Ink Jet Printing for Direct Mask Deposition in Printed Circuit Board Fabrication

Drop deposition has been studied over a wide range of time scales under conditions relevant to direct printing of etch resist patterns on printed circuit boards. Early-stage impact-driven spreading of 80 pl drops of UV ink and phase change resist was imaged by 20 ns duration flash-based photography, while a 27,000 fps highspeed camera was used to study the later stages of spreading up to 130 ms postimpact. The presence of an attached ligament at impact was shown to reduce the effect of impact inertia and the tendency for recoil, although this was less significant in the later, capillary phase. The effects of surface wetting appeared to be insignificant during the impact and relaxation spreading phases but dominated the behavior during capillary spreading. Cooling by conduction from the substrate was shown to be effective in arresting drop spreading for the phase-change ink on a submillisecond time scale. (C) 2009 Society for Imaging Science and Technology. [DOI: 10.2352/J.ImagingSci.Technol.2009.53.5.050304]