One of the ways we make our LCD controller boards better suited for harsher environments is to add a conformal coating. The conformal coating helps protect against moisture, dust, and fungus.
As an example, we use Humiseal 1B73 which is a clear acrylic type conformal coating and ideally suited to our controller boards, a brochure for this is attached (link HumiSeal-1B73-TDS.pdf). The specific benefits of this coating include fluorescence under UV light (for inspection), easy reworkability and compliance with MIL, IPCC and RoHS standards. It is used as standard on the following models and as an option on other models:
In summary, the production process we follow is:
- Using a dedicated coatings facility, the conformal coating is a spray that is applied by machine.
- The coating is then verified under UV light and the thickness verified by a gauge.
What is a Conformal Coating?
A conformal coating is a protective coating or film applied to a printed circuit board that ‘conforms’ to the circuit board topology. The purpose is to protect electronic circuits from harsh environments for example in respect of high humidity, airborne contaminants, and temperatures. One particular benefit is to help prevent corrosion in some environments, eg salty air. A conformal coating is also electrically insulating.