Patent ID: 6713687
Filing Date: 2004-03-30
Classification: H05K,Y10T

Abstract:
A printed wiring board comprising:an insulator board having a via-hole, a first surface and a second surface that is opposite the first surface; first and second conductor patterns that are respectively located on the first surface and the second surface to cover the via-hole, and that include a metal; a unified conductive compound provided in the via-hole and including a first metal and a second metal having a higher melting point than a heating temperature required for interconnecting the first and second conductor patterns; and first and second solid phase diffusion layers formed from the metal in the first and second conductor patterns and the first metal in the unified conductive compound diffused into the metal in the first and second conductor patterns, the first and second solid diffusion layers located between the unified conductive compound and the first and second conductor patterns; wherein a sidewall of the unified conductive compound in the via-hole is concave in shape and approaches a center axis of the via-hole approximately halfway between the first surface and the second surface of the insulator board; and the first and second conductor patterns are electrically interconnected by the unified conductive compound and the first and second solid phase diffusion layers.