First Solar, Inc. v. JinkoSolar

First Solar, Inc., an American publicly traded manufacturer known for its rigid thin-film cadmium telluride (CdTe) solar panels, initiated a patent infringement lawsuit against JinkoSolar Holding Co., Ltd., a Chinese global leader and one of the world's largest manufacturers of crystalline silicon solar modules. The litigation centers on JinkoSolar's alleged infringement through its N-type Tunnel Oxide Passivated Contact (TOPCon) solar modules, such as the "Tiger Neo 66HL4M-BDV," which are marketed for their high efficiency. First Solar alleges that JinkoSolar manufactures these products overseas using a process that infringes First Solar's patent and then unlawfully imports and sells the resulting cells and modules in the United States.

The patent at issue is US Patent 9,130,074, titled "High-efficiency solar cell structures and methods of manufacture." This patent describes solar cell structures and fabrication methods generally involving a central substrate, various conductive, antireflection, and passivation layers, and electrodes. It particularly details multifunctional layers providing combined functions of passivation, transparency, and conductivity for vertical carrier flow, and covers methods of manufacturing TOPCon crystalline silicon photovoltaic (PV) solar cells. First Solar acquired this patent, along with related international counterparts, through its 2013 acquisition of TetraSun, Inc. The lawsuit was filed on February 25, 2025, in the United States District Court for the District of Delaware (Case Number 1:2025cv00223) and is presided over by Judge Jennifer L. Hall. Delaware is a prominent venue for patent litigation due to the high number of corporations incorporated there, which, following the TC Heartland Supreme Court decision, often makes it a mandatory venue. The court also boasts a highly experienced judiciary conversant with complex patent law, offering predictability in such cases.

This case is notable for its involvement in a broader pattern of intellectual property disputes within the rapidly advancing solar industry, particularly concerning TOPCon technology, which is emerging as a dominant cell architecture. Adding to its significance, JinkoSolar's Inter Partes Review (IPR) petition challenging the validity of US Patent 9,130,074 was denied by the USPTO Director in January 2026, allowing the patent to remain intact for the ongoing infringement litigation. This dispute extends beyond the district court, as First Solar also initiated a Section 337 investigation at the U.S. International Trade Commission (ITC) in March 2026, seeking to prevent the importation of infringing TOPCon solar cells and modules into the U.S., naming JinkoSolar and numerous other manufacturers as respondents. While the U.S. patent remains active, a Chinese counterpart of the same patent was recently invalidated by the China National Intellectual Property Administration (CNIPA) in May 2026, a development that could influence arguments in other international proceedings but does not impact the U.S. litigation.

The patent infringement litigation between First Solar, Inc. and JinkoSolar in the U.S. District Court for the District of Delaware, Case No. 1:25-cv-00223, concerns U.S. Patent No. 9,130,074, related to Tunnel Oxide Passivated Contact (TOPCon) solar technology.

Here's a chronological summary of the key legal developments:

