Methods and apparatus for forming uniform layers of phosphor material on an LED encapsulation structure

1. A method for forming a wavelength-conversion LED encapsulant structure, comprising:

forming a layer of a wavelength-conversion material on a first surface;

immersing the first surface in an amount of heat-curable material to cause the wavelength-conversion material to be in contact with a surface region of the heat-curable material;

applying a pressure between the first surface and the surface region of the heat-curable material to embed at least a portion of the wavelength-conversion material in the heat-curable material;

separating the layer of wavelength-conversion material from the first surface; and

applying heat to cure the heat-curable material to produce the wavelength-conversion LED encapsulant structure.

2. The method of claim 1 , wherein the wavelength-conversion material includes phosphor.

3. The method of claim 1 , wherein the wavelength-conversion LED encapsulant structure is a lens.

4. The method of claim 1 , wherein the heat-curable material comprises a silicone material.

5. The method of claim 1 , wherein the heat-curable material comprises a B-stage polymer material.

6. The method of claim 1 , wherein the heat-curable material comprises a thermal plastic material.

7. The method of claim 1 , wherein the heat-curable material comprises a glass material.

8. The method of claim 1 , wherein the heat-curable material comprises at least a surface layer that includes silicone material.

9. The method of claim 1 , wherein the heat-curable material comprises at least a surface layer that includes a B-stage polymer material.

10. The method of claim 1 , wherein the heat-curable material comprises at least a surface layer of a thermal plastic material.

11. The method of claim 1 , wherein the heat-curable material comprises at least a surface layer of a glass.

12. The method of claim 1 , further comprising coating a surface of the heat-curable material with a binder material.

13. The method of claim 1 , further comprising coating the surface of the heat-curable material with a partially cured binder material or a B-stage polymer material.

14. The method of claim 1 , further comprising softening a surface portion of the heat-curable material with a heating process.

15. The method of claim 1 , wherein forming a layer of the wavelength-conversion material on the first surface comprises:

providing an electrostatic field between the first surface and the powder;

disposing the first surface in a proximity of a powder that includes the wavelength-conversion material; and

forming a layer of the wavelength-conversion material on the first surface at least partially by using the electrostatic field.

16. The method of claim 15 , further comprising removing the electrostatic field to allow the powder to transfer to the surface of the heat-curable material.

17. The method of claim 1 , wherein forming the layer of the wavelength-conversion material on the first surface comprises forming the layer of the wavelength-conversion material on a layer of a binder material overlying the first surface.

18. The method of claim 17 , wherein separating the first surface from the heat-curable material causes the layer of the wavelength-conversion material and the layer of the binder material to be attached to the heat-curable material.

19. The method of claim 1 , further comprising forming a second layer of wavelength-conversion material on the wavelength-conversion LED encapsulant structure.

20. The method of claim 19 , wherein the second layer of wavelength-conversion material has a different optical property from the first layer of wavelength-conversion material.

21. The method of claim 20 , further comprising repeated application of two or more layers of wavelength conversion material.

22. The method of claim 1 , wherein the heat-curable material comprises an epoxy material.

23. The method of claim 1 , wherein the heat-curable material is a transparent material.

24. The method of claim 1 , wherein the heat-curable material is a silicone powder.

25. A method for forming a LED encapsulant structure, comprising:

providing a heat-curable material having a surface layer that includes a B-stage polymer;

curing the heat-curable material using a first heating process;

forming a layer of a LED phosphor material on the surface layer of the heat-curable material;

softening the surface layer of the heat-curable material using a second heating process; and

embedding at least a portion of the LED phosphor material at least partially beneath the softened surface layer of the heat-curable material,

wherein forming the layer of the LED phosphor material on the surface layer of the heat-curable material comprises:

forming a layer of the LED phosphor material on a first surface;

embedding at least a portion of the wavelength-conversion material in the heat-curable material by disposing the LED phosphor material on the first surface to be in contact with the surface layer of the heat-curable material; and

separating the first surface from the layer of wavelength-conversion material.

26. The method of claim 25 , wherein forming a layer of the LED phosphor material on the first surface comprises:

disposing the first surface in a proximity of a powder including the LED phosphor material;

providing an electrostatic field between the first surface and the powder; and

forming a layer of the LED phosphor material on the first surface at least partially by using the electrostatic field.

27. The method of claim 25 , wherein forming a layer of the LED phosphor material on the first surface comprises:

disposing the first surface in an interior of a chamber;

forming an airborne distribution of particles of the LED phosphor material in the interior of the chamber in a vicinity of the first surface;

forming electrostatic charges on the first surface; and

forming a layer of the LED phosphor material on the first surface at least partially by using the static electric charges.

28. A method for forming a LED encapsulant structure, comprising:

providing an LED-forming material having a surface layer;

forming a layer of a wavelength converting material on the surface layer of the LED forming material, including:

forming a layer of a wavelength converting material on a first surface; and

transferring the wavelength converting material to the surface layer of the LED-forming material;

softening the surface layer of the LED-forming material using a heating process to at least partially embed beneath the surface of the softened surface layer of the LED-forming material; and

causing at least a portion of the wavelength converting material to be separated from the first surface.

29. The method of claim 28 , wherein the LED-forming material is a transparent material.

30. The method of claim 28 , wherein the LED-forming material comprises a silicone material, a B-stage polymer material, a thermal plastic material, a glass material, or an epoxy material.