JP2014060455A - Circuit board manufacturing method, film with metal film, and adhesive film with metal film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board manufacturing method which can efficiently form an insulation layer and a metal film layer having excellent adhesion to the insulation layer and excellent uniformity, and which is excellent in laser workability in formation of a blind via by laser beams; and provide a film with a metal film and an adhesive film with the metal film which are used for the manufacturing method.SOLUTION: In a circuit board manufacturing method, a film with a metal film having a plastic film layer, a mold release layer formed on the plastic film layer and a metal film layer formed on the mold release layer in which a contact face of the mold release layer with the metal film layer is formed of one and more kinds of water soluble resins selected from a water soluble cellulose resin, a water soluble polyester resin and a water soluble acryl resin, and the water soluble resin contains one and more kinds selected from metal compound powder, carbon powder, metal powder and a black die is used. Alternatively, an adhesive film with a metal film in which a curable resin composition is formed on the metal film layer of the film with the metal film is used.

Description

  The present invention relates to a film with a metal film or an adhesive film with a metal film. Moreover, it is related with the manufacturing method of circuit boards, such as a multilayer printed wiring board using these films.

  Conventionally, a method of transferring a metal film layer such as a copper film onto an adherend as a plating seed layer has been attempted. For example, in Patent Documents 1 and 2, a film with a metal film in which a copper film is formed on a support by vapor deposition or the like through a release layer is prepared, and the copper film of the film with the metal film is formed on an inner circuit board. A method is disclosed in which a conductor layer is formed by plating or the like on a transferred copper film after being transferred to the resin composition layer surface or the prepreg surface. Patent Document 3 discloses an adhesive film in which a copper film is formed directly on a support by vapor deposition or the like, and a resin composition layer is formed thereon.

  However, in the methods of Patent Documents 1 and 2, the peelability of a polyethylene terephthalate (hereinafter abbreviated as “PET”) film from the metal film is deteriorated, so that it is difficult to transfer the uniform metal film. Further, in the method described in Patent Document 3, since the support of the adhesive film does not have a release layer, it is difficult to form a uniform metal film layer such as wrinkles and damages on the metal film layer.

  In addition, when a blind via is formed with a laser in an insulating layer to which a metal film has been transferred, there is a problem that workability is inferior because laser light is reflected by the metal film. If the laser energy is increased in order to improve the workability, problems such as damage to the underlying metal layer and the tendency of the shape of the blind via tend to deteriorate occur. Therefore, improvement in workability with the lowest possible laser energy is required. For example, as a method of drilling by laser from a metal layer such as a metal-clad laminate, a method of bonding a laser energy absorbing sheet having an adhesive layer on a metal film layer and peeling the sheet after drilling However, there is a problem that the process and cost increase. Further, the transferred thin metal film has a problem that the metal film is easily damaged when the laser energy absorbing sheet is peeled off.

JP 2004-230729 A JP 2002-324969 A JP-A-9-296156

  An object of the present invention is to provide a method for producing a circuit board, which can easily peel a plastic film as a support from a metal film layer formed on an insulating layer, and is excellent in laser processability in forming a blind via by a laser, and the method It is providing the film with a metal film and adhesive film with a metal film which are used for.

  As a result of intensive studies to solve the above problems, the present inventors have formed a specific release layer in a film with a metal film and an adhesive film with a metal film, and when using them to manufacture a circuit board Furthermore, the present inventors have found that the plastic film as the support can be easily peeled off. Furthermore, in forming a blind via to an insulating layer with which the metal film layer is in close contact, it was found that the processability of the blind via is improved by irradiating the laser from the plastic film, and the present invention has been completed.

That is, the present invention includes the following contents.
[1] A film with a metal film having a plastic film layer, a release layer formed on the plastic film layer, and a metal film layer formed on the release layer, wherein at least the metal film of the release layer A film having a metal film formed of one or more water-soluble resins selected from water-soluble cellulose resin, water-soluble polyester resin and water-soluble acrylic resin on the surface in contact with the layer, is formed on the inner layer circuit board. Laminate the resin composition layer so that the metal film layer is in contact with the surface of the curable resin composition layer, cure the curable resin composition to form an insulating layer, and then irradiate the plastic film layer with laser. And the manufacturing method of a circuit board including the process of forming a blind via | veer.
[2] The adhesive film with a metal film in which the curable resin composition layer is formed on the metal film layer of the film with a metal film as described in [1] above, the curable resin composition layer is in contact with the inner layer circuit board surface. The method of manufacturing a circuit board includes a step of forming a blind via by irradiating a laser beam on the plastic film layer after the curable resin composition is cured and laminated to form an insulating layer.
[3] The release layer is formed from a water-soluble resin, which is disposed on the metal film layer side, and a silicone resin, alkyd resin, or fluororesin, which is disposed on the plastic film layer side. The method for producing a circuit board according to the above [1] or [2], comprising a release layer.
[4] The method according to [1] to [1], further including a step of peeling the plastic film layer after forming the blind via and dissolving and removing the release layer formed from the water-soluble resin existing on the metal film layer with an aqueous solution. The method according to any one of [3].
[5] The method according to any one of [1] to [4], further including a step of forming a conductor layer on the metal film layer by plating.
[6] The method according to any one of [1] to [5] above, wherein the laser is a carbon dioxide laser.
[7] The method according to any one of [1] to [6], wherein the plastic film layer contains one or more selected from metal compound powder, carbon powder, metal powder, and black dye.
[8] The method according to any one of [1] to [7], wherein the plastic film is a polyethylene terephthalate film.
[9] The water-soluble polyester resin is a water-soluble polyester having a sulfo group or a salt thereof and / or a carboxyl group or a salt thereof, and the water-soluble acrylic resin is a water-soluble acrylic resin having a carboxyl group or a salt thereof. The method according to any one of [1] to [8] above.
[10] The method according to any one of [1] to [9], wherein the metal film layer is formed by one or more methods selected from a vapor deposition method, a sputtering method, and an ion plating method.
[11] The method according to any one of [1] to [10], wherein the metal film layer is formed of copper.
[12] The method according to any one of [1] to [11] above, wherein the metal film layer has a thickness of 50 nm to 5000 nm.
[13] The method according to any one of [1] to [12] above, wherein the release layer has a thickness of 0.1 μm to 20 μm.
[14] The method according to any one of [1] to [13] above, wherein the plastic film layer has a thickness of 10 μm to 70 μm.
[15] A film with a metal film having a plastic film layer, a release layer formed on the plastic film layer, and a metal film layer formed on the release layer, wherein at least the metal film of the release layer The surface in contact with the layer is formed of one or more water-soluble resins selected from water-soluble cellulose resins, water-soluble polyester resins and water-soluble acrylic resins, and the plastic film layer is made of metal compound powder, carbon powder, metal powder And a film with a metal film, comprising at least one selected from black dyes.
[16] An adhesive film with a metal film, wherein a curable resin composition layer is formed on the metal film layer of the film with a metal film according to [15].

  The “circuit board” in the present invention is not particularly limited as long as it has an insulating layer and a conductor layer formed with a circuit, and includes various circuit boards such as a multilayer printed wiring board and a flexible printed wiring board. . Further, among the circuit boards, in particular, when referred to as “inner circuit board”, pattern processing was performed on one side or both sides of a glass epoxy board, metal board, polyester board, polyimide board, BT resin board, thermosetting polyphenylene ether board (circuit). An intermediate product that has a conductor layer (formed) and on which an insulating layer and a conductor layer are to be formed when a circuit board is manufactured.

  According to the present invention, a metal film adhered on a cured product of a curable resin composition when a circuit board is produced by forming a specific release layer in a film with a metal film or an adhesive film with a metal film. The plastic film can be easily peeled from above, and then the water-soluble resin release layer on the metal film layer can be dissolved and removed with an aqueous solution, so the mechanical load acting on the metal film layer is small and a uniform metal film Layer formation is possible. In addition, since a highly adhesive metal film layer is formed on the extremely smooth insulating layer (cured material layer) surface, a circuit board suitable for miniaturization can be manufactured. Furthermore, it has been found that the blind via processability is improved by irradiating a laser beam on the plastic film in forming the blind via in the insulating layer to which the metal film is adhered. That is, a circuit board suitable for fine wiring is provided by a method excellent in productivity and economy.

The present invention is a film with a specific metal film, an adhesive film with a metal film, and a method of manufacturing a circuit board using them.
[Plastic film layer]
The plastic film layer is a film or sheet having a self-supporting property, and one that functions as a support when a film with a metal film or an adhesive film with a metal film is prepared. Examples of the plastic film include a polyethylene terephthalate film, a polyethylene naphthalate film, a polyimide film, a polyamideimide film, a polyamide film, a polytetrafluoroethylene film, and a polycarbonate film, and a polyethylene terephthalate film and a polyethylene naphthalate film are preferable. An inexpensive polyethylene terephthalate film is particularly preferred. The plastic film surface may be subjected to a surface treatment such as a mat treatment or a corona treatment.

