Dielectric Plug and Polymer Island Layout for Package Crack Relief

The continuous polymer layer is segmented into discrete polymer islands that are spaced apart from each other. Each polymer island covers a specific redistribution line or interconnect structure, while the spacing between islands allows stress to be distributed and prevents crack propagation across the entire structure. This segmentation maintains protective coverage where needed while eliminating the stress concentration problem of a continuous layer.

The polymer layer is configured with non-uniform local properties: discrete polymer islands provide coverage and protection specifically over the redistribution lines and interconnect structures that need protection, while the spaced regions provide stress relief. This local quality approach ensures that protection is applied only where necessary rather than uniformly across the entire structure, thereby reducing stress exposure of underlying dielectric layers while maintaining protection of critical conductive elements.