Midas Green Tech LLC v. Immersion Systems LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Midas Green Technologies, LLC (Texas)
  • Defendant: Immersion Systems LLC (Texas)
  • Plaintiff’s Counsel: Hunt Pennington Kumar & Dula, PLLC
• Case Identification: 4:20-cv-00555, N.D. Tex., 05/29/2020
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has a place of business within the Northern District of Texas and has committed acts of infringement in the district.
• Core Dispute: Plaintiff alleges that Defendant’s immersion cooling systems infringe a patent related to the design and operation of systems for cooling electronic appliances by immersing them in a dielectric fluid.
• Technical Context: The technology addresses high-density heat dissipation for electronic components, such as computer servers in data centers, using liquid immersion cooling to improve thermal management efficiency and reliability.
• Key Procedural History: The complaint alleges that Plaintiff sent Defendant a demand letter with a claim chart on February 7, 2020, putting Defendant on notice of the alleged infringement prior to the filing of the lawsuit.

Case Timeline

Date	Event
2012-12-14	'457 Patent Earliest Priority Date (Prov. App. 61/737,200)
2014-04-30	'457 Patent Application Filing Date
2019-09-03	'457 Patent Issue Date
2020-02-07	Plaintiff sent demand letter to Defendant
2020-05-29	Complaint Filing Date

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

U.S. Patent No. 10,405,457 - "Appliance Immersion Cooling System" (issued Sep. 3, 2019)

The Invention Explained

• Problem Addressed: The patent describes prior art immersion cooling systems, such as those used for Cray supercomputers, as having several drawbacks. These include the necessity of draining the entire tank to service a single component, non-uniform fluid flow leading to uneven cooling, poor scalability, and a lack of "fail-soft" or redundant operation ('457 Patent, col. 2:1-46).
• The Patented Solution: The invention is an immersion cooling system architecture designed for improved efficiency and serviceability. It features a tank with a horizontally integrated weir and an external recovery reservoir to manage the circulation of a dielectric cooling fluid ('457 Patent, col. 3:45-56). A plenum at the bottom of the tank is designed to dispense the fluid "substantially uniformly upwardly" through slots holding the electronic appliances ('457 Patent, col. 4:11-26). The system also incorporates distinct primary and secondary fluid circulation facilities, along with a control system to coordinate their operation based on fluid temperature, providing operational redundancy ('457 Patent, Abstract; col. 5:15-45).
• Technical Importance: The design aims to overcome key operational hurdles of earlier immersion cooling systems by providing a more modular, scalable, and reliable solution for high-density data center environments ('457 Patent, col. 9:1-6).

Key Claims at a Glance

• The complaint asserts independent claims 1, 6, and 11 (Compl. ¶15).
• Independent Claim 1 (System):
  • a tank adapted to immerse a plurality of electrical appliances in respective slots;
  • a weir integrated horizontally into a long wall of the tank with an overflow lip to facilitate uniform fluid recovery;
  • a dielectric fluid recovery reservoir positioned vertically beneath the weir's overflow lip;
  • a primary circulation facility with a plenum at the bottom of the tank to dispense fluid uniformly upward;
  • a secondary fluid circulation facility to extract heat from the primary fluid; and
  • a control facility to coordinate the operation of the primary and secondary facilities based on fluid temperature.
• Independent Claim 6 (Tank Module):
  • This claim recites a "tank module" comprising many of the same core elements as claim 1: the tank with slots, the weir, the recovery reservoir, and the primary circulation facility with its plenum.
  • It includes a control facility adapted to control the primary fluid circulation facility as a function of temperature, but does not recite the secondary circulation facility.
• Independent Claim 11 (Tank Module):
  • This claim is structurally very similar to claim 6, also directed to a "tank module," and includes parenthetical references to figures in the patent.

III. The Accused Instrumentality

Product Identification

The "Immersion System" as marketed by Defendant Immersion Systems LLC (Compl. ¶15).

Functionality and Market Context

The complaint identifies the accused instrumentality as an "apparatus for an appliance immersion cooling system" (Compl. ¶15). Based on the allegations, the accused product is a system used to cool electronic appliances by immersing them in a circulating dielectric fluid. The complaint does not provide further technical details about the product's specific operation or market position, other than alleging it is used for immersion cooling.
No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint states that exemplary claim charts detailing the alleged infringement of claims 1, 6, and 11 are attached as Exhibits B, C, and D, respectively (Compl. ¶¶ 20-22). However, these exhibits were not provided with the complaint document. As such, a detailed claim-chart analysis is not possible.

