Abstract
Discolored bondpads failure was investigated. SEM & EDX techniques were used to identify the root causes. The results show that discolored bondpads are caused by many holes on bondpads due to galvanic corrosion. It is most severe at power-line pads and less severe on rest of pads in the die. These bondpad holes have led to poor contact between the wire & integrated circuits and faulty computer chips. The holes are most likely to be caused by galvanic corrosion as there is a nucleus centered inside almost all holes. EDX results on the nucleus show high Cu concentration comparing to that on normal area. It is concluded that galvanic corrosion was due to DI water problem during wafer sawing at assembly. In this paper, the mechanism of galvanic corrosion will be further discussed.
