Semiconductor device, wiring board and method of making same

A wiring board comprising:

• an insulating substrate
• a wiring provided on the insulating substrate;
• an opening that is formed at a predetermined position in said insulating substrate, one end of said opening being shut by said wiring to form the bottom of said opening;
• a thin film conductor that is formed on the surface of said wiring and at the bottom of said opening;
• and
• an embedded conductor layer that is provided in said opening while contacting said thin film conductor formed at the bottom of said opening;
• wherein said thin film conductor includes gold plating layer formed on the surface, and said embedded conductor layer is of a conductor that has a rate of solution to tin or an alloy including tin lower than that of gold.

A method of making a wiring board, comprising the steps of;

• forming an opening at a predetermined position in an insulating substrate;
• forming a wiring pattern on the surface of said insulating substrate such that one end of said opening is shut by said wiring pattern to form the bottom of said opening;
• forming a thin film conductor on the surface of said wiring and at the bottom of said opening;
• and
• forming an embedded conductor layer in said opening such that said embedded conductor layer contacts said thin film conductor formed at the bottom of said opening;
• wherein said thin film conductor includes gold plating layer formed on the surface, and said embedded conductor layer is of a conductor that has a rate of solution to tin or an alloy including tin lower than that of gold.