonding the conductive adhesive film with the metal reinforcing plate to the polyimide film was measured by a 90 占 peeling test. Specifically, a conductive adhesive film and a metal reinforcing plate having a thickness of 200 占 퐉 (Ni plating the surface of the SUS plate) were plated with a press at a temperature of 120 占 폚, a time of 5 seconds, and a pressure of 0.5 MPa, To prepare a conductive adhesive film having a reinforcing plate. Next, the polyethylene terephthalate film on the conductive adhesive film was peeled off, and the polyimide film side of the copper foil laminated polyimide film (hereinafter referred to as the copper foil laminated film) was adhered to the conductive adhesive film under the same conditions as the above hot pressing , And further adhered under the conditions of a temperature of 170 DEG C, a time of 30 minutes, and a pressure of 3 MPa in a press machine to produce a copper foil laminated film having a metal reinforcing plate. Next, as shown in Fig. 6, the copper foil laminated film was peeled off at a tensile rate of 50 mm / min and a peeling angle of 90 deg. By a tensile tester (product name: AGS-X50S, manufactured by Shimadzu Corporation) Were measured. If it is 10 N / cm or more, it can be used without any problem. 6, the copper foil is laminated on the entire surface (not shown), and the polyimide film is exposed on the opposite side.

(Adhesion to polyimide film)

The adhesion between the conductive adhesive film and the polyimide film was measured by a 90 占 peeling test. Specifically, a conductive adhesive film and an SUS plate metal reinforcing plate having a thickness of 200 mu m were plated using a press machine under the conditions of a temperature of 120 DEG C, a time of 5 seconds, and a pressure of 0.5 MPa to prepare a conductive adhesive film with a metal reinforcing plate Respectively. Next, the polyethylene terephthalate film on the conductive adhesive film was peeled off, and the polyimide film side of the copper foil laminated film and the conductive adhesive film were adhered under the same conditions as in the above thermal compression bonding, 30 minutes and a pressure of 3 MPa to prepare a copper foil laminated film having a metal reinforcing plate. Next, as shown in Fig. 7, the conductive adhesive film was peeled off at a tensile rate of 50 mm / min and a peeling angle of 90 deg. By a tensile tester (product name: AGS-X50S, manufactured by Shimadzu Corporation) Respectively. If it is 10 N / cm or more, it can be used without any problem. 7, the copper foil is laminated on the entire surface (not shown), and the polyimide film is exposed on the opposite side.

(Adhesion with gold-plated copper foil)

The adhesion between the gold plating formed on the surface of the copper foil of the copper clad laminate and the conductive adhesive was measured by a 90 ° peeling test. Specifically, a conductive adhesive film and an SUS plate metal reinforcing plate having a thickness of 200 mu m were plated using a press machine under the conditions of a temperature of 120 DEG C, a time of 5 seconds, and a pressure of 0.5 MPa to prepare a conductive adhesive film with a metal reinforcing plate Respectively. Next, the gold plated layer of the copper foil laminated film having the gold plating layer formed on the surface of the copper foil of the copper foil laminated film and the conductive adhesive film were adhered under the same conditions as in the above thermal compression bonding, 30 minutes and a pressure of 3 MPa to prepare a copper foil laminated film having a metal reinforcing plate. Next, as shown in Fig. 8, the copper foil laminated film was peeled off at a tensile rate of 50 mm / min and a peeling angle of 90 占 with a tensile tester (product name: AGS-X50S, manufactured by Shimadzu Corporation) Were measured. If it is 10 N / cm or more, it can be used without any problem.

1 polyimide film
2 protective layer
3 metal layer
4 conductive adhesive layer
5 ground part
6 Insulation adhesive
7 Cover Ray Film
8 metal reinforcing plate
9 Cover Ray
10 Copper foil
11 opening
12 Gold plated layer
13 Polyimide film side of copper clad laminate
14 Metal reinforcement plate made of SUS
110 Printed wiring board main body
111 Insulation film (Coverage)
112 base member
113 Adhesive layer with insulation
114 Wiring pattern for ground
115 Conductive adhesive layer
116 reinforcing member
117 Electronic Components
118 hole

Claims (6)

A polyurethane polyurea resin (F) obtained by reacting a urethane prepolymer (D) obtained by reacting a polyol compound (A), a diisocyanate compound (B) and a carboxyl group-containing diol compound (C) with a polyamino compound (E)
An epoxy resin (G) having two or more epoxy groups,
And at least a conductive filler (H)
Wherein the polyurethane polyurea resin (F) is a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH / g and a polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH / . The method according to claim 1,
Wherein the polyurethane polyurea resin (F-2) is 30 to 300 parts by mass based on 100 parts by mass of the polyurethane polyurea resin (F-1). The method according to claim 1 or 2,
Wherein the epoxy resin (G) is contained in an amount of 50 to 500 parts by mass per 100 parts by mass of the polyurethane polyurea resin (F). A conductive adhesive film having a releasable base material and an adhesive layer comprising the conductive adhesive composition according to any one of claims 1 to 3. An electromagnetic wave shielding film comprising at least an insulating layer and a conductive adhesive layer, wherein the conductive adhesive layer comprises the conductive adhesive composition according to any one of claims 1 to 3. A base member having a ground wiring pattern on at least one surface thereof,
A cover ray covering the ground wiring pattern and provided with an opening so that a part of the ground wiring pattern is exposed,
A conductive reinforcing plate disposed opposite to the ground wiring pattern,
A conductive adhesive layer for bonding the ground wiring pattern of the base member and the conductive reinforcing plate in a conductive state,
And an electronic component disposed on the other surface of the base member at a position corresponding to the conductive reinforcing plate,
Wherein the conductive adhesive layer has the conductive adhesive composition according to any one of claims 1 to 3.

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