By Super Awesome Sylvia and her dad, James
Did you ever want to upgrade your bread-boarded circuits to something more permanent? Or maybe you’ve got a hankering to make your own metal jewelry? Today we’ll show you how you can do both. With super simple copper etching. Lets go!
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For this coppertastic build, we’ll need:
- Eye protection and gloves (rubber/latex/nitrile, any kind will do)
- Ferric chloride etchant (Found at some electronics stores, or online)
- Regular printer paper
- Printable plastic film or really thin glossy magazine pages, and access to a laser printer or copier
- A clothes iron
- Some fine steel wool
- and finally, some paper towels (it gets messy!)
For making jewelry, we’ll also need:
- Some solid pieces of copper or brass (found at fancy art stores)
- and a plastic or glass container than can fit your piece to be etched
For circuit boards, instead we’ll need:
- A copper clad PC board
- A brand new kitchen sponge (for the Sponge etch method pioneered by our friend Jim from TechShop!)
First things first, we need an image. What are we putting on our copper? If you’ve got a circuit design ready in your cad software, export a high resolution monochrome image of just the traces you want, or a high contrast piece of art for your jewelry, carefully print your design out on plastic or magazine paper.
For the solid copper, roughly cut out what you need from your main piece, for the circuit board you’ll have to score it, then snap it cleanly off (wear eye protection). Once ready, scrub it with your steel wool a bit, till it’s nice and shiny.
Now heat your iron to its highest setting (no steam!), and ensuring that your work surface can take the excess heat, put your piece down flat and let the iron heat up your copper or board fully (depending on size, this usually takes about 2 minutes).
Now for the tricky part. Carefully take your printout (making sure the toner side is down), and center it above the hot metal where you want it to go, slowly lowering it down. As soon as the toner touches, it should melt onto the metal. Put the paper back on and press and smooth firmly with the iron for another three minutes or so, lifting and checking for bubbles as you go.
Toner is the black stuff put on paper by laser printers, and it’s actually a type of plastic. This will melt and stick to the hot board to resist our etchant, keeping the areas it hides safe from being eaten away. There are lots of ways to do this step (even some permanent markers can do the job) so you could even draw your design directly on the board.
After ironing, let it cool then carefully peel up the plastic film. If you’re using magazine paper, let the piece soak completely in warm water, then carefully rub off the paper. And there’s your finished image! Use a permanent marker to clean up any rough edges or broken lines.
Now to etch!
WARNING!: ferric chloride stains and will burn your skin! Always be careful while handling it, making sure to use it in a ventilated area and always wear your safety goggles and gloves when working with it.
For solid copper: Tape off any areas you don’t want etched, put on your goggles and your gloves, then pour about 6mm of ferric chloride into the container. Now, to submerge your pieces. Once covered, carefully swish the fluid back and forth, again and again. Keep this up, anywhere from 20 minutes to an hour, depending on how deep you want your etch. When done, carefully pour your etchant back in the bottle.
For circuit boards: Cut a little square out of your sponge, and carefully put a small amount of Ferric Chloride onto the square, and start to wipe your board. The ferric chloride will eat away at the copper everywhere you wipe. You know you’re done when the copper is gone and you can see the fiberglass backing.
Once etched, wash everything off with water, dry, then gently swirl away the toner and oxidation, and you’re done! This solid brass etch took about 40 minutes for 100 microns deep. Small, but effective.
Try filling the voids with acrylic paint or nail polish, or round the edges of your metal to make a pendant. Or drill holes in your circuit board and you’ll be ready to solder in your components.
With the power to etch metal, you can do it all! Remember to experiment with different metals, be safe, take your projects to the next level, and get out there and MAKE something!
- Circuit Skills: Circuit Board Etching, sponsored by Jameco
- Salt and vinegar circuit etching
- Laser cutting circuit boards
- Cheap, Friendly, and Precise PCB Etching
- Printing circuit boards lecture @ 27C3
- Etching a portrait into a PCB
- PCB Etching Using Toner Transfer Method
- The 5-minute circuit board agitator, or, making temporary tools