Multilayer ceramic capacitor and board having the same

Abstract

A multilayer ceramic capacitor may include: three external electrodes disposed on a mounting surface of a ceramic body to be spaced apart from one another. When a thickness of an active layer including a plurality of first and second internal electrodes disposed therein is defined as AT, and a gap between a first or second lead part of the first internal electrode and a third lead part of the second internal electrode is defined as LG, the following Equation may be satisfied: 0.00044≦LG*log[1/AT]≦0.00150.

What is claimed is: 
     
         1 . A multilayer ceramic capacitor comprising:
 internal electrodes alternately disposed in a ceramic body in a width direction of the ceramic body, having opposing polarities when in operation, having lead portions exposed to one main surface of the ceramic body and spaced apart from each other in a length direction of the ceramic body; and   external electrodes connected to the lead portions, respectively,   in which:   0.00044 m(meters)≦LG*log[1/AT]≦0.00150 m
 wherein 
 AT is a width of an active layer which comprises a plurality of the internal electrodes, and 
 LG is an interval between the lead portions. 
   
     
     
         2 . The multilayer ceramic capacitor of  claim 1 , wherein the internal electrodes are spaced apart from both end surfaces of the ceramic body in the length direction. 
     
     
         3 . The multilayer ceramic capacitor of  claim 1 , wherein the interval LG between the lead portions is greater than 100 μm. 
     
     
         4 . The multilayer ceramic capacitor of  claim 1 , further comprising cover layers formed on both side surfaces of the active layer including the plurality of internal electrodes in the width direction. 
     
     
         5 . The multilayer ceramic capacitor of  claim 1 , wherein a range of thickness of the external electrodes is 10 to 40 μm. 
     
     
         6 . The multilayer ceramic capacitor of  claim 1 , wherein the external electrodes include conductive layers in contact with the lead portions corresponding to the external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 the conductive layers each having a thickness of 5 to 25 μm.   
     
     
         7 . The multilayer ceramic capacitor of  claim 1 , wherein the external electrodes include conductive layers in contact with the lead portions corresponding to the external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 the nickel plating layers each having a thickness of 2 μm or more.   
     
     
         8 . The multilayer ceramic capacitor of  claim 1 , wherein the external electrodes include conductive layers in contact with the lead portions corresponding to the external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 the tin plating layers each having a thickness of 3 μm or more.   
     
     
         9 . The multilayer ceramic capacitor of  claim 1 , wherein the external electrodes include conductive layers in contact with the lead portions corresponding to the external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 a sum of thicknesses of the nickel plating layers and the tin plating layers being 15 μm or less.   
     
     
         10 . The multilayer ceramic capacitor of  claim 1 , wherein the external electrodes extend from one main surface of the ceramic body to portions of both side surfaces of the ceramic body in the width direction. 
     
     
         11 . The multilayer ceramic capacitor of  claim 1 , wherein the internal electrodes include a plurality of first and second internal electrodes alternately disposed with a dielectric layer interposed between the plurality of first and second internal electrodes to form the active layer,
 each of the first internal electrodes having first and second lead portions is exposed to one main surface of the ceramic body and are spaced apart from each other in the length direction of the ceramic body, and   each of the second internal electrodes having a third lead portion is exposed to one main surface of the ceramic body and disposed between the first and second lead portions,   the external electrodes include first and second external electrodes disposed on one main surface of the ceramic body, spaced apart from each other in the length direction of the ceramic body and connected to the first and second lead portions, respectively, and a third external electrode disposed between the first and second external electrodes and connected to the third lead portion.   
     
     
         12 . The multilayer ceramic capacitor of  claim 11 , wherein each of the first internal electrodes further has fourth and fifth lead portions exposed to the other main surface opposing one main surface of the ceramic body and are spaced apart from each other in the length direction of the ceramic body,
 each of the second internal electrodes further has a sixth lead portion exposed to the other main surface of the ceramic body and disposed between the fourth and fifth lead portions, and   an insulating layer is disposed on the other main surface of the ceramic body.   
     
     
         13 . The multilayer ceramic capacitor of  claim 11 , wherein each of the first internal electrodes further has fourth and fifth lead portions exposed to the other main surface opposing the one main surface of the ceramic body and spaced apart from each other in the length direction of the ceramic body,
 each the second internal electrodes further has a sixth lead portion exposed to the other main surface of the ceramic body and disposed between the fourth and fifth lead portions, and   the external electrodes further include fourth and fifth external electrodes on the other main surface of the ceramic body, spaced apart from each other in the length direction of the ceramic body and connected to the fourth and fifth lead portions, respectively, and a sixth external electrode disposed between the fourth and fifth external electrodes and connected to the sixth lead portion.   
     
     
         14 . The multilayer ceramic capacitor of  claim 13 , wherein an interval LG between the fourth or fifth lead portion and the third lead portion is greater than 100 μm. 
     
     
         15 . The multilayer ceramic capacitor of  claim 13 , wherein a thickness of each of the fourth to sixth external electrodes is 10 to 40 μm. 
     
     
         16 . The multilayer ceramic capacitor of  claim 13 , wherein the fourth to sixth external electrodes include conductive layers in contact with the lead portions corresponding to the fourth to sixth external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 the conductive layers each having a thickness of 5 to 25 μm.   
     
     
         17 . The multilayer ceramic capacitor of  claim 13 , wherein the fourth to sixth external electrodes include conductive layers in contact with the lead portions corresponding to the fourth to sixth external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 the nickel plating layers each having a thickness of 2 μm or more.   
     
     
         18 . The multilayer ceramic capacitor of  claim 13 , wherein the fourth to sixth external electrodes include conductive layers in contact with the lead portions corresponding to the fourth to sixth external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 the tin plating layers each having a thickness of 3 μm or more.   
     
     
         19 . The multilayer ceramic capacitor of  claim 13 , wherein the fourth to sixth external electrodes include conductive layers in contact with the lead portions corresponding to the fourth to sixth external electrodes, respectively, nickel (Ni) plating layers covering the conductive layers, and tin (Sn) plating layers covering the nickel plating layers,
 a sum of thicknesses of the nickel plating layers and the tin plating layers being 15 μm or less.   
     
     
         20 . The multilayer ceramic capacitor of  claim 13 , wherein the fourth to sixth external electrodes extend from the other main surface of the ceramic body to portions of both side surfaces of the ceramic body in the width direction. 
     
     
         21 . A board having a multilayer ceramic capacitor comprising:
 a circuit board on which a plurality of electrode pads are disposed; and   the multilayer ceramic capacitor of  claim 1 ,   wherein the plurality of electrode pads are provided with external electrodes disposed on the plurality of electrode pads, respectively.