Etching of printed circuit boards. Solution for etching boards Etching in hydrogen peroxide

To prepare the solution, you need to take 100 ml of peroxide, 50 grams of citric acid and one teaspoon of salt. Pour the peroxide into a plastic container, add salt and lemon juice, then stir everything until completely dissolved. There should not be any water in the solution!

For clear example effectiveness of this etching method, I will etch two identical pieces of textolite, one in a solution of ferric chloride, and the other in a solution of hydrogen peroxide and citric acid. So, I prepared the solutions, placed pieces of foil PCB there and timed them.

After just 30 seconds, the solution with peroxide and lemon began to actively release bubbles. This indicates that the reaction is going well. In the ferric chloride solution, there is still silence.

After some 50 minutes, the board made from a solution of peroxide and lemon juice was completely etched, the liquid acquired a dark turquoise color. The board that was in the liquid solution was etched only after 2 hours!

From all of the above, I will draw some conclusions and talk about the pros and cons.

Peroxide and lemon.

The board etching time ranges from 50 to 100 minutes, depending on the area, this is a plus. You can reuse the solution, but no more than 2-3 times. The ingredients are accessible and not expensive; 50 g of lemon and 100 ml of peroxide cost me 32 rubles. The solution leaves holes on clothes and fabric items, this is a huge disadvantage, so be careful, wear gloves and do not touch the clothes. Here's what happened to my rag the next day:

Ferric chloride.

This ingredient costs from 50 rubles per 100 gram jar. You can only get it in cities where there are radio stores and chemical stores. The board etching time ranges from 2 hours or more, depending on the area. But there is a big plus, with a ferric chloride solution, you can etch many more boards, for example, after each etching, I pour the ferric chloride solution into a bottle and use it again, for about a year now and every month, I collect 2-4 circuits and a solution still alive, significant savings!

It’s not difficult for me to say who won, peroxide and lemon are considered a disposable solution, but they poison the boards quickly. Ferric chloride is not available to everyone, the etching time is from two hours, but the solution serves for a long time. I'll finish here, don't forget to write comments!

Good day, dear colleagues, beginners and not so amateur radio enthusiasts! I decided to publish my article on Habré. Today we will try to make a printed circuit board using hydrogen peroxide etching at home. The technology is called LUT (laser ironing technology). Use a mother's or wife's iron, one-sided fiberglass foil, a 100 ml bottle of hydrogen peroxide, 80-100 g citric acid, a teaspoon of table salt. I’ll say right away that this is my first board, I’ve never etched before, but since I decided to run my own website radioenot.ru, I did it with detailed description and photographs. So, if I could do it, you can do it too!

Some people recommend a special old-style iron, but I personally can do it with this one.

But first we need to buy photo paper. Photo paper sticks better to fiberglass, so don’t waste your time and choose the best, there will be fewer problems later. I later tried to use this board plain paper and everything turned out very badly, although it was passable, but some of the paths had to be completed with a waterproof marker. By the way, buy a marker, I recommend a marker for writing on CDs/DVDs or another marker, for example good feedback I've heard of a varnish marker. Actually we need more laser printer, not just any kind, but laser.

In the Sprint-Layout program we open finished project or we draw it ourselves, but to begin with, of course, it’s better to use something that has already been tested by others, and we print it on photographic paper, having previously removed any auxiliary elements from the print, if any will be displayed in the drawing. Once printed, you can proceed to applying the design to the board. Before this, the fiberglass laminate must be cleaned with fine sandpaper.

Then we place our paper pattern down on the board and begin ironing it with a heated iron. You can first iron one side while holding the other with your finger so that the paper does not move to the side. You need to iron for about 5-10 seconds. In general, it is difficult to say how long it takes, it all depends on how hot the iron is and with what force you press on the board. I haven't measured it personally exact time, but having learned that some people do this until the drawing begins to appear a little through the paper, I took this into account and used the method, the only thing was to remove the iron as soon as something began to appear a little on the paper.

After ironing, we need to remove the paper from the board. Let's pour warm water into the container and put our board there, after a few minutes you can begin to rub the wet paper with your finger carefully so as not to damage the design on the board.

It turned out that in some places there were some shortcomings. A marker came in handy and I used it to fill in the gaps.

Now prepare the solution for etching with peroxide. Pour a bottle of peroxide into a container, stir a teaspoon of salt and 100 grams of citric acid until the salt and acid dissolve.

We put our board in the solution. But first I would like to talk about how it was best to pickle at home, the home conditions were not very suitable because during pickling a pungent smell of acid appeared, after which I decided to put the whole thing on the balcony, but since it was outside cold, the oxidation process slows down. I did the following: I poured a bowl of hot water and put the container with the board there, it turned out water bath, after which the etching process began right before our eyes. After about half an hour, the board was etched.

Now we need to remove the paint. This is done very simply, with some kind of swab soaked in acetone.

Drill holes with a small drill.

Every hole is clearly visible. This is what was required.

Next you need to tin the board. Some people actually drill holes after tinning. Some serve, some don't. I followed the path of the first ones, coated the tracks with flux and gradually began to apply solder. I used a homemade flux made from rosin and alcohol.

This is the board we made for you. If I could do it, so can you. Good luck!

This is an edited repost from my LiveJournal

For etching, we will need 37% hydrogen peroxide (optional) or, in extreme cases, 3% pharmaceutical grade, citric acid, table salt and hot water or microwave (if the peroxide is pharmaceutical grade). Personal protective equipment includes gloves and tight-fitting goggles (for swimming) to protect your eyes.

After an unsuccessful first experience of etching with 37% hydrogen peroxide with boiling of the electrolyte, red eyes and cough (), conclusions were drawn and the concentrations were changed.

My sad experience with electrolyte boiling was very useful. And I took note of a few points:

1. Etching in a hot solution goes very quickly. So fast it's worth the risk of boiling over.


2. It is necessary to be able to drain or cool the solution.


3. The solution foams madly, and this is a mega plus - because... no bulbulator is required, it happens naturally.


4. We need to be smarter and more attentive.

In general, this time I did it very strictly. First, I placed the container in a bucket so that if it boiled, it wouldn’t run away. Secondly, I did not make boiling water, but approximately the temperature when the first bubbles begin to appear, but it does not boil. There was 1.7 liters of water. 100 grams of 37% peroxide (please note that the total concentration is even lower than from the pharmacy), 2 full tablespoons of citric acid (then I added 2 more), a tablespoon of table salt.

Hellish gurgles

The result was not long in coming. The board was 10x15 cm (the size of a standard photograph). I dropped everything, saw that it was bubbling, added a little more acid (the bubbling became stronger, after the second spoon nothing changed). And he went to the kitchen to drink some water. I came back and the board was already etched!

Result

• It is necessary to poison in small concentrations, but with a very hot solution. For pharmacy peroxide, heat OPEN in the microwave.


• It is necessary to be able to either quickly cool the solution (by pouring cold water), or dispose of it by pouring it down the sink. Therefore, it is not suitable to use low utensils such as plates! Only with high sides.


• You need to monitor the solution, or make such hellish devices, like mine


• Poison ONLY in vertical containers!

In general, I recommend using hydrogen peroxide for etching. Poisons quickly, cleanly and affordably. Doesn't stain clothes. If anything, the stains are all wiped off with vinegar.

ZY The etching speed is very important when etching such small parts!