Bosch has announced the serial production of silicon carbide semiconductors (SiCs) which have applications in off-board DC fast chargers, onboard chargers, EV powertrains and automotive lighting for LEDs.
Silicon carbide chips are superior to silicon chips in some applications due to higher power density and lower cooling requirements.
The chips will replace silicon chips in many electric vehicles. SiC technology is useful in electric vehicle applications because it has a very wide bandgap, making it better suited to high-power applications than silicon.
While silicon has a breakdown voltage of around 600V, silicon carbide can potentially accommodate several times the voltage. SiC technology also has the benefit of superior switching, unlocking faster charge speeds. For example, onboard chargers can convert AC power to DC power faster.
A real-world application for SiCs is 800V charging. The adoption of 800V charging requires replacing Si IGBT modules with SiC power devices.
“The future for silicon carbide semiconductors is bright. We want to become a global leader in the production of SiC chips for electromobility,” says Harald Kroeger, member of the board of management of Robert Bosch GmbH, “Silicon carbide power semiconductors make particularly efficient use of energy. This material’s advantages really come to the fore in energy-intensive applications such as electromobility.”
Bosch’s silicon carbide chips will also work well with future graphene EV batteries, providing the wide bandgap and rapid switching the technology needs.
At present, most automakers use silicon chips in their power electronics. The exception is the Tesla Model 3, which uses SiCs. The Tesla Model 3 is one of the most efficient electric cars in the world.
The new Bosch SiC chips will be made in Dresden, Germany, with debutant vehicles expected in 2022.