In a U.S. District Court patent ruling against Rambus, the judge highlighted some of the company's aggressive tactics for targeting and suing memory chip manufacturers.
On Friday, Judge Sue L. Robinson, in the U.S. District Court in Delaware, ruled that Rambus' patent suit against Micron Technology is "unenforceable," citing "spoliation," defined as the "destruction or alteration of evidence." This occurs when a party has "intentionally or negligently breached its duty to preserve potentially discoverable evidence," Judge Robinson wrote in her opinion.
As a result, 12 Rambus patents are not enforceable against Micron, the largest U.S. manufacturer of memory chips.
Shares of Los Altos, Calif.-based Rambus, which licenses technology for high-speed memory architectures, plunged almost 40 percent, to $11.42 in afternoon trading Friday.
In the opinion, Judge Robinson also cited Rambus' tactics for aggressively suing companies. One September 29, 1999 e-mail quoted in the opinion said that a consensus had been reached by Rambus on the "need to sue a dram company to set an example" and that Rambus should publicize the patents and the suits to "put all dram/controller companies that use sdram/ddr...on notice." (SDRAM stands for Synchronous Dynamic Random Access Memory; DDR stands for Double Data Rate.)
Robinson also declared in the opinion that "in light of Rambus' litigation conduct, the very integrity of the litigation process has been impugned...(and) that the appropriate sanction for the conduct of record is to declare the patents in suit unenforceable against Micron."
Micron had been a target of Rambus, along with other companies including Hitachi, Hynix, and Samsung. "We are pleased with the Delaware Court's ruling that the 12 patents Rambus asserted against Micron in the Delaware case are unenforceable," said Rod Lewis, Micron's Vice President of Legal Affairs and General Counsel, in a statement. "We believe that the decision is applicable to other pending cases, and we are reviewing the ruling to determine its potential impact," he said.
"Micron believes that the Delaware Court's ruling applies to the remaining patents in (a separate) California case and expects to file a motion with the California Court seeking a ruling of unenforceability based on the Delaware Court's decision," Micron said.
Rambus disagreed with the ruling. "We respectfully, but strongly, disagree with this opinion, and at the appropriate juncture plan to appeal," said Tom Lavelle, senior vice president and general counsel at Rambus.
"This opinion is highly inconsistent with the findings of the Court in the Northern District of California which looked at the same conduct and found there was nothing improper with our document retention practices. We are confident in the strength of our position and will continue to vigorously pursue fair compensation for the use of our patented inventions," Rambus said.