soldering open issue

Issue Des. : Currently we find parts(EP3C5F256C6N)have open issue after soldering process at the ICT test station in our production line.

Total input: 100 pcs

Failure QTY:44 pcs ( 43 pcs in 44 is manufactured in MALAYSIA, while the rest one is from Korea which we used before with no issue)

Failure rate: 44%

1. We have done 5D XRAY inspection with no findings regarding to the soldering condition, the soldering seems no obvious problem.

2. Reheat 5 pcs failure EP3C5F256C6N on board, retest the ICT with 1 pc test pass and 4 pcs still failed

3. Replace the NG EP3C5F256C6N(Malaysia) with a new EP3C5F256C6N(Korea), ITC test pass