JP5133724B2 - Method for producing polyimide resin laminate and method for producing metal-clad laminate - Google Patents

Description

  The present invention relates to a film-like or layer-like polyimide resin laminate having an adhesive layer and a method for producing a metal-clad laminate in which a metal layer is laminated on the surface thereof. This metal-clad laminate is suitable for printed wiring boards.

  In an electronic circuit of an electronic device, a printed wiring board obtained by processing a laminated board made of an insulating material and a conductive material is used. A printed wiring board is formed by fixing a conductive pattern based on electrical design on the surface (and inside) of an insulating substrate with a conductive material. It is roughly divided into a board and a flexible printed wiring board which is rich in flexibility. The flexible printed wiring board is characterized by having flexibility, and is a necessary part for connection in a movable part that constantly bends. In addition, since the flexible printed wiring board can be stored in a bent state in an electronic device, it is also used as a space-saving wiring material. In a flexible substrate as a material for a flexible printed wiring board, polyimide ester or polyimide resin is often used as an insulating resin as a base material, but the amount of heat-resistant polyimide resin is overwhelmingly large. On the other hand, copper foil is generally used as the conductive material from the viewpoint of conductivity.

  The flexible substrate includes a three-layer flexible substrate and a two-layer flexible substrate because of its structure, and is a metal-clad laminate having a conductive material layer such as a copper foil layer and an insulating material layer such as a polyimide resin layer. A three-layer flexible substrate is made by bonding a base film such as polyimide and a copper foil with an adhesive such as an epoxy resin or an acrylic resin to form a base film layer (main layer of an insulating resin layer), an adhesive layer, and a copper foil layer. Composed of layers. On the other hand, the two-layer flexible substrate is a laminated board composed of two layers, a base film layer and a copper foil layer, using a special construction method without using an adhesive. Since the two-layer flexible substrate does not include an adhesive layer with low heat resistance such as an epoxy resin or an acrylic resin, the two-layer flexible substrate has high reliability, and the entire circuit can be thinned, and the amount of use is increasing. On the other hand, from a different viewpoint, the base film layer of the flexible substrate is desired to have a low thermal expansion coefficient in order to prevent curling, but a polyimide resin having a low thermal expansion coefficient is inferior in adhesiveness. When using all the polyimide resin without using an adhesive, it was necessary to provide a good adhesion polyimide resin layer as an adhesion-imparting layer on the adhesive surface side. A flexible substrate having a copper foil layer on both sides is also known. After manufacturing a single-sided flexible substrate having a copper foil layer on one side, a method of stacking two flexible substrates on top of each other or copper on a single-sided flexible substrate A method of laminating and stacking foils is known.

  In recent years, there is an increasing demand for higher performance and higher functionality in electronic devices, and accordingly, higher density of printed wiring boards, which are circuit board materials used in electronic devices, is desired. In order to increase the density of the printed wiring board, it is necessary to reduce the width and interval of the circuit wiring, that is, to make the pitch finer, and at the same time, dimensional stability during circuit processing is also required. Further, the etching accuracy at the time of etching of the polyimide resin layer is not an exception, and the requirements for the processing shape after etching are severe. In general, the thermoplastic polyimide used as the adhesive layer differs from the low thermal expansion polyimide, which is the base of the polyimide resin layer, in properties such as dissolution rate (etching rate) with an alkali treatment solution, etc. There arises a problem that an undercut occurs or the adhesive layer remains in a hook shape.

  In order to solve these problems, a material in which the thickness of the thermoplastic polyimide layer, which is an adhesive layer, is reduced is proposed. For example, in Japanese Unexamined Patent Publication No. 2006-190824 (Patent Document 1), the thickness of a polyimide layer in contact with a conductor is set to 2.0 μm in order to prevent wiring sinking when an IC chip is mounted in a COF (chip on film) manufacturing process. The following laminates have been proposed. On the other hand, a method has been proposed in which the thickness ratio of the thermoplastic polyimide in the outermost layer of the non-thermoplastic polyimide is defined to control overetching or undercut during wet etching (Patent Document 2). However, in these methods, since it is necessary to pay sufficient attention to the etching rate of non-thermoplastic polyimide and thermoplastic polyimide, it is difficult to accurately control the etching shape including overetching and undercutting. Moreover, in order to improve the etching shape at the time of the etching process of a polyimide resin layer, the material which made the polyimide resin layer the single layer is proposed (patent document 3). However, such a polyimide resin layer has a thermoplastic polyimide as a base layer, and its thermal expansion coefficient is larger than that of metal, so that it has been difficult to control the dimensional stability of the material.

JP-A-2006-190824 Japanese Patent Laid-Open No. 2005-111858 Japanese Patent Laid-Open No. 2004-276413

  In addition, as a method for forming a polyimide resin layer having an adhesive layer, a precursor solution of a non-thermoplastic polyimide resin is applied on a substrate and dried, and a precursor solution of a thermoplastic polyimide resin is applied thereon and dried. However, a method of curing is conventionally known, and for example, disclosed in Patent Document 1. In this case, the thermoplastic polyimide resin layer becomes the adhesive layer, but a thickness of a certain level or more is necessary to give the desired adhesiveness, and as a result, the problem of the etching shape or the like occurs as described above.

  The present invention provides an adhesive layer having features such as forming a specific adhesive layer on a polyimide resin layer to provide high adhesion to a metal layer and excellent polyimide etching shape. The manufacturing method of the polyimide resin layer which has this is provided. Another object of the present invention is to provide a metal-clad laminate that can cope with an extremely thin insulating resin layer while ensuring sufficient adhesive strength to meet the fine pitch of printed circuit boards. Another object is to provide a method for producing a double-sided metal-clad laminate.

  In order to achieve the above-mentioned object, the present inventors have studied, and by appropriately improving the formation of the adhesive layer of the polyimide resin layer, the polyimide resin layer using this has an adhesive strength with the metal layer. And the inventors have found that it is easy to control the shape during polyimide etching and have completed the present invention.

That is, the present invention includes the following steps I) to III),
I) A step of applying a polyamic acid solution and drying to form a layer which becomes a low thermal expansion polyimide resin layer (X) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K). ,
II) The precursor resin (A ′) of the non-thermoplastic polyimide resin (A) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K ) and the glass transition temperature in the range of 200 to 320 ° C. A mixed solution containing a precursor resin (B ′) of a certain thermoplastic polyimide resin (B), the precursor resin (A ′) with respect to a total of 100 parts by weight of the precursor resins (A ′) and (B ′) ) Is applied to a mixed solution containing 30 to 85 parts by weight and dried to form an adhesive layer (Y) having a thickness in the range of 0.1 to 3.0 μm, and
III) a step of imidizing to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y). After performing Steps I) and II) in any order, Step III) It is the manufacturing method of the polyimide resin laminated body which has an adhesive layer in the at least single side | surface of the low thermal expansion polyimide resin layer characterized by performing. Here, the value which remove | divided the thickness of the low thermal expansion polyimide resin layer (X) by the thickness of the adhesive layer (Y) exists in the range of 1-40.

The present invention also includes the following steps a) to d),
a) A layer which becomes a low thermal expansion polyimide resin layer (X) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the substrate and drying. Forming a process,
b) On the layer that becomes the low thermal expansion polyimide resin layer (X), a precursor resin (A ′) of a non-thermoplastic polyimide resin (A) and a precursor resin (B) of a thermoplastic polyimide resin (B) A mixed solution containing 30) to 85 parts by weight of the precursor resin (A ') with respect to a total of 100 parts by weight of the precursor resins (A') and (B ') and dried. And forming a layer to be an adhesive layer (Y) having a thickness in the range of 0.1 to 3.0 μm,
c) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y); and
d) a step of superimposing a metal foil on the surface of the adhesive layer (Y) and thermocompression bonding, or a step of depositing a metal thin film layer on the surface of the adhesive layer (Y),
It is a manufacturing method of the metal-clad laminated board characterized by providing.

Furthermore, the present invention provides the following steps f) to h),
f) On the metal foil, applying the mixed solution and drying to form a layer to be the adhesive layer (Y),
g) A low thermal expansion coefficient having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the layer to be the adhesive layer (Y) and drying it. Forming a layer to be the polyimide resin layer (X), and
h) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y);
It is a manufacturing method of the metal-clad laminated board characterized by providing.

