Printed Circuit Board (PCB)
PCB is the most important part in electronic equipment. It is possible to separate printed circuits by using simple or complex boards and their size. A printed circuit board consists of a number of electrical circuits that connect electronic components using conductive grooves, strips, and features etched from multi-layer copper sheets on a non-conductive substrate. And it can be one-sided (one layer of copper), two-sided (two layers of copper) or even multiple layers. Electronic boards together with semiconductor or semiconductor components and connectors and other components on these boards form a printed circuit and prepare the board for use in different electronic components.
PCBs are found in many parts and types of electronic devices such as televisions, mobile phones, digital cameras, graphics cards and computer components such as motherboards, as well as PCBs in many fields such as medical equipment, industrial machinery, automobiles, lighting and… are used.

Types of smart electronic board:
1-Single-layer electronic board
Single PCB has a simple design and low price compared to other models. This electronic board is made of thin copper. It should be noted that in single-layer printed circuit boards, all electrical components and accessories are placed on one side of the PCB.
Each board is widely used to design and manufacture electrical and electronic devices.

2-Double layer electric board
Another type of board is the double layer electrical board (Double layer PCB), the thin copper in this type of board is visible on both sides of the fiber. Therefore, unlike single-layer boards, in double-layer boards, SMD electronics can be assembled on both sides of the board.
Double-layer PCB is widely used in the structure of many modern and complex electrical and electronic devices. In addition, through the metal holes in the board structure, it is possible to connect the two sides of the printed fiber. Therefore, more space is provided to the user for the arrangement of components and parts.

3- Multi-layer electronic board
is used in the construction of printed circuit with more than two layers of copper. In a multilayer electronic board, the circuit layers are connected through holes in the board. This type of electronic board is used in advanced electronic devices due to its complexity and high cost.

All kinds of electronic board parts:

1. 1. Battery (providing the required voltage on the printed circuit board)
2. 2. Resistance (function of controlling and managing electric current)
3. 3. Transistor (responsible for amplifying the electrical load of the board)
4. 4. Capacitor (essential role in maintaining and storing electric charge)
5. 5. Switch (opening or blocking the flow of current)
6. 6. LED, a type of light emitting diode that lights up when the current passes in one direction)
7. 7. Diode (function of allowing and blocking electric current from one side to another)

Dip
DIP stands for Dual in-line, meaning a two-line package, an electronic package that has a compartment and two parallel rows with an electrical connection base. The package is mounted to a PCB board through holes. DIP boards have a separate LED for each of the three primary colors. Also, DIPs occupy space at the bottom or behind the printed circuit board. There it is soldered, resulting in sharp points where the solder meets the leads.
DIP is used for integrated circuits (IC). DIP devices include resistor networks, DIP switches, split and LED displays, and electromechanical relays.
SMD (Surface Mount Device)
SMD means components mounted on the surface. (Surface mounting components; electronic components are connected to printed circuit boards using surface mounting technology).
(Surface Mount Technology) SMT is called the method of mounting electronic components on the printed circuit board. SMT is to satisfy the desire of printed circuit board manufacturers to use smaller and faster components, in addition, it is more efficient and cheaper when assembling components on PCBs has come into existence.
SMD is designed to be mounted directly on the PCB. The biggest advantage of SMD components is the reduction of electromagnetic noise into the circuit. SMD components can be easily recognized from their package. The most common example of these parts is in a smartphone. which has parts that must be packed very tightly in a narrow compartment.
The small size of SMD components reduces the board size in terms of physical size and production cost. and provides the possibility of using the board in limited spaces. It is also easy to install these parts on the board and use both sides of the PCB. Reducing assembly cost, increasing production speed and reducing human error are other advantages of using SMD components.

Advantages of SMD technology

• Reducing production errors and human intervention
• It reduces the percentage of product defects
• Increase production speed
• Electrical control and possible troubleshooting of assembled boards
• good performance
• High assembly quality
• It reduces the production of heat and electricity
• Creating transformation and continuous improvement in the production process
• Reducing tin consumption and saving the size of printed circuits and reducing environmental pollutants
• Lack of excessive flow of parts on the board
• Greater strength of the board against mechanical forces
• the possibility of drawing connections very close to each other; Because you don’t need to leave a lot of space for soldering the socket parts