A symmetrical signal generator that includes a first signal part configured to produce a first output pulse signal using a first input pulse signal and a second input pulse signal asymmetrical to each other, and a second signal part configured to produce a second output pulse signal using the first input pulse signal and the second input pulse signal. In the method, for example, the substrate is temporarily stopped before being loaded on the processing table. A method of assembly for attaching a wire to a capacitor and an electrode may include an assembly carrier for housing and securing the wire, capacitor, and electrode during assembly. The piezoelectric element is provided on a first surface of the plate and transmits vibrating force to the electronic device.