Patent on capacitors invalidated in inter partes review. PRESIDIO v. AVX

A patent is a set of exclusive rights granted to the inventor of an invention. To obtain a patent in the United States an inventor must file a patent application with the United States Patent and Trademark Office. The patent application is reviewed by a patent examiner at the USPTO to ensure that the invention described in the patent application meets all the criteria for patent protection. If the patent application meets all the criteria for patentability then the inventor will be granted a patent on the invention. A patent grants the inventor the exclusive right to make, use, sell and import the patented invention in the United States. If someone attempts to exercise one of these exclusive rights, without the permission of the patent owner, that can be considered patent infringement.

After a patent is granted it is not impervious. The patent applicant and the examining attorney at the USPTO rigorously review the patent application but sometimes details are missed. Inter partes review is a trial proceeding conducted at the Patent Trial and Appeal Board to review the patentability of one or more claims in a patent only on a ground that could be raised under §§ 102 or 103, and only on the basis of prior art consisting of patents or printed publications. The inventor and the patent examiner do their best to consider all the relevant prior during the patent application process, but sometimes relevant prior art is overlooked. If a member of the public discovers a piece of prior art which anticipates a patent which has been granted they may request an inter partes review of the patent. An inter partes review can result in invalidation of some or all of the claims of a patent.

PRESIDIO COMPONENTS, INC., v. AVX CORPORATION, 2019-2182 (C.A.F.C. 2020) is an example of a case where prior art was found that rendered an invention unpatentable.

Appellant in this case, Presidio, owns U.S. Patent No. 7,075,776 (the ’776 patent) and U.S. Patent No. 7,307,829 (the ’829 patent). Traditional capacitors have a limited ability to pass different frequencies of alternating current. The patents are directed to capacitor structures that have a monolithic body containing multiple individual capacitors with different frequencies and capacitance values. This inventions described in the patents to to perform effectively across a broader range of frequencies.

Appellee filed for inter partes review before challenging the claims of the ’776 patent and ’829 patent. Two main pieces of prior art were cited. Japanese Patent Application Publication No. H5- 21429, published March 19, 1993, with named inventor Yoichi Kuroda (“Kuroda”), is directed to multilayer capacitors with high capacitance capacitor portions and low capacitance capacitor portions formed in a single sintered body. Kuroda teaches that this configuration allows the device to function effectively across a broader range of frequencies. And U.S. Patent Application Publication No. 2002/0195700 A1 (“Li”) is directed to an electronic assembly that includes one or more capacitors connected to a housing.

The PTAB found that the claims of the patents were anticipated and/or obvious in light of the prior art. Appellant appealed that decision to the Court of Appeals for the Federal Circuit. On appeal the Appellant’s main argument was that the PTAB misinterpreted claims of the ’776 patent and the ’829 patent.

With respect to the ’776 patent the Federal Circuit found that the Appellant failed to explain how the PTAB’s interpretation of the prior art was erroneous. Further Appellant failed to identify any structural differences between the capacitor described in Kuroda and the capacitor claimed in the ‘776 patent.

For the ’829 patent the Appellant argued that “end” of a capacitor should be limited to the lengthwise dimension instead of any part that lies at the boundary of the capacitor. Therefore Kuroda did not disclose capacitors on opposite “ends” of the device. Federal Circuit found that argument unpersuasive because Appellant failed to show that the specification of the patent limited the definition of “end” to the lengthwise dimension of the capacitor.

Based on these findings the Federal Circuit held that the PTAB’s decision, did not rely on improper claim construction, was supported by substantial evidence and affirmed the decision.

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