Oct 17 2007
Dow Corning Corp. today introduced three new two-part high refractive index (HRI) silicone encapsulants to serve the fast-growing light-emitting diode (LED) market. Dow Corning's new encapsulants offer increased light output, a range of hardnesses to suit a variety of applications, and superior resistance to heat, chemical and ultraviolet (UV) light exposure compared to other LED encapsulants on the market today.
Market research firm Strategies Unlimited expects worldwide LED sales to grow more than 60% during the next three years, reaching $8 billion during 2010, as LEDs make steady inroads into the general lighting market as well as applications in automobiles, cellular phones and LCD laptop and television back-lighting systems. Silicone encapsulants are helping to enable the LED market's growth by improving device performance and durability.
Most LEDs are coated with protective encapsulants to prevent electrical and environmental damage while increasing light output and minimizing heat build-up. Encapsulants also can be molded into lenses to create specific light distribution patterns. Until recently, encapsulants were commonly made of epoxy and other organic materials because of their hardness, transparency and low cost.
Silicone encapsulants increasingly are gaining favor, however, as the electronics industry develops more powerful, high-brightness LEDs. Silicone encapsulants can withstand much higher LED operating temperatures than epoxy, and are compatible with lead-free solder reflow manufacturing processes. Silicone encapsulants also offer high light transmittance, excellent adhesion to a variety of materials, low moisture absorption, and availability in a wide range of hardnesses and viscosities.
Dow Corning's new two-part HRI encapsulants are available in three formulations, each optimized for different uses and manufacturing processes. DOW CORNING(R) OE-6665 A and B offers maximum hardness along with low viscosity. DOW CORNING(R) OE-6630 A and B offers a softer formulation with similarly low viscosity. DOW CORNING(R) OE-6635 A and B also offers a softer composition, but with twice the viscosity. All three products are highly transparent, with a refractive index of 1.53, compared with 1.4 for other silicone encapsulants on the market.
"These new encapsulants offer significantly more light output than previous formulations, along with silicone's inherent heat resistance and durability," said Billy Han, Dow Corning's global market manager for LED and light management products. "LED encapsulants are a high-growth opportunity for Dow Corning, and we are pleased to be assisting the market's growth by developing new materials with superior thermal properties and stability."