3D Printer For Making Prototype PC Boards?

[Paul Alciatore]

I often need to make a prototype PC board. In the past I have used a number of methods from hand drawing the circuit pattern with a Sharpie pen to just biting the bullet and just ordering them from a commercial PC board house. The former method is crude and not very good for modern, surface mount components. Ordering them can get somewhat expensive, especially if you need to make revisions and additional prototype boards. Besides, it takes a long time with factory lead time and shipping. No circuit designer likes that wait.

So I am wondering, has anyone developed a way to use a 3D printer for making prototype PCBs? I am talking about using the printer to lay down a layer of some kind of plastic or ink that acts as a resist and then etching the board with a chemical bath. Then that resist layer would need to be removed. That last step would be the key, how to remove the resist layer after etching.

I am going to do an internet search, but I know the group here has a lot of knowledge, so I am asking.

[portlandRon]

There is a filament for 3D printers that is conductive. The melting temp for printing it is 215 - 230 C.

[AD5MB]

depositing hot melted goo on a hot melted goo substrate is not the best way

CNC milling works better:

http://www.instructables.com/id/Make-your-own-PCBs-on-an-inexpensive-desktop-CNC-m/

https://buildyourcnc.com/PCBIsolationRouting.aspx

[alsinaj]

Alternatively, you can coat your board with a "ground" (see: http://www.cronite.com/etchsup.htm), design your board for isolation routing and use a CNC engraver to remove the ground from the areas you want to etch away. Cronite carries professional-grade grounds designed for use with hand or machine engravers.

[BCRider]

I assume that you are familiar with the tried and true photoresist sensitised board and using a negative or positive depending on the sort of resistant layer?

It's pretty easy these days to make up a "film" to use for exposing the board with clear films available for laser and inkjet printers.

[elf]

The short answer is yes. Whether or not it's the best way is arguable (sounds perfect for this forum ). MIT has developed several commercial conductive inks and filaments. I saw a demo a few years ago of the technology.

[RB211]

Sounds like nothing is going to be at the level that Paul would like... Yet.

[Paul Alciatore]

I am aware of and DEFINITELY NOT interested in any kind of conductive ink, conductive filament, or combination of chemicals that wind up depositing a metallic trace like silver. All of these are crude ways to imitate real PCB traces. So please forget suggestions of this type.

I am thinking about using a 3D printer to deposit a RESIST on a copper clad board. Then using normal etching chemicals. It seems to me that this would be capable of maintaining the fine detail needed for modern, small components. And it should be a fairly fast way to make a prototype board.

[BCRider]

Well, 3D printers are used to transfer very precise amounts of plastic per pass. I don't see why it should not work if your board is flat enough and perhaps if you heat it up a little to aid in getting a good fusing. Then lay a .02mm thick layer down. I'm not sure how you would get it off later though.

But it did get me thinking about low laser printers fuse a layer of toner to the paper. So I googled for "printing PCB boards". Out of that I found some hits on toner transfer to use laser printed layouts to the copper then etch the boards directly. Have you heard about this technique?

Here's one video with two guys showing how to do laser printer transfers to copper. One of them is highly annoying and they start out with a lot of background. Jump to 1:10 and watch from there for the toner transfer method. Seems like a pretty neat and direct way to handle the issue. And the toner cleans away easily afterwards.

[engineerd3d]

You can do a single layer transfer of PLA onto a clean copper clad board, it should stick relatively well. I would not got much less than .4mm traces though. The other thing is that transferring plastic to a copper clad board like that involves a good leveling. For the effort involved in depositing plastic on copper clad then using chemicals to etch away the material, if you own a reasonably decent ridgit enough 3d printer, just install a small spindle and turn it into a router, it will save allot of time and reduce the need of hazardous chemicals.

[elf]

I think you'll only be able to make very crude designs with an FDM 3d printer whether you're using conductive filaments or using the plastic extrusion as a resist.

ABS dissolves in acetone, so it would be my first choice as a resist material.

An SLA 3d printer will have the resolution needed.

