Knobbe Martens Obtains Favorable Ruling for Japanese Materials and Chemical Manufacturer in Post Grant Review Proceeding

Patent and Trial Appeals Board invalidates 15 claims in patent held by Fujifilm

San Diego, Calif., June 23, 2023 – A Knobbe Martens team led by Nathanael Luman, Ph.D. secured a ruling that 15 claims are unpatentable for failure to meet the written description requirement in a patent held by Fujifilm Electronic Materials U.S.A., Inc. on behalf of Tokyo Ohka Kogyo Co., Ltd., a Japanese-based materials and chemical manufacturing company.

The Patent and Trial Appeals Board (PTAB) issued a final written decision holding all challenged claims unpatentable in Fujifilm’s patent on a cleaning composition for semiconductors by finding that the claims lacked adequate written description. The three judge PTAB panel agreed that Tokyo Ohka Kogyo had shown that the patent’s specification failed to show a skilled artisan that the inventors were in possession of a cleaning composition having the claimed features—and thus did not meet the written description requirement.  The PTAB rejected Fujifilm’s attempts to obtain a construction of the claims that would add unrecited limitations in order to preserve patentability. 

Mr. Luman was assisted in the proceeding by Washington, D.C. partner Jonathan Bachand, and Orange County partners Dan Altman and David Schmidt, Ph.D.

Commenting on the successful outcome, Mr. Luman said, “We are very pleased that the PTAB judges agreed with us that all challenged claims are unpatentable.”

A copy of the decision may be found here.

About Knobbe Martens

Knobbe Martens is one of the most highly respected intellectual property law firms, offering all aspects of intellectual property and technology law. The firm’s litigation group handles cases throughout the U.S. and coordinates strategy for disputes worldwide. Founded in California in 1962, the firm has about 300 lawyers and scientists based in offices located in Orange County, Los Angeles, New York, San Diego, San Francisco, Seattle and Washington D.C.  Knobbe Martens serves a diverse international client base, from multinational corporations to emerging businesses of all stages. More information about the firm can be found at