A Study of Thermally Stable In-Au Microjoints Prepared by Solid- Liquid Interdiffusion Bonding

• Main Authors: Sheen, J. G., 沈建國
• Other Authors: F. S. Shieu
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/68652591054165627169

碩士 === 國立中興大學 === 材料工程學研究所 === 86 === Indium and its alloys exhibit good service life and reliability, and are well suited for applications such as solder interconnections in electronic packaging. In this study, two types of Au-In microjoints, i.e. Au/In/Au in which In foil was used and Au/In, were prepared by either solid state interdiffusion (SSID) or solid-liquid interdiffusion (SLID) bondings for a single lap tensile test. Deposition of the Au and In thin films was carried out by thermal evaporation on a polyethylene terephthalate (PET) sstrate. It was found that the shear strength of the Au/In microjoints is higher than that of which using In foil, i.e. Au/In/Au. In addition, it is observed that the fracture mode of the Au-In microjoints depends on the types of In used. Failure of the Au/In microjoints appeared to be along the joint-substrate interfaces, whereas it occurred within the In foil for the other type of specimens. Examination of the Au/In microjoints by glancing angle X-ray diffraction reveals the presence of intermetallics In2, Au10In3, and Au9In4, in small amount, in addition to the two major constitutent phases, Au7In3 and Au. On the other hand, only intermetallic AuIn2 and pure In were obtained in the Au/In/Au microjoints, where the thickness of In is much higher than that of Au.