Recent advances in conductive adhesives for direct chip attach applications

Conductive adhesives are widely used in electronics packaging applications such as in bare chip attachment and interconnection, component fixing, display interconnection and for heat transfer purposes. This paper gives a summary of recent achievements in the use of conductive adhesives in direct flip-chip attach applications. Special emphasis is placed on the emerging technology of the use of anisotropically conductive adhesives as electronics interconnection materials. Some flip-chip application examples on low-cost printed circuitry are given. These examples include a flip-chip ACF bonded electronics SBU-based six layer board for Casio´s radio electronics and memory chips assembled with the same technique in a Hitachi laptop computer. Current research activities and achievements to date are also presented. Different possible failure mechanisms for conductive adhesives are elaborated. Finally, future challenges and development trends are discussed. The paper shows that conductive adhesives play a significant role in electronics packaging applications and more applications are expected in the years to come