Wiring board with an insulating layer to prevent gap formation during etching

摘要

A wiring board structure includes a board made of a material which can be etched by a given solution, an electrically conductive portion, which is thermally conductive, having a portion which extends from the board and which can be etched by the given solution, and an insulating layer having a portion which is in contact with the board and only the side surface of the electrically conductive portion and which prevents the board from being etched when the electrically conductive layer is etched.