Automated fabrication of hybrid printed electronic circuits

Printed electronics offer great potential for new applications such as Internet of Things devices and wearables. However, to date, only a limited number of electronic functions and integration densities can be realised by printing processes. Hence, hybrid printed electronic circuits are actually created by mounting silicon electronic components. Since both printed materials and processes are continuously evolving, an accompanying structured development methodology is required. This paper highlights a digital workflow from design to automated fabrication using the example of a demonstrator circuit. A mull-layer vector ink-jet printing process to print electronic devices onto foil substrates with three functional inks is presented. This printing process is improved using a newly set-up printing system: Integrating a piezo print head into the path planning of the printing system and its control as a virtual stepper axis enable highly precise vector printing. This leads to printed resistors with low tolerances. Adaptations of surface mount technology for assembling silicon electronic components onto printed foil substrates are discussed. Finally, image processing methods to cope with deformations of the flexible foil substrates in the fabrication process are introduced.