In a recent decision in Amkor Tech., Inc. v. Tessera, Inc., the Patent Trial and Appeal Board declined to change the claim construction standard from the traditional “broadest reasonable construction” standard in response to a terminal disclaimer filed by the patent owner late in the proceeding. IPR2013-00242, Paper 129 at 12. Claim terms in an unexpired patent are analyzed using their broadest reasonable interpretation by the Board. Id. at 3. The patent owner had filed a terminal disclaimer with the goal of causing the disputed patent to be effectively expired such that the broadest reasonable interpretation standard no longer applies. Id. at 2, 5.

The Board rejected the patent owner’s argument, stating: “It is not feasible, at this late stage of the proceeding, to change the standard by which the challenged claims will be interpreted, as all of the arguments and evidence we have before us have applied the broadest reasonable interpretation standard.” Id. at 6-7 (emphasis in original). To use a new standard would require the proceeding to be restarted, which would prevent the proceeding from being completed in a timely manner. Id. at 7. Consequently, the Board decided to “hold the terminal disclaimer in abeyance until the conclusion of the proceeding” so as to avoid interfering with the IPR proceeding. Id. at 11.

The Board did not decide whether the case would have been different if the terminal disclaimer were filed earlier, but did suggest that the analysis might have been different if the terminal disclaimer were filed before or with the preliminary response or the patent owner response. Id. at 8-10. However, the Board also noted that voluntarily filing a terminal disclaimer is different than the patent naturally expiring, suggesting that even an earlier terminal disclaim may have no effect on the claim interpretation standard. Id. at 10-11. In addition to the issue of timing, the Board was also sensitive to the issue of using gamesmanship to disrupt the proceeding. Id. at 8, 11-12. Future attempts to use a terminal disclaimer to effect the claim construction applied by the Board will likely need to address why timing and gamesmanship are not of concern in their proceedings.