Battery control in high current CMOS

Important results from the project

The purpose is the integration of control electronics together with battery cells/modules for an active configuration of cells to achieve higher energy utilization and improved handling of fault conditions. A major focus has been on achieving low total on-state resistance for switch transistors, both intrinsically in the transistor chip and in the interfaces between the chip, package and pcb. Chips with discrete transistors as well as half-bridge transistors with integrated drive electronics have been produced in 3.3V and 16V MOSFET technology for 200A.

Expected long term effects

The project has evaluated solutions for high-current bonding of transistor chips for low resistance as well as requirements for electronics for controlling transistors in switchable battery packs, which contain many transistors for switching series and parallel-connected battery cells. This knowledge is now used in the parallel Mistra-funded project BattVolt with a duration of 2020-2023 and in the newly started Vinnova funded project Configurable battery packs for cost-effective fossil-free transportation, with duration 2022-2024.

Approach and implementation

Transistor design based on lateral CMOS has been used as opposed to vertical technology in commercial components for higher voltages. Several challenges have arisen in the design of the contact system for transistor chips. Above all, these methods apply to ashieve a contact system to join the chip and the pcb with high precision and to achieve low resistance and good heat conduction. Several actors both within and outside of Sweden have been hired for their special expertise and equipment.