Various embodiments of the teachings herein include power electronics assemblies. An example assembly includes: a substrate with a metallization forming first and second structures separated from each other by interspaces and with thickness of at least 300 μm; a power semiconductor mounted on the first structure; and an electric insulator having a thermal conductivity of at least 50 W/mK arranged at least sectionally in such a way that the structures adjacent to the respective interspace are thermally connected by the insulator.