Effects of different structures and allocations on fluid flow and heat transfer performance in 3D-IC integrated micro-channel interlayer cooling

Abstract

3D-IC is getting increasingly attractive, as it improves speed and frequency and reduces power consumption, noise and latency. However, three-dimension (3D) integration technology brings a new serious challenge to chip thermal management with the power density increased exponentially. Interlayer micro-channel liquid cooling is a promising and scalable solution for high heat flux removal in 3D-IC. The effects of geometric parameters on fluid flow and heat transfer characteristics in interlayer micro-channel cooling for 3D-IC with triangular reentrant cavities (TRC) and fan-shaped reentrant cavities (FRC) are numerically investigated. 3D-IC with TRC and FRC for pitch=0.1/0.2mm and height=0.2mm are analyzed and compared with rectangular micro-channel (RMC) for 1cm2 heat areas. Results show that the heat rate and pressure drop distributions of each layer for length=5mm and pitch=0.2mm are more uniform. The micro-channels of pitch=0.1mm have better heat transfer performance, simultaneously cause the pressure drop and pumping power increasing sharply, which are undesirable and uneconomical for 3D-IC. For smaller Re, the micro-channels with surface enhancement structures TRC and FRC deteriorate heat transfer. While at the larger Re, heat transfer is enhanced, which can be attributed to heat transfer area increased, boundary layer thinned, boundary layer interrupted and chaotic advection by generating vortices. The 3D-IC with FRC-L5-P0.2 has better heat transfer performance and lowest pumping power, which is more suitable and economical for 3D-IC inter-layer cooling. For channel length of 10mm, the fluid temperature is higher in the last 5mm, which deteriorates heat transfer effect, simultaneously the longer length leads to pumping power and flow resistance enlarged. Besides, 3D-IC with FRC decreases the laminar stagnation zones and improves the heat transfer performance, due to owning bigger included angle of the expansion and constriction walls in channel.