Effective cooling stands and falls with good thermal conductivity. Therefore thermal interfaces are used between a component and a cooling unit. The latter may be a simple heat sink, a thermal or a housing assembly. The thermal interface ensures maximum thermal coupling. Although not visible to the naked eye, the housing of a component is not flat. On a microscopic level, the surface appears to be very rough, and the same applies to the surface of the heat sink. The resulting gaps between both surfaces can be effectively filled with a thermal interface material, enhancing the conductivity.
However, a thermal interface does more just than fill holes! The material also helps the heat transferring to the cooling unit more equally, enhancing the overall efficiency. Thicker, softer interface materials can also help to absorb mechanical stress. Because of the wide variety of cooling solutions Telerex offers a number of different thermal interfaces such as gap fillers, electrically conductive or insulating interfaces, thermal tapes, pastes, greases and even phase changing interfaces. The thinner the thermal interface, the lower the thermal resistance and the higher the conductivity.
Thermal interfaces up to 8W / mK for the filling of larger gaps, in thicknesses from 0.25 to 2.10 mm, in increments of 0.25 mm. Softer types, such as 05 Shore 00, help eliminating mechanical stress and height difference. Various materials are also silicone-free, high-recoverable, dispensable and may be provided with special coatings and / or other materials.
Electrically insulating interfaces
Thermally conductive material having a high electrical insulating property (10 to 000V or more). These materials are available in several thicknesses (from 0.076 to 0.76mm). They can be pre-cut to client specific needs or supplied on a roll.
Electrically conductive interfaces
Thermally conductive material that also conduct electricy (advantage at EMC, called koolpadshields).
Double-sided thermally conductive adhesive tape. The adhesive function is more important here than the thermal conductivity. This can cause various oC negative difference on the hot spot and is not always a good thermal choice.
Various thermal pastes to 3.8 W / mK, even silicone-free, in various formats such as syringes or containers for automated 'dispensing'.
Phase changing interfaces
Phase changing materials offer the best thermal conductivity for processors cooling. Heated at about 50 °C the material partly liquefies and flows to fill all remaining gaps. Available in thicknesses from 0.076 to 0.40mm and in screen printable versions, up to 5.4W / mK
Thermally conductive PCB materials
Structures of copper or aluminum may be laminated, together with the PCB. This requires a more complex PCB design, but heat dissipation can increase 3 ~ 8 times. PCB costs will rise exponentially, however.