High efficiency solid-state light source and methods of use and manufacture

• US 20050152146A1
• Filed: 11/08/2004
• Published: 07/14/2005
• Est. Priority Date: 05/08/2002
• Status: Active Grant

• Current Assignee: Phoseon Technology, Inc.
• Original Assignee: Silicon Valley Bank (SVB Financial Group)
• Inventors: Vlach, Francois, McNeil, Tom, Owen, Mark D.
• Granted Patent: US 8,192,053 B2
• Time in Patent Office: Days
• US Class Current: 362/294
• CPC Class Codes: A61L 2/0047 Ultraviolet radiation
• CPC Class Codes: A61L 2/10 Ultraviolet radiation
• CPC Class Codes: A61L 2/26 Accessories or devices or components used for biocidal treatment
• CPC Class Codes: A61L 2202/14 Means for controlling sterilisation processes, data processing, presentation and storage means, e.g. sensors, controllers, programs
• CPC Class Codes: A61L 2202/17 Combination with washing or cleaning means
• CPC Class Codes: A61L 9/20 Ultraviolet radiation
• CPC Class Codes: B41F 23/0409 Ultraviolet dryers
• CPC Class Codes: B41F 23/0453 by ultraviolet dryers
• CPC Class Codes: C02F 1/325 Irradiation devices or lamp constructions
• 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: F21V 29/00 Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems lighting fixtures combined with outlets for air-treatment systems F24F13/078
• CPC Class Codes: F21V 29/56 using liquid coolants F21V29/51 takes precedence
• CPC Class Codes: F21V 29/57 characterised by control arrangements
• CPC Class Codes: F21V 29/673 the fans being used for intake
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G03F 7/7005 by multiple sources, e.g. light-emitting diodes [LED] or light source arrays addressable array sources specially adapted to produce patterns without a mask G03F7/70391
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 33/64 Heat extraction or cooling elements
• CPC Class Codes: H05B 47/10 : Controlling the light source
• CPC Class Codes: H05B 47/165 : following a pre-assigned programmed sequence; Logic control [LC]

Abstract

A high-intensity light source is formed by a micro array of a semiconductor light source such as a LEDs, laser diodes, or VCSEL placed densely on a liquid or gas cooled thermally conductive substrate. The semiconductor devices are typically attached by a joining process to electrically conductive patterns on the substrate, and driven by a microprocessor controlled power supply. An optic element is placed over the micro array to achieve improved directionality, intensity, and/or spectral purity of the output beam. The light module may be used for such processes as, for example, fluorescence, inspection and measurement, photopolymerzation, ionization, sterilization, debris removal, and other photochemical processes.

Claims

1. A lighting module comprising:

a substrate thermally coupled to a heat sink and having drive circuitry to provide power to an array of solid-state light emitting devices surface disposed on the substrate, the module producing a light output of one or more wavelength bands with a total power density of at least about 50 mW/cm².

2. The lighting module of claim 1, wherein the solid-state light emitting devices are LEDs, VCSELs, or laser diodes.

3. The lighting module of claim 1, wherein the substrate comprises a thermally transmissive material and supports the drive circuitry.

4. The lighting module of claim 3, wherein the substrate is made of one of metal coated dielectric, ceramic, semiconductor, glass, or a dielectric with thermal vias.

5. The lighting module of claim 1, wherein the substrate includes a reflective coating for enhancing the light power output efficiency of the module.

6. The lighting module of claim 1, wherein each module includes at least 2 solid-state light emitting devices.

7. The lighting module of claim 1, wherein conversion efficiency of electrical energy to photoenergy is greater than 10%.

8. The lighting module of claim 1, wherein the heat sink is associated with cooling means.

9. The lighting module of claim 8, wherein the cooling means includes a temperature sensor for controlling the temperature of the heat sink.

10. The lighting module of claim 1, further comprising a controller for controlling the voltage, current, pulse width and/or profiling of the drive circuitry associated with one or more to the solid-state light emitting devices.

11. The lighting module of claim 1, further comprising at least one optical element coupled to the LEDs for optically transmitting light at the predetermined wavelength.

12. The lighting module of claim 11, wherein at least one optical element performs spectral filtering of the light output.

13. The lighting module of claim 11, wherein at least one optical element includes a lens micro array of optically reflective, transmissive, refractive, and/or diffractive optical elements that focus and/or optically intensify collimate, or uniformally distribute the light output in one or more axes.

14. The lighting module of claim 1, wherein the module includes means for controlling the light output over a target surface.

15. The lighting module of claim 1 wherein the controlling means is capable of performing a light output averaging over a target material.

16. The lighting module of claim 11, wherein at least one optical element is optically transmissive and has an optical coating to modify the light output in a predetermined manner.

17. The lighting module of claim 11, further including a transmissive liquid or gas disposed between the solid-state light emitting devices and at least one optical element, wherein the liquid or gas is optically matched to the solid-state light emitting devices, the substrate, and/or the at least one optical element to minimize transmission losses and enhance thermal dissipation.

18. The lighting module of claim 1, wherein the module is capable of outputting light in a wavelength less than about 425 nm.

