JP2008201117A - Metal thin film with plastic, printed-circuit board, its manufacturing method, multilayer wiring board, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal thin film with plastic in which a fine wiring pattern can be sufficiently excellently formed and which does not need to use a polyimide film when forming a metal layer. <P>SOLUTION: The metal thin film with plastic 100 has a support body 1, a first metal layer 2 formed on the support body 1 by a vapor deposition method, a second metal layer 3 formed on the first metal layer 2, and a resin layer 4 comprising an insulating resin composition formed on the second metal layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin-coated metal thin film, a printed circuit board and a manufacturing method thereof, and a multilayer wiring board and a manufacturing method thereof.

  A laminated board for a printed wiring board can be obtained by stacking a predetermined number of prepregs having a resin composition having electrical insulation as a matrix, and heating and pressing to integrate them. In the production of a printed wiring board, when a printed circuit is formed by a subtractive method, a metal-clad laminate is used. This metal-clad laminate is manufactured by stacking a metal foil such as a copper foil on the surface (one side or both sides) of the prepreg and heating and pressing.

  Thermosetting resins such as phenol resin, epoxy resin, polyimide resin, bismaleimide-triazine resin, etc. are widely used as the resin having electrical insulation. In addition, a thermoplastic resin such as a fluororesin or a polyphenylene ether resin may be used. On the other hand, with the widespread use of information terminal devices such as personal computers and mobile phones, printed circuit boards mounted on them are becoming smaller and higher in density. The mounting form has progressed from a pin insertion type to a surface mounting type, and further to an area array type represented by a BGA (ball grid array) using a plastic substrate.

  In a substrate on which a bare chip such as a BGA is directly mounted, the chip and the substrate are generally connected by wire bonding by thermosonic bonding. For this reason, the substrate on which the bare chip is mounted is exposed to a high temperature of 150 ° C. or higher, and the electrically insulating resin needs a certain degree of heat resistance.

  Further, in such a substrate, there is a case where so-called repairability in which a chip once mounted is removed is also required. In this case, the same level of heat as that applied during chip mounting is applied, and then the chip mounting is again performed on the substrate, and further heat treatment is performed. Therefore, in a substrate that requires repairability, cyclic thermal shock resistance at high temperatures is also required. In the conventional insulating resin, peeling may occur between the fiber base material and the resin.

  Therefore, in a printed circuit board, a prepreg impregnated with a resin composition containing polyamideimide as an essential component in a fiber substrate is used in order to improve the fine wiring formability in addition to thermal shock resistance, reflow resistance, and crack resistance. It has been proposed (see, for example, Patent Document 1). In addition, a heat-resistant base material in which a fiber base material is impregnated with a resin composition composed of a silicone-modified polyimide resin and a thermosetting resin has been proposed (for example, see Patent Document 2).

  Furthermore, since the miniaturization of the printed circuit board is progressing with the miniaturization and high performance of the electronic equipment, the semi-additive method has recently been generalized as a circuit forming method. The semi-additive method is a method of forming a circuit pattern by performing electrolytic plating of a predetermined pattern on a thin-film power feeding layer made of metal and then removing the power feeding layer by etching. In this semi-additive method, a finer circuit pattern can be formed as the above-described feeding layer becomes thinner and flatter.

  The power feeding layer is usually formed by electroless plating, but an extremely thin copper foil can be used as the power feeding layer. However, a power feeding layer formed by a sputtering method is preferably used because it is superior in surface smoothness. For example, Non-Patent Document 1 discloses a method of forming a power feeding layer made of copper on the surface of a polyimide film by sputtering. Non-Patent Document 1 describes that according to this method, a copper circuit pattern having a line width of 10 μm or less is formed.

  By the way, as a flexible substrate based on polyimide, generally, a two-layer type in which a polyimide film and a copper foil are directly laminated, and a three-layer type in which a polyimide film and a copper foil are bonded together by an adhesive layer made of an adhesive. Things are used. Of these, a two-layer type flexible substrate is obtained by applying a paste containing polyamic acid, which is a polyimide precursor, to a predetermined thickness on the surface of a copper foil and curing the paste. However, it is necessary to perform heat treatment at a high temperature of about 300 to 400 ° C. during the curing.

  Moreover, since the adhesiveness between polyimide and copper is usually low, a so-called roughened copper foil having a fine concavo-convex shape on the surface is employed as the copper foil. When forming a circuit pattern from a flexible substrate, a subtractive method is conventionally used in which a circuit pattern is formed by etching a copper foil into a predetermined shape. However, if a fine circuit pattern is to be formed from the above roughened copper foil by a subtractive method, circuit disconnection due to the uneven shape on the surface of the roughened copper foil is likely to occur.

As a flexible substrate that can prevent such circuit disconnection, a two-layer type that is obtained by laminating a metal layer such as nickel or chromium on the surface of a polyimide film by sputtering and then laminating copper by sputtering. Has been proposed (see, for example, Patent Document 3). According to this technology, the adhesion between the polyimide film and the copper layer is inferior to the two-layer type obtained by applying a paste containing polyamic acid to the copper foil, but the interface between the polyimide film and the copper layer Is extremely flat and suitable for forming a fine circuit.
JP 2003-55486 A JP-A-8-193139 Japanese Patent Publication No.57-33718 Supervised by Junichi Sugimoto, “The Frontier of Illustrated Printed Wiring Board Materials”, Industrial Research Co., Ltd., published on January 15, 2005, page 154

  When a metal layer is formed on the surface of the polyimide film by sputtering, the polyimide film is exposed to conditions necessary for forming the metal layer under reduced pressure. However, exposing the polyimide film to such a condition is not suitable for mass productivity because the production cost becomes high in consideration of the material cost of the polyimide film and the yield when forming the metal layer. Moreover, when forming a metal layer, the film used as the board | substrate is heated by high temperature. Therefore, the conventional film for flexible substrates which consists of materials other than a polyimide film cannot be applied to the board | substrate for metal layer formation.

  Furthermore, since polyimide has substantially no softening point, molding by heating and pressing is extremely difficult. Therefore, it is practically impossible to form a multilayer wiring board using the above-described flexible substrate. Moreover, it replaces with a polyimide film and the method of forming a multilayer wiring board using the film | membrane of resin which expresses fluidity by heating is considered. However, such a resin cannot withstand the heating when the metal layer is formed by the sputtering method in the first place.

  Therefore, the present invention has been made in view of the above circumstances, a metal thin film with a resin that can form a fine circuit pattern sufficiently satisfactorily and does not require the use of a polyimide film when forming a metal layer, It is an object of the present invention to provide a printed circuit board using the same and a manufacturing method thereof, and a multilayer wiring board and a manufacturing method thereof.

  To achieve the above object, the present invention provides a support, a first metal layer formed on the support by a vapor deposition method, and a second metal layer formed on the first metal layer. And a resin-coated metal thin film comprising a resin layer made of an insulating resin composition formed on the second metal layer.

  The present invention also includes a step of removing the support from the resin-coated metal thin film, and a first metal layer and a second metal layer serving as a power feeding layer on the first metal layer exposed through the removal step. And a method of manufacturing a printed circuit board including a step of forming a third metal layer by a semi-additive method to obtain a circuit.

  The printed circuit board of the present invention obtained by this manufacturing method includes an insulating layer made of a cured product of an insulating resin composition, a circuit provided on the insulating layer, and a patterned second metal A first metal layer provided on the second metal layer and formed by vapor deposition and patterned, and a patterned third metal layer provided on the first metal layer A printed circuit board.

