Apparatus for providing radiant energy

• US 5,278,432 A
• Filed: 08/27/1992
• Issued: 01/11/1994
• Est. Priority Date: 08/27/1992
• Status: Expired due to Term

• Current Assignee: Quantum Devices Inc.
• Original Assignee: Quantam Devices Incorporated
• Inventors: Ignatius, Ronald W., Martin, Todd S.
• Primary Examiner(s): Mintel, William
• Assistant Examiner(s): TRAN, MINH LOAN
• Application Number:
  US07/936,570
• Time in Patent Office: 502 Days
• Field of Search: 257/88, 257/98, 257/99, 257/723, 257/706, 257/918, 313/500, 313/512, 362/800, 307/311, 47/DIG. 6
• US Class Current: 257/88
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/19041 being a capacitor
• 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: H01L 33/64 Heat extraction or cooling elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The monolithic hybrid LED array includes a metal heat sink substrate, a ceramic layer on the substrate, and a plurality of series-connected epitaxially-formed LEDs connected by interconnects such as conductive ink strips. The array preferably includes three to six sets of series-connected LEDs that are tightly packed on the substrate. The LEDs are housed in a modular housing having a power regulating circuit and an override feature for overriding the regulator to produce the maximum LED output for brief periods of time. The regulator may continuously vary the light intensity output from the equivalent of 0 to 2000 micromols per second per meter squared.

Claims

1. An array of optoelectronic devices comprising:

a thermally-conductive substrate;

a substantially non-electrically conductive layer disposed on said substrate;

a first optoelectronic device disposed on said layer, including

at least one first heterojunction;

a first electrode interconnected with said first heterojunction;

a second electrode interconnected with said first heterojunction;

a second optoelectronic device disposed on said layer and connected in series with said first optoelectronic device, said second optoelectronic device including

at least one second heterojunction;

a third electrode interconnected with said second heterojunction;

a fourth electrode interconnected with said second heterojunction;

a first electrically-conductive interconnect disposed above said substantially non-conductive layer having a first end in electrical connection with said first electrode and having an opposite interconnect end in electrical connection with said fourth electrode;

a regulator that is adapted to continuously vary the output of said first and second optoelectronic devices; and

override means for briefly overriding said regulator to thereby briefly increase the output of said first and second optoelectronic devices.

2. The array of claim 1, wherein said thermally-conductive substrate is made from a material containing a metal.

3. The array of claim 2, wherein said metal is aluminum or copper.

4. The array of claim 1, wherein said substantially non-electrically conductive material includes a ceramic material.

5. The array of claim 1, wherein said electrically-conductive interconnect is made from a conductive ink.

6. The array of claim 1, further comprising:

a wire connected between said opposite interconnect end and said fourth electrode.

7. The array of claim 1, wherein said at least one first heterojunction includes two heterojunctions.

8. The array of claim 1, wherein said first heterojunction includes a plurality of epitaxial layers.

9. The array of claim 1, wherein said first and second optoelectronic devices are substantially monochromatic.

10. The array of claim 9, wherein said monochromatic devices have a peak wavelength emission in the range of 620 to 680 nanometers.

11. The array of claim 1, wherein said first heterojunction is substantially enclosed in a passivation material.

12. The array of claim 1, wherein said first heterojunction is made from a material containing at least one of gallium aluminum arsenide and silicon carbide.

13. The array of claim 1, further comprising:

a protective coating disposed on said first and second optoelectronic devices and on said interconnect.

14. The array of claim 1, wherein said first and second optoelectronic devices are light emitting diodes.

15. The array of claim 1, wherein said first electrode and said third electrode have a first polarity, and wherein said second electrode and said fourth electrode have a second polarity opposite to said first polarity.

16. The array of claim 1, further comprising:

a third optoelectronic device connected in series with said second optoelectronic device, including a fifth electrode and a sixth electrode;

a second electrically-conductive interconnect disposed above said layer having a first end in electrical connection with said third electrode and having an opposite second interconnect end in electrical connection with said sixth electrode.

17. The apparatus of claim 1, wherein said override means includes:

means for providing maximum output of said first and second optoelectronic devices for a period of 0.3 to 2 seconds.

18. An apparatus that provides radiant energy to at least one living cell, comprising:

a housing;

an array of optoelectronic devices disposed within and supported by said housing, said array including

a thermally-conductive substrate;

a substantially non-electrically conductive layer disposed on said substrate;

a first optoelectronic device disposed on said layer and having a first electrode and a second electrode;

a second optoelectronic device disposed on said layer and having a third electrode and a fourth electrode;

a conductive interconnect disposed above said layer having one end electrically connected to said first electrode and having an opposite end electrically connected to said fourth electrode;

a power source that supplies power to said array;

a regulator that is adapted to continually vary the energy emitted from said array; and

override means for briefly overriding said regulator to thereby briefly increase the energy emitted by said array.

19. The apparatus of claim 18, wherein said first and second optoelectronic devices are light emitting diodes.

20. The apparatus of claim 18, wherein said first electrode and said third electrode have a first polarity, and wherein said second electrode and said fourth electrode have a second polarity opposite to said first polarity.

21. The apparatus of claim 18 wherein said housing has an interior, said apparatus, further comprising:

cooling means for removing heat from the interior of said housing that was transferred from said optoelectronic devices through said thermally-conductive substrate.

22. The apparatus of claim 21, wherein said cooling means includes a fan interconnected with said housing.

23. The apparatus of claim 18, wherein said power source is a DC power supply.

24. The apparatus of claim 18, wherein said radiant energy includes emitted light, and wherein said regulator is adapted to continuously vary said emitted light from between 0 to 2000 micromols per second per meter squared.

25. The apparatus of claim 18, wherein said override means includes:

means for providing maximum energy output for a period of 0.3 to 2 seconds.

26. The apparatus of claim 18, further comprising:

a glass cover disposed above said array and supported by said housing.

27. The apparatus of claim 18, wherein said array includes a plurality of sets of optoelectronic devices, each of said sets having at least two series-connected optoelectronic devices connected by a conductive interconnect.

28. The apparatus of claim 18, wherein said thermally-conductive substrate is made from a material containing a metal.

29. The apparatus of claim 18, wherein said substantially non-electrically conductive material includes a ceramic material.

30. The apparatus of claim 18, wherein said electrically-conductive interconnect is made from a conductive ink.

31. The apparatus of claim 18, wherein said first and second optoelectronic devices are substantially monochromatic.

32. The apparatus of claim 31, wherein said monochromatic devices have a peak wavelength emission in the range of 620 to 680 nanometers.

33. The apparatus of claim 18, further comprising:

a protective coating disposed on said first and second optoelectronic devices and on said conductive interconnect.