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A11 A1 A14 A21 Alloy Codes -1st Fail -2P 0.1% -2P Mean -3P Gamma A32 A62 A66 0.00 0.50 1.00 1.50 2.00 2.50 Relative LifeThis paper reports results of a four-year industrial consortium effort to develop leadfree solders for high-temperature applications (up to 160∞C). Work included preliminary evaluations of 32 tin-based alloys, a screening of the thermomechanical fatigue performance of 13 promising alloys, and a full manufacturability and fatigue testing of the seven most promising of those alloys, namely . Eight different components were used on the reliability test vehicle, and the alloys were compared through Weibull analysis. In addition, the same seven experimental alloys were tested with ball grid array packages cycled up to 100∞C or 125∞C. All the leadfree alloys performed well, but those containing bismuth showed especially outstanding performance. In general, the ternary and higher alloys performed as well or better than the industry standard tin-silver eutectic, suggesting that solders other than the tin-silver eutectic should be considered for high-reliability, high-temperature applications.

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