The melting temperatures of most lead-free solder alloys are somewhat higher than that of eutectic Sn/Pb solder, and many of the alloys tend to wet typical contact pads less readily. This tends to narrow down the fluxing and mass reflow process windows for assembly onto typical organic substrates and may enhance requirements on placement accuracy. Flip chip assembly here poses some unique chall...

Abstract At present, Sn-3.0Ag-0.5Cu (SAC305) solder is one of the commonly used lead-free solders, and copper-clad laminate PCB substrate. SAC copper substrate mainly generate two intermetallic compounds (IMCs) Cu6Sn5 Cu3Sn during soldering process. Based on first principles, this paper analyzes formation difficulty kinds IMCs generated in soldering, failure mechanism Sn/IMC IMC/Cu interfaces. ...

Power HEXFET transistors encapsulated in TO-220-style and SOT223-style plastic packages were subjected to preconditioning per the JEDEC JESD22-A113 standard, which includes solder reflow simulation and flux application, and to environmental stress testing: highly accelerated biased temperature and humidity test (HAST) and multiple temperature cycling. Electrical measurements and C-SAM mode acou...