Elimination of opens failure between via holes and traces in LTCC multilayer substrate by coherent shrinkage

Abstract

MCM-C technology is based on the use of a multilayer ceramic substrate as the carrier for the various chip devices. Low temperature co-fired ceramic (LTCC), with the advantage of higher wiring density and lower dielectric constant, is widely used as the multilayer substrate for high density electronic packaging, such as MCM-C. The low firing temperature enables the use of precious metals in the conducting layers. With the development of MCM technology, the LTCC substrate is larger and has many more layers to satisfy the increasing assembly performance requirements. However, with the enlargement of substrate area, the firing shrinkage mismatch between the metal conductor and the ceramic matrix leads to the more serious problem of open failures (Imanaka et al., 1992; Miura et al., 1994; Itagaki et al., 1993). In this work, the open failure between via holes and traces in LTCC substrates was studied. The effect of compacting temperature, ceramic particle size, softening point, stack process and firing profile was reported. Finally, by means of coherent shrinkage, the open failure between via holes and traces in LTCC was eliminated effectively.