  The upper limit of the thickness of the plastic film layer is preferably 70 μm, more preferably 60 μm, still more preferably 50 μm, and still more preferably 40 μm, from the viewpoint of ensuring practicality in terms of cost. The lower limit value of the thickness of the plastic film layer is preferably 10 μm, more preferably 15 μm from the viewpoint of preventing the handling layer and the releasability of the support layer from being lowered and preventing the formation of a smooth metal film layer. Preferably, 20 μm is more preferable. The surface of the support in contact with the curable resin composition layer may be subjected to a surface treatment such as a corona treatment. Further, the surface of the support that does not contact the curable resin composition layer may be subjected to surface treatment such as mat treatment or corona treatment.

  The plastic film layer surface on the side where the release layer is formed has an arithmetic average roughness (Ra value) of 50 nm or less (0 or more and 50 nm or less), from the viewpoint of preventing cracks when producing a film with a metal film, It is preferably 40 nm or less, more preferably 35 nm or less, and further preferably 30 nm or less. The arithmetic average roughness (Ra value) can be measured using a known method, for example, using a non-contact type surface roughness meter (WYKO NT3300 manufactured by Beec Instruments) or the like. In order to facilitate winding of the film after the release layer or metal film layer is formed, the Ra value is generally preferably 5 nm or more, and more preferably 10 nm or more.

  In addition, the arithmetic average roughness (Ra) of the surface of the plastic film layer on the side where the release layer is not formed is not particularly limited, but when the film with a metal film is wound into a roll shape, the unevenness of the surface is large. Then, there is a risk of causing cracks due to contact with the metal film layer. For example, by making it within the same range as described above, there is no fear of such a problem.

  The plastic film of the present invention may contain a laser energy absorbing component in order to further improve the workability of the brid via by laser. As the laser energy absorbing component, known materials such as carbon powder, metal compound powder, metal powder or black dye can be used. Moreover, these are any 1 type, or can use 2 or more types together.

  Examples of the carbon powder include carbon black powder such as furnace black, channel black, acetylene black, thermal black, and anthracene black, graphite powder, and a powder of a mixture thereof. As metal compound powder, titania such as titanium oxide, magnesia such as magnesium oxide, iron oxide such as iron oxide, nickel oxide such as nickel oxide, zinc oxide such as manganese dioxide and zinc oxide, silicon dioxide, Aluminum oxide, rare earth oxide, cobalt oxide such as cobalt oxide, tin oxide such as tin oxide, tungsten oxide such as tungsten oxide, silicon carbide, tungsten carbide, boron nitride, silicon nitride, titanium nitride, aluminum nitride, sulfuric acid Examples thereof include powders of barium, rare earth oxysulfides, or mixtures thereof. Examples of metal powders include silver, aluminum, bismuth, cobalt, copper, iron, magnesium, manganese, molybdenum, nickel, palladium, antimony, silicon, tin, titanium, vanadium, tungsten, zinc, or alloys or mixtures thereof. Is mentioned. Black dyes include azo (monoazo, disazo, etc.) dyes, azo-methine dyes, anthraquinone dyes, quinoline dyes, ketone imine dyes, fluorone dyes, nitro dyes, xanthene dyes, acenaphthene dyes, quinophthalone dyes, aminoketone dyes, methine dyes, perylenes And dyes, coumarin dyes, perinone dyes, triphenyl dyes, triallylmethane dyes, phthalocyanine dyes, incrophenol dyes, azine dyes, or mixtures thereof. The black dye is preferably a solvent-soluble black dye in order to improve dispersibility. These laser energy absorbing components may be used alone or in combination with different types. The laser energy absorbing component is preferably carbon powder, particularly carbon black, from the viewpoint of conversion efficiency of laser energy into heat, versatility, and the like. The upper limit of the average particle diameter of the laser energy absorbing component is preferably 20 μm, more preferably 10 μm, from the viewpoint of efficiently absorbing laser energy. On the other hand, the lower limit of the average particle diameter of the laser energy absorbing component is preferably 0.001 μm, more preferably 0.002 μm from the viewpoint of dispersibility. The “average particle diameter” as used herein can be measured by a particle size distribution measuring apparatus or BET method. The BET method is a method for obtaining a specific surface area of a sample from the amount of molecules adsorbed on the surface of powder particles at the temperature of liquid nitrogen. The average particle diameter was determined from the specific surface area determined by this BET method.

  The upper limit of the blending amount of the laser energy absorbing component can be set in all the components constituting the plastic film layer containing the component (the total content including the plastic and the laser energy absorbing component is 100% by mass). From the viewpoint of preventing a decrease in flexibility, 40 mass% is preferable, 20 mass% is more preferable, and 10 mass% is still more preferable. On the other hand, the lower limit of the blending amount of the laser energy absorbing component is preferably 0.01% by mass from the viewpoint of obtaining the effect of the laser energy absorbing component in all the components constituting the plastic film layer containing the component. 0.03 mass% is more preferable, and 0.05 mass% is further more preferable. The laser energy absorbing component may be contained in the release layer.

  A commercially available plastic film can also be used, for example, T60 (manufactured by Toray Industries, Inc., polyethylene terephthalate film, Ra = 22 nm), A4100 (manufactured by Toyobo Co., Ltd., polyethylene terephthalate film, smooth surface side Ra = 12 nm). , Q83 (manufactured by Teijin DuPont Films, polyethylene naphthalate film, smooth surface Ra = 32 nm), Diafoil (registered trademark) B100 (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., black polyethylene terephthalate film, Ra = 33 nm) Etc.

[Release layer]
The release layer in the present invention is formed of at least one water-soluble resin selected from a water-soluble cellulose resin, a water-soluble polyester resin and a water-soluble acrylic resin at least on the surface in contact with the metal film layer. A water-soluble cellulose resin and a water-soluble polyester resin are more preferable, and a water-soluble cellulose resin is particularly preferable. As the water-soluble polyester resin, a water-soluble polyester having a sulfo group or a salt thereof and / or a carboxyl group or a salt thereof is preferable because of good peelability. Moreover, the water-soluble acrylic resin is preferably a water-soluble acrylic resin having a carboxyl group or a salt thereof because of good peelability.

  Usually, any water-soluble resin is used alone in the water-soluble resin release layer, but two or more water-soluble resins may be mixed and used. In addition, the water-soluble resin release layer is usually formed as a single layer, but may have a multilayer structure formed of two or more layers in which the water-soluble resins used are different. Also, the release layer has another release layer formed of silicone resin, alkyd resin, fluororesin, etc., between the water-soluble resin release layer and the plastic film layer in order to improve the peelability between these layers. May be present. That is, when a water-soluble resin is applied to the release layer, it is sufficient that at least the surface of the release layer that adheres to the metal film layer is formed of the water-soluble resin. For example, the release layer may be a water-soluble resin release layer. Or a release layer formed with a water-soluble resin (a release layer disposed on the metal film layer side) so that a surface that adheres to the metal film layer is formed with a water-soluble resin. A two-layer structure with another release layer (release layer disposed on the plastic film layer side) can be formed. By adopting such a release layer in which at least the surface to be bonded to the metal film layer is formed of a water-soluble resin, the plastic between the plastic film layer and the release layer is cured after the curable resin composition as the adherend is cured. The film can be peeled, and thereafter, the release layer remaining on the metal film layer is easily removed with an aqueous solution, so that a metal film layer having excellent uniformity can be formed on the adherend. Peeling of the plastic film between the plastic film layer and the release layer is performed at the interface between the plastic film and the release layer when the release layer is formed of only the water-soluble resin, and the release layer is formed of the water-soluble resin. In the case where the release layer is composed of two layers, that is, a release layer formed of silicone resin, alkyd resin, or fluororesin, it is performed at the interface between the other release layer and the water-soluble resin release layer. Is called. In addition, as a mold release agent of alkyd resin, AL-5 (made by Lintec Corporation) is mentioned.

  The upper limit of the layer thickness of the release layer prevents the metal film layer from cracking due to the difference in thermal expansion coefficient between the metal film layer and the release layer when the curable resin composition layer is thermally cured. In view of the above, 20 μm is preferable, 10 μm is more preferable, 3 μm is further preferable, 2 μm is still more preferable, and 1 μm is even more preferable. On the other hand, the lower limit value of the layer thickness of the release layer is preferably 0.01 μm, more preferably 0.02 μm, and still more preferably 0.03 μm, from the viewpoint of preventing a decrease in peelability of the support layer. The “layer thickness” here is the thickness when the release layer is a single layer, and the total thickness of the multilayer when it is a multilayer. For example, as described above, when the release layer is composed of a water-soluble resin release layer and another release layer such as a silicone resin, an alkyd resin, or a fluororesin, the total of these release layers The layer thickness is set in the above range.

(Water-soluble cellulose resin)
The “water-soluble cellulose resin” as used in the present invention refers to a cellulose derivative that has been subjected to a treatment for imparting water-solubility to cellulose, and preferred examples include cellulose ether and cellulose ether ester.

