Silicone solutions for high-performance LEDs
The LUMISIL® product line comprises high-performance optical-grade silicones for LED manufacturers with high requirements.
All LUMISIL® products provide impressive product properties: They enable very efficient, cost-effective production and exhibit optimized flow and crosslinking characteristics, as well as high photostability. As an encapsulant, they effectively protect the LED chip against environmental influences that would shorten the chip's service life. Moreover, they show extreme thermal resistance during lead-free soldering of LEDs.
Depending on the application, the refractive index is decisive for the choice of the lens-system's material. LUMISIL® is available for both HRI and NRI refractive index variants. LUMISIL® silicones for HRI combine high luminous intensity with low gas permeability, which protects the LED interior against corrosion. This makes them particularly suitable for high-end applications in TVs and car headlights. LUMISIL® HRI silicones are based on a technology developed and patented by WACKER.
For NRI, WACKER offers a series of silicones that are especially efficient to process. LUMISIL® grades with a normal refractive index are ideal for high-performance LEDs, since they can withstand intense radiation and heat. A further field of application is general lighting, where the cost aspect and thus processing efficiency play a key role.
Depending on the lens geometry required, WACKER LUMISIL ® offers two processing techniques: dispensing/jetting and molding.
To directly encapsulate the LED chips, LUMISIL® silicones can either be dispensed or applied in a contact-free jet process. These processes enable very short cycle times and are thus predestined for mass production.
Certain LUMISIL® grades are suitable for a special process that make it possible to generate optimal lenses via one-step mold-free dispensing on the semiconductor.
The molding processing method is always preferred when a lens system must be mounted on the LED using precisely formed geometry, usually with a pronounced arch.