Two-phase and single-phase immersion cooling are key technologies for AI server thermal management. Single-phase cooling fluid remains in liquid state throughout the process, with lower construction costs and simpler maintenance. Two-phase liquid cooling systems utilize low-boiling-point dielectric fluids, achieving heat transfer coefficients of thousands of W/m²·K through nucleate boiling and latent heat of phase change to remove substantial amounts of heat, forming a cooling cycle where the coolant evaporates and vaporizes to carry away significant thermal energy before condensing back. This provides higher heat dissipation efficiency but with more complex systems.

Immersion cooling technology submerges electronic devices completely in non-conductive coolant, which seems to provide direct heat dissipation. However, the thermal conductivity of coolant is far lower than that of metal heat sinks. Liquid convection alone cannot effectively handle the concentrated heat generated by electronic components. Thermal pads can fill microscopic gaps between components and heat dissipation structures, providing higher thermal conductivity pathways, overcoming boundary layer limitations, and replacing easily dissolved traditional thermal paste to ensure optimal heat dissipation efficiency in immersion systems