Two-Phase Cold Plate

Overview

Two-Phase Cold Plate technology uses dielectric fluids that undergo phase change (boiling) within the cold plate to transfer heat from processor dies. Unlike single-phase liquid cooling — where heat transfer relies on convective warming of the coolant — two-phase systems exploit the latent heat of vaporization, achieving significantly higher heat flux removal per unit area. This makes two-phase cold plates a candidate for next-generation GPU cooling where thermal design power exceeds what Direct-to-Chip Cooling single-phase or air cooling can handle efficiently, particularly as GPU TDPs push toward 1,000W+ per chip.

The key engineering challenges are fluid selection (balancing boiling point, latent heat, GWP, and material compatibility), multi-vendor interoperability (ensuring different fluid suppliers' products work with the same cold plate hardware), and system-level integration (managing two-phase flow, condensation, and pressure in the Liquid Cooling TCS loop). OCP's Cooling Environments project, with ZutaCore leading the workgroup, has begun standardizing requirements for two-phase dielectric fluids to enable a competitive supplier ecosystem. These fluid specifications are a key focus of Standards Harmonization efforts to align OCP requirements with ASTM, AHRI, and ASHRAE frameworks.