Zirconia diaphragm structure and piezoelectric/electrostrictive element incorporating same

• US 5,517,076 A
• Filed: 10/12/1994
• Issued: 05/14/1996
• Est. Priority Date: 10/14/1993
• Status: Expired due to Term

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Takeuchi, Yukihisa, Takeuchi, Katsuyuki, Nanataki, Tsutomu, Masumori, Hideo
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US08/321,912
• Time in Patent Office: 580 Days
• Field of Search: 310/324, 310/328, 310/358
• US Class Current: 310/358
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2237/348 Zirconia, hafnia, zirconates or hafnates
• CPC Class Codes: C04B 2237/704 of one or more of the ceramic layers or articles
• CPC Class Codes: C04B 2237/80 Joining the largest surface of one substrate with a smaller surface of the other substrate, e.g. butt joining or forming a T-joint
• CPC Class Codes: C04B 35/486 Fine ceramics
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/008 using piezoelectric devices piezoelectric resonators G01L9/0022; surface acoustic waves G01L9/0025
• CPC Class Codes: H10N 30/2047 Membrane type

Abstract

A zirconia diaphragm structure, and a method of producing such structure. The zirconia diaphragm structure includes a zirconia substrate having at least one window, and a zirconia diaphragm plate formed integrally with the zirconia substrate so as to close each window, the zirconia substrate comprising a zirconia material as a major component, and containing 0.1-5.0% by weight of one of combinations consisting of (i) alumina and calcia, (ii) alumina, calcia and magnesia, (iii) alumina, calcia and silica, and (iv) alumina, calcia, magnesia and silica.

Claims

1. A zirconia diaphragm structure comprising:

a zirconia substrate having at least one window and containing 0.1-5.0% by weight of one of combinations consisting of (i) alumina and calcia, (ii) alumina, calcia and magnesia, (iii) alumina, calcia and silica, and (iv) alumina, calcia, magnesia and silica;

a zirconia diaphragm plate formed integrally with said zirconia substrate to close each of said at least one window of said zirconia substrate, at an open end of said each window, said diaphragm plate including at least one diaphragm portion which corresponds to said at least one window.

2. A zirconia diaphragm structure according to claim 1, wherein said zirconia substrate and said zirconia diaphragm plate comprise partially stabilized zirconia as a major component.

3. A zirconia diaphragm structure according to claim 1, wherein said zirconia substrate contains 0.1-5.0% by weight of alumina and calcia.

4. A zirconia diaphragm structure according to claim 3, wherein said zirconia substrate contains 0.5-3.0% by weight of alumina and calcia.

5. A zirconia diaphragm structure according to claim 1, wherein said zirconia substrate contains 0.1-5.0% by weight of alumina, calcia and magnesia.

6. A zirconia diaphragm structure according to claim 5, wherein said zirconia substrate contains 0.5-3.0% by weight of alumina, calcia and magnesia.

7. A zirconia diaphragm structure according to claim 1, wherein said zirconia substrate contains 0.1-5.0% by weight of alumina, calcia and silica.

8. A zirconia diaphragm structure according to claim 7, wherein said zirconia substrate contains 0.3-3.0% by weight of alumina, calcia and silica.

9. A zirconia diaphragm structure according to claim 1, wherein said zirconia substrate contains 0.1-5.0% by weight of alumina, calcia, magnesia and silica.

10. A zirconia diaphragm structure according to claim 9, wherein said zirconia substrate contains 0.3-3.0% by weight of alumina, calcia, magnesia and silica.

11. A piezoelectric/electrostrictive film element comprising:

a zirconia diaphragm structure including a zirconia substrate, and a zirconia diaphragm plate formed integrally with said zirconia substrate, said zirconia substrate having at least one window and containing 0.1-5.0% by weight of one of combinations consisting of (i) alumina and calcia, (ii) alumina, calcia and magnesia, (iii) alumina, calcia and silica, and (iv) alumina, calcia, magnesia and silica, said zirconia diaphragm plate closing each of said at least one window of said zirconia substrate, at an open end of said each window, said diaphragm plate including at least one diaphragm portion which corresponds to said at least one window; and

at least one piezoelectric/electrostrictive unit formed on said zirconia diaphragm structure, each of said at least one piezoelectric/electrostrictive unit including a lower and an upper electrode and a piezoelectric/electrostrictive layer interposed between said lower and upper electrodes.