The Influence of Sintering Conditions on the Inkjet Printed Paths Resistance

The sintering of elements performed with the inkjet printing technique is one of the stages of flexible printed circuit manufacturing process. It is a crucial factor to determining the printed paths conductivity playing often an important role in the printed circuit. In this paper the study of the influence of thermal sintering conditions (temperature, time) on the resistance of paths made with inkjet printing on flexible substrates by using two electrically conductive inks was presented. The results of the investigations show that the sintering temperature is the main factor determining the paths resistance. Therefore, in some applications the sintering temperature higher than the one specified by the ink manufacturer can be used to decrease the paths resistance and to improve some circuit parameters. However, it should be noticed that the effective resistance decrease occurs only up to a certain temperature due to the appearance cracks in the printed paths.