SANKEN ELECTRIC completes purchase of POLARFAB

Saitama, Japan, July 12, 2005 -- Sanken Electric Company, Ltd., a semiconductor manufacturer headquartered in Saitama Japan, today announced its purchase of US analog semiconductor foundry, PolarFab, LLC for $83 million. The legal entity will become Polar Semiconductor Inc. (PSI). The acquisition is part of the Sanken Group's efforts to expand wafer fabrication capacity while obtaining advanced sub-micron process technology.

Polar, located in Bloomington, MN, is an analog semiconductor foundry with annual sales of $75 million. Polar currently supports 45 customers, including Allegro MicroSystems, Inc., a wholly-owned US subsidiary of Sanken Electric. Sanken President, Yuji Morita, stated that the purchase was critical to the Sanken Group. "This acquisition builds on the very successful relationship the Sanken Group has developed with Polar and satisfies our need for additional wafer capacity, advanced process technology and process development talent." He further stated that the acquisition provides significant advantages over the construction of a new fab facility in that it eliminates any delay in time-to-production and provides access to an experienced, knowledgeable and stable workforce.

Sanken's immediate plans for Polar include the transfer of Sanken Electric's BCD power semiconductor manufacturing process and quick ramp of the Polar 8-inch manufacturing line. Morita further stated that Polar, as "The Flexible Foundry," will continue to support its existing foundry customers.

About Sanken Electric

Sanken Electric Co., Ltd., headquartered in Saitama-ken, Japan, is a $1.5 billion diversified electronics manufacturer specializing in power transistors and high voltage diodes, power hybrids, and power supplies. Sanken Electric Co., Ltd. acquired Allegro MicroSystems, Inc. from Sprague Technologies in December 1990. Further information about Sanken can be found at

About Allegro MicroSystems

Allegro MicroSystems, Inc., headquarted in Worcester, Massachusetts, is a supplier of advanced mixed-signal power semiconductors and Hall-effect sensors targeted toward the automotive, communications, computer/office automation, consumer and industrial markets. It maintains a leadership position in the integrated magnetic sensor and integrated motor driver product segments. Further information about Allegro can be found at

About Polar Semiconductor

Polar Semiconductor provides silicon solutions for customer-designed integrated circuits (ICs) through proven design methodologies accessing a broad range of bipolar and BiCMOS manufacturing processes. Polar's focus is on exceptional customer support provided by a creative, flexible and responsive staff of professionals. The company offers six-inch and eight-inch wafer processing, testing and failure analysis services meeting the analog, mixed signal and smart power IC requirements of fabless and fab-lite semiconductor companies. Further information about Polar can be found at