First Solar widens its TOPCon patent campaign to JA Solar and a Corning unit

The story

First Solar has expanded its patent-enforcement campaign against makers of high-efficiency crystalline-silicon solar cells, filing a federal lawsuit that names four JA Solar companies and American Panel Solutions, a solar-manufacturing subsidiary of Corning. The complaint alleges that the defendants manufacture, import and sell products made through processes covered by U.S. Patent No. 9,130,074. The allegations have not been adjudicated, and neither JA Solar nor Corning had publicly answered them when the action was announced.

The docket in the U.S. District Court for the District of Delaware shows that First Solar filed the complaint on September 28 and requested a jury trial. The listed defendants are JA Solar Technology, JA Solar International, JA Solar Vietnam, JA Solar Industrial and American Panel Solutions. A notice to the U.S. Patent and Trademark Office identifies the asserted patent, while summonses were issued the following day. First Solar publicly announced the case on October 1.

The patent, titled High-efficiency solar cell structures and methods of manufacture, describes cell architectures and manufacturing steps that use very thin passivating interface layers and conductive films around a crystalline-silicon wafer. Those structures are associated with tunnel oxide passivated contact, or TOPCon, cells. The approach reduces charge-carrier recombination at contacts, helping cells convert a larger share of incoming light into electricity while retaining a manufacturing path compatible with silicon technology.

First Solar obtained the portfolio through its 2013 acquisition of TetraSun. Patent records show U.S. Patent No. 9,130,074 was granted in 2015, with TetraSun's inventors named on the document and First Solar later recorded as an assignee. The company says related rights exist in multiple jurisdictions and extend into 2030 and beyond. A granted patent, however, does not by itself establish that a specific product infringes; the court must compare properly interpreted claims with the accused manufacturing processes and products.

The new case is commercially notable because TOPCon is not a niche laboratory design. It has become one of the solar industry's most widely adopted crystalline-silicon cell formats, prized for higher conversion efficiency than older passivated-emitter designs. JA Solar is a major global module supplier, while American Panel Solutions owns the Arizona module-assembly facility that Corning acquired from JA Solar in 2025. First Solar itself primarily produces cadmium-telluride thin-film modules, so the asserted portfolio reaches into a different branch of photovoltaic manufacturing from its core product line.

Reuters reported that the lawsuit follows First Solar's decision in September to withdraw a Section 337 complaint from the U.S. International Trade Commission and concentrate on federal-court litigation. The company is already pursuing related cases involving affiliates of Canadian Solar, JinkoSolar, T1 Energy and Trina Solar. PV Tech separately reported that the latest complaint is built around the same '074 patent and that First Solar began publicly investigating potential infringement by major manufacturers in 2024.

Moving from the trade commission to district court changes the available pathway but not the unresolved technical questions. The ITC can block infringing imports but does not award damages. Federal court can assess damages and, in appropriate circumstances, issue injunctions, yet the process may take longer and gives defendants opportunities to challenge claim construction, infringement and validity. First Solar has not disclosed a requested damages figure in its announcement.

INNOVOX analysis: the case highlights how intellectual property can shape clean-energy supply chains after a technology becomes standard practice. Manufacturing scale, factory location, tariffs and material costs normally dominate solar economics. Patent exposure adds another layer: a process may be technically mature and broadly deployed while the legal right to use particular steps remains contested. Because solar margins are often thin, even modest licensing costs or import uncertainty can affect supplier selection and investment decisions.

The central issue is not whether TOPCon is generally useful or whether First Solar owns every form of the technology. It is whether the defendants' accused methods meet the limitations of specific patent claims that survive any validity challenge. Technical evidence about layer composition, thickness, doping, thermal treatment and where relevant steps occur in a cross-border production chain is likely to matter more than broad labels attached to finished modules.

What to watch next is the defendants' formal response. They may deny infringement, argue that the patent claims do not cover their processes, attack validity, seek a stay or pursue administrative review. A settlement or license could clarify the portfolio's commercial value without producing a definitive court interpretation. A contested ruling, by contrast, could influence several parallel cases and help determine whether First Solar's acquired TOPCon rights become a recurring cost for manufacturers selling into the United States.

INNOVOX analysis

This case is bigger than a bilateral solar-industry quarrel because TOPCon has become a mainstream route to higher-efficiency crystalline-silicon cells. If First Solar establishes that widely used production flows fall within its claims, licensing and litigation costs could become another variable in where modules are manufactured and sold. If the defendants narrow or invalidate the asserted claims, the result could limit the leverage of First Solar's portfolio across its other cases.

What to watch

Watch the defendants' answers, any challenge to the patent's validity or claim scope, and whether First Solar asks for an injunction, damages or both. Also watch for consolidation with related Delaware cases, licensing settlements, and evidence connecting particular production steps or imported products to the asserted claims.