Micron Technology Inc. v. Yangtze Memory Technologies Co Ltd.

Micron Technology Inc. (Micron), an American multinational semiconductor company and a global leader in memory and storage products, including DRAM and NAND flash memory, is engaged in a high-stakes patent dispute with Yangtze Memory Technologies Co Ltd. (YMTC). YMTC, a Chinese state-backed integrated device manufacturer specializing in 3D NAND flash memory, is a key player in China's strategic efforts to develop its domestic chip industry. This Inter Partes Review (IPR) case, IPR2025-00228, was filed by Micron against YMTC, challenging the validity of YMTC's U.S. Patent No. 11,101,276, titled "Memory string architecture and method of manufacturing the same." This patent generally relates to advanced 3D NAND flash memory structures and manufacturing processes.

This IPR is part of a broader, intensifying patent conflict between the two memory giants. YMTC initiated litigation in November 2023, filing a patent infringement lawsuit against Micron in the U.S. District Court for the Northern District of California, and later in the Eastern District of Texas, accusing Micron's 3D NAND flash products (including 96, 128, 176, and 232-layer designs) and certain DDR5 SDRAM products of infringement. Micron's IPR petition before the Patent Trial and Appeal Board (PTAB) of the USPTO, which was instituted on July 25, 2025, serves as a defensive measure to challenge the patentability of YMTC's asserted patent claims. The PTAB panel assigned to this case includes Administrative Patent Judges Ken B. Barrett, James A. Tartal, and Ryan H. Flax.

The case is highly notable due to the escalating "chip war" and geopolitical tensions between the United States and China, with both countries vying for dominance in the semiconductor industry. YMTC's placement on the U.S. Department of Commerce's Entity List in October 2022 has introduced significant national security concerns into the legal proceedings. Micron has argued that YMTC is a proxy for the Chinese government and that allowing such challenges threatens U.S. economic and strategic interests. While the PTAB has acknowledged these concerns, it has indicated limitations on its authority to consider foreign policy or national security implications in institution decisions under current USPTO guidance. Furthermore, in related IPRs filed by YMTC against Micron, the USPTO Director recently vacated institution and denied the petitions, citing YMTC's failure to identify all real parties in interest, specifically its ties to Chinese state-owned enterprises. This ongoing legal battle highlights the intersection of intellectual property, trade policy, and national security in the global technology landscape.

Micron Technology Inc. initiated an Inter Partes Review (IPR) proceeding against Yangtze Memory Technologies Co Ltd. before the Patent Trial and Appeal Board (PTAB) of the USPTO, challenging U.S. Patent No. 11,101,276. This case is an IPR and not a traditional district court patent infringement litigation, thus the standard litigation milestones like jury trial, extensive discovery, and claim construction (Markman) hearings as typically understood in district court proceedings do not directly apply.

Here are the key legal developments for IPR2025-00228:

• IPR Petition Filing (2024-11-29): Micron Technology Inc. filed a petition for Inter Partes Review, challenging claims 1-18 of U.S. Patent No. 11,101,276, owned by Yangtze Memory Technologies Co Ltd.. The petition asserted grounds for unpatentability based on obviousness over the prior art references Kim and Fang.
• IPR Institution (2025-07-25): The PTAB instituted the Inter Partes Review on July 25, 2025. During the pre-institution phase, Micron argued against a discretionary denial of the IPR, noting that any parallel district court trial date was distant (June 15, 2026), that minimal investment had been made in any co-pending litigation regarding the '276 patent, and that Micron had stipulated not to pursue the same invalidity grounds in district court to avoid issue overlap.
• Parallel District Court Litigation (Filed 2025-10-07): A related patent infringement lawsuit, Micron Technology, Inc. et al v. Yangtze Memory Technologies Company Ltd. (Case No. 5:25-cv-08588), was filed by Micron in the U.S. District Court for the Northern District of California on October 7, 2025. This district court case was filed after the IPR petition was filed and after the IPR was instituted.
• IPR Case Closure (2026-07-06): The IPR proceeding, IPR2025-00228, closed on July 6, 2026. While the specific nature of the closure (e.g., Final Written Decision, settlement leading to termination) is not detailed in the available snippets, this date indicates the formal conclusion of the IPR proceeding at the PTAB.

It is important to note that separate IPRs filed by Yangtze Memory Technologies Co. (YMTC) against Micron Technology were resolved by a Director review decision in January 2026. Those IPRs were denied institution not on the merits, but due to YMTC's failure to identify all real parties in interest, specifically its ties to Chinese state-owned enterprises. That controversy is reportedly heading to the Federal Circuit on appeal. This distinct development pertains to IPRs where YMTC was the petitioner and does not directly affect the status of IPR2025-00228, where Micron is the petitioner.

Micron Technology Inc., the petitioner in IPR2025-00228, is represented by attorneys from Orrick, Herrington & Sutcliffe LLP.

The following counsel has been identified:

• Name: Jared Bobrow
• Role: Lead Counsel (inferred from his co-leadership of the firm's global IP practice and his specific mention of appearing in related IPR proceedings for Micron)
• Firm: Orrick, Herrington & Sutcliffe LLP
• Office Location: Silicon Valley (Menlo Park, CA)
• Relevant Patent Litigation Experience: Jared Bobrow is a nationally recognized patent trial lawyer with nearly 30 years of experience litigating patent disputes nationwide, including in district courts and at the Patent Trial and Appeal Board (PTAB). He focuses on the semiconductor, communications, cloud computing, and medical device industries. Bobrow previously co-chaired Orrick's global Intellectual Property practice and teaches patent litigation at U.C. Berkeley Law School.

While Orrick, Herrington & Sutcliffe LLP is the firm of record for Micron Technology Inc. in this IPR, specific other attorneys from the firm explicitly designated as counsel of record for IPR2025-00228 were not individually identified in the public search results.

Yangtze Memory Technologies Co Ltd. is represented by counsel from Latham & Watkins LLP in IPR2025-00228.

Attorney: Inge A. Osman

• Role: Counsel for Patent Owner (likely lead counsel or a key member of the legal team given her role in filing substantive briefs for the Patent Owner).
• Firm: Latham & Watkins LLP, Washington, D.C.
• Experience: Ms. Osman advises domestic and multinational clients on high-stakes intellectual property litigation, including before federal district and appellate courts, as well as the Patent Trial and Appeal Board (PTAB). She is recognized among the "Top 50 Women in PTAB Trials" as of 2025, with a record of over 100 proceedings, and has successfully represented clients in matters involving various technologies, including semiconductors. She previously clerked for Judge Kimberly A. Moore of the US Court of Appeals for the Federal Circuit.

No other specific attorneys have been identified as counsel of record for Yangtze Memory Technologies Co Ltd. in IPR2025-00228 from the provided search results.