Furthermore, the present invention provides the following steps i) to m),
i) A step of forming a layer to be the adhesive layer (Y) by applying and drying the mixed solution on the metal foil,
j) A low thermal expansion coefficient having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the adhesive layer (Y) and drying it. Forming a layer to be the polyimide resin layer (X) of
k) Furthermore, the mixed solution is applied onto the layer to be the low thermal expansion polyimide resin layer (X) and dried to form an adhesive layer (Y having a thickness in the range of 0.1 to 3.0 μm). A step of forming a layer to be)
l) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y); and
m) a step of superimposing a metal foil on the surface layer of the adhesive layer (Y) and thermocompression bonding; or e) a step of depositing a metal thin film layer on the surface layer of the adhesive layer (Y). It is a manufacturing method of a metal-clad laminate.

A preferred embodiment of the present invention will be described below.
1) A method for producing a polyimide resin laminate as described above, wherein Step II), Step I), Step II), and then Step III) are performed.
2) The manufacturing method of said polyimide resin laminated body whose linear thermal expansion coefficient of a non-thermoplastic polyimide resin (A) is the range of 1-30 (x10 < ^-6 > / K).
3) The manufacturing method of said polyimide resin laminated body whose glass transition temperature of a thermoplastic polyimide resin (B) is the range of 200-320 degreeC.
4) The above polyimide resin laminate in which the precursor resin (A ′) of the non-thermoplastic polyimide resin (A) is the same kind as the polyamic acid used to form the low thermal expansion polyimide resin layer (X). Manufacturing method.

  According to the present invention, it is possible to provide high adhesion between the polyimide resin layer and the metal layer, and it is possible to prevent the occurrence of undercut or hook-like etching residue during polyimide etching. It becomes possible to provide. Moreover, the adhesive layer obtained by this invention can suppress the malfunction by generation | occurrence | production of foaming under high temperature heating. Furthermore, in the production method of the present invention, a special resin raw material or special resin synthesis is not required, a conventionally known inexpensive resin raw material can be used, and a high-performance adhesive layer can be obtained by simply mixing the resin. Therefore, its industrial value is high.

  Hereinafter, the present invention relating to a method for producing a polyimide resin laminate having an adhesive layer will be described, and then the present invention relating to a method for producing a metal-clad laminate will be explained, but common parts will be explained simultaneously.

  The polyimide resin laminate having an adhesive layer obtained by the production method of the present invention has an adhesive layer (Y) on at least one surface of the low thermal expansion polyimide resin layer (X). The adhesive layer (Y) is also composed of a polyimide resin layer, but has higher adhesiveness than the polyimide resin layer (X). The polyimide resin laminate having an adhesive layer is advantageously a polyimide resin layer or film, and in the case of a polyimide resin layer, a metal foil, a substrate such as a resin film, or a protective film such as a release film Can be present on top of or in between.

  Hereinafter, the polyimide resin laminate having an adhesive layer obtained by the production method of the present invention is sometimes referred to as a polyimide resin laminate or a laminate. The polyimide resin layer (X) and the adhesive layer (Y) are also collectively referred to as an insulating resin layer. Polyamic acid is a polyimide resin precursor, but in order to distinguish between the polyimide resin precursor forming the polyimide resin layer (X) and the polyimide resin precursor forming the adhesive layer (Y), the former It is called polyamic acid only when referring only to the precursor. Since the polyimide resin and its precursor are in the relationship between the product and the precursor, the structure of the other can be understood by explaining one of them.

  The aspect of the polyimide resin laminate having an adhesive layer is not particularly limited, and may be a film or an isolated film or sheet. Moreover, the thing of the state laminated | stacked on base materials, such as metal foil, a glass plate, and a resin film, may be sufficient. The base material here refers to a sheet-like resin on which a polyimide resin layer is laminated (either a polyimide resin or a laminate on which a resin is laminated), a metal foil, or the like. The total thickness of the polyimide resin layer having an adhesive layer is in the range of 3 to 100 μm, preferably 3 to 50 μm. A polyimide resin laminate having an adhesive layer can be expressed as X / Y, Y / X / Y, X / Y / as the layer structure if the polyimide resin layer (X) is represented by X and the adhesive layer (Y) is represented by Y. It can take a structure such as X / Y. However, it has at least one X / Y layer structure on the surface side and Y on the surface. Moreover, it can have the base material S as needed, and can take structures such as S / X / Y, S / Y / X / Y, S / X / Y / X / Y, and the like. Here, the laminated body which consists of a polyimide resin layer (X) and an adhesive layer (Y), and does not have the base material S, or its layer structure is also called this laminated body.

  The polyimide resin can be formed by imidizing (curing) a polyimide resin precursor (polyamic acid). Details of imidization will be described later.

  Examples of the polyimide resin that can be applied as the polyimide resin layer include heat-resistant resins having an imide group in a structure such as polyamideimide, polybenzimidazole, polyimide ester, polyetherimide, polysiloxaneimide, and the like including so-called polyimide resins.

In the polyimide resin laminate having the adhesive layer of the present invention, a low thermal expansion polyimide resin layer is suitable as the polyimide resin layer (X). Specifically, the linear thermal expansion coefficient is 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), preferably 1 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K), more preferably 15 When a low thermal expansion polyimide resin layer in the range of × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K) is applied, a great effect can be obtained. Therefore, as the polyamic acid layer that becomes the low thermal expansion polyimide resin layer (X), a layer that gives the polyimide resin layer by imidizing it is used. Such a low thermal expansion polyimide resin is a non-thermoplastic polyimide resin. A non-thermoplastic polyimide resin is excellent in low thermal expansion, but has a feature of poor adhesion.

As a polyimide resin which comprises a polyimide resin layer (X), the polyimide resin which has a structural unit represented by following General formula (1) is preferable. In General Formula (1), Ar ₁ represents a tetravalent aromatic group represented by Formula (2) or Formula (3), and Ar ₃ represents a divalent group represented by Formula (4) or Formula (5). R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and X and Y independently represent a single bond or a divalent hydrocarbon having 1 to 15 carbon atoms. A divalent group selected from the group, O, S, CO, SO ₂ or CONH, n independently represents an integer of 0 to 4, q represents the molar ratio of constituent units, 0.1 to 1 0.0, preferably in the range of 0.5 to 1.0.

  The structural unit may be present in the homopolymer or may be present as a structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may exist as a block or may exist randomly.

Since a polyimide resin is generally produced by reacting a diamine and an acid anhydride, a specific example of the polyimide resin can be understood by explaining the diamine and the acid anhydride. In the above general formula (1), Ar ₃ can be referred to as a diamine residue, and Ar ₁ can be referred to as an acid anhydride residue. Therefore, a preferred polyimide resin will be described using a diamine and an acid anhydride. However, it is not limited to the polyimide resin obtained by this method.

Examples of the acid anhydride include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, Preferred is 4,4′-oxydiphthalic anhydride.
Also, 2,2 ', 3,3'-, 2,3,3', 4'- or 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 2,3', 3,4 '-Biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,3 ', 3,4'-diphenyl ether tetracarboxylic dianhydride, bis (2, Preferable examples include 3-dicarboxyphenyl) ether dianhydride. Also 3,3``, 4,4 ''-, 2,3,3``, 4 ''-or 2,2 '', 3,3 ''-p-terphenyltetracarboxylic dianhydride 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis (2,3- Alternatively, 3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride and the like are preferable.

  Other acid anhydrides include 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7- Anthracene tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 2,3,6,7- Naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2, 3,5,6,7-Hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic acid Dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2,3,6,7-) tetracarboxylic acid di Anhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclopentane- 1,2,3,4-tetracar Boronic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5- Examples thereof include tetracarboxylic dianhydride and 4,4′-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride.

Examples of the diamine include 4,4′-diaminodiphenyl ether, 2′-methoxy-4,4′-diaminobenzanilide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-amino). Phenoxy) benzene, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'- Preferred examples include diaminobiphenyl and 4,4′-diaminobenzanilide.
Also, 2,2-bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy)] biphenyl, bis [4- (3-aminophenoxy) biphenyl, bis [1- (4-aminophenoxy)] biphenyl, bis [1- (3-aminophenoxy)] biphenyl, Bis [4- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-amino Phenoxy) phenyl] ether, bis [4- (4-aminophenoxy)] benzophenone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 ′-(4-aminophenoxy)] benzanilide, bis [ Four, 4 ′-(3-aminophenoxy)] benzanilide, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) phenyl] fluorene and the like are preferable. Can be mentioned.

