Effect of oxidation on mold compound-copper leadframe adhesion

摘要

The effect of oxidation on adhesion between mold compound and copper leadframe material was investigated for an OCN and a DCP molding compounds and one copper alloy. The oxidation temperatures selected were 175 and 200 C and the bake times werevaried between 5 minutes and 118 hours. Adhesion strength results obtained by the button shear test method indicated that the DCP mold compound-Cu adhesion was virtually unaffected by oxidation of the Cu at both 175 and 200 C for exposure times up to 50minutes. The adhesion in the case of the OCN mold compound was lower and exhibited a sharp decrease with increasing bake time at both temperatures. The degradation in adhesion strength was attributed primarily to the low cohesive strength of the copperoxide layer.