Patent ID: 7931354

Claim:
A circuit board comprising: a plurality of electrode rows arranged on one surface of a board; wirings formed on said one surface and connected to a plurality of electrodes, respectively, included in said electrode rows; through-holes formed in the board, corresponding to said plurality of electrodes, respectively; and electrode connection sections each comprising a metal layer formed on an electrode layer—arranged between the metal layer and other surface of the board—and on an inner surface of the through-hole to face and be connected to an external electrode group via an electrically conductive brazing filler metal deposited on the metal layer in the through-hole and on the metal layer on the electrode layer, said metal layer having an area larger than an area of said electrode and being connected to said electrode through said through-hole, wherein the wiring connected to the electrode included in one of said electrode rows is formed to pass between the electrodes included in other electrode row in an arrangement direction of said electrode rows, said through-hole has an area smaller than the area of said electrode, and the electrode layer is made of the same material as a material forming the electrode.