  Furthermore, the present invention provides a step of preparing a flexible circuit board comprising a flexible substrate and a first circuit provided on the main surface of the substrate, and the resin-coated metal thin film on the flexible circuit board. The first metal layer exposed through the step of laminating the substrate and the surface of the first circuit and the surface of the resin layer, the step of removing the support from the metal thin film with resin, and the step of removing First, a step of forming a third metal layer by a semi-additive method using the metal layer and the second metal layer as a power feeding layer to obtain a second circuit, the first circuit and the second circuit, And a method of manufacturing a multilayer wiring board having a step of electrically connecting the two.

  The multilayer wiring board of the present invention obtained by this manufacturing method includes a flexible substrate, a first circuit provided on the main surface of the substrate, and provided on the substrate and the first circuit. An insulating layer made of a cured product of a conductive resin composition, and a second circuit provided on the insulating layer, the second patterned metal layer being provided on the second metal layer A second circuit having a first metal layer formed by vapor deposition and patterned, and a patterned third metal layer provided on the first metal layer; A connection portion that electrically connects the circuit and the second circuit is provided.

  In the above-mentioned present invention, the support constituting the metal thin film with resin functions as a substrate for vapor deposition when the first metal layer is formed. And this support body is removed from the metal thin film with resin, when manufacturing a printed circuit board and a multilayer wiring board. Therefore, this support does not function as an insulating layer for the printed circuit board and the multilayer wiring board. What functions as such an insulating layer is an insulating layer (cured product of the resin layer in the metal thin film with resin) made of a cured product of the insulating resin composition. Therefore, according to the present invention, it is not necessary to use a polyimide film when forming the first metal layer. As a result, if a relatively inexpensive film is used for the support, a resin-coated metal thin film, a printed circuit board, and a multilayer wiring board can be manufactured at a lower cost than in the past.

  In addition, the circuit in the printed circuit board and the second circuit in the multilayer wiring board are not formed from the roughened copper foil, but a third metal layer is provided on the first metal layer by a semi-additive method. Is formed. Therefore, a finer circuit pattern can be formed satisfactorily as compared with the conventional method of forming a circuit pattern by a subtractive method of etching the roughened copper foil.

  Furthermore, it is not necessary to employ a polyimide resin as a resin constituting the insulating layer, and an acrylic resin, an epoxy resin, or a polyamideimide resin can be applied. As a result, the uses of the printed circuit board and the multilayer wiring board are broader than those formed using the conventional metal foil with resin.

  In addition, since the resin layer is not hardened in the above-described metal thin film with resin, the metal thin film with resin of the present invention can be suitably used for manufacturing printed circuit boards and multilayer wiring boards.

  According to the present invention, since the first metal layer is formed by the vapor deposition method, it is possible to provide a printed circuit board and a multilayer wiring board that are thinner than conventional ones. In addition, it is possible to produce printed circuit boards and multilayer wiring boards that are not only higher in design tolerance than those in the past but also excellent in heat resistance.

  In the above-mentioned present invention, it is preferable that the first metal layer has a thickness of 0.01 to 0.5 μm. The second metal layer preferably has a thickness of 0.1 to 2.0 μm. As a result, it is possible to form a circuit pattern while minimizing a decrease in bending property based on the multilayer wiring board and the flexible substrate provided in the printed circuit board as required. Further, by having such a thickness, the first and second metal layers can function as a power feeding layer better when forming a circuit by a semi-additive method, and have a desired shape. A pattern can be formed.

  In the present invention, the first metal layer preferably contains copper. Moreover, it is preferable that the second metal layer contains copper. These metal layers can function better as a power feeding layer when forming a circuit.

  Moreover, it is preferable that the above-mentioned resin layer has a thickness of 70 μm or less. Thereby, more sufficient bendability can be ensured.

  Further, it is preferable that the resin composition is a thermosetting resin composition because it is further excellent in heat resistance. It is preferable that the thermosetting resin composition contains an epoxy resin because heat resistance and insulation can be improved. In addition, when the thermosetting resin composition contains an acrylic resin, a resin composition having further excellent heat resistance and flexibility can be obtained, and the bendability of the printed circuit board and the multilayer wiring board can be improved. It is.

  Moreover, it is preferable that a thermosetting resin composition contains the polyamide-imide resin which has a structure represented by following General formula (1). By using such a polyamideimide resin, higher adhesion between the metal thin film or circuit and the resin layer or insulating layer, and higher heat resistance of the resin layer and insulating layer can be obtained.

  According to the present invention, a metal thin film with a resin capable of forming a fine circuit pattern sufficiently satisfactorily and without using a polyimide film when forming a metal layer, a printed circuit board using the same, and a production thereof A method, a multilayer wiring board, and a manufacturing method thereof can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

  FIG. 1 is a cross-sectional view schematically showing a resin-coated metal thin film according to a preferred embodiment of the present invention. The resin-coated metal thin film 100 includes a support 1, a first metal layer 2 formed on the support by a vapor deposition method, and a second metal layer 3 formed on the first metal layer 2. And a resin layer 4 made of an insulating resin composition formed on the second metal layer 3. The support 1, the first metal layer 2, and the second metal layer 3 are also used as the base material 110 when the resin layer 4 is formed.

  The support 1 is not particularly limited as long as metal can be deposited thereon, and is preferably composed of a material different from the resin layer 4 described later. More specifically, the support 1 is preferably a film containing a flexible organic material as a main component, and is preferably a film obtained by curing a resin composition. Such a film can be easily peeled and removed from the resin-coated metal thin film 100. From the above viewpoint, the support 1 is particularly preferably a polyethylene terephthalate (PET) film and a polyethylene naphthalate (PEN) film.

  When a PET film is employed as the support 1, the thickness is preferably 10 to 100 μm, and more preferably 30 to 60 μm. When this thickness is less than 10 μm, resistance to metal deposition tends to be reduced. Moreover, since flexibility will fall when this thickness exceeds 100 micrometers, it exists in the tendency for peeling and removing the support body 1 from the metal thin film with a resin.

  The first metal layer 2 is formed by vapor deposition on the support 1 as a substrate. The first metal layer 2 functions as a release layer when peeling the second metal layer 3 and the support 1 which will be described later, and also serves as a power feeding layer for electrolytic plating during the semiadditive process described later. Function. The metal constituting the first metal layer 2 is not particularly limited as long as it can function as the release layer and the power feeding layer, and examples thereof include nickel, aluminum, and copper. These metals are used individually by 1 type or in combination of 2 or more types. Among these, the metal constituting the first metal layer 2 can be easily removed by the viewpoint of more effectively functioning as a release layer and a power feeding layer, and by etching when producing a printed circuit board and a multilayer wiring board. From the viewpoint, copper is preferable.

  The method for forming the first metal layer 2 is not particularly limited as long as it is a vapor deposition method, but a physical vapor deposition method is preferable. Examples of the physical vapor deposition include vacuum vapor deposition, sputtering, and ion plating.

  The thickness of the 1st metal layer 2 should just be the thickness which can function as a mold release layer, and it is preferable in it being 0.01-0.5 micrometer, and it is more preferable in it being 0.01-0.05 micrometer. If this thickness is less than 0.01 μm, it tends to be difficult to ensure releasability from the support 1. On the other hand, when the thickness exceeds 0.5 μm, the circuit formability tends to decrease.

