PURPOSE: To prevent generation of stray capacitance and to improve frequency characteristics by a method wherein a part of the double-layer covered conductor on the outer circumference is formed into a helical shape, and the above-mentioned double-layer is composed of an inner insulating layer and an outer earthing conductor layer.
CONSTITUTION: A linear conductor 1, consisting of conductive Cu and the like, is formed in rectilinear-shaped both ends and the intermediate part wound in helical form, the conductor 1 is covered by a double-layer excluding a part on both ends for connection. The double layer is composed of an insulating layer 2 on the side of the conductor 1 and an earthing conductive layer 3 located on the outside, the insulating layer 2 consists of the organic material and the like such as epoxy resin and the like having a very low dielectric constant, for example, and it is formed by coating, dipping and the like. In the inductance of the constitution, and the outside of the conductor 1 is coated with an earthing conductive layer 3 through the intermediary of an interposed insulating layer 2. When the earthing conductive layer 3 is earthed, the generation of stray capacitance, which might be grown between the adjacent wires of the helical conductor 1, is prevented, no resonance is generated, and an inductor having excellent frequency characteristics is obtained. Also, if the conductive layer is formed with conductive material having magnetism, the conductor is magnetically shielded.
YAMAOKA OSAMU
YUASA HISAO
KURIHARA HIDEOMI
