MKS Instruments Files Suit against AEI

May 15, 2003 by Jeff Shepard

MKS Instruments Inc. has filed suit against Advanced Energy Industries Inc. (AEI, Fort Collins, CO) alleging that AEI's latest reactive gas generator, Xstream, infringes upon MKS patents. Specifically, MKS claims infringement of US patent 6,150,628 and four additional patents. AEI reported that it is confident that its product is not in violation of any MKS patent. The suit follows previous legal sparring between the companies that concluded last year with MKS winning a jury ruling against AEI on the 6,150,628 patent.

MKS was awarded $4.2 million in damages to compensate it for AEI's manufacture and sale of its Rapid product. Now MKS is claiming that AEI has infringed upon its technology again, on the same patent and four related patents that have been granted to MKS in the intervening period. AEI stated that it designed Xstream with full knowledge and respect of MKS' 6,150,628 patent. Additionally, AEI filed an action in a Federal Court in Denver last month for a declaratory ruling of non-infringement in order to permit it to market its Xstream technology.