Before designing a printed circuit board, it is necessary to determine whether to use a single-layer or multi-layer PCB. Both design types are common. So which type is right for your project? What’s the difference? As the name implies, a single-layer board has only one layer of base material, also called a substrate, while a multilayer PCB has multiple layers.

Advantages and applications of single-layer boards
Single-layer boards are sometimes called single-sided boards. Generally speaking, there are components on one side of the board and copper traces on the other side. The single-layer board consists of a base layer, a conductive metal layer, and a protective solder mask. Film and silk screen composition.

01
Advantages and disadvantages of single-layer PCB

Advantages: lower cost, simpler design and production, shorter delivery time
Disadvantages: For complex projects, especially when the number of components is large, if the size requirements are small, a single panel cannot handle a lower operating capacity, a larger size, and a larger weight.
02
Single layer PCB application

Single panel has become the preferred choice for various electronic products due to its low cost and relatively easy production. Although multi-layer boards are becoming more and more popular as electronic technology becomes more and more complex, single-layer boards are still widely used. They usually appear in devices with a single function and do not need to store large amounts of data or access the network.
Single-layer PCBs are generally used in small household appliances (such as coffee machines). They are also the PCB used in most calculators, radios, printers and LED lights. Simpler storage devices such as solid-state drives often use single-sided PCBs, as do components such as power supplies and many different types of sensors.

Advantages and applications of multi-layer boards
Multi-layer PCBs are made of three or more double-sided boards stacked on top of each other. Generally, the number of layers of a multilayer board is generally an even number of layers, between 4 and 12 layers. Why not use an odd number of layers? Because the odd number of layers will cause problems such as warpage and distortion after welding.
There are conductive metals on both sides of each substrate layer on the multilayer board. A special adhesive is used to connect these boards together, and there is an insulating material between each board. At the outermost edge of the multilayer board is the solder mask.
Multilayer boards use through holes to make different layers communicate with each other. Through holes are generally divided into three categories:
Through hole: through each layer of the circuit board;
blind hole: connect the outer layer to the inner layer;
Buried via: Connect two inner layers, and they cannot be seen from the outside.

01
Advantages and disadvantages of multilayer PCB

Advantages: able to handle more complex functions, higher quality, greater power, greater operation capability and faster speed, enhanced durability, smaller size and lighter weight.
Disadvantages: higher cost, more complicated design and production, longer delivery time, more complicated maintenance.

02
Multilayer PCB application

With the advancement of technology, multilayer PCBs have become more and more common. Many electronic devices today have complex functions and small sizes, so multiple layers must be used on their circuit boards.
Multilayer printed circuit boards appear in many computer components, including motherboards and servers. From laptops and tablets to smart phones and smart watches. Smart phones usually require about 12 layers. Other products are not as complicated as smart phones, but are too complicated for single-sided printed circuit boards, usually using 4 to 8 layers. Such as microwave ovens and air conditioners.
In addition, due to the reliability, small size and lightweight design required by medical equipment, they can usually run on a board with more than three layers. Multilayer printed circuit boards are also used in X-ray machines, heart monitors, CAT scanning equipment and many other applications.
The automotive and aerospace industries are also increasingly using electronic components that are both durable and lightweight, and these generally use multilayer boards. These components must be able to withstand wear, high temperatures and other harsh conditions. On-board computers, GPS systems, engine sensors, and headlight switches generally also use multilayer boards.

How to determine the need for single-layer or multi-layer PCB
In order to determine whether your project requires a single-layer or multilayer printed circuit board, you need to consider the needs of the project and the most suitable type. Ask yourself the following five questions:
1. What level of functionality do I need? If it is more complex, multiple layers may be required.
2. What is the maximum size of the board? Multilayer boards can accommodate more functions in a smaller space.
3. Is durability given priority? If so, use multiple layers.
4. What is my budget? For a more modest budget, single-layer boards work best.
5. How soon do I need a PCB? Compared with multilayer printed circuit boards, single-layer printed circuit boards have a shorter lead time.