Abstract
Sintered-silver is a candidate material to supplant solders for interconnects in power electronic packaging for many reasons including its desirably high electrical and thermal conductivities and compliance to Restriction of Hazardous Substances (RoHS) guidelines. The shear failure stress of interconnects though is limited by whatever constituent is the weakest, and that includes any employed plating. In the present study, silver-platings were processed electrolytically, electrolessly, and through sputter deposition and their influence on the entire “interconnect system” shear strength was examined. Test sets employing gold plating and no plating were included for comparison and to aid interpretation. Ambient-air, reflow-oven-processed, pressureless-sintered-silver interconnects were identically fabricated with all plating test sets. It was found that all considered silver-plating methods produced consistently strong (characteristic failure stresses > 55 MPa) sintered-silver interconnects. Because failures tended to be adhesive in all six sets, differences in failure stress among the silver-plated sets and the gold-plated or unplated sets were likely due to differences in the adhesive strength of the sintered silver with silver-plating, gold-plating, or direct bonding with copper.
| Original language | English |
|---|---|
| Pages (from-to) | 20189-20198 |
| Number of pages | 10 |
| Journal | Journal of Materials Science: Materials in Electronics |
| Volume | 29 |
| Issue number | 23 |
| DOIs | |
| State | Published - Dec 1 2018 |
Funding
Research sponsored by the Electric Drive Technologies Program, DOE Vehicle Technologies Office, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. The authors thank USDOE’s S. Rogers and ORNL’s B. Ozpineci for their financial and programmatic support, S. Campbell for reflow oven assistance, R. Wiles for CAD assistance, M. Lance for surface roughness measurements, K. Jones for formatting assistance, and E. Gurpinar, E. Lara-Curzio, and L. Marlino for their reviews and helpful inputs. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).