Method of controlled etching in the manufacture of a color selection mask for a color cathode ray tube

摘要

A method of forming a pattern of electron-transmissive apertures in a color selection mask for a color cathode ray tube. The method includes providing an electrically conductive preformed blank comprising a relatively thin aperture-defining layer on a relatively thick substrate layer; establishing a first etchant-resistant structure on the aperture-defining layer; etching through the blank to form preliminary sized and shaped apertures in the aperture-defining layer; establishing a second etchant-resistant structure on the aperture-defining layer; etching the aperture-defining layer forming ultimate apertures in the aperture-defining layer; and stripping the etchant-resistant structure from the aperture-defining layer.