MICROSCALE OPTOELECTRONIC DEVICE PACKAGES

• US 20080290353A1
• Filed: 05/24/2007
• Published: 11/27/2008
• Est. Priority Date: 05/24/2007
• Status: Active Grant

• Current Assignee: Wolfspeed, Inc.
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Ibbetson, James, Medendorp, Nicholas W. JR.
• Granted Patent: US 8,436,371 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01S 5/0206 Substrates, e.g. growth, shape, material, removal or bonding; specific crystal orientation H01S5/3202
• CPC Class Codes: H01S 5/06825 Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation

Abstract

An optoelectronic device article comprises a substrate containing at least one electrically conductive microvia, at least one emitter diode and at least one ESD diode, optionally formed in situ, disposed in or on the substrate, and an electrically conductive path between the foregoing elements. A reflector cavity may be defined in the substrate for receiving the emitter diode(s), with retention elements on the substrate used to retain a lens material. High flux density and high emitter diode spatial density may be attained. Thermal sensors, radiation sensors, and integral heat spreaders comprising one or more protruding fins may be integrated into the article.

Claims

1. An optoelectronic device article comprising:

a substrate containing at least one electrically conductive microvia;

at least one emitter diode adapted to emit radiation and disposed in or on the substrate;

at least one ESD diode disposed in or on the substrate; and

a first electrically conductive path between the at least one emitter diode and the at least one microvia, the path being in electrical communication with the at least one ESD diode.

2. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises a laser diode.

3. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises a LED.

4. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises a plurality of emitter diodes.

5. The optoelectronic device article of claim 4, wherein the substrate defines a reflector cavity, and the plurality of emitter diodes is disposed substantially within the reflector cavity.

6. The optoelectronic device article of claim 4, wherein each emitter diode of the plurality of emitter diodes is independently controlled.

7. The optoelectronic device article of claim 4, wherein the plurality of emitter diodes includes diodes adapted to emit different wavelengths.

8. The optoelectronic device article of claim 1, further comprising an electrical driver circuit fabricated in or on the substrate.

9. The optoelectronic device article of claim 1, further comprising an electrically isolated thermal contact pad in thermal communication with the at least one emitter diode.

10. The optoelectronic device article of claim 1, wherein the at least one ESD diode is substantially embedded in the substrate.

11. The optoelectronic device article of claim 1, wherein the substrate has a front surface along which radiation is transmitted outward from the at least one emitter diode, wherein the at least one ESD diode is disposed in or on the substrate adjacent to the front surface.

12. The optoelectronic device article of claim 1, wherein the substrate has a back surface, and the at least one ESD diode is disposed in or on the substrate adjacent to the back surface.

13. The optoelectronic device article of claim 1, wherein the substrate defines a reflector cavity, and the at least one emitter diode is disposed substantially within the reflector cavity.

14. The optoelectronic device article of claim 13, wherein the reflector cavity extends downward from a front surface of the substrate, has at least one sidewall, and is bounded from below by a reduced-thickness membrane portion of the substrate, and the optoelectronic device article further comprises an electrical trace extending from the membrane portion up the at least one sidewall to the front surface.

15. The optoelectronic device article of claim 13, wherein the reflector cavity has any of a depth of less than about 250 microns and a width of less than about 2 millimeters.

16. The optoelectronic device article of claim 13, further comprising at least one electrically conductive contact disposed within the reflector cavity and at least one wirebond communicatively coupled between the at least one contact and the at least one microvia.

17. The optoelectronic device article of claim 1, wherein the substrate defines an integrated retention element adapted to retain any of an encapsulant and a lens.

18. The optoelectronic device article of claim 17, further comprising any of an encapsulant and a lens disposed over the at least one emitter diode and secured to the retention element.

19. The optoelectronic device article of claim 17, wherein the retention element comprises any of:

cavity adapted to receive and retain any of an encapsulant and a lens material;

a raised feature protruding from the substrate adapted to retain any of an encapsulant and a lens material; and

roughened surface of the substrate adapted to retain any of an encapsulant and a lens material.

