Rambus designs, develops and licenses high-bandwidth chip-connection technologies which enable semiconductor memory devices to keep pace with faster generations of processors and controllers. The company owns more than 100 patents, which it has licensed to around 30 chip-makers.
The dispute involved the SDRM (synchronous dynamic random access memory), and DDR (double data rate) memory chips. These chips allow fast transfer of data, are more efficient than the traditional DRAM chips and are replacing them in most new PCs. Rambus owns patents that it claims cover these technologies.
In 2000, Rambus sued Infineon, Europe's third largest chip manufacturer, claiming that the company uses technologies covered by Rambus patents without a licence. Rambus had already licensed these technologies to Toshiba, Hitachi and Oki Electric.
Infineon denied the allegations and filed a lawsuit in retaliation. The Munich-based company claimed that Rambus does not own the intellectual property in the patents in question, and that its lawyers illegally manipulated Rambus's existing RDRAM patent, several years after the original filing, to include SDRAM technologies.
The company also accused Rambus of fraud in seeking royalties, by failing to submit details of existing patents and prior art in filing amendments to its patents with the US Patent and Trademark Office. Rambus, Infineon alleged, also tried to hide certain patent applications from the chip industry's standard-setting body, JEDEC.
Finally, Infineon claimed that Rambus stole information from JEDEC committee meetings and used it in its patent amendments, thus giving it control of industry standard SDRAM technology.
Rambus was initially found guilty of fraud due to the non-disclosure of patents and patent applications to JEDEC. The court also issued an injunction barring Rambus from enforcing a number of patent claims against the German chip maker.
Rambus asked for a re-trial, claiming that the jury erred in its verdict. Yesterday, the federal Court of Appeals in Virginia sided with Rambus's arguments and reversed the original decision.
The court said: "substantial evidence does not support the implicit jury finding that Rambus breached the relevant disclosure duty during its participation in the [JEDEC] standards committee."
The damages awarded to Infineon and the injunction are now removed, and the case will go back to the lower court for a re-trial.