Abstract
The effect of coupling agents which are one of raw materials, was studied to improve the adhesion strength of epoxy molding compounds for semiconductors to leadframes. It was reported that a certain coupling agent had an effect to increase the adhesion strength to a silver plated Cu leadframe9). In this report, there were studied the effect of coupling agents on the adhesion strength to Cu and Fe-Ni alloy leadframes and also the reacting ability of coupling agents to the same leadframes. We used 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and n-propyltrimethoxysilane, as a coupling agent repectively.
The adhesion strength was measured at 240°C in the atmosphere using a test piece. The adhesion strengths of the molding compounds including coupling agents to Cu and Fe-Ni alloy leadframes were not so strong compared with those of the molding compounds without any coupling agents. The reacting ability of coupling agents to the leadframes after the heat treatment was estimated by measuring Cu2p3 and Fe2p spectrum binding energy peak values and half value widths of X ray photoelectron spectroscopy. We found that a certain kind of coupling agents had the ability to react with each leadframe. Based on the fact of oxidation advancement in Cu and Fe-Ni leadframes at 175 °C for 8 hours, it is supposed that the effect of coupling agents on the increase of adhesion strength is small and the oxidation of leadframes during heating has considerable contribution to the adhesion strength of the compounds.
