Although the ever-increasing number of 5G roll-outs and climbing consumer electronic devices sales will predominantly create a favourable environment for the RF power semiconductor demand growth, automotive industry also remains among the key consumer areas of RF power modules.
Currently, the automotive industry is undergoing a dynamic electric and digital revolution. A surging number of vehicles are subject to electrification, autonomy, and ready-for-connectivity. It all boils down to the rising importance of energy efficiency and will accelerate the automotive industry’s transformation by manifold. However, an important aspect that will remain crucial to bring about this transformation, is the RF power semiconductor, as it has played a pivotal role in enabling EVs and hybrid EVs (HEVs).
Participating in the industry’s “zero emission” shift, the world’s leading automakers have been taking remarkable efforts in ramping up their vehicle electrification projects. Research-driven projections indicate that a majority of OEMs are prominently eyeing the targets for EVs and HEVs, to be met in 2025. This scenario clearly prompts at the significant opportunities for highly efficient RF power semiconductors that would effectively function at elevated temperatures. Manufacturers of RF power modules are thus constantly focusing their strategies on the development of products based on SiC (silicon carbide), GaN (gallium nitride), and WBG (wide band-gap) technologies.
GaN Emerging as a Choice of Material for RF Power Semiconductors
Despite a number of R&D efforts prevailing in the WBG semiconductor realm, the SiC variant has remained the traditional choice for EVs and HEVs, over the recent past. However, on the other side, SiC has already arrived at the maturity stage in market and is being challenged by other competitor technologies that are gaining ground over it – particularly in case of power electronics and other demanding applications in electric and hybrid electric vehicles.
While EVs and HEVs typically utilize SiC based RF power semiconductors for regulation of DC/DC converters in the powertrain, the transition time tends to restrict their switching frequencies between 10 kHz and 100 kHz. Currently, almost every automaker around the world is putting efforts in innovative around the GaN designs of RF power semiconductors.
Introduction of GaN semiconductor held the promise to potentially overcome this longstanding challenge by enabling switching time within the nanosecond range and operation at temperatures as high as 200°C. The faster functionality of GaN semiconductor results on high switching frequency and thereby, low switching loss. Moreover, the lower power electronic volume translates into reduced overall weight, which subsequently supports lightweight and more efficiency economy.
Several studies advocate de facto potential of GaN based semiconductor for high power conversion at high speed. Moving to a new era of power electronics that would best complement the objective of EVs and HEVs, key attributes of GaN semiconductor materials, such as superior switching speed, high operating temperatures, lesser switching and conductivity losses, compact-sized packaging, and potential cost competitiveness, will continue to place GaN-based RF semiconductors over all other counterparts.
Potential Challenges Limiting Expanse of RF Power Semiconductor in EVs & HEVs
Despite all the innovations and positive outcomes entering markets, a few challenges still remain as the barriers to RF power semiconductor’s functionality in electric vehicles. After all, driving a high-power component within nanoseconds is a complex chore and comes with multiple difficulties that are yet to be resolved. One of the most prominent challenges is the improvement of voltage ratings. Enhancing efficient operability at higher temperatures without altering conventional designs is another important challenge that continues to capture R&D interests in the RF semiconductor space.
The fact repeatedly highlights that applications of power electronic modules in EVs and HEVs are highly demanding and their performance relies not only on voltage- and performance-based innovations. A constant push in terms of structural and design technology improvements ensure endurance, reliability, and thermal resistance of RF devices within hybrid and pure/battery electric vehicles.
Packaging challenges are capturing attention
While distortion of surrounding electronic parts has been another factor challenging suitability of RF semiconductor devices within EV designs, EMC (epoxy molding compound) semiconductor packaging has emerged as a highly lucrative area of research, as it allows operation without disturbing the neighboring electronic components.
Moreover, although overmolded RF power modules are already being perceived as the mainstream of the near future, the designs still have a scope for improvement in terms of thermal management. Leading companies in the RF semiconductor landscape are thus emphasizing widening their efforts related to packaging to achieve improved reliability for usage in electric vehicles.
Better future for WBG – Is there any?
