Trina Solar Co Ltd v. Jiangsu Runergy New Energy Technology Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Trina Solar Co., Ltd. (China)
  • Defendant: Jiangsu Runergy New Energy Technology Co., Ltd. (China)
  • Plaintiff’s Counsel: Orrick, Herrington & Sutcliffe, LLP
• Case Identification: 2:24-cv-07694, C.D. Cal., 09/10/2024
• Venue Allegations: Venue is asserted on the basis that the defendant is a foreign entity and not a resident of the United States.
• Core Dispute: Plaintiff alleges that Defendant’s N-type Tunnel Oxide Passivated Contact (TOPCon) solar cells infringe two U.S. patents related to the specific structure and manufacturing of high-efficiency solar cells.
• Technical Context: The lawsuit concerns TOPCon technology, a key innovation in the photovoltaic industry aimed at increasing solar cell efficiency by reducing energy losses at the electrical contacts.
• Key Procedural History: The complaint notes that a separate lawsuit alleging infringement of the same patents was previously filed against Defendant's U.S. subsidiaries in the District of Delaware. The complaint also alleges that Defendant was put on notice of the patents-in-suit during a meeting with Plaintiff's representatives in March 2024, a fact which forms the basis for the willfulness allegations.

Case Timeline

Date	Event
2014-11-28	Earliest Priority Date for '104 and '009 Patents
2017-08-01	U.S. Patent No. 9,722,104 Issued
2019-03-12	U.S. Patent No. 10,230,009 Issued
2023-09-01	Approximate Date Defendant Began Selling Accused Products
2024-03-01	Approximate Date Defendant Allegedly Notified of Patents
2024-09-10	Complaint Filed

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

U.S. Patent No. 9,722,104 - “Solar cell and method for manufacturing the same,” Issued August 1, 2017

The Invention Explained

• Problem Addressed: The patent background describes the fundamental operation of a solar cell, where light generates electron-hole pairs that are separated at a p-n junction to produce electrical power (’104 Patent, col. 1:39-51). While not explicitly stated as a problem, improving the efficiency of this process is the implicit goal.
• The Patented Solution: The invention describes a solar cell with a specific multi-layer structure designed to improve performance. The core concept involves a very thin "tunnel layer" placed on the semiconductor substrate, followed by a "first conductive type semiconductor region" deposited on top of the tunnel layer (’104 Patent, Abstract; col. 2:55-65). This architecture, depicted in figures such as FIG. 2, allows charge carriers to "tunnel" through the passivating layer to the electrode, which can reduce energy losses from carrier recombination that occur in conventional cell designs.
• Technical Importance: This structure relates to Tunnel Oxide Passivated Contact (TOPCon) technology, which represented a significant step forward in achieving higher efficiencies for crystalline silicon solar cells by minimizing recombination at the metal-semiconductor interface (’104 Patent, col. 7:55-8:5).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶23).
• Essential elements of independent claim 1 include:
  • A semiconductor substrate.
  • A tunnel layer on a first surface of the substrate.
  • A first conductive type semiconductor region on the tunnel layer.
  • A second conductive type semiconductor region on the opposite surface of the substrate.
  • First and second passivation films and corresponding first and second electrodes.
  • A specific "isolation portion" at an edge of the substrate that excludes the tunnel layer and the first semiconductor region.
  • A requirement that the first passivation film covers both the first surface of the substrate and the isolation portion together.
• Plaintiff reserves the right to assert other claims (Compl. ¶28).

U.S. Patent No. 10,230,009 - “Solar cell and method for manufacturing the same,” Issued March 12, 2019

The Invention Explained

• Problem Addressed: As a continuation of the application that led to the ’104 Patent, the ’009 Patent addresses the same general objective of improving solar cell structure and performance (’009 Patent, col. 1:20-23).
• The Patented Solution: The invention describes the same fundamental TOPCon structure as its parent patent, featuring a passivating layer between the semiconductor substrate and a doped semiconductor region to facilitate charge carrier tunneling (’009 Patent, Abstract; col. 6:49-54). The primary distinction from the ’104 Patent lies in the specificity of the claim language.
• Technical Importance: The technology provides the same benefits as described for the ’104 Patent related to increasing solar cell efficiency (’009 Patent, col. 5:58-6:12).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶38).
• Essential elements of independent claim 1 are structurally similar to claim 1 of the ’104 Patent but use more specific terms:
  • A silicon semiconductor substrate.
  • An "oxide layer" (instead of "tunnel layer") on a first surface of the substrate.
  • A "polysilicon layer" (instead of "first conductive type semiconductor region") on the oxide layer.
  • An emitter region on the opposite surface.
  • First and second passivation films and corresponding electrodes.
  • An "isolation portion" at an edge that excludes the oxide layer and the polysilicon layer.
  • A requirement that the first passivation film covers both the first surface of the silicon substrate and the isolation portion together.
• Plaintiff reserves the right to assert other claims (Compl. ¶43).