  Cellulose ether is an ether formed by conversion of one or more hydroxyl groups present in one or more anhydroglucose repeating units of a cellulose polymer to give one or more ether linking groups to the cellulose polymer. In general, the alkyl group may be substituted with one or more substituents selected from a hydroxyl group, a carboxyl group, an alkoxy group (1 to 4 carbon atoms) and a hydroxyalkoxy group (1 to 4 carbon atoms). (C1-C4) is mentioned. Specifically, hydroxyalkyl groups (1 to 4 carbon atoms) such as 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl; 2-methoxyethyl, 3-methoxypropyl, 2-methoxypropyl, 2-ethoxy Alkoxy (C1-C4) alkyl group (C1-C4) such as ethyl; hydroxyalkoxy (C1-C4) such as 2- (2-hydroxyethoxy) ethyl or 2- (2-hydroxypropoxy) propyl ) Alkyl groups (1 to 4 carbon atoms), carboxyalkyl groups such as carboxymethyl (1 to 4 carbon atoms), and the like. The ether linking group in the polymer molecule may be a single species or a plurality of species. That is, it may be a cellulose ether having a single type of ether linking group or a cellulose ether having a plurality of types of ether linking groups.

  Specific examples of the cellulose ether include, for example, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, hydroxyethyl ethyl cellulose, carboxymethyl cellulose, and water-soluble salts thereof (for example, alkali metal salts such as sodium salt). Is mentioned.

  In addition, although the average number of moles of the ether group substituted per unit glucose ring in cellulose ether is not specifically limited, 1-6 are preferable. The molecular weight of cellulose ether is preferably 20000 to 60000 in weight average molecular weight.

  On the other hand, a cellulose ether ester is an ester formed between one or more hydroxyl groups present in cellulose and one or more organic acids or reactive derivatives thereof, thereby forming an ester linking group in the cellulose ether. is there. The “cellulose ether” herein is as described above, and the “organic acid” includes an aliphatic or aromatic carboxylic acid (having 2 to 8 carbon atoms), and the aliphatic carboxylic acid is acyclic (branched) Or unbranched) or cyclic, saturated or unsaturated. Specific examples of the aliphatic carboxylic acid include substituted or unsubstituted acyclic aliphatic dicarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, malonic acid, succinic acid, glutaric acid, fumaric acid, and maleic acid. Acids; acyclic hydroxy-substituted carboxylic acids such as glycolic acid or lactic acid; acyclic aliphatic hydroxy-substituted di- or tri-carboxylic acids such as malic acid, tartaric acid, and citric acid. The aromatic carboxylic acid is preferably an aryl carboxylic acid having 14 or less carbon atoms, and includes an aryl group such as a phenyl or naphthyl group having one or more carboxyl groups (for example, 1, 2 or 3 carboxyl groups). Aryl carboxylic acids are particularly preferred. The aryl group is substituted with one or more (for example, 1, 2 or 3) groups which may be the same or different and selected from hydroxy, alkoxy having 1 to 4 carbon atoms (for example, methoxy) and sulfonyl. May be. Preferable examples of the aryl carboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid (1,2,4-benzenetricarboxylic acid) and the like.

  Where the organic acid has one or more carboxyl groups, preferably only one carboxyl group of the acid forms an ester linkage to the cellulose ether. For example, in the case of hydroxypropylmethylcellulose succinate, one carboxyl group of each succinate group forms an ester linkage with cellulose and the other carboxy group is present as a free acid. An “ester linking group” is formed by reaction of cellulose or cellulose ether with a suitable organic acid as described above or a reactive derivative thereof. Suitable reactive derivatives include, for example, acid anhydrides such as phthalic anhydride.

  The ester linking group in the polymer molecule may be a single type or a plurality of types. That is, it may be a cellulose ether ester having a single type of ester linking group or a cellulose ether ester having a plurality of types of ester linking groups. For example, hydroxypropyl methylcellulose acetate succinate is a mixed ester of hydroxypropyl methylcellulose having both succinate and acetate groups.

Suitable cellulose ether esters are hydroxypropylmethylcellulose or esters of hydroxypropylcellulose, specifically hydroxypropylmethylcellulose acetate, hydroxypropylmethylcellulose succinate, hydroxypropylmethylcellulose acetate succinate, hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcellulose Trimellitate, hydroxypropyl methylcellulose acetate phthalate, hydroxypropyl methylcellulose acetate trimellitate, hydroxypropyl cellulose acetate phthalate, hydroxypropyl cellulose butyrate phthalate, hydroxypropyl cellulose acetate phthalate succinate and B hydroxypropyl cellulose acetate trimellitate succinate, etc. These may be used alone or in combination.
Among these, hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcellulose acetate succinate, and hydroxypropylmethylcellulose acetate phthalate are preferable.

  In addition, the average number of moles of the ester group substituted per unit glucose ring in the cellulose ether ester is not particularly limited, but is preferably 0.5 to 2. The molecular weight of the cellulose ether ester is preferably 20000 to 60000 in weight average molecular weight.

  Cellulose ethers and cellulose ether esters are well known in the art, and can be obtained by reacting an etherifying agent and an esterifying agent in accordance with a conventional method using natural cellulose (pulp) as a raw material. May be used. Examples thereof include “HP-55” and “HP-50” (both hydroxypropylmethylcellulose phthalate) manufactured by Shin-Etsu Chemical Co., Ltd.

(Water-soluble polyester resin)
The “water-soluble polyester resin” as used in the present invention is synthesized by an ordinary polycondensation reaction using a polyvalent carboxylic acid or an ester-forming derivative thereof and a polyhydric alcohol or an ester-forming derivative thereof as main raw materials. It is a polyester resin made of a substantially linear polymer, and has a hydrophilic group introduced in the molecule or at the molecular end. Here, examples of the hydrophilic group include an organic acid group such as a sulfo group, a carboxyl group, and a phosphoric acid group or a salt thereof, and a sulfonic acid group or a salt thereof, a carboxylic acid group or a salt thereof is preferable. As the water-soluble polyester resin, those having a sulfo group or a salt thereof and / or a carboxyl group or a salt thereof are particularly preferable.

  Representative examples of the polyvalent carboxylic acid component of the polyester resin include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, and the like. These may be used alone or in combination of two or more. In addition to the above-mentioned various compounds, hydroxycarboxylic acids such as p-hydroxybenzoic acid and unsaturated carboxylic acids such as maleic acid, fumaric acid or itaconic acid may be used in combination in small amounts.

  Representative examples of the polyhydric alcohol component of the polyester resin include ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexane glycol, 1,4-cyclohexane methanol, and xylylene. Examples thereof include glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, and poly (tetramethylene oxide) glycol. These may be used alone or in combination of two or more.

  The introduction of a hydrophilic group into the molecule or the molecular end of the polyester resin may be carried out by a known and conventional method, but an ester-forming compound containing a hydrophilic group (for example, an aromatic carboxylic acid compound, a hydroxy compound, etc.) A mode of polymerization is preferred.

  For example, when introducing a sulfonate group, 5-sulfonic acid sodium isophthalic acid, 5-sulfonic acid ammonium isophthalic acid, 4-sulfonic acid sodium isophthalic acid, 4-methylsulfonic acid ammonium isophthalic acid, 2-sulfonic acid sodium terephthalic acid It is preferable to copolymerize one or more selected from potassium isophthalic acid 5-sulfonate, potassium isophthalic acid 4-sulfonate, potassium terephthalic acid 2-sulfonate, and the like.

  In addition, when introducing a carboxylic acid group, for example, one or two kinds selected from trimellitic anhydride, trimellitic acid, pyromellitic anhydride, pyromellitic acid, trimesic acid, cyclobutanetetracarboxylic acid, dimethylolpropionic acid and the like. It is preferable to copolymerize the above, and after the copolymerization reaction, the carboxylate group can be introduced into the molecule by neutralization with an amino compound, ammonia or an alkali metal salt.

  The molecular weight of the water-soluble polyester resin is not particularly limited, but the weight average molecular weight is preferably 10,000 to 40,000. If the weight average molecular weight is less than 10,000, the layer formability tends to decrease, and if it exceeds 40000, the solubility tends to decrease.

  In the present invention, a commercially available product can be used as the water-soluble polyester resin. For example, “Plus Coat Z-561” (weight average molecular weight: about 27,000), “Plus Coat Z-” manufactured by Kyoyo Chemical Industry Co., Ltd. 565 "(weight average molecular weight: about 25000) and the like.

(Water-soluble acrylic resin)
The “water-soluble acrylic resin” referred to in the present invention is an acrylic resin that is dispersed or dissolved in water by containing a carboxyl group-containing monomer as an essential component.

  More preferably, the acrylic resin is a monomer component in which a carboxyl group-containing monomer and a (meth) acrylic ester are essential, and if necessary, other unsaturated monomers as monomer components. Acrylic polymer.

