KR101988778B1 - Copper foil for printed wiring board, and copper-clad laminated board - Google Patents

Abstract

assignment
A copper foil for a wiring board and a copper clad laminate having good visibility after formation of a circuit pattern, high state peel strength, and high heat peel strength can be provided.
Solution
Wherein at least one surface of the copper foil has a roughening particle layer composed of roughened particles having an arithmetic mean height of 0.05 to 0.5 mu m and the roughening particle layer contains at least nickel and zinc, (Mass ratio) of the adhesion amount to the above-mentioned roughening particle layer is in the range of 0.5 to 20, wherein the copper foil having a diffusion reflectance (R _d ) at a wavelength of 600 nm measured at the one surface side is 5 to 50% A copper clad laminate having a copper foil and a copper clad laminate within a range and chroma (C *) of 30 or less, and a polyimide resin layer containing a specific anti-corrosive agent on the one surface side of the copper foil.

Description

TECHNICAL FIELD [0001] The present invention relates to a copper foil for a printed wiring board and a copper clad laminate,

The present invention relates to a copper foil and a copper-clad laminate for a wiring board, and more particularly to a copper-clad laminate for a wiring board which is excellent in resin adhesion and resin permeability after formation of a circuit pattern (visibility) The present invention relates to a copper foil to be used for this.

BACKGROUND ART [0002] A wiring board is used as a substrate or a connecting material in various electronic devices, and a copper foil is generally used for a conductive layer of a wiring board.

The copper foil used for the wiring board is generally supplied in the form of a rolled copper foil or an electrolytic copper foil.

In general, a copper foil such as an electrolytic copper foil and a resin film such as polyimide are bonded to a wiring board to form a circuit pattern by etching. The wiring board on which the circuit pattern is formed may be subjected to the positioning by recognizing the alignment mark or the like with the camera by passing the resin film where the copper foil is etched and removed at the subsequent mounting step. For this reason, it is required that the light transmitted through the resin film does not diffuse and that the resin transparent visibility is clearly recognizable by a camera. Hereinafter, this resin transparency visibility is expressed simply as " visibility ".

The visibility of the resin film is generally expressed by a haze value (haze value). The haze value of the resin film relative to the total light transmittance (T _t ) and the diffusion transmittance (T _d )

(T _d / T _t ) × 100 (%)

Respectively. The smaller this value is, the higher the visibility is. For the evaluation of the visibility, a haze value of a wavelength of 600 nm is generally employed.

If the types of the resin films are the same, the haze value of the resin film depends on the surface shape. If the surface is rough, the diffuse transmission component becomes large and the haze value becomes high. Therefore, in order to improve the visibility, it is necessary to make the surface smooth to some extent.

Further, the surface shape of the resin film transfers the surface shape of the mated copper foil. Therefore, in order to obtain a smooth resin surface, it is necessary to use a smooth copper foil.

On the other hand, for use as a wiring board, adhesion between the resin film and the copper foil is required. In order to improve the adhesion, the surface of the copper foil is roughened to increase the contact surface area and often use an anchor effect. Therefore, the improvement of the adhesion leads to the deterioration of the visibility on the one hand, and the compatibility between the resin adhesion and the visibility becomes difficult.

As a method of roughening the copper foil surface (roughening treatment), it is general that the copper foil is subjected to particulate copper plating (harmonious plating). In addition, a method of roughening the surface by etching, a method of performing plating by plating with a metal or alloy plating other than copper is used.

Patent Document 1 discloses an electrolytic copper foil in which adhesion of two secondary roughening particles onto a primary roughening particle is enhanced by performing two kinds of roughening plating of copper. However, since the surface of the electrolytic copper foil is excessively coarse, the adhesion is excellent, but the visibility is low and there is room for improvement.

Patent Document 2 discloses a copper clad laminate in which a multilayer polyimide film obtained by special thermocompression bonding is thermocompression bonded to a smooth copper foil under special conditions. However, this copper-clad laminate has many restrictions on the constitution of the resin and the method of producing the copper-clad laminate, and can be said to be feasible only under certain specific conditions.

With respect to the adhesion between the copper foil and the resin film, in particular, the adhesiveness with the polyimide resin used as the substrate of the flexible printed wiring board (FPC) (Hereinafter referred to as heat peel strength) after the heat load is applied for a long period of time from the viewpoint of long-term reliability.

The heat-resisting peel strength of a printed wiring board based on a polyimide resin is generally measured after a heat load of 1000 hours is applied in an air atmosphere at 150 캜.

Copper atoms on the surface of the copper foil become copper ions during the application of the heat load under the above conditions to the printed wiring board and this causes a phenomenon of decomposing the polymer resin (hereinafter referred to as copper harm). Therefore, generally, the heat peel strength is low as compared with the state peel strength.

In order to improve the heat peeling strength, there is a means for improving the anchor effect by the above-mentioned harmony. However, if the coarsened particles are excessively large, the visibility is lowered. Therefore, there is a limit to improving the heat peeling strength only by improving the anchor effect.

In addition to the enhancement of the anchor effect by harmony, a heterogeneous metal atom layer (hereinafter referred to as a diffusion preventing layer) other than copper made of nickel and zinc is formed on the surface of a smooth copper foil which is not subjected to harmonization treatment (harmonious plating) To prevent deterioration of the resin due to thermal diffusion of copper, and to improve the peel strength. With this method alone, the peel strength is maintained at a certain value or more with a low thermal history of 50 hours at 150 ° C. However, since the copper foil is smooth, an anchor effect can hardly be obtained. Therefore, it is difficult to maintain the peel strength at a high level after a test with a high heat load of 150 hours at a temperature of 150 占 폚. Further, in Patent Document 3, nickel and zinc are adhered to a large extent, and the etching property of the copper foil is sacrificed. In addition, the removal amount of the metal component from the plating solution used for the treatment of nickel and zinc increases, which is disadvantageous in view of the manufacturing cost.

There is a method of adding an antifungal agent to the resin in order to prevent frost damage to the resin during the heat resistance test. By chelating copper ions by an antidise agent, it is possible to inhibit the copper ions from being inactivated and the peroxides to catalytically decompose to generate oxy radicals. That is, oxidation deterioration of the polymer material can be suppressed by the addition of the anti-shudder agent. Specifically, examples of the antifouling agent include oxalic acid derivatives, salicylic acid derivatives, hydrazide derivatives, benzotriazole, and the like.

However, it is difficult to prevent the deterioration of the heat peel strength by the addition of the anti-freezing agent only in the FPC using the copper foil having a small surface unevenness and excellent visibility with strict heat load of 150 hours at the temperature of 150 占 폚, which is the heat resistance test condition of the FPC.

