We are living in a technological era, and for a lot of reasons, printed circuit boards are now more crucial than they have ever been. PCBs are essential now because they help technicians develop compact, powerful gadgets such as smartphones. Moreover, they are compact, easy to produce, and cheap to manufacture. And with emerging technology such as PCB 3D printing, their production is bound to become less expensive and more efficient.
Additionally, there are three types of printed circuit boards: rigid PCBs, flexible PCBs, and rigid-flexible PCBs. However, out of all these circuit boards, rigid PCBs tend to be the most manufactured circuit boards in the electronics industry. So why are these printed circuit boards so popular in the electronics industry? Are they more efficient than other types of PCBs? And which manufacturers should you entrust with the production of these circuit boards?
Rigid Printed Circuit Boards in a Nutshell
Rigid PCBs are the most traditional printed circuit boards in the electronics and PCB industries. Even though they have been in the industry for decades, they are still popular and in use among many consumer and industrial products.
Rigid printed circuit boards are a type of PCB which are inflexible and solid as per their structure. Due to their properties, you can’t flex or bend them.
Moreover, these printed circuit boards encompass multiple layers, which include:
- Silkscreen layer
- Solder mask layer
- Copper layer
- Substrate layer
Rigid PCB’s substrate layer which also goes by the name base material is generally made using fiberglass. Moreover, for the substrate component, most technicians utilize FR4 since it provides impeccable stiffness and rigidity to the circuit board.
Technicians also utilize epoxies and phenolic as base components, but these materials aren’t as effective as FR4. Even though they are less efficient, these substitute base components tend to be less expensive compared to FR4 and they also harbor a unique smell.
Moreover, phenolic tends to have a low decomposition temperature. Therefore, if you place solder for an extended period in PCBs made using phenolic, you might end up delaminating circuit board layers.
After the substrate layer, you find the CU (copper) layer which is generally copper foil that technicians laminate onto the circuit board using adhesive and heat.
In most cases, technicians add the copper layer on either side of the circuit board. However, you might sometimes find cheap printed circuit boards with only one copper layer.
Moreover, you should also note that different circuit boards have different thicknesses. It all depends on the design requirements of the circuit board. We describe the thickness using ounces per square foot.
The Solder Mask Layer
The solder mask layer rests above the CU layer. Moreover, you place this crucial layer to add insulation to the board’s CU layer hence shielding this layer from external damage. Furthermore, it also helps shield the circuit board from short circuits.
The Silkscreen Layer
After the solder mask layer, we refer to the next layer as the silkscreen layer. Technicians utilize this layer to add important symbols and characters to the circuit board, which helps other users understand the circuit board better. Moreover, most technicians use white color to generate the silkscreen layer. However, different variations also exist which include:
In the fabrication process, you merge all these layers using heat and adhesive to generate a solid-state non-flexible printed circuit board.
While some PCBs are only multilayered, double-sided, or single-sided. Rigid printed circuit boards can easily take up any of these PCB forms. However, the form that a rigid PCB takes mostly depends on the design requirements.
Additionally, once production of rigid PCBs is complete, you can’t change or modify them.
Rigid VS Flexible Printed Circuit Boards
Both flexible and rigid PCBs serve to effectively connect multiple electronic components in different non-consumer and consumer gadgets. However, these printed circuit boards tend to differ regarding their physical structure. As we have seen earlier, rigid PCBs are solid-state circuit boards that you can’t flex or bend. On the other hand, we use flexible components to manufacture flexible PCBs or flex circuit boards, which gives these PCBs the ability to fold, twist and even bend.
Even though flexible and rigid PCBs typically function similarly, in terms of their properties, they are entirely different. For starters, the production process of rigid PCB is not the same as that of flexible PCBs. Moreover, these PCB offer different performance drawbacks and benefits.
Differences between Flexible and Rigid PCBs
Rigid printed circuit boards are what most people imagine whenever they hear the term PCB. That is because these PCBs are pretty common and have been in the industry for a long time.
