Abstract: A bidirectional hinge is used to pivot between two independent devices, allowing the two independent devices to be opened and closed with respect to each other after being pivoted. A structure and feature of a coiled spring is applied to the hinge, such that the hinge can rotate clockwise and counterclockwise according to requirements, and different torsional force depending upon a direction of rotation can be resulted, so as to increase application requirements.

Abstract: A method for making condenser microphones includes: forming a fixed electrode layer structure of a plurality of fixed electrode units; forming a sacrificial layer of a plurality of sacrificial units on one side of the fixed electrode layer structure; forming a diaphragm layer structure of a plurality of diaphragm units on the sacrificial layer; forming a patterned mask layer on an opposite side of the fixed electrode layer structure opposite to the sacrificial layer; forming a plurality of etching channels, each of which extends through the patterned mask layer and the fixed electrode layer structure; removing a portion of the sacrificial layer of each of the sacrificial units so as to form a spacer between a respective one of the fixed electrode units and a respective one of the diaphragm units; and removing the patterned mask layer.

Abstract: A method for making condenser microphones includes: forming a fixed electrode layer structure of a plurality of fixed electrode units; forming a sacrificial layer of a plurality of sacrificial units on one side of the fixed electrode layer structure; forming a diaphragm layer structure of a plurality of diaphragm units on the sacrificial layer; forming a patterned mask layer on an opposite side of the fixed electrode layer structure opposite to the sacrificial layer; forming a plurality of etching channels, each of which extends through the patterned mask layer and the fixed electrode layer structure; removing a portion of the sacrificial layer of each of the sacrificial units so as to form a spacer between a respective one of the fixed electrode units and a respective one of the diaphragm units; and removing the patterned mask layer.