How to Make Printed Circuit Boards
Making printed circuit boards is an art. Each one can have their own variations around a basic technique, thus obtaining results that individualize their montages, with a special touch that each reader can imagine. In this article we take readers, mainly beginners, students and hobbyists, some fundamental techniques for making printed circuit boards. You can also take services from a company like MAD PCB which is best printed circuit Board Company in China.
As we stated in the introduction, there are many ways to make a printed circuit board, to the point that each reader can give special characteristics to its assembly, which will identify it as the manufacturer.
Thus, exploring all the manufacturing techniques for these plates in one article would be impossible, since there are as many as those who manufacture them. But we can summarize some of the basics of PCB making techniques, and give inexperienced readers a simple basic process.
Once you have understood these basic aspects, the reader will be able to make your assemblies on printed circuit boards with ease, either with commercial equipment that exists for this purpose, or with materials purchased separately.
Printed circuit board:How to Make Printed Circuit Boards
The function of a printed circuit board in an assembly is twofold: at the same time it serves as a support for the components that make up the circuit, and makes the electrical interconnection of them according to the way in which the components should work.
A printed circuit board can be made of fiber or phenolite. A thin layer of copper is deposited on this plate, which after a “printing” process is cut by chemical means to form strips that act as connecting wires between the components
The arrangement of these conductive strips or regions must be planned according to the circuit to be assembled, that is, a printed circuit board designed for an amplifier of a certain type only serves for that amplifier.
The components are then placed on the board by threading their terminals into the holes, so that they can be soldered to the copper-plated regions. With this, a perfect contact between them and the copper strips that must conduct the current can be guaranteed
The secret to making a printed circuit board is in the technique used to transfer to copper the “drawing” corresponding to the strips or regions that must conduct the currents in the circuit, and there are various options that we will analyze in this article.
Corrosion:How to Make Printed Circuit Boards
To have a printed circuit board according to a design taken as a pattern, we must corrode certain regions of the copper surface in order to leave the strips or regions that will act as wires.
For this purpose, Iron Perchloride is used, which is a substance that attacks it in contact with the copper of the plates, without affecting the phenolite
What is done, then, is to coat the regions that must remain on the plate, forming the conductive parts, with some substance that is not attacked by the perchloride, exposing the regions that must be eliminated.
Later we will see the techniques to make the cover in the desired places. Now we are interested in the corrosion process.
Perchloride dissolved in water is used in a ratio that can be 1: 1 or 2: 1, that is, one part of water for each part of perchloride, or two parts of water for each part of perchloride. This last solution is obviously weaker, and it takes longer to make the plate.
Perchloride comes in bottles, in liquid form, or in powder form. In the case of the liquid form, its use is immediate since we already have the solution. In the case of perchloride powder, it must be diluted in water and therefore done slowly
Once the solution is obtained, it can be used many times, that is, it can be saved to make many printed circuit boards.
You notice that the solution is weakening due to the increasing delay in the corrosion of a plate.
When the corrosion time approaches one hour, it is a sign that the solution must already be renewed.
The equipment for making printed circuit boards has a small plastic tray where the perchloride for corrosion is placed. These trays are of the type used in photo development laboratories.
The reader can also use plastic or even glass molds for this purpose.
To accelerate the process of corrosion of a plate, the solution must be stirred, which can be achieved by rhythmically lifting the edges of the tray to form waves, or by carefully moving the same plate with any object that touches its edges.
There are more complicated systems for making printed circuit boards that use, for example, “bubbler” devices of the type found in aquarium aeration, to move the solution and thus accelerate the corrosion process.
As we have seen, there are various techniques that make it possible to obtain waterproofed regions on a printed circuit board, according to the pattern design.
All these techniques require substances and materials that are not attacked by perchloride.