MULTILAYERED CERAMIC BOARD HAVING CAVITY AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To prevent the occurrence of cracks in a cavity and suppress the occurrence of inclined portions, by suppressing the contraction of the front surface, in a multilayer ceramic board equipped with cavity and contraction of the inside of the cavity. SOLUTION: A first ceramic green sheet laminate and a second ceramic green sheet laminate, having a through hole are stacked and crimped to form the multilayered ceramic board having the cavity. On top and bottom faces of the board, constraint layers formed mainly of alumina are formed. Then, the unbaked multilayer ceramic board is baked, and thereafter the constraint layers are removed. In manufacturing the multilayer ceramic board, a cavity constraint layer which is mainly formed of alumina and is larger than the through hole is formed at a part of the first ceramic green sheet laminate, corresponding to the through hole. The first and second ceramic green sheet laminates are so stacked that the peripheral edge of the cavity constraint layer so as to overhang the through hole and then are crimped to fabricate the multilayered ceramic board. Since a part of the cavity constraint layer remains at a part between the first and second ceramic green sheet laminates at the bottom of the cavity, the multilayer ceramic board has an interposed portion having a high concentration of alumina. COPYRIGHT: (C)2006,JPO&NCIPI