TW201610057A - Electroconductive adhesive composition - Google Patents

Abstract

Provided is an electroconductive adhesive composition having at least: a polyurethane polyurea resin (F) obtained by reacting a polyamino compound (E) and a urethane prepolymer (D) obtained by reacting a polyol compound (A), a diisocyanate compound (B), and a diol compound (C) having a carboxyl group; an epoxy resin (G) having two or more epoxy groups; and an electroconductive filler (H); the polyurethane polyurea resin (F) being a polyurethane polyurea resin (F-1) having an acid value of 1-6 mg KOH/g and a polyurethane polyurea resin (F-2) having an acid value of 18-30 mg KOH/g.

Description

Conductive adhesive composition Technical field

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

Background technique

In the printed wiring board, the conductive adhesive film, and the electromagnetic wave shielding film, a conductive adhesive composed of a conductive filler and a resin composition has been used. The conductive adhesive is required to have high heat resistance in the reflow-resistant step, maintain durability of high adhesion and low connection resistance even when exposed to a high-temperature and high-humidity environment, and can be provided to an opening provided in a printed substrate. The filling of the conductive adhesive is filled. Further, in the printed circuit board on which the electronic component is mounted, if the printed circuit board is bent during use, the portion where the electronic component is mounted is deformed, and the electronic component is broken. Therefore, a reinforcing plate made of stainless steel or the like may be provided at a position facing the printed circuit board at a position where the electronic component is mounted. The reinforcing plate is adhered to the conductive adhesive film, and is press-formed into a specific shape, and then fixed to the printed circuit board. Here, the conductive adhesive film is required to be temporarily bonded to a metal reinforcing plate when pressed into a specific shape, and the adhesion after fixing to a printed circuit board (also referred to as positive And then the adhesion).

Patent Document 1 describes a conductive resin composition containing a polyurethane polyurea resin and an epoxy resin as a composition of such a conductive adhesive. Patent Documents 2 and 3 disclose an adhesive composition containing a polyurethane polyurea resin and an epoxy resin.

Advanced technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-143981

Patent Document 2: International Publication No. 2007/032463

Patent Document 3: Japanese Laid-Open Patent Publication No. 2005-298812

Invention

The conductive resin composition described in Patent Documents 1 to 3 is improved to some extent in terms of heat resistance and adhesion after exposure to a high-temperature and high-humidity environment, but is temporarily adhered to the printed substrate after hot pressing. The sexuality (the adhesion after the formal follow-up) and the heat resistance cannot be satisfied.

Therefore, an object of the present invention is to provide a conductive adhesive which is excellent in heat resistance, temporary adhesiveness, adhesion after the final adhesion, and adhesion to a substrate, and a conductive adhesive sheet and electromagnetic wave using the same. Shielding film.

The present inventors focused on the use of a plurality of polyurethane urethane resins contained in a conductive adhesive.

Then, it was found that by combining a resin having a low acid value and having a high acid value The resin is used as a polyurethane polyurea resin, and is excellent in adhesion to a substrate, temporary adhesion, and adhesion after the final bonding, and the present invention described below is finally completed.

[1] A conductive adhesive composition comprising at least a polyurethane urethane resin (F) for reacting a urethane prepolymer (D) with a polyamine compound (E) The urethane prepolymer (D) is obtained by reacting a polyol compound (A), a diisocyanate compound (B), and a diol compound (C) having a carboxyl group; and an epoxy resin (G) ) having two or more epoxy groups; and a conductive filler (H); and, the polyurethane urethane resin (F) is a polyurethane polyurea having an acid value of 1 to 6 mgKOH/g. Resin (F-1) and polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH/g.

[2] The conductive adhesive composition according to [1], wherein the polyurethane urethane resin (F-2) is used in an amount of 100 parts by mass based on 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 any one of [1] or [2] wherein the epoxy resin (G) is 50% per 100 parts by mass of the polyurethane polyurea resin (F). 500 parts by mass.

[4] A conductive adhesive film comprising a release substrate and an adhesive layer comprising the conductive adhesive composition according to any one of [1] to [3].

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

[6] A printed wiring board comprising: a base member having at least one of the ground wiring patterns; a cover layer covering the ground wiring pattern; and an opening for providing the ground wiring One of the patterns is partially exposed; the conductive reinforcing plate is disposed to face the grounding wiring pattern; and the conductive adhesive layer is electrically connected to the grounding wiring pattern and the conductive reinforcing plate of the base member; And an electronic component disposed at a position corresponding to the conductive reinforcing plate on the other surface of the base member; and the conductive adhesive layer has the conductive material according to any one of [1] to [3] Sexual binder composition.

According to the present invention, a conductive adhesive composition excellent in heat resistance, adhesion to a substrate, temporary adhesiveness, and adhesion after the final adhesion, and a conductive adhesive film and an electromagnetic wave shielding film using the same can be obtained. .

1‧‧‧ Polyimine film

2‧‧‧Protective layer

3‧‧‧metal layer

4‧‧‧ Conductive adhesive layer

5‧‧‧ Grounding Department

6‧‧‧Insulating adhesive layer

7‧‧‧ Cover film

8‧‧‧Metal reinforcing plate

9‧‧‧ Coverage

10‧‧‧ copper foil

11‧‧‧ openings

12‧‧‧ gold plating

13‧‧‧ Polyimide film side of copper-clad laminate

14‧‧‧SUS metal reinforcement board

16‧‧‧ arrow

110‧‧‧Printed wiring board body

111‧‧‧Insulation film (covering layer)

112‧‧‧Substrate components

113‧‧‧Insulating adhesive layer

114‧‧‧ Grounding wiring pattern

115‧‧‧layer with conductive adhesive

116‧‧‧Reinforcing components

117‧‧‧Electronic parts

118‧‧‧ Hole Department

Fig. 1 is a schematic view showing 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 substrate using an electromagnetic wave shielding film having a metal layer.

3 is a schematic view of a first circuit substrate with a conductive bonding film followed by a reinforcing plate.

4 is a schematic view of a second circuit substrate with a conductive bonding film followed by a reinforcing plate.

Fig. 5 is a schematic view showing the measurement of temporary adhesiveness.

Fig. 6 is a schematic view showing a state in which the adhesion after the measurement is officially followed.

Fig. 7 is a schematic view showing the measurement of adhesion to a polyimide film.

Fig. 8 is a schematic view showing the measurement of adhesion to a gold-plated copper foil.

Form for implementing the invention

Hereinafter, the present invention will be described in detail.

