Our partner received in part#: SAK-TC1797-512F180EF AC D/C:2220 with observed lines and slight contamination on the underside of the chips. Random checks shows that 6pcs picked show similar occurence.
1. If the lines would pose any electrical issues during soldering or usage.
2. How did the lines and contamination could have occur during production.
Attached pics for reference.
Thank you in advance.