Dynamic thermal management has been recognized by the EU Horizon Program and U.S. DARPA as a critical post-Moore technology. Two-phase flow boiling, with its high latent heat efficiency, is ideal for cooling high-power 3D integrated circuits (3DICs), yet its response to transient thermal loads remains underexplored. The present study investigates the transient flow boiling mechanisms under four pulsed heat sources—Gaussian, Square, Sawtooth, and Sinusoidal—and compares them with steady-state heating. A coupled heat–fluid–vapor–liquid interface model is developed, accounting for wall roughness, turbulence, surface tension, and TSV effects. Simulations using the VOF method reveal distinct two-phase flow responses: Gaussian pulses induce the highest thermal stress (77.8 °C, vapor volume fraction 0.616), while Sinusoidal pulses reduce junction temperature by 0.3 °C and pressure drop by 0.17 kPa, offering better thermal uniformity and efficiency. These findings demonstrate the critical role of pulse waveform design in optimizing 3DIC cooling under real-world, time-varying power conditions.
 

3D integrated circuits, Pulsed Heat Sources, Bubble Dynamics, Flow Boiling 3D integrated circuits, Pulsed Heat Sources, Bubble Dynamics, Flow Boiling