If you have ever produced your own PCBs at home, you know that it can be somewhat of a time consuming process. Spending 20 or so minutes manually agitating a board is a drag, and while aquarium bubbler setups improve the process, they are far from ideal. [Christian Reed] knew that if he really wanted to streamline his PCB production he had to emulate the big boys and build a PCB sprayer of his own.

His spray etcher is contained in a custom acrylic case built mostly of scraps from previous projects. It contains two compartments – one for spraying etchant on the PCBs, and another for rinsing the finished work. The system is impressive to say the least, featuring a maze of tubes and piping which allow him to etch boards and manage his chemicals with ease.

[Christian] says that although the parts list might seem daunting at first, it really is pretty easy to assemble the device. Seeing as he can etch and wash a board in about two minutes flat, we think that any amount of effort would be worth the results.

[Christian] points out that he was unable to find a guide for building this type of PCB sprayer anywhere online, so he documented the process in painstaking detail in order to make it as easy as possible to replicate his work. Be sure to check out the video below to see his etch tank in action – we’re pretty sure it will have you itching to build one this weekend.

Eminent steampunker [Jake Von Slatt] wrote a small article on etching candy tins for The Steampunk Bible, but the limited space available in the book didn’t allow for a full exposition. To make amends for his incomplete tutorial, he posted this walk through to compliment the Bible’s article.

The process is very similar to the many tutorials we’ve seen on home-etching PCBs using the toner transfer method. Removing the paint from the Altoid tin, creating a mask, printing it on the Sunday circulars, and taking an iron to the tin is old hat for home fabbers.

Unlike PCB manufacturing, [Mr. Von Slatt] doesn’t bother with Ferric Chloride or other nasty chemicals – he does everything with electrolysis. After adding a few tablespoons of table salt to a bucket of water, [Jake] takes a DC power supply and connects the positive lead to the lid and the negative lead to the base. a bit of electrical tape around the corners of the lid keeps the metal from getting too thin.

A nice Copper finish can be applied to a finished tin by swabbing on a solution of Copper Sulfate – a common ingredient in “Root Kill” products. Of course that’s not a necessary step; you can easily enjoy and elegant Altoid tin bare metal.

[Martin] had been using standard perf board for most of his electronics projects, but as he was starting to utilize more surface mount ICs, he quickly realized that it was time to start making his own PCBs. Having never etched any PCBs using the toner transfer method, he figured it was as good a time as any to give it a try.

Rather than make a board for a particular project, he decided to try his hand at etching a very detailed map of the Paris Metro as a test pattern instead. He grabbed a large image of the subway map, then printed it out on the back of a supermarket flyer. He attached it to his PCB and ran it through a lamination machine to transfer the toner. He figured that the laminator would be easier than an iron to use, and was right for the most part. The only issue he had was that the laminator did not generate enough heat, so he supplemented the its heat output with a hair dryer.

When everything was said and done, he had a pretty good looking PCB on his hands. Most of the Metro tracks and text came out just fine, though he admits there is a bit of room for improvement. It looks nice when mounted in a frame, though we would love to see a functional circuit made out of a PCB map like that. Heck, we’d even settle for a double-sided PCB with a street-level map on one side an the Metro on the other!

[Stephen] often finds the need to make his own PCBs at home, and when he got the urge to do some etching recently, he realized that he was fresh out of “Ferret Chloride and Bureaucratic Acid*.” Undeterred by his empty chemical cabinet, he poked around in his kitchen mixing together anything and everything that might have the ability to strip copper from a PCB.

Now, we don’t necessarily recommend this course of action, but it seems that he finally hit upon a winner. He discovered a formula that can be made at home from simple and safe household ingredients which does the job quite nicely. A fair warning however, standard ferric chloride disposal procedures need to be followed when using this solution.

If you want to know what he concocted in his kitchen as well as the chemistry behind it, you will have to visit his site, we won’t ruin it for you. You can however, see the solution at work in the video we have posted below.

