KR100761804B1 - An Antenna cooling device for inductively coupled plasma generator - Google Patents

Abstract

The present invention relates to an antenna cooling apparatus of an inductively coupled plasma generator, and by manufacturing a metal tube forming an antenna as a heat pipe, the cooling apparatus is simplified and the cooling efficiency of the antenna is improved to improve the performance of the plasma generator. It is to ensure that, a single or a plurality of heat pipes (H1, H2) having a refrigerant filled therein and the heat dissipation portion 20 is formed at one end of the inductively coupled plasma generator (10) It generates high frequency power to the power end and ground end of both ends to generate induction electric field and heat dissipation in the heat dissipation part by phase change of refrigerant filled inside the antenna made of heat pipe. By making it possible to prevent the degradation of the plasma generating device due to heat generation The.

Inductive coupling, plasma, antenna, heat pipe, cooling, heat dissipation

Description

An antenna cooling device for inductively coupled plasma generator

1A is a schematic configuration diagram of an antenna cooling apparatus of an inductively coupled plasma generator in a manner of circulating a cooling fluid into a conventional antenna;

Figure 1b is a schematic configuration diagram showing a circulation structure of the cooling fluid in a conventional parallel antenna,

2 is a perspective view showing a first embodiment of an antenna cooling apparatus using a heat pipe according to the present invention;

3 is a perspective view of a second embodiment of an antenna cooling apparatus according to the present invention;

Figure 4a is a perspective view showing a third embodiment of the antenna cooling apparatus according to the present invention,

4B is a perspective view illustrating a fourth embodiment of a loop antenna in which two heat pipes are connected by conductive connectors;

FIG. 5 is a perspective view showing a fifth embodiment in which one loop antenna (serial type) is configured with a plurality of heat pipes; FIG.

FIG. 6 is a perspective view showing a sixth embodiment in which a cochlear antenna (serial type) is formed of a plurality of heat pipes; FIG.

FIG. 7 is a perspective view illustrating a seventh embodiment in which a radial antenna (parallel type) is configured with a plurality of heat pipes.

* Explanation of symbols for main parts of the drawings

H1, H2, H3, H4, H5: Heat Pipe P: Powered End

G: ground end 10: antenna

20: heat dissipation part 22: heat dissipation fins

30,30a, 30b, 30c, 30d: conductive connector

The present invention relates to an antenna cooling apparatus of an inductively coupled plasma generator, wherein a single or a plurality of heat pipes filled with a refrigerant and having a heat dissipation part at one end are configured as an antenna of the inductively coupled plasma generator to apply high frequency power. By generating an induction electric field as well as by the phase change of the refrigerant filled in the heat pipe during the heat generation of the antenna made of heat pipe to enable effective heat dissipation.

The antenna of the inductively coupled plasma generator is usually formed using a metal made of copper, which has good electrical conductivity. If necessary, a plating layer such as silver may be formed on the outside to improve the electrical conductivity. However, even if the material has good electrical conductivity, there is a specific resistance, and as the current flowing through the antenna increases, heat generation due to Joule-heating cannot be suppressed.

As the plasma generator becomes larger and denser, the RF power applied to the antenna increases and the current flowing through it increases. Therefore, it is important to remove such heat efficiently due to heat generation. This is because the resistance of the antenna is further increased, and the applied RF power is consumed in the antenna, not in the plasma, and also causes instability in matching.

Conventionally, in order to solve such heat generation, as shown in FIG. 1A, the antenna 1 is formed of a tube made of metal such as copper, and inside the tube, a refrigerant such as water, DI water, and galden is heat exchanged to the outside. The antenna was cooled by circulating while maintaining a constant temperature by means of the radiator 2 (heat radiating part) and the circulation pump 3. However, in such a conventional technology, there was a burden of operating an expensive heat exchanger 2 and a refrigerant, and the maintenance of the antenna and the plasma generator is cumbersome and difficult due to the complexity of the equipment. There was also a risk that a great loss of equipment could occur if the refrigerant leaked near the connector 4 between 1) and the refrigerant circulation tube (5).

