DCT

4:25-cv-00532

Shanghai Jinko Green Energy Enterprises Management Co Ltd v. Waaree Solar Americas Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 4:25-cv-00532, S.D. Tex., 02/07/2025
  • Venue Allegations: Venue is alleged to be proper in the Southern District of Texas because Defendant Waaree Solar Americas Inc. is incorporated in Texas, has a regular and established place of business in the district, and allegedly sells the accused products in the district. Venue over the foreign parent, Waaree Energies Limited, is asserted based on it being a foreign company.
  • Core Dispute: Plaintiff alleges that Defendant’s N-Type TOPCon solar modules infringe a patent related to the specific micro-level surface structures of high-efficiency solar cells.
  • Technical Context: The lawsuit concerns Tunnel Oxide Passivated Contact (TOPCon) solar cell technology, a key area of innovation for increasing the conversion efficiency of photovoltaic panels.
  • Key Procedural History: No prior litigation, licensing history, or other procedural events are mentioned in the complaint.

Case Timeline

Date Event
2021-08-04 ’136 Patent Priority Date
2023-11-21 ’136 Patent Issue Date
2023-12-22 Waaree announces it has supplied over 4 GW of modules to the U.S.
2024-09-11 Waaree displays TOPCON solar panels at Re+24 conference
2025-02-07 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,824,136 - "Solar cell, manufacturing method thereof, and photovoltaic module"

  • Patent Identification: U.S. Patent No. 11,824,136, issued November 21, 2023.

The Invention Explained

  • Problem Addressed: In the manufacturing of N-type TOPCon solar cells, certain processes can result in a polished rear surface that is too flat. The patent suggests this flat structure may "directly affect the manufacturing of the tunnel oxide layer and the polycrystalline silicon layer," which in turn could negatively impact the cell's passivation performance and conversion efficiency (’136 Patent, col. 1:31-38).
  • The Patented Solution: The invention proposes a solar cell with distinct surface textures on its front and rear sides. The front (light-receiving) surface has a conventional "pyramid-shaped microstructure," while the rear surface has a novel "non-pyramid-shaped microstructure" composed of two or more "partially stacked" substructures (’136 Patent, col. 2:48-59; Fig. 3). This dual-texture design is intended to improve open-circuit voltage, reduce electrical resistance, and ultimately enhance the solar cell's overall efficiency (’136 Patent, col. 2:42-47).
  • Technical Importance: By creating specific, engineered textures on both surfaces of the substrate, the invention aims to optimize both light capture and the electrical properties of the passivated contact, a critical interface in advanced solar cells.

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶31).
  • The essential elements of independent claim 1 include:
    • A semiconductor substrate with two different surface textures.
    • A rear surface having a "first texture structure" that is "non-pyramid-shaped," includes "two or more first substructures at least partially stacked on one another," and has specific dimensional limitations (e.g., top surface of the outermost substructure is a polygonal plane with a size ≤ 45 µm).
    • A front surface having a "second texture structure" that is "pyramid-shaped" with a specific height limitation (≤ 5 µm).
    • A series of specific layers deposited on these textured surfaces: a first passivation layer on the front, and a tunnel oxide layer, a doped conductive layer, and a second passivation layer on the rear.
  • The complaint does not explicitly reserve the right to assert dependent claims but notes infringement of "one or more claims" (Compl. ¶30).

III. The Accused Instrumentality

Product Identification

  • The accused products are Waaree’s "TOPCON N-type solar module series," including a detailed list of model numbers such as the BiN-03, BiN-02, and BiN-17 series, among others (Compl. ¶23).

Functionality and Market Context

  • The accused products are high-efficiency solar panels based on "N-type TOPCon" technology, the same field as the asserted patent (Compl. ¶10). The complaint cites Waaree's own press releases and marketing materials to allege a "major presence in the U.S. solar market," including supplying over 4 GW of modules to U.S. customers by the end of 2023 and securing a multi-year, 1.5 GW supply contract for projects in the U.S. (Compl. ¶¶25-26). The complaint includes a product specification sheet for the BiN-03 series, which identifies the product as a "G12 N-type TOPCon Bifacial" solar panel (Compl. p.9).

