Effect of Sn Addition to Cu Substrate on the Interfacial Reaction with Lead Free Solder

• Main Authors: Tzu-Hsuan Chiu, 丘子軒
• Other Authors: 高振宏
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/zbv6b2

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 107 === Fan-out wafer-level packaging (FOWLP) technology is gaining popularity for its performance and for its ability to meet high I/O counts. However, cracks were detected on Cu RDL under thermal stress. The material that can replace Cu must have better mechanical properties and good solder joint reliability after soldering and thermal aging. The fact that Cu-Sn alloys have good strengthening effect when tin is below 10wt% has been studied. Few studies have investigated the interfacial reaction between solder and Cu-Sn alloys. In this study, the interfacial reaction between Cu-xSn(x=0, 3, 6 and 10wt%) substrates and SAC305 solder after reflow, and aging at 150℃, 180℃, 200℃, respectively, are investigated. The morphology and the thickness of intermetallic compound (IMC) can be observed. Moreover, the activation energy and the growth rate of IMC corresponding to the diffusion can be obtained. The experimental result shows that the growth rate of Cu3Sn is slightly accelerated if there is higher concentration of Sn in Cu-xSn substrates. In addition, all the morphology of IMC in Cu-3Sn/solder、Cu-6Sn/solder、Cu-10Sn/solder are similar to that of Cu/solder.