JP2014078574A - Electromagnetic wave shielding coverlay film, method for producing flexible printed wiring board, and flexible printed wiring board - Google Patents

Abstract

An electromagnetic wave shielding coverlay film having a function of shielding electromagnetic noise on a coverlay film, the electromagnetic wave shielding coverlay film having a function of shielding electromagnetic noise on a coverlay film, and heating To provide an electromagnetic wave shielding coverlay film having excellent tack after pressing, blocking between insulating layer surfaces, and excellent workability.
The problem is that an insulating resin layer (A) containing a colorant (a), a conductive layer (B) made of a metal thin film (b), and an insulating adhesive layer (C) are sequentially formed. The problem is solved by a laminated electromagnetic wave shielding coverlay film and a method for producing a flexible printed wiring board.
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Description

  The present invention relates to an electromagnetic wave shielding coverlay film that is used for a flexible printed wiring board that is repeatedly bent and is suitably used for shielding electromagnetic noise generated from an electric circuit, and a method for manufacturing a flexible printed wiring board.

  A flexible printed wiring board in which signal wiring and ground wiring are formed on a base film base material and a coverlay film is laminated on the wiring surface has flexibility, so that recent office automation equipment, communication equipment, mobile phones In order to meet the demand for further high performance and downsizing, etc., it is frequently used to incorporate an electronic circuit inside a casing having a narrow and complicated structure. With such downsizing and high frequency of electronic circuits, countermeasures against unnecessary electromagnetic noise generated therefrom are becoming more and more important. Therefore, an electromagnetic wave shielding adhesive film that shields electromagnetic noise generated from an electronic circuit has been conventionally attached to a flexible printed wiring board.

In addition to the electromagnetic wave shielding property, the electromagnetic wave shielding adhesive film itself is required to have thinness and excellent bending resistance so as not to impair the bending resistance of the bonded flexible printed wiring board as a whole. Therefore, an electromagnetic wave shielding adhesive film having a basic structure in which a conductive layer is provided on a thin base film is widely known.
As a conventional electromagnetic wave shielding adhesive film, the cover film has a conductive adhesive layer on one side of the cover film and, if necessary, a shield layer made of a metal thin film layer, and the adhesive layer and the releasable reinforcing film on the other side. There is known a reinforcing shield film in which and are sequentially laminated (see Patent Document 1).

  Further, a shield film having a base film made of a conductive adhesive layer and / or a shield layer having a metal thin film and an aromatic polyamide resin is known (see Patent Document 2).

Also known is a shielding adhesive film in which a cover film is formed by coating a resin on one side of a separate film, and a shield layer composed of a metal thin film layer and an adhesive layer is provided on the surface of the cover film. (See Patent Document 3).
These conventional electromagnetic wave shielding adhesive films are separately laminated on one side or both sides of a flexible printed wiring board to which a cover lay has been pressure-bonded. Accordingly, the thickness of the flexible printed wiring board is increased by the lamination of the electromagnetic wave shielding adhesive film, and in recent years, it has become impossible to meet the demands for thinning and high bending particularly required for flexible printed wiring boards for mobile phones. Furthermore, since the process of laminating | stacking an electromagnetic wave shielding adhesive film is required separately, a manufacturing process increased and the problem that the manufacturing cost of a flexible printed wiring board increased as a result arose.

  As means for solving these problems, a coverlay film in which a conductive layer and an adhesive layer are sequentially laminated on an engineering plastic typified by polyimide has been proposed (see Patent Document 4). However, the above-mentioned engineering plastics cannot meet the demand for flexing resistance that has become increasingly severe in recent years.

  Therefore, in order to meet the demand for bending resistance, Patent Document 5 proposes an electromagnetic shielding coverlay film in which an electromagnetic shielding adhesive sheet and a coverlay film are integrated. In this proposal, the flexibility can be improved by using an insulating resin formed from the polyurethane polyimide resin composition (I) or the polyurethane polyurea resin composition (II). However, since the surface of the insulating layer after the hot pressing process has tack, the production yield is poor due to adhesion of dust / foreign matter to the surface of the insulating layer, blocking between the surfaces of the insulating layer, and further, punching workability. There was a problem that decreased.

JP 2003-298285 A JP 2004-273577 A JP 2004-95566 A JP 2002-361770 A JP 2010-233870 A

  Therefore, the present invention is an electromagnetic wave shielding coverlay film having a function of shielding electromagnetic noise on the coverlay film, and is an electromagnetic wave shield excellent in tack after heat pressing, blocking between insulating layer surfaces, and punching processability. An object is to provide a protective coverlay film.

In order to solve the above-mentioned problems, the present inventors have intensively studied to complete the present invention.
That is, in the present invention, the insulating resin layer (A) containing the colorant (a), the conductive layer (B) made of the metal thin film (b), and the insulating adhesive layer (C) are sequentially laminated. It is related with the electromagnetic wave shielding coverlay film which becomes.

  The present invention also relates to the electromagnetic shielding coverlay film, wherein the colorant (a) contains at least one colorant selected from the group consisting of black, green, blue and red.

  In the present invention, the metal thin film (b) is an alloy composed of at least one selected from the group consisting of gold, silver, copper, nickel and aluminum, or two or more selected from the above group. It is related with the said electromagnetic wave shielding coverlay film characterized.

  Further, the present invention is characterized in that at least one of the insulating resin layer (A) and the insulating adhesive layer (C) contains a binder resin (D) and a thermosetting compound (E). The present invention relates to the electromagnetic shielding coverlay film.

  In the invention, the binder resin (D) contains at least one selected from the group consisting of urethane resin, acrylic resin, ester resin, phenoxy resin, amide resin and imide resin. It is related with a sex coverlay film.

  In the present invention, the thermosetting compound (E) comprises at least one selected from the group consisting of an epoxy group-containing compound, a non-blocked isocyanate compound, a blocked isocyanate compound, and a β-hydroxyalkylamide group-containing compound. It contains about the said electromagnetic wave shielding coverlay film characterized by containing.

  In the present invention, through holes are formed in the electromagnetic wave shielding coverlay film, and the insulating adhesive layer (C) surface is superposed on the wiring circuit surface of the wiring circuit for the flexible printed wiring board and insulated by heating. The conductive resin layer (A), the conductive layer (B) and the insulating adhesive layer (C) are cured, and the conductive layer (B) and the wiring circuit are electrically connected inside the through hole. The present invention relates to a method for manufacturing a flexible printed wiring board.

