Film forming device, manufacturing method of electrode foil for electrolytic capacitor, and manufacturing method for electrolytic capacitor
A film-forming device disclosed is a film-forming device for forming a film on a metal foil having a porous portion on a main surface thereof by a gas phase method, and includes a film-forming region in which the film is formed on the metal foil, conveyors to provided downstream of the film-forming region and drawing the metal foil from the film-forming region, and a control unit that controls the stress applied to the metal foil from the conveyors to 21 N/mm 2 or less. This provides a film-forming device which does not cause defects easily on a film-forming target metal foil.
1 . A film-forming device for forming a film on a metal foil used for producing an electrode foil for an electrolytic capacitor, having a porous portion on a main surface thereof by a gas phase method, the film-forming device comprising:
a film-forming region in which the film is formed on the metal foil;
a conveyor provided downstream of the film-forming region and drawing the metal foil from the film-forming region; and
a control unit that controls a stress applied to the metal foil from the conveyor to 21 N/mm 2 or less,
wherein the conveyor includes a plurality of rollers,
the plurality of rollers include a first roller that is disposed closest to the film-forming region among the plurality of rollers, and a second roller that is a take-up roller,
the plurality of rollers have a diameter of 50 mm or more,
the second roller has a diameter of 70 mm or more,
the porous portion has a thickness of 20 μm or more, and
the film has a thickness of 7 nm or more.
2 . The film-forming device of claim 1 , wherein the metal foil has a core part continuous to the porous portion, and
the core part has a thickness of 10 μm or more.
3 . The film-forming device of claim 1 , wherein the film includes a dielectric.
4 . The film-forming device of claim 1 , wherein the conveyor is a columnar or cylindrical roller.
5 . The film-forming device of claim 1 , wherein the gas phase method is an atomic layer deposition method.
6 . The film-forming device of claim 1 , wherein:
the stress applied to the metal foil from the first roller is higher than the stress applied to the metal foil from the second roller.
7 . A method for producing an electrode foil for an electrolytic capacitor, the method including:
a step of preparing a metal foil having a porous portion on a main surface thereof;
a step of forming a film on the metal foil in a film forming region of a film forming device; and
a step of drawing the metal foil from the film forming region by a conveyor provided downstream of the film-forming region, wherein:
a stress applied to the metal foil from the conveyor is 21 N/mm 2 or less,
the conveyor includes a plurality of rollers,
the plurality of rollers include a first roller that is disposed closest to the film-forming region among the plurality of rollers, and a second roller that is a take-up roller,
the plurality of rollers have a diameter of 50 mm or more,
the second roller has a diameter of 70 mm or more,
the porous portion has a thickness of 20 μm or more, and
the film has a thickness of 7 nm or more.
8 . The method of claim 7 , wherein the metal foil has a core part continuous to the porous portion, and
the core part has a thickness of 10 μm or more.
9 . The method of claim 7 , wherein the film includes a dielectric.
10 . A method for producing an electrolytic capacitor, the method comprising:
a step of preparing a metal foil having a porous portion on a main surface thereof;
a step of forming a film on the metal foil in a film forming region of a film forming device to obtain an electrode foil;
a step of drawing the metal foil from the film forming region by a conveyor provided downstream of the film-forming region; and
a step of forming a solid electrolyte layer covering at least a portion of the film, wherein:
a stress applied to the metal foil from the conveyor is 21 N/mm 2 or less,
the conveyor includes a plurality of rollers,
the plurality of rollers include a first roller that is disposed closest to the film-forming region among the plurality of rollers, and a second roller that is a take-up roller,
the plurality of rollers have a diameter of 50 mm or more,
the second roller has a diameter of 70 mm or more,
the porous portion has a thickness of 20 μm or more, and
the film has a thickness of 7 nm or more.
11 . The method of claim 10 , wherein the metal foil has a core part continuous to the porous portion, and
the core part has a thickness of 10 μm or more.
12 . The method of claim 10 , wherein the film includes a dielectric.