<Electrically conductive adhesive composition>

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

The polyurethane urethane resin (F) contained in the conductive adhesive composition of the present invention is obtained by reacting a urethane prepolymer (D) with a polyamine compound (E). The urethane prepolymer (D) is obtained by reacting a polyol compound (A), a diisocyanate compound (B), and a diol compound (C) having a carboxyl group.

(Polyol compound (A))

The polyol compound in the present invention is not particularly limited, and a well-known polyol used in the synthesis of a urethane can be used. As such a polyol, For example, a polyester polyol, a polyether polyol, a polycarbonate polyol, and other polyols can be mentioned.

The polyester polyol may, for example, be an aliphatic dicarboxylic acid (for example, succinic acid, adipic acid, sebacic acid, glutaric acid, sebacic acid, etc.) and/or an aromatic dicarboxylic acid (for example, isophthalic acid). Dicarboxylic acid, terephthalic acid, etc.), and low molecular weight diols (such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexamethylene di Polycondensation of alcohol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, etc.).

Specific examples of such a polyester polyol include poly(ethylene adipate) diol, poly(butylene succinate) diol, and polyhexamethylene hexacarboxylate diol. , polypentamethylene adipate diol, polyadipate extended ethyl / butyl butyl glycol, polyadipyl neopentyl / hexyl diol, poly-3-adipate Methyl pentanyl diol, poly(butylene terephthalate) diol, polycaprolactone diol, poly-3-methyl valerolactone diol, and the like.

Specific examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and the like, and random/block copolymers thereof. Specific examples of the polycarbonate polyol include polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyneopentyl carbonate diol, and polyhexamethylene group. A carbonate diol, a poly(1,4-cyclohexane dimethylene carbonate) diol, and the like/random/block copolymer thereof.

Specific examples of the other polyhydric alcohols include dimer alcohol, polybutadiene polyol and hydrogenated product thereof, polyisoprene polyol and hydrogenated product thereof, acrylic polyol, epoxy polyol, and polyether ester. Polyol, decane modified polyol, α, ω-polymethyl methacrylate polyol, α, ω-polybutyl methacrylate polyol, and the like.

The number average molecular weight (Mn, quantitative by 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, there is a tendency that the cohesive force of the urethane bond is hard to be exhibited and the mechanical properties are lowered. Further, the crystalline polyol having a number average molecular weight of more than 3,000 may cause whitening when it is formed into a film. Further, the polyol compound (A) may be used alone or in combination of two or more.

Further, as the reaction component for obtaining the urethane prepolymer (D), a short-chain polyol component and/or a diamine component is preferably used as needed. Thereby, it becomes easy to control the hardness, viscosity, etc. of the polyurethane polyurea resin (F). Specific examples of the short-chain polyol component include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexamethylene glycol, and neopentane. An aliphatic diol such as a diol and an alkylene oxide low molar addition product thereof (the number average molecular weight is less than 500 by quantification of terminal functional groups); 1,4-bishydroxymethylcyclohexane, 2-methyl group An alicyclic diol such as 1-, 1-cyclohexanedimethanol or a low molar addition of alkylene oxide (the number average molecular weight is less than 500, supra); an aromatic diol such as benzene dimethyl glycol and Its alkylene oxide low molar additive (the number average molecular weight is less than 500, the same as above); bisphenol A, thiobisphenol, sulfobisphenol and other bisphenols and their alkylene oxide low molar additions (quantity The average molecular weight is less than 500, the same as above; an alkyldialkanamine such as an alkyl diethanolamine of C1 to C18.

Specific examples of the diamine compound include aliphatic diamines such as methylene diamine, ethylene diamine, trimethylene diamine, hexamethylene diamine, and octamethylene diamine. a compound; phenyldiamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4'-methylenebis(phenylamine), 4,4'-di Amine An aromatic diamine compound such as phenyl ether or 4.4'-diaminodiphenylphosphonium; cyclopentyldiamine, cyclohexyldiamine, 4,4'-diaminodicyclohexylmethane, 1,4-two An alicyclic diamine compound such as aminocyclohexane or isophorone diamine. Further, as the diamine compound, an anthracene such as ruthenium, carbon ruthenium dioxime, diammonium adipate, bismuth sebacate or dioxonium phthalate can be used. Further, examples of the long chain include long chain alkyl diamine, polyoxyalkylene diamine, terminal amine polyamine, and decane modified polyamine. These diamine compounds may be used alone or in combination of two or more.

(diisocyanate compound (B))

The diisocyanate compound (B) in the present invention is not particularly limited, and a previously known diisocyanate compound used in the production of a polyurethane may be used. Specific examples of the diisocyanate compound (B) include toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, and 4-isopropyl-1,3-extension. Phenyl diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4 '-Methylene bis(phenylene isocyanate) (MDI), decylidene diisocyanate, tolidine diisocyanate, benzoyl diisocyanate (XDI), 1,5-naphthalene diisocyanate, benzidine II Aromatic diisocyanates such as isocyanate, o-nitrobenzidine diisocyanate and 4,4'-dibenzyl diisocyanate; methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene Aliphatic diisocyanates such as bis-isocyanate and 1,10-decamethylene diisocyanate; 1,4-cyclohexyl diisocyanate, methylene bis(4-cyclohexyl isocyanate), 1,5-tetrahydronaphthalene Isocyanate, isophorone diisocyanate, hydrogenated MDI, hydrogenated XDI, etc. alicyclic diisocyanate; A polyurethane prepolymer obtained by reacting a cyanate ester with a low molecular weight polyol or polyamine in such a manner that the terminal is an isocyanate.

(diol compound (C) having a carboxyl group)

The diol compound (C) having a carboxyl group in the invention is not particularly limited, and examples thereof include dimethylol alkanoic acid such as dimethylolpropionic acid and dimethylolbutanoic acid; and dimethylol alkanoic acid. The alkylene oxide low molar additive (the number average molecular weight by the terminal functional group is less than 500); the ε-caprolactone low molar additive of the dimethylol alkanoic acid (by the terminal functional group) Quantitative number average molecular weight of less than 500); half esters derived from anhydride of dimethylol alkanoic acid and glycerol; hydroxyl group of dimethylol alkanoic acid, monomer having unsaturated bond, and having carboxyl group and unsaturated A compound obtained by subjecting a monomer of a bond to a radical reaction. Among them, dimethylol alkanoic acid such as dimethylolpropionic acid or dimethylolbutanoic acid is preferred from the viewpoints of ease of availability and ease of adjustment of acid value.

