JPS621226Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an electron beam type evaporation apparatus that performs evaporation by melting and evaporating the evaporation material in the hearth by irradiating it with an electron beam.

In this type of evaporation apparatus, an evaporation section for the evaporation material is installed at the inner bottom of the evaporation chamber. It consists of a so-called crucible furnace section. In this case, when the electron beam is irradiated onto the vapor deposition material inside the hearth, the hearth main body is heated to a high temperature as the vapor deposition process progresses, so it is necessary to cool the hearth main body.

Conventionally, for this cooling, for example,
No. 22144〓Cooling device for cathode grounded topography evaporation device〓As typically shown in the publication, a cooling device has a structure in which a certain amount of cooling water is sprayed and circulated from a supply pipe hung below the bottom of the hearth body. However, this method has the following drawbacks. That is, if the cooling effect is not sufficient and the water supply is stopped, there will be no cooling water at the bottom of the hearth body, and the hearth body will immediately become overheated. On the other hand, if a large amount of water is supplied from the start of the vapor deposition process, it will take time for uniform heating and melting by the electron beam to occur, which is not efficient.

The present invention provides an electron beam type evaporation apparatus that solves these drawbacks.

The electron beam evaporation apparatus of the present invention is equipped with a cooling device that efficiently cools the bottom of the hearth (container) that houses the evaporation material. An overflow type cooling water circulation system consisting of a drain pipe having an overflow surface near the bottom of the hearth in the center of the cooling chamber, and a means for supplying and circulating cooling water into the cooling chamber; Until the bottom of the hearth rises in temperature, the amount of cooling water is suppressed to uniformly and quickly melt the vapor deposition material, and when the bottom of the hearth reaches a high temperature, the amount of cooling water is increased to prevent overheating and maintain the proper temperature. Guarantees temperature regulation at the bottom of the hearth.

The illustrated embodiment will be described below.

In the figure, reference numeral 1 denotes a hearth main body in which a storage portion 1H for a vapor deposition material 2 is formed, and is vertically installed on a base 3 via a cylindrical leg portion 1F. The filament part (beam gun) 7
The material 2 is heated and melted by being irradiated with an electron beam as shown by the arrow, and the material 2 is deposited onto an object to be deposited (not shown).

The electron beam is generated by the generation of electrons when a constant voltage is applied to the filament part 7. It is bent greatly and the material 2 inside the hearth 1 is irradiated.

8 is a holder for the filament portion 7, and 9 and 10 are coils for forming magnetic poles 11 and 12, respectively. Two coils 10 are placed opposite each other in a direction perpendicular to the plane of the drawing, with the coil 9 sandwiched between them. Reference numerals 11 and 12 constitute magnetic poles of an electromagnet, and the degree of bending of the electron beam is adjusted depending on the magnitude of the magnetic force.

As described above, by irradiating the vapor deposition material 2 with the electron beam, the material 2 is heated and melted from the surface portion, and the entire material 2 is melted and vaporized. As the melting by the electron beam progresses, the entire hearth is overheated and destroyed, so it is necessary to cool it down.

The present invention is designed to perform this cooling extremely efficiently. The configuration will be explained below.The cylindrical leg 1F integrated with the hearth main body 1
A cavity 1C is formed inwardly, and the upper part thereof forms a conical surface 1K, and has a top surface parallel to the bottom surface of the hearth 1H at a position close to the bottom of the hearth 1H.
This cavity 1C is filled with cooling water to form a cooling chamber for cooling the hearth, but the leg portion 1F is fixed to the base 3 via a seal member 6 to prevent the cooling water from leaking.

The cooling chamber 1C has a supply port 3R drilled in the base 3.
Cooling water is supplied via the water supply pipe 16. Reference numeral 4 denotes a drainage pipe installed vertically on the base 3 at the central position of the cooling chamber 1C, and its upper end surface constitutes an overflow surface, and the cooling water supplied from the bottom of the cooling chamber 1C overflows from this overflow surface. The water is then drained from the drain pipe 4. 5 is a fixing screw for this drain pipe 4. The height of the drain pipe 4 is set high so that the overflow surface is close to the bottom of the hearth. This is to minimize the danger when the water supply is cut off, as will be explained later.

Below the drain pipe 4 is a drain port 3 drilled in the base 3.
P, and overflow cooling water is discharged from the drain port 3P to the drain pipe 17. 18
is a pressure gauge, and 19 is a flowmeter.

