Effects of Kogation on the Operation and Lifetime of Bubble Jet Thin-Film Devices

抄録

The phenomenon that ink ingredients are thermally decomposed and deposited on the surface of bulbble jet thin-film heaters (“kogation”) is investigated. Several experimental techniques are examined, including optical and scanning electron microscopy, ion milling. Auger spectroscopy, enhanced phase-measurement interferometry, and diamond-stylus surface profiling. The stylus surface profiling technique appears to be an efficient and accurate method for measuring the thickness of kogation on top of heaters. Kogation patterns of several inks are examined, and effects of miscellaneous ink ingredients on kogation are experimentally studied. It is found that kogation may cause both “soft” and “hard” failures of the bubble jet heater device. It is also shown that heater lifetime depends on both the nature and the thickness of the kogation layer, and that dye is one of the most important ingredients determining kogation characteristics. Possible kinetics of kogation is also discussed.