JP5215182B2 - Method for modifying surface of polyimide resin layer and method for producing metal-clad laminate - Google Patents

Description

  The present invention relates to a surface treatment method for a polyimide resin layer and a method for producing a metal-clad laminate in which a polyimide resin layer is laminated on a metal foil, and more specifically, a surface treatment method for a polyimide resin layer suitable for a printed wiring board and The present invention relates to a method for producing a metal-clad laminate.

  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 forming a conductive pattern based on electrical design on the surface (and inside) of an insulating substrate with a conductive material. Depending on the type of insulating resin used as a substrate, a plate-shaped rigid printed wiring board And flexible printed wiring boards that are flexible. 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. 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. It is a laminated board 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. In addition, a flexible substrate having a copper foil layer on both sides is also known, and after manufacturing a single-sided flexible substrate having a copper foil layer on one side, a method of laminating two single-sided flexible substrates on each other or a single-sided flexible substrate A method of laminating copper foils is known. Also in this case, a flexible substrate that does not include an adhesive layer or an adhesion-imparting layer is desired.

  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 increase the fine pitch. In order to increase the density and fine pitch of a printed wiring board, it has been desired to use a copper foil having a low surface roughness. However, a copper foil having a low surface roughness has a small anchoring effect, that is, the biting of the insulating resin layer into the irregularities on the surface of the copper foil, so that the mechanical adhesive strength cannot be obtained, and therefore the adhesive strength to the insulating resin is low. There was a problem. Therefore, it is an issue to increase the adhesive force between the copper foil having a low surface roughness and the insulating resin.

  Polyimide resins are generally known to have poor adhesion. In addition, the base film layer of the laminate used for the printed wiring board is desired to be a polyimide resin layer having a low thermal expansion coefficient in order to prevent the occurrence of curling. There are conflicting relationships. In order to improve the adhesive strength, various surface modification techniques for polyimide films have been reported. As an example, there is a surface modification method by plasma treatment, but there is a problem that an expensive apparatus is required and a running cost is increased. Examples of the method for modifying the surface of a polyimide film by plasma treatment include, for example, JP-A-5-222219, JP-A-8-12779, JP-A-11-209488, JP-A-2004-51712, JP-A-2006. Specific examples are disclosed in Japanese Patent Publication No. 7518. However, in these conventional technologies, it is currently impossible to obtain a satisfactory adhesive strength between the copper foil having a low surface roughness and the polyimide resin layer.

  In addition, a surface modification method by wet etching, which is advantageous in terms of cost, is attracting attention, but in general, adhesion is not sufficient as compared with a surface modification method by dry etching such as plasma treatment, so this point is further improved. There was a need for improvement. As such a surface modification method by wet etching, for example, JP-A-11-49880 can be cited. According to this, a method of thermocompression bonding between a polyimide treated in a polar solvent containing an aliphatic primary amine and a metal via a polyimide adhesive is disclosed. However, this method has a problem that it is necessary to provide a polyimide adhesive layer, and the insulating resin layer becomes thick.

JP-A-5-222219 Japanese Patent Laid-Open No. 8-12779 JP-A-11-209488 JP 2004-51712 A JP 2006-7518 A JP 11-49880 A

  An object of the present invention is to improve the adhesion by modifying the surface of a polyimide resin layer. In addition, the surface of a low thermal expansion polyimide resin layer suitable as a base film layer is modified to improve adhesiveness, and the adhesive polyimide resin layer or adhesive layer that becomes an adhesion-imparting layer can be omitted. Objective. Another object is to provide a method for producing a copper clad laminate having an extremely thin adhesive layer, and to ensure that the insulating resin layer is extremely thin while ensuring sufficient adhesive strength to meet the fine pitch of printed circuit boards. It aims at providing the manufacturing method of the copper clad laminated board which can respond also to this. Another object of the present invention is to improve an adhesion method in which polyimide resin layer surfaces are superposed and thermocompression bonded. Another object is to provide a method for producing a double-sided metal-clad laminate.

  In order to achieve the above object, the present inventors have studied, and by appropriately improving the wet etching method, the polyimide resin layer using the wet etching method has almost no change in the thickness of the polyimide resin layer. The inventors have found that an excellent adhesive polyimide resin layer having high adhesive strength with a metal foil can be provided, and have completed the present invention.

  The present invention includes: a) a step of treating the surface of the polyimide resin layer with an aqueous alkali solution to form an alkali treated layer; and b) impregnating and drying a polar solvent solution containing an amino compound on the surface of the alkali treated layer. And a step of forming an amino compound-containing layer. The present invention relates to a method of forming a modified layer on the surface of a polyimide resin layer.

  The present invention also includes a) a step of treating the surface side of the polyimide resin layer with an aqueous alkali solution to form an alkali-treated layer, and b) impregnating and drying a polar solvent solution containing an amino compound on the surface of the alkali-treated layer. Forming a modified layer on the surface of the polyimide resin layer comprising: a step of forming an amino compound-containing layer; and c) a step of imidizing the amino compound-containing layer to form a modified imidized layer. Regarding the method.

The present invention also relates to a method for producing a metal-clad laminate comprising: I) a step of forming a modified layer on the surface of the polyimide resin layer; and II) a step of forming a metal layer on the surface of the modified layer. ,
Step I)
a) a step of forming an alkali-treated layer by treating the surface of the polyimide resin layer with an alkaline aqueous solution; and b) impregnating and drying a polar solvent solution containing an amino compound on the surface of the alkali-treated layer to contain an amino compound-containing layer. And a step of forming a metal-clad laminate.

  The present invention also includes a) a step of treating the surface side of the polyimide resin layer with an aqueous alkali solution to form an alkali-treated layer, and b) impregnating and drying a polar solvent solution containing an amino compound on the surface of the alkali-treated layer. And a step of forming an amino compound-containing layer and d) a step of superimposing a metal foil on the surface of the amino compound-containing layer and thermocompression bonding.

  Further, the present invention includes a) a step of treating the surface side of the polyimide resin layer with an alkaline aqueous solution to form an alkali treated layer, and b) impregnating and drying a polar solvent solution containing an amino compound on the alkali treated layer surface. And forming a metal thin film layer on the surface of the amino compound-containing layer, and a method for producing a metal-clad laminate.

  The present invention also includes a) a step of treating the surface side of the polyimide resin layer with an aqueous alkali solution to form an alkali-treated layer, and b) impregnating and drying a polar solvent solution containing an amino compound on the surface of the alkali-treated layer. Forming an amino compound-containing layer, c) imidizing the amino compound-containing layer to form a modified imidized layer, and d) overlaying a metal foil on the surface of the modified imidized layer. And a method of manufacturing a metal-clad laminate including the steps of thermocompression bonding.

  Further, the present invention includes a) a step of treating the surface side of the polyimide resin layer with an alkaline aqueous solution to form an alkali treated layer, and b) impregnating and drying a polar solvent solution containing an amino compound on the alkali treated layer surface. Forming an amino compound-containing layer, c) imidizing the amino compound-containing layer to form a modified imidized layer, and e) forming a metal thin film layer on the surface of the modified imidized layer. The manufacturing method of a metal-clad laminated board provided with the process to form.

In addition, the present invention is a method of bonding the polyimide resin layer by overlapping the first polyimide resin layer surface and the second polyimide resin layer surface,
A) For the first polyimide resin layer surface, a) a step of forming an alkali treatment layer by treating the surface side layer of the polyimide resin layer (P1) with an alkaline aqueous solution,
B) For the second polyimide resin layer, a) a step of treating the surface side of the polyimide resin layer (P2) with an alkaline aqueous solution to form an alkali treatment layer, b) a polarity containing an amino compound on the alkali treatment layer surface A step of impregnating and drying a solvent solution to form an amino compound-containing layer;
C) A process of superimposing the amino compound treatment layer surface of the second polyimide resin layer (P2) on the alkali treatment layer surface of the first polyimide resin layer (P1) and thermocompression bonding,
The present invention relates to a method for bonding a polyimide resin layer.

Furthermore, the present invention provides a method for producing a double-sided metal-clad laminate having a metal foil on both sides of a polyimide resin layer by laminating and bonding two single-sided metal-clad laminates having a metal foil on one side of a polyimide resin layer.
A) For the first single-sided metal-clad laminate, a) a step of treating the surface side of the polyimide resin layer (P1) with an alkaline aqueous solution to form an alkali-treated layer;
B) For the second single-sided metal-clad laminate, a) a step of treating the surface side of the polyimide resin layer (P2) with an alkaline aqueous solution to form an alkali-treated layer, b) an amino compound on the surface of the alkali-treated layer A step of impregnating and drying a polar solvent solution to form an amino compound-containing layer;
C) The process of superimposing the amino compound-containing layer surface of the polyimide resin layer (P2) of the second single-sided metal-clad laminate on the alkali-treated layer surface of the polyimide resin layer (P1) of the first single-sided metal-clad laminate, and thermocompression bonding The present invention relates to a method for producing a double-sided metal-clad laminate.

  The thickness of the alkali treatment layer formed in step a) is preferably in the range of 0.005 to 3.0 μm. Moreover, the polyimide resin layer can be a polyimide resin layer that forms the surface layer of the laminate, or can be a polyimide resin layer that forms the surface layer of the polyimide resin film.

The amino compounds used in step b) above are advantageously selected from aliphatic amines having at least three primary amino groups as functional groups and diaminosiloxanes .

  Examples of the silane coupling agent having an amino group include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (amino At least one selected from ethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine and N-phenyl-3-aminopropyltrimethoxysilane; is there.

ここで、Ar₂及びAr₇は２価の炭化水素基を示し、R₃〜R₆は炭素数１〜６の炭化水素基を示し、mは１〜２０の数を示す。As diaminosiloxane, there is a diaminosiloxane oligomer represented by the following general formula (1).

Here, Ar < ₂ > and Ar < ₇ > show a bivalent hydrocarbon group, R < ₃ > -R < ₆ > shows a C1-C6 hydrocarbon group, m shows the number of 1-20.

  As the metal foil used in the thermocompression performed in the step d) or d2), a copper foil, a copper alloy foil or a stainless steel foil is preferable.

  Hereinafter, the present invention will be described in detail.

