ELECTROLYTIC CAPACITOR AND METHOD FOR PRODUCING ELECTROLYTIC CAPACITOR
An electrolytic capacitor has a capacitor element having an anode foil having a dielectric layer formed thereon, a cathode foil and a separator placed between the anode foil and the cathode foil and an electrolytic solution impregnated in the capacitor element. The anode foil or the cathode foil is obtained by forming a sintered material of a composition containing a metal powder in a foil form (is composed of a foil-form sintered material) or forming a sintered material film composed of the sintered material on a surface of a base material, and the viscosity μ [cP] of the electrolytic solution at 25 [° C.] is 400 [cP] or less.
1 . An electrolytic capacitor comprising:
a capacitor element having an anode foil having a dielectric layer formed thereon, a cathode foil and a separator placed between the anode foil and the cathode foil; and
an electrolytic solution impregnated in the capacitor element:
which is characterized in that
the anode foil or the cathode foil is obtained by forming a sintered material of a composition containing a metal powder in a foil form or forming a sintered material film composed of the sintered material on a surface of a base material, and
the viscosity μ [cP] of the electrolytic solution at 25° C. is 400 cP or less.
2 . The electrolytic capacitor according to claim 1
which is characterized in that the particle size D [μm] of powder particles of the metal powder or sintered particles of the metal powder is 5.0 μm or less
(wherein the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
3 . The electrolytic capacitor according to claim 1 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. further satisfies the expression (1) below
μ
≤
9.438
D
+
227
(
1
)
(wherein D means the particle size D [μm] of powder particles of the metal powder or sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
4 . A method for producing an electrolytic capacitor having a capacitor element having an anode foil having a dielectric layer formed thereon, a cathode foil and a separator placed between the anode foil and the cathode foil and an electrolytic solution impregnated in the capacitor element:
which is characterized in that
at least one of the anode foil and the cathode foil is configured by forming a sintered material of a composition containing a metal powder in a foil form or configured by forming a sintered material film composed of the sintered material on a surface of a base material, and
the viscosity μ [cP] of the electrolytic solution at 25° C. is adjusted to 400 cP or less.
5 . The method for producing an electrolytic capacitor according to claim 4
which is characterized in that the particle size D [μm] of powder particles of the metal powder or sintered particles of the metal powder is adjusted to 5.0 μm or less
(wherein the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
6 . The method for producing an electrolytic capacitor according to claim 4 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. is adjusted to further satisfy the expression (1) below
μ
≤
9.438
D
+
227
(
1
)
(wherein D means the particle size D [μm] of powder particles of the metal powder or sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
7 . The electrolytic capacitor according to claim 2 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. further satisfies the expression (1) below
μ
≤
9.438
D
+
227
(
1
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
8 . The electrolytic capacitor according to claim 1 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. further satisfies the expression (2) below
μ
≤
6.726
D
+
162
(
2
)
(wherein D means the particle size D [μm] of powder particles of the metal powder or sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
9 . The electrolytic capacitor according to claim 2 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. further satisfies the expression (2) below
μ
≤
6.726
D
+
162
(
2
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
10 . The electrolytic capacitor according to claim 2 which is characterized in that the expression (3) below is further satisfied when the viscosity μ [cP] of the electrolytic solution at 25° C. is 50 cP or less
1.552
/
(
D
μ
2
)
≤
0.5
(
3
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
11 . The electrolytic capacitor according to claim 3 which is characterized in that the expression (3) below together with the expression (1) is further satisfied when the viscosity μ [cP] of the electrolytic solution at 25° C. is 50 cP or less
1.552
/
(
D
μ
2
)
≤
0.5
(
3
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
12 . The electrolytic capacitor according to claim 7 which is characterized in that the expression (3) below together with the expression (1) is further satisfied when the viscosity μ [cP] of the electrolytic solution at 25° C. is 50 cP or less
1.552
/
(
D
μ
2
)
≤
0.5
(
3
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
13 . The electrolytic capacitor according to claim 8 which is characterized in that the expression (3) below together with the expression (2) is further satisfied when the viscosity μ [cP] of the electrolytic solution at 25° C. is 50 cP or less
1.552
/
(
D
μ
2
)
≤
0.5
(
3
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
14 . The electrolytic capacitor according to claim 9 which is characterized in that the expression (3) below together with the expression (2) is further satisfied when the viscosity μ [cP] of the electrolytic solution at 25° C. is 50 cP or less
1.552
/
(
D
μ
2
)
≤
0.5
(
3
)
(wherein D means the particle size D [μm] of the powder particles of the metal powder or the sintered particles of the metal powder, and the particle size D means the median diameter at a cumulative value of 50% in a particle size distribution based on volume of the powder particles measured by the laser diffraction-scattering method or the sintered particles measured by observation with a scanning electron microscope).
15 . The electrolytic capacitor according to claim 1 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. is 2 cP or more.
16 . The electrolytic capacitor according to claim 1 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. is 10 cP or more.
17 . The electrolytic capacitor according to claim 1 which is characterized in that the viscosity μ [cP] of the electrolytic solution at 25° C. is 30 cP or more.