Advantages and disadvantages of conformal coating vs potting/encapsulation
The electronics industry is one of the most dynamic industries nowadays. This is why its growth is expected to remain stable in the coming years.
A key element of today's electronics, whether designed for consumer, automotive, industrial, or military use, is the printed circuit board (PCB). In addition to choosing the best PCB material, manufacturers must also choose an appropriate protection method. This is where electronics contract manufacturers (ECMs) face the protection dilemma: conformal coating and potting.
Protecting Electronics: Conformal Coating and Potting/Encapsulation
During use, electronic devices are exposed to various conditions and factors, such as heat, which can burn the PCB. For example, manufacturing and mining PCBs should be resistant to vibration, dust and chemical exposure. Without protection against such extreme conditions, electronic equipment is vulnerable to damage.
When determining which PCB encapsulant to use, consider the intended use of the device and the elements it will expose. Factors to consider include:
Degree of protection from environmental factors required
The housing design where the PCB will be used
Whether the enclosure is designed to primarily protect the environment
Both conformal coating and potting are organic polymers that provide electrical insulation, heat resistance, and chemical resistance. However, the level of protection they offer varies. That's why it's crucial to determine which one is best for your needs。
conformal coating electronics
Conformal coating of electronics is one of the primary methods of protecting PCBs. Using this method, a dielectric material is applied to the PCB to form a protective layer. Typically, the thickness of the enhanced fluid coating is between 25 and 250 microns, depending on the level of protection necessary.
Conformal coatings are available in a variety of materials, including:
In most cases, the coating is transparent to allow easy identification of coating components and rework of the coating if required. Often, the coating has a UV tracer to aid inspection.
Advantages and disadvantages of conformal coatings
Depending on your electronics environment, conformal coatings may be the ideal solution. The pros and cons of conformal coatings vary slightly depending on the material used, but in general, the breakdown is as follows:
advantage:
Contributes minimal weight gain to equipment
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flexible
long lasting
Reduce the need for complex enclosures
relatively cheap
shortcoming:
Minimal protection against heavy threats
Certain materials/solvents contain hazardous volatile organic compounds (VOCs)
Rework can be difficult depending on the material
PCB Potting and Packaging
Another effective way to protect printed circuit boards from external damage is PCB encapsulation, sometimes referred to as PCB potting.
As the name suggests, the package is designed to surround the PCB rather than just cover it. A jar or enclosure is built on the PCB, and the liquid is poured into the enclosure, sealing the PCB.
As a two (component) system, the PCB potting process involves mixing a resin (Part A) with a hardener (Part B). This initiates a chemical reaction that forms a cross-linked polymer. To improve performance, resins contain mineral fillers and have higher viscosity. Most resins are designed to cure at room temperature and are VOC free. Therefore, circuit board coating spraying is not required.
While 0.5mm sleeves can be used, they are usually much thicker. As thickness increases, so does the weight, resulting in an increased expense per coat. On the other hand, the components will be better protected due to the increased thickness.
advantage:
Provides better protection against water and shock
Dark colors add design security
Easy to use in high volume applications
shortcoming:
More expensive than conformal coatings
significant weight gain
Added process steps