The Director denied institution of Infineon’s IPR challenging Mosaid’s patent after concluding that the petitioner failed to reconcile materially different claim construction positions taken before the PTAB and a parallel district court. Infineon Techs. Am. Corp. v. Mosaid Techs. Inc., No. IPR2025‑01456, Pap. No. 27 (PTAB Mar. 17, 2026). This decision reflects the Director’s continued focus on how claim construction positions are presented across parallel proceedings, particularly where differences are not clearly explained.
The ruling builds on Revvo Techs., Inc. v. Cerebrum Sensor Techs., Inc., IPR2025‑00632, Pap. No. 20 (PTAB Nov. 3, 2025) (precedential) (“Revvo”), in which the Director held that a petitioner may not take materially inconsistent claim construction positions before the PTAB and a parallel district court without a sufficient explanation. Where a petitioner advances alternative constructions, the “petitioner should, at a minimum, explain why alternative positions are warranted.” Revvo, Paper 20 at 3–4.
Infineon’s IPR petition challenged claims 1–17 of U.S. Patent No. 10,140,028 B2, which was directed to non‑volatile memory devices and asserted in a co‑pending district court action where claim construction briefing was underway. In the petition, Infineon states that, “no claim terms presently require a formal construction” yet proceeded to “map[] the prior art based on two [different claim] interpretations of ‘clock’ signal.” IPR2025-01456, Pap. No. 2 (Petition), at 7-8. One set of mappings was tied to a narrower, periodic and synchronous clock‑based interpretation. The other set reflected a broader understanding that could encompass data‑strobe‑type signals. Infineon indicating the latter was included specifically to address a construction it anticipated the patent owner intended to advance in the litigation. By contrast, in district court, Infineon advanced a specific construction defining the term as a periodic signal used to synchronize system operations. In its petition, Infineon offered stipulations, including agreeing to abide by any district court construction and withdrawing certain grounds depending on how the district court ruled.
Applying Revvo, Director concluded that the petition did not reconcile Infineon’s statement that no formal construction was needed with its simultaneous advocacy of a specific construction in district court litigation. The Director further rejected Infineon’s argument that multiple constructions were needed to account for its own district court construction and the patent owner’s anticipated construction and avoid unfairness if the district court adopted a broader construction. Instead, the Director found this as an improper attempt to preserve multiple theories inconsistent with Revvo’s requirement of predictability and procedural fairness.
The Director also rejected Infineon’s stipulations as an insufficient basis to provide multiple constructions. Specifically, the Director found these stipulations unpersuasive, characterizing them as a wait and see approach that seeks an unfair advantage. Citing additional Revvo‑based Director decisions, the Director held that such strategies do not cure the underlying inconsistency problem. The decision stated that the PTAB does not serve as a forum for evaluating multiple competing claim constructions.
Viewed together, the decision underscores the Director’s focus on consistency and transparency in how claim construction positions are presented across forums and a petitioner’s need to provide sufficient rationale when presenting potentially-inconsistent constructions. While earlier PTAB practice sometimes more easily tolerated alternative mappings, the analysis here reflects increased scrutiny where a petitioner disclaims the need for construction before the Board while advocating a specific construction in parallel district court litigation. More broadly, the Director has framed this consistency requirement as necessary to promote predictability and certainty in the patent system, and has indicated that unexplained divergence may warrant discretionary denial even where the prior-art merits are otherwise strong. The decision also suggests that conditional strategies—such as advancing alternative grounds or offering “wait and see” stipulations tied to future district court outcomes—may carry limited weight absent a sufficient explanation reconciling the petitioner’s positions at the outset. For practitioners, the case highlights the importance of aligning—or expressly explaining divergences between—PTAB and district court claim construction approaches when seeking institution.
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