Abstract: A method for fabricating a multi-layer laminated charge plate for an ink jet printer. The charge plate is produced by selectively etched layers of photosensitive glass. By exposure of the photosensitive glass and controlled etching, the intermediate layers are provided with slots partially or completely etched through the thickness of the layers for the conductors to connect a charge electrode hole with pin connector pads. A heat treating process is used to bond the various layers of different thickness and configuration together by self-diffusion bonding. Metallization of the conductor paths is carried out with suitable alloys. The alloys with melting points higher than the bonding temperature can be deposited on appropriate layers prior to laminating. An alternate approach is to laminate the charge plate and produce metallization of the conductor path with a low melting point conductor by capillary flow.

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.