High-speed PCB circuit board in the over-hole design

In the process of designing high-speed PCB circuit boards, the seemingly simple over-hole, a silent is likely to bring a great negative effect on the circuit board. Today WeiFu circuit board manufacturers to tell you how to over-hole design in the high-speed PCB Circuit Board, to reduce the adverse effects of the parasitic effect of the over-hole:.

1, the power supply and ground pins to be close to the over-hole, the shorter the lead between the over-hole and the pin, the better, because they can lead to an increase in inductance. At the same time, the power supply and ground leads should be as thick as possible to reduce impedance.

2, PCB circuit boards on the signal alignment as far as possible without changing layers, that is, try not to use unnecessary holes.

3, the use of thinner PCB circuit boards to help reduce the two parasitic parameters of the vias.

4, from both the cost and signal quality considerations, choose a reasonable size of the hole size. For example, for the 6-10 layer memory module PCB circuit board design, the choice of 10/20Mil (drill / pad) over-hole better, for some high-density small size of the board, you can also try to use 8/18Mil over-hole. Under the current technical conditions, it is difficult to use smaller size vias. For the power supply or ground vias can be considered to use larger sizes to reduce impedance.

5, in the signal to change the layer near the vias placed some ground vias, in order to provide the nearest circuit for the signal. You can even place a large number of redundant ground vias on the PCB board. Of course, in the design also needs to be flexible and versatile.

The previously discussed vias model is the case of each layer has pads, there are times when we can reduce or even remove the pads of some layers. Especially in the case of a very high density of vias, which may lead to the formation of a circuit break in the copper layer, to solve such problems in addition to moving the location of the vias, we can also consider reducing the size of the vias in the copper layer of the pads.

By reading the above, I think we all have an understanding of the high-speed PCB circuit board in the over-hole design, Wei Fu circuit board to share this, if you want to know more about the information, you can consult our customer service staff online, or enter the Wei Fu official website Oh!