The effect of molding pressure on void performance has
been investigated by experiment.
It is proved that molding process play an important role in void reduction.
By enhancement of transfer pressure, the attach performance can be improved significantly with void percentage reduction.
Voids for DAF are formed in the interface between die and substrate since die bonding process and reduced under molding pressure.
Generally they have the characteristics of fixed location and similar pattern, which are correlative with substrate surface topography. The root cause of void is that
some large gaps on the substrate haven’t been filled sufficient by film.
The filling capability is closely relative with cure ratio.
Excessive cure reaction in DAF makes get worse.
Under high transfer pressure, the substrate can be touched effectively
by DAF with formation of steady bond and large gaps can be
filled furthest by thermal deformation and pressure-induced
flow