Patent ID: 8404981

Claim:
A printed circuit board comprising: at least two embedded copper interconnect lines separated by an insulator in the vertical direction, wherein each of the at least two interconnect lines intersect a common through-hole; an inner seed layer disposed on an interior surface of the through-hole from one of the interconnect lines to the other, wherein the diameter of the through-hole proximate to an external planar surface of the printed circuit board is substantially equal to the diameter of the through-hole between the at least two interconnect lines; and an outermost surface of the through-hole proximate to the external planar surface of the printed circuit board consists essentially of an insulating surface containing no or negligible amounts of seed laver; and wherein the diameter of the through-hole proximate to an opposite external planar surface of the printed circuit board is substantially equal to the diameter of the through-hole between the at least two interconnect lines, and an outermost surface of the through-hole proximate to the opposite external planar surface of the printed circuit board consists essentially of an insulating surface containing no or negligible amounts of seed layer.