| 摘要 |
PURPOSE:To eliminate a short-circuit between wiring layers by a method wherein a baked ceramic board on which unbaked wiring layers made of copper oxide paste are formed and an unbaked green sheet on which wiring layers made of copper oxide paste are formed are bonded to each other by thermocompression bonding at a specific temperature and under a specific pressure. CONSTITUTION:Wiring layers 2 made of copper oxide paste are screen-printed on a baked alumina board 1 beforehand and dried. Then wiring layers 2 made of copper oxide paste are formed on an unbaked green sheet 3 in which holes 4 are formed at required positions and dried. The baked alumina board 1 and the unbaked green sheet 3 are laminated and bonded to each other by thermocompression bonding at a temperature of 50-80 deg.C and under a pressure of 100-300kg/cm<2>. The multilayered board after bonding is heated in the air to eliminate organic components in the paste and the green sheet completely for debindering. Then, after the copper oxide is reduced into metal copper in a nitrogen gas atmosphere containing hydrogen gas, the metal copper and the green sheet are baked in a nitrogen gas atmosphere. |
