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Stack-type piezoelectric element and process for producing the same

Assignee: Hitachi Ltd
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Filing: 1989-07-14
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Granted: —
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Expires: 2009-07-14
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Abstract

Abstract According to the present invention, there are provided a stack-type piezoelectric element constructed of a stacked body comprising plural layers (1) of sintered piezoelec­tric ceramic material and electrodes (2, 3) which lie between the respective layers (1, 1) of the piezoelectric ceramic material, wherein said electrodes (2, 3) are formed of a material capable of diffusion-bonding with said piezoelectric ceramic material at a lower temperature than the sintering temperature of said ceramic material, a process for producing the same, and a stack-type piezo­electric device using said stack-type piezoelectric element.

Inventors

  • 👤 Akiomi Kohno
  • 👤 Masatugu Arai
  • 👤 Takeshi Harada

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-29 01:32
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/87; H10N30/871; H10N30/01; H10N30/05; H10N30/053; H10N30/057; H10N30/50

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 62 words
A stack-type piezoelectric element constructed of a stacked body comprising plural layers (1) of sintered piezoelectric ceramic material and electrodes (2,3) which lie between the respective layers (1,1) of the piezoelectric ceramic material, wherein said electrodes (2,3) are formed of a material capable of diffusion-bonding with said ceramic material at a lower temperature than the sinter­ing temperature of the piezoelectric ceramic material.
Claim 2
Dependent Claim 62 words
A stack-type piezoelectric element constructed of a stacked body comprising plural layers (1) of sintered piezoelectric ceramic material and electrodes (2,3) which lie between the respective layers (1,1) of the piezoelectric ceramic material, wherein said electrodes (2,3) are formed of a material capable of diffusion-bonding with said ceramic material at a lower temperature than the sinter­ing temperature of the piezoelectric ceramic material.
Claim 3
Dependent Claim 76 words
A stack-type piezoelectric element constructed of a stacked body comprising plural layers (1) of sintered piezoelectric ceramic material and electrodes (2,3) which lie between the respective layers (1,1) of the piezoelectric ceramic material, wherein said respective electrodes are formed of a metallic material comprising one or more layers (22,21) of at least one member selected from aluminum and aluminum alloy or one or more layers of at least one member selected from nickel and nickel alloy.
Claim 4
Dependent Claim 76 words
A stack-type piezoelectric element constructed of a stacked body comprising plural layers (1) of sintered piezoelectric ceramic material and electrodes (2,3) which lie between the respective layers (1,1) of the piezoelectric ceramic material, wherein said respective electrodes are formed of a metallic material comprising one or more layers (22,21) of at least one member selected from aluminum and aluminum alloy or one or more layers of at least one member selected from nickel and nickel alloy.
Claim 5
Dependent Claim 98 words
A stack-type piezoelectric device comprising a stacked body formed of plural layers (1) of sintered piezoelectric ceramic material and electrodes (2,3) which lie between the respective layers (1,1) or the piezoelectric ceramic material, said respective electrodes (2,3) being provided such that the positive poles and the negative poles are alternately arranged in the stacking direc­tion, an external lead (4) which connects the positive poles together, and an external lead (5) which connects the negative poles together, both provided at the side of said stacked body, wherein said stacked body is a stack­type piezoelectric element according to claim 1.
Claim 6
Dependent Claim 98 words
A stack-type piezoelectric device comprising a stacked body formed of plural layers (1) of sintered piezo­electric ceramic material and electrodes (2,3) which lie between the respective layers (1,1) of the piezoelectric ceramic material, said respective electrodes (2,3) being provided such that the positive poles and the negative poles are alternately arranged in the stacking direc­tion, an external lead (4) which connects the positive poles together, and an external lead (5) which connects the nega­tive poles together, both provided at the side of said stacked body, wherein said stacked body is a stack-type piezoelectric element according to claim 2.
Claim 7
Dependent Claim 44 words
A process for producing a stack-type piezo­electric element which comprises stacking sintered piezoelectric ceramic material layers (1) and electrode layers (2,3) alternately, and then heating the stacked product at a lower temperature than the sintering temperature of said piezoelectric ceramic material to effect bonding.
Claim 8
Dependent Claim 44 words
A process for producing a stack-type piezo­electric element which comprises stacking sintered piezoelectric ceramic material layers (1) and electrode layers (2,3) alternately, and then heating the stacked product at a lower temperature than the sintering temperature of said piezoelectric ceramic material to effect bonding.
Claim 9
Dependent Claim 52 words
A process for producing a stack-type piezo­electric element according to claim 5 which further comprises applying a voltage to the piezoelectric ceramic at a higher temperature by 20-70°C than the Curie point of said ceramic in the course of cooling succeeding to the bonding step, thereby to effect polarization of said ceramic.
Claim 10
Dependent Claim 47 words
A process for producing a stack-type piezoelectric element which comprises stacking sintered piezoelectric ceramic layers (1) and electrode layers (2,3) alternately, and then applying heat and pressure to the stacked product at a lower temperature than the sinter­ing temperature of said piezoelectric ceramic material to effect bonding.
Claim 11
Dependent Claim 47 words
A process for producing a stack-type piezoelectric element which comprises stacking sintered piezoelectric ceramic layers (1) and electrode layers (2,3) alternately, and then applying heat and pressure to the stacked product at a lower temperature than the sinter­ing temperature of said piezoelectric ceramic material to effect bonding.
Claim 12
Dependent Claim 27 words
A process for producing a stack-type piezo­electric element according to claim 7 wherein the stacked product is cooled without removal of applied pressure after the bonding step.
Claim 13
Dependent Claim 52 words
A process for producing a stack-type piezo­electric element according to claim 7 which further comprises applying a voltage to the piezoelectric ceramic at a higher temperature by 20-70°C than the Curie point of said ceramic in the course of cooling succeeding to the bonding step, thereby to effect polarization of said ceramic.
Claim 14
Dependent Claim 48 words
A process for producing a stack-type piezo­electric element which comprises sintering piezoelectric ceramic green sheets, then providing electrode layers (2,3) between the respective ceramic layers (1), and heating the whole at a lower temperature than that in said sinter­ing, thereby diffusion-bonding the ceramic materials with the electrode materials.
Claim 15
Dependent Claim 48 words
A process for producing a stack-type piezo­electric element which comprises sintering piezoelectric ceramic green sheets, then providing electrode layers (2,3) between the respective ceramic layers (1), and heating the whole at a lower temperature than that in said sinter­ing, thereby diffusion-bonding the ceramic materials with the electrode materials.
Claim 16
Dependent Claim 52 words
A process for producing a stack-type piezo­electric element according to claim 10 which further comprises applying a voltage to the piezoelectric ceramic at a higher temperature by 20-70°C than the Curie point of said ceramic in the course of cooling succeeding to the bonding step, thereby to effect polarization of said ceramic.

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