Recent advances in conductive adhesives for direct chip attach applications

Conductive adhesives are widely used in electronics packaging applications such as in naked 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 put on the emerging technology of using anisotropically conductive adhesives as electronics interconnection materials. Some flip-chip application examples on low-cost printed circuitry are given. These examples include flip-chip ACF bonded electronics SBU-based six layer board for Casio's radio electronics as well as memory chips assembled with the same technique in the latest Hitachi laptop computer. Current research activities as well as achievements so far 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 will be expected in the years to come.