In addition, as the shape of the antenna becomes more complicated, the path through which the refrigerant is circulated also becomes more complicated. For example, as shown in FIG. 1B, when some antennas 1 and 1 'are connected in parallel, cooling of some antennas is performed. Inadequate or difficult to solve the problem of electrical insulation between the antenna (1,1 ') and the connection of the flow path for maintaining the sequential circulation and water tightness of the refrigerant at the same time, this problem is to improve the uniformity of the plasma antenna In the case of a radially parallel antenna having a complicated shape of the antenna, there has been a problem that becomes more serious, and thus has been a obstacle in implementing a high performance antenna shape.

 The present invention has been made in order to solve the above-mentioned conventional problems, the object of the present invention is made of a simple structure is easy to maintain, and nevertheless of the inductively coupled plasma generator that can exhibit excellent cooling performance An antenna cooler is provided.

In addition, the present invention can be easily applied even if the shape of the antenna is complex, such as a parallel antenna using a plurality of antennas to improve the uniformity of the plasma, and a cooling device suitable for an antenna for a plasma generator that requires high performance due to excellent cooling efficiency. To provide.

In order to achieve the above object, the present invention manufactures an antenna of a metal tube inductively coupled plasma generator as a heat pipe to replace a complicated cooling device for circulating and supplying existing cooling fluid into the metal tube. In addition, the present invention provides an antenna cooling apparatus of an inductively coupled plasma generator that can improve the performance of the plasma generator by the excellent cooling efficiency of the heat pipe itself.

The heat pipe applied in the present invention has a liquid refrigerant that is responsible for heat transfer by phase change in a sealed metal pipe, absorbs heat, vaporizes the liquid refrigerant, moves to a condensation unit (heat dissipation unit), and heats to the outside. The heat transfer rate is very fast and the cooling efficiency is excellent by repeating the circulating operation by liquefying and circulating the gaseous refrigerant again. The structure has a porous wick installed on the inner wall of the metal pipe, and a very small amount of liquid The working fluid is saturated inside the wick. The vessel evaporator is a vapor passage of the working fluid. The heat pipe consists of three elements in the longitudinal direction: the evaporator, the condenser, and the heat insulator. When heat is applied to the evaporator, it is absorbed by the heat of vaporization of the liquid, and steam is transferred to the condensation unit (heat dissipation unit). When heat is released from the condenser, steam condenses and is absorbed into the wick. This condensate can be returned to the evaporator by the capillary pressure difference produced at the wick's gas-liquid interface between the condenser and the evaporator. In this way, the working fluid performs a phase change cycle, thereby allowing heat to be transferred from the evaporator to the condenser without applying external power.

The benefits of such heatpipes are due to their many advantages such as no-power heat transfer, high reliability with a life span of more than 10 years, significant thermal conductivity over hundreds of times compared to copper rods of the same size, and simple structure of small size. It is applied to cooling devices in various fields such as repeater enclosure cooling, heating, and laser printer.

Hereinafter, with reference to the accompanying drawings, preferred embodiments that do not limit the present invention will be described in detail.

FIG. 2 is a perspective view showing a first embodiment of an antenna cooling apparatus according to the present invention. An antenna 10 of an inductively coupled plasma generator having a powered end P at one end and a ground end G at the other end thereof is provided. ) Is formed of a heat pipe (H1), and the heat dissipation unit 20 made of a plurality of heat dissipation fins 22 is formed at one end of the antenna 10.

The heat dissipation fin 22 is to increase the surface area of the heat dissipation unit 20 so that the heat dissipation by the cooling method by natural contact with the outside air, but to improve the heat dissipation, a forced cooling method or a heat dissipation fin 22 to add a separate cooling fan. It is also possible to add a nozzle for blowing cold air, as well as other types of heat sink can be used.

