VIA FORMING METHOD IN MULTILAYER CIRCUIT BOARD

摘要

PROBLEM TO BE SOLVED: To provide a via forming method which can contract the time required for a via forming process and can contribute to the increase of the density of wiring structures in a multilayer circuit board. SOLUTION: The via forming method in the multilayer circuit board includes a process for laminating a photoresist on its circuit wiring surface having a conductor layer; a process for so forming an opening portion in the photoresist by the exposure and development of the photoresist as to expose a portion of the conductor layer to the external; a process for so filling a conductive paste into the opening portion as to form a via post whose outer contour is specified by the opening portion; and a process for removing therefrom the photoresist.