Influences of molding conditions on die-pad behavior in IC encapsulation process analyzed by Hall element method

It is important to analyze the dynamic die-pad behavior during the integrated circuit (IC) encapsulation process in order to reduce such defects caused by the die-pad movement as exposure of the IC chip on the package surface or breakage of bonding wires. In this study, experiments were carried out to investigate the influences of transfer time, internal pressure after the filling process, polyimide tapes pasted on lead frames, and viscosity of the resin on the die-pad behavior using the Hall element method developed in the previous study. The results showed that 1) the die-pad moved more when the transfer time was longer in this mold, 2) the internal pressure after the filling process had little influence on the die-pad behavior, 3) polyimide tapes restrained the die-pad movement along the thickness direction, and 4) the die-pad displaced larger with higher-viscosity resin.