Light emitting diodes with enhanced thermal sinking and associated methods of operation
View Patent ↗Solid state lighting devices and associated methods of thermal sinking are described below. In one embodiment, a light emitting diode (LED) device includes a heat sink, an LED die thermally coupled to the heat sink, and a phosphor spaced apart from the LED die. The LED device also includes a heat conduction path in direct contact with both the phosphor and the heat sink. The heat conduction path is configured to conduct heat from the phosphor to the heat sink.
1. A light emitting diode (LED) device, comprising:
a substrate with a thermal conductivity of greater than about 1.0 W/(m·K);
an LED die carried by the substrate, the LED die being thermally coupled to the substrate;
an insulating material on the LED die, the insulating material being at least partially transparent;
a converter material spaced apart from the LED die, the converter material including a phosphor; and
a conduction material in direct contact with both the converter material and the substrate, the conduction material having a thermal conductivity greater than about 1.0 W/(m·K), wherein the conduction material includes a lateral portion across from a forward-facing surface of the LED die and at least one vertical portion extending from the lateral portion toward the substrate such that the conduction material at least substantially covers the LED die.
2. The LED device of claim 1 wherein:
the substrate includes at least one of silicon (Si), gallium nitride (GaN), aluminum nitride (AIN), copper (Cu), aluminum (Al), tungsten (W), stainless steel (Fe), diamond (C), glass (SiO 2 ), silicon carbide (SiC), and aluminum oxide (Al 2 O 3 );
the LED die includes an N-type gallium nitride (GaN) material, an indium gallium nitride (InGaN) material, and a P-type GaN material on one another in series;
the insulating material includes at least one of a polyimide, a solvent-soluble thermoplastic polyimide, a ceramic material, and glass, the insulating material having a thermal conductivity less than about 0.15 W/(m·K);
the converter material includes at least one of cerium(III)-doped yttrium aluminum garnet (“YAG”), neodymium-doped YAG, neodymium-chromium double-doped YAG, erbium-doped YAG, ytterbium-doped YAG, neodymium-cerium double-doped YAG, holmium-chromium-thulium triple-doped YAG, thulium-doped YAG, chromium(IV)-doped YAG, dysprosium-doped YAG, samarium-doped YAG, and terbium-doped YAG, CaS:Eu, CaAlSiN 3 :Eu, Sr 2 Si 5 N 8 :Eu, SrS:Eu, Ba 2 Si 5 N 8 :Eu, Sr 2 SiO 4 :Eu, SrSi 2 N 2 O 2 :Eu, SrGa 2 S 4 :Eu, SrAl 2 O 4 :Eu, Ba 2 SiO 4 :Eu, Sr 4 All 4 O 25 :Eu, SrSiAl 2 O 3 N:Eu, BaMgA 1 10 O 17 :Eu, Sr 2 P 2 O 7 :Eu, BaSO 4 :Eu, and SrB 4 O 7 :Eu; and
the conduction material includes at least one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and zinc oxide (ZnO).
3. The LED device of claim 1 wherein the conduction material is between the converter material and the insulating material.
4. The LED device of claim 1 wherein the converter material is between the conduction material and the insulating material.
5. The LED device of claim 1 wherein the vertical portion of the conduction material includes two opposing vertical portions extending from the lateral portion toward and in direct contact with the substrate.
6. The LED device of claim 1 wherein:
the vertical portion of the conduction material includes two opposing vertical portions extending from the lateral portion toward and in direct contact with the substrate; and
the converter material generally encapsulates the conduction material.
7. The LED device of claim 1 wherein:
the vertical portion of the conduction material includes two opposing vertical portions extending from the lateral portion toward and in direct contact with the substrate;
the lateral portion of the conduction material includes a surface facing away from the LED die; and
the converter material is on the surface of the conduction material and with a width generally corresponding to an emission area of the LED die.
8. The LED device of claim 1 wherein:
the conduction material is a first conduction material between the converter material and the insulating material; and
the LED device further includes a second conduction material spaced apart from the first conduction material and in direct contact with the converter material.
9. The LED device of claim 1 wherein:
the conduction material is a first conduction material between the converter material and the insulating material;
the LED device further includes a second conduction material spaced apart from the first conduction material and in direct contact with the converter material;
the converter material includes a plurality of vias extending from the first conduction material to the second conduction material; and
the plurality of vias individually contain a third conduction material.
10. The LED device of claim 1 wherein:
the LED die is a first LED die;
the LED device further includes a second LED die carried by the substrate in a side-by-side arrangement with the first LED die; and
at least one of the insulating material, the converter material, and the conduction material encapsulates the first and second LED dies.
11. The LED device of claim 1 wherein at least a portion of the conduction material comprises an at least generally transparent material.
12. The LED device of claim 1 wherein the insulating material, the conduction material, and the converter material are adjacent to each other in series.