US 2006/0138908 A1 · Stacked piezoelectric element and method of fabrication thereof

Abstract

This invention provides a stacked piezoelectric element that has excellent durability and reliability by ensuring reliable electrical conduction between internal electrode layer and conductive adhesive, and a method of fabricating such a stacked piezoelectric element. The stacked piezoelectric element 1 comprises: a ceramic stack 10 constructed by alternately stacking piezoelectric layers 11 made of a piezoelectric material and internal electrode layers 21, 22 having electrical conductivity; and external electrodes 32 bonded to the side faces 101 and 102 of the ceramic stack 10 via an electrically conductive adhesive 31. The side faces 101 and 102 of the ceramic stack 10 are provided with electrode recesses 23 each formed by indenting a portion of the edge of each of the internal electrode layers 21, 22 in the stacking direction thereof thereby forming a gap between it and the overlying piezoelectric layer 11, and the conductive adhesive 31 is applied so as to enter the electrode recesses 23 from the side faces 101 and 102 of the ceramic stack 10.

Claims7

Dependent claims

A stacked piezoelectric element comprising:

a ceramic stack constructed by alternately stacking a piezoelectric layer made of a piezoelectric material and an internal electrode layer having electrical conductivity;
and an external electrode bonded to side faces of said ceramic stack via an electrically conductive adhesive, wherein
said each side face of said ceramic stack is provided with an electrode recess formed by indenting a portion of an edge of said internal electrode layer in a stacking direction thereof thereby forming a gap between said portion of an edge of said internal electrode layer and said piezoelectric layer, and
said electrically conductive adhesive is applied so as to enter said electrode recess.

1 more element

A method of fabricating a stacked piezoelectric element comprising:

a ceramic stack constructed by alternately stacking a piezoelectric material and an internal electrode layer having electrical conductivity;
and an external electrode bonded to side faces of said ceramic stack via an electrically conductive adhesive, wherein said method includes:
a sheet-forming step for forming a green sheet from which to form said piezoelectric layer;
a printing step for printing on said green sheet an electrode material from which to form said internal electrode layer;
a recessed-portion-forming step for forming a recessed portion by pressing a portion of an edge of said electrode material from above thereby indenting said portion of said edge of said electrode material and said green sheet thereunder in a thickness direction thereof;
an intermediate-stack-forming step for forming an intermediate stack by cutting said green sheet into sheet pieces and stacking said sheet pieces, and for forming an electrode recess by exposing said recessed portion in said side face and thus forming a gap between said portion of said edge of said electrode material and said green sheet stacked thereover;
a calcining step for forming said ceramic stack by calcining said intermediate stack;
and
an electrode-bonding step for applying said electrically conductive adhesive over said side faces and bonding said external electrode to said side face.

6 more elements

Dependencies are inferred from the claim text.

Stacked piezoelectric element and method of fabrication thereof

Life of this patent

Stacked piezoelectric element and method of fabrication thereof

Life of this patent

Abstract

Claims7