IC Package Thermal Structure for Low-Height Chip Heat Dissipation

The patent applies local quality by selectively placing mold compound only on non-heat-generating devices or areas where thermal conduction is not critical, while leaving heat-generating devices exposed or covered with thermally conductive materials. This allows the exterior surface to be planar in appearance while maintaining excellent thermal conduction paths from heat-generating devices to heat sinks, thus resolving the contradiction between achieving a planar exterior surface and maintaining effective heat dissipation.

The patent introduces thermal interface materials (TIMs) or thermally conductive adhesives as intermediary layers between heat-generating devices and thermal structures. These intermediary materials have high thermal conductivity to facilitate heat transfer, replacing or supplementing the traditional mold compound in critical thermal paths. This resolves the contradiction by providing both mechanical protection (through the intermediary layer) and excellent thermal conduction (through the TIM), eliminating the thermal resistance problem caused by using mold compound in heat-generating device areas.

The patent resolves the planarity issue by extending the thermal structure laterally beyond the heat-generating device footprint, or by creating an elevated thermal management structure that provides a planar top surface for heat dissipation. This dimensional approach allows the thermal structure to maintain direct contact with the heat-generating device (low thermal resistance) while presenting a planar exterior surface at a different spatial level, thus resolving the contradiction between thermal performance and exterior planarity.