SEG Manufacturing Inc. et al. v. Zhejiang Jinko Solar Co Ltd et al.

This Inter Partes Review (IPR) originates from a patent infringement dispute within the competitive solar energy industry, specifically targeting N-type Tunnel Oxide Passivated Contact (TOPCon) solar cell technology. The Petitioners, SEG Manufacturing Inc., New Energy Imports Inc., SEG Solar Inc., PT. SEG Solar Manufaktur Indonesia, and SEG Energy Singapore Pte. Ltd., are entities related to SEG Solar, a U.S.-based manufacturer of photovoltaic (PV) modules headquartered in Houston, Texas, with manufacturing operations in both the U.S. and Indonesia. SEG Solar aims to establish a fully integrated, non-Foreign Entity of Concern (FEOC) compliant supply chain for the U.S. market. The Patent Owners, Zhejiang Jinko Solar Co Ltd and Jinko Green Energy Shanghai Management Co Ltd, are subsidiaries of JinkoSolar Holding Co., Ltd., a globally leading Chinese PV module manufacturer listed on the NYSE, known for its extensive portfolio in solar products, including silicon ingots, wafers, cells, and modules, with a particular focus on N-type TOPCon technology.

The IPR, filed on February 18, 2026, before the Patent Trial and Appeal Board (PTAB) of the USPTO, challenges the validity of US Patent No. 11,824,136. This patent, titled "Solar cell, manufacturing method thereof, and photovoltaic module," describes a solar cell design incorporating specific textured structures and passivation layers to enhance the uniformity and performance of tunnel oxide layers in N-type TOPCon cells, thereby improving their efficiency and stability. The IPR is a defensive measure in response to an underlying patent infringement lawsuit filed by JinkoSolar against SEG Solar and its subsidiaries in the U.S. District Court for the Southern District of Texas (Case No. 4:25-cv-05226). In that district court action, JinkoSolar alleges that SEG's N-type TOPCon solar module series, including specific models like SEG-435-BTE-BG and SEG-495-BTD-BG, infringe the '136 patent.

This case is notable as it highlights the escalating patent litigation in the global solar industry, estimated to be valued at US$175 billion in 2023, particularly concerning advanced N-type TOPCon solar cell technologies. JinkoSolar has demonstrated an aggressive strategy in enforcing its intellectual property, initiating multiple patent infringement lawsuits to protect its leading position in TOPCon technology. For SEG Solar, a successful IPR could invalidate the asserted claims, impacting the ongoing district court litigation and its strategic efforts to expand U.S. domestic manufacturing with compliant supply chains. The outcome of such disputes can have significant implications for market competition and technological development within the rapidly evolving solar energy sector.

The intellectual property dispute involves both a patent infringement lawsuit filed in a U.S. District Court and a parallel Inter Partes Review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB).

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

District Court Litigation: Shanghai Jinko Green Energy Enterprise Management Co Ltd et al v. SEG Solar, Inc. et al. (S.D. Texas, Case No. 4:25-cv-05226)

• 2025-10-31 – Complaint Filed: Zhejiang Jinko Solar Co., Ltd. and Shanghai Jinko Green Energy Enterprise Management Co., Ltd. (collectively, "JinkoSolar") filed a patent infringement lawsuit against SEG Solar, Inc., SEG Manufacturing Inc., New Energy Imports Inc., PT. SEG Solar Manufaktur Indonesia, SEG Energy Singapore Pte. Ltd., and SEG Solar Jiangsu Co., Ltd. (collectively, "SEG entities") in the U.S. District Court for the Southern District of Texas. The complaint alleges infringement of U.S. Patent No. 11,824,136, which covers n-type TOPCon solar cell technology.
• 2026-01-09 – Initial Conference Set: An initial conference was scheduled by video before Magistrate Judge Yvonne Y. Ho.