  In the present invention, the insulating adhesive layer (C) surface of the electromagnetic wave shielding coverlay film is superposed on the wiring circuit surface of the flexible printed wiring board wiring circuit, and heated to heat the insulating resin layer (A), The conductive layer (B) and the insulating adhesive layer (C) are cured, a through hole is formed in the flexible printed wiring board on which the electromagnetic wave shielding coverlay film is laminated, and the conductive layer ( The present invention relates to a method for manufacturing a flexible printed wiring board, wherein B) and a wiring circuit are electrically connected.

  The present invention is also characterized in that the conductive layer (B) and the wiring circuit are electrically connected using any one selected from the group consisting of a conductive paste, a conductive bump and a plating treatment. The present invention relates to a method for manufacturing a printed wiring board.

  Furthermore, this invention relates to the flexible printed wiring board manufactured by the manufacturing method of the said flexible printed wiring board.

  The electromagnetic wave shielding coverlay film of the present invention has an insulating resin layer containing a colorant, a conductive layer, and an insulating adhesive layer as one body, and a flexible printed wiring board manufactured using the insulating resin layer is a hot press. It was possible to reduce the subsequent tack and improve the punching processability.

  The electromagnetic wave shielding coverlay film of the present invention is formed by sequentially laminating an insulating resin layer (A), a conductive layer (B), and an insulating adhesive layer (C). The insulating resin layer (A) and the insulating adhesive layer (C) are in a so-called semi-cured state in which the curing component exists in an unreacted state in the layers. And after overlapping an electromagnetic wave shielding coverlay film on the wiring circuit surface of the wiring circuit for flexible printed wiring boards, a flexible printed wiring board can be manufactured by hardening the hardening component of each layer by heating.

First, the insulating resin layer (A) containing the colorant (a) will be described.
The insulating resin layer (A) plays a role of protecting the flexible printed wiring board from physical and chemical stress in addition to the insulating coating of the conductive layer (B), and requires excellent flexibility. is there. From such a viewpoint, examples of the material constituting the insulating resin layer (A) include acrylic resin, urethane resin, ester resin, epoxy resin, amide resin, and imide resin.

  The acrylic resin in the present invention, which will be described later in detail, refers to a resin having an acrylic ester or / and a methacrylic ester copolymer as a main skeleton. The urethane resin in the present invention refers to a resin having a main skeleton of a copolymer obtained by reacting a monomer or oligomer having a hydroxyl group with a diisocyanate compound.

  Furthermore, the ester resin in the present invention is a condensed ester resin obtained by polycondensation reaction of a polyvalent carboxylic acid and a polyalcohol to form an ester group, or / and a polyvalent carboxylic acid and a diepoxy compound. It refers to an addition-type ester resin having a high molecular weight by an addition reaction to form an ester group.

  Furthermore, the epoxy resin in the present invention is a compound having an epoxy group composed of a copolymer of a diol compound and epichlorohydrin, and the above compound and a curing agent represented by amine or acid anhydride are mixed and heat cured. In addition, a high molecular weight resin is also included.

  Furthermore, the amide resin in the present invention refers to an amide resin having a high molecular weight by polycondensation reaction between a polycarboxylic acid and a diamine compound to form an amide group.

  Subsequently, the imide resin in the present invention is a polyimide resin obtained by dehydrating and ring-closing a polyamic acid obtained from a polybasic acid anhydride and a diamine compound, or / and decarboxylating and ring-closing from a polybasic acid anhydride and a diisocyanate compound. Refers to the polyimide resin obtained.

  Among these, acrylic resins, urethane resins, and ester resins have a high degree of freedom in monomer design and are suitable for satisfying the flexibility and insulation reliability required for electromagnetic wave shielding coverlay films. These can be selected according to the purpose, and may be used alone or in combination.

  As the colorant (a), organic pigments, inorganic pigments, dyes and the like can be used. Among them, it is preferable to use a colorant selected from the group consisting of black, green, blue and red.

  Examples of the black colorant include carbon black, titanium black, aniline black, anthraquinone black pigment, perylene black pigment, specifically C.I. I. PigmentBlack6, 7, 12, 20, 31, 32, and the like.

  Examples of the green colorant include C.I. I. Green pigments such as Pigment Green 7, 10, 36, and 37 can be used.

  Examples of the blue colorant include C.I. I. Blue pigments such as Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, and 64 can be used.

  Examples of the red colorant include C.I. I. PigmentRed 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 144, 146, 149, 168, 169, 177, 178, 180, 181, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 246, 254, 255, 264, 272, C.I. I. Red pigments such as Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73, and orange pigments can be used.

  Any of the colorants is preferably dispersed with a resin as required, and pigments other than those described above can also be mixed and used. Furthermore, the colorant may be used alone, but may be used by mixing two or more kinds.

The blending ratio of the colorant (a) selected from the group consisting of black, green, blue and red used in the insulating resin layer (A) used in the present invention is black and green with respect to 100 parts by weight of the resin. The colorant (a) selected from the group consisting of blue and red is preferably 3 to 200 parts by weight. Furthermore, it is preferable that it is 10-100 weight part. When the amount of the colorant (a) is less than 3 parts by weight with respect to 100 parts by weight of the resin, the tack of the insulating resin layer surface may become strong. For example, the insulating resin layer surfaces are overlapped in the manufacturing process. At that time, it becomes defective due to blocking. Moreover, the punching workability in the manufacturing process is deteriorated, and the product yield is reduced.
On the other hand, when the amount of the colorant (a) is more than 200 parts by weight, the strength of the resin layer becomes insufficient, which causes a decrease in chemical resistance to alkali or acid on the surface of the insulating resin layer and a decrease in abrasion resistance.

  Among the colorants (a) selected from the group consisting of black, green, blue and red, carbon black is preferable in terms of concealment. Some carbon blacks are excellent in conductivity, but in the case of the present invention, such a carbon black is not preferable. Carbon black having excellent conductivity generally has π electron conductivity. Accordingly, the carbon black that is suitably used in the present invention is preferably one that has been surface-modified so that the particle surface prevents π-electron conjugation. An example is MA-100 manufactured by Mitsubishi Chemical Corporation.

  In the insulating resin layer (A), if necessary, a silane coupling agent, an antioxidant, a pigment, a dye, a tackifier resin, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling adjusting agent, a filler, A flame retardant etc. can also be included.

Next, the conductive layer (B) made of the metal thin film (b) will be described.
The metal thin film (b) of the present invention is, for example, a metal foil such as gold, silver, copper, nickel, or aluminum, a vapor deposition film, a sputtered film, or ink dispersed in a nanosize such as gold, silver, or copper at a high temperature. It is the metal film produced by sintering with.

