Dielectric composition and capacitor component using the same

Abstract

A dielectric composition includes a ceramic powder, a high polymerization binder, and a low polymerization binder type dispersant having a degree of polymerization between 100 and 1,000.

What is claimed is: 
     
         1 . A dielectric composition, comprising:
 a ceramic powder;   a high polymerization binder; and   a low polymerization binder type dispersant having a degree of polymerization between 100 and 1,000.   
     
     
         2 . The dielectric composition of  claim 1 , wherein the low polymerization binder type dispersant is a polyvinyl butyral dispersant. 
     
     
         3 . The dielectric composition of  claim 1 , wherein the low polymerization binder type dispersant is included in 0.5 to 1 part by weight based on the ceramic powder of 100 parts by weight. 
     
     
         4 . The dielectric composition of  claim 1 , wherein the high polymerization binder has a degree of polymerization greater than 1,000. 
     
     
         5 . The dielectric composition of  claim 1 , wherein the high polymerization binder comprises 4.5 to 9.0 parts by weight based on the ceramic powder of 100 parts by weight. 
     
     
         6 . The dielectric composition of  claim 1 , wherein the ceramic powder is selected from the group consisting of BaTiO 3 , (Ba 1-x Ca x )(Ti 1-y Ca y )O 3 , (Ba 1-x Ca x )(Ti 1-y Zr y )O 3 , Ba(Ti 1-y Zr y )O 3 , or (Ba 1-x Ca x )(Ti 1-y Sn y )O 3 , wherein x is 0 to 0.9, and y is 0 to 0.9, and a mixture thereof. 
     
     
         7 . The dielectric composition of  claim 2 , wherein the polyvinyl butyral dispersant is a compound represented by the following formula (I): 
       
         
           
           
               
               
           
         
         wherein: 
         R is n-propyl; 
         l is an integer from 1 to 200; 
         m is an integer from 1 to 200; and 
         n is an integer from 1 to 200. 
       
     
     
         8 . A capacitor component, comprising:
 a body comprising a dielectric layer, and first and second internal electrodes opposing each other with the dielectric layer interposed therebetween; and   first and second external electrodes disposed externally on the body and electrically connected to the first and second internal electrodes, respectively,   wherein the dielectric layer contains phosphorus (P) in an amount of 0.1 wt % or lower.   
     
     
         9 . The capacitor component of  claim 8 , wherein, when an energy dispersive spectrometer analysis is performed, P is not detected in the dielectric layer. 
     
     
         10 . The capacitor component of  claim 8 , wherein the dielectric layer is formed of a dielectric composition comprising a ceramic powder, a high polymerization binder, and a low polymerization binder type dispersant having a degree of polymerization between 100 and 1,000. 
     
     
         11 . The capacitor component of  claim 8 , wherein the ceramic powder is selected from the group consisting of BaTiO 3 , (Ba 1-x Ca x )(Ti 1-y Ca y )O 3 , (Ba 1-x Ca x )(Ti 1-y Zr y )O 3 , Ba(Ti 1-y Zr y )O 3 , or (Ba 1-x Ca x )(Ti 1-y Sn y )O 3 , wherein x is 0 to 0.9, and y is 0 to 0.9, and a mixture thereof. 
     
     
         12 . The capacitor component of  claim 8 , wherein the low polymerization binder type dispersant is a polyvinyl butyral dispersant. 
     
     
         13 . The capacitor component of  claim 8 , wherein the polyvinyl butyral dispersant is a compound represented by the following 
       
         
           
           
               
               
           
         
         wherein: 
         R is n-propyl; 
         l is an integer from 1 to 200; 
         m is an integer from 1 to 200; and 
         n is an integer from 1 to 200. 
       
     
     
         14 . The capacitor component of  claim 8 , wherein a thickness of the first and second internal electrodes is less than 1 μm, and a thickness of the dielectric layer is less than 2.8 μm. 
     
     
         15 . The capacitor component of  claim 8 , wherein, when a thickness of the first and second internal electrodes is defined as te, and a thickness of the dielectric layer is defined as td, te and td satisfy td>2*te. 
     
     
         16 . The capacitor component of  claim 8 , wherein the first and second external electrodes each comprise an electrode layer and a conductive resin layer disposed on the electrode layer. 
     
     
         17 . The capacitor component of  claim 16 , wherein the electrode layer comprises glass and one or more conductive metals selected from a group comprised of copper (Cu), silver (Ag), nickel (Ni) and alloys thereof. 
     
     
         18 . The capacitor component of  claim 16 , wherein the conductive resin layer comprises a base resin and one or more conductive metals selected from a group comprised of copper (Cu), silver (Ag), nickel (Ni) and alloys thereof. 
     
     
         19 . The capacitor component of  claim 16 ,
 wherein the body comprises first and second surfaces opposing each other, third and fourth surfaces connected to the first and second surfaces and opposing each other, and fifth and sixth surfaces connected to the first to fourth surfaces and opposing each other,   wherein the first external electrode is disposed on the third surface, and comprises a band portion extending to portions of the first and second surfaces, and   wherein a distance from the third surface to an end of the band portion of the electrode layer is shorter than a distance from the third surface to an end of the band portion of the conductive resin layer.