Monday, January 24, 2011

From Cricut, to Circuit - Part I - Making a layout

1. I have found a few layouts that other people have done on various sites, and through GIS. I selected a few to work with and first tried on a ValveCaster pedal design by Freekmagnet from DIYStompboxes.


2. I imported this into InkScape and created another layer on top of the image to draw a path on. First I started drawing boxes for each copper bus, and circles for the pads, but kept getting SCAL to make unwanted cuts through the pattern. I discovered that I would have to use the pen tool instead of the shapes tool to draw around the entire pattern to get a workable layout without any extra cutting through the entire layout.



3. I imported this into SCAL, and prepared to cut out the design by making copies of the image, and placed multiples across the page.

4. I then examined the cutout to make sure that it matched the SVG I created. So far so good.

5. I then cut 110# Cardstock on the Cricut to test the cutting pattern.



6. At this point I ran into several failures in trying to get the layout transferred onto the copper. I tried to mark it with an Industrial Sharpie marker, an MG Chemicals Etch-Resist pen (also a branded Sharpie marker), even Enamel spray paint. All of these methods proved that the paper absorbs too much, and bleeds through making a really, really messy transfer.

I received a suggestion from two independent sources to use adhesive backed stencil material. Cricut sells this stuff at any craft store, or you can find it on the cheap at the right hardware stores.

I tried it out and got much different results in getting a workable transfer onto the copper. I applied a section of Cricut Transfer Tape to the top of the Vinyl cutout, removed the backing on the Vinyl, and applied it to the copper, thoroughly pressing it down with the included applicator stick and then with a warm iron. I then SLOWLY removed the vinyl from the copper. The transferred pattern turned out very clean, and on the first try I got a 90% transfer rate, only losing one layout to a missing trace, which I then promptly scratched out with a fine-tip Sharpie since it was unusable.



Then things became interesting once I dropped this board into the Ferric Chloride bath....

2 comments:

  1. Wow... you are skilled. Awesome blog. Can't wait for more posts on this project!

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  2. I am a beginner into electronics around a year and this is cool stuff i havent even messed with printing boards. I have reverse engineered a few but never printed. I will have to look into this when i have more money. I currently solder every joint on my projects making them not reliable.

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