Soldering terminology

Plate equipped with transistors and other components used for the preparation of PCBs. In most cases, a plastic plate is coated with a copper foil from which the conductive pattern is etched out. Thin ceramic plates (mainly made of alumina, A₂ O₃) coated with a conductive paste can also be used as substrate for the assembly of electronic components (ceramic substrate). Recently, substrates are often made of  AlN ( aluminum nitride). Since the above-mentioned conventional substrates have a low thermal conductivity, it may also occur that metallic aluminum is isolated by anodic oxidation (Al₂ O₃) and then serves as substrate for electronic components. These so-called metallic substrates prevent the assembly from overheating.