(urethane prepolymer (D))

The urethane prepolymer (D) of the present invention is 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) having a hydroxyl group of the diol compound (C) having a carboxyl group is preferably from 1.1 to 2.5. In the above range, it is preferable from the viewpoint of obtaining a conductive adhesive composition having high heat resistance and high mechanical strength. The reaction temperature is not particularly limited, and may be, for example, 60 to 100 ° C.

(reaction stop agent)

Making the polyol compound (A), the diisocyanate compound (B) and having a carboxyl group When the diol compound (C) is reacted to obtain the urethane prepolymer (D), the molecular weight of the urethane prepolymer is adjusted, and a reaction stopper can be used as needed. As the reaction stopper, a monool compound or a monoamine compound, an alkanolamine compound or the like can be used. As the monool, for example, methanol, ethanol, butanol, isopropanol or the like can be used. Further, as the monoamine compound, butylamine, dibutylamine or the like can be used. Further, as the alkanolamine, monoethanolamine, diethanolamine or the like can be used.

(polyamine compound (E))

The polyamino compound (E) in the present invention is not particularly limited, and a previously known polyamino compound used in the production of a polyurea resin can be used. Specific examples of the polyamino compound (E) include ethylenediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, and isophorone diamine. 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexane Diamines such as diamine and 1,2-propanediamine; aminoethylethanolamine, aminopropylethanolamine, aminohexylethanolamine, aminoethylpropanolamine, aminopropylpropanolamine, amine group A compound such as an aminoalkylalkanolamine such as hexylpropanolamine.

(Polyurethane polyurea resin (F))

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

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

The acid value of the polyurethane polyurea resin (F-1) is preferably less than 3 from the viewpoint of the temporary adhesiveness and the adhesion to the gold-plated copper foil.

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

The acid value of the polyurethane polyurea resin (F-2) is preferably more than 25 from the viewpoint of the temporary adhesiveness and the adhesion to the gold-plated copper foil.

Further, the conductive adhesive film obtained by using the conductive adhesive composition of the present invention by using the polyurethane urethane resin (F-1) and (F-2) having the acid value of the above specific range The reflow resistance (heat resistance) is improved. Further, by using the polyurethane urethane resins (F-1) and (F-2) having the acid value of the above specific range, it is advantageous in both temporary adhesion and adhesion after the final adhesion. .

The combination of the polyurethane urethane resin (F-1) and (F-2) constituting the polyurethane polyurea resin (F) is not particularly limited as long as it is within the above specific range. As such a combination, a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH/g and a polyurethane polyurea having an acid value of 18 to 30 mgKOH/g can be used. a combination of a resin (F-2); and a polyurethane resin (F-1) having an acid value of 1 to less than 3 mgKOH/g and a polyaminocarboxylic acid having an acid value of 18 to 30 mgKOH/g. a combination of ester polyurea resin (F-2); and a polyurethane polyurea resin (F-1) having an acid value of 1 to 2.5 mgKOH/g and A combination of polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH/g; and a polyurethane polyurea resin (F-1) having an acid value of 1 to 6 mgKOH/g. Combination with polyurethane polyurea resin (F-2) having an acid value of more than 25 mgKOH/g to 30 mgKOH/g; and a polyurethane polyurea having an acid value of 1 to less than 3 mgKOH/g A combination of a resin (F-1) and a polyurethane urethane resin (F-2) having an acid value of more than 25 mgKOH/g to 30 mgKOH/g; and a polyamine group having an acid value of 1 to 2.5 mgKOH/g. a combination of a formate polyurea resin (F-1) and a polyurethane polyurea resin (F-2) having an acid value of more than 25 mgKOH/g to 30 mgKOH/g; and an acid value of 1 to 6 mgKOH/g. a combination of a polyurethane polyurea resin (F-1) and a polyurethane urethane resin (F-2) having an acid value of 26 mgKOH/g to 30 mgKOH/g; and an acid value of 1~ Combination of polyurethane polyurea resin (F-1) of less than 3 mgKOH/g and polyurethane polyurea resin (F-2) having an acid value of 26 mgKOH/g to 30 mgKOH/g; Polyurethane polyurea resin (F-1) having an acid value of 1 to 2.5 mgKOH/g and polyurethane polyurea resin (F-2) having an acid value of 26 mgKOH/g to 30 mgKOH/g Combinations, etc.

Further, from the viewpoint of excellent adhesion after the final adhesion, the combination of the polyurethane urethane resin (F-1) having an acid value of less than 3 mgKOH/g and the polyurethane urethane resin The acid value of (F-2) is preferably more than 25 mgKOH/g.

Further, the polyurethane urethane resins (F-1) and (F-2) may be used in combination of two or more kinds as long as they satisfy the respective acid value.

Further, the acid value of the polyurethane polyurea resin in the present invention is measured in accordance with JIS K 0070 Neutralization and titration.

Further, regarding the polyurethane polyurea resins (F-1) and (F-2), the weight average molecular weight thereof is usually from 50,000 to 100,000.

In addition, when the conductive adhesive film of the conductive adhesive of the present invention is excellent in adhesion to a substrate, the adhesion to the substrate includes adhesion to a resin sheet such as a polyimide film. And two kinds of adhesion to metal materials such as gold-plated copper foil or conductive reinforcing plate.

In the present invention, the temporary adhesive property refers to the adhesion between the conductive adhesive film and the reinforcing plate when the reinforcing plate and the conductive adhesive film are temporarily pressed, and then pressed into a specific shape or the peelable substrate is peeled off. .

Further, in the present invention, the adhesion after the final bonding refers to the adhesion between the printed substrate and the conductive adhesive film after the conductive substrate is fixed (formally followed by) the printed substrate. In addition, temporary adhesiveness is also called temporary adhesiveness and workability. Moreover, the adhesion after the formal follow-up is also called formal adhesion.

The measurement method of the temporary adhesiveness and the adhesiveness after the formal follow-up is described in detail in the examples.

The ratio of polyurethane polyurea resin (F-1) to polyurethane polyurethane resin (F-2), relative to the mass of polyurethane polyurethane resin (F-1) 100 The polyurethane urethane resin (F-2) is preferably 30 to 300 parts by mass. When the ratio of the polyurethane polyurea resin (F-1) to the polyurethane urethane resin (F-2) is within the above range, the adhesion between the conductive adhesive film and the printed wiring board is good. Temporary adhesion and filling.

