Kwa miongo kadhaa, PCB ya safu nyingi have been the main content of the design field. As electronic components shrink, allowing more circuits to be designed on one board, their functions increase the demand for new PCB design and manufacturing technologies that support them. Sometimes 6-layer board stacking is just a way to get more traces on the board than is allowed by a 2-layer or 4-layer board. Now, creating the correct layer configuration in a 6-layer stack to maximize circuit performance is more important than ever.

Due to poor signal performance, incorrectly configured PCB layer stacks will be affected by electromagnetic interference (EMI). On the other hand, a well-designed 6-layer stack can prevent problems caused by impedance and crosstalk, and improve the performance and reliability of the circuit board. A good stack configuration will also help protect the circuit board from external noise sources. Here are some examples of 6-layer stacked configurations.

What is the best 6-layer stack configuration?

The stacking configuration you choose for the 6-layer board will largely depend on the design you need to complete. If you have a lot of signals to be routed, you need 4 signal layers for routing. On the other hand, if priority is given to controlling the signal integrity of high-speed circuits, the option that provides the best protection needs to be selected. These are some different configurations used in 6-layer boards.

The original stacking configuration used many years ago for the first stack option:

1. Highest signal

2. Internal signal

3. Ground level

4. Power Plane

5. Internal signal

6. Bottom signal

This is probably the worst configuration because the signal layer does not have any shielding, and two of the signal layers are not adjacent to the plane. As signal integrity and performance requirements become more and more important, this configuration is usually abandoned. However, by replacing the top and bottom signal layers with ground layers, you will again get a good 6-layer stack. The disadvantage is that it only leaves two internal layers for signal routing.

The most commonly used 6-layer configuration in PCB design is to place the internal signal routing layer in the middle of the stack:

1. Highest signal

2. Ground level

3. Internal signal

4. Internal signal

5. Power Plane

6. Bottom signal

The planar configuration provides better shielding for the internal signal routing layer, which is usually used for higher frequency signals. By using a thicker dielectric material to increase the distance between the two internal signal layers, this stacking can be better enhanced. However, the disadvantage of this configuration is that the separation of the power plane and the ground plane will reduce its plane capacitance. This will require more decoupling in the design.

The 6-layer stack is configured to maximize the signal integrity and performance of the PCB, which is not common. Here, the signal layer is reduced to 3 layers in order to add an additional ground layer:

1. Highest signal

2. Ground level

3. Internal signal

4. Power Plane

5. Ground plane

6. Bottom signal

This stacking places each signal layer next to the ground layer to obtain the best return path characteristics. In addition, by making the power plane and the ground plane adjacent to each other, a planner capacitor can be created. However, the disadvantage is still that you will indeed lose a signal layer for routing.

Use PCB design tools

How to create a stack of layers will have a huge impact on the success of a 6-layer PCB design. However, today’s PCB design tools can add and remove layers from the design in order to select any layer configuration that is most suitable. The important part is to choose a PCB design system that provides maximum flexibility and power consumption for easy design to create a 6-layer stack type.