Different from component level reliability tests, the purpose of board-level 
reliability test is to investigate the robustness of the solder joints between the 
IC package and PCB. In electronic assembly process, semiconductor devices 
experience various mechanical and thermal conditions. Similarly, these devices 
also experience diverse end-use conditions during their useful life, for example, 
handheld products are subjects to being dropped. Package-to-board 
interconnects are required to survive these conditions.