  The second metal layer 3 functions as a power feeding layer for electrolytic plating during a semi-additive process described later. Therefore, the metal constituting the second metal layer 3 is not particularly limited as long as it can function as a power feeding layer for electrolytic plating. However, it is preferable that the metal constituting the second metal layer 3 is copper from the viewpoint of functioning more effectively as a power feeding layer and from the viewpoint of being easily removed by etching when producing a printed circuit board and a multilayer wiring board. It is.

  The second metal layer 3 is formed on the first metal layer 2. The formation method is preferably a physical vapor deposition method. Examples of physical vapor deposition include vacuum vapor deposition, sputtering, and ion plating. Among these, sputtering is preferable from the viewpoint of excellent film formability and low cost.

  The thickness of the 2nd metal layer 3 should just be the thickness which can function as an electric power feeding layer, and it is preferable in it being 0.1-2.0 micrometers. When the thickness is less than 0.1 μm, it tends to be difficult to function as a power feeding layer in the semi-additive process. This is presumed to be because the electric resistance in the second metal layer 3 is increased because a part of the second metal layer 3 is not sufficiently formed. Moreover, when this thickness exceeds 2.0 micrometers, it exists in the tendency for formation of a fine circuit pattern to become difficult.

  The resin layer 4 is made of an insulating resin composition. The insulating resin composition is preferably a thermosetting resin composition because it requires heat resistance when producing a printed circuit board or a multilayer wiring board. The thermosetting resin composition is cured by heating to form an insulating cured product. The thermosetting resin composition preferably contains a thermosetting resin having a crosslinkable functional group. Examples of such thermosetting resins include epoxy resins, polyimide resins, unsaturated polyester resins, polyurethane resins, bismaleimide resins, triazine-bismaleimide resins, and phenol resins. These are used singly or in combination of two or more.

  The thermosetting resin is preferably a resin having a glycidyl group, and more preferably an epoxy resin. By using an epoxy resin, the thermosetting resin composition can be cured at a temperature of 180 ° C. or less, and the formed cured product has particularly excellent thermal, mechanical, and electrical characteristics. .

  The epoxy resin preferably has two or more glycidyl groups. The more glycidyl groups, the better, and more preferably 3 or more. Specific examples of the epoxy resin include polyglycidyl obtained by reacting polychlorophenol such as bisphenol A, novolak type phenol resin, orthocresol novolac type phenol resin or polyhydric alcohol such as 1,4-butanediol with epichlorohydrin. N-glycidyl derivatives of polyglycidyl esters, amines, amides or heterocyclic nitrogen base compounds obtained by reacting polybasic acids such as ether, phthalic acid, hexahydrophthalic acid and epichlorohydrin, and alicyclic epoxy resins Can be mentioned.

  When using an epoxy resin, it is preferable to use the curing agent in combination. Moreover, you may use a hardening accelerator. The greater the number of glycidyl groups that the epoxy resin has, the smaller the blending amount of the curing agent and curing accelerator.

  The curing agent and curing accelerator for the epoxy resin can be used without limitation as long as they react with the epoxy resin or accelerate the curing of the epoxy resin. For example, amines, imidazoles, polyfunctional phenols, acid anhydrides and the like can be used. Examples of amines include dicyandiamide, diaminodiphenylmethane, and guanylurea. Examples of polyfunctional phenols include hydroquinone, resorcinol, bisphenol A and their halogen compounds, and novolak-type phenol resins and resol-type phenol resins that are condensates with formaldehyde. Examples of acid anhydrides include phthalic anhydride, benzophenone tetracarboxylic dianhydride, and methyl hymic acid. As the curing accelerator, alkyl group-substituted imidazole, benzimidazole and the like can be used as imidazoles.

  In the case of amines, the amount of the curing agent or the curing accelerator is preferably such that the equivalent of the active hydrogen of the amine is approximately equal to the epoxy equivalent of the epoxy resin. In the case of imidazole which is a curing accelerator, it is not simply an equivalent ratio with active hydrogen, and empirically, 0.001 to 10 parts by weight is preferable with respect to 300 parts by weight of epoxy resin. In the case of polyfunctional phenols and acid anhydrides, phenolic hydroxyl groups and carboxyl groups of 0.6 to 1.2 equivalents are preferred with respect to 1 equivalent of epoxy resin. If the amount of the curing agent or the curing accelerator is small, an uncured epoxy resin remains, and the Tg (glass transition temperature) becomes low. If too large, an unreacted curing agent and a curing accelerator remain, and insulation of the cured product Tend to decrease.

  Moreover, the thermosetting resin composition may contain a high molecular weight resin component for the purpose of improving flexibility and heat resistance. Examples of such high molecular weight resin components include acrylic resins and polyamideimide resins.

  As the acrylic resin, for example, an acrylic acid monomer, a methacrylic acid monomer, acrylonitrile, a polymer obtained by polymerizing an acrylic monomer having a glycidyl group alone, or a copolymer obtained by copolymerizing a plurality thereof can be used. The molecular weight of the acrylic resin is not particularly specified, but is preferably 300,000 to 1,000,000, and more preferably 400,000 to 800,000 in terms of standard polystyrene equivalent weight average molecular weight.

  It is preferable to add an epoxy resin, a curing agent, a curing accelerator, or the like to these acrylic resins as appropriate. Examples of acrylic resins include HTR-860-P3 (manufactured by Nagase ChemteX Corporation, trade name, weight average molecular weight 850,000), HM6-1M50 (manufactured by Nagase ChemteX Corporation, trade name, weight average molecular weight 500,000), and the like. it can.

The polyamideimide resin preferably contains in the main chain a structure represented by the above general formula (1), more specifically a structure represented by the following general formula (2).

  By using the polyamideimide resin including the specific structure, higher adhesion between the metal thin film or circuit and the resin layer or insulating layer, and higher heat resistance of the resin layer and insulating layer can be obtained.

式（３）の脂環式ジアミンは、例えばワンダミンＨＭ（新日本理化株式会社製）として商業的に入手可能である。 Polyamideimide resin containing the structure of Formula (1) or (2), for example, reacts diamine containing alicyclic diamine represented by the following general formula (3) with trimellitic anhydride to diimidedicarboxylic acid. And a step of reacting diimide dicarboxylic acid and diisocyanate to produce an amide group to obtain a polyamideimide resin. Diimide dicarboxylic acid is a compound having two imide groups and two carboxyl groups.

The alicyclic diamine of the formula (3) is commercially available, for example, as Wandamine HM (manufactured by Shin Nippon Rika Co., Ltd.).

  The diamine to be reacted with trimellitic anhydride preferably includes an aromatic diamine having two or more aromatic rings and a siloxane diamine in addition to the alicyclic diamine of the formula (3). In this case, the mixing ratio (molar ratio) of the amount a of the alicyclic diamine of the formula (3) and the total amount b of the aromatic diamine and the siloxane diamine is preferably a / b = 0.1 / 99.9 to It is 99.9 / 0.1, More preferably, it is in the range of a / b = 10 / 90-50 / 50, More preferably, a / b = 20 / 80-40 / 60.

