1 Layer FPC: All You Need to Know About Single Layer Flexible PCB  Board

//

Oakley Mae

Home » Blog » Flexible PCB » 1 Layer FPC: All You Need to Know About Single Layer Flexible PCB  Board

The 1-layer FPC is one of the several types of PCBs that electrical components need to function.

And the trends we’re seeing today regarding such circuits indicate the industry’s dynamic nature.

Also, their wide use of phones and other small-sized electronic items like wearable devices proves that demand for these FPCs is not declining soon.

Manufacturers have no choice but to create thinner, high-density FPCs to capture this ever-growing market. Read on to learn about single-layer PCB boards.

Table of Contents

What Is a Single Layer FCB?

As the name suggests, this board consists of a sole layer of conducting material on one side of the flexible PCB, while on the other side of the board are different electronic components.

Many sometimes refer to this board as a single-sided or 1 layer-flexible PCB.  

Generally, users use this type of board design across various electronic sectors that must work with tight budgets.

Manufacturers build this board using materials like FR4, woven fiberglass cloth with epoxy resin binder and copper foil, or paper reinforced with phenolic resin and copper foil. 

Difference Between Single-Layer FCB and Single Layer Rigid PCB

First, the boards comprise different materials. Single FCBs have a flexible base; hence in addition to copper-clad laminates, they comprise polyamide.

In contrast, single-layer PCBs have a rigid base, necessitating building them using stiffer materials such as FR4. 

With such flexibility comes unique mechanical properties, another difference between single-layer FCBs and single-layer rigid PCBs.

For example, the single-layer FCB circuits and factors such as vibrations, bending, folding into varying shapes, and heat dissipation.

On the other hand, single-layer rigid PCBs have ample strength and rigidity. Also, they offer great support for components and thermal resistance.

Lastly, though relatively cost-effective in the long term, single-layer FCBs have higher production costs than their rigid counterparts.

Single Layer Flexible PCB Structure

Image of polyamide granules

(Caption: Image of polyamide granules)

As mentioned earlier, the base of the single-layer flexible circuit board comprises polyamide to enable flexibility, plus copper and adhesive layers.

Now the polyamide layer is the substrate on both sides of the board.

Then the copper is chemically etched on the board into the patterns needed to form the circuit layer.

And this copper layer is on the center of the board.

The adhesive binds the polyamide film, and to protect the circuit is an additional polyamide layer as a coverlay

Sometimes users must strengthen the flexible board by applying reinforcing ribs made of steel sheet, aluminum sheet, or FR4.

These harden the circuit board area and are especially necessary for boards assembled using SMT or through holes. 

As a result, the circuit board becomes more wear-resistant, the solder joints stronger, and there’s less heat dissipation and strain.      

Advantages of 1 Layer FPC

Single-layer FPCs have several advantages, including:

  • They’re easy to fold and bend, allowing users to arrange the board arbitrarily based on the space layout specifications. Also, such features mean it’s possible to expand or move the board in any space that has three-dimensional capabilities. 
  • They significantly reduce the weight and size of electrical products, making the boards ideal for high reliability, high density, and miniaturized electronic components. As a result, you’ll find these flexible circuits employed in various innovative and compact electronic devices. 
  • These boards provide ideal heat dissipation, great solderability, and easy assembly. 
  • They have relatively lower overall production costs. 

1 Layer FPC: Single Layer FCB Applications

1-layer flexible PCBs are popular for two primary structural applications – static and dynamic.

For the static implementation, the boards utilize flex-to-install or flex-to-fit applications in which the circuit undergoes flexing during installation to fit into the intended application.

But for dynamic implementations, users flex the circuit during actual usage of the final product.

(Caption: flexible PCB cable)

Some common examples of dynamic applications include printer heads, laptops, and cell phones. Other applications of single-layer PCBs are:

  • Medical devices
  • Automotive electronics
  • Aerospace and defense
  • Cameras
  • Battery packs
  • Wearable devices
  • Fuel pumps
  • Motion systems
  • Satellites
  • GPS systems
  • Telecommunications

FAQs

What Are Single-Layer PCBs?

Single-layer (or single-sided or 1-layer) PCBs are circuit boards with one layer of conducting material on only one side of the board. Then a range of electronic components is on the other side of the board. 

What Are Single-Layer PCBs Used For?

Their unique mechanical properties make these boards very popular in various applications.

These include mobile phones, power supplies, copiers and printers, cameras, automobile electronics, and wearable medical devices like hearing aids and pulse generators. The list is endless.  

What Is the Difference Between Single-Sided and Double-Sided FPC?

Sigle-sided FPCs have a chemically etched conductive pattern comprising rolled copper foil on one side of the flexible insulating substrate.

On the other hand, double-sided FPCs comprise a conductive pattern made by etching on both sides of the insulating base film. That way, it increases the density for each unit area. 

Conclusion

We encounter several 1 layers of FPC applications in our daily lives, including phones, tablets, laptops, cameras, and printers.

And in some cases, we even get these boards hosted inside our bodies in the form of pacemakers, defibrillators, and cochlear implants.

It’s no wonder, in recent years, the FPC industry has grown significantly, primarily due to the spread of lighter and smaller electro-medical and wearable devices.