DCT

4:25-cv-05226

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

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 4:25-cv-5226, S.D. Tex., 10/31/2025
  • Venue Allegations: Plaintiff alleges venue is proper in the Southern District of Texas because two SEG defendants are incorporated and have regular and established places of business in the district. Venue over other domestic and foreign defendants is asserted based on alleged business operations, acts of infringement within the district, and statutory provisions for foreign residents.
  • Core Dispute: Plaintiff alleges that Defendant’s N-type TOPCon solar cells and modules infringe a patent related to specific surface microstructures on the front and rear of a solar cell's semiconductor substrate.
  • Technical Context: The technology at issue is N-type TOPCon (Tunnel Oxide Passivated Contact) solar cells, a prominent high-efficiency photovoltaic technology where incremental improvements in surface engineering can yield significant performance gains.
  • Key Procedural History: The complaint notes that Plaintiff has previously asserted the same patent in other U.S. district courts against different competitors, beginning in December 2024. This history may be relevant to the complaint's allegations of pre-suit knowledge and willful infringement.

Case Timeline

Date Event
2021-08-04 ’136 Patent Priority Date
2023-11-21 ’136 Patent Issue Date
2024-12-06 Plaintiff filed suit asserting the ’136 Patent against Abalance Corp.
2025-02-07 Plaintiff filed suit asserting the ’136 Patent against Waaree Solar Americas
2025-04-29 Defendant announced launch of N-type solar cell production line in Indonesia
2025-10-31 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," issued November 21, 2023

The Invention Explained

  • Problem Addressed: The patent's background section describes a challenge in manufacturing high-efficiency N-type TOPCon solar cells. After a standard manufacturing step polishes the rear surface of the silicon wafer, the resulting flat surface can negatively impact the formation and performance of subsequent critical layers (the tunnel oxide and polycrystalline silicon layers), thereby limiting the cell's overall 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 to optimize performance. The front, light-receiving surface features a "pyramid-shaped microstructure" to trap light effectively, a common technique in the industry (’136 Patent, col. 5:4-11; FIG. 2). The key innovation resides on the rear surface, which is engineered to have a "non-pyramid-shaped microstructure" that includes "two or more first substructures at least partially stacked on one another" (’136 Patent, Abstract; FIG. 3). This specific rear-surface topography is designed to improve the quality of the subsequently deposited layers, thereby enhancing the cell's open-circuit voltage and overall efficiency (’136 Patent, col. 2:42-47).
  • Technical Importance: The patent addresses the need for precise surface engineering in advanced solar cells, where the interface structure between layers is critical to achieving higher efficiency and better electrical contact properties (Compl. ¶11).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and reserves the right to assert additional claims (Compl. ¶35, ¶37).
  • Essential Elements of Independent Claim 1:
    • A semiconductor substrate with two different 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," with the top surface of the substructure being a "polygonal plane."
    • A front surface having a "second texture structure" that includes a "pyramid-shaped microstructure."
    • A first passivation layer located on the front surface's texture structure.
    • A tunnel oxide layer located 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.

III. The Accused Instrumentality

Product Identification

  • The complaint identifies Defendant's "N-type TOPCon solar module series," specifically naming the "Alpine N and Yukon N series" and listing numerous associated model numbers (Compl. ¶28).

Functionality and Market Context

  • The accused products are described as N-Type TOPCon solar cells and modules manufactured, imported, and sold in the United States for residential, commercial, and utility-scale projects (Compl. ¶14, ¶17). The complaint alleges that the N-type solar cells are manufactured at Defendant's facility in Indonesia and then imported into the U.S. for assembly into modules at facilities in Texas (Compl. ¶30). A press release photo included in the complaint depicts the roll-out of the "FIRST PV CELL!" from this Indonesian facility, which the complaint alleges supplies the U.S. market (Compl. p. 8). The complaint further alleges that Defendant is a direct competitor to Plaintiff and has supplied over 6 GW of solar modules to customers, including in the U.S. (Compl. ¶18, ¶31).

IV. Analysis of Infringement Allegations

The complaint does not contain an explicit claim chart but alleges that the Accused Solar Modules meet every limitation of at least claim 1 of the ’136 Patent (Compl. ¶36). The infringement theory appears to be that Defendant's N-type TOPCon solar cells possess the specific combination of front and rear surface microstructures recited in the claim.

