Patent ID: 7968043
Filing Date: 2011-06-28
Classification: B32B,C04B,H05K,Y10T

Abstract:
1. A process for producing a ceramic substrate, comprising the steps of: forming an auxiliary-layer-lined unfired ceramic body comprising a plane-shaped unfired ceramic body and first and second auxiliary layers arranged to cover substantially the entire area of respective first and second principal surfaces of the unfired ceramic body from one edge of the unfired ceramic body to an opposed edge of the unfired ceramic body, the auxiliary layers being made of a material which is substantially unsinterable at a firing temperature of the unfired ceramic body; deforming a predetermined region of the auxiliary-layer-lined unfired ceramic body, while the thickness of the unfired ceramic body is maintained over substantially the entire area thereof and while the adhesion between the unfired ceramic body and the auxiliary layers is maintained, so as to form a step portion on each of the first and second principal surfaces of the auxiliary-layer-lined unfired ceramic body, the step portion on one of the first and second principal surfaces of the auxiliary-layer-lined unfired ceramic body being formed to include substantially vertical and linear side walls and the step portion on the other of the first and second principal surfaces of the auxiliary-layer-lined unfired ceramic body being formed to include gently curved side walls; and subjecting the auxiliary-layer-lined unfired ceramic body having the step portion to firing conducted at a temperature at which the unfired ceramic body is sinterable but the auxiliary layers are substantially unsinterable, while the auxiliary layers remain adhered to the unfired ceramic body without being removed.