Method for adjusting piezoelectric/electrostrictive device

• US 8,680,742 B2
• Filed: 10/05/2012
• Issued: 03/25/2014
• Est. Priority Date: 04/18/2008
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Goto, Naoki, Ohnishi, Takao
• Primary Examiner(s): Dougherty, Thomas
• Application Number:
  US13/645,829
• Publication Number:
  US 20130093291A1
• Time in Patent Office: 536 Days
• Field of Search: 310/312, 310/365
• US Class Current: 310/312
• CPC Class Codes: G01N 2291/2697 Wafer or (micro)electronic parts
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00
• CPC Class Codes: G01N 29/4454 Signal recognition, e.g. specific values or portions, signal events, signatures
• CPC Class Codes: H10N 30/04 Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning
• CPC Class Codes: H10N 30/06 Forming electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: H10N 30/87 Electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part

Abstract

There is provided a method for testing a piezoelectric/electrostrictive actuator, wherein the displacement of a piezoelectric/electrostrictive actuator is estimated on the basis of the relations between one or more frequency characteristic values selected from the group consisting of the heights and areas of the peaks of the resonance waveforms and the difference of the maximum and minimum of the first order or first to higher orders of the resonance frequency characteristic values of the piezoelectric/electrostrictive actuator and the k-th order (k=1 to 4) of the first or first to higher orders of resonance frequencies. According to this piezoelectric/electrostrictive actuator testing method, a piezoelectric/electrostrictive actuator can be tested with high precision without actually driving the same as a product and without being accompanied by any disassembly/breakage.

Claims

1. A method for adjusting a piezoelectric/electrostrictive actuator, the method comprising:

trimming an upper electrode with regard to at least some of a plurality of actuators to adjust the displacement of the piezoelectric/electrostrictive actuators uniformly;

wherein the trimming is performed by forming pattern comprising one or more openings, surrounded by remaining portions of the upper electrode layer within the bounds of a peripheral shape of the upper electrode, in the vicinity of a central portion of the upper electrode.

2. The method for adjusting a piezoelectric/electrostrictive actuator according to claim 1, wherein the trimming is performed in at least a portion where the maximum displacement of the piezoelectric/electrostrictive actuator is generated.

3. The method for adjusting a piezoelectric/electrostrictive actuator according to claim 1, wherein the trimming is performed in a portion having the maximum amplitude in the first order of the resonance mode.

4. The method for adjusting a piezoelectric/electrostrictive actuator according to claim 1, wherein, when the pattern has circular through-holes, the through-holes have different diameters.

5. The method for adjusting a piezoelectric/electrostrictive actuator according to claim 1, wherein, when the pattern has slits, the slits have different widths.

6. A piezoelectric/electrostrictive actuator obtained by adjusting the displacement uniformly by using a method for adjusting a piezoelectric/electrostrictive actuator according to claim 1.