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

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Shanghai Jinko Green Energy Enterprise Management Co., Ltd. and Zhejiang Jinko Solar Co., Ltd. (China)
  • Defendant: Waaree Solar Americas Inc. (Texas) and Waaree Energies Limited (India)
  • Plaintiff's Counsel: Foley & Lardner LLP
• Case Identification: 4:25-cv-532, S.D. Tex., 06/10/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant Waaree Solar Americas Inc. is incorporated in Texas and has a regular and established place of business in the district. Venue over Waaree Energies Limited, a foreign entity, is alleged to be proper in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant's TOPCON N-type solar modules infringe a patent related to the specific micro-structural design of solar cells.
• Technical Context: The technology at issue involves high-efficiency N-type TOPCon (Tunnel Oxide Passivated Contact) solar cells, a leading technology in the modern photovoltaic industry where incremental improvements in cell structure can yield significant performance and commercial advantages.
• Key Procedural History: The complaint alleges Defendant had knowledge of the asserted patent and its infringement since at least December 6, 2024, the date Plaintiff filed a lawsuit asserting the same patent against other defendants in the Northern District of California, one of whom is alleged to be a supplier to Defendant.

Case Timeline

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

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

Issued: November 21, 2023

The Invention Explained

• Problem Addressed: The patent's background describes challenges in manufacturing N-type TOPCon solar cells, noting that the conventional process of polishing the rear surface of the silicon wafer results in a flat structure that can negatively affect the performance of subsequently applied layers (the tunnel oxide and polycrystalline silicon layers), thereby degrading the cell's overall passivation and conversion efficiency '136 Patent, col. 1:21-38
• The Patented Solution: The invention proposes a solar cell with distinct textures on its front and rear surfaces. While the front (light-receiving) surface has a conventional pyramid-shaped texture for light trapping, the rear surface is engineered with a novel "non-pyramid-shaped microstructure" composed of two or more "partially stacked" substructures '136 Patent, abstract '136 Patent, col. 2:48-58 This specific rear surface topography, depicted as a "step" profile in the patent's figures, is intended to improve the uniformity and performance of the critical tunnel oxide layer formed upon it '136 Patent, Fig. 3 '136 Patent, col. 8:19-26
• Technical Importance: This design aims to optimize the complex interplay between surface morphology and thin-film deposition in advanced solar cells, addressing a specific manufacturing challenge to enhance open-circuit voltage and overall cell efficiency '136 Patent, col. 2:42-47

Key Claims at a Glance

• The complaint asserts infringement of at least independent claim 1 Compl. ¶31
• The essential elements of Claim 1 include:
  • A semiconductor substrate with two distinct surface textures.
  • A rear surface having a "first texture structure" that is a "non-pyramid-shaped microstructure" and includes "two or more first substructures at least partially stacked on one another," where the top surface of the substructure is a polygonal plane and has a size of 45 µm or less.
  • A front surface having a "second texture structure" that includes a "pyramid-shaped microstructure" with a height of 5 µm or less.
  • A first passivation layer on the front surface's texture structure.
  • A tunnel oxide layer on the rear surface's texture structure.
  • A doped conductive layer on the tunnel oxide layer.
  • A second passivation layer on the doped conductive layer.
• The complaint does not explicitly reserve the right to assert dependent claims but states 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 numerous specific models such as BiN-03, BiN-02, BiN-17, and BiN-08 series panels Compl. ¶23

Functionality and Market Context

The accused products are solar modules used in residential, commercial, and utility-scale projects in the United States Compl. ¶10 The complaint alleges Defendant is a major supplier to the U.S. market, having supplied over 4 GW of modules by December 2023 and securing a 1.5 GW supply contract with Acciona Energia for projects in Texas and other states Compl. ¶25 Compl. ¶26 One of the complaint's visuals is a map from Defendant's materials showing project locations across the United States, which Plaintiff presents as evidence of Defendant's substantial business in the country Compl. p. 4 A product specification sheet for the BiN-03 series identifies the cell technology as "G12 N-type TOPCon Bifacial" Compl. p. 9

IV. Analysis of Infringement Allegations

The complaint alleges that WAAREE's TOPCON N-type solar modules meet every limitation of claim 1 of the '136 Patent Compl. ¶31 The complaint incorporates by reference an accompanying claim chart (Exhibit 2); however, this exhibit was not included in the provided court filing Compl. ¶31 The body of the complaint does not provide a detailed, element-by-element breakdown of the alleged infringement. Therefore, the complaint does not provide sufficient detail for a tabular analysis of the infringement allegations.

