Conductive filament exists, but it takes more than that to 3D print something like a circuit board. The main problem is that traces made of conductive filament are basically resistors; they don’t act like wires. [hobochild]The interesting way to get around this problem is to use electroplating to coat the 3D printed traces with metal, thus creating a kind of 3D printed circuit board. [hobochild] He doesn’t have many essential details to share yet, but his process seems pretty clear. (Update: good news! Here’s the project page and GitHub repository with more details.)
The usual problem with electroplating is that the object to be coated must be conductive. [hobochild] addresses this by using two different materials to create your test board. The base layer is printed on regular (non-conductive) plastic, and the extra thick board prints are printed on conductive filament. Electroplating takes care of coating the conductive traces, resulting in a pretty cool 3D printed circuit board whose conductors have real metal. [hobochild] Proto-paste used conductive filament and the board is a proof-of-concept flashing LED circuit. Welding can be challenging given the underlying material is still plastic, but dual material printing is an interesting angle that even allows for plated vias and through holes.
We have seen the use of conductive filaments to successfully print viable electrical connections, but the applications are limited due to the nature of the filament. Electroplating, a technology accessible to virtually every hacker’s workbench, continues to be applied to 3D printing in interesting ways and could be a way around these limitations.