In the backdrop of SiC’s maturity and GaN’s proven superiority, the market is however failing to resolve the reliability concerns associated with WBG, which is eventually limiting market penetration of WBG type FR semiconductors in the long run. The only way to achieve engineering of more robust WBG type semiconductors lies in deeper understanding of their failure mechanisms in harsh operational conditions. Experts also opine that WBG might attain maturity in market without any concrete strategic support that would re-establish their reliability for further utilization.
What the Industry’s Behemoths are up to?
Wolfspeed, the U.S.-based Cree Inc. company specialized in premium SiC and GaN RF power products, recently launched a new product that brings about more than 75% reduction in the inverter losses of EV drivetrain. With such improved efficiency, engineers are likely to discover new parameters to innovate in terms of battery usage, range, design, thermal management, and packaging.
The high-voltage circuitry of inverters in electric and hybrid electric vehicles generate a lot of heat and this problem needs to be addressed with efficient cooling mechanism. Research has been recommending time and again that the reduction of size and weight of inverters is the key to attaining improved cooling of the automotive components in EVs and HEVs.
On a similar line, a majority of leaders in the industry (Hitachi, Ltd., for an instance) remain focused on inverter mass and size with the help of a double cooling technology that uses either liquid or air to directly cool the desired high-voltage RF power module. Such a mechanism also allows adds to the compactness and flexibility of the overall design and thereby, to the efforts in reducing the power generation losses.
Looking forward to the importance of a compact design to raise the RF power semiconductor’s applicability in electric vehicles, the likes of Mitsubishi’s ultra-compact SiC inverter emerges as a trailblazer. Mitsubishi Electric Corporation has particularly developed this ultra-compact RF power product for hybrid EVs and claims it to be the world’s smallest-ever SiC device of its kind. The reduced packaging volume of this device consumes significantly lesser space in the vehicle interior and thus underpins higher fuel and energy efficiency. The device’s commercialization is anticipated in the next couple of years. Partly supported by the New Energy and Industrial Technology Development Organization (NEDO, Japan), the company will also commence with mass production of the ultra-compact SiC inverter, soon.
Last year, the industry’s first revolutionary field programmable control unit (FPCU) was launched as a novel semiconductor architecture that can be potentially responsible for boosting the range and performance of electric and hybrid electric vehicles. This RF semiconductor device is engineered by Silicon Mobility, based in France, with an objective to enable the existing EV and HEV technologies to achieve their maximum potential. Silicon Mobility’s manufacturing partner in the development of FPCU is the US-based semiconductor manufacturer – GlobalFoundries.
RF Power Semiconductor Demand to Surge in the Asia Pacific Region
As the world is rapidly switching to low-carbon sources of energy to achieve energy-efficient transportation, the pressure of minimizing carbon footprint on energy-efficient vehicles in a building up. Even if the mass production has been commenced just about a decade ago, the market for EVs is already outpacing the market for conventional vehicles that run on ICE (internal combustion engine). The rate of expansion of the former is reportedly almost 10X that of the later and towards the end of 2040, more than 1/3rd of the total new vehicle sales will be accounted by EVs.
The latest data of the China Association of Automobile Manufacturers implies that over half a million EVs were sold in China alone, in the year 2016, which majorly included commercial vehicles and buses. While China will remain the largest market for EVs in the long run, the rate of EV production has been on a constant high in the entire Asia Pacific region.
In addition to the significantly flourishing consumer electronics industry, the region has been witnessing considerable growth of the EVs market, recently, thereby creating a strong opportunity for the penetration of RF power semiconductors, preferably based on GaN.
The global valuation of RF power semiconductor market is roughly US$ 12 billion (as of 2018 end). With breakthrough opportunities arising from the onset of 5G technology, extensive adoption of wireless network infrastructure and IIoT (Industrial Internet of Things) technology, prosperous outlook of the consumer electronics landscape, and growing electric vehicle (EV) sales, the RF power semiconductor market revenues are likely to expand at an impressive 12% compound annual growth rate through 2027.
Aditi Yadwadkar is an experienced market research writer and has written extensively on the Electronics and Semiconductor industry. At Future Market Insights (FMI), she works closely with the Electronics and Semiconductor research team to serve the needs of clients from across the globe. These insights are based on a recent study on RF Power Semiconductor Market by FMI.