Electronic Flexible PCB for LED: A Concise Introduction


Oakley Mae

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Electronic flexible PCB for LED is the future of our lighting applications.

They are durable, compact, and reliable for long-term use in our homes and businesses.

Amazingly, their durability and low power consumption are cheaper than most lighting systems.  

If you’re working on a LED project, having the right know-how of flexible PCBs guarantees success.

And that’s what we are providing in today’s article. Let’s get rolling

Table of Contents

What is a flexible LED PCB?

A flexible PCB is a printed circuit board whereby manufacturers watch copper circuit traces on non-conductive flexible material like polyimide.

Next, they interconnect the various layers using buried vias or plated holes. 

Additionally, depending on the board, you can mount electronic components on either side.

And sometimes, they have stiffeners at the end for mechanical support and better connection with devices or adjacent connections. 

Flexible LED PCB Structure and Materials

Most flexible PCBs use the following materials and structures: 

Polyimide (PI) Layers

They are the layers that guard the copper circuit sections of the board. They are the same materials as the substrate but are thinner.

Additionally, manufacturers use the two outermost PI layers as the coverlays that protect the board against environmental hazards.

Consequently, they serve a similar role as the solder masks in rigid PCBs. 

PI Substrate

The substrate is the core of the flexible printed circuit board. Manufacturers often use polyimide or polyester as the substrate as they are flexible and have high heat resistance. 


The ends of a flexible PCB strip

(The ends of a flexible PCB strip)

Printed circuit board stiffeners are materials manufacturers add to the end of flexible PCBs.

They serve as connection points between the PCBs and the device interfaces.

Furthermore, you can use stainless steel stiffeners or FR4 stiffeners, depending on the material. 

Adhesive Layers

With flexible PCBs, you don’t require to add sticky layers.

Typically, they serve as a connection between the PI and copper layers.

However, if you opt to do so, you’ll notice that flex PCBs with adhesive appear darker.

Conversely, those without the adhesive appear light and closely resemble the PI materials in color. 

Rolled Copper Foils

(Copper layers on a flexible PCB)

Copper foils act as conductive pathways for the flexible PCBs.

Moreover, they increase the board’s flexibility to ensure it fits well within the installation space. 


We laser drill vias into flexible PCB to interconnect the various circuit layers.

If they go through all the layers, refer to the vias as plated-through holes.

Conversely, blind vias connect external layers with internal ones but do not go through them. 

Flexible LED PCB Width

Holding flexible LED strips for decorative lighting

(Holding flexible LED strips for decorative lighting)

Flexible LED PCBs come in widths ranging from 4 mm up to 15 mm and more.

Here, we are looking at the roles of the various widths in LED applications. 

4 to 6 mm – Ultra Slim

The ultra-slim PCBs are very flexible, allowing them to fit into tight spaces that others would not.

Moreover, they are bright and produce a respectable color rendering index. 

8 to 10 mm – Regular

If you have come across PCBs lighting in homes or automobiles, chances are high that they are regular LED strips.

Moreover, they are suitable for most lighting applications producing decent light for daily use. 

12 mm – High-Power

The high-power or RGB or RGBW LED strips are 12 mm wide.

The thicker layers allow the LEDs to generate bright light without causing heat dissipation challenges within the system.

Consequently, we use them for high-performance lighting applications. 

15 mm or Wider

Beyond 15 mm, the LED strips produce the brightness light.

As a result, we use them for high-density lighting applications, including commercial and industrial lighting. 

Challenges And Cost Considerations Of Flexible LED PCBs

An electrician soldering a PCB in an assembly line

(An electrician soldering a PCB in an assembly line)

We are still in the process of improving the current flexible LED PCBs.

Thus, their shortcoming may make their manufacturing process challenging and costlier.

Some of the challenges you may encounter include the following: 

  • First, flexible PCBs have a high prototype design and manufacturing cost relative to rigid PCBs. 
  • Second, the circuit boards are challenging to repair since you must change the base map successfully. 
  • Thirdly, you’ll encounter size limitations since you cannot make the PCB as large as some rigid circuit boards. 

Consequently, it would be best if you deliberately chose a qualified manufacturer for your LED PCB.

Luckily, we’re seeing global advances in material science and flexible PCB development.

Moreover, manufacturers are focusing on building PCBs with the following: 

  • Faster data processing speeds
  • Thinner and lighter structures
  • Greater working temperatures
  • PCBs with a larger surface area and greater flexibility resistance


What are the differences between rigid PCBs and flexible PCBs?

We have differences between rigid PCBs and flexible PCBs.

First, rigid PCBs are hard and do not bend or twist along the direction of the force you are applying.

On the other hand, flexible PCBs bend, twist, and rotate as you apply a force. 

Second, manufacturers make rigid PCBs from a hard substrate like fiberglass, whereas flexible PCBs come from flexible substrates.

Third, flexible PCBs can conform to irregular shapes, whereas rigid PCBs are generally rectangular or square. 

What’s the future of flexible PCBs?

The future of flexible PCBs looks bright as they are gaining popularity in more industrial applications.

The reason for such is that they have unique properties that make the boards better than the traditional rigid PCBs.

Case example, advancement in material science and manufacturing processes has made it easier to develop reliable materials. 

The circuit board materials then allow for compact and lightweight flexible PCBs. Additionally, the miniaturization of electronic devices calls for smaller circuit boards.

Such is achievable only with the use of flexible PCBs. You can manufacture one that is as thin as 50 microns. 

Can I use a rigid PCB instead of a flex PCB?

You can use a rigid PCB instead of a flex circuit board.

Generally, the type of circuit board doesn’t contribute to the overall structural integrity of a device.

Moreover, you can design a flex with an exact circuit as the rigid PCB and use them interchangeably. 

If you use a device that needs the board to be hard mounted, you can opt for rigid-flex PCBs.

They’re flexible PCBs with some rigid sections for mounting the board onto a device. 

The Takeaway

Flexible PCBs for use with LEDs are transforming how we light up our homes, businesses, or commercial spaces.

And the good thing is that we have a flexible PCB for any lighting application you have. 

Hopefully, you have taken enough time to go through the whole guide.

Surprisingly, you’ll enjoy dealing with flexible circuit boards while working on your LED project.