  Examples of the aromatic diamine include 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (3-aminophenoxy) phenyl] sulfone, and bis [4- (4- Aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] methane, 4,4′-bis (4- Aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ketone, 1,3-bis (4-aminophenoxy) benzene, 1,4- Bis (4-aminophenoxy) benzene, 2,2′-dimethylbiphenyl-4,4′-diamine, 2,2′-bis (trifluoro) (Romethyl) biphenyl-4,4′-diamine, 2,6,2 ′, 6′-tetramethyl-4,4′-diamine, 5,5′-dimethyl-2,2′-sulfonyl-biphenyl-4,4 '-Diamine, 3,3'-dihydroxybiphenyl-4,4'-diamine, (4,4'-diamino) diphenyl ether, (4,4'-diamino) diphenyl sulfone, (4,4'-diamino) benzophenone, There are (3,3′-diamino) benzophenone, (4,4′-diamino) diphenylmethane, (4,4′-diamino) diphenyl ether, and (3,3′-diamino) diphenyl ether.

  Examples of the siloxane diamine include those represented by the following general formula (11), (12), (13) or (14). In these formulas, n and m each independently represent a positive integer.

  Examples of the siloxane diamine represented by the formula (11) include KF-8010 (amine equivalent 450, manufactured by Shin-Etsu Chemical Co., Ltd.) and BY16-853 (amine equivalent 650, manufactured by Toray Dow Corning Silicone Co., Ltd.). Examples of the siloxane diamine represented by formula (12) include X-22-9409 (amine equivalent 700) and X-22-1660B-3 (amine equivalent 2200) (manufactured by Shin-Etsu Chemical Co., Ltd.).

An aliphatic diamine may be used as the diamine. Examples of the aliphatic diamine include a compound represented by the following general formula (5).

In formula (5), X represents a methylene group, a sulfonyl group, an oxy group, a carbonyl group or a single bond, and R ¹ and R ² each independently represent a hydrogen atom, an alkyl group or a phenyl group which may have a substituent. Represents a group, and p represents an integer of 1 to 50. The alkyl group as R ¹ and R ² preferably has 1 to 3 carbon atoms. As a substituent which a phenyl group has, a C1-C3 alkyl group and a halogen atom can be illustrated. From the viewpoint of achieving both low elastic modulus and high Tg, X in Formula (5) is preferably an oxy group. Specific examples of such aliphatic diamines include Jeffamine D-400 (amine equivalent 200) and Jeffamine D-2000 (amine equivalent 1000).

The diisocyanate to be reacted with diimide dicarboxylic acid is represented, for example, by the following general formula (6).
^OCN-R 3 -NCO (6)

In formula (6), R ³ represents a divalent organic group having at least one aromatic ring or a divalent aliphatic hydrocarbon group. The diisocyanate of the formula (6) is an aromatic diisocyanate when R ³ is a divalent organic group having an aromatic ring, and is an aliphatic diisocyanate when R ³ is a divalent aliphatic hydrocarbon group. As the diisocyanate, it is preferable to use an aromatic diisocyanate. In this case, it is more preferable to use an aromatic diisocyanate and an aliphatic diisocyanate in combination.

Preferred examples of the divalent organic group having an aromatic _{ring, -C 6 H 4 -CH 2 -C} 6 H 4 - , a group represented by is a tolylene group and a naphthylene group. Preferable examples of the divalent aliphatic hydrocarbon group include a hexamethylene group, a 2,2,4-trimethylhexamethylene group, and an isophorone group.

  Examples of aromatic diisocyanates include 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, and 2,4-tolylene dimer. it can. Among these, MDI is particularly preferable. By using MDI, the flexibility of the resulting polyamideimide resin can be further improved.

  Examples of the aliphatic diisocyanate include hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and isophorone diisocyanate. When using an aromatic diisocyanate and an aliphatic diisocyanate in combination, it is preferable to add the aliphatic diisocyanate to about 5 to 10 mol% with respect to the aromatic diisocyanate, and this combination further improves the heat resistance of the resulting polyamideimide resin. Can be made.

  The thermosetting resin composition may contain an additive-type flame retardant for the purpose of improving flame retardancy. As the additive type flame retardant, a filler containing phosphorus is preferable. As fillers containing phosphorus, OP930 (trade name, manufactured by Clariant, phosphorus content 23.5%), HCA-HQ (trade name, manufactured by Sanko, phosphorus content 9.6%), melamine polyphosphate PMP-300 (Phosphorus content 13.8%) PMP-200 (Phosphorus content 9.3%) PMP-300 (Phosphorus content 9.8%) (The above-mentioned product name made by Nissan Chemical Co., Ltd.) etc. are mentioned.

  The thickness of the resin layer 4 is preferably 70 μm or less, and more preferably 10 to 60 μm. When this thickness exceeds 70 micrometers, it exists in the tendency for the flexibility of the printed circuit board produced using the metal thin film 100 with a resin, and a multilayer wiring board to fall. Moreover, when the thickness of the resin layer 4 is less than 10 μm, the embedding property of the circuit pattern applied to the inner layer substrate when it is multilayered tends to be lowered.

  The resin layer 4 is obtained as follows, for example. First, the above-mentioned components contained in the resin composition are mixed, dissolved, and dispersed in an organic solvent to produce a resin varnish. Any organic solvent may be used as long as it can dissolve the resin. For example, dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, γ-butyllactone, sulfolane, cyclohexanone, and the like can be used.

  Next, the produced resin varnish is applied on the second metal layer 3. Then, the resin layer 4 is obtained by, for example, heating at 80 ° C. to 180 ° C. to remove part or all of the organic solvent. The heating time can be set in consideration of the gelation time of the resin varnish. The organic solvent used for the production of the resin varnish is preferably volatilized and removed by 80% by mass or more. The resin layer 4 is preferably in a B-stage state in which the resin varnish is semi-cured, but may be in a cured C-stage state. The thickness of the resin layer 4 after removing part or all of the organic solvent is preferably 70 μm or less, and more preferably 10 to 60 μm.

  Next, a printed circuit board using the metal thin film with resin 100 and a manufacturing method thereof will be described. FIG. 2 is a schematic process diagram illustrating a method of manufacturing a printed circuit board according to a preferred embodiment of the present invention. The method for manufacturing a printed circuit board according to the present embodiment includes a metal thin film preparation step for preparing a metal thin film with resin according to the present invention, an FPC preparation step for preparing a flexible circuit board (hereinafter referred to as “FPC”), and an FPC. It has a laminating step of laminating a metal thin film with resin to obtain a laminated body, a support removing step of removing the support from the metal thin film with resin, and a semi-additive step of forming a circuit by a semi-additive method. The semi-additive process further includes a resist forming process for forming a resist pattern on the laminate, a circuit forming process for forming a circuit pattern, a resist removing process for removing the resist pattern, and an etching that performs etching after the resist removing process. Process. Hereinafter, each step will be described.

  First, in the metal thin film preparation step, the above-described metal thin film with resin 100 is prepared (see FIG. 2A). In FIG. 2A, the resin-attached metal thin film 100 in FIG. 1 is shown upside down.

  Moreover, FPC200 is prepared in a FPC preparation process simultaneously with a metal thin film preparation process (refer Fig.2 (a)). The FPC 200 includes a flexible substrate 6 and a first circuit 5 provided on one main surface of the substrate 6. Such an FPC 200 can be manufactured by a conventional method, or a commercially available product can be obtained. For example, a flexible substrate manufactured on a flexible film such as Iupilex (trade name) by Upilex (manufactured by Ube Industries, Ltd.), Kapton (manufactured by Toray DuPont), or by impregnating a fiber base with a resin. You may produce by laminating | stacking metal foil, such as copper foil, on the top, and giving a circuit process to the insulating board with metal foil obtained by it.

