TCL Elektronika has seen a significant rise in demand for ceramic circuits. Here the company reveals why original equipment manufacturers are increasingly choosing this material.
Printed Circuit design engineers are increasingly finding that traditional PCB laminates are insufficient for advanced projects.
Key drivers for choosing ceramic include high temperature tolerance (ceramics withstand over 300°C) and superior thermal conductivity (up
to 180W/mK). Likewise, low coefficient of thermal expansion ensures stability under thermal stress; low signal loss suits high- frequency applications; and chemical and water resistance, where ceramics resist outgassing and water.
Applications in aerospace, defence, wireless communication, automotive electronics, medical devices and power electronics are increasingly specifying ceramics. Power electronics engineers, in particular, favour ceramics for high thermal conductivity and temperature resilience. With gallium nitride (GaN) devices replacing silicon, operating temperatures often exceed 200°C, making ceramics essential as standard FR4 or IMS boards are inadequate.
TCL Elektronika collaborates with customers to select the most suitable ceramic substrate, including: alumina oxide Al2O3 (96 and 99.6 per cent), aluminium nitride (ALN) and silicon nitride (SiN).
Regarding production method, primary options include:
Direct bonded copper (DBC) where copper is bonded to the ceramic substrate using a high- temperature oxidation process, allowing for heavy copper thickness (140 to 350 μm). The copper layers are etched using standard PCB technology. However, conventional PTH processing is unsuitable for DBC. Active metal brazing (AMB) forms substrates without metallisation. Under a high-temperature vacuum, copper is brazed directly to the ceramic base, supporting copper weights up to 800μm on thin ceramic substrates, making AMB ideal for power electronics.
Direct plated copper (DPC) is the newest and most popular production method. It involves vacuum sputtering to plate copper to the substrate, with a thin titanium layer as a bonding interface. This method allows fine tracks and reduced undercutting. Panels are plated up to
the required thickness (10 to 140μm). DPC enables incorporation of plated or filled vias, allowing for different copper thicknesses in selected areas, making it possible to have both control and power sections on the same layer.