In June, DuPont filed a law suit against Heraeus and its client SolarWorld Industries America, alleging that the two parties infringed on DuPonts U.S. Patent No. 8,158,504 B2, relating to silver pastes used in the production of solar cells.
At the time, SolarWorlds Ben Santarris branded the claim "surprising and incomprehensible." He added, "As a mere customer of Heraeus, we naturally dont have any insight into the patent law situation of the various paste patents. We will now, however, discuss the issue with Heraeus and so far Heraeus position is that the accusations are unsubstantiated."
Now Heraeus has responded by filing several counterclaims. "Heraeus asserts that it is not infringing and has not infringed any valid claims of the patent in question (U.S. Patent 8,158,504). Heraeus further asserts that the 504 patent is invalid and requests that the judge assigned to this case make a ruling declaring it to be invalid," said the company in a statement released.
It went on to say that by making "false statements in press releases and in letters to customers" DuPont is "engaging in unlawful trade practices."
"We are filing counterclaims against DuPont to defend our innovative photovoltaic products and the 40-year history of Heraeus as an industry-leading developer and manufacturer of silver metallization pastes," stated Andy London, Global Manager for the Photovoltaics Business Unit. "We will continue to produce our paste products at sites worldwide and supply them to our customers. And in the interests of ourselves and our customers, we will continue to defend ourselves against unlawful threats."