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Comparison from 10 Aspects About Rigid and Flex PCB

Printed circuit boards connect electrical components in one place through discreet wiring, an aspect that results in a functional and complete unit. Printed circuit boards can be as simple as a single layer of copper, though they are far more likely to consist of many layers. Two main types of PCB are flexible circuits and rigid boards. As their names suggest, rigid PCBs are inflexible, while flexible PCBs can easily bend or otherwise shaped to fit inside a designated system. While rigid PCB remains to be popular, primarily due to their low cost, flex PCB are lately siphoning the market share from rigid PCB based on their versatility, among other merits that come with them. Flexible boards are recommended and preferred based on the following reasons:

Printed circuit boards connect electrical components in one place through discreet wiring, an aspect that results in a functional and complete unit. Printed circuit boards can be as simple as a single layer of copper, though they are far more likely to consist of many layers. Two main types of PCB are flexible circuits and rigid boards. As their names suggest, rigid PCBs are inflexible, while flexible PCBs can easily bend or otherwise shaped to fit inside a designated system. While Rigid and Flex PCB remains popular, primarily due to their low cost, lately siphoning the market share from rigid PCB based on their versatility, among other merits that come with them. Flexible boards are recommended and preferred based on the following reasons:

Flexibility

Unlike rigid printed circuit boards, flexible PCB remains a popular choice because they bend easily, fold, or even creased to fit or match the end application. The ability to effortlessly turn is an aspect that allows the designer to have circuitry that provides the device instead of having the end device built around electronics and the circuit board. Unlike rigid printed circuit boards that may not be suitable for wearable electronics, flexible printed circuit boards are ideal for wearable electronics and medical devices, foldable phones, sensors, and implants, among others.

a heart pacer where flexible PCB is used in medical cases.jpg

Connectivity

Unlike rigid printed circuit boards, flexible printed circuit boards provide excellent connectivity between other circuit boards, the user interfaces in electronic packaging, and electronic components. These are some of the reasons why a lot of designers prefer them to rigid printed circuit boards. Additionally, flexible printed circuit boards provide excellent connectivity in applications where the circuit needs to flex over a device’s working life constantly. Thus, flexible printed circuit boards find substantial use in foldable electronics, laptop computers, and display connectivity.

A mobile phone from China’s Huawei has a folding screen. The flexible circuit’s excellent connectivity is adopted to make the entire mobile phone screen operation more flexible and the performance more comprehensive.

Application phone folding screen.jpg

Light Weight of Flexible PCB

When it comes to matters to do with weight, rigid printed circuit boards are slightly heavier than flexible printed circuit boards. A circuit board with a lower pressure brings about a lighter end product, which is essential in the current electronic market where electronic device designers and consumers prefer miniature/small, lightweight devices. Rigid printed circuit boards aren’t ideal for many applications based on the fact that they are a little bit heavy compared to flexible printed circuit boards. Flexible circuits are suitable for drones, several medical devices, and uncrewed vehicles, based on the fact that they are light in weight.

Application of flexible PCB in microelectronics.jpg

Flexible PCB Has Good Durability

Even though rigid printed circuit boards are generally thicker and somewhat sturdy compared to flexible printed circuit boards, flex PCB can withstand shocks and vibrations more effectively. In other words, when it comes to matters to do with durability, flex PCB is somewhat durable compared to rigid PCB. Flex PCB contributes to long-term reliability, functionality, and product life. Flexible PCB finds much use in weapons, missile guidance systems, medical electronics, satellites, and applications that demand superb environmental survivability. 

 a highly durable flexible keyboard.jpg

Flexible PCB Durable

Another reason as to why designers prefer using flexible printed circuit boards compared to rigid PCB is based on the fact that flex PCB is highly resistant. Rigid printed circuit boards are highly at risk of warping or damage from chemicals, heat, and radiation, unlike flex PCB. Flexible printed circuit boards are highly resistant to harmful environmental conditions such as extreme weather. The ability to withstand extreme weather conditions, radiation, or chemicals explains the heavy application or use of flexible printed circuit boards in many applications such as automotive electronics.

Pictures about automotive electronics, application of flexible boards.jpg

Miniaturized Versions of Existing Technologies

In recent years, there’s been a proliferation of electronic applications that require small packages, lower power consumption, and increased functionality. Miniaturization, low volume, and low weight are also evident when it comes to printed circuit boards. By using flexible printed circuit board technology, engineers can create printed circuit boards with strict size constraints. With flexible printed circuit boards, it is now possible for manufacturers to create even smaller electronic and optical products and devices. Apt examples of such products and accessories include computers, mobile phones, and most medical devices. Unlike rigid printed circuit boards, flexible printed circuit boards meet the requirements of miniaturization.

