Firm Will Move Manufacturing Jobs From O.C. : Technology: Computer circuits maker Silicon Systems will transfer about 150 people to a new plant, but it plans to keep its headquarters and about 800 workers in Tustin.

Silicon Systems, a fast-growing Tustin company that makes computer circuits, confirmed Tuesday that it is moving its manufacturing operations out of Orange County.

The privately held company, a subsidiary of Tokyo-based TDK Corp., said it plans to keep its corporate headquarters, main design center and about 800 workers in Tustin. It will move its remaining 150 manufacturing workers to a new plant, the site for which has not yet been selected.

Silicon Systems, which makes computer microchips found in many disk drives, has about 2,000 workers worldwide, most of them in Orange County, Santa Cruz or Singapore. About four years ago, the company moved its major manufacturing operations from Orange County to Santa Cruz, where it now employs 450.

The company said Tuesday it is looking in Oregon, Nevada and the Sacramento area for manufacturing sites.

“We have no plans to move our corporate headquarters, but our manufacturing will be phased out of Tustin by 1995,” said Mark Jorgensen, spokesman for the company. “We will not be a major Orange County manufacturer anymore.”

The company is projecting sales of about $320 million this year, a 30% increase from 1993.

Jorgensen described the move as a “technology shift.” The company’s manufacturing operation in Santa Cruz is not only bigger than its Orange County facility, he said, but also newer and more high-tech. Because of that, he said, expanding there is more cost-effective than at sites such as the 22,000-square-foot manufacturing facility in Orange County, which was built in 1981.

The 150 workers affected by the move will probably be transferred rather than laid off, the company said.

Also on Tuesday, the company said it has replaced Alan V. King as president and chief executive officer. Yutaka Mori, 53, became president and chief executive officer effective Tuesday. Mori, a 24-year veteran of parent company TDK, joined Silicon Systems in May, 1989.

Rick Goerner, 46, is the new chief operating officer and Bill Bendush, 45, the chief financial officer.

King, 59, will remain with the company as vice chairman of the board of directors.