While silicon chips for power electronics are an American innovation, their production slipped away from manufacturers in the United States to those in East Asia. Victor Veliadis is doing his best to keep that from happening with silicon carbide (SiC) chips, which outperform silicon.
Veliadis, executive director, chief technology officer and principal investigator at PowerAmerica, has a stake in where the superior SiC chips are made. PowerAmerica, an institute within Manufacturing USA, was instrumental in fostering production processes, developing a reliability center and establishing a domestic fabrication industry for SiC chips.
“We, as PowerAmerica, supported the SiC fabrication industry in the United States that mimics that of silicon so we didn’t have the hemorrhage overseas of our technology,” he said. “We ended up having companies from China and Europe coming to the United States to make SiC parts. We’re very, very competitive in making these devices.”
SiC chips and their wide bandgap (WBG) semiconductor cousins, those made of gallium nitride (GaN), are more efficient than silicon ones, can be smaller, less complex, lower in weight and are proven to be highly robust and reliable, according to the website for chip maker X-FAB, which has a foundry, aka fab, in Texas. With its high thermal conductivity, SiC is the material of choice for high-temperature use, such as industrial and powertrain applications, traction or rail inverters and smart power grids. GaN is superior for power supply or chargers for consumer products, audio amplifiers or 48V board net conversion systems that save fuel and reduce emissions in vehicles.
East Asia already dominates in production of GaN chips.
Development of WBG chips has come so far largely due to their energy efficiency in the wide range of applications cited by X-FAB, in addition to military propulsion and weapons systems. The U.S. Department of Defense funded the early days of their domestic development, Veliadis said.
The U.S. can remain competitive in the SiC industry by retrofitting old silicon chip fabs and automating production, he said. Current domestic production is primarily through leveraging capacities in existing silicon chip fabs.
“What you can do with SiC is breathe new life into otherwise-obsolete fabs that do older silicon technology that’s kind of running out of steam,” Veliadis said. “By using older, fully depreciated equipment, overhead costs go down.”
Needed now is mass production to further reduce the chips’ price, he added. The best hope for the demand for mass-produced SiC chips lies with consumer and fleet electric vehicles (EVs). And EVs are primed to be some of the best hope for living with and mitigating climate change. They also happen to be a big part of President Joe Biden’s proposed infrastructure plan, which may include funneling taxpayer dollars for research and development and providing consumer income tax credits to further the growth of the EV industry.
“What I’m really excited about is the push that this administration is bringing to green technologies and clean energy,” the latter of which is PowerAmerica’s focus, Veliadis said. “I think that electric vehicles, because of their higher efficiency, combined with electricity produced in a renewable way, are extremely good ways to decrease CO2 emissions that are part of the greenhouse effect. I think this is all in the right direction and that if we make the right strategic moves it can bring huge manufacturing growth to the United States and contribute to our national security.”
Washington’s push for clean energy may come at an opportune time for PowerAmerica, as the institute is at the end of its six-year funding from the Department of Energy.
The institute is continuing by funding projects selected by members. And it is sustainably supported by member dues, said Randy Bickford, director of research administration and communication.
“We are also looking for additional federal funding,” he said. “We think there’s a desire on the part of Manufacturing USA and related federal agencies that they’d like to see us continue.”
High efficiency consumes less energy
While Veliadis and Bickford hash out PowerAmerica’s future, the institute’s funded projects continue to roll along.
In one of PowerAmerica’s recent projects, robotics, power, heavy electrical equipment and automation technology multinational ABB is working with Virginia Polytechnic Institute and State University on a low-voltage, high-current GaN-based 48V-1V, 300A single-stage LLC converter with a wide range to be used in high-performance computers and data center servers.
The device offers industry-leading efficiencies and occupies less than half the board space of equivalent solutions.
“Efficiency and power density are two of the major performance factors for power converters in the data center,” V.R. Ramanan, executive consulting scientist at ABB and principal investigator for the converter research, said.
“High efficiency consumes less energy, and high power density enables a smaller footprint, giving more space for other components, such as CPU/GPU [central and graphics processing units],” he added.
PowerAmerica provided half of the project’s funding, as well as a connection to WBG device manufacturers, Ramanan said.
When ABB needs to have its high-tech research device independently tested, he can call on Group NIRE (National Institute for Renewable Energy).
PowerAmerica provided funding in a 50-50 cost-sharing plan for Group NIRE to set up an independent WBG testing facility. Texas Tech University, which established Group NIRE in 2010, according to the company’s website, provided guidance as a partner in the testing facility project.
“We needed an independent center for applications engineers to confirm reliability and ruggedness beyond what the manufacturer claims,” Veliadis said. “This builds confidence by [providing] independent testing.”
Because next-generation SiC and GaN engineering sample power devices are typically in short supply, PowerAmerica operates a device bank for researchers like Ramanan to obtain them quickly.
Also, the institute has trained more than 400 university students in the technology to do the kind of work Ramanan does for ABB, and it has educated 3,500 participants in WBG technology in its short courses, tutorials and webinars.
“The idea is to train the existing workforce to bring awareness of these technologies and through universities train the people who, within a year or two, find themselves in industry working on these technologies and training others, or who staff universities as professors training the next generation of students,” said Veliadis, himself a professor of electrical and computer engineering at North Carolina State University, where PowerAmerica is based.