Method for manufacturing vibrating gyrosensor and vibrating element

• US 20060202591A1
• Filed: 02/27/2006
• Published: 09/14/2006
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takahashi, Kazuo, Suzuki, Koji, Honda, Junichi, Inaguma, Teruo, Nakashio, Eiji
• Granted Patent: US 7,723,901 B2
• Time in Patent Office: Days
• US Class Current: 310/348
• CPC Class Codes: B81B 2201/0285 Vibration sensors
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 3/0067 Mechanical properties
• CPC Class Codes: G01C 19/5663 Manufacturing; Trimming; Mounting; Housings
• CPC Class Codes: G01P 15/0802 Details

Abstract

A vibrating gyrosensor includes a support substrate on which a wiring pattern having a plurality of lands is formed, and a vibrating element mounted on a surface of the support substrate. The vibrating element includes a base part having a mounting surface on which a plurality of terminals, and a vibrator part integrally projected in a cantilever manner from one of the sides of the base part and having a substrate-facing surface coplanar with the mounting surface of the base part. The vibrator part has a first electrode layer, a piezoelectric layer, and a second electrode layer, which are formed on the substrate-facing surface in that order. Furthermore, a reinforcing part is formed at the base end of the vibrator part so that the sectional area of the vibrator part gradually increases toward the base part.

Claims

1. A vibrating gyrosensor comprising:

a support substrate on which a wiring pattern having a plurality of lands is formed; and

a vibrating element mounted on a surface of the support substrate;

wherein the vibrating element includes a base part having a mounting surface on which a plurality of terminals to be connected to the lands is formed, and a vibrator part integrally projected in a cantilever manner from one of the sides of the base part and having a substrate-facing surface coplanar with the mounting surface of the base part;

the vibrator part has a first electrode layer, a piezoelectric layer, and a second electrode layer, which are formed on the substrate-facing surface in that order; and

a reinforcing part is formed at the base end of the vibrator part so that the sectional area of the vibrator part gradually increases toward the base part.

2. The vibrating gyrosensor according to claim 1, wherein the upper surface of the vibrator part is stepped down from the upper surface of the base part through an inclined part;

and

the reinforcing part is formed on the upper surface of the base end of the vibrator part along the inclined part.

3. The vibrating gyrosensor according to claim 1, wherein the reinforcing part is formed so that the width of the base end of the vibrator part gradually increases toward the side of the base part.

4. The vibrating gyrosensor according to claim 3, wherein the reinforcing part is curved at both sides of the base end of the vibrator part.

5. The vibrating gyrosensor according to claim 1, wherein the edges between the upper surface and the both side surfaces of the vibrator part are melted to form chamfered parts.

6. The vibrating gyrosensor according to claim 1, wherein at least one of the edges between the upper surface and the side surfaces of the vibrator part is curved.

7. The vibrating gyrosensor according to claim 1, wherein at least a portion of the surfaces other than the substrate-facing surface of the vibrator part is melted to form a smooth surface.

8. A vibrating gyrosensor comprising:

a support substrate on which a wiring pattern having a plurality of lands is formed; and

a vibrating element mounted on a surface of the support substrate;

wherein the vibrating element includes a base part having a mounting surface on which a plurality of terminals to be connected to the lands is formed, and a vibrator part integrally projected in a cantilever manner from one of the sides of the base part and having a substrate-facing surface coplanar with the mounting surface of the base part;

the vibrator part has a first electrode layer, a piezoelectric layer, a second electrode layer, and an insulating protective layer for sealing the first electrode layer, the piezoelectric layer, and the second electrode layer, which are formed on the substrate-facing surface in that order; and

a reinforcing part is formed at the base end of the vibrator so that the sectional area of the vibrator part gradually increases toward the base part.

9. The vibrating gyrosensor according to claim 8, wherein the insulating protective layer contains at least a silicon oxide layer.

10. The vibrating gyrosensor according to claim 9, wherein an adhesive layer is formed on at least the lower side of the silicon oxide layer.

11. The vibrating gyrosensor according to claim 10, wherein the adhesive layer is an alumina layer.

12. The vibrating gyrosensor according to claim 8, wherein the insulating protective layer has a thickness of at least 2 times that of the second electrode layer.

13. The vibrating gyrosensor according to claim 8, wherein the insulating protective layer is wider than the first electrode layer and is formed so that the substrate-facing surface of the vibrator is exposed along the peripheral line of the vibrator part.

