The surface-mount diodes improve insulation, support high-voltage systems in cars and industry, and are easy to install on existing designs.
ROHM has introduced surface-mount silicon carbide (SiC) Schottky barrier diodes (SBDs) designed to enhance insulation resistance by increasing the creepage distance between terminals. The initial release includes eight models, designated SCS2xxxNHR.
Application examples for these diodes include automotive uses such as onboard chargers (OBCs) and DC-DC converters, as well as various industrial equipment, including AC servo motors for industrial robots, photovoltaic (PV) inverters, power conditioners, uninterruptible power supplies (UPS), and more.
The growing electric vehicle (xEV) market is accelerating demand for power semiconductors, including SiC SBDs, due to their low heat generation, high-speed switching, and high-voltage capabilities, essential in applications like onboard chargers. Manufacturers can improve production efficiency by using compact surface-mount devices (SMDs) compatible with automated assembly. However, these compact SMDs often have smaller creepage distances, presenting a design challenge in maintaining high-voltage tracking prevention. By adopting an optimised package design, these diodes achieve a minimum creepage distance of 5.1mm, significantly enhancing insulation performance compared to standard products.
The products feature an innovative design that eliminates the centre pin at the bottom of the package, achieving a creepage distance of at least 5.1mm—approximately 1.3 times greater than standard products. This design significantly reduces the risk of tracking (creepage discharge) between terminals, eliminating the need for insulation treatment like resin potting when surface mounting the device on circuit boards for high-voltage applications. Furthermore, these devices are compatible with the same land patterns as standard TO-263 packages, allowing for easy replacement on existing circuit boards.
Available in two voltage ratings, 650V and 1200V, these SBDs support 400V systems commonly used in electric vehicles (EVs) and are prepared for higher-voltage systems anticipated to grow in popularity. The automotive-grade SCS2xxxNHR models are AEC-Q101 qualified, ensuring they meet the stringent reliability standards required in automotive applications.
