JP4976070B2 - Deposition equipment - Google Patents

Description

  The present invention relates to a film forming apparatus for forming a film of lithium metal or lithium alloy used for a lithium secondary battery or the like, and more particularly to measures for facilitating film forming work.

  In recent years, with the advancement of mobile phones and the development of mobile devices such as notebook personal computers and PDAs, higher density of batteries has been demanded. A secondary battery using lithium metal as a negative electrode material (so-called lithium secondary battery) can realize a high energy density per weight and per volume. A lithium secondary battery generally employs a structure in which a positive electrode film or a lithium metal film is wound in a cylindrical shape in order to increase the density of the battery region. Therefore, in the manufacturing process of a lithium secondary battery, the technique of forming a lithium metal film on a substrate is a particularly important process, and various proposals have been made conventionally.

  Patent Document 1 describes that a thin film of metallic lithium is formed by a CVD method or a sputtering method using a block-like lithium metal as a supply source. Patent Document 2 discloses a method for forming a film on a substrate by vapor deposition using electron beam heating using a metal wire such as Co as a supply source as a method for performing film formation with high efficiency for a long time. It is disclosed.

Japanese Patent Laid-Open No. 2003-303587 JP-A-6-33226

  When the conventional film forming apparatus of Patent Document 1 is used, since a block-like lithium metal is used as a supply source, it is not possible to ensure a long period until the block-like lithium metal is replaced. Therefore, it is conceivable to supply the raw material for a long time by applying the technique of Patent Document 2 and using wire-like lithium metal as a supply source.

  However, when a lithium metal wire is used as a supply source, the lithium metal adheres to the roll member from which the wire is led out, so that the lithium metal wire may be wound around the roll member, making it impossible to supply the wire.

  An object of the present invention is to provide a film forming apparatus capable of smoothly forming a film by using means for suppressing adhesion of lithium metal or lithium alloy to a roll member while using a lithium metal or lithium alloy wire. There is to do.

  The film forming apparatus of the present invention uses a wire of lithium metal or lithium alloy (hereinafter also referred to as lithium metal) as a gas particle source, and at least a surface portion of a roll member for sending the wire to the gas particle generation unit Is made of a material mainly composed of a polymer resin to which lithium metal or the like hardly adheres. However, there may be another roll member that does not have a portion made of a polymer resin. This is because if the roll member does not contact the wire so strongly, the adhesion may not be a problem.

  Thereby, a wire such as lithium metal is not wound around the roll member or partly peeled off, and gas particles can be generated for a long time. Therefore, the manufacturing process using a wire of lithium metal or the like can be facilitated.

  Since the film forming apparatus of the present invention has the following limitations, additional effects can be obtained.

  Since the entire roll member is made of a material mainly composed of a polymer resin, even if the surface of the roll member is worn, the period until the roll member can be replaced can be ensured as long as possible.

  By using at least one material selected from polypropylene, polyethylene, and polyethylene terephthalate that is inexpensive and highly versatile as the polymer resin, the manufacturing cost can be reduced.

  When the material mainly composed of the polymer resin contains an inorganic filler, the wear resistance of the roll member is improved, and the replacement of the roll member and the maintenance frequency can be reduced.

  Since the film forming unit has a mechanism for continuously feeding the sheet-like base material, continuous film formation is possible, which means that the gas particle generating unit can generate gas particles for a long time. Therefore, it is possible to improve the efficiency of the film forming process.

  According to the film forming apparatus of the present invention, smooth film formation can be performed while adopting a structure in which a wire such as lithium metal is supplied to the gas particle generating unit.

(Embodiment)
FIG. 1 is a side view showing a main part of a film forming apparatus 10 according to an embodiment of the present invention. As shown in the figure, the film forming apparatus 10 of this embodiment includes a vacuum chamber 11 and an attached chamber 12 attached to the vacuum chamber 11. A supply roll 21 around which a wire 20 made of lithium metal or the like is wound and a guide roll 22 for guiding the wire 20 are arranged in the attachment chamber 12. Further, in the vacuum chamber 11, a gas particle generation unit 13 having a tungsten boat 27, a boat table 28, and the like attached on the floor surface of the vacuum chamber 11, and a film formation attached to the ceiling surface of the chamber 11. Part 14 is provided.

