Thermal Grizzly's new thermal pad has a phase-changing design — the pad changes from solid to liquid above 45C

Thermal Grizzly has introduced a new thermal pad product for cooling CPUs and GPUs. Known as PhaseSheet PTM, the new pad uses phase-changing technology and is electrically nonconductive.

As the name implies, the new PhaseSheet PTM takes advantage of a phase-changing material that changes its physical properties depending on temperature. At room temperature, the sheet is solid (just like any ordinary thermal pad). Still, at temperatures above 113 degrees Fahrenheit (45 degrees Celsius), the thermal pad turns into a very low-viscosity liquid that behaves similarly to the thermal paste.

The phase-changing tech is designed to minimize the pump-out effects of traditional thermal paste. Pump-out is an effect where the thermal paste is slowly pressed out between a heatsink and a GPU die or CPU IHS due to micro expansions and contractions in the metal that occur in the heatsink contact plate or CPU IHS; the effect can reduce cooling performance over a lengthy period.

Thermal Grizzly's Phaseheet PTM is much less susceptible to pump-out, giving it a long service life. Additionally, the thermal pad is reusable and non-electrically conductive, so it can be used safely on components that don't have an IHS, such as mobile CPUs and GPUs. This starkly contrasts Thermal Grizzly's Kryosheet thermal pads, which are electrically conductive and can be damaged easily if re-used.

The Phaseheet PTM requires 300 to 400 newtons (67 to 90 pounds) of pressure to be used optimally with the lowest possible layer thickness (i.e., best performance). Once deployed, the thermal pad develops and stabilizes its maximum thermal conductivity after around ten cycles above 60C. Thermal Grizzly is selling one size of the Phaseheet PTM, 50 x 40mm, which costs $10.59 for one pad.

Thermal pads like PhaseSheet have several advantages over traditional thermal paste. Their solid nature makes them very easy to replace if required and enables them to last long without succumbing to pump-out losses.