Flex PCB Cable: Everything You Need to Know


Oakley Mae

The Flex PCB cable is a handy device that’s one of the options you have for connecting PCBs.

See, you cannot directly connect two boards.

Yet it would be best to do that often to transfer signal current from one board to another.

Read on to learn more about this linking method, including how it functions, its composition, and its characteristic features.

Table of Contents

What Is a Flex PCB Cable?

A flex PCB cable is a lightweight electrical cable that seamlessly conforms to fit into small spaces and all kinds of contoured shapes.

Mind you, it does all this while performing a host of functions. 

Now the primary function of the PCB cable is to connect two related products or parts.

See, often, flex circuit assemblies consist of several PCBs.

Such circuitry comprises several connections, and that’s where a flex PCB cable comes in.

The circuitry’s many connections utilize the cable. 

For this reason, you’ll find that so many products today use the flex PCB cable.

And that’s especially because of how flexible it is.

Some flex PCB cable products include mobile devices, printers, and tablets. 

It’s important to note that connectors are specifically designed for PCB cables.    

Flexible PCB Cable Composition and Parameters

Interestingly, the flexible PCB cable is a kind of FPC and looks like a circuit board. It comprises an insulated solid core that’s solid or stranded and appears elongated.

And both ends have a special design that allows the cable to function as pluggable pins that you can either weld or directly connect to a device. 

Then, the middle part typically consists of a circuit.

Remember, such cables need a certain level of flexibility.

Therefore, the base material engineers use to construct these cables is rolled copper.

And that’s because of how capable rolled copper is and how it can take twists and turns without suffering damage.   

Image depicting flexibility of a flexible PCB cable

(Caption: Image depicting flexibility of a flexible PCB cable) 

Characteristic Features of an FCB Cable

A More Flexible Connection

Interestingly, the FCB cable is an ideal connection tool that’s been around for years.

And one of the reasons it’s popular is that many signal cables have a flexible insulation coating, such as silicone, PVC, or PTFE.

Thus, if the application you intend to use it on has several bends, then the flex PCB cable is ideal.

Only ensure you consider the dynamic bends and bend radius. 

Current Rating

Usually, comparing metal quantity in the track and cable connection impacts the amount of current the cable can carry.

See, the thickness of the copper plays a circuit’s functionality and, by extension, the current rating.

So because there’s a smaller amount of metal in the track than in the cable connection, it translates to a lower current rating.

Therefore, you must be familiar with your current needs. 

Space Envelope

Usually, there needs to be some spacing to facilitate a PCB-to-cable connection.

And the amount of space usually depends on two factors.

First is the actual height of the cable connector, and it should be greater than that of the equivalent board mounting.

The other factor determining the spacing is the cables vertically exiting the back of the connection.

These require spacing to enable bend radius. 

Sometimes, you may add extra padding on the alternate device, enclosure, or board.

That way, you’ll ensure the bent cable does not wear after frequent use.

Note the FPC exits the SMF connector at right angles, then you can eliminate both aspects of such a connection height without causing any errors. 

Advantages of FCB Cable

First, using a flex FCB cable can help to reduce the weight and volume of electrical products.

This is ideal for developing devices with critical aspects like high density, enhanced reliability, and miniaturization. 

Secondly, the cable can allow for arbitrary arrangements. With the FCB cable, you can integrate connections of wiring and components that are stretchable and movable in 3-D spaces. 

Disadvantages of FCB Cable

First, the FCB cable is a unique device designed for specialized applications.

For example, they allow initial circuit makeup, photographic master plates, and wiring.

As a result, you can expect the price to go up.

So, to keep costs to a minimum, unless there’s an urgent need to apply soft FPC, avoid applying it.

And if you must, then only apply it to small applications.   

Another disadvantage of FCB cables is that a lot of energy goes into making a flex FCB cable.

And there’s also the burden of maintenance to take into account.

Typically, it looks like soldering and rework, requiring trained technicians.


What Is the Difference Between Flex and Non-Flex PCB?

A flex PCB is one built on a flexible base, typically polyimide.

Thus, unlike the non-flex PCB built on a rigid base, it can fold, bend, or twist without causing damage. 

What are the Uses of Flex PCB?

Flex PCBs get used in consumer electronic devices like cell phones, calculators, cameras, and LCD televisions.

Also, engineers use them in the medical sector for making wearable devices like pacemakers, hearing aids, and heart monitors.

In some cases, you’ll also find them used in manufacturing processing machines, robotic arms, and barcode equipment.  

What is the Disadvantage of Flex PCB?

Generally, flex PCB cables often get used in specialized applications. Thus, the initial costs associated with the circuit tend to be higher than that of rigid PCBs.


Undoubtedly, flex PCB cables make it possible to implement various connections.

In turn, these help in various applications in various industries.

Thankfully, you now know how they function, their composition, and their characteristic features.

So now, hopefully, you can take full advantage of the capabilities of these devices.