  Other diamines include 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis- [4- (3-aminophenoxy) phenyl] hexafluoropropane, 4,4 '-Methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 4,4'-diaminodiphenylpropane, 3,3'-diamino Diphenylpropane, 4,4'-diaminodiphenylethane, 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3 ' -Diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, benzidine, 3, 3'-di Minobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4 ''-diamino-p-terphenyl, 3,3 ''-diamino-p-ter Phenyl, m-phenylenediamine, p-phenylenediamine, 2,6-diaminopyridine, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4'- [1,4-phenylenebis (1-methylethylidene)] bisaniline, 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisaniline, bis (p-aminocyclohexyl) methane, bis (p- β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminopentyl) benzene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl) -5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis (β-amino-t-butyl) toluene 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2, Examples include 5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like.

  Each of acid anhydrides and diamines may be used alone or in combination of two or more. In addition, other acid anhydrides or diamines not included in the general formula (1) can be used together with the above acid anhydrides or diamines. In this case, the other acid anhydrides or diamines are used in a proportion of 90 mol. % Or less, preferably 50 mol% or less. Control the thermal expansion, adhesiveness, glass transition point (Tg), etc. by selecting the type of acid anhydride or diamine and the molar ratio of each of two or more acid anhydrides or diamines. be able to.

  The synthesis of the polyamic acid which is a precursor of the polyimide resin can be performed by reacting approximately equimolar acid anhydride and diamine in a solvent. Examples of the solvent to be used include N, N-dimethylacetamide (DMAc), n-methylpyrrolidinone, 2-butanone, diglyme, xylene and the like, and these may be used alone or in combination of two or more. it can.

  The synthesized polyamic acid is used as a solution. Usually, it is advantageous to use as a reaction solvent solution, but if necessary, it can be concentrated, diluted or replaced with another organic solvent. Moreover, since polyamic acid is generally excellent in solvent solubility, it is advantageously used.

  The method for forming the polyimide resin layer is not particularly limited. For example, the polyimide resin layer can be formed by applying a polyamic acid solution on a substrate and then drying and imidizing. However, the method for applying the polyimide resin layer is not particularly limited. It can be applied with a coater such as a knife or a lip. Then, it dries and imidizes to make a polyimide resin layer.

  Moreover, the method of drying and imidation is not particularly limited, and for example, a heat treatment of heating for 1 to 60 minutes under a temperature condition of 60 to 400 ° C. is suitably employed. By performing such heat treatment, dehydration and ring closure of the polyamic acid proceeds, so that a polyimide resin layer can be formed. The thickness of the polyimide resin layer is 3 to 100 μm, preferably 5 to 50 μm.

  The polyimide resin layer (X) may be formed of only a single layer or may be formed of a plurality of layers. When multiple polyimide resin layers are used, a polyamic acid solution is applied on the base material or a layer to be an adhesive layer, and after drying, a predetermined polyamic acid layer is formed and then imidized. A polyimide resin layer. When the polyimide resin layer is composed of three or more layers, the same polyamic acid may be used twice or more. Two layers or a single layer, in particular a single layer, having a simple layer structure can be advantageously obtained industrially. Even in the case of a plurality of layers, each polyimide resin layer is the above-mentioned low thermal expansion polyimide resin layer.

  In the case where the polyimide resin layer (X) is composed of two or more layers, in order to further improve the etching shape, the etching rate of each polyimide resin layer constituting the layer is preferably 5 μm / min or more, More preferably, it is 10 μm / min or more. When the etching rate is less than 5 μm / min, it is difficult to obtain a good etching shape, and a higher etching rate value is preferable because a good etching shape is obtained. In addition, in order to obtain a good etching shape, it is preferable to control the ratio of the etching rate of each layer. The polyimide resin layer showing the fastest etching rate (H) and the polyimide resin showing the slowest etching rate (L) The layer etch rate ratio (H / L) is advantageously about 1-2, preferably about 1-1.6. In addition, the measurement of the etching rate said by this invention is based on the method described in the below-mentioned Example.

  The adhesive layer (Y) is coated with a mixed solution containing a precursor resin (A ′) of a non-thermoplastic polyimide resin (A) and a precursor resin (B ′) of a thermoplastic polyimide resin (B), dried, It is formed by imidization.

  As the precursor resins (A ′) and (B ′), a precursor resin of a polyimide resin obtained from a known acid anhydride and diamine can be applied, and can be produced by a known method. For example, it can be obtained by dissolving tetracarboxylic dianhydride and diamine in an organic solvent in approximately equimolar amounts and stirring at 0 to 100 ° C. for 30 minutes to 24 hours to cause a polymerization reaction. In the reaction, it is preferable to dissolve the reaction components so that the precursor resin of the obtained polyimide resin is 5 to 30% by weight, preferably 10 to 20% by weight in the organic solvent. As the organic solvent used in the polymerization reaction, it is preferable to use a polar one. Examples of the organic polar solvent include N, N-dimethylformamide, N, N-dimethylacetamide (DMAc), N-methyl. -2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfate, phenol, halogenated phenol, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme and the like. Two or more of these can be used in combination, and some aromatic hydrocarbons such as xylene and toluene can also be used.

  The precursor resins (A ′) and (B ′) are 30 to 85 parts by weight of the precursor resin (A ′), preferably 100 parts by weight of the precursor resins (A ′) and (B ′). Is used as a mixed solution mixed so as to be 30 to 70 parts by weight, more preferably 30 to 60 parts by weight. Usually, it is advantageous to use a mixed solution as each reaction solvent solution, but if necessary, it can be concentrated, diluted or replaced with another organic solvent. When the mixing ratio of the precursor resin (A ′) in the mixed solution is less than the above lower limit, the etching characteristics of the obtained adhesive layer (Y) tend to be similar to the characteristics of the thermoplastic polyimide resin (B). There is a possibility that a shape defect or the like may occur during etching of the insulating resin layer. Moreover, when the mixing ratio of precursor resin (A ') exceeds the said upper limit, the adhesiveness of an adhesive layer (Y) will be inferior.

  The adhesive layer (Y) is present so as to be laminated on one side or both sides of the low thermal expansion polyimide resin layer (X). The method for providing the adhesive layer (Y) is not particularly limited. For example, the mixed solution is applied on the polyamic acid layer to be the polyimide resin layer (X) and dried to form at least two precursor resin layers. After forming, the method of imidating by heat processing is mentioned. Conversely, there is a method in which a polyamic acid layer to be a polyimide resin layer (X) is formed on a layer to be an adhesive layer (Y) and then imidized by heat treatment. When providing one or both of the polyimide resin layer (X) and the adhesive layer (Y), a layer to be the adhesive layer (Y) is formed, and then the polyimide resin layer (X) is formed thereon. There is a method in which a layer is formed, and a layer to be an adhesive layer (Y) is formed, followed by imidization by heat treatment. In addition, when the adhesive layer (Y) is laminated on both surfaces of the low thermal expansion polyimide resin layer (X), for example, the mixed solution is applied on a substrate, dried, and then the same as the above-described lamination method. Then, after forming at least three precursor resin layers, a method of imidizing is mentioned. The laminate having the adhesive layer (Y) on both sides can be advantageously used for producing a metal-clad laminate having metal foil on both sides.

  The value obtained by dividing the thickness of the low thermal expansion polyimide resin layer (X) by the thickness of the adhesive layer (Y) (the total thickness of the two adhesive layers when the adhesive layer is on both sides) is 1 to It is preferably in the range of 40, more preferably in the range of 2-30.

  When the adhesive layer (Y) is on both sides of the low thermal expansion polyimide resin layer (X), the materials and thicknesses of the two adhesive layers may be the same or different from each other.

