Imagine a scorching hot day in the summer. You’ve been trying to use a fan to cool yourself, but it just isn’t enough. So what is the best way to cool down? Jumping into a pool. Spending time in a pool on a hot day is very effective, because the water completely surrounds you and provides a better medium than air for the heat to transfer out of your body. We have taken this same concept and applied it to potting and encapsulation of electronics, such as batteries, chargers, electric motors and power electronics. In a world where the demand for high power density – the amount of power per unit volume – is growing, electronics are operating at higher temperatures, so the need for thermal management is greater every day. Due to this demand, we have developed CoolTherm, a robust portfolio of potting and encapsulation materials to address increasing thermal management needs.
Potting is the process of displacing the air space around electronics with a liquid polymer system (typically two components), but unlike in the pool example where the heat transfer medium (water) remains liquid, the polymer system will cure to a solid material that maintains intimate contact with the hot electronic components, as well as the heat sink – the place to which the heat will be transferred. Air is the enemy of heat transfer, essentially trapping heat in whatever it surrounds. This makes air the best medium for home insulation so that the heating/cooling bill isn’t too high, but awful for hot electronics. Displacing the air with our CoolTherm potting materials for thermal management allows the electronics to operate at high power while still maintaining lower temperatures than would be possible otherwise. Without thermal management, these electronics could overheat and malfunction, catch fire or even explode. In addition, potting materials provide chemical resistance, environmental protection, vibration protection and electrical insulation, which leads to more robust electronic modules.
One of the most interesting successes with CoolTherm has come from potting of electric motors. Through internal and external testing, we’ve found that we can decrease motor operating temperature by up to 50°C and increase power output by up to 30%. A general assumption about motors is that a 10°C reduction in operating temperature can double the life of the motor, so by using our CoolTherm materials, motor life and power output can be drastically increased.
To have effective thermal management when potting electronic components, correct application of the material is key. Mixing or stirring can introduce air pockets into the potting materials, and with air being the enemy of heat transfer, even tiny air bubbles trapped in the potting material will impact the effectiveness of the potting material’s ability to transfer heat. Our video, How to Use Potting Material Samples for Prototype Builds, shows how to effectively mix the components to remove any air bubbles. Equally important is ensuring that the correct mix ratio is adhered to. Procedures for checking your mix ratio and potting procedure area are explained in How to Pot a Charger.
When looking for the best way to keep your electronics protected, contact us to learn about the best options for your product. Our application engineers are available to help you select the correct solution and improve performance.