*His joke, not ours

[Bart] built a giant laser etcher from scratch. One of his first test engravings included the Hackaday skull-and-wrenches on a polished granite floor tile (we love it when people do that). He used an XMOS controller and Mach3 CNC software to handle the device. With just two axes to worry about this seem like an easy project. The difficult bit is controlling, cooling, and focusing the laser.  Oh, and if you screw up, you could be blinded, burned or horribly maimed. But if you start from the beginning you’ll see that [Bart] knows what he’s doing.

Ever annoyed by those pesky stickers on your fruit?  They never seem to pull off in one piece and they always leave a little glue behind. Well, the industry might be moving away from them in favor of laser etching each piece of fruit. They are using a low energy carbon dioxide laser to etch the skin. The FDA is in the final stages of approval for using this in the states. It is already in use in New Zealand. We might find this a bit weird, but we’ve seen weirder.

[via slashdot]

This clever Instructable demonstrates how to etch beautiful aluminum control panels for electronics projects. We like how similar this process is to DIY circuit board etching. Both abide by the same technique and use blue transfer paper. The primary difference is in the use of muriatic acid and hydrogen peroxide for etching aluminum.

It might be a little bit of overkill, but this etching container agitator sure looks convenient. There’s not much to it technically, a small circuit with an ATtiny45. For those beginning with this stuff, he has written a pretty good tutorial on working with basic microcontrollers. If you are more interested in a tutorial on etching, we did a  guide on how to etch a single sided PCB.

The Motori plotter is fast and high precision. One image shows that it is drawing lines at .5mm. Like others in the flickr set, we keep thinking of how we could apply this to PCB creation. Great job [svofski]. If you want one that’s not as precise, but might have a much cooler drawing mechanism, you might want to check out the lego arm plotter we posted back in May.

[xander] built this LED valentine for his loved one. It’s interesting because he used Pyralux, a flexible circuit board material from DuPont. He describes the consistency as “tough plastic tissue-paper”, but had no trouble using standard toner transfer etching. It has an ATtiny45 microcontroller that pulses the 16 LEDs at an approximation of his heart beat. To avoid soldering a bunch of surface mount resistors, he used two constant current shift registers.

Many people use protoboard and point-to-point wire everything, but needing multiple copies of the same circuit is the reason that forces many away from using protoboard. After making your first circuit board, you might not point-to-point wire anything again!

For your first circuit board, one goal is to keep the circuit single sided so you can etch using single sided copper clad. This will allow you to gain some experience before moving on to double-sided. If you need topside traces, simply run a few jumper wires on the top. There are many complete circuit layouts you could try like the Hack a Day design challenge winner.

Here is a list of materials you will need to produce a single-sided board. With the exception of the copper clad and PCB drills, everything on this list is easily obtained at your local store.

Materials: Muratic acid, common household hydrogen peroxide, safety goggles, good quality magazine pages (cut to 8×11), laser printer, single sided 1 ounce copper clad, a plastic container the board will fit in, soft plastic brush, clothes iron, lacquer thinner, rubber gloves, paper towel, tin snips, drill or rotary tool, PCB drill bits, Scotch Brite scrubbing pad, good ventilation, 5-gallon plastic pail full of water.

Now, here is how you do it:

Print the bottom side layer on a piece of paper from a high quality magazine. Use one actual page from the magazine, the thicker and shinier the magazine paper the better, but do not use the cover. You must use a laser printer, not an inkjet. If your printer uses ink cartridges and not toner cartridges, it will not work. If you do not have a laser printer, you can work around this by printing to white paper and using a photocopier set to the darkest setting to copy the layout to the magazine paper. If the paper jams in the printer, you are not using a thick-enough magazine page. Again, do not use the magazine covers, as they do not work.

Magazine pages are used because they work well, and they are cheap! The reason they work is because the paper is very glossy and the toner does not adhere well to the glossy pages. The printing used on the magazine page is ink and it does not come off, but toner does. Toner is actually a plastic polymer, and different toners may yield varied results. In our experience, a genuine HP toner cartridge was used with great success; an Office Max brand yielded poor results. The sole purpose of the toner is the protect the copper below it from etching away, you only want the uncovered areas to etch.