  The polyimide resin layer used in the present invention is not particularly limited, and may be a film (sheet) made of polyimide resin, and is a polyimide laminated on a substrate such as a copper foil, a glass plate, or a resin film. It may be a resin layer. The base material here refers to a sheet-like resin or metal foil on which a polyimide resin layer is laminated. However, at least one surface of the polyimide resin layer exists as a surface layer. The thickness of the polyimide resin layer is in the range of 3 to 100 μm, preferably 3 to 50 μm. By performing surface treatment, the polyimide resin layer has at least two layers of an initial polyimide resin layer (unmodified polyimide resin layer) and a modified layer.

  Examples of the polyimide resin that forms the polyimide resin layer include heat-resistant resins having an imide group in the structure such as polyamide imide, polybenzimidazole, polyimide ester, polyether imide, and polysiloxane imide, including so-called polyimide resins. Moreover, a commercially available polyimide resin or a polyimide film can also be used conveniently.

Among the polyimide resin layers, the method of the present invention is suitable for a polyimide resin layer having low adhesion and low thermal expansion. Specifically, the coefficient of thermal expansion is 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), preferably 1 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K), and more preferably 15 ×. When applied to a low thermal expansion polyimide resin layer of 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K), a great effect is obtained. However, it can also be applied to a polyimide resin layer that exceeds the thermal linear expansion coefficient, and improves adhesion.

但し、Ar₁は式(3)又は式(4)で表される4価の芳香族基を示し、Ar₃は式(5)又は式(6)で表される2価の芳香族基を示し、R₁は独立に炭素数1〜6の1価の炭化水素基又はアルコキシ基を示し、X及びYは独立に単結合又は炭素数1〜15の2価の炭化水素基、O、S、CO、SO、SO₂若しくはCONHから選ばれる2価の基を示し、nは独立に0〜4の整数を示し、qは構成単位の存在モル比を示し、0.1〜1.0の範囲である。As a polyimide resin used for a polyimide resin layer, the polyimide resin which has a structural unit represented by General formula (2) is preferable.

However, Ar ₁ represents a tetravalent aromatic group represented by Formula (3) or Formula (4), and Ar ₃ represents a divalent aromatic group represented by Formula (5) or Formula (6). R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, X and Y independently represent a single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms, O, S , CO, SO, SO ₂ or CONH represents a divalent group, n independently represents an integer of 0 to 4, q represents an abundance ratio of structural units, and ranges from 0.1 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 resins having such a structural unit, a polyimide resin that can be suitably used is a non-thermoplastic polyimide resin.

Since a polyimide resin is generally produced by reacting a diamine and an acid dianhydride, a specific example of the polyimide resin can be understood by explaining the diamine and the acid dianhydride. In the general formula (1), Ar ₃ can be referred to as a diamine residue, and Ar ₁ can be referred to as an acid dianhydride residue. Therefore, a preferred polyimide resin will be described using a diamine and an acid dianhydride. However, it is not limited to the polyimide 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'- 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'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4 ''-diamino-p-terphenyl, 3,3 ' '-Diamino-p-terphenyl, 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-biphenyl (β-amino-t-butyl) toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, Examples include 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like.

Examples of the acid dianhydride include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride 4,4′-oxydiphthalic anhydride is preferred.
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 dianhydrides 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 Dianhydride, 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-tetraca Rubonic 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, 4,4-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride and the like.

  Each of diamine and acid dianhydride may be used alone or in combination of two or more. In addition, other diamines and acid dianhydrides that are not included in the general formula (1) can be used together with the above diamine or acid dianhydride, and in this case, the proportion of other diamines or acid dianhydrides used. Is 90 mol% or less, preferably 50 mol% or less. By selecting the type of diamine and acid dianhydride, or the molar ratios when using two or more diamines or acid dianhydrides, thermal expansion, adhesion, glass transition point (Tg), etc. Can be controlled.

  The method for producing the polyimide resin layer is not particularly limited. For example, after applying a polyamic acid resin solution, which is a polyimide resin precursor, on the substrate, it is dried and imidized to form the polyimide resin layer on the substrate. There is a way. The method for applying the polyamic acid resin solution on the substrate is not particularly limited, and it can be applied by a coater such as a comma, a die, a knife, or a lip.

  Moreover, the method of drying and imidation is not particularly limited, and for example, heat treatment such as heating for 1 to 60 minutes at a temperature of 80 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 on the substrate. The polyimide resin layer in which the polyimide resin layer is formed on the substrate may be used as it is, or may be used after being peeled off.

  The polyimide resin layer may be formed of only a single layer or may be formed of a plurality of layers. In the case where a plurality of polyimide resin layers are used, other polyimide resins can be sequentially formed on a polyimide resin layer made of different components. When the polyimide resin layer is composed of three or more layers, the polyimide resin having the same configuration 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. The polyimide resin layer has a thickness in the range of 3 to 100 μm, preferably 3 to 50 μm, more preferably 5 to 30 μm.

  In the method for forming a modified layer on the surface of the polyimide resin layer of the present invention, a) a step of forming an alkali treatment layer by treating the surface side of the polyimide resin layer with an aqueous alkali solution (step a), b) A step (step b) of forming an amino compound-containing layer by impregnating and drying a polar solvent solution containing an amino compound on the surface of the alkali treatment layer. Further, if necessary, c) a step of imidizing the amino compound-containing layer to form a modified imidized layer (step c) is provided.

  In the method for producing a metal-clad laminate of the present invention, a step of forming a modified layer on the surface of the polyimide resin layer (Step I)) and a step of forming a metal layer on the surface of the modified layer (Step II)) With. Here, the step I) includes the step a and the step b. If necessary, a step c is provided. Step II) is a step (d) in which metal foil is superimposed on the surface of d) an amino compound-containing layer or a modified imidized layer (both are called modified layers) and thermocompression-bonded (step d), or e) the amino compound-containing layer Forming a metal thin film layer on the surface of the layer or the modified imidized layer (step e). Step d is a step of superimposing a metal foil on the surface of the amino compound-containing layer or the modified imidized layer and thermocompression bonding. When distinguishing the cases of pressure bonding, the former is referred to as step d1, and the latter is referred to as step d2. Similarly, step e is a step of forming a metal thin film layer on the surface of the amino compound-containing layer or the modified imidized layer. When distinguishing, the former is referred to as step e1, and the latter is referred to as step e2.

  In the method for bonding a polyimide resin layer and the method for producing a double-sided metal-clad laminate of the present invention, in addition to the above steps a and b, a second polyimide resin layer is formed on the alkali-treated layer surface of the first polyimide resin layer (P1). A step (step C) in which the amino compound-containing layer surface of (P2) is superposed and thermocompression bonded.

  Steps a and b can be performed in the same manner regardless of the case. The same applies to the other steps c to e. Therefore, the process a, the process b, and the process c will be described as a representative method for forming a modified layer on the surface of the polyimide resin layer.

  In step a, the surface layer of the polyimide resin layer is treated with an alkaline aqueous solution to form an alkali-treated layer. As the alkaline aqueous solution, it is preferable to use an alkaline aqueous solution of sodium hydroxide or potassium hydroxide having a liquid temperature of 0.5 to 50 wt% and a liquid temperature of 5 to 80 ° C., and dipping, spraying, brushing, etc. can be applied. it can. For example, when applying the dipping method, it is effective to perform the treatment for 10 seconds to 60 minutes. The treatment is preferably carried out with an alkaline aqueous solution of 1 to 30 wt% and a liquid temperature of 25 to 60 ° C. for 30 seconds to 10 minutes. Depending on the structure of the polyimide resin layer, the processing conditions can be appropriately changed. In general, when the concentration of the alkaline aqueous solution is low, the surface treatment time of the polyimide resin layer becomes long. Further, when the temperature of the alkaline aqueous solution increases, the processing time is shortened. When the treatment is performed with the alkaline aqueous solution, the alkaline aqueous solution penetrates from the surface side of the polyimide resin layer, and the polyimide resin layer is alkali-treated. This alkali treatment reaction is considered to be mainly hydrolysis of imide bonds. The thickness of the alkali treatment layer formed by the alkali treatment is 1/200 to 1/2, preferably 1/100 to 1/5 of the polyimide resin layer thickness. Moreover, from another viewpoint, 0.005-3.0 micrometers, Preferably it is 0.05-2.0 micrometers, More preferably, 0.1-2.0 micrometers is good. Furthermore, from another viewpoint, 0.005 to 0.1 μm, preferably 0.01 to 0.1 μm, and more preferably 0.05 to 0.1 μm is preferable (for example, in the case of subjecting to step e). When the thickness of the alkali treatment layer is out of the above range, sufficient adhesion strength between the polyimide resin layer and the metal layer is hardly exhibited. When the polyimide resin layer is a polyimide resin film, both surfaces may be modified at the same time.

  In the alkali treatment layer formed by the alkali treatment, a salt of an alkali metal and a carboxyl group at the end of the polyimide resin due to the alkali aqueous solution may be formed, and therefore it is preferable to wash with an acid aqueous solution. Any aqueous solution can be used as long as it is acidic. In particular, an aqueous hydrochloric acid solution or an aqueous sulfuric acid solution is preferable. Further, the concentration is preferably in the range of 0.5 to 50 wt%, but preferably in the range of 0.5 to 5 wt%. More preferably, the pH is 2 or less. Then, after washing with water, it is good to dry and use for the process b.

  In step b, the surface of the alkali-treated layer is impregnated with a polar solvent solution containing an amino compound and dried to form an aromatic amino compound-containing layer. Preferred examples of the amino compound include aromatic amino compounds, aliphatic amino compounds, silane coupling agents having amino groups, diaminosiloxanes, and polyimide precursor resins.

