Patent Fight

National Semiconductor Corp., which makes high-performance computer chips, accused smaller rival Micrel Semiconductor Inc. of infringing two patents used in the chip-manufacturing process. In its suit, Santa Clara, Calif.-based National Semiconductor says it is the owner of patents awarded in 1982 and 1984 protecting methods used for controlling corrosion and regulating voltage. Officials of Micrel were not immediately available to comment on the suit.