A circuit pattern is formed on a printed circuit board, and a plating
surface of a projecting stripe on a substrate is connected to the circuit
pattern by soldering. Further, adhesive agent is filled in a gap between
a coarsened surface of a non-circuit unit and the printed circuit board.
When the adhesive agent is filled in the gap, the adhesive agent comes in
an uneven portion of the coarsened non-circuit unit and is hardened in
the recessed portion, so that a chemical bonding force of the adhesive
agent itself and an anchoring effect act. For this reason, a fixing force
and the bonding force increase.