Thermal design modifications to improve firing frequency of back shooting inkjet printhead

This paper presents design modifications of a backshooter type inkjet printhead, DomeJet, to enhance the firing frequency. DomeJet is a thermally driven monolithic inkjet printhead that consists of dome-shaped ink chambers and omega-shaped heaters over the chambers. Since it is monolithic, the manufacturing is very cost effective. As the firing frequency increases, the residual heat accumulated in heater layer may cause unstable droplet ejection. Thus, an efficient heat passage is necessary to increase the firing frequency. Contrary to a roofshooter architecture printhead, a backshooter type printhead has disadvantage in heat release since the heater is confined to a thin film which has low thermal conductivity. In this study, four models are proposed and studied. Compared to the basic model of DomeJet, all the proposed models are found to improve heat dissipation capability. The best performing model is found to operate at a frequency of 40 kHz, a much higher frequency than 15 kHz of the basic model. (C) 2003 Elsevier B.V. All rights reserved.