JP2024024248A - evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporator for forming a zinc fine line on a film for a film capacitor.

SOLUTION: In an evaporator for evaporating zinc onto a film on a cooling roller 20, a zinc evaporator 100 includes: a lower surface plate 120 with a predetermined thickness that is a longitudinal metal plane body and in which an electric heating rod 160 is embedded; two side surface plates 130; an upper surface plate 110 in which a longitudinal window 111 communicating in a thickness direction is formed; two edge surface plates 140 closing both edges of a square cylinder formed with these four surface plates; and a mask plate 150 in which a slit 151 with a predetermined width of 0.5 mm or more and 2.0 mm or less for engaging the upper surface plate 110 is formed. The evaporator can be used by making a distance between the cooling roller 20 and the slit 151 close to become 1.5 mm or less.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to an evaporator for forming a zinc-based vapor deposited film on a film for a film capacitor, and particularly to an evaporator that can form so-called heavy edges as fine lines.

Film capacitors, which form patterns by vapor-depositing aluminum on a strip of film that is continuously fed into contact with a cooling roller, are highly productive and have excellent withstand voltage, temperature characteristics, and frequency characteristics.

It is also possible to provide a film with self-healing properties, and films in which a zinc vapor-deposited layer is formed on one end of the film in addition to aluminum as a heavy edge are also widely manufactured.

Here, in recent years, in order to improve the performance of capacitors and meet various physical property requirements, there are cases where it is required to make the width of the zinc evaporated film as narrow as possible.
However, the metal evaporation device that houses and heats the crucible for evaporating zinc has a complicated external shape, such as a long rectangular tube of a predetermined height attached to the upper side of the periphery of a cylinder that is laid on its side. . For this reason, distortion occurs in an environment heated to about 600 degrees to 700 degrees, and distortion is also likely to occur due to heat cycles, etc., so it is necessary to space it 5 mm or more from the cooling roller.
Therefore, even if the slit for zinc diffusion in the evaporator is 1 mm, there is a problem in that it is difficult to form fine zinc-based wires, for example, there is a part on the film that widens to 3 mm. .

JP2007-109845 JP2016-79430 JP2021-134387

The present invention has been made in view of the above, and an object of the present invention is to provide an evaporation device capable of forming thin zinc wires on a film for a film capacitor.

The evaporation device according to claim 1 relates to an evaporation device for depositing zinc or zinc alloy onto a strip-shaped film capacitor film that is brought into contact with a cooling roller and continuously supplied, and the evaporation device accommodates a crucible inside. In an evaporation device that has a prismatic external shape and is placed horizontally in a vacuum chamber, there is a bottom flat plate that is a long metal flat plate with a predetermined thickness filled with heat generating resistance rods, and a heat generating resistor rod. Two side plates, which are long metal flat plates of a predetermined thickness and filled with resistance rods, and a long metal plate of a predetermined thickness and filled with heat generating resistance rods, communicating in the thickness direction. The flat plate for the top surface having a longitudinal hole formed in the longitudinal direction, and the flat plate for the ends, which are metal flat plates of a predetermined thickness that respectively close both ends of the rectangular cylinder formed by the four metal flat plates. and a mask body, which is a metal flat plate body that is joined from the top surface to the flat plate body for the top surface, and in which a slit of a predetermined width of 0.1 mm or more and 2.0 mm or less is formed, and the distance between the cooling roller and the slit is It is characterized in that it can be used when the two are placed close to each other within 5.0 mm.

In other words, the invention according to claim 1 is achieved by assembling thick, simple-shaped metal plates, so that even if each plate expands and contracts due to heat, distortions such as twisting and waving can be prevented from forming in the entire structure of the prismatic housing. This can be made less likely to occur, and the distance from the cooling roller can be made closer. This makes it possible to form a vapor-deposited film of thin zinc wires on the film.
The deposited zinc can be made into a thin line depending on the slit width and the distance between the cooling rollers. That is, if the interval is 3 mm, it is possible to form a thin line of about 1.0 mm with a slit width of 0.5 mm, and a thin line of about 4.0 mm with a slit width of 2.0 mm.
Further, if no contact occurs, the distance between the surface of the cooling roller (more precisely, the film in contact with the cooling roller) and the slit can be set to 0.1 mm. Considering the safety factor, the spacing may be 0.2 mm.

