The Difference Between Flex and Rigid Printed Circuit Boards

Printed CircuitBoards or simply PCBs are one of the more important concepts in electronics; yet people often forget what a PCB is.

It is an electronic circuit, comprising of thin strips of a conducting material (mostly copper), that has been etched from a layer that is, in turn, fixed to a flat insulating sheet. This is the printed circuit board where integrated circuits and other components are also attached. The use of this board’s base is to physically support and provide wiring to surface mounted components that can be found in most electronics. Other than this, PCBs are used in the aerospace, automotives and telecommunications industries among others.

Most people looking to design a printed circuit board often get confused over the types available. PCB manufacturers, such as Super PCB, produce online quotes for both flexible PCBs and rigid PCB fabrication.

Let’s explore the difference between the two;

What Are Flexible Circuits?

Also known as flex circuits or flexible electronics; it’s a technology by which electronic circuits are assembled with the help of mounting electronic devices on flexible plastic substrates (polyimide, PEEK, or transparent conductive polyester). Identical components that are used to produce rigid printed circuit boards are used for the assembly of flexible electronics. This enables the flexibility quality of the board during usage.  

The Applications of Flexible Circuit Boards

Often used as connectors in various applications, flex circuits makes it easier where flexibility, space savings and/or production constraints are limiting use of rigid circuit boards. Computer boards are the most common application is which these boards are used.

In addition, most flex circuits act as passive wiring structures and are used to interconnect electronic components (integrated circuits, resistors, capacitors, etc). However, they can also be used to interconnect other electronic assemblies - either directly or with help from connectors.

Types of Flexible Circuit Boards

As far as flex circuits are concerned, following are its different types;

1. Single-sided Flex Circuits
2. Double Access or Back Bared Flex Circuits
3. Sculptured Flex Circuits
4. Multi-layer Flex Circuits
5. Double-sided Flex Circuits
6. Polymer Thick Film Flex Circuits
7. Rigid-Flex Circuits

The Closest To Rigid Printed Circuit Boards Are Rigid Flex

Most people don’t realize this; but rigid circuit boards aren’t manufactured anymore. The rigid flex is a sort of hybrid printed board as both flexible and rigid board technologies are used in its production. Most boards (rigid flex) are made of multiple layers of flexible circuit substrates that are attached to one or more rigid boards either externally and/or internally. This depends on the intended design of the application.

When it comes to designing printed circuit boards, rigid flex are more challenging than designing a typical rigid board environment. The boards are designed in a 3D space which is why spatial efficiency is increased as well as ability to twist, fold and roll the design of flexible board substrates to achieve the desired shape.

There’s a reason why PCB design and production should only be given to an expert PCB fab house. Too often, minor errors during the design process make a project far more costly due to delays. When in doubt, always go for the best. For more information on PCB manufacturing, visit http://www.superpcb.com/.