19. A system for inducing a predetermined material transformation in a predetermined target material, the system including the lighting module of claim 1, wherein the module is capable of a power output sufficient to cause the desired material transformation in the target material.

20. The lighting module of claim 19, wherein the wavelength output is less than about 425 nm and the at least one optical element includes a reflective, refractive, or diffractive micro lens array that collimates the light output to less than about 5 degrees.

21. The system of claim 19, wherein the system is adapted to perform a photolithography operation.

22. The lighting module of claim 1, wherein the solid-state light emitters in the array are arranged in a center-to-center spacing of about 3 mm or less.

23. The lighting module of claim 1, wherein the module is movably disposed on a support relative to a target material to improve the uniformity of the light output striking the target.

24. The lighting module of claim 23, wherein the light module is disposed relative to a target so that light output striking the target covers at least about 90% of the target area.

25. The lighting module of claim 1, wherein the drive circuitry includes passive components in series or parallel with the solid-state light emitting devices and which can be laser trimmed to improve the uniformity of light output of the array.

26. The lighting module of claim 1, wherein the solid-state light emitting devices output wavelengths representing red, green, and blue regions of the spectrum.

27. The lighting module of claim 26, wherein the drive circuitry allows emitters for each of a red, green, and blue color to be turned on separately and pulsed for durations less than 100 msec.

28. A projection system including the lighting module of claim 26, wherein the output of one or more solid-state light emitting devices for each color wavelength is greater than 800 lumens.

29. A system for inducing secondary light emission including the lighting module of claim 1, wherein the module is capable of a light output at a wavelength of less than about 425 nm, and wherein the module is capable of a power output density greater than about 10 mW/cm², and the module is adapted to induce a target molecule to fluoresce or phosphoresce in an inspection, measurement, or material analysis application.

30. The system of claim 29 wherein the system is adapted so that fluorescence or phosphorescence in a first target material is used to illuminate, sterilize, inspect, detect or measure characteristics of a second target material.

31. A sterilization system including the lighting module of claim 1, wherein the module is capable of a light output in spectral region that causes death or loss of reproductive capabilities of undesirable microorganisms that may be disposed on a target material.

32. A semiconductor materials inspection system including the lighting module of claim 1, wherein the solid-state light emitting devices are capable of emitting light in the infrared region between about 1050 nm and about 2.5 um.

33. The lighting module of claim 1, wherein the drive circuitry includes a programmable current source to control the solid-state light emitting devices to sequence, balance, or otherwise modulate power to the module.

41. The lighting module of claim 1 or 34, wherein the drive circuitry allows one or more emitters to be turned on separately and pulsed for durations less than 100 msec.

34. A lighting module comprising:

a substrate having drive circuitry to provide power to an array of LEDs disposed on the substrate, the LEDs being arranged in a center-to-center spacing of about 3 mm or less.

35. The lighting module of claim 34 wherein a heat sink is thermally coupled to the substrate.

36. The lighting module of claim 35 wherein the lighting module is capable of a power output of at least about 50 mW/cm².

37. The lighting module of claim 36 further comprising a housing in which the module is enclosed, the housing including a window for transmission of light emitted from the LEDs.

38. The lighting module of claim 37, wherein the module further includes a controller for controlling the voltage, current, pulse width and/or profiling of a drive circuitry associated with one or more LEDs in the array.

39. The lighting module of claim 38, further including a temperature controlling means associated with the module.

40. The lighting module of claim 39 wherein the temperature controlling means includes a temperature sensor.

42. A method of radiating a target object comprising:

providing a substrate thermally coupled to a heat sink and having drive circuitry to provide power to an array of solid-state light emitting devices surface disposed on the substrate, the module producing a light output power density of at least about 50 mW/cm²; and

activating the module so that radiation emitted from the module is transmitted to a surface of the target object.

44. The method of claim 42 or 43, wherein the emitted light is of a predetermined wavelength that induces a material transformation in a predetermined target object.

45. The method of claim 42 or 43 wherein the target object is a semiconductor object, liquid crystal array, stencil, hybrid circuit, electronic component, circuit board, adhesive, epoxy, auto repair materials (bondo), DVD, ink, coating, potting, paint, medical or dental material.

46. The method of claim 42 or 43, wherein the emitted light is of a selected wavelength for sterilizing a surface of the target object, and the light is emitted for a time sufficient to achieve a desired degree of sterilization.

47. The method of claim 46 wherein the target object being sterilized is a foodstuff, air or gas, water, or a biological material, or the implements for handling or performing functions on a biological material, and the material transformation causes the death or loss of reproductive capabilities of undesirable microorganisms that may be disposed on the target object.

48. The method of claim 42 or 43, wherein the material transformation is an ionization reaction.

49. The method of claim 42 or 43, wherein the material transformation results in photo-ablation of the target object.

50. The method of claim 42 or 43, wherein the material transformation results in the initiation, termination, acceleration, or deceleration of a predetermined chemical or biological process.

43. A method of radiating a target object comprising:

providing a substrate having drive circuitry to provide power to an array of LEDs disposed on the substrate, the LEDs being arranged in a center-to-center spacing of about 3 mm or less; and

activating the module so that radiation emitted from the module is transmitted to a surface of the target object.