  Next, in the stacking step, the resin-coated metal thin film 100 is stacked on the FPC 200 to obtain a stacked body 300 (see FIG. 2B). In this case, first, the substrate 6 and the first circuit 5 of the FPC 200 and the resin layer 4 of the metal thin film with resin 100 are in contact with each other, and they are arranged. Next, the resin-coated metal thin film 100 and the FPC 200 are brought into close contact with each other by a method such as pressing, roll laminating, and press laminating. The resin layer 4 is hardened by performing heat treatment as necessary during or after the close contact, and the insulating layer 10 made of the cured product is formed.

  Subsequently, in the support body removing step, the support body 1 is peeled and removed from the laminated body 300 described above. As a result, the surface of the first metal layer 2 is exposed.

  Next, in a resist formation step, a resist pattern 7 having a predetermined pattern is formed on the surface of the first metal layer 2 (see FIG. 2C). For the formation of the resist pattern 7, a known pattern forming method such as photolithography can be employed. Through this resist formation step, a part of the surface of the first metal layer 2 is covered with the resist pattern 7 and the other part is exposed. The resist material is preferably a resist material for electrolytic plating.

  Next, in the circuit forming step, electrolytic plating is performed on the exposed portion of the surface of the first metal layer 2. Thereby, the circuit pattern 8 is formed (see FIG. 2D). For the electroplating, a known method can be adopted, and the first metal layer 2 and the second metal layer 3 function as the power feeding layer. The material of the circuit pattern 8 formed by electrolytic plating may be a known material, and examples thereof include metals such as copper, solder, nickel, rhodium and gold. In these, copper is suitable from a viewpoint generally used as a conductor material of a printed circuit board.

  The thickness of the circuit pattern 8 is preferably 3 to 40 μm, and more preferably 5 to 20 μm. If the thickness exceeds 40 μm, it tends to be difficult to form a fine circuit pattern 8. If the thickness is less than 3 μm, the circuit pattern 8 tends to be easily removed in the subsequent etching process.

  Thereafter, in the resist removing step, the resist pattern 7 is removed (see FIG. 2E). The removal method of the resist pattern 7 may be a known method, and examples thereof include removal with an organic solvent such as methylene chloride and removal with an alkaline solution such as sodium hydroxide. As a result, the surface of the first metal layer 2 covered with the resist pattern 7 is exposed.

  Next, an etching process is performed in an etching process to obtain a printed circuit board 700 (see FIG. 2F). The etching method may be a known method such as spray etching. Moreover, the etching solution used for the etching process is not particularly limited as long as it is an etching solution that can dissolve the metal constituting the first metal layer 2 and the second metal layer 3. Thereby, a part of the 1st metal layer 2 and the 2nd metal layer 3 is removed from the surface side of the 1st metal layer 2 exposed through the resist removal process. Prior to the etching process, it is preferable to cover a portion to be a second circuit 15 described later with a known etching resist.

  The printed circuit board 700 thus obtained is provided on the insulating layer 10, the substrate 6 having flexibility, the first circuit 5, the insulating layer 10 made of a cured product of an insulating resin composition, and the insulating layer 10. A second metal layer 3 patterned, and a first metal layer provided on the second metal layer 3 and patterned in the same pattern as the second metal layer 3 2 and a second circuit 15 having a second metal layer 3 provided on the first metal layer 2 and a third metal layer 8 patterned in the same manner as the first metal layer 2; Are stacked in this order.

  Next, a multilayer wiring board using the metal thin film with resin 100 and a manufacturing method thereof will be described. 3 and 4 are schematic process diagrams showing a method for manufacturing a multilayer wiring board according to a preferred embodiment of the present invention. The manufacturing method of the multilayer wiring board according to the present embodiment includes a metal thin film preparation process for preparing a metal thin film with resin according to the present invention, an FPC preparation process for preparing FPC, and a metal thin film with resin so as to sandwich the FPC. A lamination step for obtaining a laminate, a circuit connection step for connecting the circuits, a support removal step for removing the support from the resin-coated metal thin film, and a semi-additive step for forming a circuit by a semi-additive method. The semi-additive process further includes a resist forming process for forming a resist pattern on the laminate, a circuit forming process for forming a circuit pattern, a resist removing process for removing the resist pattern, and an etching that performs etching after the resist removing process. Process. Hereinafter, each step will be described.

  First, in the metal thin film preparation step, the two metal thin films with resin 100 described above are prepared (see FIG. 3A). In addition, the FPC 800 is prepared in the FPC preparation process simultaneously with the metal thin film preparation process (see FIG. 3A). The FPC 800 includes a flexible substrate 6 and first circuits 5 provided on both main surface sides of the substrate 6. Such an FPC 800 can be manufactured by a conventional method or a commercially available product can be obtained in the same manner as the FPC 200 described above.

  Next, in the laminating step, the laminate 900 is obtained by laminating the two metal thin films 100 with resin so that the FPC 800 is sandwiched from both main surface sides (see FIG. 3B). At this time, first, the substrate 6 of the FPC 800 and the first circuits 5 on both main surfaces thereof are arranged so that the resin layers 4 of the respective metal thin films with resin 100 are in contact with each other. Next, the two metal thin films with resin 100 and the FPC 800 are brought into close contact with each other by a method such as pressing, roll laminating, and press laminating. The resin layer 4 is hardened by performing heat treatment as necessary during or after the close contact, and the insulating layer 10 made of the cured product is formed.

  Next, in the circuit connection step, first, a hole is made from the both support 1 sides of the laminated body 900 so that the predetermined first circuit 5 is exposed (see FIG. 3C). Drilling may be performed using a known laser. As a result, the hole 18 is formed, the predetermined first circuit 5 is exposed, and a part of the first metal layer 2 and the second metal layer 3 is also exposed. Subsequently, electroless plating is performed from the side of both supports 1 of the laminated body 900 after drilling (see FIG. 3D). For the electroless plating, a known method can be adopted. Examples of the electroless plating solution include electroless plating solutions such as copper, nickel, tin, and gold. Examples of the reducing agent include formaldehyde, hypophosphite ions, hydrazine and the like. Thereby, the electroless plating film 9 is formed on the surface of the support 1, the inner wall of the hole 18, and the surface of the first circuit 5, and the first circuit 5, the first metal layer 2 and the second metal layer 3 are formed. Are electrically connected. Since the first metal layer 2 and the second metal layer 3 constitute the second circuit 15 in a later process, the first circuit 5 and the second circuit 15 are electrically connected through this circuit connection process. Will be connected.

  Next, in the support removing step, the support 1 is peeled and removed (see FIG. 4A). As a result, the surface of the first metal layer 2 is exposed. Further, the electroless plating film 9 formed on the surface of the support 1 is also removed. Therefore, the electroless plating film 9 remains on the inner wall of the hole 18 and the surface of the first circuit 5.

