AD9 how to draw a 4-layer PCB board

The new PCB file defaults to the 2-layer board, which teaches you how to set 4 layers or even more multilayer boards.

On the toolbar, click design-->layer Stack Manager. After entering the display is a two-layer board, added as a 4-layer board, usually first point top layer, then add layer, and then add layer, so it becomes a 4-layer board . See figure below.

Some people do not point to add layer, but point to add plane, the difference is that the add layer is generally an increased signal layer , and add plane adds the power layer and GND stratum . Some 6-layer boards and even multilayer boards will have add layer and add plane. Choose according to your needs.
Also need to set is each layer of copper thickness, core and prepreg thickness, double-click to be able to modify.

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Among the many working layers provided by the system, there are two layers of electrical layers, namely the signal layer and the inner layer, which have completely different properties and methods of use.

The signal layer is called the positive layer, generally for the pure line design, including the outer line and the inner line, and the inner layer is called the negative layer, that is, the area without wiring, not placing any components is completely covered by the copper film, and the place where the wiring or placing the element is lined with copper film.

The add layer is a signal layer.
Add plane is the addition of a power layer, a stratum

Analysis of different cascade schemes
Scenario 1

This scheme is the industry's current four-layer PCB main selection scheme, in the component surface has a ground plane, the key signal preferred cloth top layer.

TOP-----------------------

GND-----------------------

POWER-----------------------

BOTTOM-----------------------

Scenario 2

GND-----------------------

S1-----------------------

S2-----------------------

POWER-----------------------

In order to achieve the desired shielding effect, this scenario has at least the following drawbacks:
A, the power supply, the ground is too far apart, the power plane impedance is large
B, power supply, ground plane due to component pads and other effects, very incomplete
C, because the reference surface is not complete, the signal impedance is not continuous
In the current large number of surface-mount devices, and the device is becoming more dense, the power supply of the scheme can hardly be used as a complete reference plane, the expected shielding effect is very difficult to achieve; Scenario 2 is limited in scope. However, in an individual single board, scenario 2 is the best layer setup scenario.

Scenario 3

This scenario is similar to Scenario 1 and is suitable for situations where the primary device is routed at the bottom layout or the underlying signal, and in general, restricts the use of this scenario.

TOP-----------------------

GND-----------------------

POWER-----------------------

BOTTOM-----------------------

Conclusion: Optimization scheme 1, can be used in scenario 3.

For the current high-density PCB design, has felt that through the hole is not very suitable, wasted a lot of valuable wiring channel. In order to solve this contradiction, there are blind hole and buried hole technology, it not only realizes the function of conduction hole, but also saves many wiring channels, so that the wiring process is more convenient, smooth and more perfect. In most tutorials, the use of blind and buried holes in the design of multilayer boards is also advocated. This can make wiring work easier, but it also increases the cost of PCB design. Therefore, whether to choose this technology, according to the actual circuit complexity and economic capacity to determine. This technique is not necessarily used in the design of the four-ply board, depending on cost. If you feel that the number of vias is too large, you can limit the maximum punch value in the routing rules before routing.

before wiring, pre-set the top layer in the routing rules with horizontal cabling, while the bottom is vertical wiring. This allows the top and bottom wiring to be perpendicular to each other, thus avoiding parasitic coupling, while connecting the wires between the pins

Avoid using right angles or sharp corners as they affect electrical performance in high-frequency circuits.

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Ask the ad's experts, ad how to draw 4 layer board.

The main problems are:

1, the internal electrical layer set;

2, the inner electric layer safety distance;

3, the VCC, GND, and so on network settings inside the electrical layer.

For:

The add layer is a signal layer.
Add plane is the addition of a power layer, a stratum
plane layer is not allowed to walk the line, only copper, can be divided.

Among the many working layers provided by the system, there are two layers of electrical layers, namely the signal layer and the inner layer, which have completely different properties and methods of use.

The signal layer is called the positive layer, generally for the pure line design, including the outer line and the inner line, and the inner layer is called the negative layer, that is, the area without wiring, not placing any components is completely covered by the copper film, and the place where the wiring or placing the element is lined with copper film.

In the multilayer board design, because the stratum and the power layer is generally to use the whole piece of copper skin to do the line (or as a few larger block of the division area), if you want to use Midlayer (middle layer) is a positive layer to do, must adopt the method of copper can be achieved, this will make the entire design data volume is very large, Not conducive to the exchange of data, but also affect the speed of design refresh, and the use of the internal layer to do, it is only in the corresponding design rules set with the outer layer of the connection, is very conducive to design efficiency and data transfer.

The Altium Designer 7.0 system supports up to 16 layers of internal electrical layer and provides comprehensive control of the internal electrical layer connection and DRC calibration. A network can designate multiple internal layers, and an inner layer can be split into multiple zones to set up multiple different networks.

1 internal electrical Layer

In the PCB design, the addition and editing of the inner point layer is also done through the layer stack manager. The following is a practical design case to introduce the operation of the internal electrical layer. Please first build a PCB design file or open a ready-made PCB design file.

In the PCB editor, execute the "Design" | "Layer Stack Manager" command to open the layer stack manager.

Click to select the signal layer and the newly added inner layer will be located below it. At the signal layer selected here, after clicking the "ADD Layer" button, a new inner layer is added below the selected signal layer.

Double-click on the newly created inner layer to enter the Edit Layer dialog box to set its properties, as shown in Figure 7-13. In the dialog box, you can set the name of the inner layer, the thickness of the copper skin, the network connected to it, and the width of the obstacle . The obstacle here is "pullback", which is a closed de-copper boundary set at the edge of the inner layer to ensure that the inner layer boundary has a safe distance from the PCB boundary, and the inner layer boundary will be automatically rolled back from the plate body boundary according to the setting.

execute the "Design" | "Board Layers & Colors ..." command, in the Open tab "Board Layers & Colors", the "Show" check box after the "Ground" of the inner layer added in, This is shown in Figure 7-14 so that it can be displayed in the PCB work window.

For details, please see the annex, "Altium Designer" inner and inner layer split. pdf