  In the monomer component, examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, maleic anhydride, monomethyl maleate, monobutyl maleate , Monomethyl itaconate, monobutyl itaconate and the like, and one or more of them can be used. Among these, (meth) acrylic acid is preferable.

  Examples of the (meth) acrylic acid ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid. Isobutyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) Examples thereof include alkyl methacrylates having 1 to 18 carbon atoms such as nonyl acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like. Species or two or more can be used.

  Examples of other unsaturated monomers include aromatic alkenyl compounds, vinyl cyanide compounds, conjugated diene compounds, halogen-containing unsaturated compounds, and hydroxyl group-containing monomers. Examples of the aromatic alkenyl compound include styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, and the like. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Examples of the conjugated diene compound include butadiene and isoprene. Examples of the halogen-containing unsaturated compound include vinyl chloride, vinylidene chloride, perfluoroethylene, perfluoropropylene, and vinylidene fluoride. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl. Examples thereof include acrylate, 4-hydroxybutyl methacrylate, α-hydroxymethylethyl (meth) acrylate and the like. These can use 1 type (s) or 2 or more types.

  As will be described later, in the present invention, the release layer is preferably formed by a method of applying and drying a coating liquid containing a material used for the release layer on the plastic film layer. When a water-soluble acrylic resin is used, the coating solution can be used in an emulsion form or an aqueous solution form.

  When a water-soluble acrylic resin is used in the form of an emulsion, a core-shell type emulsion is preferable, and in the core-shell type emulsion, it is important that a carboxyl group is present in the shell of the core-shell particle. And an acrylic resin containing a (meth) acrylic acid ester.

  A commercially available product (emulsion) of such core-shell particles can be used. For example, Jonkrill 7600 (Tg: about 35 ° C.), 7630A (Tg: about 53 ° C.), 538J (Tg: about 66 ° C.) ), 352D (Tg: about 56 ° C.) (both manufactured by BASF Japan Ltd.) and the like.

  When the water-soluble acrylic resin is used in the form of an aqueous solution, the acrylic resin is an acrylic resin containing a carboxyl group-containing monomer and a (meth) acrylic acid ester, and it is important that the molecular weight is relatively low. Therefore, it is preferable that the weight average molecular weight is 1000 to 50000. If the weight average molecular weight is less than 1000, the layer formability tends to be reduced. If the weight average molecular weight exceeds 50000, the adhesion to the plastic film layer is high. It becomes the tendency for the peelability of the plastic film layer after hardening to fall.

  As such an aqueous solution of a water-soluble acrylic resin, a commercially available product can be used, and examples thereof include Jonkrill 354J (manufactured by BASF Japan Ltd.).

  In addition, the emulsion and the aqueous solution of water-soluble acrylic resin are easy to be thinned because the emulsion has a higher molecular weight. Accordingly, a water-soluble acrylic resin emulsion is preferred.

  The method for forming the release layer is not particularly limited, and a known laminating method such as hot pressing, hot roll laminating, extrusion laminating, coating / drying of a coating solution can be adopted, but it is a simple and highly uniform layer. In view of easy formation of the coating layer, a method of applying and drying a coating liquid containing a material used for the release layer is preferable. For example, a resin varnish in which a resin component (such as a water-soluble resin) constituting the release layer is dissolved or dispersed in an organic solvent is prepared, and the resin varnish is applied onto a plastic film layer using a bar coater or the like, and heated. Or it can manufacture by drying an organic solvent by hot air spraying etc. and forming a release layer. The organic solvent for preparing the coating solution is not particularly limited, and examples thereof include ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate. , Carbitols such as cellosolve and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. The organic solvent may be used alone or in combination of two or more.

  When the release layer contains a laser energy absorbing component, for example, the resin component (water-soluble resin, etc.) constituting the release layer is dissolved or dispersed in an organic solvent, and the laser energy absorbing component is further dispersed. The resin varnish may be prepared, and the resin varnish may be applied and dried on the plastic film layer in the same manner as described above. The upper limit of the average particle diameter of the laser energy absorbing component is preferably 40 μm, more preferably 20 μm, and even more preferably 10 μm, from the viewpoint of efficiently absorbing laser energy. On the other hand, the lower limit of the average particle diameter of the laser energy absorbing component is preferably 0.001 μm, more preferably 0.002 μm from the viewpoint of dispersibility. Here, the “average particle diameter” is measured by the method described above.

<Metal film layer>
As metal used for the metal film layer, gold, platinum, silver, copper, aluminum, cobalt, chromium, nickel, titanium, tungsten, zinc, iron, tin, indium, etc., simple metals, nickel / chromium alloy, etc. However, from the viewpoint of versatility of metal film formation, cost, ease of removal by etching, etc., chromium, nickel, titanium, nickel-chromium alloy, aluminum, zinc, copper Nickel alloy, copper / titanium alloy, gold, silver and copper are preferable, chromium, nickel, titanium, nickel / chromium alloy, aluminum, zinc, gold, silver and copper are more preferable, and copper is particularly preferable. Further, the metal film layer may be a single layer or a multilayer structure in which two or more different metals are laminated. For example, a water-soluble polymer may be used in a system in which thermal degradation (decomposition) of the resin is a concern due to diffusion of the copper layer into the curable resin composition layer when the curable resin composition layer is thermally cured. After the copper layer is formed on the release layer, a chromium layer, a nickel-chromium alloy layer, or a titanium layer can be further provided on the copper layer.

  The thickness of the metal film layer is not particularly limited, but is 50 nm to 5000 nm, preferably 50 nm to 3000 nm, more preferably 100 nm to 3000 nm, and particularly preferably 100 nm to 1000 nm. If the layer thickness is too small, the metal film tends to crack after the production of the film with the metal film, and the metal film layer is dissolved by acid washing or the like in the desmear process in the production of the multilayer printed wiring board. The surface of the insulating layer may be roughened. On the other hand, if the layer thickness is too large, it takes a long time to form the metal film, and the cost tends to be inferior. The total layer thickness in the case of the two-layer structure of the copper layer / chromium layer, nickel / chromium alloy layer or titanium layer as described above is the same as above, and the chromium layer, nickel / chromium layer or titanium layer has the same thickness. The thickness is preferably 5 nm to 100 nm, more preferably 5 nm to 50 nm, particularly preferably 5 nm to 30 nm, and most preferably 5 nm to 20 nm.

<Curable resin composition layer>
The adhesive film with a metal film in the present invention has a structure in which a curable resin composition layer is formed on the metal film layer of the above-described adhesive film with a metal film. That is, the adhesive film with a metal film in the present invention has a curable resin composition layer in addition to the plastic film layer and the metal film layer. Moreover, it is preferable to have a mold release layer between a plastic film layer and a metal film layer like a film with a metal film. In the adhesive film with a metal film, the curable resin composition used for the curable resin composition layer can be used without particular limitation as long as the cured product has sufficient hardness and insulation, for example, epoxy A composition in which at least the curing agent is blended with a curable resin such as a resin, a cyanate ester resin, a phenol resin, a bismaleimide-triazine resin, a polyimide resin, an acrylic resin, or a vinylbenzyl resin is used. A composition containing an epoxy resin is preferable as the curable resin, and for example, a composition containing at least (a) an epoxy resin, (b) a thermoplastic resin, and (c) a curing agent is preferable.

  (a) Examples of the epoxy resin include bisphenol A type epoxy resin, biphenyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, bisphenol F type epoxy resin, phosphorus-containing epoxy resin, bisphenol S type epoxy resin, and alicyclic ring Epoxy resin, aliphatic chain epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, epoxy resin having butadiene structure, diglycidyl etherified product of bisphenol, diglycidyl ether of naphthalenediol , Glycidyl etherification products of phenols, diglycidyl etherification products of alcohols, and alkyl-substituted products, halides and hydrogenated products of these epoxy resins It is below. These epoxy resins may be used alone or in combination of two or more.

  Among these, the epoxy resin has a bisphenol A type epoxy resin, a naphthol type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, and a butadiene structure from the viewpoint of heat resistance, insulation reliability, and adhesion to a metal film. Epoxy resins are preferred. Specifically, for example, liquid bisphenol A type epoxy resin (“Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.), naphthalene type bifunctional epoxy resin (“HP4032”, “HP4032D” manufactured by Dainippon Ink & Chemicals, Inc.) ), Naphthalene type tetrafunctional epoxy resin ("HP4700" manufactured by Dainippon Ink & Chemicals, Inc.), naphthol type epoxy resin ("ESN-475V" manufactured by Tohto Kasei Co., Ltd.), epoxy resin having a butadiene structure (Daicel Chemical) "PB-3600" manufactured by Kogyo Co., Ltd.), epoxy resins having a biphenyl structure ("NC3000H", "NC3000L" manufactured by Nippon Kayaku Co., Ltd., "YX4000" manufactured by Japan Epoxy Resin Co., Ltd.), and the like.

