Semiconductor light emitting devices including a luminescent conversion element
Methods of packaging a semiconductor light emitting device include dispensing a first quantity of encapsulant material into a cavity including the light emitting device. The first quantity of encapsulant material in the cavity is treated to form a hardened upper surface thereof having a selected shape. A luminescent conversion element is provided on the upper surface of the treated first quantity of encapsulant material. The luminescent conversion element includes a wavelength conversion material and has a thickness at a middle region of the cavity greater than proximate a sidewall of the cavity.
1. A packaged semiconductor light emitting device, comprising:
a body having a sidewall portion defining a cavity;
a light emitting device positioned in the cavity;
a first quantity of cured encapsulant material in the cavity including the light emitting device; and
a luminescent conversion element on an upper surface of the first quantity of encapsulant material, the luminescent conversion element including a wavelength conversion material and having a thickness at a middle region of the cavity greater than at a region proximate a sidewall of the cavity, wherein a variation in the thickness of the luminescent conversion element as the luminescent conversion element extends radially outward from the middle region to the sidewall is selected to provide a desired total correlated color temperature (CCT) variation.
2. The device of claim 1 wherein the thickness of the luminescent conversion element continuously decreases as the luminescent conversion element extends radially outward from the middle region to the sidewall.
3. The device of claim 1 wherein the thickness of the luminescent conversion element varies by more than ten percent of a maximum thickness of the luminescent conversion element.
4. The device of claim 1 wherein the luminescent conversion element has a biconvex, plano-convex or concavo-convex shape.
5. The device of claim 1 wherein the light emitting device comprises a light emitting diode (LED).
6. The device of claim 1 wherein the device has a minimum color temperature no more than 30 percent below a maximum color temperature thereof over a 180 (+/−90 from central axis)-degree range of emission angles.
7. The device of claim 1 wherein the device has a primary emission pattern having a total correlated color temperature (CCT) variation of less than about 1000K over a 180 (+/−90 from central axis)degree range of emission angles.
8. The device of claim 1 wherein the device has a primary emission pattern having a total CCT variation of about 500K over a 180 (+/−90 from central axis)-degree range of emission angles.
9. The device of claim 1 wherein the device has a primary emission pattern having a total correlated color temperature (CCT) variation of less than about 1000K over a 120 (+/−45 from central axis)-degree range of emission angles.
10. The device of claim 1 wherein the device has a primary emission pattern having a total correlated color temperature (CCT) variation of less than about 500K over a 90 (+/−45 from central axis)-degree range of emission angles.
11. The device of claim 1 wherein the body comprises a reflector and wherein the cavity comprises a reflective cavity.
12. A packaged semiconductor light emitting device, comprising:
a body having a sidewall portion defining a cavity;
a light emitting device positioned in the cavity;
a first quantity of cured encapsulant material in the cavity including the light emitting device; and
a luminescent conversion element having a piano-convex shape with a convex surface extending away from the light emitting device or a concavo-convex shape on an upper surface of the first quantity of encapsulant material, the luminescent conversion element including a wavelength conversion material and having a thickness at a middle region of the cavity greater than at a region proximate a sidewall of the cavity, wherein the first quantity of encapsulant material has an index of refraction different from an index of refraction of the luminescent conversion element and wherein the thickness of the luminescent conversion element is selected to compensate for variations in a light path length of light from the light emitting device caused by an interface between the luminescent conversion element and the first quantity of cured encapsulant material.
13. The device of claim 12 wherein the thickness of the luminescent conversion element continuously decreases as the luminescent conversion element extends radially outward from the middle region to the sidewall.
14. The device of claim 12 wherein the thickness of the luminescent conversion element varies by more than ten percent of a maximum thickness of the luminescent conversion element.
15. The device of claim 12 wherein the device has a minimum color temperature no more than 30 percent below a maximum color temperature thereof over a 180 (+/−90 from central axis)-degree range of emission angles.
16. The device of claim 12 wherein the device has a primary emission pattern having a total correlated color temperature (CCT) variation of less than about 1000K over a 180 (+/−90 from central axis)-degree range of emission angles.
17. The device of claim 12 wherein the device has a primary emission pattern having a total CCT variation of about 500K over a 180 (+/−90 from central axis)-degree range of emission angles.
18. The device of claim 12 wherein the device has a primary emission pattern having a total correlated color temperature (CCT) variation of less than about 1000K over a 120 (+/−45 from central axis)-degree range of emission angles.
19. The device of claim 12 wherein the device has a primary emission pattern having a total correlated color temperature (CCT) variation of less than about 500K over a 90 (+/−45 from central axis)-degree range of emission angles.
20. The device of claim 12 , further comprising a lens contacting the luminescent conversion element, wherein the luminescent conversion element acts as a mechanical stop for the lens.
21. The device of claim 12 , wherein the first quantity of encapsulant material includes a scattering material selected to increase angular uniformity of light emission from the packaged semiconductor light emitting device.
22. A packaged semiconductor light emitting device, comprising:
a substrate;
a light emitting device positioned on the substrate;
a first quantity of cured encapsulant material on the light emitting device; and
a luminescent conversion element on an upper surface of the first quantity of encapsulant material, the luminescent conversion element including a wavelength conversion material and having a thickness over a middle region of the light emitting device greater than over a region displaced from the middle region, wherein a variation in the thickness of the luminescent conversion element as the luminescent conversion element extends radially outward from the middle region to the region displaced therefrom is selected to provide a desired total correlated color temperature (CCT) variation.
23. A packaged semiconductor light emitting device, comprising:
a substrate;
a light emitting device positioned on the substrate;
a first quantity of cured encapsulant material on the light emitting device; and
a luminescent conversion element having a plano-convex shape with a convex surface extending away from the light emitting device or a concavo-convex shape on an upper surface of the first quantity of encapsulant material, the luminescent conversion clement including a wavelength conversion material and having a thickness over a middle region of the light emitting device greater than over a region displaced from the middle region.