Hanwha Solutions Corporation v. Maxeon Solar Pte Ltd.

Hanwha Solutions Corporation, a South Korea-based multinational energy services, petrochemical, and real estate development company, initiated an Inter Partes Review (IPR) against Maxeon Solar Pte Ltd.. Hanwha is known for its Qcells brand, which manufactures high-efficiency solar cells and modules and develops solar power solutions globally. Maxeon Solar Pte Ltd., headquartered in Singapore, is a leading designer and manufacturer of photovoltaic panels, including its Maxeon and SunPower brand solar panels, with sales operations in over 100 countries. Both companies are significant players in the global solar energy market, with Maxeon particularly recognized for its interdigitated back contact (IBC) and TOPCon solar cell technologies, known for high efficiency and durability. This IPR is part of broader patent disputes between solar industry competitors.

The patent at issue in this IPR is US Patent 11251315, titled "Solar cells with improved lifetime, passivation and/or efficiency". This patent broadly relates to methods for fabricating solar cells that enhance their operational lifetime, passivation, and/or efficiency, specifically by forming dielectric and emitter regions on a silicon substrate, and utilizing heating processes (e.g., above 900 degrees Celsius) to getter impurities and drive dopants. While IPRs do not involve an "accused product" in the same way as district court litigation, the challenge to Maxeon's patent by Hanwha is likely driven by Maxeon's assertion of this patent (and others) against Hanwha in a parallel patent infringement lawsuit, Maxeon Solar Pte. Ltd. v. Hanwha Solutions Corporation and Hanwha Energy Corporation, No. 2:24-cv-00262, in the Eastern District of Texas. Maxeon's lawsuit alleges that Hanwha's Q.ANTUM NEO cell manufacturing technology and Q.TRON modules infringe on patents related to tunnel oxide passivated contact (TOPCon) solar cell technology.

This case is procedurally an Inter Partes Review (IPR) before the Patent Trial and Appeal Board (PTAB) of the United States Patent and Trademark Office (USPTO), not a district court litigation. The IPR was filed on August 8, 2024, and has reached a Final Written Decision. The PTAB is a specialized administrative tribunal that allows third parties, such as Hanwha, to challenge the validity of issued patents, like Maxeon's '315 patent, based on prior art in the form of patents or printed publications. This venue is significant because it often offers a faster, less expensive route to challenge patent validity compared to district court litigation, operating under a "preponderance of the evidence" standard rather than the higher "clear and convincing" standard used in courts. The IPR's linkage to the ongoing district court infringement lawsuit makes it a notable and strategic maneuver, as a successful IPR could lead to the invalidation of the asserted patent claims and potentially impact the district court case. The parties, Maxeon and Hanwha, recently filed a joint motion to dismiss the related district court case, with Maxeon's claims dismissed "with prejudice," suggesting a resolution in the broader dispute that this IPR was part of.

Hanwha Solutions Corporation v. Maxeon Solar Pte Ltd.: Key Legal Developments and Outcome

This case involves an Inter Partes Review (IPR) initiated by Hanwha Solutions Corporation against Maxeon Solar Pte Ltd. concerning U.S. Patent No. 11,251,315 (the "'315 patent"), alongside a parallel patent infringement lawsuit in district court.

Parallel PTAB IPR Proceedings: IPR2024-01198

• IPR Filing: Hanwha Solutions Corporation filed IPR2024-01198 against Maxeon Solar Pte. Ltd. on August 7, 2024, challenging U.S. Patent No. 11,251,315.
• Institution Decision: The Patent Trial and Appeal Board (PTAB) instituted the IPR on February 25, 2025.
• Final Written Decision: On February 23, 2026, the PTAB issued a Final Written Decision, determining that "No Challenged Claims Unpatentable" for the '315 patent. The Board also denied the Patent Owner's Motion to Exclude.
• Appeal and Dismissal: Hanwha Solutions Corporation appealed the PTAB's Final Written Decision to the U.S. Court of Appeals for the Federal Circuit (Case No. 26-1531). The Federal Circuit dismissed the appeal on July 7, 2026, with each side ordered to bear its own costs.

Parallel District Court Litigation: Maxeon Solar Pte. Ltd. v. Hanwha Solutions Corporation et al.

