U.S. Patent Trial and Appeal Board Invalidates Trina's TOPCon Patents

Canadian Solar (NASDAQ: CSIQ) said the U.S. Patent Trial and Appeal Board issued Final Written Decisions on April 17, 2026 invalidating all claims of two TOPCon solar cell patents previously asserted by Trina against certain Canadian Solar subsidiaries.

Rhea-AI Summary

Canadian Solar (NASDAQ: CSIQ) said the U.S. Patent Trial and Appeal Board issued Final Written Decisions on April 17, 2026 invalidating all claims of two TOPCon solar cell patents previously asserted by Trina against certain Canadian Solar subsidiaries.

The company framed the rulings as a validation of its IP defenses and reiterated commitment to independent R&D and protecting its global intellectual property.

Positive

• PTAB invalidated all claims of two TOPCon patents (Final Written Decisions, Apr 17, 2026)
• Removes asserted patent risk against certain Canadian Solar subsidiaries

Negative

• None.

Argus Apr 17 session

+1.69% close to close Open Argus

Details

News Market Reaction – CSIQ

On Apr 17, the day this news came out, CSIQ closed 1.69% above the previous close.

Data tracked by StockTitan Argus for the Apr 17 session.

Market Context

This announcement highlights a favorable PTAB outcome for Canadian Solar, with all claims of two TOP...

Analysis

This announcement highlights a favorable PTAB outcome for Canadian Solar, with all claims of two TOPCon patents asserted by a competitor invalidated. It adds to a recent stream of operational wins in storage and project development, while the stock still trades below the 200-day MA of $17.32 and well under the 52-week high of $34.59. Investors may watch how future legal, earnings, and large-contract updates interact with broader solar sector volatility.

Historical Context

5 past events · Latest: Apr 10

5 events

1. Apr 10

   Annual report filing

   24h Move

   +0.7%

   Form 20-F filing detailing business segments and global risk factors.

2. Mar 31

   Storage contract win

   24h Move

   +6.7%

   e-STORAGE to deliver 420 MWh AC battery systems for Drax in the UK.

3. Mar 19

   Earnings release

   24h Move

   -26.9%

   Q4 2025 results with $1.2B revenue and $86M GAAP net loss plus guidance.

4. Mar 17

   Large U.S. storage deal

   24h Move

   +1.9%

   500 MW / 2,493 MWh DC storage agreement supporting U.S. data center demand.

5. Feb 24

   Asset sale

   24h Move

   +3.2%

   Sale of 200 MWh Fort Duncan storage facility with revenue in Q1 2026.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

patent trial and appeal board, u.s. patent and trademark office, tunnel oxide passivated contact, intellectual property rights

4 terms

patent trial and appeal board regulatory

"the Patent Trial and Appeal Board ("PTAB") of the U.S. Patent and Trademark Office"

The Patent Trial and Appeal Board is an administrative body that reviews and decides challenges to the validity of issued patents and hears appeals of patent office decisions. For investors, its rulings can make or break a company’s exclusive rights to a product or technology—similar to a referee overturning a game-winning call—affecting future revenue, legal costs, and the value of related securities.

u.s. patent and trademark office regulatory

"PTAB") of the U.S. Patent and Trademark Office ("USPTO") has issued Final"

The U.S. Patent and Trademark Office is the federal agency that reviews and grants patents and registers trademarks, like a land office that issues official property deeds for inventions and brand names. For investors, its decisions matter because patents and trademarks can create legal protection and exclusive market rights that boost a company’s revenue potential, reduce competition, and change risk and valuation dynamics.

tunnel oxide passivated contact technical

"Final Written Decisions invalidating all claims of two TOPCon (Tunnel Oxide Passivated Contact)"

A tunnel oxide passivated contact is a specialized interface in a solar cell where an ultra-thin insulating layer and a carefully designed metal or doped silicon layer work together to let electrical charge flow out while protecting the silicon surface from losses. Think of it like a guarded gate that lets people through but prevents crowding and damage; for investors, it matters because it boosts panel efficiency and long-term performance, potentially improving energy output and reducing cost per watt.

intellectual property rights regulatory

"we respect and value the intellectual property rights of all companies as we do our own"

Legal protections that give a company exclusive control over creations like inventions, brand names, designs, formulas, software and creative works, similar to owning the lock and key to a recipe or product design. For investors, these rights matter because they can create durable revenue streams, reduce competition and justify higher company value, while weak or contested rights increase the risk of lost sales and costly legal disputes.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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KITCHENER, ON, April 17, 2026 /PRNewswire/ -- Canadian Solar Inc. (the "Company" or "Canadian Solar") (NASDAQ: CSIQ) today announced that the Patent Trial and Appeal Board ("PTAB") of the U.S. Patent and Trademark Office ("USPTO") has issued Final Written Decisions invalidating all claims of two TOPCon (Tunnel Oxide Passivated Contact) solar cell patents. These patents were previously asserted by Trina Solar Co., Ltd. ("Trina") against certain subsidiaries of Canadian Solar.

