What kinds of circuit boards are classified

Usually, PCB circuit boards can be divided into three main classifications according to the number of layers: single-sided boards, double-sided boards and multilayer circuit boards.

1. Single-sided circuit boards:

In a basic line PCB board, the parts are concentrated on one of the sides and the wires are concentrated on the other side. Because the wires appear only on one side, this type of board is called a single-sided board (Single-sided).2 oz copper thickness in mm Because the single-sided board in the design of the line has many strict restrictions (because only one side, the wiring can not be crossed and must be around a separate path), so only the early circuits or the alignment of particularly simple circuits to use this type of board.

2. Double-sided circuit boards:

This board has wiring on both sides, but in order to realize the two-sided wires, there must be a proper circuit connection between the two sides. This "bridge" between the circuits is called a guide hole (via). Vias are small holes filled or coated with metal on the circuit board PCB, which can be connected to both sides of the wire. Because the area of the double-sided circuit board than the single-sided circuit board is twice as large, and double-sided circuit board to solve the single-sided circuit board because the wiring staggered in the difficulties (can be through the guide hole to the other side), it is more suitable for use in more complex circuits than the single-sided circuit board.

3. Multilayer boards:

In order to increase the area that can be wired, multilayer circuit boards use more single- or double-sided wiring boards. By alternating a double-sided board as the inner layer, two single-sided as the outer layer or two double-sided as the inner layer, two single-sided as the outer layer of the circuit board PCB and interconnecting them through the positioning system and insulating bonding material, a four-layer, six-layer circuit board PCB is formed.Although the number of layers of the board does not refer to the number of layers of the wiring, but in special cases will be added to the empty layer to control the thickness of the board, usually the number of layers are even and include the outer two layers.

Most motherboards are 4 to 8 layer structures, but theoretically it is possible to do nearly 100 layers of PCBs.plated through hole vs via large supercomputers mostly use quite multilayer motherboards, but since such computers can be replaced by clusters of many ordinary computers, ultra-multilayer circuit boards are gradually being phased out of use. Because the layers in a PCB are tightly coupled, it is generally not easy to see the actual number of layers, but if you look closely at the motherboard, you can still see that it is a several-layer board.

PCB circuit boards have the following types of boards:

1. FR-1: Flame retardant copper-clad phenolic paper laminate.

2. FR-4:

- Flame retardant copper-clad epoxy E glass fiber cloth laminate and its bonding sheet material.

- Flame retardant copper-clad modified or unmodified epoxy E glass fiber cloth laminate and its bonding sheet material.

- Flame retardant copper-clad epoxy/PPO fiberglass cloth laminates and bonding sheets.

- Flame retardant copper-clad modified or unmodified epoxy glass fabric laminates and their bonding sheets.

- Flame retardant copper-clad epoxy/EPO glass cloth laminates (for catalytic addition method).

For the classification of PCB circuit board is introduced here for you. Nowadays in our life, cell phones, computers, home appliances, automobiles, military industry and so on there are PCB circuit boards, all need circuit board conduction to run. And the more streamlined the circuit board, the better the conduction performance, representing the better the operation of electronic products, thus promoting the country's rapid economic development.

In addition, there are some common circuit board terms to understand:

1. through-hole: the previous PCB board has been described in detail in the various types of holes, and will not repeat here.

2. pad (Pad): pad is used to fix components, and components of the pins and PCB board copper film wire connected to the base point.

3. Network (Net): Network is a set of logical and physical connectivity connection. 4.

4. copper film conductor (Track): copper film conductor is the completion of the PCB design after the copper plate after corrosion processing and other processes, the printed circuit board in the formation of the actual copper alignment, usually referred to as the conductor.

5. Copper: Copper is the copper film laid in the end of the PCB wiring, in the area where no wires traveled.

6. safety spacing: in order to avoid or minimize the wire, vias, pads, as well as mutual interference between components, the need to leave a certain distance between them to become a safety spacing.