Study of Optimizing Stress-Strain Curve of Adhesive for High Expansion Tape

This paper repots on a novel pick-up and place process for FO-WLP using high expansion tape and tape expansion machine device. We previously reported that we have developed the novel tape expansion machine with a new function allowing that tapes can be expanded in four directions to individually control these expansions. However, the tapes which are generally used as conventional dicing tape have problems such as tape breaking during high expansion and uneven chip distances after expansion. In this study, the effect of stress-strain curve of adhesive for expansion tape is investigated in order to achieve both properties of chip distances and chip accuracies after expanding. As a result of evaluation, average chip distance increases to 2,930μm (initial chip distance; 35^m) with 3mm square Si chips and the standard deviation is 43μm.