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The MicroSlice is a Build-It-Yourself kit, uses Open Source Software, and can be easily assembled at home by just about anyone.
The MicroSlice is a Build-It-Yourself kit, uses Open Source Software, and can be easily assembled at home by just about anyone.
524 backers pledged £95,427 to help bring this project to life.

PCB Engraving & Etching.

Posted by Gregory L Holloway (Creator)
9 likes

Hi,

One of the bigger questions I get asked is about PCBs, and can you make them with the MicroSlice. Well I can now answer that question; Yes, you can make PCBs using the MicroSlice!

How is it done?

I designed a simple circuit in Illustrator;

 The design is saved as an SVG and imported into Inkscape where the Laser-Engraver Plug-In generates G-Code and stores it in a file.

 The G-Code is then loaded into Zapmaker's Grbl Controller;

I have used standard blank copper PCB which has been sprayed with two light coats of black Acrylic paint, left to dry, and then placed on the MicroSlice Cutting Table. To get the best results you'll need to make sure the laser is correctly focused onto the PCB.

Next the G-Code is sent to the MicroSlice;

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 The tracks have to be engraved several times to make sure the laser cuts through both the paint and any residue left behind.

After the laser has done its work the PCB is put into a Ferric Chloride bath and agitated for about an hour. 

By holding the cleaned PCB up to a light you can check the etching has cut all the way through the exposed copper. If it hasn't quite worked it can be put back in the etching solution for a bit longer.

Still needs a bit more etching to clear the tracks.
Still needs a bit more etching to clear the tracks.
Next using an Isopropyl alcohol cleaner wipe off the acrylic paint.
Next using an Isopropyl alcohol cleaner wipe off the acrylic paint.
Tin the contacts with solder where the components will be soldered to the PCB.
Tin the contacts with solder where the components will be soldered to the PCB.
Solder on the components.
Solder on the components.
Insert a battery and push the On button!
Insert a battery and push the On button!

While it is possible to make PCBs using the MicroSlice the process isn't perfect. So far I have only been able to etch the PCB effectively by using the new 250mw diode unlocked at the £55,00 Stretch Goal. I have not been able to do it successfully using the 100mw diode.

Hopefully this won't be a problem as the £65,000 Stretch Goal which unlocks a 200mw diode for the Standard kit isn't too far away!

Michael Straßburger, 堀内周, and 7 more people like this update.

Comments

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    1. Curt Gridley on

      I wonder if this would work better if you used a very light coating of spray adhesive to attach a sheet of very thin mylar (like the mylar they use to make fancy balloons in the USA) to a bare copper board, then laser cut the mylar and etch through the laser cut mylar. I think the thin mylar might cut more easily than paint. Anyway, very cool project indeed!

    2. Gregory L Holloway 4-time creator on

      @Jonas | I don't know. It shouldn't matter as the laser cuts through the paint rather than the copper underneath. The copper is dissolved with the etching fluid. It should still work with different copper thicknesses. It will take longer to etch with the thicker copper.

      @Robin | Thanks for the tip. I don't have a blue ray diode at the moment but I'll give it a go when I do.

    3. Missing avatar

      Jonas Gartmann on

      Thanks Gregory
      One more question: What was the copper thickness? 0.5oz/ft^2 (17um), 1oz.(35um), 2 oz...?

      Thanks in advance =]

    4. Robin Patenall on

      Regarding using a photoresist coated board. I will suspect that this won't work well with a red laser because, as far as I understand, most photoresists are UV sensitive. It might work with a blue laser though (say a 405nm Bluray type one).

    5. Gregory L Holloway 4-time creator on

      @Steve | That's what I will be investigating next.
      P.S. Bird is the word :P

      @Jonas | The gap is about 0.5mm wide. The laser is switched on and off only, the power is not variable.

    6. Robin Patenall on

      Excellent! This is one of the things that I wanted to have a go at once I got a Microslice, and had assumed that it was going to be achievable. It's nice to know that it will actually work.

    7. Missing avatar

      Steve Todd on

      Damned autocorrect, that should have been board not bird.

    8. Missing avatar

      Steve Todd on

      Interesting. You may get better results (and it may work with the 100mW laser) if you use photoresist coated bird rather than acrylic paint.

    9. Missing avatar

      Jonas Gartmann on

      Awesome! few questions:
      - what is the with of the lasered gaps?
      - is the laser power also controlled with GCODE?