DCT

3:24-cv-08828

Shanghai Jinko Green Energy Enterprises Management Co Ltd v. Abalance Corp

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

Case Timeline

Date Event
2021-08-04 Priority Date for ’454 and ’136 Patents
2023-02-14 U.S. Patent No. 11,581,454 Issued
2023-11-21 U.S. Patent No. 11,824,136 Issued
2024-12-06 Initial Complaint Filed
2025-05-07 First Amended Complaint Filed

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

U.S. Patent No. 11,581,454 - *"Solar cell, manufacturing method thereof, and photovoltaic module"*

  • Patent Identification: U.S. Patent No. 11,581,454, "Solar cell, manufacturing method thereof, and photovoltaic module," issued February 14, 2023 (’454 Patent).

The Invention Explained

  • Problem Addressed: In the manufacturing of high-efficiency N-type TOPCon solar cells, a chemical polishing process is used on the rear surface of the silicon wafer. The patent notes that this process can result in a flat rear surface, which may negatively affect the performance of subsequent critical layers (the tunnel oxide and polycrystalline silicon layers), thereby limiting the cell's overall conversion efficiency (’454 Patent, col. 1:32-41).
  • The Patented Solution: The invention proposes creating a specific, non-flat texture on the rear surface of the solar cell. This "first texture structure" is described as a "non-pyramid microstructure" composed of two or more "partially stacked" substructures with polygonal top surfaces, where the distance between the stacked layers and the size of the substructures are controlled within specific dimensional ranges (’454 Patent, col. 2:49-62; Fig. 3). By matching this specific rear texture with a conventional pyramid-shaped texture on the front, the invention claims to improve open-circuit voltage and overall efficiency (’454 Patent, col. 1:42-49).
  • Technical Importance: The invention provides a method for texturing the rear surface of a TOPCon solar cell to optimize the interface for the passivated contact layers, addressing a manufacturing challenge that can impact the performance of this advanced solar technology (Compl. ¶15).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶41).
  • Essential elements of Claim 1:
    • A solar cell comprising a semiconductor substrate with a rear surface having a "first texture structure."
    • The first texture structure has a "non-pyramid microstructure" that includes "two or more first substructures at least partially stacked on one another."
    • The top surface of the first substructure is a "polygonal plane."
    • A distance between the top surface of an outermost substructure and an adjacent substructure is less than or equal to 2µm.
    • A one-dimensional size of the top surface of the outermost first substructure is less than or equal to 45 µm, with an average size ranging from 10 µm to 15 µm.
    • The cell includes a tunnel oxide layer on the first texture structure and subsequent doped conductive and passivation layers.
  • The complaint does not explicitly reserve the right to assert dependent claims.

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

  • Patent Identification: U.S. Patent No. 11,824,136, "Solar cell, manufacturing method thereof, and photovoltaic module," issued November 21, 2023 (’136 Patent).

The Invention Explained

  • Problem Addressed: The ’136 Patent is a divisional of the application that led to the ’454 Patent and shares an identical specification. It addresses the same technical problem of optimizing the rear surface of a TOPCon solar cell to improve efficiency (’136 Patent, col. 1:24-40).
  • The Patented Solution: The solution is also the same: creating a specific "non-pyramid microstructure" on the rear surface of the solar cell to be used in combination with a pyramid-shaped texture on the front surface (’136 Patent, Abstract; col. 1:41-48). The claims of the ’136 Patent, however, more explicitly recite the combination of both the front and rear surface textures.
  • Technical Importance: As with the parent ’454 Patent, this invention provides a specific structural configuration for TOPCon solar cells intended to enhance performance and manufacturing consistency (Compl. ¶15).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶49).
  • Essential elements of Claim 1:
    • A solar cell comprising a semiconductor substrate with a rear surface having a "first texture structure" which is a "non-pyramid-shaped microstructure" with at least two "partially stacked" substructures.
    • A front surface of the semiconductor substrate has a "second texture structure" which includes a "pyramid-shaped microstructure."
    • The top surface of the first substructure (on the rear) is a "polygonal plane."
    • The one-dimensional size of the top surface of the outermost first substructure is less than or equal to 45 µm.
    • The cell includes a first passivation layer on the front (second) texture structure and a tunnel oxide layer on the rear (first) texture structure.
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

  • The complaint identifies the "Accused Solar Panels" as "VSUN's TOPCON N-type solar module series" (Compl. ¶¶ 1, 33). A list of specific model numbers is provided, and the VSUN575N-144BMH-DG module is identified as a representative example (Compl. ¶33).

