Wafer for LED mounting, method for manufacturing same, and LED-mounted structure using the wafer

• US 8,890,189 B2
• Filed: 07/29/2010
• Issued: 11/18/2014
• Est. Priority Date: 07/31/2009
• Status: Active Grant

• Current Assignee: Denki Kagaku Kogyo Kabushiki Kaisha (TDK Corporation)
• Original Assignee: Denki Kagaku Kogyo Kabushiki Kaisha (TDK Corporation)
• Inventors: Hirotsuru, Hideki, Ishihara, Yosuke, Tsukamoto, Hideo
• Primary Examiner(s): Chen, Yu
• Assistant Examiner(s): Kilpatrick, Warren H
• Application Number:
  US13/387,606
• Publication Number:
  US 20120168802A1
• Time in Patent Office: 1,573 Days
• Field of Search: 257/98, 438/106
• US Class Current: 257/98
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/04 by applying fluid pressure , e.g. by cold isostatic pressing [CIP]
• CPC Class Codes: C04B 2235/3826 Silicon carbides
• CPC Class Codes: C04B 2235/427 Diamond
• CPC Class Codes: C04B 2235/5427 millimeter or submillimeter sized, i.e. larger than 0,1 mm
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5472 Bimodal, multi-modal or multi-fraction
• CPC Class Codes: C04B 35/185 Mullite 3Al2O3-2SiO2
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/581 based on aluminium nitride
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4523 applied from the molten state vitreous materials C04B41/5022; Thermal spraying, e.g. plasma spraying
• CPC Class Codes: C04B 41/4529 applied from the gas phase
• CPC Class Codes: C04B 41/4564 Electrolytic or electrophoretic processes, e.g. electrochemical re-alkalisation of reinforced concrete desalination C04B41/53
• CPC Class Codes: C04B 41/4572 Partial coating or impregnation of the surface of the substrate
• CPC Class Codes: C04B 41/4574 Coating different parts of the substrate with different materials
• CPC Class Codes: C04B 41/5031 Alumina
• CPC Class Codes: C04B 41/5111 : Ag, Au, Pd, Pt or Cu
• CPC Class Codes: C04B 41/5116 : Ag or Au
• CPC Class Codes: C04B 41/5144 : with a composition mainly composed of one or more of the metals of the iron group
• CPC Class Codes: C04B 41/5155 : Aluminium
• CPC Class Codes: C04B 41/52 : Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/522 : Multiple coatings, for one of the coatings of which at least one alternative is described
• CPC Class Codes: C04B 41/90 : at least one coating being a metal
• CPC Class Codes: C22C 1/1036 : starting from a melt
• CPC Class Codes: C22C 1/1094 : comprising an after-treatment
• CPC Class Codes: C22C 26/00 : Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
• CPC Class Codes: C22C 29/065 : based on SiC
• CPC Class Codes: C22C 29/16 : based on nitrides containing cubic BN or wurtzitic BN and diamond C22C26/00
• CPC Class Codes: C23C 16/00 : Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes reactive sputtering or vacuum evaporation C23C14/00
• CPC Class Codes: C25D 7/12 : Semiconductors
• 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 33/0093 : Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/60 : Reflective elements
• CPC Class Codes: H01L 33/641 : characterized by the materials
• CPC Class Codes: Y10T 428/23 : Sheet including cover or casing

Abstract

Provided is a wafer for LED mounting having a small difference in thermal expansion coefficient from an LED and having excellent heat conductivity, a method for manufacturing the wafer for LED mounting, and an LED-mounted structure manufactured by using the wafer for LED mounting. The wafer for LED mounting (6) is constituted of a metal infiltrated ceramic composite (61) and a protective layer (62) that is formed therearound. The metal infiltrated ceramic composite (61) preferably has a thin metal layer (63) on a surface thereof. The method for manufacturing the wafer is characterized by comprising filling at least one selected from the group consisted of porous ceramic bodies, ceramic powder compacts and ceramic powders into a tubular body made of metal or ceramic, then impregnating a metal into the void of at least one selected from the group consisted of porous ceramic bodies, ceramic powder compacts and ceramic powders, and thereafter performing a process.

Claims

1. A wafer, comprising:

a metal infiltrated ceramic composite; and

a protective layer formed only around the circumference of the composite.

