How To Make A Printed Circuit Board – 2022 Guide2022-08-21
How To Make A Printed Circuit Board
Printed circuit board (PCB or printed wiring board, PWB)-a dielectric board that forms a conductive circuit of an electronic circuit on the surface and/or inside it. Printed circuit boards are designed for electrical and mechanical connection of various electronic components. There are PCB design software that can design PCB in seconds. The electronic components on the printed circuit board are usually found through solder to connect the elements connected to the conductive pattern by soldering.
Unlike surface mounting, the printed circuit board is made of foil and is completely placed on an insulating base. There are holes and pads on the printed circuit board for mounting output or flat components. Also, the PCB has holes that allow foil pieces on different layers of the board to be connected electrically.
From the outside, the board is usually given a protective coating (called a “solder mask”) and markings (based on the auxiliary drawings and text of the design document) based on the pcb layout.
According to the number of layers with conductive patterns, printed circuit boards are divided into:
One side (OPP): Only one layer of foil is attached to one side of the dielectric sheet.
Double-sided (DPP): two-layer foil.
Multi-layer (MPP): not only on both sides of the board, but also on the inner layer of the dielectric with foil. The multilayer printed circuit board is obtained by bonding several single-sided or double-sided boards together.
As the complexity of design equipment and mounting density increase, the number of layers on the board also increases.
The base of a PCB is dielectric, and glass fiber and wood grain paint are the most common materials used to make them. A printed circuit board can also be made with a metal substrate covered with a dielectric (like anodized aluminum) and a layer of copper foil on which tracks are placed. These printed circuit boards are used in power electronics to get rid of heat from electronic parts in an efficient way. In this case, the heat sink is connected to the metal base of the circuit board.
As a material for printed circuit boards operating in the microwave range and at temperatures up to 260°C, glass fiber reinforced fluoroplastics (such as FAF-4D) and ceramics are used. The flexible board is made of polyimide material (for example, kapton).
What material will we use to make the circuit board
The most common and affordable materials used to manufacture circuit boards are Getinax and Fiberglass. Getinax paper is impregnated with bakelite paint and epoxy glass fiber for textiles. We will definitely use fiberglass!
Foil-shaped glass fiber is a sheet made of glass fiber, impregnated with an epoxy resin-based adhesive, and lined with 35 μm thick electrolytic foil on both sides. The maximum allowable temperature is -60ºС to +105ºС. It has very high mechanical and electrical insulation properties, and is very suitable for cutting, drilling and stamping.
Glass fiber is mainly used on one or both sides, with a thickness of 1.5 mm, and the thickness of layer of copper foil is 35 microns or 18 microns. We will use a single-sided glass fiber with a thickness of 0.8 mm and a foil with a thickness of 35 μm (why will be discussed in detail below).
Method for making printed circuit board at home
The board can be made by chemical and mechanical methods.
When using chemical methods, protect the foil on the board with varnish, toner, paint, etc., where there should be traces (painting). Next, put the circuit board in a special solution (ferric chloride, hydrogen peroxide, or another solution) that “corrodes” the copper foil but doesn’t hurt the protective parts. Because of this, copper stays in the protective mix. After that, a solvent is used to remove the protective compound, and the finished board is kept.
For hand-made work, mechanical methods use scalpels or milling machines. The aluminum foil was cut into slots with a special cutter, and the necessary pattern was left on the island.
Milling machines and milling cutters are both expensive and hard to find. We won’t use this method because of this.
The simplest chemical method is manual. Risograph paint draws the track on the board, and then etch the solution. This method does not allow the production of complex circuit boards with very fine tracks-so this is not the case.
Photoresist is the next thing that will be used to make the board. This is a very common method. This is how plates are made at the factory, and many people use it at home as well. On the Internet, there are many articles and guides that explain how this technology can be used to make circuit boards.
It gives very good results over and over again. But we don’t have a choice.
The main reasons are that photoresist, which breaks down over time, and other tools are very expensive (UV, laminator). Photoresist will be unbeatable if you can make a lot of circuit boards at home, so you should definitely learn how to use it. Also, it’s important to note that the photoresist technology and equipment allow us to make screen printing and protective films for circuit boards.
Millions of articles on the Internet describe how to use this technology to make circuit boards. However, this technology has many disadvantages, requires direct hands-on and takes a long time to expand. That is, it must be felt. The payment does not appear for the first time, but is obtained every other time.
There are many improvements-the use of a laminator (rework required-usually insufficient temperature) can achieve very good results. There are even methods for constructing special hot presses, but all of these require special equipment. The main disadvantages of LUT technology:
Overheating-the path spreads-getting wider and wider
Overheating-traces left on the paper
The paper is “fried” onto the board, making it hard to remove even when wet, which could damage the toner. On the Internet, there is a lot of information to choose from.
When the glossy paper is taken off, there are still tiny holes in the toner. The board is also etched through these holes, which will cause dents. You can drill holes using a driller.
Repeatability of results: Today’s are good, tomorrow’s are bad, and then they’re good again. It’s hard to get stable results because you need a constant temperature to heat the toner and a constant pressure on the board.
I can’t make planks this way, by the way. I tried to do this in magazines and on paper with a coating. Because of this, he even broke the circuit board because the copper on it melted from being too hot.
There isn’t much information about another way to transfer toner on the Internet (cold chemical transfer method). Since the toner doesn’t dissolve in alcohol but does dissolve in acetone. So, if a mixture of acetone and alcohol will only soften the toner, you can “glue” it from the paper to the board.
This method is great, and I can see results right away—the first board is ready. But I later found out that I hadn’t been able to find any detailed information that could give me 100% results. We need a way to do this that even kids can pay for. But the second time, the board of directors didn’t work, and it took a long time to find the right ingredients.
As a result, after taking a series of long-term measures, all ingredients were selected, even if not 100%, it can reach 95%. The most important thing is that this process is very simple and children can pay completely independently.
This is the method we will use. (Of course, you can continue to make it ideal-if it works better for you, please write). The advantages of this method:
All reagents are cheap, affordable and safe
No other tools needed (iron, lamp, laminator-nothing, although not-you need a pan)
There is no way to destroy the circuit board-the circuit board will not heat up at all
The paper leaves by itself-the result of the toner transfer is visible-the translation is not performed
No holes in the toner (they are sealed by paper)-so no kimchi
Do 1-2-3-4-5 and always get the same result-almost 100% repeatability
Before we start, let us see which boards we need and what we can do at home using this method.
Basic requirements for wood-based panels
We will use modern sensors and microcircuits to make devices on the microcontroller. Microchips are becoming smaller and smaller. Therefore, the following board requirements must be met:
The board should be double-sided (usually, it is very difficult to separate the single board, it is very difficult to make a four-layer board at home, the microcontroller needs a ground layer to protect them from interference)
The track should be 0.2 mm thick-this size is sufficient-0.1 mm or even better-but there may be pickling, the path will be left when welding
The spacing between the tracks-0.2mm-is suitable for almost all schemes. Reducing the gap to 0.1mm is full of the merge of traces and the difficulty of monitoring whether the circuit board is shorted.
We will not use protective masks or screen printing, as this complicates production, and it is not necessary if you make your own circuit boards. Similarly, there is a lot of information on the Internet. If you want, you can make a “marafet” yourself.
We will not deceive the circuit board, which is also unnecessary (unless you manufacture the device for 100 years). For protection, we will use varnish. Our main goal is to quickly, efficiently and inexpensively pcb manufacture the circuit board of the device at home.
This is the appearance of the finished board. Made by our method-tracking 0.25 and 0.3 with a distance of 0.2