Do you know what are the four specifications for PCB classification?

When PCB meets artwork, it's amazing!

The process and reason of PCB conductive hole plug hole are explained in detail. In fact, PCB printed circuit boards used in electronic equipment are different, and PCB printed circuit boards are classified differently according to different specifications. 1、 According to the distribution of printed circuits, the printed circuit boards can be divided into three types: single-sided aluminum substrate, double-sided board and multi-layer high layer board. The single-sided aluminum substrate is on the insulating layer base steel plate with a thickness of 0.2-5mm. Only one surface layer can be coated with copper foil, and printed circuits can be generated on the base steel plate according to printing and etching methods. Simple production and manufacturing of single aluminum substrate

In fact, PCB printed circuit boards used in electronic equipment are different, and PCB printed circuit boards are classified differently according to different specifications.

1、 Classified according to the distribution of printed circuits

According to the distribution of printed circuit, the circuit board can be divided into three types: single-sided aluminum substrate, double-sided board and multi-layer high-level board

• Single sided aluminum substrate

The single-sided aluminum substrate is on the insulating layer base steel plate with a thickness of 0.2-5mm. Only one surface layer can be coated with copper foil, and printed circuits are generated on the base steel plate according to printing and etching methods. Single sided aluminum substrate is easy to manufacture, and the assembly line is convenient. It is applicable to a charging and discharging circuit, such as tape recorder, TV, etc; The discomfort is used to specify places with high assembly relative density or complicated power circuits.

• Double sided board

The double panel is printed on both sides of the insulating layer based steel plate with a thickness of 0.2-5mm. It is applicable to electronic equipment of general provisions, such as computers, instruments and instrument panels. Because the relative wiring density of double-sided printed circuit is higher than that of single-sided aluminum substrate, it can reduce the volume of machinery and equipment.

The printed circuit board printing about 3 layers of printed circuits on the insulating layer based steel plate is called solid wood multilayer board. This is composed of multilayer thin single-sided aluminum substrate or double-sided plate, which is generally 1.2-2.5 mm thick. In order to find out the power circuit sandwiched in the middle of the insulating layer based steel plate, the holes for installing components on the solid wood multilayer board must be metallized, that is, the metal material layer is coated on the surface of the small round hole to connect it with the printed circuit sandwiched in the middle of the insulating layer based steel plate.

The following figure is the construction plan of solid wood multilayer PCB board. The components commonly used in solid wood multilayer boards are mostly patch type components, and their characteristics are:

1. Cooperate with integrated circuit chip to make the whole equipment practical and reduce the net weight of the whole equipment;

2. It improves the relative density of wiring, reduces the spacing of electronic devices, and reduces the transmission path of data signals;

3. The electric welding points of electronic devices are reduced, and the repair rate is reduced;

4. The shielding layer is added, and the data signal frame loss of the power circuit is reduced;

5. The heat pipe heat dissipation layer of the grounding device is introduced, which can reduce some overheating conditions and improve the reliability of the whole equipment;

2、 Classified by sheet properties

According to the characteristics of the board, the circuit board can be divided into two types: stiffness and flexibility.

Stiffness printed circuit board

The rigid printed circuit board has a certain impact toughness, and the components decorated with it have a leveling condition. In general, rigid printed circuit boards are used in electronic equipment.

Flexible printed circuit board

Soft printed circuit board shall be made of soft mylonite plastic or other soft plastic insulating layer materials. The components made of the utility model can be bent and retractable, and can be bent according to the installation regulations during application. Soft printed circuit board is generally used in unique places. For example, some digital multimeter displays can rotate, and soft printed circuit board is usually used inside; Display, function keys, etc. on the phone.

The following figure shows the flexible printed circuit board on the mobile phone. Polyimide is selected as the board, and rust removal is carried out for the surface layer. The minimum figure boundary line spacing is set to 0.1mm. The protruding characteristics of flexible printed circuit boards are that they can be bent, rolled and expanded, and can connect rigid printed circuit boards and theme activity components, so as to enable three-dimensional wiring and maintain three-dimensional space interconnection. They are light, very light, and convenient assembly lines. They are suitable for electronic equipment with small indoor space and high assembly density.

3、 Classification by application area

The circuit board can be divided into high-frequency and high-frequency circuit boards according to the application field.

High frequency of electronic products is a development trend, especially in today's increasingly developing trend of wifi network and satellite communication, information content products are moving towards high speed and high frequency, and communication products are moving towards the standardization of video, voice, video and statistical data transmission of large and faster wireless data. Therefore, the new generation of commodities in the development trend must have high frequency printed circuit board, and its foil plate can be composed of raw materials with low dielectric loss and dielectric constant, such as polytetrafluoroethylene, homoethylene, polyethylene, polytetrafluoroethylene laminated glass cloth, etc.

4、 Type of unique printed circuit board

At this stage, there are also some unique printed circuit boards such as metal core printed circuit boards, surface mounted printed circuit boards, carbon film printed circuit boards, etc.

Metal material core printed circuit board

The metal material core printed circuit board is to replace the epoxy resin laminated glass cloth board with a very thin and thick metal sheet. After a unique solution, the electrical conductor power circuits on both sides of the Jinji board are connected to each other, and part of the height width ratio insulation layer is made of the metal material. The advantage of metal core printed circuit board is that the heat pipe has good heat dissipation and specification reliability, which can avoid mutual interference due to the shielding effect of aluminum, iron and other magnetic materials.

Surface mounted printed PCB board

Surface mounted printed PCB board is a kind of printing board that can meet the requirements of "light, thin, short and small" electronic equipment, and is developed and designed by cooperating with the relative density of pins and the installation and processing process of low-cost surface mounted PCB components. The printed circuit board has the characteristics of small diameter, small graphic boundary and spacing, high precision, and the base steel plate is specified for colleges and universities.