Piezoelectric vibrating member and its producing process

• US 6,198,203 B1
• Filed: 04/09/1997
• Issued: 03/06/2001
• Est. Priority Date: 04/12/1996
• Status: Expired due to Term

• Current Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Original Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Inventors: Hotomi, Hideo
• Primary Examiner(s): Ramirez, Nestor
• Assistant Examiner(s): MEDLEY, PETER M
• Application Number:
  US08/838,717
• Time in Patent Office: 1,427 Days
• Field of Search: 310/324, 310/328, 310/330-332, 347/68-72
• US Class Current: 310/324
• CPC Class Codes: B41J 2/14233 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: H10N 30/045 by polarising
• CPC Class Codes: H10N 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/081 by coating or depositing using masks, e.g. lift-off
• CPC Class Codes: H10N 30/2047 Membrane type

Abstract

A piezoelectric actuator 52 is produced by providing a common electrode 22 on one planar surface of a thin vibrating plate 20 of non-piezoelectric material, providing a slurry 28 prepared by dispersing a calcined powder of piezoelectric material in a solvent containing dissolved coupling agent on the common electrode, drying the slurry to produce a flexible green sheet 30, pressure molding the green sheet to produce a plurality of precursor members 34 arranged at a predetermined space, sintering the precursor members and thereby growing piezoelectric particles to produce unpolarized piezoelectric members 24, forming individual electrodes on the piezoelectric members to oppose the common electrode, and polarizing the piezoelectric members.

Claims

1. A piezoelectric vibrating structure, comprising:

a thin plate;

a first electrode formed on one portion of a surface of said thin plate;

a continuous piezoelectric layer disposed on said thin plate and covering said first electrode, said piezoelectric layer including a plurality of spaced-apart, parallel piezoelectric members and non-polarized connecting members disposed between and connecting said piezoelectric members, said piezoelectric members having a thickness which is greater than a thickness of said connecting members;

a plurality of second electrodes, each of said plurality of second electrodes being respectively arranged on a surface of one of said piezoelectric members, said surfaces that receive said plurality of second electrodes being opposite said first electrode;

wherein said continuous piezoelectric layer is formed by providing a slurry on said thin plate and covering said first electrode, said slurry being prepared by dispersing a calcined powder of piezoelectric material in a solvent containing dissolved coupling agent, drying said slurry to produce a green sheet, pressure molding said green sheet to produce a plurality of precursor members arranged at a predetermined space with connecting material therebetween, sintering said green sheet, and polarizing said sintered piezoelectric members by applying a voltage between said first and second electrodes.

3. A piezoelectric vibrating structure as claimed in claim 1, wherein said first electrode comprises a plurality of electrode members spaced apart from each other, each of said electrode members corresponding to one of said plurality of second electrodes.

2. A piezoelectric vibrating structure, comprising:

a thin plate made of nickel or stainless steel which comprises a first electrode;

a plurality of piezoelectric members arranged in parallel on said first electrode, wherein adjacent piezoelectric members are joined by non-polarized connecting members; and

a plurality of second electrodes, each of said plurality of second electrodes being respectively arranged on a surface of one of said piezoelectric members, said surfaces that receive said plurality of second electrodes being opposite said first electrode;

wherein said piezoelectric members are formed by providing a slurry on said first electrode, said slurry being prepared by dispersing a calcined powder of piezoelectric material in a solvent containing dissolved coupling agent, drying said slurry to produce a green sheet, pressure molding said green sheet to produce a plurality of precursor members arranged at a predetermined space with connecting material therebetween, sintering said green sheet, and polarizing said piezoelectric members by applying a voltage between said first and second electrodes.

4. A piezoelectric vibrating structure, comprising:

a thin plate of electrically conductive material, said thin plate forming a first electrode;

a continuous piezoelectric layer disposed on said first electrode, said piezoelectric layer including a plurality of parallel, spaced-apart piezoelectric members and non-polarized connecting members disposed between and connecting said piezoelectric members, said piezoelectric members having a thickness which is greater than a thickness of said connecting members;

a plurality of second electrodes, each of said plurality of second electrodes being respectively arranged on a surface of one of said piezoelectric members, said surfaces that receive said plurality of second electrodes being opposite said first electrode;

wherein said continuous piezoelectric layer is formed by providing a slurry on said first electrode, said slurry being prepared by dispersing a calcined powder of piezoelectric material in a solvent containing dissolved coupling agent, drying said slurry to produce a green sheet, pressure molding said green sheet to produce a plurality of precursor members arranged at a predetermined space with connecting material therebetween, sintering said green sheet, and polarizing said sintered piezoelectric members by applying a voltage between said first and second electrodes.

5. A piezoelectric vibrating member, comprising:

a vibrating plate;

a first electrode disposed on a first surface of said vibrating plate;

a piezoelectric layer disposed on said first surface of said vibrating plate and covering said first electrode, said piezoelectric layer being a continuous layer having a plurality of spaced apart first portions and having non-polarized second portions which connect said first portions, said first portions of said piezoelectric layer having a thickness which is greater than a thickness of said second portions, said first portions being polarized; and

a plurality of top electrodes, each of said plurality of top electrodes being arranged on a top surface of each respective one of said first portions of said piezoelectric layer, each said top surface being opposite said first electrode;

wherein an electric potential can be applied across said first electrode and any one of said top electrodes to form an electric field across a corresponding one of said first portions of said piezoelectric layer.

6. A piezoelectric member in accordance with claim 5, wherein said first electrode comprises a plurality of spaced apart electrode members, each of said plurality of electrode members confronting one of said first portions of said piezoelectric layer on a side opposite said top electrode.

7. A piezoelectric vibrating member, comprising:

a thin plate;

a plurality of spaced apart first electrodes arranged on a first surface of said thin plate;

a piezoelectric layer disposed on said first surface of said thin plate and covering said plurality of first electrodes, said piezoelectric layer being a continuous layer having a plurality of spaced apart first portions and having non-polarized second portions which connect the first portions, said first portions of said piezoelectric layer having a thickness which is greater than a thickness of said second portions, each of said first portions confronting and corresponding to one of said plurality of first electrodes; and

a plurality of second electrodes, each of said plurality of second electrodes being arranged on a top surface of each respective one of said first portions of said piezoelectric layer, each said top surface being opposite a respective one of said plurality of spaced apart first electrodes;

wherein said first portions of said piezoelectric layer are polarized and wherein an electric potential can be applied across said any one of said first electrodes and a corresponding one of said second electrodes to form an electric field across a corresponding one of said first portions of said piezoelectric layer.