What Are Rigid PCBs?
Rigid PCBs are hard circuit boards that are fabricated on a non-bending base or substrate material, which can be fiberglass, metal, PTFE, or ceramic. This rigid platform provides a stable base that increases physical stress resistance for the components mounted on board.
Why Use Rigid PCBs?
Cost Effectiveness
Rigid circuit boards have the advantage of being more affordable than their flexible counterparts because the materials used to make them and their manufacturing processes are cheaper. Also, their design challenges are not as many, meaning this initial stage is easier to maneuver. So if space is not a major constraint, such as in TVs, computers, and industrial equipment control boards, rigid PCBs are the best options to use. The low-cost PCB assembly associated with rigid boards also contributes to their cost effectiveness.
High Thermal Stability
Thermal stability refers to the circuit board’s ability to withstand high temperatures without disintegrating (affecting the physical and electrical properties). The materials used to make the PCB ultimately influence its thermal stability, and rigid materials generally have a higher Tg and thermal conductivity, which means they are more stable when ambient or internal temperatures rise and dissipate heat faster in case of hotspots.
Durability
Rigid PCBs can be double-edged swords when considering the durability factor. On one hand, rigid materials are more stable and provide reliable resistance from mechanical stress, such as bending. On the other hand, these materials might break easily when exposed to continuous vibrations or excessive stretching, which is where flex PCBs excel. So to provide maximum durability, rigid PCBs should not be used where vibrations and bending or stretching are extreme.
What Are Flexible PCBs?
Flexible PCBs are circuits built on flexible substrate materials, most commonly polyimide, which enables them to bend and twist to conform to irregular shapes or ergonomic designs. The primary advantage of this bending nature is that the circuits can fit into tight spaces while also reducing the overall weight of the final product.
Why Use Flexible PCBs?
Flexibility
This is arguably the biggest advantage of using flexible circuit boards. They can twist, bend, or even fold to conform to irregular shapes, which is critical in making wearables. Devices like smartwatches and smart glasses must be designed and built to fit around the human body, meaning ergonomics is paramount. This is only achievable using flexible PCBs, which can be bent around the arm or glass frames to house the required electronic components and functions in a tiny space.
To Save Weight and Space
The flexibility properties of these circuit boards also enable miniaturization, which is essentially saving weight and space. This makes it possible to build compact smartphones with features like folding displays, implantable medical devices, small car electronics, and wearables.
What About Rigid-Flex PCBs?
Rigid-flex PCBs feature both rigid and flexible circuit boards combined into a single unit to give you the benefits of both worlds. Although these boards are more expensive to make than flexible PCBs, they can be more cost-effective than using separate rigid and flexible boards. This is because their assembly costs are lower, owing to reduced components and manual assembly steps needed to piece them together, such as the separate wiring harnesses needed to interconnect the rigid and flexible sections.
From the reliability perspective, these boards also reduce the interconnections in the circuit (solder joints and connectors), which are considered typical failure points in demanding applications, such as medical, aerospace, and military. The setup also increases the durability of the circuit, providing vibration resistance and mechanical stress resistance where necessary.
So if miniaturization, functionality, and durability are critical factors, rigid-flex circuit boards provide the best alternative for building modern electronics.
Wrapping Up
Although rigid-flex PCBs are more suitable for developing resilient and reliable miniaturized modern electronics, the rigid and flexible types are still relevant as they have several applications they are more suitable for. Regardless of the PCB type you choose for your project or electronic products, you need a skilled partner to help you develop these critical circuits. OurPCB is one such partner that you can rely on to help you from design to final product testing as the company is a turnkey PCB electronics manufacturer. Contact them to get a PCB online quote, as well as to learn more about their capabilities and the best way to partner for your project.