Insulated metal substrates
Another way of dealing with the build-up of heat is to give the entire printed circuit board a metal base. To do this, a base material is combined with a 1.6 mm layer of aluminum or copper that absorbs the heat and then releases it across the largest possible surface area into the surrounding air or to a heat sink fitted to the underside of the PCB.
The core feature of this base material is the electrically insulating dielectric layer, which prevents unwanted electrical contact between the signal-conducting layer and the heat-absorbing metal layer. The dielectric layer is also highly thermally conductive due to the mix of different, mostly ceramic components. Such systems are used in LED lighting systems and power electronics for controlling battery charging.