Intermetallic evolution of Sn-3.5Ag-1.0Cu-0.1Zn/Cu interface under thermal aging

• Published in: Advanced Materials Research
• Main Author: Yahya I.; Ghani N.A.A.; Abiddin N.N.Z.; Hamidi A.H.; Mayappan R.
• Format: Conference paper
• Language: English
• Published: 2013
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84871861957&doi=10.4028%2fwww.scientific.net%2fAMR.620.142&partnerID=40&md5=42b0524616d586a996592cebc941a393

Due to environmental concerns, lead-free solders were introduced in replacing the leadbased solders in microelectronics devices technology. Although there are many lead-free solder available, the Sn-Ag-Cu is considered the best choice. But the solder has its draw backs in terms of melting temperature and intermetallic formations. To improve the solder, a fourth element Zn was added into the solder. The new composite solders were synthesized via powder metallurgy route. This research studies the effect of 0.1wt% Zn addition on the hardness and intermetallic formation on Cu substrate. For the hardness results, the micro Vickers values were reported. For intermetallic, the solders were melted at 250°C and aged at 150°C until 400 hours. The microhardness value for Zn based composites solder shows higher micro Vickers hardness compared to un-doped counterparts. The phases formed and its growth was studied under SEM and by energy dispensive x-ray (EDX). The SEM results show the presence of Cu6Sn5 and Cu3Sn intermetallics and the Cu5Zn8 intermetallic was not detected. The addition of 0.1wt% Zn has retarded the growth of the Cu3Sn intermetallic but not the total intermetallic thickness. © (2013) Trans Tech Publications, Switzerland.