High-speed synchrotron x-ray analysis of non-contact jetting process

The ability to dispense minute volumes of functional fluids accurately on substrates is of importance in a large number of applications such as the pharmaceutics, electronics, and printing industries. Non-contact methods of application, such as inkjet printing and jet printing of fluids are growing in importance due to their flexibility of use, increased electronic design space, lower manufacturing cycle times, and decreased cost.

The sub-millimeter dimensions of the jetting devices together with the high operating frequencies, as well as their opaque materials of manufacturing, make experimental monitoring of the working device challenging. The use of high-energy photon-based methods with high spatial and temporal resolution offers the possibility to probe the inner workings of the ejection process and use this information to guide the development of future jet printing heads together with numerical simulations.

In this work, a photon-based imaging using a synchrotron light source together with a high-speed image acquisition device to record the development of the front of the fluid ejection process in order to ascertain the effect of front shape on deposition accuracy and repeatability. The imaging was performed at 150 kHz and with a pixel size of 1 um. It is known that the filling of the nozzle affects the volume and quality of the resulting deposit. The experimental data was compared with numerical simulations of the jetting system using the IPS IBOFlow package [G.E. Mårtensson, SSMT. 33 (2021)].