Method for manufacturing samll crystal resonator

• US 20040191944A1
• Filed: 03/25/2004
• Published: 09/30/2004
• Est. Priority Date: 03/28/2003
• Status: Active Grant

• Current Assignee: Citizen Holdings Co., Ltd. (Citizen Electronics Company Limited)
• Original Assignee: Citizen Holdings Co., Ltd. (Citizen Electronics Company Limited)
• Inventors: Shioji, Akihiro, Yanagisawa, Tohru
• Granted Patent: US 7,138,288 B2
• Time in Patent Office: Days
• US Class Current: 438/48
• CPC Class Codes: H03H 2003/026 the resonators or networks being of the tuning fork type
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 9/215 consisting of quartz
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A crystal resonator area and side electrode shielding/formation blocks thereabout are formed on a crystal substrate through etching with both areas kept separate from each other with a gap. Vapor deposition is diagonally applied through this gap toward the side of the crystal substrate to thereby form an electrode film divided into two portions in the thickness direction of the substrate on the side.

Claims

1. A method of manufacturing a crystal resonator using a crystal substrate, comprising the steps of:

forming a crystal resonator area and side electrode shielding/formation blocks thereabout on said crystal substrate through etching by leaving a partial connection section and with both areas kept separate from each other with a gap; and

applying vapor deposition through said gap diagonally toward the side of said crystal substrate, producing an area where a film is formed on said side and an area where film formation is prevented by the existence of the side electrode shielding/formation blocks and thereby forming an electrode film bisected in the thickness direction of the substrate on the side.

2. The method of manufacturing a small crystal resonator according to claim 1, wherein by adjusting the size of the gap between said crystal resonator area and the side electrode shielding/formation block, said side electrode shielding/formation block is constructed of an area where said bisected electrode film is formed and an area where formation of the electrode film is prevented.

3. The method of manufacturing a small crystal resonator according to claim 1, wherein vapor deposition toward the side of said crystal substrate is performed in a range of angle of incidence of ±

45°

to 55°

with respect to the side of the crystal substrate.

4. The method of manufacturing a small crystal resonator according to claim 1, wherein said electrode film divided into upper and lower portions is formed on the side of the vibration section of the crystal resonator.

5. The method of manufacturing a small crystal resonator according to claim 4, wherein 0.15 t ≦

d≦

0.25 t is held where t is the thickness of said vibration section and d is said gap.

6. The method of manufacturing a small crystal resonator according to claim 1, wherein said crystal resonator is a quartz crystal tuning fork including a vibration section made up of a base and a plurality of vibration tines which extend from the base and said electrode film divided into upper and lower portions is formed on the side of the vibration section and the side of the base.

7. The method of manufacturing a small crystal resonator according to claim 1, wherein said crystal resonator is a resonator for a vibration gyro having three vibration tines and said electrode film divided into upper and lower portions is provided on the side of the tine for detection of Coriolis force out of said three vibration tines.

8. The method of manufacturing a small crystal resonator according to any one of claims 1 to 7, wherein the thickness t of said crystal resonator is 100 μ

m ≦

t≦

350 μ

m.

9. The method of manufacturing a small crystal resonator according to claim 1, wherein said crystal resonator is a quartz crystal tuning fork including a vibration section made up of a base and a plurality of vibration tines which extend from the base and part of side electrode shielding/formation block is provided so as to insert between said vibration tines.

10. A small crystal resonator created using the manufacturing method according to any one of claims 1 to 9 claims 1 to 7 and 9.

11. A small crystal resonator created using the manufacturing method according to claim 8.