| AVS 63rd International Symposium & Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuP |
| Session: | Applied Surface Science Division Poster Session |
| Presenter: | James Ohlhausen, Sandia National Laboratories |
| Authors: | J.A. Ohlhausen, Sandia National Laboratories P. Vianco, Sandia National Laboratories |
| Correspondent: | Click to Email |
Low Temperature Co-fired Ceramic (LTTC) substrates are used for high frequency electronics assemblies. The LTCC material is comprised of alumina particles in a silica-based, glassy phase; the latter also includes Na, Mg and Ca oxides. The surface conductor traces and pads are a Au/Pt/Cu/Ti metallization where Ti is the adhesion layer. Delamination was experienced at the interface between the Ti layer and LTCC. Determining a root-cause to the delamination was made difficult by the complexity of the LTCC material and air exposure of the test samples before being introduced into the vacuum chamber for surface analysis. This air exposure of already de-adhered interfaces potentially compromises the cleanliness of the mutual, interface surfaces due to oxidation and adventitious contamination that caused significant challenge for the Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) assessment.
ToF-SIMS was used to analyze the de-adhered interfaces as well as to evaluate the unexposed interface by means of the depth profile mode. The ToF-SIMS tool was able to identify key Pb, Na, K, and Ca markers that confirmed the widespread coverage of the surface by the glassy phase. The role of organic contamination was similarly documented at the de-adhesion sites. The data obtained from these ToF-SIMS assessments confirmed that delamination was caused primarily by the propensity of the glassy phase to cover the LTCC surface. Small variations to the glass phase composition accounted for the intermittent presence of delamination. This poster will outline the specific ToF-SIMS test steps as well as the data analysis and methodologies that allowed for a conclusion to be developed for the delamination event.
**Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.