JP2018168323A - Thermosetting composition, cured product, electromagnetic wave shield film and method for producing the same, and printed wiring board with electromagnetic wave shield film and method for producing the same - Google Patents

Abstract

A thermosetting composition capable of forming an insulating resin layer and an adhesive layer with less cure shrinkage, excellent adhesion, and improved flame retardancy, and a cured product thereof, the thermosetting composition, or the cured product The electromagnetic wave shielding film provided with the layer containing this, its manufacturing method, the printed wiring board with an electromagnetic wave shielding film, and its manufacturing method are provided. An electromagnetic wave shielding film having an insulating resin layer, a metal thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the metal thin film layer opposite to the insulating resin layer. Then, at least one of the insulating resin layer 10 and the adhesive layer 24 is the electromagnetic wave shielding film 1 which is a thermosetting composition containing a specific compound or a cured product thereof. [Selection] Figure 1

Description

  The present invention relates to a thermosetting composition, a cured product, an electromagnetic wave shielding film and a production method thereof, a printed wiring board with an electromagnetic wave shielding film, and a production method thereof.

  In order to shield electromagnetic wave noise generated from a flexible printed wiring board and electromagnetic wave noise from the outside, an electromagnetic wave shielding film comprising an insulating resin layer, a metal thin film layer adjacent to the insulating resin layer, and an adhesive layer is used as an insulating film ( It may be provided on the surface of the flexible printed wiring board via a cover lay film) (see, for example, Patent Document 1).

  The electromagnetic wave shielding film is, for example, a coating liquid containing a thermosetting resin, a curing agent, and a solvent is applied to one side of a first release film that is a carrier film, and dried to form an insulating resin layer. It is manufactured by providing a metal thin film layer and an adhesive layer (for example, a conductive adhesive layer) on the surface of the insulating resin layer.

  The first release film is formed by attaching an electromagnetic wave shielding film to the surface of an insulating film provided on the surface of a flexible printed wiring board (FPC) so that the conductive adhesive layer is in contact with the insulating film, and then insulating the film. It peels from the resin layer.

JP 2006-086120 A

  Improvement in flame retardancy is required for an electromagnetic wave shielding film attached to an FPC or the like. Conventionally, in the production of an electromagnetic wave shielding film, the base film may be curled when an insulating resin layer or an adhesive layer is formed on the base film, and it is required to suppress this curling. Furthermore, conventionally, in the production of an electromagnetic wave shielding film, a laminating process for adhering an insulating resin layer or an adhesive layer to a metal thin film layer may be repeated a plurality of times, and a reduction in the number of times is also required.

  The present invention provides a thermosetting composition capable of forming an insulating resin layer and an adhesive layer having a low curing shrinkage (shrinkage upon curing), excellent adhesion, and improved flame retardancy, and a cured product thereof, and the thermosetting The electromagnetic wave shielding film provided with the layer containing an adhesive composition or the said hardened | cured material, its manufacturing method, a printed wiring board with an electromagnetic wave shielding film, and its manufacturing method are provided.

[1] One or more types of epoxy group-containing compounds and one or more types selected from the group of compounds (1) represented by the following formula (1), wherein the compound (1) is at 25 ° C. and 1 atm. A thermosetting composition that is a liquid.
[2] The thermosetting composition according to [1], wherein the compound (1) is a compound represented by the following formula (1b).
[3] The thermosetting composition according to [1], wherein the compound (1) is a compound represented by the following formula (1b-1).
[4] The thermosetting composition according to any one of [1] to [3], further including a black colorant.
[5] The thermosetting composition according to any one of [1] to [3], further including conductive particles.
[6] The thermosetting composition according to any one of [1] to [5], further including one or more selected from the group of compounds represented by the following formula (2).
[7] The thermosetting composition according to any one of [1] to [6], further including a solvent.
[8] A cured product of the thermosetting composition according to any one of [1] to [7].
[9] An electromagnetic wave shielding film having an insulating resin layer, a metal thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the side of the metal thin film layer opposite to the insulating resin layer, An electromagnetic wave shielding film in which at least one of the insulating resin layer and the adhesive layer is the thermosetting composition according to any one of [1] to [7] or the cured product according to [8].
[10] The electromagnetic wave shielding film according to [9], wherein the adhesive layer is an anisotropic conductive adhesive layer.
[11] A printed wiring board provided with a printed circuit on at least one side of a substrate, an insulating film adjacent to the surface of the printed wiring board on which the printed circuit is provided, and the adhesive layer on the insulating film The printed wiring board with an electromagnetic wave shielding film which has an electromagnetic wave shielding film as described in [9] or [10] provided so that it might adjoin.
[12] The method for producing an electromagnetic wave shielding film according to [9], wherein the coating film formed by applying the thermosetting composition to a base film is heated to be cured to an arbitrary degree. The manufacturing method of the electromagnetic wave shielding film which has the process of forming at least one among the said insulating resin layer and the said adhesive bond layer.
[13] The method for producing an electromagnetic wave shielding film according to [9], wherein the insulating resin layer, the metal thin film layer, and the adhesive layer are laminated in this order, and a heating and pressurizing laminating process is performed. The manufacturing method of the electromagnetic wave shielding film which has a process of performing at least one adhesion | attachment among adhesion | attachment of the said insulating resin layer and the said metal thin film layer, and adhesion | attachment of the said metal thin film layer and the said adhesive bond layer by giving.
[14] The method for manufacturing a printed wiring board with an electromagnetic wave shielding film according to [11], wherein the adhesive layer of the electromagnetic wave shielding film is overlapped with a surface of the insulating film of the printed wiring board. The manufacturing method which has the crimping | compression-bonding process which adhere | attaches the said adhesive bond layer on the surface of the said insulating film by crimping these.
[15] The production method according to [14], wherein the insulating resin layer and the adhesive layer are pressed while being heated in the pressure bonding step.
[16] The method according to [14] or [15], further including a curing step of curing the thermosetting composition by further heating the insulating resin layer and the adhesive layer after the crimping step. Production method.

In the formula (1), R ₁ , R ₂ and R ₃ are each independently a hydrogen atom or an arbitrary substituent, and R ₁ and R ₂ may be bonded to each other to form a ring.
In the formula (1b), R ₂ is a hydrogen atom or an arbitrary substituent, and R ₂ may be bonded to a phenyl group bonded to a phosphorus atom to form a ring; R ₃ is a hydroxyl group or a carboxyl group Is an arbitrary substituent having at least one of them. ]

  In the formula (2), L1 and L2 are each independently a single bond or a divalent linking group having 1 to 8 carbon atoms, m and n are each independently an integer of 1 to 5, and m + n is 2 to 2. 6 out of the hydrogen atoms bonded to the benzene ring, any one or more hydrogen atoms are replaced by a (HO-L1-) group, and any other one or more hydrogen atoms are (-L2 Any one or more hydrogen atoms that are substituted by a (—COOH) group and not substituted with a (HO-L1-) group and a (—L2-COOH) group may be substituted with any substituent. . ]

According to the thermosetting composition and the cured product thereof of the present invention, an insulating resin layer and an adhesive layer with improved flame retardancy and adhesiveness can be formed.
The electromagnetic wave shielding film and the printed wiring board with an electromagnetic wave shielding film of the present invention have improved flame retardancy.
According to the method for producing an electromagnetic wave shielding film of the present invention, since there is little shrinkage at the time of curing of a coating film made of a thermosetting composition coated on a base film, the base film and an insulating resin formed thereon Curling of the layer or adhesive layer can be suppressed. Moreover, the frequency | count of the lamination process which adhere | attaches an insulating resin layer or an adhesive bond layer on a metal thin film layer can be reduced.
According to the method for producing a flexible printed wiring board with an electromagnetic wave shielding film of the present invention, since the adhesiveness of the adhesive layer is excellent, the metal thin film and the adhesive layer can be easily bonded by pressure bonding.

It is sectional drawing which shows one Embodiment of the electromagnetic wave shield film of this invention. It is sectional drawing which shows other embodiment of the electromagnetic wave shielding film of this invention. It is sectional drawing which shows the manufacturing process of the electromagnetic wave shielding film of FIG. It is sectional drawing which shows the manufacturing process of the electromagnetic wave shielding film of FIG. It is sectional drawing which shows one Embodiment of the printed wiring board with an electromagnetic wave shield film of this invention. It is sectional drawing which shows the manufacturing process of the printed wiring board with an electromagnetic wave shielding film of FIG.

The following definitions of terms apply throughout this specification and the claims.
“Epoxy” is a radical name for an —O— group attached to a diatomic carbon bonded by a carbon chain.
The “(meth) acryloyl group” is a general term for an acryloyl group and a methacryloyl group.
The “isotropic conductive adhesive layer” means a conductive adhesive layer having conductivity in the thickness direction and the surface direction.
The “anisotropic conductive adhesive layer” means a conductive adhesive layer having conductivity in the thickness direction and not having conductivity in the surface direction.
The “conductive adhesive layer having no conductivity in the plane direction” means a conductive adhesive layer having a surface resistance of 1 × 10 ⁴ Ω or more.
For the average particle size of the particles, 30 particles are randomly selected from the microscopic image of the particles, the minimum and maximum diameters are measured for each particle, and the median of the minimum and maximum diameters is the particle size of one particle. This is a value obtained by arithmetically averaging the measured particle diameters of 30 particles. The same applies to the average particle size of the conductive particles.
The thickness of the film (release film, insulating film, etc.), coating film (insulating resin layer, conductive adhesive layer, etc.), metal thin film layer, etc. is observed at a cross section of the object to be measured using a microscope. Thickness was measured and averaged.
The storage elastic modulus is calculated as one of the viscoelastic characteristics using a dynamic viscoelasticity measuring device that is calculated from the stress applied to the measurement object and the detected strain and outputs it as a function of temperature or time.
The surface resistance is measured by using two thin film metal electrodes (length 10 mm, width 5 mm, distance 10 mm between electrodes) formed by depositing gold on quartz glass, placing an object to be measured on the electrodes, and measuring the surface resistance. This is a resistance between electrodes measured by pressing a 10 mm × 20 mm region of the object to be measured with a load of 0.049 N from above the object with a measurement current of 1 mA or less.

<< thermosetting composition >>
1st aspect of this invention contains 1 or more types of an epoxy group containing compound, and 1 or more types chosen from the group of the compound (1) represented by following formula (1), The said compound (1) is 25 It is a thermosetting composition that is liquid at 1 ° C. at a temperature.

