STM32F103REY6TR We bought this part at different times，Now，Different appearance phenomena are found on the surface of the chip，One has a specular sheen and one has a matte black，I wonder if both are normal phenomena？At the same time, attach a picture

[nowhereman]

If so, what are the reasons for the difference，If not, which phenomenon is normal? Please see picture， Thank you very much

[raptorhal2]

Two clues: no ST logo and part number not recognized with a search on the ST web site.

If this is a clone, you may have to ask the clone manufacturer representative.

Cheers, Hal

[Tesla DeLorean]

Only marking of one actually provided

The 32F103E6 / 93 marking is consistent with parts used on INEMO-M1 which was a STM32F103REY6 WLCSP.

Where it was packaged would have an impact, as would how the wafer is ground/polished for a CSP