JP6477494B2 - Release polyimide film with adhesive layer, laminate with release polyimide film with adhesive layer, laminate, single or multilayer wiring board with release polyimide film with adhesive layer, and method for producing multilayer wiring board - Google Patents

Description

  The present invention relates to a release polyimide film with an adhesive layer, a laminate with a release polyimide film with an adhesive layer, a laminate, a single-layer or multilayer wiring board with a release polyimide film with an adhesive layer, and a method for producing a multilayer wiring board.

  Conventionally, a multilayer wiring board is manufactured through a hot press process. This hot pressing step is a prepreg obtained by impregnating and coating a resin composition on a fiber substrate on a circuit board having an inner layer circuit on one side or both sides, or a resin film not containing a fiber substrate, and a copper foil. Are laminated, heated and pressurized. Moreover, the hot press process has been frequently used because of its high productivity.

  In recent years, with the miniaturization and high integration of electronic devices, there is a demand for fine wiring of multilayer wiring board materials. As a method of forming fine wiring, after electroless copper plating is applied to the surface on which the circuit is to be formed, electrolytic copper plating is performed only on the necessary portions, and the electroless copper plating layer on the unnecessary portions is removed by etching. A semi-additive method for forming a wiring is preferably used. A circuit formation method mainly used in build-up type multilayer wiring boards as described in Patent Documents 1 to 3 is a semi-additive method. In this method, the thinner the copper layer to be etched away, that is, the thinner the copper layer plated on the surface forming the circuit with the smaller surface roughness is formed and removed, thereby further miniaturizing the wiring. Is possible. However, when a copper plating layer is formed on a surface on which a circuit with a small surface roughness is formed, the problem is that the adhesive force between the surface on which the circuit is formed and the copper plating layer (circuit layer) is small.

  Also, in the production of a multilayer wiring board using a hot press process, the copper foil is laminated between the surface on which the circuit is formed and the press board during the hot press process. It was necessary (see, for example, Patent Document 4). Since the surface roughness of the copper foil is transferred to the surface on which the circuit to be multilayered is formed, the surface roughness of the surface on which the circuit is formed is as large as about 0.3 μm.

  In order to solve this, the use of a film material such as PET having a small surface roughness instead of copper foil is also being studied (for example, see Patent Document 5). There was room for further improvement from the influence on the insulating layer, which is a cured product of the film.

  Furthermore, the multilayer wiring board obtained by the hot press process using copper foil has a problem in flatness.

Japanese Patent No. 3290296 Japanese Patent No. 3654851 Japanese Patent No. 378549 JP 2003-251739 A Japanese Patent No. 5212578

  In view of the current situation, the object of the present invention is that etching after the hot pressing process is unnecessary, peeling of the film is easy, and an insulating layer having a surface roughness suitable for the semi-additive method can be obtained. It is an object of the present invention to provide a material that can produce a single-layer or multilayer wiring board having excellent adhesive strength with a layer and excellent flatness.

  As a result of intensive studies to achieve the above object, the present inventors have found that a release polyimide film having an adhesive layer shown below, that is, a release polyimide film with an adhesive layer, is in accordance with the above purpose. The headline, the present invention has been reached.

That is, the present invention provides the following materials.
(1) A release layer with an adhesive layer, comprising a release layer and an adhesive layer on the surface of the polyimide film, wherein the adhesive layer contains a polyfunctional epoxy resin, an epoxy resin curing agent and a phenolic hydroxyl group-containing polyamide resin. Type polyimide film.
(2) The release polyimide film with an adhesive layer according to (1), wherein the release layer has a thickness of 0.01 to 10 μm.
(3) The mold release polyimide film with an adhesive layer as described in (1) or (2) whose thickness of the said polyimide film is 10-150 micrometers.
(4) The release layer with an adhesive layer according to any one of (1) to (3), wherein the surface roughness (Ra) of the surface on which the release layer of the polyimide film is formed is 0.2 μm or less. Polyimide film.
(5) The release polyimide film with an adhesive layer according to any one of (1) to (4), wherein the release layer contains an alkyd resin.
(6) Lamination with release polyimide film formed by laminating the adhesive layer side of the release polyimide film with adhesive layer according to any one of (1) to (5) on at least one surface of a prepreg or an insulating layer Board.
(7) A laminate obtained by peeling off the release polyimide film of the laminate according to (6).
(8) The adhesive layer side of the release polyimide film with an adhesive layer according to any one of (1) to (5) is laminated on one surface of the prepreg or the insulating layer, and the other surface of the prepreg or the insulating layer is A single-layer or multilayer wiring board with a release polyimide film with an adhesive layer, which is laminated on a single-layer or multilayer wiring board that has been processed.
(9) Single layer or multilayer wiring board with release polyimide film with adhesive layer by laminating the release polyimide film with adhesive layer according to any one of (1) to (5) on a single layer or multilayer wiring board The manufacturing method of a multilayer wiring board which has the process of forming a circuit board, the process of removing a release polyimide film from the single layer with a release polyimide film with an adhesive layer or multilayer wiring board after formation, and the process of forming a circuit.

  According to the present invention, in the production of a multilayer wiring board by molding such as hot plate press, roll laminator, double press, etc., it is excellent in releasability from the adhesive layer, and also in use at a high temperature such as 200 ° C. or higher. In addition to the heat resistant strength that prevents the film from fusing, fine wiring can be formed by the semi-additive method, and the adhesive layer and the separation layer with the adhesive layer capable of obtaining a multilayer wiring board satisfying the wiring adhesive strength can be obtained. A polyimide film and a method for producing a multilayer wiring board using the same can be provided.

[Release polyimide film]
The release polyimide film has a release layer on the surface of the polyimide film.
As the polyimide film used for the release polyimide film of the present invention, one having an appropriate strength and not causing tearing or the like when the polyimide film is peeled is suitably used. For example, an aromatic polyimide in which aromatic compounds are directly linked by an imide bond is preferable in terms of film strength, and an aromatic polyimide having a structural unit represented by the following formula (I) is more preferable.

