Embedding of SMD Populated Circuits into FDM Printed Objects

This paper introduces the concept of a highly integrated 3D-printing device which is capable of printing plastic parts with integrated, fully assembled electronic circuits in a single process. It is based on a standard FDM 3D-printer that has been augmented by a screw-driven conductive paste extruder for electronic circuit printing, a vacuum nozzle to pick and place SMD-components and a vision system to find and precisely align the components before placing. To control the printer, an existing host software system has been extended to synchronize the communication with the printer for interactive operations and to generate the required movements from camera data by means of image processing. A number of objects, containing circuits on both the surface and inside of the object, has been successfully printed already. Quality and durability of the generated parts have been evaluated by analyzing the curing characteristics of the conductive ink during the process and the adhesion of the components which are placed directly on the wet ink. The design concept aims for a practical, affordable approach that can be widely used by developers to lower the entrance barrier to the field of 3D-printed electronics. Hence, the hardware is kept as simple as possible, avoiding complex and expensive components as laser or CNC-milling devices, focusing on algorithmic improvements in the preprocessing and control software. All developed hard- and software-components are available under open source licenses and compatible to common existing projects.