With metal foils such as gold, silver, copper, nickel, and aluminum, electrolytic foils manufactured by electrolysis or the like and rolled foils manufactured by rolling metal can be used, and the thickness ranges from 0.1 μm to 50 μm. Is preferred. More preferably, it is in the range of 0.5 μm to 30 μm. A foil thinner than 0.1 μm is difficult to handle, and conversely, if it is thicker than 50 μm, the flexibility becomes poor when affixed to a flexible printed wiring board as an electromagnetic shielding coverlay.
A vapor deposition film such as gold, silver, copper, nickel, and aluminum is formed on the surface of the insulating resin layer (A) by heating and vaporizing or sublimating a metal under vacuum conditions. The thickness of the metal vapor deposition film is preferably in the range of 0.01 μm to 5 μm. More preferably, it is the range of 0.05-2 micrometers.

  In addition, the sputtered metal film such as gold, silver, copper, nickel, and aluminum generates a metal atom by colliding a rare gas element or nitrogen element ionized at a high voltage with a metal under a vacuum condition. It is formed on the surface of the insulating resin layer (A). The thickness of the metal sputter layer is preferably in the range of 0.01 μm to 5 μm. More preferably, it is the range of 0.05-2 micrometers.

  Furthermore, a metal film produced by sintering ink dispersed in nanosize such as gold, silver, copper, etc. at a high temperature is a nanosize ink made of an insulating resin layer (A) or an insulating adhesive layer ( It is applied to C) and sintered by applying heat of 150 ° C. or higher. The thickness of the metal film is preferably in the range of 0.01 to 3 μm. More preferably, it is the range of 0.05-2 micrometers.

Next, the insulating adhesive layer (C) of the present invention will be described. The insulating adhesive layer (C) plays a role of adhering the electromagnetic wave shielding coverlay film of the present invention to the wiring board on which the wiring is formed, and insulates and protects the wiring of the conductive layer (B) and the wiring board. Take a role.
As the resin that can be used for the insulating resin layer (C), the resin used in the insulating resin layer (A) can be used.

Further, at least one of the insulating resin layer (A) and the insulating adhesive layer (C) of the electromagnetic wave shielding coverlay film of the present invention contains a binder resin (D) and a thermosetting compound (E). To do.
As the binder resin (D), the urethane resin, acrylic resin, ester resin, phenoxy resin, amide resin and imide resin are preferable.

Further, the insulating resin layer (A) and the insulating adhesive layer (C) containing the colorant (a) may contain a thermosetting compound (E).
The thermosetting compound (E) is a compound containing at least one selected from the group consisting of an epoxy group-containing compound, a non-blocked isocyanate compound, a blocked isocyanate compound, and a β-hydroxyalkylamide group-containing compound. .

In the present invention, the epoxy group-containing compound is not particularly limited as long as it is a compound containing an epoxy group in the molecule.
Specific examples of compounds containing two epoxy groups in the molecule include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A and epichlorohydrin. Type epoxy resin, bisphenol F / epichlorohydrin type epoxy resin, biphenol / epichlorohydrin type epoxy resin, glycerin / epichlorohydrin adduct polyglycidyl ether, resorcinol diglycidyl ether, polybutadiene diglycidyl ether, hydroquinone Diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, neopentyl glycol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hydrogenated bisphenol Nord A type diglycidyl ether, polypropylene glycol diglycidyl ether, diphenylsulfone diglycidyl ether, dihydroxybenzophenone diglycidyl ether, biphenol diglycidyl ether, diphenylmethane diglycidyl ether, bisphenol fluorenediglycidyl ether, biscresol fluoric glycidyl ether, bis Phenoxyethanol full orange glycidyl ether, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyl toluidine, JP 2004-156024 A, special Examples of the epoxy compound having excellent flexibility disclosed in Japanese Unexamined Patent Application Publication Nos. 2004-315595 and 2004-323777. That.

  Examples of the compound containing 3 or more epoxy groups in the molecule include trishydroxyethyl isocyanurate triglycidyl ether, triglycidyl isocyanurate, “Epicoat 1031S”, “Epicoat 1032H60” manufactured by Mitsubishi Chemical Corporation. In addition to “Epicoat 604” and “Epicoat 630”, phenol novolac type epoxy resins, cresol novolak type epoxy resins, dicyclopentadiene type epoxy resins disclosed in JP-A No. 2001-240654, naphthalene Type epoxy resin, polyglycidyl ether of ethylene glycol / epichlorohydrin adduct, pentaerythritol polyglycidyl ether, trimethylolpropane polyglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylenediamyl , And the like. Moreover, the compound which has other thermosetting groups other than an epoxy group can also be used. For example, the silane modified epoxy resin currently disclosed by Unexamined-Japanese-Patent No. 2001-59011 and 2003-48953 is mentioned.

  In particular, when an isocyanurate ring-containing epoxy compound such as trishydroxyethyl isocyanurate triglycidyl ether or triglycidyl isocyanurate is used in the present invention, the adhesion to polyimide or copper tends to be improved. ,preferable. In addition, “Epicoat 1031S”, “Epicoat 1032H60”, “Epicoat 604”, and “Epicoat 630” manufactured by Mitsubishi Chemical Corporation are multifunctional and have excellent heat resistance. It is very preferable in the invention, and an epoxy compound of an aliphatic type or an epoxy compound described in JP-A No. 2004-156024, JP-A No. 2004-315595, or JP-A No. 2004-323777 is flexible. Since it is excellent in property, it is preferable. In addition, the dicyclopentadiene type epoxy compound, the phenol novolak type epoxy resin, the cresol novolak type epoxy resin, the biphenol / epichlorohydrin type epoxy resin, etc. described in JP-A No. 2001-240654 are used in the present invention. It is preferable from the viewpoint of durability of the cured coating film including curability, hygroscopicity and heat resistance.

  In the present invention, for the purpose of adjusting the crosslinking density of the cured product, a compound having one epoxy group in the molecule may be used in combination. Specific examples include compounds such as N-glycidyl phthalimide, glycidyl, and glycidyl (meth) acrylate.

  In the present invention, the isocyanate group-containing compound is not particularly limited as long as it is a compound having an isocyanate group in the molecule. Examples of the diisocyanate compound include aromatic diisocyanates having 4 to 50 carbon atoms, aliphatic diisocyanates, araliphatic diisocyanates, and alicyclic diisocyanates.

  Aromatic diisocyanates include, for example, 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate. Range isocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 " -Triphenylmethane triisocyanate etc. are mentioned.

  Aliphatic diisocyanates include, for example, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2, Examples include 4,4-trimethylhexamethylene diisocyanate.

  Examples of the araliphatic diisocyanate include ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene, 1, Examples include 4-tetramethylxylylene diisocyanate and 1,3-tetramethylxylylene diisocyanate.

