US-based thin-film PV solar tech manufacturer First Solar has announced that the United States Patent and Trademark Office (USPTO) has rejected three Inter Partes Review (IPR) petitions that challenged its TOPCon patents. JinkoSolar has filed an IPR against US Patent No. 9,130,074, which was denied on November 20, 2025, while a similar petition from Canadian Solar regarding the same patent was rejected on December 18. Mundra Solar has separately challenged US Patent No. 9,666,732, with the USPTO denying the petition on December 11. The patents cover methods for manufacturing TOPCon crystalline silicon PV cells. First Solar has ongoing patent infringement lawsuits against all three companies in the US District Court for the District of Delaware. This TOPCon patent portfolio was acquired by First Solar via its’s acquisition of TetraSun in 2013, with patents issued between 2015 and 2017 and validity extending beyond 2030 across multiple jurisdictions. Recently, First Solar has inaugurated a $1.1 billion AI-enabled Louisiana factory, adding 3.5 GW capacity.