Light-emitting dies incorporating wavelength-conversion materials and related methods
View Patent ↗In accordance with certain embodiments, semiconductor dies are embedded within polymeric binder to form, e.g., freestanding white light-emitting dies and/or composite wafers containing multiple light-emitting dies embedded in a single volume of binder.
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; and
disposed on the first face of the semiconductor die, at least two spaced-apart contacts each having a free terminal end (i) not covered by the polymeric binder and (ii) available for electrical connection, the contacts each 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, (ii) 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, and (iii) at least a portion of the surface of the polymeric binder comprises a texture configured to enhance extraction of light from the polymeric binder, the texture having an average roughness in the range of about 0.5 μm to about 10 μm.
2. The electronic device of claim 1 , wherein at least portions of the contacts protrude from the polymeric binder.
3. 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.
4. The electronic device of claim 1 , wherein the polymeric binder defines a rectangular solid having approximately 90° corners between adjacent faces thereof.
5. The electronic device of claim 1 , wherein the polymeric binder comprises at least one of-silicone or epoxy.
6. The electronic device of claim 1 , further comprising one or more additional semiconductor dies suspended within the polymeric binder.
7. The electronic device of claim 1 , wherein the wavelength-conversion material comprises at least one of a phosphor or quantum dots.
8. 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.
9. The electronic device of claim 1 , wherein the mixed light is substantially white light.
10. The electronic device of claim 9 , wherein the substantially white light has a correlated color temperature in the range of 2000 K to 10,000 K.
11. The electronic device of claim 1 , wherein the polymeric binder has a thickness between 5 μm and 4000 μm.
12. The electronic device of claim 1 , wherein a dimension of the polymeric binder perpendicular to the thickness is between 25 μm and 50 mm.
13. The electronic device of claim 1 , further comprising an optical element positioned to receive light from the semiconductor die.
14. The electronic device of claim 1 , further comprising a reflecting layer over or within at least a portion of the polymeric binder.
15. The electronic device of claim 14 , wherein the reflecting layer comprises at least one of (i) a reflecting film or (ii) a plurality of particles.
16. The electronic device of claim 14 , wherein the reflecting layer has a reflectivity of at least 25% to a wavelength of light emitted by the wavelength-conversion material within the polymeric binder.
17. The electronic device of claim 1 , wherein the polymeric binder comprises a plurality of discrete regions, at least one of which comprises the polymeric binder without wavelength-conversion material therein.
18. The electronic device of claim 1 , wherein the active semiconductor layers of the semiconductor die are not disposed on a semiconductor substrate.
19. 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.
20. The electronic device of claim 1 , wherein the polymeric binder coats the first face of the semiconductor die, the at least one sidewall, and at least a portion of the second face of the semiconductor die.