A novel center-hybrid pin-fin microchannel heat sink with embedded secondary microchannels for hotspot thermal management

With the rapid advancement of microelectronics technology, the issue of excessive localized heat flux in electronic devices has become increasingly prominent. This study introduces a center-hybrid pin-fin microchannel heat sink (CHPFMHS) for hotspot thermal management, comprising a central hexagonal pin-fin region flanked by two lateral straight microchannel zones located at the inlet and outlet. Furthermore, four types of various secondary microchannels are integrated within the pin-fins of CHPFMHS (Case 1: with no secondary microchannel; Case 2–5: with 3-direction, 4-direction, 6-direction, and vertical intersecting secondary microchannels, respectively) for effective heat dissipation with low pressure drop. The performances of CHPFMHSs and non-hybrid straight microchannel heat sink (NHSMHS) are evaluated with Re = 50–400. For all flow rates, the pressure drops in Cases 2–5 are lower than that in Case 1, with Case 4 exhibiting the lowest pressure drop among all CHPFMHSs. The thermal resistance (R_th) and temperature non-uniformity (δT) of Case 5 with hotspot area (A_h) of 2.25 mm² and pin-fin region length (L_rpf) of 3 mm are 47.3 % and 30.8 % lower than those of NHSMHS, respectively. Among Case 1–5, the configuration of Case 5 is the most optimal. The impacts of hotspot and the pin-fin region size of the CHPFMHS have also been investigated. As A_h rises to 6.25 mm², in comparation with NHSMHS, R_th and δT of Case 5 decrease by 52.7 % and 40.2 %, respectively. As L_rpf rises, the values of both δT and R_th, for Case 5, approach their minimum when L_rpf is close to the length of the hotspot. However, they exhibit slight changes as L_rpf continues to increase.