Material Properties and Interfacial Reactions of New High Temperature Lead-Free Solders
Date Issued
2009
Date
2009
Author(s)
Chiang, Chih-Feng
Abstract
After 1 July 2006, the RoHS banned the use of Lead (Pb) and several other materials contained in electronic products. However, RoHS guidelines exempt the use of Pb internal to (at the first-level interconnect) flip-chip packages until 2010. A suitable Pb-free alternative to replace high Pb solder( e.g., 95Pb-5Sn, with a melting range from 308oC to 312oC) has not been found and the pressure to move to lead free will continue for the entire industry. In this study, three Bi-based solders, Bi-2.8Se, Bi-2.8Mn and Bi-1.8Mg, were used to observed the melting range, hardness and wetting behavior. Moreover, the interfacial reaction between Bi-based solders and Cu were also observed. Our result shows that the hardness of these three Bi-based solders are lower than Sn-10Sb. And the wetting behavior are worse than Pb-10Sn and Sn-3Ag-0.5Cu. There are no intermetallic compounds formation at Bi-1.8Mg/Cu and Bi-2.8Se/Cu interface. In addition, Se would encourage the consumption of Cu. Finally, two intermetallics, Bi4Cu4Mn3 and BiMn(Cu), formed between Bi-2.8Mn and Cu after reaction.
Subjects
high temperature Pb-free solders
interfacial reaction
DSC
wetting test
hardness.
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-R96527044-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):aeeb1ab6cef5b5559932eec975d3dfca