(In Formula (I), Z ¹ is a C 6-18 tetravalent aromatic hydrocarbon group, and Z ² is a C 6-18 divalent aromatic hydrocarbon group.)

The tetravalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ¹ is preferably a tetravalent aromatic hydrocarbon group having 6 to 12 carbon atoms.
Preferred examples of the tetravalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ¹ include the following aromatic hydrocarbon groups.

The divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by Z ^2, is preferably a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms.
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms Z ² represents, for example, aromatic hydrocarbon groups below are preferably exemplified.

  Examples of commercially available polyimide films include Ube Industries, Ltd., trade names: Upilex R, Upilex S, Upilex SGA, Toray DuPont Co., Ltd., trade names: Kapton H, Kapton V, Kapton E, Kapton EN, Kapton ENZT, Product name: Apical AH, Apical NPI, etc., manufactured by Kaneka Corporation. In order to improve the adhesion to the release layer, the surface of these commercially available films may be subjected to plasma treatment, corona discharge treatment or the like.

  What is necessary is just to select suitably according to the objective about the thickness of a polyimide film. From the viewpoint of the followability and peelability of the polyimide film, for example, 10 to 150 μm is preferable, 20 to 50 μm is more preferable, and 25 to 50 μm is more preferable.

  The surface roughness (Ra) of the polyimide film is, for example, preferably 0.2 μm or less, more preferably 0.1 μm or less from the viewpoint of improving the flatness of the molded body or laminated body after peeling. Further, it is preferably 0.08 μm or less. Here, “surface roughness of the polyimide film” indicates at least the surface roughness of the surface on the side where the release layer is formed.

  Since the polyimide film has a strength that does not thermally melt in a high temperature range, it is preferably used at, for example, 150 to 300 ° C., does not exhibit a clear glass transition temperature in the range, and further has a storage elastic modulus (10 Hz) of 1 GPa. Is preferably exceeded.

(Release layer)
The thickness of the release layer is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 5 μm, and still more preferably 0.05 to 2 μm. It exists in the tendency for favorable peelability to be acquired because the thickness of a mold release layer exists in the range of 0.01-10 micrometers. Moreover, it tends to be suppressed that the components of the release layer are transferred to the insulating layer after hot plate pressing, and adversely affect the peelability. Furthermore, there is a tendency that a decrease in heat resistance or the like of the insulating layer due to the transfer of the components of the release layer to the insulating layer can be suppressed.

  As a release agent for forming the release layer, for example, silicone (silicon (Si) polymer) -based resin, fluorine-based resin, polyolefin-based resin, alkyd-based resin, and the like can be preferably used. Moreover, it is also possible to add a lubricant, an antistatic agent, etc. in a release layer as needed. In the hot pressing process, static electricity is frequently generated, so it is preferable to add an antistatic agent. Alternatively, the antistatic layer may be formed by application to a surface on which no release layer is formed.

  The material for the release agent can be appropriately selected depending on the application. As an example, a silicone resin is preferable because it generates less harmful gas at the time of incineration, and a polydimethylsiloxane compound suitable for forming a thin film on the entire film is also preferable because the surface tension is easy to adjust. preferable.

  Further, as the mold release agent, a thermosetting resin is preferable in which the components of the mold release agent are transferred to the insulating layer during the hot press step and hardly adversely affect the peelability. Examples of the thermosetting resin include alkyd resins such as amino alkyd resins and silicone-containing amino alkyd resins.

  On the other hand, depending on applications, it may be preferable not to use a silicone resin. This is because when a silicone-based resin is used, the electrical characteristics may be affected by the transfer of the release agent component to the insulating layer during the hot press process. Therefore, the release agent in the present invention can be appropriately selected according to the required requirements.

  As a method for forming the release layer on at least one surface of the polyimide film, for example, there is a method of applying to the polyimide film using a reverse roll coater, a gravure coater, a rod coater, an air doctor coater or the like.

[Release polyimide film with adhesive layer]
The release polyimide film with an adhesive layer of the present invention has a release layer and an adhesive layer on the surface of the polyimide film, and the adhesive layer is a polyfunctional epoxy resin, an epoxy resin curing agent, and a phenolic hydroxyl group-containing polyamide resin. It contains. The polyimide film, the release layer, and the adhesive layer of the release polyimide film with an adhesive layer are preferably arranged in this order. That is, the release polyimide film with an adhesive layer of the present invention has a release layer on the surface of the polyimide film, and an adhesive layer on the surface of the release layer where the polyimide film is not provided, The adhesive layer contains a polyfunctional epoxy resin, an epoxy resin curing agent, and a phenolic hydroxyl group-containing polyamide resin.
In the present specification, “contains” means that the contained product does not react and is contained as it is, and at least a part of the contained product is contained in a reacted state. It means that it may be in any state.

(Adhesive layer)
The adhesive layer comprises a resin composition containing (A) a polyfunctional epoxy resin, (B) an epoxy resin curing agent, and (C) a phenolic hydroxyl group-containing polyamide resin (hereinafter referred to as an adhesive layer resin). Sometimes referred to as a composition). Here, the adhesive layer of the present invention exists in a semi-cured state (so-called B-stage state) on the release polyimide film before being made a part of a layer for a wiring board laminate or a single-layer or multilayer wiring board. It is preferable to do. Hereinafter, the epoxy resin, the epoxy resin curing agent, and the phenolic hydroxyl group-containing polyamide resin will be described.

As the (A) polyfunctional epoxy resin (hereinafter sometimes referred to as the component (A)), for example, an epoxy resin having two or more epoxy groups in the molecule is preferable. Examples of the epoxy resin include phenol novolac type epoxy resins, cresol novolac type epoxy resins, aralkyl type epoxy resins, naphthalene type epoxy resins, naphthalene novolak type epoxy resins and the like. Among these, as the polyfunctional epoxy resin, for example, an aralkyl novolac epoxy resin and a naphthalene novolac epoxy resin are preferable. Moreover, from the viewpoint of adhesive strength with plated copper, the polyfunctional epoxy resin of the adhesive layer preferably has, for example, a biphenyl structure.
These may be used alone or in admixture of two or more.
Among these, for example, an aralkyl novolak type epoxy resin having a biphenyl structure (biphenyl aralkyl type epoxy resin) is preferable. Examples of commercially available aralkyl novolak epoxy resins having a biphenyl structure include NC-3000 and NC-3000-H manufactured by Nippon Kayaku Co., Ltd.

