Tell you the basic principle and important function of Via hole

I hope it will help you to read the passage through the Via hole.Here are some basics.

In what circumstances should I hit the hole?

There is a saying that multiple holes can destroy the continuity and integrity of the formation.The effect is counterproductive.

A: first of all, if more holes are punched, the power layer and formation can be continuous and complete. This situation is resolutely avoided.These holes will shadow

Sound to power integrity, which leads to signal integrity problems, which is very harmful.

Ground holes usually occur in the following three situations:

1. The ground hole is used for heat dissipation;

2. The ground hole is used to connect the stratigraphic strata;

3. The location of the hole in the ground hole for high-speed signal replacement;

But all of this should be done in case of power integrity.

That is to say, as long as you control the spacing of the hole, is it allowed?Is there no problem in a fifth of the wavelength of the spacing hole?

If I want to ensure the connection of the multilayer board, the multi-hole perforation, although there is no partition, that will not affect the formation and the integrity of the power supply layer?

A: if the copper cover of the power layer and the stratum is not affected by the partition, it is not very large.

In current electronic products, EMI is generally tested with a maximum range of 1Ghz.So the wavelength of the 1Ghz signal is 30cm,

1Ghz signal 1/4 wavelength is 7.5cm = 2952mil.If the spacing of the holes is less than 2952mil, it can be very good

To satisfy the formation of the connection, good shielding effect.It is generally recommended that every 1000mil should be perforated.

What is the function and principle of grounding Via hole near Via hole?

Answer: pcb prototype board's perforation, according to its function classification, can be divided into the following:

1. Signal overhole (minimum impact of the over-hole structure)

2. Power supply and ground pass hole (the distribution inductance of the over-hole structure is minimal)

3. Heat dissipation holes (minimum thermal resistance of overhole structure)

The overhole mentioned above belongs to the hole of the earth type, and the effect of adding ground Via hole near the Via hole of the line is to provide the shortest signal

Backflow path.Note: the signal is in the overhole of the change layer, which is the discontinuity point of the impedance. The backflow path of the signal will be disconnected from here, for

To reduce the area of the return path of the signal, the shortest signal backflow path must be given in the surrounding area of the signal overhole to reduce the backflow path

The emi radiation of the signal.This radiation increases the signal frequency and increases significantly.