Described is the process of a fast, cheap and safe way to etch printed circuit boards using readily available tools at hand - salt, hydrogen peroxide and citric acid.
Necessary
- - citric acid - 1 packet;
- - hydrogen peroxide 3% - 1 bottle 100 ml;
- - table salt - 2 teaspoons.
Instructions
Step 1
Let's take a suitable container for etching the board, so that the board goes there completely. Pour in 1 teaspoon of salt, 30 g of citric acid, half a bottle of hydrogen peroxide. Mix thoroughly until the salt and acid are completely dissolved in peroxide. This solution is relatively safe for humans - it does not corrode the skin and clothes, but copper poison perfectly.
Step 2
We put in the container the blank of the printed circuit board with the tracks applied, for example, by the "laser-ironing" method. We discussed this method of preparing the board in detail in one of the previous articles.
Step 3
Now we wait until the acid etches the unprotected areas of the copper. Depending on the thickness of the copper layer, this can take from half an hour to 1.5 hours. It is better not to interfere with the process, but only to make sure that everything is going as it should. After a couple of minutes, you will see seething and active formation of gas bubbles on the surface of the board, and after 10 minutes the solution will begin to turn bluish-green: it means the chemical reaction is going well.
Step 4
When the etching is finished, we drain the spent solution and take out the board. It is advisable to rinse the board with a weak vinegar solution, and then with warm water. We clear the tracks from the toner. It remains only to plow the contact pads and the printed circuit board can be used!