The complaint’s infringement theory can be inferred from its description of the patented invention, which it alleges the accused product embodies (Compl. ¶¶ 10, 15, 19). Plaintiff alleges that Defendant’s Immersion System is an apparatus that contains all the elements of at least claim 1 of the ’457 Patent, including a tank with appliance slots, a weir for fluid recovery, a recovery reservoir, a primary circulation facility with a plenum for uniform upward fluid distribution, a secondary circulation facility for heat extraction, and a control facility to coordinate the system (Compl. ¶¶ 10, 19). The infringement allegations for claims 6 and 11 follow a similar logic for the "tank module" configuration (Compl. ¶¶ 11-12, 19).

• Identified Points of Contention:
  • Scope Questions: A central question may be whether the components in the accused system meet the specific structural definitions in the claims. For example, does the accused system's fluid overflow and collection mechanism constitute a "weir, integrated horizontally into the long wall" and a "dielectric fluid recovery reservoir positioned vertically beneath the overflow lip," as the patent describes?
  • Technical Questions: The complaint's theory relies on the accused product performing specific functions. A potential point of contention is whether the accused system's fluid delivery mechanism qualifies as a "plenum...adapted to dispense the dielectric fluid substantially uniformly upwardly." The meaning of "substantially uniformly" and the evidence required to prove it may be a key issue for the court. Similarly, the nature and extent of the "coordination" performed by the accused system's control facility will likely be scrutinized.

V. Key Claim Terms for Construction

• The Term: "weir, integrated horizontally into the long wall of the tank" (from Claim 1)

  • Context and Importance: This term defines a core component of the fluid management system. The infringement analysis will depend on whether the accused product's overflow structure can be properly characterized as a "weir" with the specified integration and location. Practitioners may focus on this term because its construction will dictate whether a broad range of overflow designs or only a specific integrated structure falls within the claim's scope.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue for the plain and ordinary meaning of "weir" as any dam-like structure over which fluid flows, without being limited to the exact depiction in the patent figures.
    • Evidence for a Narrower Interpretation: The specification repeatedly links the weir (22) to its integration into the "long wall of the tank 14 adjacent all appliance slots 18" ('457 Patent, col. 3:52-56). The specific embodiment shown in Figures 5 and 6 could be used to argue for a narrower construction tied to this structural arrangement.

• The Term: "plenum...adapted to dispense the dielectric fluid substantially uniformly upwardly" (from Claim 1)

  • Context and Importance: This functional limitation is critical to the patent's claimed improvement of providing even cooling. The dispute will likely center on the degree of evenness required by "substantially uniformly."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party may argue the term does not require perfect uniformity, but rather a general, non-turbulent upward flow sufficient to cool the appliances, as distinct from prior art with "generally non-uniform flow patterns" ('457 Patent, col. 2:31-32).
    • Evidence for a Narrower Interpretation: The patent describes a specific structure for achieving this function: a plenum plate (36a) with "at least one row of orifices vertically aligned with each appliance slot" ('457 Patent, col. 4:17-19). An opposing party could argue that "substantially uniformly" should be construed in light of this disclosed embodiment, requiring a comparably engineered solution.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Defendant induces infringement by publishing "documents for using...the Accused Product in an infringing manner" and through advertising (Compl. ¶24). It further alleges that customers' use of the products to cool electronics puts all elements of the asserted claims into service (Compl. ¶24).
• Willful Infringement: The complaint alleges that Defendant’s infringement has been "knowing, intentional, and willful" at least since February 7, 2020, the date Plaintiff delivered its notice letter and claim chart to Defendant (Compl. ¶25).

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

• A core issue will be one of definitional scope: can the structural terms central to the invention, such as "weir" and "plenum", be construed to read on the specific components and architecture of the Defendant’s accused cooling system? The outcome may depend heavily on whether these terms are given their plain meaning or are limited by the specific embodiments disclosed in the patent.
• A key evidentiary question will be one of functional performance: does the accused product’s fluid circulation system actually achieve "substantially uniform" upward flow, and does its control system "coordinate" the primary and secondary cooling loops as required by claim 1? Plaintiff will need to present technical evidence to substantiate these functional allegations.
• Finally, the allegation of willfulness raises a question of post-notice conduct: did the Defendant's actions after receiving a detailed notice letter on February 7, 2020, rise to the level of egregious conduct that would justify enhanced damages, should infringement be found?