This article presents the results of numerical simulation of a free jet of a high Prandtl number fluid impinging perpendicularly on a solid substrate of finite thickness containing electronics on the opposite surface. The numerical model was developed considering both solid and fluid regions and solved as a conjugate problem. The influence of different operating parameters such as jet velocity, heat flux, plate thickness, nozzle height, and plate material were investigated. Computed results were validated with available experimental data. It was found that the local Nusselt number is maximum at the center of the disk and decreases gradually with radius as the flow moves downstream. The average Nusselt number and the maximum temperature occurring in the solid varied significantly with impingement velocity, disk thickness, and thermal conductivity of the disk material.