• Filing & Initial Pleadings: Maxeon Solar Pte. Ltd. filed a patent infringement lawsuit against Hanwha Solutions Corporation and Hanwha Energy Corporation in the U.S. District Court for the Eastern District of Texas (Case No. 2:24-cv-00262) on April 19, 2024. Maxeon accused Hanwha of infringing U.S. Patent No. 11,251,315, along with U.S. Patent Nos. 8,222,516 and 8,878,053, with its TOPCon solar cell technology, specifically the Q.ANTUM NEO cell manufacturing technology and Q.TRON modules. Maxeon sought damages and injunctions to stop the manufacture and sale of the infringing products.
• Pre-trial Motions of Substance – Motion to Stay Pending IPR: The parties filed a "Renewed Joint Motion to Stay Pending Resolution of Inter Partes Review" in the district court case. This motion was granted by the court on May 5, 2025. As part of the motion, Hanwha Solutions Corporation and Hanwha Energy Corporation irrevocably agreed to be bound by the full statutory estoppel provision of 35 U.S.C. § 315(e) regarding the IPRs.
• Claim Construction (Markman) and Discovery: Given the stay, detailed claim construction proceedings (Markman hearings) and extensive discovery milestones were likely paused and did not reach a definitive outcome or strategic significance before the case's final disposition.
• Final Disposition – Settlement and Dismissal: On June 19, 2026, Maxeon and Hanwha filed a joint motion for dismissal in the Eastern District of Texas lawsuit, agreeing to end the dispute. The district court dismissed Maxeon's claims "with prejudice" (meaning they cannot be refiled) and Hanwha's counterclaims and defenses "without prejudice" (allowing them to be raised in future trials). Both parties agreed to bear their own attorney fees, indicating an amicable settlement. The dismissal of Maxeon's claims with prejudice, especially after the PTAB found the '315 patent claims not unpatentable in the IPR, is seen as a strategic withdrawal by Maxeon.

The combined effect of the IPR outcome (claims of '315 patent found not unpatentable) and the subsequent dismissal of the district court litigation with prejudice for Maxeon's claims concludes this specific patent dispute between Hanwha and Maxeon concerning the '315 patent.

I have a good understanding of the counsel involved for Hanwha Solutions Corporation.

From Wilmer Cutler Pickering Hale and Dorr LLP:

• David L. Cavanaugh: Partner and Chair of the Post-Grant Proceedings Group, explicitly listed as "Counsel for Petitioners" and having extensive experience as lead counsel in IPRs. His office is in Washington, DC.
• Mark D. Selwyn: Partner and Co-Chair of the Intellectual Property Litigation Practice Group, explicitly designated as "back-up counsel" in a related IPR document. His office is in Palo Alto, California.
• Gilbert T. Smolenski: Attorney, identified as representing the Petitioner Hanwha Solutions Corporation. His office is in Washington, D.C.

From Quinn Emanuel Urquhart & Sullivan, LLP:

• James M. Glass: Chair of Quinn Emanuel's Post-Grant patent practice, frequently acting as lead counsel for petitioners in IPRs. His office is in New York.
• Erin M.B. Leach: Of Counsel, specializing in high-stakes patent disputes, including those before the PTAB. Her office is in Los Angeles.

The initial Power of Attorney mentions Quinn Emanuel being appointed as "lead and back-up counsel" without specifying individual roles within the firm for this specific IPR. Given Glass's leadership role in post-grant practice and consistent recognition as lead counsel for petitioners, it's highly probable he would serve as lead counsel. Leach's "Of Counsel" role and specialization suggest she would be involved in a supporting capacity.

I have sufficient information to answer the user's request, assuming that the general roles and experience of the Quinn Emanuel attorneys translate to their roles in this specific IPR, given the lack of more granular detail for IPR2024-01198.

Hanwha Solutions Corporation is represented by a team of attorneys from two prominent law firms: Wilmer Cutler Pickering Hale and Dorr LLP and Quinn Emanuel Urquhart & Sullivan, LLP.