• 2024-09-26: Pre-suit Notice of Infringement. First Solar sent a notice letter to JinkoSolar, alleging infringement of its TOPCon technology patents. This pre-suit knowledge forms the basis for a claim of willful infringement in the subsequent lawsuit.
• 2025-02-25: Complaint Filed. First Solar, Inc. initiated the patent infringement lawsuit against JinkoSolar Holding Co., Ltd. and several related entities in the U.S. District Court for the District of Delaware. The complaint alleges that JinkoSolar's TOPCon solar cells infringe First Solar's manufacturing method patent, and that these cells and modules are unlawfully imported and sold in the U.S. The patent at issue, U.S. Patent No. 9,130,074, was acquired by First Solar through its 2013 acquisition of TetraSun Inc.
• 2025-06-27: Defendants' Answer, Affirmative Defenses, and Counterclaims. JinkoSolar filed its answer, affirmative defenses, and counterclaims to First Solar's complaint for patent infringement.
• 2025-07-17 / 2025-07-18: IPR Petition Filed. JinkoSolar Co., Ltd. filed an Inter Partes Review (IPR) petition (IPR2025-01130) with the Patent Trial and Appeal Board (PTAB) of the USPTO, challenging claims 1-8 of U.S. Patent No. 9,130,074.
• 2025-08-14: Stipulation and Order to Amend Scheduling Order. A stipulation and order to amend the scheduling order was filed in the district court case.
• 2025-10-30: Patent Owner Preliminary Response. First Solar filed its preliminary response in the IPR proceeding.
• 2025-11-19: IPR Petition Denied. The Director of the USPTO issued a discretionary denial of JinkoSolar's IPR petition (IPR2025-01130). The denial was based on discretionary grounds, consistent with the USPTO's "Settled Expectations" doctrine, which considers the longer a patent has been in force, the stronger the patent owner's expectations should be. The patent at issue was issued in 2015. JinkoSolar expressed disagreement with the discretionary denial, stating confidence that a merits-based review in federal court would find the patent invalid.
• 2026-01-20: Public Announcement of IPR Denial. First Solar publicly announced that the USPTO Director had denied three separate IPR applications, including JinkoSolar's petition against U.S. Patent No. 9,130,074. The company noted that these denials allow the infringement litigation in the District of Delaware to continue.

The case in the U.S. District Court for the District of Delaware remains ongoing following the denial of the IPR petition. No information on claim construction, significant discovery milestones, trial events, verdict, or post-trial motions has been publicly reported as of May 25, 2026. The denial of the IPR means the validity challenge for patent 9,130,074 will proceed in the district court.

Plaintiff First Solar, Inc. is represented by a combination of national and local counsel in this patent infringement case. Jason Dymbort serves as in-house counsel for First Solar.

The following attorneys have been identified as counsel of record for First Solar, Inc.:

Cravath, Swaine & Moore LLP

• Firm Location: New York, NY (Primary office for patent litigation)
• Role: Likely lead counsel
• Attorneys: (Specific attorneys from Cravath, Swaine & Moore LLP who have entered appearances for First Solar in this case could not be identified through the provided search results. The firm is listed generally as counsel.)
• Relevant Experience: Cravath, Swaine & Moore is a highly-regarded firm with extensive experience in high-stakes intellectual property and patent litigation.

Morris, Nichols, Arsht & Tunnell LLP

• Firm Location: Wilmington, DE
• Role: Local counsel
• Attorneys:
  • Brian P. Egan
    • Role: Local Counsel
    • Firm: Morris, Nichols, Arsht & Tunnell LLP, Wilmington, DE
    • Relevant Experience: Brian P. Egan is a partner at Morris Nichols who focuses on intellectual property litigation, particularly in patent infringement cases in the District of Delaware.
  • Megan E. Dellinger
    • Role: Local Counsel
    • Firm: Morris, Nichols, Arsht & Tunnell LLP, Wilmington, DE
    • Relevant Experience: Megan E. Dellinger is an attorney at Morris Nichols with experience in patent litigation and other complex commercial disputes in Delaware's federal and state courts.

First Solar, Inc. (In-House Counsel)

• Jason Dymbort
  • Role: Executive Vice President, General Counsel, and Secretary
  • Firm: First Solar, Inc. (In-house)
  • Relevant Experience: Oversees First Solar's legal strategy and has been vocal regarding the company's intent to defend its intellectual property rights, particularly concerning TOPCon technology patents.

Based on the available public information, the specific counsel of record representing JinkoSolar in First Solar, Inc. v. JinkoSolar (United States District Court for the District of Delaware, Case No. 1:25-cv-00223) could not be definitively identified from the provided search results.

While docket entries confirm that "counsel for Defendants" have made filings in the case (e.g., a stipulation related to an extension of time in March 2025), the names of these attorneys or their firms are not explicitly listed in the summaries.

It is important to note that JinkoSolar has been represented by Perkins Coie attorneys Louise Lu, Miguel Bombach, and Abigail Gardner in a separate patent infringement case where JinkoSolar was the plaintiff in the United States District Court for the Northern District of California. However, this representation is for a different lawsuit and role, not definitively for JinkoSolar as a defendant in the Delaware case brought by First Solar.