The working principle of printed circuit board

The circuit board can be called a printed circuit board or a printed circuit board, and the English name is (Printed Circuit Board) PCB, Flexible Printed Circuit Board (FPC circuit board, also known as flexible circuit board flexible circuit board), or a polyester film is a kind of high reliability, excellent deflection printing circuit board. The name of the circuit board is: ceramic circuit board, aluminum aluminum ceramic circuit board, aluminum nitride ceramic circuit board, circuit board, PCB board, aluminum substrate, high frequency board, thick copper plate, impedance board, PCB, ultra-thin circuit board, ultra-thin circuit board, printing (copper carving technology) circuit board, etc.

Working principle

The working principle of the circuit board is to use plate-based insulation material to isolate the surface conductivity layer of copper foil, so that current can flow along the pre-designed paths in various components, such as work, amplification, attenuation, modulation, demodulation, encoding, etc. Function.

composition

The circuit board is mainly composed of pads, perforations, mounting holes, wires, components, connecting Watford circuit board SMT Patch Watford circuit board, film circuit SMT Patch, filling, electric border, etc. The main functions of each component are as follows:

Pad: Metal holes used for welding component pins.

Horcho: There are metal over -pores and non -metal pores, where metal pores are used to connect the top of the component between layers.

Installation holes: used for fixed circuit boards.

Route: Electric network copper film for connecting component pins.

Plug-in: Components used between circuit boards.

Fill: Copper application for ground networks can effectively reduce impedance.

Electrical boundary: It is used to determine the size of the circuit board, and the components on all circuit boards cannot exceed the boundary.

Classification

If the circuit board is divided into three main categories: single panel, double panel, and multi-layer circuit board,

Multi-layer board: means a printed board having an insulating material having a conductive pattern layer of more than three layers and the insulating material therebetween, and the conductive pattern interconnects. Multi-layer line board is the product of the development of electronic information technology towards high speed, multifunctional, large capacity, large volume, small volume, thin, lightweight direction.

Single panel: On the most basic PCB, parts are concentrated on one side, and the wires are concentrated on the other side. Because the wire only appears on one side, this PCB is called a single-sided line board. Single panels are usually simple and low in cost, but the disadvantage is that they cannot be applied to overly complex products.

Double panel: It is an extension of a single surface panel. When the single-layer wiring cannot meet the needs of electronic products, the double panel must be used. Both sides have copper covering and wiring, and can be used to drive the line between the two layers through holes to form the required network connection.

Circuit boards are divided into soft boards (FPC), hard boards (PCB), and hard and hard binding boards (FPCB).

Working level

The circuit board includes many types of working layers, such as signal layer, protective layer, screen printing layer, inner layer, etc. The role of the various levels is briefly described as follows:

(1) Protective layer: It is mainly used to ensure that there is no need to be plated on the circuit board, which is not plated, thus ensuring the reliability of the circuit board. Among them, Top Paste and Bottom Paste are top welded layers and bottom welded layers; TOP Solder and Bottom Solder are tin paste protective layers and bottom tinpro -oachy protective layers, respectively.

(2) Signal layer: It is mainly used to place components or wiring. Protel DXP usually contains 30 intermediate layers, i.e. Mid Layer1 ~ Mid Layer30. The middle layer is used to arrange signal lines, and the top and bottom layers are used to place metal components or copper.

(3) Silk printing layer: It is mainly used to print the flowing water number, production number, and company name of the component on the circuit board.

(4) Internal layer: It is mainly used as a signal wiring layer.

(5) Other layers: mainly includes 4 types of layers.
Drill Guide : It is mainly used for drilling on the circuit board.
Keep-out layer : It is mainly used to draw the electrical boundary of the circuit board.
Drill Drawing: It is mainly used to set the shape of the drill.
Multi-layer : It is mainly used to set up multi-faceted layers.