Ceramic substrate, ceramic package for housing light emitting element

• US 20060147746A1
• Filed: 12/02/2005
• Published: 07/06/2006
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: NGK Spark PLUG Company Limited (Niterra Co., Ltd.)
• Original Assignee: NGK Spark PLUG Company Limited (Niterra Co., Ltd.)
• Inventors: Uchida, Atsushi, Kimura, Kazuo, Nagai, Makoto, Wakako, Hisashi, Morita, Masahito
• Granted Patent: US 7,648,775 B2
• Time in Patent Office: Days
• US Class Current: 428/627
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48235 connecting the wire to a via metallisation of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• 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 2924/00014 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 2924/1301 Thyristor
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H05K 1/0274 Optical details, e.g. printed circuits comprising integral optical means H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/092 Dispersed materials, e.g. conductive pastes or inks
• CPC Class Codes: H05K 1/183 Components mounted in and supported by recessed areas of the printed circuit board
• CPC Class Codes: H05K 2201/0347 Overplating, e.g. for reinforcing conductors or bumps; Plating over filled vias
• CPC Class Codes: H05K 2201/09781 Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2201/2054 Light-reflecting surface, e.g. conductors, substrates, coatings, dielectrics
• CPC Class Codes: H05K 3/246 Reinforcing conductive paste, ink or powder patterns by other methods, e.g. by plating
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence
• CPC Class Codes: Y10T 428/12361 : having aperture or cut
• CPC Class Codes: Y10T 428/12528 : Semiconductor component
• CPC Class Codes: Y10T 428/12576 : Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/12611 : Oxide-containing component
• CPC Class Codes: Y10T 428/12639 : Adjacent, identical composition, components
• CPC Class Codes: Y10T 428/12806 : Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/12819 : Group VB metal-base component
• CPC Class Codes: Y10T 428/12826 : Group VIB metal-base component
• CPC Class Codes: Y10T 428/1284 : W-base component
• CPC Class Codes: Y10T 428/12861 : Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12868 : Group IB metal-base component alternative to platinum group metal-base component [e.g., precious metal, etc.]
• CPC Class Codes: Y10T 428/12875 : Platinum group metal-base component
• CPC Class Codes: Y10T 428/12889 : Au-base component
• CPC Class Codes: Y10T 428/12896 : Ag-base component
• CPC Class Codes: Y10T 428/12903 : Cu-base component
• CPC Class Codes: Y10T 428/12944 : Ni-base component
• CPC Class Codes: Y10T 428/131 : Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]
• CPC Class Codes: Y10T 428/1317 : Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/26 : Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/265 : 1 mil or less

Abstract

A ceramic substrate comprising a metallic layer on its surface, wherein said metallic layer includes: a silver layer containing silver; a gold layer containing gold; and a nickel layer containing nickel, in this order from an outermost layer of said metallic layer.

Claims

1. A ceramic substrate comprising a metallic layer on its surface, wherein said metallic layer includes:

a silver layer containing silver;

a gold layer containing gold; and

a nickel layer containing nickel, in this order from an outermost layer of said metallic layer.

5. The ceramic substrate according to claim 1, wherein said metallic layer further includes a metallized layer containing tungsten or molybdenum, so that said metallized layer, said nickel layer, said gold layer and said silver layer are provided in this order.

6. The ceramic substrate according to claim 1, wherein said gold layer provided between said nickel layer and said silver layer has a thickness being smaller than that of said nickel layer and being smaller than that of said silver layer.

7. The ceramic substrate according to claim 1, wherein said silver layer has a thickness of more than 3 μ

m and no more than 20 μ

m.

8. The ceramic substrate according to claim 1, wherein said nickel layer has a thickness of from 0.5 to 20 μ

m, said gold layer has a thickness of from 0.03 to 0.20 μ

m, and said silver layer has a thickness of more than 3 μ

m and no more than 20 μ

m.

9. The ceramic substrate according to claim 1, wherein said silver layer has a thickness of more than 3 μ

m and no more than 10 μ

m.

10. The ceramic substrate according to claim 1, wherein said silver layer has a surface glossiness of 0.2 or more.

11. The ceramic substrate according to claim 1, wherein said silver layer has a center-line average surface roughness of 3 μ

m or less.

2. A ceramic substrate for housing a semiconductor element, comprising:

a substrate body;

a cavity formed in said substrate body for housing said semiconductor element; and

a metallic layer on an inner face of said cavity,

wherein said metallic layer includes;

a silver layer containing silver;

a layer containing a metal being other than silver and being nobler than nickel; and

a nickel layer containing nickel, in this order from an outermost layer of said metallic layer.

3. The ceramic substrate according to claim 2, wherein said metal being other than silver and being nobler than nickel is at least one of Ru, Rh, Pd, Os, Ir, Pt, Cu and Au.

4. The ceramic substrate according to claim 2, wherein said metal being other than silver and being nobler than nickel is Au.

12. A ceramic package comprising:

a substrate body comprising ceramics;

a cavity opened in a surface of said substrate body for mounting a light emitting element on its bottom face; and

a light reflecting layer provided on a side face of said cavity,

wherein said light reflecting layer includes a silver layer containing silver and having a thickness of more than 3 μ

m and no more than 10 μ

m.

13. The ceramic package according to claim 12, wherein said silver layer has a surface glossiness of 0.2 or more.

14. The ceramic package according to claim 12, wherein said silver layer has a center-line average surface roughness of 3 μ

m or less.