Direct deposition of thick film pastes to form fine line patterns

Direct writing (DW) means a method used for direct deposition of thick film or polymer paste on a substrate to form electrical circuits together with their elements (conductors, inductors, or resistors such as shielding etc.). It is a non-vacuum process, fully compatible with standard thick film technology that enables us to create thick film patterns directly on the substrate without using a photoresistive process. The aim of this study is to examine and verify the possibility to construct a simple writing deposition equipment that would be able to provide repeatable and reliable process deposition. The developed equipment is controlled by a computer automated unit that enables precision printing of non-diluted screen printing pastes. The pattern is drawn on the substrate by a non-contact nozzle which is fixed in the dispensing unit. Its movement is controlled by x, y, z axis table. This procedure was chosen as a low cost alternative to deposition of fine line thick film pastes, e.g. in hybrid IC´s, but especially in other nonconventional applications, such as the front sides of solar cells, biosensors etc. The pastes were deposited on Al2O3 substrate, fired and then various parameters were measured.