Fine Metal Line Patterning on Hydrophilic Non-Conductive Substrates Based on EHD Printing with Laser Sintering

In this paper, we report the successful EHD printing and laser sintering of a 5 um width of metal line patterns, with the line thickness of over 340 nm, on a hydrophilic non-conductive glass substrate without any prior surface treatment for the repair of FPDS. There are two critical issues to overcome: 1) Printing on a non-conductive substrate such as glass is subject to sprays scattered around the patterned line due to the disturbance of the original electrostatic field by the charges accumulated on the printed lines. 2) Printing on a hydrophilic surface such as glass without prior surface treatment is subject to ink spreading such that the width of printed line patterns becomes as much as 5 times larger than the actual diameter of jetting. To find the optimal setting of parameters, an array of extensive experimentations were conducted under various parameter settings. The application of laser sintering to the above, EHD printed, metal line was successful for meeting the required electrical resistivity of less than 60 mu Omega-cm, while avoiding thermal damages.