DCT
1:24-cv-00557
Trina Solar Co Ltd v. Runergy USA Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Trina Solar Co., Ltd (China)
- Defendant: Runergy USA Inc. (Delaware) and Runergy Alabama Inc. (Delaware)
- Plaintiff’s Counsel: Richards, Layton & Finger, P.A.
- Case Identification: 1:24-cv-00557, D. Del., 08/22/2024
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because both Defendant entities are incorporated in the State of Delaware.
- Core Dispute: Plaintiff alleges that Defendant’s Tunnel Oxide Passivated Contact (TOPCon) solar cells, and products containing them, infringe two patents related to solar cell structure and manufacturing.
- Technical Context: The lawsuit concerns n-type TOPCon solar cells, a high-efficiency photovoltaic technology that has gained significant market traction as an advancement over prior solar cell architectures.
- Key Procedural History: The complaint alleges that Plaintiff's representatives met with Defendant's representatives in March 2024 to discuss Plaintiff's TOPCon patent portfolio, and at that meeting provided Defendant with a list of patents that included the patents-in-suit. This event is cited as establishing pre-suit knowledge for the purposes of willful infringement.
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 Issues |
| 2019-03-12 | U.S. Patent No. 10,230,009 Issues |
| 2023-09-01 | Alleged first offer for sale of Accused Products begins (approx.) |
| 2023-12-13 | Defendant's manager discusses its n-Type cell capacity at a conference (approx.) |
| 2024-03-01 | Plaintiff allegedly provides Defendant notice of patents-in-suit (approx.) |
| 2024-08-22 | First Amended Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,722,104
- Patent Identification: 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 operates in the context of generating electric power from solar energy using semiconductor-based solar cells, which rely on a p-n junction to separate generated electron-hole pairs ('104 Patent, col. 1:22-42). The implicit problem is the ongoing need to improve the efficiency of this energy conversion process.
- The Patented Solution: The invention describes a solar cell with a specific multi-layer structure designed to improve performance. A key feature is a "tunnel layer" placed on one surface of a semiconductor substrate, which separates the substrate from a "first conductive type semiconductor region" formed on top of the tunnel layer ('104 Patent, Abstract; Fig. 2). This structure, along with specific passivation films and an "isolation portion" at the cell's edge, is intended to improve the cell's open-circuit voltage by providing an effective passivation characteristic while still allowing charge carriers to tunnel through ('104 Patent, col. 7:15-18, 8:60-64).
- Technical Importance: This "passivated contact" architecture allows for higher conversion efficiencies by reducing carrier recombination at the metal-semiconductor interface, a critical performance limiter in conventional solar cells.
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶21).
- Essential elements of 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 on the respective semiconductor regions.
- First and second electrodes connected through openings in the respective passivation films.
- An isolation portion at an edge of the first surface that prevents contact between the first and second semiconductor regions.
- A requirement that the isolation portion excludes the tunnel layer and the first conductive type semiconductor region.
- A requirement that the first passivation film covers both the first surface of the substrate and the isolation portion.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent, but notes that its examples are preliminary and non-limiting (Compl. ¶26).
U.S. Patent No. 10,230,009
- Patent Identification: 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 family leading to the '104 Patent, the '009 Patent addresses the same general problem of improving solar cell efficiency ('009 Patent, col. 1:20-41).
- The Patented Solution: The '009 Patent describes a solar cell architecture that is structurally similar to that of the '104 Patent but is claimed with more specific material limitations. Instead of a generic "tunnel layer," claim 1 explicitly requires an "oxide layer." Instead of a generic "first conductive type semiconductor region," claim 1 requires a "polysilicon layer" on the oxide layer ('009 Patent, Claim 1). This structure of a silicon substrate, a thin oxide layer, and a doped polysilicon layer is characteristic of what is commercially known as TOPCon technology, and aims to reduce recombination losses and improve cell voltage ('009 Patent, col. 8:55-64).
- Technical Importance: By specifying the materials as an oxide and polysilicon layer, the patent claims a structure that directly corresponds to a dominant commercial implementation of high-efficiency passivated contact solar cells.
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶37).
- Essential elements of Claim 1 include:
- A silicon semiconductor substrate.
- An oxide layer on a first surface of the substrate.
- A polysilicon layer on the oxide layer.
- An emitter region on the opposite surface of the substrate.
- First and second passivation films on the polysilicon layer and emitter region, respectively.
- First and second electrodes connected through openings in the respective passivation films.
- An isolation portion at an edge of the first surface that prevents contact between the polysilicon layer and the emitter region.
- A requirement that the isolation portion excludes the oxide layer and the polysilicon layer.
- A requirement that the first passivation film covers both the first surface of the substrate and the isolation portion.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent, but notes its examples are preliminary and non-limiting (Compl. ¶42).
