Method and apparatus for fabricating phosphor-coated LED dies

1. A lighting apparatus, comprising:

a light-emitting device that includes:

a first doped semiconductor layer;

a light-emitting layer disposed over the first doped semiconductor layer; and

a second doped semiconductor layer disposed over the light-emitting layer, the second doped semiconductor layer having a different type of conductivity than the first doped semiconductor layer;

a photo-conversion layer coated around the light-emitting device; and

a lens that houses the light-emitting device and the photo-conversion layer within;

wherein:

the lens includes a first sub-layer and a second sub-layer; and

the first and second sub-layers have different characteristics.

2. The lighting apparatus of claim 1 , wherein:

the first sub-layer contains phosphor particles; and

the second sub-layer contains diffuser particles.

3. The lighting apparatus of claim 2 , wherein the diffuser particles include silica, PMMA, ZrO 2 , or silicon.

4. The lighting apparatus of claim 1 , wherein;

the first sub-layer contains first phosphor particles;

the second sub-layer contains second phosphor particles; and

the first and second phosphor particles are different color phosphor particles.

5. The lighting apparatus of claim 1 , wherein the lens has a transmittance greater than about 90% and a refractive index between about 1.4 and about 2.

6. The lighting apparatus of claim 1 , further comprising a substrate on which the light-emitting device is disposed.

7. The lighting apparatus of claim 6 , wherein the substrate is a Metal Core Printed Circuit Board (MCPCB) substrate, a ceramic substrate, or a copper substrate.

8. The lighting apparatus of claim 1 , wherein the photo-conversion layer comprises a phosphor film.

9. The lighting apparatus of claim 1 , wherein the light-emitting device comprises a light-emitting diode (LED) die.

10. The lighting apparatus of claim 9 , further comprising a lighting module on which the LED die is disposed.

11. The lighting apparatus of claim 10 , further comprising a lamp in which the lighting module is disposed.

12. A lighting apparatus, comprising:

a light-emitting diode (LED) chip that includes:

a first doped semiconductor layer;

a light-emitting layer located over the first doped semiconductor layer; and

a second doped semiconductor layer located over the light-emitting layer, wherein the first and second doped semiconductor layers have different types of conductivity;

a phosphor film coated around the LED chip; and

a lens that covers the LED chip and the phosphor film, the lens having a transmittance greater than about 90% and a refractive index between about 1.4 and about 2;

wherein:

the lens includes a plurality of sub-layers; and

the sub-layers have different material compositions.

13. The lighting apparatus of claim 12 , wherein:

one of the sub-layers contains phosphor particles but is free of diffuser particles; and

another one of the sub-layers contains diffuser particles but is free of phosphor particles.

14. The lighting apparatus of claim 12 , wherein;

one of the sub-layers contains yellow phosphor particles; and

another one of the sub-layers contains red phosphor particles.

15. The lighting apparatus of claim 12 , further comprising a substrate on which the light-emitting device is disposed, wherein the substrate comprises a Metal Core Printed Circuit Board (MCPCB) substrate, a ceramic substrate, or a copper substrate.

16. The lighting apparatus of claim 12 , wherein the LED is disposed on a lighting module that is implemented inside a lamp.

17. A lighting apparatus, comprising:

a substrate that is a printed circuit board substrate, a ceramic substrate, or a copper substrate;

a plurality of phosphor-coated light-emitting diode (LED) dies that are disposed over the substrate, wherein the phosphor-coated LED dies each include:

a first doped III-V compound layer;

a multiple quantum well (MQW) layer disposed over the first doped III-V compound layer;

a second doped III-V compound layer disposed over the MQW layer, wherein the first and second doped III-V compound layers have different types of conductivity; and

a phosphor film coated on each of the LED dies; and

a plurality of molded lenses that each house a respective one of the phosphor-coated LED dies within;

wherein:

the molded lenses each have a transmittance greater than about 90% and a refractive index between about 1.4 and about 2;

the molded lenses each include a plurality of sub-layers; and

the sub-layers each contain particles having different characteristics.

18. The lighting apparatus of claim 17 , wherein:

one of the sub-layers contains phosphor particles but is free of diffuser particles; and

another one of the sub-layers contains diffuser particles but is free of phosphor particles.

19. The lighting apparatus of claim 17 , wherein;

one of the sub-layers contains yellow phosphor particles; and

another one of the sub-layers contains red phosphor particles.

20. The lighting apparatus of claim 17 , further comprising a lamp in which the substrate and the one or more LED dies are implemented.