Advantages of high-speed PCB:
Multilayer PCB is generally used in high-speed PCB design. Multilayer circuit boards are actually formed by laminating and bonding several etched single or double-sided boards. Compared with single-layer and double-layer circuit boards, multilayer circuit boards have many advantages, especially in small electronic products.
The assembly density of high-speed PCB boards is high and the volume is small. As the volume of electronic products becomes smaller and smaller, the electric property of high-speed PCBs also is under higher requirements, and the demand for multilayer circuit boards is also increasing.
The use of multilayer circuit boards facilitates wiring so that the wiring length is greatly shortened. And the wiring between electronic components is shortened, which also increases the speed of signal transmission.
For the high-frequency circuit, after the ground layer has been added, the signal line will form a constant low impedance to the ground so that the circuit impedance is greatly reduced, and the shielding effect is better.
For electronic products with high heat dissipation requirements, a high-speed PCB can be equipped with a metal-cored heat dissipation layer, which is convenient to meet the needs of special functions such as shielding and heat dissipation.
In terms of performance, the higher the number of layers is, the greater the production costs, and the relatively longer the processing time is, and the more complicated quality inspection is. However, under the cost comparison of the same area, although the cost of multilayer circuit boards is higher than that of single-layer and double-layer, the cost difference between the two is not so obvious when the noise reduction factor is concluded into consideration. As technology advances, PCB boards with more than 100 layers have already been used in sophisticated aerospace instruments and medical equipment.
The most common high-speed PCBs are the four-layer and the six-layer PCBs, which are used in computers that we are familiar with in daily life. The difference between the two kinds of PCBs above is that the six-layer PCB is thicker than the four-layer PCB because there are two signal layers are added between the ground layer and the power layer in the six-layer PCB. It’s easy to identify the single-layer and the double-layer PCBs with naked eyes. When holding the board under the light and looking at it, you will find the board is transparent except the traces on both sides. However, if there are no relative marks on the boards, it's not so easy to differentiate the four-layer and the six-layer PCBs.
When it comes to the overall layout of high-speed PCB, multilayer PCBs, with its flexible design, advantaged economy, stable electric property, and other advantages, have been widely applied to producing electrical productions.