A superior and versatile coating technique
Coating of SMD and PCB is done to protect components and devices that is placed in environments exposed to dust, fungus, corrosive vapors e.g. salty vapors, liquids and moisture. We consider Parylene coating as the best protection coating of conformal sensitive SMD components in harsh environments.
It's hard to see, but...
... this board was protected before coating by dispensing rubber mask on all three connectors and the gold plated fingers.
After coating rubber mask is removed.
Result: you have a perfect protected PCB.
Why choose Parylene coating?
High electric strength
The Dielectric strength of insulating media must be higher than the electric stress.
Electrical resistivity quantifies how strongly a given material opposes the flow of electric current.
Heat generated by electronic devices must be dissipated to improve reliability & performance.
The dielectric constant is practically insensitive to increased frequency.
Parylene is versatile and serve many purposes
Sensors in harsh environments (e.g. fuel / air sensors in vehicles)
Hydrophobic coating (moisture barrier in e.g. bio-medical hoses, displays devices and instruments)
Barrier (e.g. for filtering, membranes or valves)
Electronics and electronical applications in harsh environments
Microwave electronics and radiography equipment as well as for space, avionics and military applications
Corrosion protection on metal surfaces
Reinforcements of micro structures
Abrasion protection (protection from wear and tear)
Protection of plastics, rubber and similar materials in harmful environments
Reduce friction on e.g. catheters, acupuncture needles and micro electromechanical systems (MEMS).
Electric insulation in very limited spaces (e.g. as dielectric in VLSI circuits).