Abstract: An electrostatic actuator has: an upper structure that is connected, via an arm, to a supporting base provided on a substrate and is supported in a space existing over the substrate; a lower structure that is provided in a substrate position in such a way as to oppose the upper structure; an inclination structure that is provided with respect to either one of the upper structure and the lower structure so as to make small the distance between the upper structure and the lower structure; and one or more electrodes that are provided with respect to the other structure in corresponding relationship to the inclination structure.

Abstract: There is provided a semiconductor device including a semiconductor pellet having a plurality of bump electrodes on a surface thereof, a wiring board having a plurality of pad electrodes on a surface thereof, each one of the pad electrodes being engaged to an associated one of the bump electrodes when the wiring board is coupled to the semiconductor pellet, and a resin layer sandwiched between the semiconductor pellet and the wiring board for connecting them with each other therethrough, each of the bump electrodes being formed with one of a projection and a recess into which the projection is able to be fit, and each of the pad electrodes being formed with the other. For instance, the bump electrodes are formed by compressing a molten ball formed at a tip end of a gold wire onto the semiconductor pellet, and the projection is formed on the bump electrodes by cutting the gold wire so that a tip end portion of the gold wire leaves on the bump electrodes.