Masao Yoshimura


  • J.D., Georgetown University Law Center, 2001
  • Ph.D., Physics, University of Maryland, 1996
  • B.S., Pure and Applied Sciences, University of Tokyo, Japan, 1985


  • Morgan, Lewis & Bockius LLP, 1996-2005


  • Hitachi Research Laboratory, Hitachi, Ltd., Japan, 1985-1989


  • California
  • District of Columbia
  • Virginia
  • U.S. Patent & Trademark Office
  • United States Court of Appeals for the Federal Circuit, CAFC

Masao Yoshimura, Ph.D.

Attorney at Law, Patent Attorney
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Silicon Valley Office:
2445 Augustine Dr., Suite 150
Santa Clara, California 95054 USA

Phone: +1.408.753.1130
Fax: +

Masao Yoshimura's practice focuses on patent/technology licensing negotiations, technical and legal analysis, including due diligence analysis for pre-negotiation/pre-suit investigation, infringement and validity opinions, patent prosecution and other client counseling work relating to IP laws. In addition to numerous experiences as a first-chair negotiator, Masao also has hands-on experience in managing and overseeing large-scale U.S. patent litigations for various technologies, working with prominent large litigation law firms in the U.S. For example, in 2008, Masao played the central role in developing litigation strategies as well as in settlement negotiation for a patent infringement lawsuit brought by a U.S. company against a major Japanese corporation that went through a jury trial in the District Court for Eastern District of Texas, Marshall.

Before co-founding Chen Yoshimura LLP, Masao worked in the patent practice group of a leading U.S. general practice law firm for over nine years, initially as a Patent Agent and later as an attorney at law. Prior to that, he conducted research and development on semiconductor devices at Hitachi Research Laboratory, Hitachi, Ltd., Japan, as a research associate, and earned a Ph.D. degree in the U.S. in the field of non-equilibrium statistical quantum field theory. Through his industrial, academic and legal experiences across Japan and the U.S., Masao possesses an extensive technical background in the field of semiconductor devices, particularly Liquid Crystal Displays (LCDs), Thin Film Transistors (TFTs), semiconductor device fabrication processes, mask designs, device analytical methods, such as X-ray diffraction, TEM, and SEM, electrical and control circuits, and complex mechanical apparatus; he can discuss complex legal and technical issues both in English and Japanese.

In recent years, he is focusing on developing a cost efficient, high quality patent prosecution system utilizing his extensive experiences in patent prosecution before the U.S. Patent and Trademark Office and in patent litigation/license negotiations.