Types of Flex Circuits - Single Sided and Multi-Layer Flex PCBs

13 October 2022
New

Flex circuits — and to a lesser extent, flex PCBs — are often used to protect electronics and other components underneath. But they do far more than just this. There are many different types of flex circuits that can provide added functionality and aesthetics in an application. In this guide, we discuss the single sided and multilayer flex circuit boards. We will also look at some characteristics of each type, along with their applications. By getting to know more about these types of flex circuits and their functionalities you can make better decisions on what you want to use in your next design.

Single Layer Flex PCB

Single-sided flex PCBs are just that—flexible circuit boards with a single layer of copper. This means that the boards can have a more organic shape, since they do not have a rigid internal structure to support. However, they do have the same functionality as other PCBs—they can be used in the same way and with the same components. Though they are flexible, they are also quite durable.

Single sided flex circuit boards are used in a wide range of products from hand held electronic devices to large industrial machines. They are also used to create prototype PCBs before the final design is printed onto the copper layer.

Characteristics of Single-Sided PCBs

Single-sided flex PCBs are great for mass production. They can be created quickly because there are no extra layers to deal with. They are also more cost effective than other types of circuit boards because they use less material. Although they cannot be used in some applications, they are ideal for certain situations.
Single-sided flexible PCBs are more broadly compatible with the latest technology because they allow for the thinnest traces and component placement of any printed circuit board material.
Single-sided flexible PCBs have better environmental durability than double-sided PCBs because they do not have a second side on which cracking can occur or corrosion can build up.
One disadvantage of using single-sided flex PCBs is that they are not suitable for applications that require high heat dissipation - like power electronics or heating elements - due to their low thermal conductivity compared to multilayer flex PCBs which have multiple layers of copper laminate instead of one layer like single sided flex PCBs.
The copper layer is only on one side of the substrate, not both. This means that there is no copper on the opposite side of the substrate, which makes it easier to route traces between layers. The resulting design can be smaller and more compact than double-sided flex PCBs, which makes them ideal for applications that require less space. The lack of copper on the other side also means that single-sided flex PCBs cannot be used in situations where they will be subject to thermal expansion or contraction during use because there would be nothing holding the layers together.

Multilayer Flex PCB

Multilayer Flex PCBs are a special kind of flex circuit board, which has multiple layers. The basic structure of a multilayer flex PCB is similar to that of the standard FR-4 PCB. However, instead of using one layer of copper foil on top, the multilayer flex PCB uses multiple layers of copper. In some cases these layers have insulating layers between them. This allows for flexibility because different parts of the board will bend at different rates depending on how many layers they have. The multiple layers also allow for greater density on smaller boards, making them even more useful in tight spaces.

Characteristics of Multilayer PCBs

Due to the nature of the material, multilayer flex PCBs can be manufactured in much larger sizes than rigid PCBs. This makes them ideal for use in large-scale projects such as automobiles, where a single board could span entire vehicles without breaking or bending too much due to its flexibility.
Multilayer flex PCB has a high density interconnect which makes it highly efficient in terms of performance. It also helps in saving space and power consumption.
Multilayer flex PCB offers high thermal conductivity which ensures that heat generated due to operation of electronic devices is quickly dissipated and does not accumulate inside them. This helps in increasing their life span as well as reducing their weight because less heat means less power consumption too.
The main disadvantage is that it is difficult to repair a multilayer flex PCB, because the layers are so close together. The tracks on each layer have to be cut out before they can be soldered back into place. This can be done by hand or machine, depending on the size of the damage. It takes time and skill, and it is not always possible to get it right if you are not highly experienced.

Common Applications for Single-Sided Flex pcb and Multilayer flex PCB

The main difference between these two types of circuit boards is their complexity - while single-sided flexible PCBs are relatively simple, multilayer flex PCBs provide higher functionality due to their multiple layers.

Single-sided flexible PCBs are mainly used for the production of flexible PCBs. The applications include:

Flexible displays, such as OLED and E Ink displays
Flexible sensors, such as pressure and force sensors
Flexible solar panels

Multilayer Flex PCBs have many more applications than single-sided flexible PCBs. Some of them are:

I/O ports in smartphones and other devices
Touch screens on smartphones and tablets
Display screens on laptops and TVs

Bottom Line

There are a few benefits to consider when deciding whether a single-sided or a multi-layered PCB is the better option. While there is no hard and fast rule, these three factors will hopefully help you make the best choice for your project: complexity, price, and quantity. Regardless of what you choose, though, both options will get the job done. The key is finding one that is right for your specific application.

We hope you have found this guide helpful and have gained a general understanding of the most common types of flex circuits manufactured today. To dive deeper, check HemeixinPCB for additional multilayer flex PCB notes, and the products offered.