What is a Flexible Printed Circuit?

These flex circuits can bend and they have great differences from PCBs regarding the functionality, fabrication, and design. Designers usually make a common mistake, which is designing a flexible circuit making use of the similar rules as the printed circuit board.

What are the Benefits of Flex Circuits?

Flexible PCBs have some great and amazing benefits. Some of them include the following:

Durability: The reduced number, reduced weight, and flexibility of the interconnects present in the PCB makes it possible for them to handle the ever-changing external forces, as well as improve their ability to resist vibration and shock.

Reduced weight and shape: Majority of the benefits of flexible printed circuit board usually can be seen in their low weight and volume. The fact is, making use of a flexible PCB rather than the rigid PCB or rigid circuit boards could lead to a specific space reduction by more than 50%, as well as a weight reduction of about 95%. This includes the maintenance of the reliability and function of the printed circuit.

Signal Integrity

The flexible PCBs usually function in different environments. Therefore, signals will keep performing smoothly even with exterior conditions. Also, this helps in improving the signal reliability of the printed circuit board (PCB).

Minimized Errors

As a result of the mechanical connectors elimination, as well as reduced variations present in the assembly methods, the flexible PCBs usually go through a reduction in wiring errors.

Higher Density

With the smaller parts and thin flex layers of flexible PCBs, they can support higher circuit densities.

Heat Dissipation

Thinner materials of the flex PCB permit a higher surface area to volume ratio. This improves the heat dissipation.

Low Cost

As a result of the fewer steps in the assembly of flexible PCBs, you can expect them to have a relatively low cost.

What are the Materials Used for the Flex Circuits?


The flexible circuits usually come in multi-layered, double-sided,and single-sided forms. Furthermore, each of these needs different materials to function effectively.

Top manufacturers like RayMing uses branded materials gotten from only trusted suppliers. Some of the materials of the flex PCB that you can select from include:


You may select from different final finishes that meets your project’s requirements. Some of the finishes that you can select from include HASL, ENIG, immersion tin, organic materials, immersion silver, Pb-free HASL. Every option brings different results. Also, it is majorly suited for different applications. This is why it is very important that you consult with RayMing to know which finish suits your needs.


An application’s requirement, and the conductor’s dimensions usually guides the best adhesive selection. Furthermore, some of the well-known adhesives present on the market are epoxies, acrylics, adhesive-free base materials, and pressure-sensitive adhesives.


The insulators are very important. There is a need to have the best and right insulating material. This helps in supporting the flexible PCB application. Working with a wrong insulator could cause PCB failure with time.

Also, PCB insulators usually combine the flexible substrates and the overlay materials in different thicknesses and form factors. Some frequently used insulators are polyester, photo imageable coverlays, polyimides, polyethylene terephthalate, polyethylene naphthalate, solder masks, and screen printed dielectric insulators.

What are the Advanced Features of the Flexible Printed Circuit?

There has been a continuous expansion in the world’s flex circuit market. With this expansion, the advances in technology have also grown. This includes the following:

Hot Bar Solder

The connection of a hot bar solder is more of an option to the standard connection. This helps in getting rid of the presence of a connector present between a flex circuit and a hardboard. This could result in a very durable and efficient connection, which is usually less expensive.

Graphic Overlays

The graphic overlays can be described as polyester nor acrylic covers for the PCBs, which offer a specific user interface having the circuit beneath. The overlays usually include switches, LCDs, and LEDs. This allows the interaction of the user with the printed circuit board (PCB) in the right and desired fashion.

Laser Skived Holes and Slots

Back then, razors were useful in cutting flex circuits, and this process’ success depended on that individual cutting up the lines. However, with the modern lasers, you can cut the lines with extreme control and precision. This results in circuit designs that are finer in the flexible PCBs.

Pressure-sensitive Adhesives

The short form of this is PSAs. There are pressure sensitive and short adhesives that are useful by taking out a protective liner as well as press an object in the adhesive so as to help secure it. The material is usually useful in PCB applications in securing an area of the circuit in its place without having to solder it.


This process has to do with the assembling of PCBs in the large panels of the multiple units. Also, it has the ability to expedite the assembly process of your flex circuit substantially. This is mostly important in the pick and place assembly lines. Immediately, you are done assembling the units, there is a need to break these groups apart.


Polyamide and FR4 stiffeners are usually added to the flex circuits in the areas where the printed circuit may require additional support, like the connection areas. Note that this helps in improving the longevity and strength of the circuit.


Right from time, electromagnetic interference has been an issue. This holds most especially in the applications whereby electronics are very sensitive to any interference. This issue has reduced though with the presence of the improved shielding technology recently. This controls the signal line impedance and reduces noise.

What are the Engineering Services Related to the Flexible Printed Circuit?

The benefits of working with a top PCB manufacturer like RayMing PCB & Assembly goes beyond the advanced features, tolerances, and cutting edge specification of our circuit boards. These PCB manufacturers are glad to offer you different engineering services so as to assist your business meet the desired performance and quality needs.