Japanese Patent Application Laid-Open No. 11-340596 Japanese Laid-Open Patent Publication No. 2011-119759 Japanese Patent Publication No. 4090467

An object of the present invention is to provide a copper foil for a wiring board and a copper clad laminate which have good visibility after formation of a circuit pattern, have a high state peel strength and a high heat-resisting peel strength.

The inventors of the present invention conducted a harmonization treatment having a concavo-convex height within a range that does not deteriorate visibility on one surface of a copper foil to form a coarse particle layer having a specific particle height and to form a coarse particle layer having a specific particle height of at least nickel and zinc It has been found that high heat resistance peel strength and high toughness can be realized by controlling the diffusion reflectance and chroma of the one surface side of the copper foil having the diffusion preventing coating of nickel / zinc adhesion ratio and the roughened treatment to a predetermined range. Here, the diffuse reflectance refers to the ratio of the diffuse reflection (diffuse reflection) of the light flux (light flux) incident on the surface of the object, and is an index for determining the degree of irregularity of the surface of the object. Saturation is also one of the three properties of color, a measure of the clarity of color. The present inventors have also found that the polyimide resin layer used as the insulating layer contains at least one anti-corrosion agent selected from an oxalic acid derivative, a salicylic acid derivative, a hydrazide derivative, and triazole in an entirely new copper It was found that a clad laminate was obtained. The present invention has been completed based on this finding.

That is, according to the present invention, the following means are provided.

(1) A copper foil having a roughening particle layer composed of roughening particles having an arithmetic average height of 0.05 to 0.5 탆 on at least one surface of a copper foil and having at least nickel and zinc on the roughening particle layer, Wherein a ratio (mass ratio) of the amount of nickel adhering to the roughening particle layer to the amount of nickel adhering to the surface of the copper foil is in the range of 0.5 to 20. The copper foil has a diffuse reflectance R _d at a wavelength of 600 nm, Is in the range of 5 to 50% and the chroma (C *) is 30 or less.

(2) A copper clad laminate having the copper foil according to (1).

(3) A polyimide resin layer comprising at least one kind of anti-corrosive agent selected from an oxalic acid derivative, a salicylic acid derivative, a hydrazide derivative and triazole, is coated on a surface of the copper foil of the copper foil according to (1) Laminates.

It is possible to provide a copper foil for a printed wiring board and a copper clad laminated board excellent in both visibility and resin adhesion after formation of a circuit pattern by the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining a method of measuring the height of a coarse particle according to the present invention. Fig.

The copper foil of the present invention has at least one surface thereof with a roughened particle layer composed of roughened particles having an arithmetic average height of 0.05 to 0.5 탆 and at least nickel and zinc on the roughening particle layer, (Mass ratio) of nickel to the surface of nickel is in the range of 0.5 to 20, wherein a diffuse reflectance (R _d ) at a wavelength of 600 nm measured at the one surface side is 5 to 50 % And a chroma (C *) of 30 or less.

The copper foil of the present invention can be suitably used for a printed wiring board.

The total light transmittance of the resin film is roughly determined by the type and thickness of the resin, and varies slightly depending on the resin surface shape, but the degree of change is small. Therefore, the haze value for evaluating the visibility is greatly influenced by the diffusion transmittance. The diffusion transmittance of the resin is greatly influenced by its surface shape. The surface shape of the resin is the surface shape of the copper foil transferred. Therefore, the shape of the copper foil greatly affects the diffusion transmittance of the resin.

If the diffuse reflectance of the surface of the copper foil at a wavelength of 600 nm is greater than 50%, the resin having the transferred surface shape increases in diffuse transmittance and adheres well but visibility deteriorates. On the other hand, if the diffuse reflectance is less than 5%, the surface of the copper foil having an extremely good gloss is obtained, but since it is excessively smooth, the visibility is excellent but the adhesion with the resin is deteriorated.

(C *) is calculated by the formula (1) in the CIE L * a * b * color system represented by the coordinates on the uniform color space consisting of the luminosity index L * and the chromaticity index a *, b *. The lower the saturation, the grayer the surface. The reflectance of a highly saturated surface differs greatly depending on the wavelength. On the other hand, a surface having a low saturation has a flat spectral reflectance.

Equation (1)

The color of the copper foil surface varies greatly depending on the surface treatment. However, the haze value is generally used for the evaluation of the wavelength of 600 nm.

Note that the evaluation of the haze value generally adopts a value of a wavelength of 600 nm, the inventors of the present invention have found that the reflectance at a wavelength of 600 nm is higher than a certain level on a surface of any color by having a saturation (C *) of 30 or more And that the copper foil having such a surface has excellent visibility of the resin film on which the surface is transferred.

Further, since the visibility is determined on the surface of the copper foil, it has been found that it is difficult to depend on the type of resin, the method of producing resin, and the method of producing a wiring board.

In the copper foil used for the printed wiring board of the present invention, the arithmetic average height of the coarsened particles in the coarsened layer formed on at least one surface of the copper foil in contact with the insulating layer made of polyimide resin is 0.05 mu m to 0.5 mu m. If it is lower than 0.05 탆, the initial peel strength and the heat peel strength are lowered. If it is higher than 0.5 占 퐉, the visibility is lowered.

The shape of the harmonized layer is summarized in Table 1.

The cross-sectional shape of the copper foil specified in the present invention corresponds to the shape 1 in Table 1.

On the contrary, shapes 2 to 5 show shapes outside the range defined by the present invention.

Even if the height of the harmonic particle is the same as that of the shape 1 as in the shape 2, the diffuse reflectance and chroma exceed the specification of the present invention when the outermost surface becomes gentle. In addition, since the anchor effect due to the surface unevenness is small, the adhesion is deteriorated.

Even if the height of the roughened particle is the same as that of the shape 1 as in the shape 3, the diffuse reflectance becomes less than the specification of the present invention when the roughened particles become finer. The visibility is good, but the coarsened particles tend to fall off (the coarsened particles tend to break at the base), and the adhesion decreases.

When the height of the roughening particle is high as in the shape 4, the diffuse reflectance and the saturation exceed the specification of the present invention. Since the coarsened particles are large, the anchoring effect is large and the adhesion is satisfied, but the visibility of the resin after the copper foil etching is deteriorated.

If the height of the roughened particle is small as in the shape 5, the diffuse reflectance becomes less than the specification of the present invention. As the unevenness is small, the anchor effect is small, so the adhesion is reduced.

