Manufacturing method for multilayer printed circuit board

Abstract

A method of manufacturing a multilayer printed circuit board, which ensures connections between vias. First, insulating sheets are attached to respective end faces of inner via holes formed through an insulating layer, and then a new insulating layer is formed on the insulating layer. Then, a circuit pattern is formed on the new insulating layer, and then each land formed on the new insulating layer at a location opposed to a corresponding one of the inner via holes is perforated by using a laser beam to have a hole continuous with an inner hole of the corresponding inner via hole. Thereafter, plating is carried out to form a build-up via for connecting between each of the lands and the corresponding inner via hole. The same process is repeatedly carried out whenever a new insulating layer is provided on the existing layers.

Dependencies are inferred from the claim text.