In this way, the cooling water is circulated below the hearth body by the overflow type cooling water circulation system which has a drain pipe with an overflow surface below the bottom of the hearth, thereby cooling the bottom of the hearth. Therefore, the cooling water supplied from the supply port 3R is always filled up to the conical surface 1K position of the cooling chamber 1C, and the cooling water is always filled up to the position near the bottom of the hearth, so that the bottom of the hearth cannot be cooled. I can do it enough. In addition, even if the water supply pump (not shown) in the cooling water circulation system stops due to a power outage or other reason, the cooling water will not overflow and will remain in the cooling chamber 1C, so the cooling effect will be maintained for a certain period of time. This prevents the risk of immediate melting and destruction of the bottom of the hearth due to the electron beam.

In addition, in the present invention, a pore 1S is bored at the bottom of the hearth from the outside of the hearth body 1, and the thermocouple 1 is
5 is inserted so that the temperature of the hearth at the bottom surface 1T of the hearth can be detected. The thermal activation force (signal) of the thermocouple 15 corresponding to the temperature at the bottom of the hearth is input to the signal shaping circuit 14, and the output is controlled in pulse width or amplitude according to the temperature at the bottom of the hearth through a flow control valve installed in the water supply pipe 16. 13. The signal shaping circuit 14 is connected to the power supply circuit and uses its power to drive the flow rate control valve 13, but the signal shaping circuit 14 has a function of adjusting the magnitude of the supplied power in accordance with the hearth bottom temperature. Further, although not shown in the figure, a constant voltage is applied to the filament section 7 to generate an electron beam, and at the same time, a signal is input to the signal shaping circuit 14, so that the signal shaping circuit 14 starts operating. There is. Of course, when the electron beam starts to be generated, the material 2 inside the hearth is not melted that much, so the temperature at the bottom of the hearth is not rising, and the supply of cooling water is controlled to a small amount, making it possible to supply cooling water economically. It will be done.

According to the present invention, since the signal from the signal shaping circuit 14 is small, the flow rate control valve 13 controls the supply amount of cooling water to a small amount when heating and melting of the material by the electron beam starts. As the electron beam continues to be generated, the vapor deposition material 2 begins to melt and the temperature at the bottom of the hearth rises, and the amount of cooling water supplied gradually increases accordingly. Since the cooling water is controlled so that the temperature rises to such an extent that the bottom of the hearth is not destroyed, the material 2 is uniformly dissolved, and the material 2 is effectively dissolved and evaporated. Therefore, the amount of cooling water and power supply are kept to a minimum, making it economical.

The invention is not limited to the illustrated embodiment. For example, the shape of a hearth is not limited to a circular shape,
Further, the shape of the cooling chamber is preferably shown in the illustrated example since it has an excellent cooling effect, but is not limited to this shape.

The method of driving the flow rate control valve as a means for controlling the amount of cooling water supplied is not limited to the method using the output signal from the signal shaping circuit as shown in the illustrated example. The installation method and position of the thermocouple for temperature detection are not limited to the illustrated example. Although it is preferable to synchronize the start of operation of the flow control valve with the start of electron beam generation, the method is not limited to this method. Installation of flow meters and pressure gauges is also not an essential requirement.

Since the electron beam vapor deposition apparatus of the present invention has the hearth cooling structure as described above, the amount of cooling water and the consumption of supplied power can be minimized, and energy saving can be achieved. In addition, the conventional drawback that the bottom of the hearth is too cool and it is difficult to melt the entire material uniformly has been completely eliminated, and the entire material is melted uniformly, with less fluctuation in surface temperature.
Therefore, the equilibrium state is stabilized, and the time required to reach the equilibrium state can be shortened. Since the vapor deposition material in the hearth is uniformly and stably dissolved, a uniform vapor deposited film can be obtained, and the reproducibility thereof is also excellent.

[Brief explanation of the drawing]

The drawing is a schematic diagram of an embodiment of the present invention. 1... Hearth body, 1C... Cooling room, 1F...
Cylindrical leg part, 1T... Hearth bottom surface, 1K... Conical surface, 2... Vapor deposition material, 3... Base, 4... Drain tube, 7... Filament part, 8... Holder, 9,
10... Coil, 11, 12... Magnetic pole, 13...
Flow rate control valve, 14...signal shaping circuit, 15...thermocouple, 16...water supply pipe, 17...drainage pipe.

Claims (1)

[Scope of utility model registration request] In an electron beam type evaporation device that uses an electron beam to melt and evaporate the evaporation material in the hearth, there is a hollow cooling chamber provided below the bottom of the hearth body, and an overflow surface near the bottom of the hearth in the center of the cooling chamber. An overflow type cooling water circulation system consisting of a drainage pipe having a drain pipe and a means for supplying and circulating cooling water into the cooling chamber, and a control means for controlling the amount of cooling water circulation according to the temperature at the bottom of the hearth body. Features: Electron beam type evaporation equipment.