Powerex

When operating at altitudes above 40,000 feet, precision and reliability are non-negotiable. Every component must perform flawlessly. Yet, for years, a major hurdle persisted for carrier-based fighter jets—their generator units struggled to maintain the reliability needed for their demanding missions, and the mean time between failures (MTBF) would be around 200 hours. Then came Powerex.

A leader in power semiconductor innovation for over seven decades, Powerex redesigned Silicon-Controlled-Rectifier (SCR) power modules to provide a solution. The combined technology updates of the Powerex SCR module and OEM generator catapulted MTBF from 150 hours to an unparalleled 1220 hours—setting a new standard in power resilience. That’s where Powerex stands apart. More than a quick fix, the team always brings forth a breakthrough rooted in their bold reengineering.

But how did Powerex accomplish this leap? Through a process Powerex is familiar with across many demanding applications, it worked with the OEM to redesign the module and its performance. With its vertically integrated workflow covering everything from silicon chip fabrication to final module assembly to guarantee peak reliability, Powerex has become an extension of the OEM engineering effort.

Three significant changes were made to redesign the SCR module for the generator system. Transitioning from manual hand-soldering to an automated chip-mounting process, it achieved unmatched module consistency and precision. To tackle heat dissipation, Powerex introduced and upgraded the SCR chip and ceramic components, optimizing heat transfer and cutting power losses—a win for both performance and lifespan. To resolve a reliability issue on an accessory that controls the SCR module, Powerex also added heat pipes to the module to more efficiently funnel heat from the SCR gate driver circuit board mounted on top of the module to the heat-sink thus reducing the circuit board operating temperatures by a remarkable 25°C—a vital leap in thermal management and gate driver board reliability.

Powerex currently supports more than 36 military platforms, each with over 30 years of proven operational history.

“It’s our wealth of experience, cutting-edge design capabilities and state-of-the-art in-house manufacturing that come together to ensure every component is engineered for reliability. Our mission is not just to meet the standards but to set new ones to support client’s mission success in the most demanding environments,” says Joseph Wolf, CEO.

Crafting Custom Modules Together with Clients

Powerex acts as an extension of the client’s engineering team, diving deep into the client’s requirements from the moment they request a new power module.

Rather than simply following the provided specifications and offering off-the-shelf solutions, it considers every tiny detail, ensuring the final design is built to the client’s precise needs. This close partnership sets the stage for a truly tailored solution.

Once the initial design is crafted, Powerex conducts a preliminary design review (PDR) with the client. This involves presenting a 3D CAD model that shows the module’s internal and external features, making sure the chips remain within safe operating temperatures.

The model then gets integrated into commercially available simulation software or finite element analysis tools to validate the design. Simulations encompass mechanical stress, thermal behavior, electrical inductance and electrostatic performance. The comprehensiveness of the process ensures a deep understanding of the design’s capabilities even before building the first prototype.

Following the PDR, Powerex incorporates client feedback and makes any necessary changes to refine the design. The project then progresses to the critical design review (CDR), where every aspect is scrutinized. It undergoes extensive qualification testing, including reliability tests, lifetime assessments, environmental tests, moisture and temperature cycling, moisture resistance evaluations and power cycling tests.

“Throughout these steps, we keep the communication channels wide open with clients—ensuring everyone is on the same page as the project moves forward,” says Ron Yurko, COO. “We provide a clear trail of quality assurance for each component that leaves the factory.”

Trusted by Industry Leaders

A pivotal project landed at Powerex when Lockheed Martin required the original supplier of the F22 generator to collaborate with Powerex to address ongoing reliability issues with a module in the generator.

Powerex took the lead by conducting an in-depth failure analysis of the existing module, uncovering significant weaknesses in both the design and material choices that compromised its performance.

The process began with mechanical stress analysis to understand the demands of the module. After agreeing on the size and weight requirements, Powerex used finite element analysis to explore different material options, considering the harsh conditions the module would endure. Ultimately, a high-strength and high temperature material was selected for the module’s casing, providing the durability needed for the extreme environment.

