JPH0539565A - Vaporizing tank for sublimating material chip - Google Patents

Abstract

PURPOSE:To provide a vaporizing tank for a sublimating material to be used for vacuum vapor deposition plating so that chips of the sublimating material to be vaporized can be continuously supplied at a proper position and that a uniform high-quality vapor deposition plating layer can be formed. CONSTITUTION:This vaporizing tank has such a structure that the bottom part 12A can be freely moved up and down, the side wall part is equipped with paths 13a for a coolant, and a rotating supply member (roll 11, 11) for pushing down having a transverse rotating axis is provided at the upper aperture of the tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimable material piece evaporation tank for vacuum vapor deposition plating using electron beam irradiation, and more specifically, it continuously supplies a sublimable material piece accurately and stably to an electron beam irradiation site. The present invention relates to an evaporation tank for a sublimable material piece capable of carrying out the vapor deposition plating.

[0002]

2. Description of the Related Art A vacuum vapor deposition method has been industrialized in which a vaporization raw material is heated and vaporized in a vacuum or a dilute gas atmosphere to form a plating layer on the surface of a material to be treated such as a steel plate or a synthetic resin film material. Among them, there are a resistance heating method, a high frequency heating method, an electron beam heating method, an ion beam heating method, a laser beam heating method, an arc discharge method, etc. as a heating evaporation method for evaporating an evaporation raw material. It is properly used depending on the difference in the plating film forming method and the like.

Among them, the electron beam heating method has a high evaporation rate and a high heating efficiency because the electron beam has a high energy and a high energy density, so that evaporation of metals and various ceramics having a low vapor pressure and a high melting point is performed. It is possible and has the advantage of high productivity. Further, the electron beam can be deflected by using a magnetic field, the surface of the evaporation raw material can be scanned, and two or more evaporation raw materials can be alternately heated and vaporized by using one electron gun. It is considered to be an advantageous method as a means for forming a plating layer or a composite plating layer. Therefore, the electron beam heating method is widely used as a heating and evaporation means in the vacuum evaporation plating method.

By the way, as the evaporating tank for storing the evaporating raw material used in the electron beam heating method, a cooling metal evaporating tank and a ceramic evaporating tank are selectively used according to the kind of the evaporating raw material. FIG. 9 shows a structure in which the crucible side wall portion 13 has a hollow cross-sectional structure, and a cooling medium can be passed through this hollow portion. For example, a water-cooled copper evaporation tank is used, and if it is of the forced cooling type, part of the side wall of the evaporation tank does not elute into the molten evaporation raw material, Almost no impurities are mixed in, and a high-purity vapor deposition plating layer can be formed.
On the other hand, since the heat energy supplied by the electron beam is quickly taken away by the evaporation tank, there is a drawback that the heating efficiency is poor. Therefore, ceramics evaporation tanks cannot be used, and highly oxidizable metallic materials (such as Ti)
For the metal material forming the high melting point molten bath, such a cooling type metal evaporation tank had to be used, and it was necessary to dispose a high-power electron gun.

On the other hand, ceramic evaporation tanks are roughly classified into graphite evaporation tanks and oxide ceramic evaporation tanks, and they are used properly according to the evaporation raw material. These ceramic evaporation tanks have the advantage of low thermal conductivity and high heating evaporation efficiency.

However, the material forming the evaporation tank is likely to be mixed as an impurity in the evaporation raw material, which may deteriorate the properties of the plating layer. In particular, in the case of the evaporation raw material for forming the molten bath, impurities from the evaporation tank act as a starting point to cause a phenomenon of scattering from the surface of the molten bath, which may significantly impair the appearance of the plating layer surface. Also, ceramic evaporation tanks have poor spalling resistance and are prone to cracking when subjected to repeated thermal expansion and contraction, and have the problem of a short service life and number of times. The composition which complements the raw material reduced by the above must be added. FIG. 7 is an explanatory view showing an example of a material supply method when the evaporation raw material can be drawn into a wire and forms a molten bath. Al, Ti, Zn, Cu, F
It is used when e and the like and alloys containing them as a main component are used as evaporation raw materials. That is, the wire 5 wound on the bobbin 22 is continuously supplied into the melting bath 4a by the pinch roll 21 through the guide nozzle 6. According to this, the supply amount of the wire 6 can be adjusted by controlling the rotation speed of the pinch roll 21. In some cases, the shield chamber 23 separates the vacuum chamber side from the wire supply side, which improves the workability of replacing the wire bobbin 22.

When the evaporation raw material cannot be drawn into a wire shape, it is continuously supplied as a granular, pellet-shaped, briquette-shaped, or fragment-shaped raw material 26 into the melting bath 4a by a device as shown in FIG. I.e. raw material in hopper 24
26 is charged, and the vibrator 25 is driven to continuously drop and supply the raw material 26 into the evaporation tank 2.