In the embodiment of FIG. 2, the heat dissipation unit 20 is installed at the power end P side of one end of the heat pipe H1 constituting the antenna 10, that is, in a direction in which current flow is shorted at the power end P. High frequency power is also supplied to the heat dissipation unit 20, but there is no voltage difference between the heat dissipation fins 22 forming the heat dissipation unit 20, so that problems such as plasma generation or arc generation do not occur. In more detail, in the antenna, the high voltage applied to the powered end P from one end of the power end P to the other end of the ground end G is determined by the length of the antenna so that it is zero at the ground end G. Along the path through which the current flows.

On the other hand, when looking at the opposite direction from the power end (P) to the ground end (G) side, although the electrical connection is connected, but the current flow path is short-circuited, so no current flows and no voltage drop occurs. It maintains the same potential as (P). Therefore, although the high voltage equal to the voltage applied to the power end P is applied to the heat dissipation fins 22, since there is no voltage difference between the heat dissipation fins 22, plasma generation or arc generation between the heat dissipation fins 22 occurs. The problem does not occur. However, due to the high voltage applied to the heat dissipation fins 22, the heat dissipation fins 22 should be installed so as not to be located close to the chamber or the surrounding apparatus.

In the present invention, since the current can flow only between the power end P of one end of the antenna 10 and the ground end G of the other end, the longer the antenna due to the formation of the heat dissipation part 20 changes the shape of the current flow. It does not change the performance of the antenna. Therefore, the heat dissipation unit 20 is preferably installed in a direction opposite to the ground end G, that is, the current flows shorted at the point where the RF power and the antenna are connected, which is a current flow in the heat dissipation unit 20. As a result, problems such as performance of the antenna, heat generation in the heat dissipation unit, and arcs between the heat dissipation fins 22 can be solved.

In addition, in the conventional one-turn antenna as in the present embodiment, the portion where the most heat is generated throughout the antenna from one end of the powered end P to the other end of the ground G is grounded. The end (G) part is due to the wavelength characteristics of the RF power. In more detail, as the frequency of the RF power increases or as the length of the antenna lead increases, the voltage and current distributions are not constant over the length of the lead and have a sinusoidal distribution. This is the same as the distribution of the germ-node in the microwave waveguide. Looking at the distribution of the voltage from the ground end (G) at the other end to the end of the powered end (P), the ground end (G) at the other end is grounded, so the voltage is always zero and the sine wave in the direction of the end of the powered end (P). Will increase. As described above, in the shorted transmission line model in which the other end of the ground end G is grounded, the current distribution is maximized at the other end of the ground end G as opposed to the voltage distribution, and cosine toward one end of the powered end P. The wave form decreases, so that the amount of heat generated at the ground end G at the other end having the largest current magnitude is the highest. Therefore, it is effective to configure the heat dissipation part by viewing the ground end G of the other end as the heat generating part.

In addition, the surface of the heat pipe (H1) may be formed of a metal plating layer having a high electrical conductivity or silver for improving the electrical conductivity.

3 is a perspective view showing a second embodiment of the antenna cooling apparatus according to the present invention, which is very similar to the embodiment of FIG. 2, but the heat dissipation unit 20 is formed at the ground end G side of the other end of the antenna 10. In this case, the voltage difference does not exist between the heat dissipation fins 22 because a path through which a current can flow is shorted as in the embodiment of FIG. In addition, the voltage applied to the heat dissipation fins 22 becomes 0 V, such as the voltage applied to the ground end G, so that a risk that may be caused by the voltage difference may be caused even when contacting the surrounding chamber or the apparatus. There will be no. Also in this case, the heat dissipation unit 20 is preferably installed in the opposite direction of the power end (P) side, that is, the current flow is short-circuited at the point where the antenna and the ground end is connected.

In addition, as described above, since the most heat is generated at the ground end G, when the heat dissipation unit 20 is installed at the ground end G end as in this embodiment, the generated heat may be radiated within the shortest time. There are also advantages.

