Every Word Counts – Specification Naming conventions can limit claim scope
Appeal from the Patent Trial and Appeal Board.
Summary: A patent’s specification established a naming convention that applied to terms in the patent’s claims. Appeal from the Patent Trial and Appeal Board.
Summary: A patent’s specification established a naming convention that applied to terms in the patent’s claims.
Microchip Technology filed an IPR, arguing all claims of HD Silicon Solutions’ patent were invalid. The challenged patent was for a method to form local-circuit connections by “depositing second film… comprising of tungsten.” According to the Board, “comprising of tungsten” can include elemental tungsten or tungsten compounds. The Board rejected all claims except one as obvious based on this construction. The court noted that both the claims and specification of the patent consistently used “tungsten” as a single term, and the specification described material properties of elemental titanium. The court compared this to the specification’s convention that uses open-ended modifiers, e.g. “chlorine based etchants”, when referencing materials containing compounds of an element as well as the element itself. The court concluded that the claimed “tungsten” without any modifier referred to only elemental tungsten. Despite adopting a narrower construction than the Board’s, the Federal Circuit affirmed the Board’s finding of obviousness because Microchip’s asserted prior art reference disclosed elemental tungsten.
Editor: Sean Murray
