Adhesion and RF properties of electrically conductive adhesives

Adhesives used for mechanical bonding and electrical/thermal transport in high performance electronic packages require high adhesion strength and electrical properties at elevated temperatures. Adhesion strengths of electrically/thermally conductive adhesives on Ni, Cu and Sn surfaces at room temperature and elevated temperature (100 °C) were studied. Their high temperature adhesion strengths on those metal surfaces were improved by surface pretreatment with an adhesion promoter (AP). The Tg > 100 °C and the low coefficient of thermal expansion (CTE) of the ECA help maintain the low thermal coefficient of resistance (TCR) at 100 °C similar to that of bulk silver. High frequency properties of the ECA at an elevated temperature are presented and show great stability of the insertion loss in the 1 to 8 GHz frequency range. Also, the ECA shows good high frequency performance compared with Cu.