  Examples of the alicyclic diisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate [also known as isophorone diisocyanate], 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, Methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,3-bis (isocyanatemethyl) cyclohexane, 1,4-bis (isocyanatemethyl) cyclohexane Etc.

  Specifically, the isocyanate group-containing compound having one or three or more isocyanate groups in the molecule includes (meth) acryloyloxyethyl isocyanate, 1, as a monofunctional isocyanate having one isocyanate group in one molecule. Examples include 1-bis [(meth) acryloyloxymethyl] ethyl isocyanate, vinyl isocyanate, allyl isocyanate, (meth) acryloyl isocyanate, isopropenyl-α, α-dimethylbenzyl isocyanate. In addition, 1,6-diisocyanatohexane, isophorone diisocyanate, 4,4′-diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, xylylene diisocyanate, tolylene 2,4-diisocyanate, toluene diisocyanate, 2,4-diisocyanic acid Toluene, hexamethylene diisocyanate, 4-methyl-m-phenylene diisocyanate, naphthylene diisocyanate, paraphenylene diisocyanate, tetramethylxylylene diisocyanate, cyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, cyclohexyl diisocyanate, tolidine diisocyanate, 2,2 , 4-Trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate Nitrate, m-tetramethylxylylene diisocyanate, p-tetramethylxylylene diisocyanate, diisocyanate ester compounds such as dimer acid diisocyanate and hydroxyl group, carboxyl group, and amide group-containing vinyl monomers are reacted in equimolar amounts. It can be used as an ester compound.

  Examples of the polyfunctional isocyanate having three or more isocyanate groups in one molecule include aliphatic polyisocyanates such as aromatic polyisocyanates and lysine triisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates. And a trimethylolpropane adduct of diisocyanate described above, a burette reacted with water, and a trimer having an isocyanurate ring.

  The blocked isocyanate group-containing compound is not particularly limited as long as the isocyanate group is an isocyanate group-containing compound protected with ε-caprolactam, MEK oxime, or the like. Specific examples include those obtained by blocking the isocyanate group of the isocyanate group-containing compound with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, phenol and the like.

  Examples of the β-hydroxyalkylamide group-containing compound include various compounds such as N, N, N ′, N′-tetrakis (hydroxyethyl) adipamide (Primid XL-552 manufactured by Ems Chemie).

  In the present invention, one or a plurality of thermosetting compounds (E) can be used in combination. The amount of the thermosetting compound used may be determined in consideration of the application of the electromagnetic wave shielding coverlay film of the present invention, and is not particularly limited, but is a layer containing the thermosetting compound (E). When the total amount of the resin contained in 100 parts by weight is 100 parts by weight, it is preferably added at a rate of 0.5 to 100 parts by weight, more preferably 1 to 80 parts by weight. By using the thermosetting compound, the crosslink density of the electromagnetic wave shielding coverlay film of the present invention can be adjusted to an appropriate value, so that various physical properties of the cured coating film can be further improved. By making the usage-amount of a thermosetting compound 0.5 parts weight or more, the crosslinked density of hardened | cured material can be made high enough, and adhesiveness and heat resistance can be made compatible. On the other hand, when the amount used is 100 parts by weight or less, it is possible to suppress the cross-linking density of the cured product from becoming excessive, and it is possible to maintain high adhesiveness.

  Furthermore, in the present invention, in addition to the above curing agent, a compound that directly contributes to the curing reaction or a thermosetting auxiliary that contributes catalytically can be used. For example, examples of the thermosetting aid that directly contributes to the curing reaction include dicyandiamide, carboxylic acid hydrazide, acid anhydrides, and β-hydroxyalkylamide group-containing compounds. In addition, examples of thermosetting assistants that contribute catalytically include tertiary amine compounds, phosphine compounds, and imidazole compounds.

  Examples of the thermosetting aid that directly contributes to the curing reaction include succinic acid hydrazide and adipic acid hydrazide. Examples of the acid anhydride include hexahydrophthalic anhydride and trimellitic anhydride. Examples of the β-hydroxyalkylamide group-containing compound include various compounds such as N, N, N ′, N′-tetrakis (hydroxyethyl) adipamide (Primid XL-552 manufactured by Ems Chemie).

  As a thermosetting auxiliary agent that contributes catalytically to the curing reaction, tertiary amine compounds include triethylamine, benzyldimethylamine, 1,8-diazabicyclo (5.4.0) undecene-7, 1,5-diazabicyclo (4.3 0.0) Nonene-5 and the like. Examples of the phosphine compound include triphenylphosphine and tributylphosphine. Further, in the imidazole compound, imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2,4-dimethylimidazole, 2-phenylimidazole, and the imidazole compounds A latent curing accelerator with improved storage stability such as a type in which an epoxy resin is reacted to insolubilize in a solvent or a type in which an imidazole compound is encapsulated in microcapsules is preferable.

  Two or more of these thermosetting aids may be used in combination, and the amount added is 100 parts by weight of the total of the resins contained in the insulating resin layer (A) and the insulating adhesive layer (C). In this case, the range of 0.1 to 30 parts by weight is preferable.

  The insulating resin layer (A) and the insulating adhesive layer (C) constituting the electromagnetic wave shielding coverlay film of the present invention may further include a solvent, a silane coupling agent, a dye, a pigment, a flame retardant, if necessary. Antioxidants, polymerization inhibitors, antifoaming agents, leveling agents, ion scavengers, moisturizers, viscosity modifiers, antiseptics, antibacterial agents, antistatic agents, antiblocking agents, ultraviolet absorbers, infrared absorbers, filling An agent or the like can be added. In particular, it is preferable to add a filler for the purpose of controlling the heat resistance and the fluidity of the adhesive.

  Examples of the filler include inorganic fillers such as silica, alumina, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium carbonate, titanium oxide, zinc oxide, antimony trioxide, magnesium oxide, talc, montmorillonite, kaolin, and bentonite. And metal fillers such as aluminum, gold, silver, copper and nickel. Among these, silica, alumina, and aluminum hydroxide are preferable from the viewpoint of dispersibility. In particular, hydrophobic silica obtained by modifying a silanol group on the silica surface with a halogenated silane can be suitably used because it can reduce water absorption and improve heat resistance. The blending amount of the filler is preferably 0.1 to 100 parts by weight when the total amount of resins contained in the insulating resin layer (A) and the insulating adhesive layer (C) is 100 parts by weight, It is more preferable that it is 0.2-50 weight part.

  Next, although the manufacturing method of the electromagnetic wave shielding coverlay film of this invention is demonstrated, a manufacturing method is not limited to this.

