New substrates improve thermal management of power circuits

December 14, 2017 // By Christoph Hammerschmidt
Rogers Power Electronics Solutions (PES), has unveiled new high-performance ceramic substrates. Thanks to their low thermal resistance, they are suited as circuit carriers for power electronics applications with increased power density, such as advanced battery technologies for electric and hybrid vehicles, renewable energies and medical technology.

Substrates are base material of a circuit board. As such, they play a decisive role in the design of compact assemblies, as they must have high thermal conductivity. Only then can they dissipate the heat generated by the components efficiently and quickly from the conductor layers. The better this is done, the more current a trace can carry.

The new individual substrates from PES such as curamik Power, curamik Power Plus and curamik Performance are designed for different capacities and thicknesses and can also be implemented according to customer’s specification. The metallized ceramic substrate curamik Power, based on aluminium oxide (Al2O3), is suited for cost-efficient power electronic circuits. Its thermal conductivity is 24 W/mK. The substrate offers a very good price/performance ratio and is used, for example, in cost-sensitive circuits with low and medium power output, such as photovoltaic inverters and semiconductor modules for industrial applications.

curamik Power Plus is designed for circuits with somewhat higher power requirements. Rogers achieves an improved thermal conductivity of 26 W/mK using zirconium dioxide doping (ZrO2) of the Al2O3 substrate. Another advantage: The material is more robust. Power Plus is mainly used in applications with medium power output, such as inverters for wind turbines and power modules in the automotive industry.

The ceramic performance substrates are based on Si3N4 ceramics. They offer an optimum ratio between robust mechanical properties, long service life and a high thermal conductivity of 90 W/mK. This makes them ideal for applications such as drive inverters in electric and hybrid vehicles. In addition to standard products, Rogers also supplies tailor-made solutions as a development partner. The thermal resistance of Al2O3 DBC substrates is determined not only by thermal conductivity but also by the thickness of the ceramic used. Therefore Rogers can offer its ceramic substrates in different thicknesses of 0.25 - 1.00 mm.