Harsh solder joint reliability tests by impact drop and highly accelerated life test (HALT)

Abstract

In this work, board level impact drop test and highly accelerated life test (HALT) were conducted on lead-free soldered assemblies. Harsh solder joint reliability testing are needed for impact drop requirements particularly for portable electronics. Highly accelerated life testing (HALT) is increasingly used for high-end workstation server systems. For drop test, the acceleration and strain were measured for clamped-clamped PCB assemblies along the longer edge. The failure criteria was set at a daisy chain resistance of 1000ohms. Bare PCB and populated PCB with BGA, QFP, TSSOP component with lead free Sn-3.8Ag-0.7Cu solder were investigated. Three different surface finishes such as Ag, Ni/Au and OSP are used for populated PCB. For populated PCB, drop height of 1m was fixed. HALT test was also conducted for populated PCB including high temperature storage, low temperature storage, thermal shock, random vibration, and combined thermal shock and random vibration tests. High-speed camera was used to capture dynamic response of the PCB and PQFP lead during random vibration test. The displacement result can be used in FEA analysis as input boundary condition.