IV. Analysis of Infringement Allegations

The complaint alleges that the accused products meet every limitation of at least claim 1 of the ’136 patent and incorporates by reference a claim chart in an unattached exhibit (Compl. ¶31). As the claim chart exhibit is not provided with the complaint, a detailed element-by-element analysis is not possible. The complaint’s infringement theory rests on the allegation that Waaree's TOPCON N-type solar panels possess the specific layered structure and dual-surface textures recited in the asserted claims.

A product specification sheet for the accused BiN-03 series is included as a visual in the complaint, providing mechanical and electrical characteristics for the solar module (Compl. p.9, Design Specifications). However, this high-level datasheet does not provide the microscopic structural details necessary to confirm or deny the presence of the claimed "pyramid-shaped" or "non-pyramid-shaped" microstructures.

Identified Points of Contention

  • Technical Questions: A primary factual dispute will concern the physical structure of the accused solar cells at the micro- and nano-scale. Discovery will likely focus on imaging and analysis of the accused cells to determine if their rear surfaces feature a "non-pyramid-shaped microstructure" with "partially stacked" substructures, and if the front surfaces have a "pyramid-shaped microstructure" meeting the specific dimensional limitations required by claim 1.
  • Scope Questions: The case may raise questions about the scope of the claim language itself. For example, the parties may dispute what range of physical forms constitutes a "non-pyramid-shaped microstructure" or a "polygonal plane" in the context of solar cell manufacturing.

V. Key Claim Terms for Construction

  • Term: "non-pyramid-shaped microstructure"

    • Context and Importance: This term is central to distinguishing the invention's rear surface from the front surface and potentially from prior art. The patent contrasts this structure (Fig. 3) with the explicitly "pyramid-shaped microstructure" (Fig. 2) on the front. The infringement analysis will depend entirely on whether the accused products' rear surface texture falls within the definition of this term.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The claim itself does not limit the term to a single configuration, only that it is "non-pyramid-shaped." This could be argued to encompass any surface texture that is not a regular pyramid.
      • Evidence for a Narrower Interpretation: The specification describes this structure as presenting a "substantially 'step' profile" and shows it as comprising stacked, polygonal layers (’136 Patent, col. 8:48-50; Fig. 3). A defendant may argue the term should be limited to such "step-like" or terraced structures.

  • Term: "at least partially stacked on one another"

    • Context and Importance: This phrase defines the required relationship between the "substructures" on the rear surface. Practitioners may focus on this term because its interpretation will determine whether a variety of multi-featured but not perfectly layered surfaces meet the limitation.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The term "partially stacked" could be interpreted broadly to include any arrangement where substructures overlap vertically, even if they are not perfectly aligned or concentric.
      • Evidence for a Narrower Interpretation: Figures 4a and 4b depict discrete, relatively flat layers overlapping. A party could argue the term requires distinct, semi-planar substructures to be layered, not merely a continuous but irregular surface.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Defendants "understand, intend, and encourage" the use of the accused solar panels in the United States, knowing they infringe (’136 Patent, ¶33). It also alleges contributory infringement, asserting the accused panels are a "material part of the invention" and are not staple articles of commerce with substantial non-infringing uses (’136 Patent, ¶34).
  • Willful Infringement: Willfulness is alleged based on both pre- and post-suit knowledge. The complaint alleges pre-suit knowledge on the belief that Waaree, as an "active competitor," would have investigated Jinko’s patent portfolio (’136 Patent, ¶28). Post-suit knowledge is based on the filing of the complaint itself (’136 Patent, ¶29).

VII. Analyst’s Conclusion: Key Questions for the Case

  1. A central issue will be one of structural identity: does the physical microstructure of Waaree's N-Type TOPCon solar cells, particularly on the rear surface, actually embody the specific "non-pyramid-shaped," "partially stacked" texture with the precise dimensional constraints required by the '136 patent claims?
  2. The case will also turn on a question of definitional interpretation: how broadly will the court construe key claim terms like "non-pyramid-shaped microstructure" and "at least partially stacked"? The outcome will depend on whether the patent's specific embodiments are read as merely exemplary or as limitations on the scope of the claims.
  3. A key evidentiary question will concern pre-suit knowledge: what evidence can Jinko provide to support its allegation that Waaree, as a competitor, knew of the ’136 patent and its applicability to Waaree's products before the lawsuit was filed, which is the basis for the pre-suit willfulness claim?