As a result of new legislation, cost saving and energy reduction requirements, LEDs (light emitting diodes) will continue to replace incandescent bulbs for street and traffic lighting.
In fact, the use of LEDs in signage, sports arena displays, passenger information panels, traffic signs, car headlights, warning systems, under-water lighting, and other applications continues to increase rapidly. One big difference with this new technology is that nearly all applications require drive/control circuitry, in the form of a printed circuit board, to control the functionality of these devices as the LED’s require low voltage Direct Current, as opposed to AC.
Many of these applications, will end up in exterior locations, likely to be exposed to a combination of temperature extremes, atmospheric moisture, corrosive gases, and other sources of corrosion.
The visual impression of the display is the key output, and importantly ensuring the output is consistent throughout the life of the product. A key requirement in ensuring consistent device output and life, can be accomplished through conformal coating use. Further information on LEDs can be found here.
Keeping the lights on…. The correct conformal coating can help
The use of conformal coating on drive circuitry and LED lead-frames can mitigate corrosive effects of the operating environment. Conformal coatings serve as an effective barrier to contaminants, allowing for preservation of the circuit’s integrity, as well as mitigating the potential effects of tin whiskers.
One of the unique challenges with coating SMT LED assemblies is the sensitivity of these devices to solvents and certain organic compounds present in certain coating materials. This incompatibility could result in discoloration and deterioration of the LEDs.
HumiSeal products provide a wide range of environmentally compliant, low-outgassing, solvent as well as solvent-free chemistries. Whatever your requirements, the HumiSeal team has the solution.