Engineered-phosphor led packages and related methods

Abstract

In accordance with certain embodiments, a phosphor element at least partially surrounding a light-emitting die is shaped to influence color-temperature divergence.

1 .- 35 . (canceled) 
     
     
         36 . A light-emitting device comprising:
 a light-emitting die having (i) a top face and a bottom face opposite the top face, the top face being configured for emission of light therefrom, and (ii) at least one sidewall spanning the top and bottom faces; and   first and second phosphor elements disposed over the light-emitting die,   wherein the first phosphor element (i) is disposed over the second phosphor element, (ii) has a top surface, (iii) has a base opposite the top surface, and (iv) has a first light-absorption efficiency,   wherein the second phosphor element (i) is disposed over substantially all of the top face of the light-emitting die, (ii) has a base, (iii) has a top surface opposite the base, (iv) has a second light-absorption efficiency, and (v) comprises (a) a binder and (b) disposed within the binder, one or more wavelength-conversion materials for absorbing at least a portion of light emitted from the light-emitting die and emitting converted light having a different wavelength, converted light combining with unconverted light emitted from the light-emitting die to form substantially white light, and   wherein (i) the second light-absorption efficiency is greater than the first light-absorption efficiency and (ii) a divergence of color temperature of the substantially white light emitted from the device varies, over an angular range of 10° to 85°, no more than 0.01 in terms of Δu′v′ deviation from a spatially weighted averaged chromaticity.   
     
     
         37 . The light-emitting device of  claim 36 , wherein the divergence of color temperature of the substantially white light emitted from the device varies, over an angular range of 0° to 85°, no more than 0.01 in terms of Δu′v′ deviation from a spatially weighted averaged chromaticity. 
     
     
         38 . The light-emitting device of  claim 36 , wherein the divergence of color temperature of the substantially white light emitted from the device varies, over an angular range of 0° to 85°, no more than 0.005 in terms of Δu′v′ deviation from a spatially weighted averaged chromaticity. 
     
     
         39 . The light-emitting device of  claim 36 , wherein at least a portion of the top surface of the second phosphor element is curved. 
     
     
         40 . The light-emitting device of  claim 39 , wherein a vertical distance between the top surface of the second phosphor element and the top face of the light-emitting die has a minimum at approximately a center of the top face of the light-emitting die. 
     
     
         41 . The light-emitting device of  claim 39 , wherein a vertical distance between the top surface of the second phosphor element and the base of the first phosphor element has a maximum between the center of the top face of the light-emitting die and an outer edge of the base of the second phosphor element. 
     
     
         42 . The light-emitting device of  claim 36 , wherein (i) the base of the first phosphor element is disposed on the top surface of the second phosphor element and (ii) the top surface of the first phosphor element is curved. 
     
     
         43 . The light-emitting device of  claim 36 , wherein the second phosphor element has an index of refraction substantially the same as an index of refraction of the first phosphor element. 
     
     
         44 . The light-emitting device of  claim 36 , wherein an angular intensity distribution of unconverted light emitted through an outer surface of the first phosphor element substantially matches an angular distribution of phosphor-converted light emitted through the outer surface of the first phosphor element. 
     
     
         45 . The light-emitting device of  claim 36 , wherein the binder comprises at least one of silicone or epoxy. 
     
     
         46 . The light-emitting device of  claim 36 , wherein the one or more wavelength conversion materials comprise one or more phosphor particles. 
     
     
         47 . The light-emitting device of  claim 36 , further comprising, disposed beneath at least one of (i) at least a portion of the light-emitting die or (ii) the second phosphor element, a mounting surface reflective to at least one of converted light or unconverted light emitted by the light-emitting die. 
     
     
         48 . The light-emitting device of  claim 47 , wherein the mounting surface has a reflectivity to visible light of approximately 95% to approximately 98%. 
     
     
         49 . The light-emitting device of  claim 36 , wherein the light-emitting die is a bare light-emitting diode die. 
     
     
         50 . The light-emitting device of  claim 36 , wherein the light-emitting die comprises a GaN-based semiconductor material. 
     
     
         51 . The light-emitting device of  claim 36 , further comprising at least one additional light-emitting die at least partially surrounded by the second phosphor element. 
     
     
         52 . The light-emitting device of  claim 36 , further comprising a second device that comprises:
 a second light-emitting die having (i) a top face and a bottom face opposite the top face, the top face being configured for emission of light therefrom, and (ii) at least one sidewall spanning the top and bottom faces; and   third and fourth phosphor elements disposed over the second light-emitting die,   wherein the third phosphor element (i) is disposed over the fourth phosphor element, (ii) has a top surface, (iii) has a base opposite the top surface, and (iv) has a third light-absorption efficiency,   wherein the fourth phosphor element (i) is disposed over substantially all of the top face of the second light-emitting die, (ii) has a base, (iii) has a top surface opposite the base, (iv) has a fourth light-absorption efficiency, and (v) comprises (a) a second binder and (b) disposed within the second binder, one or more second wavelength-conversion materials for absorbing at least a portion of light emitted from the second light-emitting die and emitting converted light having a different wavelength, and   wherein the fourth light-absorption efficiency is greater than the third light-absorption efficiency.   
     
     
         53 . The light-emitting device of  claim 52 , wherein a divergence of color temperature of the substantially white light emitted from the second device varies, over an angular range of 10° to 85°, no more than 0.01 in terms of Δu′v′ deviation from a spatially weighted averaged chromaticity. 
     
     
         54 . The light-emitting device of  claim 52 , wherein converted light combines with unconverted light emitted from the second light-emitting die to form substantially white light. 
     
     
         55 . The light-emitting device of  claim 52 , wherein the second phosphor element and the fourth phosphor element are separated by a web therebetween, the web comprising at least one of the binder or the second binder. 
     
     
         56 . The light-emitting device of  claim 36 , wherein the first phosphor element comprises a second binder and no wavelength-conversion material. 
     
     
         57 . The light emitting-device of  claim 36 , further comprising a substrate having a plurality of conductive elements disposed thereon, wherein the light-emitting die has at least two contacts (i) on the bottom face and (ii) each electrically coupled to a different conductive element on the substrate. 
     
     
         58 . The light-emitting device of  claim 57 , wherein the at least two contacts are each electrically coupled to a different conductive element via at least one of a conductive adhesive, an anisotropic conductive adhesive, a wire bond, or solder. 
     
     
         59 . The light-emitting device of  claim 57 , wherein the substrate is flexible. 
     
     
         60 . The light-emitting device of  claim 36 , wherein an outer surface of the first phosphor element at least partially defines a substantially cubic or rectangular solid shape. 
     
     
         61 . The light-emitting device of  claim 36 , wherein the top surface of the second phosphor element defines a first shape and an outer surface of the first phosphor element defines a second shape different from and not conforming to the first shape.