Here is the abstract you requested from the CICMT_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|System Analysis of a DoD Print Head for Direct Writing of Conductive Circuits|
|Keywords: Drop-on-Demand, Piezo Control Signal, System Analysis|
|The Inkjet-Printing principle is becoming more and more important for new (electrical) applications besides conventional graphic printing. Based on a drop-on-demand (DoD) micro feeding system, a colloidal ink printer was developed to print conductive circuits. The printer has a stationary piezo-driven print head with a nozzle diameter of 100 microns. With such a nozzle, conductive paths with a width between 110 µm and 250 µm can be realized. A waveform generator is used to actuate the print head’s piezo actuator. The most common control signal is a nearly rectangular voltage pulse. Shape, duration and amplitude of the piezo control signal influence the stability of the printing process and thus the quality of the printed electrical structures significantly. Satellite droplets, fluctuations of the droplet volume or slow droplet speeds are unwanted during printing. Different rise and dwell times or pulse shapes e.g. saw tooth can be considered to optimize the printing process. In this article, the piezo control signal’s shape is analyzed, varied and the print head’s system behaviour is characterized. In a performance and energy study, the influence of the piezo signal’s shape on droplet formation and print parameters such as droplet radius and speed is identified. An optimized piezo control signal shall be achieved. Conductive paths and areas of different widths and thicknesses are presented. They are characterized by conductivity measurement, light microscopy and whitelight interferometry for layer thickness measurement and surface homogeneity. The thickness of these fired conductive elements is about five to ten microns and their electrical properties almost comparable with those of conventional thick-film conductors.|
|Dominik Cibis, Scientific Assistant
Helmut-Schmidt-University/University of the Federal Armed Forces Hamburg