The non-thermoplastic polyimide resin (A) preferably has a linear thermal expansion coefficient in the range of 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), more preferably 1 × 10 ^{−6 to} 25 × 10. ⁻⁶ (1 / K), more preferably 15 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K). As such a polyimide resin, those applicable to the low thermal expansion polyimide resin layer (X) are preferably used, and a polyimide resin having a structural unit represented by the general formula (1) is preferable. By using such a resin, it is possible to suppress problems due to foaming under high temperature heating. The non-thermoplastic polyimide resin (A) is selected so that the difference from the linear thermal expansion coefficient of the low thermal expansion polyimide resin layer (X) is 5 × 10 ⁻⁶ (1 / K) or less. Is preferred. By selecting such a resin, it is possible to suppress warpage when the metal layers are stacked. The polyimide resin of the low thermal expansion polyimide resin layer (X) is preferably the same type of non-thermoplastic polyimide resin (A) or similar in etching characteristics. By selecting, the polyimide etching shape is also improved. Note that that the etching characteristics are similar means that the etching rate ratio is in the range of about 0.5 to 2 under the etching conditions. Further, the etching rate of the non-thermoplastic polyimide resin (A) is preferably 5 μm / min or more, more preferably 10 μm / min or more. Also, the same type of polyimide resin means that the types of diamine and acid anhydride used to obtain the polyimide resin are the same, or that the components of diamine and acid anhydride are 80 mol% or more in common. In other words, it indicates substantially the same thermal expansion coefficient, adhesiveness or etching characteristics.

The thermoplastic polyimide resin (B) is preferably a polyimide precursor resin having a structural unit represented by the general formula (6). In General Formula (6), Ar ₄ represents a divalent aromatic group represented by Formula (7), Formula (8), or Formula (9), and Ar ₅ represents Formula (10) or Formula (11). R ₂ represents independently a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and V and W independently represent a single bond or 1 to 15 carbon atoms. A divalent hydrocarbon group, a divalent group selected from O, S, CO, SO ₂ or CONH, m independently represents an integer of 0 to 4, p represents an existing mole of a structural unit; It is in the range of 1 to 1.0.

  The structural unit may be present in the homopolymer or may be present as a structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may exist as a block or may exist randomly. Among the polyimide precursor resins having such a structural unit, a polyimide precursor resin that can be suitably used is a polyimide precursor resin that becomes a thermoplastic polyimide resin after imidization.

In the general formula (6), Ar ₄ can be referred to as a diamine residue, and Ar ₅ can be referred to as an acid dianhydride residue. Therefore, a preferable polyimide resin will be described using a diamine and an acid dianhydride. However, it is not limited to the polyimide precursor resin obtained by this method.

  Examples of the diamine include 4,4′-diaminodiphenyl ether, 2′-methoxy-4,4′-diaminobenzanilide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-amino). Phenoxy) benzene, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'- Diaminobiphenyl, 4,4′-diaminobenzanilide and the like can be mentioned. In addition, the diamine mentioned by description of the said polyimide resin can be mentioned.

  Examples of the acid dianhydride include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride 4,4′-oxydiphthalic anhydride. In addition, the acid dianhydride mentioned by description of the said polyimide resin can be mentioned.

  Each of diamine and acid dianhydride may be used alone or in combination of two or more. In addition, diamines and acid dianhydrides other than those described above can be used in combination.

  The thermoplastic polyimide resin (B) preferably has a glass transition temperature in the range of 200 to 320 ° C. By using such a polyimide resin, the adhesive strength with the metal layer is improved. Preferred diamines used to synthesize this polyimide resin include 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane and 2,2-bis [4- (4-aminophenoxy) phenyl. There is one or more diamines selected from propane, 1,3-bis- (3-aminophenoxy) benzene, paraphenylenediamine, 3,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl ether. Preferred acid anhydrides include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, There is one or more acid anhydrides selected from 3,3,4,4'-diphenylsulfonetetracarboxylic dianhydride. About the said diamine and an acid anhydride, only 1 type may respectively be used and it can also be used in combination of 2 or more type.

  The precursor resin (A ′) of the non-thermoplastic polyimide resin (A) is preferably the same type as the polyamic acid that forms the low thermal expansion polyimide resin layer (X). By selecting such a resin, the etching characteristics of the adhesive layer (Y) tend to be similar to the etching characteristics of the low thermal expansion polyimide resin layer (X), and the polyimide etching shape is further improved.

  Next, details of the method for producing the metal-clad laminate of the present invention will be described. The manufacturing method of the metal-clad laminate of the present invention includes a manufacturing method (manufacturing method A) including steps a) to d) and a manufacturing method (manufacturing method B) including steps f) to h) as described above. There is a production method (production method C) comprising j) to m).

Manufacturing method A is
a) A layer which becomes a low thermal expansion polyimide resin layer (X) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the substrate and drying. Forming a process,
b) On the layer that becomes the low thermal expansion polyimide resin layer (X), a precursor resin (A ′) of a non-thermoplastic polyimide resin (A) and a precursor resin (B) of a thermoplastic polyimide resin (B) A mixed solution containing 30) to 85 parts by weight of the precursor resin (A ') with respect to a total of 100 parts by weight of the precursor resins (A') and (B ') and dried. And forming a layer to be an adhesive layer (Y) having a thickness in the range of 0.1 to 3.0 μm,
c) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y); and
d) a step of superimposing a metal foil on the surface of the adhesive layer (Y) and thermocompression bonding, or a step of depositing a metal thin film layer on the surface of the adhesive layer (Y),
It is a manufacturing method of a metal-clad laminated board provided with.

Production method B is
f) A mixed solution containing a precursor resin (A ′) of a non-thermoplastic polyimide resin (A) and a precursor resin (B ′) of a thermoplastic polyimide resin (B) on a metal foil, the precursor A mixed solution containing 30 to 85 parts by weight of the precursor resin (A ′) is applied to a total of 100 parts by weight of the resins (A ′) and (B ′) and dried to have a thickness of 0.1 to 3.0 μm. Forming a layer to be an adhesive layer (Y) in the range of
g) A low thermal expansion coefficient having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the layer to be the adhesive layer (Y) and drying it. Forming a layer to be the polyimide resin layer (X), and
h) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y);
It is a manufacturing method of a metal-clad laminated board provided with.

Manufacturing method C is
i) A mixed solution containing a precursor resin (A ′) of a non-thermoplastic polyimide resin (A) and a precursor resin (B ′) of a thermoplastic polyimide resin (B) on a metal foil, the precursor A mixed solution containing 30 to 85 parts by weight of the precursor resin (A ′) is applied to a total of 100 parts by weight of the resins (A ′) and (B ′) and dried to have a thickness of 0.1 to 3.0 μm. Forming a layer to be an adhesive layer (Y) in the range of
j) A low thermal expansion coefficient having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the adhesive layer (Y) and drying it. Forming a layer to be the polyimide resin layer (X) of
k) Furthermore, the mixed solution is applied onto the layer to be the low thermal expansion polyimide resin layer (X) and dried to form an adhesive layer (Y having a thickness in the range of 0.1 to 3.0 μm). A step of forming a layer to be)
l) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y); and
m) Step d1 of superposing metal foil on the surface layer of the adhesive layer (Y) and thermocompression bonding, or step d2 of depositing a metal thin film layer on the surface layer of the adhesive layer (Y)
It is a manufacturing method of a metal-clad laminated board provided with.

  In the metal-clad laminate obtained by the production method (A) of the present invention, a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y) are disposed on a substrate, and the adhesive layer (Y) A metal layer is disposed through the gap. And process a) respond | corresponds with process I) in the manufacturing method of a polyimide resin laminated body. Step b) corresponds to step II) in the method for producing a polyimide resin laminate. Step c) corresponds to step III) in the method for producing a polyimide resin laminate. Therefore, steps a) to c) can be performed by the same method as described for steps I) to III) in the method for producing a polyimide resin laminate. Step d) includes a step d1 of superimposing a metal foil on the surface of the adhesive layer (Y) and thermocompression bonding, or a step d2 of depositing a metal thin film layer on the surface of the adhesive layer (Y).

The step d) can be performed by the step d1 for thermocompression bonding or the step d2 for vapor deposition.

  In step d1, the metal foil used is iron foil, nickel foil, beryllium foil, aluminum foil, zinc foil, indium foil, silver foil, gold foil, tin foil, zirconium foil, stainless steel foil, tantalum foil, titanium foil, copper foil , Lead foil, magnesium foil, manganese foil and alloy foils thereof. Among these, copper foil (copper alloy foil) or stainless steel foil is suitable. The copper foil here means copper or a copper alloy foil containing copper as a main component. Preferably, the copper foil has a copper content of 90% by mass or more, particularly preferably 95% by mass or more. Examples of the metal contained in the copper foil include chromium, zirconium, nickel, silicon, zinc, and beryllium. An alloy foil containing two or more of these metals may also be used. The stainless steel foil is not limited in material, but for example, a stainless steel foil such as SUS304 is preferable.

