Electronics Cooling 101 – What’s the Point?

Overview

When it comes to electronic devices, there are a few key attributes that a component has which will determine the functionality and implementation of its use. Electrical ratings – maximum voltage allowed, maximum current allowed, and dissipation through heat – are a few of the key ratings to keep an eye on. Apart from that, a very crucial rating that electrical units have is the range of temperatures that they should be run at to ensure proper functionality. Heat directly correlates to the life expectancy of electrical devices and as the temperature changes, so too does the expected life of the unit until failure. This correlation has been proven and has been coined “10°C – Twice Law”. A component’s life will be rated for X amount of hours at a certain temperature, say 50°C. As this temperature fluctuates, the life expectancy fluctuates as well. A change in temperature from 50°C to 60°C will cut the life hours in half, whereas a decrease in temperature, 50°C down to 40°C, will double the expected life.

Different Forms of Cooling

Electronic devices can be cooled in a multitude of different ways, each having their own benefits as well as drawbacks. A few of the more common methods – using cooling fans, heat sinks, and liquid cooling – offer low to no maintenance and minimal additional space needed for implementation.

• Air Cooling
  • Cooling Fans
    • The use of cooling fans keeps the flow of air moving and allows a more evenly distributed heat. This allows the overall ambient temperature to be slightly higher, but also moves the concentrated heat from the components which are causing it
    • Advantageous in the fact that even though the air isn’t the best thermal conductor, the availability, non-corrosive nature, and insulation capabilities make it a highly sought after method
  • Heat Sinks
    • Creating a larger surface area for the heat to spread throughout creates a lower overall temperature. These tend to be used in combination with some form of the fan to create circulation, allowing the heat sink to have some way of properly dispersing excess heat
• Liquid Cooling
  • Thermosyphon Cooling
    • Natural convection of water allows the heated, less dense liquid to rise up while the cooler liquid stays at the bottom which continuously cycles so long as a heat source is applied
    • Drawback – MUST be positioned in a vertical direction to ensure the proper cycle of hot and cold liquid is performed
  • Turbulent Flow Cooling
    • Water or a water/glycol mixture is primarily used as the transfer medium
    • Efficiency can be increased through the use of coils within the system or microchannels within the system
      • Drawback – High risk of blockage within the system

In the world of electronics, it’s great practice to periodically verify that cooling systems and devices are properly working. Though the main purpose of this is to avoid cutting the life expectancy of components down, it also directly will lead to better production numbers when machines don’t have to be out of production while repair work is done. When we repair drive units here at Precision Zone, part of our standard reconditioning process is to replace any form of cooling devices to keep the repaired units running as long as possible.