Method for manufacturing a shadow mask

摘要

A method for manufacturing a shadow mask for use in a cathode ray tube includes providing a thin metal web having a first and second major surfaces. Photosensitive layers are formed on the first and second major surfaces. The first photosensitive layer is exposed to a first patterned light and the second photosensitive layer is exposed to a second patterned light. The exposure is continued until respective accumulated exposure of the photosensitive layers reaches a predetermined value. Next, a first protective film is applied to the second photosensitive layer to prevent etching of the second surface. The first surface is then etched to form a first cavity. The first cavity has a depth that is less than a distance from the first surface to the second surface. A second protective film is applied to the first surface to prevent additional etching of the first surface. Then the first protective film is removed and the second surface is etched to form a second cavity. The second cavity communicates with the first cavity. Finally, the second protective film and the photosensitive layers are removed.