By Dave Cochran and Robby Breetz

The PTAB denied institution of a follow on petition filed five months after an initial petition by the same petitioner, even though the two petitions were directed to different claims.[1]  The Board found no persuasive explanation for the delay.  And, it was particularly perturbed because the delay precluded Board consolidation, thus a second proceeding would expend the Board’s finite resources on redundant issues.

In IPR2020-00047, the second petition, the petitioners LONGi Green Energy Tech. Co. et al. challenged claims 1-11 and 15-16 of Patent No. 9,893,215 directed to a method of manufacture of a solar cell.  Five months earlier, however, LONGi filed a first petition in IPR 2019-01072 directed at claims 12-14 of the same patent.  The original petition was filed in response to a district court action[2] and an ITC action[3] which alleged infringement only of claims 12-14.

The Board considered the seven General Plastic factors[4] and the Board’s Trail Practice Guide[5] in deciding to deny institution of the second petition under 35. U.S.C. § 314(a).  In doing so, the Board made a series of findings including: (1) although the second petition was directed at different claims than the first petition, there was significant overlap between claim limitations; (2) the Petitioner likely knew of the prior art used in the second petition at the time of filing the first petition because many of the references were asserted in the first petition or cited in the ITC action; and (3) there was no gamesmanship because the second petition was filed before the Board’s institution of the first petition, among others.

The Board was particularly concerned with the sixth and seventh General Plastics factors, however, which refer to the finite resources of the Board and the requirement of issuing a final determination within one year of institution.  The Board noted that due to the substantial overlap between the two petitions, it would have been more efficient to consolidate the proceedings.  But, due to the five-month filing delay of the second petition, it would be “difficult, if not impossible” to coordinate the two proceedings and still meet the one-year statutory mandate for the first proceeding.  To move “forward with separate proceedings involving overlapping issues, but having different evidentiary records and schedules, would have a significant impact on the Board’s resources.”

Ultimately, the Board found that the delay in filing the second petition combined with the petitioner’s failure to provide sufficient explanation for the delay and the difficulties the delay causes in consolidation weighed against institution.


It can be dangerous to challenge a patent piecemeal when all claims are not addressed in the first petition.  If multiple petitions are necessary, then Petitioners should consider filing the petitions together to permit Board consolidation.  Otherwise, without a persuasive reason for the delay, the Board may deny institution as they did here.


[1] Longi Green Energy Tech. Co. Ltd. et al. v. Hanwha Solutions Corp., IPR 2020-00047, Paper 18 (PTAB, Apr. 27, 2020).

[2] Hanwha Q CELLS & Advanced Materials Corp. v. LONGi Green Energy Technology Co., Ltd. et al., No. 1:19-cv-00451-MN (D. Del)

[3] Certain Photovoltaic Cells and Products Containing Same, Inv. No. 337-TA-1151 (U.S.I.T.C.)

[4]  The General Plastic factors include:

  1. whether the same petitioner previously filed a petition directed to the same claims of the same patent;
  2. whether at the time of filing of the first petition the petitioner knew of the prior art asserted in the second petition or should have known of it;
  3. whether at the time of filing of the second petition the petitioner already received the patent owner’s preliminary response to the first petition or received the Board’s decision on whether to institute review in the first petition;
  4. the length of time that elapsed between the time the petitioner learned of the prior art asserted in the second petition and the filing of the second petition;
  5. whether the petitioner provides adequate explanation for the time elapsed between the filings of multiple petitions directed to the same claims of the same patent;
  6. the finite resources of the Board; and
  7. the requirement under 35 U.S.C. § 316(a)(11) to issue a final determination not later than 1 year after the date on which the Director notices institution of review.

General Plastic Co. v. Canon Kabushiki Kaisha IPR2016-01357, Paper 19 (PTAB Sept. 6, 2017).

[5] The Board’s Consolidated Trial Practice Guide available at

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For more than 25 years Dave has provided clients with a full range of patent legal services, including as lead counsel in more than 50 post-grant trials at the Patent Trial and Appeal Board of the United States Patent Office. Dave was part of the three-lawyer Jones Day team that prevailed at the Supreme Court in SAS Institute, Inc. v. Iancu, fundamentally changing PTAB litigation practice at the United States Patent Office.