INDUCTANCE ELEMENT AND RADIO TERMINAL

摘要

PROBLEM TO BE SOLVED: To prevent stripping of conductive film and lowering of the quality factor Q and the self resonance frequency by specifying the surface roughness of a base and forming a conductive film on the base. SOLUTION: A base 11 is made by pressing or extruding an insulating material and a conductive film 12 is deposited thereon by plating or sputtering. A trench 13 is made in the base 11 and the conductive film 12 through irradiation with a laser beam or mechanical grinding. A protective material 14 is applied to a part of the base 11 and the conductive film 12 where the trench 13 is made and terminal electrodes are formed at terminal parts 15, 16. The trench 13 and the protective material 14 are provided between the terminal parts 15, 16. Surface roughness of the base 11 is set in the range of 0.15-0.5μm, preferably in the range of 0.2-0.3μm.