Board of Patent Appeals Decision on Optimization of Ranges

MARK TERRY, ESQ.

A Board of Patent Appeals and Interferences decision involving Applied Materials addressed the familiar obviousness issue of optimizing a known range or operating variable.

Patent law generally treats routine optimization as obvious when the prior art discloses the general conditions and the claimed difference is merely a concentration, temperature, position, or similar variable.

An applicant can rebut that showing by demonstrating that the claimed range is critical—often through evidence of unexpected results compared with the prior-art range.

Applied Materials claimed an optimized calibration used in a semiconductor manufacturing process. The Board upheld the obviousness rejection because the record did not establish criticality or unexpected results tied to the selected calibration.

Practical takeaway: A newly selected range is stronger when the application and prosecution record connect it to a surprising technical effect rather than an expected improvement from routine experimentation.