  The metal foil may be treated with a silane coupling agent on the surface on which the polyimide resin layer is laminated. The silane coupling agent is preferably a silane coupling agent having a functional group such as an amino group or a mercapto group, more preferably a silane coupling agent having an amino group. Specific examples include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyl. Examples include trimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and the like. Among these, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyl It may be at least one selected from dimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine and N-phenyl-3-aminopropyltrimethoxysilane. In particular, 3-aminopropyltriethoxysilane and / or 3-aminopropyltrimethoxysilane are preferable.

  The silane coupling agent is used as a polar solvent solution. As the polar solvent, water or a polar organic solvent containing water is suitable. The polar organic solvent is not particularly limited as long as it is a polar liquid having an affinity for water. Examples of such a polar organic solvent include methanol, ethanol, propanol, isopropanol, acetone, tetrahydrofuran, dimethylformamide, dimethylacetamide and the like. The silane coupling agent solution has a concentration of 0.01 to 5% by weight, preferably 0.1 to 2.0% by weight, more preferably 0.5 to 1.0% by weight.

  The silane coupling agent treatment is not particularly limited as long as it is a method in which a solution of a polar solvent containing a silane coupling agent contacts, and a known method can be used. For example, a dipping method, a spray method, a brush coating method or a printing method can be used. The temperature may be 0 to 100 ° C., preferably 10 to 40 ° C. Moreover, as for immersion time, when applying the immersion method, it is effective to process for 10 second-1 hour, Preferably it is 30 second-15 minutes. Dry after treatment. The drying method is not particularly limited, and natural drying, spray drying with an air gun, oven drying, or the like can be used. The drying conditions depend on the type of polar solvent, but are 10 to 150 ° C. for 5 seconds to 60 minutes, preferably 25 to 150 ° C. for 10 seconds to 30 minutes, more preferably 30 to 120 ° C. for 1 minute to 10 minutes. It is.

  An example in which the metal foil is a copper foil includes a case where the metal foil is used for a flexible substrate. The preferred thickness of the copper foil when used as this application is in the range of 3 to 50 μm, more preferably in the range of 5 to 30 μm, but the copper-clad laminate used in applications where fine pitch is required, A thin copper foil is preferably used, and in this case, a range of 5 to 20 μm is suitable. Moreover, since the adhesiveness with respect to a resin layer is acquired even if it uses copper foil with small surface roughness, this invention is suitable especially when using copper foil with small surface roughness. The preferred surface roughness of the copper foil is 10-point average roughness in the range of 0.1 to 3 μm. Particularly for copper foils used in applications requiring a fine pitch, a surface roughness of 10-point average roughness of 0.1 to 1.0 μm is suitable.

  An example in which the metal foil is a stainless steel foil is a case where the metal foil is used for a suspension (hereinafter referred to as HDD suspension) mounted on a hard disk drive. The preferred thickness of the stainless steel foil when used for this purpose is in the range of 10 to 100 μm, more preferably in the range of 15 to 70 μm, and still more preferably in the range of 15 to 50 μm.

  In step d1, the method for thermocompression bonding of the metal foil is not particularly limited, and a known method can be appropriately employed. Examples of the method of laminating the metal foil include a normal hydro press, a vacuum type hydro press, an autoclave pressurizing vacuum press, and a continuous thermal laminator. Among the methods of laminating metal foils, a vacuum hydropress and a continuous thermal laminator are used from the viewpoint that sufficient pressing pressure is obtained, residual volatiles can be easily removed, and oxidation of the metal foil can be prevented. It is preferable to use it.

  In thermocompression bonding, it is preferable to press the metal foil while heating in the range of 150 to 450 ° C. More preferably, it exists in the range of 150-400 degreeC. Furthermore, it is preferably in the range of 150 to 380 ° C. From another point of view, the temperature is preferably equal to or higher than the glass transition temperature of the polyimide resin layer or the modified imidized layer. The press pressure is usually about 1 to 50 MPa, although it depends on the type of press equipment used.

  Next, the case where step d) is performed by the step d2 of vapor deposition will be described.

In step d2, the metal thin film layer is formed by a vapor deposition method. The vapor deposition method is not particularly limited. For example, a vacuum vapor deposition method, a sputtering method, an electron beam vapor deposition method, an ion plating method, or the like can be used, and the sputtering method is particularly preferable. This sputtering method includes various methods such as DC sputtering, RF sputtering, DC magnetron sputtering, RF magnetron sputtering, EC sputtering, and laser beam sputtering, but is not particularly limited and can be appropriately employed. Regarding the conditions for forming the metal thin film layer by sputtering, for example, argon gas is used as the sputtering gas, and the pressure is preferably 1 × 10 ^{−2 to 1} Pa, more preferably 5 × 10 ^{−2 to} 5 × 10 ⁻¹ Pa. The sputtering power density is preferably 1 to 100 Wcm ⁻² , more preferably 1 to 50 Wcm ⁻² . In this case, the metal layer comprising the metal thin film layer can be made sufficiently thin. A thick conductive metal layer may be appropriately formed on the thin metal film layer thus formed by electroless plating or electrolytic plating.

  Examples of metals suitable for the metal thin film layer provided by vapor deposition include copper, nickel, chromium, and alloys thereof. The vapor deposition method has an advantage that a metal thin film can be formed, but is not suitable for forming a thick film. Therefore, when the metal thin film layer is thickened to lower the electrical resistance or increase the strength, a relatively thick copper thin film layer may be provided thereon.

  Formation of the metal thin film by the vapor deposition method preferably uses copper as the thin film layer. Under the present circumstances, the base metal thin film layer which improves adhesiveness more may be provided in a surface treatment polyimide resin layer, and a copper thin film layer may be provided on it. Examples of the base metal thin film layer include nickel, chromium, and an alloy layer thereof. When the base metal thin film layer is provided, the thickness is 1/2 or less, preferably 1/5 or less of the thickness of the copper thin film layer, and is preferably about 1 to 50 nm. This underlying metal thin film layer is also preferably formed by sputtering.

  The copper used here may be alloy copper partially containing other metals. The copper or copper alloy formed by the sputtering method preferably has a copper content of 90% by mass or more, particularly preferably 95% by mass or more. Examples of the metal that copper can contain include chromium, zirconium, nickel, silicon, zinc, and beryllium. Moreover, the copper alloy in which these metals contain 2 or more types may be sufficient.

  The thickness of the metal thin film layer formed in step d1 is preferably in the range of 0.01 to 1.0 μm, preferably 0.05 to 0.5 μm, more preferably 0.1 to 0.5 μm. . When the thin film layer is further thickened, it may be thickened by electroless plating or electrolytic plating. The metal layer formed in this way can be formed into a circuit by a subtractive method or a semi-additive method.

  The laminate obtained by this metal-clad laminate production method (A) is a laminate having a metal foil on one or both sides of a polyimide resin layer. A laminate having a metal foil on one side can be obtained by using the base material used in step a) as a material other than the metal foil, or using a peelable metal foil or a material other than the metal foil. A laminate having metal foil on both sides can be obtained by using a metal foil as the base material used in step a). Moreover, it can obtain also by manufacturing the laminated board which has metal foil on one side by this manufacturing method (A), peeling a base material and laminating | stacking metal foil on a peeling surface.

  Next, the manufacturing method (B) of a metal clad laminated board is demonstrated. Step f) of the metal-clad laminate manufacturing method (B) is a step of providing a layer to be the adhesive layer (Y), and corresponds to step b) of the manufacturing method (A). Therefore, it can be performed in the same manner as in step b) except that this is provided on the metal foil. Step g) is a step of providing a layer to be the polyimide resin layer (X) and corresponds to step a) of the production method (A). Therefore, it can be performed in the same manner as in step b) except that it is provided on the layer to be the adhesive layer (Y). Step h) is a step of imidizing to form the polyimide resin layer (X) and the adhesive layer (Y), and corresponds to step c) of the production method (A). Therefore, it can be performed in the same manner as in step c).

  The laminate obtained by this metal-clad laminate production method (B) is a single-sided metal-clad laminate having a layer structure of metal foil / adhesive layer (Y) / polyimide resin layer (X).

