Greenthread LLC v. Sony Group Corporation et al.

This Inter Partes Review (IPR) proceeding, IPR2023-00375, involved patent owner Greenthread LLC and petitioners Sony Group Corporation, Dell, Inc., and several affiliated Sony and Dell entities. Greenthread LLC is identified as a Patent Assertion Entity (PAE) or Non-Practicing Entity (NPE) that focuses on monetizing intellectual property in semiconductor technology, particularly patents originating from inventor G.R. Mohan Rao. The various Sony and Dell entities are prominent global operating companies, with Sony known for its electronics and entertainment products, and Dell for its computers and related technology services. In the context of this IPR, the operating companies challenged the validity of Greenthread's patent, US 10734481.

The patent at issue, U.S. Patent No. 10,734,481, titled "Graded dopant concentration in semiconductor devices," generally relates to semiconductor devices that incorporate graded dopant concentrations within a single drift layer and/or an embedded well region. This design aims to create static electric fields to facilitate the movement of minority charge carriers, thereby enhancing device performance and mitigating undesirable effects. While there is no "accused product" within the IPR itself, these proceedings typically arise in response to underlying patent infringement lawsuits. Greenthread LLC has asserted patents from this family against Sony, Dell, and other major semiconductor and electronics companies in district court, alleging infringement by various semiconductor devices containing graded dopant regions, including Intel's 10th, 11th, and 12th generation semiconductors found in Dell laptops.

This IPR was filed at the Patent Trial and Appeal Board (PTAB), an administrative body within the U.S. Patent and Trademark Office (USPTO), which serves as an alternative forum to federal district courts for challenging patent validity. The PTAB is often chosen by accused infringers due to its potentially faster proceedings, lower costs, and a lower burden of proof for invalidity compared to district courts. The case is notable as it exemplifies the strategy of operating companies using IPRs to challenge patents asserted by NPEs in parallel district court litigation. Greenthread LLC's assertion patterns, backed by an investment manager, against major players in the semiconductor and electronics industries, underscore the financial significance and strategic interplay between district court litigation and PTAB proceedings in the current patent landscape. The ultimate settlement of this IPR indicates a resolution that likely encompassed both the IPR challenge and any corresponding infringement claims.

Legal Developments and Outcome for Greenthread LLC v. Sony Group Corporation et al. (IPR2023-00375)

This case, IPR2023-00375, involves an Inter Partes Review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB) challenging U.S. Patent No. 10,734,481. Sony Group Corporation and other Sony entities are the petitioners, seeking to invalidate claims of the patent, while Greenthread LLC is the patent owner. The proceeding concluded in a settlement.

While Greenthread LLC is actively involved in broader patent infringement litigation campaigns in district courts against other entities, particularly concerning semiconductor devices (e.g., against ON Semiconductor Corporation in the District of Delaware (Case No. 1:23-cv-00443) and Intel Corp. in the Western District of Texas (No. 6:22-cv-00105-ADA)), no specific district court patent infringement lawsuit by Greenthread LLC directly asserting U.S. Patent No. 10,734,481 against Sony Group Corporation or its affiliates has been identified in the public record. Therefore, the IPR proceeding itself represents the primary legal interaction between these specific parties concerning this patent.

Here are the key legal developments and outcome for IPR2023-00375:

Filing & Initial Pleadings (IPR Context)

• Petition Filing (2022-12-19): Sony Group Corporation and other Sony entities filed a petition for Inter Partes Review (IPR2023-00375) against Greenthread LLC, challenging the patentability of claims of U.S. Patent No. 10,734,481. The petition argued that certain claims of the patent were unpatentable based on prior art. This IPR was part of a series of IPRs filed by Sony against Greenthread, including IPR2023-00324 and IPR2023-00325, also challenging Greenthread's patents.

Pre-Institution Phase

• Preliminary Response: As the patent owner, Greenthread LLC would have had the opportunity to file a preliminary response to the petition, arguing against the institution of the IPR. This response typically asserts that the petition fails to establish a reasonable likelihood that the petitioner would prevail on at least one challenged claim.

Institution Decision

• Institution Decision (No specific date found, but implied prior to settlement): The Patent Trial and Appeal Board (PTAB) would have reviewed the petition and the patent owner's preliminary response to determine whether to institute an inter partes review. While the specific institution decision date for IPR2023-00375 could not be definitively identified in publicly available search results, the subsequent settlement indicates that the proceeding progressed beyond the initial filing phase.

Discovery & Claim Construction (IPR Context)

• In IPR proceedings, discovery is limited compared to district court litigation, generally focusing on evidence relevant to patentability arguments. Claim construction, while occurring, is typically based on the "broadest reasonable interpretation" in light of the patent specification and prosecution history, rather than a formal Markman hearing as in district court.

Outcome – Settlement

• Settlement and Termination: The IPR proceeding, IPR2023-00375, concluded in a settlement. According to PTAB procedure, an IPR "shall be terminated with respect to any petitioner upon the joint request of the petitioner and the patent owner, unless the Office has decided the merits of the proceeding before the request for termination is filed." Additionally, any settlement agreement must be filed with the USPTO before termination. While the precise date of the settlement agreement or the PTAB's order terminating IPR2023-00375 due to settlement could not be located, the overall status is recorded as settled. The settlement resolved the challenge to U.S. Patent No. 10,734,481 between Sony and Greenthread in this IPR.

This IPR proceeding, IPR2023-00375, initiated by Sony Group Corporation against Greenthread LLC, concluded in a settlement, which is a common outcome in patent disputes. While specific financial terms or detailed reasons for the settlement were not publicly reported for this particular IPR, the broader context of Greenthread LLC's litigation campaigns against major tech companies like Dell, Intel, and Sony has garnered some attention from legal news outlets. RPX Corporation, a provider of patent risk solutions, reported on Greenthread's assertion of semiconductor fabrication patents, including U.S. Patent No. 10,734,481, against Dell and Intel in a Western District of Texas lawsuit (6:22-cv-00105). This lawsuit targeted Intel's 10th, 11th, and 12th generation semiconductors found in various Dell laptops. The news also noted that Greenthread's patent monetization efforts are backed by an investment funder.

Further reporting from RPX Corporation highlighted Greenthread's broader litigation strategy, including cases against Cirrus Logic, Micron Technology, and Western Digital in the District of Delaware. It also indicated that claims against Intel in the Western District of Texas case were transferred to the District of Oregon, while the case remained active as to Dell and Sony. In general, the articles portray Greenthread LLC as a Patent Assertion Entity (PAE) actively litigating a portfolio of patents related to semiconductor devices with "graded dopant regions," a technology aimed at improving device performance and scaling down feature sizes. The patent at issue in this IPR, 10734481, is part of a family of seven patents, all naming G.R. Mohan Rao as the sole inventor. RPX Corporation's reports also touch upon related IPRs filed against Greenthread's patents by other companies, noting the strategic interplay between district court litigation and PTAB proceedings in these campaigns. For instance, IPR2023-00375 itself is listed as being terminated on May 18, 2023, due to settlement.

While specific details about the settlement in IPR2023-00375, such as damages sought or awarded, were not explicitly covered in the accessible news articles, the reporting emphasizes the strategic nature of these legal challenges. The case exemplifies how operating companies utilize IPRs to challenge the validity of patents asserted by NPEs in parallel district court litigation. The patent family at the core of Greenthread's assertions has been the subject of multiple IPRs and district court lawsuits, with some IPRs leading to invalidation of claims and others, like IPR2023-00375, concluding in settlement. For example, Covington & Burling LLP reported on victories for their clients, Cirrus Logic and GlobalFoundries, in a series of IPRs that invalidated claims across six Greenthread patents, which was seen as undermining Greenthread's broader litigation strategy. This context suggests that while settlements like the one in IPR2023-00375 resolve individual disputes, the larger campaign involving Greenthread's patent portfolio is an ongoing area of interest in intellectual property news.

Sources

• mondaq.com
• rpxcorp.com
• rpxcorp.com
• uspto.gov
• uspto.gov
• uspto.gov
• bannerwitcoff.com
• cov.com

I'll research counsel for Greenthread LLC (the patent owner in this IPR, and the plaintiff in the parallel district court litigation).

Strong lead: McKool Smith appears to represent Greenthread. Let me verify the specific mandatory notices and the district court appearance.

Let me pin down the exact IPR2023-00375 mandatory notice and the district court docket appearances.

Counsel of Record — Plaintiff/Patent Owner (Greenthread LLC)

Terminology caveat (mirroring the defendant-side section). In this IPR, the party on the plaintiff side of the underlying dispute is the patent owner, Greenthread, LLC — the "respondent" in PTAB nomenclature and the plaintiff in the parallel district court case, Greenthread, LLC v. Dell Inc. et al., No. 6:22-cv-00105-ADA (W.D. Tex.). Greenthread is represented across its entire Greenthread/Rao-portfolio campaign by a single outside firm, McKool Smith, P.C. I identify below (a) the counsel of record for Greenthread in IPR2023-00375 itself and (b) the counsel of record for Greenthread-as-plaintiff in the underlying W.D. Tex. litigation.

Grounding note. I was able to confirm the McKool Smith team through the Board's termination decision and, more fully, through the joint-termination papers reproduced as Exhibit 2070 (File History of the '481 Patent) in the related IPR2023-01243 — the May 17, 2023 service block captioned to IPR2023-00375. I could not open the exact IPR2023-00375 Mandatory Notice PDF (Paper 4, filed Dec. 29, 2022) or its Amended Mandatory Notice (Paper 7, Feb. 15, 2023) in full, so I cannot rule out a minor variance between the as-filed notices and the team listed on the termination papers. Treat the roster below as well-sourced but not a verbatim copy of Paper 4.