  The blending amount of the component (A) is preferably 20 to 80% by mass and more preferably 40 to 70% by mass in the ratio of the resin composition for the adhesive layer. (A) When the compounding quantity of a component is 20-80 mass%, adhesive strength with a circuit conductor and solder heat resistance can be made into a favorable state.

As the (B) epoxy resin curing agent (hereinafter sometimes referred to as the component (B)) of the adhesive layer of the present invention, for example, various phenol resins, acid anhydrides, amines, hydragits and the like can be used. . As the phenol resins, for example, novolak type phenol resins, resol type phenol resins and the like can be used. As acid anhydrides, for example, phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl hymic acid and the like can be used. Examples of amines that can be used include dicyandiamide, diaminodiphenylmethane, and guanylurea.
These may be used alone or in admixture of two or more.
Among these, from the viewpoint of improving reliability, for example, a novolac type phenol resin is preferable.

  (B) It is preferable that the compounding quantity of a component is 0.5-1.5 equivalent with respect to the epoxy group of (A) component. (A) It is 0.5-1.5 equivalent with respect to the epoxy group of a component, prevents the adhesive fall with outer-layer copper, and prevents Tg (glass transition temperature) and insulation fall. There is a tendency to be able to.

In addition to the component (B), a curing accelerator can be used as necessary. As the curing accelerator, for example, various imidazoles which are latent thermosetting agents, BF ₃ amine complexes, phosphorus curing accelerators, and the like can be used.
It is preferable that the compounding quantity of a hardening accelerator is 0.1-5 mass% with respect to the compounding quantity of an epoxy resin.
From the viewpoint of storage stability of the adhesive layer resin composition, handling property of the B-stage (semi-cured) adhesive layer resin composition, and solder heat resistance, imidazoles and phosphorus curing accelerators are preferred.

  Examples of imidazoles include 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-ethyl-1-methylimidazole, 1, 2-diethylimidazole, 1-ethyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2 -Feni -4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 2,4-diamino-6 [2'-Methylimidazolyl- (1 ')] ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')] ethyl-s-triazine, 2,4-diamino Imidazole compounds such as -6- [2'-ethyl-4'-methylimidazolyl- (1 ')] ethyl-s-triazine; addition reaction product of the imidazole compound and trimellitic acid; the imidazole compound and isocyanuric acid Addition reaction product; addition reaction product of imidazole compound and hydrobromic acid; addition reaction product of imidazole compound and epoxy resin; imidazo Such as addition reaction product of an Le compounds and cyanate resins. Among these, 2-phenylimidazole and 2-ethyl-4-methylimidazole are preferable.

As a phosphorus hardening accelerator, the hardening accelerator which contains a phosphorus atom and accelerates | stimulates the hardening reaction of an epoxy resin is preferable. For example, a phosphorus curing accelerator may be used alone, or one or more other curing accelerators may be used in combination.
Examples of phosphorus curing accelerators include triphenylphosphine, diphenyl (alkylphenyl) phosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) phosphine, tris (alkylalkoxyphenyl) phosphine, and tris (dialkylphenyl) phosphine. , Tris (trialkylphenyl) phosphine, tris (tetraalkylphenyl) phosphine, tris (dialkoxyphenyl) phosphine, tris (trialkoxyphenyl) phosphine, tris (tetraalkoxyphenyl) phosphine, trialkylphosphine, dialkylarylphosphine, alkyl Organic phosphines such as diarylphosphine; complexes of these organic phosphines with organic borons; addition of tertiary phosphine and quinones Things and the like.
Furthermore, as the phosphorus-based curing accelerator, an adduct of a tertiary phosphine and a quinone that can exhibit high adhesiveness when the curing reaction of the adhesive layer resin composition proceeds sufficiently is more preferable. The third phosphine is not particularly limited. For example, dibutylphenylphosphine, butyldiphenylphosphine, ethyldiphenylphosphine, triphenylphosphine, tris (4-methylphenyl) phosphine, tris (4-methoxyphenyl) phosphine, etc. And a tertiary phosphine having an aryl group. Examples of quinones include o-benzoquinone, p-benzoquinone, diphenoquinone, 1,4-naphthoquinone, and anthraquinone. Further, in addition to adhesiveness, an adduct of triphenylphosphine and p-benzoquinone is more preferable from the viewpoints of heat resistance and storage stability.

  (C) A phenolic hydroxyl group-containing polyamide resin (hereinafter sometimes referred to as the component (C)) is necessary for obtaining good adhesive strength with the plated copper. The reason why such an effect is obtained is not necessarily clear, but the following reasons are conceivable. That is, since the phenolic hydroxyl group-containing polyamide resin can react with the epoxy resin, the resin tends to be toughened while maintaining good heat resistance of the epoxy resin. Furthermore, since it has many amide groups with high adhesiveness with copper, there exists a tendency for the high adhesive force with plated copper to be acquired.

