I am going to walk you through the process of prototyping a Printed Circuit Board using a laser cutter and supplies from your local Radioshack and hardware store. This is a process I have perfected after several prototypes I created as part of my thesis, modular//neuroid.
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Signing UpStep 1: Prepare the board
Remove the bare copper PC Board from the plastic being careful not to get oily fingerprints on it. Place it on a clean, suitable spraying surface (newspaper or cardboard are great). Using flat black spray paint (I used Krylon brand) coat the copper 3 - 5, allowing time for each coat to dry before applying the next. If your PC Board is double sided, be sure to repeat this step for the other side. By the end of this step, your board should look completely black, no bumps or unevenness, and certainly no copper visible at all.
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Are there any specifications for the type of board? I read about one Radioshack board where the copper would separate from the board when it was heated.
http://www.lpkfusa.com/pcb-etching.html
Probably should be "blank copper PC Board"?
It isn't black until after you've spray painted it. ;^)
This is my local one -
http://www.portlandtechshop.com/
There's one Menlo Park as well. Don't know other locations I'm afraid.
We have a nice laser cutter, and are making room in our new location to add a second one.
So you can copper etch the PCB's as "panels", then put them back in the laser to cut out the individual boards using the board outlines. Assuming you didn't leave copper over the board outlines.
It is easy, it is quick, but the edge can be a little "ugly". The fiberglass fibers etch unevenly, giving a ragged edge, and it tends to be discolored. A few swipes of a file will clean the edges up.
So take into account the filing needed and allow +/-20mils for alignment accuracy when planning your board outline to nearest layout features. 30-50mils, depending how much filing you plan to do.
You can also try to cut vias with the laser, but I had registration problems on the order of 5 to 20mils when taking boards out and putting them back in later. So I couldn't get the registration accurate enough for this to be viable.
A real high powered laser could at most melt the SiO2, but will not burn and cut it.
so, cutting circuit boards with a laser cutter may be a bad idea.
sales.jinzulaser@hotmail,and welcome to our website www.jinzulaser.com
then open this file in Adobe Illustrator or the like.
Also, give auto primer a try - it etches the copper making the paint stick much better and you can get away with two coats.
*Also, for those interested, I've got a Epilog Helix 45w, and the best setting for me is super hot, medium speed, bottom up engraving. As the author said, you *DO NOT* want to burn twice as the results are always less predictable.
I was getting 5-20mil variations between lasering the top and bottom, so the through holes didn't line up without going to something like 30/15 layout on the bottom.
As far as cutting the boards, I used a bandsaw. It worked nicely, however BE WARNED: it produces quite a bit of dust, and this FIBER GLASS dust, which is VERY HARMFUL if inhaled. I tried a couple other things like scoring and snapping, etc, and they just produced cracked boards like the one pictured below. That's my partner in crime (aka the godfather) who was trying to find healthier, safter alternatives to the bandsaw. None worked, hence the disappointed face.
Link some of your projects! I'd love to see.
Copper fumes, and for the type of laser cutters being used by our suppliers to fabricate wood, plastic and metal model airplane parts, you'd have slots between the traces.
You're using an ablative process here that is dependent on the melting point of the various materials, copper being more resistant than the thin layer of paint, or the fiberglass reinforced epoxy below.
Is anyone producing a pulsed laser system that has adjustable cut depth? And at what cost?