Advantages and Applications of Multilayer PCBs

The printed circuit board is at the heart of most electronic products today, with a combination of components and routing mechanisms that determine basic functionality. While most PCBs in the past were relatively simple and limited by manufacturing technology, today's PCBs are much more complex. From advanced flexible options to bizarre varieties, PCBs are more diverse in today's electronics world. Particularly popular, however, are multilayer PCBs.

While PCBs for simple electronic devices with limited functionality typically consist of a single layer, more complex electronic devices, such as computer motherboards, consist of multiple layers. These are so-called multi-layer PCBs. With the increasing complexity of modern electronics, these multilayer PCBs are more common than ever, and manufacturing techniques have allowed them to shrink significantly in size.

Read on to learn more about the uses and benefits of multilayer PCBs.

The definition of a multilayer PCB is a PCB made of three or more layers of conductive copper foil. These are shown as several layers of double-sided circuit boards, laminated and bonded together with thermal insulation between them. The entire structure is arranged such that two layers are placed on the surface side of the PCB for connection to the environment. All electrical connections between layers are made through vias such as plated, blind, and buried vias. The application of this method results in the creation of highly complex PCBs of different sizes.

Due to the constant changes in the electronics industry, multilayer PCBs came into being. Over time, the functions of electronic products have become more and more complex, requiring more complex PCBs. Unfortunately, PCBs are limited by issues such as noise, stray capacitance, and crosstalk, so certain design constraints need to be followed. These design considerations make it difficult to achieve satisfactory levels of performance for single-sided or even double-sided PCBs - hence the emergence of multilayer PCBs.

Multilayer PCBs are becoming more and more popular in electronics by encapsulating the power of double-layer PCBs into a fraction of the size. They are available in a variety of sizes and thicknesses to suit the needs of their extended applications, with variants ranging from four to twelve layers. The number of layers is usually even, as odd layers can cause issues such as warping in the circuit and are not cost-effective to produce.

While their production tends to be more expensive and labor-intensive, multilayer PCBs are becoming an essential part of modern technology. This is mainly due to the many benefits they offer, especially compared to single- and double-layered varieties.

From a technical point of view, multilayer PCBs offer several design advantages. These benefits of multilayer PCBs include:

Small size: One of the most prominent and praised benefits of using multilayer PCBs is their size. Due to their layered design, multilayer PCBs are inherently smaller than other PCBs with similar functionality. This brings significant benefits to modern electronics as the current trend is towards smaller, more compact but more powerful gadgets such as smartphones, laptops, tablets, and wearables.

Lightweight construction: The smaller the PCB, the lower the weight, especially when the multiple connectors required to interconnect separate single-layer and double-layer PCBs are eliminated in favor of multi-layer designs. This again favors modern electronics, which are more inclined towards mobility.

High quality: Due to the amount of work and planning that must be done to create a multilayer PCB, these types of PCBs tend to be superior in quality to single-layer and double-layer PCBs. Therefore, they also tend to be more reliable.

Increased durability: Multilayer PCBs tend to be durable by their nature. These multilayer PCBs must not only withstand their own weight but must also be able to withstand the heat and pressure used to bond them together. In addition to these factors, multilayer PCBs use multiple layers of insulation between circuit layers, bonding them together with prepreg adhesives and protective materials.

Increased flexibility: While this does not apply to all multilayer PCB assemblies, some do use flexible construction techniques, resulting in flexible multilayer PCBs. This can be a very desirable characteristic for applications where slight bends and bends may occur on a semi-regular basis. Again, this does not apply to all multilayer PCBs, the more layers included in a flex PCB, the less flexible the PCB will be.

More powerful: Multilayer PCBs are extremely dense components that combine multiple layers into a single PCB. These close proximities make circuit boards more connected, and their inherent electrical properties allow them to achieve greater capacity and speed despite their smaller size.

Single connection point: Multilayer PCBs are designed to work as a single unit, not in series with other PCB components. Therefore, they have only one connection point instead of the multiple connection points required with multiple single-layer PCBs. This has proven to be beneficial in electronic product designs as well, as they only need to include a single connection point in the final product. This is especially beneficial for small electronics and gadgets designed to minimize size and weight.

These advantages make multilayer PCBs very useful in a variety of applications, especially mobile devices and high-function electronics. In turn, with so many industries turning to mobile solutions, multilayer PCBs are finding a place in an increasing number of industry-specific applications.

