PRINTED WIRING BOARD, ELECTRONIC DEVICE, AND METHOD FOR MANUFACTURING ELECTRONIC DEVICE

摘要

An electronic device comprises: a printed wiring board that comprises a substrate, pads formed on the substrate, and an insulating film layer covering a surface of the substrate on which the pads are formed; and an electronic element that comprises external terminals electrically connected to the pads and that is mounted on the printed wiring board. The insulating film layer comprises at least one connecting opening section each exposing at least part of one of the pads. At least part of an inner wall of the connecting opening section comprises at least one step section.