［式（１）中、Ｒ_１、Ｒ_２及びＲ_３はそれぞれ独立に水素原子又は任意の置換基であり、Ｒ_１及びＲ_２が互いに結合して環を形成してもよい。］

[In Formula (1), R ₁ , R ₂ and R ₃ are each independently a hydrogen atom or an arbitrary substituent, and R ₁ and R ₂ may be bonded to each other to form a ring. ]

Arbitrary substituents of R ₁ , R ₂ and R ₃ of the compound (1) may be monovalent substituents or may be bonded to each other with a divalent substituent to form a ring. .
Examples of the monovalent substituent of R ₁ , R ₂ and R ₃ of the compound (1) include an aromatic group, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and 1 carbon atom. -10 alkoxy groups, halogen and the like. Except when one or more methylene groups of the alkyl group are bonded to each other, -O-, -C (= O)-, -C (= O) O-, -O-C (= O)-, -NH-, or -S- may be substituted.
Examples of the aromatic group include a phenyl group, a naphthyl group, and an anthracenyl group. The aromatic group may be bonded to a phosphorus atom or an oxygen atom via a linking group having 1 to 3 carbon atoms.

  From the viewpoint of further enhancing the function of the compound (1) as a flame retardant and a curing agent, the compound (1b) represented by the following formula (1b) is preferable.

［式（１ｂ）中、Ｒ_２は水素原子又は任意の置換基であり、リン原子に結合したフェニル基にＲ_２が結合して環を形成していてもよく；Ｒ_３は水酸基及びカルボキシル基のうち少なくとも一方を１つ以上有する任意の置換基である。］

[In Formula (1b), R ₂ is a hydrogen atom or an arbitrary substituent, and R ₂ may be bonded to a phenyl group bonded to a phosphorus atom to form a ring; R ₃ is a hydroxyl group or a carboxyl group Is an arbitrary substituent having at least one of them. ]

The optional substituent of R _{2 in} the compound (1b) may be a monovalent substituent, or a divalent substituent that substitutes an arbitrary hydrogen atom of the phenyl group bonded to the phosphorus atom. They may be bonded to form a ring.
Examples of the monovalent substituent of R ₂ of the compound (1b) include the same substituent as R _{2 of} the compound (1) described above.

R _{3 in the} compound (1b) is a substituent having one or more hydroxyl groups, a substituent having one or more carboxyl groups, or a substituent having one or more hydroxyl groups and carboxyl groups. Is preferred.

As the substituent represented by R ₃ of the compound (1b), one or more hydrogen atoms of the linear, branched or cyclic alkyl group having 1 to 20 carbon atoms are substituted with a hydroxyl group or a carboxyl group. Preferred substituents. Especially, it is a C1-C20 branched alkyl group, Comprising: It is more preferable that it is a substituent which has one or more hydroxyl groups or carboxyl groups in each branched chain. In addition, one or more of the methylene groups of the alkyl group are —O—, —C (═O) —, —C (═O) O—, or —O—C, except when oxygen atoms are bonded to each other. It is preferably substituted by (═O) —, and more preferably substituted by —C (═O) O— or —O—C (═O) —.
The compound (1b) having the above preferred substituent is likely to be a liquid with high fluidity at 25 ° C. and 1 atm, is excellent in dispersibility in the thermosetting composition, has less curing shrinkage, and is excellent in adhesiveness. An insulating resin layer and an adhesive layer can be formed.

  Preferable specific examples of compound (1b) include phosphorus compounds represented by the following formula (1b-1). This phosphorus compound is liquid at 25 ° C. and 1 atm, and a glycol solvent such as ethylene glycol or propylene glycol is preferably used as a dilution solvent.

(Epoxy group-containing compound)
The epoxy group-containing compound contained in the thermosetting composition is preferably a compound having two or more epoxy groups, more preferably a resin having two or more epoxy groups (epoxy resin), More preferably, the resin is an epoxy resin having an epoxy group at both ends of the resin.
When the above-mentioned suitable epoxy group-containing compound is used, the thermosetting composition has little curing shrinkage, can increase the adhesive force, and can easily form an adhesive layer having excellent adhesion to metal.
The epoxy group-containing compound contained in the thermosetting composition may be one type or two or more types.

In this specification, an epoxy group is a monovalent group obtained by removing one arbitrary hydrogen atom from an epoxy. Examples of the epoxy include epoxy ethane (also known as ethylene oxide) and 1,3′-epoxypropane (also known as trimethylene oxide and oxetane).
The epoxy group-containing compound is preferably a glycidyl group-containing compound having a glycidyl group in which a methylene group is bonded to a monovalent bond of an epoxy group.

A known epoxy resin can be applied as the epoxy resin, and can be appropriately selected according to the use of the thermosetting composition. The epoxy resin contained in the thermosetting composition may be one type or two or more types.
Specific examples of the epoxy resin include an epoxy resin obtained by a condensation reaction of bisphenol having two hydroxyphenyl groups and epichlorohydrin. Examples thereof include bisphenol A type epoxy resin and bisphenol F type epoxy resin. Other examples include polyfunctional epoxy resins such as dicyclopentadiene type epoxy resins, cresol novolac type epoxy resins, phenol novolac type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, and the like. it can.

The content ratio of the epoxy group-containing compound and the compound (1) in the thermosetting composition is preferably a content ratio sufficient for the compound (1) to cure the epoxy group-containing compound. Specifically, it is preferable that the number of moles of active hydrogen groups in the compound (1) is 0.01 mole or more and 1.5 moles or less per mole of epoxy groups of the epoxy group-containing compound. Here, the active hydrogen group means hydrogen, a hydroxyl group and a carboxyl group bonded to the phosphorus atom of the compound (1).
When the amount is not less than the above lower limit, the amount of the compound (1) that reacts with the epoxy group-containing compound is increased, the curing shrinkage of the thermosetting composition is further reduced, and the flame retardancy, hardness, and adhesive strength of the cured product are further increased. Can be increased.
When the amount is not more than the above upper limit, the curing rate of the thermosetting composition becomes moderate, the hardness of the cured product tends to be uniform, and the hardness can be suppressed from becoming excessively high or excessively low.
When the thermosetting composition contains a curing agent other than the compound (1), the content ratio of the compound (1) and the epoxy group-containing compound may be outside the above range.

In the thermosetting composition, the total content of the compound (1) with respect to the total 100 parts by mass of the epoxy group-containing compound is preferably 10 parts by mass or more and 1000 parts by mass or less, and 50 parts by mass or more and 500 parts by mass or less. More preferably, it is more preferably 100 parts by mass or more and 300 parts by mass or less.
When the amount is not less than the above lower limit, the amount of the compound (1) that reacts with the epoxy group-containing compound is increased, the curing shrinkage of the thermosetting composition is further reduced, and the flame retardancy, hardness, and adhesive strength of the cured product are further increased. Can be increased.
When the amount is not more than the above upper limit, the curing rate of the thermosetting composition becomes moderate, the hardness of the cured product tends to be uniform, and the hardness can be suppressed from becoming excessively high or excessively low.

(Additive)
The thermosetting composition may contain one or more additives other than the epoxy group-containing compound and the compound (1) as optional components as long as the curing is not hindered.
Examples of the additive include a conductive material, a colorant, a filler, a solvent, a curing agent, a curing accelerator, and a stress reducing agent.

The thermosetting composition preferably contains a compound (2) represented by the following formula (2).
In the compound (2) in the thermosetting composition, the epoxy group of the epoxy group-containing compound and the active hydrogen group of the hydroxyl group or carboxyl group of the compound (2) react with heat to function as a curing agent. Moreover, the adhesiveness with respect to the metal of the hardened | cured material of the said thermosetting composition can be improved by including a compound (2).

  Particularly suitable examples of the compound (2) include 4-hydroxybenzoic acid represented by the following formula (2a) and gallic acid (gallic acid) represented by the following formula (2b).

In the formula (2), L1 and L2 are each independently a single bond or a divalent linking group having 1 to 8 carbon atoms, m and n are each independently an integer of 1 to 5, and m + n is 2 to 2. 6 out of the hydrogen atoms bonded to the benzene ring, any one or more hydrogen atoms are replaced by a (HO-L1-) group, and any other one or more hydrogen atoms are (-L2 Any one or more hydrogen atoms that are substituted by a (—COOH) group and not substituted with a (HO-L1-) group and a (—L2-COOH) group may be substituted with any substituent. .
In the formula (2a) and the formula (2b), any one or more hydrogen atoms bonded to the benzene ring may be substituted with any substituent.

In the formula (2), m is preferably 1 to 3, and n is preferably 1 to 3.
In the formula (2), except for the case where m = 1 and n = 1, the hydrogen atom of the carboxyl group of the (—L2-COOH) group is linear, branched or cyclic having 1 to 10 carbon atoms. May be substituted with an alkyl group in order to form a carboxylic acid ester.

In the formula (2), the divalent linking group having 1 to 8 carbon atoms represented by L1 and L2 is preferably an alkylene group having 1 to 8 carbon atoms and an alkenylene group having 2 to 8 carbon atoms. One or more methylene groups constituting the alkylene group and the alkenylene group are —O—, —C (═O) —, —C (═O) O—, except when oxygen atoms are bonded to each other. It may be substituted by —O—C (═O) —, —NH—, or —S—.
When m is 2 or more, the plurality of L1s may be the same as or different from each other.
When n is 2 or more, the plurality of L2s may be the same as or different from each other.

  Examples of the optional substituent that may be substituted on the hydrogen atom of the benzene ring include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. , Halogen and the like. One or more methylene groups of the alkyl group are —O—, —C (═O) —, —C (═O) O—, —O—C (=, except when oxygen atoms are bonded to each other. O)-, -NH-, or -S- may be substituted.

Specific examples of the compound (2) include monohydroxy compounds such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid (salicylic acid), 2- (hydroxymethyl) benzoic acid, vanillic acid, and syringic acid. Hydroxybenzoic acid and its derivatives;
2,3-dihydroxybenzoic acid (2-pyrocatechuic acid), 2,4-dihydroxybenzoic acid (β-resorcinic acid), 2,5-dihydroxybenzoic acid (gentisic acid), 2,6-dihydroxybenzoic acid (γ- Resorcinic acid), 3,4-dihydroxybenzoic acid (protocatechuic acid), 3,5-dihydroxybenzoic acid ([alpha] -resorcinic acid), 3,6-dihydroxybenzoic acid, dihydroxybenzoic acid such as orceric acid and derivatives thereof;
Trihydroxybenzoic acid and its derivatives such as 3,4,5-trihydroxybenzoic acid (gallic acid), 2,4,6-trihydroxybenzoic acid (phloroglucinol carboxylic acid);
Hydroxycinnamic acid and its derivatives, such as merirotic acid, furoletic acid, umbelic acid, caffeic acid, ferulic acid, sinapinic acid;
And aromatic dicarboxylic acids having one or more hydroxy groups, such as 5-hydroxyisophthalic acid, 2-hydroxyterephthalic acid, and 2,5-dihydroxyterephthalic acid, and derivatives thereof.
The compound (2) contained in the thermosetting composition may be one type or two or more types.