  In the vacuum chamber 11, feed rolls 24 and 25 that are roll members for feeding the wire 20 from the supply roll 21 that is a supply unit that supplies the wire 20 to the gas particle generation unit 13 (boat 27), and a guide A roll 23 is arranged. That is, the wire 20 is fed from the supply roll 21 to the gas particle generating unit 13 by rotating in a state where the wire 20 is strongly pinched by the two feed rolls 24 and 25. A guide roll 23 is also arranged between the feed rolls 24 and 25 and the guide roll 22. Here, each of the rolls 21, 22, 23, 24, 25 has flange portions 21 a, 22 a, 23 a, 24 a, 25 a that are in contact with the wire 20, and shaft portions 21 b, 22 b, 23 b, 24 b, 25 b. Each has.

  The boat 27 is heated by a resistance heating mechanism (not shown), and evaporates the wire 20 to generate lithium or lithium alloy vapor (gas particles). The wire 20 may be pure lithium metal having a purity of about 99.8%, or may be a lithium alloy containing several percent of Al. The wire referred to in the present invention includes not only a wire having a cross-sectional shape of a circle or a square but also a flat plate having a rectangular cross-sectional shape.

  The film forming unit 14 is wound with a sheet supply roll 32 around which the base sheet 31 is wound, a support roll 33 that supports the base sheet 31 fed from the sheet supply roll 32, and the formed base sheet 31. A take-up roll 34 is disposed. A shielding plate 36 having an opening is disposed below the support roll 33, and the vapor of lithium or lithium alloy generated by the gas particle generation unit 13 reaches the base sheet 31 through the opening.

  The base material sheet 31 is made of copper or a copper alloy serving as a negative electrode base material for a lithium secondary battery. Then, lithium or lithium alloy vapor adheres to the lower surface of the base sheet 31 and solidifies / deposits to form a lithium metal or lithium alloy film serving as a negative electrode material of the lithium secondary battery. The feed rate of the wire 20 varies depending on the film deposition rate, but is controlled so that the amount of raw material such as lithium metal on the boat 27 is substantially constant.

  Here, in the present embodiment, the entire flange portions 21a, 22a, 23a, 24a, and 25a of the supply roll 21, guide rolls 22 and 23, and feed rolls 24 and 25 are made of a material mainly composed of a polymer resin. ing. As the polymer resin, polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polyamide, polyacetal, polycarbonate vinyl chloride, or the like can be used. In particular, polyethylene, polypropylene, and polyethylene terephthalate are low-priced and versatile. By using these, manufacturing costs can be reduced.

  However, only the surfaces of the flange portions 21a, 22a, 23a, 24a, and 25a of the supply roll 21, the guide rolls 22 and 23, and the feed rolls 24 and 25 may be coated with a material mainly composed of a polymer resin. However, when forming a film of lithium metal or the like, since the lubricant cannot be used between the wire 20 and each of the rolls 21, 22, 23, 24, and 25 in order to prevent impurities from being mixed, the roll surface is worn. It's easy to do. Accordingly, the entire flange portion 21a, 22a, 23a, 24a, 25a of these rolls is made of a polymer resin, so that the usable period of the roll is extended even if it is worn by contact with the wire 20. be able to.

  Further, not only the flange portions 21a, 22a, 23a, 24a, 25a of the supply roll 21, the guide rolls 22, 23 and the feed rolls 24, 25 but also the shaft portions 21b, 22b, 23b, 24b, 25b as a whole are high. You may be comprised with the material which has molecular resin as a main component. In that case, cost reduction can be achieved by integral molding.

  Further, it is not necessary that at least the surface portions of all of the supply roll 21, the guide rolls 22 and 23, and the feed rolls 24 and 25 are made of a material mainly composed of a polymer resin. It is sufficient that at least the surface portion of the substrate is made of a material mainly composed of a polymer resin. This is because the other rolls 21, 22, and 23 do not come into strong contact with the wire 20, so even if they are made of metal or the like, for example, the adhesion amount of lithium metal or the like is relatively small.

  In addition, as described above, since the roll surface is easily worn during the film formation of a lithium metal or lithium alloy film, the material containing the polymer resin as the main component contains an inorganic filler. The wear resistance is increased, and the usable period of the roll can be further extended. As the inorganic filler, short ceramic fibers, various ceramics such as mica and alumina, various metals, and the like can be used.

