Laminated structure, piezoelectric actuator and method of manufacturing the same

Abstract

A laminated structure having an electrode hard to peel off and a method of manufacturing the laminated structure. The laminated structure has: a backing substrate; a lower electrode including an adhesive layer containing a metal oxide and a conductive layer formed on the backing substrate with the adhesive layer therebetween; a dielectric layer disposed on the lower electrode; and an upper electrode disposed on the dielectric layer. Further, the method includes the steps of: (a) disposing a lower electrode by forming a conductive layer on a backing substrate with an adhesive layer containing a metal oxide therebetween; (b) disposing a dielectric layer by spraying powder of a dielectric material to the lower electrode for deposition; (c) heat-treating the dielectric layer; and (d) forming an upper electrode on the dielectric layer before or after step (c).

1 . A laminated structure comprising: 
 a backing substrate;    a first electrode including an adhesive layer containing a metal oxide and a conductive layer formed on said backing substrate with said adhesive layer therebetween;    a dielectric layer disposed on said first electrode; and    a second electrode disposed on said dielectric layer.    
   
   
       2 . A laminated structure comprising: 
 at least one intermediate electrode; and    a plurality of dielectric layers stacked with said at least one intermediate electrode therebetween;    wherein said at least one intermediate electrode includes an adhesive layer containing a metal oxide and a conductive layer formed on said dielectric layer with said adhesive layer therebetween.    
   
   
       3 . The laminated structure according to  claim 2 , further comprising: 
 a backing substrate on which said at least one intermediate electrode and said plurality of dielectric layers are stacked.    
   
   
       4 . The laminated structure according to  claim 2 , further comprising: 
 a backing substrate; and    an electrode formed on a main surface of said backing substrate, said at least one intermediate electrode and said plurality of dielectric layers being stacked on said electrode.    
   
   
       5 . The laminated structure according to  claim 4 , wherein said electrode includes an adhesive layer containing a metal oxide and a conductive layer formed on said backing substrate with said adhesive layer therebetween.  
   
   
       6 . The laminated structure according to  claim 1 , wherein said adhesive layer includes a thin film formed by employing an oxide of at least one material of titanium, zirconium, aluminum, nickel, hafnium, vanadium, magnesium, niobium, chromium, tantalum and tungsten.  
   
   
       7 . The laminated structure according to  claim 2 , wherein said adhesive layer includes a thin film formed by employing an oxide of at least one material of titanium, zirconium, aluminum, nickel, hafnium, vanadium, magnesium, niobium, chromium, tantalum and tungsten.  
   
   
       8 . The laminated structure according to  claim 1 , wherein said conductive layer includes a metal thin film formed by employing at least one material of platinum, ruthenium, iridium, rhenium, osmium and rhodium.  
   
   
       9 . The laminated structure according to  claim 2 , wherein said conductive layer includes a metal thin film formed by employing at least one material of platinum, ruthenium, iridium, rhenium, osmium and rhodium.  
   
   
       10 . The laminated structure according to  claim 1 , wherein said conductive layer includes a thin film formed by employing an oxide of at least one material of platinum, ruthenium, iridium, rhenium, osmium and rhodium.  
   
   
       11 . The laminated structure according to  claim 2 , wherein said conductive layer includes a thin film formed by employing an oxide of at least one material of platinum, ruthenium, iridium, rhenium, osmium and rhodium.  
   
   
       12 . The laminated structure according to  claim 1 , wherein said dielectric layer is formed by spraying powder of a material to an under layer for deposition.  
   
   
       13 . The laminated structure according to  claim 2 , wherein said dielectric layer is formed by spraying powder of a material to an under layer for deposition.  
   
   
       14 . The laminated structure according to  claim 2 , wherein, in said dielectric layer, a surface on which said adhesive layer is disposed has roughness of at least 0.3 μm.  
   
   
       15 . A piezoelectric actuator comprising: 
 a laminated structure including a plurality of piezoelectric layers, a first intermediate electrode and a second intermediate electrode stacked in an order of the piezoelectric layer, the first intermediate electrode, the piezoelectric layer and the second intermediate electrode;    a first side electrode disposed in a first side region of said laminated structure; and    a second side electrode disposed in a second side region different from the first side region of said laminated structure;    wherein each of said first and second intermediate electrodes includes an adhesive layer containing a metal oxide and a conductive layer formed on said dielectric layer with said adhesive layer therebetween, said first intermediate electrode is connected to said first side electrode and insulated from said second side electrode, and said second intermediate electrode is connected to said second side electrode and insulated from said first side electrode.    
   
