Patent ID: 7422449

Claim:
A wiring board comprising: at least one electrode pad formed on the wiring board; and at least one lead pin of which head portion is attached to the electrode pad with a conductive agent, wherein the head portion of the lead pin has an end face which is formed in a conically protruded shape, the end face facing the electrode pad, wherein the head portion of the lead pin has multiple notch portions formed in a peripheral edge portion of the head portion, wherein the multiple notch portions are filled with the conductive agent when the lead pin is attached to the electrode pad, and wherein the multiple notch portions extend from a top to a bottom of the head portion and are cut out in a direction of a thickness of the head portion which increases a length of the peripheral edge of the head portion thereby increasing a contact area between the conductive agent and the head portion thus increasing the bond strength between the lead pin and the electrode pad.