Visible light communication LED having a spiral inductance coil and a circle core and preparation method thereof

• US 20180103516A1
• Filed: 04/18/2017
• Published: 04/12/2018
• Est. Priority Date: 10/11/2016
• Status: Active Grant

• Current Assignee: South China Normal University (Guangdong Education Department)
• Original Assignee: South China Normal University (Guangdong Education Department)
• Inventors: SHUN, Huiqing, YANG, Xian, GUO, Zhiyou, HUANG, Yong, HUANG, Hongyong, SUN, Jie, HUANG, Jing, ZHANG, Zhuding, LIU, Yang
• Granted Patent: US 10,237,933 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• 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
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04B 10/502 LED transmitters
• CPC Class Codes: H05B 45/40 Details of LED load circuits

Abstract

A visible light communication LED having a spiral inductance coil and a circular core is provided, comprising a sapphire substrate provided with a positive electrode welding spot and a negative electrode welding spot, and a plurality of LED cores deposited on the sapphire substrate. The negative electrode of a former core is connected with the positive electrode of a latter core, and the positive electrode of the first core and the negative electrode of the last core are respectively connected to the positive electrode welding spot and the negative electrode welding spot on the substrate. According to the present invention, each of the LED cores is surrounded by a spiral inductance coil, and a pin of one end of the spiral inductance coil is connected via a connecting wire with the negative electrode of an adjacent LED core, while the other end is directly connected with the positive electrode of the LED core that is surrounded by the spiral inductance coil.

Claims

1. A visible light communication LED having a spiral inductance coil and a circular core, comprising

a sapphire substrate provided with a positive electrode welding spot and a negative electrode welding spot, and

a plurality of LED cores deposited on the sapphire substrate, wherein

a negative electrode of a former core is connected with a positive electrode of a latter core, and a positive electrode of a first core and a negative electrode of a last core are respectively connected to the positive electrode welding spot and the negative electrode welding spot on the substrate, wherein

each of the LED cores is surrounded by a spiral inductance coil, and one end of the spiral inductance coil is connected with a negative electrode of a LED core that is surrounded by the spiral inductance coil, while the other end of the spiral inductance coil is connected with a positive electrode of an adjacent LED core.

2. The visible light communication LED according to claim 1, comprising sixteen LED cores which are configured to form a 4×

4 matrix.

3. The visible light communication LED according to claim 1, wherein the LED core comprises a GaN/InGaN epitaxial wafer, a transparent conductive layer is provided on a p-type layer of the epitaxial wafer, an annular positive electrode is provided on the transparent conductive layer, and the core is divided into an inner annular emission region, a middle annular emission region and an outer annular emission region by the annular positive electrode.

4. The visible light communication LED according to claim 3, wherein the GaN/InGaN epitaxial wafer comprises from its bottom to top a buffer layer, an n-type layer, a multiple quantum well layer, and a p-type layer.

5. The visible light communication LED according to claim 1, wherein the spiral inductance coil has an inductance value in a range of 20 nH-200 nH.

6. The visible light communication LED according to claim 1, wherein the spiral inductance coil has an outer diameter of 300 μ

m×

300 μ

m, an inner diameter of 170 μ

m×

170 μ

m, a line width of 5 μ

m, and a line distance of 10 μ

m.

7. A preparation method for a visible light communication LED having a spiral inductance coil and a circular core, comprising:

growing a plurality of independent GaN/InGaN epitaxial wafers on a sapphire substrate, and forming a positive electrode welding spot and a negative electrode welding spot on the substrate;

depositing a transparent conductive layer on a p-type layer of the epitaxial wafer by magnetron sputtering, and forming N annular positive electrodes on the transparent conductive layer, thereby providing a plurality of LED cores;

connecting a negative electrode of a former core with a positive electrode of a latter core, and connecting a positive electrode of a first core and a negative electrode of a last core respectively to the positive electrode welding spot and the negative electrode welding spot on the substrate, thereby allowing the plurality of LED cores to form a matrix, and connecting the plurality of LED cores in series;

evaporate plating a spiral inductance coil at periphery of each of the LED cores;

connecting one end of the spiral inductance coil directly with a negative electrode of a LED core that is surrounded by the spiral inductance coil, and connecting a pin of the other end of the spiral inductance coil with a positive electrode of an adjacent LED core.

8. The preparation method according to claim 7, wherein growing a GaN/InGaN epitaxial wafer on a sapphire substrate comprises:

using trimethyl gallium, trimethyl indium and NH₃ as a Ga source, an In source and a N source respectively, and SiH₄ and CP₂Mg as a n-type doping source and a p-type doping source,

performing heat treatment at 1100°

C. in a H₂ atmosphere on the sapphire substrate,

growing a buffer layer at 550°

C.,

heating to 1070°

C. to grow a n-type layer of the epitaxial wafer,

cooling to 760°

C. to grow a quantum well layer,

heating to 970°

C. to grow a p-type layer, and

annealing at 750°

C. in a N₂ atmosphere.

9. The preparation method according to claim 7, wherein evaporate plating a spiral inductance coil at periphery of a core comprises:

sputtering a layer of metal as a marker at a back side of the substrate according to a pre-determined position where the spiral inductance coil is to be installed;

sputtering a seed layer at a front side of the substrate, applying a photoresist, and evaporate plating the spiral inductance coil and an annular electrode after exposing and developing;

removing the photoresist, and removing the seed layer by dry etching;

sputtering another seed layer at the front side of the substrate, applying a photoresist, plating a pin of the spiral inductance coil after exposing and developing, removing the photoresist, and removing the seed layer by dry etching;

applying an insulation protective layer while keeping the pin of the inductance coil uncovered; and

evaporate plating a metal connecting wire on the insulation protective layer, to respectively connect with a negative electrode of a former LED core and a pin of an outer end of a latter spiral inductance coil.

10. The preparation method according to claim 9, wherein the insulation protective layer is a silicon dioxide insulation protective layer.