EV/HEVs: a catalyst for innovation
EV/HEV technology is leading to an acceleration in applications for power module related patents, says Knowmade
Knowmade has released a new Next-Generation Power Modules patent landscape report, covering the wide-bandgap (WBG) power modules and generic/IGBT power modules addressing critical challenges for the next generation of power modules (heat dissipation, thermomechanical issues, management of parasitic signals, module miniaturisation, etc.) and more specifically challenges arising from EV/HEV high requirements.
According to Knowmade, the last decade has seen EV/HEV applications driving packaging innovation in power electronics and creating new equations to solve for module makers, in particular further downsizing, higher power density, higher reliability and lower cost/higher manufacturability.
On top of that, automotive OEMs are asking for highly standardised power modules, while most module makers focus on proprietary module designs through which they can offer more differentiating added value.
In this context, automotive OEMs and Tiers-1 are expected to become more and more intrusive in the power module area.
Furthermore, EV/HEV applications are also pushing the adoption of new wide-bandgap (WBG) semiconductor technologies, especially SiC-MOSFETs whose commercial availability has continuously increased. However, to fully benefit from power SiC technology, it is crucial to enable high-temperature operation in SiC modules (200- 300degC), e.g. through new packaging materials, as well as high-speed operation, by minimising parasitic inductance.
As a result, the last decade was marked by extensive innovation in power module design and packaging, leading to a very high volume of patent publications.
Knowmade’s analysts have selected and analysed more than 7,000 inventions filed by more than 300 different organisations, with a focus on EV/HEV modules and SiC power modules, which are driving the innovation at design and packaging levels.
“The IP competition is becoming more global and module makers have been progressively joined by competitors from the EV/HEV supply chain”, affirms Rémi Comyn, technology and patent analyst Compound Semiconductors and Electronics at Knowmade. Top module makers in Europe (Infineon, Semikron) and Japan (Mitsubishi Electric, Fuji Electric, Hitachi) have been very active to keep their leadership in the power module patent landscape since 2010. “Interestingly, major foreign module makers are increasingly competing with their counterparts in Europe, by filing more and more European patent applications”, addsComyn. Certain automotive OEMs (Toyota Motor, Hyundai Motor) and Tiers-1 (Denso, Bosch) are now well-established patent assignees. In addition, several notable players from the EV/HEV supply chain have joined the IP competition: semiconductor manufacturers (Cree/Wolfspeed), OEMs (Ford, BYD), and Tiers-1 (Valeo, Continental, ZF).
For EV/HEV applications, the difficult challenges have led to several IP collaborations between module makers/automotive Tiers-1 and automotive OEMs (Hyundai Motor/Infineon, ABB/Audi, Toyota Motor/Denso, Valeo/Siemens, etc. In China, major modules makers (CRRC, Macmic, Starpower) have demonstrated moderate patenting activity as of 2020, while new IP players have stepped up (CETC).
The WBG power module patent landscape is dominated by leading SiC MOSFET IP players. “Numerous IP players in the power module patent landscape have built up a significant portfolio of patents related to SiC MOSFET technologies, especially trench MOSFET technology (Rohm, Infineon, Fuji Electric, Toyota Motor, etc.) targeting automotive applications. Accordingly, they now develop their own technology for full- SiC power modules”, notes Rémi Comyn. “Most of them already had a foot in power module technology, except Cree / Wolfspeed, which started from APEI’s acquisition filing patents specifically for SiC power modules”, adds Comyn.
Knowmade’s anaysts expects the number of patents for SiC power modules to continue growing in the next five years, as development is still on-going for many module makers (at die and module levels). According to the present segmentation, IP players such as Hitachi, Mitsubishi Electric and Toyota Motor are also developing key technologies (reduction of stray inductance, silver and copper sintering, TLP for die- attach) to address WBG-related challenges. Lately, Knowmade has identified several newcomers to the WBG power module patent landscape, including Audi, On Semiconductor, Danfoss & Shindengen Electric Manufacturing.
In the Next-Generation Power Modules IP report, the patent corpus is segmented into four main challenges which are common to IGBT modules and SiC modules: parasitics, heat dissipation, thermomechanical issues, thermal reliability and miniaturisation.
“Overcoming these challenges will be even more critical for SiC power modules to become mainstream, since the added value of the technology depends on their capability to operate at higher switching speed and higher temperature than IGBT modules”, says Comyn.
The patent corpus is also segmented by key technologies that are developed for next-generation power modules, for instance in die-attach (copper and silver sintering, TLP bonding), in encapsulation (transfer molding), and double-sided cooling structure. Furthermore, the report includes additional segments for patents related to intelligent power modules (IPM), hybrid modules (Si IGBT/SiC diodes or MOSFETs and GaN/Si cascode) and EV/HEV applications.
A significant part of this report is dedicated to the in-depth analysis of 40 leading players' IP portfolio. Knowmade’s IP analysts provide an overview of the portfolio (IP dynamics, enforceability, protected countries, technology, technical challenges, applications, etc.), highlight the noteworthy patents relating new products and technology developments related to WBG, EV/HEV and related challenges, and review the very latest patented inventions.