2. The wafer of claim 1, wherein the composite comprises at least one selected from the group consisting of silicon carbide, aluminum nitride, silicon nitride, diamond, and graphite, and is formed by a process comprising impregnating a porous body or a powder compact having a porosity of 10 to 50 volume % with a metal, and

the composite has a plate thickness of 0.05 to 0.5 mm, a surface roughness (Ra) of 0.01 to 0.5 μ

m, a three-point bending strength of at least 50 MPa, a thermal conductivity of 150 to 500 W/mK at a temperature of 25°

C., a thermal expansion coefficient of 4 to 9×

10<sup>−

6</sup>/K from a temperature of 25°

C. to 150°

C., and a volume resistivity of 10<sup>−

9</sup> to 10<sup>−

5</sup> Ω

·

m.

3. The wafer of claim 1, wherein the protective layer comprises at least one metal selected from the group consisting of Ni, Co, Pd, Cu, Ag, Au, Pt, Ti, W, and Mo, or at least one ceramic having a porosity of at most 3% selected from the group consisting of alumina, mullite, aluminum nitride, and silicon nitride, and the protective layer has a thickness of at most 3 mm (not including 0), and a volume occupancy of the protective layer is at most 20 volume % (not including 0).

4. The wafer of claim 1, wherein the composite comprises, on a surface, a thin metal layer having a thickness of 0.5 to 10 μ

m and comprising at least one metal selected from the group consisting of Ni, Co, Pd, Cu, Ag, Au, Pt, and Sn.

5. The wafer of claim 4, wherein the thin metal layer comprises at least one metal selected from the group consisting of Ni and Au.

6. The wafer of claim 1, wherein the protective layer has a thickness of 0.002 to 2 mm.

7. The wafer of claim 6, wherein a volume occupancy of the protective layer is from 0.1 to 15 volume %.

8. The wafer of claim 7, wherein the protective layer comprises at least one metal selected from the group consisting of Ni, Co, Pd, Cu, Ag, Au, Pt, Ti, W, and Mo.

9. The wafer of claim 8, wherein the protective layer comprises Ni.

10. The wafer of claim 8, wherein the protective layer comprises Ti.

11. The wafer of claim 8, wherein the protective layer comprises W.

12. The wafer of claim 8, wherein the protective layer comprises Mo.

13. The wafer of claim 1, wherein said protective layer surrounds and is in contact with a center portion consisting of said metal infiltrated ceramic composite.

14. The wafer of claim 13, wherein:

the metal infiltrated ceramic composite comprises at least one selected from the group consisting of silicon carbide, aluminum nitride, silicon nitride, diamond, and graphite, and is formed by a process comprising impregnating a porous body or a powder compact having a porosity of 10 to 50 volume % with a metal;

the metal infiltrated ceramic composite has a plate thickness of 0.05 to 0.5 mm, a surface roughness (Ra) of 0.01 to 0.5 μ

m, a three-point bending strength of at least 50 MPa, a thermal conductivity of 150 to 500 W/mK at a temperature of 25°

C., a thermal expansion coefficient of 4 to 9×

10<sup>−

6</sup>/K from a temperature of 25°

C. to 150°

C., and a volume resistivity of 10<sup>−

9</sup> to 10<sup>−

5</sup> Ω

·

m; and

the protective layer comprises at least one metal selected from the group consisting of Ni, Co, Pd, Cu, Ag, Au, Pt, Ti, W, and Mo, or at least one ceramic having a porosity of at most 3% selected from the group consisting of alumina, mullite, aluminum nitride, and silicon nitride, and the protective layer has a thickness of at most 3 mm (not including

     0), and a volume occupancy of the protective layer is at most 20 volume % (not including

     0).

15. A wafer, comprising:

a metal infiltrated ceramic composite; and

a protective layer around the composite,

wherein the protective layer has a thickness of 0.002 to 2 mm;

a volume occupancy of the protective layer is from 0.1 to 15 volume %; and

wherein the protective layer comprises at least one ceramic having a porosity of at most 3% selected from the group consisting of alumina, mullite, aluminum nitride, and silicon nitride.

16. The wafer of claim 15, wherein the protective layer comprises alumina.

17. The wafer of claim 15, wherein the protective layer comprises mullite.

18. The wafer of claim 15, wherein the protective layer comprises aluminum nitride.

19. The wafer of claim 15, wherein the protective layer comprises silicon nitride.