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A guide to 4-layer PCB in PCB manufacturing and design

A guide to 4-layer PCB in PCB manufacturing and design

PCB boards play a vital role in the success of the electronics industry. Electronic designers use them for medical devices, consumer electronics, industrial equipment, auto parts, and more. 4-layer PCB boards are becoming more and more popular in electronics, mainly complex devices. In fact, 4-layer PCB is ideal for high-strength signals. A PCB with 4 layers is also capable of helping very high level complex devices.How much do you know about 4-Layer PCB? Well, this is what the article is about.

What is a 4-layer PCB?

What is a 4-layer PCBIn general, a 4-Layer PCB depicts and determines a PCB that has glass fiber’s four layers in it. In a 4-Layer PCB, there are four major wiring layers. They include GND, VCC, the bottom layer, and top layer.

4-Layer PCB is widely used in different areas and applications. They are often preferred over double-sided boards. It is generally because they are compact in their design and can improve noise immunity to a significant extent. Not to mention, they are rather easier to lay out and design.

What are the types of 4-layer PCB?

There are two primary types of 4-Layer PCB. They are often referred to as Type 1 and Type 2 4-Layer PCBs. It should be noted that the key signal is present and found in the top layer in both the type 1 of the 4-Layer PCB designs.Meanwhile, the ICCB is balanced and it plays an important role in decreasing the power supply’s impedance.

Meanwhile, the Type 2 4-Layer PCB is used when a person does not want to connect all kinds and types of ground pins through routes. In order to raise the board’s EMC performance, the signal layers are quite close to each other.

What’s the material of 4-layer PCB?

Actually, in order to make a 4-layer PCB, there exist different kinds of materials that might be used. However, some of the widely used materials for the construction of 4-Layer PCB is epoxy and glass fiber. However, it is worth noting that in 4-Layer PCB, four layers of copper are laminated together.

Still, it depends upon the choice of the designer. Other materials can also be considered on the basis of required specifications and outcomes.

Construction of 4-layer PCB

Construction of 4-layer PCBGenerally, a 4-Layer PCB’s stack-up is quite effective and robust. In fact, it tends to include a top layer, a bottom layer, and even Inner Layers 1 and 2. It is important to note that these layers are used for routing electrical signals. In between the bottom and top layers, both inner layers are placed. Therefore, it can be said that a 4-layer PCB exhibits and uses four layers that can be represented as: a ground layer + a positive voltage layer + 2 signal layers.

As far as 4-Layer PCB is concerned, they tend to possess higher surface areas. It can be used for traces in a more effective manner. A better and more suitable routing is offered by the design structure itself.

What’s the application of 4 layer PCB?

4-Layer PCB is quite popular in electronics because they are used widely in complex devices. In fact, they are an ideal choice when there is a need for high signal intensity. It is important to note that these PCB can be used in different complex gadgets and devices.

Some of the most important applications of 4-Layer PCB include GPS technology, computers, heart monitors, file servers, and signal transmission among others. They are even used in fiber optic receptors and atomic accelerators.

What’s the advantages of 4 layer PCB?

There are several benefits and advantages of 4-Layer PCB. The first benefit is concerned with quality-driven and smaller designs. In fact, it is a major reason why a 4-layer PCB should be used. They are rather small in size and it is beneficial for different modern devices like laptops and tablets.

Another critical benefit of a 4-Layer PCB is that it is quite durable. These circuit boards are capable of withstanding not only heat but also applied pressure. Due to several insulation layers, their durability increases to a significant extent.

In the case of 4-Layer PCB, it would not be wrong to say that they are quite lightweight. They require several connectors and with the presence of double-layered circuit boards, the circuit design is simplified and the weight is reduced. Again, it means that they can be better suited for modern lightweight equipment and devices.

How is a-4 layer PCB made?

How is a-4 layer PCB madeFirst of all, laminates of the copper plate are cleaned chemically for removing the protective coating. Then, the surface is roughened and coated with a dry film. Then, the second and third circuit layers are generated on the laminate. On the surface, UV light is applied and it hardens the photoresist present under the transparent film.

Prior to the lamination process, testing of the inner layers is performed. After that, two external copper layers are installed on the inner plate. The 4-Layer board is then drilled mechanically and the holes are electroplated using copper. In the end, the edges of 4-Layer PCBs are treated and shaped.

Consideration about 4 layer PCB prototype

When a prototype PCB is to be manufactured, an important thing to consider is whether the it delivers the desired readings and outputs or not. In case the required outputs are not delivered, the 4-Layer PCB prototype is inadequate.

● Control production quantity, reduce cost and maintain quality

● Specially confirm the device packaging to avoid proofing failure due to packaging errors.

● Carry out a comprehensive electrical inspection to improve the electrical performance of the PCB board.

● Do a good job of signal integrity layout, reduce noise and improve PCB stability.

Consideration about 4 layer PCB design and layout

When setting the design and layout of 4-Layer PCB, there are several factors that must be considered. They include design density, power planes, and board size. It is important to note that these aspects are capable of influencing the performance of the 4-Layer PCB.

● Try not to put wires between pins, especially between and around IC pins
● The lines between different layers should not be parallel as much as possible, so as not to form actual capacitance
● The wiring should be as straight as possible, or a 45-degree broken line to avoid electromagnetic radiation.
● Pay attention to even distribution of components for easy installation, plug-in, soldering operations
● The structure of the four-layer board can be adjusted according to the needs of each layer

FAQ about 4-layer PCB


How can you tell a 4-layer PCB?

Well, you can either check the pin density or you can look for vias. If the pin density lies in 0.6-1.0, it means that the PCB has four layers. If there are vias on both the top layer and the bottom side, it indicates that it is a 4-layered PCB.

How thick is a 4-layer PCB?

It is possible for a 4-layer PCB to have several thicknesses. It can have a thickness of 1.6, 1.2, 1.0, 0.8, and 0.5mm.

Why do PCB have even layers?

Generally, in order to perform complex applications, there is a need for more wiring and circuitry. It is only possible through the addition or installation of multiple layers in printed circuit boards.


Multilayer PCB is one of the types of PCB that has gained tremendous popularity in various industries this year. The common ones are 2-layer PCB and 4-layer PCB. Through this article, we have learned about the structure and advantages of 4-layer PCB. You can also browse other articles on the website to learn more types of PCB.



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