WIRING BOARD AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a wiring board wherein a base board composing the wiring board is formed of metal material, conductive via electrodes which are provided to the base board so as to electrically connect its surfaces together and have a coaxial structure, through-holes are small in diameter and provided to the base board, and the ratio of the diameter of the through-hole to the thickness of the metal board is set large. SOLUTION: The wiring board is equipped with the metal board provided with the through-holes that are formed penetrating through both the surfaces of the metal board, an insulating layer which covers both the surfaces of the metal board and the inner surfaces of the through-holes, a wiring layer which is formed on the top surface of the insulating layer formed on the one surface of the metal board, and the conductive via electrodes formed inside the through-holes. The through-hole is 100 μm or below in diameter, snd the ratio of the diameter of the through-hole to the thickness of the metal board is set at 1.0 or above, preferably 1.2 or above. COPYRIGHT: (C)2006,JPO&NCIPI