Component (C) can be synthesized, for example, by the following method. That is, an equivalent amount of diamine is added to a dicarboxylic acid component containing a dicarboxylic acid having a phenolic hydroxyl group, and these are added, for example, by using a condensing agent in the presence of a phosphite ester and a pyridine derivative to form N-methyl- A polyamide resin containing a phenolic hydroxyl group can be produced by heating and stirring and condensing in an inert solvent such as nitrogen in an organic solvent such as 2-pyrrolidone.
The component (C) may be a copolymer of a phenolic hydroxyl group-containing polyamide and polybutadiene, or may be a copolymer of a phenolic hydroxyl group-containing polyamide and polybutadiene-acrylonitrile. Such a phenolic hydroxyl group-containing polyamide can be synthesized, for example, by the following method. That is, an excess amount of diamine is added to a dicarboxylic acid component containing a dicarboxylic acid having a phenolic hydroxyl group, and these are added, for example, by using a condensing agent in the presence of a phosphite ester and a pyridine derivative to form N-methyl. A polyamide oligomer containing a phenolic hydroxyl group is produced by heating and stirring and condensing in an inert solvent such as nitrogen in an organic solvent such as -2-pyrrolidone. As a result, polybutadiene or polybutadiene-acrylonitrile copolymer having a carboxyl group at both ends is added to the obtained phenolic hydroxyl group-containing polyamide oligomer solution in which both ends are amino groups, and can be obtained by polycondensation. it can. In addition, the dicarboxylic acid component is made excessive with respect to the diamine to synthesize the polyamide having both ends become carboxylic acid groups, and this is reacted with polybutadiene or polybutadiene-acrylonitrile copolymer having both ends amino groups. May be. Furthermore, the terminal of these polyamide, polybutadiene or polybutadiene-acrylonitrile copolymer can be modified and reacted. In this case, for example, one may be modified with a vinyl group and the other with an —NH group or —SH group. In the step of synthesizing the phenolic hydroxyl group-containing polyamide, a compound containing a phenolic hydroxyl group in part or all of the diamine may be used.

  In the above, polybutadiene having various functional groups at both ends is commercially available as Hycar CTB from Goodrich, for example, and polybutadiene-acrylonitrile copolymer is commercially available as Hycar CTBN from Goodrich, for example. It can be used to react with a phenolic hydroxyl group-containing polyamide oligomer.

Examples of the dicarboxylic acid having a phenolic hydroxyl group used when the component (C) is synthesized include hydroxyisophthalic acid such as 5-hydroxyisophthalic acid and 4-hydroxyisophthalic acid, 2-hydroxyphthalic acid, and 3-hydroxyphthalic acid. And the like, and hydroxyterephthalic acid such as 2-hydroxyterephthalic acid.
Examples of the dicarboxylic acid having no phenolic hydroxyl group used for synthesizing the component (C) include phthalic acid, isophthalic acid, terephthalic acid, dicarboxyl naphthalene, succinic acid, fumaric acid, glutaric acid, adipic acid, Examples include 1,3-cyclohexanedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 3,3′-methylenedibenzoic acid, and the like.
The dicarboxylic acid used when synthesizing the component (C) may be used alone or in combination of two or more.

Examples of the diamine containing a phenolic hydroxyl group used when the component (C) is synthesized include 3,3′-diamine-4,4′-dihydroxyphenylmethane, 2,2-bis (3-amino-4-). Hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) difluoromethane, 3,4-diamino-1,5-benzenediol, 3,3′-dihydroxy-4,4′-diamino Bisphenyl, 3,3′-diamino-4,4′-dihydroxybiphenyl, 2,2-bis (3-amino-4-hydroxyphenyl) ketone, 2,2-bis (3-amino-4-hydroxyphenyl) Sulfide, 2,2-bis (3-amino-4-hydroxyphenyl) ether, 2,2-bis (3-amino-4-hydroxyphenyl) sulfone, , 2-bis (3-amino-4-hydroxyphenyl) propane, 2,2-bis (3-hydroxy-4-aminophenyl) propane, 2,2-bis (3-hydroxy-4-aminophenyl) methane, etc. Is mentioned.
Examples of the diamine containing no phenolic hydroxyl group used for the synthesis of the component (C) include 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, and diaminonaphthalene. Piperazine, hexanetylenediamine, tetramethylenediamine, m-xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 2,2'-bis (4-aminophenyl) propane, 3,3 Examples include '-diaminodiphenylsulfone, 3,3'-diaminodiphenyl, 3,3', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, and the like.
Among these, for example, 3,4′-diaminodiphenyl ether and 3,3 ′, 5,5′-tetraethyl-4,4′-diaminodiphenylmethane are preferable.
(C) The diamine which can be used when synthesize | combining a component may be used individually or in mixture of 2 or more types.

Examples of commercially available phenolic hydroxyl group-containing polybutadiene-modified polyamide resins include BPAM-155 manufactured by Nippon Kayaku Co., Ltd.
Moreover, as a commercial item of a phenolic hydroxyl group containing polybutadiene-acrylonitrile copolymer modified polyamide resin, Nippon Kayaku Co., Ltd. BPAM-01 etc. are mentioned, for example.

  The blending ratio of the component (C) in the present invention is preferably 3 to 50 parts by mass and more preferably 3 to 30 parts by mass with respect to 100 parts by mass in total of the components (A) and (B). Preferably, it is 5-30 mass parts. (C) When the compounding quantity of a component is 3 mass parts or more, there exists a tendency for favorable adhesiveness with plated copper to be obtained. Moreover, in the case of 50 mass parts or less, there exists a tendency for favorable heat resistance and the tolerance to the chemical | medical solution at the time of a roughening process to be acquired.

You may mix | blend an inorganic filler with the resin composition for contact bonding layers of this invention. Examples of the inorganic filler include silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, Examples include strontium titanate, calcium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. Among these, fumed silica and alumina are preferable, for example.
These inorganic fillers may be used alone or in combination of two or more.
The inorganic filler can be appropriately selected depending on the purpose. From the viewpoint of forming fine wiring in the insulating layer, for example, the specific surface area is preferably 10 m ² / g or more.
The specific surface area is preferably determined by a measurement method usually performed by those skilled in the art. For example, BET method etc. are mentioned. This is a method in which molecules having a known adsorption occupation area are adsorbed on the surface of powder particles at the temperature of liquid nitrogen, and the specific surface area of the sample is obtained from the amount. In the specific surface area analysis, the BET method using an inert gas such as nitrogen is most often used.
Further, from the viewpoint of reducing the surface shape after the roughening treatment in the plating process, for example, the average primary particle size is preferably 100 nm or less.
The “average primary particle size” here refers to the average particle size of aggregated particles, that is, not the secondary particle size, but the average particle size of single particles that are not aggregated. The primary average particle diameter can be determined by measuring with a laser diffraction particle size distribution meter, for example.
Examples of commercially available inorganic fillers having an average primary particle size of 100 nm or less include AEROSIL R972 (trade name) and AEROSIL R202 manufactured by Nippon Aerosil Co., Ltd., PL-1 (trade name, ratio) manufactured by Fuso Chemical Industries, Ltd. Surface area 181 m ² / g) and PL-7 (trade name, specific surface area 36 m ² / g), CIK Nanotech Co., Ltd. A-6 (trade name, specific surface area 55 m ² / g). These inorganic fillers may be used by a known kneading and dispersing method such as a kneader, a ball mill, a bead mill, a three roll, a nanomizer and the like for the purpose of improving dispersibility.