However, the above-mentioned raw material replenishing method has the following problems (a) and (b). (B) Since the position of supplying the evaporation raw material into the evaporation tank is always constant, when the evaporation raw material forms a molten bath, the surface temperature of the melting bath at this supply position becomes low, the evaporation rate is small, and the width of the evaporation tank is small. A uniform amount of evaporation in the direction cannot be obtained. Therefore, when the material to be treated is one that continuously travels like a steel strip, the amount of adhesion in the strip width direction becomes non-uniform, and product quality deteriorates.
Further, when the raw material 26 is put on the surface of the high temperature molten bath, a scattering phenomenon occurs on the surface of the molten bath and stable vapor deposition plating cannot be performed. (B) On the other hand, when the evaporation material is a sublimable material, even if the material is supplied using the hopper 24 as shown in FIG. It will just be deposited. Therefore, the discharge port of the hopper 24 must be arranged above the irradiation area of the electron beam, but since the temperature of the additionally supplied evaporation raw material itself is low, the surface temperature of the sublimable material being heated and evaporated is It rapidly decreases and it takes time to reach a stable evaporation rate. For this reason, the evaporation amount becomes unstable, and in the case of a continuous material to be processed, non-uniformity occurs in the vapor-deposited plating layer, causing deterioration in quality.

Therefore, the means shown in FIG. 9 has been proposed as a means for solving the above problem (b). That is, a powdery sublimable material is formed into an ingot shape, and the bottom portion 12 supporting the material 4c is configured to be able to rise, and the sublimable material 4c is raised to compensate for consumption of the evaporation raw material by electron beam irradiation. It has been attempted to arrange the upper surface of the sublimable material 4c at a position suitable for electron beam irradiation.

[0010]

However, even such a device has the following problems. That is, the portion of the surface of the sublimable material irradiated with the electron beam evaporates and disappears from the surface portion, but the peripheral portion that is not irradiated remains as it is, and it is the evaporation raw material to supplement the disappeared portion. When the entire sublimable material 4c is raised, the remaining portion rises from the upper surface of the evaporation tank and finally overflows from the evaporation tank. Such a raised portion becomes an obstacle that obstructs the path of the electron beam and causes a problem in the operation of the electron beam, or when a large number of evaporation tanks are installed next to each other, the sublimable material that overflows causes other evaporation. It becomes impossible to achieve the intended composition and deposition amount of the vapor deposition plating layer by mixing in the bath.

In order to prevent the above problems from occurring, it is desirable to set the electron beam irradiation area on the surface of the evaporation tank as large as possible and to keep the proportion of the remaining portion on the surface of the sublimable material small. .. However, as shown in FIG. 9, when the side wall of the evaporation tank is made of a cooling type metal hearth and a part of the evaporation tank is directly irradiated with an electron beam for some reason, a cooling medium passage is formed. The wall surface is melted and the cooling medium is released into the vacuum chamber, causing an accident of filling the vacuum chamber, resulting in production failure. When such an accident occurs, it takes a lot of time to repair or replace the evaporation tank.

Therefore, an object of the present invention is to continuously evaporate a sublimable material by an electron beam and to supply the material appropriately, and to sublimate the evaporation tank itself without damaging it. The purpose is to provide a vaporization tank for a conductive material.

[0013]

According to the present invention, which has achieved the above object, the bottom of an evaporation tank is configured to be vertically movable along the side wall surface of the evaporation tank, and a cooling medium passage is provided on the side wall of the evaporation tank. Is formed, and a rotary thrusting member having a lateral rotation axis is provided on the upper opening side edge of the evaporation tank.

[0014]

FIG. 1 is an explanatory view showing a typical embodiment of the present invention, in which the material S to be treated is arranged in the vacuum chamber 1 so as to continuously run in the direction of the arrow, and its lower portion. Is provided with an evaporation tank 3 filled with briquette-shaped sublimable material 4b. The side wall portion 13 of the evaporation tank 3 is composed of a cooling type metal hearth in which a refrigerant passage 13a is formed, and has a structure for preventing thermal deformation of the side wall portion 13. That is, when the sublimable evaporation raw material is heated by the irradiation of the electron beam, the heat is transferred to the side wall portion, but when the side wall portion is thermally deformed by this heat,
The bottom portion 12A described later cannot be smoothly raised.

As shown in FIG. 3, the bottom portion 12A is configured to be movable up and down in the direction of the arrow by a hydraulic cylinder or the like (not shown) so that the sublimable material 4b can be pushed upward. Further, as shown in FIGS. 2 and 3, a pair of rolls 11 and 11 are horizontally installed as a rotation falling member at the side edge of the upper opening of the side wall portion 13. The rolls 11 and 11 are rotatably supported and may be either of a type in which they are rotationally driven by themselves or a type in which they are not driven. The rolls 11 and 11 are provided in order to move the sublimable material in the region not irradiated with the electron beam to the center part where the electron beam is irradiated. As shown in FIG. The uppermost sublimable material 4b ₁ thus acted receives the component force f ₁ by the guide action of the roll 11 and is pushed to the center of the evaporation tank as shown by the white arrow, and disappears by electron beam irradiation. Move to fill the space.

