The present study endeavors to investigate the thermal dissipation capability of a chip-on-board package by means of a comprehensive experimental and numerical analysis. For this purpose, a BiCMOS chip is designed and fabricated in conjunction with three different printed circuit board (PCB) configurations, including a single-sided board, a thermal via board, and a copper frame board. Transient thermal measurements are carried out on all three packages, and the results are subsequently transformed into cumulative structure functions. Then the finite element models are established for each package configuration, and their validity is confirmed through comparison with the experimental structure functions. The models are then characterized in accordance with the Joint Electron Device Engineering Council (JEDEC) 38-set boundary conditions, followed by a series of optimizations targeted toward the PCB, including the board stack-up and the board sizes. Parametric studies are performed to quantitatively assess the impact of these parameters on the thermal performance. Finally, the present study provides a comprehensive discussion of the optimal application scenarios for each board configuration, with a view to achieving good thermal performance. The findings of this study will contribute to the development of more thermally effective chip-on-board packages for high-performance electronic systems.