Single-phase immersion cooling technology has emerged as a promising solution to effectively manage the thermal needs of electronics in modern high-heat-flux-density data centres. This approach involves submerging electronic components, such as heat-generating chips, into a thermally conductive dielectric liquid. The present study investigates the thermal performance of a multichip server module under single-phase immersion cooling using NOVEC 7500 (C 9 H 5 F 15 O) as dielectric flow media. A wavy fin heat sink design with varying number of fins on each heat sink is proposed to overcome the poor thermal performance of the dielectric fluid. Initially, an optimal plane fin combination is determined; it reduced the maximum temperature (Tmax ) and Root Mean Square Error of all chips by 22.4 and 7.7 0 C compared to the alternative combinations. Following this, the effect of amplitude (A) and wavelength (λ) of the wavy fin surface for the optimal fin combination from the initial result is studied. Average temperature (Tavg ) monotonically reduces with A and increases with an increase in λ. Due to the implementation of a wavy fin surface, Tavg and Tmax were further reduced by 3.9 and 5.3 0 C, respectively. The outcomes of the present study offer valuable insights into improving the thermal performance of single-phase immersion cooling systems and mitigating the thermal shadowing effect.