China Yangtze Storage achieves ban on Micron in Germany – 3D NAND supply threat

China’s Yangtze Storage Corp. has obtained an injunction in Germany against U.S. company Micron Technology as part of a patent dispute that has lasted about three years. The German court found that Micron infringed two Yangtze Storage patents related to 3D NAND technology.

Image source: Micron Technology

According to news Tom’s HardcoreOn September 18, the court determined that Micron had two patent infringement cases and issued an injunction against Micron. They could limit the company’s product supplies to Germany and impact the broader European NAND memory market. Micron disagrees with the court’s decision, has filed an appeal, and continues to challenge the validity of the relevant patents in separate lawsuits in different countries.

Yangtze Storage filed a lawsuit with the Munich First District Court (General Court) at the end of 2025, and finally issued the latest injunction. The company has filed five cases involving four German patents and one European patent. The court issued an injunction on patents with a 10-year protection period – DE202020006166U1 (Case No. 7O12615/25) and DE202021004551U1 (Case No. 12614/25), and the hearing of the remaining cases was postponed. So far, these decisions have been made by courts of first instance and may be suspended if Micron successfully appeals to the Higher Regional Court of Munich.

The patent conflict between the two companies began in 2023, when Yangtze Storage filed a lawsuit against Micron in California, accusing it of infringing eight 3D NAND architecture patents. Since then, the dispute has expanded to involve more than 20 patents and triggered a series of lawsuits and counterclaims in China, the United States, the United Kingdom, Germany and other European countries. The lawsuits include patent infringement, determination of ownership, spyware, defamation, false advertising and patent invalidity.

Micron denies wrongdoing and has been filing documents to invalidate Yangtze Storage’s patents since 2024. The first such case came after Yangtze Storage filed a lawsuit in a Chinese court over a related dispute. So far, seven of the challenged patents have been invalidated, but Micron said it will continue to protect its intellectual property rights.

3D NAND is used in smartphones, SSD hard drives and enterprise storage systems. Unlike planar NAND, the memory’s cells are arranged vertically in multiple layers, which increases storage density and lowers the cost per bit. The ruling on the two German patents was made in Germany on September 18, and their further validity depends on Micron Technology’s appeal.