Method of manufacturing a piezoelectric device

• US 6,584,660 B1
• Filed: 06/08/1994
• Issued: 07/01/2003
• Est. Priority Date: 06/08/1993
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited, Seiko Epson Corporation (Seiko Group)
• Original Assignee: NGK Insulators Limited, Seiko Epson Corporation (Seiko Group)
• Inventors: Kimura, Koji, Takeuchi, Yukihisa, Shimogawa, Natsumi
• Primary Examiner(s): Tugbang, A. Dexter
• Application Number:
  US08/257,020
• Time in Patent Office: 3,310 Days
• Field of Search: 310/328, 310/357-359, 310/330-332, 310/366, 310/367, 310/368, 347/68, 347/71, 29/253.5, 298/901, 298/52, 219/121.68, 219/121.69
• US Class Current: 29/25.35
• CPC Class Codes: B41J 2/14233 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: H04R 17/08 signals being recorded or played back by vibration of a stylus in two orthogonal directions simultaneously
• CPC Class Codes: H10N 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49401 Fluid pattern dispersing device making, e.g., ink jet

Abstract

A method for making a piezoelectric device wherein residual stresses in the piezoelectric transducer element of the piezoelectric device are relieved by forming a groove or grooves extending into a thick-walled region of the peripheral wall of a ceramic substrate in the piezoelectric device. The stresses to be relieved are caused by a difference in shrinkage between the ceramic substrate and the piezoelectric transducer as a result of sintering the substrate and the transducer to form an integral product.

Claims

1. A method of manufacturing a piezoelectric device comprising (i) a ceramic substrate having at least one a cavity therein defined by a thin-walled diaphragm region and at least one peripheral wall having a thick-walled region surrounding the cavity;

(ii) at least one film-type piezoelectric transducer formed integrally with the ceramic substrate by sintering and arranged on an outer surface of said thin-walled diaphragm region, wherein said film-type piezoelectric transducer is comprised of a material that is different from a material of said ceramic substrate, said method comprising the step of;

relieving residual stresses in the piezoelectric transducer arising from a difference in shrinkage between said ceramic substrate and said piezoelectric transducer as a result of said sintering, by forming, after integration of said at least one film-type piezoelectric transducer with said ceramic substrate by said sintering, at least one groove that extends into said thick-walled region along said peripheral wall.

2. The method according to claim 1, wherein said groove is formed so as to permit simultaneous displacements of said thin-walled diaphragm region and said thick-walled region between said cavity and said groove, to thereby cause a volumetric change of said cavity.

3. The method according to claim 1, wherein said groove has a depth that is greater than the thickness of said thin-walled diaphragm region.

4. The method according to claim 1, wherein said at least one groove is formed by a laser beam process.

5. The method according to claim 4, wherein said laser beam process is performed by using a Nd-YAG laser having a Gaussian energy distribution in the beam and using a TEM 00 single mode resonance.

6. The method according to claim 4, wherein said laser beam process is performed by controlling a pulse width of the laser beam to be 140 ns or less.

7. The method according to claim 6, wherein said laser beam process is performed by controlling the pulse width to be 100 ns or less.

8. The method according to claim 4, wherein said laser beam process is performed by carrying out a pulsation control by means of a Q-switch at a predetermined frequency.

9. The method according to claim 4, wherein said laser beam process is performed by concentrating the laser beam diameter to be 50 μ

m or less.

10. The method according to claim 9, wherein said laser beam process is performed by concentrating the laser beam diameter to be within a range of 5-10 μ

m.

11. The method according to claim 9, wherein said laser beam process is performed at a speed of 50 mm/sec or less.

12. The method according to claim 1, wherein said groove is formed to have a length that is at least ⅛

of the length of a longitudinal edge of the cavity.

13. The method according to claim 12, wherein said groove is formed to have a length that is at least ¼

of the length of the longitudinal edge of the cavity.