Study of Bondable Laser Release Material Using 355 nm Energy to Facilitate RDL-First and Die-First Fan-Out Wafer-Level Packaging (FOWLP)

A thorough evaluation on selecting a bondable laser release material for redistribution layer (RDL)-first and die-first fan-out wafer-level packaging (FOWLP) is presented in this article. Four laser release materials were identified based on their absorption coefficient at 355 nm. In addition, all four of these materials possess thermal stability above 350 °C and pull-off adhesion on a Ti/Cu layer...