  The inorganic filler may be surface-treated with a surface treatment agent such as a silane coupling agent in order to improve moisture resistance. Moreover, in order to improve dispersibility, it may be hydrophobized.

  As content of an inorganic filler, it is preferable that it is 10 mass% or less in the resin composition for contact bonding layers. When the blending amount is 10% by mass or less, a good surface shape after the roughening treatment can be maintained, and deterioration of plating characteristics and interlayer insulation reliability can be prevented.

You may mix | blend an organic filler with the resin composition for contact bonding layers of this invention. Examples of organic fillers include resin particles having a uniform structure made of polyethylene, polypropylene, polystyrene, polyphenylene ether resin, silicone resin, tetrafluoroethylene resin, acrylate ester resin, methacrylate ester resin, and conjugated diene resin. And a core-shell resin particle having a glassy shell layer made of an acrylic ester resin, a methacrylic ester resin, an aromatic vinyl resin, a vinyl cyanide resin, etc. Can be mentioned.
The content of the organic filler is, for example, preferably 0.5 to 10 parts by mass and more preferably 1 to 8 parts by mass with respect to 100 parts by mass of the total resin components.

  In the resin composition for an adhesive layer in the present invention, various additives such as a thixotropic agent, a surfactant, a coupling agent and the like used in a normal resin composition can be appropriately blended. After sufficiently stirring these, the resin composition for the adhesive layer can be obtained by standing until the bubbles disappear.

The adhesive layer resin composition in the present invention is preferably mixed in a solvent and diluted or dispersed to form a varnish from the viewpoint of workability. Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; aromatic solvents such as xylene and toluene; ethylene glycol monoethyl ether alcohol solvents; ester solvents such as ethyl ethoxypropionate; Nitrogen atom-containing solvents such as N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like can be mentioned. These solvents may be used alone or in combination of two or more.
These organic solvents are appropriately selected from the viewpoint of the solubility of the resin and the appearance after coating. Among these, a nitrogen atom-containing solvent is preferable.
The ratio of the solvent to the resin composition for the adhesive layer is appropriately adjusted according to the equipment for forming the coating film of the resin composition for the adhesive layer. For example, the solid content of the resin composition excluding the solvent is 8 to 40 in the varnish. It is preferable to adjust the amount of the solvent used so as to be mass%.

  The adhesive layer is obtained by applying a resin composition for an adhesive layer (or a varnish containing the same) on a release polyimide film and drying it. The method for applying the adhesive layer resin composition to the release polyimide film is not particularly limited. For example, a reverse coater, a gravure coater, an air doctor coater, a die coater, a lip coater or the like may be used. it can. Also, the drying conditions are not particularly limited. For example, the drying can be performed at 80 to 230 ° C. for 30 to 600 seconds.

  Here, when the adhesive layer of the present invention is laminated with a B-stage prepreg or the like and reacted, it is important to control the degree of curing. The degree of cure can be measured by the reaction rate measured from a differential scanning calorimeter. At that time, the reaction rate of the adhesive layer is preferably 50 to 99%. By setting it to 50% or more, it is possible to prevent the adhesive layer from being mixed with the prepreg during lamination and curing. By setting it as 99% or less, it can suppress that the adhesive force of the interface with a prepreg falls, and the adhesive force with plated copper falls.

  The prepreg is not particularly limited as long as it is for a wiring board, and a commercially available product can also be used. As a commercial item, Hitachi Chemical Co., Ltd. product GEA-67N, GEA-679F, GEA-679GT, GEA-700G (R), GEA-705G etc. are mentioned, for example.

  Further, when the release polyimide film with an adhesive layer of the present invention is applied to a laminate for a wiring board or a single layer or a multilayer wiring board as described later, the surface of the insulating layer (adhesive layer after thermosetting) is roughened. Processing is performed. The surface roughness (Ra) of the insulating layer after the roughening treatment is preferably 0.3 μm or less, and more preferably 0.2 μm or less. When the surface roughness (Ra) is 0.2 μm or less, it is possible to sufficiently cope with the higher density of the semiconductor package. In addition, the roughening process conditions demonstrated later can be applied to the conditions of a roughening process.

[Laminate with Release Polyimide Film with Adhesive Layer, Laminate by Exfoliating Release Polyimide Film of Laminate, Single or Multilayer Wiring Board with Release Polyimide Film with Adhesive Layer, and Manufacturing Method of Multilayer Wiring Board]
The laminated board with a release polyimide film with an adhesive layer of the present invention is formed by laminating the adhesive layer side of the release polyimide film with an adhesive layer on at least one surface of a prepreg or an insulating layer.

The laminated plate with a release polyimide film with an adhesive layer of the present invention is obtained by stacking a release polyimide film with an adhesive layer on one or both sides of a prepreg or an insulating layer so that the adhesive layer is on the inside, and further stacking an end plate on the outside. Can be press-molded and manufactured.
Moreover, the laminated board with a release polyimide film with an adhesive layer of the present invention is formed by, for example, stacking a release polyimide film with an adhesive layer on one side or both sides of a prepreg or an insulating layer so that the adhesive layer is on the inside. It can be manufactured by heating and pressurizing with a laminator using a sheet and then heating and curing after the lamination.

The heating temperature (temperature of the hot plate) in the press molding is preferably 150 to 260 ° C. The pressure during pressurization is preferably 0.5 to 10 MPa. Moreover, it is preferable that the heating temperature in the laminator using a heat resistant rubber sheet shall be 80-150 degreeC. The pressure during pressurization is preferably 0.3 to 10 MPa.
In any method, after the lamination molding, the release polyimide film can be appropriately peeled off to obtain a laminate.

