Process Recipes for Additively Printed Copper-Ink Flexible Circuits using Direct Write Methods

In this paper, the process-recipes and process-performance relationships for additive-printing of copper circuits using direct-write methods have been studied. The process has been implemented on the direct write platform. Interest in the use of additive printing methods for the manufacture of micro-circuits has grown immensely in recent times. Direct write methods have been shown to have the ability to create circuits in a limited manner. However, the process recipes and the effect of process parameters on the manufactured properties are not well understood. Copper ink is a good and cost-effective alternative to silver ink but its use has lagged owing to an increased propensity for oxidation. In this paper, photonic curing has been used to sinter copper ink to make the traces conductive. The method flashes high energy light that sinter metal particles instantaneously and the temperature of the substrate remains low. The effect of the different photonic sintering profiles on the mechanical and electrical properties of the printed traces has been studied in this paper. The print process parameters also play an important role in the line width and height that has been studied to print with the desired line profile for the end application. An LC filter circuit is been printed with SMD components been attached using an electrically conductive adhesive (ECA). The manufactured flexible LC filter is been tested for its frequency sweep to compare with the commercially available LC filer with the help of the Bode plot.

Automated summary

This paper investigates the process-recipes and process-performance relationships for additive-printing of copper circuits using direct-write methods, with a focus on the photonic curing of copper ink and the impact of print process parameters on manufactured properties. The study demonstrates the feasibility of using copper ink as a cost-effective alternative to silver ink for creating conductive traces, highlighting the importance of understanding the effects of different photonic sintering profiles on mechanical and electrical properties. Additionally, the research explores the role of print process parameters in achieving desired line profiles for end applications, exemplified by the fabrication and testing of a flexible LC filter circuit with SMD components using an electrically conductive adhesive.