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Why are Multi-Layer PCBs Commonly Used

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Tues, Apr 07, 2020


Printed circuit boards can be used in various kinds of applications out there. From a simple electronic device to heavy-duty industrial devices, a PCB is highly important. Basically, there are three major types of PCBs that are most commonly used, which include the following one:

1、Single-Sided PCB  - Single-sided printed circuit boards are generally made of a single copper layer above or below the substrate layer.

2、Double-Sided PCB  - These printed circuit boards consist of two copper layers applied over and below the middle substrate layer.

3、Multi-Layer PCB  -This is the most commonly used PCB in the industry as of right now. As the name suggests, this structure can be built with a number of substrate layers covered on both sides with thin layers of copper.

Since multi-layer PCBs include multiple layers, they can be used for various applications. Therefore, in this article, we will talk about  Multi-Layer PCBs  and why they are the most commonly used PCBs in general. Make sure that you read the article until the very end so that you can learn everything about such PCBs, including their features, advantages, uses, and much more.

What are Multi-layered PCBs?

As mentioned above, a Multi-layer PCB is distinguished by the number of layers it is using. There are always 3 or more layers of material or substrate present in a multi-layer PCB. A great thing about such printed circuit boards is that they can have multiple layers of printed resistors and capacitors. They are able to work with less noise since they can easily match and block various PCB functions. On the other hand, standard PCBs have a lot of electronic noise as they use the traditional end to end transitions. This is improved by the micro transitions that get used by multi-layer PCBs.

Multi-layered PCBs have multiple layers of copper foil around the core material of PCB because of a special manufacturing process. This process simply includes heat treating the PCB structure under high temperature and pressure. The high pressure forbids air-bubble formation in the PCB, which might cause further problems in the future. The conductive layers are completely enclosed in a resin material along with a strong adhesive that allows waterproofing as well as a tight fit.

Why are Multi-Layer PCBs Commonly Used?

If we talk about the applications, multi-layer PCBs are generally observed in professional electronics. This includes things such as military-grade computers and the aerospace industry.

In other words, you can expect them to be used in all sorts of heavy-duty equipment. Another great thing about Multi-layered PCBs is that they use a polyimide dielectric. As a result, the signal propagation speed is higher when using such circuits. Not only that, but the required thickness of strip packets is also quite less as compared to conventional boards.

One special thing about electric circuits is their function or performance cannot be seen by the eye; it can only be judged by their output. In the modern age of technology, electronics products are getting more and more compact and portable. As a result, there is a need for denser packaging of PCBs so that the overall volume of the components can be reduced.

In the case of other PCBs such as single-sided or even double-sided ones, the number of layers is defined as one and two, respectively. Since these PCBs have less number of layers, they cannot be used for a compact design. On the other hand, increasing the number of layers in a PCB also improves its performance while providing some useful functionalities such as:

1 Satisfactory Performance

2  Noise Reduction

3 Diverged Capacitance

4  Crosstalk etc.

Major Advantages of Multi-layered PCBs

Unlike a standard PCB, multi-layer PCBs have a lot of advantages that make them useful for various applications. This includes the following advantages:

1      Compact Design As mentioned above, the increased number of layers gives the PCB a compact nature, which can result in an increased number of applications. The small size is a major plus point for the manufacturers as well as for the developers as the manufacturing cost is reduced, and more supporting parts can be installed alongside the multi-layered PCB. It also results in a smaller form factor of the final product that is using multi-layer PCBs.

2       Reduced Weight : In comparison to single and double-sided PCBs, the multi-layered PCBs are lightweight. This has a positive effect on the final product and the ergonomics of the circuit board.

3        High Compatibility:  Because of the multiple layers available in the PCB, the amount of wiring and circuiting space is also increased gradually. This increases the overall compatibility of a multi-layered PCB with other devices and components.

4       More Endurance A multi-layered PCB is more durable than other PCBs because of the increased number of layers. With each consecutive layer, there is a film of prepreg, resin, and the adhesive used in its construction. This increases the overall strength and endurance of a given PCB.

5      Higher Moisture Resistance Due to the amount of insulation available in a Multi-layered PCB, it offers comparatively higher moisture resistance. This is a really important parameter for handheld applications, such as a mobile phone. As you would expect, such devices often come in contact with moisture or water. Therefore, it is better to have a high moisture resistance or even water resistance in some cases for the delicate parts of the system.

7      Required Flexibility or Rigidity:  Another great feature of the multi-layered PCB is that the designer can easily adjust the flexibility of the PCB. This is possible by changing the number of layers used in it. As the layers are increased, the PCB becomes rigid, which is useful for heavy-duty devices and applications. On the other hand, a lower number of layers can be used for making flexible PCBs in mobile devices.

Similarly, there are many more advantages and benefits of using a multi-layer PCB. This makes them perfect for all kinds of applications ranging from mobile phones, computers, vehicles, and even industrial applications like military, aerospace, and much more.


Multi-layer PCBs are highly useful because of their characteristics and features. All of these features result in various benefits while using such PCBs. You can learn more about the advantages of such PCBs and why multi-layer PCBs are commonly used. If you liked this article, make sure to share your thoughts in the comments section. You can also post any questions down there if you have any!