| 摘要 |
PROBLEM TO BE SOLVED: To improve accuracy in the respective processes such as the mounting of electric components by preparing a practically circular motherboard, baking the circular motherboard, and restraining generation of undesired strain in the motherboard after sinterning. SOLUTION: A plurality of ceramic green sheets are stacked and pressed, and a motherboard 11 in the raw state before baking is obtained. The raw motherboard 11 is baked. For example, the motherboard 11 is baked at a temperature of 980 deg.C in a neutral atmosphere. Thus the motherboard 11 after baking is obtained. The motherboard 11 is shrinks in the baking process, and radiant heat at the time of baking is isotropically applied to the motherboard 11, since it is practically circular. As a result, shrinking of the motherboard 11 which accompanies sintering progresses while the circular shape is maintained, so that the shape of the motherboard 11 prior to baking and the shape of it after baking become practically similar. |
