A novel flip chip technology using nonconductive resin sheet

A novel hip chip packaging technology using nonconductive resin sheet has b een studied [1], [2], [5], The process flow of this new packaging system is as follows. First, epoxy b ase resin sheet is laminated onto substrate to cover the substrate surface including land electrodes. Bumped chip alignment and attachment was done th rough the resin sheet, in the second stage with pressure and temperature. T he bumps under the chip penetrate with removing resin sheet material and ev entually reaching to the metal land of the substrate in this process. Metal connection and curing of the interface resin have completed in the third s tage. This new process has big potential to make dip chip package simple co mpared with current flip chip packaging process using liquid resin with dis pensing system. The through put time can be reduced to less than 10 s/units in actual model case even large flip chip package which has over 15 x 15 ( mm) square area IC chip. The other advantages are thermal stability of material in the process, mois ture related performance, and warpage control performance. For current unde rfill process the only choice is to use anhydride type resin system which h as many disadvantages. This new process made it possible to introduce moist ure and thermally stable epoxy resin with phenol curing system for flip chi p packaging [1], [2], [4], Drastic process ability improvement can be achie ved by the new process and material, As a typical improvement of thermal sh ock performance, it was confirmed that the life of chip damage becomes over 10 times longer by flip chip bonding parameters which can be controlled on ly by this new flip chip packaging process.