Etching of board with hydrogen peroxide and citric acid: fineness of board processing

Etching board hydrogen peroxide and citric acid - a recipe that is very popular with radio amateurs. This is not only a quick, but also a safe way to get the canvas ready for soldering the elements of a future appliance.

How have the boards been etched in the past?

Previously, to make a circuit board, it took a lot of effort. At first the scheme was divorced on paper, then holes were made in the workpiece, after which the tracks were transferred to foil-shaped textolite or getinax, using paintwork. After drying the coating, it was torn off, and the board was immersed in a container with a meadow for etching.

The hardest thing was to etch the board. Since for these purposes a meadow based on ferric chloride was used. In the radio circle, such a tool was not scarce, but at home it was necessary to look for an alternative, which most often was copper sulfate.

The processing of the board carried one more secret: the board was etched unevenly. Some tracks were corroded, and in some places the surface was not etched. All because of the inexperience of the craftsmen or the repeated use of the lacunar solution.

Modern methods of processing boards

Etching board hydrogen peroxide and citric acid is not a novelty. Many have heard of this method before. Having chosen such an option of board preparation, you will discover not one advantage in comparison with etching in the chlorine iron. For example, the quality of processing, safety and environmental friendliness of peroxide in combination with an oxidizer.

Home Board Recipe

All that is necessary in order to carry out the etching of the board with hydrogen peroxide and citric acid, you will find in your medicine cabinet and in the kitchen or you can easily purchase. Another undeniable advantage of processing boards in this way is the cost of ingredients to create a solution. Here is another advantage of the hydrogen mixture - it will cost much less than chlorine iron.

Component composition

• Hydrogen peroxide 3% -100 ml.
• The citric acid is 30 grams.
• Table salt - 5 grams (as an auxiliary component of the reaction).
• Water (if necessary).

Important! A solution prepared in this proportion is enough to etch copper foil with a thickness of 35 microns and an area of 100 square meters. cm.

Preparing the board

1. Draw and print the board.
2. Cut out the required piece of textolite.
3. Transfer the toner to the textolite and leave to soak, then remove.

How to prepare a solution?

1. Preheat hydrogen peroxide: put the bottle in a water bath and wait until the temperatures of the two substances are leveled.
2. Take the cup. Any one will do, but not metal one.
3. Pour the heated peroxide into a clean dry container and pour in citric acid.
4. Stir the mixture thoroughly.
5. Stirring, add salt, which in the solution plays the role of a catalyst.

How to properly etch the board?

To etch the board with hydrogen peroxide and citric acid passed faster, you can use two containers. Just place a smaller meadow in a larger container and pour hot water into it. This will speed up and strengthen the process.

The etching of the board in the hydrogen peroxide solution is carried out as follows: the board is placed in the meadow by the side on which the tracks are drawn, downwards, so that the decay products easily descend to the bottom of the container. For the reaction to proceed more evenly, the solution needs to be slightly stirred from time to time. The whole process takes no more than 10 minutes.

At the end of the grass, the board must be neutralized and rinsed under running water.

This method of processing the board is completely safe. You can now make payments at work, at home, and at the office, and it's not necessary to work with unsafe reagents.

Important! If the solution is strongly foamed, then you poured too much salt. Pour in more peroxide, otherwise the reaction will be too active, the tracks can be damaged.

If during the reaction you pull out the board and look at it, then you will not be able to notice the differences, compared to how the etching of the printed circuit board in the chlorine gland passes, they simply do not exist. The main difference is a quick reaction and a less dangerous process for a person.

How to understand that the board is already etched?

In the hydrogen-acidic medium, the reaction proceeds according to the formula: Cu + H3Cit + H2O2 → H [CuCit] + 2H2O. The etching of the printed circuit board in hydrogen peroxide can be considered complete if any reactions in the solution have stopped: it no longer hisses and does not bubble.

The board is cleaned and washed with water. Toner or paint is washed with acetone. After that, the board is carefully wiped and degreased.

Important! Check the integrity of the tracks after processing the board. The damaged circuit will not work.

As you can see, etching the board with hydrogen peroxide at home is not only possible, but also safe. It will not be difficult to find the necessary ingredients for the preparation of the herbal composition, and the process itself will take no more than 15 minutes. Today, any radio amateur, thanks to simple and accurate advice, will be able to experiment at home without harming himself and others.