First Solar Achieves Major Success in Patent Dispute: U.S. Patent and Trademark Office Rejects Petitions Against First Solar TOPCon Patents

Tempe (USA) - The U.S. Patent and Trademark Office (USPTO) has rejected three seperate Inter Partes Review (IPR) petitions filed against patents held by First Solar. The proceedings were initiated by Jinkosolar, Mundra Solar, and Canadian Solar, who sought to challenge the validity of the U.S. manufacturer’s TOPCon patents.

Jinkosolar and Canadian Solar aimed to have U.S. Patent No. 9,130,074 declared invalid, while Mundra Solar targeted U.S. Patent No. 9,666,732. Both patents relate to processes for manufacturing TOPCon crystalline silicon photovoltaic cells. In parallel, First Solar has filed lawsuits in the United States alleging patent infringement. These cases are pending before the District Court for the District of Delaware.

First Solar views the decisions as confirmation of the strength of its patent portfolio. “First Solar believes the USPTO properly exercised its discretion in each of the cases brought by Jinko, Canadian Solar and Mundra,” said Jason Dymbort, Executive Vice President, General Counsel, and Secretary of First Solar. He also referred to the USPTO’s doctrine of “settled expectations,” emphasizing that the patents were granted in 2015 and 2017, “long before each of these manufacturers’ petitions were filed.”

First Solar acquired the TOPCon patents in 2013 through the acquisition of TetraSun. The portfolio includes granted patents in multiple countries and regions, including the United States, the European Union, China, and Japan. As early as July 2024, First Solar announced its intention to license and enforce its TOPCon technology patent portfolio and to initiate infringement investigations against several leading manufacturers of crystalline silicon solar cells.

In the 2025 stock market year, First Solar shares closed with a gain of 30 percent at EUR 226.40 and have since given back some of those gains. In yesterday’s trading, First Solar shares gained 1.4 percent to EUR 208.85 in yesterday’s trading

Source: IWR Online, 22 Jan 2026