Patent ID: 6972382
Filing Date: 2005-12-06
Classification: H05K,Y10T

Abstract:
1. A multilayer circuit board having inverted microvias, comprising: at least a first substrate core and a second substrate core each of said first substrate core and said second substrate core having a top conductive layer on at least a top side; a microvia on a bottom side of at least one among the first substrate core and the second substrate core, wherein the microvia would reach to the top conductive layer on at least the top side of at least one among the first substrate core and the second substrate core; a conductive layer applied to the microvia interconnecting a bottom conductive layer to the top conductive layer of at least one among the first substrate core and the second substrate core; an adhesive/bonding layer between at least the first substrate core and the second substrate core; a hole through the first substrate core, the adhesive/bonding layer and the second substrate core; a conductive layer applied to the hole to interconnect at least two among the top conductive layer of the first substrate core, the top conductive layer of the second substrate core, the bottom conductive layer of the first substrate core, and the bottom conductive layer of the second substrate core; and an external dielectric layer on at least one among the top side of the first substrate core and the top side of the second substrate core and an external conductive layer on the external dielectric layer, the external dielectric layer having a microvia with a conductive layer, wherein the conductive layer of the microvia of the external dielectric layer contacts the conductive layer of the microvia of the first substrate core or the second substrate core and wherein the microvias are vertically aligned with one another.