CelLink Corp. v. Manaflex LLC

Background

CelLink Corp. brought the action against Manaflex LLC for alleged infringement of U.S. Patent Nos. 11,116,070, 12,035,459, and 12,040,511. The complaint also asserted trade-secret misappropriation and correction of inventorship. The patents concern interconnect circuits, including circuits used with battery packs and methods for forming those circuits.

The parties asked the court to construe, meaning determine the legal meaning and scope of, ten terms in the asserted patents. The court held a claim-construction hearing after receiving written briefs.

Rulings on the ’070 and ’459 Patents

The court ruled that the term concerning damage to the substrate maintaining the orientation of conductive portions required no construction. It rejected Manaflex’s proposed wording because the patent did not require a cause-and-effect relationship between damage and maintaining orientation.

For the thermal-conductivity term, the court corrected the apparent typographical error in the claim and adopted “of at least 0.2 W/mK.” The court therefore did not find that term indefinite.

The court found that “second insulator is laminated to the conductive layer through the additional conductive portion” was not indefinite and required no construction. It understood “through” to mean by means of or by the instrumentality of the additional conductive portion, without requiring the second insulator to be physically connected directly to the conductive layer.

The court found that “separated by [a first/second . . . ]” required no construction and rejected Manaflex’s proposed replacement of “separated by” with “divided by.” It likewise found that “positioned between the first conductive portion and the second conductive portion” required no construction and rejected Manaflex’s proposal that the term mean “spanning from” one conductive portion to the other.

For “insulator,” the court adopted CelLink’s proposed construction: “an insulating layer, permanent insulator, or electrical insulator, that may be thermally conductive.” The court relied on the patent specification’s express description of those terms as interchangeable and its statement that an insulator may be thermally conductive while electrically insulating.

For “pattern opening(s),” the court adopted “opening(s) formed by patterning.” It rejected Manaflex’s proposed limitation to “gaps, slits, or other spaces” because the patent did not limit pattern openings to those examples, but it agreed that the openings must be formed by patterning.

Rulings on the ’511 Patent

For “freestanding,” the court adopted Manaflex’s construction: “does not have any portions of an insulating layer attached to it.” The term describes the fusible link in claim 5. The court rejected CelLink’s proposed phrase “not mechanically supported by a supporting layer” because it could introduce ambiguity and did not resolve the parties’ dispute.

The court found “increasing fatigue life” indefinite. It concluded that the claim required an actual increase in fatigue life but did not identify a reference point, comparison material, or circumstances for determining whether an increase occurred. The court held that the patent therefore failed to provide an objective standard that would inform skilled readers of the claim’s scope with reasonable certainty.

The parties stipulated to a construction for “overlap,” “overlaps,” and “overlapping.” The court adopted “partially or fully [overlap, overlaps, overlapping].”

Conclusion and Further Proceedings

The court entered the stated claim constructions, including several findings that no construction was necessary, the construction of “of at least 0.2 W/mK,” the finding that one term was not indefinite, the adopted definitions of “insulator,” “pattern opening(s),” “freestanding,” and the overlap terms, and the finding that “increasing fatigue life” was indefinite.

Judge Haywood S. Gilliam, Jr. also set a telephonic case-management conference for November 4, 2025, at 2:00 p.m. The court directed the parties to meet and confer and submit a joint case-management statement by October 28, 2025.