Abstract: An integrated two-phase immersion cooling system for electronic devices includes a tank containing a dielectric working fluid in which one or more electronic modules are immersed. Each electronic module is thermally coupled to a heat-spreading assembly supporting a boiling-enhancement surface configured to promote controlled nucleate boiling of the dielectric working fluid. Vapor generated at the boiling-enhancement surface rises into a vapor region and is guided toward a condensation assembly, where the vapor is condensed and returned to the working-fluid region through one or more condensate-return pathways. A coolant-delivery subsystem provides directed liquid-phase dielectric working fluid toward the boiling-enhancement surface to reinforce surface wetting, regulate local heat flux, and reduce reliance on bulk fluid circulation.