  As a first example of a method for producing an electromagnetic wave shielding coverlay film, a step of applying and drying a resin composition on one side of a peelable film 1 to form an insulating resin layer (A), the insulating resin layer ( A) a step of forming a conductive layer (B) on the surface, a step of applying an insulating adhesive on the conductive layer (B) and drying to form an insulating adhesive layer (C), the insulating adhesive layer (C) A step of superposing the peelable film 2 on top.

  As a 2nd example of the manufacturing method of an electromagnetic wave shielding coverlay film, the process of apply | coating and drying the resin composition on one side of the peelable film 1 to form an insulating resin layer (A), the insulating resin layer ( A) a step of forming a conductive layer (B) on the surface, a step of forming an insulating adhesive layer (C) by applying and drying an insulating adhesive on one side of the peelable film 2, and the conductive layer (B ) And the insulating adhesive layer (C).

  As a third example of the method for producing an electromagnetic wave shielding coverlay film, a process of applying and drying a resin composition on one side of the peelable film 1 to form an insulating resin layer (A), Step of forming insulating adhesive layer (C) by applying and drying insulating adhesive, step of forming conductive layer (B) on insulating adhesive layer (C), insulating resin layer (A) And a conductive layer (B).

  As a fourth example of the method for producing an electromagnetic wave shielding coverlay film, a step of applying and drying an insulating adhesive on one side of the peelable film 2 to form an insulating adhesive layer (C), the insulating adhesive A step of forming a conductive layer (B) on the agent layer (C), a step of forming an insulating resin layer (A) by applying and drying a resin composition on the conductive layer (B), the insulating property This is a step of superposing the peelable film 1 on the resin layer (A).

  The peelable film in the present invention is a film having a release treatment on one side or both sides, or a film having an adhesive applied on one side or both sides. The peelable film is laminated on one side of the insulating resin layer (A) or the insulating adhesive layer (C) of the electromagnetic wave shielding coverlay film which is not touching the conductive layer (B), and adheres to or contaminates foreign matter. In addition, it plays a role of improving the handleability of a very thin electromagnetic wave shielding coverlay film, and a mount for external processing.

  As the substrate of the peelable film, polyethylene terephthalate, polyethylene naphthalate, polyvinyl fluoride, polyvinylidene fluoride, rigid polyvinyl chloride, polyvinylidene chloride, nylon, polyimide, polystyrene, polyvinyl alcohol, ethylene / vinyl alcohol copolymer, Plastic sheets such as polycarbonate, polyacrylonitrile, polybutene, soft polyvinyl chloride, polyvinylidene fluoride, polyethylene, polypropylene, polyurethane, ethylene vinyl acetate copolymer, polyvinyl acetate, glassine paper, fine paper, kraft paper, coated paper, etc. Paper, various non-woven fabrics, synthetic paper, metal foil, and composite films combining these.

  As the mold release treatment method, there is a method in which a mold release agent is applied to one or both sides of a film, or a physical matting treatment is performed. Release agents include hydrocarbon resins such as polyethylene and polypropylene, higher fatty acids and their metal salts, higher fatty acid soaps, waxes, animal and vegetable fats and oils, mica, talc, silicone surfactants, silicone oils, silicone resins, and fluorine-based agents. Surfactants, fluorine resins, fluorine-containing silicone resins, and the like are used.

  As a method for applying the release agent, conventionally known methods such as gravure coating method, kiss coating method, die coating method, lip coating method, comma coating method, blade coating method, roll coating method, knife coating method, spray coating method, It can be performed by a bar coating method, a spin coating method, a dip coating method, or the like.

  As a coating method used when the resin composition constituting the insulating resin layer (A) and the insulating adhesive layer (C) used in the electromagnetic wave shielding coverlay film of the present invention is applied and dried. Is a conventionally known method, for example, gravure coating method, kiss coating method, die coating method, lip coating method, comma coating method, blade coating method, roll coating method, knife coating method, spray coating method, bar coating method, spin coating method. The dip coating method can be used.

  The electromagnetic wave shielding cover lay film of the present invention uses a conductive layer (any one selected from the group consisting of an electrically conductive paste, an electrically conductive bump, and a plating treatment in the through hole formed in the electromagnetic wave shielding cover lay film. By electrically connecting B) and the ground wiring, an electromagnetic wave shielding function is imparted to the flexible printed wiring board.

  In the present invention, the conductive paste refers to a conductive filler dispersed in a binder resin. The conductive filler is preferably a metal filler, a carbon filler, or a mixture thereof. Examples of the metal filler include metal powders such as silver, copper and nickel, alloy powders such as solder, silver-plated copper powder, metal-plated glass fibers and carbon fillers. Examples of the binder resin include acrylic resins, urethane resins, epoxy resins, phenol resins, polyester resins, and mixtures thereof.

In addition, the conductive bump preferably used in the present invention is a metal having a conical shape or a truncated cone shape. Examples of the metal forming the conductive bump include aluminum, copper, silver, gold, and alloys thereof. Examples of methods for producing these conductive bumps include a method of etching a metal foil, and a method of forming bumps on a peelable base substrate by a plating method.

  Furthermore, the plating treatment suitably used in the present invention refers to depositing a metal in a layer form by chemical reaction or electrolysis using a solution in which metal ions are dissolved. Examples of the metal suitably used for the plating treatment used in the present invention include copper, silver, gold, tin, nickel, lead, and alloys thereof.

  Finally, a specific embodiment of the method for producing a flexible printed wiring board using the electromagnetic wave shielding coverlay film of the present invention will be described.

  As a 1st aspect of the flexible printed wiring board using the electromagnetic wave sealing coverlay film of this invention, the copper clad laminated board by which copper foil is laminated | stacked on the single side | surface of the base base film represented by the polyimide film. By etching the copper foil, signal wiring and ground wiring are formed on the base substrate film. Next, a through hole is formed in the electromagnetic wave shielding coverlay film, and the peelable film laminated on the insulating adhesive layer (C) side is peeled off to expose the insulating adhesive layer (C). Subsequently, the surface of the insulating adhesive layer (C) is overlaid on the ground wiring so that the through-holes overlap, and heat-pressed to heat the insulating resin layer (A) and the insulating adhesive layer (C). Harden. Finally, a conductive paste is filled and heat-cured inside the through hole, and the conductive layer (B) of the electromagnetic wave shielding coverlay film is electrically connected to the ground wiring to manufacture a flexible printed wiring board. .

