In an appeal from an inter partes re-examination of a patent having both original and newly presented claims, the US Court of Appeals for the Federal Circuit ruled that a decision in earlier inter partes reexaminations of related patents had a preclusive effect that collaterally estopped the Patent Trial and Appeal Board from making new findings on the same issue that was determined in the prior re-examinations. SynQor, Inc. v. Vicor Corp, Case No. 19-1704 (Fed. Cir. Feb. 22, 2021) (Hughes, J.), (Dyk, J., dissenting).
In 2011, SynQor asserted several patents, including the ‘190 patent, the ‘702 patent and the ‘290 patent, against Vicor. Vicor petitioned for reexamination of the ‘190, ‘702 and ‘290 patents, arguing that the claims of the ‘190 patent were unpatentable over two references: Steigerwald and Cobos. SynQor argued that an artisan would not have combined Steigerwald and Cobos because they taught circuits that operated at incompatible frequencies.
Past Appeals of Related Patents
On appeals from the reexaminations of the ‘702 and ‘290 patents, the Board affirmed that the challenged claims of the ‘702 patent were not unpatentable, because “there are incompatibilities in frequency between [Cobos and Steigerwald].” Similarly, after finding SynQor’s evidence that Steigerwald and Cobos operated at incompatible frequencies more credible than Vicor’s opposing evidence, the Board found the challenged claims of the ‘290 patent not unpatentable based on a combination of Steigerwald, Cobos and a third reference.
SynQor and Vicor had previously appealed the Board’s decisions in the reexaminations of the ‘702 and ‘290 patents to the Federal Circuit. As to the ‘290 patent, the Federal Circuit had affirmed the patentability of the challenged claims, holding that substantial evidence supported the Board’s finding that an artisan would not combine Steigerwald and Cobos because of their frequency incompatibility. The Court had also affirmed the Board’s decision finding the ‘702 patent not unpatentable, but did not (and was not asked to) reach the Board’s finding that Steigerwald and Cobos were incompatible.
Board Re-xamination of the ‘190 Patent
As to the ‘190 patent (at issue in this appeal), the Board found that Steigerwald and Cobos were not incompatible. In concluding that the challenged claims of the ‘190 patent were unpatentable over Steigerwald and Cobos, the Board was “not persuaded that the switching frequency differential is sufficient to render the combination unsuitable.” It found a new claim unpatentable based on a new ground of rejection, and SynQor opted to re-open prosecution of the new claim.
The ‘190 patent expired in January 2018. In February 2019, the Board issued its decision regarding the claims in the ‘190 reexamination, again rejecting SynQor’s argument that Steigerwald and Cobos had incompatible frequencies, and concluded that “the evidence points strongly to the lack of a frequency range discrepancy between Cobos and Steigerwald.” SynQor appealed.
Appeal as to the ‘190 Patent
On appeal, SynQor argued that common law issue preclusion arising from the ‘702 and ‘290 patent re-examinations should have collaterally estopped the Board from finding that an artisan would be [...]