The content ratio of the epoxy group-containing compound and the compound (2) in the thermosetting composition may be a content ratio sufficient for the compound (2) to cure the epoxy group-containing compound. Specifically, it is preferable that the number of moles of active hydrogen groups in the compound (2) is 0.5 moles or more and 1.5 moles or less per mole of epoxy groups of the epoxy group-containing compound. Here, an active hydrogen group means both the hydroxyl group and carboxyl group which a compound (2) has.
When the amount is not less than the lower limit, the amount of the compound (2) that reacts with the epoxy group-containing compound increases, and the hardness and adhesive strength of the cured product of the thermosetting composition can be further increased.
When the amount is not more than the above upper limit, the curing rate of the thermosetting composition becomes moderate, the hardness of the cured product tends to be uniform, and the hardness can be suppressed from becoming excessively high or excessively low.

In the thermosetting composition, the total content of the compound (2) with respect to the total 100 parts by mass of the epoxy group-containing compound is preferably 1 part by mass or more and 100 parts by mass or less, and more preferably 5 parts by mass or more and 50 parts by mass or less. More preferably, it is more preferably 10 parts by mass or more and 30 parts by mass or less.
When the amount is not less than the lower limit, the amount of the compound (2) that reacts with the epoxy group-containing compound increases, and the hardness and adhesive strength of the cured product of the thermosetting composition can be further increased.
When the amount is not more than the above upper limit, the curing rate of the thermosetting composition becomes moderate, the hardness of the cured product tends to be uniform, and the hardness can be suppressed from becoming excessively high or excessively low.

  When the thermosetting composition is applied to an adhesive layer of an electromagnetic wave shielding film described later, a conductive adhesive layer can be formed by adding a conductive material to the thermosetting composition. As the conductive material, conductive particles are preferable.

Examples of the conductive particles include metal particles such as silver, platinum, gold, copper, nickel, palladium, aluminum, and solder, graphite powder, fired carbon particles, plated fired carbon particles, and the like.
Suitable average particle diameters of the conductive particles include, for example, about 0.1 μm or more and 50 μm or less, as will be described later.
As content of the electroconductive particle with respect to the total mass of solid content except the solvent of the said thermosetting composition, 1 mass% or more and 50 mass% or less are mentioned, for example, 10 mass% or more and 30 mass% or less are preferable. . Within this range, a conductive adhesive layer to be described later can be easily formed.

Examples of the stress reducing agent (stress relaxation agent) include vinyl acetate resins and silicone compounds.
As content of the low stress agent with respect to the total mass of solid content except the solvent of the said thermosetting composition, although based also on the kind, 10 mass% or more and 80 mass% or less are mentioned, for example, 30 mass % To 70% by mass is preferable. Within this range, a cured product having good flexibility can be easily formed.

Examples of the colorant include carbon black, azo dyes, metal complexes, and the like. Among these, a black colorant is preferable.
The content of the colorant with respect to the total mass of the solid content excluding the solvent of the thermosetting composition is, for example, 1% or more and 30% or less, depending on the type, and 5% or more and 20% or less. Is preferred.
Since it can fully color in the above range, an insulating resin layer distinguishable from the release film can be easily formed.

  Examples of the filler include powders of quartz glass, talc, fused silica, crystalline silica, alumina, and the like.

  The solvent is preferably one that can dissolve or disperse the epoxy group-containing compound and the compound (1). For example, esters (butyl acetate, ethyl acetate, methyl acetate, isopropyl acetate, ethylene glycol monoacetate, etc.), ketones (methyl ethyl ketone) Methyl isobutyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, etc.), alcohol (methanol, ethanol, isopropanol, butanol, propylene glycol monomethyl ether, propylene glycol, etc.) and the like.

  Examples of the curing agent include dicyclopentadiene type phenol resins, phenol novolac resins, cresol novolac resins, phenol aralkyl resins, biphenyl type phenol resins, and polyfunctional phenol resins such as triphenylmethane type phenol resins.

  Examples of the curing accelerator include organic phosphorus compounds such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine, imidazole compounds such as 2-ethyl-4-methylimidazole, 2-methylimidazole and phenylimidazole, 1,8- And tertiary amine compounds such as diazabicyclo (5.4.0) undecene-7 (DBU), 1,5-diazabicyclo (4.3.0) nonene-5 (DBN), and N-aminoethylpiperazine.

  As said additive, you may contain other components other than the said component. Examples of other components include a release agent, a flame retardant other than the compound (1), a pigment, an ion trapping agent, a coupling agent, and a heat resistance agent.

  The content of each of the curing agent, the curing accelerator, the filler, and the other components with respect to the total mass of the thermosetting composition is not particularly limited. For example, the total content is 0.1. It can be prepared in the range of mass% to 30 mass%.

(Method for producing thermosetting composition)
The thermosetting composition of the first aspect of the present invention is, for example, appropriately mixed with a solvent, the epoxy group-containing compound, the compound (1), an additive, and the like, and mixed by a conventional method using a ball mill, a blender, or the like. Can be prepared.

<Effect>
Since the compound (1) contained in the thermosetting composition of the present invention has flame retardancy and is liquid at 25 ° C. and 1 atm, it has excellent dispersibility in the thermosetting composition, and its cured product. The distribution inside is also uniform, and it is difficult to reduce the hardness of the cured product or coating film. Furthermore, since it is liquid, the adhesiveness with respect to a base material is improving, and the layer containing the hardened | cured material can fully adhere | attach with respect to base materials, such as a metal thin film layer, by a comparatively gentle lamination process.
The compound (1) contained in the thermosetting composition of the present invention functions as a flame retardant at the combustion temperature of the cured product. The details of this chemical mechanism are not yet elucidated, but by the same mechanism as that of the conventional triphenyl phosphate, the compound (1) forms a flame-retardant char during combustion, and the combustion of the cured product is suppressed. It is thought.
Moreover, the compound (1) contained in the thermosetting composition of the present invention functions as a stress reducing agent that suppresses curing shrinkage when the thermosetting composition is cured. Although the details of this chemical mechanism are unclear, the substituent of the compound (1) reacts with the epoxy group by heat, and the compound (1) is added to the epoxy group-containing compound to be cured and cured. It is thought that the contraction is suppressed.

《Hardened product》
The second aspect of the present invention is a cured product of the thermosetting composition of the first aspect. The degree of curing of the cured product may be any of a state that is closer to uncured than the B stage, a state that is B stage (semi-cured), or a state that is completely cured.
As an example of embodiment of hardened | cured material, the coating film formed by hardening | curing the thermosetting composition apply | coated to the surface of a base material is mentioned, for example.
Since the adhesiveness of the coating film to the substrate is excellent, the coating film is useful as an adhesive layer. Moreover, when the said base material is metal, when the said compound (2) is contained in the said coating film, the adhesiveness with respect to the metal surface will be more excellent. For this reason, the said coating film exhibits the adhesiveness outstanding as an insulating resin layer and an adhesive bond layer laminated | stacked on the metal thin film layer of the electromagnetic wave shield film mentioned later.
The film thickness in particular of the said coating film is not restrict | limited, For example, 1 micrometer or more and 100 micrometers or less are mentioned.

The method for obtaining the cured product is not particularly limited as long as it is a method capable of supplying heat for reacting and curing the epoxy group-containing compound and the compound (1). For example, it is injected into a container or a mold and heated. And a method of applying to the surface of the substrate and heating.
The heating temperature at the time of obtaining the cured product may be not less than the temperature at which the reaction occurs, and is preferably not less than room temperature. It is preferable to cure under the following heating conditions.
The curing reaction may be completely cured by one heating, or may be cured stepwise through the B stage by multiple heating.

<Effect>
Since the hardened | cured material of the 2nd aspect of this invention contains the said epoxy group containing compound and compound (1), it exhibits the adhesiveness outstanding with respect to the base material which was contacting at the time of hardening. Moreover, since compound (1) is contained, it is excellent also in a flame retardance.

《Electromagnetic wave shielding film》
The third aspect of the present invention is an electromagnetic wave shielding film having an insulating resin layer, a metal thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the metal thin film layer on the side opposite to the insulating resin layer. And at least one is the electromagnetic wave shielding film which is a hardened | cured material of a 2nd aspect among the said insulating resin layer and an adhesive bond layer.
Hereinafter, although it demonstrates with reference to drawings, the dimension ratio in drawing may differ from an actual thing for convenience of explanation.

FIG. 1 is a cross-sectional view showing the electromagnetic wave shielding film 1 of the first embodiment, and FIG. 2 is a cross-sectional view showing the electromagnetic wave shielding film 1 of the second embodiment.
The electromagnetic wave shielding film 1 includes an insulating resin layer 10; a metal thin film layer 22 adjacent to the insulating resin layer 10; an adhesive layer 24 adjacent to the opposite side of the metal thin film layer 22 from the insulating resin layer 10; A first release film 30 adjacent to the side opposite to the metal thin film layer 10; and a second release film 40 adjacent to the side opposite to the metal thin film layer 22 of the adhesive layer 24.

The electromagnetic wave shielding film 1 of the first embodiment is an example in which the adhesive layer 24 is an anisotropic conductive adhesive layer 24.
The electromagnetic wave shielding film 1 of the second embodiment is an example in which the adhesive layer 26 is an isotropic conductive adhesive layer 26.

(Insulating resin layer)
The insulating resin layer 10 is a protective layer for the metal thin film layer 22 after the electromagnetic wave shielding film 1 is attached to the surface of the insulating film provided on the surface of the flexible printed wiring board and the first release film 30 is peeled off. It becomes.

  As the insulating resin layer 10, a coating film formed by applying and semi-curing or curing a paint containing a thermosetting resin and a curing agent; a coating film formed by applying a paint containing a thermoplastic resin; Examples thereof include a layer made of a film obtained by melt-molding a composition containing a thermoplastic resin. From the viewpoint of heat resistance during soldering or the like, a coating film formed by applying a paint containing a thermosetting resin and a curing agent and semi-curing or curing is preferable.

