Abstract
To investigate degradation factors of Ag-epoxy conductive adhesive after reliability test, the electrical resistance and adhesion strength of the samples were evaluated. Reliability tests, such as 358K/85% test and thermal shock test were carried out for 0, 250, 500, 750 and 1000 hours/cycles respectively. The crack was formed at the interface between chip and conductive adhesive due to the difference of thermal expansion coefficient and the shrinkage occurred during the thermal shock test. The crack was initiated at the joint, and propagated along the joint between chip and conductive adhesive. While approaching to another edge of the chip, the crack tended to advance into the matrix of conductive adhesive. Moreover, it is presumed that the oxide film generated at the interface between Sn/Ni plating of chip and conductive adhesive during the 358K/85% test, or the moisture moving into the crack during reliability test, will impact the joint reliability, namely, electrical resistance and adhesion strength. On the other hand, the reliability of conductive adhesive deteriorated with silver particle content in conductive adhesive increased.
