In this study, numerical investigations are performed to examine the influence of unsteady submerged dielectric liquid (HFE-8401HT) jets impinging on electronic chip surfaces. The problem considered here involves conjugate heat transfer. Two different jet inlet velocity waveforms are studied—step and sinusoidal—over the range of frequencies 0.03–4.0 Hz, with the Reynolds number, based on jet inlet width, of up to 100. Results for chip surface temperatures and average Nusselt numbers are presented for both velocity waveforms over the range of frequencies considered, and the trends are discussed. A lumped-capacitance analysis for the chip is presented in terms of nondimensional parameters. The chip temperatures obtained from the analysis are compared to results obtained numerically.