Flexible Printed Circuits: Types, Benefits and its Applications
Flex circuits can easily be termed as circuits which are flexible or can flex. Flexible circuits are basically made from a thin insulating polymer film with a pattern of conductive traces mounted bonded onto the substrate. Flex circuits have been in use since the Second World War and they’re applications are still growing exponentially.
Types of Flex Circuits:
There are many types of flex circuits and here we will discuss the major ones
1: Single Sided Flex:
Single sided flex circuits are the most basic and consist of a single layer of metal traces on one side of a dielectric layer. The dielectric can be polyimide or polymer. A polyimide overlay is added for insulation and protections from environmental degradation.
2: Double Sided Flex:
A double sided flex circuit has multiple layers on both sides of a single dielectric layer. The two layers are plated by metalized through holes to make connections.
3: Multi-Layer Flex:
Multi-Layer flex circuits has several copper layers separated by dielectric layers. The metal layers are again connected by through holes. There are more complex interconnections, layer design surface mounting.
4: Rigid Flex Circuits:
In rigid flex circuits the circuits consists of multiple circuit layers connected by an epoxy pre-preg bonding film, almost like a multi-layer flex circuit. Flex circuits are almost a combination of rigid circuit boards and flex circuits. Rigid flex circuits have higher component density.
Materials Used in Flex Circuits:
Now we will discuss the basic materials used in making flex circuits.
· Conductors:Conductors allow the electrical current to flow freely. Copper is the most commonly used conductor while other materials used include aluminum, carbon, silver ink etc.
Benefits of Flex Circuits:
There are many benefits of flex circuits which make them more useful compared to traditional cables and rigid boards.
· There is a huge decrease in assembly errors as the design is accurate and the production is fully automated.
Applications of Flex Circuits:
There are two basic types of applications of flex circuits:
· Static Application:An application in which flex circuits are installed to fit into the specific application. It can be understood as a one-time bending. (also known as flex-to-fit)
Flex circuits are being used in electronics such as calculators, cell phones, printers, LCD televisions. Cameras. They are used in the medical fields in heart monitors, pace makers, hearing aids. They are used in manufacturing of robotic arms, processing machines, bar code equipment etc. They are even used in satellites and GPS systems. In fact the applications are endless for flex circuits.