Warpage control by mesh ground structures in organic interposers

Abstract Conventional warpage reduction methods rely on material or process modifications. This work proposes a purely design-based method to reduce thermal warpage in organic interposers for high-bandwidth memory (HBM) packaging. A patterned mesh ground structure was introduced as a mechanical design solution without altering material composition or fabrication conditions. Finite element simulations showed that a 24% reduction in warpage was achieved when a 0.5 μm thick mesh ground with a 72% fill factor was applied. The warpage reduction effect was enhanced as the mesh ground thickness increased, whereas the influence of mesh geometry was minor when the fill factor was fixed. In addition, a mesh pattern concentrated in the central region of the interposer more effectively limited curvature growth toward the edges. The effect of mesh ground position within the build-up layers was also examined, showing that the top-layer configuration most effectively reduced bending. Wafer-level simulation on a 300 mm substrate confirmed a 46% reduction in overall warpage. These results demonstrate that the proposed design-based mesh ground structure provides a practical and scalable strategy for warpage reduction of organic interposers in advanced HBM packaging. The findings offer practical design guidelines for developing cost-effective, high-performance organic interposers technologies.