Micron Appeals YMTC’s German 3D NAND Sales Injunctions

Munich I Regional Court Hands YMTC Two 3D NAND Injunctions Against Micron​

The most detailed account comes from Florian Mueller's patent-litigation outlet ip fray, which reported on the day of the ruling that the 7th Civil Chamber, under presiding judge Dr. Oliver Schoen ("Schön"), granted YMTC injunctions over two German utility models, which it described as unexamined patents with a 10-year lifespan. Tom's Hardware, citing a Digitimes report, carried the same date and outcome.

TechNode adds scope. It reports that the court ruled that Micron infringed two German utility models held by Yangtze Memory Technologies, and issued injunctions covering the sale of related infringing products in Germany. TechNode also describes the ruling as Yangtze Memory's first substantive injunction victory since its global patent dispute with Micron escalated in November 2023.

Micron's position is consistent across reports. The company said it disagreed with the decision, filed an appeal and was challenging the validity of the relevant rights. Tom's Hardware adds that Micron is fighting the validity of the related patents in separate cases in several countries.

The judgments themselves, including any list of the specific Micron part numbers they cover, have not been published in anything we could find. No official announcement from the Munich court surfaced either. The details below therefore come from specialist reporting, not the court record.

Two Utility Models, Not a European Patent: What DE202020006166U1 and DE202021004551U1 Cover​

YMTC filed five cases in Munich in late 2025. According to Tom's Hardware, they involved four German utility models and one European patent. Only two of the five produced injunctions on September 18:

ip fray's text gives the first adjourned case number as "7 O 12609725", which looks like a typo for 7 O 12609/25. The European patent, EP3931868, was not part of either injunction. Coverage that describes the win as a European patent ruling gets this wrong.

The two titles that won point at the hardest parts of making 3D NAND. Tom's Hardware explains that 3D NAND stacks memory cells vertically in many layers, where older planar NAND laid them side by side on a flat surface. Stacking packs more storage into the same area and lowers the cost per bit, and modern chips can have hundreds of layers. A "staircase structure" and "barrier layers for word line contacts" both concern how a chip that tall is built and wired. Treat that as our reading of the titles, not the court's construction of the claims, which has not been published.

ip fray also notes that the intellectual property rights-in-suit are utility models derived from patent applications. That was a deliberate choice of weapon.

Why German Utility Models Give YMTC Speed and Micron an Opening​

A Gebrauchsmuster, or German utility model, is a different kind of right from a patent, and the difference shapes both sides' strategy. Germany's patent office, the DPMA, says utility models are registered without any check for novelty, inventive step or industrial application. That makes them quicker, easier and cheaper to get than a patent. The DPMA also warns that they carry a greater risk of being challenged and cancelled, because those substantive requirements are only examined later, in cancellation or infringement proceedings. Protection lasts up to ten years, against up to twenty for a patent.

For YMTC, that means a faster enforceable right in a court known for moving quickly. For Micron, the lack of examination at registration is the obvious line of attack. That fits Micron's statement that it is challenging the validity of the rights. An injunction does not settle whether those two utility models will survive.

ip fray explains the wider reason for the filing strategy. German infringement cases usually involve patents granted by the European Patent Office, but some companies still file national patents with the German Patent and Trademark Office. The outlet expects that route to matter more because the UPC will at some point gain exclusive jurisdiction over EPO-granted patents (the transitional period ends in 2030, and may or may not be extended). The UPC is the Unified Patent Court, the EU's new cross-border patent court. National rights such as German utility models stay outside its jurisdiction.

The Munich Higher Regional Court Now Decides How Much the Micron Injunctions Bite​

The next stage is the appeal. ip fray expects that enforcement will likely begin soon unless the appeals court (the Munich Higher Regional Court) stays both injunctions. Tom's Hardware describes the rulings as first-instance decisions that could be suspended if Micron wins on appeal.

Both statements are forecasts. No report we found says YMTC has started enforcing, that Micron has asked for a stay, or that one has been granted. The accurate status on September 23, 2026 is this: two injunctions have been granted, Micron has appealed, and whether any German sales stop depends on the next procedural steps.

How seriously the two sides take this part of the dispute is clear from the lawyers in the room. ip fray notes that both sides were represented by very large teams of attorneys-at-law and patent attorneys, a fact that reflects the high stakes of the German part of this global dispute. The three adjourned cases, including the European patent, are still open and could give YMTC more leverage or give Micron some relief.

