Heatsink thermal compound sometimes is also referred to as thermal grease or thermal paste. Different kinds of heat sink compounds are mainly used in computers and audio amplifiers to help transfer the heat to heatsinks. Microprocessor chips generate a great deal of heat. To help dissipate it heat sinks are cemented to the tops of chips that generate a lot of heat, like CPUs and GPUs . The surface of a chip always has some microscopic areas that are lower than the rest of the surface. The bottom surface of the heat sink is also not completely flat. The air space serves as an insulator and keeps the heat sink from cooling the chip and reduce the efficiency of the heat sink. This can result in microprocessor failure. Effective heat dissipation also help boost the performance of the microchip. You will be amazed how much faster a computer can be when the cooling is properly optimized.
What heat sink compound does
To prevent such problems, heat sink compound, a specially formulated paste with very high thermal conductivity, is often used. When the heat sink is fitted to the top of the microchip the compound fills all the holes to prevent air pockets. The paste should not form a layer between the chip and the heat sink. The level of thermal conductivity of the compound is higher than air, but not nearly as high as metal. It is intended only to fill in the holes, not to spread on the whole area where the microchip is in contact with the heat sink.
Different kinds of heat sink compounds
- Ceramic compounds are among the least expensive heat sink compounds, and have the additional advantage of not being conductive.
- Metal compounds conduct heat better than the ceramic ones, but they also conduct electricity, which can be a big disadvantage.
- Carbon compounds are the most conductive, thermally speaking, but also the most expensive.
How to use heat sink compound
- If your chip or heat sink is not new, scrape the old compound off with a credit card or a coin.
- Polish the surface of the chip and the heat sink with a cotton swab soaked in rubbing alcohol.
- Put a dab of compound on the chip and spread it with a credit card. Do the same with the heat sink.
- Attach the heat sink to the chip.
- Install the chip and the fan.
- Start the system and monitor the chip’s temperature for a while to make sure there were no glitches in installation.
Selecting and using a proper heat sink compound is one of the most important things to a computer builder or an audio system DIYer. Matching the compound the to thermal conductivity is needed and selecting the most cost-effective option within that range helps identify the right compound for the application. With care in installation your heat sink compound will help your microchips function and keep their top performance for their whole expected lifespan.