WHITE LED PACKAGE STRUCTURE HAVING A SILICON SUBSTRATE AND METHOD OF MAKING THE SAME

• US 20080191605A1
• Filed: 04/18/2007
• Published: 08/14/2008
• Est. Priority Date: 02/08/2007
• Status: Active Grant

• Current Assignee: Walsin Lihwa Corporation
• Original Assignee: TOUCH MICRO-SYSTEM TECHNOLOGY CORP. (Walsin Lihwa Corporation)
• Inventors: Lin, Hung-Yi, Chang, Hong-Da
• Granted Patent: US 7,741,772 B2
• Time in Patent Office: Days
• US Class Current: 313/501
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 33/50 Wavelength conversion elements

Abstract

A white light emitting diode package structure having a silicon substrate is disclosed. The white light emitting diode package structure comprises a silicon substrate having a plurality of cup-structures thereon, one of a plurality of blue light emitting diodes is respectively disposed in each cup-structure, and a phosphor structure covering the silicon substrate and the cup-structures. The blue light emitting diodes have various wavelengths and the phosphor structure has a plurality of kinds of phosphor powders and a sealing material. Each kind of phosphor powder is able to convert blue light within a certain wavelength into yellow light.

Claims

1. A white LED package structure having a silicon substrate comprising:

a silicon substrate having a plurality of cup-structures thereon;

a reflective layer covering a top surface of the silicon substrate;

a transparent insulating layer covering the reflective layer;

a plurality of metal bumps respectively disposed on the transparent insulating layer in each cup-structure;

a plurality of electrodes disposed on the silicon substrate between the cup-structures;

a plurality of blue LEDs having a plurality of various wavelengths, respectively disposed on each metal bump in each cup-structure, and the blue LEDs electrically connected to the electrodes; and

a phosphor structure covering the cup-structures of the silicon substrate, the phosphor structure comprising a plurality of kinds of phosphor powders and a sealing material, and each kind of the phosphor powder capable of converting blue light within certain wavelength into yellow light.

2. The white LED package structure of claim 1, wherein a top view shape of each cup-structure is geometric.

3. The white LED package structure of claim 1, wherein the cup-structures are arranged in a rectangular array.

4. The white LED package structure of claim 1, wherein a distance between the adjacent cup-structures is substantially less than 10 micrometer.

5. The white LED package structure of claim 1, wherein the wavelengths of the blue LEDs comprises three specifications, 450±

5 μ

m, 460±

5 μ

m and 470±

5 μ

m.

6. The white LED package structure of claim 1, wherein a shape of the phosphor structure is a flattop pyramid-shaped, a top surface of the flattop pyramid is flat, and sidewalls of the flattop pyramid are inclined.

7. The white LED package structure of claim 1, wherein sidewalls of each cup-structure are inclined.

8. The white LED package structure of claim 1, wherein the reflective layer is a metal or an optical film.

9. A method of making a white LED package structure having a silicon substrate comprising:

providing a silicon substrate, and performing an etching process to form a plurality of cup-structures on a top surface of the silicon substrate;

forming a reflective layer on the top surface of the silicon substrate;

forming a transparent insulating layer on the reflective layer;

forming a plurality of metal bumps on the transparent insulating layer respectively in each cup-structure, and forming a plurality of electrodes on the transparent insulating layer between the cup-structures;

respectively bonding a plurality of blue LEDs on each metal bump in each cup-structure, and electrically connecting respectively the blue LEDs to the electrodes, wherein the blue LEDs have various wavelengths; and

mixing a plurality of kinds of phosphor powders corresponding to the wavelengths of the blue LEDs and adding a sealing material, and then, performing a sealing process to form a phosphor structure on the cup-structures.

10. The method of claim 9, wherein each cup-structure has inclined sidewalls.

11. The method of claim 10, wherein the etching process making the inclined sidewalls of the cup-structures comprises a reactive ion etching process.

12. The method of claim 10, wherein the etching process making the inclined sidewalls of the cup-structures comprises a Bosch process.

13. The method of claim 10, wherein the etching process making the inclined sidewalls of the cup-structures comprises a wet etching process utilizing KOH solution as an etching solution.

14. The method of claim 10, wherein the etching process making the inclined sidewalls of the cup-structures comprises a wet etching process utilizing TMAH solution as an etching solution.

15. The method of claim 10, wherein the etching process making the inclined sidewalls of the cup-structures comprises a wet etching process utilizing EDP solution as an etching solution.

16. The method of claim 10, wherein the reflective layer is formed on the silicon substrate by sputtering, evaporation or chemical deposition.

17. The method of claim 9, wherein the transparent insulating layer is formed on the silicon substrate by sputtering, evaporation or chemical deposition.

18. The method of claim 9, wherein the metal bumps are formed on the transparent insulating layer by lift-off.

19. The method of claim 9, wherein the metal bumps are formed on the transparent insulating layer by electroplating.

20. The method of claim 9, wherein the blue LEDs are bonded on the metal bumps by die attachment using glass frit.

21. The method of claim 9, wherein the sealing process is a molding process.

22. The method of claim 9, wherein the sealing process is an encapsulating process.

23. A method of making a white LED package structure having a silicon substrate comprising:

providing a silicon substrate, and performing an etching process to form a plurality of cup-structures on a top surface of the silicon substrate;

forming a reflective layer on the top surface of the silicon substrate;

forming a transparent insulating layer on the reflective layer;

forming a conductive layer on the transparent insulating layer;

respectively bonding a plurality of blue LEDs on the conductive layer in each cup-structure, wherein the blue LEDs have various wavelengths; and

mixing a plurality of kinds of phosphor powders corresponding to the wavelengths of the blue LEDs and adding a sealing material, and then performing a sealing process to form a phosphor structure on the cup-structures.

24. The method of claim 23, wherein each cup-structure has inclined sidewalls.

25. The method of claim 24, wherein the etching process fabricating the inclined sidewalls of the cup-structures comprises a reactive ion etching process.

26. The method of claim 24, wherein the etching process fabricating the inclined sidewalls of the cup-structures comprises a Bosch process.

27. The method of claim 24, wherein the etching process fabricating the inclined sidewalls of the cup-structures comprises a wet etching process utilizing KOH solution as an etching solution.

28. The method of claim 24, wherein the etching process fabricating the inclined sidewalls of the cup-structures comprises a wet etching process utilizing TMAH solution as an etching solution.

29. The method of claim 24, wherein the etching process fabricating the inclined sidewalls of the cup-structures comprises a wet etching process utilizing EDP solution as an etching solution.

30. The method of claim 23, wherein the reflective layer is formed on the silicon substrate by sputtering, evaporation or chemical deposition.

31. The method of claim 23, wherein the transparent insulating layer is formed on the silicon substrate by sputtering, evaporation or chemical deposition.

32. The method of claim 23, wherein the conductive layer are formed on the transparent insulating layer by lift-off.

33. The method of claim 23, wherein the conductive layer are formed on the transparent insulating layer by electroplating.

34. The method of claim 23, wherein the blue LEDs are bonded on the metal bumps by flip chip attachment.

35. The method of claim 23, wherein the sealing process is a molding process.

36. The method of claim 23, wherein the sealing process is an encapsulating process.