Solderability of Kovar{trademark}
The wettability of bare Kovar by liquid 60Sn-40Pb solder was examined as a function of two surface preparation techniques. Adequate solderability was achieved with four organic acid fluxes when the Kovar surfaces were chemically etched in an acid solution; however, wetting was poor with the use of a rosin-based, mildly activated (RMA) flux. Changing to an electropolishing treatment with an acetic acid/perchloric acid electrolyte improved solder wetting, particularly with the RMA flux. Growth of the solder-substrate metallurgical reaction layer was examined after elevated-temperature annealing treatments. Intermetallic compounds grew both along the solder-substrate interface as well as in the solder phases, at rates much less than observed for the copper-solder system.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 10110073
- Report Number(s):
- SAND--92-0400C; CONF-9211132--1; ON: DE93004067
- Country of Publication:
- United States
- Language:
- English
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