DCT

1:23-cv-01228

Teamtechnik Maschinen und Anlagen GmbH v. SolarJuice American Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-01228, D. Del., 10/27/2023
  • Venue Allegations: Venue is asserted in the District of Delaware on the basis that both defendants are Delaware corporations.
  • Core Dispute: Plaintiff alleges that Defendant’s importation and use of photovoltaic cell soldering stringer machines infringe patents related to apparatuses for manufacturing solar cell strings.
  • Technical Context: The technology concerns automated machinery for connecting individual photovoltaic cells with conductive strips to form "strings," a fundamental process in solar panel manufacturing.
  • Key Procedural History: The complaint alleges that Plaintiff provided Defendant with notice of the asserted patents and its infringement allegations on or around May 2, 2023, approximately five months prior to filing the complaint.

Case Timeline

Date Event
2005-12-30 Earliest Priority Date for ’681 and ’009 Patents
2012-08-21 ’681 Patent Issued
2012-08-28 ’009 Patent Issued
2023-02-06 Alleged Importation of Accused Products
2023-05-02 Plaintiff Notified Defendant of Alleged Infringement
2023-10-27 Complaint Filed

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

U.S. Patent No. 8,247,681 - “Solar cell connecting apparatus”, issued August 21, 2012

The Invention Explained

  • Problem Addressed: The patent describes prior art solar cell manufacturing systems that use a transport plate to hold and move cells as being disadvantageous due to low cycle rates, inflexibility with different cell sizes, and "movement with no load" when the plate is returned, which negatively affects yield (’681 Patent, col. 2:10-24).
  • The Patented Solution: The invention proposes a modular, continuous-flow apparatus to solve this problem. It uses a "strip retaining element" that is placed on top of the solar cell and conductive strips to hold them together during transport on conveyor belts through various processing stations, such as a soldering oven (’681 Patent, Abstract; col. 2:46-62). This obviates the need for a dedicated transport plate that must be returned, allowing for a more flexible and efficient manufacturing line (’681 Patent, col. 3:5-12).
  • Technical Importance: This approach sought to improve throughput and flexibility in automated solar cell string manufacturing by adopting continuous-flow principles over batch-style, plate-based transport systems (’681 Patent, col. 2:46-50).

Key Claims at a Glance

  • The complaint asserts at least Independent Claim 1 (Compl. ¶23).
  • Essential elements of Independent Claim 1 include:
    • A first module for joining solar cells and strips together.
    • A second module, connected to the first, for connecting the strips to the solar cells.
    • A third module for transporting the solar cells from the first module through the second.
    • The first module includes a retaining apparatus with a strip retaining means for fixing the strips on the solar cell.
    • The third module includes a first transport device for transporting the retaining apparatus together with the solar cell and fixed strips.
  • The complaint notes that its infringement contentions are not limited to the identified claim (Compl. ¶24).

U.S. Patent No. 8,253,009 - “Strip retaining apparatus for a solar cell connecting apparatus”, issued August 28, 2012

The Invention Explained

  • Problem Addressed: The patent addresses the same manufacturing challenges as the ’681 patent, focusing specifically on the apparatus used to hold the conductive strips in place on the solar cells during automated assembly (’009 Patent, col. 2:2-11).
  • The Patented Solution: The invention is a specific "strip retaining apparatus" designed for use in a solar cell connection system. It consists of a frame with a central window (to allow access for soldering) and multiple "retaining heads" arranged in rows. These heads have needles that pivot to press down on the conductive strips, holding them in position on the solar cell by force of gravity or spring force (’009 Patent, col. 5:6-17; col. 5:21-24). The frame is designed to rest on conveyor belts for transport through the manufacturing line (’009 Patent, col. 5:10-12).
  • Technical Importance: This design provides a specific mechanical implementation for temporarily securing components during a continuous-flow soldering process, aiming for precise and repeatable application of force without damaging the delicate solar cells (’009 Patent, col. 5:42-49).

Key Claims at a Glance

  • The complaint asserts at least Independent Claim 1 (Compl. ¶34).
  • Essential elements of Independent Claim 1 include:
    • A strip retaining apparatus for use in a solar cell connection apparatus.
    • A frame with elements defining a window in the central area.
    • At least two frame elements having contact surfaces on an edge area.
    • A multiplicity of retaining heads in at least two rows at opposite sides of the window.
    • Each retaining head has a retaining needle.
    • The retaining heads are pivotally supported on the frame to enable the needles to move on to a strip.
  • The complaint notes that its infringement contentions are not limited to the identified claim (Compl. ¶35).

III. The Accused Instrumentality

Product Identification

  • The accused products are "MBB Photovoltaic Cell Soldering Stringers" imported from Wuxi Autowell Supply Chain (“ATW”) (Compl. ¶1, ¶17).

Functionality and Market Context

  • The complaint alleges that the defendants import and use these machines in their U.S. facilities for the purpose of manufacturing photovoltaic cells (Compl. ¶1, ¶16-17). The complaint provides a screenshot from a since-removed YouTube video showing a long, modular machine identified as an Accused Product in use at Defendant's Sacramento facility (Compl. ¶19). Based on the product name ("Soldering Stringer"), its function is to solder conductive strips to solar cells to create electrical strings, which is the subject matter of the asserted patents.
  • The complaint alleges the importation of four such machines on a specific date, suggesting they are used for commercial-scale manufacturing (Compl. ¶17).

