Basic Knowledge about Single Sided PCB, Double Sided PCB and Multi-layer PCB

Single Sided PCB, Double Sided PCB and Multi-layer PCB

1. What is a single sided PCB?

Single sided pcb is the basic simple PCB, parts is layouted on one side and the circuit is on the other side. As there is only layer conductor, it is called single sided pcb (Single-sided pcb or one layer pcb. It is restricted in the circuit design (because there is only one side conductor, and no cross permitted, each line must have its own path), so it is more frequently used in the early printed circuits pcb.

Single sided PCB diagram mainly use network printing (Screen Printing) .That is to print resist on the bare copper, etch and then print solder mask, finally punching to finish parts plated hole and profile. In addition, some small amount of various products usually use

photoresist to pattern circuit.

2. What is the double-sided PCB?

 What is double sided PCB (2 layers circuit pcb)? How to identify a board is double-sided and what is double-sided circuit board? These questions may be fuzzy for green hands new engaged in printed circuits filed. It is frequently heard single sided board, double sided pcb, multilayer pcb, aluminum pcb, impedance pcb board, FPC circuits board etc..But usually they couldn't be distinguished. Today we will lead these new friends learn about how to confirm double layer pcb.

Strictly speaking, double sided circuit board is a kind of very important PCB. It is widely used. To recognize a double-sided PCB board is also very simple. After you understand what is single layer pcb, two side pcb is the extension of one side pcb. When a single side circuit is not enough, it will need to go to the opposite side. There will be conductor/line on both two sides. Two Layer pcb with another feature is that it have PTH vias. Simply speaking, double sided pcb is with two-sided traces, top layer and bottom layer.

Some may ask a pcb with double side traces, but only one side electronic components, is double layer board or single layer? The answer is obvious, such board is double-sided, just assembly component at one side( component sides).

3. What is multi-layer pcb

How to identify a pcb board is multi layer or not? What character does multi-layer circuit pcb board have? What kind of printed circuit boards pcb is multi layers pcb? What is multi-layer pcb used for? Let's check it.

Multilayer pcb is as the name implies, that is PCB boards with more than two layers, for example, four layers, six layers, eight layers, etc. Since it is double-sided multiple, then they have many common features with double layers pcb: more than two layers conductive traces, separated by insulating material between the layers, and the layer between the conductive traces must connected through drilling, lamination as required .The advantage of multilayer circuit boards is with multi layer conductive wire, high density drilling, the volume will be relatively small and the weight is relatively light accordingly. The high density line reduces the space of components which means more reliable. As there are more layers circuits, it will be flexible for PCB design / layout. And it plays the role of impedance speed transmission circuit forming. Except these advantages, multi-layer circuit boards also have its disadvantage, such as higher cost, long production time, difficult testing etc.

However, these deficiencies of multi layers printed circuits do not affect their use. Multi-layer printed circuit boards is the result of the development of electronic technology to high-speed, multi-function, high-capacity, small size. With the continuous development of electronic technology, especially extensive application of large-scale and ultra large scale integrated circuit, multi-layer circuit pcb with more requirement on fine line width, small aperture through , blind and buried vias, high aperture ratio in developing high-density, high-precision, high layer to meet the needs of the market. Due to the high-speed circuits need for computer and aerospace industries, improve the packing density, smaller discrete components in size is necessary. Together with the rapid development of microelectronics, electronic equipment volume is reducing, and weight is losing. As single layer and double layer printed pcb are with available space constraints, it is difficult to improve further in assembly or mounting density. Therefore, it is necessary to consider the use of more than double layers printed circuit pcb, which lead to the appearance of multi-layer circuit boards.