Light emitting device, light emitting system comprising the same, and method of fabricating thereof

• US 8,638,046 B2
• Filed: 12/21/2012
• Issued: 01/28/2014
• Est. Priority Date: 03/23/2009
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Hyun
• Primary Examiner(s): Choi, Jacob Y
• Assistant Examiner(s): LUONG, HENRY T
• Application Number:
  US13/723,947
• Publication Number:
  US 20130106284A1
• Time in Patent Office: 403 Days
• Field of Search: 315/291, 315/294, 315/298, 315/311, 315/246
• US Class Current: 315/291
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45139 Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• 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 2924/12044 OLED
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/42 Antiparallel configurations

Abstract

A light emitting device that provides white light of various color temperatures by using a double-sided light emitting element, a light emitting system comprising the same, and a method of fabricating thereof are provided. The light emitting device includes a double-sided light emitting element including a first light emitting element on one side of a substrate and emits light having a first wavelength and a second light emitting element on the other side of the substrate and emits light having a second wavelength, wherein the first wavelength and the second wavelength are different each other, a first variable resistor coupled to the first light emitting element and adjusting a first driving power applied to the first light emitting element, and a second variable resistor coupled to the second light emitting element and adjusting a second driving power applied to the second light emitting element.

Claims

1. A light emitting device comprising:

a support substrate;

a power supply pattern which is disposed on the support substrate to apply a power to a light emitting element; and

a variable resistor for adjusting a driving power applied to the light emitting element, the variable resistor being connected to the power supply pattern and controlled to change a color temperature of white light, wherein the variable resistor includes a resistor pattern, multiple conductive patterns formed on the resistor pattern, and a resistance control wire that connects at least two conductive patterns selected from the multiple conductive patterns.

2. The light emitting device of claim 1, wherein a lead electrode is connected to the power supply pattern through a via formed in the support substrate.

3. The light emitting device of claim 1, wherein the light emitting element includes first and second light emitting elements and the color temperature of white light is changed by adjusting a resistance value of the variable resistor such that the first light emitting element has a maximum light emission efficiency, and the second light emitting element does not have a maximum light emission efficiency.

4. The light emitting device of claim 1, further comprising a phosphor layer including a phosphor.

5. The light emitting device of claim 4, wherein the phosphoris at least one selected from a group consisting of a nitride/oxynitride phosphor, mainly activated by lanthanoids including at least one of Eu and Ce;

an alkaline earth halogen apatite phosphor, mainly activated by lanthanoids or by transition metal elements;

an alkaline earth metal borate halogen phosphor;

an alkaline earth metal aluminate phosphor;

an alkaline earth silicate phosphor;

an alkaline earth sulfide phosphor;

an alkaline earth thiogallate phosphor;

an alkaline earth silicon nitride phosphor;

a germinate phosphor;

a rare earth aluminate phosphor, mainly activated by lanthanoids including Ce;

a rare earth silicate phosphor;

norganic and organic complexes, mainly activated by lanthanoids including Eu;

ZnS;

Eu;

Zn₂GeO₄;

Mn; and

MGa₂S₄;

Eu, wherein M is at least one selected from the group consisting of Sr, Ca, Ba, Mg, and Zn.

6. The light emitting device of claim 5, wherein the nitride phosphor includes at least one selected from the group consisting of M₂Si₅N₈:

Eu, wherein M is at least one selected from the group consisting of Sr, Ca, Ba, Mg, and Zn), MSi₇N₁₀;

Eu, and M₁₈Si₅O_0.2N₈;

Eu, M_0.9Si₇O_0.1N₁₀;

Eu.

7. The light emitting device of claim 5, wherein the oxynitride phosphor includes MSi₂O₂N₂:

Eu, wherein M is at least one selected from the group consisting of Sr, Ca, Ba, Mg, and Zn.

8. The light emitting device of claim 5, wherein the alkaline earth halogen apatite phosphor includes M₅(PO₄)₃X:

R, wherein M is at least one selected from the group consisting of Sr, Ca, Ba, Mg, and Zn, X is at least one selected from the group consisting of F, Cl, Br, and I, and R is at least one selected from the group consisting of Eu and Mn.

9. The light emitting device of claim 5, wherein the alkaline earth metal boron halogen phosphor includes M₂B₅O₉X:

R, wherein M is at least one selected from the group consisting of Sr, Ca, Ba, Mg, and Zn, X is at least one selected from the group consisting of F, Cl, Br, and I, and R is at least one selected from the group consisting of Eu and Mn.

10. The light emitting device of claim 5, wherein the alkaline earth metal aluminate phosphor includes SrAl₂O₄:

R, Sr₄Al₁₄O₂₅;

R, CaAl₂O₄;

R, BaMg₂Al₁₆O₂₇;

R, BaMg₂Al₁₆O₁₂;

R, and BaMgAl₁₀O₁₇;

R, wherein R is at least one selected from the group consisting of Eu and Mn.

11. The light emitting device of claim 5, wherein the alkaline earth sulfide phosphor includes La₂O₂S:

Eu, Y₂O₂S;

Eu, and Gd₂O₂S;

Eu.

12. The light emitting device of claim 5, wherein the rare earth aluminate phosphor includes at least one selected from the group consisting of a YAG-based phosphor including at least one of Y₃Al₅O₁₂:

Ce, (Y_0.8Gd_0.2)₃Al₅O₁₂;

Ce, Y₃(Al_0.8Ga_0.2)O₁₂;

Ce, and (Y, Gd)₃ (Al, Ga)₅ O₁₂, and Tb₃Al₅O₁₂;

Ce and Lu₃Al₅O₁₂;

Ce where a part or whole of Y is substituted by Tb or Lu.

13. The light emitting device of claim 5, wherein the alkaline earth silicate phosphor includes silicate.

14. The light emitting device of claim 1, wherein a resistance value of the variable resistor is controlled by a number of the multiple conductive patterns that conduct current through the resistance control wire.

15. The light emitting device of claim 1 further comprising a lead electrode on which the light emitting element is mounted and a housing into which the lead electrode is inserted, the housing surrounding the light emitting element.

16. The light emitting device of claim 15, wherein the variable resistor is connected to the lead electrode.