“All of this was achieved before even prototyping started. Advanced simulation tools allowed us to anticipate and address potential challenges early in the process,” says Scott Leslie, chief technologist.

The company’s in-house chip manufacturing capability also came in handy here, allowing for precise chip customization to fit the module’s unique requirements. The ability to tailor both the chips and the module design resulted in a component that matched the exact shape and functionality needed, significantly enhancing reliability.

Shaping the Future of High-Voltage Power Modules

Twenty years of research and development experience places Powerex as a leader in tackling the challenges of packaging disruptive technology wide bandgap power chips, such as silicon carbide (SiC) and gallium nitride (GaN).

Strategically collaborating with prominent players in the SiC chip production industry—including Wolfspeed, General Electric, GeneSiC (now Navitas), Mitsubishi and United Silicon Carbide (now part of Qorvo)—Powerex addresses a critical gap in the market. While these companies excel in chip technology, they lack in-house module assembly capabilities, making Powerex an essential partner that provides the expertise needed for packaging and customizing high-performance modules.

A significant milestone for Powerex occurred in 2010 when it developed a 10,000-volt SiC MOSFET module utilizing Wolfspeed chips as part of a Defense Advanced Research Projects Agency (DARPA) program. This initiative aimed to advance solid-state transformer technology, driving a new era of efficiency and reliability. Powerex’s engineers went beyond simply building a module, demonstrating SiC technology could support demanding applications that traditional silicon solutions could not meet.

With several years of developing high voltage WBG modules for DOD and DOE ARPA-e R&D programs, Powerex developed a commercial 10kV, 140A SiC module in 2022 for a major US power electronics firm for 13.8 kV Medium Voltage (MV) motor drives and Ultra High Voltage (UHV) Solid State Circuit Breakers (SSCB). Powerex is also supplying this module to two major US universities for testing/evaluation and research into advanced power electronics systems under DOE ARPA-e programs.

The military took notice, and so did the industry. Army projects for electric vehicle propulsion and other demanding applications required custom modules that could survive the harshest conditions. Powerex delivered again, creating the first 1200V, 1,000-amp SiC MOSFET module with liquid cooling, proving its expertise in building rugged, high-performance solutions.

Currently, Powerex is supplying 10 kV modules for testing at several universities and an OEM, solidifying its role as a key contributor to the advancement of power electronics and energy solutions.

Cleanroom Expansion for Next-Gen Power Electronics

Earlier this year, Powerex expanded its power module cleanroom facility, originally built in 2013. The expansion added 4,000 square feet to the original 10,000 square feet and introduced new automated equipment for handling power chips and substrates, paving the way for advanced manufacturing techniques.

One of these advancements is using silver nanoparticle paste, which involves mounting the chips under heat and compression to form a solid silver joint rather than relying on traditional solder. These silver joints provide superior electrical and thermal conductivity, outperforming solder joints in temperature and power cycling. As a result, the chips can better withstand heat and electrical fluctuations, enhancing overall performance.

Powerex also implements new design features and process techniques to reduce internal inductance in their modules. This is important because wide bandgap chips, like SiC, can operate at much higher frequencies than traditional silicon chips. To fully use their potential, they need to minimize internal module inductance. Powerex’s improvements in packaging help the chips run at higher temperatures and switch more efficiently, maximizing their capabilities.

While many competitors discontinue power modules over time, Powerex remains a trusted partner by redesigning and requalifying existing modules. It updates these modules with the latest silicon or SiC technology, enabling defense contractors to extend the lifecycle of mission-critical systems despite component obsolescence.

For example, the Bradley Fighting Vehicle’s motor controller drive faced issues with outdated electronics, but rather than replacing the entire system, Powerex retained the original design by supplying its durable Darlington transistors. Manufactured in Youngwood, Pennsylvania, these transistors have supported the Bradley platform for over 25 years.

Such unconventional tactics and successful outcomes make Powerex the industry’s go-to partner for crafting systems. Whether elevating a fighter jet’s performance or keeping ground operations moving, its promise to deliver customized solutions—rooted in a deep understanding of each system’s unique needs—empowers clients to operate with absolute confidence.