Multilayer ceramic capacitor, method of manufacturing the same, and board having the same

1. A multilayer ceramic capacitor, comprising:

an active part including dielectric layers and internal electrodes which are alternately stacked therein in a stacking direction; and

cover parts disposed on an upper surface and a lower surface of the active part, respectively,

wherein each of the cover parts includes an active part protective cover and an exterior cover, each of the active part protective covers being disposed adjacent to the active part and each of the exterior covers extending in the stacking direction to an external surface of the multilayer ceramic capacitor,

wherein a porosity of each of the exterior covers is higher than a porosity of each of the active part protective covers, respectively, and

wherein the porosity of at least one of the exterior covers is about 12 vol % to 43 vol %.

2. The multilayer ceramic capacitor of claim 1 , wherein at least one of the cover parts is configured such that a removal rate of residual carbon in the exterior cover is faster than a removal rate of residual carbon in the active part protective cover.

3. The multilayer ceramic capacitor of claim 1 , wherein the porosity of at least one of the active part protective covers is about 1 vol % or less.

4. The multilayer ceramic capacitor of claim 1 , wherein at least one of the exterior covers is configured such that grains therein located closer to the active part protective cover have smaller diameters than grains therein located farther from the active part protective cover.

5. The multilayer ceramic capacitor of claim 1 , wherein a thickness of at least one of the active part protective covers is about 0.5 μm to 100 μm.

6. The multilayer ceramic capacitor of claim 1 , wherein a thickness of at least one of the cover parts is about ½ or more of a thickness of the active part.

7. A board having a multilayer ceramic capacitor, the board comprising:

a printed circuit board on which a plurality of electrode pads are disposed;

the multilayer ceramic capacitor of claim 1 mounted on the printed circuit board; and

solders connecting the plurality of electrode pads and the multilayer ceramic capacitor to each other.

8. A multilayer ceramic capacitor, comprising:

an active part including dielectric layers and internal electrodes which are alternately stacked therein; and

cover parts disposed on an upper surface and a lower surface of the active part, respectively, so as to be above and below, respectively, an outermost internal electrode,

wherein each of the cover parts includes an active part protective cover and an exterior cover, each of the active part protective covers being disposed adjacent to the active part, and

wherein an average diameter of grains contained in each of the exterior covers is larger than an average diameter of grains contained in each of the active part protective covers, respectively.

9. A multilayer ceramic capacitor, comprising:

an active part including dielectric layers and internal electrodes which are alternately stacked therein; and

a cover part disposed on at least one of an upper surface or a lower surface of the active part,

wherein the cover part includes an active part protective cover and an exterior cover, the active part protective cover being disposed adjacent to the active part, and

wherein the exterior cover contains metal particles formed by reducing a peroxidized metal.

10. A multilayer ceramic capacitor, comprising:

a ceramic body having an active part including a plurality of dielectric layers and first and second internal electrodes disposed to face each other with at least one of the plurality of dielectric layers interposed therebetween, the plurality of dielectric layers and the first and second internal electrodes are alternately stacked therein in a stacking direction, and cover parts disposed on an upper surface and a lower surface of the active part, respectively; and

first and second external electrodes disposed on outer surfaces of the ceramic body to be connected to the first and second internal electrodes, respectively,

wherein each of the cover parts includes an active part protective part and a thickness reinforcing part, each of the active part protective parts being disposed adjacent to the active part, and each of the thickness reinforcing parts being disposed on an exterior surface of the active part protective part so as to extend in the stacking direction to an external surface of the multilayer ceramic capacitor,

wherein a porosity of at least one of the thickness reinforcing parts is higher than a porosity of the active part protective part, and

wherein the porosity of at least one of the thickness reinforcing parts is about 12 vol % to 43 vol %.

11. The multilayer ceramic capacitor of claim 10 , wherein a thickness of the ceramic body is T 1 and a width of the ceramic body is W 1 , the ceramic body satisfies about 0.95≦W 1 /T 1 ≦1.05.

12. The multilayer ceramic capacitor of claim 10 , wherein an average size of grains contained in at least one of the thickness reinforcing parts is larger than an average size of grains contained in the active part protective part.

13. The multilayer ceramic capacitor of claim 10 , wherein at least one of the thickness reinforcing parts is configured such that grains therein located closer to the active part protective part have smaller diameters than grains therein located farther from the active part protective part.

14. The multilayer ceramic capacitor of claim 10 , wherein at least one of the thickness reinforcing parts contains metal particles formed by reducing a peroxidized metal.

15. A board having a multilayer ceramic capacitor, the board comprising:

a printed circuit board on which a plurality of electrode pads are disposed;

the multilayer ceramic capacitor of claim 10 mounted on the printed circuit board; and

solders connecting the plurality of electrode pads and the multilayer ceramic capacitor to each other.

16. A multilayer ceramic capacitor, comprising:

an active part including dielectric layers and internal electrodes which are alternately stacked therein in a stacking direction; and

cover parts disposed on an upper surface and a lower surface of the active part, respectively,

wherein each of the cover parts includes a first portion and a second portion having a different composition than the first portion, each of the first portions being located closer to the active part than the second portion,

wherein each of the second portions extends in the stacking direction to an external surface of the multilayer ceramic capacitor,

wherein a porosity of at least one of the second portions is higher than a porosity of the first portion, and

wherein the porosity of at least one of the second portions is about 12 vol % to 43 vol %.

17. The multilayer ceramic capacitor of claim 16 , wherein the different composition includes different materials.

18. The multilayer ceramic capacitor of claim 16 , wherein the different composition includes different average diameter of grains, an average diameter of grains contained in at least one of the second portions is larger than an average diameter of grains contained in the first portion.

19. The multilayer ceramic capacitor of claim 16 , wherein at least one of the cover parts is composed of at least one dielectric layer.

20. The multilayer ceramic capacitor of claim 19 , wherein at least one of the second portions contains metal particles.

21. The multilayer ceramic capacitor of claim 16 , further comprising an external electrode connected to the internal electrodes.

22. The multilayer ceramic capacitor of claim 21 , wherein the external electrode is disposed on a side surface of the active part and a side surface of at least one of the cover parts.