Inventors:
Carlton Edward Olsen - San Jose CA
Leroy Jasper Serpa - Campbell CA
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G03C 500
Abstract:
A double exposure and double etch technique for producing precision parts from a photosensitive material is described. The process is described in terms of producing an array of ink jet charge electrodes which comprise a series of small through holes on accurately defined centers. The process comprises the steps of exposing the photosensitive material through a mask to develop an undersized through hole and heat treating the photosensitive material to change its characteristics so that an etchable material is produced in the exposed area. The material is then etched to form the undersized through hole which is substantially tapered. The material is then exposed again with a full sized mask including any conductor patterns and the material is again heat treated. The material is again etched and this etching, in the nature of a surface etch, reduces the taper because of the lower etch rate of the unexposed material as compared to the much higher etch rate of the previously unetched tapered material.