Next, wash your hands to remove any oils. Keep handling to a minimum once the pages are printed and do not touch the laser printing with your fingers; this could get oils on the printing. Keep pages as flat as possible.

Very carefully, remove the copper clad from the packaging. Do not touch the copper surface for the same reason as above. You can cut the copper clad to size using a tin snip if needed. Use the Scotch Brite scrubbing pad to gently buff the surface (Scotch Brite is a popular brand of of plastic scrubbing pad meant to emulate steel wool). Do not use steel wool because it will embed steel into the copper. Clean off the residual dust with a slightly damp paper towel.

Find a hard, very flat, sturdy, heat resistant surface. Empty the water out of the clothes iron and set the iron on the hottest setting. Allow the iron to get hot.

This is both side of a piece of copper clad. Place the blank side facing down and copper side facing up. Align printing/paper onto copper clad board with the printing facing the copper. Do not allow it to move.

Firmly press the iron onto the back of the magazine paper, sandwiching it between the copper clad and the iron. Pressing hard without moving the iron, hold the iron perfectly still for one full minute. Do not move the iron at all during this minute, and push hard, really hard!

Then, for four more minutes, slowly move the iron around making sure to put a lot of pressure on the paper, but not allowing the paper to slide on the copper. When done, let the board fully cool before you move it at all. This will allow the toner to adhere to the copper and prevent you from being burned.

Put the board in cold water and let soak for five minutes. After five minutes, try to peel the wet paper from the board leaving only the toner/print from your laser printer. Only the toner should be left adhering to the copper. If the paper does not come off easily, let it soak in the water for a while longer. If necessary, rub with your finger to remove any paper, leaving only the toner. It’s ok if there are a few excess paper fibers stuck to the toner.

If you find not every trace adhered to the copper clad or it is misaligned, use lacquer thinner and paper towel to clean the toner from the copper board and start over. If the traces look good then move on. Inspect the traces carefully, however, because what you see now will be your finished product.

In a well-ventilated area with a fan, add 2-cups hydrogen peroxide to a plastic container. Gently pour in 1-cup Muriatic acid, to create the etching solution. Always wear goggles, gloves, and do not inhale the fumes. Do not use any metal containers, measuring cups, stainless steel sinks, or tools with this mixture as this mixture will aggressively etch metal. Acid safety, think “triple A”, for Always Add the Acid, it’s whatever is in the container that will end up splashing. This etching solution, while made with common chemicals, should command respect. It is dangerous to yourself and surroundings, treat it with respect. Ferric Chloride is another common etching solution, it is not a safer solution to use, both are equally dangerous.

Put the board copper side up in the plastic container filled with etching solution. Use a soft plastic brush to gently wipe the board. You will notice the copper begin to dissolve. It takes about 3-4 minutes to get all the exposed copper dissolved. You just have to watch to make sure it is gone in all areas between the traces. Do not leave the board in the etching mix for too long as the traces will dissolve under the toner that is protecting them.

Use lacquer thinner (paint thinner and acetone do not work well) and a paper towel to remove any toner left on top of the copper traces.

Tinning prevents the copper from oxidizing, which can make it hard to solder to in the future. If you choose, you can tin all the traces with solder and a soldering iron now. This actually makes drilling much easier because it helps to center the drill bit. Make sure to clean off excess flux if you do this. You could use Tinit to chemically plate the copper. Here is a different tutorial describing its use.

Drill all the holes for the through-hole parts using the correct size PCB drill bit and rotary tool. Drill large mounting holes with a normal drill. PCB drill bits are carbide and made to drill through fiber glass that would quickly dull standard bits. There are a few very common sizes of bits and these are often sold in packs. We use .0260″ for IC holes and .0310″ for resistors and caps.

Print out the top side silkscreen layer on magazine paper and iron this onto the top side, using the same processes as above. Again, run under water and peel off the paper. Now you have the component ID’s on the top side.

Here is a different video using essentially the same method:

You can make really nice PCBs of your own circuit design using this simple method, and we look forward to seeing your future projects using this method coming in on the tip line. Look for more How-Tos like this one in the How-To category.