How Conformal Coating protects PCB
  • 01 Sep 2020

How Conformal Coating protect PCB

Conformal coating is a protective coating over a printed circuit board, it is a thin breathable film of polymer that is sprayed over the PCB and it fits the topology of the board. A conformal coating protects the circuit from harsh environmental conditions and also allows any trapped moisture to escape after cleaning.


Precision analog circuitry may suffer degraded accuracy if insulating surfaces become contaminated with ionic substances such as fingerprint residues, which can become weakly conductive in the presence of moisture. (The classic symptom of micro-contamination on an analog circuit board is sudden changes in performance at high humidity, for example when a technician breathes on it). 


This protective coating ensures the expected working of the components and protects the PCB against the factors that can potentially affect the working of a PCB like, airborne containments, dust particles, humidity, moisture, various temperature ranges, and smoke.

The conformal coating on a PCB reduces the need for replacement and service of the printed circuit board and hence increases the mean lifetime of the board before failure.  


Conformal coating can be applied to any PCB by spraying or brushing. The coating can also be done on a specific part by brushing the polymer coating on it.


Why conformal coating?


The answer is simple if the PCB is not protected; there are higher chances of component and device dysfunction. Large scale electronic equipment and industrial equipment experience a vast range of working environments, the shear stress and industrial are a common reason for PCB malfunction.


Conformal coating a printed circuit board not only increases the work efficiency and lifetime of the equipment but also protects the PCB from mechanical pressure in the environment; hence reduce the cost of a sophisticated casing for the board. It also provides resistance from thermal expansion and vibrations.


Conformal coating sprays contain UV dyes; it can be easily identified using an ultraviolet light source. This makes it valuable as it helps in verifying complete coverage and for making sure that the coating is free of air bubbles, flakes, dust, or any foreign particle during manufacturing.


Today every industry prefers robot labor and automated manufacturing units, all the credit goes to the integrated circuits and the driver boards. They act as the brain and heart of all electronic and modern devices and as a result, the PCBs must be assembled with a proper protection coating to avoid the malfunction and thus exponentially increasing the efficiency.


Conformal coating can protect the PCB in a chemical industry from corrosion and fungal degradation in a biological environment like farms and agro-industry. 

Countless companies provide a sophisticated enclosure for PCB which guarantees lifetime protection of the board, but most of them still fail to resist the thermal shocks and vibration, in extreme cases, they can also suffer from breakage and hence damaging the working of PCB. This is another reason why conformal coating is preferred by manufacturers.


With the miniaturization of electronic devices, processor board manufacturers have also reduced the dimensions of PCB, and hence their conformal coating has become a mainstream task for the manufacturers.