Previous methods to produce microvias are based on complex technologies such as laser, plasma or photo imaging. Chemical Via is a new chemical method to make microvias for high density printed multilayer circuits. Microvias are used to interconnect adjacent layers and consist of a small diameter hole (usually 70µm) with a thin metallic deposit covering their cylindrical walls to ensure the local conductivity between the bottom and top layers. Microvias of any shapes and dimensions are made possible at a low production costs. The technology was used by CERN PCB manufacturing workshop for the production of PCboards for HEP needs.