20. The optoelectronic device article of claim 1, wherein:

the substrate has an upper surface and a lower surface, with a backside cavity defined in the lower surface; and

the at least one emitter diode is disposed along the upper surface.

21. The optoelectronic device article of claim 20, further comprising an integrated heat spreader protruding into the cavity.

22. The optoelectronic device article of claim 21, wherein the integrated heat spreader comprises a plurality of fins.

23. The optoelectronic device article of claim 1, wherein the substrate comprises a first reduced-thickness membrane portion having a thickness of less than or equal to about 20 μ

m and arranged to support the at least one emitter diode, wherein any of the at least one microvia is defined in the first membrane portion.

24. The optoelectronic device article of claim 23, further comprising at least one second reduced-thickness membrane portion not proximate to the at least one emitter diode, wherein any of the at least one microvia is defined in the at least one second membrane portion.

25. The optoelectronic device article of claim 1, wherein the at least one microvia has a lateral dimension of less than or equal to about 50 μ

m.

26. The optoelectronic device article of claim 1, wherein the substrate comprises a N-type layer and a P-type layer.

27. The optoelectronic device article of claim 26, further comprising a sinker implant element penetrating a junction between the N-type layer and the P-type layer.

28. The optoelectronic device article of claim 27, wherein the optoelectronic device article is diced along an edge thereof, and the sinker implant element is adapted to isolate the junction from dicing damage.

29. The optoelectronic device article of claim 1, further comprising a phosphor material layer deposited on or over the at least one emitter diode.

30. The optoelectronic device article of claim 1, further comprising at least one thermal sensing element in thermal communication with the at least one emitter diode.

31. The optoelectronic device article of claim 30, wherein the at least one thermal sensing element comprises a thin-film resistor.

32. The optoelectronic device article of claim 30, wherein the at least one thermal sensing element provides a thermal sensing element output signal, and the article further comprises a control element adapted to control any of voltage and current supplied to the at least one emitter diode responsive to the thermal sensing element output signal

33. The optoelectronic device article of claim 30, wherein the at least one thermal sensing element comprises a plurality of thermal sensing elements.

34. The optoelectronic device article of claim 1, further comprising at least one radiation sensing element adapted to provide a radiation sensing element output signal.

35. The optoelectronic device article of claim 34, further comprising a control element adapted to activate the at least one emitter diode responsive to the radiation sensing element output signal.

36. The optoelectronic device article of claim 34, further comprising a control element adapted to control any of voltage and current supplied to the at least one emitter diode responsive to the radiation sensing element output signal.

37. The optoelectronic device article of claim 34, wherein the radiation sensing element is adapted to sense any of ambient light intensity, presence of ambient light, and motion of a body proximate to the optoelectronic device article.

38. The optoelectronic device article of claim 34, wherein the radiation sensing element is adapted to sense any of intensity, color, wavelength, and frequency output of the at least one emitter diode.

39. The optoelectronic device article of claim 34, wherein the at least one emitter diode comprises a plurality of LED dies, and the radiation sensing element is adapted to sense any of aggregated color, aggregated wavelength, and aggregated frequency output of the plurality of LED dies.

40. The optoelectronic device article of claim 1, having a thermal resistance of less than about 3 K/W between the at least one emitter diode and a heat dissipating structure.

41. The optoelectronic device article of claim 40, wherein the heat dissipating structure comprises a heat spreader integrated with the substrate.

42. The optoelectronic device article of claim 1, further comprising at least one die attach pad disposed between the substrate and the at least one emitter diode.

43. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises a plurality of emitter diodes, each emitter diode of the plurality of emitter diodes has an emitter diode width, and each emitter diode of the plurality of emitter diodes has a center-to-center spacing relative to an adjacent emitter diode of no more than about 110% of the emitter diode width.

44. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises plurality of emitter diodes, and the plurality of emitter diodes is arranged with a spatial density of at least about 20 square millimeters of emitter diodes per cm²

45. The optoelectronic device article of claim 44, wherein the plurality of emitter diodes is arranged with a spatial density of at least about 60 square millimeters of emitter diodes per cm².

