Multilayered piezoelectric element and method of manufacturing the same

Abstract

In a multilayered piezoelectric element having a multilayered structure in which electrode layers and piezoelectric material layers are alternately stacked, an internal electrode and a side electrode can be strongly connected. The element includes a first electrode layer having an end portion that protrudes to an outer side than adjacent piezoelectric material layers on a first side surface of the multilayered structure and providing a first insulating region between a second side surface and itself, a second electrode layer having an end portion that protrudes to an outer side than adjacent piezoelectric material layers on the second side surface of the multilayered structure and providing a second insulating region between the first side surface and itself, a first side electrode connected to the end portion of the first electrode layer, and a second side electrode connected to the end portion of the second electrode layer.

1 . A multilayered piezoelectric element having a multilayered structure in which at least one first electrode layer and at least one second electrode layer are alternately stacked with a piezoelectric material layer therebetween, said multilayered piezoelectric element comprising: 
 plural piezoelectric material layers;    a first electrode layer having an end portion at least a part of which protrudes to an outer side than adjacent piezoelectric material layers on a first side surface of said multilayered structure, and formed such that a first insulating region is provided between said first electrode layer and a second side surface of said multilayered structure;    a second electrode layer having an end portion at least a part of which protrudes to an outer side than adjacent piezoelectric material layers on the second side surface of said multilayered structure, and formed such that a second insulating region is provided between said second electrode layer and the first side surface of said multilayered structure;    a first side electrode formed on the first side surface of said multilayered structure, connected to the at least a part of the end portion of said first electrode layer, and insulated from said second electrode layer by said second insulating region; and    a second side electrode formed on the second side surface of said multilayered structure, connected to the at least a part of the end portion of said second electrode layer, and insulated from said first electrode layer by said first insulating region.    
   
   
       2 . A multilayered piezoelectric element having a multilayered structure in which at least one first electrode layer and at least one second electrode layer are alternately stacked with a piezoelectric material layer therebetween, said multilayered piezoelectric element comprising: 
 plural piezoelectric material layers;    a first electrode layer having an end portion at least a part of which protrudes to an outer side than adjacent piezoelectric material layers on each of a first side surface and a second side surface of said multilayered structure;    a second electrode layer having an end portion at least a part of which protrudes to an outer side than adjacent piezoelectric material layers on each of the first side surface and the second side surface of said multilayered structure;    a first insulating film for covering the end portion of said first electrode layer on the second side surface of said multilayered structure;    a second insulating film for covering the end portion of said second electrode layer on the first side surface of said multilayered structure;    a first side electrode formed on the first side surface of said multilayered structure, connected to the at least a part of the end portion of said first electrode layer, and insulated from said second electrode layer by said second insulating film; and    a second side electrode formed on the second side surface of said multilayered structure, connected to the at least a part of the end portion of said second electrode layer, and insulated from said first electrode layer by said first insulating film.    
   
   
       3 . A multilayered piezoelectric element according to  claim 1 , wherein each of said plural piezoelectric material layers is formed according to an aerosol deposition method by spraying powder of a piezoelectric material toward one of a substrate, said first electrode layer and said second electrode layer, and depositing the piezoelectric material thereon.  
   
   
       4 . A multilayered piezoelectric element according to  claim 2 , wherein each of said plural piezoelectric material layers is formed according to an aerosol deposition method by spraying powder of a piezoelectric material toward one of a substrate, said first electrode layer and said second electrode layer, and depositing the piezoelectric material thereon.  
   
   
       5 . A multilayered piezoelectric element according to  claim 1 , wherein said first electrode layer and said second electrode layer are formed by one of sputtering and plating.  
   
   
       6 . A multilayered piezoelectric element according to  claim 2 , wherein said first electrode layer and said second electrode layer are formed by one of sputtering and plating.  
   
   
       7 . A multilayered piezoelectric element according to  claim 1 , wherein each of said first electrode layer and said second electrode layer includes a conducting layer, and an adhesion layer formed between said conducting layer and said piezoelectric material layer.  
   
   
       8 . A multilayered piezoelectric element according to  claim 2 , wherein each of said first electrode layer and said second electrode layer includes a conducting layer, and an adhesion layer formed between said conducting layer and said piezoelectric material layer.  
   