Examples of the thermosetting resin include amide resin, epoxy resin, phenol resin, amino resin, alkyd resin, urethane resin, synthetic rubber, and ultraviolet curable acrylate resin. As the thermosetting resin, an amide resin and an epoxy resin are preferable from the viewpoint of excellent heat resistance.
As a hardening | curing agent, the well-known hardening | curing agent according to the kind of thermosetting resin is mentioned.

The insulating resin layer 10 is either one of a colorant (pigment, dye, etc.) and a filler or the like in order to conceal the printed circuit of the printed wiring board or to give design properties to the printed wiring board with an electromagnetic wave shielding film. Both may be included.
As one or both of the colorant and the filler, a pigment or a filler is preferable from the viewpoint of weather resistance, heat resistance, and concealment. From the viewpoint of concealment and design of the printed circuit, a black pigment or a black pigment is used. Combinations with other pigments or fillers are more preferred.

The insulating resin layer 10 may contain a flame retardant other than the compound (1).
The insulating resin layer 10 may contain other components as necessary within a range not impairing the effects of the present invention.

The surface resistance of the insulating resin layer 10 is preferably 1 × 10 ⁶ Ω or more from the viewpoint of electrical insulation. The surface resistance of the insulating resin layer 10 is preferably 1 × 10 ¹⁹ Ω or less from a practical point of view.
The thickness of the insulating resin layer 10 is preferably 0.1 μm or more and 30 μm or less, and more preferably 0.5 μm or more and 20 μm or less. If the thickness of the insulating resin layer 10 is not less than the lower limit of the above range, the insulating resin layer 10 can sufficiently exhibit the function as a protective layer. If the thickness of the insulating resin layer 10 is not more than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned.

(Conductive layer)
As the conductive layer 20, a metal thin film layer 22 adjacent to the insulating resin layer 10 and a conductive adhesive layer (an anisotropic conductive adhesive layer 24) that is the outermost layer on the opposite side of the conductive layer 20 from the insulating resin layer 10. Alternatively, a conductive layer (I) having an isotropic conductive adhesive layer 26); or a conductive layer (II) consisting only of the isotropic conductive adhesive layer 26 may be mentioned. As the conductive layer 20, the conductive layer (I) is preferable because it can sufficiently function as an electromagnetic wave shielding layer.

(Metal thin film layer)
The metal thin film layer 22 is a layer made of a metal thin film. Since the metal thin film layer 22 is formed so as to spread in the surface direction, it has conductivity in the surface direction and functions as an electromagnetic wave shielding layer or the like.

  Examples of the metal thin film layer 22 include a vapor deposition film formed by physical vapor deposition (vacuum vapor deposition, sputtering, ion beam vapor deposition, electron beam vapor deposition, etc.) or CVD, a plating film formed by plating, a metal foil, and the like. From the point of excellent surface direction conductivity, a vapor deposition film and a plating film are preferable, the thickness can be reduced, and even if the thickness is small, the surface direction conductivity is excellent and can be easily formed by a dry process. A vapor deposition film is more preferable, and a vapor deposition film formed by physical vapor deposition is more preferable.

  Examples of the metal constituting the metal thin film layer 22 include aluminum, silver, copper, gold, and conductive ceramics. From the viewpoint of electrical conductivity, copper is preferable, and from the viewpoint of chemical stability, conductive ceramics are preferable.

  The surface resistance of the metal thin film layer 22 is preferably 0.001Ω to 1Ω, and more preferably 0.001Ω to 0.5Ω. If the surface resistance of the metal thin film layer 22 is not less than the lower limit of the above range, the metal thin film layer 22 can be made sufficiently thin. If the surface resistance of the metal thin film layer 22 is less than or equal to the upper limit of the above range, the metal thin film layer 22 can sufficiently function as an electromagnetic wave shielding layer.

  The thickness of the metal thin film layer 22 is preferably 0.01 μm or more and 1 μm or less, and more preferably 0.05 μm or more and 1 μm or less. When the thickness of the metal thin film layer 22 is 0.01 μm or more, the surface conductivity is further improved. If the thickness of the metal thin film layer 22 is 0.05 μm or more, the electromagnetic noise shielding effect is further improved. If the thickness of the metal thin film layer 22 is equal to or less than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. Further, the productivity and flexibility of the electromagnetic wave shielding film 1 are improved.

(Conductive adhesive layer)
The conductive adhesive layer has conductivity at least in the thickness direction and has adhesiveness.
As the conductive adhesive layer, an anisotropic conductive adhesive layer 24 having conductivity in the thickness direction and having no conductivity in the surface direction, or having conductivity in the thickness direction and the surface direction, etc. An electrically conductive adhesive layer 26 is exemplified. As the conductive adhesive layer in the conductive layer (I), the conductive adhesive layer can be made thin and the amount of conductive particles can be reduced. As a result, the electromagnetic wave shielding film 1 can be made thin, and the electromagnetic wave shielding film 1 is flexible. From the viewpoint of improving the properties, the anisotropic conductive adhesive layer 24 is preferable. As the conductive adhesive layer in the conductive layer (I), the isotropic conductive adhesive layer 26 is preferable in that it can sufficiently function as an electromagnetic wave shielding layer.

As the conductive adhesive layer in the present embodiment, a coating film made of the thermosetting composition of the first aspect of the present invention or the cured product of the second aspect is used. Since the said coating film is thermosetting, it is excellent in heat resistance. Moreover, since the said compound (1) is contained, there is little shrinkage | contraction at the time of hardening, while being able to suppress the curl of a film, it is excellent also in the flame retardance after hardening. Furthermore, when the said epoxy group containing compound and compound (2) are contained, the adhesiveness with respect to the metal thin film layer 22 is especially excellent.
The degree of curing of the thermosetting composition constituting the conductive adhesive layer is not particularly limited, and may be any of an uncured state, a B-staged state, or a completely cured state.
The cured product constituting the conductive adhesive layer may be in an uncured state, a B-staged state, or a completely cured state than the B-stage.

The thermosetting anisotropic conductive adhesive layer 24 is composed of, for example, a thermosetting composition 24a including conductive particles 24b.
The thermosetting isotropic conductive adhesive layer 26 is constituted by, for example, a thermosetting composition 26a including conductive particles 26b.

The thermosetting composition may contain a rubber component for imparting flexibility (carboxy-modified nitrile rubber, acrylic rubber, etc.), a tackifier, and the like.
The thermosetting composition may contain a flame retardant other than the compound (1) as necessary.
The thermosetting composition may contain a cellulose resin and microfibril (such as glass fiber) in order to increase the strength of the conductive adhesive layer and improve the punching characteristics.
The said thermosetting composition may contain the other component as needed in the range which does not impair the effect of this invention.

  Examples of the conductive particles include metal (silver, platinum, gold, copper, nickel, palladium, aluminum, solder, etc.) particles, graphite powder, calcined carbon particles, plated calcined carbon particles, and the like. As the conductive particles, metal particles are preferable and copper particles are preferable from the viewpoint that the conductive adhesive layer has an appropriate hardness and can reduce pressure loss in the conductive adhesive layer during hot pressing. More preferred.

  The average particle diameter of the conductive particles 24b in the anisotropic conductive adhesive layer 24 is preferably 2 μm to 26 μm, and more preferably 4 μm to 16 μm. If the average particle diameter of the conductive particles 24b is equal to or greater than the lower limit of the above range, the thickness of the anisotropic conductive adhesive layer 24 can be ensured, and sufficient adhesive strength can be obtained. If the average particle diameter of the conductive particles 24b is equal to or less than the upper limit of the above range, the fluidity of the anisotropic conductive adhesive layer 24 (followability to the shape of the through holes of the insulating film) can be secured, and the insulating film The inside of the through hole can be sufficiently filled with a conductive adhesive.

  The average particle diameter of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.2 μm or more and 1 μm or less. When the average particle diameter of the conductive particles 26b is equal to or greater than the lower limit of the above range, the number of contact points of the conductive particles 26b increases, and the conductivity in the three-dimensional direction can be stably increased. If the average particle diameter of the conductive particles 26b is less than or equal to the upper limit of the above range, the fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through holes of the insulating film) can be secured, and the insulating film The inside of the through hole can be sufficiently filled with a conductive adhesive.

  The proportion of the conductive particles 24b in the anisotropic conductive adhesive layer 24 is preferably 1% by volume to 30% by volume and preferably 2% by volume to 15% by volume in 100% by volume of the anisotropic conductive adhesive layer 24. The following is more preferable. When the ratio of the conductive particles 24b is equal to or higher than the lower limit of the above range, the conductivity of the anisotropic conductive adhesive layer 24 is improved. When the ratio of the conductive particles 24b is equal to or less than the upper limit of the above range, the adhesiveness and fluidity (followability to the shape of the through hole of the insulating film) of the anisotropic conductive adhesive layer 24 are improved. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

  The proportion of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 50% by volume or more and 80% by volume or less in 100% by volume of the isotropic conductive adhesive layer 26, and 60% by volume or more and 70% by volume. The following is more preferable. When the ratio of the conductive particles 26b is equal to or higher than the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 is improved. When the ratio of the conductive particles 26b is equal to or less than the upper limit of the above range, the adhesiveness and fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through hole of the insulating film) are improved. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

The storage elastic modulus at 180 ° C. of the conductive adhesive layer is preferably 1 × 10 ³ Pa or more and 5 × 10 ⁷ Pa or less, and more preferably 5 × 10 ³ Pa or more and 1 × 10 ⁷ Pa or less. If the storage elastic modulus at 180 ° C. of the conductive adhesive layer is equal to or higher than the lower limit of the above range, the conductive adhesive layer has a further appropriate hardness, and the conductive adhesive layer during hot pressing. The pressure loss at can be reduced. As a result, the conductive adhesive layer and the printed circuit of the printed wiring board are sufficiently bonded, and the conductive adhesive layer is securely electrically connected by the printed circuit of the printed wiring board through the through hole of the insulating film. The If the storage elastic modulus at 180 ° C. of the conductive adhesive layer is not more than the upper limit of the above range, the flexibility of the electromagnetic wave shielding film 1 is improved. As a result, the electromagnetic wave shielding film 1 easily sinks into the through hole of the insulating film, and the conductive adhesive layer is reliably electrically connected by the printed circuit of the printed wiring board through the through hole of the insulating film.