46. The optoelectronic device article of claim 44, wherein the plurality of emitter diodes is arranged with a spatial density of at least about 80 square millimeters of emitter diodes per cm².

47. The optoelectronic device article of claim 1, having an average flux density of at least about 250 mW/mm² per watt of input power, as measured at an upper surface of the device article.

48. The optoelectronic device article of claim 1, having an average flux density of at least about 500 mW/mm² per watt of input power, as measured at an upper surface of the device article.

49. The optoelectronic device article of claim 1, having an average flux density of at least about 800 mW/mm² per watt of input power, as measured at an upper surface of the device article.

50. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises at least one hundred emitter diodes.

51. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises at least one thousand emitter diodes.

52. The optoelectronic device article of claim 1, wherein the at least one ESD diode comprises two ESD diodes corresponding to an emitter diode of the at least one emitter diode.

53. The optoelectronic device article of claim 1, wherein the at least one emitter diode has a top surface area of less than or equal to about 1 mm².

54. The optoelectronic device article of claim 1, further comprising at least one thermally conductive fin protruding from a portion of the substrate and adapted to dissipate heat emanating from the at least one emitter diode.

55. An optoelectronic device comprising the optoelectronic device article of claim 1.

56. The optoelectronic device of claim 55, outputting light having a color rendering index value of greater than about 80.

57. The illumination device of claim 55, outputting light having a color rendering index value of greater than about 90.

58. The optoelectronic device article of claim 1, wherein the at least one emitter diode comprises a plurality of LED dies adapted to emit different wavelengths, wherein each LED die of the plurality of LED dies is independently controlled.

59. A color mixing illumination device adapted to sequentially output a plurality of different wavelengths, the device comprising the optoelectronic device article of claim 58.

60. A display device adapted to display any of images and text, the display device comprising the optoelectronic device article of claim 58.

61. An optoelectronic device article comprising:

a substrate containing at least one electrically conductive microvia;

at least one emitter diode adapted to emit radiation and disposed in or on the substrate;

at least one ESD diode disposed in or on the substrate; and

a first electrically conductive path between the at least one emitter diode and the at least one microvia, the path being in electrical communication with the at least one ESD diode;

wherein the optoelectronic device article has a flux density of at least about 250 mW/mm² per watt of input power, as measured at an upper surface of the device article.

62. The optoelectronic device article of claim 61, having a flux density of at least about 500 mW/mm² per watt of input power, as measured at an upper surface of the device article.

63. The optoelectronic device article of claim 61, having a flux density of at least about 800 mW/mm² per watt of input power, as measured at an upper surface of the device article.

64. An optoelectronic device article comprising:

a substrate containing a plurality of electrically conductive microvias;

a plurality of emitter diodes adapted to emit radiation and disposed in or on the substrate;

at least one ESD diode disposed in or on the substrate; and

for each emitter diode of the plurality of emitter diodes, a first electrically conductive path between the emitter diode and a microvia of the plurality of microvias, the path being in electrical communication with the at least one ESD diode;

wherein the plurality of emitter diodes is arranged with a spatial density of at least about 20 square millimeters of emitter diodes per cm².

65. The optoelectronic device article of claim 64, wherein the plurality of emitter diodes is arranged with a spatial density of at least about 60 square millimeters of emitter diodes per cm².

66. The optoelectronic device article of claim 64, wherein the plurality of emitter diodes is arranged with a spatial density of at least about 80 square millimeters of emitter diodes per cm².

67. The optoelectronic device article of claim 64, wherein each emitter diode of the plurality of emitter diodes has an emitter diode width, and each emitter diode of the plurality of emitter diodes has an center-to-center spacing relative to an adjacent emitter diode of no more than about 110% of the emitter diode width.

68. An optoelectronic device article comprising:

a substrate containing at least one electrically conductive microvia;

at least one emitter diode adapted to emit radiation and disposed in or on the substrate;

at least one ESD diode disposed in or on the substrate;

a first electrically conductive path between the at least one emitter diode and the at least one microvia, the path being in electrical communication with the at least one ESD diode; and

an electrically isolated thermal contact pad in thermal communication with the at least one emitter diode

69. The optoelectronic device article of claim 68, having a thermal resistance of less than about 3 K/W between the at least one emitter diode and a heat dissipating structure.

