Thermal Analysis for a Novel 3D Heterogenous Integrated Platform MorPack

This paper presents a thermal analysis result for a novel 3D heterogeneous integrated platform MorPack (morphing package). The MorPack platform is stacked by heterogeneous sub-modules composed of bare dies, a substrate, connection bridges, and solder balls. Since the MorPack platform owns the tiny, heterogeneous and integrable characteristics, the fabrication structure must be high-density and laminal. Thus, the cooling ability of forced convection is restricted due to limited space. It can be only cooled by increasing conduction and radiation capabilities. In order to improve the cooling ability of MorPack platform, we created three indications to optimize the thermal solution. First, the vertical thermal conductivity can be improved by filling up whole MorPack with mold material. This skill efficiently cools down the 0.5-W consuming chip by 10°C more than non-filled-up structure. Second, the bare die chip with highest power consumption should be put on the lowest layer of this 3D structure because the bottom layer owns the best cooling ability. It achieves cooling a 0.5-W consuming chip by 12°C more than it is put on the top layer. Third, in order to lessen more volume of MorPack, the density of laminal structure was increased by reducing 50 % height of the platform. To realize it, we removed the connection bridges and cut out the substrate to make a room space for chip placement. With result shown, 50 % height and volume of MorPack can be minimized with only a few temperature rising.