How Flexible Printed Circuits Can Be Used in Electronics
Flexible Printed Circuits Can Be Used in Electronics
A flexible printed circuit, also called a flex or FPC for short, is a circuit on a thin, flexible substrate with conductive traces. It may have surface mount devices (SMD) like LEDs and resistors, and it typically has a termination point or connector for integration with other components.
Many different types of electronic products can be optimized with flex circuits. These include laptops, mobile phones, LCD TVs, calculators, cameras, hearing aids and satellites.
Flex circuits have the potential to improve reliability and durability of these devices, as they can replace wire harnesses that add weight and take up more space. They can also reduce maintenance interventions and improve product appearance. The main advantages of a printed flexible circuits are their flexibility and low profile, which make them ideal for use in tight spaces or for connecting sub-assemblies that need to be bent during normal operation.
Compared to traditional rigid PCBs, which use solder to connect components and offer no flexibility, flexible circuits allow for a thinner profile. The thin polyimide substrates used for flex circuits are also thermally stable and can withstand repeated bending and rolling, without damage or loss of conductivity. Additionally, they are less costly and easier to manufacture than traditional rigid boards.
How Flexible Printed Circuits Can Be Used in Electronics
In addition, the copper layers on a flexible circuit are deposited using a screen printing method, which allows for more freedom in design than rigid PCBs. This makes them an excellent choice for complex, high-density arrangements. Additionally, flex circuits can be made with both plated through-hole and surface-mounted components.
The first thing to consider when designing a flexible circuit is the amount of bending that it will need to tolerate. The design process involves determining this early on, as the layout of the components will be affected by it. The thickness of the conductive foil, usually made from copper, is also a factor.
Another consideration is the type of circuitry needed. Depending on the device, a flex circuit can be designed for either static or dynamic bending. For example, a camera would use a rigid printed circuit board for the core components and a flex circuit for interconnections to the USB connector, which will be used for data transfer. A flex circuit would be more appropriate than a rigid PCB in this application, since it can be bent and rolled with the camera when needed.
A flex circuit can be made from a variety of materials, but copper foils are the most popular option. It is also possible to create a flex circuit on polyester, which is less expensive and has some of the same properties as polyimide. However, polyester substrates are limited in the number of layers and scale that can be achieved with a flex circuit, so they are best suited for simpler applications or when cost is a major concern. Moreover, it is important to consider the environment in which the flex circuit will be used, as this will influence the performance and reliability of the final product.