The single-layer or multilayer wiring board with the release polyimide film (release polyimide film with an adhesive layer) of the present invention is laminated on one side of the prepreg or insulating layer of the release polyimide film with an adhesive layer, The other surface of the prepreg or insulating layer is laminated on a single-layer or multilayer wiring board formed by circuit processing. Any of the prepregs may be a prepreg before curing, or may be a prepreg that is at least partially cured.
Here, “being circuit-processed” includes a case where a process that can be normally performed in the manufacture of a wiring board is performed after the circuit is processed. Specifically, after the circuit is processed, plating is performed. Including cases where processing is performed. A single-layer wiring board refers to a wiring board having a single circuit layer when a prepreg or insulating layer is laminated on only one side, and when a prepreg or insulating layer is laminated on both sides. Each of the wiring boards has one circuit layer (that is, a total of two circuit layers). On the other hand, a multilayer wiring board is a core on which at least one surface is processed, and at least one prepreg or insulating layer is laminated on the surface of the core on which the circuit is processed. The circuit is processed on the layer.
The present invention further includes a step of forming a single layer or a multilayer wiring board with a release polyimide film with an adhesive layer by laminating the release polyimide film with an adhesive layer on a single layer or a multilayer wiring board, an adhesive layer after formation There is also provided a method for producing a multilayer wiring board, which comprises a step of removing the release polyimide film from the single-layer or multilayer wiring board with attached release polyimide film and a step of circuit processing.

The multilayer wiring board of the present invention can be manufactured as follows, for example.
A release polyimide film with an adhesive layer is laminated on a prepreg or an insulating layer so that the adhesive layer is on the inside, and a single layer or a circuit layer is formed on the surface opposite to the surface on which the adhesive layer of the prepreg or the insulating layer is superimposed Overlay the multilayer wiring board. At this time, an adhesive layer may be overlapped on both surfaces of a single-layer or multilayer wiring board obtained by circuit processing using two prepregs or insulating layers. Further, a mirror plate is stacked on the outside and press-molded. After the molding, the polyimide film is removed, and circuit processing is performed by sequentially performing roughening treatment, electroless plating treatment, resist formation, electroplating treatment, etc. It can be manufactured by applying a plating treatment.

In addition, the multilayer wiring board of the present invention can be manufactured as follows, for example.
A release polyimide film with an adhesive layer is laminated on a prepreg or an insulating layer so that the adhesive layer is on the inside, and a single layer or a circuit layer is formed on the surface opposite to the surface on which the adhesive layer of the prepreg or the insulating layer is superimposed At this time, two prepregs or insulating layers may be used to overlap both sides of a single-layer or multilayer wiring board that has been subjected to circuit processing. And it is laminated by heating and pressurizing with a laminator using a heat-resistant rubber sheet, heating and curing after lamination, removing the support, roughening treatment, electroless plating treatment, resist formation, electroplating treatment, etc. Can be manufactured by performing circuit processing by sequentially applying, and further performing plating treatment as necessary.

  Here, as a material of the prepreg and the insulating layer used in the method for manufacturing a multilayer wiring board of the present invention, a generally used material that is not particularly limited can be applied. For example, a polyfunctional epoxy resin, an epoxy resin curing agent, a curing accelerator, a solvent and, if necessary, a mixture of inorganic fillers may be used as the material for the insulating layer, and the glass cloth for laminated plates may be impregnated or A prepreg obtained by coating may be used. A commercial item can also be used as a prepreg, As a commercial item, Hitachi Chemical Co., Ltd. product GEA-67N, GEA-679F, GEA-679GT, GEA-700G etc. are mentioned, for example.

  The inner layer circuit board in the multilayer wiring board formed by the circuit processing is, for example, an inner layer substrate having a first circuit layer (inner layer wiring) formed on the surface thereof, and is used in an ordinary wiring board as the inner layer substrate. Known laminates such as glass cloth-epoxy resin, paper-phenolic resin, paper-epoxy resin, glass cloth or glass paper-epoxy resin can be used without any particular limitation. Further, a BT substrate impregnated with a bismaleimide-triazine resin, a polyimide film substrate using a polyimide film as a base material, and the like can also be used.

  There is no particular limitation on the method for forming the circuit. For example, a known wiring board manufacturing method such as a semi-additive method in which a circuit is formed using a plating process or an additive method in which a circuit is formed by electroless plating at a necessary portion of an insulating substrate can be used.

When a circuit is processed by a plating process on the adhesive layer of the laminate or multilayer wiring board of the present invention, first, roughening is performed. Examples of the roughening liquid in this case include an oxidizing roughening liquid such as a chromium / sulfuric acid roughening liquid, an alkaline permanganic acid roughening liquid, a sodium fluoride / chromium / sulfuric acid roughening liquid, and a borofluoric acid roughening liquid. Can be used. As the roughening treatment, for example, as a swelling liquid, an aqueous solution of diethylene glycol monobutyl ether and NaOH is first heated to 70 ° C., and the laminate or single layer or multilayer wiring board is immersed for 5 minutes. Next, as a roughening solution, an aqueous solution of KMnO ₄ and NaOH is heated to 80 ° C. and immersed for 10 minutes. Subsequently, neutralizing solution, for example, a method of neutralizing by immersion for 5 minutes at room temperature to an aqueous hydrochloric acid solution of stannous chloride (SnCl ₂₎ and the like.

After the roughening treatment, a plating catalyst application treatment for adhering palladium is performed. The plating catalyst treatment is performed by immersing in a palladium chloride plating catalyst solution. Next, an electroless plating treatment is performed by immersing in an electroless plating solution to deposit an electroless plating layer (conductor layer) having a thickness of 0.3 to 1.5 μm on the entire surface of the plating process primer layer.
Next, after forming a plating resist, electroplating is performed to form a circuit with a desired thickness at a desired location. As the electroless plating solution used for the electroless plating treatment, a known electroless plating solution can be used, and there is no particular limitation. As the plating resist, a known plating resist can be used, and there is no particular limitation. Also, the electroplating treatment can be performed by a known method and is not particularly limited. These platings are preferably copper platings. Furthermore, the outer layer circuit can be formed by etching away the electroless plating layer at unnecessary portions.