The advantages and comparisons discussed above begs the question: what are the real-world uses of multilayer PCBs? The answer is pretty much any use.

For many industries, multilayer PCBs have become the first choice for a variety of applications. Much of this preference stems from the continued push for mobility and functionality across all technologies. Multilayer PCBs are a logical step in this process, enabling greater functionality while reducing size. As a result, they have become quite common and are used in many technologies, including:

Consumer electronics: Consumer electronics is a broad term used to cover a variety of products used by the general public. This tends to include everyday products such as smartphones and microwave ovens. Each of these consumer electronics products contains a PCB, but more and more of them are using multilayer PCBs instead of the standard single layer. Why? Much of the reason lies in consumer trends. People in the modern world tend to prefer multifunctional gadgets and smart devices that are integrated into their lives. From universal remotes to smartwatches, these types of devices are fairly common in the modern world. They also tend to use multilayer PCBs to increase functionality and reduce size.

Computer electronics: Multilayer PCBs are used for everything from servers to motherboards, mainly because of their space-saving properties and high functionality. For these applications, performance is one of the most important characteristics of a PCB, while cost is relatively low on the priority list. Therefore, multilayer PCBs are the ideal solution for many technologies in this industry.

Telecom: Telecom equipment often uses multilayer PCBs in many general-purpose applications, such as signal transmission, GPS, and satellite applications. The reason for this is mainly due to their durability and functionality. PCBs for telecom applications are often used in mobile devices or outdoor towers. In such applications, durability is essential while still maintaining a high level of functionality.

Industrial: Multilayer PCBs do prove to be more durable than several other options on the market today, making them ideal for applications where rough handling may occur on a daily basis. As a result, multilayer PCBs have become popular in a variety of industrial applications, most notably industrial control. Used to run machinery throughout manufacturing and industrial applications, from industrial computers to control systems, multilayer PCBs are favored for their durability as well as their small size and functionality.

Medical devices: Electronics are becoming an increasingly important part of the healthcare industry, playing a role in everything from treatment to diagnosis. Multilayer PCBs are particularly favored by the medical industry due to their small size, lightweight, and impressive features compared to single-layer alternatives. These advantages have led to the use of multilayer PCBs in modern X-ray equipment, heart monitors, CAT scan equipment, and medical test equipment, among others.

Military and defense: Favored for their durability, functionality, and lightweight, multilayer PCBs can be used for high-speed circuits, which are becoming an increasingly important priority in military applications. They are also favored as the defense industry increasingly moves towards highly compact engineering designs, as the small size of multilayer PCBs provides more room for other components to perform existing functions.

Automotive: Modern cars are increasingly reliant on electronic components, especially with the rise of electric vehicles. From GPS and onboard computers to electronically controlled headlight switches and engine sensors, using the right kind of components is increasingly important in automotive design. This is why many automakers are beginning to favor multilayer PCBs over other alternatives. Although they are small and durable, multilayer PCBs are also highly functional and relatively heat resistant, making them ideal for the interior environment of an automobile.

Aerospace: Like cars, jets, and rockets, in modern times there is a heavy reliance on electronics, all of which have to be very precise. From computers used on the ground to those used in the cockpit, aerospace PCB applications must be reliable and able to handle the pressures of atmospheric travel while leaving enough room for the rest of the surrounding equipment. In this case, multilayer PCBs offer an ideal solution, with a large protective layer to prevent heat and external stress from damaging the connections, and the ability to be made of flexible materials. Their higher quality and functionality also contribute to this utility in the aerospace industry, as aerospace companies prefer to use the best materials to keep their people and equipment safe.

There are more! Multilayer PCBs are widely used in other industries, including the scientific research industry, and even home appliances and security. Everything from alarm systems and fiber optic sensors to atomic accelerators and weather analysis equipment uses multilayer PCBs, taking advantage of the space and weight savings this PCB format offers, as well as their enhanced capabilities.

The above describes the application and advantages of multi-layer PCB in detail. If you want to know more or want to buy PCB, please contact us.

Singo is a professional custom PCB board manufacturer. Mainly engaged in PCB assembly and OEM/ODM electronic manufacturing services since 2006. The products involve home appliances, digital products, industrial control, and medical equipment. After years of hard work, we have established long-term cooperative relations with some well-known international companies. Some of our products are often required to operate in harsh environments where quality and reliability are paramount. With years of experience, we have won a good reputation among customers in the field of electronic production with reasonable prices, abundant resources and on-time delivery.