<p>As microelectronic devices have become increasingly complex and miniaturized, the demand for effective cooling solutions has grown substantially. The increasing heat fluxes in integrated circuit (IC) chips, driven by the rapid increase in transistors per square millimeter, have challenged the efficacy of traditional rectangular microchannels. To address these challenges, it is imperative to propose optimized structures or alternative methods for enhanced heat transfer, thereby improving the heat dissipation in these confined spaces and extending the lifespan of components or ICs. Therefore, a three-dimensional numerical analysis was conducted to establish a validated and robust methodology for evaluating novel microchannel shapes that facilitate more efficient heat transfer. The computational 3D model was developed using experimentally tested microchannel heat exchangers (MCHE) and validated with experimental data, showing a variation of 3–5% for hot fluid and 6–12% for cold fluid across the entire design of experiments (DoEs) for the baseline design. This study aims to identify novel channel shapes for MCHE through numerical analysis, which can achieve a higher j-factor and lower f-factor under the same operating conditions as the baseline design. To examine and identify novel channel configurations, segmented channel microchannel heat exchangers (MCHEs) with varying channel cross sections were assessed. The findings were compared to a baseline design of straight MCHEs with equivalent volumes and areas under identical operating conditions, focusing on the goodness factor (j/ƒ) and effectiveness. Upon comparing the goodness factor across all 24 configurations, it was determined that the trend of the superior design mirrored that observed in the hot fluid temperature and balanced flow design of experiments (DoEs), albeit with differing percentage changes. It was further concluded that a 40% step height at the bottom of a perforated straight channel (with holes) exhibited the best performance, followed by a 40% step height at the bottom of a non-perforated straight channel (without holes). The performance of a 20% step height at both the top and bottom surfaces was also comparable to the 40% step height at the bottom. The change in the goodness factor increased by approximately 20%-30% across the entire unbalanced flow DoE, balanced flow DoE, and hot fluid temperature DoE for the aforementioned designs compared to the baseline design. This study aims to guide researchers and industry professionals for developing and modifying their baseline design, when seeking enhanced heat-transfer efficiency with the same volume and area installation.</p>