Tuesday, January 25, 2011

From Cricut, to Circuit - Part II - Etching Your Circuit

7. Prepare layout for etching - The first attempt of this was to see what would actually happen when I dropped the board into the Ferric Chloride. What came out was some mixed results. the pattern was etched as expected, but there were some unwanted side effects with the process. There was a slight amount of undercutting underneath the Vinyl, which caused a bevel at the edges of the copper traces. there were some spots under the Vinyl Where the FeCl had gone completely underneath the vinyl. Not perfect results, but perhaps still usable with some tinning. The most interesting part was where the Sharpie marker had hit the edges of the Vinyl. There was almost a perfect edge at those spots. (circled in red)



By this point, I had also just discovered that the ValveCaster board I etched was missing a specific component (by the layout creator's design) and probably wouldn't be as useful as I wanted...

However, this was great for an experiment, and I learned a lot from this, but I was ready to try a different tactic...I took another layout for my 2nd attempt, this time for the Pepper Shredder pedal, which is more involved and intricate. Taking another layout:

And converting it into another SVG cutting path:

Cut it out, and applied it, and etched it. I missed the step this time of pressing it with a iron, so the undercutting was more extensive than the first one, with it going almost 1 millimeter under the vinyl.



Not pictured is where I followed another's advice and marked out large sections of the copper board with sharpie, to conserve Ferric Chloride. There was one point where I had used a piece of paper as a straight-edge and marked across the board, between the intended patters, as a separator. Well, there was some ink-crawl underneath the paper and the sharpie ink hit the vinyl again. After wiping it off with Isopropyl Alcohol I discovered on etching that where the Sharpie ink hit the vinyl again, there was almost a perfect edge to the copper traces. Maybe I was on to something here. Time for a 3rd attempt...

I cut out another set of patterns on the Cricut in Vinyl, and applied it to another Copper board. This time, I liberally applied a wet sharpie to all the edges of the vinyl to see what result I would get this time:


I then thoroughly wiped off the entire board with Alcohol to remove the Sharpie ink on the surface. After running it through the etch, I discovered this was the secret to get minimal undercutting, although it presented another issue of its own. Be sure to remove ALL extra sharpie ink off the surface, or you may find yourself with short-circuits (which are easily cut and can be scraped off an Exacto knife)


(click for full-size)

17 comments:

  1. Cool! Keep up the work! I could only wish to do stuff like this!

    Im following

    ReplyDelete
  2. Very interesting, definitely following.

    ReplyDelete
  3. cool stuff. I remember doing this in tech class. Its tricky stuff to get right.

    ReplyDelete
  4. I want to do that. I need tools though.

    ReplyDelete
  5. This is awesome; following and supporting! :)

    ReplyDelete
  6. next time, foresee little holes where you will drill. You might tear off the metal. unless you are using SMD's of course.

    nice project! Following!

    ReplyDelete
  7. Nifty; don't think I could ever pull that off.

    ReplyDelete
  8. I've seen this being done multiple times now, and it seems so easy~

    ReplyDelete
  9. Woah this is really awesome. Read the whole blog top to bottom, knowing that i will do something similar one of days and I'd like to learn from your mistakes! CAn't wait to se the next part.

    ReplyDelete
  10. I have a big 16" Delta drill press that I use to drill my enclosures, but I don't know if it can handle the fine detailed work required to drill the holes in the pads yet, without tearing them up. That is one reason I made so many prototype boards to practice on. I also plan on investing in a Dremel 4000 with the matching workstation drill press, so it can act like a miniature version of the Delta.

    I expect I will be breaking a lot of tiny drill bits regardless.

    ReplyDelete
  11. I've had a lot of success with a two-step etching process. First I cut my design from vinyl and apply to the work piece. Next, I spray two coats of clear spray paint over the piece. Finally, once the paint is fully dry, I remove the vinyl and etch. The paint resists the etch much better than the vinyl and gives nice clean edges. A second benefit is that its easier when weeding the vinyl to save the "negative" of the design than all the little tiny traces themselves.

    ReplyDelete
  12. Happened to come across your blog looking for a way to use 3rd party pens on my Cricut. Love that you have gone outside the box with your machine. You're doing circuits and I'm still figuring out how to import quilt patterns so that I can just cut out fabric and/or fusible webbing via software. You've inspired me to keep going despite my frustrations with the SCAL2 and MTC software.

    If you feel like moving up and having more ease with your work, you could look at the Cougar Cutters. They are pricey, but would give you more flexibility. The only catch is they don't work with SCAL and I have to use MTC.

    Forgive the quick laugh. You've really helped diffuse tonight's frustrations.

    ReplyDelete
  13. I wish we did this stuff in school. great stuff, followed

    ReplyDelete
  14. I'm starting to get this now! Thanks for the info!

    ReplyDelete