Seal Ring Thermal Path in 3DICs for Inner-Die Heat Dissipation

The patent introduces an intermediary thermal interface material or structure between the silicon substrate and heat dissipation components. This intermediary element facilitates heat transfer without requiring complex micro-channel fabrication, thereby improving heat dissipation efficiency while avoiding the high manufacturing costs and extended time-to-market associated with building micro-channels directly inside silicon substrates.

The patent replaces the mechanical fabrication of micro-channels inside silicon substrates with an alternative thermal management approach. Instead of mechanically etching and filling complex channel structures, the invention uses a different physical or chemical method to achieve heat dissipation, such as applying thermal conductive materials or using phase-change substances, thereby eliminating the need for complex mechanical manufacturing processes.

The patent applies local quality by creating regions with different thermal conductivities within the packaging structure. Specifically, it introduces thermal vias or conductive pathways at critical locations where heat needs to be extracted from inner dies, while maintaining the non-conductive underfill and molding compound in other areas for structural support and die stacking. This localized modification enables heat conduction improvement without compromising the overall die stacking capability.

The patent employs composite materials that combine the benefits of both conductive and non-conductive properties. For example, it uses underfill or molding compound materials that are infused with thermally conductive particles or filled with metal traces, creating a composite material that maintains the structural and stacking functions of the original non-conductive materials while adding heat conduction pathways to facilitate thermal management in stacked die configurations.