Development of die-bonding film for semiconductor packages applied reaction-induced phase separation

Low-modulus die-bonding films are useful for stacked multi-chip packages which are suitable for compact electronic devices. In particular, to cope with the widespread application of very thin semiconductor wafers and Pb-free solders, the films are expected to have both low viscosity in the attaching process and high bonding reliability in the high-temperature reflow process. We studied the phase structure and the properties of a new reaction-induced polymer alloy consisting of a low-modulus acrylic polymer and a highly heat-resistant epoxy resin. As a result, this alloy film was shown to have both high resin flow and good reflow-crack resistance.