The flat plate for the bottom, the flat plate for the sides, and the flat plate for the top are long rectangles when viewed in the thickness direction, and because they form a rectangular cylinder that is tilted sideways (when in use), they should be roughly the same shape and have the same thickness. is preferred. It is preferable that the flat plate for the end also has the same thickness as the flat plate described above. Although the thickness of the mask body may be different from these, the metal composition of all these plate bodies is, in principle, the same.
The heating resistance rod is a so-called heating wire, and can be a round rod of nichrome with an insulating layer provided on its surface.
In addition, a thin metal inner cover is separately interposed on the inner surface of the "tank", which includes the flat plate for the bottom, the flat plate for the sides, and in some cases, the flat plate for the ends, in order to prevent zinc from adhering or sticking. You can do it like this.
In addition, when joining the top flat plate to the side flat plate (and sometimes to the end flat plate), it is recommended to sandwich a gasket such as a metal sheet or carbon fiber sheet in order to ensure thermal conductivity and airtightness. You can also do it.
An example can be given in which a large number of slits are provided at regular intervals in the longitudinal direction, and each slit itself extends in a direction perpendicular to the longitudinal direction (the short side direction of the rectangle in plan view) and communicates in the thickness direction.

The evaporator according to claim 2 is the evaporator according to claim 1, in which the flat plate for the bottom surface, the flat plate for the side surfaces, the flat plate for the top surface, the flat plate for the ends, and the mask body are made of SUS having the same composition. The flat plate for the bottom, the flat plate for the side surfaces, and the flat plate for the top surface form a rectangular tube by fastening with multiple screws, and the mask body is also joined to the flat plate for the top surface by fastening with multiple screws. It is characterized by being worn.

The invention according to claim 2 makes it possible to provide an evaporator that is made of the same material so that it is difficult to cause distortion, that is easy to procure and process, and that can be replaced individually. In addition to the prismatic structure or shape itself, distortion is also suppressed by fastening with multiple screws.

Note that the screws are preferably made of a material different from that of the flat plate body, such as carbon steel, to prevent them from sticking due to heat.

In the evaporator according to claim 3, in the evaporator according to claim 1, the heating resistance rods are two symmetrically arranged with respect to the center line in the longitudinal direction of the metal flat plate, or one symmetrically arranged with the end bent back. As a book, a flat metal plate divided into two in the thickness direction is fitted into a fitting groove provided, and the three parts are integrated to form a flat plate for the bottom, a flat plate for the sides, and a flat plate for the top. It is characterized by

That is, the invention according to claim 3 improves thermal efficiency by using a sandwich structure, and also realizes uniform heating of the crucible by using a symmetrical arrangement. Moreover, since it is unitized, it becomes easy to replace the flat plate bodies individually.

In addition, the bending may be in a manner in which the resistance rod once comes out of the flat plate body and then returns, or in a manner in which it returns in a U-shape within the flat plate body. If the bending is repeated not once but an odd number of times, the target arrangement can be realized.

The evaporator according to claim 4 is the evaporator according to claim 1, which includes: a first heating system in which heat generating resistance rods of a bottom flat plate body and two side face flat plate bodies are connected; and a first heating system. and a second heating system consisting of a heating resistance rod of a flat plate body for the upper surface, which is independent from the second heating system.

That is, the invention according to claim 4 can easily implement heating control to prevent zinc from re-depositing on the evaporator, and improve the quality of vapor deposition.

