The unstoppable wave of transport electrification is not just a headline for German newspapers after Dieselgate, it is real – and the wave is originating in China. Chinese car makers have now more than half of the sales for battery and plug-in hybrid electric vehicles (BEV and PHEV), in an exploding market. In 2017, people bought 1.2 million BEVs and PHEVs, a 52% increase compared to 2016. Car makers sold 2.8 million full and mild HEVs last year, a 22% year-to-year increase. The new Yole Développement report “Power electronics for EV/HEV 2018” provides all the details on this market’s evolution and its impact on power devices and power modules. Want to know more?
If you are looking at the growth of the BEV and PHEV market at the car level, yes, more than 50% of sales are from Chinese car makers. Renault Nissan, Toyota and Tesla complete the picture with significant sales in the rest of the world. The picture is the same at the system level, as most suppliers of components for Chinese electrified cars are also Chinese manufacturers. Governments locally and globally have pushed heavily to make this happen and have provided the right rules, funding and incentives to achieve this goal. But at the power device level the picture is totally different. More than 90% of the insulated-gate bipolar transistor (IGBT) modules used in Chinese cars are manufactured outside China, and 100% of SiC-based modules. The government is leading several financial and industrial initiatives in order to change this, but it is a rather complex proposition. The semiconductor industry is not just about putting cash on the table to make an investment.
But what’s happening outside China in the power electronic industry for EV/HEV? The answer is: Growth and innovation. Having assessed how each type of electrified vehicle market will evolve, Yole Développement expects double-digit compound annual growth rates (CAGR) for 2018-2023. This means some 10 million EV/HEVs will be sold by around 2020, and up to 18 million by 2023, across all categories.
Several European car manufacturers launched their 48V mild hybrid models in 2017. This cost-effective solution, which electrifies vehicle auxiliary systems and at the same time reduces CO2 emissions, will proliferate in 2018-2019 among all European car makers, followed by the Chinese ones. Yole Développement believes that the 48V system will rapidly boost the market. We forecast a CAGR for 2017-2023 of 50% for mild hybrids, because these low cost electrified vehicle models are attractive. The approach can be easily implemented in any car, from city cars to higher end luxury models.
This new Yole Développement report “Power electronics for EV/HEV 2018” describes battery pack technologies and the challenges they face in powering electric vehicles. Production cost is one of the main barriers today, but the possibility to use higher voltage batteries is one of the development directions for several carmakers. Porsche is one of the most active companies doing this, and afterwards the Volkswagen group will likely take advantage of this technology. One clear advantage of using higher system voltages is the possibility of using fast charging technologies.
At the IGBT power module level, a shift in design has happened in recent years. Modules have changed from classical packaging technologies, with a plastic casing, silicone gel encapsulation and a ceramic substrate. Now they are more compact, transfer-molded epoxy modules with organic isolation, although this has been a big step for traction inverter IGBT modules. These compact and flexible designs help integrate power converters better. As part of this, double-sided cooling modules have spread throughout the EV/HEV industry. The first double-sided cooling modules were in Lexus cars, but now we have the well-known fourth-generation Toyota Prius PowerCards and the latest Bosch, Infineon or Dynex modules. This has built a pathway towards power electronics and cooling system integration and optimized thermal management systems.
Another important aspect is the arrival of organic insulator foils that avoid expensive and rigid ceramic substrates. Surprisingly, the isolation layer itself shows lower thermal conductivity of up to 10 W/mK, compared to 24 W/mK for alumina and up to 90 W/mK for silicon nitride. However, it offers design flexibility, with thicker insulated-metal substrate (IMS)-type structures with copper layers on top and bottom, which can optimize the thermal paths for each custom design. This new business will obviously threaten the ceramic substrate suppliers, who therefore need to counterattack with new, better adapted ceramic propositions. Integrated ceramic and baseplate substrate solutions, which can be found in Mitsubishi Electric modules, go in that direction.
(Source: Power Electronics for EV/HEV 2018, Yole Développement, April 2018)
And what about SiC? Lastly, the report “Power electronics for EV/HEV 2018” discusses the penetration of SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) in electric and hybrid vehicle converters extensively. Some early adopters have already started using SiC, such as Chinese carmaker BYD in its on-board chargers, or US EV icon Tesla for its Model 3 inverter. Even Renault has announced a partnership with STMicroelectronics. Nevertheless, SiC is still used in only small volumes, requiring a back-up solution with silicon IGBTs. Other car makers are even more conservative and do not see enough system-level benefits to adopt SiC MOSFETs. Yole Développement gives its vision of the industry and its evolution related to SiC penetration into the automotive supply-chain. We also analyze the potential of GaN power devices, which could take time to realize.
The EV/HEV market is hot, so take a look at it in more detail with the new Yole Développement report.
Who will benefit from the EV/HEV market’s explosive growth? Get more