Effect of porous copper on the properties of electrically conductive adhesives

In this study, effect of porous Cu as conductive filler on the properties of electrically conductive adhesive (ECA) was investigated. Four types of Cu fillers which included a porous Cu, a submicron-sized Cu, and two different types of micron-sized Cu fillers were applied as conductive fillers in ECA. Cu fillers in this study were characterized by using scanning electron microscope, X-ray diffraction and nitrogen adsorption. Properties of the Cu filled ECAs in this study were investigated in terms of electrical resistivity and shear strength of the ECA joint. Significant difference could be found in the electrical percolation threshold of the ECAs prepared in this study. Lowest percolation filler content was observed in the porous Cu filled ECA, whereas relatively high percolation filler content was found in the micron-size Cu filled ECAs. Thermal reliability of the ECAs was evaluated under hygrothermal aging at 85 °C/85 % RH for 1000 h.