Digital micro-dispension of non-conductive adhesives (NCA) by inkjet printer

The increasing demand for miniaturization of electronic packages and assemblies necessitates tighter tolerances in dispensing interconnects and robotic control for placement. In fact, due to increasing requirements in regards to cycle time and accuracy of interconnects (i.e. surface mount adhesives), contactless dispensing is constantly gaining acceptance. In this study, inkjet printing of adhesives is proposed as a promising contactless methodology, in which a precise volume control of dispensed material is applicable. Exploiting the drop-on-demand (DOD) process of inkjet printing, the deposition of non-conductive adhesives (NCA) by means of inkjet printer equipped with an industrial inkjet print-head were investigated. Correspondingly, individual droplets of different kinds of NCA were jetted from small diameter vessels directly to a specified position on the substrate to create the bonding patterns for die-attachment. The resulting die-attach was subsequently characterized, in terms of uniformity, thickness and flatness.