3D integration technology with photosensitive mold for fan-out package

Abstract

An innovative 3D packaging and integration technology with a newly developed photosensitive mold material was successfully demonstrated. This technology needs neither a tall Cu pillar electroplating nor a laser drilling. A test die was mounted face up on a substrate, then a more than 100 μm thick photosensitive mold film was laminated on the whole substrate. The lithography process on the mold film was executed to make openings with depth of 10 μm on the embedded die, and with depth of 110 μm on the substrate. The Cu redistribution layer formed the electrical contacts between the die and the substrate through the photosensitive vias with different diameters and depths. The developed 3D package passed 1000 thermal cycles at −55/125 °C. This work disclosed future capability of a fan-out process using a photosensitive mold, thereby realizing a rapid growth of 3D integrated modules.

5-in-1 Fan-Out Wafer-Level Packaging Technology with One AI Chip and Four Memory Chips for Internet of Things Modules

“…14,2021 that electrically connects the logic and memory in three dimensions by using RDL technology. [11][12][13] In that work, we characterized a low elasticity mold resin with photosensitivity, which eliminates the need for an expensive Cu pillar process. In the future era of higher-capacity memory, FOWLP technology is expected to find increasing demand not only for 3D structures but also for 2D structures.…”