  Next, the manufacturing method (C) of a metal clad laminated board is demonstrated. Steps i) and j) of the method (C) for producing a metal-clad laminate are steps for providing a layer to be an adhesive layer (Y) and a layer to be a polyimide resin layer (X) on a metal foil. ) Corresponding to steps f) and g). Therefore, it can be carried out in the same manner as in steps f) and g). Step k) is a step of providing a layer to be an adhesive layer (Y) on a layer to be a polyimide resin layer (X), and corresponds to step i). Therefore, it can be performed in the same manner as in step i) except that this is provided on the layer to be the polyimide resin layer (X). Step l) is a step of imidizing to form a polyimide resin layer (X) and an adhesive layer (Y), and corresponds to step c) of the production method (A). Therefore, it can be performed in the same manner as in step c). Step m) is a step d1 of providing a metal layer on the surface of the adhesive layer (Y) by thermocompression or a step d2 of depositing a metal thin film layer, and corresponds to step d) of the production method (A). Therefore, it can be performed in the same manner as in step d1 or d2 of production method (A).

  The laminate obtained by the method (C) for producing a metal-clad laminate is a double-sided structure having a metal foil / adhesive layer (Y) / polyimide resin layer (X) / adhesive layer (Y) / metal layer structure. It is a metal-clad laminate.

  EXAMPLES Hereinafter, although an Example demonstrates this invention based on an Example, this invention is not limited at all by these Examples. In the examples of the present invention, unless otherwise specified, various measurements and evaluations are as follows.

[Measurement of adhesive strength]
The adhesive strength was evaluated by measuring 90 °, 1 mm peel strength at room temperature for a sample cut into 1 mm width strips using a strograph VES05D (Toyo Seiki Seisakusho).

[Measurement of linear thermal expansion coefficient]
The coefficient of linear thermal expansion was determined by using a thermomechanical analyzer (manufactured by Seiko Instruments Inc.), raising the temperature of the sample to 250 ° C., holding the sample at that temperature for 10 minutes, and then cooling at a rate of 5 ° C./min. To an average linear thermal expansion coefficient (CTE) from 100 ° C to 100 ° C.

[Measurement of glass transition temperature]
Using a viscoelasticity analyzer (RSA-II, manufactured by Rheometric Science Effy Co., Ltd.), using a 10 mm wide sample, raising the temperature from room temperature to 400 ° C. at a rate of 10 ° C./min while applying 1 Hz vibration Of the loss tangent (Tanδ).

[Measurement of adhesive layer thickness]
The thickness of the adhesive layer was measured by setting the transmission mode using a scanning transmission electron microscope (manufactured by Hitachi High-Technologies Corporation), observing the cross section of the sample, and confirming the thickness of the adhesive layer.

[Measurement of etching rate]
The polyimide film was immersed in an etching solution heated to 80 ° C. (ethylene diamine 11.0 wt%, ethylene glycol 22.0 wt%, potassium hydroxide 33.5 wt%), and the time when the polyimide was completely dissolved was measured. It was determined by dividing the film thickness by the measurement time.

[Measurement of polyimide etching shape]
First, a 100 mm square metal-clad laminate was used, the metal layer side was etched, and a 100 μm diameter via was formed as a test piece. Thereafter, using the metal layer as an etching mask, an aqueous solution of 33.5 wt% potassium hydroxide, 11 wt% ethylenediamine, and 22 wt% ethylene glycol was used as an etching solution, and the test piece was immersed in an etching solution at 80 ° C. for 10 to 60 seconds. . After immersion, the cross section of the test piece was polished, and the side etching shape of the insulating resin layer was observed.
In addition, in the insulating resin layer after etching, the level where the boundary between the polyimide resin layer and the adhesive layer is not confirmed is “excellent”, and the level where the boundary between the polyimide resin layer and the adhesive layer is slightly confirmed Although it was judged as “good”, the boundary between the polyimide resin layer and the adhesive layer could be confirmed, but those having no unevenness were evaluated as “good”. Moreover, the thing with an unevenness | corrugation confirmed in the boundary of a polyimide resin layer and an adhesive layer was evaluated as "impossible."

Next, the present invention will be specifically described based on the following examples. Of course, the present invention is not limited to this. In addition, the symbol used for the present Example is as follows.
MABA: 2'-methoxy-4,4'-diaminobenzanilide
DAPE44: 4,4'-diaminodiphenyl ether
m-TB: 4,4'-Diamino-2,2'-dimethylbiphenyl
TPE-R: 1,3-bis (4-aminophenoxy) benzene
APB: 1,3-bis (3-aminophenoxy) benzene
PMDA: pyromellitic anhydride
BTDA: 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride
DMAc: N, N-dimethylacetamide

Production Example 1
In a 500 ml separable flask, 20.7 g MABA (0.08 mol) was dissolved in 343 g DMAc with stirring. Next, 28.5 g PMDA (0.13 mol) and 10.3 g DAPE44 (0.05 mol) were added to the solution in a nitrogen stream. Thereafter, stirring was continued for about 3 hours to conduct a polymerization reaction, thereby obtaining a viscous polyimide resin precursor solution s1.
The obtained precursor solution s1 was applied on a stainless steel substrate, dried at 130 ° C. for 5 minutes, heated to 360 ° C. over 15 minutes to complete imidization, and laminated on the stainless steel substrate. A polyimide resin layer was obtained, and this resin layer was peeled off from the stainless steel substrate to obtain a polyimide film S1 having a thickness of 25 μm. The linear thermal expansion coefficient of this film was 14.6 × 10 ⁻⁶ (1 / K). The etching rate was 13 μm / min.

Production Example 2
In a 500 ml separable flask, with stirring, 12.08 g m-TB (0.057 mol), 4.75 g TPE-R (0.016 mol) and 1.63 g DAPE44 (0.008 mol) Was dissolved in 264 g of DMAc. The solution was then added 17.55 g PMDA (0.08 mol) under a stream of nitrogen. Thereafter, the polymerization reaction was continued for about 3 hours to obtain a viscous polyimide resin precursor solution s2.
The obtained precursor solution s2 is coated on a stainless steel substrate, dried at 130 ° C. for 5 minutes, heated to 360 ° C. over 15 minutes to complete imidization, and polyimide laminated on the stainless steel substrate A resin layer was obtained, and this resin layer was peeled off from the stainless steel substrate to obtain a polyimide film S2 having a thickness of 25 μm. The linear thermal expansion coefficient of this film was 17.0 × 10 ⁻⁶ (1 / K). The etching rate was 12 μm / min.

Production Example 3
In a 500 ml separable flask, 29.5 g APB (0.1 mol) was dissolved in 367 g DMAc with stirring. The solution was then charged with 9.1 g PMDA (0.04 mol) and 20.2 g BTDA (0.06 mol) in a stream of nitrogen. Thereafter, stirring was continued for about 3 hours to carry out a polymerization reaction to obtain a viscous polyimide resin precursor solution s3.
The obtained precursor solution s3 is coated on a stainless steel substrate, dried at 130 ° C. for 5 minutes, heated to 360 ° C. over 15 minutes to complete imidization, and polyimide laminated on the stainless steel substrate A resin layer was obtained, and this resin layer was peeled off from the stainless steel substrate to obtain a polyimide film S3 having a thickness of 25 μm. The glass transition temperature of this film was 218 ° C. The etching rate was 7 μm / min.

Production Example 4
A silane coupling agent solution was prepared by mixing 5 g of 3-aminopropyltrimethoxysilane, 500 g of methanol and 2.5 g of water and stirring for 2 hours. After pre-washing stainless steel foil 1 (SUS304 H-TA manufactured by Nippon Steel Corp., thickness 20 μm) for 30 seconds in a silane coupling agent solution (liquid temperature of about 20 ° C.), the steel foil was once pulled up into the atmosphere to remove excess The liquid was dropped. Then, it was dried by blowing compressed air for about 15 seconds. Then, heat processing were performed for 30 minutes at 110 degreeC, and the stainless steel foil 2 of a silane coupling agent process was obtained.