[Table 1]

The copper foil used in the printed wiring board of the present invention comprises at least nickel and zinc on the surface of the copper foil on the side in contact with the insulating layer made of polyimide resin and has an adhesion amount to the surface of nickel (The mass ratio of Ni / Zn) is in the range of 0.5 to 20. If the deposition rate is higher than 20, the copper foil will become an obstacle when etching the copper foil, resulting in a short circuit of the wiring. If the coating weight ratio is lower than 0.5, the effect of preventing the diffusion of copper is lowered and the heat peeling strength is lowered.

Here, the diffusion preventing coating may be performed on the entire surface of the surface of the copper foil, or on a part thereof. When a part of the surface of the copper foil is coated with a diffusion preventing agent, it is preferable that the coating rate is 50% or more. Here, the coating rate refers to the ratio of the coated area when the overall area of the surface of the copper foil is 100%.

As the polyimide resin laminated on the copper foil, a commercially available polyimide film can be used as it is. From the viewpoint of easy control of the thickness and physical properties of the polyimide resin layer as the insulating layer, polyimide produced by a so-called cast (coating) method in which a polyamic acid solution is directly applied on a copper foil and then dried and cured by heat treatment Resins are preferred. The polyimide resin may be formed as a single layer. Considering the adhesion of the polyimide resin and the copper foil, it is preferable to form a polyimide resin layer composed of a plurality of layers. When the polyimide resin layer is composed of a plurality of layers, it is possible to form the polyamic acid solution by sequentially applying a polyamic acid solution composed of different constituent components.

The polyamic acid solution which is a precursor of the polyimide resin can be prepared by polymerizing an optional diamine and an optional acid dianhydride (acid dianhydride) in the presence of a solvent according to a conventional method. As this solvent, any solvent can be used in accordance with the conventional method.

Examples of the diamine used as a raw material of the polyimide resin include 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,4- Methylene di-o-toluidine, 4,4'-methylene di-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 2,4- Phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3,3'-diamino 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, Diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, ) Benzene, benzidine, 3,3'-diamine Naphthophenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4'-diamino- bis (p-aminocyclohexyl) methane, bis (p-? -amino-t-butylphenyl) ether, bis (1,1-dimethyl-5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis Diamino toluene, 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, 2,2'-dimethyl- Diaminobenzofuran, 1,5-diaminofluorene, dibenzo-p-dioxin-2,7-diamine, and 4,4'-diaminobenzyl.

Examples of the acid dianhydride used as a raw material of the polyimide resin include pyromellitic acid dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 2,2', 3, 3'-benzophenonetetracarboxylic acid dianhydride, naphthalene-1,2,5,6-tetracarboxylic acid dianhydride, naphthalene-1,2,4,6-tetracarboxylic acid dianhydride, 1,2,4,5-tetracarboxylic acid dianhydride, naphthalene-1,4,5,8-tetracarboxylic acid dianhydride, naphthalene-1,2,6,7-tetracarboxylic acid dianhydride, 4 , 8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid dianhydride, 4,8-dimethyl- 6,7-hexahydronaphthalene-2,3,6,7-tetracarboxylic acid dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,7-dichloro Naphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 1,4,5,6- 8-tetrachloro Naphthalene-2,3,6,7-tetracarboxylic acid dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracar Biphenyltetracarboxylic acid dianhydride, 3,3 '', 4,4''-p-terphenyltetracarboxylic acid dianhydride, 2,2'-biphenyltetracarboxylic acid dianhydride, 3 '' - p-terphenyltetracarboxylic acid dianhydride, 2,3 '', 4''-p-terphenyltetracarboxylic acid dianhydride, 2,2-bis (2 Bis (2,3-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, perylene-2,3,8,9-tetracarboxyl Acid dianhydride, perylene-3,4,9,10-tetracar Perylene-4,5,10,11-tetracarboxylic acid dianhydride, perylene-5,6,11,12-tetracarboxylic acid dianhydride, phenanthrene-1,2,7,8 -Tetracarboxylic acid dianhydride, phenanthrene-1,2,6,7-tetracarboxylic acid dianhydride, phenanthrene-1,2,9,10-tetracarboxylic acid dianhydride, cyclopentane-1,2 , 3,4-tetracarboxylic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride, thiophene 2,3,4,5-tetracarboxylic acid dianhydride, 4,4'-oxydiphthalic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, and the like.

The insulating layer made of the polyimide resin for use in the printed wiring board of the present invention is preferably composed of a polyimide resin containing at least one kind selected from oxalic acid derivatives, salicylic acid derivatives, hydrazide derivatives and triazoles as anti- Do.

The antidiscoactive agent used in the present invention is an oxalic acid derivative such as 2,2'-oxamide-bis [ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (N-salicyloyl) amino-1,2,4-triazole and the like, triazole derivatives such as N, N'-bis [3- (3,5- ) Propionyl] hydrazine and the like can be used. These antifouling agents may be used alone or in combination of two or more. As a commercially available antifouling agent containing a plurality of antifouling agents and the like in advance, Adekastab ZS-27 (trade name, product of ADEKA Co., Ltd.) may be used.

Among them, when the salicylic acid derivative such as 3- (N-salicyloyl) amino-1,2,4-triazole and the triazole are used, the effect of the present invention becomes more remarkable.

The amount of the anti-freezing agent to be added is preferably 0.05 to 5.0 parts by mass based on 100 parts by mass of the polyimide resin as the base resin. If the addition amount of the antifouling agent is too small, a desired effect can not be obtained. If the amount is too large, there arises a problem that the antifouling agent blooms on the resin surface and an increase in cost is caused.

Further, in the present invention, in addition to the anti-freezing agent, an antioxidant used in a commercially available polymer material may be used in combination. By using the antifreezing agent and the antioxidant in combination, the oxidative deterioration of the polymer material can be more effectively suppressed. The antioxidant used in the present invention has a function of decomposing peroxide generated during the oxidative deterioration of the polymer material and stopping the cycle of the subsequent autoxidation.

Specifically, antioxidants such as a phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant can be used in combination with the composition comprising the polyimide resin and the antifouling agent according to the present invention, if necessary.

