Apparatus for manufacturing of electrets

摘要

In order to manufacture a small-size thin-film electret having a charge distributed in a very homogeneous way, even on its edges, use is made of apparatus comprising an earthed electrode (2) for supporting a dielectric (1) to be charged, means for generating ions (3) in the vicinity of the dielectric, a grid (4) extending parallel to the surface of the dielectric to be charged, at a slight distance from this face, and taken to an electrical potential different from that of earth, and a conducting frame (7) insulated from the electrode and electrically connected to the grid, the said frame surrounding the dielectric and forming a single unit with the electrode.