USPTO’s PTAB has cancelled Trinasolar’s TOPCon patent claims asserted against Canadian Solar in the US
Trinasolar is also pursuing an RMB 1 billion damages claim against Canadian Solar in China
Patent disputes around TOPCon are expanding globally, influencing technology choices
The US Patent and Trademark Office (USPTO) has invalidated all claims of TOPCon solar cell patents previously asserted by Trina Solar Co., Ltd. against certain subsidiaries of Canadian Solar.
According to Canadian Solar, the Patent Trial and Appeal Board (PTAB) of the USPTO has issued final written decisions cancelling Trinasolar’s patent claims.
Trinasolar filed a patent infringement suit against Canadian Solar in the US District Court for the District of Delaware in October 2024. It also names 3 of Canadian Solar’s US subsidiaries as directly or indirectly infringing on 2 of its TOPCon-related US patents. Canadian Solar called it a ‘frivolous lawsuit’ (see TOPCon Patent War Heating Up: Trinasolar & Canadian Solar New Additions).
In February 2025, Trinasolar also filed a patent infringement lawsuit against Canadian Solar in China while seeking over RMB 1 billion in damages. The China lawsuit relates to Solar Cell Module (Patent No. ZL201710975923.2) and Solar Cell and Its Manufacturing Method (Patent No. ZL201510892086.8) (see Trinasolar Seeking RMB 1 Billion+ In Damages From Canadian Solar).
Canadian Solar says the PTAB ruling reinforces its long-standing, successful track record of managing international disputes. Earlier this year, PTAB ruled in favor of the Canada-headquartered solar PV manufacturer in the Maxeon Solar Technologies patent infringement lawsuit (see Canadian Solar Wins PTAB Ruling Against Maxeon Patent Claims).
Canadian Solar President and President of e-STORAGE, Colin Parkin, said, “Canadian Solar has always remained committed to organic and independent R&D. We possess a deep and comprehensive understanding of our proprietary technologies. While we respect and value the intellectual property rights of all companies as we do our own, we firmly oppose the abusive use of IP to extort or hinder competition. We will continue to vigorously defend our legitimate business interests.”
In January 2026, Canadian Solar, JinkoSolar, and Mundra Solar had their 3 Inter Partes Review (IPR) applications rejected by the USPTO in First Solar’s patent disputes with these companies regarding TOPCon technology (see USPTO Rejects IPRs Against First Solar’s TOPCon Patents).
Legal disputes around the current industry workhorse TOPCon technology are widespread, influencing business decisions. For example, some companies in the US are choosing older PERC technology to avoid costly, lengthy patent conflicts linked to TOPCon, which continue to grow.
In March 2026, the USITC opened a Section 337 probe into TOPCon solar imports, based on a complaint by First Solar, naming 47 respondents across the US, China, India, Vietnam, Japan, and Germany. It could potentially restrict the import and sale of TOPCon products in the US (see First Solar Complaint Prompts USITC Section 337 Probe).