Examples of the phenolic antioxidant include Irganox 1010 (trade name: Irganox1010, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (Manufactured by BASF Japan), Irganox 1076 (trade name: Irganox1076, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, BASF Japan (Trade name: Irganox 1330, 3,3 ', 3 ", 5,5', 5" -hexa-t-butyl- ?,? ',? "- Mesitylene-2,4,6-triyl) tri-p-cresol, manufactured by BASF Japan Ltd.), Irganox 3114 (trade name: Irganox 3114, (1H, 3H, 5H) -triene, BASF Japan Co., Ltd.), Irganox 3790 (manufactured by BASF Japan) Tris ((4-t-butyl-3-hydroxy-2,6-xylyl) methyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -thione, produced by BASF Japan Ltd.), Irganox 1035 (trade name: Irgano butylphenyl) propionate], BASF Japan Co., Ltd.), Irganox 1135 (trade name: Irganox 1135, trade name: (C7-C9 branched alkyl ester of benzenepropanoic acid 3,5-bis (1,1-dimethylethyl) -4-hydroxy, BASF Japan Ltd.), Irganox 1520L (trade name: Irganox 1520L, Irganox 565 (trade name: Irganox3125, manufactured by BASF Japan Ltd.), Irganox 565 (trade name: Irganox 565, manufactured by BASF Japan Ltd.), 4,6-bis (octylthiomethyl) : 2,4-bis (n-octylthio) -6- (4-hydroxy 3 ', 5'-di-t-butyl anilino) -1,3,5-triazine, product of BASF Japan ), Adecastab AO-80 (trade name: ADK STAB AO-80, 3,9-bis (2- (3- (3- (5,5) undecane, manufactured by ADEKA), Sumilizer BHT (trade name: Sumilizer BHT, Sumitomo Chemical Co., Ltd.) (Sumilizer GS, Sumitomo Chemical Co., Ltd.), Sumilizer GA-80 (Sumilizer GA-80, Sumitomo Chemical Co., Ltd.) 1790 (trade name: Cyanox 1790, manufactured by Cytec) and vitamin E (for example, manufactured by Eisai Co., Ltd.).

The content of the phenolic antioxidant is preferably 0.001 to 10 parts by mass, more preferably 0.05 to 5 parts by mass based on 100 parts by mass of the polyimide resin as the base resin.

Examples of the phosphorus antioxidant include Irgafos 168 (trade name: Irgafos 168, tris (2,4-di-t-butylphenyl) phosphite, BASF Japan Ltd.), Irgafos 12 (Irgafos 12, material name: tris [2- [[2,4,8,10-tetra-t-butyldibenzo [d, f] [1,3,2] dioxaphosphin- Bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphoric acid, Irgafos 38 (trade name: Irgafos 38, Adekastab PEP-8 (trade name, product of ADEKA Co., Ltd.), ADEKASTAB PEP36 (trade name, product of ADEKA), Adekastab PEP-8 ), Sandstab P-EPQ (trade name, manufactured by Clariant), Weston 618 (trade name: Weston 618, by GE), Weston 619G (trade name: Weston 619G by GE), Ultranox 626 : Ultranox 626, manufactured by GE) and Sumilizer GP (trade name: Sumilizer GP, material: 6- [3- (3- butyl dibenz [d, f] [1.3.2] dioxaphosphperine) (commercially available from Sumitomo Chemical Co., Ltd.) Manufactured by Kaku Co., Ltd.).

The content of the phosphorus antioxidant is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass based on 100 parts by mass of the polyimide resin.

Examples of the sulfur-based antioxidant include dialkyl thiodipropionates such as 2-mercaptobenzimidazole, dilauryl thiodipropionate, dimyristyl thiodipropionate and distearyl thiodipropionate, and pentaerythritol tetra (β- Dodecyl mercaptopropionate), and the like can be given as examples of the? -Alkylmercaptopropionic acid esters of polyols.

The content of the sulfur-based antioxidant is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass based on 100 parts by mass of the polyimide resin.

It is preferable that the anti-freezing agent is contained in the polyimide resin because the heat peel strength can be further improved.

Hereinafter, one embodiment of the present invention will be described in detail.

It is preferable that the copper foil of the present invention to be used has a degree of gloss of 10 or more at a point before the surface to be laminated with the polyimide resin (the surface to be subjected to the various treatments described below including the roughening treatment before lamination) This is because the untreated copper foil before use is about 0 to 30 in matte foil and 100 to 500 in glossy foil, and it is difficult to obtain sufficient visibility after roughening treatment in a surface shape with less than 10 gloss.

The copper foil having the desired surface gloss can be produced under the following conditions. Hereinafter, an electrolytic copper foil will be described as an example. The production conditions of the electrolytic copper foil are merely examples, and the present invention is not limited thereto.

[Electrolytic copper foil manufacturing conditions]

Sodium 3-mercapto-1-propanesulfonate: 0.5 to 3.0 ppm

Hydroxyethylcellulose: 2-20 ppm

Glue (molecular weight = 3000): 1 to 10 ppm

Cu: 40 to 150 g / L

H ₂ SO ₄ : 60 to 160 g / L

Liquid temperature: 40 ° C to 60 ° C

Current density: 30 to 90 A / dm ²

(Preferably at least one of the M surface (matte surface) or the S surface (Shine surface) (preferably the M surface) of at least one surface of the copper foil (at least one of the rolled surface in the case of rolled copper foil) And executes harmonization processing. It is difficult to achieve both visibility and resin adhesion as copper foils in an unharmed state. It is important to adjust the foil surface to a proper state by the post-treatment described below.

One typical example of the harmonization treatment is a copper (Cu) based plating in which fine granular copper is formed on the copper foil surface by electroplating. Copper sulfate plating solution is used for pure copper plating. The concentration of sulfuric acid in the coarsening plating solution is preferably 50 to 250 g / L, more preferably 70 to 200 g / L. When the sulfuric acid concentration is too low, the conductivity is low and the electrodeposition property of the coarse particles deteriorates. If the sulfuric acid concentration is too high, corrosion of the equipment is promoted.

The copper concentration of the copper-based harmonic plating solution is preferably 6 to 100 g / L, more preferably 10 to 50 g / L. If the copper concentration is too low, the electrodepositability of the coarsened particles deteriorates. When the copper concentration is too high, a larger current is required to be plated with the particle, and this is not realistic in terms of equipment.

As a representative example of another roughening treatment, there is an alloy-based plating in which a fine grain-like Cu-Co-Ni alloy is formed on the copper foil surface by electroplating. The Cu-Co-Ni alloy plating is formed by electroplating a ternary alloy layer as if it has a copper content of 5 to 15 mg / dm ^{2 and} a cobalt-20 to 90 μg / dm ² nickel of -100 to 900 μg / dm ² It is possible to carry out the above-described processes. If the Co deposition amount is too low, the peeling strength after the heat resistance test may be lowered. If the Co deposition amount is too high, etching residues tend to occur, which is not preferable. If the Ni adhesion amount is too low, the peel strength after the heat resistance test may be lowered. On the other hand, if the Ni deposition amount is too high, etching residues tend to occur, which is not preferable. A more preferred coating weight Co is 30 ~ 80 ㎍ / dm ^2, and more preferred nickel coating weight is 200 ~ 400 ㎍ / dm ^2.

