IP Law Daily, PATENT—Fed. Cir.: PTAB properly rejected Micron’s obviousness challenges to rival’s memory module patent, (Feb 23, 2026)

By Ravindra Kumar Singh, B.L.

PTAB correctly construed the claim term “specified data rate” and reasonably found no motivation to combine prior art embodiments that would have undermined performance objectives.

In a non-precedential disposition, the U.S. Court of Appeals for the Federal Circuit has affirmed two final written decisions of the Patent Trial and Appeal Board (PTAB) holding that Micron Technology, Inc., and its affiliates, failed to prove that claims of a memory module patent owned by Netlist, Inc., were unpatentable as obvious. The appellate court rejected Micron’s claim construction challenge to the term “specified data rate,” upheld the Board’s motivation-to-combine analysis, and concluded that any alleged error regarding chip select signal construction was immaterial (Micron Technology, Inc. v. Netlist, Inc., No. 24-1312 (Fed. Cir. Feb. 20, 2026)).

Background. The appellant, Micron Technology, Inc., and related entities, are semiconductor manufacturers that develop and sell memory products. The appellee, Netlist, Inc., develops advanced memory module technologies. The dispute arose from two inter partes review (IPR) proceedings in which Micron challenged the validity of Netlist’s patent before the PTAB.

The patent at issue was U.S. Patent No. 10,489,314 (“the ’314 patent”), directed to a memory module operable in a computer system to communicate data with a memory controller at a specified data rate. The patent disclosed a module containing multiple “ranks” of memory devices and a logic circuit that processed data between the ranks and an external memory controller. Independent claim 1 required that the memory module communicate with the memory controller at “a specified data rate,” and that the ranks receive or output data at “the specified data rate.” Independent claim 15 required logic configured to output a first plurality of registered chip select signals, including one active signal and one or more non-active signals, with the ranks configured to receive those signals.

Micron filed IPR2022-00744, challenging claim 1 and several dependent claims as obvious over a patent application directed to memory modules named Halbert. In a separate petition, IPR2022-00745, Micron challenged independent claims 15 and 28, as well as related dependent claims, again primarily relying on Halbert.

Specified data rate. In the -744 proceeding, the Board construed “specified data rate” to refer to the same rate at which data is communicated between the memory module and the memory controller and between the logic circuit and the ranks. Applying that construction, the Board found that Halbert disclosed ranks that operated at half the rate of the module’s communication with the controller. Because Halbert did not teach matching data rates as required by claim 1, the Board concluded that Micron failed to establish obviousness.

On appeal, Micron argued that the Board implicitly misconstrued “data rate” by limiting it to a particular unit of measurement. The Federal Circuit disagreed. The court explained that claim 1’s plain language referred to a transmission rate between components, not to a ratio between two different rates or to data per strobe cycle. The court therefore rejected Micron’s broader interpretation and affirmed the Board’s conclusion that Halbert did not disclose the claimed limitation.

Motivation to combine. In the -745 proceeding, Micron argued that a skilled artisan would have combined Halbert’s Figure 2 embodiment, which disclosed chip select signals, with Halbert’s Figure 4 memory module embodiment. The Board found that Figure 4 relied on concurrently operated ranks to increase throughput, and that incorporating Figure 2’s active and non-active chip select scheme would have eliminated concurrent operation and reduced performance. Because Micron failed to explain why a skilled artisan would have made that performance-sacrificing modification, the Board found no sufficient motivation to combine.

The Federal Circuit held that the Board applied the correct legal standard. Citing KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007), and Adidas AG v. Nike, Inc., 963 F.3d 1355 (Fed. Cir. 2020), the court reiterated that the obviousness inquiry asks whether a skilled artisan would have been motivated to combine references, not merely whether the references could be combined. The Board properly considered fundamental differences between the embodiments and reasonably found that Micron failed to account for them.

The court also rejected Micron’s argument that the Board improperly focused on claim limitation 15.6 in isolation. Relying on Sanofi-Synthelabo v. Apotex, Inc., 550 F.3d 1075 (Fed. Cir. 2008), the court explained that the Board evaluated the claimed invention as a whole and did not dissect the claim into isolated components.

Chip select signals. Micron further argued that the Board erred in construing claim 15’s requirement regarding active and non-active chip select signals. The Federal Circuit declined to resolve the broader construction dispute. It noted that, even under Micron’s theory, the prior art showed active chip select signals sent to a multiplexer rather than to the ranks themselves. Because claim 15 required the ranks to be configured to receive the signals, and Micron did not dispute the Board’s finding that Halbert did not disclose that configuration, Micron’s alternative motivation-to-combine theory failed regardless of the precise construction of the non-active signal limitation.

Thus, the Federal Circuit affirmed both PTAB decisions and awarded costs to Netlist.

The Case is No. 24-1312.

Judge: Reyna, J.

Attorneys: Michael Rueckheim (Winston & Strawn LLP) for Micron Technology, Inc. Philip J. Warrick (Irell & Manella LLP) for Netlist, Inc.

Companies: Micron Technology, Inc.; Netlist, Inc.

Cases: Patent TechnologyInternet FedCirNews