HIGH CONDUCTIVE TYPE STRAIGHT SUSPENSION WIRE

摘要

PROBLEM TO BE SOLVED: To obtain stable straight spring function and high conductivity by applying linear straightening treatment to a composite metal wire formed by covering the outer periphery of a springy metallic conductor with a high conductivity metal layer.;SOLUTION: The outer periphery of a conductor 2 having spring quality formed by drawing a beryllium copper alloy wire, a phosphor bronze alloy wire or a stainless steel wire is covered with high conductivity metal 3, such as electroplated copper to form a composite metal wire 4. After drawing, the composite metal wire 4 is straightened in a wire straightener system by a device provided with two cylindrical basket-type straightening heads and a plurality of cemented carbide dies, and then subjected to aging treatment. The composite metallic wire 4 preferably has a Young's modulus of 80 GPa or higher, conductivity of 20% IACS or higher and straightness of 1,000 mm or higher, and is used as a feed suspension member of fine diameter for optical pickup requiring relatively large current, while contributing to the miniaturization and weight reduction of a device. A lead alloy solder layer containing 5-90 wt.% of tin is suitably provided at the outer periphery to improve solder wet performance or the like.;COPYRIGHT: (C)2000,JPO