On 25 July 2025, K&L Gates secured an important win for its client, Midas Green Technologies, LLC. Acting USPTO Director Coke Morgan Stewart granted Director review and denied institution of an inter partes review (IPR) petition filed by Midas Green’s competitor, Green Revolution Cooling, Inc., which had sought to invalidate U.S. Patent No. 10,405,457—currently being asserted by Midas Green in a parallel lawsuit pending in the Western District of Texas. The patent describes a modular immersion cooling system that circulates dielectric fluid to cool vertically mounted electronic appliances, such as computer servers, in a tank.
The Director’s decision vacated a prior institution decision by a three-judge PTAB panel, which had instituted the IPR in May 2025. In doing so, the Director agreed with Midas that the Board erred in its application of the Fintiv factors governing discretionary denial based on parallel district court litigation.
Although the Petitioner had entered into a so-called Sotera stipulation—agreeing not to pursue any invalidity grounds that were or reasonably could have been raised in the IPR in the co-pending litigation—the decision found that the PTAB gave the stipulation too much weight, particularly because the stipulation did not apply to certain system art already asserted in the litigation. The decision emphasized that the district court trial is scheduled to begin roughly four months before the final written decision would issue, and that no stay had been granted in the district court litigation.
Weighing all the Fintiv factors, the decision found that the advanced stage of the litigation and lack of overlapping issues outweighed the stipulation, and that “the efficiency and integrity of the system” favored denial of the petition. As a result, Green Revolution Cooling will now need to meet the higher “clear and convincing evidence” standard to prevail on its invalidity theories in district court, rather than the lower “preponderance of the evidence” standard available in IPR.
