Wiring substrate

Abstract

A wiring substrate includes an insulating layer, a conductor layer formed on the insulating layer and including a conductor pad having a rectangular planar shape, and a solder resist layer formed on the insulating layer such that the solder resist layer is covering the conductor layer formed on the insulating layer. The solder resist layer has an opening formed such that the opening is exposing 50% or more of an area of a surface of the conductor pad on the opposite side with respect to the insulating layer and exposing a side surface and the surface of the conductor pad at side portions of a peripheral edge of the conductor pad and that the solder resist layer is covering the side surface and the surface of the conductor pad at one or more of corner portions of the peripheral edge of the conductor pad.

Dependencies are inferred from the claim text.