According to the present invention, it is possible to provide an evaporation device for forming thin zinc wires on a film for a film capacitor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram of a vacuum evaporation apparatus equipped with a zinc evaporation apparatus according to the present invention. FIG. 1 is an external perspective view of a zinc evaporation device of the present invention. FIG. 2 is a plan view showing the zinc evaporation device of the present invention with the mask plate and the top plate removed.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Embodiments of the present invention will be described in detail below with reference to the drawings. Here, a vacuum deposition apparatus for manufacturing a deposited film for a film capacitor will be described. FIG. 1 is a conceptual diagram of a vacuum evaporation apparatus equipped with a zinc evaporation apparatus according to the present invention. FIG. 2 is an external perspective view of the zinc evaporation device of the present invention. FIG. 3 is a plan view showing the zinc evaporation apparatus of the present invention with the mask plate and the top plate removed. Note that the scales in each figure are not necessarily the same for convenience of explanation.

The vacuum deposition apparatus 1 includes a film unwinding roller 10, a cooling roller 20, a film take-up roller 30, a masking section 40, an aluminum evaporator 50, and a zinc evaporator 100 as main components. Although not shown in the drawings, an electron beam irradiation section, a plasma irradiation section, and the like are appropriately provided to perform modification, curing, solidification, and the like. Further, depending on the specification, a configuration in which other metals are deposited or a dielectric layer is separately formed may be included.
The vacuum evaporation apparatus 1 performs evaporation while degassing the room to a predetermined degree of vacuum using a degassing device (not shown).

The film unwinding roller 10 is wound with a wide film for film capacitors having a predetermined dielectric constant, and continuously unwinds the film at a constant supply speed. As an example of a film, mention may be made of an OPP (biaxially oriented polypropylene) film. The width of the film is not particularly limited, but is approximately 300 mm to 900 mm, and an example of a width of 500 mm will be described here. Typical ranges include a film thickness of 1.0 μm to 10 μm and a winding length of 5,000 m to 100,000 m.

The film winding roller 30 continuously winds up the film on which the aluminum pattern and the heavy edge of the thin zinc wire are formed. The winding speed is the same as the film supply speed, but a constant tension is applied to prevent the deposited film from sagging. Note that after the vapor deposition is completed, the vapor-deposited film is appropriately processed into a capacitor in a subsequent process.
The winding/unwinding speed can be adjusted from 0.5 m/min to 500 m/min, and is appropriately determined depending on the thickness of the aluminum or zinc to be deposited, the diameter of the cooling roller 20, and the surface temperature.

The cooling roller 20 is a cylinder having an axial length of 600 mm and a diameter of 800 mm, and wraps the film unwound from the film unwinding roller 10 by a predetermined center angle so that the film width direction is the axial direction. The surface is plated with iron, and the surface is cooled from the inside (cooling mechanism not shown). Metal vapor is blown onto the surface of the film, and the film is cooled by the backing of the cooling roller 20, and aluminum and zinc are condensed (deposited) to form a desired pattern.

The masking unit 40 has a configuration in which a nozzle plate is attached to one surface of a columnar housing that is elongated in the axial direction (approximately 600 mm). This nozzle plate faces the cooling roller 20 closely, and has ejection holes arranged at regular intervals on a straight line in the axial direction on its surface, and ejects oil heated inside. The masking section 40 reciprocates in the axial direction as appropriate to form a predetermined pattern on the surface of the film. The masked portion becomes a protective layer and will eventually be exposed.

The aluminum evaporator 50 is a long evaporator that houses a crucible 51 containing an aluminum ingot, and evaporates aluminum from the opening side facing the cooling roller 20 to deposit aluminum on a film. At this time, aluminum is not deposited on the previous pattern portion, forming a margin portion.

Next, the zinc evaporator 100 will be explained.
The zinc evaporator 100 has a prismatic outer shape, houses an open crucible 101 for melting zinc, and is placed close to the cooling roller 20 at a distance of 1 mm, with its longitudinal direction coinciding with the axial direction of the cooling roller 20. It is placed horizontally so that Then, zinc vapor is released from the slits in this proximal surface (mask plate) to form a heavy edge made of thin zinc wires on the film.

