Co-sintering of multilayer ceramics

A better understanding of stress evolution and the origin of sintering damage during the co-sintering of dissimilar materials is needed for the co-sintering of next generation integrated ceramic packaging and solid oxide fuel cells. This requires the determination of the sintering strain history as a function of heating rate, powder characteristics and green body properties. In addition we must quantify the changes in the viscoelastic properties of the porous materials during sintering. In Low Temperature Co-fired Ceramics (LTCC) it is important to monitor liquid phase redistribution during sintering. This paper discusses the establishment of a testing protocol for developing a fundamental understanding of the co-sintering process. The protocol is based on the determination of the modulus, sintering strain rate and viscosity of the individual components. Some of the tools that will be discussed include cyclic loading dilatometry and asymmetric bilayer experiments. Results from our current work on co-sintering of laminated structures, and inductors embedded in an LTCC package are presented.