| 摘要 |
PROBLEM TO BE SOLVED: To provide a substrate in which a through hole has small diameter of such as 70 to 130μm, no breaking in penetrating conductors occurs and extremely high density wiring can be achieved. SOLUTION: A plurality of the through holes 3 having diameters of 70 to 130μm and enlarging their diameters outward are formed from an upper surface to a lower surface of both sides of copper-clad plate in which surface layer conductive bodies 2A, 2B comprising copper foils with a thickness of 3 to 12μm and plated layers on the copper foil are attached to an upper and lower surfaces of an insulating resin plate 1 with a thickness of 0.2 to 0.8 mm. The penetrating conductors 4 comprising plated metal layer for connecting the surface layer conductive bodies 2A, 2B of the upper and lower surfaces are attached to an inner wall of the through holes 3. COPYRIGHT: (C)2004,JPO
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