Patent ID: 7679004

Claim:
A circuit board in which a circuit portion is formed on an insulating substrate by a conductive layer and there provided a through hole and/or a non-through hole having an internal wall covered or filled with the conductive layer, wherein a land of the through hole and/or the non-through hole is formed continuously like a concentric circle with respect to the hole, a maximum height of the conductive layer in a non-coupling portion of the land is equal to or greater than −5 μm with a corner portion of the insulating substrate set to be a reference point and is equal to or smaller than a thickness of the conductive layer in a circuit portion, and a land width from the reference point is 0 to 40 μm, wherein the land width falls between a maximum value and a minimum value, and wherein a difference between the maximum and minimum values is equal to or less than 8 μm and greater than 0 μm.