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

• US 8,748,929 B2
• Filed: 11/20/2013
• Issued: 06/10/2014
• Est. Priority Date: 01/24/2012
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Cooledge Lighting Inc.
• Inventors: Tischler, Michael A.
• Primary Examiner(s): GREEN, TELLY D
• Application Number:
  US14/085,046
• Publication Number:
  US 20140077686A1
• Time in Patent Office: 202 Days
• Field of Search: 257/89, 257/98, 438/27, 438/28, 438/29, 438/25, 438/31, 313/503, 313/501, 313/512, 362/231, 362/97.3, 362/237, 362/606
• US Class Current: 257/98
• CPC Class Codes: H01L 21/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
• CPC Class Codes: H01L 2224/13022 the bump connector being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/16145 the bodies being stacked
• CPC Class Codes: H01L 2224/73259 Bump and HDI connectors
• CPC Class Codes: H01L 24/96 the devices being encapsulated in a common layer, e.g. neo-wafer or pseudo-wafer, said common layer being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 25/00 Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereofdevices consisting of a plurality of solid state components formed in or on a common substrate H01L27/00; photovoltaic modules or arrays of photovoltaic cells H01L31/042 ; panels or arrays of photo electrochemical cells H01G9/2068
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/14 including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation radiation-sensitive components structurally associated with one or more electric light sources only H01L31/14; couplings of light guides with optoelectronic elements G02B6/42
• CPC Class Codes: H01L 29/00 Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor H01L31/00 - H01L33/00, H10K10/00, H10N take precedence; details other than of semiconductor bodies or of electrodes thereof H01L23/00; devices consisting of a plurality of solid state components formed in or on a common substrate H01L27/00
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/07802 not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/07811 Extrinsic, i.e. with electrical conductive fillers
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/12043 Photo diode
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape
• 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 31/0203 : Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/022425 : for solar cells
• CPC Class Codes: H01L 31/02322 : comprising luminescent members, e.g. fluorescent sheets upon the device
• CPC Class Codes: H01L 31/02327 : the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 31/048 : Encapsulation of modules
• CPC Class Codes: H01L 31/055 : where light is absorbed and re-emitted at a different wavelength by the optical element directly associated or integrated with the PV cell, e.g. by using luminescent material, fluorescent concentrators or up-conversion arrangements
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/505 : characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/60 : Reflective elements
• CPC Class Codes: H05B 33/02 : Details
• CPC Class Codes: H05B 33/12 : Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: Y02E 10/52 : PV systems with concentrators

Abstract

In accordance with certain embodiments, semiconductor dies are embedded within polymeric binder to form, e.g., light-emitting dies and/or composite wafers containing multiple light-emitting dies embedded in a single volume of binder.

Claims

1. An electronic device comprising:

a solid shaped volume of a polymeric binder;

suspended within the polymeric binder, a semiconductor die having a first face, a second face opposite the first face, and at least one sidewall spanning the first and second faces, the semiconductor die being a bare-die light-emitting element comprising a plurality of active semiconductor layers that cooperatively emit light;

a reflecting layer disposed on a surface of the polymeric binder or disposed within at least a portion of the polymeric binder proximate the semiconductor die; and

disposed on the first face of the semiconductor die, at least two spaced-apart contacts each (i) having a free terminal end not covered by the polymeric binder, (ii) being available for electrical connection, and (iii) contacting a different active semiconductor layer of the semiconductor die,

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 reflecting layer has a reflectivity of at least 50% to a wavelength of light emitted by the light-emitting element within the polymeric binder.

2. The electronic device of claim 1, wherein the polymeric binder contains therein a wavelength-conversion material for absorption of at least a portion of light emitted from the semiconductor die 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.

3. The electronic device of claim 2, wherein the reflecting layer has a reflectivity of at least 50% to a wavelength of light emitted by the wavelength-conversion material.

4. The electronic device of claim 2, wherein the wavelength-conversion material comprises at least one of a phosphor or quantum dots.

5. The electronic device of claim 2, wherein the mixed light is substantially white light.

6. The electronic device of claim 5, wherein the substantially white light has a correlated color temperature in the range of 2000 K to 10,000 K.

7. The electronic device of claim 2, wherein the polymeric binder comprises a plurality of discrete regions, at least one of which comprises the polymeric binder without wavelength-conversion material therein.

8. The electronic device of claim 1, wherein at least a portion of the reflecting layer is substantially parallel to the first face of the semiconductor die.

9. The electronic device of claim 1, wherein the reflecting layer is approximately parallel to and approximately coplanar with the first face of the semiconductor die.

10. The electronic device of claim 1, wherein the reflecting layer has a reflectivity of at least 75% to a wavelength of light emitted by at least one of the light-emitting element or the wavelength-conversion material.

11. The electronic device of claim 1, wherein the reflecting layer is a substantially diffuse reflector.

12. The electronic device of claim 1, wherein the reflecting layer is a substantially specular reflector.

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

14. The electronic device of claim 1, wherein only a portion of each said sidewall protrudes from the polymeric binder, a portion of each said sidewall being covered with the polymeric binder.

15. The electronic device of claim 1, wherein the polymeric binder and the semiconductor die collectively define an approximately rectangular solid having approximately 90°

corners between adjacent faces thereof.

16. The electronic device of claim 1, wherein the polymeric binder comprises at least one of silicone or epoxy.

17. The electronic device of claim 1, further comprising one or more additional semiconductor dies suspended within the polymeric binder.

18. The electronic device of claim 1, wherein the light-emitting element comprises a semiconductor material comprising at least one of GaAs, AlAs, InAs, GaP, AlP, InP, ZnO, CdSe, CdTe, ZnTe, GaN, AlN, InN, silicon, or an alloy or mixture thereof.

19. The electronic device of claim 1, wherein the polymeric binder has a thickness between 5 μ

m and 4000 μ

m.

20. The electronic device of claim 1, further comprising an optical element positioned to receive light from the semiconductor die.

21. The electronic device of claim 1, wherein the reflecting layer comprises at least one of (i) a reflecting film or (ii) a plurality of particles.

22. The electronic device of claim 1, wherein the active semiconductor layers of the semiconductor die are not disposed on a semiconductor substrate.

23. The electronic device of claim 1, further comprising one or more alignment marks on the surface of the polymeric binder for at least one of alignment or orientation of the semiconductor die.

24. The electronic device of claim 1, wherein the polymeric binder coats the second face of the semiconductor die, the at least one sidewall, and at least a portion of the first face of the semiconductor die.

25. The electronic device of claim 1, wherein at least a portion of the surface of the polymeric binder comprises a texture configured to enhance extraction of light from the polymeric binder.

26. The electronic device of claim 25, wherein the texture has an average roughness in the range of about 0.5 μ

m to about 10 μ

m.

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

28. The electronic device of claim 1, wherein the first face of the semiconductor die comprises at least two non-coplanar portions each having at least one said contact thereon.

29. The electronic device of claim 1, wherein at least a portion of a top surface of the polymeric binder is curved.

30. The electronic device of claim 1, further comprising, at least partially suspended within the polymeric binder, at least one additional semiconductor die having a first face, a second face opposite the first face, and at least one sidewall spanning the first and second faces, the semiconductor die being a bare-die light-emitting element comprising a plurality of active semiconductor layers that cooperatively emit light.