Example 1
The precursor was adjusted so that the weight ratio of the precursor component a1 in the precursor solution s1 obtained in Production Example 1 and the precursor component b3 in the precursor solution s3 obtained in Production Example 3 was 70:30. After the body solution s1 and the precursor solution s3 were mixed, DMAc was added and diluted to prepare a mixed solution p1 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
Precursor solution s1 was applied on a stainless steel substrate and dried at 130 ° C. for 2 minutes to form a polyimide precursor resin layer so that the thickness after curing was 25 μm. On this precursor resin layer, the above mixed solution p1 is applied with a wet thickness of about 30 μm, dried at 130 ° C. for 2 minutes, and then heated to 360 ° C. over 15 minutes to complete imidization. The polyimide resin layer laminated | stacked on the material was obtained, and the polyimide film L1 which has an adhesive layer was produced by peeling this resin layer from a stainless steel base material. The thickness of the adhesive layer of this film was 1.0 μm.
The surface of the adhesive layer of the obtained film is overlaid with the silane coupling agent-treated surface of stainless steel foil 2 and pressed with a high-performance high-temperature vacuum press machine at 370 ° C., 20 MPa for 1 minute, and polyimide resin A metal-clad laminate 1 composed of a layer, an adhesive layer and a stainless foil layer was obtained. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 1 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was very good. The adhesive strength of 0.5 kN / m or more was regarded as no problem.

Example 2
The precursor was adjusted so that the weight ratio of the precursor component a1 in the precursor solution s1 obtained in Production Example 1 and the precursor component b3 in the precursor solution s3 obtained in Production Example 3 was 50:50. After the body solution s1 and the precursor solution s3 were mixed, DMAc was added and diluted to prepare a mixed solution p2 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
A metal-clad laminate 2 composed of a polyimide resin layer, an adhesive layer and a stainless steel foil layer in the same manner as in Example 1 except that the above mixed solution p2 was used instead of the mixed solution p1 in Example 1. Got. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 2 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was also good.

Example 3
The precursor was adjusted so that the weight ratio of the precursor component a1 in the precursor solution s1 obtained in Production Example 1 and the precursor component b3 in the precursor solution s3 obtained in Production Example 3 was 30:70. After the body solution s1 and the precursor solution s3 were mixed, DMAc was added and diluted to prepare a mixed solution p3 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
A metal-clad laminate 3 composed of a polyimide resin layer, an adhesive layer and a stainless steel foil layer in the same manner as in Example 1 except that the above mixed solution p3 was used instead of the mixed solution p1 in Example 1. Got. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 3 was excellent in adhesive strength, and there was no problem with the shape of the insulating resin layer after etching.

Example 4
The precursor component a2 in the precursor solution s2 obtained in Preparation Example 2 and the precursor component b3 in the precursor solution s3 obtained in Preparation Example 3 have a weight ratio of 70:30. After the body solution s2 and the precursor solution s3 were mixed, DMAc was added to dilute to prepare a mixed solution p4 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
A metal-clad laminate 4 composed of a polyimide resin layer, an adhesive layer and a stainless steel foil layer in the same manner as in Example 1 except that the above mixed solution p4 was used instead of the mixed solution p1 in Example 1. Got. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 4 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was also good.

Example 5
The precursor was adjusted so that the weight ratio of the precursor component a2 in the precursor solution s2 obtained in Production Example 2 and the precursor component b3 in the precursor solution s3 obtained in Production Example 3 was 50:50. After the body solution s2 and the precursor solution s3 were mixed, DMAc was added to dilute to prepare a mixed solution p5 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
A metal-clad laminate 5 composed of a polyimide resin layer, an adhesive layer, and a stainless steel foil layer in the same manner as in Example 1 except that the above mixed solution p5 was used instead of the mixed solution p1 in Example 1. Got. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 5 was excellent in adhesive strength, and there was no problem with the shape of the insulating resin layer after etching.

Example 6
The precursor component a2 in the precursor solution s2 obtained in Production Example 2 and the precursor component b3 in the precursor solution s3 obtained in Production Example 3 have a weight ratio of 30:70. After the body solution s2 and the precursor solution s3 were mixed, DMAc was added and diluted to prepare a mixed solution p6 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
A metal-clad laminate 6 composed of a polyimide resin layer, an adhesive layer, and a stainless foil layer, in the same manner as in Example 1, except that the above mixed solution p6 was used instead of the mixed solution p1 in Example 1. Got. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 6 was excellent in adhesive strength, and there was no problem with the shape of the insulating resin layer after etching.

Example 7
The polyimide film L1 having an adhesive layer obtained in Example 1 was used, and set in an RF magnetron sputtering apparatus (ANELVA; SPF-332HS) so that a metal raw material was formed on the adhesive layer surface of this film. Then, after reducing the pressure in the tank to 3 × 10 ⁻⁴ Pa, argon gas was introduced to make the degree of vacuum 2 × 10 ⁻¹ Pa, and plasma was generated by an RF power source. A nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter referred to as a nichrome layer (first sputtering layer)] was formed on the polyimide film by this plasma so as to have a film thickness of 30 nm. After forming the nichrome layer, in the same atmosphere, 0.2 μm of copper (99.99 wt%) was further formed on the nichrome layer by sputtering to obtain a second sputtering layer.
Next, a copper plating layer having a thickness of 8 μm was formed in an electrolytic plating bath using the sputtered film (second sputtering layer) as an electrode. As an electrolytic plating bath, a copper sulfate bath (copper sulfate 100 g / L, sulfuric acid 220 g / L, chlorine 40 mg / L, anode is phosphorus-containing copper) is used, and a plating film is formed at a current density of 2.0 A / dm ² . did. After plating, the metal-clad laminate 7 was prepared by washing with sufficient distilled water and drying. The adhesive strength between the insulating resin layer and the metal layer and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 7 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was very good.

Example 8
The mixed solution p1 prepared in Example 1 was prepared, and this mixed solution p1 was applied to the silane coupling agent-treated surface of the stainless steel foil 2 with a wet thickness of about 30 μm and dried at 130 ° C. for 2 minutes. On this layer, the precursor solution s1 is applied so that the thickness after curing is 25 μm, dried at 130 ° C. for 2 minutes, and then heated to 360 ° C. over 15 minutes to complete imidization, A metal-clad laminate 8 composed of a stainless steel foil layer, an adhesive layer and a polyimide resin layer was obtained. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 8 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was very good.

Example 9
The mixed solution p1 prepared in Example 1 was prepared, and this mixed solution p1 was applied to the silane coupling agent-treated surface of the stainless steel foil 2 with a wet thickness of about 30 μm and dried at 130 ° C. for 2 minutes. On this layer, the precursor solution s1 was applied so that the thickness after curing was 25 μm, dried at 130 ° C. for 2 minutes, and then the mixed solution p1 was further wetted on this layer with a wet thickness of about 30 μm. After applying and drying at 130 ° C. for 2 minutes, the temperature was raised to 360 ° C. over 15 minutes to complete imidization, and the laminate 9 composed of a stainless steel foil layer, an adhesive layer, a polyimide resin layer, and an adhesive layer 'Made.
The surface of the adhesive layer of the obtained laminate 9 ′ is superposed on the surface treated with the silane coupling agent of the stainless steel foil 2 and pressed with a high-performance high-temperature vacuum press at 370 ° C., 20 MPa for 1 minute. Then, a metal-clad laminate 9 composed of a polyimide resin layer, an adhesive layer, and a stainless steel foil layer was obtained. The adhesive strength between the insulating resin layer and the stainless steel foil and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 9 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was very good.

Example 10
An RF magnetron sputtering apparatus (ANELVA; SPF-332HS) was set so that a metal raw material was formed on the surface of the adhesive layer of the laminate 9 ′ obtained in Example 9, and the inside of the tank was 3 × 10 After depressurizing to ^-4 Pa, argon gas was introduced to make the degree of vacuum 2 × 10 ^-1 Pa, and plasma was generated by an RF power source. A nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter referred to as a nichrome layer (first sputtering layer)] was formed on the polyimide film by this plasma so as to have a film thickness of 30 nm. After forming the nichrome layer, in the same atmosphere, 0.2 μm of copper (99.99 wt%) was further formed on the nichrome layer by sputtering to obtain a second sputtering layer.
Next, a copper plating layer having a thickness of 8 μm was formed in an electrolytic plating bath using the sputtered film (second sputtering layer) as an electrode. As an electrolytic plating bath, a copper sulfate bath (copper sulfate 100 g / L, sulfuric acid 220 g / L, chlorine 40 mg / L, anode is phosphorus-containing copper) is used, and a plating film is formed at a current density of 2.0 A / dm ² . did. After plating, the metal-clad laminate 10 was produced by washing with sufficient distilled water and drying. The adhesive strength between the insulating resin layer and the metal layer and the etching shape of the insulating resin layer were evaluated. The results are shown in Table 1. The obtained metal-clad laminate 10 was excellent in adhesive strength, and the shape of the insulating resin layer after etching was very good.

