Laminate-type piezoelectric element and method of producing the same

• US 20070164638A1
• Filed: 12/19/2006
• Published: 07/19/2007
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kadotani, Shige, Iwase, Akio, Yamaguchi, Teruaki
• Granted Patent: US 7,554,250 B2
• Time in Patent Office: Days
• US Class Current: 310/363
• CPC Class Codes: F02M 63/0026 using piezoelectric or magnetostrictive actuators
• CPC Class Codes: H10N 30/063 Forming interconnections, e.g. connection electrodes of multilayered piezoelectric or electrostrictive parts
• CPC Class Codes: H10N 30/503 with non-rectangular cross-section orthogonal to the stacking direction, e.g. polygonal, circular
• CPC Class Codes: H10N 30/872 Connection electrodes of multilayer piezoelectric or electrostrictive devices, e.g. external electrodes

Abstract

A laminate-type piezoelectric element 1 having a ceramic laminated body 10 obtained by alternately laminating piezoelectric layers 11 made of a piezoelectric material and inner electrode layers 20 having electrical conductivity, and having outer electrodes 34 joined to the side surfaces 101 and 102 of the ceramic laminated body 10 via an electrically conductive adhesive 33, wherein the electrically conductive adhesive 33 has buried therein mesh bodies 4 obtained by forming a mesh by using a nonmetallic material. The mesh bodies 4 are desirably constituted by using any one of a resin, ceramic, carbon or glass.

Claims

1. A laminate-type piezoelectric element having a ceramic laminated body obtained by alternately laminating piezoelectric layers made of a piezoelectric material and inner electrode layers having electrical conductivity, and having outer electrodes joined to the side surfaces of said ceramic laminated body via an electrically conductive adhesive, wherein said electrically conductive adhesive has buried therein at least parts of mesh bodies obtained by forming a mesh by using a nonmetallic material.

2. A laminate-type piezoelectric element according to claim 1, wherein said mesh bodies are constituted by using any one of a resin, ceramic, carbon or glass.

3. A laminate-type piezoelectric element according to claim 1, wherein said mesh bodies are constituted by knitting a fiber made of a nonmetallic material.

4. A laminate-type piezoelectric element according to claim 3, wherein the fiber constituting said mesh bodies is a fiber aggregate obtained by bundling fine fibers.

5. A laminate-type piezoelectric element according to any one of claim 1, wherein the surfaces of said mesh bodies are covered with an electrically conductive material.

6. A laminate-type piezoelectric element according to claim 5, wherein said electrically conductive material contains at least one or more kinds of Pt, Pd, Ta, Au, Ag, Cu, Ni, Zn and Sn.

7. A laminate-type piezoelectric element according to any one of claim 1, wherein said laminate-type piezoelectric element is a piezoelectric actuator for an injector used as a drive source of the injector.

8. A method of producing a laminate-type piezoelectric element having a ceramic laminated body obtained by alternately laminating piezoelectric layers made of a piezoelectric material and inner electrode layers having electrical conductivity, and having outer electrodes joined to the side surfaces of said ceramic laminated body via an electrically conductive adhesive, the method comprising:

a laminated body-forming step of forming said ceramic laminated body by alternately laminating said piezoelectric layers and said inner electrode layers;

an adhesive-applying step of applying said electrically conductive adhesive to the side surfaces of said ceramic laminated body;

a mesh body-arranging step of burying at least parts of mesh bodies obtained by forming a mesh by using a nonmetallic material in said electrically conductive adhesive; and

an external electrode-joining step of joining said external electrodes to said electrically conductive adhesive.

9. A method of producing a laminate-type piezoelectric element according to claim 8, wherein said mesh bodies are constituted by using any one of a resin, ceramic, carbon or glass.

10. A method of producing a laminate-type piezoelectric element according to claim 8, wherein said mesh bodies are constituted by knitting a fiber made of a nonmetallic material.

11. A method of producing a laminate-type piezoelectric element according to claim 10, wherein the fiber constituting said mesh bodies is a fiber aggregate obtained by bundling fine fibers.

12. A method of producing a laminate-type piezoelectric element according to any one of claim 8, wherein the surfaces of said mesh bodies are covered with an electrically conductive material.

13. A method of producing a laminate-type piezoelectric element according to claim 12, wherein said electrically conductive material contains at least one or more kinds of Pt, Pd, Ta, Au, Ag, Cu, Ni, Zn and Sn.