GaN Patent Dispute What's Behind the Sales Halt for Infineon's CoolGaN Chips

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The sales halt for certain CoolGaN products in China is just a snapshot of a larger patent dispute between Infineon and Innoscience. An overview of proceedings, markets, and the significance for GaN power semiconductors.

It's a familiar sight at major trade shows: sometimes an exhibit is covered with a cloth, other times something has to be removed. This is usually due to patent disputes and complaints from competitors. This time, Infineon has been affected in China.

On the opening day of "electronica China" in Shanghai in early July 2026, Infineon had to remove part of its display again, reported the Chinese financial portal Shidai Caijing. Representatives of the Chinese chip manufacturer Innoscience had discovered several GaN components at the booth of their Munich-based (Germany) competitor that had previously been subjected to a sales ban by a Chinese court.

Following this objection, the trade fair organizer removed the disputed exhibits from Infineon's booth, Innoscience stated on its official WeChat account on July 2, 2026. It is reportedly the first time that a sales ban in China's relatively young gallium nitride industry has been enforced so publicly, and that on an international leading trade fair, according to Chinese comments.

The two companies are already battling in court in Germany and the USA, with several rulings having favored Infineon. Recently, however, Innoscience launched a "counteroffensive" in its hometown Suzhou, near Shanghai, as the financial portal described it. On May 27, the Intermediate People's Court of Suzhou ruled in the first instance that Infineon had infringed two of Innoscience's invention patents, according to Shidai Caijing—as previously reported.

The court ordered an immediate halt to the sale, offering, and import of the affected products in China, awarded Innoscience ten million yuan (approximately 1.2 million euros / $1.3 million) in damages, and issued an injunction. Since Innoscience is headquartered in Suzhou, this was essentially a home-court victory.

Not Without my Lawyer

Infineon fought back. The company attempted to have the two patents declared invalid and appealed to the Supreme People's Court. Both attempts failed, according to Shidai Caijing. The Chinese Patent Office CNIPA fully upheld the validity of both patents in November 2025, and a subsequent objection by Infineon was dismissed by the Beijing Intellectual Property Court.

On June 12, the Intellectual Property Tribunal of the Supreme People's Court upheld the ruling and rejected all objections, Innoscience stated in a press release. This made the ban enforceable in China. The two patents, which Innoscience asserted in Suzhou at the end of 2024, are considered fundamental for 650-volt GaN devices on a silicon basis. They pertain to their design and manufacturing, according to Chinese media reports. Ten products from Infineon's CoolGaN-G3 series are affected.

Where Profits Await

The background to the dispute lies in one of the most lucrative areas of power electronics. GaN switches faster and with lower losses than conventional silicon, paving the way for data centers to adopt 800-volt power supplies, as demanded by the significantly increased power consumption of AI servers. According to market researcher Yole Group, Innoscience and Infineon were among the world's five largest GaN manufacturers in 2023 and 2024, as reported by the South China Morning Post. Market researcher Trendforce data showed that Innoscience led the global GaN power device market in 2024 with 29.9 percent, while Infineon ranked fourth with 10.3 percent. According to Infineon's financial report, China and Hong Kong accounted for 38 percent of the company's revenue in the 2025 fiscal year.

Both companies are suppliers to Nvidia. Innoscience is working with Nvidia on GaN power supply solutions for its 800-volt architecture, according to the South China Morning Post in Hong Kong. Other industry reports suggest that both corporations, Innoscience and Infineon, are on Nvidia's list of approved suppliers for this transition.

A Verdict With Impact?

How significant the sales ban in China is remains a matter of differing opinions. The ruling has a "very limited effect" on the GaN business, as it only concerns a small part of the portfolio, an Infineon spokesperson told the South China Morning Post. The company strongly disagrees with the decision and will "exhaust all legal means to defend its innovation leadership in GaN technology."

In contrast, the patent consultancy PRIP Research expects a "significant impact" on Infineon's business, particularly for Infineon's high-margin high-voltage products for industrial and server applications, as well as modules for the automotive sector. The ruling caused short-term stock price jumps among Chinese chip manufacturers. Innoscience's Hong Kong-listed shares rose by 16.6 percent on the following Monday. Shanghai-based compound semiconductor manufacturers Silan Microelectronics and Sanan Optoelectronics hit their daily limit of ten percent, while China Resources Microelectronics shares increased by more than 13 percent.

The dispute is a "system-level confrontation" over dominance in third-generation semiconductors, the South China Morning Post quoted Zhang Guobin, the founder of the Chinese chip portal eetrend.com. With the explosive growth in demand for efficient power components for AI data centers, electric vehicles, and renewable energy, competition in the GaN market will further intensify, Zhang said.

A Dispute in Multiple Instances

Infineon was the first to take its Chinese competitor to court, Shidai Caijing reported. In the US, the Munich-based company sued the Chinese firm in March 2024 before a federal court in California. Later, they petitioned the trade authority ITC for an import ban. In May 2026, the ITC ruled that an already discontinued legacy product from Innoscience infringed an Infineon patent and imposed an import ban for it.

The current GaN products were unaffected by this, Innoscience emphasized at the time. In Germany, Infineon filed a lawsuit in June 2024 before the Munich I Regional Court and won in the first instance in August 2025. On June 18, 2026, the same court found Innoscience guilty in two more cases of infringing a patent and a utility model. "Today's ruling demonstrates the value of our GaN portfolio and underscores our commitment to vigorously defend our intellectual property," stated Johannes Schoiswohl, Head of Infineon's GaN Division, in a press release.

The final word has not yet been spoken. Infineon denied that there had been a "final victory" for Innoscience in China, as claimed by its rival. The decision by the Supreme People's Court only concerned the preliminary injunction; the main proceedings are still ongoing, the company told the industry service ip Fray. Additional cases involving other patents are pending. Meanwhile, the market over which both companies are fiercely battling is only just beginning to expand with the growth of AI data centers in China and the US.