Wafer Level Packaging (WLP) technology uses a wafer reconstruction process, where Known Good Die (KGD) and other types of devices, packages or components are placed side-by-side and embedded with epoxy mold compound. This is followed by a thin-film processing, repassivation and metallization on one or both sides of the wafer to fan out interconnections from original die pads to external pad locations.
The KGD are mounted face down on a carrier with sticky tape. Molding compound is added then baked to set the compound. The carrier is then turned right side up and the carrier and sticky tape are removed.
Fan-out wafer level packaging (FOWLP) uses mold compound to embed various functional dies.
Photo Source: Beth Keser
YES polyimide cure ovens offer a vacuum thermal cure that is a critical step for FOWLP and offers:
As dielectric materials have evolved to meet the challenges of WLP, the need for a perfect cure became a critical step.
Needed results for a proper cure:
A proper cure time and temperature ramp rate IMPROVES STABILITY!