This ruling reinforces Canadian Solar's long-standing, successful track record of managing international disputes. As a global leader in solar and energy storage technology innovation, the Company has always prioritized organic R&D and has established a comprehensive and effective system to manage, commercialize, and defend its global IP rights which cover all key aspects of the industry value chain.

Colin Parkin, President of Canadian Solar and President of e-STORAGE, commented, "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."

About Canadian Solar Inc.
Canadian Solar is one of the world's largest solar technology and renewable energy companies. Founded in 2001 and headquartered in Kitchener, Ontario, the Company is a leading manufacturer of solar photovoltaic modules; provider of solar energy and battery energy storage solutions; and developer, owner, and operator of utility-scale solar power and battery energy storage projects. Over the past 25 years, Canadian Solar has successfully delivered over 174 GW of premium-quality, solar photovoltaic modules to customers across the world. Through its subsidiary e-STORAGE, Canadian Solar has shipped over 18 GWh of battery energy storage solutions to global markets as of December 31, 2025, boasting a $3.6 billion contracted backlog as of March 13, 2026. Since entering the project development business in 2010, Canadian Solar has developed, built, and connected approximately 12 GWp of solar power projects and 6.2 GWh of battery energy storage projects globally. Its geographically diversified project development pipeline includes 24 GWp of solar and 83 GWh of battery energy storage capacity in various stages of development. Canadian Solar is one of the most bankable companies in the solar and renewable energy industry, having been publicly listed on the NASDAQ since 2006. For additional information about the Company, follow Canadian Solar on LinkedIn or visit www.canadiansolar.com.

Safe Harbor/Forward-Looking Statements

Certain statements in this press release, including those regarding the Company's expected future shipment volumes, revenues, gross margins, and project sales are forward-looking statements that involve a number of risks and uncertainties that could cause actual results to differ materially. These statements are made under the "Safe Harbor" provisions of the U.S. Private Securities Litigation Reform Act of 1995. In some cases, you can identify forward-looking statements by such terms as "may", "will", "expect", "anticipate", "future", "ongoing", "continue", "intend", "plan", "potential", "prospect", "guidance", "believe", "estimate", "is/are likely to" or similar expressions, the negative of these terms, or other comparable terminology. These forward-looking statements include, among other things, our expectations regarding global electricity demand and the adoption of solar and battery energy storage technologies; our growth strategies, future business performance, and financial condition; our transition to a long-term owner and operator of clean energy assets and expansion of project pipelines; our ability to monetize project portfolios, manage supply chain fluctuations, and respond to economic factors such as inflation and interest rates; our outlook on government incentives, trade measures, regulatory developments, and geopolitical risks; our expectations for project timelines, costs, and returns; competitive dynamics in solar and storage markets; our ability to execute supply chain, manufacturing, and operational initiatives; access to capital, debt obligations, and covenant compliance; relationships with key suppliers and customers; technological advancement and product quality; and risks related to intellectual property, litigation, and compliance with environmental and sustainability regulations. Other risks were described in the Company's filings with the Securities and Exchange Commission, including its annual report on Form 20-F filed on April 10, 2026. Although the Company believes that the expectations reflected in the forward-looking statements are reasonable, it cannot guarantee future results, level of activity, performance, or achievements. Investors should not place undue reliance on these forward-looking statements. All information provided in this press release is as of today's date, unless otherwise stated, and Canadian Solar undertakes no duty to update such information, except as required under applicable law.

Canadian Solar Inc. Investor Relations Contact

Wina Huang
Investor Relations
Canadian Solar Inc.
investor@canadiansolar.com

View original content:https://www.prnewswire.com/news-releases/us-patent-trial-and-appeal-board-invalidates-trinas-topcon-patents-302745689.html

SOURCE Canadian Solar Inc.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did Canadian Solar announce about Trina's TOPCon patents on April 17, 2026 (CSIQ)?

The PTAB issued Final Written Decisions invalidating all claims of two TOPCon patents, ending those asserted claims. According to the company, the rulings were issued on April 17, 2026 and relate to patents previously asserted by Trina against Canadian Solar subsidiaries.

Does the PTAB decision remove litigation risk for Canadian Solar (CSIQ)?

Yes, the invalidation eliminates the asserted patent claims tied to those two TOPCon patents. According to the company, the Final Written Decisions invalidate all claims, reducing the specific patent risk raised by Trina against Canadian Solar subsidiaries.

How did Canadian Solar describe its IP strategy after the April 17, 2026 PTAB ruling (CSIQ)?

Canadian Solar emphasized commitment to organic, independent R&D and defending global IP rights. According to the company, it maintains a comprehensive system to manage, commercialize, and defend intellectual property across the industry value chain.

Which technology was at issue in the PTAB Final Written Decisions involving CSIQ and Trina?

The disputes concerned TOPCon (Tunnel Oxide Passivated Contact) solar cell patents that Trina had asserted. According to the company, the PTAB invalidated all claims of the two TOPCon patents on April 17, 2026.

What immediate impact did Canadian Solar highlight after the PTAB ruling on April 17, 2026 (CSIQ)?

Canadian Solar highlighted the ruling as reinforcing its track record managing international disputes and defending IP. According to the company, the decisions validate its approach to R&D and its system for protecting proprietary technologies globally.