Multilayer ceramic electronic component having an average surface roughness to provide adhesion strength between a dielectric layer and inner electrode and fabrication method thereof

1. A multilayer ceramic electronic component comprising:

a ceramic main body including a dielectric layer; and

first and second inner electrodes disposed to face each other, within the ceramic main body, with the dielectric layer interposed therebetween, wherein:

when an average thickness of the dielectric layer is td and an average thickness of the inner electrodes is te, 0.1 μm≦te≦0.5 μm and (td+te)/te≦2.5 are satisfied, and

when an average surface roughness on a virtual surface roughness center line of the inner electrode is Ra and an average roughness of ten points of the inner electrode is Rz, 150 nm≦Rz≦td/2, and 8≦Rz/Ra≦20 are satisfied.

2. The multilayer ceramic electronic component of claim 1 , wherein the average thickness td of the dielectric layer satisfies 0.15≦td≦0.75 μm.

3. The multilayer ceramic electronic component of claim 1 , wherein the average thickness td of the dielectric layer is obtained from a section of the ceramic main body in lengthwise and thicknesswise directions cut in a central portion of the ceramic main body in a widthwise direction.

4. The multilayer ceramic electronic component of claim 1 , wherein the average thickness of the inner electrodes is obtained from a section of the ceramic main body in lengthwise and thicknesswise directions cut in a central portion of the ceramic main body in a widthwise direction.

5. The multilayer ceramic electronic component of claim 1 , wherein the inner electrodes are formed of a metal powder including first particles, and second particles having a particle diameter smaller than that of first particles.

6. The multilayer ceramic electronic component of claim 5 , wherein the particle diameter of the first particles is 1.5 times to 2.5 times greater than that of the second particles.

7. The multilayer ceramic electronic component of claim 5 , wherein a content of the first particles is 9 to 20 weight parts based on 100 weight parts of the metal powder.

8. A multilayer ceramic electronic component comprising:

a ceramic main body including a dielectric layer, and first and second inner electrodes disposed to face each other with the dielectric layer interposed therebetween, wherein;

when an average thickness of the dielectric layer is td and an average thickness of the inner electrodes is te, td≦1.5 μm and 0.1 μm≦te≦0.5 μm are satisfied,

when an average surface roughness on a virtual surface roughness center line of the inner electrode is Ra and an average surface roughness of ten points of the inner electrode is Rz, 8≦Rz/Ra≦20 is satisfied, and

the average surface roughness Rz satisfies 150 nm≦Rz≦td/2.

9. The multilayer ceramic electronic component of claim 8 , wherein the average thickness td of the dielectric layer and the average thickness te of the inner electrodes satisfy (td+te)/te≦2.5.

10. The multilayer ceramic electronic component of claim 8 , wherein the average thickness of the dielectric layer is obtained from a section of the ceramic main body in lengthwise and thicknesswise directions cut in a central portion of the ceramic main body in a widthwise direction.

11. The multilayer ceramic electronic component of claim 8 , wherein the average thickness of the inner electrodes is obtained from an average thickness of inner electrodes disposed in a central portion of a section of the ceramic main body in lengthwise and thicknesswise directions cut in a central portion of the ceramic main body in a widthwise direction.

12. The multilayer ceramic electronic component of claim 8 , wherein the inner electrodes are formed of a metal powder including first particles, and second particles having a particle diameter smaller than that of first particles.

13. The multilayer ceramic electronic component of claim 12 , wherein the particle diameter of the first particles is 1.5 times to 2.5 times greater than that of the second particles.

14. The multilayer ceramic electronic component of claim 12 , wherein a content of the first particles is 9 to 20 weight parts based on 100 weight parts of the metal powder.

15. A method of fabricating a multilayer ceramic electronic component, the method comprising:

forming dielectric layers formed of ceramic green sheets including dielectrics;

forming inner electrode patterns on the ceramic green sheets by using a metal paste including a metal powder having first particles, and second particles having a particle diameter smaller than that of the first particles, wherein a content of the first particles is 9 to 20 weight parts based on 100 weight parts of the metal powder; and

laminating the green sheets with the inner electrode patterns formed thereon and sintering the same to form a ceramic main body, in which an average thickness te of inner electrodes satisfies 0.1 μm≦te≦0.5 μm, an average surface roughness Ra on a virtual surface roughness center line of the inner electrode satisfies 5 nm≦Ra≦30 nm, and a ratio Rz/Ra of an average surface roughness Rz of ten points of the inner electrode to the average surface roughness Ra satisfies 8≦Rz/Ra≦20.

16. The method of claim 15 , wherein the particle diameter of the first particles is 1.5 times to 2.5 times greater than that of the second particles.

17. The method of claim 15 , wherein an average thickness td of the dielectric layers satisfies 0.15≦td≦0.75 and (td+te)/te≦2.5.