A new top-cool packaging approach is reshaping thermal management in power-hungry systems, promising cooler, more efficient, and more compact designs for EVs, solar and industrial power gear.
A newly introduced power packaging format by Onsemi is aiming to alleviate one of the toughest engineering bottlenecks in today’s high-voltage designs: heat. With power demands surging across electric vehicles, renewable energy infrastructure and industrial systems, conventional thermal management has forced designers into trade-offs between cooling performance and electrical efficiency. The emerging top-cool approach tackles this head-on by rerouting heat directly into external heatsinks rather than forcing it through circuit boards, reducing junction temperatures and component stress.
The key features are:
- Top-cool thermal path that directs heat straight into the system heatsink for lower junction temperatures.
- Enhanced design flexibility with a range of on-resistance options (e.g., 12 mΩ – 60 mΩ).
- Low stray inductance for faster switching and reduced energy loss.
- Superior thermal efficiency that helps expand power density and compactness.
- Broad applicability for EV, solar, energy storage, and industrial power systems.
The latest devices leverage advanced silicon carbide (SiC) MOSFETs housed in an industry-standard top-cool package. Early shipments are already flowing to key customers, with broader availability slated through the end of 2025. By integrating the top-cool format across its portfolio of both 650 V and 950 V devices, the technology is being positioned as a versatile option for automotive and industrial power stages where efficiency, size and reliability are critical.
Designers struggling with the thermal limits of printed circuit boards will find this approach promising: direct thermal coupling to heatsinks slashes thermal resistance and helps maintain low stray inductance, a perennial concern in fast-switching power electronics. This has knock-on benefits for system size and complexity, potentially simplifying designs that traditionally required elaborate cooling structures.
Industry analysts see this as part of a broader shift toward packaging innovations that extract heat more effectively while preserving or improving electrical performance, a necessity as electrification and energy transition trends drive ever-higher power densities. Whether top-cool packaging becomes a new standard for SiC power stages will depend on how quickly adopters translate the thermal gains into real-world system advantages.