  (b) The thermoplastic resin is blended for the purpose of imparting appropriate flexibility to the cured composition, for example, phenoxy resin, polyvinyl acetal resin, polyimide, polyamideimide, polyethersulfone. And polysulfone. These may be used alone or in combination of two or more. The thermoplastic resin is preferably blended in a proportion of 0.5 to 60% by mass, more preferably 3 to 50% by mass, when the nonvolatile component of the curable resin composition is 100% by mass. When the blending ratio of the thermoplastic resin is less than 0.5% by mass, since the resin composition viscosity is low, it tends to be difficult to form a uniform curable resin composition layer, and when it exceeds 60% by mass, Since the viscosity of the resin composition becomes too high, embedding in the wiring pattern on the substrate tends to be difficult.

  Specific examples of the phenoxy resin include, for example, FX280, FX293 manufactured by Toto Kasei Co., Ltd., YX8100, YL6954, YL6974 manufactured by Japan Epoxy Resin Co., Ltd., and the like.

  The polyvinyl acetal resin is preferably a polyvinyl butyral resin, and specific examples of the polyvinyl acetal resin include those manufactured by Denki Kagaku Kogyo Co., Ltd., Electric Butyral 4000-2, 5000-A, 6000-C, 6000-EP, Sekisui Chemical Co., Ltd. ) Made S-Rec BH series, BX series, KS series, BL series, BM series and the like.

  Specific examples of polyimide include polyimide “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Also, a linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (as described in JP 2006-37083 A), a polysiloxane skeleton-containing polyimide (JP 2002-2002). And modified polyimides such as those described in JP-A No. 12667 and JP-A No. 2000-319386.

  Specific examples of the polyamideimide include polyamideimides “Vilomax HR11NN” and “Vilomax HR16NN” manufactured by Toyobo Co., Ltd. In addition, modified polyamideimides such as polysiloxane skeleton-containing polyamideimides “KS9100” and “KS9300” manufactured by Hitachi Chemical Co., Ltd. may be mentioned.

  Specific examples of polyethersulfone include polyethersulfone “PES5003P” manufactured by Sumitomo Chemical Co., Ltd.

  Specific examples of the polysulfone include polysulfone “P1700” and “P3500” manufactured by Solvay Advanced Polymers Co., Ltd.

  (c) Examples of the curing agent include amine curing agents, guanidine curing agents, imidazole curing agents, phenol curing agents, naphthol curing agents, acid anhydride curing agents, or epoxy adducts and microencapsulation thereof. And cyanate ester resins. Of these, phenol-based curing agents and naphthol-based curing agents are preferable. In addition, in this invention, a hardening | curing agent may be 1 type, or may use 2 or more types together.

  Specific examples of the phenol-based curing agent and naphthol-based curing agent include, for example, MEH-7700, MEH-7810, MEH-7851 (manufactured by Meiwa Kasei Co., Ltd.), NHN, CBN, GPH (manufactured by Nippon Kayaku Co., Ltd.) ), SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (manufactured by Tohto Kasei Co., Ltd.), LA7052, LA7054, LA3018, LA1356 (manufactured by Dainippon Ink & Chemicals, Inc.), and the like.

  In the case of a phenolic curing agent or a naphtholic curing agent, the blending ratio of (a) epoxy resin and (c) curing agent is such that the phenolic hydroxyl group equivalent of these curing agents is 0.4 to 1 with respect to the epoxy equivalent of epoxy resin. A ratio in the range of 2.0 is preferable, and a ratio in the range of 0.5 to 1.0 is more preferable. When the reactive group equivalent ratio is outside this range, the mechanical strength and water resistance of the cured product tend to be lowered.

  In addition to (c) the curing agent, (d) a curing accelerator can be further blended in the curable resin composition. Examples of such curing accelerators include imidazole compounds and organic phosphine compounds, and specific examples include 2-methylimidazole and triphenylphosphine. (d) When using a hardening accelerator, it is preferable to use in 0.1-3.0 mass% with respect to an epoxy resin.

  In addition, the curable resin composition may contain (e) an inorganic filler in order to reduce the thermal expansion of the cured composition. Examples of the inorganic filler include silica, alumina, mica, mica, silicate, barium sulfate, magnesium hydroxide, and titanium oxide. Silica and alumina are preferable, and silica is particularly preferable. The inorganic filler preferably has an average particle size of 3 μm or less and more preferably 1.5 μm or less from the viewpoint of insulation reliability. The content of the inorganic filler in the curable resin composition is preferably 20 to 60% by mass, more preferably 20 to 50% by mass when the nonvolatile component of the curable resin composition is 100% by mass. is there. When the content of the inorganic filler is less than 20% by mass, the effect of decreasing the coefficient of thermal expansion tends not to be sufficiently exhibited. When the content of the inorganic filler exceeds 60% by mass, the mechanical strength of the cured product decreases. It becomes a tendency to do.

  In the curable resin composition, other components can be blended as necessary. Examples of other components include organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone flame retardants, flame retardants such as metal hydroxides, fillers such as silicone powder, nylon powder, and fluorine powder. Thickeners such as Orben and Benton, silicone-based, fluorine-based, polymer-based antifoaming or leveling agents, imidazole-based, thiazole-based, triazole-based, and silane-based coupling agents such as phthalocyanines, Coloring agents such as blue, phthalocyanine / green, iodin / green, disazo yellow, and carbon black can be used.

  The curable resin composition layer may be a prepreg obtained by impregnating the above-described curable resin composition in a sheet-like reinforcing base made of fibers. As the fiber of the sheet-like reinforcing substrate, for example, a glass cloth or an aramid fiber, which is commonly used as a prepreg fiber, can be used. The prepreg can be formed by impregnating a curable resin composition by a sheet-like reinforcing base material hot melt method or a solvent method and semi-curing by heating. In addition, the hot melt method, without dissolving the resin composition in an organic solvent, once coated the resin composition on the resin composition and good peelable coated paper, and laminate it on a sheet-like reinforcing substrate, Or it is the method of manufacturing a prepreg by coating directly with a die coater. The solvent method is a method in which a sheet-like reinforcing base material is immersed in a varnish obtained by dissolving a resin composition in an organic solvent, the varnish is impregnated into the sheet-like reinforcing base material, and then dried.

  The thickness of the curable resin composition layer varies depending on the thickness of the inner circuit conductor layer, but is preferably 10 to 150 μm, more preferably 15 to 80 μm from the viewpoint of insulation reliability between layers.

The metal film is preferably formed by one or more methods selected from a vapor deposition method, a sputtering method and an ion plating method, and particularly preferably formed by a vapor deposition method and / or a sputtering method. These methods can be used in combination, but usually any one method is used alone.
As the sputtering method, a known method can be used. For example, a plastic film having a release layer is placed in a vacuum vessel, an inert gas such as argon is introduced, a DC voltage is applied, and an ionized inert gas is applied. A gas can be collided with a target metal, and a film can be formed on the release layer by the struck metal.
As the vapor deposition method (vacuum vapor deposition method), a known method can be used. For example, a plastic film having a release layer is placed in a vacuum container, and a metal is heated and evaporated to form a film on the release layer. be able to.
As the ion plating method, a known method can be used. For example, a plastic film having a release layer is placed in a vacuum vessel, and the metal is heated and evaporated in a glow discharge atmosphere. Film formation can be performed on the layer.

  The adhesive film with a metal film can be produced by forming a curable resin composition layer on the surface of the metal film layer after the step of forming the metal film layer of the film with the metal film. A known method can be used as a method for forming the curable resin composition layer. For example, a resin varnish obtained by dissolving a resin composition in an organic solvent is prepared, and this resin varnish is attached to a metal film using a die coater or the like. It can be produced by coating on a metal film layer of the film and further drying the organic solvent by heating or blowing hot air to form a resin composition layer.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. , Aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. Two or more organic solvents may be used in combination.

  The drying conditions are not particularly limited, but the drying is performed so that the content of the organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Depending on the amount of organic solvent in the varnish and the boiling point of the organic solvent, for example, a resin composition layer is formed by drying a varnish containing 30 to 60% by mass of an organic solvent at 50 to 150 ° C. for 3 to 10 minutes. The

  In addition, the adhesive film with a metal film is an adhesive film in which a curable resin composition layer is formed on a support separately from the film with a metal film, and the film with the metal film and the adhesive film are cured with the metal film layer. It can also produce by the method of bonding together on heating conditions so that it may contact with an adhesive resin composition layer. As the support for the adhesive film, the above-mentioned plastic film layer can be used, and the curable resin composition layer is the same as described above. The adhesive film can be produced by a known method. When the curable resin composition layer is a prepreg, the prepreg may be laminated on the support by, for example, a vacuum laminating method.

The film with the metal film and the adhesive film are laminated by hot pressing the film with the metal film and the adhesive film so that the metal film layer of the film with the metal film and the curable resin composition layer of the adhesive film face each other. Then, heat press with a heat roll or the like. The heating temperature is preferably 60 to 140 ° C, more preferably 80 to 120 ° C. The crimping pressure is preferably in the range of 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ), and ^{2 to} 7 kgf / cm ² (19.6 × 10 ^{4 to} 68.68. A range of 6 × 10 ⁴ N / m ² ) is particularly preferred.

