Establishing a Ti-Cu-Pt-Au Thin Film – On – Low Temperature Co-Fired Ceramic (LTCC) Technology for High Temperature Electronics
Authors: P. Vianco, J. Rejent, M. Grazier, A. Kilgo, B. McKenzie, A. Allen, E. Guerrero and W. Price Company: Sandia National Laboratories and Honeywell Inc. Date Published: 9/27/2015
Abstract: A study was performed to evaluate the mechanical properties of solder of solder joints made to a 0.200Ti-4.0Cu-2.0Pt-0.25Au (µm) thin film conductor on low-temperature co-fired ceramic (LTCC) substrates. The solder joints were made with 63Sn-37Pb (wt.%, abbreviated Sn-Pb) or the 95.5Sn-3.9Ag-0.6Cu (SAC396) alloys. Pull strength and failure modes were analyzed as a function of soldering parameters. The effects of solid-state aging were also assessed for the Sn-Pb solder joints. Both Sn-Pb and SAC396 solder joints exhibited similar pull strength magnitudes as well as a nominal loss of such strength with increased severity of the process conditions. Solid-state aging of Sn-Pb solder joints caused a general decrease of pull strength. In all instances, the decreases of strength was accompanied by an increased occurrence of the solder failure mode. The fracture surface morphology (crack path) was more sensitive to the effects of both soldering process and solid-state aging than was the more generalized failure mode metric or the pull strength performance. Aside from the role of the Pt-Sn IMC layer in the fracture surface morphology (Area #1), the adhesion and integrity of the Ti-Cu-Pt-Au thin film did not control the mechanical performance of the Sn-Pb solder joints.
Thin film conductor, low-temperature co-fired ceramic, Pb-free solder