While PVA is known globally for its world-class dispensing and conformal coating equipment, what truly sets us apart from our competitors is our technical knowledge and award-winning service.
What Are Conformal Coatings?
A conformal coating is a thin polymeric film applied to a printed circuit board (PCB) in order to protect the board and its components from the environment and corrosion. The film is typically applied at 25-250µm and ‘conforms’ to the shape of the board and its components, covering and protecting solder joints, the leads of electronic components, exposed traces, and other metallised areas from corrosion, ultimately extending the working life of the PCB.
Why do I need a Conformal Coating?
A newly manufactured printed circuit board will generally perform well, but performance can quickly deteriorate due to external factors in its operating environment. Conformal coatings can be used in a wide range of environments to protect printed circuit boards from moisture, salt spray, chemicals and temperature extremes in order to prevent such things as corrosion, mould growth and electrical failures. The protection provided by conformal coatings allows for higher voltage gradients and closer track spacing, in turn enabling designers to meet the demands of miniaturisation and reliability.
Which industry requires Conformal Coatings?
The use of conformal coatings is particularly important in automotive, military, aerospace, marine, lighting, industrial and green energy applications. However due to the rapid expansion of the electronics industry, conformal coatings are also finding their way into the domestic and mobile electronics industries, providing the necessary combination of high performance and reliability within a vast array of electronic devices.
Conformal Coating Selection and Best Practice:
Whilst it is tempting to choose your coating based on cost factors, it is important to remember that to achieve the right level of protection from your coating material you will need to carefully select the right material for your application. Different types of coating will perform better in different operating environments, therfore selecting the best coating for your application is paramount to achieving the levels of protection you require. We have provided the basis for you to make your selection here, however our unrivalled technical support team are always on hand to answer any queries you may have and to assist you in selecting the right material.
Conformal Coating Types
Coatings can be categorised by their base chemistry, each option having its own beneficial properties for the different environments the PCB will be operating in. The most widely used materials are historically solvent-based, the benefits of which include:
Ease of processing and application
Simple viscosity adjustment
Suitability for a range of application methods
Tailored application and cure
Acrylic Coatings
Acrylics combine reasonable price with good environmental protection; they retain clarity and can resist darkening and hydrolysis during extended exterior exposure. They do however have a limited solvent resistance, making them suitable for re-work but not applications where chemical resistance is important.
Acrylic coatings offer good flexibility and all round protection
They offer excellent humidity and salt mist protection
They are easy to apply and remove and dry quickly at room temperature via simple solvent evaporation
They have a wide operating temperature range.
They have excellent adhesion to a wide variety of substrates
