Planar type mirror galvanometer and method of manufacture

A planar type mirror galvanometer comprising:

• a semiconductor substrate having a planar movable plate and a torsion bar for axially supporting said movable plate so as to be swingable in a perpendicular direction relative to said semiconductor substrate formed integrally therewith, a permanent magnet provided on at least an upper face peripheral edge portion of said movable plate, and a reflecting mirror provided on an upper face central portion of said movable plate, and a planar coil for generating a magnetic field by means of an electric current, provided on semiconductor substrate portions beside the opposite sides of the movable plate which are parallel with the axis of said torsion bar.

A method of manufacturing a planar type mirror galvanometer comprising the steps of:

• piercing a semiconductor substrate excluding a portion forming a torsion bar, by anisotropic etching from the substrate lower face to the upper face to form a movable plate which is axially supported on the semiconductor substrate by the torsion bar portion so as to be swingable, forming a planar coil on the upper face periphery of the movable plate by electroplating, forming a reflecting mirror on a central portion of the movable plate which is surrounded by the planar coil by vapor deposition of aluminum, fixing an upper substrate and a lower substrate to upper and lower faces of the semiconductor substrate by anodic splicing, and fixing magnets to upper and lower substrate portions which correspond to the opposite edges of the movable plate which are parallel with the axis of the torsion bar.

A method of manufacturing a planar type mirror galvanometer comprising the steps of:

• piercing a semiconductor substrate excluding a portion forming a torsion bar, by anisotropic etching from the substrate lower face to the upper face to form a movable plate which is axially supported on the semiconductor substrate by the torsion bar so as to be swingable, forming a thin film permanent magnet on the upper face of the movable plate, forming a reflecting mirror on a central portion of said movable plate by vapor deposition of aluminum, forming a planar coil on semiconductor substrate portions beside the opposite edges of the movable plate which are parallel with the axis of said torsion bar by electroplating, and fixing an upper substrate and a lower substrate to upper and lower faces of the semiconductor substrate by anodic splicing.