[Manufacture of circuit boards]
The manufacturing method of the circuit board using the film with a metal film of this invention or the adhesive film with a metal film is demonstrated. First, the lamination process which laminates | stacks a film with a metal film or an adhesive film with a metal film on an inner-layer circuit board is performed. When using a film with a metal film, the metal film layer is laminated so as to be in contact with the surface of the curable resin composition layer present between the inner circuit boards. When using an adhesive film with a metal film, the curable resin composition layer is laminated on the inner circuit board as an adhesive surface.

  A known method can be used to form the curable resin composition layer on the inner layer circuit board. For example, an adhesive film in which the curable resin composition layer is formed on the plastic film layer as described above is used as the inner layer circuit. The curable resin composition layer can be formed on the inner circuit board by laminating on the substrate and removing the plastic film layer by peeling or the like. The lamination condition of the adhesive film is the same as the lamination condition in the adhesive film with a metal film described later.

  In the present invention, when a prepreg is used to manufacture a circuit board, a single-sided or double-sided surface layer of a laminated body in which a single prepreg or a multi-layered prepreg is laminated on an inner circuit board A film with a metal film can be laminated and laminated on a certain prepreg so that the metal film layer is in contact with the prepreg surface. Similarly, a film with a metal film is laminated on one side or both sides of a single prepreg or a multilayer prepreg obtained by stacking a plurality of prepregs so that the metal film layer is in contact with the surface of the prepreg, and heated. The prepreg can be cured by pressurization to produce a metal-clad laminate.

  Lamination | stacking of the adhesive film with a metal film and the film with a metal film laminate | stacks a film on a to-be-adhered body surface by a roll, press press bonding, etc. from the point which is easy to obtain workability | operativity and a uniform contact state. Especially, it is suitable to laminate | stack under reduced pressure by the vacuum laminating method. The lamination method may be a batch method or a continuous method using a roll.

Lamination conditions generally include a pressure of 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ) and an air pressure of 20 mmHg (26.7 hPa). Lamination is preferably performed under the following reduced pressure.

  The vacuum lamination can be performed using a commercially available vacuum laminator. As a commercially available vacuum laminator, for example, a batch type vacuum pressure laminator MVLP-500 manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a roll type dry coater manufactured by Hitachi Industries, Ltd., Examples include a vacuum laminator manufactured by Hitachi IC Corporation. After the lamination step, the laminated film may be smoothed by hot pressing with a metal plate, if necessary. The smoothing step can be performed by heating and pressurizing the film with a metal plate such as a heated SUS mirror plate under normal pressure (atmospheric pressure). As heating and pressurizing conditions, the same conditions as in the laminating step can be used. The said lamination process and smoothing process can be continuously performed with the commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nichigo Morton, and the like.

  Next, a step of curing the curable resin composition layer to form an insulating layer is performed. Curing is usually performed by thermosetting. The curing conditions vary depending on the type of curable resin, but generally the curing temperature is 120 to 200 ° C. and the curing time is 15 to 90 minutes. In addition, it is preferable from the viewpoint of preventing wrinkles on the surface of the insulating layer to be formed that the curing is performed in a stepwise manner from a relatively low curing temperature to a high curing temperature.

Next, a step of forming a blind via by laser irradiation is performed. Laser irradiation is performed on the release layer formed from a water-soluble resin. Examples of the laser include a carbon dioxide laser, a YAG laser, and an excimer laser, and a carbon dioxide laser is particularly preferable from the viewpoint of processing speed and cost. In general, a laser having a wavelength of 9.3 to 10.6 μm is used as the carbon dioxide laser to be irradiated. The number of shots is selected from 1 to 5 shots, although it varies depending on the depth and hole diameter of the blind via to be formed. From the viewpoint of increasing the processing speed of the blind via and improving the productivity of the circuit board, it is preferable that the number of shots is small, and the number of shots is preferably 3 or less. The energy of the carbon dioxide laser depends on the number of shots, the depth of the blind via, the thickness of the metal film layer, and the thickness of the release layer, but is preferably set to 0.5 mJ or more, more preferably 2 mJ or more. Is set. The upper limit is preferably 20 mJ or less, more preferably 15 mJ or less, more preferably 10 mJ or less, and even more preferably 5 mJ or less.
On the other hand, if the energy of the carbon dioxide laser is too high, the underlying conductor layer of the blind via is easily damaged, and the shape of the blind via tends to deteriorate, for example, the metal film layer around the blind via rises.

  The top diameter of the blind via is preferably 100 μm or less, more preferably 90 μm or less, and even more preferably 80 μm or less in order to cope with the reduction in the thickness of the circuit board and the increase in the wiring density.

  Note that when processing with multiple shots, the burst mode, which is a continuous shot, traps the processing heat in the holes, so there is a tendency for differences in workability between the inorganic filler and the thermosetting resin composition, and the taper of the vias. Therefore, the cycle mode, which is a plurality of shots with a time interval, is preferable.

  The pulse width of the carbon dioxide laser is not particularly limited. However, if the pulse width is large, the metal film at the opening of the blind via protrudes, and the shape of the periphery of the via tends to deteriorate. It is preferable to carry out in the range, and more preferably in the range of 1 to 14 μs.

  The energy of the carbon dioxide gas laser is the energy value of the laser on the surface of the insulating layer per shot, and is adjusted by the output of the oscillator, collimation lens (energy adjustment lens), and mask diameter in the carbon dioxide laser device. can do. The mask diameter is actually selected according to the diameter of the blind via to be processed. The energy value can be measured by placing a measuring device (power sensor) on a pedestal that performs laser processing and actually measuring the energy at the surface height of the insulating layer of the circuit board to be processed. Note that a commercially available carbon dioxide laser device is equipped with a measuring device, and the energy on the irradiation target surface can be easily measured. Examples of commercially available carbon dioxide laser devices include Mitsubishi Electric Corporation ML605GTWII, Hitachi Via Mechanics Co., Ltd. LC-G series, Matsushita Welding System Co., Ltd. substrate drilling laser processing machine, and the like.

  After the step of forming the blind via, a step of peeling the plastic film layer is performed. The plastic film may be peeled manually or mechanically. As described above, the release is performed at the interface of the release layer formed from the water-soluble resin, and after the release of the plastic film layer, the release layer formed from the water-soluble resin remains on the metal film layer. After film peeling, a step of dissolving and removing the water-soluble resin release layer remaining on the metal film layer is performed. The aqueous solution for dissolving and removing the release layer is preferably an alkaline aqueous solution in which sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide and the like are dissolved in water at a concentration of 0.5 to 10% by mass. Etc. The method of dissolving and removing is not particularly limited. For example, after peeling the plastic film layer, a method of dissolving and removing the inner circuit board by immersing the inner layer circuit board in the aqueous solution, a method of dissolving and removing the aqueous solution by spraying or spraying it, etc. Can be mentioned. The temperature of the aqueous solution is usually room temperature to 80 ° C., and the treatment time can be usually 10 seconds to 10 minutes with an aqueous solution such as water immersion or spraying. Examples of the alkaline aqueous solution include an alkaline developer (for example, 0.5 to 2 mass% sodium carbonate aqueous solution, 25 ° C. to 40 ° C.) for use in circuit board manufacture, and a stripping solution for a dry film stripper. (For example, 1-5 mass% sodium hydroxide aqueous solution, 40-60 ° C.), swelling liquid used in the desmear process (for example, alkaline aqueous solution containing sodium carbonate, sodium hydroxide, 60-80 ° C.), etc. You can also

  In addition, it is preferable to perform a desmear process after the process of forming a blind via, the process of peeling a plastic film, or the process of dissolving and removing a release layer. The desmear process is a process mainly for removing a via bottom residue generated by blind via formation, and may be performed for the purpose of roughening the via wall surface. Further, in the present invention, since the surface of the insulating layer is not roughened, it is advantageous for forming fine wiring, and it is advantageous for shortening the circuit board manufacturing process. The desmear process can be performed by a known method such as a dry method such as plasma or a wet method using an oxidizing agent treatment such as an alkaline permanganate solution. In particular, desmear with an oxidizing agent is preferable in that it can remove smear on the bottom of the via and, at the same time, roughen the via wall surface with the oxidizing agent and improve the plating adhesion strength. The desmear process with an oxidizing agent is usually performed by performing a swelling process with a swelling liquid, a roughening process with an oxidizing agent, and a neutralizing process with a neutralizing liquid in this order. Examples of the swelling liquid include an alkaline solution and a surfactant solution, and an alkaline solution is preferable. Examples of the alkaline solution include a sodium hydroxide solution and a potassium hydroxide solution. In addition, when using an alkaline solution for a desmear process, the process of dissolving and removing the said mold release layer and a desmear process can also be performed simultaneously. Examples of the commercially available swelling liquid include Swelling Dip Securiganth P (Swelling Dip Securiganth P) and Swelling Dip Securiganth SBU (ABUTEC Japan). be able to. Examples of the oxidizing agent include an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. Roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is usually performed by subjecting to an oxidizing agent solution heated to 60 to 80 ° C. for 10 to 30 minutes. Further, the concentration of permanganate in the alkaline permanganate solution is generally 5% to 10%. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as Concentrate Compact CP, Dosing Solution Securigans P manufactured by Atotech Japan Co., Ltd. The neutralizing solution is preferably an acidic aqueous solution, and a commercially available product is Reduction Solution Securigant P (neutralizing solution) manufactured by Atotech Japan Co., Ltd.

