PCBs or Printed Circuit Boards are by far some of the most innovative developments to have come about.
An innovation dating back to the latter half of the 20 th century, it has today become widely used in every field imaginable.
Indeed, one could say that the modern world would be utterly impossible, without the existence of these often overlooked electronic components.
A great way to replace wires to a large extent, and sometimes even entirely, PCBs are today found everywhere, with applications only limited by the human imagination more than anything else.
Of the many kinds of PCBs around, one of the more interesting and unique varieties around is that of Flexible PCBs.
Created as a way to make printed circuits that are flexible, they found widespread use in applications where there was a need for moving circuits. In other words, rather than being designed traditional circuitry where the base was solid and fixed in position, the flexible PCBs were made for applications that had to be in constant motion, such as those in moving machinery.
This allowed for the circuits to continue carrying out their function, while at the same time remaining intact rather than getting damaged in any way, while the circuitry was moving.
There is a lot that can be said about printed circuit boards, regarding both their design and function.
Some key details about the same are explained in the points given below.
The Basic Structure & Design
As the name would suggest, flexible PCBs are those PCBs, which are ‘flexible’ in nature.
The design principles of flexible PCBs are fairly similar to that of rigid PCBs, in the sense that they use the same ‘printed’ circuits to carry signals. At the same time, however, the manufacturing process varies between the two. Although the exact nature of the PCB design can vary, the layout explained below is a fairly common template used across industries.
To begin with, flexible PCBs comprise a substrate and overlay, which comprises of the main layer or the substrate. It is usually made up of a polyamide insulating resin material, which is known for its high resistance to temperature, as well as flexibility. The next step involves a polyester-based insulating material, which serves as the second layer of the PCB.
With the main ‘base’ layer ready, the next one to be used is that of the copper layer, which is bonded to the substrate, with the help of an adhesive. On top of this layer goes the overlay, which is a protective film that acts as an insulative and protective layer on the circuits.
The Pros & Cons of Flexible PCBs
As with any electronics, or for that matter anything else, there are advantages and disadvantages to Flexible PCBs as well.
Given in the points below are some of the most important pros and cons worth looking into when it comes to Flexible PCBs.
To start off, let’s look at the pros of flexible PCBs.
There are several advantages when it comes to using flexible PCBs. Some of them include the following:
As the name would suggest, flexibility is one of the biggest advantages of the board, which makes them ideal for use in applications where this is of prime importance.
High Density –
They can be used in applications where high-density circuitry and designs are required, which may not be possible with rigid PCBs.
Space Savings –
The previous point has an advantage of its own, which is that it helps to reduce the amount of space required to set up an assembly, which would otherwise have increased manifold.
4. Assembly Process Reduction – There is a great reduction in the assembly process, meaning that less effort is required to get the finished product with flexible PCBs, in comparison to rigid ones.
With regard to the cons of using flexible PCBs, a couple of them are worth mentioning. Some of them include the following:
Easily Damaged –
Although PCBs are strong and sturdy in general, including flexible ones, they are not as strong as rigid PCBs.
This means that they are relatively easier to get damaged when subjected to impact. As a result, the degree to which they can be used, are fairly limited.
In addition to this, it should also be noted this necessitates greater care in handling, not just in the manufacturing stage of the board, but until the end of its use.
2. Cost Factor – Another major issue would be that of the cost factor. In comparison to rigid PCBs,
flexible PCBs are relatively expensive to manufacture, which adds to the final cost factor for the end-user.
Temperature Resistance –
Temperature issues are sometimes a problem, especially towards the higher end. This is because the boards are designed with a focus on flexibility in mind, rather than temperature resistance and resilience.
Due to this, it is possible that towards the higher end of the temperature levels, there may be issues in the board’s functionality, in comparison to those boards which are rigid.
Sensitivity to Scratches –
As much as it is a part of the first point, it is a point unto itself as well.
Due to the nature and design of flexible PCBs, they tend to be particularly sensitive to scratches. Also, the sensitivity here refers to the fact that sometimes, even the smallest of damages can result in the entire board being obsolete, making it necessary to replace the entire component to restore everything to normal.
Reparability Issues –
Although damages to flexible boards may be possible to a certain extent, the boards are largely rendered useless when damaged.
In other words, it is next to impossible to repair damages that may occur on flexible PCBs, in comparison to rigid ones. This means that in the event that there is an issue with any sort of damage, one may be required to replace the entire board, rather than make a few repairs to restore it to normal.
Uses of Flexible PCBs
As already mentioned above, the use of flexible PCBs is largely in applications where there is a need for circuitries to exist on and across moving parts.
In addition to this, they are also used in applications where the circuits are required in corners or other areas, where there may be a need for ‘bent’ or ‘curved’ circuits.
Some common uses of flexible circuits include, among others, moving machinery, robotics, handheld devices, applications where electricity and data are to be carried across moving joints, aerospace, medical applications, defense use, etc.
To sum up, the above-mentioned points lay out some of the most important details about flexible PCBs.
There are indeed many more that can be mentioned, all of which make them the unique technological components that they are.