PTAB challenges

Proceedings overview

Two AIA trial proceedings have been filed against US patent 9,130,074, both of which are Inter Partes Reviews (IPRs) and both were denied institution. This gives a defendant a challenging defensive posture through PTAB, as the patent has survived two IPR challenges without any claims being invalidated.

IPR2025-01432 — Canadian Solar (USA) Inc. et al. v. Oliver Schultz-Wittmann et al

• Type: Inter Partes Review
• Filed: 2025-08-22
• Status: Discretionary Denial - The PTAB declined to institute the IPR.
• Judge panel: Not publicly available in the provided information.
• Petition grounds: Not publicly available in the provided information.
• Institution decision: Denied - 2026-01-21. The panel's reasoning for discretionary denial is not detailed in the provided information, but the status indicates it was denied institution.
• Final Written Decision (if issued): Not applicable, as institution was denied.
• Settlement / termination: Not applicable.
• Appeal: Not applicable.
• Defensive value: This proceeding indicates that Canadian Solar's challenge to the patent through IPR was unsuccessful, and no claims were invalidated. This makes an IPR-based defense harder for parties facing assertion of this patent on the grounds raised by Canadian Solar.

IPR2025-01130 — JinkoSolar Holding Co., Ltd. et al. v. Oliver Schultz-Wittmann et al

• Type: Inter Partes Review
• Filed: 2025-07-18
• Status: Discretionary Denial - The PTAB declined to institute the IPR.
• Judge panel: Not publicly available in the provided information.
• Petition grounds: Not publicly available in the provided information.
• Institution decision: Denied - 2025-12-23. The panel's reasoning for discretionary denial is not detailed in the provided information, but the status indicates it was denied institution.
• Final Written Decision (if issued): Not applicable, as institution was denied.
• Settlement / termination: Not applicable.
• Appeal: Not applicable.
• Defensive value: This proceeding indicates that JinkoSolar's challenge to the patent through IPR was unsuccessful, and no claims were invalidated. This makes an IPR-based defense harder for parties facing assertion of this patent on the grounds raised by JinkoSolar.

Strategic summary

All eight claims of US 9,130,074 remain SUSTAINED and UNTESTED on the merits at the PTAB, as both IPRs filed against the patent were denied institution on discretionary grounds. This means that the PTAB did not reach the merits of the patentability challenges, and thus no claims were invalidated or even substantively reviewed in a trial. The patent owner, First Solar Inc., has successfully defended against these initial challenges at the institution phase.

The estoppel landscape is therefore somewhat unique. While the petitions were denied, the exact nature of the discretionary denial (e.g., related to parallel district court litigation, insufficient grounds, or another factor) would dictate the precise preclusive effect. However, typically, a denial of institution does not result in statutory estoppel under 35 U.S.C. § 315(e)(2) for the petitioner because a trial was not instituted. Therefore, theoretically, the same petitioners (Canadian Solar and JinkoSolar) could potentially raise the same or similar prior-art grounds in other venues, or different petitioners could bring new IPRs. The current assignee, First Solar Inc., has been aggressively pursuing litigation, as evidenced by the ITC investigation and Delaware District Court lawsuits, and their success in fending off these IPRs at the institution stage signals a strong defense of their intellectual property.

Recommended next steps

Given that both IPRs were denied institution, a defendant currently facing assertion of this patent would need to thoroughly analyze the reasons for the discretionary denials in IPR2025-01432 and IPR2025-01130. This information is critical to understand what arguments or procedural hurdles led to the denial, and whether similar PTAB challenges could be structured differently to overcome those issues. As the patent remains strong from a PTAB perspective, exploring non-PTAB defensive strategies, or identifying novel prior art not previously presented, would be crucial.

To obtain the specific reasoning for the discretionary denials, one would need to access the institution decisions for IPR2025-01432 and IPR2025-01130 via the USPTO PTAB E2E system.