Design Rule Check

The capabilities of RayMing’s design rule check means that the company double checks every chip layout and ensures that it works in line with the necessary design rules and parameters. Also the company has top manufacturing partners who will maximize space use. This helps them to deliver high-quality boards to you, which performs well for all their intended applications.

Design for Manufacturability

RayMing’s design for manufacturability (DFM) capabilities means that the company will be able to create PCB solutions, which will help in optimizing all the manufacturing steps from the fabrication section to the assembly, then to the testing and finally to the delivery.

When you take advantage of the capabilities, it means that you will get reliable and quality PCBs much quickly. Also, you will be able to deliver client satisfaction.

Controlled Impedance Modeling

If you seek controlled impedance for use in your PCBs, then trust us to deliver controlled impedance modeling. Next, we will adjust the physical relationships between the circuit board components and the copper thickness as required. By so doing, we make sure of high quality boards, which will run between the 100 MHz and the 3 GHz.

DFX to Gerber Conversions

There are businesses that possess DFX files, which CAD programs have been able to generate for them. Therefore, if that specific company possesses DFX files, then there will be a need for you to convert them into more flexible, efficient, and standard Gerber files. Work with RayMing PCB & Assembly to assist you in providing very quick delivery times as well as reduce errors in production


For PCB Panelization, it helps in the arrangement of individual PCBs in one unified panel. This is usually a very important step in engineering because of its ability to increase the accuracy during the automated assembly. It also assists in ensuring high quality boards. Top PCB manufacturing companies offer Panelization services including rectangular and polygon PCB, with very intricate designs.

What are the Applications of Flexible Printed Circuit Board?

The flex circuit board is just the same as the flex circuit board. The main difference is flexible PCB or flexible printed circuit board makes use of a form of flexible base material in making its circuit connections.

Now, this is very helpful for any product, which will not be a stationary device. Furthermore, the size and durability of the flexible PCB, and the reducing and shrinking sizes of the electronics, has led to their adoption by an increasing number of different industries. Below are just a few of the applications and industries using the flexible printed circuit boards.

Consumer Electronics

The flexible printed circuits are usually useful in smaller electronic products such as cameras, tablets, video recorders, cell phones, as well as other smaller gadgets present on the market. You can transport these products or handle them regularly. This makes the resistance of the flexible circuit (flexible PCB) to vibration and shock a very useful feature.


Due to the fact that there has been an increase of the automotive industry towards electronic components, flex circuits or flexible circuits that have the ability to handle the stresses and vibration of the interior of a vehicle has become very important. In addition, the flexible printed circuit boards provide an effective and valuable options for the automotive industry, coupled with offering a cost-effective option.


Today, LED lighting is very popular both in commercial and residential applications. Why is this so? This is due to the strong power efficiency of the LED technology. Most times, heat is usually the major concern. This can be mitigated using flexible printed circuit boards, as well as its effective properties of heat transfer.


The industrial electronics usually deal with huge stress and vibration. Therefore, flexible circuit boards featuring anti-vibration and shock absorption capabilities are very important.

RF, Microwave and High-Speed Digital Applications

The flexible PCB or flexible circuit boards are very reliable. This is why they are great for dealing with high frequency signals.

Power Electronics

This is another advantage of the flexible circuit board. You can couple it with highly thin and flexible layers of copper. This means that the circuit board will be able to handle the heavier power currents.

Medical Systems

The dense and small electronic designs are now becoming a very important factor in the medical industry. With electronic implants and handheld surgical technology increasing in popularity. You can apply the flexible circuit board in the two cases, therefore meeting the size and durability requirements of the surgical technology, as well as the required flexing ability for the implants.

The flexible printed circuits can solve the majority of the problems facing the engineers of today. If you are searching for broader flexibility, improved stretch, as well as simple use with the help of packaging changes, then this is the time to talk about the flexible PCB. Whether you need multi-layer or single-sided boards, work with PCB manufacturers that will make sure that the completed product will have the best quality.

What are the Different Types of Flexible Circuits?

Below are the different options of the flexible circuits.

Single sided flexible circuits

The design of single sided flex circuits deal with one conductive layer of copper, which can be bonded in-between the two insulation layers or built using just one insulating layer of polyimide and an uncovered side.

Double sided flex circuits

This has two conductive layers as well as a polyimide insulation layer present between them. Here, the outer sides of the conductive layer can either have covers or be exposed.

Rigid flex circuits

This is called the rigid flexible circuits that feature a design that is slightly different and costs more than other options of flexible printed circuits. These models make use of at least two conductive layers. However, the insulation material that sandwiches each of the conductive elements could be either a flexible or rigid insulation.

Multilayer Flex Circuits

The multilayer flexible circuits combine the double sided and multiple layers (single layers). These connect at least three conductive layers that are flexible with the insulating layers present between each. The most appropriate solution to overcome crosstalk, crossovers, as well as shielding and impedance requirements.

Sculptured flex circuits

This combines the double- or single-sided flex, without or with PTH.


We hope you understand everything regarding the flexible printed circuit. If you have any more questions, feel free to reach out to us.

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