PCBA reliability test

After the PCBA reliability test, the component's high resistance value is abnormal, how to find the failure point?

The so-called WLCSP wafer-level chip size package, the full name of Wafer Level Chip Scale Packaging, refers to the entire wafer-level packaging process after the completion of the cutting process, after cutting, the package size is equal to the original die size The subsequent use of the redistribution layer (RDL) can directly pull the I/O out of the array solder ball to the PCB.