(epoxy resin (G))

The epoxy resin (G) in the present invention is not particularly limited, and can be used for a known epoxy resin having two or more epoxy groups in one molecule. As such an epoxy tree For example, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol epoxy resin, spiro epoxy resin, naphthalene epoxy resin, and the like can be used. Benzene type epoxy resin, terpene type epoxy resin, tris(glycidoxyphenyl)methane, tetrakis(glycidoxyphenyl)ethane and other glycidyl ether type epoxy resin, tetraglycidyl diamine group Glycidylamine type epoxy resin such as diphenylmethane, tetrabromobisphenol A type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, α-naphthol novolac type epoxy resin, bromine A phenolic epoxy resin such as a phenol novolak type epoxy resin or a rubber modified epoxy resin.

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 preferred to use an epoxy equivalent of 800 to 10,000 (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) are also of the same type, and may have different chemical structures.

As the epoxy resin (G1), those having an epoxy equivalent of 800 to 10,000 are preferably used. Therefore, it is preferable to further improve the adhesion with the reinforcing plate. The lower limit of the above epoxy equivalent is preferably 1,000, more preferably 1,500. The upper limit of the above epoxy equivalent is preferably 5,000, more preferably 3,000. Further, as the epoxy resin (G1), it is preferred to use a solid at room temperature. The term "solid at normal temperature" means a solid state which does not have fluidity at 25 ° C in a solvent-free state.

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

The above epoxy resin (G2) is particularly preferably an epoxy equivalent of from 90 to 300.

Thereby, the effect of improving the heat resistance of the resin can be obtained. The lower limit of the above epoxy equivalent is preferably 150, more preferably 170. The upper limit of the above epoxy equivalent is preferably 250, more preferably 230. Further, as the epoxy resin (G2), it is preferred to use a solid at room temperature.

The epoxy resin (G2) is preferably a novolac type epoxy resin. Although the phenolic epoxy resin has a higher density of the epoxy resin, since the miscibility with other epoxy resins is good and the difference in reactivity between the epoxy groups is small, the entire coating film can be uniformly made high. Joint density.

The phenolic epoxy resin is not particularly limited, and examples thereof include a cresol novolac epoxy resin, a phenol novolak epoxy resin, an α-naphthol novolak epoxy resin, and a brominated phenol novolak epoxy resin.

As a commercially available epoxy resin usable as the above-mentioned epoxy resin (G2), EPICLON N-660, N-665, N-670, N-673, N-680, N-695, N-655 are mentioned. -EXP-S, N-662-EXP-S, N-665-EXP, N-665-EXP-S, N-672-EXP, N-670-EXP-S, N-685-EXP, N-673 -80M, N-680-75M, N-690-75M, N-740, N-770, N-775, N-740-80M, N-770-70M, N-865, N-865-80M (Commodity Name, DIC Co., Ltd.), jER152, 154, 157S70 (trade name, manufactured by Mitsubishi Chemical Corporation), YDPN-638, YDCN-700, YDCN-700-2, YDCN-700-3, YDCN-700- 5, YDCN-700-7, YDCN-700-10, YDCN-704, YDCN-700-A (trade name, Nippon Steel Chemical Co., Ltd.) and so on.

Further, in the case where a phenolic epoxy resin is used as the epoxy resin (G2), it is preferable to use an epoxy resin other than the phenolic epoxy resin which is solid at normal temperature. When the adhesive layer is composed of only a novolac type epoxy resin, there is a problem in that the adhesion is insufficient. Therefore, it is preferable to use an epoxy resin (G1) other than the novolac epoxy resin.

In the present invention, the ratio of the polyurethane urethane resin (F) to the epoxy resin (G) is preferably 100 parts by mass relative to the polyurethane urethane resin (F), and the epoxy resin ( G) is 50 to 500 parts by mass, more preferably 50 to 300 parts by mass, and if it is focused on the adhesion after the formal follow-up, it is preferably 50 to 200 parts by mass. The reason for this is that the degree of crosslinking with the polyurethane polyurea resin can be appropriately adjusted by setting the ratio within the above range, and the flexibility and printing of the conductive adhesive composition and the electromagnetic wave shielding film can be appropriately performed. The adhesion, temporary adhesion, and filling property of the wiring board are good. In particular, the epoxy resin (G) is 50 parts by mass or more based on 100 parts by mass of the polyurethane polyurea resin (F), whereby the reflow resistance, the adhesion after the final adhesion, and the resin sheet are obtained. On the other hand, when it is 500 mass parts or less, the adhesiveness with respect to the metal material, such as gold plating, improves.

(conductive filler)

The conductive adhesive film of the present invention contains a 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 the like can be used. As the metal filler, there are copper powder, silver powder, nickel powder, silver coated copper powder, gold coated copper powder, silver coated nickel powder, gold coated nickel powder, and the metal powder can be atomized by electrolysis or atomization. Made by law and reduction method.

Further, in particular, in order to easily obtain contact between the fillers, the average particle diameter of the conductive filler is preferably from 3 to 50 μm. Further, examples of the shape of the conductive filler include a spherical shape, a flake shape, a dendritic shape, and a fibrous shape.

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

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

Further, in the conductive adhesive film, a decane coupling agent, an antioxidant, a pigment, a dye, an adhesive resin, a plasticizer, an ultraviolet absorber, or a defoaming agent may be added in a range in which the solder reflow resistance is not deteriorated. Agent, leveling agent, filler, flame retardant, etc.

<Electrically conductive film>

The conductive adhesive film of the present invention can be produced by applying a conductive adhesive composition to a release substrate (release film). In addition, the coating method is not particularly limited, and a known coating machine typified by die coating, lip coating, comma coating, or the like can be used.

The release film can be used on a base film such as polyethylene terephthalate or polyethylene naphthalate, and a release coating of a lanthanum or non-lanthanide is applied to the surface of the conductive adhesive layer. Adult. Further, the thickness of the release film is not particularly limited, and can be determined by appropriately considering the ease of use.

The conditions for applying the conductive adhesive composition to the release film may be appropriately set. The thickness of the obtained conductive adhesive layer is preferably 15~100μm. If it is thinner than 15 μm, the filling property is insufficient, and if it is thicker than 100 μm, it is disadvantageous in cost and does not correspond to the requirement of thinning. In the conductive adhesive layer having such a thickness, it is preferable that the shape of the recessed portion is changed by moderate flow when the substrate has irregularities, and the adhesion can be favorably followed.

<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 an electromagnetic wave shielding film having no metal layer as described in detail below or a conductive adhesive film for bonding with a reinforcing plate, it can be used as an isotropic conductivity. Agent layer.

Further, in the case of the 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.