III. The Accused Instrumentality

Product Identification

The complaint identifies the "Accused Solar Cells" as Defendant's Tunnel Oxide Passivated Contact (“TOPCon”) solar cells, which are incorporated into its N-Type solar panel modules, including models such as DH108N8B, DH144N8, and DH156N8, and products sold under the "Hyperion brand" (Compl. ¶¶4, 15-17).

Functionality and Market Context

The complaint alleges that Defendant publicly markets its products as using "cutting-edge N-type PV module family" and "TOPCon technology" (Compl. ¶¶3, 9, 16). It is this specific TOPCon architecture that Plaintiff alleges infringes the patents-in-suit (Compl. ¶4). Plaintiff further alleges that Defendant has positioned itself as a leader in TOPCon technology, stating its production is at the "forefront of the industry" and that the "U.S. market is essential" to its mission (Compl. ¶¶3, 16). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

9,722,104 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
[a] a semiconductor substrate;	The accused TOPCon cells are alleged to be built upon a semiconductor substrate.	¶26-27	col. 6:49-54
[b] a tunnel layer on a first surface of the semiconductor substrate;	The accused TOPCon cells are alleged to include a tunnel oxide layer characteristic of TOPCon architecture.	¶26-27	col. 7:51-8:5
[c] a first conductive type semiconductor region on the tunnel layer...;	The accused TOPCon cells are alleged to include a doped semiconductor region on the tunnel layer.	¶26-27	col. 8:43-51
[d] a second conductive type semiconductor region on a second surface opposite to the first surface...;	The accused N-type cells are alleged to have a second conductive region on the opposite surface.	¶26-27	col. 10:46-51
[e] a first passivation film on the first conductive type semiconductor region;	The accused TOPCon cells are alleged to include a first passivation film.	¶26-27	col. 10:62-11:2
[f] a first electrode formed on the first passivation film and connected to the first conductive type semiconductor region...;	The accused TOPCon cells are alleged to include a first electrode connected through the first passivation film.	¶26-27	col. 12:4-11
[g] a second passivation film on the second conductive type semiconductor region;	The accused TOPCon cells are alleged to include a second passivation film.	¶26-27	col. 10:62-11:2
[h] a second electrode formed on the second passivation film and connected to the second conductive type semiconductor region...;	The accused TOPCon cells are alleged to include a second electrode connected through the second passivation film.	¶26-27	col. 12:18-24
[i] an isolation portion for preventing a contact between the first conductive type semiconductor region and the second... region,	The accused TOPCon cells are alleged to have a structure that performs this isolation function.	¶26-27	col. 13:19-24
[j] wherein the isolation portion excludes the tunnel layer and the first conductive type semiconductor region, and is in an edge portion...;	The accused TOPCon cells are alleged to have an isolation portion with this specific structure and location.	¶26-27	col. 13:10-14
[k] wherein the first passivation film covers the first surface of the semiconductor substrate and the isolation portion together.	The accused TOPCon cells are alleged to have a first passivation film that covers both the substrate and isolation portion.	¶26-27	col. 14:48-61

10,230,009 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
[a] a silicon semiconductor substrate having a first conductive type;	The accused TOPCon cells are alleged to be built upon a silicon semiconductor substrate.	¶41-42	col. 6:49-54
[b] an oxide layer on a first surface of the silicon semiconductor substrate;	The accused TOPCon cells are alleged to include a tunnel oxide layer.	¶41-42	col. 8:14-18
[c] a polysilicon layer on the oxide layer and having the first conductive type;	The accused TOPCon cells are alleged to include a doped polysilicon layer on the oxide layer.	¶41-42	col. 8:43-51
[d] an emitter region at a second surface of the silicon semiconductor substrate...;	The accused N-type cells are alleged to have an emitter region on the opposite surface.	¶41-42	col. 10:18-22
[e] a first passivation film on the polysilicon layer;	The accused TOPCon cells are alleged to include a first passivation film.	¶41-42	col. 10:62-11:2
[f] a first electrode connected to the polysilicon layer through an opening...;	The accused TOPCon cells are alleged to include a first electrode connected through the first passivation film.	¶41-42	col. 12:4-11
[g] a second passivation film on the emitter region;	The accused TOPCon cells are alleged to include a second passivation film.	¶41-42	col. 10:62-11:2
[h] a second electrode connected to the emitter region through an opening...;	The accused TOPCon cells are alleged to include a second electrode connected through the second passivation film.	¶41-42	col. 12:18-24
[i] an isolation portion for preventing a contact between the polysilicon layer and the emitter region,	The accused TOPCon cells are alleged to have a structure that performs this isolation function.	¶41-42	col. 13:19-24
[j] wherein the isolation portion excludes the oxide layer and the polysilicon layer, and is in an edge portion of the first surface...;	The accused TOPCon cells are alleged to have an isolation portion with this specific structure and location.	¶41-42	col. 13:10-14
[k] the first passivation film covers the first surface of the silicon semiconductor substrate and the isolation portion together.	The accused TOPCon cells are alleged to have a first passivation film that covers both the substrate and isolation portion.	¶41-42	col. 14:48-61

