发明名称 |
LEAD-FREE TIN-SILVER-COPPER ALLOY SOLDER COMPOSITION |
摘要 |
A solder composition and associated method of formation. The solder composition comprises a substantially lead-free alloy that includes tin (Sn), silver (Ag), and copper. The tin has a weight percent concentration in the alloy of at least about 90 %. The silver has a weight percent concentration X in the alloy. X is sufficiently small that formation of Ag3Sn plates (57, 58) is substantially suppressed when the alloy in a liquefied state is being solidified by being cooled to a lower temperature at which the solid Sn phase is nucleated. This lower temperature corresponds to an undercooling .delta.T relative to the eutectic melting temperature of the alloy. Alternatively, X may be about 4.0 % or less, wherein the liquefied alloy is cooled at a cooling rate that is high enough to substantially suppress Ag3Sn plate (57, 58) formation in the alloy. The copper has a weight percent concentration in the alloy not exceeding about 1.5 %. |
申请公布号 |
CA2475491(C) |
申请公布日期 |
2012.03.27 |
申请号 |
CA20032475491 |
申请日期 |
2003.02.11 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
CHOI, WON K.;GOLDSMITH, CHARLES C.;GOSSELIN, TIMOTHY A.;HENDERSON, DONALD W.;KANG, SUNG K.;PUTTLITZ, KARL SR.;SHIH, DA-YUAN |
分类号 |
B23K1/00;C22C13/00;B23K35/26;B23K101/42;H01L21/60;H01L23/12;H01L23/488;H05K3/34 |
主分类号 |
B23K1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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