| 摘要 |
PROBLEM TO BE SOLVED: To provide a push button switch which enables communication with a portable device even if a coil antenna having a coil conductor wound around a magnetic material core is attached to a lower surface of a wiring board.SOLUTION: A push button switch 100 for an immobilizer system includes a wiring board 3, in which an electronic component 8 is mounted on one surface, and electric power is supplied to a portable device from the one surface of the wiring board 3. A coil antenna 1 composed of a magnetic material core 1b and a coil conductor 1a wound around the magnetic material core 1b is attached to the other surface of the wiring board 3. The wiring board 3 has a wiring layer on its inner layer. A conductor pattern 5 is formed in the wiring layer on the inner layer so as to enclose the coil conductor 1a when viewed in a plan view. A direction of a current flowing through the coil conductor 1a is set to the same direction as a current flowing through the conductor pattern 5. |
