Canadian Solar (NASDAQ:CSIQ) announced a milestone victory in its ongoing intellectual property battle with Trina Solar.
On April 17, 2026, the U.S. Patent Trial and Appeal Board (PTAB) issued Final Written Decisions invalidating all challenged claims of two TOPCon (Tunnel Oxide Passivated Contact) solar cell patents that Trina had previously asserted against certain Canadian Solar subsidiaries.
The rulings are a decisive blow to the litigation strategy pursued by Trina Solar, which had sought to claim proprietary control over key aspects of TOPCon technology—the current industry standard for high-efficiency solar modules.
By successfully challenging the validity of these patents, Canadian Solar has cleared a path for its continued deployment of advanced solar solutions without the threat of these specific infringement claims.
Canadian Solar framed the PTAB’s decisions as a clear validation of its own independent research and development efforts and its robust IP defense strategy.
The company has invested heavily in its N-type TOPCon technology, which offers superior conversion efficiency and lower degradation rates compared to older P-type technologies.
The victory comes at a critical time for the solar industry, as major manufacturers shift their entire production capacities toward TOPCon technology to meet global decarbonization targets.
For Canadian Solar, the invalidation of these patents removes potential royalty burdens and legal uncertainties that could have impacted its margins in the lucrative U.S. market.