Flexible Circuit Board Manufactures – Complete Guide – Keypad-FD

hqtJun 10, 2020

Flexible Circuit – Everything you need to know about it

Keypad-FD has advanced facility and years of experience that enables our team to give the quick turnaround time on flexible circuit. Our team of engineers helped clients conceptualizes, designs, and manufacture complex designs effectively.

Before getting into deep conversation we would like to put some shed to the main definition of Flexible Circuit then we will take you through its brief discussion.

What is Flexible Circuit? A small Intro

Combination of many printed circuits and components that are placed on substrates is known as Flexible Circuit. Flex circuit boards, flex PCBs, flex circuits, or flexible printed circuits are few of their other names.  Same components are used to designed rigid printed circuit boards and flexible printed circuit boards.

But the major difference is that for manufacturing flexible circuit board, the board used in it is very flexible even can adopt any desired shape during process.

Structure of Flex Board:

These circuits are very thin and light weight with contoured shapes. They are composed of strips of metal which are conductive mainly copper, with dielectric material which is of polyimide. Because of it circuit can easily bend and can easily bear high temperature. They are very similar to printed circuit boards but it is more flexible. Connectors used by it are less expensive; it is another plus point for using such flex circuits. They are popular and widely used because it provides mechanical flexing at its best.  In short we can say that flexible printed circuit board tech offers many possibilities in terms of designs and attributes for many products. Now let’s have a look below to its brief discussion to have complete knowledge about Flexible Circuit Boards.

Let’s have a look to the types of Flex Circuit Board



There are many configuration and specification for designing circuit boards but they are divided on the basis of layers and configuration.

Classification of Flexible Circuit on the basis of Configurations

Flexible Circuit is classified into two types based on configuration.

1: Rigid-Flex PCBs: 

By its name we can get an idea that it’s a configuration of rigid and flex PCBs, in simple words we says that rigid-flex PCB configuration features a rigid circuits in a series that are held together by flex circuits. These days lot of manufacturers utilizes these hybrid circuits because it improves the capability of circuit and makes it more reliable.

Manufacturer used it for mounting connectors and components in the rigid areas while the flexible areas provide vibration-free resistance because of their flexibility. This type of circuit comes up with lots of more advantages so designers utilize these circuits fully especially for challenging applications.

2: HDI Flexible PCBs:

The full form of HDI is high density interconnect. These circuits are used for those applications which demands higher performance. These circuits are famous because they provide the best layout, construction and designs. One of the main features of this circuit is micro-vias. The main difference b/w HDI flexible PCBs and regular flexible PCBs is that HDI flexible PCBs utilize thinner substrate which plays an important role in utilizing the packaging size and also improves the electrical performance.

Classification of Flexible Circuit on the basis of Layers

Flexible Circuit is classified into four types based on layers.

1: Single-Sided Flexible Circuit Boards:

It is usually known as a basic type of flexible circuit board. It is composed of single layer of flexible polyimide film with a thin layer of copper. This is called single-sided flexible circuit because copper layer can be accessed only from one side of circuit.

2: Single-Sided Flexible Circuit Boards with Dual Access:

Well! this circuit is also a single sided but the main difference is that the copper layer can access easily from both side.

3: Double-Sided Flexible Circuit Boards: 

This circuit is composed of two layers on each side of base polyimide layer but the electrical connection is created by using metalized plated via holes.

4: Multi-Layered Flexible Circuits:

This circuit is composed of both single and double-sided flexible circuits. Connection b/w these circuits are created via plated-through holes.

Advantages of using Flex Circuit

Because of its benefits and amazing features Flexible circuit are so popular and widely used. We are going to put some shed to its main benefits, let’s have a look below to few of them.

Small Package Size and Light weight:

These are very light weight and easily can fit their body to any of the circuit because of flexibility. Its biggest advantage is that such type of boards are not only thinned but can also be creased easily. One can fold it and placed it to any area that is why we strongly recommend our engineers to utilize the benefits of 3D packaging geometry in order to facilitate the client with more package size reduction.

Accurate Designs:

These circuits are usually made by using automatic machinery so because of this; these circuits come up with zero error and 100% accuracy.

Freedom of Design:

Because of flexibility this circuit is not limited to 2 layers. Designers can makes lot of designs by using it. Major advantage of these circuit is that it can be made as a single sided with single access, single sided with double access and multi-layered also. Because of its flexibility it can be configured with lot of interconnections.

Possibility of High Density Configuration:

This circuit another good advantage is that it provides both -plated through-hole and surface mounted components. Because of this combination one can easily make high density combination and in such a way we can have a more free space for adding more components.


These circuits because of flexibility can connect with multiple planes while processing. During installation such circuits can flexed to variety of levels.

High Heat Dissipation:

Designer creates tiny thermal parts because of compact design which helps in dissipating the heat quicker. Another good point about this circuit is that it dissipates heat from both sides.

Improved Air Flow:

Because of flexibility and heat dissipation it improves the airflow.  Because of this feature circuit remains cooler and it’s performed for long life.

Durability and Long-term Performance:

This circuit is much better than rigid one because of its durability and long term performance. Such circuits can easily flex up to 500 million times. Because of Low ductility and mass, these circuits easily bear vibrations and shocks.


These circuits popularity is because of reliability, other circuit boards main problem was interconnection but now it is possible to design circuits with fewer interconnections.

Suitable for Application with high temperature:

Usage of polyimide material can bear high temperatures and provides high resistant against acids, oils, and gases. This is the reason that these circuit can even survive in applications with 400 degree centigrade.

Cost Saving:

Because of flexibility and small size it can be fit to any area which plays an important role in reducing overall assembly cost.

Few other benefits of this circuit are that they provide strong signal with 100% quality and reduced the wiring errors that is why flexible circuit seems very simple and easy to understand.

Material used for Flexible Circuit:

Material Selection is very important; if you are using a good material then the final results will be more effective.

Copper is widely used for such circuits so Keypad-FD will recommend you to go after this material. But Keypad-FD is also willing to give services by using materials with conductors such as aluminum, Electrodeposited (ED) copper, Rolled Annealed (RA) copper, Constantan, Inconel, silver ink, and more. We always fulfill our customer’s requirement with 100% satisfaction.

As our engineers are into this field since decades so they can easily provide you flexible circuits in any material that you want. The choice of material is completely on you, just pass an order we are here to fulfill it with 100% accuracy and reliability.

Use of Flex Board:

These circuits are very versatile in nature. Flexible circuit widely used by dynamic flexing as well as static application.

Difference b/w Dynamic Flexing and Static Application

Dynamic Flexing: Such circuits are designed for regular flexing.

Static Application: Such circuits are designed for minimal flexing.

Few common examples of such circuits are robots, cellphones and printers. Their main use has been found in electronic devices because space saving is the main concern for such devices so it perfectly fit to such applications.

Why to choose Keypad-FD for flexible circuit?

Our team of engineers can design simple application to complex one, we always come up with extra ordinary and quality boards, our main motto isWe Go Where Others Will Not…

If you are really looking for amazing quality yet reasonable and flexible PCBs, then Our Company Keypad-FD is everything what you need. Simply give us a call today, one of our team members will reach you in his early convenience.