The surface resistance of the anisotropic conductive adhesive layer 24 is preferably 1 × 10 ⁴ Ω to 1 × 10 ¹⁶ Ω, more preferably 1 × 10 ⁶ Ω to 1 × 10 ¹⁴ Ω. If the surface resistance of the anisotropic conductive adhesive layer 24 is not less than the lower limit of the above range, the content of the conductive particles 24b can be kept low. If the surface resistance of the anisotropic conductive adhesive layer 24 is not more than the upper limit of the above range, there is no problem in anisotropy in practice.

  The surface resistance of the isotropic conductive adhesive layer 26 is preferably 0.05Ω to 2.0Ω, more preferably 0.1Ω to 1.0Ω. If the surface resistance of the isotropic conductive adhesive layer 26 is equal to or greater than the lower limit of the above range, the content of the conductive particles 26b can be kept low, the viscosity of the conductive adhesive does not become too high, and the coatability is further increased. It becomes good. Further, the fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through hole of the insulating film) can be further ensured. If the surface resistance of the isotropic conductive adhesive layer 26 is less than or equal to the upper limit of the above range, the entire surface of the isotropic conductive adhesive layer 26 has uniform conductivity.

  The thickness of the anisotropic conductive adhesive layer 24 is preferably 3 μm or more and 25 μm or less, and more preferably 5 μm or more and 15 μm or less. If the thickness of the anisotropic conductive adhesive layer 24 is equal to or greater than the lower limit of the above range, the fluidity of the anisotropic conductive adhesive layer 24 (followability to the shape of the through hole of the insulating film) can be secured, The through hole of the insulating film can be sufficiently filled with the conductive adhesive. If the thickness of the anisotropic conductive adhesive layer 24 is equal to or less than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

  The thickness of the isotropic conductive adhesive layer 26 is preferably 5 μm or more and 20 μm or less, and more preferably 7 μm or more and 17 μm or less. If the thickness of the isotropic conductive adhesive layer 26 is equal to or greater than the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 becomes good and can sufficiently function as an electromagnetic wave shielding layer. Further, the fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through hole of the insulating film) can be ensured, and the through hole of the insulating film can be sufficiently filled with the conductive adhesive. The bendability can be secured and the isotropic conductive adhesive layer 26 will not be torn even if it is repeatedly bent. If the thickness of the isotropic conductive adhesive layer 26 is equal to or less than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

(First release film)
The first release film 30 serves as a carrier film for the insulating resin layer 10 and the conductive layer 20 and improves the handling properties of the electromagnetic wave shielding film 1. The first release film 30 is peeled from the insulating resin layer 10 after the electromagnetic wave shielding film 1 is attached to a printed wiring board or the like.

  The first release film 30 includes a release film body 32 and an adhesive layer 34 provided on the surface of the release film body 32 on the insulating resin layer 10 side.

  As the resin material of the release film body 32, polyethylene terephthalate (hereinafter also referred to as PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, ethylene-vinyl acetate. Examples thereof include a copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, and a liquid crystal polymer. As the resin material, PET is preferable from the viewpoint of heat resistance (dimensional stability) and price when the electromagnetic wave shielding film 1 is manufactured.

The release film body 32 may contain one or both of a colorant (pigment, dye, etc.) and a filler.
Either one or both of the colorant and the filler is different from the insulating resin layer 10 in that it can be clearly distinguished from the insulating resin layer 10 and is easily noticed after the first release film 30 is peeled off after hot pressing. Colored ones are preferred, and white pigments, fillers, or combinations of white pigments with other pigments or fillers are more preferred.

The storage elastic modulus of the release film body 32 at 180 ° C. is preferably 8 × 10 ⁷ Pa or more and 5 × 10 ⁹ Pa, more preferably 1 × 10 ⁸ Pa or more and 8 × 10 ⁸ Pa. If the storage elastic modulus at 180 ° C. of the release film body 32 is equal to or higher than the lower limit of the above range, the first release film 30 has an appropriate hardness, and the first release at the time of hot pressing. The pressure loss in the mold film 30 can be reduced. If the storage elastic modulus at 180 ° C. of the release film main body 32 is equal to or less than the upper limit of the above range, the flexibility of the first release film 30 is good.

  The thickness of the release film main body 32 is preferably 3 μm or more and 75 μm or less, and more preferably 12 μm or more and 50 μm or less. If the thickness of the release film main body 32 is not less than the lower limit of the above range, the handling property of the electromagnetic wave shielding film 1 will be good. If the thickness of the release film main body 32 is equal to or less than the upper limit of the above range, heat is easily transmitted to the conductive adhesive layer when the conductive adhesive layer of the electromagnetic wave shielding film 1 is hot-pressed on the surface of the insulating film. .

  The pressure-sensitive adhesive layer 34 is formed, for example, by applying a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive to the surface of the release film main body 32. When the first release film 30 has the pressure-sensitive adhesive layer 34, the second release film 40 is peeled from the conductive adhesive layer, or the electromagnetic wave shielding film 1 is attached to a printed wiring board or the like by hot pressing. In this case, the first release film 30 can be prevented from peeling from the insulating resin layer 10, and the first release film 30 can sufficiently serve as a protective film.

The pressure-sensitive adhesive is such that the first release film 30 is not easily peeled off from the insulating resin layer 10 before hot pressing, and the first release film 30 can be peeled off from the insulating resin layer 10 after hot pressing. It is preferable to impart appropriate tackiness to the pressure-sensitive adhesive layer 34.
Examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesive, urethane pressure sensitive adhesive, and rubber pressure sensitive adhesive.
The glass transition temperature of the pressure-sensitive adhesive is preferably -100 to 60 ° C, more preferably -60 to 40 ° C.

  The thickness of the first release film 30 is preferably 25 μm or more and 125 μm or less, and more preferably 38 μm or more and 100 μm or less. If the thickness of the 1st release film 30 is more than the lower limit of the said range, the handleability of the electromagnetic wave shielding film 1 will become favorable. If the thickness of the first release film 30 is equal to or less than the upper limit of the above range, heat is applied to the conductive adhesive layer when the conductive adhesive layer of the electromagnetic wave shielding film 1 is hot-pressed on the surface of the insulating film. Easy to communicate.

(Second release film)
The second release film 40 protects the conductive adhesive layer and improves the handling properties of the electromagnetic wave shielding film 1. The second release film 40 is peeled from the conductive adhesive layer before the electromagnetic wave shielding film 1 is attached to a printed wiring board or the like.

  The second release film 40 includes, for example, a release film main body 42 and a release agent layer 44 provided on the surface of the release film main body 42 on the conductive adhesive layer side.

Examples of the resin material for the release film main body 42 include the same resin materials as those for the release film main body 32.
The release film main body 42 may contain a colorant, a filler, and the like.
The thickness of the release film main body 42 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 150 μm or less, and further preferably 25 μm or more and 100 μm or less.

The release agent layer 44 is formed by treating the surface of the release film main body 42 with a release agent. When the second release film 40 has the release agent layer 44, the second release film 40 can be easily peeled off when the second release film 40 is peeled off from the conductive adhesive layer. The adhesive layer becomes difficult to break.
As the release agent, a known release agent may be used.

  The thickness of the release agent layer 44 is preferably 0.05 μm or more and 30 μm or less, and more preferably 0.1 μm or more and 20 μm or less. When the thickness of the release agent layer 44 is within the above range, the second release film 40 is further easily peeled off.

(Thickness of electromagnetic shielding film)
The thickness of the electromagnetic shielding film 1 (excluding the release film) is preferably 5 μm or more and 50 μm or less, and more preferably 8 μm or more and 30 μm or less. If the thickness of the electromagnetic wave shielding film 1 that does not include a release film is equal to or greater than the lower limit of the above range, it is difficult to break when the first release film 30 is peeled off. If the thickness of the electromagnetic shielding film 1 that does not include the release film is equal to or less than the upper limit of the above range, the printed wiring board with the electromagnetic shielding film can be thinned.

<< Method for Producing Electromagnetic Shielding Film >>
4th aspect of this invention is a manufacturing method of the electromagnetic wave shielding film of 3rd aspect.
In the first embodiment of the present aspect, by heating the coating film formed by applying the thermosetting composition of the first aspect to the base film, the insulating resin layer and the It is the manufacturing method of the said electromagnetic wave shield film which has the process of forming at least one among adhesive layers.

  The form of the base film is not particularly limited, and examples thereof include a carrier film, a first release film, and a second release film. A metal thin film layer may be formed in advance on the application surface of the base film of the thermosetting composition. Specifically, for example, the base film may be a laminated film of a carrier film and a metal thin film layer.

  The temperature and time for heating the coating film are not particularly limited as long as the thermosetting composition is cured to a desired level, and for example, 50 ° C to 200 ° C, 10 seconds to 10 minutes. Is mentioned.

<Effect>
In this embodiment, since the compound (1) is contained in the thermosetting composition, the curing shrinkage can be suppressed when the coating film is cured. As a result, curling of the base film on which the insulating resin layer or the adhesive layer is formed is suppressed, and the production yield of the electromagnetic wave shielding film can be improved.

  In the second embodiment of the fourth aspect, the insulating resin layer, the metal thin film layer, and the adhesive layer are laminated in this order, and subjected to a laminating process that heats and pressurizes the insulating resin layer, It is a manufacturing method of an electromagnetic wave shield film which has a process of performing adhesion of at least one among adhesion of the metal thin film layer, and adhesion of the metal thin film layer and the adhesive layer.

As a method of laminating each layer in the above order, for example, the insulating resin layer and the metal thin film layer are formed in this order on a first release film, and the adhesive layer is formed on a second release film. And a method of placing the second release film on the first release film so that the adhesive layer is attached to the metal thin film layer.
Instead of the above method, the insulating resin layer is formed on the first release film, the adhesive layer and the metal thin film layer are formed in this order on the second release film, and the metal thin film layer A method of placing the first release film on the second release film so as to attach the insulating resin layer can also be exemplified.
The conditions for the heating temperature and pressure for the laminating treatment are preferably those in the step (c3) described in detail later.

<Effect>
In this embodiment, since the compound (1) is contained in at least one of the insulating resin layer and the adhesive layer, the insulating resin layer containing the compound (1) and the adhesive layer with respect to the metal thin film It has excellent adhesion and can be easily bonded by a relatively gentle lamination process. As a result, the manufacturing efficiency of the electromagnetic wave shielding film can be improved.
Hereinafter, in more detail, the manufacturing method of the electromagnetic wave shielding film concerning this invention is illustrated.

  The electromagnetic wave shielding film of the present invention is produced, for example, by the following method (α), the following method (β), or the like. As a method for producing the electromagnetic wave shielding film of the present invention, the method (α) is preferable because the adhesion between the insulating resin layer and the metal thin film layer is improved.