FIG. 6 shows a case where the roll 11 is driven to rotate in the direction of arrow R, and the sublimable material 4 on the uppermost portion is shown.
b ₁ receives the component force f ₁ and moves in the direction of the white arrow, and can move in a direction closer to the central portion than in the example shown in FIG. That is, the rolls 11 and 11 move to the electron beam irradiation region so that the sublimable material 4b is not caught by the upward force exerted by the rise of the bottom portion 12A. On the other hand, when the side wall portion 13 is formed with a tapered surface such that the space between the side wall portions gradually decreases upward, it is possible to move the sublimable material located in the vicinity of the side wall portion to the central portion side. At this time, the sublimable material is caught in the side wall portions so as to be clogged, so that the bottom portion 12A cannot be lifted.

It is preferable to form a gap G between the side wall portion 13 and the outer edge of the bottom portion 12A as shown in FIG. 3 when the side wall portion 13 and / or the bottom portion 12A are thermally deformed. However, the bottom 12A can be smoothly moved up and down. Further, it is preferable that the side wall portion 13 is made of copper or a copper alloy having a high thermal conductivity, and a general water cooling system is adopted as the cooling medium.

FIG. 4 is a side cross-sectional explanatory view showing another example of the evaporation tank. The bottom 12A has a cooling medium passage 12b formed therein to prevent thermal deformation, and the bottom 12A is made of stainless steel or It is made of a Ni-based heat-resistant alloy, and its upper surface is covered with a ceramic plate such as graphite or alumina. Further, the inside of the side wall portion 13 is formed with a taper 13c such that the space between the side wall portions gradually expands upward, so that the sublimable material 4c spreads upward and spreads smoothly without any biting. ..

Since the roll 11 may be directly irradiated with the electron beam, it is preferable to form the roll 11 with a heat-resistant material such as a Ni-based heat-resistant alloy or ceramics or a water-cooled structure. It is preferable that a motor for use is provided outside the vacuum chamber 1 to transmit power to the roll rotation shaft via various transmission mechanisms. Further, it is expected that evaporated metal will adhere to the surface of the roll 11, but if the roll itself rotates, the adhesion layer will not be unevenly distributed in a part, and the roll 11 will be in contact with the roll 11. A surface grinding chip 15 may be provided on the inner surface of the roll 11 to grind the peripheral surface of the roll 11 to remove the adhered metal such as evaporated metal. The shape of the roll 11 is not limited to the one shown in the figure, and may be one having an outer surface having gear-shaped irregularities, a roll having a different diameter, or a roll that is divided in the longitudinal direction of the roll to be miniaturized.

On the other hand, it is preferable to dispose protective plates 14 and 14 above the rolls 11 and 11 for shielding the irradiation of electron beams. The protective plate 14 is made of various ceramic materials or water-cooled metal plates. Is recommended. In particular, as shown in FIG. 1, when a plurality of evaporation tanks 2 and 3 are provided and the electron beam is irradiated while jumping them with one electron gun 7, the electron beam will pass on the roll 11, so the roll 11 The protection plate 14 must be provided in order to prevent the damage.

Examples of the sublimable material to which the present invention is applied include metal materials such as Cr, Mg and the like in the form of pellets, briquettes, fragments and the like, and ceramic materials such as Al ₂ O ₃ and SiO _2. it can.

[0022]

Since the present invention is constructed as described above, it is possible to replenish the sublimable material pieces evaporated by the electron beam irradiation to replenish the material to an appropriate position, and to continuously heat the electron beam irradiation. It became possible to form a uniform and high-quality vapor-deposited plating layer by performing evaporation. In addition, the accidental damage to the side wall of the evaporation tank due to electron beam irradiation, etc. is no longer caused.

[Brief description of drawings]

FIG. 1 is an overall explanatory view showing a typical embodiment of the present invention.

FIG. 2 is a plan view showing an example of the evaporation tank of the present invention.

3 is a side cross-sectional explanatory view of FIG.

FIG. 4 is a side sectional view showing another embodiment of the present invention.

FIG. 5 is an explanatory view showing the operation of the embodiment of the present invention.

FIG. 6 is an explanatory view showing the operation of the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a conventional example.

FIG. 8 is an explanatory diagram showing a conventional example.

FIG. 9 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 3 Evaporation tank 4b Sublimable material 11 Roll 12A Bottom 13 Sidewall 14 Protective plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Kato 2-10-6 Kitaaoki, Higashinada-ku, Kobe-shi (72) Inventor Atsushi Kihara 2-3-1 Shinohara Aunt Noyama-cho, Nada-ku, Kobe-shi (72) Inventor Koji Imamura 4-5-12 Uzumoridai, Higashinada-ku, Kobe-shi

Claims (2)

[Claims] 1. An evaporation tank for a sublimable material piece for vacuum evaporation by irradiating an electron beam to heat and evaporate the sublimable material piece, wherein the bottom of the evaporation tank is along the side wall surface of the evaporation tank. And a cooling medium passage is formed in the side wall of the evaporation tank, and a rotary thrusting member having a lateral rotation axis is provided at an appropriate position in the upper opening of the side wall of the evaporation tank. An evaporation tank for a sublimable material piece, which is characterized by being formed. 2. The evaporation tank for a sublimable material piece according to claim 1, wherein the rotary drop-down member is formed of a roll-shaped heat-resistant material and is configured to be rotationally drivable.