German Court Sides With China's YMTC in Patent Dispute Against Micron

In a ruling that strengthens YMTC's position in Europe, a German court has handed down injunctions against Micron Technology over alleged violations of 3D NAND flash memory patents. The decision represents the latest chapter in an intensifying dispute between the two memory manufacturers that has sprawled across courts worldwide.

On September 18, the Munich 1 Regional Court determined that Micron had infringed two of YMTC's 3D NAND technology patents, according to reporting from Digitimes. The injunctions carry the potential to constrain Micron's ability to sell products in Germany and could reverberate through the broader European NAND market. Micron has rejected the court's findings and announced plans to appeal the decision at the Munich Higher Regional Court. The company is simultaneously contesting the validity of the patents through separate proceedings in multiple jurisdictions.

YMTC initiated the lawsuit that produced these injunctions in late 2025 at the Munich 1 Regional Court, filing five separate cases that encompassed four German utility models and one European patent. The court granted injunctions on two utility models—DE202020006166U1 (case No. 7O12615/25) and DE202021004551U1 (case No. 12614/25)—each carrying 10-year protection periods, while postponing decisions on the remaining cases. Because these are first-instance rulings, they remain subject to suspension should Micron prevail on appeal.

The Munich decision caps a prolonged confrontation that began in 2023 when YMTC sued Micron in California, claiming the company had violated eight 3D NAND architecture patents. The dispute has since metastasized into a sprawling legal campaign involving more than 20 patents, with both companies filing suits and countersuit across multiple continents. The litigation encompasses claims of patent infringement, declaratory judgment, spyware allegations, libel, false advertising, and patent invalidation actions, with filings in courts throughout China, the United States, the United Kingdom, Germany, and elsewhere in Europe.

Micron has consistently maintained its innocence and has mounted multiple challenges to the validity of YMTC's patents beginning in 2024, shortly after YMTC brought the company before Chinese courts. Seven of the disputed patents have already been invalidated, and Micron has signaled its intention to continue defending its intellectual property through further legal action.

What 3D NAND Technology Does

3D NAND represents a flash memory storage architecture deployed in devices ranging from smartphones and solid-state drives to enterprise storage infrastructure. Traditional planar NAND arranges memory cells horizontally across a flat surface, whereas 3D NAND stacks cells vertically across multiple layers. This vertical arrangement enables manufacturers to achieve higher storage density within the same physical footprint while reducing the cost per bit of storage. Contemporary NAND chips frequently incorporate hundreds of these stacked layers, making the underlying architecture and production methods highly valuable commercial assets.

Broader U.S.-China Technology Competition

The Micron-YMTC patent dispute unfolds within the context of intensifying technology competition between Washington and Beijing. The United States has progressively restricted China's access to cutting-edge semiconductor manufacturing equipment and related chip technologies, while China has imposed export controls on numerous materials critical to semiconductor production.