Charles R Wirebond Manufacturing Tan CL Proces Manufacturing
Sankar Process Engineering Ashok QAD1 Team Composition :
D2 Problem Description :WHAT NSOP Not Detected During X-ray
RescreenWHEN WW4511
MAGNITUDE Three units of NSOP rejects were not screened out
during 100% inspection
D3 Containment Actions :1.0 Check Assy WIP of the affected
device. Who: Kho YLWhen: 4-Nov11Status: Done Result: 3 lots before
/after running @ production with no abnormality found2.0 Increase
3rd optical sampling inspection from 1strip to 2 strip per
magazine. Who: Kho YL When: 4Nov 11Status: On-going (3 weeks)
3.0 Check machine buy-off for wirebond machine used on the
affected machine Who: AE When: 4-Nov11Status: Done Result: All
buy-off requirements met specifications.
4.0 Recertified 3 rd opt X-ray MS who missed out the 3 units of
NSOP rejects Who: Li Lay Ting When: 8-Nov11Status: Done
D4 : Define and Verify Rootcause:MethodEquipmentUndetected NSOP
at X-raywrong judgement employed at X-rayIncreased to Half-yearly
certification from yearly for X-rayUsed wrong magnifying scope
(should be 10X, not 5X) to verify rejectMan
D4 Root Cause Analysis :5.0 Summary / Findings : Due to a lack
of experience and frequency in doing X-ray rescreen, the MS
employed wrong method of judging several strips, thus the escapees
happened
The MS certification has hence been changed to half-yearly from
yearly
The setting of magnifying scope was not properly used as well
(it should be 10X, not 5 X) to verify the suspected rejects
