Patent ID: 9609746
Date: 2017-03-28
CPC Classifications: H05K

Claim:
1. A manufacturing method of a circuit board structure, comprising: providing an inner circuit structure, wherein the inner circuit structure comprises a core layer having an upper surface and a lower surface opposite to each other, a first patterned circuit layer disposed on the upper surface, a second patterned circuit layer disposed on the lower surface, and a conductive through hole connecting the first patterned circuit layer and the second patterned circuit layer; forming a metal pillar on a portion of the first patterned circuit layer; performing a build-up process to press a first build-up circuit structure on the first patterned circuit layer, wherein the first build-up circuit structure at least comprises an inner dielectric layer, and the inner dielectric layer directly covers the upper surface of the core layer and the first patterned circuit layer; using a contact distance detector to detect an upper surface of the metal pillar relatively far away the first patterned circuit layer; and using the upper surface of the metal pillar to serve as a depth reference surface, performing a hole drilling process on the first build-up circuit structure to remove a portion of the first build-up circuit structure and at least a portion of the metal pillar so as to form a cavity extending from a first surface of the first build-up circuit structure relatively far way the inner circuit structure to a portion of the inner dielectric layer, wherein the cavity exposes an inner surface of the inner dielectric layer, and the inner dielectric layer has an opening connecting the cavity and exposing a portion of the first patterned circuit layer, a hole diameter of the opening is smaller than a hole diameter of the cavity, and a height difference is in between an inner surface of the inner dielectric layer exposed by the cavity and a top surface of the first patterned circuit layer exposed by the opening.