In July 2013, Zond brought suit against multiple semiconductor companies and others including Renesas and Renesas Electronics America, alleging that the companies infringed eight of its U.S. patents (one of which was later withdrawn at Zond’s request) covering production-related technologies such as plasma discharge. Renesas and other defendants challenged the patentability of Zond’s remaining patents in inter partes reviews (IPR) with the Patent Trial and Appeal Board (PTAB) of the United States Patent and Trademark Office (USPTO).

By January 2016, all seven patents had been ruled unpatentable by the PTAB. Zond appealed the rulings to the United States Court of Appeals for the Federal Circuit (CAFC), but later Zond voluntarily dismissed some of those appeals. On January 18, 2017, CAFC upheld the PTAB’s rulings for the remaining patents. Zond did not appeal the CAFC’s decision to the U.S. Supreme Court, and thus the unpatentability of the patents became final.

Following the decision concluding unpatentability of the Zond patents, on July 14, 2017 EDT, United States District Court for the District of Massachusetts entered final judgment in favor of Renesas and Renesas Electronics America.