  Then, in the semi-additive process, the second circuit 15 is formed by a semi-additive method in the same manner as in the case of manufacturing the above-described printed circuit board 700 from both main surface sides of the laminate 910 after the support 1 is removed. It forms (refer FIG.4 (b)). The multilayer wiring board 50 thus obtained has the first circuit 5 and the insulating layer 10 made of a cured product of an insulating resin composition so that the inner layer substrate 6 having flexibility is sandwiched from both main surface sides, A circuit provided on the insulating layer 10, which is a patterned second metal layer 3, provided on the second metal layer 3, and patterned in the same pattern as the second metal layer 3. A first metal layer 2 formed on the first metal layer 2 and a third metal layer 8 provided on the first metal layer 2 and patterned in the same manner as the second metal layer 3 and the first metal layer 2. And a second circuit 15 having the above structure. The multilayer wiring board 50 has a hole 18 opened from both main surfaces toward a part of the first circuit 5, and the inner wall of the hole 18 and the surface of the first circuit 5 are provided. An electroless plating film 9 is provided. The electroless plating film 9 functions as a connection portion that electrically connects the first circuit 5 and the second circuit 15.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof.

  For example, in another embodiment of the present invention, the multilayer wiring board may have a through hole. FIG. 5 is a schematic process diagram showing a method for manufacturing a multilayer wiring board according to another embodiment of the present invention. In this multilayer wiring board manufacturing method, first, a laminate 900 is obtained in the same manner as in the multilayer wiring board manufacturing method of the preferred embodiment.

  Next, in the circuit connection step, holes are formed in the stacking direction so as to penetrate through the predetermined first circuit 5 from one support body 1 side of the stack 900 (see FIG. 5A). Drilling may be performed using a known drill. As a result, the through hole 19 is formed, the predetermined first circuit 5 is exposed, and a part of the first metal layer 2 and the second metal layer 3 is also exposed. Subsequently, electroless plating is performed from the both support 1 sides of the laminated body 900 after drilling (see FIG. 5B). The electroless plating method, the electroless plating solution, and the reducing agent may be the same as those according to the preferred embodiment. Thereby, the electroless plating film 29 is formed on the surface of the support body 1 and the inner wall of the through hole 19, and the first circuit 5 and the first metal layer 2 and the second metal layer 3 are electrically connected. The Since the first metal layer 2 and the second metal layer 3 constitute the second circuit 15 in a later process, the first circuit 5 and the second circuit 15 are electrically connected through this circuit connection process. Will be connected.

  Next, in the support removing step, the support 1 is peeled and removed (see FIG. 5C). As a result, the surface of the first metal layer 2 is exposed. Further, the electroless plating film 29 formed on the surface of the support 1 is also removed. Therefore, the electroless plating film 29 remains on the inner wall of the through hole 19.

  Then, in the semi-additive process, the second circuit 15 is formed by a semi-additive method in the same manner as in the case of manufacturing the above-described printed circuit board 700 from both main surface sides of the laminate 910 after the support 1 is removed. Form. The multilayer wiring board 60 thus obtained has the first circuit 5 and the insulating layer 10 made of a cured product of an insulating resin composition so as to sandwich the flexible inner layer substrate 6 from both main surface sides, A circuit provided on the insulating layer 10, which is a patterned second metal layer 3, provided on the second metal layer 3, and patterned in the same pattern as the second metal layer 3. A first metal layer 2 formed on the first metal layer 2 and a third metal layer 8 provided on the first metal layer 2 and patterned in the same manner as the second metal layer 3 and the first metal layer 2. And a second circuit 15 having the above structure. The multilayer wiring board 60 has a through hole 19 penetrating in the stacking direction, and an electroless plating film 29 is provided on the inner wall of the hole 19. The electroless plating film 29 functions as a connection portion that electrically connects the first circuit 5 and the second circuit 15.

  In still another embodiment, the resin layer 4 in the metal thin film with resin may be formed as follows. First, a resin varnish containing the above insulating resin composition is applied on a substrate such as a PET film and dried to form a resin film. Next, the resin layer 4 is obtained by laminating the resin film on the surface of the second metal layer 3.

  Although the printed circuit board 100 described above and the FPC including the flexible substrate 6 and the first circuit 5 are provided, the printed circuit board of the present invention is not necessarily provided with the FPC. Furthermore, the resin layer 4 may be converted to the insulating layer 10 by heating and pressing the metal thin film with resin of the present invention in the laminating direction of each member.

  In still another embodiment, the resin-attached metal thin film of the present invention may further include another metal layer between the second metal layer and the resin layer. The purpose of this metal layer is to improve the adhesion between the second metal layer and the resin layer. An example of the material for this metal layer is nickel.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

(Example 1)
(Production of metal thin film with resin)
A first copper layer corresponding to the first metal layer was formed by vacuum deposition of copper on a PET film having a thickness of 50 μm corresponding to the above support. The thickness of this first copper layer was 0.05 μm. Next, a second copper layer corresponding to the second metal layer was formed on the first metal layer by sputtering of copper. The thickness of this second copper layer was 0.2 μm. Further, a nickel layer was formed on the second metal layer by sputtering of nickel. The nickel layer had a thickness of 0.01 μm. In this way, the base material H for forming the below-mentioned resin layer was obtained.

  11. DDS (diaminodiphenyl sulfone), which is a diamine having two or more aromatic rings, in a 1 L separable flask equipped with a 25 mL moisture meter with a cock connected to a reflux condenser, a thermometer and a stirrer. 5 g (0.05 mol), reactive silicone oil KF-8010 (trade name, amine equivalent 430), which is a siloxane diamine, 43.0 g (0.05 mol), Jeffamine D2000 (manufactured by Mitsui Chemical Fine) , Trade name, amine equivalent 1000) 74.0 g (0.37 mol), Wandamine HM (trade name, manufactured by Shin Nippon Rika Co., Ltd.) which is an alicyclic diamine represented by the above formula (3) 054 mol), 80.7 g (0.42 mol) of TMA (trimellitic anhydride) and NMP (N- G of chill-2-pyrrolidone) 589 g, was stirred at 80 ° C. 2.5 min.

  Then, 150 mL of toluene, which is an aromatic hydrocarbon azeotropic with water, was added, and then the temperature was raised and refluxed at about 160 ° C. for 2 hours. Confirm that water has accumulated in the moisture determination receiver more than 7.2mL and that no water is being distilled, and while removing the distillate collected in the moisture determination receiver, The temperature was raised to 190 ° C. to remove toluene.

  Thereafter, the reaction solution was returned to room temperature (25 ° C.), and 55.1 g (0.22 mol) of MDI (4,4′-diphenylmethane diisocyanate), which is an aromatic diisocyanate, was added thereto and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of polyamideimide resin was obtained.

  NMP solution of the obtained polyamideimide resin 250.0 g (resin solid content 32% by mass) and epoxy resin EPPN-502H (manufactured by Nippon Kayaku Co., Ltd., trade name) 22.4 g (resin solid content 50% by mass dimethyl) Acetamide solution) and HP-4023D (trade name, manufactured by Dainippon Ink Co., Ltd.) 45.6 g (dimethylacetamide solution having a resin solid content of 50% by mass), and 0.2 g of 2-ethyl-4-methylimidazole are mixed to form a resin. The mixture was stirred for about 1 hour until it became uniform, and then allowed to stand at room temperature for 24 hours for defoaming. Thus, a varnish (resin varnish) of a thermosetting resin composition containing a polyamideimide resin having the structure of the above formula (1) was obtained.

  The obtained resin varnish was applied on the surface of the nickel layer in the base material H, and a part of the solvent was volatilized and removed by heating at 150 ° C. for 15 minutes to obtain a resin layer having a thickness of 50 μm. . Thus, the metal thin film A with resin was completed.

