Self-constrained sintering of mixed low-temperature-cofired ceramic laminates

A self-constrained low-temperature-cofired ceramic (LTCC) system, composed of a low-fire La2O3-B2O3-CaO-Al2O3-based glass (LBG)+alumina (LBGA) and high-fire BaO-B2O3-SiO2-based glass (BBSG)+alumina (BBSGA), has been developed. As the densification temperature range required for the LBGA is lower than that for the BBSGA, both systems densify and constrain alternatively during cofiring of a multilayer LBGA/BBSGA laminate. This results in the linear shrinkage of multilayer LBGA/BBSGA laminate taking place only in the Z direction with little shrinkage in the X-Y directions, exhibiting promising characteristics of self-constrained densification.