Functionality and Market Context

  • The Accused Solar Panels are N-type solar panels that allegedly use the same TOPCon technology as Plaintiff's products and compete directly for the same customers (Compl. ¶¶ 17, 18). Defendants market the products as being "engineered in Japan" (Compl. ¶19). A screenshot from Defendant’s website describes VSUN as a "Japanese-invested solar solution provider" that offers "high efficiency solar products" (Compl. ¶19). The complaint alleges the products are sold and used in the U.S., citing installations in Manheim, Pennsylvania, and at the Cincinnati Zoo & Botanical Garden in Ohio (Compl. ¶35).

IV. Analysis of Infringement Allegations

The complaint alleges that claim charts detailing the infringement of claim 1 of each asserted patent are attached as Exhibits 3 and 4 (Compl. ¶¶ 41, 49). However, these exhibits were not provided with the complaint.

The narrative infringement theory asserts that Defendants' products, including the exemplary models, "meet each and every one of the claim limitations of at least claim 1" of both the ’454 and ’136 Patents, both literally and under the doctrine of equivalents (Compl. ¶¶ 40-41, 48-49). Without the claim chart exhibits, the complaint does not provide a public, element-by-element mapping of the accused product features to the specific limitations of the asserted claims.

  • Identified Points of Contention:
    • Technical Questions: A primary technical question will be whether the rear surfaces of the accused TOPCon solar panels actually possess the specific microstructures recited in the claims. This includes determining if the rear surface has a "non-pyramid microstructure," if that structure contains "substructures at least partially stacked on one another," and if those substructures meet the specific dimensional limitations regarding inter-layer distance (≤ 2µm) and size (≤ 45 µm, average 10-15 µm). Answering this question may require physical inspection and analysis (e.g., via scanning electron microscopy) of the accused products.
    • Scope Questions: Should a direct comparison of the accused products to the claim language fail, the invocation of the doctrine of equivalents raises the question of how different the accused microstructure can be while still being considered equivalent. The analysis may focus on whether any differences between the accused product's rear surface texture and the claimed texture are insubstantial.

V. Key Claim Terms for Construction

  • The Term: "non-pyramid microstructure" (’454 Patent, Claim 1)

  • Context and Importance: This term is central to defining the novel rear surface texture of the invention, distinguishing it from the conventional pyramid-shaped texture on the front surface. The determination of infringement will likely depend heavily on the scope of this negative limitation.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent does not provide an explicit definition for the term. A party may argue that it should be given its plain and ordinary meaning, encompassing any surface texture that is not composed of the regular, anisotropic-etched pyramids characteristic of the front surface of a monocrystalline silicon wafer.
    • Evidence for a Narrower Interpretation: The specification describes the first texture structure as presenting a "non-pyramid-shaped microstructure profile" that may be a "substantially 'step' profile," with the substructure regarded as a "stair of the 'step'" (’454 Patent, col. 7:47-51). Figure 3 provides a visual example of this structure. A party may argue the term should be limited to such "step-like" or terraced structures.

  • The Term: "substructures at least partially stacked on one another" (’454 Patent, Claim 1)

  • Context and Importance: This phrase describes the specific spatial arrangement of the elements that form the "non-pyramid microstructure." Infringement will depend on whether the accused product's rear surface features this stacked arrangement.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A party could argue that "partially stacked" requires only some degree of vertical overlap between adjacent features, without needing to be discrete, well-defined layers.
    • Evidence for a Narrower Interpretation: Figures 3, 4a, and 4b depict distinct, layered, or terraced features. The description of a "'step' profile" further supports this interpretation (’454 Patent, col. 7:49-50). A party could argue that the term requires a clear, step-like configuration and is not met by general or random surface roughness that happens to have some vertical variation.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement allegations are based on Defendants allegedly encouraging importation and sale in the U.S. with knowledge of infringement (Compl. ¶¶ 43, 51). The contributory infringement allegations state that the Accused Solar Panels are a material, non-staple component of the invention, especially made or adapted for infringement (Compl. ¶¶ 44, 52).
  • Willful Infringement: Willfulness is alleged based on two theories of knowledge. First, upon information and belief, Defendants had pre-suit knowledge because as an "active competitor," they "would have periodically investigated Jinko's patent portfolio" (Compl. ¶37). Second, Defendants have had actual knowledge since at least the filing of the initial complaint on December 6, 2024 (Compl. ¶38).

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

  • A central evidentiary question will be one of microscopic structure: does the rear surface of the accused VSUN TOPCon solar panels physically embody the claimed "non-pyramid microstructure" composed of "partially stacked" polygonal substructures that fall within the specific dimensional constraints of the asserted claims? The resolution of this issue will likely depend on expert testimony and detailed physical analysis of the accused products.
  • A core legal issue will be one of definitional scope: how will the court construe the claim terms "non-pyramid microstructure" and "at least partially stacked"? The case may turn on whether these terms are interpreted broadly to cover a range of non-pyramidal, rough surfaces or are limited more narrowly to the specific "step-like" embodiments illustrated and described in the patent specification.