Study on the adhesion and reliability of Epoxy Molding Compound and shaped Pd Preplated leadframes

The weak adhesion between the Epoxy Molding Compound (EMC) and Pd Preplated leadframes (Pd PPF´s) often causes delaminations and reduces the reliability of integrated circuit. This paper reports on a practical method of dramatically improving the adhesion of EMC and Pd PPF´s using electroplating shaped nickel layers. Button shear tests indicate that the adhesions between the EMC and three different shaped nickel PPFs is 169% higher than that of conventional PPFs. The reliability of the adhesion improvement effects was detected by Moisture Sensitivity Level 1(MSL-l) test and high temperature button shear test, which proved the high reliability of the shaped PPF´s. The mechanical interlocking effects caused by increased surface roughness are the major reason for the improved adhesion as well as the transition of failure modes from adhesive failure to cohesive failure.