This company offers two new encapsulation compounds for light-emitting diodes (LED). LUMISIL® 740 and 70 cure to form highly transparent silicone elastomers. Both silicones reportedly withstand high operating temperatures and strong light radiation without yellowing or becoming brittle.
The new LED encapsulants are two-component systems. They cure at room temperature via a platinum-catalyzed addition reaction. The cured rubber grades reportedly have a refractive index of 1.41, which is typical of polydimethylsiloxanes. The two products thus belong to the group of normal refractive index (NRI) encapsulants. They can effectively protect the sensitive LED semiconductor chip against environmental influences. They can additionally serve as carriers for luminescent dyes, which can selectively influence the color of the light emitted by the LED.
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