MANUFACTURING METHOD OF WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To effectively prevent peeling or cracks in an insulation layer without increasing the number of processes in a manufacturing method of a wiring board.SOLUTION: A manufacturing method of a wiring board includes the steps of: forming pads on a support medium; forming an insulation layer coating the pads on the support medium; forming multiple spaces for vias which expose the pads on the insulation layer; filling the multiple spaces for the vias with plating to form vias connected with the pads; forming a wiring layer connected with the vias on the insulation layer; and removing the support medium. The multiple vias are connected with the one pad. In each of the multiple vias, a wiring layer side cross section is larger than a pad side cross section.