Multilayer ceramic tape substrate having cavities formed in the upper layer thereof and method of fabricating the same by printing and delamination

Abstract

A plurality of sheets (12,16,18) of Low-Temperature-Cofired-Ceramic (LTCC) tape or other fusible ceramic tape are laminated together. A pattern (10) is printed on an external surface (12a) of the laminated structure (20) of a material having a thermal shrinkage rate which is different from that of the tape. The pattern (10) may be printed before or after lamination. The structure (20) is then baked to burn organic materials out of the tape. During this step, the pattern (10) and underlying portions (12b,12c) of the upper tape sheet (12) shrink to a different extent than the bulk of the structure (20), and delaminate therefrom to form cavities (26,28) having the same shape as the pattern (10). The structure (20) is then fired to sinter the tape and form a fused multilayer substrate (32). The cavities (26,28) may be filled with an electrically conductive or resistive material (36,38). Conductor traces (76,82;78,84) which are considerably thickner than can be fabricated using conventional thick film technology may be formed by filling cavities (72,74) with conductive material (76,78), and printing more conductive material (82,84) over the material (76,78) in the cavitities (72,74). Alternatively, cavities (94,96) may be filled with an adhesive (98,100) for bonding a component such as a cover lid (104) to a multilayer substrate (92).

Dependencies are inferred from the claim text.