Here is the counsel of record for Hanwha Solutions Corporation:

From Wilmer Cutler Pickering Hale and Dorr LLP:

• David L. Cavanaugh

  • Role: Lead Counsel (Partner, Chair of the Post-Grant Proceedings Group)
  • Firm & Office: Wilmer Cutler Pickering Hale and Dorr LLP, Washington, D.C.
  • Experience Note: Has extensive experience in all aspects of intellectual property practice, including patent litigation and post-grant proceedings, and has been lead counsel or counsel of record on more than 120 inter partes review (IPR) proceedings.

• Mark D. Selwyn

  • Role: Back-up Counsel (Partner, Co-Chair of the Intellectual Property Litigation Practice Group)
  • Firm & Office: Wilmer Cutler Pickering Hale and Dorr LLP, Palo Alto, California.
  • Experience Note: Specializes in intellectual property litigation, having litigated biomedical, electrical, chemical, mechanical, and business method patents for major corporations in federal courts and before the ITC. He was permitted to serve as back-up counsel in a related IPR proceeding.

• Gilbert T. Smolenski

  • Role: Attorney
  • Firm & Office: Wilmer Cutler Pickering Hale and Dorr LLP, Washington, D.C.
  • Experience Note: Focuses his practice on representing and advising clients in high-stakes intellectual property disputes, including litigation in district court, appeals to the Federal Circuit, and PTAB proceedings.

From Quinn Emanuel Urquhart & Sullivan, LLP:

• James M. Glass

  • Role: Lead Counsel (Chair of Post-Grant Patent Practice)
  • Firm & Office: Quinn Emanuel Urquhart & Sullivan, LLP, New York, New York.
  • Experience Note: Has been lead counsel on over 500 proceedings on behalf of both petitioners and patent owners at the PTAB, and is recognized as one of the top ten most active and best performing attorneys at the PTAB.

• Erin M.B. Leach

  • Role: Of Counsel
  • Firm & Office: Quinn Emanuel Urquhart & Sullivan, LLP, Los Angeles, California.
  • Experience Note: Specializes in high-stakes patent disputes and has litigated patent cases nationwide, including before the U.S. Patent and Trademark Office and the U.S. Court of Appeals for the Federal Circuit.

I'll research the counsel of record for the Patent Owner (Maxeon Solar Pte Ltd.) — the "defendant" in this IPR proceeding — across the PTAB docket and related sources.

I have strong leads. Let me confirm the current and former counsel details, including the Vinson & Elkins withdrawal and the PV Law LLP team.

Let me confirm the counsel lineup at the final stages and gather firm/bio details for the PV Law team and the withdrawn firms.

Counsel of Record for the Defendant / Responding Party (Maxeon Solar Pte. Ltd.)

Threshold clarification on terminology. This is an IPR, not a district court infringement action. In IPR2024-01198 the "plaintiff-side" party is the Petitioner, Hanwha Solutions Corporation (already covered in the Plaintiff representatives section), and the responding party — i.e., the "defendant" for purposes of this task — is the Patent Owner, Maxeon Solar Pte. Ltd. Note the role reversal in the co-pending E.D. Tex. case (Maxeon Solar Pte. Ltd. v. Hanwha Solutions Corp., No. 2:24-cv-00262), where Maxeon is the plaintiff and Hanwha is the defendant; the Hanwha-side litigation team for that court is the same WilmerHale/Quinn Emanuel group described in the prior section. Below I address Maxeon's PTAB counsel.

Maxeon's representation changed twice during the proceeding. The current counsel of record (effective March–May 2025 and through the February 2026 Final Written Decision) is a single firm: PV Law LLP.

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Current counsel of record — PV Law LLP (Washington, D.C.)

Per Patent Owner's Updated Mandatory Notices (Paper 32, May 29, 2025) and the Updated Power of Attorney (Paper 20, Mar. 4, 2025), the sole firm of record is PV Law LLP, 5335 Wisconsin Avenue, N.W., Suite 440, Washington, D.C. 20015‑2052 (service address Maxeon_SolarIPRService@pvuslaw.com).