Rigid PCB connect multiple electrical components via conductive tracks made out of copper and other elements, carefully arranged on a non-conductive substrate. Moreover, in rigid PCBs, the non-conductive substrates usually encompass glass. The glass components reinforce these circuit boards and provide them with enhanced rigidity and strength. As a result, rigid PCBs provide impeccable support for electrical components. Moreover, it also offers excellent thermal resistance.
Even though flexible printed circuit boards utilize conductive tracks built on non-conductive substrates like rigid PCBs, they are pretty different from rigid circuit boards from a physical structure point of view. That is because technicians utilize flexible base components such as polyimide to manufacture flex PCBs. The flexibility feature gives flex circuit boards the ability to efficiently withstand vibrations, fold up impeccably into different shapes, and dissipate heat efficiently. Due to their structural properties, flexible PCBs are in primary use in innovative and compact electronics.
Additionally, besides these differences in rigidity and base layer components, there are more differences between these components, which include:
Since flexible printed circuit boards have to flex or bend, manufacturers tend to utilize rolled annealed CU (copper), which is more flexible when you compare to electro-deposited CU as a conductive component.
While producing flexible printed circuit boards, technicians use a simple process known as coverlay or overlay instead of solder masks to effectively shield the flex PCB’s circuitry from external damage.
Generally, flexible printed circuit boards tend to be more expensive when you compare to rigid PCBs. However, since flexible PCBs can easily fit into tight spaces, manufacturers can produce smaller gadgets, leading to future savings.
Tips to help you choose between Flexible and Rigid PCBs
Flexible and rigid PCBs have multiple applications in different sectors. However, some applications tend to benefit more from only one of the two circuits. Therefore, even though they technically do the same job, sometimes you can’t substitute one for the other.
For instance, rigid printed circuit boards work seamlessly and make more sense when utilized in relatively large products, for example, desktop computers and televisions. On the other hand, flexible PCBs fit better in compact products, for example, wearable tech and smartphones.
Therefore, when selecting between flexible and rigid printed circuit boards, you should consider the following:
- Your project’s or application’s demand
- The effects of using one of these two PCBs over the other
- The preferred PCB type
You also need to select the perfect supplier to get quality PCBs manufactured for you. However, since there are many circuit board manufacturers, you might have difficulty figuring out the best manufacturer to help you out. However, some manufacturers have decades of experience and impeccable technology which they use to generate high-quality and reliable PCBs. One of these companies is Artist-3D, a famous company that has been around for a while. Moreover, to make work easier for clients, they even have an online site artist-3D.com which gives you direct access to this company. You can hence make and track your order with ease.
Other companies that also offer impeccable rigid PCB manufacturing services include:
- San Francisco Circuits
Application Areas of Rigid Printed Circuit Boards
We can use rigid printed circuit boards in multiple products for communication and work purposes. Some of these products include:
- GPS gadgets
- Mobile phones
Additionally, these components are heavy usage in the medical sector to develop various medical gadgets such as:
- MRI Systems
- CAT Scans
- Heart monitors
- X-ray machines
Additionally, rigid printed circuit boards can easily withstand high temperatures due to their aluminum and copper substrates. Therefore, these circuit boards are great for aerospace applications. In the aerospace industry, there is use of these circuit boards to manufacture crucial gadgets, which include:
- Control tower gadgets
- Temperature sensors
- Aerospace cockpit gadgets
Benefits of Working with Rigid Printed Circuit Boards
Rigid printed circuit boards have a lot of advantages which include the following:
They are Cheaper
When you compare rigid PCBs with flexible printed circuit boards, you will find that rigid PCBs are cheaper to produce and manage.
Due to the substrates we use to manufacture rigid PCBs, they tend to be more durable compared to flex PCBs.
Rigid PCBs have impeccable density and excellent quality. That is because they have been around for some time now, and hence most manufacturers have learned ways to perfect the production process of these PCBs.
Rigid printed circuit boards are, without a doubt, a marvel of engineering. These PCBs have been around for decades, and they are still as popular as ever. Moreover, they have multiple application areas, including applications in the aerospace and consumer products manufacturing industries. Their impeccable durability and reliability make them a force to reckon with. Therefore you can expect to see more of rigid PCBs in the future.