Mechanism and Fracturing Modes of Solder Joints Subjected to High-speed Shearing Forces
In packaging industry, the common way to characterize the reliability of solder joints is through board-level tests. For board-level test vehicles subjected to mechanical loads of reasonably high strain rates, such as drop/shock test for handheld products, it is frequently observed that fracturing occurs around the interface between the solder joint and the bonding pads, where intermetallic compounds (IMCs) are formed. Characterization of the strengths of IMCs therefore is crucial to the assessment of reliability of solder joints under a dynamic loading condition. However, each solder joint in a board-level test vehicle connects to two bonding pads on the package side as well as the test board side. Quite often geometric configurations and surface finishes of the two pads are distinct. It is therefore fairly difficult to specify a loading condition that allows fracturing to occur dominantly around a preferred pad, at which the IMC strength is to be examined. Direct testing on a package-level solder joint that involves only a single pad is hence desired.We develop a novel numerical simulation methodology by using LS-DYNA combining with erosion/interface fracturing elements and mass-scaled scheme in this paper to research on transient structural responses of a single package-level solder joint subjected to high-speed (＞100 mm/s) ball shear load (Fig. 1). The proposed simulation procedure is benchmarked by comparing with experimental data obtained by using INSTRON Microimpact tester (Fig.2). After the numerical model is validated, transition conditions between IMC fracturing and bulk solder fracturing modes as well as relation between impact force and joint adhesion of interfaces are identified numerically therefore(Fig.3).
Chang-Lin Yen Yi-Shao Lai
Central Labs, Advanced Semiconductor Engineering, Inc.26, Chin 3rd Rd., Nantze Export Processing Zone, Kaohsiung,811Taiwan, China
国际会议
第八届电子封装技术国际会议(2007 8th International Conference on Electronics Packaging Technology ICEPT2007)
上海
英文
636
2007-08-14（万方平台首次上网日期，不代表论文的发表时间）