Flexible VS Rigid: The Differences in the Circuit Board Assemblies

Published on March 21, 2022 , Last modified on November 7, 2024
by Hommer Zhao
a PCB

Printed circuit boards (PCBs) are layout data devices that connect electronic components in several non-consumer and consumer devices. Therefore, depending on the applications, design specifications, and manufacturing processes, you can have varied PCB types. For example, there are multilayer, rigid-flex, flexible vs. rigid printed circuits, among others. 

For today’s article, we will be elaborating on the differences between a flexible and rigid circuit. You can bend or shape a flexible PCB into a desirable designated system, while a rigid circuity is inflexible.

And so, let’s get to it.

How Are Flexible VS Rigid Circuits Different?

The following features give the notable distinction between flex and rigid circuit boards

Connectivity 

When comparing the two, flexible PCBs have better connectivity between components, other circuit boards, and user interfaces in electronic packaging

Resistance 

Flexible PCBs can survive extreme environmental conditions because they are highly resistant to higher temperatures. However, intense weather changes can warp or damage rigid PCBs. 

Conductive material

Manufacturers utilize flexible rolled annealed copper rather than electro-deposited copper as conduction materials. Rigid PCBs don’t require conductive materials. It is because they need to bend the flex circuits. 

flex PCB with copper layer

(flex PCB with copper layer)

Manufacturing process

The manufacturing process of a flexible printed circuit incorporates a cover layer of overlay to protect the board’s open circuity. On the other hand, manufacturers use solder masks in the manufacturing process of rigid PCBs. 

Typical cost

Rigid PCBs are less costly than flexible PCBs. Nonetheless, consumers prefer flex PCBs because they are malleable and can fit in compact spaces according to the product’s size. 

Material

Often, flexible PCBs use a flexible base material, for example, polyimide. Contrarily, rigid PCBs use a higher thickness and strength to reinforce the board, for instance, glass

For that reason, they both offer different amounts of durability. For example, rigid PCBs can last when absorbing shocks and vibrations, while rigid PCBs are advantageous in high-strength applications. 

Sophistication of Design

Printed flex circuits have sophisticated designs and are perfect for applications involving highly complex products. Conversely, rigid PCBs are suitable for simpler consumer devices like musical keyboards or toys. 

(Rigid PCB with a simple design)

How to Choose Between Flexible VS Rigid Circuits

While you can easily find flexible and rigid PCBs in many products, they both categorically benefit different operations. For instance, flexible printed circuits are ideal for compact products like wearable technology and smartphones. 

circuit board of a disassembled smartphone

(circuit board of a disassembled smartphone)

On the contrary, rigid PCBs are suitable for products like desktops and TVs. 

motherboard’s electronic circuit

(motherboard’s electronic circuit)

Additionally, ensure that your choice of PCB aligns with the profits gained after usage, the industry’s preference, and the application’s demand. 

Conclusion 

We have exhausted the list in the above post. Briefly, both flexible and rigid PCBs have the same purpose of connecting electronic components into a single unit. However, they possess some differences that broadly distinguish their functionality in specific applications. 

For the perfect supply of circuit boards, kindly contact us with your inquiries or orders. We will be happy to help. 

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Hommer Zhao
Hi, I'm Hommer Zhao, the founder and Chief Editor at WellPCB. With extensive experience in the PCB industry, I oversee all content to ensure it meets the highest standards of accuracy and insight. We proudly serve over 4,000 customers globally. For inquiries or more information, don't hesitate to reach out. Your satisfaction is my top priority!