PRINTED WIRING BOARD

摘要

A printed wiring board comprises a wiring substrate provided with at least one conductor circuit, a solder resist layer formed on the surface of the wiring substrate, covering the at least one conductor circuit, conductor pads formed on a part of the at least one conductor circuit exposed from respective openings provided in the solder resist layer for mounting electronic parts, and solder bumps formed on the respective conductor pads. Connection reliability and insulation reliability are easily improved by making the ratio (H/D) of a height H from solder resist layer surface the solder bump to an opening diameter of the opening 0.55 to 1.0 even in narrow pitch structure under the pitch of the opening provided in the solder resist layer of 200 µm or less.