| 摘要 |
A package body holding an acceleration sensor circuit therein has signal electrodes and four dummy electrodes insulated from the signal electrode on a mounted surface thereof. The signal electrodes are electrically connected to the sensor circuit element. The mounted surface of the package body has chamfered portions on verge portions thereof, and auxiliary electrodes are formed on the chamfered portions to be integrally connected to the signal electrodes. The thus constructed package body is mounted on a circuit board by a reflow method using a solder paste so that the signal, dummy, and auxiliary electrodes are connected to a wiring pattern on the circuit board through solder portions. In this process, the solder paste on the dummy electrodes in a fused state generate an internal pressure to retain a clearance between the package body and the circuit board. As a result, the thickness of the solder portions between the package body and the circuit board can be secured, and reliability at a mounted state is improved. |
