A first wiring board, which is a flexible printed-circuit board, is bonded to a second wiring board. A plurality of protruding member are formed on the surface of the second wiring board. An adhesive is deposited on the surface of the second wiring board such that there is a thinner layer of the adhesive on the protruding member than in other areas. Subsequently, the first wiring board is placed on the second wiring board so that a portion of the first wiring board to be used for the wire-bonding is positioned above at least one of the protruding members. The first wiring board gets bonded to the second wiring board due to the adhesive.