Electrical field accelerated GND corrosion of copper wire in high humidity conditions

Abstract

Galvanic corrosion of copper wire in high humidity conditions has been widely studied. Cu-Al system in water forms a battery cell and Al is corroded. The commonly known factors that accelerate the corrosion include humidity, ions, pH, etc. In a real case failure analysis and biased high humidity test, an accelerated corrosion was observed to be related with bias or current direction. The GND copper wire terminal disconnection was proved to be easier to occur, and electrochemical reactions identified as electrolytic cells played a dominant role. The failure mechanism is hard to be recognized sometimes for carbonized molding compound surrounded around the pad, which will lead to an improper conclusion of electrical overstress (EOS). Electrical field accelerated corrosion is a degradation process which might not cause a sudden failure.