The method (α) is a method having the following steps (a) to (c).
Process (a): The process of providing a metal thin film layer on the surface of a carrier film as needed.
Step (b): A step of providing an insulating resin layer on the surface of the metal thin film layer provided on the surface of the carrier film.
Step (c): A step of peeling the carrier film from the metal thin film layer and providing an adhesive layer on the surface of the metal thin film layer opposite to the insulating resin layer.

The method (β) is a method having the following steps (x) to (z).
Step (x): A step of providing an insulating resin layer on the surface of the first release film.
Step (y): A step of providing a metal thin film layer on the surface of the insulating resin layer.
Step (z): A step of providing an adhesive layer on the surface of the metal thin film layer.

Hereinafter, the method (α) will be described in detail.
(Process (a))
As a carrier film, what has a base material layer and the adhesive layer provided in the surface of the base material layer is mentioned.
Examples of the resin material for the base material layer include the same resin materials for the base material layer 32 of the first release film 30.
A known pressure-sensitive adhesive may be used as the pressure-sensitive adhesive for the pressure-sensitive adhesive layer.

  Examples of the method for forming the metal thin film layer include physical vapor deposition, a method of forming a vapor deposition film by CVD, a method of forming a plating film by plating, and a method of attaching a metal foil. From the point of being able to form a metal thin film layer having excellent surface conductivity, physical vapor deposition, a method of forming a vapor deposition film by CVD, or a method of forming a plating film by plating is preferable, and the thickness of the metal thin film layer can be reduced, In addition, a method of forming a deposited film by physical vapor deposition or CVD is more preferable because a metal thin film layer having excellent surface conductivity can be formed even if the thickness is small, and a metal thin film layer can be easily formed by a dry process. A method of forming a deposited film by physical vapor deposition is more preferable.

  Step (a) may be omitted by obtaining a commercially available laminate in which a metal thin film layer is provided on the surface of the carrier film.

(Process (b))
As a method of providing an insulating resin layer on the surface of the metal thin film layer, for example, a photocurable composition is applied to the surface of the metal thin film layer, and if it contains a solvent, it is dried and then irradiated with light (such as ultraviolet rays). A semi-cured or cured method.

In the step (b), a first release film may be provided on the surface of the insulating resin layer.
As a method of providing the first release film on the surface of the insulating resin layer, the first release film having the base material layer and the pressure-sensitive adhesive layer on the surface of the insulating resin layer, the insulating resin layer and the pressure-sensitive adhesive layer are used. The surface of the insulating resin layer by attaching the base material layer of the first release film to the surface of the pressure-sensitive adhesive layer after providing the pressure-sensitive adhesive layer on the surface of the insulating resin layer And a method of providing a first release film.

(Process (c))
In the step (c), a second release film with an adhesive layer in which an adhesive layer is provided on the surface of the second release film is coated with a metal on the surface of the metal thin film layer opposite to the insulating resin layer. You may affix so that a thin film layer and an adhesive bond layer may contact; you may provide an adhesive bond layer directly on the surface of a metal thin film layer. Moreover, after providing an adhesive layer on the surface of the metal thin film layer, a second release film may be attached to the surface of the adhesive layer.

  As a method of providing an adhesive layer on the surface of the second release film or metal thin film layer, an adhesive, a solvent, and optionally conductive particles are provided on the surface of the second release film or metal thin film layer. The method of apply | coating the coating liquid containing and drying is mentioned.

(One Embodiment of Manufacturing Method of Electromagnetic Shielding Film)
Hereinafter, a method for producing the electromagnetic wave shielding film 1 of the first embodiment shown in FIG. 1 will be described with reference to FIGS. 3 and 4.

Step (a):
As shown in FIG. 3, a metal thin film layer 22 is provided by vapor-depositing metal on the surface of the carrier film 100 having the base material layer 102 and the release agent layer 104 on the release agent layer 104 side.

Step (b1):
As shown in FIG. 3, on the surface of the metal thin film layer 22, an insulating resin layer forming coating liquid (thermosetting composition of the first aspect of the present invention) containing a black colorant (not shown) is applied, The insulating resin layer 10 is provided by drying while heating.

Step (b2):
As shown in FIG. 3, the first release film 30 having the base layer 32 and the adhesive layer 34 is placed on the surface of the insulating resin layer 10 so that the insulating resin layer 10 and the adhesive layer 34 are in contact with each other. paste.

Step (c1):
As shown in FIG. 4, an adhesive 24a, conductive particles 24b and a solvent are placed on the surface of the second release film 40 having the base layer 42 and the release agent layer 44 on the release agent layer 44 side. An anisotropic conductive adhesive layer 24 (adhesive layer 24) is provided by applying a coating liquid for forming an adhesive layer (thermosetting composition of the first aspect of the present invention) and drying while heating. . In this way, a second release film with an adhesive layer is obtained.

Step (c2):
As shown in FIG. 4, the carrier film 100 is peeled from the metal thin film layer 22 in the laminate obtained in the step (b2). In this way, a first release film with an insulating resin layer and a metal thin film layer is obtained.

Step (c3):
As shown in FIG. 4, a first release film with an insulating resin layer and a metal thin film layer, and a second release film with an adhesive layer, a metal thin film layer 22, an anisotropic conductive adhesive layer 24, Are bonded to each other and heated as necessary to cure the insulating resin layer and the adhesive layer, whereby the electromagnetic wave shielding film 1 is obtained.

In the step (c3), when the metal thin film layer 22 and the anisotropic conductive adhesive layer 24 are bonded together, it is preferable to perform a laminating process (a process of bonding in a laminated state) under milder conditions than hot pressing. .
As heating temperature in the said lamination process, 50-100 degreeC is preferable, for example.
The pressure in the laminating treatment is preferably 100 kPa (0.1 MPa) or less, more preferably 0.1 kPa or more and 20 kPa or less, and further preferably 1 kPa or more and 10 kPa or less.
The heating and pressurizing time in the laminating process is preferably, for example, 10 seconds to 30 minutes, and more preferably 30 seconds to 10 minutes.
By laminating at the above-mentioned preferable heating temperature, pressure, and processing time, the metal thin film layer 22 and the anisotropic conductive adhesive layer 24 can be easily bonded with sufficient adhesive force.

<Effect>
In the electromagnetic wave shielding film 1 according to the present invention, since at least one of the insulating resin layer 10 and the anisotropic conductive adhesive layer 24 is formed of the thermosetting composition of the first aspect, Also excellent. Further, during the production, shrinkage during curing of the thermosetting composition is suppressed, and the insulating resin layer 10 and the anisotropic conductive adhesive layer 24 are made of metal by laminating under relatively mild conditions. Sufficient adhesion to the thin film layer 22 can be easily obtained.
Moreover, if the said thermosetting composition contains the said compound (2), the adhesive force of the insulating resin layer 10 and the anisotropic conductive adhesive layer 24 with respect to the metal thin film layer 22 will increase more, and a release film will be used. When peeling, the metal thin film layer 22 and the insulating resin layer 10 or the anisotropic conductive adhesive layer 24 are prevented from peeling.

The electromagnetic wave shielding film according to the present invention is not limited to the illustrated embodiment as long as at least one of the insulating resin layer and the conductive adhesive layer contains the epoxy group-containing compound and the compound (1). .
For example, the second release film may have a pressure-sensitive adhesive layer instead of the release agent layer when the tackiness of the surface of the conductive adhesive layer is small. Alternatively, the second release film may be omitted.
When the mold release property of the release film main body is high, the second release film may be composed of only the release film main body without the release agent layer.
Two or more insulating resin layers may be used.

<Printed wiring board with electromagnetic shielding film>
FIG. 5 is a cross-sectional view showing an embodiment of a printed wiring board with an electromagnetic wave shielding film of the present invention.
The flexible printed wiring board 2 with an electromagnetic wave shielding film includes a flexible printed wiring board 50, an insulating film 60, and the electromagnetic wave shielding film 1 of the first embodiment.
The flexible printed wiring board 50 has a printed circuit 54 provided on at least one side of a base film 52.
The insulating film 60 is provided on the surface of the flexible printed wiring board 50 on the side where the printed circuit 54 is provided.
The anisotropic conductive adhesive layer 24 of the electromagnetic wave shielding film 1 is adhered to the surface of the insulating film 60 and cured. The anisotropic conductive adhesive layer 24 is electrically connected to the printed circuit 54 through a through hole (not shown) formed in the insulating film 60.
In the flexible printed wiring board 2 with an electromagnetic wave shielding film, the second release film 40 is peeled from the anisotropic conductive adhesive layer 24.

  When the first release film 30 becomes unnecessary in the flexible printed wiring board 2 with the electromagnetic wave shielding film, the first release film 30 is peeled off from the insulating resin layer 10.

In the vicinity of the printed circuit 54 (signal circuit, ground circuit, ground layer, etc.) excluding the portion having the through hole, the metal thin film layer 22 of the electromagnetic wave shielding film 1 is provided with the insulating film 60 and the anisotropic conductive adhesive layer 24. Are arranged opposite to each other.
The separation distance between the printed circuit 54 and the metal thin film layer 22 excluding the portion having the through hole is substantially equal to the sum of the thickness of the insulating film 60 and the thickness of the anisotropic conductive adhesive layer 24. The separation distance is preferably 30 μm or more and 200 μm or less, and more preferably 60 μm or more and 200 μm or less. When the separation distance is smaller than 30 μm, the impedance of the signal circuit is lowered. Therefore, in order to have a characteristic impedance such as 100Ω, the line width of the signal circuit has to be reduced, and the variation in the line width causes the variation in the characteristic impedance. Thus, the reflection resonance noise due to the impedance mismatch is easily applied to the electric signal. When the separation distance is larger than 200 μm, the flexible printed wiring board 2 with the electromagnetic wave shielding film becomes thick and the flexibility is insufficient.

(Flexible printed wiring board)
The flexible printed wiring board 50 is a printed circuit (a power circuit, a ground circuit, a ground layer, etc.) formed by processing a copper foil of a copper clad laminate into a desired pattern by a known etching method.
As the copper-clad laminate, one or both surfaces of the base film 52 are bonded with copper foil via an adhesive layer (not shown); a resin solution or the like that forms the base film 52 is cast on the surface of the copper foil And the like.
Examples of the material for the adhesive layer include epoxy resin, polyester, polyimide, polyamideimide, polyamide, phenol resin, urethane resin, acrylic resin, and melamine resin.
The thickness of the adhesive layer is preferably 0.5 μm or more and 30 μm or less.

(Base film)
The base film 52 is preferably a heat resistant film, more preferably a polyimide film or a liquid crystal polymer film, and even more preferably a polyimide film.
The surface resistance of the base film 52 is preferably 1 × 10 ⁶ Ω or more from the viewpoint of electrical insulation. The surface resistance of the base film 52 is preferably 1 × 10 ¹⁹ Ω or less from a practical point of view.
The thickness of the base film 52 is preferably 5 μm or more and 200 μm or less, more preferably 6 μm or more and 25 μm or less, and more preferably 10 μm or more and 25 μm or less from the viewpoint of flexibility.

(Printed circuit)
Examples of the copper foil constituting the printed circuit 54 (signal circuit, ground circuit, ground layer, etc.) include rolled copper foil, electrolytic copper foil, and the like, and rolled copper foil is preferred from the viewpoint of flexibility.
The thickness of the copper foil is preferably 1 μm or more and 50 μm or less, and more preferably 18 μm or more and 35 μm or less.
An end (terminal) in the length direction of the printed circuit 54 is not covered with the insulating film 60 or the electromagnetic wave shielding film 1 for solder connection, connector connection, component mounting, or the like.

(Insulating film)
The insulating film 60 (coverlay film) is obtained by forming an adhesive layer (not shown) on one surface of an insulating film main body (not shown) by applying an adhesive, attaching an adhesive sheet, or the like.
The surface resistance of the insulating film body is preferably 1 × 10 ⁶ Ω or more from the viewpoint of electrical insulation. The surface resistance of the insulating film body is preferably 1 × 10 ¹⁹ Ω or less from a practical point of view.
As an insulating film main body, the film which has heat resistance is preferable, a polyimide film and a liquid crystal polymer film are more preferable, and a polyimide film is further more preferable.
The thickness of the insulating film body is preferably 1 μm to 100 μm, and more preferably 3 μm to 25 μm from the viewpoint of flexibility.
Examples of the material for the adhesive layer include epoxy resin, polyester, polyimide, polyamideimide, polyamide, phenol resin, urethane resin, acrylic resin, melamine resin, polystyrene, and polyolefin. The epoxy resin may contain a rubber component (carboxy-modified nitrile rubber or the like) for imparting flexibility.
The thickness of the adhesive layer is preferably 1 μm or more and 100 μm or less, and more preferably 1.5 μm or more and 60 μm or less.

  The shape of the opening of the through hole is not particularly limited. Examples of the shape of the opening of the through hole 62 include a circle, an ellipse, and a quadrangle.

(Method for producing printed wiring board with electromagnetic shielding film)
The printed wiring board with an electromagnetic wave shielding film of the present invention can be produced by, for example, a method having the following steps (d) to (g).
Step (d): A step of obtaining a printed wiring board with an insulating film by providing an insulating film having through holes formed at positions corresponding to the printed circuit on the surface of the printed wiring board on which the printed circuit is provided.
Step (e): After step (d), the printed wiring board with an insulating film and the electromagnetic wave shielding film of the present invention from which the second release film has been peeled are contacted with the conductive adhesive layer on the surface of the insulating film. The conductive adhesive layer is adhered to the surface of the insulating film, and the conductive adhesive layer is electrically connected to the printed circuit through the through-holes by stacking and heat-pressing them. A step of obtaining a printed wiring board with a shield film.
Step (f): A step of peeling off the first release film after the step (e) when the first release film becomes unnecessary.
Step (g): A step of fully curing the anisotropic conductive adhesive layer between the steps (e) and (f) or after the step (f) as necessary.

  Hereinafter, a method for producing a flexible printed wiring board with an electromagnetic wave shielding film will be described with reference to FIG.

(Process (d))
As shown in FIG. 6, an insulating film 60 in which a through hole 62 is formed at a position corresponding to the printed circuit 54 is overlaid on the flexible printed wiring board 50, and an adhesive layer of the insulating film 60 is placed on the surface of the flexible printed wiring board 50. A flexible printed wiring board 3 with an insulating film is obtained by bonding (not shown) and curing the adhesive layer. The adhesive layer of the insulating film 60 may be temporarily bonded to the surface of the flexible printed wiring board 50, and the adhesive layer may be fully cured in the step (g).
Adhesion and curing of the adhesive layer are performed by, for example, hot pressing with a press machine (not shown) or the like.

(Process (e))
As shown in FIG. 6, the electromagnetic shielding film 1 from which the second release film 40 is peeled is superimposed on the flexible printed wiring board 3 with an insulating film, and heat-pressed, whereby the surface of the insulating film 60 is anisotropically conductive. The flexible printed wiring board 2 with the electromagnetic wave shielding film is obtained in which the adhesive layer 24 is bonded and the anisotropic conductive adhesive layer 24 is electrically connected to the printed circuit 54 through the through hole 62.

The anisotropic conductive adhesive layer 24 is bonded and cured by, for example, hot pressing with a press (not shown) or the like.
The hot pressing time is 20 seconds or more and 60 minutes or less, and more preferably 30 seconds or more and 30 minutes or less. If the hot pressing time is equal to or greater than the lower limit of the above range, the anisotropic conductive adhesive layer 24 is adhered to the surface of the insulating film 60. If the time of hot press is below the upper limit of the said range, the manufacturing time of the flexible printed wiring board 2 with an electromagnetic wave shielding film can be shortened.

  The temperature of the hot press (the temperature of the hot platen of the press machine) is preferably 140 ° C. or higher and 190 ° C. or lower, and more preferably 150 ° C. or higher and 175 ° C. or lower. If the temperature of the hot press is equal to or higher than the lower limit of the above range, the anisotropic conductive adhesive layer 24 is bonded to the surface of the insulating film 60. In addition, the time for hot pressing can be shortened. If the temperature of the hot press is not more than the upper limit of the above range, deterioration of the electromagnetic wave shielding film 1, the flexible printed wiring board 50, etc. can be suppressed.

  The pressure of the hot press is preferably 0.5 MPa or more and 20 MPa or less, and more preferably 1 MPa or more and 16 MPa or less. If the pressure of the hot press is not less than the lower limit of the above range, the anisotropic conductive adhesive layer 24 is bonded to the surface of the insulating film 60. In addition, the time for hot pressing can be shortened. If the pressure of the hot press is not more than the upper limit of the above range, damage to the electromagnetic wave shielding film 1, the flexible printed wiring board 50, etc. can be suppressed.

(Process (f))
As shown in FIG. 6, when the first release film becomes unnecessary, the first release film 30 is peeled from the insulating resin layer 10.

(Process (g))
When the time of the hot press in the step (e) is a short time of 20 seconds or more and 10 minutes or less, the anisotropic conductive adhesive layer between the step (e) and the step (f) or after the step (f) It is preferable to perform 24 main curing.
The main curing of the anisotropic conductive adhesive layer 24 is performed using a heating device such as an oven, for example.
The heating time is from 15 minutes to 120 minutes, preferably from 30 minutes to 60 minutes. If the heating time is not less than the lower limit of the above range, the anisotropic conductive adhesive layer 24 can be sufficiently cured. If heating time is below the upper limit of the said range, the manufacturing time of the flexible printed wiring board 2 with an electromagnetic wave shielding film can be shortened.
The heating temperature (atmosphere temperature in the oven) is preferably 120 ° C. or higher and 180 ° C. or lower, and preferably 120 ° C. or higher and 150 ° C. or lower. If heating temperature is more than the lower limit of the said range, heating time can be shortened. If heating temperature is below the upper limit of the said range, deterioration etc. of the electromagnetic wave shielding film 1, the flexible printed wiring board 50, etc. can be suppressed.

<Effect>
In the manufacturing method of the flexible printed wiring board 2 with the electromagnetic wave shielding film described above, since the electromagnetic wave shielding film 1 is used, the insulating resin layer 10 and the anisotropic conductive adhesive layer are bonded at the time of bonding by hot pressing. 24 cure shrinkage is small, curling can be suppressed, and flame retardancy after curing is excellent.
Moreover, since it has the electromagnetic wave shielding film 1 in the flexible printed wiring board 2 with the electromagnetic wave shielding film after manufacture, it is excellent in a flame retardance. Furthermore, if the thermosetting composition contains the compound (2), the adhesive strength of the insulating resin layer 10 and the anisotropic conductive adhesive layer 24 to the metal thin film layer 22 is further increased, and the first separation is performed. When the mold film 30 is peeled off, the metal thin film layer 22 and the insulating resin layer 10 or the anisotropic conductive layer 24 are prevented from peeling off.

(Other embodiments)
The printed wiring board with an electromagnetic wave shielding film of the present invention includes a printed wiring board, an insulating film adjacent to the surface of the printed wiring board on which the printed circuit is provided, a conductive layer adjacent to the insulating film, and a conductive layer What is necessary is just to have the electromagnetic wave shielding film of this invention electrically connected to the printed circuit through the through-hole formed in the insulating film, and is not limited to embodiment of the example of illustration.
For example, the flexible printed wiring board may have a ground layer on the back side. The flexible printed wiring board may have a printed circuit on both sides, and an insulating film and an electromagnetic wave shielding film may be attached to both sides.
Instead of the flexible printed wiring board, a rigid printed board having no flexibility may be used.
Instead of the electromagnetic shielding film 1 of the first embodiment, the electromagnetic shielding film 1 of the second embodiment or the like may be used.

Example 1
As an insulating resin layer-forming coating solution (thermosetting composition), 100 g of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, jER (registered trademark) 828) and 20 g of N-aminoethylpiperazine (curing agent). 2 g of carbon black (black colorant) and 11.0 g of the phosphorus compound represented by the formula (1b-1) (Sanko Co., Ltd., M-Ester, concentration 80% by mass, solvent: ethylene glycol) A coating solution dissolved in 200 g of a solvent (methyl ethyl ketone) was prepared. Thereby, the said phosphorus compound was mix | blended so that it might become about 0.016 mol per mol of epoxy groups of an epoxy resin.

  As a coating liquid for forming an adhesive layer (thermosetting composition), vinyl acetate resin solution (manufactured by Showa Denko KK, Vinylol (registered trademark) K-2S, solid content: 15 mass, solvent: methyl isobutyl ketone, methyl ethyl ketone, 100 g of methanol), 4.1 g of epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER (registered trademark) 1031S, solid content: 60 mass, solvent: methyl ethyl ketone) and 4.5 g of copper powder (average particle size: 8 μm) 5.8 g of a phosphorus compound represented by the formula (1b-1) (manufactured by Sanko Co., Ltd., M-Ester, concentration 80% by mass, solvent: ethylene glycol), and gallic acid represented by the formula (2b) A mixture of 0.5 g of was prepared. Thereby, it mix | blended so that the said phosphorus compound might be about 0.84 mol per mol of epoxy groups of an epoxy resin, and the active hydrogen group of gallic acid might be about 0.6 mol.

