Have you already seen a printed circuit board? These are glass fabricated plastics which have copper tracks and holes. The electronic components are soldered on the board so that it will not detach. And instead of wires, PCBs use copper tracks to connect the components. It is one of the simplest electronic boards you can use to test circuit designs.
Two Sides of a Printed Circuit Board
There are two sides of PCBs. The upper side is, usually, the component side. This is where you place your electronic components such as diodes, transistors, LED bulb, etc. On the other hand, the back side is called the copper track side. In this side, you will see lines which connect the PCBs.
How are Printed Circuit Boards made?
First, they are designed on the computer. There are many software available to design and test if the circuit is working. AutoCAD is one example of software. Yenka electronics is another. The latter can test if the circuit will work. Designing boards are easier with these programs because you can make improvements to you circuit without experiencing short circuits and wrong wiring. Actually, there is manual testing for circuits. One of those is with the use of bread boards. However, there is a big possibility of error when using bread boards compare to PCBs. So, most people prefer using PCBs than bread boards.
After designing the PCB, the board will undergo manufacturing process. The design will be printed and transferred to a copper board. After that, copper tracks should be defined and visible. To do this, you should remove excess copper from the board. There are different types of manufacturing process. There is UV etching, acid etching, silk screen, etc. This actually depends on the materials available and the preference of the manufacturer.
Once the board is etched, drilling holes is the next step. After that, the PCB is now ready to use.
Types of Printed Circuit Boards
There are three types of printed circuit boards. They are single sided board, double sided board, and multilayer boards.
• Single Sided Board
This kind of PCB is the simplest of all the boards. The upper side is the component side and the lower side is the copper track side. Components are fixed and soldered in one side. This is often used in simple circuit designs. It has a single layer substrate.
• Double Sided Board
Compared to the single layer board and the multilayer board, this type of PCB is the most common. Both sides of the substrates are used. Also, components are attached to the upper and lower sides of the board. Copper tracks are also present on both sides of the board. For assembling the components, this type uses through-hole construction.
• Multilayer Board
As it was described, it contains several layers of board. Some have 4, 6, 8, 10 layers. However, when the manufacturer uses a machine, it could exceed 42 layers. Multilayer boards are only used for large and complex circuits.
Printed Circuit Boards Manufacturing Methods
There are four methods used in creating a PCB. They are acid etching method, UV etching method, laser etching method and mechanical etching method. Here is a brief summary of each.
• Acid Etching
With the use of an etchant like FeCl or Ferric chloride, the excess copper will be removed from the board. Thus leaving the designed copper tracks.
• UV Etching
This method uses a UV etching machine. You just have to place our board between two glass boards and place it in the chamber. After a specific time, etching will be finished and copper tracks are now defined.
• Laser Etching
Big PCB companies use this expensive method for an easier and faster production. Laser beams are used to etch the printed circuit boards.
• Mechanical Etching
Same as with laser etching, this is also used by huge companies. Etching is made by a machine which removes the excess copper and leaves the desired copper tracks.