Has anyone used dark color 3D filament printed onto copper clad PCB as photo resist or etch resist?
It might be tricky printing PLA directly to copper clad PCB, but then you could expose the board to UV or etchant to make the PCB traces. Then remove the PLA plastic to expose the copper traces.
longtimelistnr · 1m ago
assumedly much much easier to buy a cheap vinyl cutter, but interesting idea
p0px · 3h ago
Wanted to show off a similar project I did. I used tracks for dupoint wires in my model and used the GPIO pins to push through the wires to create connections.
For the LED eyes, I created THT connectors using the ends of the dupoint wire ends.
There's a lot of potential for desktop rapid-prototyping with electronics. I think one of the things that is killing us is the tooling. One of the reasons I started building an autorouter was because I wanted to be able to have different "build targets"- e.g. a build target that is a PCB with no vias and only 0 ohm resistors (jumpers). If our EDA tooling supported different build outputs, then we could have earlier prototypes built with less-than-ideal equipment (e.g. conductive 3D printed filament, as the article suggests)
nickpinkston · 3h ago
People have been doing this for a long time, but it feels a little too purist to me.
The components will still be the same, so you'll still need some kind of pick-n-place functionality to make anything, so why not just have another print head for making the traces / doing the PnP?
The head could lay copper wire/foil tape for conductors and do standard PnP from trays / reels of components, which you'll need either way.
It would be a little more geometrically limited than what this post imagines, but it would have the upside that it would actually work today and with most real electronics applications, unlike the low performance conductors made via conductive polymers as the OP's process imagines.
Lerc · 2h ago
A PnP placing the components upside down onto a surface printed by another head would be interesting. You could align the heights of the resting surfaces to optimise pads needing to be connected being on the same plane. I'd still want to lay copper but if you had the ability to squirt a little solder paste from (yet another) head, you could stack everything with wire connections into a very 3d circuit.
If the base material was thermally conductive you could have a heatsink block with the circuit embedded in it.
zakqwy · 1h ago
For this in 2D, see Sam's thesis, 6.3.3 (p. 86, CNC wire plotting). 3D would add a lot of challenges.
I think the "printegrated circuits" approach is roughly the right level of abstraction.
3D Printing the PCB itself is pretty much impossible for any non-trivial application. Doing multi-layer PCBs with 0.20mm wide traces, spaced 0.20mm apart? Forget it, not happening - and requirements like those are standard for hobbyist-level chips like the RP2040 these days.
And if you're not printing your own PCB, what's left is module-level assembly and connectivity. In other words, just printing a bunch of wires.
Aurornis · 3h ago
> The head could lay copper wire/foil tape for conductors
Sounds awesome, but this is an extremely hard problem to solve. You can't simply lay down wire or foil into arbitrary shapes on 3D surfaces.
nickpinkston · 1h ago
Yea, agreed it's pretty hard, though with some tradeoffs it could be done pragmatically.
I would probably slightly overbuild the plastic and then use a heated tool to form the smoother surfaces the wire/foil would go in/on.
I've also seen laser sputtering of copper, etc. which could be the another approach, something similar is used for metalizing plastic already, though contamination would need to be controlled to maintain low resistivity.
Lerc · 2h ago
If you had a wire feeder with a actuated barrier just past the tip you can fairly easily bend wire into controlled shapes pretty well. If you printed channels for them to sit in, I think they could be placed.
joshmarinacci · 2h ago
When I worked at Markforged we had a printer that could put solid carbon fiber threads into the print using a second extruder (on the same print head), so it's certainly possible. It was $20k, though. Getting this down to something accessible to hobbyists is the challenge. I think it will happen one day, though.
Aurornis · 2h ago
CNC wire benders exist, but they're solving a different problem: They bend the wire in free space, not on to a surface. You would have to design the part and the wire such that the part never comes around into the space occupied by the head, which would limit it to only very basic and small shapes.
Xmd5a · 2h ago
Maybe lay chains instead of wires. Apply tension to the chain, ensuring that it conducts current and use fast solidifying glue to fix it in place/make it adhere to the surface/insulate it.
xg15 · 2h ago
On the one hand, I like the idea. On the other hand, I dread a future where you need an X-Ray and/or MRT machine to be able to inspect any kind of electronic device. And don't even think of disassembling or repairing...
It might be tricky printing PLA directly to copper clad PCB, but then you could expose the board to UV or etchant to make the PCB traces. Then remove the PLA plastic to expose the copper traces.
For the LED eyes, I created THT connectors using the ends of the dupoint wire ends.
https://makerworld.com/en/models/672277-wabbt-wifi-bluetooth...
The components will still be the same, so you'll still need some kind of pick-n-place functionality to make anything, so why not just have another print head for making the traces / doing the PnP?
The head could lay copper wire/foil tape for conductors and do standard PnP from trays / reels of components, which you'll need either way.
It would be a little more geometrically limited than what this post imagines, but it would have the upside that it would actually work today and with most real electronics applications, unlike the low performance conductors made via conductive polymers as the OP's process imagines.
If the base material was thermally conductive you could have a heatsink block with the circuit embedded in it.
https://cba.mit.edu/docs/theses/19.09.calisch.pdf
3D Printing the PCB itself is pretty much impossible for any non-trivial application. Doing multi-layer PCBs with 0.20mm wide traces, spaced 0.20mm apart? Forget it, not happening - and requirements like those are standard for hobbyist-level chips like the RP2040 these days.
And if you're not printing your own PCB, what's left is module-level assembly and connectivity. In other words, just printing a bunch of wires.
Sounds awesome, but this is an extremely hard problem to solve. You can't simply lay down wire or foil into arbitrary shapes on 3D surfaces.
I would probably slightly overbuild the plastic and then use a heated tool to form the smoother surfaces the wire/foil would go in/on.
I've also seen laser sputtering of copper, etc. which could be the another approach, something similar is used for metalizing plastic already, though contamination would need to be controlled to maintain low resistivity.