TWI401002B - Print circuit board and layout thereof - Google Patents

Description

Printed circuit board and wiring method thereof

The present invention relates to a printed circuit board and a wiring method therefor.

As a component connection platform, printed circuit boards occupy an absolute dominance in the electronics industry. As the functional requirements of electronic products continue to increase, printed circuit boards are becoming increasingly dense, highly integrated, and multi-layered. Multilayer printed circuit boards typically have multiple power and ground layers that flow through the sum of the currents supplied by all of the via current lines connected to the power plane.

Due to the insufficiency of the production process of the multilayer printed circuit board, the currents on the power supply layers are often unevenly distributed, so that the current power layer has an unbalanced current contribution to each via. At present, multi-layer printed circuit boards mostly connect each via with all power layers, resulting in different currents and uneven distribution of the vias. For a multilayer printed circuit board, the current of a single via has the highest upper limit. When the current exceeds the upper limit, the copper wall of the via will be melted and will not work properly.

In view of the above, it is necessary to provide a printed circuit board having a relatively uniform via current.

A wiring method for a printed circuit board, comprising the steps of: connecting a plurality of power supply layers with a small current via and a current supply with a large current via, and making the current of all the vias of the printed circuit board relatively uniform to determine The number of power layers connected to each of the vias; the vias and power planes that do not require electrical connections are isolated according to the number of power planes for each via connection determined above. The present invention also relates to a printed circuit board designed using the wiring method, including The number of vias is different, and the number of power layers electrically connected to the vias is different.

The wiring method of the printed circuit board can make all the via currents of the printed circuit board relatively evenly distributed, avoiding excessive current flowing through some via holes, causing the local temperature of the printed circuit board to be too high, and causing the printed circuit board to pass through the copper wall. It is burnt out, which improves the stability of the printed circuit board.

Referring to FIG. 1, the printed circuit board of the present invention firstly constructs a model of the printed circuit board 100 in the simulation software when the via current is adjusted. The printed circuit board 100 includes 16 vias P1-P16 and 6 power layers. L1-L6. The 16 via holes P1-P16 are connected to the six power supply layers L1-L6.

Then, the signal is input into the printed circuit board 100 in the simulation software, and the current value flowing through each of the via holes P1 - P16 is simulated, and the current flow through each of the via holes is displayed, as shown in FIG. The current distribution of the vias P1-P16 is extremely uneven. The current flowing through the via holes P9, P13, P14, P15, and P16 is large, and the current flowing through the via holes P3, P4, and P7 is small, and the current flowing through the via hole P13 is the largest, which is 7.942 amps, flowing through The current in via P7 is the smallest, 0.895 amps.

According to the principle that a small current is connected to a large number of power supply layers and a large current via is connected to a small power supply layer, the connection of the 16 vias P1-P16 and the six power supply layers L1-L6 is continuously adjusted in the simulation software. relationship. When the currents of the 16 vias P1-P16 are observed as shown in FIG. 3, the current distribution of the 16 vias P1-P16 is relatively uniform, and the 16 vias P1-P16 and the power layers L1-L6 are obtained. The number of connections is preferred.

After adjustment, the maximum current flowing through the via decreased from 7.942 amps to 3.416 amps, and the minimum current increased from 0.895 amps to 1.227 amps. Correspondingly, The difference between the maximum current and the minimum current is reduced from 7.047 amps to 2.139 amps. It can be seen that the current of the 16 vias P1-P16 can reach a relatively uniform state by changing the connection relationship between the via and the power layer. It should be noted that although the connection relationship between the via hole P4 and the six power supply layers L1 - L6 is not changed before and after the adjustment, the current flowing through the via hole P4 is increased from 1.040 amps to 1.882 amps. This is because any change in the connection relationship between any via and a power plane changes the current distribution of the power plane, thereby changing the current flowing through the other vias.

After the preferred connection number of the 16 vias P1-P16 and the power supply layer is obtained according to the simulation software, when the printed circuit board is actually wired, the connection of the 16 via holes P1-P16 and the power supply layers needs to be adjusted accordingly. Taking the via hole P1 as an example, the number of connections to the power supply layer is reduced from six to three, and the connection between the via hole P1 and the three power supply layers of the six power supply layers L1 - L6 is isolated by the anti-pad. The adjusted printed circuit board is shown in Figure 5.

Referring to FIG. 4, during the experiment, it is found that the current of the 16 vias P1-P16 is relatively evenly distributed according to the principle that a small current is connected to a plurality of power layers and a large current is connected to a small power supply layer. The connection manner of the 16 via holes P1-P16 and the power supply layer is not unique, but each connection mode can relatively homogenize the current distribution of the 16 via holes P1-P16. This method is intended to give a qualitative guide to the regulation of the printed circuit board via current.

In summary, the through-hole current adjustment method of the printed circuit board can make the current flowing through all the vias relatively uniform, avoiding excessive current flowing through some via holes, and causing the local temperature of the printed circuit board to be too high, resulting in a printed circuit board. The via copper wall is burned out to improve the stability of the printed circuit board.

In summary, the present invention complies with the requirements of the invention patent, and patents are filed according to law. Application. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be covered by the following claims.

Printed circuit board ‧‧100

Via ‧‧‧P1-P16

Power layer ‧‧‧L1-L6

Figure 1 is a schematic diagram of a printed circuit board.

Figure 2 is a table showing the distribution of via currents in the printed circuit board shown in Figure 1.

Figure 3 shows the adjusted number of vias and power plane connections and the via current distribution table.

Fig. 4 is a table showing the distribution of the number of vias connected to the power supply layer and the distribution of via currents.

Figure 5 is a schematic illustration of a printed circuit board in accordance with a preferred embodiment of the present invention.

Printed circuit board ‧‧100

Via ‧‧‧P1-P16

Power layer ‧‧‧L1-L6

Claims (5)

A wiring method for a printed circuit board, comprising the steps of: connecting a plurality of power supply layers with a small current via and a current supply with a large current via, and making the current of all the vias of the printed circuit board relatively uniform to determine The number of power layers connected to each of the vias; the vias and power planes that do not require electrical connections are isolated according to the number of power planes for each via connection determined above. The method for wiring a printed circuit board according to the first aspect of the invention, wherein the number of the power supply layers connected to each of the via holes is through a simulation of the printed circuit board model in the simulation software, and the power supply is connected according to the small current via. The principle of connecting the layers and the large current vias to the lower power supply layer determines the current of all vias in the printed circuit board model to be relatively uniform. A printed circuit board comprising a plurality of vias and a power supply layer, wherein the number of power layers electrically connected to the vias is not completely the same, and the current flowing through all of the vias is relatively uniform. The printed circuit board of claim 3, wherein the printed circuit board comprises 16 vias and 6 power layers, wherein one via is connected to one power layer, and two power layers are connected There are 4 holes, 3 vias for connecting 3 power layers, 4 vias for connecting 4 power layers, 3 vias for connecting 5 power layers, and 5 vias for connecting 6 power layers. One. The printed circuit board of claim 3, wherein the printed circuit board comprises 16 vias and 6 power layers, wherein one via is connected to one power layer, and two power layers are connected There are 2 holes, 5 vias for connecting 3 power layers, and 4 vias for connecting 4 power layers. There are three vias for connecting five power layers, and one via for connecting six power layers.