Circuit board and manufacturing method thereof

Abstract

A circuit board and a manufacturing method thereof are provided. A dielectric layer is formed on a substrate, wherein an internal circuit layer is formed on the substrate and the dielectric layer covers the internal circuit layer. A first trench, a second trench and an opening are formed in the dielectric layer. The opening is located below the first trench and connected with the first trench, and a portion of the internal circuit layer is exposed by the opening. A patterned conductive layer is formed on the dielectric layer. The patterned conductive layer covers a portion of the dielectric layer and fills the first trench, the second trench and the opening so as to form a first circuit layer, a second circuit layer and a conductive through via, respectively, wherein the conductive through via is electrically connected with the first circuit layer and the internal circuit layer.

Dependencies are inferred from the claim text.