JP2002060980A - Surface roughening treating solution for copper and copper alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface roughening treating solution for copper surfaces for firmly adhering a copper surface and a high polymer material in the production of a printed wiring board or the like. SOLUTION: This surface roughening treating solution for copper and copper alloys contains hydrogen peroxide, inorganic acid, azoles such as benzotriazole and at least one kind of organic acid selected from glycolic acid, malonic acid and glutaric acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper surface roughening solution, and more particularly, to the bonding of a copper surface to a polymer material such as a prepreg when manufacturing a printed wiring board, particularly a multilayer printed wiring board. The present invention relates to a copper surface roughening treatment liquid for strengthening properties.

[0002]

2. Description of the Related Art A multilayer printed wiring board is formed by laminating an exterior material, a prepreg, etc. on an interior material on which a circuit is formed, heating and pressurizing, forming a through hole in the integrated product, plating, and forming an exterior circuit. Manufactured in line. In this process,
In order to improve the adhesiveness of each layer, the surface of the interior copper foil is roughened.

As a roughening method, an oxidation treatment with sodium chlorite or the like is usually performed to form a copper oxide layer, which is called a blackening treatment. However, the blackening treatment has a disadvantage that the plating solution soaks in the plating process after the formation of the through-holes and the phenomenon that the copper oxide melts (pink ring) easily occurs. A method is being considered.

JP-A-10-96088 discloses a method of etching a copper surface with an etching solution containing oxo acid, peroxide, azole and halide, and JP-A-11-21517 discloses a method of etching a copper surface. A method of contacting an adhesion-promoting composition comprising an agent, an acid, a source of halide ions (especially chloride ions) and optionally a water-soluble polymer with a metal surface to produce a converted coated surface having a minute roughness on the metal surface. It is shown. However, it has been pointed out that in the composition containing a halide as described above, the dissolution rate of copper rapidly changes depending on the halide ion concentration, and it is difficult to maintain the dissolution rate constant. .

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have found that a processing solution containing no halide can strengthen adhesion to a polymer material on a copper surface and does not generate a pink ring. As a result of repeated studies for the purpose of finding a surface roughening solution for copper and copper alloy capable of obtaining a roughened surface having excellent acid resistance, the present invention was completed.

[0006]

That is, the present invention provides an aqueous solution containing hydrogen peroxide, an inorganic acid, an azole, and at least one organic acid selected from glycolic acid, malonic acid and glutaric acid. And a surface roughening treatment solution for copper and copper alloys comprising:

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The concentration of hydrogen peroxide in the surface roughening solution of the present invention is preferably from 0.2% by weight to 10% by weight, more preferably from 1% by weight to 5% by weight. It is. Examples of the inorganic acid include sulfuric acid, phosphoric acid, and nitric acid, and are preferably sulfuric acid and phosphoric acid. The concentration of the inorganic acid is preferably 1% by weight to 30% by weight. When sulfuric acid is used, 2% by weight to 10% by weight is more preferable, and when phosphoric acid is used, 5% by weight to 15% by weight. % Is more preferred. Examples of the azoles include triazole, tetrazole and imidazole, and benzotriazole is preferable. The concentration of the azole is preferably 0.05% by weight or more, and when benzotriazole is used as the azole,
5% to 1% by weight is preferred. The surface roughening solution of the present invention contains at least one organic acid among glycolic acid, malonic acid, and glutaric acid, and the content thereof is preferably 1% by weight to 15% by weight. Preferably,
2 to 12% by weight.

Further, the surface roughening solution of the present invention includes:
If necessary, stabilizers for hydrogen peroxide such as alcohols, amines and sulfonic acids, and other additives may be added.

[0009] The surface of copper and copper alloy can be treated by dipping or spraying, and the treatment temperature is in the range of 10 to 60 ° C, preferably 20 to 50 ° C. The processing time varies depending on the processing temperature and the processing method.
Minutes, preferably 1 minute to 3 minutes. still,
In this treatment liquid, the dissolved thickness (average thickness calculated from the surface area and specific gravity of copper and the weight of dissolved copper) is
The copper surface is efficiently roughened when the thickness is 0.5 to 4.0 μm, preferably 0.8 to 2.0 μm. It is preferable to determine the processing time according to the speed.

[0010]

According to the surface roughening solution of the present invention, a brownish film having a minute roughness is formed on the copper surface, and a polymer material such as a prepreg, a solder resist, a dry film resist, and an adhesive is used. Is good.

[0011]

The present invention will be described below with reference to examples. Examples 1 to 7 A copper-clad laminate for a printed wiring board was immersed in a roughening treatment solution having the composition shown in Table 1, and the copper surface of the copper-clad laminate was etched to be roughened. Table 1 shows the treatment temperature, treatment time, and dissolution thickness (average thickness calculated from the surface area and specific gravity of copper and the weight of dissolved copper). Electron micrographs of the copper surface before the surface roughening treatment and the copper surface after the treatment were taken at an angle of 30 ° are shown in FIGS. As can be seen from the electron micrographs of FIGS. 2 to 8, fine irregularities are formed on the copper surface treated with the present treatment solution, and the copper surface is roughened.

[0012]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a 5000 × electron micrograph of a copper surface before treatment.

FIG. 2 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 1.

FIG. 3 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 2.

FIG. 4 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 3.

FIG. 5 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 4.

FIG. 6 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 5.

FIG. 7 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 6.

FIG. 8 is a 5000 × electron micrograph of a copper surface roughened with the roughening solution of Example 7.

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Claims (5)

[Claims] 1. A rough surface of copper and a copper alloy comprising an aqueous solution containing hydrogen peroxide, an inorganic acid, an azole, and at least one organic acid selected from glycolic acid, malonic acid and glutaric acid. Treatment solution. 2. The method according to claim 1, wherein the concentration of the hydrogen peroxide is 0.2% by weight or less.
The surface roughening treatment liquid according to claim 1, which is 10% by weight. 3. The surface roughening solution according to claim 1, wherein the azole is benzotriazole. 4. The surface roughening treatment liquid according to claim 3, wherein the benzotriazole is present in an amount of 0.05% by weight to 1% by weight. 5. The surface roughening treatment liquid according to claim 1, wherein the organic acid is 1% by weight to 15% by weight.