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Volvo AB Invests in Silicon Carbide Transistor Company

Volvo Technology Transfer (VTT) is investing SEK 2 million (US$295,000) in TranSiC AB, a developer of developer of energy-efficient power transistors in silicon carbide. The investment was part of a SEK 4 million total round, which was co-led by Midroc New Technology AB of Sweden.

Silicon carbide (SiC) offers a range of benefits compared to conventional all-silicon semiconductors: smaller size, drastically reduced switching losses, low leakage, higher switching frequencies, and the ability to operate at much higher temperatures.

One problem with electric hybrid vehicles is that they often require cooling of both the motor and the electronics. With silicon carbide, the heat losses are small so perhaps no cooling will be needed.

—Anders Kroon, head of hybrid technology at Volvo Powertrain

The potential for using SiC to make the vehicle’s electronics far smaller and much more compact would lead to making the entire vehicle lighter and less expensive. A current MSc thesis at Volvo Powertrain is studying silicon carbide and its applications in hybrid vehicles.

Target specifications for the TranSiC BitSic power bipolar junction transistors (BJTs) are:

  • Room temperature VCESAT less than 1 V (at RT);
  • 1,200 V and 6 A device rating;
  • TO220 device package capable of 175 ºC or single die capable of 250 ºC;
  • Storage time delay less than 100 ns;
  • Rise- and fall-times less than 50 ns and nearly temperature independent switching; and
  • Wide RBSOA, short-circuit capability and excellent immunity to cosmic rays.

This investment will enable us to bring to our customers power bipolar junction transistors (BJTs) in silicon carbide (SiC). The first transistors will be rated for 1200 V and offer advantages in terms of low power losses, fast switching and excellent ruggedness. We are also planning for a package technology that can withstand temperatures up to 225º C.

—Bo Hammarlund, CEO TranSiC AB



Less cooling required, reduced electrical losses, higher overall system efficiency->greater range/MPG and either a bit less weight or bit more battery/gear for equal mass.



I wonder if this has anything to do with the fact that Volvo has built a BEV concept car (very cool).


It's not that Silicon carbide transistors are more efficient,
it's that you can fry them but they don't self-destruct.


No, they are definitely more efficient. Lower ON resistance (relative to breakdown voltage)and much lower gate capacitance mean both switching and conduction losses are slashed.

But they've been very hard to make. "State of the art" for SiC wafers is still only 3", and defects are still frequent enough to make hash of yields for large FETs.

Paul Dietz

One advantage of SiC over silicon is its thermal conductivity is 2 to 3 times higher. Now, if they could make diamond power transistors, the power density could be enormous.

allen_Z about nanotube, it has even higher thermal conductivity. Nanotubes can work as semiconductor, as well as conductor. The downside is technological immaturity of nantubes. Reliable mass production of semiconductor/conductor nanotubes are far off (structural grade may come sooner). Diamonds, are more mature and may be the placeholder for a while, until other carbon allotypes catch up.

hampden wireless

The Prius uses older technology in its high voltage electronics and while they are good, redesigning the electronics with these transistors would up the cars MPG a few percent.


The evolution continues toward smaller, cheaper and more rugged.

We laughed at the description of Iron Man's suit as "transistorized".  Maybe it won't be giggle-worthy in just a few short years.


SiC in Hybrid Applications is a hot topic. But I beliefe others already lead the way...


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