2. Planar Oblique Fin Microchannel Structure

In a conventional microchannel heat sink, boundary layers continue to develop as liquid coolant travels downstream. Consequently, convective heat transfer performance of the heat sink deteriorates in the axial direction, resulting in elevated maximum temperature, and significant temperature gradient across the heat sink. This chapter proposes a novel heat transfer enhancement scheme, employing sectional oblique fins to replace conventional parallel fins in a planar microchannel heat sink. In this chapter, a simplified simulation model is initially adopted to study the occurrence of boundary layer redevelopment and secondary flow generation through the oblique channels and the effect to fluid flow and heat transfer. This chapter also conducts experimental validation of the proposed heat transfer augmentation technique using copper-based microchannel heat sinks. In addition, catering to the non-uniform heat fluxes dissipation and mitigating hotspots on electronic devices, tailoring of local heat transfer performance using oblique fins is presented to suppress the hotspots in the later sections. Subsequently, experimental investigation with different hotspot conditions is conducted to demonstrate and validate the feasibility of this concept.