This study examines the cooling performance of two hybrid cooling schemes that capitalize on the merits of both microchannel flow and jet impingement to achieve the high cooling fluxes and uniform temperatures demanded by advanced defense electronics. The jets supply HFE 7100 liquid coolant gradually into each microchannel. The cooling performances of two different jet configurations, a series of circular jets and a single slot jet, are examined both numerically and experimentally. The single-phase performances of both configurations are accurately predicted using 3D numerical simulation. Numerical results point to complex interactions between the jets and the microchannel flow, and superior cooling performance is achieved by optimal selection of microchannel height. The two-phase cooling performance of the circular-jet configuration is found superior to that of the slot jet, especially in terms of high-flux heat dissipation. Unprecedented cooling fluxes, as high as , are achieved with the circular jets without incurring CHF.