[wombat2go]

I haven't got a "round tuit" yet, but I am nearly set up to do a board photographically.
That is because I have a photography hobby and a number of old film cameras and a darkroom here.
Presently I am limited to a max frame of 58 by 82 mm using 120 film
I have a Graflex 84 mm f/5 Photorecord lens which I have cleaned up and serviced the shutter.
Workflow:
Create thru hole artwork using the GNU pcb editor on linux.
Photograph the image from the Eizo monitor onto 120 bw film using a Graflex 4x5 camera with a 6x8 rollfilm back.

Develop the image.
Cut presensitized copper clad board (by MG Chemicals) to size,
mount in a vacuum tray
expose using the sun
develop
etch in ferric chloride
drill

The next item I have to do is to make the vacuum tray.
I used to do this for hobby boards back in the 1980's and I have forgotten how I made the tray.
I remember it was of layers of wood with clothes pins for alignment, but i can't remember it exactly.
It plugged in to a vacuuum cleaner.

[Puckdropper]

One thing I've done is use a vinyl cutter to cut vinyl to make my traces. I don't remember if I tried both ways: using the vinyl as an etch resist and using the vinyl as a stencil and shellac as an etch resist. I do remember using shellac as an etch resist. I was dealing with some fairly large traces so the tolerance wasn't that critical. Will it do SOIC-16? Hm... it might be hard to use Vinyl for that. Shellac cleans off with alcohol and whatever doesn't clean off will burn off. Based on this, I'd say there's a good chance at the 3D printed resist being successful.

My vinyl cutter is basically a 2D CNC machine that employs a drag knife. You've got me wondering if a decent stencil could be created with it so packages like SOIC-16 aren't too much of a problem. The stencil would have to be sprayed with adhesive and solidly secured, then a resist like shellac or permanent marker could be applied. Vinyl is just too flexible for something like this, but maybe thin styrene would handle it?

I've milled several PC boards on my little CNC Taig, and it works fine. As was pointed out, one of the problems is making sure the board is flat enough. I got around the issue by cutting the board fairly deeply, but it just backfired on me today: I removed the PC board from my breadboard and it broke in half. You may have better luck with a 3D printer and double stick tape. (I often need to drill my PC Boards first, so double stick tape just makes a mess. I was going to build a vacuum table but got onto other projects.)

[Paul Alciatore]

Wombat,

I have made a lot of boards using film negatives and sensitized board. I don't know what type of 120 film you have, but I believe you will find that you need a high contrast copy film to make this work well.

I usually had my negatives made at a graphics house that had high contrast film and a copy camera but those places seem to have gone the way of the dinosaurs. Today graphics work is all digital. When I asked about an actual copy camera at a local graphics house, they laughed. Were it not for that, I would make them that way today.

I have tried making transparencies with computer graphics and using them but I run into the same problem that I think you will have: exposure by the sun or a reasonable bright lamp that is rich in IR will lead to breaks in the copper or false traces if the negative is not really high contrast.

This is at least part of the reason why I am looking for an alternative method now.

I am thinking about a vacuum table to hold the board flat.

PS: I also had a photographic hobby. Darkroom work, with trays of chemicals, is in my DNA.

I haven't got a "round tuit" yet, but I am nearly set up to do a board photographically.
That is because I have a photography hobby and a number of old film cameras and a darkroom here.
Presently I am limited to a max frame of 58 by 82 mm using 120 film
I have a Graflex 84 mm f/5 Photorecord lens which I have cleaned up and serviced the shutter.
Workflow:
Create thru hole artwork using the GNU pcb editor on linux.
Photograph the image from the Eizo monitor onto 120 bw film using a Graflex 4x5 camera with a 6x8 rollfilm back.

Develop the image.
Cut presensitized copper clad board (by MG Chemicals) to size,
mount in a vacuum tray
expose using the sun
develop
etch in ferric chloride
drill

The next item I have to do is to make the vacuum tray.
I used to do this for hobby boards back in the 1980's and I have forgotten how I made the tray.
I remember it was of layers of wood with clothes pins for alignment, but i can't remember it exactly.
It plugged in to a vacuuum cleaner.

[RB211]

If one was to use ABS on a printer for a resist, you would need to heat the board considerably to make it stick