LIGHT-EMITTING DIODE

• US 20150097202A1
• Filed: 12/01/2014
• Published: 04/09/2015
• Est. Priority Date: 10/01/2008
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Formosa Epitaxy Incorporated (Ennostar, Inc.)
• Inventors: Cheng, Wei-Kang, Pan, Shyi-Ming, Li, Jia-Lin, Huang, Kuo-Chin
• Granted Patent: US 9,324,694 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• 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
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light-emitting diode (LED) is provided. An LED die includes a first semiconductor layer, a light-emitting layer, a second semiconductor layer, a first electrode and a second electrode. At least a part of the first semiconductor is exposed from the light emitting layer and the second semiconductor layer. The first electrode and the second electrode is disposed on top of the exposed first semiconductor layer and the second semiconductor layer respectively. At least two metal pads are disposed on top of the first electrode and the second electrode of the LED die respectively. Each of the metal pads has a side surface. A fluorescent layer is disposed on a surface of the LED die. The fluorescent layer directly contacts with the side surfaces of the metal pads and fills a gap between the metal pads.

Claims

1. A light-emitting diode (LED), comprising:

an LED die comprising;

a first semiconductor layer;

a light-emitting layer disposed on the first semiconductor layer;

a second semiconductor layer disposed on the light-emitting layer, wherein at least a part of the first semiconductor is exposed from the light emitting layer and the second semiconductor layer; and

a first electrode and a second electrode disposed on top of the exposed first semiconductor layer and the second semiconductor layer respectively;

at least two metal pads disposed on top of said first electrode and said second electrode of said LED die respectively, wherein each of the metal pads has a side surface; and

a fluorescent layer disposed on a surface of said LED die, wherein the fluorescent layer directly contacts with the side surfaces of the metal pads and fills a gap between the metal pads, and the top surface of the fluorescent layer is flat in a cross-section view, and the thickness of the fluorescent layer is greater than 30 μ

m, and all side surfaces of the fluorescent layer are respectively aligned with all outer side surfaces of the LED die.

2. The LED of claim 1, wherein the materials of the fluorescent layer include fluorescent powders and an organic polymer material, and the materials of said fluorescent powders are chosen from the group comprising red fluorescent powders, green fluorescent powders, blue fluorescent powders, and the combination of the fluorescent powders described above.

3. The LED of claim 1 further comprising:

a carrier is disposed on a side of the LED, and the carrier faces the fluorescent layer.

4. The LED of claim 3 further comprising:

a plurality of wires connected to the metal pads, respectively.

5. The LED of claim 4 further comprising:

a packaging glue disposed on the carrier, wherein the packaging glue covers the LED die, the metal pads and the fluorescent layer.

6. The LED of claim 5, wherein the material of the packaging glue is organic polymer.

7. The LED of claim 6, wherein the material of the packaging glue further comprises fluorescent powders.

8. The LED of claim 1, wherein said LED die has a plurality of chips.

9. The LED of claim 1, wherein the material of said fluorescent layer comprises a material selected from organic materials.

10. The LED of claim 1, wherein a thickness of the fluorescent layer is thicker than a thickness of the second electrode plus a thickness of the metal pad on top of the second electrode.

11. The LED of claim 1, wherein the fluorescent layer fills a gap between the first electrode and the light-emitting layer and a gap between the first electrode and the second semiconductor layer.

12. A light-emitting diode (LED), comprising:

an LED die comprising;

a first semiconductor layer;

a light-emitting layer disposed on the first semiconductor layer;

a second semiconductor layer disposed on the light-emitting layer, wherein at least a part of the first semiconductor is exposed from the light emitting layer and the second semiconductor layer; and

a first electrode and a second electrode disposed on top of the exposed first semiconductor layer and the second semiconductor layer respectively;

at least two metal pads disposed on top of said first electrode and said second electrode of said LED die respectively, wherein each of the metal pads has a side surface; and

a fluorescent layer disposed on a surface of said LED die, wherein the fluorescent layer directly contacts with the side surfaces of the metal pads and fills a gap between the metal pads, and the top surface of the fluorescent layer is parallel to the top surface of the light-emitting layer in a cross-section view, and the thickness of the fluorescent layer is greater than 30 μ

m, and all side surfaces of the fluorescent layer are respectively aligned with all outer side surfaces of the LED die.

13. The LED of claim 12, wherein the materials of the fluorescent layer include fluorescent powders and an organic polymer material, and the materials of said fluorescent powders are chosen from the group comprising red fluorescent powders, green fluorescent powders, blue fluorescent powders, and the combination of the fluorescent powders described above.

14. The LED of claim 12 further comprising:

a carrier is disposed on a side of the LED, and the carrier faces the fluorescent layer.

15. The LED of claim 14 further comprising:

a plurality of wires connected to the metal pads, respectively.

16. The LED of claim 15 further comprising:

a packaging glue disposed on the carrier, wherein the packaging glue covers the LED die, the metal pads and the fluorescent layer.

17. The LED of claim 16, wherein the material of the packaging glue is organic polymer.

18. The LED of claim 17, wherein the material of the packaging glue further comprises fluorescent powders.

19. The LED of claim 12, wherein said LED die has a plurality of chips.

20. The LED of claim 12, wherein the material of said fluorescent layer comprises a material selected from organic materials.

21. The LED of claim 12, wherein a thickness of the fluorescent layer is thicker than a thickness of the second electrode plus a thickness of the metal pad on top of the second electrode.

22. The LED of claim 12, wherein the fluorescent layer fills a gap between the first electrode and the light-emitting layer and a gap between the first electrode and the second semiconductor layer.