Rigid-Flex PCB Design Guidelines

Rigid-Flex PCB Design Guidelines


Rigid-flex PCBs combine the best features of rigid and flexible PCBs, making it easier for manufacturers to install PCBs in tight spaces. Before taking advantage of them, you must first understand and follow the rigid-flex PCB design guidelines.

Rigid-flex PCBs combine the best features of rigid and flexible PCBs, making it easier for manufacturers to install PCBs in tight spaces. The added flexibility enables manufacturers to precisely and easily manipulate the board during installation.

However, before taking advantage of them, you must first understand and follow the Rigid-Flex PCB design guidelines. Knowing the trade-off between flexibility and rigidity will help ensure you don't compromise on quality either.

What is a rigid-flex PCB?

As the name suggests, a rigid-flex PCB is a hybrid of a flexible circuit and a rigid circuit. Their designs offer unique solutions and applications and can replace rigid PCBs. One of the best aspects of rigid-flex PCBs is that they combine the advantages of both flexible and rigid PCBs.

In addition to being used in electronic devices, rigid-flex circuit boards have a wide range of commercial and industrial applications. They are also used in advanced aircraft-mounted weapon guidance systems; rigid-flex printed circuit boards are widely used in military and aerospace electronics manufacturing.

Other rigid-flex PCB applications include:

ABS sensor
CT scan

Digital camera

Smart jackets

Cell phone

Barcode scanner


Rigid-Flex PCB design guidelines

When you switch to rigid-flex PCB design, you need to consider many factors - some old, some new. These include:

1. Consider the number of layers

Rigid-flex PCBs are made from alternating layers of flexible and rigid PCB materials. When you're ready to make the switch, decide how many layers you need for your intended use. After that, check with your original equipment manufacturer (OEM) to make sure it can meet these requirements.

2. Heat dissipation

Heat dissipates when electrical current flows through electronics. The amount of heat released depends on factors such as device characteristics, power, and PCB design. As the heat builds up, it affects the performance of the device and can cause damage. Take steps to reduce heat dissipation.

The PCB in the device should help with heat dissipation. This can be achieved by adhering to rigid-flex PCB design guidelines.

3. Material layers

For rigid-flex boards, the material layup is a key factor. Getting the best layup requires working closely with your manufacturer on:

UL flammability rating

Appropriate materials

Minimum bend radius required

RoHS certification

Impedance control

Mechanical considerations

Lead-free assembly compatibility

Material stackup has a large impact on cost, performance, and manufacturability. Invest enough time and resources to find the best layup. After developing a suitable model, let the designer do the necessary calculations, which are then verified by the manufacturer.

Boards with different layers can be used. For example, you might have one with 20 layers and another with 12. However, it is important that they have similar stack-ups, have similar thicknesses, and adhere to rigid-flex design PCB rules. This will help reduce manufacturing issues that could derail the project.

Rigid vs. Flexible PCB: Which is better?

The debate between rigid and flexible PCB has been going on for some time. To determine which is ideal, it's best to first understand how they compare.

First, rigid PCBs are the standard type of PCB that most people think of when they think of circuit boards. They use conductive tracks and other elements arranged on a non-conductive substrate to connect electrical components. Often, non-conductive substrates also contain glass to make the circuit board stronger. In addition to a solid support, rigid circuit boards provide excellent heat resistance for electronic components.

In addition to rigid and base materials, there are some notable differences between flexible and rigid PCBs. These include:

Manufacturing process: Rigid PCBs are manufactured using a solder mask. However, for flexible PCB designs, a process called overlay or overlay is used. This ensures that the exposed circuitry of the flex PCB is protected.

Conductive material: Unlike rigid PCBs, flexible PCB boards should be able to bend. To achieve this property, flexible rolled annealed copper is used as the conductive material instead of electrodeposited copper.

Cost: Rigid PCBs are cheaper than flexible circuit boards. However, when you need a PCB that can fit in a tight space, you should be willing to incur flexible PCB costs.

How can rigid-flex PCB help you?

Both rigid and flexible PCBs have unique features that are invaluable for specific applications. However, you are not necessarily limited to one or the other. To benefit from the capabilities of both, switch to a rigid-flex PCB. To sum up, the benefits of rigid-flex boards include:

Cost effective

Reduced packaging weight

Simplified assembly

Can withstand hundreds of bending cycles

Increased circuit density

The above briefly introduces some basic characteristics of rigid-flex PCB. If you have any questions or want to customize PCB, please contact us.

PCBQuick is a professional custom PCB boards manufacturer that can provide you with professional PCB solutions. We support 24-hour online quotations and 12-hour expedited services for PCB prototypes. Specializing in the production of single-sided PCB, double-sided PCB, multi-layer PCB, rigid PCB, and flexible PCB;