IV. Analysis of Infringement Allegations

The complaint references preliminary claim charts (Exhibits 4 and 5) that were not publicly filed with the initial pleading (Compl. ¶24, ¶35). Therefore, a detailed element-by-element analysis based on the complaint's allegations is not possible. The infringement theory is summarized below in prose.

’681 Patent Infringement Allegations

The complaint alleges that the defendants' importation and use of the Accused Products directly infringe at least Claim 1 of the ’681 patent (Compl. ¶23). The narrative theory is that the accused "Soldering Stringer" machines are solar cell connecting apparatuses that embody the claimed modular system. This suggests the machines are alleged to have a first module for joining cells and strips using a retaining apparatus, a second module for soldering, and a third transport module that moves the cell-and-retainer assembly through the system, thereby meeting the limitations of Claim 1 (Compl. ¶11, ¶23).

’009 Patent Infringement Allegations

The complaint alleges that the Accused Products directly infringe at least Claim 1 of the ’009 patent (Compl. ¶34). The narrative theory is that the retaining apparatus used within the accused "Soldering Stringer" machines is the "strip retaining apparatus" recited in the claims. This implies an allegation that the machines contain a frame with a central window and pivotally supported retaining heads with needles that press onto conductive strips to hold them for soldering, as recited in Claim 1 of the ’009 patent (Compl. ¶14, ¶34).

Identified Points of Contention

  • Scope Questions: A potential issue is whether the distinct "first module," "second module," and "third module" of ’681 Claim 1 can be identified as separate-but-connected structures within the integrated design of the accused stringer machines, or if the defendants will argue their machine is a single, non-modular unit.
  • Technical Questions: A key question for the ’009 patent will be whether the mechanism in the accused machines for holding down conductive strips uses "pivotally supported" "retaining heads" with "retaining needles" as specifically described in the patent, or if it accomplishes the same function through a technically distinct mechanism. The complaint does not provide sufficient detail for analysis of the accused mechanism.

V. Key Claim Terms for Construction

The Term: "module" (e.g., "a first module," "a second module") (’681 Patent, Claim 1)

  • Context and Importance: The claim requires three distinct but connected modules for joining, connecting (soldering), and transportation. The interpretation of "module" will be critical to determining if the accused machine, which may be a single integrated assembly line, contains the claimed tripartite structure. Practitioners may focus on this term because its construction could determine whether a physically integrated machine can be mapped onto a claim structured around functionally distinct "modules."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the modules functionally (e.g., "placement module," "connecting soldering module") and notes that "Product-specific or customer-specific process intermediate steps can also be inserted at any time between these process steps," which may suggest that a "module" is a functional zone rather than a necessarily physically separate chassis (’681 Patent, col. 7:40-43).
    • Evidence for a Narrower Interpretation: Figure 2 and the accompanying text explicitly label physically distinct sections of the apparatus as modules 22, 24, 26, and 32. The description of modules being "joined together like building blocks" could support an interpretation requiring some degree of structural separability or distinct identity (’681 Patent, col. 9:26-29).

The Term: "pivotally supported" (’009 Patent, Claim 1)

  • Context and Importance: This term describes how the "retaining heads" are mounted to the frame, which is central to the claimed mechanical action. The infringement analysis will depend on whether the mechanism in the accused machine that applies pressure to the strips operates via a pivoting motion as claimed.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent does not appear to limit the term to a specific type of pivot, potentially allowing it to cover a range of rotational or hinged movements.
    • Evidence for a Narrower Interpretation: The specification provides a specific embodiment where retaining heads "lie more or less loosely in the V-shaped groove" of a bearing bar to pivot (’009 Patent, col. 5:56-62; Fig. 4c). A defendant may argue that "pivotally supported" should be limited to this or a similar type of free-pivoting arrangement, as opposed to other forms of guided movement.

VI. Other Allegations

Indirect Infringement

  • The complaint does not contain a count for indirect infringement, but the prayer for relief requests an injunction against inducing or contributing to infringement of the ’681 patent (Compl. p. 8, ¶(b)). Factual allegations to support indirect infringement are not explicitly detailed.

Willful Infringement

  • Willfulness is alleged for both patents. The claim is based on alleged knowledge of the patents "at least as early as May 2, 2023," the date Plaintiff sent a notice letter to Defendant (Compl. ¶29, ¶40). The complaint alleges that Defendant's infringement continued after receiving this notice.

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

  1. A Structural vs. Functional Question: The case may turn on whether the accused "Soldering Stringer," an integrated machine, can be mapped onto the "modular" framework of the ’681 patent's claims. The central question will be whether "module" requires structural separateness or can be defined by functional zones within a single piece of equipment.

  2. An Evidentiary Question of Mechanical Operation: For the ’009 patent, the dispute will likely focus on the specific mechanics of the accused machine. The key evidentiary question will be whether the components that hold down the conductive strips are "pivotally supported retaining heads" as claimed, or if they operate via a different, non-infringing mechanism.

  3. The Impact of Pre-Suit Notice: Given the allegation that infringement continued for over five months after a specific notice letter was sent, a core issue will be whether Defendant’s alleged conduct post-notice was objectively reckless, which will be central to the claim for willful infringement.