Variable-Thickness Thermal Interface Material for 3DIC Package Corners

The TIM is designed with varying thickness throughout its structure, with thinner regions positioned over heat-generating device dies to minimize thermal resistance and improve heat dissipation, while thicker regions are positioned at corners and edges to provide mechanical stability and absorb thermal expansion stress. This local differentiation of thickness allows the single TIM component to simultaneously optimize both thermal performance and mechanical stability.

The TIM features a non-uniform thickness profile where the central region over the device dies is minimized to reduce thermal resistance, while the peripheral regions at corners and edges are thickened to absorb stress concentration and prevent delamination. This local quality variation allows the TIM to simultaneously achieve low thermal resistance and high reliability against delamination.

The TIM is manufactured with spatially varying thickness properties, where the thickness is optimized locally for different functional requirements: thin over heat-generating areas for thermal performance, and thick at stress-prone areas for mechanical stability. This local quality approach improves heat dissipation efficiency and stress management while maintaining reasonable manufacturing feasibility through techniques such as selective deposition or molding.