Component Attachment to Inkjet Additive Printed Circuits to Achieve Flexible Signal Filters using Silver and Copper Nanoparticle Metal Inks

In this paper, process-performance interactions have been studied for Inkjet printed circuits and attachment of surface mount components. Electrical and mechanical properties are quantified along with demonstration of functional electronic circuits with surface mount components consisting of frequency filters and op-amps. While additive printing of circuits has been demonstrated in prior studies, the attachment of surface mount components using robust process recipes has been an elusive goal. Inkjet processes have the ability of high throughput of electrical print processes owing to the usage multiple nozzles and potential for high print speeds. There is need for process recipes and understanding of the print process parameters on the component attachment reliability and performance. Two most commonly used metals, silver and copper, both having their own merits, are utilized. Process-property interactions for both the material against their post-print treatments are characterized. For the silver material, thermal sintering at 130°C for 20 mins yields the resistivity of 7.42 μΩ-cm (4.6 times the bulk silver), while for copper, resistivity is found to be 5.5 times the bulk copper. In terms of shear load to failure, both the materials came fairly close of 15-20gF. From the defined print process parameters, applications are demonstrated by printing high pass filter, low pass filter, and a non-inverting op-amp. The characterization against frequency for the electronic circuits are validated by the PSpice simulations as well. The authors' aim to develop these circuits is to show the capability of Inkjet platform to successfully attach surface mount components on printed pads and establish Inkjet technology to be a viable alternate to manufacture traditional electronic circuits.