Tantalum capacitor including nickel

1 . A tantalum capacitor, comprising

a capacitor body including (i) a tantalum body including a tantalum wire extending toward a surface of the capacitor body; and (ii) a capsule portion surrounding the tantalum body such that the capsule portion does not cover an end of the tantalum wire;

a solid electrolyte layer disposed on a surface of the tantalum body and including para-toluenesulfonic acid (P-TSA);

a first metal layer on one side of the capacitor body;

a second metal layer on one side of the first metal layer; and

an external electrode connected to the first metal layer,

wherein the first metal layer includes Cr (chromium), Ti (titanium), an alloy thereof, or a mixture thereof,

the second metal layer includes Ni (nickel), an alloy including the same, or a mixture including the same,

an average thickness of the first metal layer is smaller than an average thickness of the second metal layer,

an average thickness of the first metal layer is 20 nm to 100 nm, and

an average thickness of the second metal layer is 50 nm to 500 nm.

2 . The tantalum capacitor of claim 1 , further comprising (i) a third metal layer on the surface of the capacitor body and facing the first metal layer in a first direction; and (ii) a fourth metal layer on one surface of the third metal layer,

wherein the capacitor body includes first and second surfaces facing each other in a second direction perpendicular to the first direction, third and fourth surfaces facing each other in the first direction, and fifth and sixth surfaces facing each other in a third direction perpendicular to the first and second directions,

the third metal layer includes Cr (chromium), Ti (titanium), an alloy thereof, or a mixture thereof, and

the fourth metal layer includes Ni (nickel), an alloy including the same, or a mixture including the same.

3 . The tantalum capacitor of claim 2 , wherein

the external electrode includes first and second external electrodes spaced apart from each other and disposed on the second surface of the capacitor body.

4 . The tantalum capacitor of claim 3 , wherein

the first external electrode is connected to the tantalum body, and

the second external electrode is connected to the tantalum wire.

5 . The tantalum capacitor of claim 2 , wherein

an average thickness of the third metal layer is 20 nm to 100 nm, and

an average thickness of the fourth metal layer is 50 nm to 500 nm.

6 . The tantalum capacitor of claim 1 , further comprising a base layer between the capsule portion and the external electrode.

7 . The tantalum capacitor of claim 6 , further comprising a connection electrode between the base layer and the tantalum body.

8 . A tantalum capacitor, comprising

a capacitor body including (i) a tantalum body including a tantalum wire extending toward a surface of the capacitor body and (ii) a capsule portion surrounding the tantalum body such that the capsule portion does not cover an end of the tantalum wire;

a solid electrolyte layer disposed on a surface of the tantalum body and including para-toluenesulfonic acid (P-TSA);

a first metal layer on a first side of the capacitor body;

a second metal layer on one side of the first metal layer;

a third metal layer on a second side of the capacitor body;

a fourth metal layer on one side of the third metal layer; and

an external electrode connected to the first metal layer and the third metal layer,

wherein the first and third metal layers include Cr (chromium), Ti (titanium), an alloy thereof, or a mixture thereof,

the second and fourth metal layers include Ni (nickel), an alloy including the same, or a mixture including the same,

an average thickness of each of the first and third metal layers is smaller than an average thickness of each of the second and fourth metal layers,

an average thickness of each of the first metal layer and the third metal layer is 20 nm to 100 nm, and

an average thickness of each of the second metal layer and the fourth metal layer is 50 nm to 500 nm.

9 . The tantalum capacitor of claim 8 , wherein

the capacitor body includes first and second surfaces facing each other in a second direction, third and fourth surfaces facing each other in a first direction perpendicular to the second direction, and fifth and sixth surfaces facing each other in a third direction perpendicular to the first and second directions, and

the external electrode includes first and second external electrodes spaced apart from each other and disposed on the second surface of the capacitor body.

10 . The tantalum capacitor of claim 9 , wherein

the first external electrode is connected to the tantalum body, and

the second external electrode is connected to the tantalum wire.

11 . The tantalum capacitor of claim 8 , further comprising a base layer between the capsule portion and the external electrode.

12 . The tantalum capacitor of claim 11 , further comprising a connection electrode between the base layer and the tantalum body.

13 . The tantalum capacitor of claim 8 , wherein the tantalum capacitor is a frameless tantalum capacitor.

14 . The tantalum capacitor of claim 8 , wherein the first and third metal layers include Cr (chromium) or Ti (titanium).

15 . The tantalum capacitor of claim 14 , wherein the second and fourth metal layers include Ni (nickel) or an alloy including Ni (nickel) and Cr (chromium).