The aromatic amino compound is preferably an aromatic amine having a primary or secondary amino group, particularly an aromatic amine in which the primary amino group is substituted with an aromatic ring. The number of amino groups is 1-5, preferably 1-3, more preferably 2. The molecular weight of the aromatic amino compound is 90 to 1000, preferably 100 to 600, and more preferably 110 to 500. Examples of the aromatic amino compound include compounds having at least 1, preferably 1 to 10, and preferably 1 to 4 aromatic rings. The aromatic ring is substituted with a substituent other than an amino group. It may or may not be. As the substituent other than the amino group, those having a functional group capable of condensation polymerization with a terminal carboxyl group present in the alkali-treated layer, such as a hydroxyl group and a mercapto group are preferable. Examples of the aromatic ring include condensed rings such as a benzene ring and a naphthalene ring. Compounds having a plurality of aromatic rings include Ar-X-Ar, Ar-Y-Ar-X-Ar-Y-Ar (where Ar is an aromatic ring such as a benzene ring) in addition to a biphenyl ring, etc. , X and Y are independently compounds in which an amino group is substituted on a divalent group such as CO, O, S, SO, SO ₂ , CONH and C _n H _2n ). Examples of the substituent other than the amino group include a branched or straight chain alkyl group having 1 to 18 carbon atoms (for example, methyl, ethyl, propyl, etc.), and an aromatic group having 6 to 13 carbon atoms (for example, , Phenyl), an aralkyl group having 7 to 12 carbon atoms (for example, benzyl) and the like. Hydroxyl groups can also be used as aromatic ring substituents. An example of a compound having an aromatic ring substituted with a hydroxyl group is aminophenol. Furthermore, a condensed ring system having 10 to 20 carbon atoms can be used as the aromatic amine group-containing compound of the present invention. One example of a fused ring system that can be used in the present invention is diaminonaphthalene.

  Although the specific example of an aromatic amino compound is shown next, it is not restricted to this. One or more aromatic amino compounds can be used.

  Aniline, toluidine, aminonaphthalene, aminobiphenyl, 2,2-bis- [4- (4-aminophenoxy) phenyl] propane, 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-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy)] benzophenone Bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 '-(4-aminophenoxy)] benzanilide, bis [4,4'-(3-aminophenoxy)] benzanilide, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) phenyl] fluorene, 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoro Propane, 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'-diaminodiphenylpropane, 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'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4 ''-diamino-p -Terphenyl, 3,3 ″ -diamino-p-terphenyl, 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-aminocyclohex ) 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, 2,5-diaminopyridine, 2 , 5-diamino-1,3,4-oxadiazole, piperazine and the like.

  The aliphatic amino compound is preferably an aliphatic amine having at least three primary amino groups as functional groups. Such aliphatic amino compounds are preferably composed of only carbon atoms, hydrogen atoms and nitrogen atoms, and specific examples include tris (2-aminoethyl) amine. In the case where the polyimide resin layer is bonded to the metal layer, when an aliphatic amine not having three or more primary amino groups is used, sufficient adhesive strength between the polyimide resin layer and the metal layer is hardly exhibited.

  Examples of the silane coupling agent having an amino group include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (amino At least one selected from ethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine and N-phenyl-3-aminopropyltrimethoxysilane There should be. In particular, 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane are preferable.

  As diaminosiloxane, diaminosiloxane represented by the above general formula (1) is preferably used. A specific example is preferably a diaminosiloxane represented by the following formula.

上式において、平均のm数は、１〜２０の範囲であり、好ましくは５〜１５の範囲である。この範囲を超えると銅箔との接着性が低下する。

In the above formula, the average m number is in the range of 1-20, preferably in the range of 5-15. If it exceeds this range, the adhesiveness with the copper foil is lowered.

As a polyimide precursor resin, the polyimide precursor resin which has a structural unit represented by General formula (7) is preferable. In General Formula (7), Ar ₄ represents a divalent aromatic group represented by Formula (8) or Formula (9), and Ar ₅ represents a tetravalent group represented by Formula (10) or Formula (11). R ₂ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and V and W independently represent a single bond or a divalent hydrocarbon having 1 to 15 carbon atoms. A divalent group selected from a group, O, S, CO, SO ₂ or CONH, m independently represents an integer of 0 to 4, p represents a mole of a structural unit, and ranges from 0.1 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.

In the general formula (7), Ar ₄ can be referred to as a diamine residue, and Ar ₅ can be referred to as an acid dianhydride residue. Therefore, a preferred polyimide resin will be described using diamine and 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′-diphenylsulfone tetracarboxylic 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 polyimide precursor resin is selected from the types of diamine and acid dianhydride, and when two or more diamines or acid dianhydrides are used, the respective molar ratios are selected, and these diamines and acid dianhydrides are used as organic solvents. For example, it can be obtained by reaction at a temperature of 20 to 60 ° C. Advantageously, the diamine should be in an excess condition relative to the acid dianhydride or in a condition where the end of the polyimide precursor resin is an amino group. That is, the ratio of the amount of diamine and acid dianhydride used should be more than 1.0 as diamine / acid dianhydride (molar ratio), preferably 1.001 to 10.0, more preferably 1.1 to 5.0, Particularly preferred is 1.5 to 3.0.

  Since the molecular weight increases as the molar ratio approaches 1.0, an oligomer having a low molecular weight can be obtained by increasing this ratio. In addition, when the molar ratio exceeds 2.0, unreacted diamine remains, but this is removed when drying or imidizing, and reacts with the carboxyl group at the end of the polyimide resin present in the alkali treatment layer. And enhance the surface treatment effect.

  The polyimide precursor resin may be an oligomer having a weight average molecular weight of 500 to 20,000, preferably 2,000 to 10,000, more preferably 3,000 to 6,000. By applying such a low molecular weight type polyimide precursor resin, the alkali treatment layer can be easily impregnated with the polyimide precursor resin, and most of the alkali treatment layer can be changed to a modified imidized layer. Furthermore, the thickness of the entire polyimide resin layer can be almost unchanged before and after the surface treatment of the polyimide resin layer (before step a and after step c).

  One or more of these amino compounds can be used, and two or more selected from aromatic amino compounds, aliphatic amino compounds, silane coupling agents having amino groups, diaminosiloxanes and polyimide precursor resins are used. can do.

  These amino compounds are used as solutions in polar solvents. The polar solvent is not particularly limited as long as it dissolves an amino compound. For example, polar solvents suitable for aromatic amino compounds, aliphatic amino compounds, silane coupling agents having amino groups, diaminosiloxanes and polyimide precursor resins include water or alcohols such as methanol, ethanol, propanol, butanol, Or, ketones such as acetone, dimethyl ketone, and methyl ethyl ketone; ethers such as tetrahydrofuran; tertiary amines such as N-methylpyrrolidone, dimethylacetamide, and dimethylformamide; and dimethyl sulfoxide. Suitable polar solvents for diaminosiloxane include alcohol solvents such as methanol, ethanol, propanol, isopropanol, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide Amide solvents such as N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ether solvents such as dioxane medium, acetone , Ketone solvents such as MEK, 2-pentanone, 3-pentanone, and γ-butyrolactone, and aromatic hydrocarbon solvents such as toluene and xylene. These may be used alone, or may be used by mixing several kinds thereof, or may be mixed with water. Preferably, it is methanol.

  The concentration of the solution of the polar solvent containing these amino compounds is 0.0001 to 1M (0.0001 to 1 mol / L), preferably 0.0001 to 0.1M, more preferably 0 as the concentration of the amino compound. It is suitable that it is in the range of 0.0005 to 0.1M, more preferably 0.0005 to 0.01M. The concentration of the polar solvent solution containing the polyimide precursor resin is preferably in the above range as the concentration in terms of the diamine component. From another point of view, the concentration of the polar solvent solution containing the amino compound, particularly the concentration of the silane coupling agent or diaminosiloxane solution is 0.1 to 5 wt%, preferably 0.5 to 1 wt%. .

  When the concentration of the amino compound is high, the amino compound solution is not only impregnated into the alkali treatment layer, but the amount of the amino compound solution adhering to the surface of the modified layer increases, so that a high concentration is not desirable.

  The impregnation method is not particularly limited as long as it can be brought into contact with a solution of a polar solvent containing an amino compound on the surface of the alkali treatment layer, 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 the impregnation time, when applying the dipping method, it is effective to treat for 30 seconds to 1 hour, preferably 1 to 15 minutes.

  Dry after impregnation. 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, and more preferably 30 to 120 ° C. for 1 minute to 10 minutes. For minutes.

  In this impregnation / drying treatment, a solution of a polar solvent containing an amino compound penetrates into the inside from the surface of the alkali treatment layer to form an amino compound-containing layer. The permeation thickness, that is, the thickness of the amino compound-containing layer may be 1/10 to 1.5 times, preferably 1/2 to 1.2 times, more preferably 0.8 to 1.2 times the thickness of the alkali treatment layer. The polyimide resin layer obtained by drying becomes a surface-treated polyimide resin layer having a modified layer whose surface is modified and adhesion is improved.

  Since the surface-treated polyimide resin layer in which the surface of the polyimide resin layer is modified in step a and step b has excellent adhesiveness, it is suitable for use with metal foils, resin films, other polyimide resin layers, and the like. In addition, the amino compound-containing layer is imidized by imidization to form a modified imidized layer. This modified imidized layer is also excellent in adhesiveness, so metal foil, resin film, other polyimide resin layers Suitable for adhesive applications.

  In the method for forming a modified layer on the surface of the polyimide resin layer of the present invention, it is preferable to include step c in addition to step a and step b.

  In step c, the amino compound-containing layer is imidized to form a modified imidized layer. Imidation can be either imidation by heating or chemical imidization using a catalyst, and is not limited. For example, when imidation by heating is performed, 100 to 400 ° C, preferably 150 to 400 ° C. It is preferable to completely imidize at a temperature of 1. In the case where imidization is insufficient, chemical imidization with a catalyst may be used in combination. In this imidization treatment, it is considered that the amino compound and a reaction in which the terminal carboxyl group present in the polyimide resin layer, particularly in the alkali treatment layer reacts, is imidized. Therefore, the polyimide resin having a low molecular weight and increased terminal carboxyl groups in step a is stabilized by imidizing the terminal in the state of low molecular weight in step c, and as a result, the adhesion of the polyimide resin layer is improved. It is thought to improve.

  In the method for forming a modified layer on the surface of the polyimide resin layer of the present invention, the thickness of the alkali-treated layer in step a is preferably in the range of 0.005 to 3.0 μm. The amino compound used in step b is preferably an aromatic amine having a primary or secondary amino group. And a polyimide resin layer may be a polyimide resin layer which forms the surface layer of a laminated body, and may be a polyimide resin layer which forms the surface layer of a polyimide resin film.

  Next, details of the method for producing the metal-clad laminate of the present invention will be described. The method for producing a metal-clad laminate includes a step I) of forming a modified layer and a step of providing a metal layer on the modified layer formed in step I).