III. The Accused Instrumentality
- Product Identification: The complaint identifies the "Accused Solar Cells" as Runergy's Tunnel Oxide Passivated Contact ("TOPCon") solar cells (Compl. ¶1). These cells are allegedly incorporated into Runergy's N-Type Series solar panels (including models DH108N8B, DH120N8, DH144N8, and DH156N8) and products sold under the Hyperion brand (Compl. ¶12, ¶15).
- Functionality and Market Context: The accused products are described as high-efficiency n-type solar cells (Compl. ¶13). The complaint alleges that Defendant's "TOPCon mass production project investment progress is at the forefront of the industry's N-type technology industrialization" (Compl. ¶14). It further alleges that Defendant is expanding its operations into the United States, including by founding Runergy USA Inc. and constructing a solar panel production facility in Huntsville, Alabama, with plans to produce products incorporating the Accused Solar Cells (Compl. ¶16-17).
IV. Analysis of Infringement Allegations
The complaint alleges that the Accused Solar Cells embody every limitation of at least claim 1 of each asserted patent (Compl. ¶25, ¶41). It references, but does not include, claim chart exhibits (Exhibits C and D) that purportedly detail this infringement (Compl. ¶26, ¶42). The analysis below is based on the claim limitations recited in the complaint and the general allegations made against the accused TOPCon solar cells. No probative visual evidence provided in complaint.
'104 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| [a] a semiconductor substrate; | The complaint alleges the Accused Solar Cells are manufactured on a semiconductor substrate. | ¶24[a], ¶25 | col. 5:49-54 |
| [b] a tunnel layer on a first surface of the semiconductor substrate; | The complaint alleges the Accused Solar Cells, being TOPCon cells, have a tunnel layer (e.g., a tunnel oxide layer). | ¶24[b], ¶25, ¶1 | col. 7:4-14 |
| [c] a first conductive type semiconductor region on the tunnel layer...; | The complaint alleges the Accused Solar Cells have a first conductive type semiconductor region (e.g., a doped polysilicon layer) on the tunnel layer. | ¶24[c], ¶25, ¶1 | col. 7:44-54 |
| [d] a second conductive type semiconductor region on a second surface opposite to the first surface...; | The complaint alleges the Accused Solar Cells have a second conductive type semiconductor region on the opposite surface. | ¶24[d], ¶25 | col. 9:41-49 |
| [e] a first passivation film on the first conductive type semiconductor region; | The complaint alleges the Accused Solar Cells have a first passivation film. | ¶24[e], ¶25 | col. 9:64-66 |
| [f] a first electrode formed on the first passivation film and connected to the first conductive type semiconductor region through an opening...; | The complaint alleges the Accused Solar Cells have a first electrode connected through an opening in the first passivation film. | ¶24[f], ¶25 | col. 12:4-11 |
| [i] an isolation portion for preventing a contact between the first conductive type semiconductor region and the second conductive type semiconductor region, | The complaint alleges the Accused Solar Cells have an isolation portion at the edge of the cell. | ¶24[i], ¶25 | col. 13:19-24 |
| [j] wherein the isolation portion excludes the tunnel layer and the first conductive type semiconductor region...; | The complaint alleges the isolation portion of the Accused Solar Cells has the claimed structure. | ¶24[j], ¶25 | col. 13:45-54 |
'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 complaint alleges the Accused Solar Cells are manufactured on a silicon semiconductor substrate. | ¶40[a], ¶41 | col. 6:49-54 |
| [b] an oxide layer on a first surface of the silicon semiconductor substrate; | The complaint alleges the Accused Solar Cells, being TOPCon cells, have an oxide layer. | ¶40[b], ¶41, ¶1 | col. 7:15-18 |
| [c] a polysilicon layer on the oxide layer and having the first conductive type; | The complaint alleges the Accused Solar Cells have a doped polysilicon layer on the oxide layer. | ¶40[c], ¶41, ¶1 | col. 8:55-64 |
| [d] an emitter region at a second surface of the silicon semiconductor substrate opposite to the first surface...; | The complaint alleges the Accused Solar Cells have an emitter region on the opposite surface. | ¶40[d], ¶41 | col. 10:20-27 |
| [i] an isolation portion for preventing a contact between the polysilicon layer and the emitter region, | The complaint alleges the Accused Solar Cells have an isolation portion at the edge of the cell. | ¶40[i], ¶41 | col. 13:19-24 |
| [j] wherein the isolation portion excludes the oxide layer and the polysilicon layer...; | The complaint alleges the isolation portion of the Accused Solar Cells has the claimed structure. | ¶40[j], ¶41 | col. 13:45-54 |
- Identified Points of Contention:
- Scope Questions: The '104 Patent uses the broad term "tunnel layer." The infringement analysis may focus on whether Defendant's oxide layer meets the functional definition of a "tunnel layer" as understood in the patent. Similarly, the term "first conductive type semiconductor region" in the '104 Patent raises the question of whether it reads on the specific doped "polysilicon layer" used in TOPCon cells like those accused.