Comparative Example 1
The polyimide S1 obtained in Production Example 1 was overlaid with the stainless steel foil 2 and pressed with a high-performance high-temperature vacuum press machine under the conditions of 370 ° C., 20 MPa, and 1 minute to obtain a metal-clad laminate 11. The adhesive strength between the insulating resin layer and the stainless steel foil was less than 0.1 kN / m.

Comparative Example 2
Stainless steel foil 2 was superposed on polyimide S2 obtained in Production Example 2, and pressed with a high-performance high-temperature vacuum press machine at 370 ° C., 20 MPa, for 1 minute to obtain metal-clad laminate 12. The adhesive strength between the insulating resin layer and the copper foil was less than 0.1 kN / m.

Comparative Example 3
Instead of coating the mixed solution p1 in Example 1 with a wet thickness of about 30 μm, the polyimide resin precursor solution s3 obtained in Preparation Example 3 was coated so that the thickness after curing was 1.0 μm. In the same manner as in Example 1, after obtaining a polyimide film, a metal-clad laminate 13 was produced. The obtained metal-clad laminate 13 had no problem in adhesive strength and dimensional stability, but unevenness occurred in the shape of the insulating resin layer after etching.

Comparative Example 4
The precursor was adjusted so that the weight ratio of the precursor component a1 in the precursor solution s1 obtained in Production Example 1 and the precursor component b3 in the precursor solution s3 obtained in Production Example 3 was 25:75. After the body solution s1 and the precursor solution s3 were mixed, DMAc was added and diluted to prepare a mixed solution p7 in which the solid content concentration as the precursor component was adjusted to 12% by weight.
Instead of applying the mixed solution p1 in Example 1 with a wet thickness of about 30 μm, the mixed solution p7 was applied in the same manner as in Example 1 except that the mixed solution p7 was applied so that the thickness after curing was 1.0 μm. After obtaining the polyimide film, a metal-clad laminate 14 was produced. The obtained metal-clad laminate 14 had no problem in adhesive strength and dimensional stability, but unevenness occurred in the shape of the insulating resin layer after etching.

Claims (8)

Next steps I) to III),
I) A step of applying a polyamic acid solution and drying to form a layer which becomes a low thermal expansion polyimide resin layer (X) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K). ,
II) The precursor resin (A ′) of the non-thermoplastic polyimide resin (A) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K ) and the glass transition temperature in the range of 200 to 320 ° C. A mixed solution containing a precursor resin (B ′) of a certain thermoplastic polyimide resin (B), the precursor resin (A ′) with respect to a total of 100 parts by weight of the precursor resins (A ′) and (B ′) ) Is applied to a mixed solution containing 30 to 85 parts by weight and dried to form an adhesive layer (Y) having a thickness in the range of 0.1 to 3.0 μm, and
III) a step of imidizing to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y);
The provided, step I) in any order, II) after step III) by performing,
And a value obtained by dividing the thickness of the low thermal expansion polyimide resin layer (X) by the thickness of the adhesive layer (Y) is in the range of 1 to 40 , at least one surface of the low thermal expansion polyimide resin layer A method for producing a polyimide resin laminate having an adhesive layer.   2. The method for producing a polyimide resin laminate according to claim 1, wherein Step II), Step I), Step II) and then Step III) are performed. The manufacturing method of the polyimide resin laminated body of Claim 1 or 2 whose polyimide resin which comprises a polyimide resin layer (X) is a polyimide resin which has a structural unit represented by following General formula (1) .

(In the formula, Ar ₁ represents a tetravalent aromatic group represented by Formula (2) or Formula (3), and Ar ₃ represents a divalent aromatic group represented by Formula (4) or Formula (5). R ₁ is independently a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, X and Y are independently a single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms, O , S, CO, SO ₂ or CONH represents a divalent group, n independently represents an integer of 0 to 4, q represents a molar ratio of constituent units, and 0.5 to 1.0 Range.) The polyimide resin layer (X) is composed of two or more layers, and the polyimide resin layer constituting each layer has an etching rate of 5 μm / min or more, and the polyimide resin layer having the fastest etching rate (H) and the slowest etching. The manufacturing method of the polyimide resin laminated body of Claim 1 or 2 which has the etching rate ratio (H / L) of the polyimide resin layer which shows speed | rate (L) in the range of 1-2 .   The precursor resin (A ') of the non-thermoplastic polyimide resin (A) is the same kind as the polyamic acid used to form the low thermal expansion polyimide resin layer (X). The manufacturing method of the polyimide resin laminated body which has an adhesive layer of description. Next steps a) to d),
a) A layer which becomes a low thermal expansion polyimide resin layer (X) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the substrate and drying. Forming a process,
b) Precursor of non-thermoplastic polyimide resin (A) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) on the layer to be the low thermal expansion polyimide resin layer (X) A mixed solution containing a body resin (A ′) and a precursor resin (B ′) of a thermoplastic polyimide resin (B) having a glass transition temperature in the range of 200 to 320 ° C. , the precursor resin (A ′) and Adhesiveness in which a mixed solution containing 30 to 85 parts by weight of the precursor resin (A ′) is applied to a total of 100 parts by weight of (B ′) and dried to have a thickness in the range of 0.1 to 3.0 μm. Forming a layer to be a layer (Y),
c) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y); and
d) a step of superimposing a metal foil on the surface of the adhesive layer (Y) and thermocompression bonding, or a step of depositing a metal thin film layer on the surface of the adhesive layer (Y),
Providing
And the value which remove | divided the thickness of the low thermal expansion polyimide resin layer (X) by the thickness of the adhesive layer (Y) exists in the range of 1-40, The manufacturing method of the metal-clad laminated board characterized by the above-mentioned. Next steps f) to h),
f) On the metal foil, the precursor resin (A ′) of the non-thermoplastic polyimide resin (A) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K ) and a glass transition temperature of 200 A mixed solution containing a precursor resin (B ′) of a thermoplastic polyimide resin (B) in a range of ˜320 ° C., with respect to a total of 100 parts by weight of the precursor resins (A ′) and (B ′) Applying a mixed solution containing 30 to 85 parts by weight of the precursor resin (A ′) and drying to form a layer to be an adhesive layer (Y) having a thickness in the range of 0.1 to 3.0 μm;
g) A low thermal expansion coefficient having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the layer to be the adhesive layer (Y) and drying it. Forming a layer to be the polyimide resin layer (X), and
h) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y);
Providing
And the value which remove | divided the thickness of the low thermal expansion polyimide resin layer (X) by the thickness of the adhesive layer (Y) exists in the range of 1-40, The manufacturing method of the metal-clad laminated board characterized by the above-mentioned. Next steps i) to m),
i) A precursor resin (A ′) of a non-thermoplastic polyimide resin (A) having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K ) and a glass transition temperature of 200 on a metal foil. A mixed solution containing a precursor resin (B ′) of a thermoplastic polyimide resin (B) in a range of ˜320 ° C., with respect to a total of 100 parts by weight of the precursor resins (A ′) and (B ′) Applying a mixed solution containing 30 to 85 parts by weight of the precursor resin (A ′) and drying to form a layer to be an adhesive layer (Y) having a thickness in the range of 0.1 to 3.0 μm;
j) A low thermal expansion coefficient having a linear thermal expansion coefficient in the range of 1 to 30 (× 10 ⁻⁶ / K) by applying a polyamic acid solution on the adhesive layer (Y) and drying it. Forming a layer to be the polyimide resin layer (X) of
k) Furthermore, the mixed solution is applied onto the layer to be the low thermal expansion polyimide resin layer (X) and dried to form an adhesive layer (Y having a thickness in the range of 0.1 to 3.0 μm). A step of forming a layer to be)
l) imidization to form a low thermal expansion polyimide resin layer (X) and an adhesive layer (Y); and
m) including a step of superimposing a metal foil on the surface layer of the adhesive layer (Y) and thermocompression bonding, or a step of depositing a metal thin film layer on the surface layer of the adhesive layer (Y).
And the value which remove | divided the thickness of the low thermal expansion polyimide resin layer (X) by the thickness of the adhesive layer (Y) exists in the range of 1-40, The manufacturing method of the metal-clad laminated board characterized by the above-mentioned.