The patent was obvious because it was simply an optimization of result-effective variables. In order for a variable to be result-effective, the prior art need not explain the relationship between the property and the variable; the prior art need only recognize the relationship.
The Board of Patent Appeals and Interferences (the “Board”) rejected four patents, which claimed pads for chemical mechanical polishing with surface grooves having certain ranges of depth, width, and pitch. The pads are used to flatten the surface of a substrate as circuits are created. The prior art disclosed dimensions that overlapped with the claimed ranges. The Board found that the dimensions were result-effective variables. Because the optimization of a result-effective variable is within the ordinary skill in the art, the Board held that the invention was obvious. Further, there was insufficient evidence of commercial success to outweigh the finding of obviousness.
The Federal Circuit affirmed. Substantial evidence supported the Board’s determination that the dimensions of the pads were result-effective variables. The court relied on a “basic engineering” principle to affirm the finding that depth was result-effective, and on the prior art to affirm the finding that width and pitch were result-effective. The patentee argued that the prior art did not disclose the precise impact of pitch and width on performance. But the court held that no great specificity is required; a “recognition in the prior art that a property is affected by the variable is sufficient to find the variable result-effective.” Further, a new claim “does not become nonobvious simply because the patent specification provides a more comprehensive explication of the known relationships between the variables and the affected properties.”
The patentee failed to rebut the prima facie case of obviousness. There was no evidence that the claimed variable ranges produced unexpected, beneficial results, and the mere combination of result-effective variables was within the ordinary skill in the art. Further, the patentee’s commercial success was not linked to the quality of the claimed invention.
Judge Newman wrote a brief dissent, accusing the majority of “simply rubber-stamping agency factfinding.” In his view, there was nothing in the record showing that the changes in the dimensions were obvious, and there was significant evidence of commercial success.
A copy of the opinion can be found here.