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Beautiful and
tough, LED billboards are a marvel of manufacturing skill. Similar to consumer devices like smartphones
and flat-screen TV’s, outdoor LED displays have gone high-def (HDTV). But unlike consumer devices, these displays need
to be rugged – they live outside, afterall!
Figure 1: It's beautiful when new but wet weather and dusty air can make it dim, faded and spotty.
- Constantly
exposed to ultraviolet (UV) light, they need to be made of materials that
resist yellowing.
- Clear
silicone resists yellowing but it’s porous so outdoor humidity can penetrate to
the LED chips and corrode the electrical bonding wires.
- Silicone is
also soft and sticky – so dust clings to it. In cities and along highways, LED
billboards grow dim due to a coating of dust.
Clear Epoxy for Outdoor LEDs
Digital
billboards are made of thousands of individual RGB LED packages. Each tiny
package represents an image pixel, containing three light emitting diodes
(LEDs) that light-up to a specific color depending on the display being shown. Until
now, these outdoor LEDs needed to be encapsulated in silicone because
traditional epoxies were unable to endure the junction temperatures of mid-power,
0.5 watt to 1 watt, LEDs
But today, SolEpoxy has developed a hybrid liquid epoxy compound
that can endure mid-power LED temperatures, resist UV yellowing, and provide
solid, moisture-proof and dust-resistant RGB LED encapsulation. And, SolEpoxy’s
clear epoxy hybrid is actually less costly than silicone.
Figure 2: The clear encapsulation material needs to transmit light and
protect the tiny electronics of the LED chips.
OL88-8: The new standard for Outdoor RGB LED Displays
During several visits to southern
China and with a great deal of input from outdoor LED display manufacturers, we
learned that the industry really needs an affordable, durable and easy-to-use
clear encapsulation material in order to truly unlock the potential for outdoor
LED billboards. That’s why we formulated OL88-8.
- High refractive index of 1.52
- Initial transmittance higher than 90%
- Degradation less than 5% after thousands of hours above 100°C
Figure 3: Epoxy is great for next-generation MAP-molded or MAP-cast QFN LEDs because hardened epoxy is easy to saw and it’s moisture-resistant.
OL88-8 is a water-clear epoxy hybrid that cures hard and smooth
so it will protect LED chips even in dusty, all-weather outdoor environments. And,
it’s easy to use.
- OL88-8 is a 1-part, pot-stable liquid that you can “drop-in”
your silicone encapsulation line
- Storage temperature is -20°C and shelf-life is 9 months
- Even though OL88-8 is better than silicone for outdoor
displays, it’s also cheaper
Contact us for an
OL88-8 Sample.