  The metal film layer is used as a conductor layer as it is, or a metal film layer is further grown on the metal film layer by plating (electroless plating and / or electrolytic plating) to form a conductor layer (in this case, the inner surface of the via). Etc., a metal film layer grows). In general, it is preferable to form a conductor layer on the metal film layer by electrolytic plating. Conductor layer formation by electrolytic plating can be performed by a known method such as a semi-additive method. For example, a plating resist is formed on the metal film layer, and the conductor layer is formed by electrolytic plating. The electrolytic plating layer is preferably copper, and its thickness depends on the desired circuit board design, but is generally 3 to 35 μm, preferably 5 to 30 μm. After the electrolytic plating, the plating resist is removed with a plating resist stripping solution such as an alkaline aqueous solution, and then the metal film layer is removed to form a wiring pattern (circuit). The metal film layer can be removed by etching with a solution that dissolves the metal forming the metal film layer. The etching solution is selected according to the selected metal layer. For example, in the case of copper, an acidic etching solution such as an aqueous solution of ferric chloride, an aqueous solution of sodium peroxodisulfate and sulfuric acid, or a CF manufactured by Mec Co., Ltd. An alkaline etching solution such as −6000, E-Process-WL manufactured by Meltex Co., Ltd. can be used. In the case of nickel, an etching solution mainly composed of nitric acid / sulfuric acid can be used, and commercially available products include NH-1865 manufactured by MEC, Melstrip N-950 manufactured by Meltex, and the like. Is mentioned.

  A step of forming a through hole may be added as necessary. The through hole is generally formed in the core substrate, but the through hole may be formed after the insulating layer is formed. In this case, the same process as the desmear process can be applied to the through hole. A mechanical drill is generally used for forming the through hole.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated more concretely, this invention is not limited at all by the following Examples. In the following description, “part” means “part by mass”.

Example 1
<Production of film with metal film>
Hydroxypropyl methylcellulose phthalate (manufactured by Shin-Etsu Chemical Co., Ltd., “HP-55”) at 60 ° C. in a solvent in which methyl ethyl ketone (hereinafter abbreviated as “MEK”) and cyclohexanone were mixed at a ratio of 1: 1 (mass ratio). ]) Was dissolved to a solid content of 10% by mass to obtain a hydroxypropylmethylcellulose phthalate solution. The above solution was applied with a bar coater onto a 25 μm thick black polyethylene terephthalate film (Mitsubishi Chemical Polyester Film Co., Ltd., Diafoil (registered trademark) “B100”), and the temperature was raised from room temperature to 140 ° C. using a hot air drying furnace. The solvent was removed by raising the temperature at a temperature rate of 3 ° C./second, and a water-soluble resin layer (release layer) having a thickness of about 0.5 μm was formed on the PET film. Subsequently, about 500 nm of copper layers were formed in this order by vapor deposition on the release layer, and the film with a metal film was produced.

<Preparation of adhesive film having curable resin composition layer>
28 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, “HP4700” manufactured by Dainippon Ink & Chemicals, Inc.) ) 28 parts and 20 parts of a phenoxy resin (“YX6954BH30” manufactured by Japan Epoxy Resin Co., Ltd.) were dissolved in a mixed solvent of 15 parts of MEK and 15 parts of cyclohexanone with stirring. Thereto, a solid content of 27 parts of a triazine-containing phenol novolak resin (hydroxyl equivalent 125, “LA7054” manufactured by DIC Corporation), naphthol-based curing agent (hydroxyl equivalent 215, “SN-485” manufactured by Tohto Kasei Co., Ltd.) % MEK solution 27 parts, curing catalyst (manufactured by Shikoku Kasei Kogyo Co., Ltd., “2E4MZ”) 0.1 part, spherical silica (average particle size 0.5 μm, manufactured by Admatechs Co., Ltd. “SOC2”), 30 parts of a solution having a solid content of 15% by mass in which polyvinyl butyral resin (“KS-1” manufactured by Sekisui Chemical Co., Ltd.) is dissolved in a mixed solvent of ethanol and toluene (mass ratio = 1: 1) is mixed. A resin varnish was prepared by uniformly dispersing with a rotary mixer. The varnish was coated on a polyethylene terephthalate film with a alkyd mold release agent (AL-5) manufactured by Lintec Corporation having a thickness of 38 μm using a die coater, the solvent was removed using a hot air drying furnace, and the curable resin composition layer An adhesive film having a thickness of 40 μm was produced.

<Preparation of adhesive film with metal film>
The adhesive film with a metal film was obtained by laminating at 90 ° C. so that the curable resin composition surface of the adhesive film and the metal film surface of the film with the metal film were in contact with each other.

<Lamination and curing of adhesive film with metal film on inner circuit board>
Roughening is performed on the copper layer of the glass epoxy substrate on which the circuit is formed with an 18 μm-thick copper layer by a CZ8100 (a surface treatment agent containing an azoles copper complex and organic acid (MEC Co., Ltd.)). did. Next, the release PET of the adhesive film with a metal film is peeled off so that the curable resin composition layer is in contact with the copper circuit surface, and a batch type vacuum pressure laminator MVLP-500 (product of Meiki Seisakusho Co., Ltd.) Name) was laminated on both sides of the substrate. Lamination was performed at a pressure of 13 hPa or less by reducing the pressure for 30 seconds. Thereafter, the insulating layer was formed by thermosetting at 180 ° C. for 30 minutes.

<Blind via formation>
After forming the insulating layer, a pulse width of 3 μs, a mask diameter of 3.5 mm, an energy of 1. with a laser processing machine (a carbon dioxide gas laser device manufactured by Hitachi Via Mechanics Co., Ltd .: LC-2E21B / 1C) from the PET film layer. Blind vias were formed by irradiating the laser with a total of 3 shots, 1 shot at 8 mJ (output 1.8 W, frequency 1000 Hz) and 2 shots with energy 0.6 mJ (output 0.6 W, frequency 1000 Hz). The top diameter of the blind via was about 75 μm, and the metal film layer did not rise, and a good blind via was formed.

(Example 2)
An insulating layer was formed in the same manner as in Example 1 except that PET was a transparent PET film having a thickness of 38 μm (T60 manufactured by Toray Industries, Inc.) and the thickness of the metal film layer was about 1000 nm.
<Blind via formation>
After the insulating layer is formed, a pulse width of 7 μs, a mask diameter of 4.0 mm, an energy of 3. using a laser processing machine (Hitachi Via Mechanics Co., Ltd. carbon dioxide laser device: LC-2E21B / 1C) is formed on the PET film layer. Blind vias were formed by irradiating the laser with 1 shot at 1 mJ (output 1.55 W, frequency 2000 Hz) and 1 shot at a pulse width of 10 μs and energy 5.5 mJ (output 2.75 W, frequency 2000 Hz) for a total of 2 shots. . The top diameter of the blind via was about 57 μm, and the metal film layer did not rise and a good blind via was formed.

(Comparative Example 1)
An insulating layer was formed in the same manner as in Example 2.
<Blind via formation>
After forming the insulating layer, the PET film is peeled off, and the release layer is removed with a 1% by mass sodium carbonate aqueous solution. / 1C), laser irradiation was performed under the same conditions as in Example 1 to form blind vias. The top diameter of the blind via was about 64 μm, and the rising of the metal film layer was observed, resulting in deterioration of the workability and shape of the blind via as compared with Example 1.

(Example 3)
After forming the blind via in Example 1, the PET film was peeled off. The peelability was good and it was easily peeled by hand.