  Step a and step b or step a, step b and step c in step I) can be performed in the same manner as the method for forming a modified layer on the surface of the polyimide resin layer. In the method for producing a metal-clad laminate, it is preferable to include step c in addition to step a and step b. The surface-treated polyimide resin layer obtained by this method is subjected to step II).

  Step II) is a step of providing a metal layer on the modified layer formed in step I). As a method of providing the metal layer, there is a method of overlaying a metal foil on the surface of the modified layer and thermocompression bonding (step d), or a method of forming a metal thin film layer (step e). The modified layer formed in step I) includes the modified layer obtained in step b and the modified layer obtained in step c, but step d and step e in step II) The same can be done for the modified layer. Examples of the metal constituting the metal layer include iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, stainless steel, tantalum, titanium, copper, lead, magnesium, manganese, and alloy foils thereof. . Among these, copper, copper alloy, or stainless steel is suitable. The thickness of the metal layer is 0.001 to 50 μm, preferably 0.1 to 30 μm.

  In step d, the method for thermocompression bonding 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.

  As metal foil, 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 foils and alloy foils thereof. Among these, copper foil (including 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. Moreover, although there is no restriction | limiting in the material of stainless steel foil, For example, stainless steel foil like 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 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 in 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. In particular, for copper foils used in applications where fine pitch is required, the surface roughness is suitably 10-point average roughness of 0.1 to 1.0 μm.

  As an example in which the metal foil is a stainless steel foil, there 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.

  The laminate obtained by the method for producing a metal-clad laminate of the present invention is a laminate having a metal foil on one or both sides of a polyimide resin layer. The laminated board which has metal foil on one side is obtained by laminating | stacking metal foil on the surface treatment polyimide resin layer obtained by the surface treatment method of this invention. When the surface-treated polyimide resin layer is laminated on a substrate such as glass or a resin film, it is made a laminated plate and then peeled off from the substrate as necessary. When the surface-treated polyimide resin layer is laminated on a metal foil such as a copper foil, a double-sided metal-clad laminate can be obtained by laminating the metal foil on the polyimide resin layer side. Moreover, the metal clad laminated board which has metal foil on both surfaces is obtained by laminating | stacking metal foil on this both sides, when both surfaces of the surface treatment polyimide resin layer are surface-treated other than said method. Further, after manufacturing a single-sided metal-clad laminate having a metal foil on one side, surface treatment of the polyimide resin layer is performed on at least one single-sided metal-clad laminate, It can also be manufactured by a method in which polyimide layers are superposed and thermocompression bonded.

  In the method for producing a metal-clad laminate of the present invention, the thickness of the alkali treatment layer in step a is preferably in the range of 0.005 to 3.0 μm. The amino compound used in step b is preferably an aromatic amine having a primary or secondary amino group. In addition, an aliphatic amine having at least three primary amino groups as functional groups is preferred. A silane coupling agent having an amino group is preferred. Moreover, diaminosiloxane is preferable. Moreover, a polyimide precursor resin is preferable.

  Next, a method for producing a metal-clad laminate including step e in step II) will be described. Steps a and b are carried out as described above, and then subjected to step e. In this method for producing a metal-clad laminate, it is preferable to include step c in addition to step a and step b. That is, when the step c is provided, a step e (step e2) of forming a metal thin film layer on the surface of the modified imidized layer in the step c is provided.

  In this method for producing a metal-clad laminate, the thickness of the alkali treatment layer in step a is preferably in the range of 0.005 to 3.0 μm. The amino compound used in step b is preferably an aromatic amine having a primary or secondary amino group. In addition, an aliphatic amine having at least three primary amino groups as functional groups is preferred. A silane coupling agent having an amino group is preferred. Moreover, diaminosiloxane is preferable. Moreover, a polyimide precursor resin is preferable.

In the step e, the method for forming the metal thin film layer 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 formation conditions of the metal thin film layer by the sputtering method, for example, argon gas is used as a 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 .

  For the formation of the metal thin film, copper is preferably used 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.

  Copper to be used 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 thin film in which these metals contain 2 or more types may be sufficient.

  The thickness of the copper thin film layer formed in step e (step e1 or step e2) may be in the range of 0.001 to 1.0 μm, preferably 0.01 to 0.5 μm, more preferably 0.00. It is 05-0.5 micrometer, More preferably, it is 0.1-0.5 micrometer. When the copper thin film layer is further thickened, it may be thickened by electroless plating or electrolytic plating.

Next, the adhesion method of the polyimide resin layer of the present invention will be described.
This is a method in which the polyimide resin layer surfaces of the first polyimide resin layer (P1) and the second polyimide resin layer (P2) are overlapped to adhere the polyimide resin layer, and have the following steps A), B) and C) .
A) The first polyimide resin layer (P1) is subjected to step a.
B) The second polyimide resin layer (P2) is subjected to steps a and b.
C) The amino compound-containing layer surface of the second polyimide resin layer (P2) is overlaid on the modified layer surface of the first polyimide resin layer (P1) and subjected to thermocompression bonding d3.
Here, step a and step b can be performed in the same manner as step a and step b described above. Step d3 can be performed in the same manner as step d described above.

  Prepare two polyimide resin layers, modify their surfaces, and bond them together. The first polyimide resin layer is referred to as a polyimide resin layer (P1), and the second polyimide resin layer is referred to as a polyimide resin layer (P2). The polyimide resin layer (P1) and the polyimide resin layer (P2) may be the same or different. That is, it may be the same or different in the type of polyimide resin, the laminated structure of the polyimide resin layer, the presence or absence of a substrate, and the like. The polyimide resin layer (P1) or the polyimide resin layer (P2) can be made of a single layer, but can be made of a plurality of layers. In the case of being composed of a plurality of layers, the adhesiveness is determined by the polyimide resin layer of the surface layer. Therefore, the description relating to the improvement of the adhesiveness or the surface treatment is mainly understood as the description of the polyimide resin layer of the surface layer.

  The first polyimide resin layer (P1) is attached to step a, and the second polyimide resin layer (P1) is attached to step a and step b. Then, it attaches | subjects to process d3. If necessary, a washing step, a cutting step, etc. can be added before and after these steps.

  In step d3, the amino compound treatment layer surface of the polyimide resin layer (P2) is superposed on the alkali treatment layer surface of the polyimide resin layer (P1) (the alkali treatment layer surface and the amino compound treatment layer surface are referred to as surface treatment layer surfaces), and thermocompression bonded. The surface treatment layer surface may be both surfaces or one surface. If the surface treatment layer surface is a double-sided surface, it can be laminated in three or more layers.

  The method for thermocompression bonding is not particularly limited, and the same method as in step d described in the method for producing a metal-clad laminate can be employed. If thermocompression bonding is performed under a temperature condition that causes imidization, the amino compound-containing layer is a modified imidized layer for the second polyimide resin layer (P2) subjected to steps a and b by this thermocompression bonding. Form. Thereby, adhesive force improves more.

  When both the polyimide resin layer (P1) and the polyimide resin layer (P2) do not have a metal foil, a laminate of the polyimide resin layer (P1) and the polyimide resin layer (P2) is obtained. When one or more of the polyimide resin layer (P1) and the polyimide resin layer (P2) have a substrate such as a film, the polyimide resin layer (P1) and the polyimide resin layer (P2 ) Is obtained. This substrate can be peeled off if necessary. When the physical properties of the polyimide resin layer (P1) and the polyimide resin layer (P2) are different, it is possible to have good physical properties of each. Furthermore, if necessary, one or more layers of the polyimide resin layer (P1) and the polyimide resin layer (P2) can be multilayered to form a laminate of three or more layers. A laminate suitable for a printed wiring board can be obtained by thermocompression bonding a metal foil to one or both sides of a laminate having a polyimide resin layer on the surface.

  If either polyimide resin layer (P1) or polyimide resin layer (P2) has a metal foil on one side of the polyimide resin layer and the other does not have a metal foil, this thermocompression bonding A metal-clad laminate can be obtained. Also in this case, when the physical properties of the polyimide resin layer (P1) and the polyimide resin layer (P2) are different, it is possible to have good physical properties of each. Furthermore, a double-sided metal-clad laminate can be obtained by thermocompression bonding a metal foil to the polyimide resin layer surface of the single-sided metal-clad laminate.

  When the polyimide resin layer (P1) and the polyimide resin layer (P2) have a metal foil on one side of the polyimide resin layer, a double-sided metal-clad laminate can be obtained by this thermocompression bonding. Also in this case, when the physical properties of the polyimide resin layer (P1) and the polyimide resin layer (P2) are different, it is possible to have good physical properties of each.

Next, the manufacturing method of the double-sided metal-clad laminate of the present invention will be described in detail.
Two double-sided metal-clad laminates having metal foil on both sides of the polyimide resin layer are manufactured by superimposing and bonding two single-sided metal-clad laminates having metal foil on one side of the polyimide resin layer.
A) For the first single-sided metal-clad laminate, the surface side layer of the polyimide resin layer (P1) is subjected to step a.
B) The second single-sided metal-clad laminate is subjected to step a and step b.
C) The process of superimposing the amino compound treatment layer surface of the polyimide resin layer (P2) of the second single-sided metal-clad laminate on the alkali treatment layer side of the polyimide resin layer (P1) of the first single-sided metal-clad laminate, and thermocompression bonding Attach to step d3.
Here, step a, step b, and step d3 can be performed as described above.

  Here, A) Step a performed for the first single-sided metal-clad laminate, B) Steps a and b performed for the second single-sided metal-clad laminate, and C) First single-sided metal-clad laminate The step d3 of thermocompression bonding the second single-sided metal-clad laminate is the polyimide according to the present invention, except that the prepared polyimide resin layer is a polyimide resin layer of a single-sided metal-clad laminate having a metal foil on one side. Since it is the same as Step A), Step B) and Step C), or Step a, Step b and Step d3 described in the method for bonding the resin layer, it can be performed in the same manner.

  As metal foil, 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 foils and alloy foils thereof. Among these, copper foil, copper alloy, or stainless steel foil is suitable. 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 for this purpose is in the range of 3 to 50 μm, more preferably in the range of 5 to 30 μm, but the double-sided copper-clad laminate used in applications where fine pitch is required A thin copper foil (including a copper alloy foil) is preferably used, and in this case, a range of 5 to 20 μm is suitable.

