Abstract: A method of predicting the fired shrinkage of a ceramic oxide slurry which comprises measuring the ionic impurity concentration in the ceramic oxide slurry. A ceramic oxide slurry which exhibits a predetermined fired shrinkage can be formulated by the step of adding a predetermined amount of at least one ionic dopant to the ceramic oxide slurry in another embodiment.

Abstract: A process is disclosed for etching openings in a relatively thick layer of borosilicate glass while controlling the degree of taper of the sidewalls of the opening, the taper being in excess of about 45.degree.. The process involves (1) depositing a layer of silicon nitride that contains silicon in an amount in excess of stoichoimetric in Si.sub.3 N.sub.4, (2) densifying the silicon nitride layer, (3) depositing a layer of resist, (4) exposing and developing the layer of resist to define a desired pattern of openings in the borosilicate glass layer, (5) removing the exposed silicon nitride areas, and (6) subjecting the resultant exposed borosilicate glass surface to an etchant for the glass.

Abstract: A seal glass for unitizing an array of glass nozzles of an ink jet printer. The seal glasses are corrosion resistant to alkaline and acidic inks, and have low softening points, medium high expansivities and anneal points and are compatible with the nozzle glasses.

Abstract: The lifetime of multiple capillary nozzle assemblies embedded in a glass mass, of a multiple nozzle ink-jet printer, can be increased and the thermal and mechanical compatibility of the resulting package enhanced by fabrication of the nozzles from glass compositions comprised of SiO.sub.2, ZrO.sub.2, Na.sub.2 O, K.sub.2 O and MgO. Inclusion of ZrO.sub.2 as well as minor amounts of BaO, MgO, CaO, and Al.sub.2 O.sub.3 enhances the alkali resistance of the glass nozzles. Also, the high SiO.sub.2 content of the glasses combined with the presence of ZrO.sub.2, MgO, CaO, and Al.sub.2 O.sub.3 imparts an acid resistance to the nozzles.

Abstract: A copper oxide containing seal glass is formed by a controlled low temperature process which reduces the formation of seeds in the glass. In one embodiment the glass is prepared in two portions with the first portion containing the high melting oxides and the second portion containing the low melting oxides. The copper oxide is added to the second portion and the two portions are combined to form the seal glass at temperatures below about 800.degree.C which reduces the formation of Cu.sub.2 O crystals in the glass.