Wafer-applied underfill process

摘要

A process for underfilling a bumped die surface using a lamination step and compound film such that solder bumps on the die are exposed during lamination. The compound film comprises a first layer containing an underfill material and a second layer on the first layer. The underfill material and the second layer comprise polymer materials that differ from each other. The compound film is laminated to the die, preferably at the wafer level, so that the underfill material is forced between the solder bumps and fills spaces between the bumps but does not cover the bumps. In contrast, the second layer covers the solder bumps, but is then selectively removed to re-expose the solder bumps and the underfill material therebetween.