Micron is having more China-related problems after YMTC launched legal proceedings over allegations that the US memory maker is infringing on patents relating to 3D NAND technology.

YMTC, or Yangtze Memory Technologies Company, filed its lawsuit against Micron at the US District Court for the Northern District of California late last week, accusing it of "widespread and unauthorized use of YMTC's patented innovations."

The lawsuit claims that Micron is making use of YMTC's patented tech "in an effort to fend off competition from YMTC," and to "gain and protect its own market share" by "freeriding on YMTC's innovations."

According to the complaint [PDF], filed on on November 9th, the devices at the center of this case are 96-layer, 128-layer, 176-layer and 232-layer memory chips made by Micron, which it refers to as the "Accused Memory Products." These are NAND flash components, widely used in smartphones and laptops, as well as solid state drives (SSDs) and other storage hardware.

YMTC asserts that Micron would be aware that YMTC has patents in 3D NAND technology which are "relevant to Micron's own 3D NAND products," and allges in the complaint that "many YMTC-owned patents are cited on the face of Micron's own patents," demonstrating Micron's knowledge of YMTC's patent portfolio, yet "Micron has not sought or received authorization to use those patents," it says.

There are a total of eight patents in question that the company alleges Micron is infringing upon, comprising US Patent numbers 10,950,623, 11,501,822, 10,658,378, 10,937,806, 10,861,872, 11,468,957, 11,600,342, and 10,868,031.

YMTC alleges that Micron's 96-layer chips infringe on the '623 patent, which it reckons are used in products such as Micron's own SSD model 1300 SATA and SSD model c200. The suit claims that Micron's 176-layer and 232-layer parts infringe on the '822 patent, and the 128-layer chips infringe on the '378 patent, also used in Micron SSD products.

The company is requesting a jury trial in the case, in which it hopes to be awarded damages and costs relating to the claims, and for a ruling prohibiting Micron from further infringement on its patents.

A spokesperson for YMTC confirmed that the company filed the lawsuit against Micron for infringement of patents related to "the design, manufacture, and operation of 3D NAND technology," but said they could not discuss the specifics of pending litigation.

"Just as we are committed to the pursuit of progress and product innovation, we are steadfast in our commitment to protecting our IP. We are confident that this matter will be resolved swiftly," the spokesperson told The Register.

Micron told us it does not comment on pending litigation.

The US chipmaker has endured something of a turbulent year, with revenue for the third quarter of its fiscal 2023 coming in at $3.75 billion, 57 percent down on the same period in 2022. This was due to a slump in memory prices on the back of falling demand.

Micron was also facing a ban on the purchase of Micron memory products for use in critical information infrastructure installed in China, following a ruling by China's Cyberspace Administration (CAC) that they presented a security threat. Sales to China were said to account for approximately a quarter of Micron's worldwide revenue, which it predicted might cost it $4 billion in annual revenues.

However, earlier this month, the company seemed to be back in Beijing's good books, as the Minister of Commerce Wang Wentao invited Micron to expand its investments in the country. Micron had already said it planned to invest ¥4.3 billion (just over $600 million) into upgrading its chip packaging facility in the city of Xi'an over the next several years, despite the sanctions.

In related news, YMTC was reported this month to be attempting to raise fresh capital, as it had already used up the $7 billion it received from shareholders earlier this year, including from the state-run China Integrated Circuit Industry Investment Fund, in order to help the company adapt in the face of US sanctions. ®

https://www.theregister.com//2023/11/13/ymtc_micron_lawsuit/