Further, these may be any depending on the amount of the conductive filler (H). In order to form the anisotropic conductive adhesive layer, it is preferable that the conductive filler accounts for 5% by weight or more and less than 40% by weight based on the total solid content of the conductive adhesive composition. In order to be an isotropic conductive adhesive layer, it is preferable that the conductive filler (H) accounts for 40% by weight or more and 90% by weight or less of the total solid content of the conductive adhesive composition.

(electromagnetic wave shielding film)

The electromagnetic wave shielding film using the conductive adhesive composition of the present invention preferably has a conductive adhesive layer and a protective layer. As a protective layer, as long as it is insulating The resin composition is not particularly limited, and any of the well-known ones can be used. Further, as the protective layer, a resin component (other than the conductive filler) used in the above-mentioned conductive adhesive layer may be used. Further, the protective layer may be formed of a layer composed of two or more layers or having different hardnesses. Further, a protective agent, an adhesive agent, an antioxidant, a pigment, a dye, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling agent, a filler, a flame retardant, and the like may be contained in the protective layer as needed. Viscosity regulator, anti-caking agent, etc.

The electromagnetic wave shielding film preferably has a thickness of the conductive adhesive layer in the range of 3 to 30 μm. If the thickness is less than 3 μm, the connection to the ground circuit cannot be sufficiently obtained. If it exceeds 30 μm, it is not preferable because it cannot meet the requirements for thinning.

Hereinafter, specific aspects of the method for producing the electromagnetic wave shielding film of the present invention will be described.

For example, a resin composition for a protective layer is applied onto one surface of a release film and dried to form a protective layer, and the conductive adhesive composition is applied onto the protective layer and dried to form a protective layer. A method of a conductive adhesive layer or the like.

An electromagnetic wave shielding film in a laminated state of the conductive adhesive layer/protective layer/peelable film can be obtained by the exemplified manufacturing method.

As a method of providing a conductive adhesive layer and a protective layer, a conventionally known coating method, for example, a gravure coating method, a contact coating method, a die coating method, a lip coating method, and a comma coating method can be used. The blade coating method, the roll coating method, the blade coating method, the spray coating method, the bar coating method, the spin coating method, the impregnation coating method, and the like are performed.

The electromagnetic wave shielding film can be subsequently bonded to the printed wiring board by hot pressing. 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. Thereby, the grounding circuit is electrically connected to the conductive adhesive, and the shielding effect can be improved.

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. In FIG. 1, the conductive adhesive layer 4 is formed in contact with the ground portion 5. Since the conductive adhesive layer 4 of the present invention has moderate fluidity, the filling property is good, and good electrical connection can be performed in the ground portion 5.

(Electromagnetic wave shielding film with metal layer)

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

Examples of the metal material forming the metal layer include nickel, copper, silver, tin, gold, palladium, aluminum, chromium, titanium, zinc, and an alloy containing any one or more of these materials. Further, the metal material and the thickness of the metal layer can be appropriately selected according to the required electromagnetic shielding effect, the reverse bending, and the sliding resistance, but the thickness may be a thickness of about 0.1 μm to 8 μm. Further, examples of the method for forming the metal layer include electrolytic plating, electroless plating, sputtering, electron beam evaporation, vacuum deposition, CVD, and metal organic chemical vapor deposition. Further, the metal layer may be a metal foil or a metal nanoparticle.

The electromagnetic wave shielding film having the metal layer as described above can be produced by the same method as the electromagnetic wave shielding film described above, and is preferably a structure 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. 2 . In FIG. 2, the metal layer 3 is electrically connected to the ground portion 5 via the conductive adhesive layer 4 to obtain electromagnetic wave shielding performance. At this time, since the conductive adhesive layer 4 has moderate fluidity, the filling property is good, and good electrical connection can be performed in the ground portion 5.

As the adherend to which the electromagnetic wave shielding film of the present invention can be attached, for example, a flexible substrate which is repeatedly subjected to bending is exemplified. Of course, it can also be applied to a hard printed wiring board. Furthermore, it is not limited to a one-sided shield, and a double-sided shield is also included.

The electromagnetic wave shielding film can be attached to the substrate by heating and pressing. The hot pressing in such heating and pressurization can be carried out under normal conditions, for example, at 1 to 5 MPa, 140 to 190 ° C, and 15 to 90 minutes.

<Next method>

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

In addition, as a material of the circuit board main body, any material which is insulating and can form an insulating layer can be used, and a representative example thereof is a polyimide resin.

A metal plate is preferably used as the conductive reinforcing plate, and a stainless steel plate, an iron plate, a copper plate or an aluminum plate can be used as the metal plate. It is preferable to use a stainless steel plate among them. By using a stainless steel plate, even if the plate thickness is thin, it is fully supported. Hold the strength of electronic parts. The thickness of the conductive reinforcing plate is not particularly limited, and 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 with the conductive reinforcing plate can be built in a small machine without being reluctantly built, and has sufficient strength to support the mounted electronic parts. Further, a metal layer such as Ni may be formed on the surface of the reinforcing plate by plating or the like. Further, the surface of the metal reinforcing plate may be imparted with a concave-convex shape by sandblasting or etching.

In addition, as the electronic component referred to herein, a chip component such as a resistor or a capacitor may be used in addition to the connector or the IC.

The method of using the conductive adhesive film of the present invention is a subsequent method comprising: step (1), temporarily attaching the conductive adhesive film to the bonded substrate (X) of the reinforcing plate or the flexible substrate; and the step (2) The underlying substrate (Y) on which the flexible substrate or the reinforcing plate is superposed on the substrate (X) having the conductive adhesive film obtained by the step (1) is hot pressed.

The above-mentioned conductive adhesive film is particularly suitable for use in the flexible substrate and the reinforcing plate in the flexible circuit substrate. By using a conductive metal plate or the like as a reinforcing plate, the conductive adhesive film is attached to the flexible circuit substrate, and the electromagnetic wave shielding capability can be obtained by the reinforcing plate.

By this method, the conductive adhesive film of the present invention has particularly excellent effects in terms of obtaining good adhesion properties when the reinforcing plate is subsequently reinforced. That is, the step (1) of temporarily bonding the conductive adhesive film to the adherend substrate (X) of the reinforcing plate or the flexible substrate, and the conductive adhesive film obtained by the step (1) are followed. In the step (2) of superimposing a soft substrate or a reinforcing substrate on the substrate (X) and performing hot pressing, the guide of the present invention Electrical adhesives exhibit excellent adhesion and durability in high temperature environments.

