Surface-Mounted Light-Emitting Device and Fabrication Method Thereof

• US 20170084808A1
• Filed: 12/03/2016
• Published: 03/23/2017
• Est. Priority Date: 05/24/2013
• Status: Active Grant

• Current Assignee: Quanzhou Sanan Semiconductor Technology Co., Ltd. (Sanan Optoelectronics Company Limited)
• Original Assignee: Xiamen Sanan Optoelectronics Technology Company Limited (Sanan Optoelectronics Company Limited)
• Inventors: Huang, Shaohua, Zeng, Xiaoqiang, Chao, Chih-Wei
• Granted Patent: US 10,559,732 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• 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 surface-mounted light-emitting device is fabricated by epitaxial growth: forming the LED epitaxial structure over a growth substrate through epitaxial growth; chip fabrication: determining P and N electrode regions and an isolating region over the LED epitaxial structure surface and fabricating the P and N electrode pads and the insulator over the P and N electrode regions and the isolating region, wherein the P and N electrode pads have sufficient thicknesses to support the LED epitaxial structure, and the insulator is formed between the P and N electrode pads to prevent the P and N electrode pads from a short circuit; removing the growth substrate and unitizing the LED epitaxial structure to form the chip; and SMT packaging: providing the supporting substrate and directly mounting the P and N electrode pads of the chip over the supporting substrate through SMT packaging to thereby form the surface-mounted LED light-emitting device.

Claims

1. A method of fabricating a surface-mounted light-emitting diode (LED) light-emitting device, the method comprising:

1) epitaxial growth;

form an LED epitaxial structure over a growth substrate through epitaxial growth;

2) chip fabrication;

determine P and N electrode regions and an isolating region over the LED epitaxial structure surface and fabricate P and N electrode pads and an insulator over the P and N electrode regions and the isolating region, wherein the P and N electrode pads have sufficient thicknesses to support the LED epitaxial structure, and the insulator is formed between the P and N electrode pads to prevent the P and N electrode pads from a short circuit;

remove the growth substrate and unitize the LED epitaxial structure to form a LED chip;

3) SMT packaging;

provide a supporting substrate and directly mount the P and N electrode pads of the LED chip over the supporting substrate through SMT packaging to thereby form a surface-mounted LED light-emitting device.

2. The method of claim 1, wherein in step 2), the formed insulator has opposite a first insulator surface and a second insulator surface, wherein the first surface is adjacent to the LED epitaxial structure and the second surface extrudes beyond either of the second electrode surfaces of the P and N electrode pads to prevent the P and N electrode pads from short circuiting when directly applied in the SMT packaging.

3. The method of claim 2, wherein in step 2), a melting point or softening point of the insulator material is lower than melting points of the P and N electrode pads.

4. The method of claim 2, wherein in step 3), the supporting substrate has a surface coated with a solder layer with a thickness smaller than or equal to a height difference between the second insulator surface and either of the second electrode surfaces of the P and N electrode pads, wherein the insulator extends through the solder layer and is in contact with the solder layer and the supporting substrate, wherein a distance between edges of the P and N electrode pads beyond that of the LED epitaxial structure is D, a minimum thickness of the P and N electrode pads is T, and wherein D/T is 0.5-2.

5. The method of claim 1, wherein the insulator comprises a colloid material.

6. The method of claim 1, wherein in step 2), after the growth substrate is removed, the method further comprising etching the LED epitaxial structure to form a cutting path, and physically cutting the electrode pads over the cutting path to ensure that edges of the P and N electrode pads are beyond an edge of the LED epitaxial structure with a specified distance, thereby forming a series of LED chips.

7. The method of claim 1, wherein in step 3), the P and N electrode pads of the LED chip are connected to the supporting substrate through reflow soldering.

8. A surface-mounted light-emitting diode (LED) light-emitting device, comprising a chip and a supporting substrate, wherein the chip comprises:

an LED epitaxial structure having opposite a first surface and a second surface, wherein the first surface is a light-emitting surface;

P and N electrode pads over the second surface of the epitaxial structure, which has a sufficient thickness to support the LED epitaxial structure, and the P and N electrode pads each have opposite a first electrode surface and a second electrode surface, respectively, wherein the first electrode surface is adjacent to the LED epitaxial structure;

an insulator between the P and N electrode pads to prevent the P and N electrode pads from a short circuit; and

wherein the chip is directly mounted over the supporting substrate via the P and N electrode pads through SMT packaging; and

wherein the light-emitting device is fabricated using a method comprising;

1) epitaxial growth;

forming the LED epitaxial structure over a growth substrate through epitaxial growth;

2) chip fabrication;

determining P and N electrode regions and an isolating region over the LED epitaxial structure surface and fabricating the P and N electrode pads and the insulator over the P and N electrode regions and the isolating region, wherein the P and N electrode pads have sufficient thicknesses to support the LED epitaxial structure, and the insulator is formed between the P and N electrode pads to prevent the P and N electrode pads from a short circuit;

removing the growth substrate and unitizing the LED epitaxial structure to form the chip;

3) SMT packaging;

providing the supporting substrate and directly mounting the P and N electrode pads of the chip over the supporting substrate through SMT packaging to thereby form the surface-mounted LED light-emitting device.

9. The light-emitting device of claim 8, wherein the insulator has opposite a first and a second insulator surfaces, wherein the first insulator surface is adjacent to the LED epitaxial structure and the second insulator surface extrudes beyond either of the second electrode surfaces of the P and N electrode pads to prevent the P and N electrode pads from a short circuit when directly applied in the SMT package, wherein the light-emitting device further comprises a solder layer in contact with and between the supporting substrate and the P and N electrode pads;

and wherein the insulator extends through the solder layer and is in contact with the solder layer and the supporting substrate.

10. The light-emitting device of claim 9, wherein a melting point or softening point of the insulator is lower than melting points of the P and N electrode pads.

11. The light-emitting device of claim 9, wherein the insulator comprises a colloid material.

12. The light-emitting device of claim 9, wherein a height difference between the second insulator surface and either of the second electrode surfaces of the P and N electrode pads is 20 μ

m-100 μ

m.

13. The light-emitting device of claim 8, wherein edges of the P and N electrode pads are beyond that of the LED epitaxial structure to serve as a supporting structure of the epitaxial structure.

14. The light-emitting device of claim 13, wherein a distance that edges of the P and N electrode pads are beyond that of the LED epitaxial structure is equal to or larger than 30 μ

m to prevent a side wall of LED epitaxial structure from short circuit when the P and N electrode pads are directly mounted over the supporting substrate via SMT soldering.

15. The light-emitting device of claim 8, wherein the second electrode surfaces of the P and N electrode pads are at the same level.

16. The light-emitting device of claim 8, wherein a gap between the P and N electrode pads is 20-150 μ

m.

17. The light-emitting device of claim 8, wherein the P and N electrode pads are thicker than 50 μ

m to support the LED epitaxial structure.

18. The light-emitting device of claim 8, wherein areas of the P and N electrode pads are substantially same.

19. The light-emitting device of claim 8, wherein the P and N electrode pads and the insulator cover an entire surface of the LED epitaxial structure.

20. The light-emitting device of claim 8, wherein the P and N electrode pads and the insulator are closely jointed.