Patent ID: 8309164
Filing Date: 2012-11-13
Classification: B22F,C22C,C23C,C25D,H01L,Y10T

Abstract:
1. A method for producing metallized substrate comprising the steps of: forming a base nickel plating layer on a high-melting point metal layer formed on a ceramics substrate, by electroless nickel-boron plating, electrolytic nickel plating, or electrolytic nickel-cobalt plating, said high-melting point metal being molybdenum or tungsten, thermally treating the ceramic substrate on which the base nickel plating layer is formed, in a reducing atmosphere at a temperature of 700 to 900 degree C.; forming a layered nickel-phosphorus plating layer on the thermally-treated base nickel plating layer by electroless nickel-phosphorus plating under the condition of (a) or (b): (a) plating using acid nickel-phosphorus plating bath whose pH is lower than 5.6; (b) plating using neutral nickel-phosphorus plating bath whose pH is 5.6 to 7.3, followed by thermal treatment in a reducing atmosphere at a temperature of 450 to 900 degree C.; forming a diffusion-inhibiting plating layer on the layered nickel-phosphorus plating layer in accordance with any one of the following methods (c) to (e): (c) forming a columnar nickel-phosphorus plating layer by electroless plating using neutral nickel-phosphorus plating bath whose pH is 5.6 to 7.3; (d) electroless palladium-phosphorus plating; or (e) electroless palladium plating; and forming a gold plating layer by electroless gold plating on the diffusion-inhibiting plating layer.