Specifically, the zinc evaporator 100 forms a hollow prism with six parts: a top plate 110, a bottom plate 120, two side plates 130, and two end plates 140. A mask plate 150 is bonded to 110.

All of these are flat plates made of SUS plates with a thickness of 15 mm. Among these, the top plate 110, the bottom plate 120, and the side plate 130 are long rectangles when viewed in the thickness direction, and have a common length of 600 mm, and the width of the top plate 110 and the bottom plate 120. is 100 mm, and the two side plates 130 are 70 mm. Further, the size of the two end plates 140 is 70 mm x 70 mm (x 15 mm thick). That is, a hollow prism of 100 mm x 100 mm x 600 mm is formed by the six parts, and the crucible 101 is accommodated in this hollow prism. Note that the top plate 110 has a window 111 of 550 x 30 mm open in the thickness direction.
These six faces are joined together using carbon steel hexagon socket head bolts. The screw holes are arranged symmetrically to avoid unnecessary stress that could cause distortion or twisting.

The mask plate 150 has a size of 600 mm x 100 mm x 5 mm, and is provided with a slit 151 having a length of 25 mm and a width of 0.7 mm in the width direction of 100 mm, that is, in the transverse direction. The slits 151 communicate with each other in the thickness direction and are arranged at intervals of 45 mm in the longitudinal direction. The mask plate 150 is also attached to the top plate 110 using hexagon socket head bolts.

Note that the top plate 110, the bottom plate 120, and the two side plates 130 each have a configuration in which a Kanthal electric heating rod 160 (diameter 6 mm) whose surface is coated with ceramics is sandwiched therebetween.
The details are as follows.
The upper plate 110, the lower plate 120, and the two side plates 130 are each divided into two in the thickness direction (the upper plate 110 is divided into upper plates 110a and 110b, the lower plate 120 is divided into lower plates 120a and 120b, and the side plate 130 is divided into two parts). (consisting of side plates 130a and 130b). Two fitting grooves are cut in each plate surface symmetrically with respect to the center line in the longitudinal direction, and the electric heating rod 160 is inserted into the three fitting grooves so that the three members are integrated (unitized). Note that the integration is not particularly limited, and examples include screwing and welding.
The electric heating rod 160 is bent into a U-shape outside the top plate 110, the bottom plate 120, and the side plate 130 and goes in and out. Furthermore, a removable U-shaped connector 165 is attached to the bottom plate 120 and the two side plates 130 so that they communicate as one circuit. For convenience, this will be referred to as a circuit 160A, and the U-shaped electric heating rod 160 on the top plate will be referred to as a circuit 160B.

By dividing the circuits in this way, the current and voltage values are adjusted so that the heating temperature is 600° C. in the circuit 160A, and 650° C. in the circuit 160B. (omitted). By setting the temperature of the mask body higher than the temperature of the other three surfaces, re-adhesion of zinc vapor to the casing is suppressed, and a high-quality heavy edge can be formed.

Note that a thin metal plate may be separately applied inside the prism to suppress adhesion of zinc to the inner surface of the flat plate.
In addition, a carbon fiber sheet is interposed between the mouth portion formed on the top surface by the two side plates 130 and the two end plates 140 and the top plate 110 (joint portion) to ensure airtightness. At the same time, the heat of the mouth portion (or the heat of the tank portion) may be efficiently transmitted to the top plate 110. This is suitable from the viewpoint of controlling the heating of the circuit 160B described above and preventing clogging of the slit 151 due to a drop in the temperature of the zinc vapor.

