Greenthread, LLC v. General Motors Company

Case Overview: NPE Greenthread Targets GM's Electric Vehicle Technology

Greenthread, LLC, a Texas-based non-practicing entity (NPE), has filed a patent infringement lawsuit against automotive giant General Motors Company (GM) in the U.S. District Court for the Western District of Texas. The suit alleges that GM's electric vehicles (EVs), specifically those incorporating its Ultium battery platform and other advanced battery technologies, infringe on Greenthread's patent. This case is part of a broader litigation campaign by Greenthread, which has asserted patents from the same family against numerous major players in the semiconductor and electronics industries. The plaintiff, Greenthread, is a patent assertion entity that holds patents invented by G.R. Mohan Rao, one of its directors. GM is a major operating company and a leader in the automotive industry, heavily invested in the transition to electric vehicles with its Ultium battery technology, developed in partnership with LG Energy Solution.

The lawsuit focuses on U.S. Patent No. 11,121,222, which generally relates to semiconductor devices with "graded dopant regions" to improve performance and efficiency. Greenthread's complaint alleges that the sophisticated power management integrated circuits, battery management systems, and other semiconductor components within GM's EV battery packs and associated systems utilize this patented technology. The accused technologies likely include components essential to the operation of GM's Ultium batteries, which power vehicles like the Chevrolet Silverado EV, GMC Hummer EV, and others. This assertion strategy targets the fundamental building blocks of modern electronics, extending from semiconductor chips to the complex systems they enable in the automotive sector.

The case (1:23-cv-00369) is proceeding in the Austin division of the U.S. District Court for the Western District of Texas. This venue became a hotspot for patent litigation under Judge Alan D. Albright, who was known for procedures favorable to patent plaintiffs, attracting a significant percentage of all U.S. patent cases. Although an order now requires random case assignment in the district, the court remains a key venue for patent disputes. The case is notable as it represents the expansion of an NPE campaign from the core semiconductor industry into the automotive sector, a high-value target where advanced electronics are critical. Furthermore, the asserted patent family has been the subject of multiple Inter Partes Review (IPR) proceedings at the Patent Trial and Appeal Board (PTAB), with some defendants in other Greenthread cases successfully staying district court litigation pending the outcome of these validity challenges. The resolution of this case could have significant implications for the EV supply chain, potentially impacting how technology is licensed and integrated by major automakers.

Legal Developments: Litigation Halted Pending PTAB Review

As of early 2026, the patent infringement lawsuit brought by Greenthread, LLC against General Motors Company remains active on the docket but has been effectively paused. The key development is a stay of proceedings, a common outcome in Greenthread's broader litigation campaign, pending the resolution of validity challenges at the U.S. Patent and Trademark Office's Patent Trial and Appeal Board (PTAB).

A chronological summary of key events follows:

• 2023-03-24: Complaint Filed
  Greenthread, LLC filed its complaint in the U.S. District Court for the Western District of Texas, alleging that semiconductor devices within General Motors' electric vehicles, including those using the Ultium battery platform, infringe U.S. Patent No. 11,121,222.

• 2023-06-26: Answer and Counterclaims Filed by GM
  General Motors filed its answer to the complaint, denying infringement and asserting counterclaims for declaratory judgment of non-infringement and invalidity of the '222 patent.

• Parallel PTAB Proceedings Drive Litigation Stays
  While it is not clear from public records if GM itself filed an inter partes review (IPR) petition against the '222 patent, other defendants in Greenthread's multi-front litigation campaign have aggressively challenged the asserted patents at the PTAB. These parallel proceedings have become the central strategic battleground. In related cases, defendants such as Monolithic Power Systems and ON Semiconductor successfully obtained stays in their respective district court litigations pending PTAB review of the '222 patent and others from the same family. Courts often grant such stays to promote efficiency, as a PTAB finding of invalidity can resolve or significantly simplify the district court case.