  As an example in which the metal foil is a stainless steel foil, there 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.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the examples of the present invention, various measurements and evaluations are as follows unless otherwise specified.

[Measurement of adhesive strength]
The measurement of adhesive strength was evaluated by measuring 180 °, 10 mm peel strength at room temperature for a sample cut into a 10 mm wide strip using a Tensilon tester (manufactured by Toyo Seiki Seisakusho). As a criterion for determining the adhesive strength, a case where the adhesive strength was 0.4 kN / m or more was accepted, and a case where it was less than 0.4 kN / m was rejected. Further, the case where the adhesive strength is 0.4 kN / m or more and less than 0.6 kN / m is good, and the case where the adhesive strength is 0.6 kN / m or more is good.

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

[Measurement of linear thermal expansion coefficient]
Using a thermomechanical analyzer (manufactured by Seiko Instruments Inc.), the temperature was raised to 250 ° C., held at that temperature for 10 minutes, cooled at a rate of 5 ° C./minute, and the average linear thermal expansion from 240 ° C. to 100 ° C. The coefficient (CTE) was determined.

[Measurement of modified layer thickness]
The cross section of the sample was observed using a scanning transmission electron microscope (manufactured by Hitachi High-Technologies Corporation), and the thickness of the modified layer was confirmed.

The abbreviations used in the examples represent the following compounds.
BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] propane
HAB: 4,4 '-(3,3'-dihydroxy) diaminobiphenyl
TAPM: Tris (4-aminophenyl) methanol
TAEA: Tris (2-aminoethyl) amine
DAPE: 3,4'-diaminodiphenyl ether
APES: 3-aminopropylethoxysilane
ASD: 4,4'-diaminobiphenyl sulfide
DABA: 4,4'-Diaminobenzanilide
EDA: Ethylenediamine
ETA: Ethanolamine
PSX-Me: Diaminosiloxane represented by the following formula (12) (however, the average m number is in the range of 1 to 20 and the average molecular weight is 740).
PSX-Ph: diaminosiloxane represented by the following formula (13) (however, the total number of j and n is in the range of 2 to 20, j and n are both 1 or more, and the average molecular weight is 1,320) .)

In measuring the adhesive strength of a commercially available polyimide resin layer, the following three types of polyimide films having a thickness of 25 μm were prepared.
1) Kapton EN: manufactured by Toray DuPont, 100 mm x 100 mm x 25 μm, coefficient of linear thermal expansion 16 x 10 ^-6 / K
2) Apical NPI: 100 mm × 100 mm × 25 μm, Kaneka Chemical Co., Ltd., linear thermal expansion coefficient 16 × 10 ⁻⁶ / K
3) Upilex 25S: Ube Industries, Ltd. 100mm x 100mm x 25μm, linear thermal expansion coefficient 12 x ^10-6 / K

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, of course, this invention is not limited to this.

Reference example 1
To 425 g of N, N-dimethylacetamide, 31.8 g of 2,2′-dimethyl-4,4′-diaminobiphenyl and 4.9 g of 1,3-bis (4-aminophenoxy) benzene at room temperature for 30 minutes Stir. Thereafter, 28.6 g of pyromellitic dianhydride and 9.6 g of biphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride were added, and the solution was stirred at room temperature for 3 hours under a nitrogen atmosphere. A polyamic acid resin solution having a viscosity of 28,000 poise was obtained. This polyamic acid resin solution is applied to a stainless steel substrate, dried at 130 ° C. for 5 minutes, heated to 360 ° C. over 15 minutes to complete imidization, and a polyimide film 1 laminated on the stainless steel substrate is obtained. It was. This polyimide film 1 was peeled from the stainless steel substrate. The obtained film 1 had a thermal linear expansion coefficient of 21 × 10 ⁻⁶ / K, and the polyimide layer had a thickness of 25 μm.

Reference example 2
To 200 g of N, N-dimethylacetamide, 14.9 g of 4,4′-diamino-2,2′-dimethylbiphenyl and 6.01 g of 4,4′-diaminodiphenyl ether were stirred at room temperature for 30 minutes. Thereafter, 21.4 g of pyromellitic dianhydride was added and stirred at room temperature for 3 hours under a nitrogen atmosphere to obtain a polyamic acid resin solution having a solution viscosity of 12,000 poise. This polyamic acid resin solution is applied to a stainless steel substrate, dried at 130 ° C. for 5 minutes, and heated to 360 ° C. over 15 minutes to complete imidization to form a stainless steel substrate. A laminated polyimide film 2 was obtained. This polyimide film 2 was peeled from the stainless steel substrate. The film 2 obtained had a thermal linear expansion coefficient of 24 × 10 ⁻⁶ / K, and the polyimide layer had a thickness of 25 μm.

Reference example 3
0.41 g (0.001 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane dissolved in 50 ml of diethylene glycol dimethyl ether, 0.161 g (0.0005 mol) of 3,3 ′ , 4,4'-Benzophenonetetracarboxylic dianhydride dissolved in 50 ml of diethylene glycol dimethyl ether is mixed and stirred for 2 hours to obtain a solution containing a polyimide precursor resin (weight average molecular weight 4,300). It was. After 900 ml of methanol was added to this solution, 0.101 g of triethylamine (0.001 mol) was added and stirred for 30 minutes to prepare polyimide precursor resin solution A (hereinafter also referred to as precursor A solution). .

  The weight average molecular weight of the polyimide precursor resin contained in the polyimide precursor resin solution is a column in which four TSK-GEL SUPER HM-Ms manufactured by Tosoh Corporation are connected using HLC-8220GPC manufactured by Tosoh Corporation. Measured using. A calibration curve for determining the weight average molecular weight was prepared using polystyrene as a standard substance. As a developing solvent, a solution in which lithium bromide and phosphoric acid were mixed with N, N-dimethylacetamide so as to be 0.03 mol / L was used.

Reference 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. Stainless steel foil 1 (Shin Nippon Steel Co., Ltd. SUS304 H-TA, thickness 20 μm, surface roughness on the resin layer side: 10-point average roughness Rz 0.8 μm) washed in advance with a silane coupling agent solution (liquid temperature about 20) C.) for 30 seconds and then pulled up into the atmosphere to remove excess liquid. 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
After immersing the polyimide film (Kapton EN) in a 5N potassium hydroxide aqueous solution at 50 ° C. for 5 minutes, the immersed polyimide film was sufficiently washed with ion-exchanged water, and then washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 30 seconds. After soaking, the surface-treated polyimide film a1 was obtained by thoroughly washing with ion-exchanged water, spraying compressed air, and drying. The thickness of the alkali treatment layer on one side of this surface-treated polyimide film a1 was 0.70 μm. This film was immersed in a 0.0005 M concentration BAPP methanol solution (25 ° C.) for 30 seconds, and then dried by blowing compressed air to obtain a surface-treated polyimide film b1. This film was heat-treated at 300 ° C. for 3 minutes to produce a surface-treated polyimide film c1. At this time, the thickness of the modified imidized layer on one surface of the surface-treated polyimide film c1 was 0.65 μm.
Both sides of this film are sandwiched between copper foils 1 (surface roughness: Rz = 0.8 μm, thickness: 18 μm), and are hot-pressed at 370 ° C., 20 MPa for 1 minute with a high-performance high-temperature vacuum press. A double-sided copper clad laminate f1 was produced. The adhesive strength between the polyimide film and the copper foil was 1.0 kN / m.

Example 2
In the same manner as in Example 1, except that the 0.0005M BAPP methanol solution in Example 1 was immersed for 5 minutes in a 0.001M DAPE methanol solution (25 ° C.), the surface was Treated polyimide films a2, b2 and c2 and double-sided copper clad laminate f2 were prepared. The thickness of the modified imidized layer on one side of the surface-treated polyimide film c2 was 0.52 μm.

Example 3
Surface-treated polyimide films a3, b3, and c3 were prepared in the same manner as in Example 1 except that the immersion was performed in 0.0005M BAPP in methanol in Example 1 for 5 minutes instead of 30 seconds. The polyimide film c3 was sandwiched between copper foils 2 (surface roughness: Rz = 1.5 μm, thickness: 18 μm), and hot-pressed under the same conditions as in Example 1 to prepare a double-sided copper-clad laminate f3.

Example 4
In the same manner as in Example 1, except that the 0.0005M BAPP methanol solution in Example 1 was immersed for 30 seconds in a 0.001M HAB methanol solution (25 ° C.) in the same manner as in Example 1, Treated polyimide films a4, b4 and c4 and double-sided copper-clad laminate f4 were prepared.

Example 5
Surface treatment was carried out in the same manner as in Example 1 except that 0.0005M TAPM in methanol (25 ° C.) was immersed for 30 seconds instead of 30 seconds in 0.0005M BAPP in methanol. Polyimide films a5, b5 and c5 and double-sided copper-clad laminate f5 were produced.

Example 6
Surface treatment was carried out in the same manner as in Example 1 except that 0.0005 M BAPP methanol solution in Example 1 was immersed for 1 second in 0.001 M TAEA methanol solution (25 ° C.). Polyimide films a6, b6 and c6 and double-sided copper clad laminate f6 were produced.

Example 7
The polyimide film (Iupyrex 25S) was immersed in a 5N potassium hydroxide aqueous solution (50 ° C.) for 30 minutes instead of being immersed in a 5N potassium hydroxide aqueous solution at 50 ° C. for 5 minutes. In the same manner as in Example 1, surface-treated polyimide films a7, b7 and c7 and a double-sided copper-clad laminate f7 were produced. The thickness of the alkali treatment layer on one side of the surface-treated polyimide film a7 was 0.56.

Example 8
Instead of immersing the polyimide film in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the polyimide film (film 1 of Reference Example 1) in the 5N aqueous potassium hydroxide solution (50 ° C.) for 5 minutes. Surface-treated polyimide films a8, b8 and c8 and a double-sided copper clad laminate f8 were produced in the same manner as in Example 1 except that the immersion was performed. The thickness of the alkali treatment layer on one side of the surface-treated polyimide film a8 was 0.22.

Example 9
Instead of immersing the polyimide film in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the polyimide film (film 2 of Reference Example 2) in the 5N aqueous potassium hydroxide solution (50 ° C.) for 5 minutes. Surface-treated polyimide films a9, b9 and c9 and double-sided copper clad laminate f9 were prepared in the same manner as in Example 1 except that the immersion was performed. The thickness of the alkali treatment layer on one side of the surface-treated polyimide film a9 was 0.30.