Identified Points of Contention

• Scope Questions: The dispute may center on whether the term "non-pyramid-shaped microstructure" comprising "two or more first substructures at least partially stacked on one another" can be construed to read on the specific rear-surface texture of the accused solar cells. The litigation will explore if the accused products possess this specific, multi-part structural arrangement or a different configuration.
• Technical Questions: A central evidentiary question will be whether the physical structure of the accused solar cells matches the claimed invention. This will likely require technical analysis, potentially through electron microscopy, to verify the presence, shape, and dimensions of the microstructures on both the front and rear surfaces of the semiconductor substrate, as required by the claim's specific limitations.

V. Key Claim Terms for Construction

• The Term: "non-pyramid-shaped microstructure"

• Context and Importance: This term defines the core novel feature of the claimed invention's rear surface, distinguishing it from both polished flat surfaces and conventional textured surfaces. The case's outcome may depend heavily on whether the accused products' rear surface falls within the scope of this term.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent primarily defines the term by what it is not-a pyramid shape-and provides a non-limiting example of a substantially "step" profile '136 Patent, col. 8:48-50 This may support an interpretation that covers any rear texture that is not a pyramid but meets the other claim limitations.
  • Evidence for a Narrower Interpretation: The patent repeatedly emphasizes that this microstructure includes "two or more first substructures at least partially stacked on one another" '136 Patent, abstract '136 Patent, claim 1 A party might argue the term should be limited to the specific "stair"-like stacked structures depicted in the patent's figures and electron micrograph '136 Patent, Fig. 3 '136 Patent, Fig. 4a

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

• Context and Importance: This phrase further qualifies the novel rear surface structure. The definition of "stacked" will be critical to determining if the accused cell's structure, which may involve various forms of layering or texturing from manufacturing, meets this limitation.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The schematic diagrams in Figures 4a and 4b illustrate a general vertical arrangement of overlapping planes, which could support a broad definition of "stacked" as simply layered or overlapping '136 Patent, Fig. 4a '136 Patent, Fig. 4b
  • Evidence for a Narrower Interpretation: The electron microscope image in Figure 3, which the patent presents as an embodiment, shows distinct, plate-like structures layered on top of each other '136 Patent, Fig. 3 This could support an argument that "stacked" requires the presence of discrete, overlapping substructures rather than a more continuous or undulating texture.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendants encourage the use of the accused solar panels in the United States knowing they infringe Compl. ¶33 It also alleges contributory infringement, asserting the panels are a material part of the invention and not a staple article of commerce Compl. ¶34
• Willful Infringement: Willfulness is alleged based on knowledge of the '136 Patent and the alleged infringement Compl. ¶35 The complaint asserts this knowledge arises from Defendant's position as an active competitor that would monitor Plaintiff's patent portfolio, and more specifically from at least December 6, 2024, when Plaintiff sued other parties, including an alleged supplier to Defendant, for infringement of the same patent Compl. ¶28

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

• A core issue will be one of definitional scope: can the claim term "non-pyramid-shaped microstructure" with "partially stacked" substructures, which appears to describe a novel rear-surface topography, be construed to cover the architecture of Defendant's mass-produced TOPCon solar cells, or is it limited to the specific "stair-step" embodiments detailed in the patent?
• A key evidentiary question will be one of structural identity: what will a microscopic examination of the accused solar cells reveal? The case will likely depend on highly technical evidence comparing the physical morphology and dimensions of the accused products' front and rear surfaces against the specific numeric and structural limitations recited in claim 1.
• A third question will relate to knowledge and willfulness: can Plaintiff establish that Defendant had knowledge of its alleged infringement as of December 2024 based on a separate lawsuit filed against third parties, including an alleged component supplier? The outcome may depend on evidence of the commercial relationship and communications between Defendant and the supplier regarding Plaintiff's patent assertion.