Wafer level package wafer probing shift error-proof quality control

Wafer level package (WLP) is one of the fastest growing segments in the semiconductor packaging industries. Low costs, small sizes, and the ease of logistics make WLP a main-stream packaging solution for a single chip. However, different from conventional packages, WLP has no final test (FT) and only relies on wafer level probing for functional test, which may induce the trouble that once wafer probing map shifts, the functionally failed dice will be shipped as good ones and result in huge economic compensations. In such situation, based on manufacturing experiences and actual experimental data, this paper provided preventive guidelines and detecting solutions to eliminate the impact from wafer probing shifts.