Introduction: (easily) Etch Images in Copper
Make a copper etching of any image. This takes about 1 hour, including image prep, transfer, and etching, and it works really well. Check it out!
Step 1: Overview
I was making PCBs today (using vincent's excellent 5PCB instructable!), and they were coming out really well. I thought I might try images, and after a bit of trial and error, I got that working well, too.
This instructable will leave you with a nice copper etching of a digital image of your choice.
Along the way, you will:
Do some digital image editing and manipulation
Laser print your image onto a transparency
Iron the transparency onto a copper clad board
Chemically etch the board
Step 2: Get Yo' Materials Together
Some circuit board etchant (FeCl2)
A copper clad board the size of your image
A transparency (kinko's sells them for about $1)
A laser printer
A plastic tray larger than your board (to hold the board and etchant)
Step 3: Get Some Tunes
Before you begin your labor, you'll need (for your own safety) some smooth jams to rock out to.
Slip a favorite CD into that deck of yours, or grab one of my mixes from http://www.artiswrong.com/alex/mix
Now you're ready to get down to it!
Step 4: Prepare Your Image
So, pick an image you'd like to etch. In general, you'll want something with high contrast, since , while grayscale will etch, greater contrast looks better. I used a sillhouette picture of me, and it turned out well.
OK, so using your favorite image editor, convert the image colors to grayscale. This will give you a better idea of what the image will look like once it's etched.
Now, scale the image so that it'll print to a fairly small area. Mine were 3"x4", and they worked out alright. I tried a full page image, and it's really hard to get the transfer to work for larger images. Try something small to start out with.
Remember that the image will be flipped (mirrored) when you transfer it, so you might want to flip the image before you print it (and definitely flip any text).
Print the image onto a normal sheet of paper and see how you like it. Play around with it until you're happy. Then, move on to the next step.
You might notice that I made 4 small images. Play around with it! Try inverting the colors, or playing with the contrast/brightness settings
Step 5: Print Onto the Transparency
**WARNING--You are about to put a plastic transparency into your laser printer. I've done this a bunch and haven't had any trouble (I have a HP laserjet 1200), but you should be aware that your printer has a very hot fuser and you are going to put plastic through it. I've never heard of anyone having any trouble, but I just want to mention it here. Are you done ignoring my warning? Cool--let's go on**
Load a transparency into your printer's tray.
Print your image exactly as you did before. Remember which side of the transparency your ink is on. Maybe mark it. If your image has text, this isn't a big deal--you'll just put it onto the copper so that the text (which you printed backwards, remember) looks correct (like normal text).
Step 6: Transfer the Ink Onto the Copper
Now you want to transfer the transparency onto your copper sheet.
First, you want to take a piece of steel wool to the copper sheet (both sides), and buff it until the entire sheet is shiny.
If your transparency is much larger than the copper sheet, you can trim it down, but leave some (.5 inch) room on the sides of the image.
Now, plug in your iron, and set it to a hot setting.
Put your copper board down on the ironing board. Position the transparency over it(ink side facing the board!). Put a piece of wax paper over the transparency.
Now, being careful not to slide the transparency around, put the iron on top of the wax paper. Press down with the iron, and iron all around the transparency . Iron for about 5 minutes--if you iron for less, the ink won't transfer well and you'll have to do it over again.
When you're done, set the iron to the side. The copper boards will be very hot!
I found that the ink will transfer best when the board cools down. You could either wait for ~10 minutes, or, if you're impatient like me, you can carry the board to a sink (remember that it's really hot!), and run some cold water over the other side of the board. This will cool the board down in about 10 seconds.
After the board is cool, peel back the transparency. Most of the ink should have transfered to the copper board. If you notice that it only partially transferred, it's OK. Leave the transparency on the board, put the wax paper on it again, and iron some more.
When you see a pretty faithful representation on your board of your image, you're done. Onwards!
Step 7: Etch-yer-sketch!
Now you'll use ferric chloride to etch away your copper and "develop" your boards
First, you should know that ferric chloride is really messy and can stain stuff (like floors!), so do this in an 'informal' setting. Ferric chloride is also acidic, so you'll want some nitrile gloves. I've had some on my skin, and it just irritates, rather than burning through my body, but it's not a nice sensation. Safety glasses might also be a good idea for the safety-conscious instructablee
So, put down a plastic pan that's larger than your copper board. You want a nice, heavy-duty plastic, on par with the lids of tupperware.
Put your copper board face down in the pan. Slowly pour ferric chloride over the board until the board is submerged.
Now, you sit back and wait. It took me about 30 minutes to fully etch my boards. Check in on your boards every so often to see how well the copper's etching.
When it's etched to your satisfaction (you should only see the black ink of your image, and the fiberglass board everywhere else), pull the board out and clean it off with water. Be sure to rinse off all the etchant. Remember that even a little bit of etchant can stain a porcelain sink, so do this somewhere 'informal' I sponged mine off first with paper towels, and that made things less messy.
Hang on to your etchant--you can do a bunch of boards before it'll stop working. When you do want to get rid of it, DON'T pour it down your drains.
MGchemicals.com offers this advice for disposing of Ferric Chloride:
1. Contact your local Hazardous Waste Disposal Company
2. The solution must not be put down the drain because of residual copper ions left in it. To make it safe for disposal, you can add sodium carbonate (washing soda) or sodium hydroxide to it to neutralize it, until the pH value goes up to between 7.0 and 8.0, testing it with indicator paper. Copper will be deposited as a sludge. Allow the sludge to settle, pour off the liquid, further dilute it with water and then it can be poured down the drain. Collect the sludge in plastic bags and dispose of it as required by your local waste authority.
If you're at a university, just contact your Environmental and Health Safety Office, and they'll be happy to collect it and dispose of it properly.
Step 8: Finish Up
Take some steel wool and go over your board. The blank ink should come off easily and you'll have shiny copper underneath. With any luck, your boards should come out nicely. If your board was larger than your image, you can trim it down with a paper cutter (although the fiberglass board will dull the blade)
Step 9: Cheese-it!
Cool, you're done!
Enjoy your cool etchings. I'm making two-sided etchings to use as my business cards. Now go out and do some cool stuff!