Response Predicting LTCC Firing Shrinkage: A Response Surface Analysis Study

Abstract

Low temperature cofired ceramic (LTCC) technology is used in a variety of applications including military/space electronics, wireless communication, MEMS, and medical and automotive electronics. The use of LTCC is growing due to the low cost of investment, short development time, good electrical and mechanical properties, high reliability, and flexibility in design integration (i.e., three dimensional microstructures with cavities are possible). The dimensional accuracy of the resulting x/y shrinkage of LTCC substrates is responsible for component assembly problems with a tolerance effect that increases in relation to the substrate size. Response surface analysis was used to predict product shrinkage based on specific process inputs (metal loading, layer count, lamination pressure, and tape thickness) with the ultimate goal to optimize manufacturing outputs (NC files, stencils, and screens) in achieving the final product design the first time. Three regression models were developed for the DuPont 951 tape system with DuPont 5734 gold metallization based on green tape thickness.