The zinc evaporator 100 has the above configuration and uses a thick, simple-shaped SUS plate, so distortion and twisting due to the shape are difficult to occur in the first place. By using the same material for the six faces and the mask body, and by assembling them into a simple prismatic shape, even if each component expands and contracts due to heat, it is difficult for distortions such as twisting and waving to occur structurally. There is. For this reason, in the conventional evaporator, the distance between the cooling roller and the cooling roller was at most 5 mm, but it can be used not only within 1.0 mm but also as close as 0.1 mm.
Therefore, the zinc evaporated film can be formed as a fine line having the same width, although the width on the film is slightly expanded.

In the present invention, the length of the zinc evaporator may be approximately the same as the axial length of the cooling roller, but if this length is 1000 mm, the distance between the mask body and the cooling roller may of course be 1.0 mm. Even 0.2mm can be used without contact. It is also possible to make it close to 0.1 mm by making various adjustments. That is, the ratio of the separation distance of the prism to the housing length is not only 1/1000, but also 2/10000 without any practical problem, and can also be set to 1/10000.

Note that the present invention has a simple configuration, and the top plate 110, bottom plate 120, side plate 130, end plate 140, and mask plate 150 can be partially replaced, so running costs can be reduced. It is.

A film produced by the zinc evaporation apparatus of the present invention is cut into a predetermined width and wound to produce, for example, a capacitor for a smoothing circuit during DC-AC conversion.
Note that a zinc alloy may be used instead of zinc, and in addition, magnesium or a magnesium alloy can also be used for vapor deposition.

1 Vacuum deposition device 10 Film unwinding roller 20 Cooling roller 30 Film take-up roller 40 Masking section 50 Aluminum evaporator 100 Zinc evaporator 101 Crucible 110 Top plate 111 Window 120 Bottom plate 130 Side plate 140 End plate 150 Mask plate 151 Slit 160 Electric heating rod 160A Circuit 160B Circuit 165 U-shaped connector

Claims (4)

An evaporation device for depositing zinc or zinc alloy onto a strip-shaped film capacitor film that is brought into contact with a cooling roller and continuously supplied. In an evaporator that is placed horizontally in a
A flat plate for the bottom surface, which is a long metal flat plate with a predetermined thickness, in which heating resistance rods are embedded;
two side plates, which are long metal plates of a predetermined thickness, filled with heat-generating resistance rods;
a long metal flat plate with a predetermined thickness filled with heat generating resistance rods, the upper flat plate having a longitudinal hole formed in the longitudinal direction that communicates in the thickness direction;
two end plate bodies that are metal flat plate bodies of a predetermined thickness that respectively close both ends of the rectangular tube formed by the four metal flat plate bodies;
A mask body that is a metal flat plate body that is joined from the top surface to the flat plate body for the top surface, and in which a slit of a predetermined width of 0.1 mm or more and 2.0 mm or less is formed;
An evaporation device characterized in that the cooling roller and the slit can be used close to each other within 5.0 mm. The flat plate for the bottom surface, the flat plate for the side surfaces, the flat plate for the top surface, the flat plate for the ends, and the mask body are formed of SUS plates of the same composition,
The flat plate for the bottom, the flat plate for the side, and the flat plate for the top form a rectangular tube by fastening with a plurality of screws,
2. The evaporator according to claim 1, wherein the mask body is also attached to the upper flat plate body by fastening with a plurality of screws. The heating resistance rods are two symmetrical rods symmetrically arranged with respect to the center line in the longitudinal direction of the flat metal body, or one rod bent back at the ends in a symmetrical arrangement, and fitted into the fitting groove provided in the flat metal body divided into two in the thickness direction. 2. The evaporator according to claim 1, wherein a flat plate for the bottom surface, a flat plate for the side surfaces, and a flat plate for the top surface are respectively formed by sandwiching the three members together. a first heating system that connects heating resistance rods of a flat plate for the bottom and two flat plates for the side;
a second heating system consisting of a heat generating resistance rod of a flat plate for the upper surface, which is independent of the first heating system;
The evaporator according to claim 1, further comprising: