Dielectric film coating for full conversion ceramic platelets

1. A method for preparing a light emitting device assembly, the method comprising:

providing a LED die; and

attaching a wavelength converter to the LED die, wherein the wavelength converter comprises a phosphor layer and a filter layer, and wherein the wavelength converter is manufactured by:

coating a glass substrate or a sapphire wafer with the filter layer,

laminating the glass substrate or the sapphire wafer to a phosphor material using a glue thereby forming the phosphor layer,

wherein the filter layer is directly attached to the phosphor layer,

wherein the filter layer comprises different metal oxides, and

wherein the wavelength converter has an overall thickness between 20 μm and 120 μm.

2. The method according to claim 1 , wherein the phosphor material is selected from the group consisting of (Ba,Sr) 2 Si 5 N 8 :Eu 2+ , Ca-α-SiAlON:Eu 2+ , YAG:Ce + CaAlSiN 3 :Eu, (Ca,Sr)AlSiN 3 :Eu 2+ , (Sr,Ca)Al 2 Si 2 N 6 :Eu 2+ , (Ba,Sr,Ca) 2 Si 5 N 8 :Eu 2+ and Sr(LiAl 3 N 4 ):Eu 2 .

3. The method according to claim 1 , wherein the metal oxides are selected from the group consisting of SiO 2 , Al 2 O 3 , TiO 2 , Nb 2 O 5 , Ta 2 O 5 , HfO 2 , and Y 2 O 3 .

4. The method according to claim 1 , wherein the LED die comprises GaN/InGaN based semiconductor materials.

5. The method according to claim 1 , wherein the wavelength converter has an overall thickness between 20 μm and 80 μm.

6. The light emitting device assembly prepared according to the method of claim 1 .

7. A method for preparing a wavelength converter, the method comprising:

providing a glass substrate;

coating the glass substrate with a filter layer comprising different metal oxides to prepare a coated glass substrate;

providing a phosphor material; and

attaching the coated glass substrate to the phosphor material, thereby providing the wavelength converter comprising a phosphor layer,

wherein attaching the coated glass substrate to the phosphor material comprises laminating the coated glass substrate to the phosphor material with a glue,

wherein the filter layer is directly attached to the phosphor layer, and

wherein the wavelength converter has an overall thickness between 20 μm and 120 μm.

8. The method according to claim 7 , wherein the phosphor material is selected from the group consisting of (Ba,Sr) 2 Si 5 N 8 :Eu 2+ , Ca-α-SiAlON:Eu 2+ , YAG:Ce+CaAlSiN 3 :Eu, (Ca,Sr)AlSiN 3 :Eu 2+ , (Sr,Ca)Al 2 Si 2 N 6 :Eu 2+ , (Ba,Sr,Ca) 2 Si 5 N 8 :Eu 2+ and Sr(LiAl 3 N 4 ):Eu 2 .

9. The method according to claim 7 , wherein the metal oxides are selected from the group consisting of SiO 2 , Al 2 O 3 , TiO 2 , Nb 2 O 5 , Ta 2 O 5 , HfO 2 , and Y 2 O 3 .

10. The method according to claim 7 , further comprising attaching an absorption layer to the wavelength converter.

11. The method according to claim 7 , wherein the wavelength converter has an overall thickness between 20 μm and 80 μm.

12. The method according to claim 7 , further comprising dicing the wavelength converter.

13. The wavelength converter prepared according to the method of claim 7 .

14. A method for preparing a wavelength converter, the method comprising:

providing a sapphire wafer;

coating the sapphire wafer with a filter layer comprising different metal oxides to prepare a coated sapphire wafer;

providing a phosphor material; and

attaching the coated sapphire wafer to the phosphor material, thereby providing the wavelength converter comprising a phosphor layer,

wherein attaching the coated sapphire wafer to the phosphor material comprises laminating the coated sapphire wafer to the phosphor material with a glue,

wherein the filter layer is directly attached to the phosphor layer, and

wherein the wavelength converter has an overall thickness between 20 μm and 120 μm.

15. The method according to claim 14 , wherein the phosphor material is selected from the group consisting of (Ba,Sr) 2 Si 5 N 8 :Eu 2+ , Ca-α-SiAlON:Eu 2+ , YAG:Ce + CaAlSiN 3 :Eu, (Ca,Sr)AlSiN 3 :Eu 2+ , (Sr,Ca)Al 2 Si 2 N 6 :Eu 2+ , (Ba,Sr,Ca) 2 Si 5 N 8 :Eu 2+ and Sr(LiAl 3 N 4 ):Eu 2 .

16. The method according to claim 14 , wherein the metal oxides are selected from the group consisting of SiO 2 , Al 2 O 3 , TiO 2 , Nb 2 O 5 , Ta 2 O 5 , HfO 2 , and Y 2 O 3 .

17. The method according to claim 14 , wherein the wavelength converter has an overall thickness between 20 μm and 80 μm.

18. The method according to claim 14 , further comprising attaching an absorption layer to the wavelength converter.

19. The method according to claim 14 , further comprising dicing the wavelength converter.

20. The wavelength converter prepared according to the method of claim 14 .