Lee International

Lee International successfully defended a patent relating to semiconductor manufacturing equipment in patent cancellation proceedings.

In this case, following the patentee’s request for correction, the petitioner filed an argument brief asserting, as an additional ground, that the invention defined by the corrected claims lacked an inventive step over a new combination of a prior art reference (“D1”) and a reference relating to an electrostatic chuck, which had previously been submitted as documentary evidence.  The petitioner also submitted modified drawings, in which the channel arrangements depicted in D1 had been arbitrarily colored and reconstructed.  Based on these modified drawings, the petitioner argued that a particular feature of the claimed invention was inherently disclosed in D1 and that the claimed invention could therefore have been easily conceived from D1. 

In response, Lee International argued that, regardless of whether the new combination of prior art references was otherwise permissible, a new ground for cancellation introduced after the deadline for filing a request for cancellation could not be considered in the proceeding. Lee International further contended that the petitioner’s assertion that the relevant feature of the claimed invention was inherent in D1, based on the modified drawings, amounted to an arbitrary interpretation unsupported by the prior art and impermissible hindsight reasoning. 

The Intellectual Property Trial and Appeal Board (IPTAB) determined that introducing a new combination of the prior art references after the deadline for filing a request for cancellation, i.e., six months from the publication date of the patent registration, constituted an impermissible change to the substance of the grounds for cancellation, and therefore, could not be considered in the proceedings. The IPTAB further found that, because the relevant feature had not been shown to necessarily be derived from D1, it could not be regarded as inherently disclosed therein.  Furthermore, the IPTAB determined that D1 provided no motivation or suggestion to alter the relative position of the relevant component and that the petitioner’s argument based on the modified drawings therefore relied on hindsight derived from knowledge of the patented invention. 

The IPTAB’s decision highlights three important principles: (i) a new combination of prior art references introduced after the deadline for filing a request for cancellation may constitute an impermissible change to the gist of grounds for cancellation; (ii) a feature not explicitly disclosed in a prior art reference may be regarded as inherently disclosed only if it is necessarily derivable from that reference; and (iii) modifications to drawings or reconstruction of technical features that are not supported by disclosure of the prior art reference itself may constitute impermissible hindsight reasoning.  Accordingly, when responding to a new argument submitted following a request for correction, a patentee should not only address the substantive merits of the new argument but also first determine whether the new argument constitutes an impermissible change to the gist of the grounds for cancellation in light of the grounds previously raised within the prescribed period.  The patentee should also carefully assess whether any modified drawings or reconstructed technical features are supported by the disclosure of the prior art reference itself.