| 摘要 |
Electrodes are formed on an electronic part by an initial step of forming electrodes on a ceramic substrate, dipping the ceramic substrate in a noble metal solution for activating the surface of the electrodes by the use of a noble metal, and forming a solder layer or a tin layer on the activated surface of the electrode by electroless plating using 3-valence titanium ion as a reducing agent. The electrodes to be formed on the ceramic substrate may be a double layer comprised of a first layer containing silver, silver-palladium, silver-platinum or copper and a second electroless nickel plated layer. In the step of forming a solder layer or a tin layer on the activated surface of the electrode by electroless plating using 3-valence titanium ion a reducing agent, it is preferable to add a metal ion except tin and lead in the plating bath. Preferably, the metal ion added in the plating bath may be alkali earth metal element or may be at least one ion selected from the group consisting of Mg2+, Ca2+, Sr2+, Ba2+, Al3+, Mn2+, Fe3+, Co2+, Ni2+, and Zn2+.
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