Asetek & CoolIT v. [Challenger]: Federal Circuit Dismisses Appeal as Moot After PTAB Invalidation
The Federal Circuit dismissed appeal No. 22-1049 as moot after the Patent Trial and Appeal Board held all challenged claims of US10078355 — covering liquid cooling systems for computers — unpatentable in IPR2022-01318. Asetek’s decision not to appeal the PTAB’s Final Written Decision effectively ended the patent’s enforceability, closing a 967-day proceeding without any merits ruling on appeal.
PTAB invalidation renders Federal Circuit appeal moot — patent extinguished
Filed in October 2021 at the Court of Appeals for the Federal Circuit, Case No. 22-1049 involved Asetek Holdings, Inc. and CoolIT Systems, Inc. as co-appellants asserting rights in US Patent No. 10,078,355, which protects liquid cooling system architecture for computers. The appeal concerned the patentability of the claims at issue and proceeded before the Federal Circuit while a parallel inter partes review — IPR2022-01318 — was simultaneously advancing before the Patent Trial and Appeal Board.
The Federal Circuit stayed the appeal pending the PTAB’s resolution of IPR2022-01318. On January 22, 2024, the PTAB issued its Final Written Decision in Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S, holding all claims of US10078355 that were at issue in the Federal Circuit appeal to be unpatentable. Asetek then expressed an intent not to appeal that PTAB decision, and the appeal period expired without any challenge being filed. The Federal Circuit accordingly lifted the stay and dismissed the present appeal as moot on June 7, 2024.
The 967-day duration is largely attributable to the stay period while the PTAB proceeding ran its course, a pattern consistent with Federal Circuit practice of deferring to parallel IPR outcomes. What drove the ultimate resolution was not a merits adjudication on appeal but rather Asetek’s strategic decision to let the PTAB ruling stand unchallenged. The public record does not disclose the commercial rationale behind that decision, nor the identity of the respondent/appellee in the Federal Circuit proceeding, leaving open questions about licensing history and any related district court disputes.
Filing to Unpatentable in 967 days
967 days from filing to dismissal — longer than the median Federal Circuit appeal, reflecting the stay period awaiting PTAB’s Final Written Decision
Appeal dismissed as moot: what the PTAB invalidation means for both parties
Mootness dismissal — no Federal Circuit merits ruling
When a patent’s claims are held unpatentable in a Final Written Decision and the patent owner declines to appeal, there is no longer a live controversy for the Federal Circuit to resolve. The court dismissed as moot — meaning it issued no ruling on the underlying legal questions. The PTAB’s unpatentability finding, now final and unappealable, is the operative disposition. The patent is effectively extinguished as an enforcement vehicle.
Moot — no merits adjudicationUS10078355 no longer enforceable after unchallenged PTAB ruling
Asetek Holdings and CoolIT Systems lose all enforcement rights tied to the asserted claims of US10078355. By choosing not to appeal the PTAB’s Final Written Decision, Asetek allowed the unpatentability finding to become final. Any pending or contemplated infringement suits relying on these claims are extinguished. The decision not to appeal may reflect a cost-benefit assessment or a broader portfolio strategy, but the public record is silent on the rationale.
Patent claims cancelledIPR petitioner Shenzhen Apaltek achieves full cancellation
Shenzhen Apaltek Co., Ltd., as IPR petitioner in IPR2022-01318, secured cancellation of all asserted claims without needing to defend any Federal Circuit appeal. The mootness dismissal means no appellate court will revisit the PTAB’s findings. Competitors and the petitioner alike now operate in a landscape where US10078355 cannot be enforced, lowering the IP risk profile for liquid cooling system manufacturers working in this design space.
IPR petitioner prevailsLiquid cooling IP landscape shifts as key patent is invalidated
The cancellation of US10078355 removes a potentially significant enforcement barrier in the computer liquid cooling market. Companies developing or commercialising closed-loop liquid cooling architectures should reassess FTO positions that previously cited this patent as a risk. The outcome also illustrates the strategic leverage of IPR as a cost-effective mechanism for clearing blocking patents — a tactic increasingly common in the competitive cooling hardware sector.
FTO landscape clearedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Asetek Holdings, Inc. | Company | Liquid cooling technology IP holders — co-asserters of US10078355 covering computer cooling systemsSearch in Eureka ↗ |
| Co-Plaintiff | Coolit Systems, Inc. | Company | Search in Eureka ↗ |
| Defendant | Defendant | Individual | No defendant/appellee identified in the available public record for this appealSearch in Eureka ↗ |
| Plaintiff counsel | Arpita Bhattacharyya | Attorney | Counsel for Asetek Holdings, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Robert F. McCauley | Attorney | Counsel for Asetek Holdings, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Finnegan, Henderson, Farabow, Garrett & Dunner, LLP | Law Firm | Representing Asetek Holdings, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The Federal Circuit’s dismissal language is precise and consequential: the court lifted the stay only to dismiss, issuing no ruling on the merits of the patent claims. The operative legal event is the PTAB’s Final Written Decision in IPR2022-01318, not any Federal Circuit adjudication. Because Asetek allowed the appeal period to expire without challenge, the unpatentability finding is final and binding. Parties relying on US10078355 for licensing or enforcement have no further appellate recourse on the cancelled claims.
