Abstract: Via portions are formed in a first green sheet for a first layer of a laminated substrate. Then, conductive lands are formed on a surface of the first green sheet and a wiring pattern is formed on a back face of the first green sheet to be connected to the conductive lands through the via portions. The thus formed first green sheet is joined to a second green sheet having via portions therein so that the wiring pattern of the first green sheet contacts the via portions of the second green sheet. In this case, by forming the wiring pattern on the back face of the first green sheet, lamination slippage of the wiring pattern caused by lamination of the first and second green sheets can be prevented.

Abstract: 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.