Example 1
A wire made of lithium metal having a diameter of 3 mmφ is used as the wire 20, a sheet having a width of 120 mm, a length of 50 m, and a thickness of 10 μm is used as the base sheet 31, and the supply roll 21, guide rolls 22 and 23, and feed rolls 24 and 25 are used. The flange portions 21a, 22a, 23a, 24a, and 25a were made of polypropylene. As a result, even when the wire 20 made of lithium metal contacted each roll, the lithium metal hardly adhered to the surface of each roll, and all the wires having a length of 3 mmφ and 50 m could be smoothly fed.

(Example 2)
A wire made of lithium metal having a diameter of 3 mmφ is used as the wire 20, a sheet having a width of 120 mm, a length of 50 m, and a thickness of 10 μm is used as the base sheet 31, and the supply roll 21, guide rolls 22 and 23, and feed rolls 24 and 25 are used. Each of the flange portions 21a, 22a, 23a, 24a, and 25a was constituted by “Unilate” manufactured by Unitika Ltd. “Unilate” is composed of polyethylene terephthalate as a main component and filled with an inorganic filler such as glass fiber or mica. As a result, even when the wire 20 made of lithium metal came into contact with each roll, the lithium metal hardly adhered to the surface of each roll, and the entire wire of 3 mmφ and 80 m length could be smoothly fed. Moreover, it was confirmed that there is little abrasion of each roll by containing an inorganic filler.

(Comparative example)
A wire made of lithium metal having a diameter of 3 mmφ is used as the wire 20, a sheet having a width of 120 mm, a length of 50 m, and a thickness of 10 μm is used as the base sheet 31, and the supply roll 21, guide rolls 22 and 23, and feed rolls 24 and 25 are used. The flange portions 21a, 22a, 23a, 24a, and 25a were made of SUS304. As a result, when a wire made of lithium metal comes into contact with each roll, the lithium metal adheres to each roll, and when the wire is fed by 2 m, the wire is wound around the feed rolls 24 and 25 and the supply of the wire becomes impossible. I fell.

(Other embodiments)
The structure of the embodiment of the present invention disclosed above is merely an example, and the scope of the present invention is not limited to the scope of these descriptions. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  In the above embodiment, as the gas particle generator of lithium or lithium alloy for film formation, vacuum evaporation equipment by resistance heating is used. However, a vapor deposition method by electron beam melting, a sputtering method other than the vapor deposition method, etc. Can be used.

  The film forming apparatus of the present invention can be used for forming a film of lithium metal or lithium alloy used for a lithium secondary battery or the like.

It is a side view which shows the principal part of the film-forming apparatus in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Film-forming apparatus 11 Vacuum chamber 12 Attached chamber 13 Gas particle production | generation part 14 Film-forming part 20 Wire 21 Supply roll 21a Flange part 21b Shaft part 22 Guide roll 22a Flange part 22b Shaft part 23 Guide roll 23a Flange part 23b Shaft part 24 Feed Roll 24a Flange part 24b Shaft part 25 Feed roll 25a Flange part 25b Shaft part 27 Boat 28 Boat stand 31 Base sheet 32 Sheet supply roll 33 Support roll 34 Winding roll 36 Shielding plate

Claims (6)

A gas particle generator for generating lithium or lithium alloy gas particles;
A film forming unit for forming a lithium metal or lithium alloy film on a base material from lithium or lithium alloy gas particles generated in the gas particle generating unit;
A supply unit for supplying a lithium metal or lithium alloy wire to the gas particle generation unit;
A roll member for sending the wire from the supply unit to the gas particle generation unit, at least the surface portion is made of a material mainly composed of a polymer resin;
A film forming apparatus comprising: The film forming apparatus according to claim 1,
The film forming apparatus, wherein at least the entire flange portion of the roll member is made of a material mainly composed of the polymer resin. In the film-forming apparatus of Claim 1 or 2,
The film forming apparatus, wherein the polymer resin is made of a material mainly composed of at least one material selected from polypropylene, polyethylene, and polyethylene terephthalate. In the film-forming apparatus in any one of Claims 1-3,
The film forming apparatus, wherein the material containing the polymer resin as a main component contains an inorganic filler. In the film-forming apparatus in any one of Claims 1-4,
The film forming unit has a mechanism for continuously feeding a sheet-like base material.   The film-forming method which forms into a film on a base material using the film-forming apparatus in any one of Claims 1-5.

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