Patent ID: 7211289

Claim:
A method of making a multilayered printed circuit board, said method comprising: providing a first dielectric layer having first and second opposing sides; forming a first conductive layer on said first opposing side of said first dielectric layer; forming a second conductive layer on said second opposing side of said first dielectric layer, said second conductive layer including at least one opening therein; forming a second dielectric layer having first and second opposing sides on said second conductive layer on said second opposing side of said first dielectric layer, said first opposing side of said second dielectric layer being in contact with at least part of said second conductive layer including over said at least one opening therein; forming first and second holes within said second dielectric layer using a laser, said first hole extending down to only said second conductive layer and a part of said second hole extending through said at least one opening in said second conductive layer and down to said first conductive layer, said first and second holes, including said part of said second hole extending through said at least one opening in said second conductive layer and down to said first conductive layer, each being of tapered configuration and having surfaces; forming a third conductive layer on said second opposing side of said second dielectric layer; forming a conductive coating on said surfaces of said first and second holes so as to electrically couple said first and second conductive layers with said conductive coating on said second hole and said second and third conductive layers with said conductive coating on said first hole; plating said first and second holes having said conductive coatings thereon with plating material to fill said first and second holes, including said part of said second hole extending through said at least one opening in said second conductive layer and down to said first conductive layer; and forming a substantially solid upper surface on said conductive material within each of said first and second holes.