Vibrating piece manufacturing method and vibrator manufacturing method

• US 8,191,216 B2
• Filed: 01/06/2009
• Issued: 06/05/2012
• Est. Priority Date: 01/15/2008
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yamazaki, Takashi, Funasaka, Tsukasa, Funakawa, Takeo, Furuhata, Makoto
• Primary Examiner(s): Tugbang, A. Dexter
• Application Number:
  US12/349,201
• Publication Number:
  US 20090178260A1
• Time in Patent Office: 1,246 Days
• Field of Search: 29/253.5, 295/94, 298/962.2, 298/46, 298/47, 310/348, 310/370, 310/378, 216/41, 216/52, 438/778
• US Class Current: 29/25.35
• CPC Class Codes: H03H 3/04 for obtaining desired frequency or temperature coefficient
• CPC Class Codes: H03H 9/1021 the BAW device being of the cantilever type
• CPC Class Codes: H03H 9/21 Crystal tuning forks
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49574 Musical instrument or tuning fork making

Abstract

A vibrating piece manufacturing method includes: (a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area; and (b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction.

Claims

1. A vibrating piece manufacturing method, comprising:

(a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area; and

(b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction, wherein;

before step (b), a weight metal film is formed on the second surface of each of the arms,

in step (b), a surface of the weight metal film is also etched, and

in step (b), steps are formed between a part of the second surface of each of the arms covered by the weight metal film and surfaces of etched parts of each of the arms.

2. The vibrating piece manufacturing method according to claim 1, wherein

the supporting body is made of a piezoelectric material.

3. A vibrator manufacturing method comprising:

(a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area;

(b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction, wherein;

before step (b), a weight metal film is formed on the second surface of each of the arms,

in step (b), a surface of the weight metal film is also etched, and

in step (b), steps are formed between a part of the second surface of each of the arms covered by the weight metal film and surfaces of etched parts of each of the arms;

(c) incorporating a vibrating piece manufactured by performing steps (a) and (b), into a package; and

(d) covering an opening of the package with a lid.