- Technical Questions: A central technical question for both patents will likely be the structure of the "isolation portion." Both Claim 1[j] of the '104 Patent and Claim 1[j] of the '009 Patent require that this portion "excludes" the key upper layers (the tunnel/oxide and semiconductor/polysilicon layers). The dispute may turn on evidence of how the accused cells are manufactured at their edges and whether this specific negative limitation is met.
V. Key Claim Terms for Construction
For the '104 Patent:
- The Term: "tunnel layer"
- Context and Importance: This term is the technological core of the claim. The scope of "tunnel layer" will be critical, as Defendant's products use a specific type of layer (a tunnel oxide). Practitioners may focus on this term to determine if the patent's scope is broad enough to cover various types of passivating layers or if it is functionally limited by the specification.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states the "tunnel layer may include various materials through which majority carriers can be tunneled. For example, the tunnel layer 160 may include oxides, nitrides, a semiconductor, and a conductive polymer" ('104 Patent, col. 7:7-14).
- Evidence for a Narrower Interpretation: The specification repeatedly emphasizes a silicon oxide (SiOx) layer as a preferred embodiment and details its specific thickness range (0.5 nm to 2.5 nm) for achieving the desired tunneling effect without being meager ('104 Patent, col. 7:15-18, col. 7:30-44).
For the '009 Patent:
- The Term: "an isolation portion... wherein the isolation portion excludes the oxide layer and the polysilicon layer"
- Context and Importance: This term, particularly the negative "excludes" limitation, defines a very specific required structure at the edge of the solar cell. Infringement will depend entirely on whether the accused product's edge structure meets this precise definition. Practitioners may focus on this term because negative limitations can create clear lines between infringing and non-infringing designs.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The summary of the invention suggests the isolation portion may be formed on "any one of the first surface, side, and second surface of the semiconductor substrate," which could suggest flexibility in its formation ('009 Patent, col. 2:23-26).
- Evidence for a Narrower Interpretation: The claim language itself is highly specific. The "excludes" limitation strongly suggests a structure where the oxide and polysilicon layers have been physically removed from the edge portion, leaving an exposed area of the underlying substrate that is then covered by the first passivation film, as depicted in the manufacturing process (e.g., removing layers in FIG. 13E to create the isolation portion I in FIG. 13F) ('009 Patent, Claim 1[j]-[k]; col. 13:45-54).
VI. Other Allegations
- Indirect Infringement: Plaintiff alleges both induced and contributory infringement for both patents. For the '104 Patent, inducement is alleged based on the "affirmative acts of selling, distributing, and/or otherwise making available the Accused Solar Cells" (Compl. ¶22). For the '009 Patent, the allegations are more specific, citing "providing instructions, documentation," "product manuals," and "technical support" that inform customers how to use the cells in an infringing manner (Compl. ¶38). For both patents, contributory infringement is alleged on the basis that the Accused Solar Cells are a material part of the invention, are not staple articles of commerce, and are especially adapted for an infringing use (Compl. ¶23, ¶39).
- Willful Infringement: The complaint alleges willful infringement of both patents based on pre-suit knowledge. It specifically pleads that in March 2024, Trina Solar representatives met with senior Runergy leadership and "provided with a list of Trina Solar's patents that included the '104 patent" and the "'009 patent" (Compl. ¶29-31, ¶45-47). This alleged actual notice is the primary basis for the willfulness claim, which is alternatively based on willful blindness (Compl. ¶32, ¶48).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of pre-suit knowledge and willfulness: can Plaintiff substantiate its claim that it provided Defendant with actual, unambiguous notice of the patents-in-suit during the alleged March 2024 meeting? The outcome of this factual dispute will be dispositive for the claim of willful infringement and potential for enhanced damages.
- A key technical question will be one of structural compliance: does the edge structure of Defendant's TOPCon solar cells meet the specific negative limitation of the "isolation portion" required by both asserted claims, which dictates that the portion "excludes" the overlying oxide and polysilicon/semiconductor layers? The case may turn on detailed evidence from reverse engineering or manufacturing process discovery.
- A further question will be one of claim scope: for the '104 Patent, which uses broader terminology like "tunnel layer," can the claims be construed to cover the specific "oxide layer" of the accused TOPCon cells, or will the court find the terms to be functionally or structurally distinct in a way that avoids infringement?