Example 10
Surface-treated polyimide films a10, b10 and c10 and double-sided metal-clad laminate f10 were produced in the same manner as in Example 8 except that stainless steel foil 1 was used instead of copper foil 1.

Example 11
Surface-treated polyimide films a11, b11 and c11 and a double-sided metal-clad laminate f11 were produced in the same manner as in Example 8 except that the stainless steel foil 2 was used instead of the copper foil 1.

Example 12
Surface-treated polyimide films a12, b12 and c12 and double-sided metal-clad laminate f12 were produced in the same manner as in Example 9 except that stainless steel foil 1 was used instead of copper foil 1.

Example 13
Surface-treated polyimide films a13, b13 and c13 and double-sided metal-clad laminate f13 were produced in the same manner as in Example 9 except that stainless steel foil 2 was used instead of copper foil 1.

Comparative Example 1
A polyimide film (Kapton EN) was sandwiched between copper foils 1 and hot-pressed at 370 ° C., 20 MPa for 1 minute with a high-performance high-temperature vacuum press to produce a double-sided copper-clad laminate. The adhesive strength between the polyimide film and the copper foil was 0.1 kN / m.

Comparative Example 2
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution (50 ° C.) for 5 minutes, the immersed polyimide film was sufficiently washed with ion-exchanged water, and then added to a 1 wt% aqueous hydrochloric acid solution (25 ° C.). After being soaked in minutes, it was sufficiently washed with ion-exchanged water, dried by blowing compressed air, and a surface-treated polyimide film was produced. This film was sandwiched between copper foils 1 and hot pressed under the same conditions as in Example 1 to produce a double-sided copper-clad laminate.

Comparative Example 3
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution (50 ° C.) for 5 minutes, the immersed polyimide film was sufficiently washed with ion-exchanged water, and 5% in a 1 wt% hydrochloric acid aqueous solution (25 ° C.). After being immersed for a minute, it was sufficiently washed with ion-exchanged water and dried by blowing compressed air. The film was heat treated at 300 ° C. for 3 minutes to produce a surface-treated polyimide film. This film was sandwiched between copper foils 1 and hot pressed under the same conditions as in Example 1 to produce a double-sided copper-clad laminate.

Comparative Example 4
After immersing the polyimide film (Kapton EN) in a 0.0005M BAPP methanol solution (25 ° C) for 5 minutes, sprayed with compressed air and dried, and heat-treated at 300 ° C for 3 minutes to obtain a surface-treated polyimide film. Produced. This polyimide film was sandwiched between copper foils 1 and hot pressed under the same conditions as in Example 1 to produce a double-sided copper-clad laminate.

Comparative Example 5
After immersing the polyimide film (Kapton EN) in a 0.0005M BAPP methanol solution (25 ° C.) for 5 minutes, the surface-treated polyimide film was produced by blowing compressed air and drying. This polyimide film was sandwiched between copper foils 1 and hot pressed under the same conditions as in Example 1 to produce a double-sided copper-clad laminate.

  The above conditions and results are summarized in Table 1. The adhesive strength indicates the adhesive strength between the polyimide film and the copper foil. In addition, the heat processing of Examples 1-13 and Comparative Examples 3-4 are 300 degreeC and 3 minutes, and Comparative Examples 1-2, and 5 are not heat-processed. Moreover, the formation method of a metal layer is thermocompression bonding in all the examples.

Example 14
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 5 minutes. After soaking, the surface-treated polyimide film a14 was obtained by thoroughly washing with ion-exchanged water, blowing compressed air, and drying. This film was immersed in a 0.5 wt% APES aqueous solution for 30 seconds and then dried by blowing compressed air to obtain a surface-treated polyimide film b14.
This film is heated and dried at 110 ° C. for 30 minutes, and then sandwiched between copper foils 1 and hot-pressed at 370 ° C., 20 MPa for 1 minute with a high-performance high-temperature vacuum press to produce a double-sided copper-clad laminate d14 did. The adhesive strength between the polyimide film and the copper foil was 0.4 kN / m.

Comparative Example 6
The polyimide film (Kapton EN) was immersed in a 0.5 wt% APES aqueous solution for 30 seconds, dried by spraying compressed air, and dried by heating at 110 ° C. for 30 minutes. A double-sided copper clad laminate was produced from this polyimide film in the same manner as in Example 1, but the treated layer was consolidated and could not be bonded. The above conditions and results are summarized in Table 2.

Example 15
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 5 minutes. After soaking, the surface-treated polyimide film a15 was obtained by thoroughly washing with ion-exchanged water, spraying with compressed air, and drying. After immersing this film in the polyimide precursor resin solution A (25 ° C.) of Reference Example 5 for 5 minutes, the surface-treated polyimide film b15 was obtained by blowing compressed air and drying. This film was heat-treated at 300 ° C. for 3 minutes to prepare a surface-treated polyimide film c15.
This film was sandwiched between copper foils 1 and hot-pressed with a high-performance high-temperature vacuum press at 370 ° C., 20 MPa for 1 minute to produce a double-sided copper-clad laminate f15. The adhesive strength between the polyimide film and the copper foil was 1.1 kN / m.

Example 16
The polyimide film (Iupyrex 25S) was immersed in a 5N potassium hydroxide aqueous solution (50 ° C.) for 30 minutes instead of being immersed in a 5N potassium hydroxide aqueous solution at 50 ° C. for 5 minutes. In the same manner as in Example 15, surface-treated polyimide films a16, b16 and c16 and a double-sided copper-clad laminate f16 were produced.

Example 17
Instead of immersing the polyimide film in 5N potassium hydroxide aqueous solution at 50 ° C for 5 minutes, except immersing the polyimide film (apical NPI) in 1N sodium hydroxide aqueous solution (50 ° C) for 10 minutes. In the same manner as in Example 15, surface-treated polyimide films a17, b17 and c17 and a double-sided copper clad laminate f17 were produced. The thickness of the modified layer on one side of the surface-treated polyimide film a17 was 0.73 μm.

Example 18
Instead of immersing the polyimide film in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the polyimide film (film 1 of Reference Example 1) in the 5N aqueous sodium hydroxide solution (50 ° C.) for 5 minutes. Surface-treated polyimide films a18, b18 and c18 and a double-sided copper-clad laminate f18 were produced in the same manner as in Example 15 except that the immersion was performed.

Example 19
Instead of immersing the polyimide film in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the polyimide film (film 2 of Reference Example 2) in the 5N aqueous sodium hydroxide solution (50 ° C.) for 5 minutes. Surface-treated polyimide films a19, b19 and c19 and a double-sided copper-clad laminate f19 were produced in the same manner as in Example 15 except that the immersion was performed.

Comparative Example 7
After immersing the polyimide film (Kapton EN) in the polyimide precursor resin solution A (25 ° C.) for 5 minutes, it was dried by spraying compressed air, and a heat treatment was performed at 300 ° C. for 3 minutes to prepare a surface-treated polyimide film. . This film was sandwiched between the copper foils 1 and hot pressed under the same conditions as in Example 15 to produce a double-sided copper-clad laminate.

Comparative Example 8
After immersing the polyimide film (Kapton EN) in the polyimide precursor resin solution A (25 ° C.) for 5 minutes, a surface-treated polyimide film was produced by blowing compressed air and drying. This film was sandwiched between the copper foils 1 and hot pressed under the same conditions as in Example 15 to produce a double-sided copper-clad laminate. The adhesive strength between the polyimide film and the copper foil was 0.1 kN / m. The results are shown in Table 3.

  The above conditions and results, and the adhesive strength between the polyimide film and the copper foil are summarized in Table 3. In addition, the heat processing of Examples 15-19 and the comparative example 7 are 300 degreeC and 3 minutes, and the heat processing of the comparative example 8 is not made | formed. Moreover, the formation method of a metal layer is thermocompression bonding in all the examples.

Example 20
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 5 minutes. After dipping, the surface-treated polyimide film a20 was obtained by thoroughly washing with ion-exchanged water, blowing compressed air, and drying. This film was immersed in a 0.5 wt% PSX-Ph methanol solution (25 ° C.) for 30 seconds, and then dried by blowing compressed air to obtain a surface-treated polyimide film b20.
This film is heat-dried at 110 ° C. for 30 minutes, and then sandwiched between copper foils 1 and hot-pressed at 370 ° C., 20 MPa for 1 minute with a high-performance high-temperature vacuum press machine. Was made. The adhesive strength between the polyimide film and the copper foil was 0.4 kN / m.

Example 21
Example 20 is the same as Example 20 except that it was immersed in a 0.5 wt% PSX-Me methanol solution (25 ° C.) for 30 seconds instead of being immersed in a 0.5 wt% PSX-Ph methanol solution in Example 20. Similarly, surface-treated polyimide films a21 and b21 and double-sided copper-clad laminate d21 were produced.

Comparative Example 9
The polyimide film (Kapton EN) was immersed in a 0.5 wt% PSX-Ph methanol solution (25 ° C.) for 30 seconds, dried by blowing compressed air, and heated and dried at 110 ° C. for 30 minutes. A double-sided copper clad laminate was produced from this polyimide film in the same manner as in Example 1, but the treated layer was consolidated and could not be bonded.

  The above conditions and results are summarized in Table 4. In all examples, the heat treatment is performed at 110 ° C. for 30 minutes. Moreover, the formation method of a metal layer is thermocompression bonding in all the examples.

Example 22
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 5 minutes. After soaking, the surface-treated polyimide film a22 was obtained by thoroughly washing with ion-exchanged water, spraying with compressed air, and drying. This surface-treated film was immersed in a 0.5 wt% APES aqueous solution for 30 seconds, and then dried by blowing compressed air to obtain a surface-treated polyimide film b22. The film was heat treated at 110 ° C. for 30 minutes, and then set in an RF magnetron sputtering apparatus (ANELVA; SPF-332HS) so that a metal raw material was formed on the film, and the inside of the tank was 3 × 10 ⁻⁴ Pa. After depressurizing to an argon gas, argon gas was introduced to make the degree of vacuum 2 × 10 ⁻¹ Pa, and plasma was generated by an RF power source. With this plasma, a nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter, a nichrome layer (first sputtering layer 1a)] was formed on the polyimide film to a thickness of 30 nm. After forming the nichrome layer, a copper (99.99 wt%) film was further formed on the nichrome layer by sputtering in the same atmosphere to obtain a second sputtering layer 1b.
Next, an 8 μm-thick copper plating layer (plating layer 1c) was formed in an electrolytic plating bath using the copper sputtered film (second sputtering layer 1b) 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, and the anode is phosphorous copper) is used to form a plating film at a current density of 2.0 A / dm ² . did. After plating, it was washed with sufficient distilled water and dried. In this manner, a metal-clad laminate e22 composed of polyimide film / nichrome layer 1a / copper sputter layer 1b / electroplated copper layer 1c was obtained. The adhesive strength between the polyimide film and copper was 0.4 kN / m.

