Microminiature movable device

#The present invention relates to a microminiature movable device and, more particularly, to a microminiature movable device in which an auxiliary electrode is formed on a stationary substrate together with a stationary electrode to prevent a movable electrode plate from sticking or adhering to the stationary substrate.

#To facilitate a better understanding of the present invention, a description will be given first, with reference to FIGS. 1A and 1B, of a prior art example of a microminiature movable device.

#The illustrated microminiature movable device is manufactured using a silicon (Si) single crystal wafer as the starting substrate through application of micromachining technology including thin-film growth, photolithography and etching techniques. The silicon single crystal wafer is ultimately machined into such a square support frame 10 as depicted in FIGS. 1A and 1B. The support frame 10 has formed integrally therewith anchor parts 11 located centrally on a pair of opposed sides of the frame, flexures 19 extended inwardly from the anchor parts 11 and a rectangular movable electrode plate 12 connected centrally at its both sides to inner ends of the flexures 19.

#FIG. 1A is a plan view for explaining an example of a conventional microminiature movable device applied to an optical switch;

#FIG. 1B is a sectional view of the microminiature movable device taken along the line 1B—1B in FIG. 1A;

#FIG. 2A is a plan view for explaining the operation of the conventional microminiature movable device applied to the optical switch;

#With reference to the accompanying drawings, embodiments of the present invention will be described below.

#Referring first to FIGS. 3A to 3J, a description will be given first of the steps involved in the manufacture of an optical switch using a silicon single-crystal wafer as the starting substrate through application of micromachining techniques such as thin film forming, photolithography and etching techniques.

#Step S1 (FIG. 3A): Prepare a silicon single-crystal wafer 10′ that is a starting substrate.