Wafer-level flip chip device packages and related methods

Patent metadata

Field	Value
Publication number	US-9496472-B2
Application number	US-201514953840-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Jan 24, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

In accordance with certain embodiments, semiconductor dies are at least partially coated with a polymer and a conductive adhesive prior being bonded to a substrate having electrical traces thereon.

First claim

What is claimed is:

1. An electronic device comprising:
a solid shaped volume of a polymeric binder;
suspended within the 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;
disposed on the first face of the semiconductor die, at least two spaced-apart contacts each having a terminal end not covered by the polymeric binder, the contacts each contacting a different active semiconductor layer of the semiconductor die; and
disposed over and in electrical contact with at least a portion of each of the terminal ends of the contacts, an anisotropic conductive adhesive (ACA),
wherein at least a portion of the polymeric binder is transparent to a wavelength of light emitted by the light-emitting element.

2. The electronic device of claim 1 , wherein the ACA comprises an anisotropic conductive film.

3. The electronic device of claim 1 , wherein at least a portion of the ACA opposite the contacts is free and available for electrical connection.

4. The electronic device of claim 1 , wherein the polymeric binder and semiconductor die collectively define a rectangular solid having approximately 90° corners between adjacent faces thereof.

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

6. 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.

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

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

9. 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.

10. The electronic device of claim 1 , wherein the polymeric binder has a thickness between 5 μm and 2000 μm.

11. The electronic device of claim 10 , wherein a dimension of the polymeric binder perpendicular to the thickness is between 25 μm and 50 mm.

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

13. The electronic device of claim 1 , further comprising a reflecting layer over or within at least a portion of the polymeric binder.

14. The electronic device of claim 13 , wherein the reflecting layer is disposed between at least a portion of the polymeric binder and at least a portion of the ACA.

15. The electronic device of claim 13 , 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 13 , wherein the reflecting layer has a reflectivity of at least 40% to a wavelength of light emitted by the light-emitting element.

17. The electronic device of claim 13 , wherein at least a portion of the reflecting layer is electrically conductive and is electrically coupled to at least one of the contacts.

18. The electronic device of claim 17 , wherein (i) the reflecting layer comprises at least two portions, each portion electrically coupled to a different one of the contacts and (ii) each portion of the reflecting layer is electrically isolated from each other portion.

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

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

21. The electronic device of claim 1 , wherein the terminal ends of the at least two contacts are in physical contact with the ACA.

22. The electronic device of claim 1 , wherein at least a portion of the ACA is not activated to enable electrical conduction through a thickness thereof to the at least two contacts.

23. The electronic device of claim 1 , further comprising a substrate having a plurality of conductive elements disposed thereon, wherein (i) at least two said contacts on the first face of the semiconductor die are each electrically coupled to a different conductive element on the substrate via the ACA and (ii) the at least two said contacts are electrically insulated from each other through the ACA.

24. 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 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.

25. The electronic device of claim 24 , wherein the mixed light is substantially white light.

26. The electronic device of claim 25 , wherein the substantially white light has a correlated color temperature in the range of 2000 K to 10,000 K.

27. The electronic device of claim 24 , wherein the polymeric binder comprises a plurality of discrete regions, at least one of which comprises the polymeric binder without wavelength-conversion material therein.

28. The electronic device of claim 24 , further comprising a reflecting layer over or within at least a portion of the polymeric binder, wherein the reflecting layer has a reflectivity of at least 40% to a wavelength of light emitted by the wavelength-conversion material within the polymeric binder or the light-emitting element.

Assignees

• Tischler Michael A
• Cooledge Lighting Inc

Inventors

• Tischler Michael A

Classifications

• H10W90/00

  Package configurations · CPC title

• H10W74/15

  on active surfaces of flip-chip devices, e.g. underfills · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/9413

  on encapsulations · CPC title

• H10W72/073

  of die-attach connectors · CPC title