JPS608307B2 - Chemical copper plating solution and chemical copper plating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical steel plating solution, and more particularly to a chemical steel plating solution that provides a tamped film with excellent physical properties.

Chemical copper plating solutions usually contain copper salts such as copper sulfate, mirroring agents such as ethylenediaminetetraacetic acid, reducing agents such as formalin, and pH adjusters such as sodium hydroxide, but these alone do not provide sufficient results. The plated films produced are generally brittle and pose problems when put into practical use. For example, when a conductor circuit on a printed circuit board is formed by chemical steel plating, if the plating film is brittle, circuit breakage may occur due to processing or thermal distortion of the circuit board. On the other hand, when an electrical steel plating film is used for the circuit, the tensile strength of the copper film is 50 to 60k9w/side and the elongation rate is about 4%, which is quite good, and there is no problem such as circuit breakage as mentioned above. does not occur. Considering these points, we have been adding sodium cyanide, dipyridyls, polyalkyl glycol,
By further adding non-reactive polymers such as phenanthrolines and polyalkylene glycol, oximes and polyethylene glycol, and non-reactive polymers such as nickel salts and cobalt salts, it is possible to improve the chemical steel plating liquid film. Efforts have been made to improve mechanical properties.

The plating film obtained from such a chemical steel plating solution is 3
It has an elongation rate of ~7% and a tensile strength of 35-50 kgw/rail, and can be used practically as a circuit copper film for printed circuit boards. However, printed circuit boards for computers, which require even higher reliability, require mechanical properties comparable to those of electrolytic copper plating films. Until now, no chemical steel plating solution has been obtained that satisfies these requirements and stably provides a plating film having an elongation rate of 4% or more and a tensile strength of 50 to 60 k9w/m2. SUMMARY OF THE INVENTION An object of the present invention is to provide a chemical steel plating solution that improves the above-mentioned drawbacks of the prior art and provides a plating film with excellent mechanical properties, particularly tensile strength. Its characteristics are copper salt, locking agent, reducing agent, spot adjustment agent, 2
, 2'-dipyridyl and polyethylene glycol, and an alkali-soluble silicon compound is added to the chemical steel plating solution. In the present invention, the copper salt used as a base, the oxidizing agent, the reducing agent, the conditioner, 2,
As the chemical steel plating solution containing 2'-dipyrdyl and polyethylene glycol, an aqueous solution having a known composition can be used.

An example of this is as follows. sulfuric acid steel
0.01 to 0.1 mol/ethylenediaminetetraacetic acid 0.02 to 0.2 mol/sodium hydroxide amount to adjust pH to 12.0 to 13.5 (20oo) 2.2
'-dipyridyl 0.05-0.5 mmol/polyethylene glycol 5-100 mmol/so** In addition to the above-mentioned components, the chemical steel plating solution of the present invention further contains an alkali-soluble silicon compound. Contains.

Examples of such compounds include silicates such as sodium silicate and potassium silicate, polysilicates such as sodium polysilicate and potassium polysilicate, metasilicates such as sodium metasilicate and potassium metasilicate, sodium orthosilicate, etc. Examples include orthosilicates such as potassium orthosilicate, silicon dioxide, and the like. It is preferable that at least one kind of such alkali-soluble inorganic silicon compound is contained in the chemical steel plating solution in a range of 5 to 100 parts per silicon dioxide. When the content of the compound is less than 9/5, the tensile strength of the plated film obtained is lower than 50k9w/fence, which is sufficient. In addition, if the content is 9/100 or more,
The tensile strength of the plated film is 50k9w/ground or more, but the elongation is less than 3%, which is not preferable. It is preferable to use the chemical steel plating solution of the present invention in a concentration of 60 ○ or more;
If it is less than 0, the resulting plated film will have insufficient elongation and tensile strength.

Next, the present invention will be specifically explained using examples. The surface of the example surface and the surface of the stainless steel plate that had been polished smoothly were degreased, and palladium, which is an initiator for the plating reaction, was attached to the surface and activated.

Next, chemical steel plating was performed at 70 mm using a chemical steel plating solution having the composition shown in Table 1 to obtain a plated film having a thickness of 35 to 40 mm. This plated film was peeled off from the plate and cut into pieces 1 square in width and 5 squares in length, and the tensile strength and elongation rate were measured using a tensile tester manufactured by Toyo Saiki Co., Ltd. The results are shown in Table 2.
Table 1 shows the addition of alkali-soluble inorganic silicon compounds. Note) The content of each component is per plating solution IZ.

The amount of I NaOH lost is per prepared solution IZ. Husband 2
Average molecular weight 600 loss 3 Aerosil No. 2 A case where a chemical steel plating solution that is not listed is also included as a comparative example.

Table 1 Side Paper) As is clear from the second diagram of Table 2, the present invention makes it possible to obtain a chemical steel plated film having good properties such as an elongation rate of 4% or more and a tensile strength of 50 k9w/iso or more.

Claims (1)

[Scope of Claims] 1. An alkali-soluble inorganic silicon compound is added to a chemical copper plating solution containing a copper salt, a complexing agent, a reducing agent, a pH adjuster, 2,2'-dipyrdyl, and polyethylene glycol. A chemical copper plating solution featuring: 2. The chemical copper plating solution according to claim 1, which contains an alkali-soluble inorganic silicon compound in a range of 5 to 100 mg/l in terms of silicon dioxide. 3. In a chemical copper plating method in which the plate surface is degreased, activated, and then plated with a chemical copper plating solution, the composition of the chemical copper plating solution is a copper salt, a complexing agent, a reducing agent, a pH adjuster, 2,2 1. A chemical copper plating method comprising adding an alkali-soluble inorganic silicon compound to '-dipyridyl and polyethylene glycol, and carrying out chemical copper plating by heating the plating solution to 60° C. or higher.