NXP Semiconductors NV : "The Accidental Thermal Engineer"

Heat and its consequence - temperature - can make us happy (a nice warm day!) or sad ("who turned the Air Con on in January?!") or even threaten life and wellbeing. We are surrounded by heat energy for our entire lives and we spend a lot of time and effort thermally managing our environment. We human beings are fragile: subjecting us to extreme temperatures can cause unhappiness, injury or death.

Although not as fragile as humans, it is also important that our electronic devices operate within acceptable thermal limits. Exposure to extreme temperatures can lead to premature failure and expensive running costs - just two of the undesirable consequences of heat. Good thermal design is therefore an integral part of overall successful product design. It is not something that can be "bolted on" at the end of the process, two weeks before the product is due to be released. Rather, it should form part of the initial Product Requirement Specification and be an equal factor in influencing the configuration of the final design.

Nearly two decades ago, when I first began my career as a Power Semiconductors Applications Engineer, I had little awareness or knowledge of the field of thermal management. However, after being immersed in a multitude of power semiconductor design-in problems, it quickly became apparent that a thermal question lay behind at least half of those problems. In this way, by accident rather than by design, I found myself becoming as much a Thermal Engineer as an Applications Engineer. As such, a large part of my working life is spent either designing systems which are as energy efficient as possible (and hence generate minimal heat waste) or managing the heat which any real-life system will inevitably generate.

In the average home or workplace, most of the electronic bits and pieces scattered around will probably have had someone like me influencing their design. Whether it's the PC on your desk, the battery in your mobile phone or the electric lawn strimmer in your garden shed, thermal management is important. If the thermal management is poor then the appliance may run hot, have a shortened lifespan and cause pain and suffering to anyone who tries to pick it up or use it.

In this series of blog posts I would like to share with you some of the insights I have gained into how heat behaves at the component and PCB level. Much of what I have learnt is non-intuitive, and the process has sometimes been baffling and frustrating. However, on many of those occasions, frustration has eventually been rewarded with genuine "Eureka!" moments and true insight into behaviour which has not previously been fully understood. At those times, I am particularly happy to have accidentally become a Thermal Engineer.

Next time: Using thermal simulation tools to model reality. Can we trust the model?