  If necessary, the surface of the circuit layer is surface-treated in a state suitable for adhesion, but this method is not particularly limited. For example, a copper oxide needle crystal is formed on the surface of the circuit layer 1 with an alkaline aqueous solution of sodium hypochlorite, and the formed copper oxide needle crystal is immersed in a dimethylamine borane aqueous solution for reduction. Manufacturing methods can be used.

  Thereafter, a multilayer wiring board having a large number of layers can be manufactured by repeating the same process.

[Preparation of resin varnish for adhesive layer]
(Preparation Example 1)
After adding 6.75 g of N-methyl-2-pyrrolidone (NMP) to 0.75 g of phenolic hydroxyl group-containing polybutadiene-modified polyamide (Nippon Kayaku Co., Ltd., trade name: BPAM-155), biphenylaralkyl type epoxy resin (Nippon Kayaku Co., Ltd., trade name: NC-3000H) 10 g, Cresol novolak type phenolic resin (DIC Corporation, trade name: KA-1165) 4.1 g, and further 2-phenylimidazole (Shikoku) as a curing accelerator After adding 0.1 g of Kasei Kogyo Co., Ltd., trade name: 2PZ), it was diluted with a mixed solvent consisting of NMP to obtain a resin varnish A for adhesive layer (solid content concentration of about 25% by mass).

(Preparation Example 2)
After blending 13.5 g of N, N-dimethylacetamide (DMAc) with 1.5 g of phenolic hydroxyl group-containing polybutadiene-acrylonitrile modified polyamide (manufactured by Nippon Kayaku Co., Ltd., trade name: BPAM-01), biphenylaralkyl type epoxy 10 g of resin (made by Nippon Kayaku Co., Ltd., trade name: NC-3000H), 3.6 g of novolak type phenol resin (made by DIC, trade name: TD-2090), 2-phenylimidazole (Shikoku Chemicals) as a curing accelerator Industrial Co., Ltd., trade name: 2PZ) 0.1 g was added with fumed silica (Nippon Aerosil Co., Ltd., trade name: R972) 0.9 g, and then diluted with a mixed solvent consisting of DMAc and methyl ethyl ketone (solid) Concentration of about 25% by weight). Then, the resin varnish B for contact bonding layers was obtained using the disperser (The product name: Nanomizer by Yoshida Kikai Kogyo Co., Ltd.).

(Preparation Example 3)
After adding 6.75 g of DMAc to 0.75 g of phenolic hydroxyl group-containing polybutadiene-modified polyamide (manufactured by Nippon Kayaku Co., Ltd., trade name: BPAM-155), biphenylaralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product) Name: NC-3000H) 10 g, Bisphenol A novolak (Mitsubishi Chemical Co., Ltd., trade name: YLH129) 4.1 g, and 2-phenylimidazole (Shikoku Kasei Kogyo Co., Ltd., trade name: 2PZ) 0 as a curing accelerator After adding 1 g, it was diluted with a mixed solvent consisting of DMAc to obtain a resin varnish C solid content concentration of adhesive layer of about 25% by mass).

Example 1
・ Release polyimide film with adhesive layer:
Upilex 25SGA (trade name, thickness 25 μm, surface roughness Ra 0.05 μm or less) manufactured by Ube Industries, Ltd. was used as the polyimide film. On this polyimide film, a silicone-containing aminoalkyd resin (manufactured by Hitachi Chemical Co., Ltd., trade name: Tesfine 319) is diluted with methyl ethyl ketone and toluene (methyl ethyl ketone: toluene = 3: 7) to 2.5%, The prepared preparation solution was applied using a die coater and dried at 160 ° C. for 40 seconds to obtain a release layer having a thickness of 0.2 μm.
An adhesive layer varnish A is applied to the release layer surface of the obtained polyimide film with a release layer, dried at 180 ° C. for 5 minutes to form an adhesive layer with a thickness of 5 μm, and a release polyimide film with an adhesive layer is formed. Got.

・ Laminated board:
4 sheets of prepreg (Hitachi Chemical Co., Ltd., trade name: GEA-700G, 0.10 mm thickness) are stacked, and the upper and lower layers are stacked so that the polyimide film surface of the release polyimide film with the adhesive layer is on the outside. And the cushion paper was piled up, and it heat-cured at 3.0 MPa and 240 degreeC for 1 hour using the press machine, and obtained the laminated board.

(Example 2)
Example 1 except that Kapton 100H (trade name, thickness 38 μm, surface roughness Ra 0.05 μm or less) manufactured by Toray DuPont Co., Ltd. was used as the polyimide film, and adhesive layer varnish B was used as the adhesive layer varnish. Similarly, a release polyimide film with adhesive layer and a laminate were obtained.

(Example 3)
As in Example 1, except that a preparation liquid of amino alkyd resin (manufactured by Hitachi Chemical Co., Ltd., trade name: Tessfine 303) was used as the release layer, and the adhesive layer varnish B was used as the adhesive layer varnish. A release polyimide film with adhesive layer and a laminate were obtained.

(Comparative Example 1)
A laminated board was obtained in the same manner as in Example 1 except that a polyimide film having no release layer and no adhesive layer was used instead of the release polyimide film with an adhesive layer in Example 1.

(Comparative Example 2)
A polyimide film with an adhesive layer and a laminate are obtained in the same manner as in Example 1 except that a polyimide with an adhesive layer that does not have a release layer is used instead of the release polyimide film with an adhesive layer of Example 1. It was.

(Comparative Example 3)
A release polyimide film and a laminate were obtained in the same manner as in Example 1 except that a release polyimide film having no adhesive layer was used instead of the release polyimide film with an adhesive layer of Example 1.

(Comparative Example 4)
In place of the release polyimide film of Example 1, a release polyethylene terephthalate film (manufactured by Unitika Ltd., trade name: Unipeel TR1, thickness 38 μm) was used in the same manner as in Example 1 to release with an adhesive layer. A mold film and a laminate were obtained.

As described above, in order to chemically roughen the laminates obtained in Examples and Comparative Examples, an aqueous solution of diethylene glycol monobutyl ether: 200 ml / L, NaOH: 5 g / L was prepared as a swelling liquid and heated to 70 ° C. For 5 minutes. Next, an aqueous solution of KMnO ₄ : 60 g / L and NaOH: 40 g / L was prepared as a roughening solution, heated to 80 ° C. and immersed for 10 minutes. Subsequently, it was neutralized by immersing in an aqueous solution of a neutralizing solution (SnCl ₂ : 30 g / L, HCl: 300 ml / L) at room temperature for 5 minutes.

In order to form a circuit layer to the adhesive layer-laminated plate, which is the electroless plating catalyst containing PdCl ₂ HS-202B (manufactured by Hitachi Chemical Co., Ltd.) was immersed at room temperature -10 minutes, washed with water, electroless It was immersed in a plating solution CUST-201 (manufactured by Hitachi Chemical Co., Ltd.) for copper plating at room temperature for 15 minutes, and further subjected to copper sulfate electrolytic plating. Thereafter, annealing was performed at 180 ° C. for 60 minutes to form a circuit layer having a thickness of 35 μm.
Next, in order to remove unnecessary portions of the plating conductor by etching, first, the oxide film on the copper surface is removed by polishing with # 600, followed by forming an etching resist, then etching, and then removing the etching resist. Then, a circuit was formed to produce a single-layer wiring board with an adhesive layer.

  About the single layer wiring board produced as mentioned above, the peelability after a press, the adhesive strength with an outer layer circuit, and the surface roughness of the insulating layer (adhesive layer after a press) were implemented as follows. The results are shown in Table 1.

[Peelability after pressing]
When the release film was peeled from the pressed laminate, it was visually confirmed whether or not the release film was peeled off at the interface between the release layer and the insulating layer.
A: Easy peeling at the interface.
C: It cannot peel easily at the interface.
The phrase “cannot be easily peeled at the interface” means a case where peeling is not possible, or a case where the resin composition of the adhesive layer is adhered to the release film after peeling.

[Adhesive strength with circuit layer]
A part having a width of 10 mm and a length of 100 mm is formed on a part of the circuit layer of the single-layer wiring board obtained in each example and comparative example by copper etching, and one end thereof is peeled off at the circuit layer / insulating layer interface. The load was measured when the workpiece was grasped with a grasping tool and pulled in the vertical direction at a pulling speed of about 50 mm / min at room temperature.

[Insulation layer surface roughness]
The insulating layer surface obtained by etching the circuit layer of the single-layer wiring board obtained in each Example and Comparative Example was measured using a high-precision three-dimensional surface shape roughness measurement system (Veeco, WYKONT 9100) as follows. Surface roughness Ra (μm) was measured under the conditions.
Measurement conditions Internal lens: 1x External lens: 50x Measurement range: 0.125 x 0.095mm
Measurement depth: 10 μm
Measurement method: Vertical scanning type interference method (VSI method)

From Table 1, the characteristics of the release polyimide film with adhesive layer and the laminate with adhesive layer of the present invention can be easily peeled off after high temperature hot plate pressing, as shown in Examples 1-3. A flat insulating layer surface could be obtained. Moreover, it has high adhesive strength with copper, and the surface roughness after copper etching is also low.
On the other hand, when the polyimide film which does not have the mold release agent of Comparative Examples 1-2 is used, a polyimide film cannot be peeled after pressing. In Comparative Example 4 using a film other than the polyimide film, the polyethylene terephthalate film was fused to the end plate, the release film could not be easily peeled off, and a flat insulating layer surface could not be obtained. Furthermore, in Comparative Example 3, it was confirmed that the adhesive strength with copper was low.

  The release polyimide film with an adhesive layer of the present invention can be effectively used as a release film with an adhesive layer when a multilayer wiring board is produced by a molding method using a hot plate press, a roll laminator, a double press or the like.

Claims (9)

  On the surface of the polyimide film, it has a release layer and an adhesive layer, and the adhesive layer contains a polyfunctional epoxy resin, an epoxy resin curing agent and a phenolic hydroxyl group-containing polyamide resin, and contains the phenolic hydroxyl group. A release polyimide film with an adhesive layer, wherein the polyamide resin is a phenolic hydroxyl group-containing polybutadiene-modified polyamide or a phenolic hydroxyl group-containing polybutadiene-acrylonitrile-modified polyamide.   The release polyimide film with an adhesive layer according to claim 1, wherein the release layer has a thickness of 0.01 to 10 μm.   The release polyimide film with an adhesive layer according to claim 1 or 2, wherein the polyimide film has a thickness of 10 to 150 µm. 4. The release polyimide film with an adhesive layer according to claim 1, wherein a surface roughness (Ra) of a surface of the polyimide film on which the release layer is formed is 0.2 μm or less. 5. .   The release polyimide film with an adhesive layer according to any one of claims 1 to 4, wherein the release layer contains an alkyd resin.   Lamination with a release polyimide film with an adhesive layer formed by laminating the adhesive layer side of the release polyimide film with an adhesive layer according to any one of claims 1 to 5 on at least one surface of a prepreg or an insulating layer. Board.   The laminated board formed by peeling the mold release polyimide film of the laminated board of Claim 6.   The adhesive layer side of the release polyimide film with an adhesive layer according to any one of claims 1 to 5 is laminated on one surface of the prepreg or the insulating layer, and the other surface of the prepreg or the insulating layer is subjected to circuit processing. A single layer or multilayer wiring board with a release polyimide film with an adhesive layer, which is laminated on a single layer or multilayer wiring board.   A single-layer or multilayer wiring board with a release polyimide film with an adhesive layer is formed by laminating the release polyimide film with an adhesive layer according to any one of claims 1 to 5 on a single-layer or multilayer wiring board. The manufacturing method of a multilayer wiring board which has the process, the process of removing a release polyimide film from the single layer with a release polyimide film with an adhesive layer after formation, or a multilayer wiring board, and the process of a circuit.