The lawsuit, which was filed in the US District Court for the district of New Jersey, covers the alleged infringement of three US patents and names the South Korean parent company and three US subsidiaries: Samsung Electronics America., Samsung Semiconductor and Samsung Austin Semiconductor, said Akira Kadota, a Matsushita spokesman in Tokyo.
"All three patents relate to DRAM memory circuit technology," he said. "One is about the technology used for wiring, the second is about the driver and the third one is about redundancy correction."
The filing came after negotiations between the two companies, which had been going on for two years, broke down with no agreement.
Reacting to the lawsuit, Samsung dismissed Matsushita's claims and said it believes it has not infringed the patents in question.
"I don't think this is a serious matter for our business," said James Chung, a spokesman at Samsung in Seoul. "We didn't use the Matsushita patents at any time. Samsung invests a lot of money in research and development to develop new products and also realises the importance of patent law but in this case we didn't use the Matsushita patents. We will strongly contest the lawsuit."
Matsushita pulled out of the computer memory business in 1998 to focus on system large scale integrated circuit (LSI) chips but says it decided to take action against Samsung to guard its intellectual property rights.
"The reason we made a lawsuit is to protect the fruits of our huge investment in research and development," said Kadota. "Although Matsushita stopped DRAM production at the end of 1998, we made the lawsuit to protect our intellectual property rights."
The company is also wary that if it does not police use of the patents in the DRAM business, it may be harder to stop infringement should the technology become useful in the system LSI space. "Some of the technology could be useful in system LSIs in the future," said Kadota.
Patent infringement lawsuits between semiconductor companies are not unusual. The major semiconductor makers are almost constantly involved in such cases, often suing a company while at the same time collaborating with it on some other area of research or development.