Tin whisker growth on bulk Sn–Pb eutectic doping with Nd

✍ Scribed by Meng Liu; Ai-Ping Xian

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 654 KB
• Volume: 49
• Category: Article
• ISSN: 0026-2714
• DOI: 10.1016/j.microrel.2009.03.012

✦ Synopsis

Tin whisker growth is a serious reliability concern for electronics using high-density packaging. Whisker growth behavior of tin lead eutectic solders doped with different neodymium concentration (5-0.1wt.%) was studied in present work. Results indicate that the Nd in the all of the Sn-Pb-Nd alloys mainly exists in NdSn 3 intermetallic compound, and that the distribution of the NdSn 3 phase is very non-uniform in the alloy with low Nd concentration. Tin whiskers growth was observed on all samples doped with Nd. All of these whiskers were seen to originate from the NdSn 3 phase, it appears that the Pb does not suppress whisker growth in these alloy because it does not influence the formation of the tin-rare earth intermetallic compound. These results suggest that the addition of rare earth elements into tin alloy systems renders whisker formation nearly inevitable. Therefore, any suggestion to dope tin-based solders with rare earth elements for application in high-density electronic packaging should be carefully reconsidered.