   
       9 . A method of manufacturing a multilayered piezoelectric element having a multilayered structure in which at least one first electrode layer and at least one second electrode layer are alternately stacked with a piezoelectric material layer therebetween, said method comprising the steps of: 
 (a) forming a first piezoelectric material layer;    (b) forming a first electrode layer on said first piezoelectric material layer except for a predetermined region;    (c) forming a second piezoelectric material layer on said first electrode layer;    (d) forming a second electrode layer on said second piezoelectric material layer except for a predetermined region;    (e) forming a third piezoelectric material layer on said second electrode layer;    (f) forming a first side surface and a second side surface by dicing the formed multilayered structure to protrude at least a part of an end portion of said first electrode layer to an outer side than adjacent piezoelectric material layers on the first side surface and secure a first insulating region between said first electrode layer and the second side surface, and to protrude at least a part of an end portion of said second electrode layer to an outer side than adjacent piezoelectric material layers on the second side surface and secure a second insulating region between said second electrode layer and the first side surface;    (g) forming a first side electrode, which is connected to the at least a part of the end portion of said first electrode layer and insulated from said second electrode layer by said second insulating region, on the first side surface of said multilayered structure; and    (h) forming a second side electrode, which is connected to the at least a part of the end portion of said second electrode layer and insulated from said first electrode layer by said first insulating region, on the second side surface of said multilayered structure.    
   
   
       10 . A method of manufacturing a multilayered piezoelectric element having a multilayered structure in which at least one first electrode layer and at least one second electrode layer are alternately stacked with a piezoelectric material layer therebetween, said method comprising the steps of: 
 (a) forming a first piezoelectric material layer;    (b) forming a first electrode layer on said first piezoelectric material layer;    (c) forming a second piezoelectric material layer on said first electrode layer;    (d) forming a second electrode layer on said second piezoelectric material layer;    (e) forming a third piezoelectric material layer on said second electrode layer;    (f) forming a first side surface and a second side surface by dicing the formed multilayered structure to protrude at least a part of an end portion of each of said first and second electrode layers to an outer side than adjacent piezoelectric material layers on each of the first and second side surfaces;    (g) forming a first insulating film on the second side surface of said multilayered structure to cover the end portion of said first electrode layer;    (h) forming a second insulating film on the first side surface of said multilayered structure to cover the end portion of said second electrode layer;    (i) forming a first side electrode, which is connected to the at least apart of the end portion of said first electrode layer and insulated from said second electrode layer by said second insulating film, on the first side surface of said multilayered structure; and    (j) forming a second side electrode, which is connected to the at least a part of the end portion of said second electrode layer and insulated from said first electrode layer by said first insulating film, on the second side surface of said multilayered structure.    
   
   
       11 . A method according to  claim 9 , wherein each of steps (a), (c) and (e) includes forming respective one of said first to third piezoelectric material layers according to an aerosol deposition method by spraying powder of a piezoelectric material toward respective one of a substrate, said first electrode layer and said second electrode layer, and depositing the piezoelectric material thereon.  
   
   
       12 . A method according to  claim 10 , wherein each of steps (a), (c) and (e) includes forming respective one of said first to third piezoelectric material layers according to an aerosol deposition method by spraying powder of a piezoelectric material toward respective one of a substrate, said first electrode layer and said second electrode layer, and depositing the piezoelectric material thereon.  
   
   
       13 . A method according to  claim 9 , wherein each of steps (b) and (d) includes forming respective one of said first electrode layer and said second electrode layer by one of sputtering and plating.  
   
   
       14 . A method according to  claim 10 , wherein each of steps (b) and (d) includes forming respective one of said first electrode layer and said second electrode layer by one of sputtering and plating.  
   
   
       15 . A method according to  claim 9 , wherein each of steps (b) and (d) includes forming respective one of said first electrode layer and said second electrode layer by disposing a conducting layer via an adhesion layer on respective one of said first piezoelectric material layer and said second piezoelectric material layer.  
   
   
       16 . A method according to  claim 10 , wherein each of steps (b) and (d) includes forming respective one of said first electrode layer and said second electrode layer by disposing a conducting layer via an adhesion layer on respective one of said first piezoelectric material layer and said second piezoelectric material layer.  
   
   
       17 . A method according to  claim 10 , wherein each of steps (g) and (h) includes forming respective one of said first insulating film and said second insulating film according to an aerosol deposition method by spraying powder of an insulating material toward respective one of the end portion of said first electrode layer and the end portion of said second electrode layer, and depositing the insulating material thereon.  
   
   
       18 . A method according to  claim 10 , wherein each of steps (g) and (h) includes forming respective one of said first insulating film and said second insulating film by electrodeposition.