Characterizing the failure envelope of a conductive adhesive

The importance of flip chip technology is beginning to grow as the use of such technology is seen to be more and more advantageous. The search for alternatives to lead-based solder has also led to the study of conductive adhesives as a possible replacement for solder interconnect technology. Under a grant from DARPA, the IBM and Universal Instruments Corporations have sought to create a flip chip package using conductive adhesive interconnects. This paper presents the preliminary results of mechanical testing designed to determine the static failure envelope of the adhesive. A difference in fracture mode was observed between the tensile and compressive samples indicating that a change in failure mechanism occurred. Further work is being conducted in order to isolate the specific failure mechanisms involved.