[Reference Example 1]
A thermoplastic fluororesin film (ETFE: ethylene-trifluoroethylene copolymer, “Toyoflon” manufactured by Toray Industries, Inc.) having a thickness of 50 μm is used as a plastic film layer having a release function, and the thermoplastic fluororesin film is formed on the thermoplastic fluororesin film. By sputtering (E-400S, manufactured by Canon Anelva Co., Ltd.), a copper layer of about 500 nm and a chromium layer of about 20 nm were formed on the copper layer, and a metal film with a metal film layer of about 520 nm was produced.
28 parts of liquid bisphenol A type epoxy resin (828EL) and 28 parts of naphthalene type tetrafunctional epoxy resin (HP-4700) were heated and dissolved in a mixed solvent of 15 parts of MEK and 15 parts of cyclohexanone with stirring. There, 50 parts of a novolak resin (a phenolic hydroxyl group equivalent of a solid material, “LA7052” manufactured by Dainippon Ink & Chemicals, Inc., MEK solution having a solid content of 60% by mass) as a phenolic curing agent, a phenoxy resin (molecular weight) 50000, 20 parts of “E1256” manufactured by Japan Epoxy Resin Co., Ltd., 40 parts by mass of MEK solution), 0.1 part of curing catalyst (2E4MZ), 55 parts of spherical silica (SOC2), polyvinyl butyral described in Example 1 30 parts of a resin solution and 3 parts of an epoxy resin having a butadiene structure (molecular weight 27000, “PB-3600” manufactured by Daicel Chemical Industries, Ltd.) were mixed and uniformly dispersed with a high-speed rotary mixer to prepare a resin varnish. The varnish was applied onto a PET film having a thickness of 38 μm using a die coater, the solvent was removed using a hot air drying furnace, and an adhesive film having a thickness of the curable resin composition layer of 40 μm was produced.
In the same manner as in Example 1, the adhesive film was bonded to the metal film-attached film to prepare an adhesive film with a metal film, and the adhesive film with the metal film was laminated on a circuit board. Thereafter, the curable resin composition layer was cured at 150 ° C. for 30 minutes and further at 180 ° C. for 30 minutes to form an insulating layer (cured product layer). When observed from a transparent thermoplastic fluororesin film, many wrinkles were found in the metal film layer. Further, the peelability of the thermoplastic fluororesin film layer was poor and it was peeled off by hand, but part of the thermoplastic fluororesin film remained without being peeled from the metal film, and could not be completely peeled off.

[Reference Example 2]
A 20 μm-thick release PET film (“Fine Peel”, manufactured by Reiko Co., Ltd.) having a melamine release resin is used, and the melamine release resin layer is sputtered (E-400S, Canon Anelva Corporation) )), A copper layer of about 500 nm, a chromium layer of about 20 nm is formed on the copper layer, a metal film with a metal film layer of about 520 nm is produced, and an adhesive film and a metal film are produced in the same manner as in Reference Example 1. The adhesive film was laminated to prepare an adhesive film with a metal film, and the adhesive film with the metal film was laminated on the circuit board. Thereafter, the curable resin composition layer was cured at 150 ° C. for 30 minutes and further at 180 ° C. for 30 minutes to form an insulating layer (cured product layer). Observation from above the transparent PET film revealed no abnormalities such as swelling between the resin and the metal film, wrinkles of the metal film, and cracks in the metal film. However, peeling of the PET film was difficult.

[Reference Example 3]
Using a release PET film having a thickness of 38 μm having an acrylic release resin (“Therapy HP2” manufactured by Toray Film Processing Co., Ltd.), the acrylic release resin layer is sputtered (E-400S, Canon Anelva ( Co., Ltd.), a copper layer of about 500 nm, and a chromium layer of about 20 nm formed on the copper layer to produce a metal film with a metal film layer of about 520 nm. The film-attached film was laminated to prepare a metal film-attached adhesive film, and the metal film-attached adhesive film was laminated on the circuit board. Thereafter, the curable resin composition layer was cured at 150 ° C. for 30 minutes and further at 180 ° C. for 30 minutes to form an insulating layer (cured product layer). Observation from above the transparent PET film revealed no abnormalities such as swelling between the resin and the metal film, wrinkles of the metal film, and cracks in the metal film. However, peeling of the PET film was difficult. The acrylic release resin on the PET film did not dissolve in either water or an alkaline aqueous solution.

[Reference Example 4]
A solution having a solid content of 15% by mass in which polyvinyl alcohol (“PVA-203” manufactured by Kuraray Co., Ltd.) was dissolved in a mixed solution of ethanol and water (mass ratio = 1: 1) was applied onto a PET film by a die coater. The solvent was removed by raising the temperature from room temperature to 140 ° C. at a rate of temperature rise of 3 ° C./second using a hot air drying furnace, and a polyvinyl alcohol resin layer of about 1 μm was formed on the PET film. Sputtering on the polyvinyl alcohol resin layer (E-400S, manufactured by Canon Anelva Co., Ltd.), forming a copper layer of about 500 nm, and further forming a chromium layer of about 20 nm on the copper layer, and forming a metal film layer with a metal film layer of about 520 nm. Produced.
30 parts of prepolymer of bisphenol A dicyanate (cyanate equivalent 232, "BA230S75" manufactured by Lonza Japan Co., Ltd., MEK solution with a solid content of 75%), phenol novolac type polyfunctional cyanate ester resin (cyanate equivalent 124, Lonza Japan Co., Ltd.) "PT30") 10 parts, naphthol type epoxy resin (epoxy equivalent 340, Toto Kasei Co., Ltd. "ESN-475V") solid content 65 mass% MEK solution 40 parts, liquid bisphenol A type epoxy resin (828EL) ) 5 parts, 15 parts of a phenoxy resin solution (“YP-70” manufactured by Tohto Kasei Co., Ltd., 40% by weight solid content solution using a mixed solvent of MEK and cyclohexanone (mass ratio = 1: 1)), as a curing catalyst Solid content of cobalt (II) acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) 1 DMF solution 4 parts of amount%, and spherical silica (SOC2) 40 parts were mixed, and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish.
The resin varnish was coded on the metal film-coated film to produce a metal film-coated adhesive film, and the metal film-coated adhesive film was laminated on a circuit board. Thereafter, the curable resin composition layer was cured at 150 ° C. for 30 minutes and further at 180 ° C. for 30 minutes to form an insulating layer (cured product layer). Observation from above the transparent PET film revealed no abnormalities such as swelling between the resin and the metal film, wrinkles of the metal film, and cracks in the metal film. However, peeling of the PET film was difficult.

  This application is based on patent application No. 2008-222730 filed in Japan, the contents of which are incorporated in full herein.

Claims (16)

  A film with a metal film having a plastic film layer, a release layer formed on the plastic film layer, and a metal film layer formed on the release layer, and is in contact with at least the metal film layer of the release layer A curable resin composition having a film with a metal film, the surface of which is formed from one or more water-soluble resins selected from water-soluble cellulose resins, water-soluble polyester resins, and water-soluble acrylic resins, on an inner circuit board Laminate the layer so that the metal film layer is in contact with the surface of the curable resin composition layer, cure the curable resin composition to form an insulating layer, and then irradiate the laser on the plastic film layer, A method of manufacturing a circuit board, including a step of forming a blind via.   An adhesive film with a metal film in which a curable resin composition layer is formed on the metal film layer of the film with a metal film according to claim 1 is stacked so that the curable resin composition layer is in contact with the inner layer circuit board surface. A method of manufacturing a circuit board, comprising: laminating and curing an curable resin composition to form an insulating layer, and then irradiating a laser from the plastic film layer to form a blind via.   A release layer is disposed on the metal film layer side and is formed from a water-soluble resin, and a release layer is disposed on the plastic film layer side and is formed from a silicone resin, an alkyd resin, or a fluororesin. The method for manufacturing a circuit board according to claim 1, comprising:   4. The method according to claim 1, further comprising a step of peeling off the plastic film layer after forming the blind via and dissolving and removing the release layer formed from the water-soluble resin existing on the metal film layer with an aqueous solution. The method according to claim 1.   The method of any one of Claims 1-4 further including the process of forming a conductor layer by plating on a metal film layer.   The method according to any one of claims 1 to 5, wherein the laser is a carbon dioxide laser.   The method according to any one of claims 1 to 6, wherein the plastic film layer contains one or more selected from metal compound powder, carbon powder, metal powder and black dye.   The method according to claim 1, wherein the plastic film layer is a polyethylene terephthalate film.   The water-soluble polyester resin is a water-soluble polyester having a sulfo group or a salt thereof and / or a carboxyl group or a salt thereof, and the water-soluble acrylic resin is a water-soluble acrylic resin having a carboxyl group or a salt thereof. The method of any one of -8.   The method according to any one of claims 1 to 9, wherein the metal film layer is formed by one or more methods selected from an evaporation method, a sputtering method, and an ion plating method.   The method according to claim 1, wherein the metal film layer is made of copper.   The method according to claim 1, wherein the metal film layer has a thickness of 50 nm to 5000 nm.   The method according to claim 1, wherein the release layer has a thickness of 0.1 μm to 20 μm.   The method of any one of Claims 1-13 whose layer thickness of a plastic film layer is 10 micrometers-70 micrometers.   A film with a metal film having a plastic film layer, a release layer formed on the plastic film layer, and a metal film layer formed on the release layer, and is in contact with at least the metal film layer of the release layer The surface is formed from one or more water-soluble resins selected from water-soluble cellulose resin, water-soluble polyester resin and water-soluble acrylic resin, and the plastic film layer is made of metal compound powder, carbon powder, metal powder and black dye. A film with a metal film, comprising at least one selected from the group consisting of:   The adhesive film with a metal film in which the curable resin composition layer is formed on the metal film layer of the film with a metal film according to claim 15.