On the other hand, in the present embodiment, when the amount of current increases and there is a large amount of heat even between the one end of the powered end P and the other end of the ground end G, the heat cannot be effectively dissipated, so its use is somewhat limited. In this case, however, the heat dissipation unit is configured and used as in the following third embodiment.

4A illustrates a third embodiment of the present invention, in which a heat dissipation unit 20 is provided at both ends of a powered end P and a ground end G of one antenna 10 formed in a loop shape. have. This means that the ground end (G) of the other end is viewed as a heating part, and the heat dissipation part is installed at both ends to effectively radiate heat from the ground end (G) which generates the most heat, but between the powered end (P) and the ground end (G). It can also dissipate heat generated.

On the other hand, when the heat dissipation portion is formed at both ends of the antenna composed of one heat pipe as in the third embodiment, since the heat dissipation path is divided at both ends, in this case, the performance of the heat pipe is 2/3 compared to when the heat dissipation portion is at one end only. It is known to fall to the level. Therefore, it is desirable to ensure sufficient heat dissipation capacity of the heat pipe, and in order to provide more efficient heat dissipation, it is more preferable to install as in the following fourth embodiment.

FIG. 4B illustrates a fourth embodiment of the present invention, and in implementing the third embodiment, two heat pipes H1 and H2 are used, and one end of each heat pipe H1 and H2 is an antenna. The power end P and the ground end G of 10 are formed, and the other ends of the heat pipes H1 and H2 are connected by the conductive connector 30 so that two heat pipes H1 and H2 are connected. One loop type antenna 10 is formed, and heat dissipation parts 20 and 20 are formed at the power end P and the ground end G, which are one ends of each heat pipe H1 and H2, respectively.

FIG. 5 illustrates a fifth embodiment of the present invention in which a single antenna is formed of several heat pipes. In the present embodiment, three heat pipes H1, H2, and H3 are connected in series to form a loop. Each heat pipe (H1, H2, H3) is connected by conductive connectors (30, 30a), and the heat pipe (H1) at the front end and the heat pipe (H3) at the end are configured. Powered end P and ground end G are formed, respectively, so as to form one completed loop-type antenna 10 identical to the embodiments illustrated in FIGS. 2 to 4.

In the antenna 10 according to the embodiment of FIG. 5, since the heat generated from the antenna 10 is shared by the heat radiating unit 20 provided at one end of each of the heat pipes H1, H2, and H3, the heat pipes are separated from each other. It is suitable for increasing the heat radiation efficiency when the length of the antenna to be formed is long compared to the length. In such a case, for example, as shown in FIG. 6, a spiral or cochlear shape is formed from the center of the chamber to the outside. When the long series antenna 10 is formed, the length of the heat pipe is limited by connecting several heat pipes H1, H2, H3, H4, H5 to the conductive connectors 30, 30a, 30b, and 30c in series. In addition to solving the problem, the heat dissipation efficiency of the antenna can be improved.

In the heat pipes H1 to H5 used in the present invention, the cooling function is normally maintained even when the bending process is performed in order to manufacture a specific type of antenna, and a plurality of heat pipes are used as shown in FIGS. 5 and 6. In the case of the serial antenna, a predetermined position of the heat pipe is bent to allow one end of the heat dissipation part 22 to branch from the antenna path (in the form of an antenna) and to be positioned above or outside the antenna. ) Can be designed so that it does not interfere with chambers or other plasma generators.

In addition, in the present invention, the conductive connectors 30, 30a, 30b, and 30c for connecting the heat pipes may be manufactured in a shape and size to accommodate the one end of the heat pipe and the approximately bent portion of another heat pipe. It is necessary to have a binding force capable of stably maintaining the electrical connection between the received heat pipes and stably maintaining the designed antenna shape. The shape of the conductive connector is the shape of the heat pipes to be coupled to each other. Can be produced in various forms according to.

