Semiconductor light-emitting element assembly with a composite substrate

• US 7,745,832 B2
• Filed: 09/12/2005
• Issued: 06/29/2010
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Tsai, Chia-Fen, Wang, Jen-Shui, Yin, Chou-Chih, Hsu, Chia-Liang, Hsieh, Min-Hsun, Wang, Chien-Yuan
• Primary Examiner(s): Purvis; Sue
• Assistant Examiner(s): QUINTO, KEVIN V
• Application Number:
  US11/222,803
• Publication Number:
  US 20060076571A1
• Time in Patent Office: 1,751 Days
• Field of Search: 257/79, 257/88, 257/99, 257/100, 257/678, 257/680, 257/701, 257/706, 257/E23.101, 257/E23.11, 257/E23.111, 257/E23.112, 257/E23.113, 257E33001-E33077
• US Class Current: 257/79
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/641 characterized by the materials

Abstract

A semiconductor light-emitting element assembly, comprising a composite substrate, a circuit layout carrier, a connecting structure, a recess, and a semiconductor light-emitting element, is disclosed. The connecting structure is used for bonding the composite substrate with the circuit layout carrier. The recess is formed by the circuit layout carrier and extends toward the composite substrate. The semiconductor light-emitting element is deposited in the recess and electrically connected to the circuit layout carrier.

Claims

1. A semiconductor light-emitting element assembly comprising:

a composite substrate with a thermal expansion coefficient substantially smaller than or equal to 12×

10<sup>−

6</sup>/°

C., and a thermal conductivity coefficient substantially greater than or equal to 150 W/mK;

a circuit layout carrier;

a connecting structure for bonding the composite substrate with the circuit layout carrier;

a semiconductor light-emitting element disposed on one side of the composite substrate and electrically connected to the circuit layout carrier; and

a recess formed on the circuit layout carrier and extending toward the composite substrate, wherein the semiconductor light-emitting element is deposited in the recess.

2. The semiconductor light-emitting element assembly of claim 1, wherein the composite material is selected from a group consisting of a metal matrix composite (MMC), a polymer matrix composite (PMC), ceramic matrix composite (CMC), and combinations thereof.

3. The semiconductor light-emitting element assembly of claim 1, wherein the difference between a thermal expansion coefficient of the semiconductor light-emitting element and the thermal expansion coefficient of the composite substrate is substantially smaller than or equal to 10×

10<sup>−

6</sup>/°

C.

4. The semiconductor light-emitting element assembly of claim 1, wherein the circuit layout carrier is selected from a group consisting of a semiconductor substrate, a printed circuit board (PCB), a flexible printed circuit (FPC), a Si substrate, a ceramic substrate and an equivalent or combination thereof.

5. The semiconductor light-emitting element assembly of claim 1, wherein the composite substrate comprises a composite material that includes a fiber that is one of a carbon fiber and a ceramic fiber, and the composite material is formed by mixing the fiber with one of metals, polymers and ceramics.

6. The semiconductor light-emitting element assembly of claim 1, wherein the connecting structure comprises a flexible adhesive layer.

7. The semiconductor light-emitting element assembly of claim 6, wherein the flexible adhesive layer comprises a material selected from a group consisting of benzocyclobutene (BCB), epoxy, polyimide, SOG (Spin On Glass), silicone, solder, and an equivalent or combination thereof.

8. The semiconductor light-emitting element assembly of claim 6, wherein the connecting structure further comprises:

a reaction layer formed on one side of the flexible adhesive layer.

9. The semiconductor light-emitting element assembly of claim 8, wherein the reaction layer comprises a material selected from the group consisting of silicon nitride (SiN_x), epoxy, titanium (Ti), chromium (Cr), and an equivalent or combinations thereof.

10. The semiconductor light-emitting element assembly of claim 1, wherein the connecting structure comprises a plurality of metal layers connecting the semiconductor light-emitting element and the composite substrate by eutectic bonding.