The Cu-Co-Ni alloy plating solution had a copper concentration of 2 to 10 g / L, a cobalt concentration of 20 to 40 g / L, a nickel concentration of 20 to 40 g / L, and a sulfuric acid concentration of 50 to 250 g / L . If the concentration of copper, cobalt and nickel is less than the above-mentioned range, the electrodeposition property of the coarse particles deteriorates. If the concentration exceeds the above-mentioned range, a larger current is required for plating into the particulate form, and this is not realistic in terms of equipment.

The current density for the pure copper system and Cu-Co-Ni alloy system plating is preferably 5 to 120 A / dm ² , and more preferably 25 to 100 A / dm ² . If the current density is too low, it is not productive because it takes time to process. If the current density is excessively high, the electrodeposition property of the coarse particles deteriorates.

Smooth copper plating (cover plating) may be performed on the surface of the roughening particle layer in order to prevent the coarse particles from falling off after the roughening treatment. At this time, the liquid composition has a copper concentration of 40 to 200 g / L, a sulfuric acid concentration of 70 to 200 g / L, a current value of 0.4 to 20 A / dm ² , a liquid temperature of 40 to 60 ° C, Sec.

In the harmonizing condition used in the present invention, the height of the formed coarse particles tends to change preferentially in the "coarsened plating" portion. On the other hand, in the " cover plating " portion, the width of the coarsened particles tends to change preferentially. In addition, since the cover plating also functions to fill the valleys between the coarsened particles, excessive height of the coarsened particles may be excessively reduced if the cover plating is excessively applied. By appropriately controlling these two types of plating, the shape of the coarsely grained particles can be controlled according to the application. For example, if the coarsened amount of electricity is small and the amount of cover plating electricity is large, the coarse particles have a large foot and a gentle shape (for example, the shape 2 shown in Table 1). Conversely, if the coarsened amount of electricity is large and the cover plating electricity quantity is small, the coarsely grained particles become elongated (for example, shape 3 shown in Table 1). With respect to the copper concentration of the coarsened plating solution, the coarsened particle shape becomes gentler when the concentration is high (for example, the shape 2 shown in Table 1) The shape 3 shown in Table 1).

Further, the roughening treatment may be carried out by a method other than roughening. Examples thereof include those obtained by etching, those obtained by oxidizing the surface of the foil by oxidizing agents or adjusting the atmosphere to roughen the surface thereof, those obtained by roughening the oxidized surface by recirculating the surface thereof, and a combination thereof.

Then, the electrolytic copper foil is subjected to PR pulse electrolysis treatment on at least one surface of the electrolytic copper foil which is subjected to at least the harmonic treatment. The PR pulse electrolysis is repeated to dissolve and precipitate the coarse particles to reduce the size of the coarse particles, to increase the number of coarse particles, to smooth the surface of the coarse particles, and to obtain a coarse particle shape that improves visibility.

As the electrolytic solution used for the PR pulse electrolytic treatment, it is preferable to use the pure copper-based coarsening plating solution and the Cu-Co-Ni alloy-based coarsening plating solution described above. The PR-pulse electrolytic treatment and the Cu-Co-Ni alloy harmonization treatment were carried out using the copper-Co-Ni alloy-based plating solution for PR pulse electrolysis treatment. Thereby, there is an advantage that the kind of the liquid to be used is reduced and the management of the plating liquid is facilitated.

It is preferable that the time of the pure pulse electrolysis and the reverse electrolysis time are in the range of 50 to 500 milliseconds. If this time is too short, the effect of the PR pulse electrolysis is hard to appear, and if it is too long, the coarse particles may be coarsened.

The forward current density of the PR pulse electrolysis is preferably 0.5 to 10 A / dm ² . If the net current density is too small, the amount of precipitation per pulse is small and it is difficult to obtain an effect on the surface shape. If it is too high, the electrodepositivity will deteriorate.

The reverse current density is preferably 1 to 20 A / dm ² . Even within this range, conditions such as below or below the net current density are not preferable. The condition of PR pulse electrolysis is determined by comprehensive judgment because each item closely influences each other.

Further, if necessary, an alkali immersion treatment is performed as a post-treatment. This treatment is carried out for the purpose of removing residues of surface contaminants such as additives for bulking agents or for smoothing the surface of harmonized particles. As the alkali solution, an aqueous solution of NaOH is used. The NaOH concentration is preferably in the range of 10 to 60 g / L. The solution temperature is preferably 20 to 50 占 폚, and the immersion time is preferably 5 to 50 seconds.

After the roughening treatment, diffusion prevention coating of nickel and zinc covering the coarse particles is carried out. In the present invention, it is preferable to use nickel-zinc continuous electroplating or nickel / zinc alloy electroplating under the following conditions, but the forming method is not limited to these methods.

[Nickel → Zinc continuous electroplating]

* Nickel plating bath

_{NiSO 4 · 6H 2 O: 45} g / L ~ 450 g / L

H ₃ BO ₃ : 10 g / L to 50 g / L

pH: 3.0 to 4.5

Bath temperature: 30 ° C to 60 ° C

Current density: 0.1 A / dm ² to 2.0 A / dm ²

Plating time: 2 seconds ~ 30 seconds

* Zinc plating bath

_{ZnSO 4 · 7H 2 O: 3} g / L ~ 100 g / L

NaOH: 20 g / L to 80 g / L

Bath temperature: 20 ℃ ~ 40 ℃

Current density: 0.1 A / dm ² to 2.0 A / dm ²

Plating time: 2 seconds ~ 30 seconds

[Nickel / zinc alloy electroplating]

_{NiSO 4 · 6H 2 O: 45} g / L ~ 450 g / L

_{ZnSO 4 · 7H 2 O: 3} g / L ~ 100 g / L

_{(NH 4) 2 SO 4:} 3 g / L ~ 30 g / L

pH: 4.0 to 6.0

Bath temperature: 30 ° C to 50 ° C

Current density: 0.1 A / dm ² to 2.0 A / dm ²

Plating time: 6 to 60 seconds

)을 목적으로 한 표면 처리를 들 수 있다. 표면처리 중 금속 표면 처리에 이용하는 처리제로서는 Cr, Si, Co, Mo의 단체 또는 수화물을 들 수 있다. 합금 표면 처리로서는 Si, Co, Mo 중 적어도 1종류의 금속 또는 1종류 이상의 금속을 함유하는 합금을 부착시킨 후 Cr을 부착시킨다.At least one surface of the electrolytic copper foil (preferably, the surface of the copper foil on the side where the roughening treatment and the diffusion preventing coating are performed) may be subjected to a laminated surface treatment. Concretely, adhesion, chemical resistance, rust prevention (

) For surface treatment. As the treatment agent used for the metal surface treatment during the surface treatment, a single substance or a hydrate of Cr, Si, Co, Mo can be exemplified. As the alloy surface treatment, Cr is adhered after attaching at least one kind of metal among Si, Co, and Mo or an alloy containing at least one kind of metal.

