SiC patenting strong in Q4 2024, says KnowMade
During Q4 2024, KnowMade's SiC Patent Monitor showed 900 new patent families and 400 newly granted patents. This period also saw over 100 patents expire or be abandoned and involved seven notable patent transfers.
There was no new IP litigation in the US or patent opposition in Europe. And the sector is "abuzz with ten notable patent collaborations and an influx of over 25 IP newcomers entering the field", according to KnowMade.
Innovation within the SiC industry, particularly in Bulk and bare wafers, has led to the emergence of better substrates and more reliable power devices. During Q4 2024, for example, NGK Insulators disclosed a composite SiC substrate with a biaxially oriented SiC layer that helps to reduce warpage. Another player, SICC, published innovations improving 3D stress distribution and reducing internal stress in large diameter SiC wafers (> 150 mm).
Sumitomo Electric continues to lead IP activities in epitaxial substrates, according to KnowMade, with four new inventions disclosed during Q4. One of these relates to issues in the epitaxial reactor, such as the presence of SiC particles on the susceptor, causing recesses in the rear surface of SiC epitaxial wafers. Another invention focuses on the reduction of certain defects (bump, pit, carrot, triangular defect, downfall) that can be imaged using a confocal scanning device.
For devices, there has been patenting activity from several Chinese automotive players, such as NIO and FAW. NIO stands out this quarter with a European patent publication related to SiC trench MOSFET. Other players from the automotive supply chain have been actively filing patents during the quarter such as Bosch (e.g., to improve the short-circuit strength of SiC FET) and Nexperia (e.g., to improve on-resistance and surge performance of SiC Schottky diodes).
In terms of modules and packaging, Onsemi has disclosed electroless plating methods and systems suitable for SiC devices, and Mitsubishi Electric has two new inventions, of which one to suppress heat occurring in a SiC MOSFET connected in parallel with a Si IGBT, without providing a temperature detection circuit and a current detection circuit. GaN specialist Navitas Semiconductor is also looking to strengthen its patent portfolio for power SiC, with a new invention providing balanced current flow in SiC power modules.
For circuits and application, ZF is has developed a method of driving parallel- connected SiC-MOSFET and Si-IGBT based on the rapid detection of the current load of the active (switched-on) device. Furthermore, a collaboration has involved BMW with CSA Catapult and University of Warwick in the UK and led to a new patent publication describing a monitoring device to measure temperature or current in SiC devices under high current load even under rough mechanical conditions (e.g., under strong vibrations, in an automotive appliances).
KnowMade closely follows SiC patenting, and has noted recently that the number of inventions disclosed in 2023 was more than 50 percent higher than it was in 2021. The number of inventions disclosed by Chinese players increased by about 60 percent between 2021 and 2023.
