An Assembly-Based Structural Model for LTCC Package Design and Reliability

Abstract

Packaging a high power radio frequency integrated circuit (RFIC) in low temperature cofired ceramic (LTCC) presents many challenges. Within the constraints of LTCC fabrication, the design must provide the usual electrical isolation and interconnections required to package the IC, with additional consideration given to RF isolation and the structural integrity issues. While iterative design and prototyping is an option for RFIC packaging development, it is a tedious and expensive process that would most likely be unsuccessful due to the complexity of the problem. To facilitate package design and optimization, thermo-mechanical assembly simulations were used to identify and manage the critical process parameters to control solder failures in the LTCC package assembly. The modeling results were confirmed through comparisons to prototype testing. This paper summarizes an assembly-based modeling approach to RFIC package design and solder failure analysis, and presents some results and key findings to date. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000