Patent ID: 9320143
Filing Date: 2016-04-19
CPC Classification: H05K,Y10T

Claim Text:
1. A wiring board comprising: a substrate having opposing first and second surfaces, the substrate having at least one through-via passing through the substrate from the first surface to the second surface; a first conductor layer formed on the first surface; a second conductor layer formed on the second surface; and a through-via conductor formed in the through-via for electrically connecting to the first conductor layer and the second conductor layer; wherein the through-via has a first depressed portion exposed in the first surface, a second depressed portion exposed in the second surface, and a cylindrical tunnel portion having a substantially constant internal diameter between the first depressed portion and the second depressed portion for connecting the first depressed portion and the second depressed portion, wherein the first depressed portion and the second depressed portion are non-coaxial, and the internal diameter of the tunnel portion is less than a diameter of the first depressed portion in the first surface and a diameter of the second depressed portion in the second surface; wherein a bore axis of the first depressed portion and a bore axis of the second depressed portion slant toward each other at an angle, which is in a range of 5 to 70 degrees, said bore axis of the second depressed portion is substantially perpendicular to said second surface of said substrate; and wherein the first depressed portion has a first opening in the first surface, the second depressed portion has a second opening in the second surface, and a vertical projection of a center point of the first opening on the second surface and a center point of the second opening are offset from each other by a distance in a range of 5 micrometer to 40 micrometers.