Professional PCB Manufacturer

China PCB Manufacturer

Six Layer PCB Stack-up & Design: Ultimate Guide 2023

Views: 641 Author: Site Editor Publish Time: 2023-04-19 Origin: Site

A printed circuit board (PCB) is one of the essential parts of an electronic device. It is used to hold electronic parts in place and connect them electrically. A PCB with more than one layer comprises multiple levels of copper and substrate, which is a material that keeps the layers from touching each other.

 Depending on the circuit design's complexity, there can be anywhere from two to tens of layers. A six-layer PCB is used in many designs because it strikes a good mix between cost, performance, and complexity. In this blog, we'll talk about how to build a six-layer PCB and how to put it together.

What's good about a six-layer PCB?

In many ways, a six-layer PCB is better than a two-layer or four-layer PCB. Here are some good things about it:

 • More freedom in design: A PCB with six layers gives you more routing options and more places for components. 

• Better power and ground planes: With more layers, you can have separate power and ground planes, which helps reduce noise and improve signal integrity. 

• Less EMI/RFI: A PCB with six layers can better block electromagnetic interference (EMI) and radio frequency interference (RFI).

 • Better thermal management: A six-layer PCB can help eliminate heat more quickly, making it less likely to overheat. 

• Higher density: A six-layer PCB can handle designs with a higher density, making it perfect for circuits with many parts.

How a six-layer PCB is put together:

 Six layers of copper and substrate are joined together to make a six-layer PCB. This is how a six-layer PCB is usually put together:

 six-layer PCB

 • Top layer: This is where most of the parts will go.

• Signal layer: This layer sends signals where they need to go.

• Power plane: This layer sends power from one place to another. • Ground plane 1: This layer is for the spread of the ground.

 • Signal layer: This layer sends signals where they need to go.

• Bottom layer: The rest of the pieces will be on this layer.

Thoughts on how to design a six-layer PCB 

When making a six-layer PCB, there are a few things to think about, like:

 • Component placement: In a six-layer PCB, component placement is critical because it affects how the board is routed and how well it works. Place the parts so that the traces are as short as possible and noise and crosstalk are less likely to happen. 

• Width of the traces: The resistance and capacitance of the circuit depending on how wide the traces are. Use wider traces for circuits with a lot of current and more minor traces for circuits with a small amount of current.

 • Placement of vias: Vias are used to link the layers of a PCB. Place the vias so that they have as little effect as possible on the signal purity and the risk of crosstalk as possible.

 • Thermal management: A six-layer PCB can eliminate heat better, but you still need to consider handling the heat on the board. Put parts that make heat far apart and use thermal vias to eliminate the heat. 

• Signal integrity: In a six-layer PCB, signal integrity is essential because noise and interference can mess with the data. Use the correct methods for grounding and shielding to lessen the effects of noise and radiation. 

• EMI/RFI: A six-layer PCB can block EMI/RFI better, but you still need to think about how noise from the outside affects the circuit. Use shielding and proper wiring to lessen the effect of noise from the outside.

Ground and power planes

With a six-layer PCB, you can have separate power and ground planes, which is a benefit. Power planes send power to the components, and ground planes give signals as an easy way to return to where they came from.

 Here are some things to keep in mind when making power planes and ground planes: 

• The power and ground planes should be next to each other to lower the loop's size and reduce noise. 

• The power and ground planes should have the same thickness to keep the impedance balanced and lower the chance of noise.

 • Multiple vias should connect the power and ground planes to lower the inductance and give the signals a low-resistance way to return to where they came from. 

• For less resistance and less voltage drop, the power and ground traces should be wider than the signal lines.

Concerns about routes 

Routing is an integral part of PCB design, and a six-layer PCB makes it even more critical because of how complicated it is. Here are some things to think about when making a six-layer PCB:

• Put high-speed messages on the inner layers to reduce the chance of noise and interference.

• Use vias to connect the layers, but keep the number of vias as low as possible to lower the resistance and improve signal integrity.

• Use teardrops to lessen the chance of solder bridges and make the board more reliable.

• For high-speed signals, use differential pairs to lessen the effect of noise and improve signal integrity. • Don't route traces close to the board's edge to lower the chance of noise and interference from outside sources.

Stack-up forms 

Even though the general stack-up of a six-layer PCB has already been described, there are other ways it can be put together to meet different design needs. Here are a few different ways to put up a six-layer PCB:

 • Power planes separated: Instead of having a single power plane, split it into two or more planes to cut down on noise and make it easier to get power to where it needs to go.

• Ground planes separated: Like split power planes, split ground planes can help reduce noise and improve how messages get back to their source.

 • Planes with mixed power and signal: In some designs, mixing the signal and power planes to meet specific needs may be necessary. In these situations, noise and interference can be lessened using the proper shielding and grounding methods.

Impedance control 

In high-speed systems, impedance control is significant, and a six-layer PCB can better control impedance than a two-layer or four-layer PCB. Here are some methods for impedance control in a six-layer PCB:

 • Use a substrate with a controlled dielectric constant (Dk) to keep the resistance the same across the board.

• Control the impedance of the traces by using stripline or microstrip wiring.

• Use a ground plane as a reference plane to lower the resistance and improve the signal integrity.

• Optimize the impedance of the traces by using impedance calculators and modeling tools.

Thermal management: 

As we've said, a six-layer PCB can help heat escape more quickly, but you still need to consider how the board will handle the heat. Here are some ways to keep a six-layer PCB from overheating:

• Separate parts that make heat from each other to prevent them from getting too hot.

 • Use thermal vias to move heat from the outside of the board to the inside layers.

• Use a heat sink or a fan to remove the board's heat.

 • Use tools for thermal modeling to ensure the board's thermal performance is at its best.

DFM stands for "design for manufacture

 Design for manufacturability (DFM) is an integral part of PCB design because it affects how many boards can be made and how much they cost. For a six-layer PCB, here are some DFM things to think about:

• Use standard PCB sizes and drill sizes to cut down on the board's cost and wait time.

 • Use the same trace width and space between traces to make the production process more accessible. • Stack the layers similarly to make the board more straightforward and cheaper.

• Use the suitable size pads and vias to ensure the soldering works right and lower the risk of solder bridges.

Conclusion 

A six-layer PCB is a complicated design that can be better in several ways than a two-layer or four-layer PCB. The extra layers help reduce noise and distortion, improve signal quality, and quickly eliminate heat. But when making a six-layer PCB, the layer stack-up, power and ground planes, routing, impedance control, temperature management, and DFM must be carefully thought out.

Following the tips in this piece, you can design a six-layer PCB that meets your needs and is reliable and cost-effective. Working with a PCB designer or maker with experience can also help you improve your design and avoid common mistakes.

In conclusion, a six-layer PCB is a good choice for high-speed, complicated designs that need to work well and reliably. You can ensure your PCB design works efficiently if you understand the design factors and follow best practices.


About The Author

I am the Engineering and Sales supervisor working in Victorypcb from 2015. During the past years, I have been reponsible for all oversea exhibitions like USA(IPC Apex Expo), Europe(Munich Electronica) and Japan(Nepcon) etc. Our factory founded in 2005, now have 1521 clients all over the world and occupied very good reputation among them.

×

Contact Us

×

Inquire

*Name
*Email
Company Name
Tel
*Message

By continuing to use the site you agree to our privacy policy Terms and Conditions.

Recruit global agents and distributors Join us

I agree