Alternating Current Light Emitting Device

• US 20080136347A1
• Filed: 01/28/2008
• Published: 06/12/2008
• Est. Priority Date: 05/13/2005
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Industrial Technology Research Institute
• Inventors: LIN, Ming-Te, YEH, Wen-Yung, YEN, Hsi-Hsuan, LIN, Ming-Yao, HUANG, Sheng-Pan
• Granted Patent: US 8,503,500 B2
• Time in Patent Office: Days
• US Class Current: 315/250
• 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 25/0753 the devices being arranged next to each other
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• 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 device and the fabrication method includes forming one or more light emitting modules on a substrate. The light emitting module receives an alternating current input and has at least two micro diodes. Each micro diode has at least two active layers and is electrically connected by a conductive structure so as to allow the active layers of the micro diodes to alternately emit light during positive and negative cycles of the alternating-current input.

Claims

14. A light emitting device, comprising:

a substrate;

a light emitting module configured to receive an alternating-current input, the light emitting module being formed on the substrate, wherein the light emitting module has a plurality of micro diodes, each micro diode having at least two active layers; and

a conductive structure formed between the micro diodes and electrically connected to each micro diode so as to allow the active layers of the micro diodes to alternately emit light during positive and negative cycles of the alternating-current input.

1. A light emitting device, comprising:

a substrate;

a light emitting module configured to receive an alternating-current input, the light emitting module being formed on the substrate and having at least two micro diodes, each micro diode having at least two active layers; and

a conductive structure formed between the two micro diodes and electrically connected to each micro diode so as to allow the active layers of the micro diodes to alternately emit light during positive and negative cycles of the alternating-current input.

2. The light emitting device of claim 1, wherein the substrate comprises a chip.

3. The light emitting device of claim 1, wherein the substrate comprises an insulating substrate.

4. The light emitting device of claim 1, wherein the active layer comprises a luminescent active layer.

5. The light emitting device of claim 1, wherein the conductive structure comprises a conductor electrically connecting the two micro diodes.

6. The light emitting device of claim 1, wherein the conductive structure is formed as a conductive bridge electrically connecting the micro diodes.

7. The light emitting device of claim 1, wherein the micro diodes or the active layers of the micro diodes are electrically connected by the conductive structure in series or in parallel.

8. The light emitting device of claim 1, wherein the micro diodes or the active layers of the micro diodes emit light at identical or different wavelengths.

9. The light emitting device of claim 1, wherein the active layers of the micro diodes have individual ohmic electrodes.

10. The light emitting device of claim 1, wherein first active layers of one micro diode and its adjacent micro diode alternately emit light during the positive and negative half cycles of alternating current.

11. The light emitting device of claim 1, wherein first active layers of one micro diode and second active layers of its adjacent micro diode alternately emit light during the positive and negative half cycles of alternating current.

12. The light emitting device of claim 1, wherein the micro diodes are fabricated by one of a flip-chip, wafer bonding or an epitaxy technique.

13. The light emitting device of claim 1, further comprising a connection layer between the two active layers.

15. The light emitting device of claim 14, wherein the substrate comprises a chip.

16. The light emitting device of claim 14, wherein the substrate comprises an insulating substrate.

17. The light emitting device of claim 14, wherein the conductive structure is formed as a conductive bridge electrically connecting the micro diodes.

18. The light emitting device of claim 14, further comprising a connection layer between the two active layers.

19. The light emitting device of claim 14, wherein the micro diodes or the active layers of the micro diodes are electrically connected by the conductive structure in series or in parallel.

20. The light emitting device of claim 14, wherein the micro diodes or the active layers of the micro diodes emit light at identical or different wavelengths.

21. The light emitting device of claim 14, wherein the active layers of the micro diodes have individual ohmic electrodes.

22. The light emitting device of claim 14, wherein first active layers of one micro diode and its adjacent micro diode alternately emit light during the positive and negative half cycles of alternating current.

23. The light emitting device of claim 14, wherein first active layers of one micro diode and second active layers of its adjacent micro diode alternately emit light during the positive and negative half cycles of alternating current.

24. The light emitting device of claim 14, wherein a first group of active layers of the micro diode are electrically connected and are arranged on four peripheral arms of a bridge rectifier and a second group of active layers of the micro diode are arranged on a connecting arm connecting first and second diagonally opposed corners of the bridge rectifier to form a bridge light emitting unit.

25. The light emitting device of claim 24 further comprising first and second conductive electrodes being disposed on third and fourth diagonally opposed corners of the bridge rectifier respectively for receiving the alternating-current input.

15-1. The light emitting device of claim 14, wherein the active layer comprises a luminescent active layer.

16-2. The light emitting device of claim 14, wherein the conductive structure comprises a conductor electrically connecting the two micro diodes.