STRESS-INDUCED CORROSION OF WIRE MICRO-JOINTS IN MICROELECTRONICS - AQUANTITATIVE MODEL

The analytical correlation between electrochemical corrosion susceptib ility and stress residue caused by ultrasonic or other welding techniq ues for wire micro-joints has been derived. The correlation is based o n a physical-chemical model of changes in the electrochemical potentia ls of crystallographic structure induced by microdefects in the most d eformed parts of the wire. The experimental confirmation of the correl ation was performed on single crystals and polycrystalline samples of Ni, as well as on 25um Aluminum wire joints. The agreement is signific ant. The unreliability of a wire joint is considered to be a strong fu nction of the corrosion susceptibility in the joint.