We’ve all been there: working or playing for extended times on our cell phone when soon the battery begins to run down quickly and the device starts to heat up. Often the only solution is to turn off your phone or tablet and give it some time to cool down. Since the beginning of the technology, one of the biggest challenges for makers of compact electronic devices is keeping them cool.
One of the more cost-effective and reliable ways to cool mobile devices is by using heat pipes. This method of passive heat transfer offers high effective thermal conductivity, vibration-free operation, and no moving parts. They work by filling the pipe with a small amount of fluid (water, nitrogen, acetone, sodium, or ammonia), which then absorbs the heat as it is vaporized. The vapor is then transported to a condenser region, where it releases the heat thanks to a cooling medium.
Improving the printed circuit board design is another way to cool devices. The latest designs have more layers of solid ground or power planes. These connect directly to the source of the heat through multiple pathways made of hollow or cylindrical copper metal transfers between the layers. This design increases the effective surface area, which in turn allows heat to spread evenly across the larger surface.
Another potential solution for overheating is the use of thermal-interface materials. These unique materials use thermal greases to fill microscopic air gaps that exist due to the uneven nature of the component surfaces. This in turn increases the thermal conductivity of the thermal interface and helps reduce damaging heat.
Perhaps the most effective way to cool any mobile device is the micro fan. Compared to the other “passive” forms of cooling, this “active” form of cooling is ultimately superior. The biggest problem comes from the challenge to make fans small enough that power consumption is not radically increased. As well, manufacturers must find a way to keep vents unblocked to avoid overheating.
In the end, Pelonis believes that mobile device designers will always rely on some form of active cooling to reduce the heat in their mobile electronics. When combined with newer circuit board designs and advanced materials, a fan-based cooling system is hard to surpass for quality, effectiveness, and durability.
To learn more about cooling electronic devices and some of the challenges it can pose, click the link below and download our eBook on Electronic Device Cooling: