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Mic Drop: PTAB Not Bound by Prior Federal Circuit Decisions

In a split decision, the US Court of Appeals for the Federal Circuit affirmed a Patent Trial and Appeal Board (PTAB) decision finding a patent invalid despite a 2011 Federal Circuit decision that upheld the validity of the same patent. Knowles Electronics LLC v. Cirrus Logic, Inc., Case No. 16-2010 (Fed. Cir., Mar. 1, 2018) (Wallach, J) (Newman, J, dissenting).

Knowles owns a patent directed to microelectromechanical system (MEMS) packages having a substrate, a microphone and a cover accommodating the microphone. According to the patent, the MEMS packages shield the microphone from interference signals or environmental conditions and improve over prior art drawbacks associated with manufacturing. Cirrus initiated an inter partes re-examination proceeding challenging certain claims of the patent. In the proceeding, the PTAB affirmed the examiner’s rejection of certain claims for anticipation based on the construction of the term “package.” The PTAB also affirmed the examiner’s finding that certain newly proposed claims were unpatentable for lack of adequate written description. Knowles appealed.

The Federal Circuit had considered the same patent seven years ago in an appeal from a decision at the US International Trade Commission. In the prior appeal, the Federal Circuit concluded that the patent was not invalid. In the current appeal, Knowles argued that the PTAB improperly construed the term “package” differently from the way the Federal Circuit construed it in the earlier proceeding. The majority found that the PTAB properly construed the term “package,” however, and explained that there was no inconsistency between the prior construction and the current broadest reasonable interpretation (BRI) by the US Patent and Trademark Office (PTO). 

Regarding the written description issue, the Federal Circuit applied the pre-America Invents Act (AIA) § 112 requirement and found that the PTAB’s written description ruling was supported by substantial evidence. The Court agreed that a person of skill in the art, reading the specification, would not have recognized that the inventor possessed solder pads “configured to” connect to a printed circuit board through a reflow process. As the panel explained, “it is not sufficient for purposes of the written description requirement that the disclosure, when combined with the knowledge in the art, would lead one to speculate as to the modifications that the inventor might have envisioned, but failed to disclose.”

In dissent, Judge Newman argued that the construction of the term “package” was different in the two cases. She argued that the PTAB was bound by the previous Federal Circuit ruling and faulted the majority for perpetuating the position that the PTAB need not apply a prior final judicial decision of the same issue of the same claims of the same patent. In Judge Newman’s view, the PTAB’s “duplicate” litigation of the same question negates the purpose of the AIA, which is “to provide a more efficient and less costly post-grant determination of certain validity issues.”

Practice Note: Although the PTAB took the position that the PTO, in determining the BRI, was not bound by the prior claim construction, the panel majority declined to address whether its prior decision was binding on the PTAB. In other words, as Judge Newman observed, the status quo is that claim construction collateral estoppel does not arise against the PTO.

© 2019 McDermott Will & Emery


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