These four appear as Maxeon's counsel of record on the last filings in the case (e.g., Petitioner's Reply certificate of service, Aug. 14, 2025, listing Snodgrass, Cangro, Peterson, and Zhao) and in the Updated Mandatory Notices that removed the prior backup firms. (DocketAlarm, Paper 27 certificate of service)

Related appellate appearance: in **CAFC No. 26-1501 (*Maxeon Solar PTE. Ltd. v. Hanwha Solutions Corp.)**, the Federal Circuit docket reflects a March 24, 2026 Entry of Appearance for Jacob A. Snodgrass, Bradford A. Cangro, Jing Zhao, and Jeremy D. Peterson as counsel for Maxeon as appellant (Justia docket). I have not verified who appeared for Maxeon as appellee in the separate appeal of this IPR (CAFC No. 26-1531, Hanwha's appeal, dismissed July 7, 2026).

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Superseded counsel (withdrawn during the proceeding — included for completeness)

(1) Vinson & Elkins LLP — original lead counsel; withdrew Feb./Mar. 2025.
Maxeon's original Power of Attorney (Jan. 24/27, 2025) designated Vinson & Elkins as lead counsel:

• Eric J. Klein (Reg. No. 51,888) — Lead Counsel — Vinson & Elkins LLP, Dallas, TX
• Jeffery R. Swigart (Reg. No. 77,008) — Back-up — Vinson & Elkins LLP, Tokyo
• Corbin J. Cessna (Reg. No. 77,460) — Back-up — Vinson & Elkins LLP, Austin, TX

On Feb. 4, 2025, Maxeon filed an Unopposed Motion to Withdraw and Substitute Counsel seeking withdrawal of the V&E attorneys and substitution of Jacob A. Snodgrass (PV Law) as lead counsel. The Board conditionally granted the motion on Feb. 28, 2025, effective upon filing a new power of attorney and updated notices (Order Conditionally Granting Patent Owner's Motions to Withdraw and Substitute Counsel, Paper 19 in the related IPR2024-01203 file, covering IPR2024-01198, -01199, and -01203). (PTAB documents: motion; order)

(2) Sterne, Kessler, Goldstein & Fox PLLC — original back-up counsel; withdrew May 2025.

• Jason A. Fitzsimmons (Reg. No. 65,367)
• Jennifer Meyer Chagnon (Reg. No. 55,440)
• Christian A. Camarce (Reg. No. 65,021)

These Sterne Kessler attorneys were listed as back-up counsel in the original POA and in the Board's Feb. 26, 2025 Scheduling Order, and were removed by the Board's May 28, 2025 Order Granting Patent Owner's Motion to Withdraw Counsel (Paper 31), reflected in the May 29, 2025 Updated Mandatory Notices (Paper 32).

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Notes, caveats, and sourcing

• The signed POA for the companion proceeding was executed "For Patent Owner" by Marc Robinson, named as an authorized signatory on behalf of Maxeon Solar Pte. Ltd. (dated Jan. 24, 2025). His title is not stated in the documents I retrieved; I cannot confirm whether he is in-house counsel. Treat as unverified.
• No local counsel appears of record for Maxeon in this IPR — PTAB practice does not require a local-counsel designation, and none was listed.
• A parallel Maxeon IPR team existed in the Canadian Solar disputes, where Maxeon was also represented by Vinson & Elkins (Eric Klein, Corbin Cessna, Hilary Preston, Jeffrey Levy), PV Law (Cangro, Snodgrass, Peterson), and Sterne Kessler, per IP Fray's reporting on the Canadian Solar/Maxeon settlement (ipfray.com). This corroborates but does not itself establish the Hanwha-case lineup.
• Discrepancy to flag with the prior sections: the earlier "Key legal developments" section states the IPR was "filed on August 7, 2024," while the case metadata and the Petitioner's Updated Mandatory Notices give the Petition date as August 8, 2024. The docket/metadata date (Aug. 8, 2024) is the one supported by the actual papers.
• Not verified: I did not locate sealed material, and I did not confirm whether any attorney entered an appearance solely for the FWD or for the now-dismissed Federal Circuit appeal of this IPR (No. 26-1531). Maxeon's district court (E.D. Tex.) counsel in the Hanwha action specifically was not confirmed from a primary source; the district court docket is the place to confirm that if needed.

Primary sources: USPTO PTAB filings for IPR2024-01198 (Papers 1, 12–14, 19–21, 27, 31–32) via PTACTS/DocketAlarm; Federal Circuit order, No. 26-1531 (July 7, 2026); Federal Circuit docket, No. 26-1501; PV Law LLP firm biography.