| 摘要 |
PURPOSE:To obtain the enclosure having performance excellent to high frequency by forming an electrode drawing lead by a ferromagnetic material and mounting a material layer not less than 20mum thick having low permeability and high conductivity on an upper surface of a base body. CONSTITUTION:The surface of the iron group lead base body 4a is plated with not less than 20mum thick copper or solder 9. When the currents of the electrode drawing leads 14 are of low frequency, currents are dispersed uniformly in proportional to the conductivity of the base body 4a and the metallic layer 9; while when they are of high frequency, since the base body 4a is made of the ferromagnetic material, a skin effect is displayed strongly, a current course is limited to one part near the surface of the base body 4a and equivalent resistance increases remarkably. The metallic layer 9, which has low permeability, in which the skin effect is difficult to be generated and which has high conductivity, compensates the increase, and currents flow approximately uniform within a range of the thickness of the layer 9. Accordingly, the enclosure displays performance which is excellent against high frequency. |
