LED
A Little Drop of Silicone
For decades, light-emitting diodes were only a niche market – used in applications such as automobile dashboard displays or standby indicators in electronic equipment or, as an infrared version, in IR transmitters for remote controls and dashboard displays. It was not until blue and white models came onto the market in the 1990s that applications for LEDs began to expand steadily. Whether as background lighting in LCD televisions, running lights in cars or as street, storefront or ambient lighting, demand is growing rapidly. OSRAM, one of the world’s leading lighting manufacturers, expects the market volume for LEDs to nearly triple by 2012.
Katrin Sinzinger from Quality Control for the Engineering Silicones division prepares rheometry samples in the lab to test deformation and flow properties of the material.
Katrin Sinzinger from Quality Control for the Engineering Silicones division prepares rheometry samples in the lab to test deformation and flow properties of the material.
Long Life, Economical Production
With an average life of 50,000 hours, LEDs last considerably longer than energy-saving bulbs, they have a higher light output, they do not require toxic mercury and their light appears warmer and more natural in color than the colder light of fluorescent tubes. The silicone lenses, which radiate the light and, at the same time, protect the semiconductor component from the environment, were previously made in a complex and expensive injection-molding process at LED manufacturers. WACKER, however, now sells a new silicone elastomer®which gives manufacturers the ability to make optical LED lenses in a single step: a drop of the silicone is dispensed directly onto the chip.
The Arch, the arc of LED light over Durban Stadium, quickly became the visual hallmark of the 2010 FIFA World Cup in South Africa. It spans this temple to soccer with over 12,000 Golden Dragon Plus LEDs.
The Arch, the arc of LED light over Durban Stadium, quickly became the visual hallmark of the 2010 FIFA World Cup in South Africa. It spans this temple to soccer with over 12,000 Golden Dragon Plus LEDs.
“LUMISIL®allows us to manufacture optical lenses for light-emitting diodes in a way that is both economical and extremely fast – at an appropriately high throughput and with no complex molding step,” explains Dr. Phillip Müller, who bore the responsibility for developing this high-performance optical silicone. The silicone is light-resistant, does not turn yellow or brittle, and protects the semiconductor chip from heat, cold and other sources of stress, such as humidity. “The use of WACKER’s UV-activated silicone plays a major part in the 15 percent increase in brightness that our LEDs produce,” says Dr. Michael Kruppa, senior manager for back-end technology materials development at OSRAM Opto Semiconductors, the lighting manufacturer’s LED subsidiary in Regensburg, Germany.
