High Expansion Tape for Fan-Out WLP Applying a Novel Stress-Strain Curve Measuring Method

摘要

This paper describes the results of novel stress-strain curve measuring method for high expansion tape. 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. Since the tapes which are generally used as conventional dicing process have problems such as tape breaking during high expansion and uneven chip distances after expansion, we try to develop the high expansion tape that can obtain the required chip distances and placement accuracies for FO-WLP. In order to improve the adhesive property, we evaluate the stress-strain curve of material. A tensile test is the simplest and most widely implemented mechanical test to determine the SS curve of material. However, since the general measuring method of tensile test is different from the actual expansion method, the results of actual expansion evaluation do not correspond with the results from the SS curve of material. In this study, measuring method of tensile test for SS curve is investigated and compared with the actual expansion results. As a result of evaluation, we establish a novel measuring method of SS curve that corresponds with the actual expansion process results.