August Tech. Corp. v. Camtek, Ltd., No. 2010-1458 (Fed. Cir. Aug. 22, 2011).

The defendant appealed a final judgment based on a jury verdict that its semiconductor wafer inspection machine infringed two claims of the plaintiff’s patent. The Federal Circuit vacated the final judgment of infringement, and the district court’s grant of a permanent injunction, and remanded the case for further proceedings on the issue of infringement. This action was due to the district court’s error in claim construction.

The asserted claims included language for both “a wafer” and “a plurality of known good quality wafers.” It was undisputed that a whole wafer is typically diced into multiple functional circuit pieces called dies. In view of this, the district court construed the term “a wafer” to mean “a thin slice of semiconductor material with circuitry thereon that is ready for electrical testing, or any part thereof.” Under this construction, any portion of a wafer having two or more dies would be “a wafer” for purposes of the claims. However, the Federal Circuit concluded that this construction was incorrect, because it allowed a single wafer to also be “a plurality of wafers.” To read the claim in this manner rendered the use of both the singular and plural terms in the claims superfluous.

According to the Federal Circuit, the correct construction for “a wafer” means a discrete object—such as a whole wafer, a discrete portion of a wafer, or even a discrete physical substrate that only includes one die. Therefore, a plurality of wafers can only mean more than one physically discrete wafer. The patentee argued that this construction did not cover the preferred embodiment in the specification. The Federal Circuit rejected this argument, because its claim construction still covered at least some embodiments in the specification and there were unasserted claims that would have covered the excluded embodiments.

A copy of the opinion can be found here.