Metal bump as liner crack

A week start with reported product scrapped due to metal bump. And this sourced from the reason liner crack.

As our QA feedback , 2 pieces previous rework product has failed their parameters, so these 2 products need to scrap inline.

They have already inked off the affected for checking.

crack line detected after back lapping.

Defect detected 100% during AVI scan , tried to salvage with bump metal removal but did not survive in lapping step.

No Choice but to accept, and start to write report for it.