Thermal Management
Thermal parts conduct, store, or move heat. Heat sinks soak it up; thermal pads bridge it from chip to sink; fans and blowers shove air across the fins; TECs actively pump heat from one face to the other.
Heat flows from hot to cool through any conductive path. Bigger surface area, higher thermal conductivity, and forced air all increase the rate. TECs use the Peltier effect to make one face cold and another hot when current flows.
In plain terms
An air-conditioner crew for your IC. Some pieces grab the heat, others throw it into moving air.
Also called: fan.
Why designers use it
- Keep CPUs, GPUs, and power transistors within rated junction temperature.
- Cool laser diodes and image sensors precisely.
- Move heat from sealed enclosures to fins outside.
Best for
- CPU / GPU cooling
- Power-stage thermal relief
- Laser temperature stabilisation
When not to use it
- Where natural convection alone is enough — adding a fan creates noise and a failure point.
Common mistakes
- Forgetting thermal interface material between chip and sink.
- Choosing a fan whose airflow can't actually push through dense fins.
Where you will find it
- A gaming PC CPU silently turns ~150 W of electricity into heat every second — a heatsink, heatpipe, and fan move that energy out into the room before the silicon hits 100°C and throttles itself to a crawl.
- Astronomy cameras use a Peltier (thermoelectric cooler) to drive their sensor down to –40°C so the noise from random thermal photons drops away — the same chip technology is in portable wine coolers.
- Your phone has a graphite heat-spreader sheet sandwiched behind the screen that drains heat from the SoC across the whole back of the device — it's why long video recording warms the entire chassis instead of melting one corner.
A short history
Thermal design brings together two different tasks: measuring temperature and providing a path for heat to escape. Thermocouples generate a small voltage related to a temperature difference, while resistive sensors change resistance. Heat sinks and interface materials serve a different job: reducing resistance along a heat-flow path. Modern IC thermal metrics describe specified test conditions, not a guarantee that the same temperature rise will occur on every circuit board.
Good to know
- A heat sink works the way a tree dissipates water — high surface area meeting moving air.
- Peltier coolers are reversible: drive a current and you get cold; warm one side and you get an electric current — used in deep-space radioisotope generators.