From Northern California to Düsseldorf: The Three-Year YMTC–Micron NAND War​

The dispute started in the United States. Micron's own securities filing, quoted by the Semicon Alpha newsletter, says that on November 9, 2023, Yangtze Memory Technologies Company, Ltd. ("YMTC") filed a patent infringement complaint against Micron and one of its subsidiaries in the U.S. District Court for the Northern District of California ("N.D. Cal."). The complaint alleges that eight U.S. patents are infringed by certain of our 3D NAND products and asks for an injunction, damages, attorneys' fees and costs. Micron responded with patent counterclaims of its own.

The California case has already shown how sensitive the technology is. Micron objected to handing over 73 pages of source-code materials about its 3D NAND fabrication processes. It lost at the Federal Circuit in early 2025. Patently-O later reported that the company petitioned the Supreme Court for a writ of mandamus to reverse a discovery order requiring the company to produce 73 pages of its most sensitive source code in paper form to YMTC. According to Patently-O, the material describes Micron's most advanced 3D NAND products, and fewer than a dozen of Micron's 50,000+ employees have access to the code.

The fight later moved to Europe and widened. YMTC filed an action in October 2025 with the UPC's Düsseldorf local division against Micron and its European subsidiaries, reportedly over three memory patents. On the same day, YMTC also initiated patent infringement lawsuits against Micron simultaneously with the U.S. District Court for the Western District of Texas and the High Court of England and Wales. The same account said UPC documents showed a German trial scheduled for September 17, 2026, one day before the ruling. ip fray separately reported that YMTC went to court in the District of Columbia accusing it of astroturfing in its campaign that led to YMTC's exclusion from the U.S. market. YMTC is pursuing claims under false advertising and unfair competition law.

Tom's Hardware puts the total at more than 20 patents, with claims ranging from infringement and declaratory judgment to spyware, libel, false advertising and invalidation, in courts in China, the U.S., the U.K., Germany and elsewhere in Europe. It also reports that Micron has been filing invalidation challenges since 2024 and that seven of the disputed patents have already been declared invalid. We could not check that count or the list of rulings behind it. The German win came just after YMTC, per ip fray, asked a U.S. district court to lift the stay on its infringement case covering several patents.

All of this sits inside the wider U.S.–China technology conflict. Washington has tightened restrictions on China's access to advanced chipmaking equipment, and Beijing has restricted exports of critical raw materials.

Digitimes Points the Micron Supply Risk at Automotive and Industrial NAND​

The obvious question for PC buyers is whether this affects SSD prices or availability. The evidence does not support a broad answer. Digitimes frames the exposure more narrowly than a general consumer shortage. Its report cites industry sources saying enforcement of the injunctions could restrict Micron's supply in Germany and reshape the European automotive and industrial-control NAND market. Tom's Hardware says more loosely that the injunctions could affect the wider European NAND market.

Both are conditional forecasts from industry sources, not observed disruption. The injunctions apply to Germany and to the products found to infringe the two utility models. Without the judgment texts, nobody outside the case can say publicly whether those products are consumer SSD components, embedded NAND for cars and factory equipment, or both. Nothing reported suggests any effect in the United States or elsewhere outside Germany at this stage.

Our inference is that the most exposed buyers are companies that source Micron NAND through German channels for long-lifecycle embedded designs, which fits the automotive and industrial angle in Digitimes' report. For those designs, changing a qualified memory part is slow and expensive. A PC user buying an SSD at a German retailer has far less at stake, because many other brands compete on the same shelf.

What this means for you​

Most Windows users and home builders need to do nothing. IT buyers and hardware engineers who source Micron NAND for German deployments should watch the appeal. Enforcement status, not the headline, will decide whether anything changes. Until the Munich Higher Regional Court acts, or Micron publishes notices for specific products, there is no confirmed supply problem to plan around.

• The Munich I Regional Court granted YMTC two injunctions on September 18, 2026, over German utility models DE202020006166U1 and DE202021004551U1. Three other cases, including European patent EP3931868, were adjourned.
• The injunctions are first-instance rulings that cover sales of the infringing products in Germany only. Micron has appealed and is challenging whether the rights are valid.
• German utility models are registered without any check of novelty or inventive step, so their validity can still be attacked even after an injunction.
• The Micron products covered have not been published. Anyone with German procurement exposure should ask their Micron distributor or account team about affected part numbers, not assume every product is affected.
• Industry sources quoted by Digitimes expect any supply effect to fall mainly on automotive and industrial-control NAND in Germany, not on the global SSD market.
• The other cases in Munich, Düsseldorf, London, Texas and California continue, so more rulings in either company's favor are likely.

In Munich, YMTC now has what it could not get in three years of U.S. litigation: a court order that can stop Micron selling products in a major European market. That makes a negotiated settlement more likely. How much the order is worth will be decided first by the Munich Higher Regional Court's response to Micron's appeal, then by whether the two utility models survive Micron's validity challenges. Until then, the ruling gives YMTC bargaining power without yet affecting what buyers can get.