onsemi has unveiled a new advanced semiconductor packaging technology designed to raise the efficiency of electric-vehicle inverters, the company announced. The packaging targets one of the most persistent loss mechanisms in EV power stages: the parasitic resistance and inductance introduced between the silicon carbide power die and the inverter module itself.

The announcement matters because inverter efficiency sits directly in the path of two commercial variables automakers care about — vehicle range and battery cost. Packaging, not the bare die, increasingly defines how much of a SiC device's theoretical performance survives in a production traction inverter. Suppliers that cut interconnect losses can either extend range at a fixed battery capacity or hold range with a smaller, cheaper pack.

Advanced packaging of this type typically reshapes the electrical and thermal path between die, substrate and cooling surface. For EV makers, that translates into lower conduction and switching losses in the traction inverter, the assembly that converts DC battery power into the AC that drives the motor.

Why packaging drives SiC value

onsemi supplies silicon carbide devices, including its EliteSiC family, to automotive customers building traction inverters and onboard chargers. In these systems, the package — how the die is attached, interconnected and cooled — often limits real-world performance more than the semiconductor itself. Parasitic inductance slows switching and forces compromises in gate drive design; thermal resistance caps how hard a die can be pushed before reliability suffers.

By advancing the package, onsemi is attacking the bottleneck that sits between its SiC dies and the efficiency figures its OEM customers advertise. The company positions the new technology as a way to improve inverter efficiency without requiring a change at the die level.

What does this mean for the EV supply chain?

The move comes as competition in SiC power semiconductors intensifies. onsemi competes with STMicroelectronics, Infineon, Wolfspeed and Rohm for automotive SiC sockets, and each has been pushing module- and package-level innovation as differentiators. Packaging has become a battleground precisely because die-level advantages among leading suppliers have narrowed.

For EV manufacturers, a more efficient inverter package offers a lever on bill-of-materials cost that does not involve redesigning the powertrain topology. Improved inverter efficiency reduces the energy wasted on every drive cycle, contributing either to longer range or to a smaller battery for the same range — a direct trade against one of the most expensive components in the vehicle.

onsemi did not disclose specific efficiency percentages, customer names or production timelines alongside the announcement. The company's broader automotive portfolio spans image sensors, power management and SiC MOSFETs, and it has previously tied packaging advances to its automotive electrification roadmap.

The rollout signals that the next round of gains in EV traction systems will come as much from the interconnects and substrates around the die as from the die itself — and that packaging innovation will remain a decisive front in the contest for automotive SiC sockets.