Example 23
After immersing a polyimide film (film 2 of Reference Example 2) in 5N potassium hydroxide aqueous solution at 50 ° C. for 30 seconds, the immersed polyimide film was sufficiently washed with ion-exchanged water, and 1 wt% hydrochloric acid aqueous solution (25 ° C. ) For 5 minutes, sufficiently washed with ion exchange water, sprayed with compressed air and dried to obtain a surface-treated polyimide film a23. The thickness of the alkali treatment layer on one side of the surface treatment film a23 was 0.02 μm. This film was immersed in a 0.0001M concentration BAPP methanol solution (25 ° C.) for 5 minutes, and then dried by blowing compressed air to obtain a surface-treated polyimide film b23. This film was heat-treated at 300 ° C. for 3 minutes to produce a surface-treated polyimide film c23. At this time, the thickness of the modified imidized layer on one surface of the surface-treated polyimide film c23 was about 0.02 μm. In order to form a metal raw material on this film, it is set in an RF magnetron sputtering apparatus (ANELVA; SPF-332HS), the inside of the tank is depressurized to 3 × 10 ⁻⁴ Pa, argon gas is introduced, and the degree of vacuum is reduced. Plasma was generated with an RF power source at 2 × 10 ⁻¹ Pa. With this plasma, a nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter, a nichrome layer (first sputtering layer 2a)] was formed on the polyimide film to a thickness of 30 nm. After forming the nichrome layer, in the same atmosphere, a copper (99.99 wt%) film having a thickness of 0.2 μm was further formed on the nichrome layer by sputtering to obtain a second sputtering layer 2b.
Subsequently, a copper plating layer (plating layer 2c) having a thickness of 8 μm was formed in an electrolytic plating bath using the sputtered film (second sputtering layer 2b) 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, and the anode is phosphorous copper) is used to form a plating film at a current density of 2.0 A / dm ² . did. After plating, it was washed with sufficient distilled water and dried. In this way, a metal-clad laminate g23 composed of polyimide film / nichrome layer 2a / copper sputter layer 2b / electroplated copper layer 2c was obtained. The adhesive strength between the polyimide film and copper was 0.9 kN / m.

Example 24
Surface treatment was carried out in the same manner as in Example 23 except that it was immersed in a 0.001 M BAPP methanol solution in Example 23 for 5 minutes instead of being immersed in a 0.001 M HAB methanol solution (25 ° C.). Polyimide films a24, b24 and c24 and a metal-clad laminate g24 were produced.

Example 25
Surface treatment was carried out in the same manner as in Example 23 except that it was immersed in a 0.001 M BAPP methanol solution in Example 23 for 5 minutes instead of being immersed in a 0.001 M ASD methanol solution (25 ° C.). Polyimide films a25, b25 and c25 and a metal-clad laminate g25 were produced.

Example 26
In the same manner as in Example 23 except that it was immersed in a 0.001M DABA methanol solution (25 ° C.) for 5 minutes instead of being immersed in 0.0001M BAPP methanol solution in Example 23. Treated polyimide films a26, b26 and c26 and metal-clad laminate g26 were produced.

Comparative Example 10
Prepare a polyimide film (Kapton EN), set it in an RF magnetron sputtering device so that a metal raw material is formed on this film, depressurize the tank to 3 × 10 ⁻⁴ Pa, and then introduce argon gas. The degree of vacuum was 2 × 10 ⁻¹ Pa, and plasma was generated with an RF power source. With this plasma, a nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter, a nichrome layer (first sputtering layer 6a)] was formed on a polyimide film so as to have a film thickness of 30 nm. After forming the nichrome layer, copper (99.99 wt%) was further formed on the nichrome layer by sputtering in the same atmosphere to form a second sputtering layer 6b.
Subsequently, a copper plating layer (plating layer 6c) having a thickness of 8 μm was formed in an electrolytic plating bath using the sputtered film (second sputtering layer 6b) 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, and the anode is phosphorous copper) is used to form a plating film at a current density of 2.0 A / dm ² . did. After plating, it was washed with sufficient distilled water and dried. In this way, a metal-clad laminate composed of polyimide film / nichrome layer 6a / copper sputter layer 6b / electroplated copper layer 6c was obtained. The adhesive strength between the polyimide film and the copper foil was less than 0.1 kN / m.

Comparative Example 11
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 5 minutes. After soaking, the plate was sufficiently washed with ion exchange water and dried by blowing compressed air. In order to form a metal raw material on this polyimide film, it is set in an RF magnetron sputtering apparatus, and after reducing the pressure in the tank to 3 × 10 ⁻⁴ Pa, argon gas is introduced and the degree of vacuum is 2 × 10 ⁻¹ Pa. And plasma was generated by an RF power source. With this plasma, a nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter, a nichrome layer (first sputtering layer 7a)] was formed on a polyimide film to a thickness of 30 nm. After forming the nichrome layer, a copper (99.99 wt%) film was further formed by sputtering on the nichrome layer in the same atmosphere to form a second sputtering layer 7b.
Subsequently, a copper plating layer (plating layer 7c) having a thickness of 8 μm was formed in an electrolytic plating bath using the sputtered film (second sputtering layer 7b) 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, and the anode is phosphorous copper) is used to form a plating film at a current density of 2.0 A / dm ² . did. After plating, it was washed with sufficient distilled water and dried. In this way, a metal-clad laminate composed of polyimide film / nichrome layer 7a / copper sputter layer 7b / electroplated copper layer 7c was obtained. The adhesive strength between the polyimide film and the copper foil was 0.1 kN / m.

Comparative Example 12
The polyimide film (Kapton EN) was immersed in a 0.5 wt% APES aqueous solution for 30 seconds, dried by blowing compressed air, and heat-treated at 110 ° C. for 30 minutes. A metal thin film was formed by setting in an RF magnetron sputtering apparatus so that a metal raw material was formed on this polyimide film. The inside of the tank in which the sample was set was depressurized to 3 × 10 ⁻⁴ Pa, and then argon gas was introduced to make the degree of vacuum 2 × 10 ⁻¹ Pa, and plasma was generated by an RF power source. With this plasma, a nickel: chromium alloy layer [ratio 8: 2, 99.9 wt%, hereinafter, a nichrome layer (first sputtering layer 8a)] was formed on a polyimide film to a thickness of 30 nm. After forming the nichrome layer, copper (99.99 wt%) was further formed on the nichrome layer by sputtering in the same atmosphere to form a second sputtering layer 8b.
Subsequently, a copper plating layer (plating layer 8c) having a thickness of 8 μm was formed in an electrolytic plating bath using the sputtered film (second sputtering layer 8b) 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, and the anode is phosphorous copper) is used to form a plating film at a current density of 2.0 A / dm ² . did. After plating, it was washed with sufficient distilled water and dried. In this manner, a metal-clad laminate composed of polyimide film / nichrome layer 8a / copper sputter layer 8b / electroplated copper layer 8c was obtained. The adhesive strength between the polyimide film and the copper foil was less than 0.1 kN / m.

  The above conditions and results are summarized in Table 5. In addition, heat processing is 110 degreeC and 30 minutes in Example 22 and Comparative Example 12, Examples 23-26 are 300 degreeC and 3 minutes, and Comparative Examples 10-11 do not have heat processing. In all examples, the metal layer is formed by sputtering + plating.

Example 27
After immersing the polyimide film (Kapton EN) in a 5N aqueous potassium hydroxide solution at 50 ° C. for 5 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and washed in a 1 wt% hydrochloric acid aqueous solution (25 ° C.) for 5 minutes. After soaking, the surface-treated polyimide film a27 was obtained by thoroughly washing with ion-exchanged water, spraying with compressed air, and drying. A part of the polyimide film a27 was used in the following example.

Polyimide film a27 modified layer surface is immersed in a 0.0005M BAPP methanol solution (25 ° C) for 30 seconds, and then dried by blowing compressed air to form an amino compound-treated layer on the polyimide film surface. Film b27 was obtained.
The surface treatment surfaces of the polyimide film a27 and the polyimide film b27 were superposed and subjected to hot pressing with a high-performance high-temperature vacuum press at 400 ° C., 20 MPa for 1 minute. The adhesive strength between the two polyimide films a27 and b27 was 1.2 kN / m.

Example 28
The modified layer surface of the polyimide film a27 obtained in Example 27 was immersed for 5 minutes in a 0.001M DAPE methanol solution (25 ° C.) instead of being immersed in a 0.0005M BAPP methanol solution for 30 seconds. In the same manner as in Example 27, a polyimide film b28 having an amino compound treatment layer formed on the polyimide film surface was obtained.
The polyimide film a27 and the surface treatment surface of the polyimide film b28 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a28 and b28 was 1.0 kN / m.

Example 29
The surface of the polyimide film a27 obtained in Example 27 was coated on the surface of the polyimide film in the same manner as in Example 27 except that the modified layer surface of the polyimide film a27 was immersed in 0.0005M BAPP methanol solution for 30 seconds instead of 30 seconds. A polyimide film b29 having an amino compound-treated layer was obtained.
The polyimide film a27 and the surface treatment surface of the polyimide film b29 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a27 and b29 was 0.9 kN / m.

Example 30
After immersing the polyimide film (apical NPI) in a 1N aqueous sodium hydroxide solution (50 ° C.) for 10 minutes, the immersed polyimide film is sufficiently washed with ion-exchanged water, and then added to a 1 wt% hydrochloric acid aqueous solution (25 ° C.). After being soaked for a minute, the surface-treated polyimide film a30 was obtained by thoroughly washing with ion-exchanged water, spraying with compressed air, and drying. A part of the polyimide film a30 was used in the following example.