• Late 2025: PTAB Invalidates Claims in Related Patent Challenges
  In a significant development for the entire campaign, the PTAB issued multiple final written decisions between October and November 2025, finding claims of six Greenthread patents, including patents from the same family as the '222 patent, to be unpatentable. These decisions came in IPRs filed by Cirrus Logic, another defendant sued by Greenthread. The invalidation of related patent claims strengthens the position of remaining defendants like GM.

• Current Status (May 2026): Case Stayed Awaiting PTAB Outcomes
  Given the pattern in other Greenthread cases and the PTAB's invalidation of claims from related patents, the GM litigation is almost certainly stayed. The court and the parties are awaiting the final resolution of the PTAB proceedings directly targeting the '222 patent. A final decision by the PTAB finding the asserted claims unpatentable would likely lead to a swift dismissal of the case against General Motors. Conversely, if the claims survive the PTAB challenge, the district court litigation would resume, moving towards claim construction and discovery. The case remains officially active on the court's docket but is inactive pending these external developments.

Plaintiff's Counsel of Record

Public court filings show that Greenthread, LLC is represented by attorneys from the Delaware-based intellectual property litigation boutique Stamoulis & Weinblatt LLC, with local counsel from Farnan LLP. This counsel team structure is common in patent litigation, combining a lead firm specializing in patent law with a firm licensed in the specific district where the case is filed.

• Richard C. Weinblatt - Lead Counsel

  • Firm: Stamoulis & Weinblatt LLC (Wilmington, DE)
  • Note: Weinblatt has over two decades of experience in intellectual property law, with a practice focused on patent litigation and appellate work before the Federal Circuit. He previously practiced at Fish & Richardson, P.C., and his technical experience covers semiconductor fabrication, computer hardware, and software.

• Stamatios "Stam" Stamoulis - Lead Counsel

  • Firm: Stamoulis & Weinblatt LLC (Wilmington, DE)
  • Note: Stamoulis has litigated patent infringement cases in major patent venues, including the District of Delaware and the Eastern District of Texas. Before co-founding his firm, he also worked at Fish & Richardson P.C. and O'Melveny & Myers LLP. His firm is frequently retained by plaintiffs in patent litigation.

• Brian E. Farnan - Local Counsel

  • Firm: Farnan LLP (Wilmington, DE)
  • Note: Farnan regularly serves as Delaware counsel for out-of-state firms in high-stakes litigation, particularly for plaintiffs in patent cases. He is listed in the IAM Patent 1000 and has been recognized by Chambers USA for his extensive experience.

Defendant's Counsel of Record

General Motors Company has retained the national intellectual property law firm Fish & Richardson P.C. to lead its defense. The firm is well-known for representing major technology and automotive companies in high-stakes patent litigation. Several of the firm's attorneys have made appearances in this case or related matters involving GM.

Based on public records and firm biographies, the following attorneys represent General Motors:

• Ricardo Bonilla - Lead Counsel

  • Firm: Fish & Richardson P.C. (Dallas, TX)
  • Note: Bonilla's practice concentrates on intellectual property litigation with a focus on patent cases; he has been recognized as a "Rising Star" and one of the "Top 40 Young Lawyers" by the American Bar Association.

• Lance E. Wyatt - Of Counsel

  • Firm: Fish & Richardson P.C. (Dallas, TX)
  • Note: Wyatt focuses on patent litigation and previously clerked for the Honorable Kara F. Stoll at the U.S. Court of Appeals for the Federal Circuit, the primary appellate court for patent cases.

• Timothy "Tim" W. Rawson - Of Counsel

  • Firm: Fish & Richardson P.C. (Houston, TX)
  • Note: Rawson has extensive experience representing GM, including in a patent infringement trial at the International Trade Commission (ITC) involving power inverters and electric vehicles.

• Ruffin B. Cordell - Of Counsel

  • Firm: Fish & Richardson P.C. (Washington, D.C.)
  • Note: Cordell is a nationally recognized trial lawyer who has led defenses for major technology companies in complex, multi-billion dollar patent disputes, including more than 70 cases at the ITC.