If it is up to Bosch, there will soon be a big step forward in the world of electromobility. The company has created new silicon carbide microchips that ensure higher switching frequencies and, on the other hand, that significantly less energy is lost in the form of heat.
Every new car rolling off the assembly line today features semiconductors, often more than 50 microchips. New silicon carbide (SiC) microchips from Bosch now provide a technological leap forward in electromobility. From now on, chips made of this prodigious material will determine the course of power electronics - the control centre of electric and hybrid vehicles. Compared to silicon chips used so far, SiC semiconductors have better electrical conductivity, according to a press release. "On the one hand, this enables higher switching frequencies and, on the other, it ensures that significantly less energy is lost in the form of heat. Silicon carbide semiconductors create more power in electric drives. For motorists, this means six per cent more range," said Bosch managing director Harald Kröger. Bosch produces the new generation of semiconductor chips at its plant in Reutlingen, 40 kilometres south of Stuttgart. There, the company has been producing several million microchips per day for decades.
Silicon carbide semiconductors are setting new standards in terms of switching speed, heat loss and size. It all starts with extra carbon atoms being inserted into the crystal structure of the high-purity silicon otherwise used to manufacture semiconductors. The chemical compound thus formed turns the semiconductor chips into real powerhouses with numerous advantages, especially for use in electric and hybrid vehicles. In power electronics, they ensure that 50 per cent less energy is lost in the form of heat. The more efficient the power electronics, the more energy available for propulsion and thus the greater the range. With one battery charge, drivers can drive six per cent further. With this, Bosch tackles one of the biggest obstacles to buying electric cars: almost one in two consumers (42 per cent) do not buy an e-vehicle for fear of running out of power on the road. In Germany, this is even true for 69 per cent of consumers (source: Consors Finanz Autobarometer 2019). As an alternative, car manufacturers can reduce the battery size at a certain range. In this way, the cost of the most expensive component of an electric car can be reduced, thus lowering the price of the vehicles themselves. "Silicon carbide semiconductors will change electromobility forever," Kröger said. Indeed, they create additional savings potential for the future: the complex cooling of drive components can be reduced due to the chips' significantly lower heat losses and the fact that they also operate at significantly higher operating temperatures. This, in turn, has a positive effect on the weight and cost of electric vehicles.
Two worlds
Bosch is consistently expanding its knowledge of semiconductors with silicon carbide technology. In the future, the company will use SiC semiconductors in its own power electronics. For customers, this brings together the best of both worlds: After all, Bosch is the only automotive supplier that also produces semiconductors. "Thanks to our in-depth knowledge of electric mobility systems, we apply the advantages of silicon carbide technology directly in the development of components and systems," Kröger said. Bosch as one of the leading manufacturers of vehicle semiconductors has been using this globally unique advantage for almost 50 years. In addition to power semiconductors, the company also supplies micro-electromechanical systems (MEMS) and application-specific circuits (ASICs).
There is hardly an area in modern automotive technology that works without microchips, whether it is airbags, seatbelt pretensioners, cruise control systems, rain sensors or powertrains. In 2018, every vehicle was equipped with chips worth $370 (about €337) (Source: ZVEI). While this amount increases by one to two per cent annually for applications such as infotainment, networking, automation and electrification, an electric vehicle is also equipped with semiconductor chips worth an average of $450 (about €410). Experts believe that automated driving will further increase this amount by around $1000 (about €910). This makes the automotive market one of the key growth factors of the semiconductor industry. In addition, core applications of the Internet of Things (IoT), such as artificial intelligence, cybersecurity, smart cities, edge computing, smart homes and connected industry will also drive growth in the sector. Bosch is well prepared for this with its semiconductor plants in Reutlingen and Dresden: "Our knowledge of semiconductors helps us both to develop new functions for vehicles and IoT applications and to develop ever better chips," said Kröger.
Competitiveness
The round discs made of silicon or silicon carbide - the wafers - undergo an extensive, up to 14-week manufacturing process before any semiconductor chips are produced. The wafers are coated with the finest structures during various chemical and physical processes, growing into chips just a few millimetres thick. In June 2018, Bosch laid the foundation stone of its state-of-the-art semiconductor plant in Dresden. Wafers with a diameter of 300 millimetres are produced there. This allows significantly more chips to be extracted from a wafer and greater scale effects to be achieved than with semiconductors based on 150- and 200-millimetre technology. Bosch produces such chips in Reutlingen, where the company will also manufacture the new SiC chips. The wafer factories in Reutlingen and Dresden complement each other perfectly. This allows Bosch to further strengthen its competitiveness. "Semiconductors are a core component of all electrical systems. They also make data a coveted raw material of the future. We want to continuously expand our production as these chips are becoming increasingly important in our fields of operation," Kröger emphasises. Bosch is investing around 1 billion euros in its wafer plant in Dresden - the largest investment in the company's history. The plants are currently being installed in the plant's cleanroom area. The first employees will start work in spring 2020. Bosch will operate the site CO2-neutral.
Source: Bosch.