11. The semiconductor light-emitting element assembly of claim 1, wherein the recess is formed in a tapered shape.

12. The semiconductor light-emitting element assembly of claim 1, wherein the recess contains a reflection layer.

13. The semiconductor light-emitting element assembly of claim 1, further comprising:

a light pervious member covering the recess.

14. The semiconductor light-emitting element assembly of claim 13, further comprising:

a wavelike array formed on the light pervious member and having a wavefront direction.

15. The semiconductor light-emitting element assembly of claim 14, wherein the semiconductor light-emitting element is substantially arranged in accordance with the wavefront direction.

16. The semiconductor light-emitting element assembly of claim 13, wherein the light pervious member is an optical lens.

17. The semiconductor light-emitting element assembly of claim 13, wherein the light pervious member comprises:

a light-entering surface facing to the semiconductor light-emitting element;

a recessed opening; and

a wing-shaped protrusion part extending from the recessed opening and towards two opposite sides of the recessed opening.

18. The semiconductor light-emitting element assembly of claim 17, wherein the recessed opening has an apex pointing to the light-entering surface.

19. The semiconductor light-emitting element assembly of claim 1, further comprising:

a wavelength-converting material disposed above the semiconductor light-emitting element for converting a wavelength of light.

20. The semiconductor light-emitting element assembly of claim 19, wherein the wavelength-converting material is selected from a group consisting of a fluorescent powder, a color filter, and an equivalent or combination thereof.

23. The semiconductor light-emitting element assembly of claim 1, wherein the semiconductor light-emitting element is selected from a group consisting of a light-emitting diode (LED), a laser diode (LD), and an equivalent or combination thereof.

24. The semiconductor light-emitting element assembly of claim 1, wherein the semiconductor light-emitting element is in a flip-chip structure.

25. The semiconductor light-emitting element assembly of claim 24, further comprising an electrical contact forming on at least one portion of the surface of the recess and electrically connected to the semiconductor light-emitting element and the circuit layout carrier.

26. The semiconductor light-emitting element assembly of claim 1, further comprising:

a convective heat transfer device connected to the composite substrate for cooling the composite substrate by heat convection.

27. The semiconductor light-emitting element assembly of claim 26, wherein the convective heat transfer device is selected from a group consisting of heat dissipation fins, porous ceramic material, porous composite material, and an equivalent or combination thereof.

28. The semiconductor light-emitting element assembly of claim 1, wherein the semiconductor light-emitting element is electrically connected to the composite substrate.

29. The semiconductor light-emitting element assembly of claim 28, wherein the semiconductor light-emitting element is electrically connected to a bottom electrical contact disposed on the other side the composite substrate.

30. The semiconductor light-emitting element assembly of claim 28, wherein the composite substrate is formed with a conductive through hole for electrically connecting to the semiconductor light-emitting element.

31. The semiconductor light-emitting element assembly of claim 1, wherein the semiconductor light-emitting element comprises:

an ultraviolet (UV) light emitter;

a wavelength-converting material being irradiated by the UV light emitter and emitting visible light.

32. The semiconductor light-emitting element assembly of claim 31, wherein the wavelength-converting material comprises europium(Eu)-activating alkaline earth silicate.

21. A semiconductor light-emitting element assembly, comprising:

a composite substrate with a thermal expansion coefficient substantially smaller than or equal to 12×

10<sup>−

6</sup>/°

C., and a thermal conductivity coefficient substantially greater than or equal to 150 W/mK;

a circuit layout carrier;

a connecting structure for bonding the composite substrate with the circuit layout carrier;

a semiconductor light-emitting element disposed on one side of the composite substrate and electrically connected to the circuit layout carrier; and

a planarizing layer formed between the composite substrate and the connecting structure.

22. The semiconductor light-emitting element assembly of claim 21, wherein the planarizing layer comprises nickel (Ni) or a material adherable to the connecting structure.