Method for manufacturing small crystal resonator

• US 7,138,288 B2
• Filed: 03/25/2004
• Issued: 11/21/2006
• Est. Priority Date: 03/28/2003
• Status: Expired due to Fees

• Current Assignee: Citizen Holdings Co., Ltd. (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Yanagisawa, Tohru, Shioji, Akihiro
• Primary Examiner(s): Smoot, Stephen W.
• Application Number:
  US10/808,485
• Publication Number:
  US 20040191944A1
• Time in Patent Office: 971 Days
• Field of Search: 438/50
• US Class Current: 438/50
• 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 a side electrode shielding/formation block on said crystal substrate through etching by leaving a partial connection section, both said crystal resonator area and said side electrode shielding/formation block being separated from each other by a gap; and

applying vapor deposition through said gap diagonally toward a side of said crystal substrate, whereby a film is formed on said side in a first area but film formation is prevented in a second area of said side due to the existence of said side electrode shielding/formation block, and thereby forming an electrode film bisected in the thickness direction of said substrate on said side.

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

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

45°

to 55°

with respect to said side.

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

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

d≦

0.25t is held where t is the thickness of said vibration section and d is the distance between two bisected electrodes on said side, said side being on a tine for detection of Coriolis force.

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 said base, and

wherein said electrode film is divided into upper and lower portions on said side, said side being a side of said vibration section and a side of said 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

wherein said electrode film is divided into upper and lower portions on said side, said side being on a 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 said base, and

wherein part of said side electrode shielding/formation block is provided between said vibration tines.