Examples of the plating solution and the plating conditions (to which the metal or the alloy is applied) for performing the above-described metal surface treatment or alloy surface treatment are shown below.

[Mo-Co plating]

_{Na 2 MoO 4 · 2H 2 O} 1 ~ 30 g / L

_{CoSO 4 · 7H 2 O 1 ~} 50 g / L

Citric acid 3 sodium dihydrate 30 ~ 200 g / L

Current density 1 to 50 A / dm ²

Bath temperature 10 ~ 70 ℃

Processing time 1 second ~ 2 minutes

pH 1.0 to 4.0

[Cr plating]

CrO ₃ 0.5 to 40 g / L

Bath temperature 20 ~ 70 ℃

Processing time 1 second ~ 2 minutes

Current density 0.1 to 10 A / dm ²

pH 1.0 to 4.0

The Ni or Mo contained in the diffusion preventing coating and adhered on the surface of the copper foil after the surface treatment by the surface treatment is a metal which deteriorates the etching property. Therefore, for these metals, it is preferable that the adhesion amount to the surface is 1 mg / dm ² or less. Further, if the amount of Zn to be adhered to the surface is excessively large, it may melt at the time of etching to deteriorate the peel strength, and therefore, it is preferably 0.2 mg / dm ² or less. In addition, if the adhesion amount is all the same, the shape of the electrolytic copper foil roughened surface after the surface treatment and the color (appearance) of the surface are not greatly damaged.

In order to improve the peel strength, it is preferable to treat the surface of the metal surface treated with the silane coupling agent (silane coupling agent treatment). As the silane coupling agent, generally used amino-based, vinyl-based, isocyanate-based, and epoxy-based materials are exemplified, but the kind of the silane coupling agent is not particularly limited in the present invention.

In the copper clad laminate according to the present invention, the use of an adhesive or thermal compression bonding is not required for the lamination of the copper foil and the polyimide resin layer. A roughening particle layer is provided on one surface of the copper foil, a diffusion preventive coating having the above specified Ni / Zn ratio is further carried out thereon, and the surface thereof is subjected to a metal surface treatment or an alloy surface treatment, a chromate treatment and a silane coupling agent It is possible to secure the adhesion of the copper foil to the polyimide resin layer by treatment and, if necessary, post-treatment with an alkali immersion treatment.

In the case of the rolled copper foil of the present invention, it is possible to use any of tough pitch copper foil and copper (copper silver) alloy foil (Cu-Ag 0.02 to 0.03 mass%). The rolled copper foil is also laminated with a polyimide resin after various treatments as in the case of the electrolytic copper foil mentioned above.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Examples 1 to 15 and Comparative Examples 1 to 12

<Preparation of copper foil>

An electrolytic copper foil (thickness: 12 占 퐉) prepared in an electrolytic copper foil production condition under which the gloss of the M plane (matte plane) was 230 and the gloss of the S plane (Shiny plane) was 100 Quot; delivered &quot;). Apart from this, a rolled copper foil (tough pitch copper, as rolled foil) (thickness: 12 占 퐉) was also prepared (hereinafter this copper foil type was abbreviated as "rolling").

[Electrolytic copper foil manufacturing conditions]

Sodium 3-mercapto-1-propanesulfonate: 0.5 to 3.0 ppm

Hydroxyethylcellulose: 2-20 ppm

Glue (molecular weight = 3000): 1 to 10 ppm

Cu: 40 to 150 g / L

H ₂ SO ₄ : 60 to 160 g / L

Bath temperature: 40 ℃ ~ 60 ℃

Current density: 30 to 90 A / dm ²

These various copper foils were subjected to degreasing and pickling in accordance with a conventional method and then subjected to a pure copper or alloy plating treatment on one surface of the copper foil (on the mat surface side in the electrolytic copper foil) under the conditions described below, A plating process was performed. The temperature of the copper-based system and alloy-based harmonic plating solution was all set at 25 캜.

The copper plating solution had a copper concentration of 70 g / L, a sulfuric acid concentration of 110 g / L, and a liquid temperature of 50 캜.

Other specific conditions are shown in Table 2. The conditions of the "coarsening plating treatment" and "cover plating treatment" were appropriately controlled as shown in Table 2 to control the shape of the coarsely grained particles.

The PR pulse electrolytic treatment was carried out on the surface of the sample after the cover plating, using the same plating liquid as that of the coarsening plating solution. The process was repeated for a predetermined period of time in the order of the pulse pure electrolysis (350 milliseconds), the pulse reverse electrolysis (100 milliseconds), and the pulse electrolysis stop (200 milliseconds). Other specific conditions are shown in Table 2.

[Table 2]

Each copper foil subjected to the above coarse plating, cover plating and PR pulse electrolytic treatment was subjected to alkali immersion treatment. The treatment liquid was NaOH at 40 g / L, the liquid temperature was 50 占 폚, and the treatment time was 32 seconds.

Diffusion preventing coating (the following nickel → zinc continuous electroplating), surface rust prevention treatment (the following Cr plating treatment), and silane coupling treatment were carried out in this order on the roughened surface of the copper foil after the alkali immersion treatment. A silane coupling agent was prepared by using an amino system (KBM-903, product of Shin-Etsu Chemical Co., Ltd.) as an aqueous solution with a concentration of 0.2 mass%, applying a coating on a copper foil and drying (120 ° C) Respectively.

[Nickel → Zinc continuous electroplating]

* Nickel plating bath

_{NiSO 4 · 6H 2 O: 45} g / L ~ 450 g / L

H ₃ BO ₃ : 10 g / L to 50 g / L

pH: 3.0 to 4.5

Bath temperature: 30 ° C to 60 ° C

Current density: 0.1 A / dm ² to 2.0 A / dm ²

Plating time: 2 seconds ~ 30 seconds

* Zinc plating bath

_{ZnSO 4 · 7H 2 O: 3} g / L ~ 100 g / L

NaOH: 20 g / L to 80 g / L

Bath temperature: 20 ℃ ~ 40 ℃

Current density: 0.1 A / dm ² to 2.0 A / dm ²

Plating time: 2 seconds ~ 30 seconds

[Cr plating] (chromate treatment)

CrO ₃ 0.5 to 40 g / L

Bath temperature 20 ~ 70 ℃

Processing time 1 second ~ 2 minutes

Current density 0.1 to 10 A / dm ²

pH 1.0 to 4.0

&Lt; Preparation of polyimide resin &

[Synthesis of polyamic acid]

N, N-dimethylacetamide was added to a reaction vessel equipped with a thermocouple, a stirrer and a nitrogen-introducing reaction vessel, and 2,2-bis [4- (4-aminophenoxy) phenyl] ) Was added and dissolved in the container while stirring. Then, pyromellitic dianhydride (PMDA) was added in such an amount that the molar ratio of the diamine (BAPP) to the acid dianhydride (PMDA) was about 1: 1, and the total amount of the monomers was 12 mass%.