Step (b1):
As shown in FIG. 3, a laminate in which a metal thin film layer is provided on the surface of a carrier film (manufactured by Toray KP Film Co., Ltd., KCP Seduc (registered trademark), copper foil with release layer, copper foil thickness: 0.00 A coating solution for forming an insulating resin layer was applied to the surface of a metal thin film layer having a thickness of 5 μm, copper foil surface resistance: 0.015Ω, and PET thickness: 50 μm using a # 8 bar coater. The coating film was dried at 150 ° C. for 1 minute to provide an insulating resin layer (thickness: 10 μm, surface resistance: 1.0E + 12Ω or more) on the surface of the metal thin film layer. At this time, it was confirmed whether or not the entire film was curled in the direction of the insulating resin layer due to curing shrinkage of the coating solution for forming the insulating resin layer.

Step (b2):
On the surface of the insulating resin layer, a first release film (manufactured by Panac, Panaprotect (registered trademark) GN, adhesive film, adhesive strength: 0.49 N / cm, PET thickness: 75 μm), and insulating resin layer The laminate was obtained by pasting so that the adhesive layer was in contact.

Step (c1):
On the surface of the second release film (manufactured by Panac, Panapeel (registered trademark) SM-1, release film, PET thickness: 50 μm) on the release agent layer side, a coating solution for forming an adhesive layer is used as a comma. It was applied at a thickness of 25 μm using a coater. The coated film is dried at 100 ° C. for 1 minute, and an anisotropic conductive adhesive layer (thickness: 10 μm, surface resistance: 1.0E + 12Ω or more Ω) is provided, and a second release film with an adhesive layer is provided. Obtained.

Step (c2):
In the laminate obtained in the step (b2), the carrier film was peeled from the metal thin film layer to obtain a first release film with an insulating resin layer and a metal thin film layer.

Step (c3):
The first release film with the insulating resin layer and the metal thin film layer and the second release film with the adhesive layer are placed at 95 ° C. and 5 kPa so that the metal thin film layer and the anisotropic conductive adhesive layer are in contact with each other. Lamination was performed under pressure to obtain an electromagnetic wave shielding film. At the time of adhesion by this lamination, when the adhesion was insufficient, the lamination treatment was performed again, and the number of times of lamination until sufficient adhesion was measured.

Step (d):
An insulating adhesive composition is applied to the surface of a 25 μm thick polyimide film (insulating film body) so that the dry film thickness is 25 μm, an adhesive layer is formed, and an insulating film (thickness: 50 μm) is formed. Obtained. A through hole (hole diameter: 150 μm) was formed at a position corresponding to the ground of the printed circuit.

A flexible printed wiring board having a printed circuit formed on the surface of a polyimide film (base film) having a thickness of 12 μm was prepared.
An insulating film was affixed to the flexible printed wiring board by hot pressing to obtain a flexible printed wiring board with an insulating film.

Step (e):
An electromagnetic shielding film from which the second release film has been peeled is overlaid on a flexible printed wiring board with an insulating film, and using a hot press device (G-12 manufactured by Orihara Seisakusho Co., Ltd.), hot plate temperature: 180 ° C., load: 3 MPa For 1 minute, and an anisotropic conductive adhesive layer was adhered to the surface of the insulating film.

Step (f):
The 1st release film was peeled from the insulating resin layer, and the flexible printed wiring board with an electromagnetic wave shielding film was obtained. The obtained flexible printed wiring board with an electromagnetic wave shielding film was dried at 150 ° C. for 1 hour to cure the insulating resin layer and the anisotropic conductive adhesive layer.

<Evaluation>
About the produced flexible printed wiring board with an electromagnetic wave shielding film, the combustion test was implemented with the following method. The results are shown in Table 1.
(Combustion test)
The flame of a gas burner was brought into contact with the lower end of the sample held vertically for 10 seconds, and the time for which the flexible printed wiring board with the electromagnetic wave shielding film continued to burn was measured. It shows that flame retardance is so high that this time is short.

(Comparative Example 1)
With an electromagnetic shielding film in the same manner as in Example 1 except that the phosphorus compound (M-Ester, manufactured by Sanko Co., Ltd.) was not added to the insulating resin layer forming coating solution and the adhesive layer forming coating solution. A flexible printed wiring board was obtained. In the same manner as in Example 1, a combustion test was performed on a flexible printed wiring board with an electromagnetic wave shielding film. The results are shown in Table 1.

Since the electromagnetic wave shielding film of Example 1 contained the compound (1) in the insulating resin layer and the anisotropic conductive adhesive layer, the flame retardancy was improved. In addition, curling of the base film (release film) was suppressed by relaxing shrinkage during curing at the time of manufacture, and sufficient adhesion to the metal thin film layer was obtained by gentle lamination. Furthermore, since the anisotropic conductive adhesive layer contains the compound (2), when removing the release sheet, the metal thin film layer and the anisotropic conductive adhesive layer did not peel off from each other. .
Since the electromagnetic wave shielding film of Comparative Example 1 did not contain the compound (1), the flame retardancy was lower than that of Example 1. Further, at the time of production, the base film was curled due to shrinkage during curing.
The above results indicate that the compound (1) not only functions as a flame retardant, but also functions as a low stress agent and an adhesive strength enhancer that suppress cure shrinkage of the epoxy group-containing compound.

  The electromagnetic wave shielding film of the present invention is useful as an electromagnetic wave shielding member in flexible printed wiring boards for electronic devices such as smartphones, mobile phones, optical modules, digital cameras, game machines, notebook computers, and medical devices.

1 electromagnetic shielding film,
2 Flexible printed wiring board with electromagnetic shielding film,
3 Flexible printed wiring board with insulating film,
10 Insulating resin layer,
22 metal thin film layer,
20 conductive layer,
24 anisotropic conductive adhesive layer,
24a thermosetting composition (adhesive),
24b conductive particles,
26 isotropic conductive adhesive layer,
26a thermosetting composition (adhesive),
26b conductive particles,
30 First release film,
32 base material layer,
34 adhesive layer,
40 Second release film,
42 base material layer,
44 release agent layer,
50 Flexible printed wiring boards,
52 Base film,
54 printed circuit,
60 insulation film,
62 through hole,
100 carrier film,
102 base material layer,
104 Release agent layer.

Claims (16)

One or more of epoxy group-containing compounds;
A thermosetting composition comprising one or more selected from the group of compounds (1) represented by the following formula (1), wherein the compound (1) is liquid at 25 ° C. and 1 atm.

[In Formula (1), R ₁ , R ₂ and R ₃ are each independently a hydrogen atom or an arbitrary substituent, and R ₁ and R ₂ may be bonded to each other to form a ring. ] The thermosetting composition according to claim 1, wherein the compound (1) is a compound represented by the following formula (1b).

[In Formula (1b), R ₂ is a hydrogen atom or an arbitrary substituent, and R ₂ may be bonded to a phenyl group bonded to a phosphorus atom to form a ring; R ₃ is a hydroxyl group or a carboxyl group Is an arbitrary substituent having at least one of them. ] The thermosetting composition according to claim 1, wherein the compound (1) is a compound represented by the following formula (1b-1).

  The thermosetting composition according to any one of claims 1 to 3, further comprising a black colorant.   The thermosetting composition according to any one of claims 1 to 3, further comprising conductive particles. The thermosetting composition as described in any one of Claims 1-5 which further contains 1 or more types chosen from the group of the compound represented by following formula (2).

Wherein L1 and L2 are each independently a single bond or a divalent linking group having 1 to 8 carbon atoms, m and n are each independently an integer of 1 to 5, and m + n is 2 to 6. , Any one or more hydrogen atoms bonded to the benzene ring are replaced by a (HO-L1-) group, and any other one or more hydrogen atoms are (-L2-COOH). Any one or more hydrogen atoms that are substituted with a group and are not substituted with the (HO-L1-) group and the (-L2-COOH) group may be substituted with any substituent. ]   The thermosetting composition according to any one of claims 1 to 6, further comprising a solvent.   Hardened | cured material of the thermosetting composition as described in any one of Claims 1-7. An insulating resin layer;
A metal thin film layer adjacent to the insulating resin layer;
An electromagnetic wave shielding film having an adhesive layer adjacent to the side opposite to the insulating resin layer of the metal thin film layer,
An electromagnetic wave shielding film, wherein at least one of the insulating resin layer and the adhesive layer is the thermosetting composition according to any one of claims 1 to 7 or the cured product according to claim 8.   The electromagnetic wave shielding film according to claim 9, wherein the adhesive layer is an anisotropic conductive adhesive layer. A printed wiring board provided with a printed circuit on at least one side of the substrate;
An insulating film adjacent to the surface of the printed wiring board on which the printed circuit is provided;
The electromagnetic wave shielding film according to claim 9 or 10, wherein the adhesive layer is provided so as to be adjacent to the insulating film,
A printed wiring board with an electromagnetic wave shielding film. It is a manufacturing method of the electromagnetic wave shielding film according to claim 9,
The step of forming at least one of the insulating resin layer and the adhesive layer by curing a coating film formed by applying the thermosetting composition on a base film to an arbitrary degree. A method for producing an electromagnetic wave shielding film. It is a manufacturing method of the electromagnetic wave shielding film according to claim 9,
By laminating the insulating resin layer, the metal thin film layer, and the adhesive layer in this order, and applying a laminating process that heats and pressurizes, the adhesion between the insulating resin layer and the metal thin film layer, and the metal The manufacturing method of the electromagnetic wave shield film which has the process of performing adhesion | attachment of at least one among adhesion | attachment of a thin film layer and the said adhesive bond layer. It is a manufacturing method of a printed wiring board with an electromagnetic wave shielding film according to claim 11,
A pressure bonding step of bonding the adhesive layer to the surface of the insulating film by overlapping the surface of the insulating film of the printed wiring board so that the adhesive layer of the electromagnetic wave shielding film is in contact with each other and pressing them. A manufacturing method comprising:   The manufacturing method according to claim 14, wherein pressing is performed while heating the insulating resin layer and the adhesive layer when pressing is performed in the pressing step.   The manufacturing method of Claim 14 or 15 which has a hardening process which hardens the said thermosetting composition by further heating the said insulating resin layer and the said adhesive bond layer after the said crimping | compression-bonding process.

Images