Patent ID: 9084339
Filing Date: 2015-07-14
Classification: H05K

Abstract:
1. A wiring substrate comprising: a wiring substrate body comprising a wiring layer and an insulating layer and comprising a first surface and a second surface opposite to the first surface; a first electrode pad comprising a first recess therein and formed on the first surface of the wiring substrate body; a second electrode pad comprising a second recess therein and formed on the first surface of the wiring substrate body; a first solder resist layer on the first surface of the wiring substrate body to cover the first and second electrode pads, the first solder resist layer comprising a first opening and a second opening whose opening area is larger than that of the first opening, wherein the first recess is exposed through the first opening and the second recess is exposed through the second opening; a third electrode pad formed on the first surface or the second surface of the wiring substrate body; and a first metal layer formed on the third electrode pad and electrically connected to the first electrode pad and made of a material whose ionization tendency is smaller than that of a material of the first electrode pad, wherein a depth of the first recess is larger than that of the second recess.