China’s Yangtze Memory Technologies (YMTC) has won its first courtroom victory in Europe over US rival Micron. On 18 September the 7th civil chamber of Munich Regional Court I found that Micron infringed two German utility models covering 3D NAND memory structures and granted injunctions.
The two rights cover a staircase structure for 3D memory and a barrier layer for word line contacts. Three further YMTC cases heard the same day, including one on a European patent, were postponed, according to Xenospectrum.
Micron’s response
Micron says it disagrees with the decisions, has appealed and is contesting the validity of the rights in separate proceedings. It stressed that German utility models are registered without substantive examination, unlike patents. Reports have not identified which Micron products are covered or whether YMTC has begun to enforce the orders.
The counter-attack in Idaho
Micron has opened its own front. In a complaint filed in Idaho on 15 September, it asks the court to transfer four US patents held by YMTC, arguing that the inventors had assigned their rights to Micron while working there. The suit, which also names a former Micron engineer, alleges misuse of trade secrets on 3D NAND manufacturing and circuit design and says at least 20 employees moved from Micron to YMTC over several years, according to Winbuzzer.
Micron says its investigation began after YMTC sued it for patent infringement in California in November 2023. YMTC added a suit in Texas in October 2025, the same month it filed the German cases. Micron filed its own infringement action against YMTC in Munich in mid-July.
The memory chip rivalry between the US and China is now being fought in German and American courtrooms as well as in export rules.
The trade backdrop
YMTC has been on the US Commerce Department’s Entity List since 2022, which restricts its access to US technology. The German cases give it a way to put pressure on Micron’s sales in Europe’s largest economy.
What to watch
- Whether the Higher Regional Court in Munich suspends the injunctions pending appeal.
- Rulings in the three postponed German cases.
- YMTC’s response to the Idaho ownership and trade-secret claims.