  As a 2nd aspect of the flexible printed wiring board using the electromagnetic wave shielding coverlay film of this invention, the copper-clad laminated board by which copper foil is laminated | stacked on the single side | surface of the base substrate film represented by the polyimide film is used. By etching the copper foil, signal wiring and ground wiring are formed on the base substrate film. Next, a through hole is formed in the electromagnetic wave shielding coverlay film, and the peelable film laminated on the insulating adhesive layer (C) side is peeled off to expose the insulating adhesive layer (C). Subsequently, the surface of the insulating adhesive layer (C) is overlaid on the ground wiring so that the through-holes overlap, and heat-pressed, so that the insulating resin layer (A), the conductive layer (B), and the insulating adhesive are bonded. The agent layer (C) is cured by heating. Finally, gold plating is applied to the inside of the through hole by electrolytic plating, and the electromagnetic wave shielding coverlay film and the ground wiring are electrically connected to produce a flexible printed wiring board.

  As a 3rd aspect of the flexible printed wiring board using the electromagnetic wave shielding coverlay film of this invention, the copper clad laminated board by which copper foil is laminated | stacked on the single side | surface of the base base film represented by the polyimide film. By etching the copper foil, signal wiring and ground wiring are formed on the base substrate film. Next, a through hole is formed in the electromagnetic wave shielding coverlay film, and the peelable film laminated on the insulating adhesive layer (C) side is peeled off to expose the insulating adhesive layer (C). Subsequently, the surface of the insulating adhesive layer (C) is overlaid on the ground wiring so that the through hole is overlapped, and heat-pressed to form the insulating resin layer (A) and the insulating adhesive layer (C). Heat cure. Finally, a copper bump is pressure-bonded on one side of the polyester film so as to overlap the through hole, and the electromagnetic wave shielding coverlay film and the ground wiring are electrically connected to produce a flexible printed wiring board.

  As a 4th aspect of the flexible printed wiring board using the electromagnetic wave shielding coverlay film of this invention, the copper clad laminated board by which copper foil is laminated | stacked on the single side | surface of the base substrate film represented by the polyimide film. By etching the copper foil, signal wiring and ground wiring are formed on the base substrate film. Next, the peelable film laminated on the insulating adhesive layer (C) side of the electromagnetic wave shielding coverlay film is peeled off to expose the insulating adhesive layer (C), and the wiring surface on the base substrate film And the surface of the insulating adhesive layer (C) are overlapped and heat-pressed to heat and cure the insulating resin layer (A), the conductive layer (B), and the insulating adhesive layer (C). Subsequently, a through hole is formed in the ground wiring portion with a drill. Finally, a conductive paste is filled and heat-cured inside the through hole, and the conductive layer (B) of the electromagnetic wave shielding coverlay film is electrically connected to the ground wiring to manufacture a flexible printed wiring board. .

  As a 5th aspect of the flexible printed wiring board using the electromagnetic wave shielding coverlay film of this invention, the copper clad laminated board by which copper foil is laminated | stacked on the single side | surface of the base substrate film represented by the polyimide film. By etching the copper foil, signal wiring and ground wiring are formed on the base substrate film. Next, the peelable film laminated on the insulating adhesive layer (C) side of the electromagnetic wave shielding coverlay film is peeled off to expose the insulating adhesive layer (C), and the wiring surface on the base substrate film And the surface of the insulating adhesive layer (C) are overlapped and heat-pressed to heat and cure the insulating resin layer (A), the conductive layer (B), and the insulating adhesive layer (C). Subsequently, a through hole is formed in the ground wiring portion with a drill. Finally, gold plating is applied to the inside of the through hole by an electroplating method, and the electromagnetic wave shielding coverlay film and the ground wiring are electrically connected to produce a flexible printed wiring board.

  As a sixth aspect of the flexible printed wiring board using the electromagnetic wave shielding coverlay film of the present invention, a copper-clad laminate in which a copper foil is laminated on one side of a base substrate film typified by a polyimide film. By etching the copper foil, signal wiring and ground wiring are formed on the base substrate film. Next, the peelable film laminated on the insulating adhesive layer (C) side of the electromagnetic wave shielding coverlay film is peeled off to expose the insulating adhesive layer (C), and the wiring surface on the base substrate film And the surface of the insulating adhesive layer (C) are overlapped and heat-pressed to heat and cure the insulating resin layer (A), the conductive layer (B), and the insulating adhesive layer (C). Subsequently, a through hole is formed in the ground wiring portion with a drill. Finally, a copper bump formed by electroless plating on one side of the polyester film is pressure-bonded so as to overlap the through hole, and the electromagnetic wave shielding coverlay film and the ground wiring are electrically connected to form a flexible printed wiring board. Can be manufactured.

  The electromagnetic wave shielding coverlay film of the present invention can be applied to a double-sided flexible printed wiring board and a rigid printed wiring board in addition to the above-described single-sided flexible printed wiring board.

  The flexible printed wiring board manufactured by the above method can be used in electronic devices such as mobile phones, personal computers, digital cameras, and digital video cameras.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited only to a following example. The following “parts” and “%” are values based on parts by weight and “% by weight”, respectively.

<Measurement of weight average molecular weight (Mw)>
For measurement of Mw, GPC (gel permeation chromatography) “HPC-8020” manufactured by Tosoh Corporation was used. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size. For the measurement in the present invention, “LF-604” (manufactured by Showa Denko KK: GPC column for rapid analysis: 6 mm ID × 150 mm size) is connected in series to the column, the flow rate is 0.6 ml / min, the column temperature. It carried out on the conditions of 40 degreeC, and the determination of the weight average molecular weight (Mw) was performed in polystyrene conversion.

Synthesis of polyurethane polyurea resin <Synthesis Example 1>
Mn = 981 obtained from adipic acid, 3-methyl-1,5-pentanediol and 1,6-hexanediol in a reaction vessel equipped with a stirrer, reflux condenser, dropping device, nitrogen inlet tube, and thermometer 390 parts of a certain diol, 16 parts of dimethylolbutanoic acid, 158 parts of isophorone diisocyanate, and 40 parts of toluene were charged and reacted at 90 ° C. for 3 hours in a nitrogen atmosphere. To this, 300 parts of toluene was added to obtain a urethane prepolymer solution having an isocyanate group at the terminal. Next, 814 parts of the resulting urethane prepolymer solution was added to a mixture of 29 parts of isophorone diamine, 3 parts of di-n-butylamine, 342 parts of 2-propanol, and 576 parts of toluene. By reacting for a period of time, a polyurethane polyurea resin solution having Mw = 43,000 and an acid value of 10 mgKOH / g was obtained. To this, 144 parts of toluene and 72 parts of 2-propanol were added to obtain a polyurethane polyurea resin solution having a nonvolatile content of 30%.