In the subsequent method of the present invention, the conductive adhesive film is first temporarily attached to the substrate (X) to be bonded. The substrate to be bonded (X) may be a reinforcing plate or a flexible substrate, but a reinforcing plate is preferred. Although the conditions are not particularly limited as long as the conductive adhesive film is fixed to the substrate to be bonded, it may be carried out without moving, and it is preferable that the surface is followed by a non-point. That is, it is preferable to temporarily follow the entire surface of the surface.

For the time being, it can be carried out by a press machine, and the subsequent conditions can be appropriately set. For example, the conditions of temperature: 120 ° C, time: 5 seconds, and pressure: 0.5 MPa can be exemplified.

The step (2) is a step of hot pressing the substrate (Y) on which the flexible substrate or the reinforcing plate is superposed on the substrate (X) having the conductive adhesive film obtained by the step (1).

Further, the substrate (X) and the substrate to be bonded (Y) are each a reinforcing plate and one is a flexible substrate.

The conditions for hot pressing can be appropriately set, and can be carried out, for example, at 1 to 5 MPa, 140 to 190 ° C, and 15 to 90 minutes.

<circuit substrate>

The circuit board using the conductive adhesive film of the present invention has at least a part of a portion in which a printed wiring board, a conductive adhesive film, and a conductive reinforcing sheet are sequentially laminated. Such a circuit board may be followed by the above-described method, or may be obtained by another method. Moreover, a schematic view of such a circuit board is shown in FIGS. 3 and 4. In FIG. 3, the circuit substrate and the reinforcing plate are then electrically connected by the conductive adhesive film of the present invention. Figure 4 In the circuit board, a wiring layer, an insulating adhesive layer, and a wiring pattern composed of a copper foil partially covered with a gold plating layer on the surface are laminated in this order, and a base member. Further, the insulating adhesive layer may be omitted by performing a CB process or the like. The material constituting the cover layer and the base member may be any material which has insulating properties and can form an insulating layer. A typical example thereof is a polyimide resin. Further, an opening portion is provided in one of the cover layers to expose one of the ground circuits from the opening. Then, the conductive adhesive composition of the present invention is filled in the opening portion. Thereby, the grounding circuit is joined to the conductive reinforcing plate by the conductive adhesive composition of the present invention in an on state. Further, by connecting the reinforcing plate to the external grounding member, the grounding circuit can be grounded to the external ground via the reinforcing plate. Further, 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.

Further, in the above circuit board, the conductive reinforcing plate is preferably present only in one part of the circuit board. That is, it is preferable that the conductive reinforcing plate is coated on a part of the circuit board having the electronic component.

In the circuit board using the conductive adhesive film of the present invention, at least a part of the surface other than the surface of the above-described reinforcing plate-covered circuit substrate is preferably covered with the electromagnetic wave shielding film. In other words, the electromagnetic wave shielding film may cover only a part of the surface other than the surface of the circuit board covering the reinforcing plate, and may cover all of the surfaces other than the surface of the circuit board covered with the reinforcing plate. In this case, the electromagnetic wave shielding film may overlap with at least a portion of the reinforcing plate. Thereby, it is preferable that good electromagnetic wave shielding performance can be obtained over the entire surface of the circuit board.

In the prior art, an example of focusing on the adhesion between a resin reinforcing plate and a polyimide film is known. However, if a prior art adhesive composition is used, a conductive reinforcing plate such as a metal plate is bonded to the polyimide. An amine film or the like obviously has a problem in workability and durability. In other words, the resin reinforcing plate and the conductive reinforcing plate have a common point of adhesion to a resin substrate (such as a polyimide film) after being fixed to the printed circuit board. In addition to these characteristics, the conductive reinforcing plate is required to have a temporary adhesive property when the conductive adhesive film is adhered to the reinforcing plate and then press-formed into a specific shape, and is filled in the opening portion of the cover layer. The conductivity is followed by the reflow resistance after the film and the adhesion to the metal wiring pattern. In the previously known adhesive composition, all of these characteristics were not satisfied, and the temporary adhesiveness and the resistance to reflow were insufficient. The reason for this is that it is not necessary to fill the opening portion provided in the coating layer with the adhesive composition when the resin reinforcing plate is used, and it is not necessary to satisfy the reflow resistance as in the present invention. In order to improve the reflow resistance, not only the conductive adhesive composition is sufficiently filled in the opening portion of about several mm ,, but also must be connected to the wiring pattern after the reflow step of about 265 ° C, and it is required to be composed of the adhesive of the prior art. More excellent physical properties.

[Symbol Description]

1‧‧‧ Polyimine film

2‧‧‧Protective layer

3‧‧‧metal layer

4‧‧‧ Conductive adhesive layer

5‧‧‧ Grounding Department

6‧‧‧Insulating adhesive

7‧‧‧ Cover film

8‧‧‧Metal reinforcing plate

9‧‧‧ Coverage

10‧‧‧ copper foil

11‧‧‧ openings

12‧‧‧ gold plating

13‧‧‧ Polyimide film side of copper-clad laminate

14‧‧‧SUS metal reinforcement board

110‧‧‧Printed wiring board body

111‧‧‧Insulation film (covering layer)

112‧‧‧Substrate components

113‧‧‧Insulating adhesive layer

114‧‧‧ Grounding wiring pattern

115‧‧‧layer with conductive adhesive

116‧‧‧Reinforcing components

117‧‧‧Electronic parts

118‧‧‧ Hole Department

[Examples]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to the examples. In addition, "parts" and "%" in the examples and comparative examples are based on the quality unless otherwise specified.

(1) Production of polyurethane polyurea resin (F)

<Synthesis Example 1>

A reaction vessel equipped with a stirrer, a reflux cooling tube, a thermometer, a nitrogen gas injection tube, and an inlet and outlet is prepared. After replacing the inside of the reaction vessel with nitrogen, 1.4 g of dimethylolpropionic acid (DMPA) and polyhexamethylene carbonate diol (trade name "PLACCEL CD220", manufactured by DAICEL Co., Ltd., by terminal function) were added. The basis weight of the quantitative average molecular weight 2000) 200.0g, dimethylformamide (DMF) 83.5g, followed by the addition of isophorone diisocyanate (IPDI) 49.0g (relative to the OH group, NCO base is 2 times equivalent) Heating to 90 ° C, the reaction was carried out until the NCO% reached 2.8%, and a urethane prepolymer was obtained. Next, 83.5 g of DMF was added and cooled to below 40 °C.

Further, 17.5 g of isophorone diamine (IPDA) was diluted with 175 g of a mixed solvent, and the mixed solvent was mixed with DMF/isopropyl alcohol (IPA) in a ratio of 7/3 by mass, and the diluent and the urethane were added dropwise. NCO-based reaction of the ester prepolymer.