’136 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a semiconductor substrate, wherein a rear surface of the semiconductor substrate has a first texture structure, the first texture structure has a non-pyramid-shaped microstructure and includes two or more first substructures at least partially stacked on one another... The complaint alleges that the accused N-type TOPCon solar cells contain a semiconductor substrate with the claimed rear surface texture (Compl. ¶19, ¶36). ¶36 col. 25:4-12
and wherein a front surface of the semiconductor substrate has a second texture structure, the second texture structure includes a pyramid-shaped microstructure... The complaint alleges the accused cells have a front surface with the claimed pyramid-shaped microstructure (Compl. ¶19, ¶36). ¶36 col. 25:13-24
a first passivation layer located on the second texture structure of the front surface of the semiconductor substrate; The accused N-type TOPCon solar cells are alleged to include this layer as part of their standard structure (Compl. ¶19, ¶36). ¶36 col. 26:25-27
a tunnel oxide layer located on the first texture structure of the rear surface of the semiconductor substrate; The accused N-type TOPCon solar cells are alleged to include this layer, a defining feature of TOPCon technology (Compl. ¶19, ¶36). ¶36 col. 26:28-30
a doped conductive layer located on a surface of the tunnel oxide layer; and The accused N-type TOPCon solar cells are alleged to include this layer as part of their standard structure (Compl. ¶19, ¶36). ¶36 col. 26:31-33
a second passivation layer located on a surface of the doped conductive layer. The accused N-type TOPCon solar cells are alleged to include this layer as part of their standard structure (Compl. ¶19, ¶36). ¶36 col. 26:34-36

Identified Points of Contention

  • Factual Question: The complaint does not provide technical evidence, such as microscopy images, demonstrating the specific surface structures of the accused solar cells. A central dispute will likely be factual: do the accused products' rear surfaces actually feature a "non-pyramid-shaped microstructure" with "partially stacked" substructures, or do they have a different topography (e.g., a flat or randomly textured surface)?
  • Scope Question: The dispute may turn on the proper interpretation of the claimed rear surface structure. The question for the court will be how to construe the term "non-pyramid-shaped microstructure... with two or more first substructures at least partially stacked on one another." The answer will determine whether the accused products' specific rear-surface topography falls within the scope of the claim.

V. Key Claim Terms for Construction

The Term: "non-pyramid-shaped microstructure"

  • Context and Importance: This term is central to distinguishing the invention from the prior art and from the cell's own front surface. Its definition will be critical for determining infringement, as the accused products must possess this specific type of rear-surface structure. Practitioners may focus on this term because it appears to be the primary point of novelty.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification suggests some flexibility, stating the structure may present a "substantially 'step' profile" and that the top surface of a substructure is a "polygonal plane" which can be a "substantially diamond, a substantially square and a substantially trapezoid" (’136 Patent, col. 7:49-51, col. 8:61-65). The use of "substantially" could support a broader reading that does not require perfect geometric forms.
    • Evidence for a Narrower Interpretation: The patent explicitly contrasts this structure with the "pyramid-shaped microstructure" on the front surface (’136 Patent, Abstract). Further, the detailed description and Figure 3 provide a distinct visual example of plate-like, shingled structures, which could be used to argue for a narrower construction limited to the disclosed embodiments (’136 Patent, FIG. 3).

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

  • Context and Importance: This phrase qualifies the "non-pyramid-shaped microstructure," defining its required three-dimensional arrangement. Infringement hinges on whether the substructures on the accused cell's rear surface exhibit this specific spatial relationship.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term "partially" could be argued to encompass any degree of vertical overlap between substructures, not just the neat, stair-like arrangement depicted in the patent's figures.
    • Evidence for a Narrower Interpretation: The patent's illustrations, particularly Figures 3 and 4a, depict a clear, ordered, and overlapping arrangement. A party could argue that "stacked" implies a more deliberate and structured layering, rather than a random or incidental overlap of surface features.

VI. Other Allegations

Indirect Infringement

  • The complaint alleges both induced and contributory infringement. The inducement allegation is based on claims that SEG encourages importation and sale of the accused products in the U.S. with knowledge of infringement (Compl. ¶38). The contributory infringement allegation posits that the accused solar modules are a material part of the invention, are not staple articles of commerce, and are known to be especially adapted for infringement (Compl. ¶39).

Willful Infringement

  • Willfulness is alleged based on SEG’s purported knowledge of the ’136 Patent. The complaint asserts pre-suit knowledge stemming from SEG's status as an active competitor that allegedly monitors industry news, including news of Plaintiff’s prior lawsuits asserting the same patent against other companies (Compl. ¶33). The complaint also alleges knowledge at least from the date the complaint was filed (Compl. ¶34).

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

  • A core issue will be one of evidentiary proof: does the physical evidence, once obtained in discovery, show that the rear surfaces of SEG's mass-produced N-type TOPCon solar cells possess the specific, multi-part "non-pyramid-shaped microstructure" with "partially stacked" substructures as claimed in the ’136 Patent? The complaint's lack of initial technical evidence places a high burden on this future discovery.
  • The case will also turn on a question of claim construction: how broadly will the court define the key limitation "non-pyramid-shaped microstructure... at least partially stacked on one another"? A narrow construction limited to the patent's specific "stair-step" embodiments would present a higher bar for infringement than a broader one covering a wider range of irregular, overlapping surface topographies.
  • A third key question relates to willfulness: can Plaintiff establish pre-suit knowledge based on the assertion that a competitor should have monitored its patent enforcement litigation against third parties, or will any potential finding of willfulness be limited to conduct occurring after the filing of the complaint?