Vibration gyro sensor and method for producing vibration gyro sensor

• US 6,391,672 B2
• Filed: 01/18/2001
• Issued: 05/21/2002
• Est. Priority Date: 10/15/1996
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Namerikawa, Masahiko, Takeuchi, Yukihisa, Shibata, Kazuyoshi
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): Simkovic, Viktor
• Application Number:
  US09/765,031
• Publication Number:
  US 20010013252A1
• Time in Patent Office: 488 Days
• Field of Search: 438/50, 438/51, 438/52, 438/53, 735/141.2, 735/141.3, 735/141.4, 735/140.2, 735/140.3, 735/140.4
• US Class Current: 438/50
• CPC Class Codes: G01C 19/5677 of essentially two-dimensional vibrators, e.g. ring-shaped vibrators

Abstract

Disclosed is a vibration gyro sensor comprising an annular frame having an approximately square planar contour with a central opening having an approximately circular planar configuration, an annular section arranged in the opening of the annular frame and having an approximately circular planar contour for constructing a vibrator, and a plurality of resilient sections which span the inner circumference of the annular frame and the outer circumference of the annular section, wherein the annular frame, the annular section, and the plurality of resilient sections are constructed by an integrated fired product made of ceramics. The vibration gyro sensor further comprises piezoelectric/electrostrictive elements (driving piezoelectric/electrostrictive elements and detecting piezoelectric/electrostrictive elements) formed on upper surfaces of the respective resilient sections. Each of the resilient sections has a thickness in its direction of height designed to be smaller than a thickness of the annular section, which is thus thin-walled so that the rigidity in the direction of vibration of the piezoelectric/electrostrictive elements is lowered to give a large amplitude of vibration caused on the annular section (vibrator).

Claims

1. A method for producing a vibration gyro sensor, comprising the steps of:

shaping a spacer layer, a substrate layer, and a thin plate layer composed of green sheets respectively;

stacking and integrating said spacer layer, said substrate layer, and said thin plate layer after said shaping respectively, followed by firing to produce a fired product having, in an integrated manner, an annular section, a support member for resiliently supporting said annular section, and a plurality of resilient sections provided between said support member and said annular section;

forming at least piezoelectric/electrostrictive elements at predetermined regions on said thin plate layer in accordance with a film formation method;

applying a trimming treatment to electrodes of said piezoelectric/electrostrictive elements to adjust electric characteristics; and

applying a trimming treatment to at least said annular section and said resilient sections to adjust mechanical characteristics.

2. A method for producing a vibration gyro sensor, comprising the steps of:

shaping a substrate layer and a spacer layer composed of green sheets respectively;

stacking and integrating said substrate layer and said spacer layer after said shaping together with an unshaped thin plate layer, followed by firing;

shaping said thin plate layer to produce a fired product having, in an integrated manner, an annular section, a support member for resiliently supporting said annular section, and a plurality of resilient sections provided between said support member and said annular section;

forming at least piezoelectric/electrostrictive elements at predetermined regions on said thin plate layer in accordance with a film formation method;

applying a trimming treatment to electrodes of said piezoelectric/electrostrictive elements to adjust electric characteristics; and

applying a trimming treatment to at least said annular section and said resilient sections to adjust mechanical characteristics.

3. A method for producing a vibration gyro sensor, comprising the steps of:

shaping a substrate layer and a spacer layer composed of green sheets respectively;

stacking and integrating said substrate layer and said spacer layer after said shaping together with an unshaped thin plate layer, followed by firing;

forming at least piezoelectric/electrostrictive elements at predetermined regions on said thin plate layer in accordance with a film formation method;

applying a trimming treatment to electrodes of said piezoelectric/electrostrictive elements to adjust electric characteristics;

shaping said thin plate layer to produce a fired product having, in an integrated manner, an annular section, a support member for resiliently supporting said annular section, and a plurality of resilient sections provided between said support member and said annular section; and

applying a trimming treatment to at least said annular section and said resilient sections to adjust mechanical characteristics.

4. A method for producing a vibration gyro sensor, comprising the steps of:

shaping a substrate layer composed of a green sheet to form connecting sections between a portion to be subsequently formed into an annular section and a portion to be subsequently formed into a support member;

shaping a spacer layer composed of a green sheet;

stacking and integrating said substrate layer and said spacer layer after said shaping together with an unshaped thin plate layer, followed by firing;

forming at least piezoelectric/electrostrictive elements at predetermined regions on said thin plate layer in accordance with a film formation method;

shaping said thin plate layer to produce a fired product having, in an integrated manner, said annular section, said support member for resiliently supporting said annular section, and a plurality of resilient sections provided between said support member and said annular section;

cutting said connecting sections remaining in said substrate layer;

applying a trimming treatment to electrodes of said piezoelectric/electrostrictive elements to adjust electric characteristics; and

applying a trimming treatment to at least said annular section and said resilient sections to adjust mechanical characteristics.