Capacitor and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10546691-B2
Application number	US-201815888351-A
Country	US
Kind code	B2
Filing date	Feb 5, 2018
Priority date	Aug 12, 2015
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

Abstract

A capacitor that includes a conductive base material with high specific surface area, a dielectric layer covering the conductive base material with high specific surface area, and an upper electrode covering the dielectric layer, in which the conductive base material with high specific surface area is formed of a metal sintered body as a whole.

First claim

The invention claimed is:

1. A capacitor comprising:
a conductive base material formed of a metal sintered body and having a porous portion with a porosity of 30% or more;
a dielectric layer covering at least the porous portion of the conductive base material; and
an electrode covering the dielectric layer, wherein
the metal sintered body is a sintered body formed from at least two kinds of metal powders each of which having a different average grain diameter, and,
of the at least two kinds of metal powders, a ratio of a first average grain diameter of a first metal powder having a smallest average grain diameter to a second average grain diameter of a second metal powder, which is a main component of the metal sintered body, is ⅓ or less.

2. The capacitor according to claim 1 , wherein each of the at least two kinds of metal powders has a different melting point.

3. The capacitor according to claim 2 , wherein a first melting point of the first metal is 100° C. or more lower than a second melting point of the second metal.

4. The capacitor according to claim 1 , wherein a metal constituting the metal sintered body is one or more kinds of metals selected from Ni, Cu, W, Mo, Au, Ir, Ag, Rh, Ru, Co and Fe.

5. The capacitor according to claim 1 , wherein the dielectric layer is an atomic layer deposited dielectric layer.

6. The capacitor according to claim 1 , wherein the electrode is an atomic layer deposited electrode.

7. A capacitor comprising:
a conductive base material formed of a metal sintered body and having a porous portion with a porosity of 30% or more;
a dielectric layer covering at least the porous portion of the conductive base material; and
an electrode covering the dielectric layer, wherein
the porous portion is a first porous portion, and the conductive base material includes a second porous portion with a porosity of 30% or more,
the dielectric layer is a first dielectric layer which covers a first principal surface of the first porous portion, and
the electrode is a first electrode which covers the first dielectric layer,
the capacitor further comprising:
a second dielectric layer which covers a second principal surface of the first porous portion opposite the first principal surface;
a third dielectric layer which covers a third principal surface of the second porous portion;
a fourth dielectric layer which covers a fourth principal surface of the second porous portion opposite the third principal surface;
a second electrode which covers the second dielectric layer;
a third electrode which covers the third dielectric layer; and
a fourth electrode which covers the fourth dielectric layer,

wherein the first porous portion, the first dielectric layer and the first electrode form a first electrostatic capacitance forming portion,
the first porous portion, the second dielectric layer and the second electrode form a second electrostatic capacitance forming portion,
the second porous portion, the third dielectric layer and the third electrode form a third electrostatic capacitance forming portion,
the second porous portion, the fourth dielectric layer and the fourth electrode form a fourth electrostatic capacitance forming portion,
the first electrostatic capacitance forming portion and the third electrostatic capacitance forming portion are disposed along a first principal surface of the conductive base material,
the second electrostatic capacitance forming portion and the fourth electrostatic capacitance forming portion are disposed along a second principal surface of the conductive base material,
the first electrostatic capacitance forming portion and the second electrostatic capacitance forming portion face each other with the first porous portion interposed therebetween, and
the third electrostatic capacitance forming portion and the fourth electrostatic capacitance forming portion face each other with the second porous portion interposed therebetween.

8. A capacitor comprising:
a conductive base material including a metal sintered body formed from a metal powder, and a metal support on which the metal sintered body is supported by necking, the conductive base material having a porous portion with a porosity of 30% or more;
a dielectric layer covering at least the porous portion of the conductive base material, the dielectric layer being formed from atoms each having an origin different from an origin of the conductive base material; and
an electrode covering the dielectric layer,
wherein
a first average diameter of necking connecting the metal sintered body and the metal support to each other is larger than a second average diameter of necking between the metal powders in the metal sintered body.

9. The capacitor according to claim 8 , wherein a first melting point of a first metal at an interface between the metal sintered body and the metal support is 100° C. or more lower than a second melting point of a second metal at a central portion of the metal sintered body.

10. The capacitor according to claim 8 , wherein a first melting point of a first metal at an interface between the metal sintered body and the metal support is 100° C. or more lower than a second melting point of a second metal of the metal support.

11. The capacitor according to claim 8 , wherein the metal powder of the metal sintered body is at least two kinds of metal powders each of which has a different average grain diameter.

12. The capacitor according to claim 11 , wherein, of the at least two kinds of metal powders, a ratio of a first average grain diameter of a first metal powder having a smallest average grain diameter to a second average grain diameter of a second metal powder, which is a main component of the metal sintered body, is ⅓ or less.

13. The capacitor according to claim 8 , wherein the metal powder of the metal sintered body is at least two kinds of metal powders each of which has a different melting point.

14. The capacitor according to claim 13 , wherein, of the at least two kinds of metal powders, a first melting point of a first metal powder is 100° C. or more lower than a second melting point of a second metal, which is a main component of the metal sintered body.

15. The capacitor according to claim 8 , wherein a metal of the metal powder is one or more kinds of metals selected from Ni, Cu, W, Mo, Au, Ir, Ag, Rh, Ru, Co and Fe.

16. The capacitor according to claim 8 , wherein the dielectric layer is an atomic layer deposited dielectric layer.

17. The capacitor according to claim 8 , wherein the electrode is an atomic layer deposited electrode.

18. The capacitor according to claim 8 , wherein
the porous portion is a first porous portion, and the conductive base material includes a second porous portion with a porosity of 30% or more,
the dielectric layer covers the first and second porous portions of the conductive base material,
the first porous portion, the dielectric layer and the electrode form a first electrostatic capacitance forming portion,
the second porous portion, the dielectric layer and the electrode form a second electrostatic capacitance forming portion,
the first and second electrostatic capacitance forming portions are adjacent to each other, and
the capacitor further comprises an insulating portion between the electrode and the conductive base material.

Assignees

• Murata Manufacturing Co

Inventors

• Inoue Noriyuki
• Arakawa Takeo
• Aoki Kensuke
• Saeki Hiromasa
• Kanryo Koichi
• Tsuru Akihiro
• Mori Haruhiko

Classifications

• H01G9/07

  Dielectric layers · CPC title

• H01G9/0525

  Powder therefor · CPC title

• H01G9/052

  Sintered electrodes · CPC title

• H01G9/0032

  formation of the dielectric layer · CPC title

• H01G4/085

  Vapour deposited · CPC title