The fact is that the shortage of power transistors is the main cause of global supply chain disruption in the global market. The queue for the production of the simplest microcircuits has reached 1 year. Manufacturers of cars, computer components, video cards, smartphones (including Apple) and other equipment that use power management components suffer from supply chain disruptions.
Power semiconductor devices work as powerful energy converters in transport, industrial plants, power supply systems, etc. They are used in electric drives, power transmission substations, high-power radio transmitters, etc.
Silicon carbide
A few years ago, the appearance of silicon carbide (SiC) transistors revolutionized the market. This is especially true for electric vehicle propulsion systems, where such electronics are required in the first place.
Traditionally, silicon power transistors have been used in the design of electric vehicles. For a long time, silicon was the most popular semiconductor material. Different materials have different properties that make them more suitable for different applications. At the same time, silicon carbide is especially attractive for high-power transistors due to its very wide bandgap (in the graph on the left).
Electrons in a semiconductor are in one of two energy bands - either in the valence band or in the conduction band. To go from one to the other, the electron needs to jump over the forbidden zone, in which the electron cannot exist physically. In silicon, this band is about 1–1.5 electron volts (eV), while in silicon carbide it is about 2.3–3.3 eV. Thus, a much higher voltage is required for breakdown. Many modern electric vehicles are powered by 400V, and Porsche is equipping its Taycan with an 800V system. The high breakdown voltage makes silicon carbide very suitable for these applications.
Porsche Taycan: the world's first 800V car
The benefits of a wide band gap apply to any design. The higher breakdown voltage and lower turn-on resistance means the 1200 V SiC matrix is 20 times smaller than a comparable silicon part. The smaller size increases the switching speed, further reducing heat loss. After all, the operating temperature of SiC semiconductors is up to 200 ° C, rather than the usual 150 ° C for silicon.
Until recently, the industry has been struggling to produce silicon carbide power electronics, mainly due to manufacturing problems. It was only a couple of years ago that we learned how to grow monocrystals with acceptable quality for cost-effective production.
SiC semiconductors are able to withstand higher voltage in a more compact package and handle more heat. This can reduce the size of the car motor inverter by 70% and reduce cooling requirements. In addition, due to lower on and off resistance, less energy is wasted in the form of heat, which improves energy efficiency and vehicle range.
The Tesla Model 3 inverter has silicon carbide power electronics, which improves efficiency and reduces cooling requirements
The technology will also find applications in chargers. SiC parts allow for more compact chargers - faster charging with less waste. As electric vehicles proliferate, the demand for fast chargers will skyrocket, so any gains in size and efficiency will pay dividends, experts say.
Silicon carbide electronics appeared on the market in large numbers around 2017-2019. Tesla Model 3 was one of the first cars with a silicon carbide inverter. It houses 24 SiC MOSFET modules from ST Microelectronics, which barely coped with this order. Since then, similar equipment has been introduced in the Model S and Model X Long Range, where silicon carbide inverters have helped increase the maximum cruising range to almost 600 km.
Bosch estimates that replacing silicon with SiC in transistors increases the electric vehicle's range by about 6% .
Technological process Bosch
The production of power electronics was originally started in Dresden, on the territory of a high-tech hub called Silicon Saxony, by analogy with Silicon Valley. There are dozens of high-tech companies, including Bosch.
Silicon Saxony
A plant in Dresden with 700 employees planned to produce silicon carbide wafers with a diameter of 300 mm. But now it is reported that production has been established at a semiconductor plant in Reutlingen with 200 mm wafers.
Silicon carbide wafers. Photo: Bosch
For sure in the coming years, all cars will switch to silicon carbide power electronics in order to gain advantages in part size, energy efficiency and performance. Silicon conductors simply cannot compete with them. Digital and low-voltage subsystems will remain their niche.
In any case, the shortage of power electronics on the market will now ease slightly. If the industry can meet the demand for basic components and eliminate disruptions in logistics, then the production of video cards, processors, smartphones and other equipment will increase.
bbabo.Net