The polyimide film a30 modified layer surface is immersed in a 0.0005M BAPP methanol solution (25 ° C.) for 20 seconds, and then dried by blowing compressed air to form an amino compound-treated layer on the polyimide film surface. b30 was obtained.
The polyimide film a30 and the surface-treated surface of the polyimide film b30 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a30 and b30 was 1.1 kN / m.

Example 31
Instead of immersing the polyimide film in 5N aqueous potassium hydroxide solution at 50 ° C for 5 minutes, except immersing the polyimide film (Upilex 25S) in 5N aqueous potassium hydroxide solution (50 ° C) for 30 minutes. In the same manner as in Example 27, a polyimide film a31 having a modified layer formed on the polyimide film surface was obtained. Further, a polyimide film b31 having an amino compound-treated layer formed on the surface of the polyimide film was obtained in the same manner as in Example 27 using the polyimide film a31.
The polyimide film a31 and the surface-treated surface of the polyimide film b31 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a31 and b31 was 1.1 kN / m.

Example 32
The polyimide film a27 obtained in Example 27 and the surface-treated surface of the polyimide film b30 obtained in Example 30 were superposed and subjected to hot pressing in the same manner as in Example 27. The adhesive strength between the polyimide films a27 and b30 was 1.0 kN / m.

Example 33
After immersing the polyimide film (film 1 of Reference Example 1) in 5N potassium hydroxide aqueous solution at 50 ° C. for 5 minutes, the immersed polyimide film was sufficiently washed with ion-exchanged water, and 1 wt% hydrochloric acid aqueous solution (25 ° C. ) For 5 minutes, sufficiently washed with ion-exchanged water, sprayed with compressed air and dried to obtain a surface-treated polyimide film a33. A part of the polyimide film a33 was used in the following example.

The modified layer surface of the polyimide film a33 is immersed in a methanol solution (20 ° C.) adjusted to a 0.001M concentration of EDA for 5 minutes, and then dried by spraying compressed air, and the amino compound treatment layer is applied to the polyimide resin layer surface. The formed polyimide film b33 was produced.
The polyimide film a33 and the surface treatment surface of the polyimide film b33 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a33 and b33 was 0.6 kN / m.

Example 34
Example 33 except that the polyimide film a33 was immersed in a 0.001 M concentration EDA methanol solution (20 ° C.) for 5 minutes instead of being immersed in a 0.001 M concentration ETA methanol solution (20 ° C.) for 5 minutes. In the same manner, a polyimide film b34 having an amino compound treatment layer formed on the surface of the polyimide resin layer was produced.
The polyimide film a33 obtained in Example 33 and the surface-treated surface of the polyimide film b34 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a33 and b33 was 0.4 kN / m.

Example 35
After immersing the polyimide film (film 2 of Reference Example 2) in 5N potassium hydroxide aqueous solution at 50 ° C. for 5 minutes, the immersed polyimide film was sufficiently washed with ion-exchanged water, and 1 wt% hydrochloric acid aqueous solution (25 ° C. ) For 5 minutes, sufficiently washed with ion exchange water, sprayed with compressed air and dried to obtain a surface-treated polyimide film a35.
The polyimide film a35 and the surface-treated surface of the polyimide film b33 obtained in Example 33 were superposed, and hot pressing was performed in the same manner as in Example 27. The adhesive strength between the polyimide films a35 and b33 was 0.7 kN / m.

Example 36
The polyimide film a35 obtained in Example 35 and the surface-treated surface of the polyimide film b34 obtained in Example 34 were superposed and hot pressed in the same manner as in Example 27. The adhesive strength between the polyimide films a35 and b33 was 0.4 kN / m.

Comparative Example 13
Two polyimide films (Kapton EN) were prepared, overlapped, and hot pressed in the same manner as in Example 27. Each polyimide film peeled easily.

Comparative Example 14
Two polyimide films (apical NPI) were prepared, superposed, and hot pressed in the same manner as in Example 27. Each polyimide film peeled easily.

Comparative Example 15
A polyimide film (Kapton EN) and a polyimide film (apical NPI) were superposed and hot pressed in the same manner as in Example 27. Each polyimide film peeled easily.

Comparative Example 16
Two polyimide films (film 1 of Reference Example 1) were prepared, and the polyimide resin layer surfaces were overlaid, and hot pressing was performed in the same manner as in Example 27. Each polyimide resin layer peeled easily.

Comparative Example 17
Two polyimide films a27 obtained in Example 27 were prepared, and the surface treatment layer surfaces of the respective polyimide films were superposed, and hot pressing was performed in the same manner as in Example 27. The adhesive strength between the polyimide films was 0.1 kN / m.

Comparative Example 18
Two polyimide films a33 obtained in Example 33 were prepared, the surface treatment layer surfaces of the respective polyimide resins were superposed, and hot pressing was performed in the same manner as in Example 27. The adhesive strength between the polyimide resin layers was less than 0.1 kN / m.

Comparative Example 19
The polyimide film a33 obtained in Example 33 and the polyimide film a35 obtained in Example 35 were prepared, the surface modification layer surfaces of the respective polyimide resins were overlapped, and hot pressing was performed in the same manner as in Example 27. The adhesive strength between the polyimide resin layers was less than 0.1 kN / m.

  The above conditions and results are summarized in Table 6 and Table 7. The bonding method of the two polyimide resin layers is thermocompression bonding in all examples.

Industrial applicability

  According to the present invention, the adhesive force of the polyimide resin layer can be dramatically improved by a simple surface treatment. Since the adhesive force can be improved even in a low-roughness copper foil suitable for fine pitch formation, a copper-clad laminate used for a high-density printed wiring board can be manufactured at low cost. Further, since it can also be used for HDD suspension applications, its industrial value is high.

Claims (13)

a) a step of forming an alkali treatment layer by treating the surface side of the polyimide resin layer with an alkaline aqueous solution; and b) an aliphatic group having at least three primary amino groups as functional groups on the surface of the alkali treatment layer. Impregnating and drying a polar solvent solution containing at least one amino compound selected from the group consisting of an amine and diaminosiloxane to form an amino compound-containing layer; and c) imidizing the amino compound-containing layer. And a step of forming a modified imidized layer. A method for forming a modified layer on a surface of a polyimide resin layer. The method for forming a modified layer according to claim 1 , wherein the thickness of the alkali treatment layer is in the range of 0.005 to 3.0 μm . The method for forming a modified layer according to claim 1, wherein the polyimide resin layer is a polyimide resin layer forming a surface layer of the laminate . The method for forming a modified layer according to claim 1, wherein the polyimide resin layer is a polyimide resin layer that forms a surface layer of a polyimide resin film . In a method for producing a metal-clad laminate comprising: I) a step of forming a modified layer on the surface of the polyimide resin layer; and II) a step of forming a metal layer on the surface of the modified layer.
Step I)
a) a step of forming an alkali treatment layer by treating the surface side of the polyimide resin layer with an alkaline aqueous solution; and b) an aliphatic group having at least three primary amino groups as functional groups on the surface of the alkali treatment layer. Impregnating and drying a polar solvent solution containing at least one amino compound selected from the group consisting of an amine and diaminosiloxane to form an amino compound-containing layer; and c) imidizing the amino compound-containing layer. And a step of forming a modified imidized layer. Step II)
6. The method for producing a metal-clad laminate according to claim 5, further comprising the step of d) superimposing a metal foil on the surface of the modified layer and thermocompression bonding . Step II)
6. The method for producing a metal-clad laminate according to claim 5, comprising a step of forming a metal thin film layer on the surface of the modified layer. The method for producing a metal-clad laminate according to any one of claims 5 to 7, wherein the alkali-treated layer has a thickness in the range of 0.005 to 3.0 µm. The method for producing a metal-clad laminate according to any one of claims 5 to 8, wherein the diaminosiloxane is a diaminosiloxane oligomer represented by the following general formula (1) .

(Here, Ar ₂ and Ar ₇ represent a divalent hydrocarbon group, R _{3 to} R ₆ represent a hydrocarbon group having 1 to ₆ carbon atoms, and m represents a number of 1 to 20). The method for producing a metal-clad laminate according to claim 6, wherein the metal foil is a copper foil, a copper alloy foil, or a stainless steel foil . In the method of laminating the polyimide resin layer surface of the first polyimide resin layer (P1) and the second polyimide resin layer (P2) and bonding the polyimide resin layer,
A) For the first polyimide resin layer (P1), a) a step of treating the surface side of the polyimide resin layer with an alkaline aqueous solution to form an alkali treated layer;
B) Regarding the second polyimide resin layer (P2), a) a step of forming an alkali treatment layer by treating the surface side of the polyimide resin layer with an alkaline aqueous solution, b) a polarity containing an amino compound on the alkali treatment layer surface A step of impregnating and drying a solvent solution to form an amino compound-containing layer;
C) superposing the amino compound-containing layer surface of the second polyimide resin layer (P2) on the surface of the alkali treatment layer of the first polyimide resin layer (P1), and thermocompression-bonding the polyimide resin layer, Bonding method. The at least one of a 1st polyimide resin layer (P1) and a 2nd polyimide resin layer (P2) is a polyimide resin layer of the single-sided metal-clad laminated board which has metal foil on the single side | surface of a polyimide resin layer. Adhesion method of polyimide resin layer. In the method for producing a double-sided metal-clad laminate having a metal foil on both sides of a polyimide resin layer by laminating and bonding two single-sided metal-clad laminates having a metal foil on one side of the polyimide resin layer,
A) For the first single-sided metal-clad laminate, a) a step of forming an alkali-treated layer by treating the surface side layer of the polyimide resin layer (P1) with an aqueous alkali solution,
B) For the second single-sided metal-clad laminate, a) a step of treating the surface side of the polyimide resin layer (P2) with an aqueous alkali solution to form an alkali treated layer, b) an amino compound on the surface of the alkali treated layer A step of impregnating and drying a polar solvent solution to form an amino compound-containing layer;
C) The process of superimposing the amino compound-treated layer surface of the polyimide resin layer (P2) of the second single-sided metal-clad laminate on the alkali-treated layer surface of the polyimide resin layer (P1) of the first single-sided metal-clad laminate, and thermocompression bonding A method for producing a double-sided metal-clad laminate, comprising: