Process for fabricating a multilayer ceramic circuit board

A process for fabricating a multilayer ceramic circuit board which comprises the steps of:

• (i) providing a sintered ceramic substrate having optionally formed via holes already filled with a conductive paste or a conductive substance;
• (ii) optionally applying an insulating paste layer in a prescribed pattern on one side or each side of the ceramic substrate;
• (iii) then, providing a ceramic green tape and forming via holes in the green tape;
• (iv) applying a conductive paste to to form a conductive pattern one side of the green tape;
• (v) laminating the green tape to one side or each side of the ceramic substrate so that the conductive pattern of the green tape faces the substrate;
• (vi) optionally pressing and heating the laminate from step (v);
• and
• (vii) applying a conductive paste to form a conductive pattern on the other side of the green tape and filling the via holes of the green tape with a conductive paste, before or after step (v).
• (viii) laminating to the above prepared green tape on the ceramic substrate a ceramic green tape having via holes formed, and optionally pressing and heating the laminate;
• (ix) applying a conductive paste to the green tape laminated in step (viii) to form a conductive pattern and to fill the via holes of the same green tape;
• (x) optionally repeating steps (viii) and (ix) until the desired number of circuit layers has been obtained;
• and
• (xi) finally pressing and sintering the assembly of the ceramic substrate and the green tapes.