| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a wiring board and an electronic device using the same with which high frequency signals may be transmitted efficiently by reducing reflection noises through adjustment of the characteristic impedance of an external connection pad within the ranger of 50Ω±10% by controlling the thickness of an insulation layer. <P>SOLUTION: The wiring substrate is formed by laminating a plurality of layers, on the principal surface of an insulation substrate 1, of an insulation layer 2 having the dielectric coefficient of 3.5 to 4.5 including an epoxy resin and an inorganic insulation filler, a signal wiring conductor 7 and a wiring conductor layer 3 consisting of a ground conductor 4 or power source conductor 5, and allocating, on the surface of an insulation film 2a located at the outer most layer, an external connection pad 8 in diameter of 400 to 1000μm connected with a high frequency signal electrode of an external electric circuit substrate opposing to the ground conductor 4 or power source conductor 5 located between the insulation layers 1. Thickness t of the insulation layer 2a between the ground conductor 4 or power source conductor 5 and external connection pad 8 opposing thereto is about 0.47 to 0.52 times the diameter w of the external connection pad 8. <P>COPYRIGHT: (C)2004,JPO</p> |