Further, when the isophorone diamine is reacted with the NCO group of the urethane prepolymer, stirring is performed until the absorption of 2,270 cm-1 based on the free isocyanate group measured by infrared absorption spectrometry disappears. A mixed solvent was added in an amount of 30% by weight, and the mixed solvent was mixed with DMF/isopropyl alcohol (IPA) in a ratio of 7/3 part by mass. Thereby, a polyurethane urethane resin (F-1-1) having an acid value of 2.2 mgKOH/g, a weight average molecular weight of 68,000, and a solid content of 30% (DMF/isopropyl alcohol = 80/20) was obtained.

<Synthesis Example 2>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol The same method as in Synthesis Example 1 was carried out except for the amount described in 1. Synthesis, a polyurethane urethane resin (F-2-1) having an acid value of 26.4 mgKOH/g, a weight average molecular weight of 65,000, and a solid content of 30% (DMF/isopropanol) was obtained.

<Synthesis Example 3>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 1.0 mgKOH/g, a weight average molecular weight of 67,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-1-2).

<Synthesis Example 4>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 5.0 mgKOH/g, a weight average molecular weight of 67,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-1-3).

<Synthesis Example 5>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 6.0 mgKOH/g, a weight average molecular weight of 68,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-1-4).

<Synthesis Example 6>

In addition to dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol The amount of addition was the amount shown in Table 1, and the synthesis was carried out in the same manner as in Synthesis Example 1 to obtain a polyamine having an acid value of 20.0 mgKOH/g, a weight average molecular weight of 69,000, and a solid content of 30% (DMF/isopropyl alcohol). Urethane polyurea resin (F-2-2).

<Synthesis Example 7>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 28.0 mgKOH/g, a weight average molecular weight of 68,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-2-3).

<Synthesis Example 8>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 3.1 mgKOH/g, a weight average molecular weight of 69,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-1-5).

<Comparative Synthesis Example 1>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 10.4 mgKOH/g, a weight average molecular weight of 66,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-1-6).

<Synthesis Example 9>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 25.0 mgKOH/g, a weight average molecular weight of 65,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-2-4).

<Synthesis Example 10>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 18.0 mgKOH/g, a weight average molecular weight of 67,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-2-5).

<Comparative Synthesis Example 2>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 32.0 mgKOH/g, a weight average molecular weight of 68,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-2-6).

<Comparative Synthesis Example 3>

In addition to dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol The amount of addition was the amount shown in Table 1, and the synthesis was carried out in the same manner as in Synthesis Example 1 to obtain a polyamine having an acid value of 0.5 mgKOH/g, a weight average molecular weight of 67,000, and a solid content of 30% (DMF/isopropyl alcohol). Carbide polyurea resin (F-1-7).

<Comparative Synthesis Example 4>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 9.0 mgKOH/g, a weight average molecular weight of 67,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-1-8).

<Comparative Synthesis Example 5>

In addition to the addition of dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), dimethylformamide (DMF), dimethylformamide (DMF) / isopropanol In the same manner as in Synthesis Example 1, the synthesis was carried out to obtain a polyurethane polyacrylate having an acid value of 15.0 mgKOH/g, a weight average molecular weight of 68,000, and a solid content of 30% (DMF/isopropyl alcohol). Urea resin (F-2-7).

The polyurethane urethane resin produced according to the above method is shown in Table 1 in terms of its composition and the like.

(2) Conductive bonding film production

A method of producing a conductive adhesive film of each of the examples and the comparative examples will be described. To 55 parts by mass of the above-prepared polyurethane polyurea resin (F), 45 parts by mass of an epoxy resin was added as shown in Table 2 to prepare a conductive adhesive composition. In addition, the epoxy resin composition is 20 parts by mass of a phenoxy type epoxy resin (trade name: jER4275, manufactured by Mitsubishi Chemical Corporation), and 20 parts by mass of a phenolic novolac type epoxy resin (trade name: jER152, manufactured by Mitsubishi Chemical Corporation). Rubber modified epoxy Resin (trade name: ERP-4030, manufactured by Asahi Chemical Co., Ltd.) was 5 parts by mass. The hand was applied to a release-treated polyethylene terephthalate film using a doctor blade (a plate-shaped blade), and dried at 100 ° C for 3 minutes to prepare a conductive adhesive film. Further, the blade is appropriately selected from the range of 1 mil to 5 mil depending on the thickness of the conductive adhesive film to be produced. Also, 1 mil = 1/1000 inches = 25.4 μm. Moreover, in each of the examples and the comparative examples, the thickness of the conductive adhesive film was made to have a specific thickness. Further, the thickness of the conductive adhesive film was measured by a micrometer.

Moreover, the following was used as a conductive filler.

Conductive filler: silver-coated copper powder (average particle size 15 μm, dendritic crystal, manufactured by Fukuda Metal Foil Powder Co., Ltd.)

(3) Production of circuit board with metal reinforcing plate

Conductive adhesive film prepared above (agglomerated with benzoic acid) using a press machine A metal reinforcing plate made of ethylene glycol diester) and a metal reinforcing plate having a thickness of 200 μm (the surface of the SUS plate is plated with Ni) are temporarily pasted at a temperature of 120 ° C, a time of 5 seconds, and a pressure of 0.5 MPa, and are attached. The conductive backing film of the metal reinforcing plate. Then, the polyethylene terephthalate film on the conductive adhesive film is peeled off, and the conductive adhesive film of the metal-reinforced plate is attached to the flexible substrate under the same conditions as the above-mentioned hot pressing, and then the press machine is further used. The circuit board with a metal reinforcing plate was produced under the conditions of temperature: 170 ° C, time: 30 minutes, and pressure: 3 MPa. Further, as the flexible substrate, a copper-clad laminate as shown in Fig. 3 was used: a copper foil 10 was formed on the polyimide film 1, and a copper foil 10 was laminated on the copper foil 10 via an insulating adhesive layer 6. The cover layer 9 composed of an imide film forms an opening portion 11 of a ground connection portion having a diameter of 1.0 mm in the cover layer 9.

(4) Physical property evaluation

The obtained circuit board with a metal reinforcing plate was evaluated based on the following evaluation criteria. The respective evaluation results are shown in Table 3.

(resistance to reflow)

Evaluation of reflow resistance was performed. Also, as a condition for reflow, the hypothesis is For the lead-free solder, the temperature of the polyimide film in the circuit board with the metal reinforcing plate was set at 265 ° C for 5 seconds. Specifically, the circuit board with the metal reinforcing plate produced above was passed through a hot air reflow furnace five times, and the number of expansions in the opening portion 6 was visually observed. Further, the number of the openings 6 is 90.

