| Conformal coatings are designed to protect printed circuit boards and related equipment from their environment. |
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| Typically applied at 25-50μm, these conformal coatings follow the contours of the board affording excellent protection and coverage, ultimately extending the working life of the PCB. The use of conformal coatings is important in automotive under-bonnet applications, in safety critical areas, military, aerospace and industrial applications. |
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| Electrolube is among the world’s foremost experts in the formulation and application of conformal coatings designed to meet international approvals (including European and American military specifications). The range of products currently available comprises acrylic conformal coatings , silicone conformal coatings , polyurethane conformal coatings , water-based conformal coatings and non-VOC conformal coatings. |
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| Electrolube can offer both transparent and pigmented conformal coatings to improve or camouflage the appearance of printed circuit boards. The range also includes a number of ancillary products to complement the use of our conformal coatings. These include conformal coating thinners and conformal coating removers, peelable conformal coating masks and thixotropic materials for the effective coating of lead ends. |
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Conformal coatings can be used in a wide range of environments to protect circuitry from hazards such as moisture, salt spray, chemicals (e.g. fuels, coolants, etc.) and high temperature. This can prevent corrosion, mould growth and electrical failures such as current leakage. The protection provided by conformal coatings allows for higher power
and closer track spacing, in turn enabling designers to meet the demands of miniaturisation
and reliability. |
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Application of conformal coatings
In order to achieve the best performance, it is imperative that the most suitable conformal coating and method of application is chosen. The main questions which need to be addressed during this selection period are: |
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Application method
Conformal coatings can be applied via spray, dip or brush methods either by manual or automated application. The correct method and conditions should be assessed for each application. Careful consideration of the advised humidity and temperature conditions for the selected coating should be taken for both application and curing stages. |
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Working environment
The conformal coating must be suitable for use under the required operating conditions. Tests must take place to ensure that the coating retains all required properties throughout the duration of the required use. |
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Electrical requirements
Conformal coatings form a protective, insulating layer. The conformal coating should exhibit high dielectric strength; the minimum required can be determined from the inter-track separation and the potential difference between adjacent tracks. |
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Board layout
The design of the board should include consideration of the placement of components that should not be coated. Selective spray equipment or the application of a peelable coating mask can be used to help avoid the coating of such components. |
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Rework and repair
If the assembly requires repair then consideration must be given to the ease of removal of the conformal coating. |
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