The use of electronic power components is growing at an exponential rate and in several sectors (railways, automotive, LEDs, solid state lasers, RF, automation, etc.).
More power implies more heat to be dissipated efficiently if you want to guarantee a long life to the component or system.
Therefore, the choice of using a metal type of thermal interface materials (TIM) characterized by a high thermal conductivity value is becoming mandatory.
As the power and therefore the heat to be dissipated increase, the superiority of the metals over the so far widely used thermal greases becomes evident. We are talking about a thermal conductivity that can even reach up to 425 W/mK for a metallic TIM compared to 3-12 W/mK of the best thermal grease on the market.
Furthermore, during use, the thermal grease tends to migrate from the centre to the periphery and over time the grease tends to pulverize: these problems are completely absent with the use of metal TIMs or non-silicone based TIMs.
Typically these TIMs are made with very soft metals or alloys such as indium and its alloys, or Tin properly doped. There are metal TIMs designed to improve the contact between two surfaces using a particular pattern for each specific application. These Tims properly used can reach up to 86W/mK. There are also some metal matrix diamond composite materials that exhibits a low coefficient of thermal expansion (6-7ppm/°C) and their thermal conductivity is very high: 475W/mK.
If your designs do not require such high performances, but the grease is creating problems, we can also suggest some different not pure metallic materials (non-silicone based polymers) which thermal conductivity is 4,5 W/mK or also completely electrically insulating thermal interfaces, highly compressible, non-silicone, non-reactive, non-curing system with no resin-filler separation, with a thermal conductivity of 20 W/mK.
Obviously there are other parameters that must be taken into account to fit the design, like the minimum and maximum thickness available, the working temperature, the electrical isolation, etc… Almost all the above TIMs can be customized to your required shape, and can be taped and reeled (depending on dimensions) for automatic placement.
According to your application, our Dimac Red’s experts can suggest the best solution to solve your dissipation problem, helping you to choose the best available thermal interface suitable to your design.
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