JPH03229862A - Electron beam evaporating device - Google Patents

Abstract

PURPOSE:To stabilize and ensure the heat transfer between the base of a hearth liner having a trapezoidal recessed part opened wide in the upper part and a crucible by providing a spacing between the base of the hearth liner and the crucible at the time of evaporating the metal for evaporation in the above- mentioned hearth liner by the electron beam. CONSTITUTION:The crucible hearth liner 6 having the recessed part which is trapezoidal in vertical cross sectional shape and is opened wide in the upper part is installed in the water-cooled crucible 9. The metal 7 for evaporation is disposed in this hearth liner 6. The metal 7 for evaporation is irradiated with thermions 2 released from an electron gun unit 5 and is thereby heated to generate vapor 8. The spacing 14 is formed between the base of the outside wall of the hearth liner 6 and the base in the recessed part of the crucible 9 of the electron beam device constituted in such a manner. The inside wall surface of the crucible 9 and the outside wall surface of the hearth liner 6 maintain contact at all times in spite of the thermal expansion of the hearth liner 6 and, therefore, the heat transfer between the hearth liner 6 and the crucible 9 is stabilized and ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electron beam evaporation apparatus used for vacuum melting and vapor deposition of metals.

(Prior Art) Conventionally, as an electron beam evaporation device used for vacuum melting or vapor deposition of metals, a metal for evaporation is placed in a water-cooled crucible, and an electron beam accelerated by an electron gun is deflected by a magnetic field, etc. There is one that uses the energy generated when it collides with metal as a heating source. In this case, if the water-cooled crucible is directly irradiated with an electron beam, the water-cooled crucible will be damaged. To prevent this, a hearth liner made of a high-melting point metal such as tungsten is installed inside the water-cooled crucible. There is a method in which the metal for evaporation is placed inside the hearth liner and irradiated with an electron beam to obtain metal vapor.

Figure 2 shows an example of this; by heating a filament 1 made of tungsten or the like by passing an electric current through it,
The emitted thermoelectrons 2 are accelerated between the Wehnelt electrode 3 having a negative potential and the anode electrode 4 having a ground potential, and fly out from the electron gun unit 5. This thermionic electron 2 that jumped out is
Thereafter, it is deflected by a magnetic or electric field (not shown) and hits the evaporation metal 7 placed within the hearth liner 6, and its kinetic energy is converted into thermal energy. When the evaporation metal 7 is sufficiently heated, the hearth liner 6
The evaporating metal 7 becomes molten inside and generates vapor 8. The hearth liner 6 is disposed in a water-cooled crucible 9, and the crucible 9 has a large number of cooling pipes 12, and the water-cooled crucible 9 is cooled by circulating cooling water inside the pipes 12.
The hearth liner 6 is also cooled.

In such a configuration, the inner bottom of the concave portion of the conventional Ruppo 9 and the bottom of the outer wall of the hearth liner 6 are brought into contact with each other, and in order to absorb the elongation due to thermal expansion of the hearth liner 6,
There is a gap 13 between the inner circumferential surface of the recess of the crucible 9 and the outer circumferential surface of the hearth liner 6 due to the expansion due to thermal expansion of the hearth liner 6.
was open.

(Problem to be Solved by the Invention) In this case, the Luppo 9 and the hearth liner 6 are in contact only at the bottom, and therefore heat is transferred only through the bottom, and the outer circumferential surface of the hearth liner 6 and the inner surface of the Luppo 9 are in contact with each other. The circumferential surface is also uncertain, as it may or may not contact depending on the state of the hearth liner 6, and the relationship between the hearth liner 6 and Ruppo 9 is
The heat transfer between the two is unstable and uncertain.

An object of the present invention is to provide an electron beam evaporation device in which heat transfer between a crucible and a hearth liner is stable and reliable.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention has a recess with a trapezoidal longitudinal section, and the area of the opening is defined as the area of the bottom inside the recess. In the larger crucible, a recess is provided which has the same external shape as the recess in the crucible, is for preventing damage to the crucible, is open at the top, and is capable of storing metal for evaporation. A crucible hearth liner is provided, and a gap is formed between the bottom surface of the outer wall of the hearth liner and the bottom surface of the recessed portion of the crucible.

(Function) Since the present invention is configured as described above, even if the hearth liner expands thermally, the inner wall surface of the crucible and the outer wall surface of the hearth liner are always in contact with each other, so that heat transfer between the hearth liner and the crucible is improved. Becomes stable and certain.

(Example) Hereinafter, an example of the present invention will be described with reference to FIG. FIG. 1 differs from the conventional method shown in FIG. 2 described above only in that the relationship between the crucible 9 and the hearth liner 6 is as follows. That is, the shape of the concave portion of the crucible 9 is a trapezoidal longitudinal section such as a conical (tapered) shape with a head notch, and the external shape of the hearth liner 9 is the same shape as the concave portion of the crucible 9, that is, a conical (tapered) shape with a head notch. ) shape, etc., and the vertical cross-sectional shape is trapezoidal, and the bottom surface of the outer wall of the hearth liner 6 and the crucible 9
A gap 14 is formed between the bottom surface of the recess and the bottom surface of the recess.

With this configuration, the outer wall surface of the hearth liner 6 and the inner wall surface of the crucible 9 are brought into mechanical contact with each other. Also, since a gap 14 is formed between the bottom surface of the inner wall of the crucible 9 and the bottom surface of the outer wall of the hearth liner 6, the hearth liner 6
Toruha 9 will be more closely attached, and Hearth liner 6
can be cooled by heat transfer under the same conditions as the crucible 9. Furthermore, when the hearth liner 6 thermally expands, the hearth liner 6 moves above the groove 9 because of the taper contact with the hearth liner 6, so that the thermal expansion of the hearth liner 6 is absorbed. As described above, heat transfer between the hearth liner 6 and the Ruppo 9 becomes stable and reliable.

[Effects of the Invention] According to the present invention described above, the crucible is placed in a crucible that has a recess having a trapezoidal longitudinal cross section and the area of the opening is larger than the area of the bottom of the recess. A crucible hearth liner is provided, which has the same external shape as the inner recess, is for preventing damage to the crucible, has a recess with an open top, and is capable of storing metal for evaporation, and has an outer wall of the hearth liner. Since a gap is formed between the bottom surface and the bottom surface in the recess of the crucible, it is possible to provide an electron beam evaporation device in which heat transfer between the crucible and the hearth liner is stable and reliable.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an electron beam evaporator according to the present invention, and FIG. 2 is a schematic diagram showing an example of a conventional electron beam evaporator. 5... Electron gun unit, 6... Rutsuha Hearthliner,
7. Metal for evaporation, 8. Steam, 9. Water cooling, 1.
2...Cooling pipe, 14...Gap.

Claims (1)

[Claims] The crucible has a recess with a trapezoidal longitudinal cross section, and the area of the opening is larger than the area of the bottom of the recess, and the crucible has the same external shape as the recess in the crucible. A crucible hearth liner is provided to prevent damage to the crucible, and the crucible hearth liner is open at the top and has a recess capable of storing metal for evaporation, and there is a gap between the bottom of the outer wall of the hearth liner and the bottom of the recess of the crucible. An electron beam evaporation device that formed .