860 – Silicone CPU Thermal Paste

This silicone-based thermal compound grease improves heat flow between heat sinks and heat-generating components. Parts like a CPU or GPU, LEDs, motors, and power components contain many transistors that produce a lot of heat as byproduct. A heat sink grease like the 860 displaces air gaps along the interface of the component and heat spreader to aid with heat transfer.

The 860 is a non-conductive thermal grease meaning there is no threats of causing short circuits. While it may not have the thermal performance of other materials like liquid metal, many users prefer grease. The 860 has sufficiently high thermal conductivity to prevent temperatures rising in many modern electronics. Thermal grease also lowers the time needed for an interface to achieve thermal equilibrium.

Though it may seem like a heat sink sits perfectly flat on components, there are many small imperfections along the interface. A heatsink thermal grease like the 860 fills in the microscopic irregularities, helping transfer heat away from the circuit. This is one advantage a grease has over thermal pads. The paste texture makes the material easy to spread and cover a large surface area.

The 860 has a modest thermal conductivity compared to other greases at just 0.7 W/mk. While this value is low compared to other compounds in the market, it is sufficient to cool most computing devices. At low bond line thickness, the 860 can lower operating temperatures by a few degrees. This temperature shift can be the difference between peak performance and failure.

At first, most applications for grease like the 860 were home computers and gaming consoles, where CPUs and graphics cards produce lots of heat. Over time, the 860 found use within other industries such as aerospace, automotive, energy and telecom. The key to using thermal grease successfully is applying it thin and even. In the case of a thermal compound, more is not better, rather, less is more.

A thin layer of thermal grease, or any thermal compound ensures there's no air pockets along the interface. These air pockets or gaps act as thermal insulators and can cause hot spots. Thin layers also lower the thermal resistance which effectively improves heat transfer between two surfaces.

While some users opt to apply gpu thermal paste along the base of the integrated heat spreader, most apply grease over the graphics card. Several techniques exist for applying thermal compound which we demonstrate in our Tech Talk 1 video. The main objectives are to cover the entire surface of the CPU/GPU and achieve a thin bond line.

One key advantage to using a silicone compound is its broad temperature range. Silicone is stable from -40 to up to 200C so it will not evaporate like other synthetic-based grease. While it is hard to say how long the applied grease will last, we suggest regular PM checks. The 860 also has good resistance against corrosion, allowing for usage in applications like marine and energy exploration.

Overall, heat sink compound is a stable product with a long shelf life. Over time, it may separate slightly with some oil visible on the surface. If this happens, simply stir the oil back into the bulk until reaching a uniform consistency. Once applied, grease works for many years as long as temperature exposure is not consistently high causing it to dry out and chalk.

If there becomes a need to remove the grease, simply use some isopropyl alcohol and a swab or brush. The paste dissolves once in contact with the solvent and cleanly wipes away. Apply more solvent if needed to remove any residues. Do not use water as the grease is hydrophobic and non-compatible with water.

For a silicone-free paste use our 8616. We carry other thermal interface materials such as thermal gels, potting compounds, adhesives and gap fillers. We also offer electrically conductive grease, dielectric grease and lubricating grease. The 860 comes in multiple packaging options depending on the scale of your project, from small packets to large pails.