JPS60218480A - chemical copper plating liquid - Google Patents

Abstract

PURPOSE:To obtain a plated film having superior physical properties by adding an alkali-soluble inorg. silicon compound and a selected org. compound to a prescribed chemical copper plating soln. so as to stabilize the plating soln. CONSTITUTION:To a chemical copper plating soln. contg. a copper salt, a complexing agent such as EDTA, a copper salt reducing agent and a pH adjusting agent are added proper amounts of an alkali-soluble inorg. silicon compound such as sodium silicate and one or more kinds of org. compounds which are effective in stabilizing the plating soln. The org. compounds are selected >=1 kind among nitrile compounds, oximes, amino acids, 2,2'-dipyridyl(derivs.), 1,10-phenanthroline(derivs.), alcohols and org. sulfur compounds. When the resulting plating soln. is used, a plated film having superior physical properties can be obtd. and the stability of the soln. can be well kept.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a chemical copper plating solution that deposits a deposited film with excellent mechanical properties, and in particular to a chemical steel suitable for thick plating in the manufacture of printed wiring boards. Regarding plating solution.

[Background of the invention]

Conventionally, chemical copper plating solutions have been known that have copper salts, complexing agents for copper salts, reducing agents for copper salts, and pH adjusters as basic components.In order to stabilize this chemical steel plating solution, organic Many compound-based additives have been proposed. However, due to thick plating, a chemical copper plating solution that provides a plating film with excellent physical properties is required for printed wiring boards that perform through-hole plating, and organic compound additives alone are insufficient to provide a plating film with sufficient physical properties. It is often difficult to obtain a 2.2'-
Improvements in the physical properties of the plating film can be expected only when using very few types of vinegar additives such as bipyridyl and polyalkylene glycol. [Object of the Invention] The object of the present invention is to eliminate the drawbacks of the prior art and provide a chemical steel plating solution that provides a plating film with excellent physical properties while applying an organic compound to stabilize the chemical copper plating. There is a particular thing.

[Summary of the invention]

The present invention is characterized in that a chemical steel plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH adjuster,
Further, additives (a) containing an alkali-soluble inorganic silicon compound, and (b) organic compounds effective in stabilizing the plating solution, such as nitrile compounds, oximes, amino acids, 2,2'-dipyridyl, and derivative,
1. Contains at least one of 10-phenanthroline, its derivatives, alcohols, and organic sulfur compounds. This makes it possible to stabilize the plating RF and obtain a plated film with excellent physical properties.

An example of adding sodium silicate or sodium metasilicate to a plating solution as an alkali-soluble inorganic silicon compound is described in Metal Surface Technology, Vol. 16, No. 11, 1965), and is well known in the art. However, the mechanical properties of the plated film obtained from the liquid composition of the above known example are insufficient, and it has not been known that the physical properties of the plated film can be improved by adding an inorganic silicon compound. Moreover, the stability of the plating solution was also insufficient, and there was also the problem that copper was easily deposited in the plating bath. , also, JP-A-54-19430
As described in the issue, when an inorganic silicon compound is further added to a chemical copper plating solution containing 2,2'-dipyridyl and polyethylene glycol, the tensile strength among the mechanical properties of the plated film can be improved. Are known.

However, in this case, the elongation rate of the plated film was hardly improved, and it was not known that both the elongation rate and tensile strength as physical properties of the plated film could be improved by adding an inorganic silicon compound.

The objects of the present invention can be achieved by using an inorganic silicon compound and an organic compound effective in stabilizing the plating solution in combination as additives.

In the present invention, applicable inorganic silicon compounds include water glass, metasilicates such as sodium metasilicate,
Examples include silicates such as sodium silicate, orthosilicates such as sodium orthosilicate, polysilicates, silicon dioxide, and silicon-containing glasses. For an inlay to be effective in improving the mechanical properties of a plated film, it is necessary to have a silicon content of 10 mg/or more. If it is less than that, no significant effect can be expected.

Organic compounds applicable to the present invention include nitrile compounds such as lactonitrile, oximes such as dimethyldalioxime, amino acids such as glycine and n-leucine, 2,2'-dipyridyl, and 4,4'-dimethyl 2
．． 2'-dipyridyl, 2. dipyridyl conductors such as 2'-biquinoline, 1.10-7 enanthroline, and 2
．． 9-dimethyl-1,10-phenanthroline, 4,7
- Phenanthroline derivatives such as diphenyl-1,10-phenanthroline, alcohols such as methyl alcohol, organic sulfur compounds such as 2-methylbenzothiazole, 2,2'-dithioglycolic acid, etc. You can use anything that makes you run.

Furthermore, the basic components of the chemical copper plating solution used in the present invention are a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH adjuster. Known materials such as copper, second chloride steel, and acetic acid steel can be used. , methane, ethylenediaminetetraacetic acid, N-hydroxyethylethylenediaminetriacetic acid, 1,2-diaminopropanetetraacetic acid, diethylenetriaminepentaacetic acid, cyclohexanediaminetetraacetic acid, etc. can be used for complexing copper salts. If monoamines such as triethanolamine, iminotriacetic acid, iminotriacetic acid, or Rotussel salt are used, it may not be possible to obtain a plated film with sufficient mechanical properties, or the stability of the plating solution may be unstable. A problem arises in that sufficient and substantial thick plating cannot be achieved. Formalin, which is commonly used, is suitable as a reducing agent for the copper salt, and IJium (hydroxide) can be used as a pH adjuster.

In addition, in the present invention, the plating temperature is 50t? The above is preferable, and if it is less than 50C, a plated film with sufficient mechanical properties cannot be obtained.

[Embodiments of the invention]

Next, the present invention will be specifically explained using examples.

Examples 1 to 15 A stainless steel plate whose surface was polished smoothly was degreased, and palladium, which is an initiator for a plating reaction, was attached to the surface. Next, with the chemical copper plating solution composition shown in Table 1,
Chemical steel plating was performed at a temperature of 0C to obtain a plated film with a thickness of about 30 μm. This plating film was peeled off from a stainless steel plate and cut to a width of 10M, with an initial tension interval of 50M.
The elongation rate and tensile strength were measured using a tensile tester manufactured by Toyo Sokki Co., Ltd. (mm). The results are shown in Table 2.

Comparative Examples 1 to 13 Examples 1 to 15 were carried out under the conditions described in the comparative stations in Table 1.
It was plated and evaluated in the same manner as above. The results are also shown in Table 2.

〔Effect of the invention〕

As is clear from the Examples and Comparative Examples, the chemical copper plating solution of the present invention makes it possible to obtain a plating film with excellent physical properties and to maintain good solution stability.

Similarly, in the chemical copper plating solution of the present invention, a third additive can be added as necessary. For example, by adding an inorganic compound such as sodium cyanide, it is possible to make the chemical copper plating solution even more stable in a kiln.

Claims (1)

[Claims] 1. A chemical steel plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH adjuster, which contains (a) an alkali-soluble inorganic silicon compound as an additive, and (b) Organic compounds effective in stabilizing the plating solution, such as nitrile compounds, oximes, amino acids, 2,2'-dipyridyl and its derivatives, 1°10-phenanthroline and its derivatives, alcohols, organic A chemical copper plating solution characterized by containing at least one type of sulfur compound. 2. A chemical copper plating solution according to claim 1, characterized in that it complexes a copper salt.