Ceramic circuit board and a method of manufacturing the ceramic circuit board

摘要

A ceramic electrically insulating circuit board (1) has an electrically conductive plug (4a) tightly filling a through-hole (2) formed in the circuit board (1) made of aluminum nitride including a low, up to 1% by weight at the most, content of an oxide phase as a sintering assistant. The conductive plug is formed by putting high melting point metal paste (10) into the through-hole and sintering either the board prior to the metal paste or sintering both, the board and the paste, simultaneously. Then, causing melted copper or copper alloy (11) to permeate into gaps or interstices in the sintered high-melting point metal plug to form a tight seal of the hole and good electrical contacts of the conductive plug and any circuits on both sides of the board.