Ceramic member and manufacturing method for the same

• US 20060073349A1
• Filed: 09/27/2005
• Published: 04/06/2006
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Nobori, Kazuhiro, Kato, Tsutomu, Matsuda, Hiroto, Aihara, Yasufumi
• Granted Patent: US 7,582,367 B2
• Time in Patent Office: Days
• US Class Current: 428/469
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3246 Stabilised zirconias, e.g. YSZ or cerium stabilised zirconia
• CPC Class Codes: C04B 2235/422 Carbon
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/608 Green bodies or pre-forms with well-defined density
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/786 Micrometer sized grains, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9661 Colour
• CPC Class Codes: C04B 2237/064 based on alumina or aluminates
• CPC Class Codes: C04B 2237/34 Oxidic
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 35/117 Composites
• CPC Class Codes: C04B 35/119 with zirconium oxide
• CPC Class Codes: C04B 35/505 : based on yttrium oxide
• CPC Class Codes: C04B 35/5626 : based on tungsten carbides
• CPC Class Codes: C04B 35/6365 : Cellulose or derivatives thereof
• CPC Class Codes: C04B 35/645 : Pressure sintering
• CPC Class Codes: C04B 37/001 : directly with other burned ceramic articles
• CPC Class Codes: C04B 37/005 : consisting of glass or ceramic material

Abstract

A ceramic member comprises a base including an alumina sintered body, and an yttria sintered body formed on the alumina sintered body and exposed to a corrosive gas; and a metallic member buried in the base.

Claims

1. A ceramic member comprising:

a base including an alumina sintered body, and an yttria sintered body formed on the alumina sintered body and exposed to a corrosive gas; and

a metallic member buried in the base.

2. The ceramic member according to claim 1, wherein a difference in thermal expansion coefficience between the alumina sintered body and the yttria sintered body is equal to or less than about 0.50×

10<sup>−

6</sup>/ K.

3. The ceramic member according to claim 1, wherein thermal expansion coefficience of the alumina sintered body is greater than thermal expansion coefficience of the yttria sintered body.

4. The ceramic member according to claim 1, wherein the alumina sintered body, the yttria sintered body, and the metallic member are formed into an integrated sintered body.

5. The ceramic member according to claim 1, further comprising an intermediate layer including yttrium and aluminium formed between the alumina sintered body and the yttria sintered body.

6. The ceramic member according to claim 5, wherein the intermediate layer includes a plurality of layers having different contents of the yttrium and the aluminium.

7. The ceramic member according to claim 1, wherein the metallic member intervenes between the alumina sintered body and the yttria sintered body.

8. The ceramic member according to claim 1, wherein a difference in thermal expansion coefficience between the metallic member and the alumina sintered body and between the metallic member and the yttria sintered body is equal to or less than about 3×

10<sup>−

6</sup>/ K.

9. The ceramic member according to claim 1, wherein the metallic member is a least one of an electrostatic electrode, a resistance heating element, and an RF electrode.

10. The ceramic member according to claim 1, wherein volume resistivity of the yttria sintered body is equal to or greater than about 1×

10¹⁵Ω

·

cm.

11. The ceramic member according to claim 1, wherein a thickness of the yttria sintered body is about 0.3 to about 0.5 mm.

12. The ceramic member according to claim 1, further comprising:

a terminal connecting the metallic member to a power supply member; and

a connecting member buried in the base, joined with the metallic member and the terminal, and connecting the metallic member to the terminal.

13. The ceramic member according to claim 12, wherein a difference in thermal expansion coefficience between the connecting member and the alumina sintered body is equal to or less than about 2×

10<sup>−

6</sup> /K.

14. The ceramic member according to claim 12, wherein the connecting member includes at least one of platinum and niobium.

15. The ceramic member according to claim 12, wherein a distance between a joint surface of the connecting member and the metallic member and a joint surface of the connecting member and the terminal is equal to or greater than about 1 mm.

16. A manufacturing method for a ceramic member, comprising:

forming an alumina sintered body;

forming an yttria sintered body;

forming a metallic member; and

integrating the alumina sintered body, the yttria sintered body and the metallic member.

17. The manufacturing method according to claim 16, wherein

the alumina sintered body or an alumina presintered body is formed,

the metallic member on the alumina sintered body or the alumina presintered body is formed,

an yttria compact on the metallic member is formed, and

the alumina sintered body or the alumina presintered body, the metallic member, and the yttria compact are integrated by sintering.

18. The manufacturing method according to claim 16, wherein

the yttria sintered body or an yttria presintered body is formed,

the metallic member on the yttria sintered body or the yttria presintered body is formed,

an alumina compact on the metallic member is formed, and

the yttria sintered body or the yttria presintered body, the metallic member, and the alumina compact are integrated by sintering.

19. The manufacturing method according to claim 16, wherein the yttria sintered body is formed using an yttria powder calcined at about 400°

C. or greater.

20. The manufacturing method according to claim 16, wherein the yttria sintered body is formed using an yttria powder, of which a water content is equal to or less than about 1%.

21. The manufacturing method according to claim 16, wherein the yttria sintered body is formed by sintering an yttria compact, of which a density is equal to or less than about 2 g/cc.