Special High Frequency PCB Factory

According to the PCB printed circuit board circuit layer classification: PCB printed circuit board is divided into a single panel, double-sided board and multilayer board. Common multilayer boards are generally 4-layer boards or 6-layer boards, complex multilayer boards up to dozens of layers.

PCB Boards Have the Following Three Main Types of Division:

a, Single-panel

Single panel (Single-Sided Boards) in the most basic PCB, the parts are concentrated on one side, the wires are concentrated on the other side. Because the wires appear only on one side, so this PCB is called a single panel (Single-sided). Because the single panel in the design of the line has many strict limitations (because only one side, the wiring can not be crossed and must be around a separate path), so only the early circuits to use this type of board.

b, Double-sided Board

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

c, Multilayer Board

Multi-layer boards (Multi-Layer Boards) in order to increase the area that can be wired, multi-layer boards with more single or double-sided wiring board. With a double-sided for the inner layer, two single-sided for the outer layer, or two double-sided for the inner layer, two single-sided for the outer layer of the printed circuit board, through the positioning system and insulating bonding material alternating with the conductive graphics according to the design requirements for interconnecting printed circuit boards have become four-layer, six-layer printed circuit boards, also known as multilayer printed circuit boards.

The number of layers of the board does not mean that there are several independent wiring layer, in special circumstances will be added to the empty layer to control the thickness of the board, usually the number of layers are an even number, and contains the outermost two layers. Most mainframe boards are 4 to 8 layer structures, although the technology is theoretically capable of nearly 100 layers of PCBs. Most large supercomputers use fairly multilayer motherboards, although because such computers have been able to be replaced by clusters of many ordinary computers, ultra-multilayer boards have fallen out of use. Because the layers in a PCB are tightly packed together, it is generally not easy to see the actual number, although if you look closely at the motherboard, you can still see it.

High-speed Multilayer Difficult PCB

In the electronic products tend to be multi-functional complexity of the premise, the integrated circuit components of the contact distance is reduced, the speed of signal transmission is relatively high, followed by the number of wiring to improve the wiring between the points of the length of local shortening of the wiring, these need to be applied to the configuration of high-density lines and micro-hole technology to achieve the purpose. Wiring and spanning basically for a single double-sided board has its difficulties to achieve, and therefore the circuit board will go to the multilayer, and because the signal line continues to increase, more power layer and ground layer for the design of the necessary means, these are prompted by the multilayer printed circuit board (Multilayer Printed Circuit Board) more common.

For the electrical requirements of high-speed signals, circuit boards must provide impedance control with AC characteristics, high-frequency transmission capability, and reduction of unwanted radiation (EMI). Strip line and microstrip structures and multilayers are necessary. In order to reduce the quality of signal transmission, low dielectric coefficient, low attenuation rate of the insulating material, in order to match the miniaturization of electronic components and array, circuit boards are also constantly improving the density in order to meet the needs of BGA (Ball Grid Array), CSP (Chip Scale Package), DCA (Direct Chip Attachment), and so on. BGA, CSP, DCA and other groups of parts assembly methods appear, and promote the printed circuit boards to an unprecedented high density.

Where the diameter of less than 150um below the hole in the industry known as micropore, the use of this micropore geometric structure of the technology made by the circuit can improve the assembly, space utilization and other benefits, but also for the miniaturization of electronic products is also a necessity.

For this type of structure of the circuit board products, the industry has had a number of different names to call such a circuit board. For example, in Europe and the United States, because the production process is a sequential construction method, the product is called SBU (Sequence Build Up Process), which is generally translated as "Sequence Build Up Method". As for the Japanese industry, because the hole structure produced by this type of product is much smaller than the previous holes, so the production technology of this type of product is called MVP (Micro Via Process), which is generally translated as "Micro Via Process". Some people also call these boards BUM (Build Up Multilayer Board) because the traditional multilayer boards are called MLB (Multilayer Board), which is generally translated as "Build Up Multilayer Board".