A polyamic acid obtained by adding 0.2 parts by mass of one kind of antifouling agent described below to 100 parts by mass of the polyamic acid thus prepared was also prepared in the same manner.

Antiseptic agent 1: Salicylic acid derivative / triazole (trade name: Adecastab CDA-1, manufactured by ADEKA)

Material name: 3- (N-salicyloyl) amino-1,2,4-triazole

[Chemical Formula 1]

Antifungal agent 2: Oxalic acid derivative (trade name: Naugard XL-1, available from Addivant)

Bis [ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]

(2)

Antihalation agent 3: Hydrazide derivative (trade name: Irganox MD1024, manufactured by BASF Japan)

N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine

(3)

A polyamic acid solution containing the antifouling agent or no antifouling agent was uniformly coated on the surface of each copper foil until the silane coupling treatment so that the thickness of the polyimide resin produced after curing was 2.5 占 퐉 After drying at 130 ° C, the solvent was removed. Subsequently, a polyamic acid solution containing no antifouling agent was uniformly applied to the coated side so that the thickness of the polyimide resin produced after curing was 20.0 占 퐉, and the solvent was removed by drying at 120 占 폚. The same polyamide acid solution (containing the antifouling agent or no antifouling agent) as applied to the first layer on the side of the coated surface was applied uniformly so that the thickness of the polyimide resin produced after curing was 2.5 占 퐉 And dried by heating at 130 DEG C to remove the solvent. Each copper foil of this elongated shape was subjected to a heat treatment for a total of about 6 minutes in a continuous curing furnace which was set at 130 DEG C and set to raise the temperature stepwise up to 300 DEG C and imidization of each polyamic acid was carried out, A copper clad laminate having a total thickness of 25 mu m in total of the polyimide resin layers composed of all three layers thus formed was obtained.

Table 3 shows the respective characteristics of the copper foils of the respective examples and comparative examples.

[Table 3]

In each of the examples and comparative examples, the measurement of each characteristic was carried out in the following manner.

(1) Measurement of diffuse reflectance

For the measurement, an ultraviolet visible spectrophotometer V-660 (trade name, integral sphere unit) manufactured by Nippon Bunko Co., Ltd. was used. The measurement light was incident perpendicularly to the roughened surface of the copper foil before being adhered to the polyimide resin, and the diffuse reflectance (Rd) was measured. The values at all wavelengths of 600 nm were used for the evaluation.

(2) Measurement of surface color (saturation (C *))

For the measurement, an ultraviolet visible spectrophotometer V-660 (trade name, integral sphere unit) manufactured by Nippon Bunko Co., Ltd. was used. The total light ray spectral reflectance of the roughened surface of the copper foil before being attached to the polyimide resin at a wavelength of 870 to 200 nm was measured. L *, a *, and b * were calculated by the software attached to the instrument in the spectrum. C * was calculated from a * and b * in accordance with the above formula 1. [

(3) Measurement of height of harmonic particles

Each of the copper clad laminates thus prepared was filled with a resin and subjected to cross-sectional exposure, and observed at 50000 magnifications using FE-SEM (field emission scanning electron microscope) (product name: SU8020, product of Hitachi Hi-tech Co., Ltd.). The height of 10 coarse particles randomly selected from the field of view of 5 占 퐉 was measured, and the arithmetic mean value thereof was regarded as the coarsened particle height. Details of the method for measuring the height of harmonic particles are shown in Fig. In other words,

[1] Draw a triangle connecting two roots of the coarsely grained particles (the coarsest grains shown in the front side of the SEM photograph shown) and the highest point of the coarsened particles at the time of single-sided exposure. It is impossible to observe a viewing angle of 5 占 퐉 by observing 50000 times and it may not be possible to observe 10 coarse particles depending on conditions. In this case, Find the average height.

[2] The height of the triangle in the case where the highest point of the height of the harmonic grains is the apex and the line connecting the roots of the roughed grains is the bottom is obtained from the triangle drawn in [1]. The arithmetic mean height is obtained as the height of the harmonic grain.

(4) Measurement of atomic weight ratio

The adhesion amount of nickel and zinc on the roughened surface of the copper foil before being attached to the polyimide resin using an ICP emission spectrometer (product of Shimadzu Seisakujo Co., Ltd., product name: ICPS-7000) was measured according to the method of JIS K 0553-2002 . The Ni deposition amount of the alloy-based roughened products was determined by summing up the amounts of Ni and Ni constituting the coarse particles and the Ni constituting the diffusion preventing layer. The ratio of Ni / Zn adhesion ratio (mass ratio) was calculated from the measured adhesion amount.

The performance evaluation of the copper foils of the respective examples and comparative examples was carried out by the following methods.

(5) Evaluation of film visibility

The copper clad laminate produced in each of the above Examples and Comparative Examples was completely dissolved in the copper chloride etching solution to prepare a polyimide film having the copper foil surface transferred on one side thereof.

For the measurement, an ultraviolet visible spectrophotometer V-660 (trade name, integral sphere unit) manufactured by Nippon Bunko Co., Ltd. was used, and a monochromatic light having a wavelength of 600 nm was used as a light source, and other measurement conditions were in accordance with JIS K 7136-2000. Measurement light was incident perpendicularly to the surface of the polyimide film on which the surface irregularities of the copper foil were transferred, and the transmitted light was allowed to enter the integrating sphere. When the same standard reflector as the inner wall of the integrating sphere is provided at the intersection of the optical axis of the incident light and the inner wall of the integrating sphere, the transmittance is the total light transmittance (T _t ) The transmittance measured when taken out and removed is the diffuse transmittance (T _d ). The measurement results are shown in Table 4.

(T _d / T _t ) × 100 (%) as a haze value.

When the haze value is less than 40 (%) is evaluated as "excellent (A)", when the haze value is less than 80 (%), the haze value is evaluated as good (B) (E) &quot;. The visibility evaluation E is poor visibility to the extent that it is not suitable for printed wiring board applications, and the visibility evaluation B is good visibility to a degree suitable for use in a printed wiring board. The visibility is higher in the order of B to A, and the visibility is more preferable than the visibility evaluation A. The haze values are also shown in Table 4.

