- Sample prep
Connects bonding wires to the die. Large metal pads so the wire can be attached without high precision. The inner box is the overglass covering part of the aluminium so as to be able to make a good contact and still maintain a good seal.
Blank pad (never bonded)
Still has a bond wire on it:
Hole left by a bond wire being forcibly pulled off:
Empty pad (never bonded). Note scratches left by probe needle during wafer test. This is not damage from a pulled bond wire.
Damaged overglass: It is very fragile and can easily get completely stripped during decapsulation. (dead image link removed)
Aluminum (M1) erosion from excessive time in acid bath: