Methods for the Production of Luminescent Diode Chips and Luminescent Diode Chip

• US 20080203410A1
• Filed: 08/04/2005
• Published: 08/28/2008
• Est. Priority Date: 09/30/2004
• Status: Abandoned Application

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Brunner, Herbert, Hahn, Berthold, Eissler, Dieter, Harle, Volker, Waitl, Gunter, Jager, Harald, Krauter, Gertrud
• Application Number:
  US11/576,057
• Publication Number:
  US 20080203410A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material

Abstract

The invention relates to a method of making LED chips provided with a luminescence conversion material containing at least one phosphor. In the method, a layer composite is prepared that includes an LED layer sequence for a multiplicity of LED chips and comprises on a main surface at least one electrical contact surface for each LED chip, for electrically connecting said chip. A layer of adhesion promoter is applied to the main surface and selectively removed from at least portions of the contact surfaces. At least one phosphor is then applied to the main surface. Alternatively, a luminescence conversion material is applied to the main surface and selectively removed from at least portions of the contact surfaces. The invention also relates to an LED chip provided with a luminescence conversion material.

Claims

1. A method of making LED chips provided with a luminescence conversion material containing at least one phosphor, comprising the steps of:

preparing a layer composite that includes an LED layer sequence intended for a multiplicity of LED chips and comprising on a main surface at least one electrical contact surface for each said LED chip, for electrically connecting the respective said LED chips;

applying a layer of adhesion promoter to said main surface of said layer composite;

selectively removing said adhesion promoter from at least portions of said contact surfaces; and

applying at least one phosphor to said main surface of said layer composite.

3. The method as in claim 1, wherein said LED layer sequence comprises an epitaxially grown semiconductor layer sequence applied to a carrier.

4. The method as in claim 1, wherein said phosphor or said luminescence conversion material is applied by doctor blading.

5. The method as in claim 1, wherein said phosphor or said luminescence conversion material is applied by immersion in a converter material containing said phosphor or said luminescence conversion material or a precursor thereof.

6. The method as in claim 1, wherein said phosphor or said luminescence conversion material is applied by means of an electrostatic powder spraying process.

8. The method as in claim 1, wherein said phosphor or said luminescence conversion material is applied by atomizing a converter material containing said phosphor or said luminescence conversion material or a precursor thereof.

9. The method as in claim 8, wherein said atomization takes place with the use of volatile propellants and/or a current of air.

10. The method as in claim 8, wherein the application of said phosphor or of said luminescence conversion material by atomization takes place more than once.

11. The method as in claim 1, wherein said adhesion promoter or said luminescence conversion material is removed by means of a lithographic process.

12. The method as in claim 11, wherein said adhesion promoter or said luminescence conversion material is removed by means of a photolithographic process.

13. The method as in claim 11, wherein said lithographic process includes the use of a prefabricated mask.

14. The method as in claim 1, wherein said adhesion promoter or said luminescence conversion material is removed with the use of laser radiation.

2. A method of making LED chips provided with a luminescence conversion material containing at least one phosphor, comprising the steps of:

preparing a layer composite that includes an LED layer sequence intended for a multiplicity of LED chips and comprising on a main surface at least one electrical contact surface for each said LED chip, for electrically connecting the respective said LED chips;

applying a luminescence conversion material to said main surface of said layer composite; and

selectively removing said luminescence conversion material from at least portions of said contact surfaces.

7. The method as in claim 2, wherein said luminescence conversion material is applied by means of a powder painting process.

17. The method as in claim 2, wherein said LED layer sequence comprises an epitaxially grown semiconductor layer sequence applied to a carrier.

18. The method as in claim 2, wherein said phosphor or said luminescence conversion material is applied by doctor blading.

19. The method as in claim 2, wherein said phosphor or said luminescence conversion material is applied by immersion in a converter material containing said phosphor or said luminescence conversion material or a precursor thereof.

20. The method as in claim 2, wherein said phosphor or said luminescence conversion material is applied by means of an electrostatic powder spraying process.

21. The method as in claim 2, wherein said phosphor or said luminescence conversion material is applied by atomizing a converter material containing said phosphor or said luminescence conversion material or a precursor thereof.

22. The method as in claim 21, wherein said atomization takes place with the use of volatile propellants and/or a current of air.

23. The method as in claim 2, wherein said adhesion promoter or said luminescence conversion material is removed by means of a lithographic process.

24. The method as in claim 2, wherein said adhesion promoter or said luminescence conversion material is removed with the use of laser radiation.

15. An LED chip comprising on a main surface at least one electrical contact surface, and wherein said main surface is provided with a luminescence conversion material, characterized in that said luminescence conversion material comprises a clearance such that said electrical contact surface is exposed.

16. The LED chip as in claim 15, characterized in that said luminescence conversion material is partially or completely covered with a protective layer.