Multilayer ceramic capacitor and manufacturing method of multilayer ceramic capacitor

Abstract

A multilayer ceramic capacitor includes: a multilayer structure in which each of a plurality of ceramic dielectric layers and each of a plurality of internal electrode layers are alternately stacked, wherein: (a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 125 degrees C.)/(a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 85 degrees C.) is more than 5 and less than 20; and a donor element concentration in the plurality of ceramic dielectric layers is 0.05 atm % or more and 0.3 atm % or less.

What is claimed is: 
     
         1 . A multilayer ceramic capacitor comprising:
 a multilayer structure in which each of a plurality of ceramic dielectric layers and each of a plurality of internal electrode layers are alternately stacked,   wherein:   (a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 125 degrees C.)/(a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 85 degrees C.) is more than 5 and less than 20; and   a donor element concentration in the plurality of ceramic dielectric layers is 0.05 atm % or more and 0.3 atm % or less.   
     
     
         2 . The multilayer ceramic capacitor as claimed in  claim 1 , wherein an average grain diameter of the plurality of ceramic dielectric layers is 80 nm or more and 200 nm or less. 
     
     
         3 . The multilayer ceramic capacitor as claimed in  claim 1 , wherein the donor element is at least one of V, Mo, Nb, La, W and Ta. 
     
     
         4 . The multilayer ceramic capacitor as claimed in  claim 2 , wherein the donor element is at least one of V, Mo, Nb, La, W and Ta. 
     
     
         5 . The multilayer ceramic capacitor as claimed in  claim 1 , wherein a thickness of the plurality of ceramic dielectric layers is 1 μm or less. 
     
     
         6 . The multilayer ceramic capacitor as claimed in  claim 1 , where a main component ceramic of the plurality of ceramic dielectric layers has a perovskite structure. 
     
     
         7 . A manufacturing method of a multilayer ceramic capacitor comprising:
 forming a green sheet of which a concentration of a donor element with respect to a main component ceramic is 0.05 atm % or more and 0.3 atm % or less;   forming a multilayer structure by alternately stacking the green sheet and a conductive paste for forming an internal electrode; and   baking the multilayer structure,   wherein the multilayer structure is sintered in the baking so that, in the multilayer structure after the baking, (a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 125 degrees C.)/(a current value at 10 V/μm when a direct voltage is applied to the plurality of the ceramic dielectric layers at 85 degrees C.) becomes more than 5 and less than 20.   
     
     
         8 . The method as claimed in  claim 7 , wherein in the forming of the green sheet, a green sheet of a main component ceramic in which the donor element of 0.05 atm % or more and 0.3 atm % or less is solid-solved in advance is formed.