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Why are Rigid-Flex PCBs Economical

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Fri, Feb 14, 2020

Rigid-flex PCBs (printed circuit boards) make for an excellent choice in the military, medical and aerospace applications. These circuit boards are exactly as the name suggests. They are hybrid boards that feature elements from both flexible circuit boards and hardboard. The design, therefore, features hard parts, for stability, and others that can be continually folded or flexed. There are several benefits to using rigid-flex PCBs, but this option isn't for everyone. It is essential to understand the scope of such boards and determine whether you can use them for your applications. Here is a brief overview of the economic benefits of rigid-flex PCBs, including the applications they suit:

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Benefits of rigid-flex PCBs

Rigid-flex PCBs offer the best of both worlds. As such, it can suit a wide variety of applications and has several advantages that neither rigid nor fully flexible boards characterize. Some of the unique benefits of rigid-flex circuit boards include:

a)  Design merging

Usually, with rigid PCBs, you require multiple cable assemblies and designs to complete the production. Rigid-flex boards, on the other hand, only need one design to facilitate. You can merge various PCBs into the same assembly and end up using fewer materials. Because of this, rigid-flex PCBs are less expensive to manufacture compared to rigid boards, albeit pricier.

b)  Fewer parts and space requirements

Rigid-flex PCBs use thin, flexible polyimide films, so they can occupy a smaller area. You can shrink the size of the final product and use fewer materials, consequently saving more on potential cost. Since you need fewer parts (cables, connectors), rigid-flex PCBs are quite cost-effective, especially in mass productions. Also, ordering fewer parts reduces risks in the supply chain.

c)  Simplified assembly

Using rigid-flex printed circuit boards simplifies the assembly process. Instead of two or three designs, you will only require one simplified PCB assembly. There is also less room for error as most rigid-flex PCBs can only be installed in a particular way. Fewer errors translate to fewer problems down the line and cost-effectiveness.

d)  Reduced cost of testing

Since rigid-flex PCBs use one assembly, they only require a single test operation rather than multiple operations. This can drastically reduce the cost of testing, compared to rigid PCBs that may require three or more tests, depending on the number of assemblies. What's more, rigid-flex boards provide room to test the full assembly before installation, which can save a lot of time and effort.

Are rigid-flex PCBs more economical?

The economics of using rigid-flex PCBs  is quite straightforward. This is why it makes more sense in the medical and military sectors where the resource economy is among the top priorities. Firstly, rigid-flex circuit boards offer the ideal solution for combining different designs into a single unit. It is also foldable in some parts, making it perfect for applications that call for augmented malleability. Compared to rigid PCBs, rigid-flex boards are very economical and cost-effective. They use fewer parts and materials, require only a single test and also occupy a smaller area and smaller shipping packages.

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Best applications for rigid-flex PCBs

Although rigid-flex printed circuit boards have several advantages, they are not suitable for all PCB applications, especially those that require a sturdy mounting surface. There are also several designs and quality varies from one manufacturer to another. Two main types of rigid-flex PCBs exist in the market. These are:

a)  Flex to install - This is the most common rigid-flex PCB application you will come across. This design allows the PCB to fold once during assembly and disassembly. It is also very stable throughout use, although it may experience some movements, mainly when used in high-vibration applications.

b)  Dynamic flex - In applications that require the circuit board to fold and bend repeatedly throughout use, dynamic flex PCBs offer the best option. They aren’t as common as flex to install and also require special consideration. The board’s design should be able to withstand the wear that comes with repeated bending. Make sure there is an adequate bend radius to provide thousands.

Rigid-flex PCBs are more suited to military, aerospace, and medical devices. They can also be implemented for commercial products. While rigid-flex PCBs come at a higher purchase price, they are very cost-effective when used in applications that demand such types of boards. The best applications for rigid-flex PCBs include:

1.  High-shock and high-vibration environments

Rigid-flex PCBs have high shock resistance and are designed to survive high-stress conditions and environments, where ordinary rigid circuit boards would cause equipment failure. Shock and vibration resistance is why these boards are suitable for aerospace devices.

2.  High-precision application

High-precision applications emphasize reliability above everything else. Issues of cost come secondary in such applications. For instance, if cable or connector failure would be dangerous, it is recommendable to use the rigid-flex circuit boards that offer more stability.

3.  High-density application

When your typical rigid PCBs lack the required surface to mount all cables and connectors, you can use rigid-flex to resolve the issue. They can economize your space and accommodate more connectors in a single assembly.

4.  Where multiple rigid boards are required

If you have applications that require connecting four different boards, replacing them with rigid-flex boards is more cost-effective and optimal. These boards reduce the package weight, increase circuit density and also decrease assembly operations.

Conclusion

There are several merits of using rigid-flex circuit boards. The goal is to find circuits that can suit your end product instead of reshaping your product around the circuit board. Rigid-flex designs are very economical and save more resources. They also last longer, making them better alternatives for the environment. However, while finding PCBs is not a daunting task, there are various aspects to review. It is recommendable to choose credible, reputable manufacturers that can guarantee premium quality boards. Not all rigid-flex PCBs you come across will depict desirable qualities. As such, you should compare existing boards carefully before making a decision. With so many options in the market, you will find varying quality and designs, so it is essential to take your time and find the best offers for your needs.