14. The vibrating gyrosensor according to claim 8, wherein a curvature control film is formed on the upper surface of the vibrator part, for controlling the curvature of the vibrator.

15. The vibrating gyrosensor according to claim 14, wherein the curvature of the vibrator part is within ±

5 μ

m.

16. A vibrating gyrosensor comprising:

a support substrate on which a wiring pattern having a plurality of lands is formed; and

a vibrating element mounted on a surface of the support substrate;

wherein the vibrating element is formed using an undoped single crystal silicon substrate as a base material and includes a base part having a mounting surface on which a plurality of terminals to be connected to the lands is formed, and a vibrator part integrally projected in a cantilever manner from one of the sides of the base part and having a substrate-facing surface coplanar with the mounting surface of the base part;

the vibrator has a first electrode layer, a piezoelectric layer, and a second electrode layer, which are formed on the substrate-facing surface in that order; and

a reinforcing part is formed at the base end of the vibrator part so that the sectional area of the vibrator gradually increases toward the base part.

17. The vibrating gyrosensor according to claim 16, wherein the undoped single crystal silicon substrate has a volume resistivity of 100 Ω

·

cm or more.

18. The vibrating gyrosensor according to claim 16, wherein the surface of the support substrate is covered with a light-shielding cover member.

19. A method for manufacturing a vibrating gyrosensor including vibrating elements each including a base part having a mounting surface on which a plurality of terminal parts is formed, and a vibrator part integrally projected in a cantilever manner from one of the sides of the base part and having a substrate-facing surface coplanar with the component surface of the base part, the vibrator part having a first electrode layer, a piezoelectric layer, and a second electrode layer laminated, which are formed on the substrate-facing surface in that order, the method comprising the steps of:

forming an etched recess in a first main surface of the silicon substrate by etching so that the etched recess has an etched inclined surface inclined at a predetermined inclination angle and a depth corresponding to the thickness of the vibrator part of the vibrating element from the first main surface;

forming the piezoelectric layer and the first and second electrode layers on a second main surface opposite to the etched recess of the silicon substrate;

forming a U-shaped outside groove within the etched groove by pattering so that the outside groove includes a through groove for forming the outer shape of the vibrator part; and

cutting the silicon substrate until both ends of the outside groove to cut out the base part of the vibrating element;

wherein in the step of forming the outside groove, both ends of the outside groove are formed at intermediate positions of the etched recess so as to form a reinforcing part at the base end of the vibrator part so that the sectional area of the vibrator gradually increases toward the base part.

20. The method according to claim 19, wherein the step of forming the outside groove includes the step of forming a resist pattern having an aperture on the second main surface of the silicon substrate, the aperture corresponding to the formation portion of the outside groove, and the resist pattern being curved at positions corresponding to both ends of the outside groove.

21. The method according to claim 19, wherein in the step of forming the outside groove, the bottom of the outside groove is overetched.

22. The method according to claim 19, further comprising the step of forming a chamfered part by laser irradiation melting a portion of the edges of the vibrator part after the cutting step.

23. The method according to claim 19, further comprising the step of forming a smooth surface by laser irradiation melting at least a portion of the surfaces other than the substrate-facing surface of the vibrator part after the cutting step.

24. The method according to claim 19, further comprising the step of forming an insulating protective layer on the substrate-facing surface of the vibrator part to seal the piezoelectric layer and the first and second electrode layers after the electrode forming step.

25. The method according to claim 24, wherein the step of forming the insulating protective layer includes the steps of forming an adhesive layer on the substrate-facing surface of the vibrator part, and forming a silicon oxide layer on the adhesive layer.

26. The method according to claim 25, wherein the silicon oxide layer is formed by sputtering in an argon gas atmosphere at a pressure of the discharge lower limit to 0.4 Pa.

27. The method according to claim 25, wherein the step of forming the insulating protective layer further includes the step of forming a resist adhesive layer on the silicon oxide layer.

28. The method according to claim 19, further comprising the step of forming a curvature control film on the surface opposite to the substrate-facing surface of the vibrator part, for controlling the curvature of the vibrator part.

29. The method according to claim 19, wherein an undoped single crystal silicon substrate cut out so that a main surface is a (100) orientation surface and a side surface is a (110) orientation surface is used as the silicon substrate.