| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent an electrolytic plating layer from swelling and electrolytic plating layers from short-circuiting by improving the adhesiveness between an electroless plating layer formed on a roughened surface of the organic resin insulating layer of a wiring substrate and a plating resist layer formed on the electroless plating layer. SOLUTION: The surface of the organic resin insulating layer is roughened to Rz=Xμm 10-point mean roughness (Rz) prescribed by JIS-B-0601 and on the organic resin insulating layer which is thus roughened, an electroless plating layer 4 of Yμm in thickness is formed. At this time, the thickness of the electroless plating layer is so set that Y <= X/3 and then the surface roughness of the electroless plating layer is equalized to that of the organic resin insulating layer. Consequently, sufficient adhesion between the plating resist and electroless plating layer is obtained to effectively prevent the plating resist layer from floating or peeling. |