Meanwhile, unlike the embodiments of FIGS. 5 and 6, when the antennas are configured in parallel, as shown in FIG. 7, each heat pipe forms a respective antenna and they form a radial antenna electrically connected in parallel. In this case, each heat pipe H1, H2, H3, H4, which is a plurality of parallel antennas, is electrically connected by the conductive connector 30d at the center of the chamber, where another heat is supplied from the outside with a high frequency power supply. One end of the pipe H5 is connected to form a powered end P, and the other end of each of the heat pipes H1, H2, H3, and H4 located outside the chamber forms a ground end G.

In the embodiment of FIG. 7, the heat dissipation unit 20 is provided at the ground end G side of each heat pipe H1, H2, H3, and H4 to discharge heat generated from each heat pipe to the outside.

The antenna cooling apparatus of the present invention configured as described above can evenly cool an antenna having a complicated shape by using a heat pipe having excellent thermal conductivity, and does not require a separate device according to the use of a refrigerant, thereby making it easy to maintain equipment. The risk of accidents due to refrigerant leakage can also be eliminated at source. In addition, in the fifth and sixth embodiments of the present invention, the heat dissipation unit for dissipating heat is configured in the middle of the antenna, but since the end of the heat dissipation unit is shorted so that no current can flow through the heat dissipation unit, the shape of the current flowing through the antenna is changed. Compared to the case of using a coolant without affecting at all, it is not necessary to consider the circulation path of the coolant, which has the advantage of facilitating the implementation of a complicated antenna shape. In addition, in the present invention, since the amount of heat generated from the antenna is easily calculated from the maximum amount of current applied when the resistance of the antenna is measured, the capacity of the heat dissipation part can be easily designed to configure an optimal heat dissipation part.

As described above, in the present invention, since the antenna consists of a heat pipe, the structure of the antenna cooling device for the inductively coupled plasma generator is simplified compared to the conventional refrigerant circulation method, and thus no additional equipment is required. It is easy to maintain and manage, and also improves the cooling efficiency of the antenna, and has a useful effect of improving the performance of the plasma generating apparatus.

Claims (8)

In the antenna cooling device of the inductively coupled plasma generator is installed on the chamber of the inductively coupled plasma generator to generate a plasma by reacting the gas inside the chamber through the RF power applied to the powered end to the ground end, The antenna is made of a heat pipe filled with a refrigerant responsible for heat transfer by a phase change therein, the heat radiation portion is provided with a plurality of heat radiation fins in parallel to one end of the antenna is formed of the inductively coupled plasma generator. Antenna Chiller. The method according to claim 1, The antenna of the inductively coupled plasma generator, characterized in that the heat dissipation unit is also provided on the other end of the antenna. The method according to claim 1, An antenna cooling apparatus of the inductively coupled plasma generator, characterized in that the surface of the heat pipe is formed with a plating layer for improving the electrical conductivity. The method according to claim 1, The antenna is a series antenna in which a plurality of heat pipes are connected in series by a conductive connector, and a heat dissipation part is formed at one end of each heat pipe, and a power end and a ground end are formed at both ends of the series antenna connected by the conductive connector. An antenna cooling device of the inductively coupled plasma generator. The method according to claim 1, The antenna is a plurality of radial parallel antennas whose one end of the heat pipe is electrically connected by a conductive connector in the center of the upper chamber, the other end of the heat pipe constituting each antenna is located outside the chamber, and radiated to the other end of each antenna Antenna cooling apparatus of the inductively coupled plasma generator, characterized in that the additional provided. delete The method according to claim 1, Cooling fan or a cooling nozzle is further provided in the heat dissipation antenna cooling apparatus of the inductively coupled plasma generator. The method according to claim 1 or 2, The radiator is an antenna cooling device of the inductively coupled plasma generator, characterized in that installed in the direction in which the current flow in the power end or ground end short-circuited.

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