Automotive Suppliers Lock In Access To High-Voltage Components

August 04, 2023 by Mike Falter

Automotive suppliers BorgWarner and Semikron Danfoss have announced long-term supply agreements with semiconductor manufacturers to secure access to critical high-voltage components for e-mobility applications.

As the electric vehicle (EV) and e-mobility markets rapidly expand, automotive sub-system suppliers continue aggressively securing access to the high-voltage semiconductor components essential to electric drivetrain and battery charging systems in passenger and commercial EVs.


EV growth drives demand for high-voltage components

EV growth drives demand for high-voltage components. Image used courtesy of BorgWarner

Onsemi has announced the expansion of its strategic collaboration with BorgWarner to include the company’s EliteSiC silicon carbide (SiC) technology for use in the VIPER power module, a key building block for BorgWarner’s EV traction inverter solution.     

The agreement expands the long-standing relationship between the companies, bringing the total value of the SiC partnership to over $1 billion in lifetime value.

In a similar deal, Infineon Technologies announced a multi-year supply agreement with Semikron Danfoss to supply that company with Infineon’s latest high voltage IGBT (Insulated Gate Drive Bipolar Transistor) and diode chipsets for use in Semikron’s commercial EV powertrain applications.  


VIPER Power Module

With the expanded agreement, BorgWarner will incorporate onsemi’s 750 V and 1200 V EliteSiC power devices into their VIPER power module, the core component of their EV traction inverters. 

According to BorgWarner, compared to other technologies,  SiC offers better conversion efficiency and smaller solution sizes that can increase EV ranges by up to 5% and allow for faster charging times.  

In addition to better conversion efficiency, the ability to quickly dissipate thermal losses from power electronics allows for lighter and more compact designs.  Key to the performance of the VIPER module is dual-sided cooling that rapidly removes heat from the module.

BorgWarner estimates that using SiC components in the VIPER power module helps reduce the weight of the traction inverter by as much as 40%.   


VIPER power module for EV traction inverters

VIPER power module for EV traction inverters. Image used courtesy of BorgWarner


Competing Technologies – Silicon Carbide and IGBT

SiC technologies, like the EliteSiC devices from onsemi, are quickly emerging as a go-to solution for EV powertrain, battery management, and charging solutions.

Compared with traditional silicon, SiC compounds offer a much higher withstand voltage, resulting in smaller channel sizes, lower on-resistances, and reduced conduction losses. 

SiC devices can also operate at faster speeds which reduces switching losses while at the same time allowing for the use of smaller passive components. Smaller components translate to smaller and lighter solutions.   

Finally, SiC can handle higher temperatures, further supporting more compact designs that reduce weight and extend EV range and other e-mobility applications.

The net benefit of SiC is more efficient power conversion and lighter solutions that allow for longer ranges and faster charging times in a competitive EV market.   

But SiC is not without its challenges. As a wide bandgap technology turning SiC switches on and off requires more complex and sophisticated drive circuitry. As a newer substrate technology, manufacturing with less proven reliability in the field can also be more expensive.

Silicon carbide substrates used to construct EliteSiC devices

Silicon carbide substrates used to construct EliteSiC devices. Image used courtesy of onsemi


Despite the many compelling advantages of SiC, other technologies, like IGBT, remain an attractive option for many e-mobility applications. IGBT is a much older high-voltage technology that combines Metal Oxide Semiconductor (MOS) gate drive technologies with Bipolar Junction Transistors (BJT).

Per the announced supply agreement, Semikron Danfoss will use Infineon’s IGBT switch and silicon diode chip sets in electric drivetrain solutions like their SKiM 63/93 six-pack power module.

The SKiM 63/93 targets EV applications requiring high reliability like electric utility vehicles, heavy-duty construction machinery, and tractors. Unlike the passenger EV market, these heavy equipment markets are less sensitive to vehicle range and charge times, with a higher premium on factors like reliability and cost—a good match for IGBT. 


Semikron SKiM power module uses IGBT switches

Semikron SKiM power module uses IGBT switches. Image used courtesy of Semikron Danfoss