US Patent 9059152 Wiring substrate and manufacturing method of the same

Embodiments of the present invention provide a wiring substrate having a structure where a plurality of projection electrodes are arranged within an electrode formation region on a substrate main surface. At least one among a plurality of the projection electrodes is a variant projection electrode which has a recess portion on an upper surface, an outer diameter at the upper end that is larger than an outer diameter at the lower end, and a reverse trapezoidal cross-section shape. Embodiments of the present invention also provide methods for manufacturing wiring substrates having one or more of said variant projection electrode.