Method of making an led device having a dome lens

Abstract

A method of making a light emitting device is disclosed herein. The method includes providing an LED die and dispensing a photopolymerizable composition to form a photopolymerizable dome lens, wherein the photopolymerizable composition is optically coupled to the LED die. The photopolymerizable dome lens may be formed by the photopolymerizable composition using a single drop or a plurality of drops. In one embodiment, the photopolymerizable composition comprises a metal-containing catalyst and a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation. The photopolymerizable dome is polymerized to form a polymerized dome lens. Light emitting devices prepared according to the methods are also described.

1 . A method of making a light emitting device, comprising:
 providing an LED die,   dispensing a photopolymerizable composition to form a photopolymerizable dome lens, wherein the photopolymerizable composition is optically coupled to the LED die.   
   
   
       2 . The method of  claim 1 , wherein the photopolymerizable composition contacts the LED die. 
   
   
       3 . The method of  claim 1 , wherein the LED die is encapsulated with an encapsulant and the photopolymerizable composition contacts the encapsulant. 
   
   
       4 . The method of  claim 1 , wherein the LED die is optically coupled to an optical element, and the photopolymerizable composition contacts the optical element. 
   
   
       5 . The method of  claim 4 , wherein the optical element comprises a lens having a convex outer surface optically coupled to the LED die, and the photopolymerizable dome lens is formed on the convex outer surface. 
   
   
       6 . The method of  claim 1 , wherein the photopolymerizable dome lens is formed from a drop of the photopolymerizable composition. 
   
   
       7 . The method of  claim 1 , wherein the photopolymerizable dome lens is formed from a plurality of drops of the photopolymerizable composition. 
   
   
       8 . The method of  claim 1 , wherein the photopolymerizable composition comprises a metal-containing catalyst and a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation. 
   
   
       9 . The method of  claim 1 , wherein the photopolymerizable composition is substantially Newtonian and has a viscosity of from about 100 to about 15,000 cP at 25° C. 
   
   
       10 . The method of  claim 1 , wherein the photopolymerizable composition is substantially Newtonian and has a viscosity of less than about 10,000 cP at 25° C. 
   
   
       11 . The method of  claim 1 , wherein the photopolymerizable composition is substantially Newtonian and has a viscosity of less than about 5,000 cP at 25° C. 
   
   
       12 . The method of  claim 1 , further comprising applying actinic radiation having a wavelength of about 700 nm or less to initiate polymerization within the photopolymerizable composition. 
   
   
       13 . The method of  claim 5 , further comprising applying actinic radiation having a wavelength of about 700 nm or less to initiate polymerization within the photopolymerizable composition. 
   
   
       14 . The method of  claim 12 , wherein applying the actinic radiation comprises forming a partially polymerized composition, and the method further comprising heating the partially polymerized composition to further polymerize the partially polymerized composition. 
   
   
       15 . The method of  claim 12 , wherein applying actinic radiation having a wavelength of about 700 nm or less forms a photopolymerized dome lens, and the photopolymerized dome lens comprises an elastomer or a non-elastic solid. 
   
   
       16 . The method of  claim 8 , wherein the silicon-containing resin comprises a first organosiloxane having units of the formula:
   R 1   a H c SiO (4-a-c)/2      wherein:   R 1  is a monovalent, straight-chained, branched or cyclic, unsubstituted or substituted, hydrocarbon group that is free of aliphatic unsaturation and has from 1 to 18 carbon atoms;   a is 0, 1, 2, or 3;   c is 0, 1, or 2; and   the sum of a+c is 0, 1, 2, or 3;   with the proviso that there is on average at least one silicon-bonded hydrogen present per molecule.   
   
   
       17 . The method of  claim 16 , wherein at least 90 mole percent of the R 1  groups are methyl. 
   
   
       18 . The method of  claim 8 , wherein the silicon-containing resin comprises a second organosiloxane, the second organosiloxane having units of the formula:
   R 1   a R 2   b SiO (4-a-b)/2      wherein:   R 1  is a monovalent, straight-chained, branched or cyclic, unsubstituted or substituted, hydrocarbon group that is free of aliphatic unsaturation and has from 1 to 18 carbon atoms;   R 2  is a monovalent hydrocarbon group having aliphatic unsaturation and from 2 to 10 carbon atoms;   a is 0, 1, 2, or 3;   b is 0, 1, 2, or 3; and   the sum a+b is 0, 1, 2, or 3;   with the proviso that there is on average at least one R 2  present per molecule.   
   
   
       19 . The method of  claim 18 , wherein at least 90 mole percent of the R 1  groups are methyl. 
   
   
       20 . The method of  claim 1 , wherein the LED die is disposed on a substrate. 
   
   
       21 . The method of  claim 1 , wherein the LED die is disposed in a reflecting cup. 
   
   
       22 . The method of  claim 3 , wherein the encapsulant comprises a photopolymerizable composition. 
   
   
       23 . The method of  claim 3 , wherein the encapsulant comprises a silicone gel, silicone gum, silicone fluid, organosiloxane, organopolysiloxane, polysiloxane, or sol-gel composition. 
   
   
       24 . The method of  claim 3 , wherein the encapsulant comprises a polyimide, a polyphosphazene, epoxy, or acrylate composition. 
   
   
       25 . The method of  claim 4 , wherein the optical element has a refractive index of about 1.75 or greater and comprises glass, diamond, silicone carbide, sapphire, zirconia, zinc oxide, polymer, or a combination thereof. 
   
   
       26 . A light emitting device prepared according to the method of  claim 1 . 
   
   
       27 . A light emitting device prepared according to the method of  claim 15 . 
   
   
       28 . A light emitting device prepared according to the method of  claim 5 . 
   
   
       29 . A light emitting device prepared according to the method of  claim 13 . 
   
   
       30 . A light emitting device comprising:
 an LED die, and   a dome lens comprising a square base,   wherein the LED die and the dome lens are optically coupled.   
   
   
       31 . A light emitting device comprising:
 an LED die, and   a dome lens comprising a rectangular base,   wherein the LED die and the dome lens are optically coupled.   
   
   
       32 . A light emitting device comprising:
 an LED die disposed on an outer surface of a substrate, and   a dome lens comprising a base, the base having the same shape as the outer surface of the substrate,   wherein the LED die and the dome lens are optically coupled.