US10078355 — Liquid cooling system architecture for computers
US Patent No. 10,078,355 (application no. US15/626,706) protects a cooling system architecture for computer systems, covering liquid-based thermal management designs. The patent falls within the competitive closed-loop liquid cooling segment, where pump, reservoir, and heat-exchanger integration define product differentiation. Its claims were held unpatentable in their entirety by the PTAB in January 2024, following an inter partes review petition filed by Shenzhen Apaltek Co., Ltd.
In the context of the rapidly growing PC and data centre cooling market, US10078355 represented a potentially blocking position for competitors designing liquid cooling solutions. Asetek and CoolIT Systems — both significant players in the OEM and retail liquid cooling segments — co-asserted the patent, suggesting it was considered commercially strategic. Its cancellation removes a key IP barrier and may affect licensing arrangements, OEM contracts, and competitive positioning across the sector.
Should you run an FTO analysis referencing US10078355?
Hardware engineers and product managers developing closed-loop liquid cooling systems for PCs or servers should note that US10078355 has been cancelled — its claims are no longer enforceable. If your FTO landscape previously flagged this patent as a risk, that specific risk is resolved. However, Asetek and CoolIT Systems hold broader patent portfolios in liquid cooling, and related patents covering overlapping architectures may still present freedom-to-operate concerns.
PatSnap Eureka’s FTO Search Agent can map the remaining active patent landscape around liquid cooling architectures, identify related Asetek and CoolIT filings that remain in force, and surface prior art clusters relevant to your product design. Running a targeted FTO now — while the landscape is in flux following the US10078355 cancellation — gives R&D and legal teams the clearest possible view of residual risk before next-generation products move to production.
Run a freedom-to-operate analysis on US10078355B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit appeals in computer cooling and hardware IP
Explore Federal Circuit cases involving liquid cooling, thermal management, and computer hardware patents dismissed or decided following parallel PTAB inter partes review proceedings.
What this case signals for the computer cooling IP landscape
The cancellation of US10078355 via IPR and subsequent mootness dismissal reshapes enforcement risk for liquid cooling hardware developers.
IPR remains the most effective tool for clearing liquid cooling patents
Shenzhen Apaltek’s success in IPR2022-01318 confirms that inter partes review continues to be a high-leverage mechanism for invalidating hardware patents covering thermal management architectures. Companies facing assertions from liquid cooling patent holders should evaluate IPR petitions early, particularly where claims appear broad or prior art is well-documented.
A patent owner’s decision not to appeal a PTAB ruling is strategically significant
Asetek’s choice to let the Final Written Decision stand — rather than appeal to the Federal Circuit — is a consequential strategic signal. It may reflect weakness in the underlying claim positions, resource constraints, or portfolio reprioritisation. For licensees or defendants in related disputes, an unchallenged PTAB cancellation typically forecloses future enforcement of those specific claims.
Asetek v Defendant — key questions answered
The Federal Circuit dismissed Case No. 22-1049 as moot on June 7, 2024. The appeal had been stayed pending PTAB proceedings in IPR2022-01318. After the PTAB held all asserted claims of US10078355 unpatentable, Asetek chose not to appeal, and the Federal Circuit dismissed the appeal without reaching the merits.
In Shenzhen Apaltek Co., Ltd. v. Asetek Danmark A/S, IPR2022-01318 (Jan. 22, 2024), the Patent Trial and Appeal Board issued a Final Written Decision holding all challenged claims of US10078355 unpatentable. Asetek did not appeal that decision, making it final and effectively cancelling the patent claims at issue.
No. The PTAB’s Final Written Decision in IPR2022-01318 held all asserted claims of US10078355 unpatentable, and Asetek did not appeal within the statutory period. The claims are therefore cancelled and cannot be enforced. The Federal Circuit’s mootness dismissal confirms no appellate override is available.
The appeal was dismissed as moot because the subject patent claims were cancelled by the PTAB before the Federal Circuit could rule on them. Once a patent’s claims are held unpatentable in a final, unappealed PTAB decision, there is no live controversy for the court to adjudicate — the standard legal basis for a mootness dismissal.
By choosing not to appeal the PTAB’s Final Written Decision, Asetek allowed the unpatentability finding to become final and binding. This foreclosed any possibility of reinstating the cancelled claims through Federal Circuit review. It is a strategically significant decision that effectively surrendered the enforceability of US10078355, potentially impacting licensing arrangements and related litigation positions.
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