ABSTRACT
The effect of constant heating and shrinkage rate on flaw generation during cofiring of multilayer electronic substrates was investigated. The substrates studied consisted of a low temperature cofireable ceramic (LTCC) insulator material and one of three silver conductor materials: a fritted silver powder, a fritless silver powder and a fritless silver flake. Rate controlled sintering (RCS) was used to impose constant shrinkage rates on the sample substrates. Delaminations, conductor film discontinuities, and conductor film thickening were all observed for constant heating rate sintering and alleviated to varying degrees by RCS. Multilayer shrinkage anisotropy and conductor film thickness measurements indicated that the RCS profiles tended to increase the overlap in conductor and insulator densification rates during the early stages of cofiring.
