Light-emitting dies incorporating wavelength-conversion materials and related methods

• US 9,343,444 B2
• Filed: 03/18/2015
• Issued: 05/17/2016
• Est. Priority Date: 02/05/2014
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Cooledge Lighting Inc.
• Inventors: Spiga, Gianmarco, Ip, Henry, Pinnington, Thomas, Amini, Alborz, Tischler, Michael A.
• Primary Examiner(s): COLEMAN, WILLIAM D
• Application Number:
  US14/661,742
• Publication Number:
  US 20150221623A1
• Time in Patent Office: 426 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/11 Manufacturing methods
• CPC Class Codes: H01L 2224/19 Manufacturing methods of high density interconnect preforms
• CPC Class Codes: H01L 25/165 Containers
• 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 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• 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

In accordance with certain embodiments, electronic devices feature a polymeric binder, a frame defining an aperture therethrough, and a semiconductor die (e.g., a light-emitting or a light-detecting element) suspended in the binder and within the aperture of the frame.

Claims

1. An illumination device comprising:

a polymeric binder;

suspended within the polymeric binder, a bare-die light-emitting element having (i) a first face, (ii) a second face opposite the first face, (iii) at least one sidewall spanning the first and second faces, and (iv) disposed on the first face of the light-emitting element, at least two spaced-apart contacts each having a free terminal end; and

a frame (i) having a bottom surface, (ii) having a top surface opposite the bottom surface, (iii) having a thickness spanning the top and bottom surfaces, and (iv) defining an aperture (a) extending fully through the thickness and (b) having a sidewall, the top surface of the frame surrounding the aperture,

wherein the light-emitting element is disposed within the aperture of the frame such that (i) the second face of the light-emitting element is opposite the bottom surface of the frame, (ii) the sidewall of the aperture redirects light emitted from the light-emitting element away from the bottom surface of the frame, (iii) the free terminal ends of the contacts of the light-emitting element are (a) not covered by the polymeric binder and (b) available for electrical connection, and (iv) a bottom exposed surface of the illumination device includes at least a portion of the first face of the light-emitting element.

2. The illumination device of claim 1, wherein the polymeric binder has a top surface disposed over the second face of the light-emitting element.

3. The illumination device of claim 1, wherein at least portions of the contacts protrude from the polymeric binder.

4. The illumination device of claim 1, further comprising one or more additional light-emitting elements at least partially suspended within the polymeric binder.

5. The illumination device of claim 1, wherein the light-emitting element comprises a light-emitting diode.

6. The illumination device of claim 1, wherein the light-emitting element comprises active semiconductor layers that are not disposed on a semiconductor substrate.

7. The illumination device of claim 1, further comprising a reflective layer over or within at least a portion of the polymeric binder.

8. The illumination device of claim 1, further comprising an optical element positioned to receive light from the light-emitting element.

9. The illumination device of claim 1, further comprising a first conductive pad electrically coupled to one of the two spaced-apart contacts and disposed over at least a portion of the bottom surface of the frame.

10. The illumination device of claim 1, further comprising an insulating layer disposed over or on at least a portion of a surface of the frame.

11. The illumination device of claim 1, further comprising at least one of an active or passive electronic component disposed over or on the bottom surface of the frame.

12. The illumination device of claim 1, wherein the frame comprises a semiconductor material, and further comprising at least one of an active or passive electronic component disposed within or on the semiconductor material.

13. The illumination device of claim 1, further comprising:

suspended within the polymeric binder, a second bare-die light-emitting element having (i) a first face, (ii) a second face opposite the first face, (iii) at least one sidewall spanning the first and second faces, and (iv) disposed on the first face of the second light-emitting element, at least two spaced-apart contacts each having a free terminal end,

wherein;

the frame defines a second aperture fully through the thickness of the frame, the second aperture having a sidewall not perpendicular to the bottom surface of the frame, and

the second light-emitting element is disposed within the second aperture of the frame such that (i) the second face of the second light-emitting element is opposite the bottom surface of the frame, (ii) the sidewall of the second aperture redirects light emitted from the second light-emitting element away from the bottom surface of the frame, and (iii) the free terminal ends of the contacts of the second light-emitting element are (a) not covered by the polymeric binder and (b) available for electrical connection.

14. The illumination device of claim 1, wherein the frame comprises at least one of a semiconductor, a plastic, a polymer, a glass, a ceramic, or a metal.

15. The illumination device of claim 1, wherein at least a portion of the sidewall of the aperture is reflective to a wavelength of light emitted by the light-emitting element.

16. The illumination device of claim 1, wherein (i) at least a portion of the polymeric binder is transparent to a wavelength of light emitted by the light-emitting element, and (ii) the polymeric binder contains therein a light-scattering material that scatters the wavelength of light emitted by the light-emitting element.

17. The illumination device of claim 1, wherein (i) at least a portion of the polymeric binder is transparent to a wavelength of light emitted by the light-emitting element, and (ii) the polymeric binder contains therein a wavelength-conversion material for absorption of at least a portion of light emitted from the light-emitting element and emission of converted light having a different wavelength, converted light and unconverted light emitted by the light-emitting element combining to form mixed light.

18. The illumination device of claim 1, wherein (i) the sidewall of the aperture forms an angle with the bottom surface of the frame, the angle having a value in the range of 15°

to 50°

, (ii) the polymeric binder extends above the frame in a direction away from the bottom surface of the frame, and (iii) a sum of the thickness of the frame and a thickness of the polymeric binder extending above the frame is in the range of 0.4 mm to 1.8 mm.

19. The illumination device of claim 2, wherein the top surface of the polymeric binder is curved.

20. The illumination device of claim 2, wherein the top surface of the polymeric binder is substantially flat.

21. The illumination device of claim 9, further comprising a second conductive pad (i) electrically coupled to the other of the two spaced-apart contacts, (ii) electrically insulated from the first conductive pad, and (iii) disposed over at least a portion of the bottom surface of the frame.

22. The illumination device of claim 13, wherein a wavelength of light emitted by the second light-emitting element is different from a wavelength of light emitted by the light-emitting element.

23. The illumination device of claim 15, wherein the at least a portion of the sidewall of the aperture has a reflectance greater than 80% to a wavelength of light emitted by the light-emitting element.

24. The illumination device of claim 15, wherein the at least a portion of the sidewall of the aperture is coated with a reflective coating that is reflective to a wavelength of light emitted by the light-emitting element.

25. The illumination device of claim 17, wherein the polymeric binder comprises a plurality of discrete regions, at least one of which comprises the polymeric binder without wavelength-conversion material therein.

26. The illumination device of claim 17, wherein at least a portion of the sidewall of the aperture is coated with a reflective coating having a reflectance greater than 80% to a wavelength of light emitted by the light-emitting element and/or the wavelength-conversion material.

27. The illumination device of claim 17, wherein the mixed light is substantially white light.

28. The illumination device of claim 27, wherein the substantially white light has a correlated color temperature in the range of 2000 K to 10,000 K.

29. The illumination device of claim 27, wherein a maximum divergence of color uniformity of the substantially white light in terms of the radially averaged Δ

u′

v′

deviation from a spatially weighted average chromaticity is less than 0.01.

30. The illumination device of claim 27, wherein a divergence of color temperature of the substantially white light emitted from the device varies, over an angular range of 0°

to 80°

, no more than 0.006 in terms of Δ

u′

v′

deviation from a spatially weighted averaged chromaticity.