Korean chipmakers face lawsuit strain from US 'patent trolls'

Reporters take photos of SK hynix's memory chip video at the company's booth at CES 2026 in Las Vegas, Friday (local time). Yonhap

Patent claims filed by Non-Practicing Entities (NPEs) in the United States are emerging as a risk for Korean chipmakers, as Washington is increasingly leaning in favor of patent holders, forcing companies to incur greater legal costs by defending themselves against so-called “patent trolls.”

The U.S. Patent Trial and Appeal Board (PTAB) on Friday (local time) rejected two petitions filed by SK hynix in August 2025 seeking to invalidate patents held by Advanced Memory Technologies, an NPE which has been staging patent battles against a series of Korean IT companies.

PTAB has put SK hynix’s two petitions, known as inter partes reviews (IPRs), into “Not Instituted” status, meaning the challenges were rejected without a review process. The board had rejected three other SK hynix IPRs in December.

Advanced Memory Technologies filed a patent infringement suit with the U.S. District Court for the Eastern District of Texas in December 2024, claiming that SK hynix had infringed on five of its patents for dynamic random access memory and flash memory technologies.

SK Hynix's inter partes review status on the United States Patent Trial and Appeal Board (PTAB) website / Captured from PTAB web portal

IPR was introduced in 2012 as a tool to prevent NPEs from abusing the patent system by demanding large settlements or licensing fees for vague patents without producing products themselves. It is designed to provide a faster and cheaper way to determine whether a patent is actually valid, allowing patents often used by patent trolls to be invalidated for being not novel or too obvious.

SK hynix is currently facing separate patent infringement suits filed by NPEs Monolithic 3D and Network System Technologies in November and October, respectively. SK hynix has yet to file IPRs against patents used for those suits.

Samsung Electronics is embroiled in a legal dispute with Netlist, an NPE founded by Hong Chun-ki, a former executive of LG Semiconductor. On Oct. 27, Samsung Electronics filed an IPR petition challenging Netlist’s patent related to memory modules.

The patent is one of six that Netlist used in its U.S. International Trade Commission (USITC) filing against Samsung, Google and Super Micro. The USITC instituted an investigation into the allegation on Dec. 30.

The same patent was also used against Micron, which in 2021 attempted to invalidate the patent through an IPR but ended up facing a Texas court decision ordering a $445 million settlement.

Netlist previously won jury verdicts against Samsung in April 2023 and November 2024, totaling $421.15 million, with the court finding that Samsung had materially breached its licensing agreements. Netlist also reached a $40 million settlement with SK hynix in 2021.

“The problem of these lawsuits is that they are focusing on legal matters, not practical technologies,” an industry official said.

“NPEs do not manufacture products or use the patented technologies by themselves, but instead file lawsuits against large companies based on vague patents registered in the past. Targeted companies often become mired in prolonged legal battles, incurring heavy defense costs and frequently opting for settlements. Critics say this dynamic drives up legal expenses while doing little to promote meaningful technological progress.”

A Samsung flag waves at Samsung Electronics' office in Seocho District, Seoul, Jan. 8. Yonhap

Industry officials said the rise in these lawsuits reflects a U.S. legal and policy environment that is becoming increasingly favorable to patent holders.

The IPR denial rate has surged since U.S. Patent and Trademark Office Director John Squires took office in late September. According to popular patent law blog Patently-O, 105 IPR petitions were processed from October to early December 2025, but only four were granted, marking a sharp drop from the 60 to 70 percent grant rate seen between 2022 and 2024.

On Oct. 17 last year, the patent office issued a notice of proposed rulemaking on IPRs, aimed at curbing repeated challenges against the same patents by multiple petitioners and limiting reviews of patents that have already been tested.

If the new rules are adopted, companies will see a slimmer chance of defending their businesses against NPEs and will be forced to spend more on legal costs rather than investing in technologies and job creation.

Industry officials said the surge in NPE attacks should be treated as a matter of survival for Korea’s semiconductor industry, calling on the government and the private sector to jointly raise their concerns with the U.S.

“As Korean chipmakers expand their global market share and revenues, they are becoming increasingly visible targets for NPEs, strengthening the incentive for litigation,” the industry official said. “Rather than simply falling victim to these so-called patent trolls, Korea should engage with the U.S. government to seek practical countermeasures.”