• Identified Points of Contention:
  • Scope Questions: A central dispute may revolve around the construction of the "isolation portion" as defined in elements [i], [j], and [k] of the asserted claims. The requirement that this portion "excludes" the tunnel/oxide and polysilicon/semiconductor layers and is located in an "edge portion" of the substrate creates a specific structural hurdle. Likewise, the limitation that the first passivation film "covers the... substrate and the isolation portion together" suggests a specific topology that will require careful construction.
  • Technical Questions: Infringement is alleged on "information and belief" based on Defendant's public statements about using TOPCon technology (Compl. ¶¶14, 27, 42). The primary technical question is whether the physical micro-structure of the accused cells, once examined, actually embodies all eleven limitations of either asserted claim, particularly the complex geometric and positional relationships of the isolation portion and passivation films at the cell's edge.

V. Key Claim Terms for Construction

• The Term: "isolation portion" (’104 Patent, cl. 1; ’009 Patent, cl. 1)

• Context and Importance: This term is critical because it defines a specific structural element with functional and locational constraints that may distinguish the patented invention from other solar cell designs. Infringement will depend on whether any feature in the accused cells meets the claim's multi-part definition.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification provides a functional definition, stating the portion is for "preventing a contact between the first conductive type semiconductor region and the second conductive type semiconductor region" (’104 Patent, col. 2:22-25). This could support an argument that any structure achieving this function meets the limitation.
  • Evidence for a Narrower Interpretation: Embodiments show the isolation portion as a specific gap at the physical edge of the substrate, created by removing the tunnel and semiconductor layers in that area (’104 Patent, FIG. 2, element I; col. 14:45-53). A party could argue the term is limited to this specific configuration formed by an edge-etching or removal process.

• The Term: "wherein the first passivation film covers the first surface of the semiconductor substrate and the isolation portion together" (’104 Patent, cl. 1; ’009 Patent, cl. 1)

• Context and Importance: Practitioners may focus on this term because it dictates the topological relationship between three distinct features: the passivation film, the substrate surface, and the isolation portion. Proof of infringement requires showing this specific coverage scheme.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The word "covers" could be interpreted to mean the film simply lies on top of both features, without requiring direct, continuous contact or a specific deposition method.
  • Evidence for a Narrower Interpretation: The figures, such as FIG. 2, depict the first passivation film (190A) as a continuous layer that extends from the top of the first semiconductor region (170), down into the isolation portion (I) where it directly contacts the substrate (100), and then continues along the side (’104 Patent, FIG. 2). This may support a narrower construction requiring the specific, contiguous coverage shown in the preferred embodiment.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement for both patents. Inducement is based on Defendant selling and distributing the accused cells, and for the ’009 patent, more specifically on providing "instructions, documentation,... product manuals, and advertisements" that encourage infringing use (Compl. ¶¶24, 39). Contributory infringement is based on allegations that the accused cells are a material part of the invention, are not staple articles of commerce, and have no substantial non-infringing use (Compl. ¶¶25, 40).
• Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge. It specifically pleads that in March 2024, Plaintiff's representatives met with Defendant’s founder, chairman, and other key executives and provided them with "a list of Trina Solar’s patents that included the ’104 patent" and the ’009 patent (Compl. ¶¶31-33, 46-48). This meeting is alleged to have put Defendant on notice of the infringement.

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

• A core issue will be one of structural and definitional scope: Can the claim term "isolation portion," which is defined by its location (edge portion), what it excludes (tunnel and polysilicon layers), and how it is covered (together with the substrate by a passivation film), be mapped precisely onto the physical structure of Defendant's commercial TOPCon cells? The outcome of the claim construction for this term and its related limitations will be pivotal.
• A key evidentiary question will be one of technical proof: Plaintiff's case is predicated on Defendant's marketing of its products as "TOPCon." The central factual dispute will be whether the specific, multi-element structure recited in the asserted claims—particularly the nuanced geometry at the cell's edge—is actually present in the accused products. This will likely require detailed analysis of physical evidence obtained through discovery.
• The allegation of willfulness introduces a significant factual question regarding the March 2024 meeting. The court will need to determine what was communicated during that meeting and whether it was sufficient to establish that Defendant acted with knowledge or willful blindness regarding its alleged infringement.