(Production of multilayer wiring board)
Next, TC-C-500 (trade name, thickness of substrate: 50 μm, manufactured by Hitachi Chemical Co., Ltd.), which is a copper clad laminate in which copper foils are laminated on both principal surface sides of a flexible substrate, is prepared. The copper foils on both sides were patterned to obtain an FPC provided with a first circuit having a predetermined pattern. The FPC substrate and the circuits on both main surfaces thereof were in contact with the resin layers of the two resin-attached metal thin films A, and they were laminated. And it pressed in those lamination directions on 200 degreeC and 90 minute conditions of 4.0 Mpa, and obtained the laminated body.

  Next, a hole having a diameter of 100 μm was formed using a carbon dioxide gas laser so that a predetermined first circuit was exposed from both support sides of the obtained laminate. Next, electroless plating is performed from both support sides of the laminated body after drilling to form an electroless copper plating film having a thickness of 2 μm covering the first circuit exposed by drilling, the support, and the inner wall of the hole. did.

Thereafter, AZ10XT (trade name, manufactured by Clariant), which is a plating resist, was applied by spin coating to the surface of the first metal layer exposed by peeling off and removing the supports on both sides to a thickness of 15 μm. Subsequently, a plating resist was processed so as to have a predetermined resist pattern by photolithography. Thereby, a part of the surface of the first metal layer was exposed. Next, electrolytic copper plating was performed on the laminated body after photolithography using the first metal layer and the second metal layer as a power feeding layer. This electrolytic copper plating was performed at a current density of 0.8 A / dm ² using a copper sulfate plating bath as a plating bath. As a result, an electrolytic copper plating film having a thickness of 12 μm was formed on the exposed surface of the first metal layer.

  Next, the plating resist is removed, and etching is performed using nitric acid / hydrogen peroxide as an etching solution from the surface of the first metal layer exposed thereby, and one of the first metal layer and the second metal layer is etched. Part was removed. Then, it washed with water and dried, and obtained the multilayer wiring board provided with the 2nd circuit on both surfaces similarly to what is shown in FIG.3 (f).

(Example 2)
A resin-coated metal thin film B was obtained in the same manner as in Example 1 except that the resin varnish prepared as described below was used. First, EPICLON 153 (trade name, manufactured by Dainippon Ink Co., Ltd.) which is an epoxy resin, FG-2000 (trade name, manufactured by Teijin Chemicals Co., Ltd.) 181 g, which is a curing agent, and 2PZ-CN (Shikoku), which is a curing accelerator. 1.0 g of Kasei Co., Ltd., trade name) was dissolved in 600.0 g of methyl isobutyl ketone. Thereto, 287.0 g of HTR-860-P3 (trade name, weight average molecular weight: 850,000, 15 mass% methyl ethyl ketone solution, manufactured by Nagase ChemteX Corporation), which is an acrylic resin, was added and stirred for 1 hour to obtain a resin varnish. Obtained.

  Then, instead of the metal thin film with resin A, the metal thin film with resin B is used as the FPC as both sides of TC-C-100 (trade name, thickness of substrate: 50 μm), which is a copper-clad laminate. A multilayer wiring board was obtained in the same manner as in Example 1 except that an FPC provided with a first circuit having a predetermined pattern by patterning the copper foil was obtained.

(Example 3)
First, a copper-clad substrate in which a copper foil was bonded to both main surfaces of a flexible polyimide film (trade name “UPILEX” manufactured by Ube Industries, Ltd.) with an adhesive was prepared. MIT-215 (trade name, manufactured by Nihon Gosei Morton Co., Ltd.), which is an etching resist, was laminated on both main surfaces of the copper-clad substrate so as to have a thickness of 15 μm. Subsequently, the etching resist was processed so as to have a predetermined resist pattern by photolithography. Thereby, a part of copper foil surface was exposed. Next, the exposed copper foil surface was etched using a ferric chloride-based copper etchant, and a part of the copper foil was removed by the etching process to obtain a circuit with a predetermined pattern. Then, it washed with water and dried and obtained the printed circuit board.

  A multilayer wiring board was obtained in the same manner as in Example 1 except that this printed circuit board was used as an FPC.

Example 4
A first copper layer corresponding to the first metal layer was formed on a PEN film having a thickness of 50 μm corresponding to the above support by vacuum deposition of copper. The thickness of this copper layer was 0.05 μm. Next, a second copper layer corresponding to the second metal layer was formed on the first metal layer by sputtering of copper. The thickness of this second copper layer was 0.2 μm. Further, a nickel layer was formed on the second metal layer by sputtering of nickel. The nickel layer had a thickness of 0.01 μm. In this way, the base material I for forming the below-mentioned resin layer was obtained.

  Next, the resin varnish obtained in the same manner as in Example 1 was applied onto the surface of the nickel layer in the base material I, and a part of the solvent was removed by volatilization by heating at 150 ° C. for 15 minutes. A resin layer having a thickness of 5 mm was obtained. Thus, the metal thin film C with resin was completed.

  Thereafter, a multilayer wiring board was obtained in the same manner as in Example 1 except that the metal thin film C with resin was used instead of the metal thin film A with resin.

(Example 5)
A first nickel layer corresponding to the first metal layer was formed by vacuum deposition of nickel on a PET film having a thickness of 50 μm corresponding to the above support. The thickness of the first nickel layer was 0.05 μm. Next, a copper layer corresponding to the second metal layer was formed on the first metal layer by sputtering of copper. The thickness of this copper layer was 0.2 μm. Further, a second nickel layer was formed on the second metal layer by sputtering of nickel. The thickness of this second nickel layer was 0.01 μm. In this way, the base material J for forming the below-mentioned resin layer was obtained.

  Next, the resin varnish obtained in the same manner as in Example 1 was applied on the surface of the second nickel layer in the base material J, and a part of the solvent was volatilized and removed by heating at 150 ° C. for 15 minutes. Thus, a resin layer having a thickness of 50 μm was obtained. Thus, the metal thin film D with resin was completed.

  Thereafter, a multilayer wiring board was obtained in the same manner as in Example 1 except that the metal thin film D with resin was used instead of the metal thin film A with resin.

(Example 6)
A first copper layer corresponding to the first metal layer was formed by vacuum deposition of copper on a PET film having a thickness of 50 μm corresponding to the above support. The thickness of this first copper layer was 0.01 μm. Next, a second copper layer corresponding to the second metal layer was formed on the first metal layer by sputtering of copper. The thickness of this second copper layer was 0.15 μm. Further, a nickel layer was formed on the second metal layer by sputtering of nickel. The nickel layer had a thickness of 0.01 μm. In this way, the base material K for forming the below-mentioned resin layer was obtained.

  Next, the resin varnish obtained in the same manner as in Example 1 was applied onto the surface of the nickel layer in the substrate K, and a part of the solvent was removed by volatilization by heating at 150 ° C. for 15 minutes to obtain 50 μm. A resin layer having a thickness of 5 mm was obtained. Thus, a metal thin film E with resin was completed.

  Thereafter, a multilayer wiring board was obtained in the same manner as in Example 1 except that the metal thin film E with resin was used instead of the metal thin film A with resin.

