Infineon and Schweizer Partner on Technology for Mild Hybrid EVs

May 06, 2019 by Scott McMahan

Infineon Technologies AG and Schweizer Electronic AG have devised a new technology for the mild-hybridization of cars, chip embedding for Power MOSFETs.

Mild hybrids may use regenerative braking and some level of power assist to the internal combustion engine, but unlike full hybrid electric vehicles, mild hybrids do not have an exclusive electric-only propulsion mode.

Infineon says that the chip embedding for power MOSFETs will significantly improve the performance of 48V systems while reducing their complexity. Continental Powertrain will be the first player to adopt the technology for chip embedding of power MOSFETS in mild hybrid EVs.

"Embedding power MOSFETs will open a new chapter of possibilities for the electrification of mild hybrid cars," said Dr. Rolf Merte, CEO at Schweizer Electronic. "The fact that one of the world's leading automotive suppliers has chosen our technology confirms its potential."

With chip embedding, the power MOSFETs are not soldered onto a circuit board, but they are integrated within.

The embedding of components offers numerous advantages including the obvious space savings. Schweizer Electronic points out that with embedding, the heat dissipation of the IC is enhanced because the power loss is now no longer distributed via the soldering area and to a slight degree via convection. Instead, the heat dissipation is distributed three-dimensionally with significantly improved heat transfers inside the PCB. The electrical performance may also exhibit a positive change from the embedding of the IC, according to Schweizer.

"The resulting thermal benefits allow a higher power density and board integration enables further improvements in system reliability" said Dr. Frank Findeis, who is heading Infineon's automotive MOSFET business. "These advantages result in higher power or more cost-effective 48 V systems."

As an initial application, Continental Powertrain has chosen to implement the new technology in a 48V starter generator for vehicles from a major European automaker. "Chip embedding allows us to increase electrical power by 60 percent compared to a traditionally designed system," said Dietmar Vogt, System Technical Project Leader at Continental Powertrain.

Infineon points out that 48V starter generators are the major contributor to the CO₂ reduction of up to about 15 percent that a mild hybrid vehicle achieves compared to a conventional drive train.

They allow the engine to be stopped more frequently and for longer periods than a 12V-based start-stop-system. Moreover, they can boost acceleration and thereby reducing the load on the combustion engine. While braking, Infineon says that they recover more of the kinetic energy than a 12V system.

Infineon contributes its MOSFET technology OptiMOS™5 to the new approach. Schweizer contributes its embedding power PCB technology called Smart p² Pack®. The partners intend to begin mass production in 2021.