摘要 |
A printed wiring board includes a core substrate having first and second surfaces, a first conductor formed on the first surface of the substrate, a second conductor formed on the second surface of the substrate, a first through-hole conductor formed through the substrate and connecting the first and second conductors, and a second through-hole conductor formed through the substrate and connecting the first and second conductors. The second through-hole conductor has a diameter which is greater than a diameter of the first through-hole conductor, the first through-hole conductor has a roughened inner wall forming an interior space, the second through-hole conductor has a roughened inner wall forming an interior space, and the roughened inner wall of the first through-hole conductor has an arithmetic average roughness which is set lower than an arithmetic average roughness of the roughened inner wall of the second through-hole conductor. |