According to news on December 8, after years of ongoing global patent litigation, Yangtze Memory Technologies Co., Ltd. (YMTC) has launched validity challenges against Chinese patents held by U.S. memory giant Micron Technology for the first time in China.

From December 3rd to December 4th, 2025, the China National Intellectual Property Administration (CNIPA) publicly disclosed information regarding three cases on YMTC’s challenging against Micron’s 3D storage patents. 

The three patents involved are titled as follows:

1. Memory arrays having substantially vertical, adjacent semiconductor structures and the formation thereof

2. Three-dimensional memory devices and methods for forming the same

3. Electric charge storage devices, systems, and methods 

Now, the U.S. Patent and Trademark Office (USPTO) is currently conducting a "national security examination" regarding two Inter Partes Review (IPR) petitions filed by YMTC in the U.S. to invalidate Micron’s patents. 

On November 10, the USPTO requested YMTC to provide reasons as to why its IPR petitions should still be accepted despite the company being listed on the Entity List. 

What should be noticed is that YMTC’s challenges against these three Micron patents in China were filed in late September and October, which is earlier than the U.S. national security examination, thus having no direct connection with it. 

Micron has also initiated validity challenges against at least 8 of YMTC’s patents in China. However, as the CNIPA does not currently have similar provisions on rejection of such challenges, all of Micron’s petitions remain under examination.

From IPRdaily

December 11th, 2025