A. IPR2023-00375 — Greenthread (Patent Owner) counsel of record

Basis: The Board's Paper 10 termination decision (May 18, 2023) lists "For PATENT OWNER: Alan Whitehurst, Nicholas T. Matich, Arvind Jairam, Stuart McCommas, Archis 'Neil' Ozarkar, MCKOOL SMITH, P.C." PTAB case trackers likewise record respondent counsel as "Whitehurst, Alan et al." The Apr. 27, 2023 Board email chain confirms Matich (nmatich@mckoolsmith.com) and the group service address Greenthread-IPR-MS@mckoolsmith.com as counsel for the patent owner in IPR2023-00375 (alongside Smith Baluch for petitioner Sony). I found no separate "of counsel," local-counsel, or in-house lawyer designated for Greenthread in the IPR itself; Greenthread's Gerald Amen (President/Head of Licensing) appears in the record as a client representative, not as counsel, and Dr. G.R. Mohan Rao (inventor) participated as a client/technical representative.

B. Underlying district court case — Greenthread (Plaintiff) counsel of record

From Greenthread's Preliminary Claim Constructions, No. 6:22-cv-00105-ADA (W.D. Tex., served Sept. 19, 2022) (signed "Attorneys for Plaintiff Greenthread, LLC"), the plaintiff's team was:

The same five names (Whitehurst, Matich, Jairam, Campbell, Dawson) appear as Greenthread's "counsel of record in District Court Cases" in later Greenthread/Rao filings, confirming continuity of the team. The W.D. Tex. case was dismissed as between Greenthread and Sony on April 27, 2023, contemporaneously with the IPR settlement (Paper 10, citing the joint motion).

C. Discrepancies, gaps, and caveats

1. "Plaintiff" does not technically exist in the IPR. In IPR2023-00375 the adversarial roles are Petitioner (Sony Group Corp.) vs. Patent Owner (Greenthread). Greenthread is the plaintiff only in the parallel district court case. I have therefore given both the IPR record and the district court record.
2. "Nicholas J. Matich" vs "Nicholas T. Matich." The district court signature block renders the middle initial as "J"; PTAB filings and McKool Smith's own notices render it "Nicholas T. Matich" (and in one Greenthread power of attorney, "Nicholas Theodore Matich, IV"). Same attorney; treat the "J" as a docket/OCR variance.
3. Registration-number variance. Matich's PTAB number appears as "L1,373" in one Greenthread notice (IPR2023-00506) but he is otherwise identified as a registered practitioner; I could not independently verify his registration number, so I flag it as uncertain rather than assert it.
4. Roster drift over time. McKool Smith's Greenthread team changed across the campaign: Scott W. Hejny (Reg. No. 45,882, McKool Smith Dallas) and Brandon Merrill (D.C.) appear in later Greenthread IPRs (e.g., IPR2023-01242/01243, IPR2024-00266) and depositions, and Matich/McCommas were withdrawn as back-up in IPR2024-00266 (2025). I did not verify that Hejny or Merrill appeared in IPR2023-00375, so I do not list them as counsel of record here.
5. Cannot confirm the as-filed Paper 4 / Paper 7 notice text. Because the mandatory notice PDFs were not retrievable in full, the precise counsel listing as of Dec. 29, 2022 / Feb. 15, 2023 may differ slightly from the May 2023 termination-stage roster above.
6. No sealed material used. The § 317(b)/§ 42.74(c) settlement agreements (Patent Owner Exs. 2001–2002) remain confidential and were not used for any counsel identification.

Bottom line: Greenthread, LLC was represented in IPR2023-00375 by McKool Smith, P.C. — Alan L. Whitehurst (lead), with Arvind Jairam, Nicholas T. Matich, Stuart McCommas, and Archis "Neil" Ozarkar as back-up counsel (D.C. and Houston offices). In the parallel plaintiff-side district court action, the same team was joined by Texas local counsel John B. Campbell (Austin) and Kaitlyn M. Dawson (Houston).

I'll research counsel of record for the petitioners/defendants.

Let me dig into the petition's mandatory notices and the parallel district court case.

Let me pin down the parallel district court case and Sony/Dell's litigation counsel.

Counsel of Record — Defendants/Petitioners (IPR2023-00375)

Terminology caveat first. This is an IPR, so the "defendants" are the petitioners. In the PTAB file, the sole petitioner is Sony Group Corporation — not the full Sony/Dell defendant group named in the case metadata (which mirrors the caption of the parallel W.D. Tex. litigation, Greenthread, LLC v. Dell Inc. et al., No. 6:22-cv-00105-ADA). See the Board's consolidated termination decision, IPR2023-00375 Paper 10 (May 18, 2023), which is captioned only "SONY GROUP CORPORATION, Petitioner, v. GREENTHREAD LLC, Patent Owner." I found no record of any Dell entity appearing as a petitioner in IPR2023-00375.

Petitioner's counsel of record (Sony Group Corporation)

Grounding: The Board's May 18, 2023 termination decision (Paper 10) lists "For PETITIONER: Matthew A. Smith, Andrew S. Baluch, SMITH BALUCH LLP." The corresponding Notice of Lead and Backup Counsel filed December 17, 2022 (Paper 2) is the source for their registration numbers, role designations, and address, and an email of April 27, 2023 from the Board docket confirms Matthew Smith as "counsel for Petitioner" for IPR2023-00324, -00325, -00375 and -00376. PTAB case-tracking databases likewise record petitioner counsel for IPR2023-00375 as "SMITH, MATTHEW et al."

No additional petitioner-side counsel (e.g., Sony in-house attorneys, or a second outside firm) appear in the publicly available mandatory notices/decision text I could retrieve. Any such designation would be in the Petition's mandatory notices (Paper 1/2) and the petitioner power of attorney, which I could not open in full.

Petitioner's technical expert (not counsel, but part of the trial team)

• R. Michael Guidash — declared in support of the petition (Petitioner Ex. 1002, with CV at Ex. 1003). Included only to clarify he is an expert witness, not counsel.

Parallel district court litigation — counsel not verified

The underlying case is Greenthread, LLC v. Dell Inc.; Dell Technologies Inc.; Sony Group Corporation; Sony Semiconductor Solutions Corp.; Sony Semiconductor Manufacturing Corp.; Sony Mobile Communications, Inc.; Sony Interactive Entertainment Inc.; Sony Interactive Entertainment LLC; Sony Corporation of America; and Sony Electronics Inc., No. 6:22-cv-00105-ADA (W.D. Tex.) (per the Second Amended Complaint, reproduced as an exhibit in the Greenthread IPRs). That case was dismissed as between Greenthread and Sony on April 27, 2023, the same date the IPR settlement was being executed (Paper 10, citing Joint Motion at 1).

I could not confirm from the sources retrieved who served as district-court counsel of record for Sony or Dell in that case. Specifically:

• One PTAB exhibit contains a service/attorney block headed "ATTORNEYS FOR DEFENDANT SONY CORPORATION" listing Carter Arnett PLLC (Dallas), Siebman Law LLP (Sherman, Tex.), and Mann Tindel Thompson (Tyler, Tex.). I could not tie that document to the Greenthread matter — the same Carter Arnett attorneys appear as local counsel for Sony Corporation in a different E.D. Tex. case, Optimum Imaging Technologies LLC v. Sony Corporation, No. 4:23-cv-00928-ALM, where Wolf, Greenfield & Sacks, P.C. (Boston/New York) is Sony's lead counsel. Treat the Carter Arnett/Siebman/Mann Tindel attribution to the Greenthread case as unverified.
• Similarly, a service list referencing Covington & Burling, Duane Morris, Locke Lord, and Barack Ferrazzano appears in a Greenthread-related proceeding, but it is a multi-party petitioner service list (associated with the Cirrus Logic/onsemi-side IPRs), not Sony's or Dell's counsel in this case. I am not attributing it to Sony or Dell.

Discrepancies and gaps to flag

1. Party mismatch. The metadata lists a broad Sony/Dell defendant group, but the IPR record shows only Sony Group Corporation as petitioner. Dell Inc. and Dell Technologies Inc. appear in the district court caption only.
2. Filing-date discrepancy. The metadata says the IPR was filed 2022-12-19; the PTAB docket and the Board's own decision recite December 17, 2022 (and Paper 10 notes a December 12, 2022 petition date in the lead case, IPR2023-00324). The Dec. 17, 2022 date is the better-sourced one.
3. No merits ruling. The case terminated pre-institution on settlement, so there is no final written decision, no institution decision, and no claim construction order naming counsel — counsel identification rests primarily on the petition's mandatory notices and the termination decision.
4. Sealed/confidential material. The settlement agreements (Patent Owner Exs. 2001–2002) and confidential Exhibit 2001 (to which Sony was not a party) were filed under § 317(b)/§ 42.74(c) and kept separate; they are not public and cannot be used to corroborate any counsel or payment information.

Bottom line: For IPR2023-00375, the only counsel of record I can verify are Matthew A. Smith (lead) and Andrew S. Baluch (backup) of Smith Baluch LLP, Washington, D.C., representing petitioner Sony Group Corporation. No verified counsel of record exists on the public record for the Dell defendants in this IPR, and I could not substantiate Sony's or Dell's district-court counsel in No. 6:22-cv-00105-ADA from the sources retrieved.