8 Layer PCB – Everything You Need to Know

8 layer PCB – everything you need to know

An 8 layer PCB refers to a circuit board that contains eight layers of conductive pathways, which are separated by insulating layers. The eight layers include both the upper and lower copper trace layers. Then there are the insulating material layers and additional conductive channel layers. Finally, the layers are connected using drilled holes. 

The use of 8 layer printed circuit boards is complex. They are applied in sophisticated electronics that need a high circuit density. Some examples of electronics that depend on an 8 layer PCB include computer motherboards, audio equipment, and networking equipment. They support fast signal transmission and have higher flexibility regarding component placement on the board.

Table of Contents

What is 8 Layer PCB?

A printed circuit board with eight layers of conducting elements is known as an 8 layer PCB. It is separated using insulating layers. It is an ideal choice for high-density circuits. Plated through-holes connect all the layers of an 8 layer PCB. These holes are drilled through the PCB.

8 Layer PCB

Contrary to the 6, 4, and 2-layer PCBs, making this PCB is a challenging procedure that must be taken into consideration. It requires sophisticated equipment and software. That is why they are used mainly in high-performance electronics that need many circuits put together in one place.

How Thick is an 8 Layer PCB?

An 8 layer PCB’s thickness will depend on its required purpose. The manufacturer’s specs will also influence how thick the PCB is. The standard thickness is usually anywhere in the region of 0.8mm and 1.6mm.

8 Layer PCB Thickness

The thickness of the insulating and copper layers will also determine how thick an 8 layer PCB will be. Note that the thickness of the individual layers of the PCB will affect its performance. For instance, thick copper layers are efficient at dissipating heat and can tolerate higher current.

Conversely, thin copper layers facilitate finer pitch routing and better designs. The thickness of the layers has an impact on electronic conductivity as well. Thinner layers have a more profound impedance control and better signal integrity.

Why Use 8 Layer PCB?

There are several benefits to using an 8 layer PCB over fewer layers. These reasons include the following:

Better Thermal Management
The extra layers of copper serve as a heat sink for an 8 layer PCB. This helps to dissipate the heat components generate on the board.

Routing Flexibility
Flexible routing schemes are made possible by the inclusion of additional tiers. This is ideal for designs with a high pin count or many hindrances.

Power Distribution
It allows better power distribution and distributing ground signals better. This not only boosts performance but also enhances signal noise control.

Signal Integrity
The additional layers present can act as avenues for ground and power planes. This then offers enhanced signal integrity and noise immunity. This is particularly great for RF applications and fast digital circuits.

High Circuit Density
More circuitry can be packed onto a smaller area using an 8 layer PCB. This is why such a PCB is perfect for electronics that require more complexity.

6 Layer PCB Vs. 8 Layer PCB

6 Layer PCB Vs. 8 Layer PCB

The quantity of conductive and insulating elements utilized is the main difference between an 8 layer PCB and a six tier alternative. For instance, a PCB with six layers has six, whereas one with eight layers has eight. Other differences worth noting include the following:

  • Since there are more layers on an 8 layer PCB, the routing is more flexible.
  • The additional copper layers in an 8 layer PCB permit better thermal management. They act as heat sink for the components on the board. They often perform effectively as an outcome than a 6 layer PCB.
  • An 8 layer PCB is costlier than a 6 layer PCB.
  • An 8 layer PCB has better noise immunity and signal integrity than a 6 layer PCB.
  • An 8 layer PCB supports higher circuit densities than 6 layer PCBs.

Applications of 8 Layer PCB

Various electronics rely on the precision of an 8 layer PCB. It delivers reliability, complexity, and high performance. A few uses for an 8 layer PCB comprise the aforementioned:

  • High-performance computing systems such as workstations, servers, and gaming computers. Such systems need good thermal management, signal integrity, and a high circuit density.
  • Telecommunications equipment such as routers, base stations, and other devices need high-frequency communication. An 8 layer PCB offers better signal integrity and noise immunity, perfect for telecommunications equipment.
  • Medical devices such as monitoring equipment, imaging systems, and surgical tools depend on precision and reliability.
  • Aerospace and defense systems such as missiles, satellites, and avionics require ruggedness and reliability.
  • Consumer electronics, such as wearables, tablets, and smartphones, depend on reliability and compactness from an 8 layer PCB.

Common 8 Layer PCB Stackup

8 Layer PCB Stackup

The precise stackup of an 8 layer PCB differs dependent on the construction needs. Typically, it follows the following PCB stackup:

1. Signal layer 1: top copper layer for routing signals.
2. Signal layer 2: ground plane for shielding and noise reduction.
3. Power plane 1: provides power to the board’s components.
4. Inner signal layer 1: right in the middle of the PCB and is used for routing signals.
5. Inner signal layer 2: used for routing signals.
6. Power plane 2: provides extra power to the board’s components.
7. Signal layer 3: provides shielding and reduces noise in the circuit.
8. Signal layer 4: bottom copper layer used for routing signals.

Techniques for Standard 8 Layer PCB Stackup Design

Perfection and meticulousness are required while creating an 8 layer PCB. Here are techniques that you can use:

  1. Use two inner layers for ground and power planes. Use split planes for signal separation and additional shielding.
    2. Route high-speed signals on the outer layers. Keep signal traces short.
    3. Place vias close to the signal pads.
    4. Use thermal vias for heat dissipation.
    5. Use high-quality PCB materials with a low dielectric constant.
    6. Think about sandwiching signal layers within neighboring layers for the ground and power planes. As a result, the signal integrity will be improved.
    7. Ensure you choose the proper manufacturer with the right capabilities.
    8. Consider testing ease and debugging. Make sure that the test points are accessible.

How to Choose an 8 Layer PCB Manufacturer?

How to Choose an 8 Layer PCB Manufacturer

Here are some tips that can help you settle on the proper 8 layer PCB manufacturer:

  • Consider the manufacturer’s lead times.
  • Check their reviews and recommendations from previous clients.
  • Consider their location if you’re looking for fast shipping times.
  • Get multiple quotes from manufacturers and compare their charges. Remember to compare the cost against the quality and reliability.
  • Identify manufacturers with credible quality control systems. They should be performing tests, inspections, and certifications.
  • Ensure that the manufacturer you select uses high-quality materials and conforms to set industry standards and regulations.
  • Consider their record for deliveries, customer service, and responsiveness.
  • Check whether they have the capabilities to produce 8 layer PCBs.
  • Consider how long they have been in the industry. Experience matters.

A printed circuit board with eight layers of conducting elements is known as an 8 layer PCB.

An 8 layer PCB’s thickness will depend on its required purpose. The manufacturer’s specs will also influence how thick the PCB is. The standard thickness is usually anywhere in the region of 0.8mm and 1.6mm.

1. Signal layer 1: top copper layer for routing signals.
2. Signal layer 2: ground plane for shielding and noise reduction.
3. Power plane 1: provides power to the board’s components.
4. Inner signal layer 1: right in the middle of the PCB and is used for routing signals.
5. Inner signal layer 2: used for routing signals.
6. Power plane 2: provides extra power to the board’s components.
7. Signal layer 3: provides shielding and reduces noise in the circuit.
8. Signal layer 4: bottom copper layer used for routing signals.

Final Thoughts

Getting top-quality PCBs should be your priority as a business. We offer support for small and large businesses looking to deliver quality to their customers. Are you searching for an 8 layer PCB industrialist? At IBE, we deliver nothing short of quality PCBs. Talk to us today to get a quote.

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