With the rapid growth in the electronics industry, the use of printed circuit board is also growing exponentially. 

PCB for different applications means the PCB is subject to different environmental conditions, they service domestic, industrial, automotive and military devices and so on.

Absorption of atmospheric moisture or electrostatic attraction of dust can cause performance issues, when the printed circuit board exposure to corrosive atmospheres or harsh chemicals can cause its performance reduced or even failure. So the pcb board must be protected to prevent the performance reduced and failure, then ensure the critical devices’ continued reliability. PCB conformal coating, potting and encapsulation resign are some of the main methods used to protect the sensitive electronic equipment.

PCB Conformal Coating

It is used for protecting the pcb board in a variety of applications, which is done by applying a thin film, typically ranging from 25-75µm. Since the film takes to the contours of the board, it provide maximum safeguard with minimal weight or dimensional change to the PCB, a big advantage of conformal coatings compared with potting and encapsulation.

Standard atmospheric conditions is most common environment that a coating can be subjected, the film needs to be tested in conditions such as humidity, temperature and more in order to determine the suitability of the film in such atmospheric conditions. 

PCB Potting and Encapsulation Resins

It goes a long way in offering a high level of production for PCB boards. Potting and encapsulating resins provide complete insulation by encapsulating the entire PCB, offers both electrical properties and mechanical protection.

The mass of the resin surrounding the unit provides a high level of protection, providing a far more substantial covering than that offered by conformal coatings. Potting and encapsulation resins need to be tested in a number of environments, so that their specifications and suitability for use can be determined. These tests typically involve exposing them to controlled atmospheric conditions over a period of time. The dimensions, weight and appearance of the resin is seen before and after the tests to check if have any changes.

Several Examples about Coatings and Resins

*Acrylic coating works well in conditions where there is sustained exposure to UV light. However acrylic coating may not work well in conditions where the humidity levels are high. In such conditions, a Non-VOC Coating would work far better. 

* Potting and encapsulation resins is a good choice for the cases where there is likely to be lots of mechanical stress or where environmental conditions are harsh. Silicon resins or polyurethane resins are known as a greater degree of flexibility. In fact, polyurethane resins are preferred for particularly low temperatures, also ideal for the device is immersed in water. Epoxy resins are preferable where exposure to chemicals is high.

* Harsh climatic conditions, potting and encapsulating resins are preferred. 

* Conformal coatings are preferred when device miniaturization and portability are necessary.

* Epoxy resins are excellent general purpose resins offering cost effective, high level protection for the PCB including flame retardancy to UL94 V-0. It can also offer superior protection in environments involving immersion in harsh chemicals

Both Conformal Coating as well as encapsulation and potting are available in different variants that make them suitable for particular applications. For standard conditions most, both of them can work well. Because both have unique advantages, you must conduct a thorough assessment of your unique requirements before deciding on the process.

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