   
       16 . A method of manufacturing a laminated structure, said method comprising the steps of: 
 (a) disposing a first electrode by forming a conductive layer on a backing substrate with an adhesive layer containing a metal oxide therebetween;    (b) disposing a dielectric layer on said first electrode by spraying powder of a dielectric material to said first electrode for deposition;    (c) heat-treating said dielectric layer; and    (d) forming a second electrode on said dielectric layer before or after step (c).    
   
   
       17 . A method of manufacturing a laminated structure, said method comprising the steps of: 
 (a) disposing a first electrode by forming a conductive layer on a backing substrate with an adhesive layer containing a metal oxide therebetween;    (b) disposing a dielectric layer on said first electrode by spraying powder of a dielectric material to said first electrode for deposition;    (c) disposing a second electrode by forming a conductive layer on said dielectric layer with an adhesive layer containing a metal oxide therebetween;    (d) disposing a dielectric layer on said second electrode by spraying powder of a dielectric material to said second electrode for deposition;    (e) heat-treating said dielectric layers; and    (f) forming, before or after step (e), a third electrode on said dielectric layer disposed at step (d).    
   
   
       18 . The method according to  claim 17 , further comprising the step of: 
 repeating steps (c) to (d) for a predetermined number of times.    
   
   
       19 . A method of manufacturing a laminated structure, said method comprising the steps of: 
 (a) disposing a dielectric layer by spraying powder of a dielectric material to a backing substrate for deposition;    (b) disposing a first electrode by forming a conductive layer on said dielectric layer with an adhesive layer containing a metal oxide therebetween;    (c) disposing a dielectric layer on said first electrode by spraying powder of a dielectric material to said first electrode for deposition;    (d) heat-treating said dielectric layers;    (e) forming, before or after step (d), a second electrode on said second dielectric layer disposed at step (c); and    (f) removing said backing substrate from said dielectric layer.    
   
   
       20 . The method according to  claim 19 , further comprising the step of: 
 repeating steps (b) to (c) for a predetermined number of times.    
   
   
       21 . A method of manufacturing a piezoelectric actuator having a laminated structure, said method comprising the steps of: 
 (a) disposing a piezoelectric layer by spraying powder of a piezoelectric material to a backing substrate for deposition;    (b) disposing a first intermediate electrode by forming a conductive layer on said piezoelectric layer with an adhesive layer containing a metal oxide therebetween;    (c) disposing a piezoelectric layer on said first intermediate electrode by spraying powder of a piezoelectric material to said first intermediate electrode for deposition;    (d) disposing a second intermediate electrode by forming a conductive layer on said piezoelectric layer with an adhesive layer containing a metal oxide therebetween;    (e) disposing a piezoelectric layer on said second intermediate electrode by spraying powder of a piezoelectric material to said second intermediate electrode for deposition;    (f) heat-treating said piezoelectric layers;    (g) removing said backing substrate from said piezoelectric layer; and    (h) forming side electrodes on at least first and second surfaces of said laminated structure.    
   
   
       22 . The method according to  claim 21 , further comprising the step of: 
 repeating steps (b) to (e) for a predetermined number of times.    
   
   
       23 . The method according to  claim 21 , further comprising the steps of: 
 forming an insulating portion on an end surface of said first intermediate electrode exposed in the first side surface of said laminated structure formed at steps (a) to (g); and    forming an insulating portion on an end surface of said second intermediate electrode exposed in the second side surface different from the first side surface of said laminated structure formed at steps (a) to (g).    
   
   
       24 . The method according to  claim 21 , wherein: 
 step (c) includes disposing said piezoelectric layer so as to cover an end surface of said first intermediate electrode on a first side of said laminated structure; and    step (e) includes disposing said piezoelectric layer so as to cover an end surface of said second intermediate electrode on a second side different from the first side of said laminated structure.    
   
   
       25 . The method according to  claim 21 , further comprising the steps of: 
 forming, before or after step (f), a first electrode on a main surface of said piezoelectric layer disposed at step (e); and    forming a second electrode on a surface from which said backing substrate has been removed at step (g).    
   
   
       26 . The method according to  claim 21 , wherein step (h) includes forming electrodes on the first and second side surfaces of said laminated structure, a main surface of said piezoelectric layer disposed at step (e) and a surface from which said backing substrate has been removed at step (g).