The Wirewound and Film Technologies Division of IRC Inc. (Boone, NC) recently developed a technique to produce custom thick-film circuits and assemblies that allow high current-carrying traces (up to 100 A) to be printed onto ceramic substrates for power hybrids or solid-state relay substrates. Typical applications for the custom thick-film circuits and assemblies are solid-state relay substrates, power amplifiers and power supplies, thermo-electric coolers, water level sensors, and high-brightness LED circuits.
By using custom thick-film circuits, design engineers can integrate current-sense resistors with values as low as 2 mΩ directly into the power hybrid substrate, which is not a possibility with direct bonded copper. With this design, the circuits can be printed directly on a heatsink, eliminating the additional costs and processes of connecting a heatsink to a power substrate. The copper-fired thick films allow different types of circuits, including thermistors and temperature sensors, high-voltage and pulse-withstanding circuits to be combined on one board.