Microchip production of microelectronic products.jpg

Shock and Vibration Resistant

Compared to rigid printed circuit boards, flexible printed circuit boards can withstand vigorous shocks and vibrations. Flexible printed circuit boards are ideal in high-vibration and high-shock environments. Flexible printed circuit boards can easily survive across high-stress environments than rigid PCBs that may fail to function as desired and bring about equipment failure, especially when it gets exposed to conditions where vibrations are vigorous and fast.

Those who work in industries that use high-vibration instruments will find flexible printed circuit boards ideal as they help offset any wear and tear that comes from constant high shocks and vibrations. If you are in search of a circuit board with the ability to offer some of the best capabilities in addition to being able to withstand vigorous vibrations, then you better go for flexible printed circuit boards.

high-vibration instruments.jpg

High Temperature and High-Density Applications

Apart from their ability to withstand shocks and vibrations, flexible printed circuit boards find substantial use in high-temperature and high-density applications. In many cases, a polyimide or similar polymer material for producing a flexible printed circuit board. Polyimide is one of those materials that dissipate heat way much better compared to rigid PCB board materials.

Flexible printed circuit boards can withstand extreme temperature conditions, a reason why they find a lot of use, especially in borehole measurements in the oil and gas industry. With the ability to withstand high- temperature conditions, flexible printed circuit boards offer plenty of benefits to manufacturers. Flexible printed circuit boards are the first choice for most engineers dealing with applications that require PCB.

Flexible PCB board.jpg

Will Flex Circuits Replace Rigid Circuit Boards for all Applications?

Without a doubt, flexible printed circuit boards are handy. However, they will not wholly replace rigid printed circuit boards for every other application. Cost efficiency is a significant obstacle towards implementing exclusive flexible circuit board designs in consumer products. Rigid printed circuit boards aren’t expensive to manufacture and install. Ideally, though, an innovative product is one that incorporates flexible circuitry where necessary while employing stable and reliable rigid circuit boards to keep assembly and manufacturing costs down. 

Some manufacturers use hybrid rigid-flex PCB to keep costs down. The use of rigid-flex PCB is widespread in medical devices and laptop computers, where rigid boards get connected by using ribbon-like flexible circuits. WellPCB creates both rigid and flexible printed circuit boards at very competitive rates. 

a flexible PCB that could probably replace all rigid PCB.jpg

About the Cost of Flexible PCB

When it comes to costs, flexible printed circuit boards are slightly expensive to manufacture and install than rigid printed circuit boards. Unlike rigid printed circuit boards, flexible printed circuit boards require the creation of some additional engineering files. Some flexible PCB designs have Coverplays, pressure-sensitive adhesives, and stiffeners, among others. Such may require an engineer to manually review the flex design and create custom programs, which is why flexible printed circuit boards are expensive compared to rigid PCB.

Even though rigid printed circuit boards are somewhat less costly to manufacture and install, it is hard to overlook the advantages of flexible printed circuit boards. Even though a flexible printed circuit board is expensive, plenty of engineers go for them since they are durable and bring about product functionality as desired. Of importance to note, though, is that the costs generally increase with the layer count. Many other factors will affect the value of the PCB. If you are interested, you can read more of our articles to understand.

Flexible PCB board cost.jpg

Summary

The applications of flexible printed circuit boards are pervasive, with their implementation growing across several industries ranging from medical, military, automotive, and many more. You’ll notice that flex PCB comes with plenty of benefits. Are you in the market for either rigid or flexible printed circuit boards?

WELLPCB With more than a decade of manufacturing experience when it comes to advanced circuitry, we pride ourselves on the precision and quality of both our rigid and flexible printed circuit boards. Contact us for more information about rigid and flexible printed circuit boards. Regardless of whether you need industrial or commercial rigid or flex PCB, our team of experts is ready to assist you. We strongly advise you to first consult with your PCB and PCBA service provider to ensure that you get a product that functions as desired.

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Hommer Zhao
Hi, I am Hommer, the founder of WellPCB. So far, we have more than 4,000 customers worldwide. If you have any questions, you can feel free to contact me. I really appreciate any help you can provide.

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