Federal Circuit Reverses Noninfringement Rulings Against VLSI in Precedential Intel Decision

The U.S. Court of Appeals for the Federal Circuit issued a precedential opinion on April 14, 2026, partially reversing summary judgments of noninfringement entered by a California federal district court against VLSI Technology LLC in its patent case against Intel Corporation (Case No. 24-1772). Chief Judge Moore authored the decision.

The Patent and the Case

The patent at issue is U.S. Patent No. 8,566,836, which covers methods and apparatus for selecting processor cores in multi-core systems by measuring and comparing the maximum CPU operating frequency of each core and using that performance data to determine which core executes a given task. VLSI brought suit in the Northern District of California alleging that Intel’s processors infringe the patent.

The district court granted Intel summary judgment of noninfringement on two grounds. First, it found that certain method claim elements were practiced outside the United States, precluding a domestic infringement finding under the extraterritoriality doctrine. Second, it ruled that prosecution history disclaimer barred VLSI from asserting infringement of apparatus claim 10 and its dependents under the doctrine of equivalents. The Federal Circuit reversed on both grounds.

Extraterritoriality: Pretrial Stipulation Controls

On the extraterritoriality issue, the Federal Circuit focused on a pretrial stipulation that the parties had freely entered, in which Intel acknowledged a U.S. nexus for the actions underlying the infringement allegations. The district court had looked past the stipulation and conducted its own extraterritoriality analysis, finding certain claim elements performed abroad.

The Federal Circuit found that the stipulation’s language was “plain and unambiguous” and that the district court erred by looking beyond it. The court held that Intel could not be “rescued” from an agreement it had voluntarily entered. With respect to the apparatus claims, the Federal Circuit also reversed, finding that the district court had improperly focused on where the claimed measuring functionality was practiced rather than on whether the accused products were reasonably capable of performing the claimed functions without significant alteration.

Doctrine of Equivalents: High Bar for Prosecution Disclaimer

On the doctrine of equivalents, the Federal Circuit reinstated VLSI’s theory for apparatus claim 10 and its dependent claims. The district court had construed claim 10 as requiring “selecting a core” to be performed in a particular manner, relying on statements made during prosecution as disclaimers. VLSI argued those statements did not amount to a clear and unmistakable disclaimer.

The Federal Circuit agreed with VLSI. Reaffirming that prosecution disclaimer carries a high evidentiary burden, the court found that the prosecution history statements at issue did not satisfy the “clear and unmistakable” standard. The court reversed the exclusion of VLSI’s doctrine of equivalents theory and permitted it to proceed on remand.

Damages: Partial Affirmance

On the question of damages, the Federal Circuit affirmed the district court’s exclusion of VLSI expert Dr. Sullivan’s net present value (NPV) and value-per-unit (VPU) damages theories, finding no abuse of discretion. VLSI’s other expert, Mr. Chandler, had offered separate damages theories that were not excluded, and those remain available to VLSI on remand.

Practical Significance

The decision carries precedential weight on two points of patent litigation practice. First, a pretrial stipulation regarding U.S. nexus is binding in extraterritoriality analyses, and a party that voluntarily enters such an agreement cannot later avoid it. Second, the decision reaffirms the high threshold for prosecution disclaimer in the doctrine of equivalents context, emphasizing that only a clear and unmistakable surrender of claim scope will operate to foreclose an equivalents theory.

VLSI and Intel have engaged in substantial litigation over the years. In a separate Texas proceeding, a jury once returned a verdict exceeding USD 2.18 billion in VLSI’s favor. The California action involves different patents. With the Federal Circuit’s reversal, the California case proceeds to jury determination on infringement, with Chandler’s damages theories available for the damages phase if infringement is found.