70. The optoelectronic device of claim 68, further comprising a plurality of fins embodied as continuously formed protruding extensions of the substrate, the plurality of fins being adapted to dissipate heat emanating from the at least one emitter diode.

71. An optoelectronic device article comprising:

a substrate containing at least one electrically conductive microvia;

at least one emitter diode adapted to emit radiation and disposed in or on the substrate;

at least one ESD diode disposed in or on the substrate;

a first electrically conductive path between the at least one emitter diode and the at least one microvia, the path being in electrical communication with the at least one ESD diode; and

at least one thermal sensing element in thermal communication with the at least one emitter diode.

72. The optoelectronic device article of claim 71, wherein the at least one thermal sensing element comprises a thin-film resistor.

73. The optoelectronic device article of claim 71, wherein the at least one thermal sensing element provides a thermal sensing element output signal, and the optoelectronic device article further comprises a control element adapted to control any of voltage and current supplied to the at least one emitter diode responsive to the thermal sensing element output signal.

74. The optoelectronic device article of claim 71, wherein the at least one thermal sensing element comprises a plurality of thermal sensing elements.

75. An optoelectronic device article comprising:

a substrate containing at least one electrically conductive microvia;

at least one emitter diode adapted to emit radiation and disposed in or on the substrate;

at least one ESD diode disposed in or on the substrate;

a first electrically conductive path between the at least one emitter diode and the at least one microvia, the path being in electrical communication with the at least one ESD diode; and

at least one radiation sensing element adapted to provide a radiation sensing element output signal to any of (A) the at least one emitter diode and (B) a control element associated with the at least one emitter diode.

76. The optoelectronic device article of claim 75, further comprising a control element adapted perform any of the following responsive to the radiation sensing element output signal:

(A) activate the at least one emitter diode;

(B) control voltage supplied to the emitter diode; and

(C) control current supplied to the emitter diode.

77. The optoelectronic device article of claim 75, wherein the at least one radiation sensing element is adapted to sense any of ambient light intensity, presence of ambient light, and motion of a body proximate to the optoelectronic device article.

78. The optoelectronic device article of claim 75, wherein the radiation sensing element is adapted to sense any of intensity, color, wavelength, and frequency output of the optoelectronic device article.

79. A method comprising:

forming a retention element in or on a substrate, said retention element being adapted to retain any of an encapsulant and a lens;

providing an emitter diode in or on the substrate;

providing an ESD diode in or on the substrate;

defining a microvia through the substrate; and

forming an electrically conductive path between the emitter diode and the microvia, the path being in electrical communication with the at least one ESD diode.

80. The method of claim 79, further comprising depositing any of an encapsulant and a lens on or over the emitter diode.

81. The method of claim 79, further comprising defining a reflector cavity in the substrate, wherein the emitter diode is disposed substantially within the reflector cavity.

82. The method of claim 79, further comprising depositing a phosphor material layer on or over the emitter diode by a method including any of spin deposition, liquid jetting, electrophoretic deposition, screen printing, and adhesion.

83. A method comprising:

providing a plurality of emitter diodes in or on a substrate;

providing a plurality of ESD diodes in or on the substrate;

defining a plurality of microvias through the substrate;

for each emitter diode of the plurality of emitter diodes, forming an electrically conductive path between the emitter diode and a microvia, the path being in electrical communication with at least one ESD diode of the plurality of ESD diodes; and

testing at least one output characteristic of at least two emitter diodes or at least two groups of emitter diodes of the plurality of emitter diodes while the plurality of emitter diodes is disposed in or on the substrate.

84. The method of claim 83, further comprising dicing or otherwise separating the substrate into a plurality of substrate portions, each substrate portion having at least one emitter diode of the plurality of emitter diodes and at least one ESD diode of the plurality of ESD diodes.

85. The method of claim 83, further comprising binning each portion of the plurality of portions of the substrate based on said at least one output characteristic.