(temporary adhesion)

The adhesion between the metal reinforcing plate and the conductive adhesive film was temporarily measured by a 180° peel test. Specifically, the metal reinforcing plate and the conductive adhesive film were temporarily adhered 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. Then, as shown in FIG. 5, the conductive adhesive film was peeled off at a normal temperature by a tensile tester (manufactured by Shimadzu Corporation, trade name: AGS-X50S) at a tensile speed of 50 mm/min and a peeling angle of 180°. , the maximum value at the time of breaking was measured. As long as it is 0.6 N/cm or more, it can be used without problems.

(formally followed by adhesion)

The adhesion between the conductive backing film of the metal-reinforced plate and the polyimide film was measured by a 90° peel test. Specifically, a conductive adhesive film and a metal reinforcing plate having a thickness of 200 μm (the surface of the SUS plate is Ni plated) were temporarily dried under the conditions of temperature: 120° C., time: 5 seconds, and pressure: 0.5 MPa. Adhesive, making a conductive adhesive film with a metal reinforcing plate. Then, the polyethylene terephthalate film on the conductive adhesive film is peeled off, and a copper foil-containing polyimide film (hereinafter referred to as a copper foil laminated film) is laminated under the same conditions as the above-described hot pressing. The surface of the polyimide film and the conductive adhesive film were followed by a press machine at a temperature of 170 ° C, a time of 30 minutes, and a pressure of 3 MPa, followed by preparation of a copper foil product with a metal reinforcing plate. Layer film. Then, as shown in Fig. 6, the copper foil laminated film was peeled off at a normal temperature by a tensile tester (manufactured by Shimadzu Corporation, trade name: AGS-X50S) at a tensile speed of 50 mm/min and a peeling angle of 90°. , the maximum value at the time of breaking was measured. As long as it is 10 N/cm or more, it can be used without problems. Further, a copper foil (not shown) is formed on the entire arrow side of the arrow side as indicated by 16 in Fig. 6, and the polyimide film is exposed on the opposite side.

(adhesion to polyimine film)

The adhesion of the conductive adhesive film to the polyimide film was measured by a 90 peel test. Specifically, a conductive adhesive film and a SUS plate metal reinforcing plate having a thickness of 200 μm were temporarily adhered by using a press machine at a temperature of 120 ° C, a time of 5 seconds, and a pressure of 0.5 MPa to prepare a metal reinforcing plate. The conductive adhesive film. Then, the polyethylene terephthalate film on the conductive adhesive film is peeled off, and the surface of the polyimide film of the copper foil laminated film is bonded to the conductive adhesive film under the same conditions as the above-described hot pressing. Further, a copper foil laminated film with a metal reinforcing plate was produced by a press at a temperature of 170 ° C, a time of 30 minutes, and a pressure of 3 MPa. Next, as shown in FIG. 7 , the conductive adhesive film was peeled off at a normal temperature by a tensile tester (manufactured by Shimadzu Corporation, trade name AGS-X50S) at a tensile speed of 50 mm/min and a peeling angle of 90°. , the maximum value at the time of breaking was measured. As long as it is 10 N/cm or more, it can be used without problems. Further, a copper foil (not shown) is formed on the entire arrow side surface shown by 16 in Fig. 7, and the polyimide film is exposed on the opposite side.

(adhesion to gold-plated copper foil)

The adhesion between the gold plating and the conductive adhesive formed on the surface of the copper foil of the copper-clad laminate was measured by a 90 peel test. Specifically, using a pressurizer The conductive adhesive film and the SUS plate-made metal reinforcing plate having a thickness of 200 μm were temporarily adhered under the conditions of a temperature of 120 ° C, a time of 5 seconds, and a pressure of 0.5 MPa to prepare a conductive adhesive film with a metal reinforcing plate. Then, under the same conditions as the above-described hot pressing, a gold plating layer of a copper foil laminated film having a gold plating layer formed on the surface of the copper foil of the copper foil laminated film and the conductive bonding film are followed by a press at a temperature: After 170 ° C, time: 30 minutes, and pressure: 3 MPa, a copper foil laminated film with a metal reinforcing plate was produced. Then, as shown in FIG. 8 , the copper foil laminated film was peeled off at a normal temperature by a tensile tester (product name: AGS-X50S, manufactured by Shimadzu Corporation) at a tensile speed of 50 mm/min and a peeling angle of 90°. , the maximum value at the time of breaking was measured. As long as it is 10 N/cm or more, it can be used without problems.

1‧‧‧ Polyimine film

2‧‧‧Protective layer

4‧‧‧ Conductive adhesive layer

5‧‧‧ Grounding Department

6‧‧‧Insulating adhesive layer

7‧‧‧ Coverage

Claims (6)

A conductive adhesive composition having at least a polyurethane urethane resin (F) obtained by reacting a urethane prepolymer (D) with a polyamine compound (E), The urethane prepolymer (D) is obtained by reacting a polyol compound (A), a diisocyanate compound (B), and a diol compound (C) having a carboxyl group; and an epoxy resin (G). Having two or more epoxy groups; and a conductive filler (H); and, the polyurethane urethane resin (F) is a polyurethane urethane resin having an acid value of 1 to 6 mgKOH/g (F) -1) Polyurethane polyurea resin (F-2) having an acid value of 18 to 30 mgKOH/g. The conductive adhesive composition of claim 1, wherein the polyurethane urethane resin (F-2) is 30% with respect to 100 parts by mass of the polyurethane polyurea resin (F-1). 300 parts by mass. The conductive adhesive composition of claim 1 or 2, wherein the epoxy resin (G) is 50 to 500 parts by mass per 100 parts by mass of the polyurethane polyurea resin (F). A conductive adhesive film having a release substrate and an adhesive layer composed of 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, the conductive adhesive layer being composed of the conductive adhesive composition according to any one of claims 1 to 3. A printed wiring board characterized by having: a base member having at least one of the ground wiring patterns; a cover layer covering the ground wiring pattern; and an opening for exposing one of the ground wiring patterns; and a conductive reinforcing plate; And a conductive adhesive layer that bonds the ground wiring pattern of the base member and the conductive reinforcing plate in an on state; and an electronic component that is disposed on the base member The other surface is a position corresponding to the conductive reinforcing plate; and the conductive adhesive layer has the conductive adhesive composition according to any one of claims 1 to 3.