Succeed where others fail: PTAB reaches a different conclusion on the same prior art in different proceedings

December 04, 2014

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On November 21, 2014, the PTAB denied Mitsubishi’s petition for a rehearing of the board’s decision denying institution of an inter partes review against some claims of Celgard’s U.S. Patent No. 6,432,586 (“‘586 Patent”) directed to a lithium battery.  Specifically, in support of its IPR petition, Mitsubishi provided an expert report from Kuzhikalail Abraham who argued that the Tojo reference invalidated some of the claims in the ‘586 patent.  The board, however, denied to institute the IPR on the basis that Mitsubishi failed to show that Tojo “blocks dendrite growth” in the battery as required by the ‘586 Patent.

Interestingly, the same claims of the ‘586 Patent had been challenged in two other IPR petition filed by SK Innovation and LG Chem, LTD respectively.  In fact, these claims were challenged using the same reference (Tojo) and the same expert (Abraham).  In these two cases, the PTAB decided to institute the IPR in view of the prior art and expert declaration.

Mitsubishi argued that the board’s refusal to institute an IPR in its case, while instituting them in the other two cases, undermines “the predictability and uniformity of decision-making by the PTAB.”  The board disagreed and found that Abraham’s arguments were different in the different cases.  The board found that, as a result, “it simply is not true that the records in all three cases present the same evidence.”

Instructively, the board noted that in making an institution determination, it decides whether the petition shows a reasonable likelihood that the patent is invalid.  Given the differences in Abraham’s declarations, the PTAB found that Mitsubishi failed to make this showing, while SK Innovation and LG Chem succeeded.  The PTAB held that the “rule [proposed by Mitsubishi] – that every petition citing the same art must be decided identically, regardless of the arguments set forth in the petition – ignores the adversarial, adjudicative nature of an inter partes review.”


Chandran Iyer


Mr. Chandran Iyer is an attorney in the Washington, DC office of Sughrue Mion, PLLC. Mr. Iyer practices in the area of patent law with a focus on patent litigation. Mr. Iyer, a registered patent attorney, has extensive experience litigating before various federal and state courts. His experience includes litigating patent cases relating to various electrical and mechanical technologies, pharmaceutical products, medical devices, computer software, and Internet technologies. Mr. Iyer’s practice also includes various ex parte and inter partes proceedings before the USPTO.