A front-end readout chip VFAT3 was designed for the muon detector gas electron multipliers (GEM). GEMs were installed at the Compact Muon Solenoid (CMS) experiment of the Large Hadron Collider (LHC) at CERN for the high luminosity upgrade.
This one is probably from a prototype batch.
Many thanks to cpresser for supplying the samples!
VFAT3b
CERN INFN-BA LUT AGH PA MD FL GD FL HP MI
Top metal imaged under LMplan 10x/0.25