Parallel PTAB IPR Proceeding: SEG Manufacturing Inc. et al. v. Zhejiang Jinko Solar Co Ltd et al. (PTAB, IPR2026-00230)

• 2026-02-18 – IPR Petition Filed: SEG Manufacturing Inc., New Energy Imports Inc., SEG Solar Inc., PT. SEG Solar Manufaktur Indonesia, and SEG Energy Singapore Pte. Ltd. (the petitioners in the IPR and defendants in the district court case) filed an Inter Partes Review petition challenging U.S. Patent No. 11,824,136B2. The IPR proceeding is currently pending before the PTAB.

Current Posture:

• District Court: The patent infringement lawsuit is in its early stages, with an initial conference held in January 2026. Given the IPR filing, it is possible that the district court case could be stayed pending the outcome of the PTAB's institution decision or final written decision in the IPR.
• PTAB IPR: The IPR is also in its early stages. The PTAB's institution decision, which determines whether to initiate a full review of the patent claims, is typically due within six months of the Patent Owner's preliminary response or one year from the petition filing date. As of May 29, 2026, the IPR is still pending, and an institution decision has not yet been issued.

The plaintiff(s) in IPR2026-00230, SEG Manufacturing Inc. et al., are represented by attorneys from Baker Botts L.L.P..

The counsel of record for the plaintiff(s) are:

• Elizabeth D. Flannery

  • Role: Lead Counsel
  • Firm: Baker Botts L.L.P., Houston, TX
  • Note: Ms. Flannery's practice focuses on intellectual property litigation, including patent litigation before district courts and the PTAB, as well as patent prosecution.

• Douglas M. Kubehl

  • Role: Backup Counsel
  • Firm: Baker Botts L.L.P., Dallas, TX
  • Note: Mr. Kubehl is experienced in patent litigation, particularly within the electrical and computer technologies sectors.

• Chad C. Walters

  • Role: Backup Counsel
  • Firm: Baker Botts L.L.P., Dallas, TX
  • Note: Mr. Walters' practice includes patent and intellectual property litigation, and he has experience with inter partes reviews.

Based on available information regarding JinkoSolar's representation in related patent litigation, particularly concerning U.S. Patent No. 11,824,136B2, the Patent Owners in IPR2026-00230, Zhejiang Jinko Solar Co Ltd and Jinko Green Energy Shanghai Management Co Ltd, are likely represented by attorneys from Perkins Coie LLP.

While a specific "Patent Owner's Mandatory Notices" document for IPR2026-00230 listing their counsel has not been directly located through public web searches, Perkins Coie has consistently represented JinkoSolar in patent infringement lawsuits involving the same patent. For instance, in Shanghai Jinko Green Energy Enterprise Management Co., Ltd. et al v. VSUN Solar USA Inc. et al (N.D. Cal.), which involved U.S. Patent No. 11,824,136, JinkoSolar was represented by counsel from Perkins Coie. It is common for companies to retain the same legal team for both district court litigation and parallel PTAB proceedings concerning the same intellectual property.

The identified counsel of record for the Patent Owners are:

• Louise Lu

  • Role: Lead Counsel (in related district court cases)
  • Firm: Perkins Coie LLP, San Francisco, CA (based on firm's general presence and location of related cases)
  • Note: Ms. Lu is a patent litigation lawyer who has represented JinkoSolar in patent infringement actions concerning its N-type TOPCon solar cell technology.

• Miguel Bombach

  • Role: Backup Counsel (in related district court cases)
  • Firm: Perkins Coie LLP
  • Note: Mr. Bombach has also been involved in representing JinkoSolar in patent disputes related to solar cell technologies.

• Abigail Gardner

  • Role: Backup Counsel (in related district court cases)
  • Firm: Perkins Coie LLP
  • Note: Ms. Gardner is part of the legal team representing JinkoSolar in its efforts to defend its intellectual property in the solar industry.

Further confirmation of their specific roles (lead/backup counsel) in IPR2026-00230 would typically be found in the Patent Owner's Power of Attorney or Mandatory Notices filed with the PTAB.