(6) Measurement of peel strength between copper foil and resin

The state peel strength and the heat peel strength as a measure of the adhesion between the copper foil and the polyimide resin layer were measured as follows. Using the specimens before and after the heat resistance test (heat treatment at 150 ° C for 1000 hours in the air) of the copper clad laminate produced in each of the above Examples and Comparative Examples, the copper foil portion was masked with a 10 mm wide tape to perform copper chloride etching The tape was removed to prepare a sample having a width of 10 mm, and the state peel strength and the heat peel strength were measured according to the standard of JIS C 6481-1996.

(A) &quot; when both of the state peel strength and the heat peel strength were 1.0 kN / m or more, and when the peel strength was 1.0 kN / m or less and 0.8 kN / m or more, And when the peel strength of either one is less than 0.6 kN / m and not more than 0.4 kN / m is referred to as &quot; (C) &quot; D) &quot;, and when one of the peel strengths was less than 0.4 kN / m, the heat (rejection) (E) was determined. Peel strength evaluation D, C, B, and A can be said to have good adhesiveness to a degree suitable for printed wiring board applications. The adhesion is increased in the order of D, C, and B, and A is more preferable. The results are also shown in Table 4.

(7) Overall evaluation of visibility and adhesion

Based on the results of (5) and (6) above, comprehensive evaluation was carried out based on the following criteria. The results are also shown in Table 4.

E, which is one of the visibility and the adhesion, is E (rejected)

D for evaluation of adhesion and visibility not for E: D (acceptance, a)

There is C evaluation in adhesion evaluation, and visibility is not E evaluation: C (acceptance, quantity)

Visibility, and adhesion are B evaluation and not E evaluation: B (acceptance, right)

In both evaluation items, evaluation A: A (acceptance, number)

[Table 4]

In Examples 1 to 15, the overall evaluation is D, C, B, and A, and it can be said that there is no problem in practical use. The shape of the roughening of the surface of the copper foil was found to have a shape represented by the shape 1 in Table 1, satisfying the requirements of the present invention.

It can be seen that the antifouling agent is contained in Examples 1 and 12 in the pure roughening treatment and in the alloying roughening treatment in Examples 14 and 15, because the heat peel strength is higher and more preferable. In Examples 11 and 14, the blend height, Rd, and Ni deposition ratio are almost the same, but it is understood that Example 11, which is a pure roughening treatment, is more preferable because the condition and the heat peel strength are high. It can be seen from comparison between Example 1 and Example 9 that Rd is more preferably at least 24%. It can be seen from the comparison between Example 10 and Example 14 that the peeling strength is higher than that of the alloy-based roughening treatment because the roughening treatment is higher than that of the alloy roughening treatment. Comparing Examples 1 to 6 and Examples 7 to 11, it can be seen that Rd is preferably from 24 to 38% and Ni adhesion ratio is from 5.6 to 20% in the case of using the antifouling agent in the pure roughening treatment. Although Example 1 and Example 13 were equal in height of harmonic grains, Example 13 had a poor haze value due to a high haze value, but was considered to be caused by unevenness due to oil pits peculiar to the rolled copper foil, Is preferable.

On the contrary, each comparative example exhibited poor properties.

In Comparative Example 1, R _d , C * and the height of harmonic particles were both higher than those in the present invention, and when the cross-section was observed, the shape was shown by Form 4 in Table 1. Therefore, although it is excellent in adhesion, it has low visibility and is not suitable for practical use.

In Comparative Example 2, contrary to Comparative Example 1, the R _d and the height of the harmonic particle were lower than those in the present invention. Therefore, all of them are excellent in visibility but are not suitable for practical use because they have low adhesion.

In Comparative Examples 3 and 4, at least one of R _d and C * is out of the range defined by the present invention and the ratio of the height of the harmonic grain and the ratio of nickel / zinc is within the specified range of the present invention and the anti- When they were carried out, they had shapes shown by shapes 2 and 3 in Table 1, respectively. At the same time, the visibility is good, but the adhesion is low, which is not suitable for practical use.

In Comparative Examples 5 and 6, the nickel / zinc adhesion ratio was lower than that of the present invention. Both are good in visibility but poor in adhesion, which is not suitable for practical use.

In Comparative Example 7, R _d , C * and height of harmonic particles were both higher than those in the present invention, and when the cross section was observed, the shape was shown by the shape 4 in Table 1. Therefore, although it is excellent in adhesion, it has low visibility and is not suitable for practical use.

In Comparative Example 8, contrary to Comparative Example 1, the R _d and the height of the harmonic particle were lower than those of the present invention, and when the cross-section was observed, the shape represented by the shape 5 in Table 1 was obtained. Therefore, although they are excellent in visibility, they are not suitable for practical use because they have low adhesion.

Comparative Examples 9 to 12 correspond to those in which the PR pulse electrolytic treatment of Examples 1, 8, 10, and 14 was not performed, respectively. Cross-sectional observation of Comparative Examples 9 to 12 revealed that the grains between the coarsened grains were deeply deepened. Therefore, the average value of the height of the harmonic grains is increased, which is similar to the shape shown by the shape 4 in Table 1. Therefore, it is not suitable for practical use because it is excellent in adhesion but low in visibility. The PR pulse electrolytic treatment of the present invention contributes to the improvement of the visibility by lowering the height of the coarsened grains by filling the grains between the coarsened grains to some extent and by making them similar to the shape 1 shown in Table 1.

As described above, it can be seen that the ratio of the height of the coarsened grains on the surface of the copper foil, the diffuse reflectance, the saturation, and the ratio of the nickel / zinc adhered amount of the diffusion preventive coating are all in accordance with the present invention. It is also found that the heat peel strength is further improved by incorporating the antifreezing agent into the polyimide resin.

Industrial availability

The present invention makes it possible to provide a copper clad laminate for a wiring board excellent in resin adhesion and visibility suitable for use as a printed wiring board and a copper foil used therefor.

Claims (3)

Wherein the copper foil has a roughening particle layer composed of roughened particles having an arithmetic average height of 0.05 to 0.5 占 퐉 on at least one surface of the copper foil and at least nickel and zinc on the roughening particle layer, (Mass ratio) of nickel to the roughening particle layer is in the range of 0.5 to 20. The copper foil has a diffuse reflectance ( _Rd ) at a wavelength of 600 nm measured at the one surface side of 5 To 50% and a chroma (C *) of 30 or less. A copper clad laminate having the copper foil according to claim 1. A copper-clad laminate having a polyimide resin layer on the one surface side of the copper foil according to claim 1, the copper-clad laminate comprising a polyimide resin layer comprising an oxalic acid derivative, a salicylic acid derivative, a hydrazide derivative and at least one antifouling agent selected from triazoles.

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