Synthesis of Polyurethane Polyimide Resin <Synthesis Example 2>
A polycarbonate diol 270 with Mw = 2000 obtained from 3-methyl-1,5-pentanediol and 1,6-hexanediol in a reaction vessel equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube and thermometer. Part, 51 parts of isophorone diisocyanate and 220 parts of toluene were heated to 60 ° C. with stirring under a nitrogen stream and dissolved uniformly. Subsequently, 0.16 part of dibutyltin dilaurate was added thereto as a catalyst and reacted at 100 ° C. for 3 hours to obtain a terminal isocyanate group-containing urethane prepolymer. Next, 380 parts of cyclohexanone and 29 parts of pyromellitic anhydride were added, stirred at 90 ° C. for 1 hour, then added with 3.5 parts of dimethylbenzylamine, heated to 135 ° C., and reacted for 4 hours. Thereafter, the temperature was lowered to 120 ° C., and 3.5 parts of EX-731 (Nagase Denacor “EX-731”: manufactured by Nagase ChemteX Corporation) was added and stirred for 6 hours at 120 ° C., Mw = 63000, acid value 35 mgKOH / G polyurethane polyimide resin solution was obtained. Cyclohexanone was added thereto to obtain a polyurethane polyimide resin solution having a nonvolatile content of 35%.

Synthesis example of acrylic resin <Synthesis example 3>
A 4-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer was charged with 98 parts of 2-ethylhexyl acrylate, 2 parts of acrylic acid, and 350 parts of acetone. The flask was heated to 80 ° C., 0.05 part of 2,2′-azobisisobutyronitrile was added, and the mixture was reacted for 2 hours. Further, 0.05 part of 2,2′-azobisisobutyronitrile was added, followed by reaction for 5 hours. After completion of the reaction, the reaction mixture was cooled and 100 parts of ethyl acetate was added to obtain an acrylic resin solution having a weight average molecular weight of 1,500,000.

Synthesis example of addition type polyester <Synthesis example 4>
To a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, thermometer, polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanedio- Copolymer polycarbonate diol of 9/1 (molar ratio): hydroxyl value = 56 mgKOH / g, Mw = 2000) 292.1 parts, containing acid anhydride group for main chain Tetrahydrophthalic anhydride (Licacid TH: manufactured by Shin Nippon Rika Co., Ltd.) 44.9 parts as a compound and 350 parts of toluene as a solvent were charged, heated to 60 ° C. with stirring under a nitrogen stream, and dissolved uniformly. Subsequently, the flask was heated to 110 ° C. and reacted for 3 hours. Then, after cooling to 40 ° C., 62.9 parts of bisphenol A type epoxy resin (YD-8125: manufactured by Nippon Steel Chemical Co., Ltd .: epoxy equivalent = 175 g / eq) and 4 parts of triphenylphosphine as a catalyst were added to form 110 parts. The temperature was raised to 0 ° C. and reacted for 8 hours. After cooling to room temperature, the non-volatile content was adjusted to 35% with ethyl acetate to obtain an addition type polyester solution. The weight average molecular weight of the addition-type polyester resin obtained in this synthesis example was 12600, and the acid value of the resin non-volatile content measured was 9.3 mgKOH / g.

Adjustment of silver nano ink <Adjustment Example 1>
Attach 200 parts of toluene and 38.9 parts of silver oleate to a separable four-necked flask with a condenser, thermometer, nitrogen gas inlet tube, and stirring device, and stir at room temperature in a nitrogen atmosphere. After that, 2.3 parts of diethylaminoethanol (0.2 mol times with respect to 1 mol of metal) was added and dissolved as a dispersant.
Thereafter, when 73.1 parts of a 20% aqueous succinic acid dihydrazide (hereinafter abbreviated as SUDH) solution as a reducing agent (2 mol times hydrazide group with respect to 1 mol of metal) was dropped, the liquid color changed from light yellow to dark brown. In order to further promote the reaction, the temperature was raised to 40 ° C. to advance the reaction. After standing and separating, the aqueous layer is taken out to remove excess reducing agent and impurities. Further, distilled water is added several times to the toluene layer, washing and separation are repeated, and silver fine particles protected with oleic acid are added to toluene. A silver nano-ink dispersed in was obtained. In the obtained silver fine particle dispersion, the average particle diameter of silver fine particles was 7 ± 2 nm, the silver concentration was 73%, and the particle diameter did not change even after being stored at 40 ° C. for one month and was stable.

<Example 1>
10 parts of black colorant (carbon black “MA-100” manufactured by Mitsubishi Chemical Corporation) and curing agent 1 (Mitsubishi Chemical Corporation) with respect to 100 parts of resin content of the polyurethane polyurea resin solution obtained in Synthesis Example 1 The epoxy resin “Epicoat 1031S”) 20 parts was blended, and a dry film was formed on the release-treated surface of the release film 1 (hereinafter referred to as “releasable film 1”) which was subjected to release treatment on one side of a 50 μm-thick PET film. An insulating resin layer (A) having a thickness of 10 μm was obtained.
Subsequently, a copper foil having a thickness of 1 μm was bonded onto the insulating resin layer (A) by heating lamination.
Further, as an insulating adhesive layer, 20 parts of curing agent 1 (1031S) is blended with 100 parts of the polyurethane polyurea resin obtained in Synthesis Example 1, and the insulating adhesive layer having a dry film thickness of 40 μm is formed as described above. An electromagnetic wave shielding coverlay film was formed on the conductive layer.

<Example 2>
One part of a PET film having a thickness of 50 μm is blended with 10 parts of a black colorant (MA-100) and 20 parts of a curing agent 1 (1031S) with respect to 100 parts of the polyurethane polyurea resin solution obtained in Synthesis Example 1. An insulating resin layer (A) having a dry film thickness of 10 μm was obtained on the release-treated surface of the release film 1 (hereinafter referred to as “releasable film 1”) subjected to release treatment.
Subsequently, a silver deposited film having a thickness of 0.5 μm was provided on the insulating resin layer (A) by vapor deposition.
Further, as an insulating adhesive layer, 20 parts of curing agent 1 (1031S) is blended with 100 parts of the polyurethane polyurea resin obtained in Synthesis Example 1, and the insulating adhesive layer having a dry film thickness of 40 μm is formed as described above. An electromagnetic wave shielding coverlay film was formed on the conductive layer.

<Example 3>
One part of a PET film having a thickness of 50 μm is blended with 10 parts of a black colorant (MA-100) and 20 parts of a curing agent 1 (1031S) with respect to 100 parts of the polyurethane polyurea resin solution obtained in Synthesis Example 1. An insulating resin layer (A) having a dry film thickness of 10 μm was obtained on the release-treated surface of the release film 1 (hereinafter referred to as “releasable film 1”) subjected to release treatment.
Subsequently, a silver nano ink was applied on the insulating resin layer (A), and sintered at 150 ° C. for 10 minutes to provide a silver nano ink film having a thickness of 0.5 μm.
Further, as an insulating adhesive layer, 20 parts of curing agent 1 (1031S) is blended with 100 parts of the polyurethane polyurea resin obtained in Synthesis Example 1, and the insulating adhesive layer having a dry film thickness of 40 μm is formed as described above. An electromagnetic wave shielding coverlay film was formed on the conductive layer.

<Example 4 to Example 7>
Using the materials shown in Table 1 as the insulating resin layer, conductive layer, and insulating adhesive layer, an electromagnetic wave shielding coverlay film was produced in the same manner as in Example 1.

<Comparative Example 1>
An electromagnetic wave shielding coverlay film was produced in the same manner as in Example 1 without using carbon black, which was used when producing the insulating resin layer of Example 1.

<Evaluation of blocking properties>
Two of the electromagnetic shielding coverlay films obtained in the examples and comparative examples were cut into 10 cm × 10 cm, and the insulating adhesive layer surface and a polyimide film having a thickness of 50 μm were laminated and bonded together.
Then, after heat-pressing at 150 ° C. for 30 minutes and a pressure of 2 MPa, the release film on the insulating resin layer is peeled off, the two insulating resin layer surfaces are overlapped, and a pressure of 0.5 MPa is applied at 40 ° C. for 24 hours. The state of the insulating resin layer surface after 24 hours was evaluated as follows.
○: No change in appearance compared to before test Δ: Color change in less than 50% in 10 cm square sheet compared to before test × ... 10 cm square compared to before test There is a color change in more than 50% of the sheet

<Punching workability evaluation>
The electromagnetic wave shielding cover lay films obtained in Examples and Comparative Examples were punched into a size of 10 mm × 30 mm with a 100 piece punching machine, and the number of defective products was evaluated as follows. A defective product is a sample that has not been partially removed after being processed into a die-cut shape.
○ ・ ・ ・ less than 10% △ ・ ・ ・ 10% or more and less than 25% × ・ ・ ・ 25% or more

<Electromagnetic wave shielding evaluation>
After the 10 mm through-holes of 10 mm from the ends of the four sides of the 150 mm square electromagnetic shielding cover film obtained in the examples and comparative examples were uniformly formed on each side, 10 electromagnetic shielding covers were formed. The insulating adhesive layer (C) of the lay film is placed on a copper foil surface of a copper-clad laminate in which a 12 μm thick copper foil is laminated on a 25 μm thick polyimide film at 150 ° C. and 1 MPa for 60 minutes. Then, the electromagnetic wave shielding coverlay film was cured. Next, a silver paste (“LS-411MK” manufactured by Asahi Chemical Research Laboratories) was filled in the through hole and dried at 150 ° C. for 30 minutes.
Using the obtained sample, the electromagnetic wave shielding property at 1 GHz was evaluated by an electromagnetic wave shielding measuring device (“TR17301” manufactured by ADVANTEST) equipped with a spectrum analyzer. The evaluation criteria are as follows.
◎: 50 dB or more ○: 40 dB or more and less than 50 dB Δ: 30 dB or more and less than 40 dB x: less than 30 dB

Black colorant: MA-100 manufactured by Mitsubishi Chemical Corporation
Blue colorant: Lionol Blue ES manufactured by Toyocolor Co., Ltd.
Green colorant: Lionol Green 6YK, manufactured by Toyocolor Co., Ltd.
Red colorant: Shinkasia Magenta BRT343D manufactured by Ciba Specialty Chemicals Co., Ltd.
Hardener 1: Epoxy resin 1031S manufactured by Mitsubishi Chemical Corporation
Hardener 2: Blocked isocyanate BL3175 manufactured by Sumika Bayer Urethane Co., Ltd.
Metal thin film 1: Copper foil film Metal thin film 2: Silver vapor deposition film Metal thin film 3: Silver nano ink film

  From the results of Table 1, the blocking property is better than the electromagnetic wave shielding coverlay film without adding the colorant by using the electromagnetic wave shielding coverlay film with the colorant added to the insulating resin layer. I understand that. Moreover, it has confirmed that the electromagnetic wave shield coverlay film which has a metal thin film was excellent also in punching property.

Claims (10)

  An electromagnetic wave shielding cover in which an insulating resin layer (A) containing a colorant (a), a conductive layer (B) made of a metal thin film (b), and an insulating adhesive layer (C) are sequentially laminated. Ray film.   The electromagnetic wave shielding coverlay film according to claim 1, wherein the colorant (a) contains at least one colorant selected from the group consisting of black, green, blue and red.   The metal thin film (b) is at least one selected from the group consisting of gold, silver, copper, nickel, and aluminum, or an alloy consisting of two or more selected from the group. Or the electromagnetic wave shielding coverlay film of 2.   At least one of the insulating resin layer (A) and the insulating adhesive layer (C) contains a binder resin (D) and a thermosetting compound (E). 3. The electromagnetic wave shielding coverlay film according to any one of 3 above.   The electromagnetic wave shielding cover according to claim 4, wherein the binder resin (D) contains at least one selected from the group consisting of urethane resin, acrylic resin, ester resin, phenoxy resin, amide resin and imide resin. Ray film.   The thermosetting compound (E) contains at least one selected from the group consisting of an epoxy group-containing compound, a non-blocked isocyanate compound, a blocked isocyanate compound, and a β-hydroxyalkylamide group-containing compound. The electromagnetic wave shielding coverlay film according to claim 4 or 5.   A through hole is formed in the electromagnetic wave shielding coverlay film according to any one of claims 1 to 6, and the insulating adhesive layer (C) surface is superposed on the wiring circuit surface of the flexible printed wiring board wiring circuit and heated. Then, the insulating resin layer (A), the conductive layer (B) and the insulating adhesive layer (C) are cured, and the conductive layer (B) and the wiring circuit are electrically connected inside the through hole. A method for producing a flexible printed wiring board, comprising:   The insulating adhesive layer (C) surface of the electromagnetic wave shielding coverlay film according to any one of claims 1 to 6 is superposed on the wiring circuit surface of the flexible printed wiring board wiring circuit, and heated to form an insulating resin layer (A ), The conductive layer (B) and the insulating adhesive layer (C) are cured, and a through hole is formed in the flexible printed wiring board on which the electromagnetic wave shielding coverlay film is laminated. A method for producing a flexible printed wiring board, wherein the layer (B) and a wiring circuit are electrically connected.   The flexible layer according to claim 7 or 8, wherein the conductive layer (B) and the wiring circuit are electrically connected using any one selected from the group consisting of a conductive paste, a conductive bump, and a plating process. Manufacturing method of printed wiring board.   The flexible printed wiring board manufactured by the manufacturing method of the flexible printed wiring board in any one of Claims 7-9.