(Example 7)
First, the metal thin film A with resin was pressed in the lamination direction at 200 ° C. for 90 minutes and 4.0 MPa to obtain a single-sided metal-clad laminate. From there, the PET film was peeled and removed to expose the surface of the first metal layer. On the exposed surface of the first metal layer, AZ10XT (trade name, manufactured by Clariant), which is a plating resist, was applied by spin coating so as to have a thickness of 15 μm. Subsequently, a plating resist was processed so as to have a predetermined resist pattern by photolithography. Thereby, a part of the surface of the first metal layer was exposed. Next, electrolytic copper plating was applied to the laminated plate after photolithography using the first metal layer and the second metal layer as power feeding layers. This electrolytic copper plating was performed at a current density of 0.8 A / dm ² using a copper sulfate plating bath as a plating bath. As a result, an electrolytic copper plating film having a thickness of 12 μm was formed on the exposed surface of the first metal layer.

  Next, the plating resist is removed, and etching is performed using nitric acid / hydrogen peroxide as an etching solution from the surface of the first metal layer exposed thereby, and one of the first metal layer and the second metal layer is etched. Part was removed. Then, it washed with water and dried and obtained the printed circuit board provided with the 2nd circuit on the single side | surface.

(Comparative Example 1)
First, a copper-clad substrate in which a copper foil was bonded to both main surfaces of a flexible polyimide film (trade name “UPILEX” manufactured by Ube Industries, Ltd.) with an adhesive was prepared. MIT-215 (trade name, manufactured by Nihon Gosei Morton Co., Ltd.), which is an etching resist, was laminated on both main surfaces of the copper-clad substrate so as to have a thickness of 15 μm. Subsequently, the etching resist was processed so as to have a predetermined resist pattern by photolithography. Thereby, a part of copper foil surface was exposed. Next, the exposed copper foil surface was etched using a ferric chloride-based copper etchant, and a part of the copper foil was removed by the etching process to obtain a circuit with a predetermined pattern. Then, it washed with water and dried and obtained the printed circuit board.

(Comparative Example 2)
A copper layer was formed by sputtering copper on a PET film having a thickness of 50 μm corresponding to the above support. The thickness of this copper layer was 0.2 μm. In this way, the base material L for forming the below-mentioned resin layer was obtained.

  Next, the resin varnish obtained in the same manner as in Example 1 was applied onto the surface of the copper layer in the base material L, and a part of the solvent was removed by volatilization by heating at 150 ° C. for 15 minutes to obtain 50 μm. A resin layer having a thickness of 5 mm was obtained. Thus, the resin-coated metal thin film F was completed.

  Thereafter, production of a multilayer wiring board was attempted in the same manner as in Example 1 except that the metal thin film F with resin was used instead of the metal thin film A with resin. However, when peeling and removing the PET film, which is the support on both sides of the laminate, the adhesive strength between the PET film and the copper layer was too strong to peel, and a circuit pattern could not be formed. .

  The circuit patterns of the obtained multilayer wiring boards of Examples 1 to 6, Example 7 and Comparative Example 1 were observed. As a result, the multilayer wiring boards of Examples 1 to 6 and the printed circuit board of Example 7 are free from short circuit or disconnection even when the line width / space width of the circuit pattern is 15 μm / 15 μm. Could be formed. On the other hand, in the printed circuit board of Comparative Example 1, the circuit pattern line width / space width was 40 μm / 40 μm, and short circuit or disconnection was observed.

  Moreover, the multilayer wiring board of Examples 1-6 and the printed circuit board of Example 7 were able to be bent arbitrarily. Specifically, no cracks or breakage occurred even when bent 180 degrees along a pin with a radius of curvature of 1 mm.

It is a schematic cross section which shows the metal thin film with resin which concerns on suitable embodiment of this invention. It is process sectional drawing which shows schematically the manufacturing method of the printed circuit board which concerns on suitable embodiment of this invention. It is process sectional drawing which shows roughly the manufacturing method of the multilayer wiring board which concerns on suitable embodiment of this invention. It is process sectional drawing which shows roughly the manufacturing method of the multilayer wiring board which concerns on suitable embodiment of this invention. It is process sectional drawing which shows roughly the manufacturing method of the multilayer wiring board which concerns on another suitable embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... 1st metal layer, 3 ... 2nd metal layer, 4 ... Resin layer, 5 ... 1st circuit, 6 ... Substrate which has flexibility, 7 ... Resist pattern, 8 ... Circuit Pattern, 9, 29 ... Electroless plating film, 10 ... Insulating layer, 15 ... Second circuit, 18 ... Hole, 19 ... Through hole, 100 ... Metal thin film with resin, 50, 60 ... Multilayer wiring board, 700 ... Printing Circuit board.

Claims (14)

A support;
A first metal layer formed by vapor deposition on the support;
A second metal layer formed on the first metal layer;
A resin layer made of an insulating resin composition formed on the second metal layer;
A metal thin film with a resin.   The metal thin film with a resin according to claim 1, wherein the first metal layer has a thickness of 0.01 to 0.5 μm.   The metal thin film with a resin according to claim 1 or 2, wherein the second metal layer has a thickness of 0.1 to 2.0 µm.   The metal thin film with a resin according to any one of claims 1 to 3, wherein the first metal layer contains copper.   The metal thin film with a resin according to any one of claims 1 to 4, wherein the second metal layer contains copper.   The metal thin film with a resin according to any one of claims 1 to 5, wherein the resin layer has a thickness of 70 µm or less.   The metal thin film with a resin according to any one of claims 1 to 6, wherein the resin composition is a thermosetting resin composition.   The metal thin film with a resin according to claim 7, wherein the thermosetting resin composition contains an epoxy resin. The metal thin film with a resin according to claim 7 or 8, wherein the thermosetting resin composition contains a polyamideimide resin having a structure represented by the following general formula (1).

  The metal thin film with a resin as described in any one of Claims 7-9 in which the said thermosetting resin composition contains an acrylic resin. Removing the support from the resin-coated metal thin film according to any one of claims 1 to 10,
A circuit is formed by forming a third metal layer by a semi-additive method on the surface of the first metal layer exposed through the removing step, using the first metal layer and the second metal layer as a power feeding layer. Obtaining
A method for manufacturing a printed circuit board comprising: An insulating layer made of a cured product of an insulating resin composition;
A circuit provided on the insulating layer, the second metal layer patterned, and the first metal layer provided on the second metal layer and formed by vapor deposition and patterned A circuit having a patterned third metal layer provided on the first metal layer, and
Printed circuit board comprising. Preparing a flexible circuit board comprising a flexible substrate and a first circuit provided on the main surface of the substrate;
The step of laminating the metal thin film with resin according to any one of claims 1 to 10 on the flexible circuit board so that the surface of the substrate and the first circuit and the surface of the resin layer are in contact with each other. When,
Removing the support from the metal thin film with resin;
On the first metal layer exposed through the removing step, a third metal layer is formed by a semi-additive method using the first metal layer and the second metal layer as a power feeding layer to form a second metal layer. Obtaining a circuit;
Electrically connecting the first circuit and the second circuit;
The manufacturing method of the multilayer wiring board which has this. A flexible substrate;
A first circuit provided on the main surface of the substrate;
An insulating layer provided on the substrate and the first circuit and made of a cured product of an insulating resin composition;
A second circuit provided on the insulating layer, the second metal layer patterned, and the first circuit provided on the second metal layer, formed by vapor deposition, and patterned. The second circuit comprising: a metal layer; and a patterned third metal layer provided on the first metal layer;
A connecting portion for electrically connecting the first circuit and the second circuit;
A multilayer wiring board comprising:

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