VLSI Technology v. Intel — Federal Circuit Revives Multi-Core Patent Infringement Claims, Reverses Summary Judgment on Extraterritoriality and Prosecution Disclaimer

Background

This appeal is the latest chapter in the years-long, multibillion-dollar patent war between VLSI Technology LLC and Intel Corporation. VLSI sued Intel in 2017 for infringement of eight patents, including U.S. Patent No. 8,566,836, which covers a method and apparatus for operating a multi-core processor by measuring the processing speed of each core, storing those values, and — when a task must run on a single core — selecting the fastest core at a given voltage to run that task.

The district court for the Northern District of California (Judge Beth Labson Freeman) granted Intel summary judgment of noninfringement on two independent grounds. First, the court concluded that the patent’s measurement-related limitations were practiced only outside the United States — an extraterritoriality bar. Second, the court rejected VLSI’s doctrine-of-equivalents (DOE) theory after construing apparatus claim 10 to include an “upon identifying” temporal limitation that the claim’s text does not contain. The court also struck certain damages theories advanced by VLSI’s expert, Dr. Sullivan, for inadequate disclosure under the local patent rules.

Critically, the parties had entered a pretrial stipulation agreeing that 70% of Intel’s accused products would be “deemed to have a United States nexus as required by each subsection of 35 U.S.C. § 271 and for determining any patent infringement damages.” The district court interpreted this stipulation as addressing only damages calculations, not the threshold question of whether infringing conduct occurred in the United States. VLSI appealed.

The Court’s Holding

Reversed in part, affirmed in part, and remanded.

On extraterritoriality: The Federal Circuit reversed summary judgment on both the method and apparatus claims. Interpreting the pretrial stipulation de novo, Chief Judge Moore wrote that the stipulation’s plain language — requiring the technical-requirements determination to be conducted “without regard to geographic considerations” — established a U.S. nexus for infringement purposes, not merely for damages. The court noted that Section 271 “is entirely about infringement, not damages,” and declined to rescue Intel from a stipulation it “freely entered” even if the strategic choice “proved unwise in retrospect.” For the apparatus claims, the court further held that VLSI presented sufficient evidence that Intel’s processors contain built-in performance measurement circuits capable of performing the claimed measuring function without product modification.

On prosecution disclaimer and DOE: The Federal Circuit reversed the district court’s construction of claim 10, which had imported an “upon identifying” temporal limitation from independent claims 1 and 20. The court found that none of the applicants’ prosecution statements amounted to a “clear and unmistakable” disclaimer of the broader scope of claim 10. A “see, e.g.” citation linking claim 10 to the “upon identifying” language was at best ambiguous — and ambiguity defeats prosecution disclaimer. This reversal reopened VLSI’s DOE theory for apparatus claims 10, 11, 13, and 17.

On damages: The court affirmed the striking of Dr. Sullivan’s net present value (NPV) and value-per-unit (VPU) damages theories, finding no abuse of discretion in the district court’s determination that VLSI’s damages contentions were insufficiently specific under the Northern District of California’s Patent Local Rule 3-8. However, VLSI retains the ability to prove damages through another expert, Mr. Chandler, on remand.

Key Takeaways

• Stipulations mean what they say. The court enforced the plain text of the parties’ pretrial stipulation establishing a U.S. nexus for infringement — a costly lesson for Intel, which could not walk back the agreement even though it was originally designed to simplify litigation involving eight patents and hundreds of accused products.
• Prosecution disclaimer remains a high bar. A single “see, e.g.” citation during prosecution was insufficient to narrow a claim that, on its face, did not contain the limitation the district court imported. Ambiguity defeats disclaimer.
• Built-in capabilities matter for apparatus claims. Apparatus claims can be infringed by products sold in the U.S. even if the claimed measurement function is only “activated” overseas during manufacturing, so long as the product contains the structural means to perform the function without modification.
• Damages disclosure requirements have teeth. The Northern District of California’s local patent rules require specific, well-supported damages contentions — vague or “scattershot” citations to internal documents will not satisfy the disclosure obligation.

Why It Matters

This decision matters for two reasons beyond the headline-grabbing dollar amounts. First, it clarifies how pretrial stipulations on geographic nexus interact with extraterritoriality defenses — a critical issue as semiconductor design and manufacturing become increasingly global. Companies negotiating similar stipulations should be precise about whether the agreed nexus applies only to damages or also to the infringement question itself. Second, the prosecution disclaimer ruling reaffirms that the Federal Circuit will not lightly narrow claims based on prosecution statements that are merely “amenable to multiple reasonable interpretations.” For patent prosecutors, the takeaway is that careful, claim-specific language during prosecution is essential — loose references linking unrelated claims can cut both ways.