KR20200026848A - Microwave System - Google Patents

Abstract

Disclosed is a microwave system. The microwave system comprises: a high-frequency semiconductor module for oscillating microwaves; an AC-DC conversion inverter converting the input AC power to DC power to supply power to a semiconductor module; an automatic control board which regulates power to reduce or cut power when reflected waves occur; an applicator which delivers microwaves by minimizing reflected wave power with power supplied and a plunger mounted; a power supply device having a gateway communicating a signal with the outside, and being connected to the applicator through a connector, a coaxial cable, and a coaxial conversion adapter to supply microwaves; and an isolator which protects the high-frequency semiconductor module by diffracting the reflected waves built-in the power supply.

Description

Microwave System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave system, and more particularly, a high frequency semiconductor generating microwaves, a transmission line thereof, an adapter such as a co-axial transition device, a matching algorithm through frequency modulation, and a circuit protection system. It relates to a microwave system comprising a.

In general, microwave is a kind of electromagnetic wave, and means a frequency (f) bandwidth of 300MHz to 30GHz (wavelength standard: 1cm-1m). 1 MHz <f <300 MHz is called Radio Frequency. f (frequency) <1 MHz is called Low Frequency. Conventionally, microwaves (microwaves) and radio waves (high-frequency, Radio-Frequency), etc. are named separately according to the frequency band as described above, but in some cases these frequencies are similar bands (for example For Hundreds of MHz frequency band, such as 300 MHz), in the present invention, commonly referred to as microwave or high frequency. When microwave or high frequency is generated using a semiconductor device, it is called Solid State Microwave (SSMW) or Solid State Radio-Frequency (SSRF).

Microwaves have the property of completely reflecting when they touch metal. However, when microwaves are irradiated onto non-metal dielectrics, they penetrate into the dielectric and rotate and vibrate the polar molecules in the molecule, generating heat by the internal friction. This heat causes heating of the microwave irradiated object. A representative example of using this closely in real life is microwave oven.

Microwave-based devices are the next generation of industrial technologies that can dramatically reduce work time, process costs, energy and labor costs. Microwave industrial applications are very wide, with applications in the food sector being heating, drying, thawing, sterilization and cooking. In particular, when microwave energy is irradiated to food, it can penetrate the surface of the food and heat the inside very quickly, thereby minimizing the taste, smell, texture, and nutritional value of the food. In other industries, existing industries include rubber processing, dyeing and drying of papermaking fabrics, and wood drying, while new businesses are actually widely used in military, semiconductor and display production, electronics production processes, and medical applications. have.

Microwaves can also be used in medical devices. Radiofrequency diathermy (high frequency diathermy, 高周波 療法) is a microwave-based medical device used to heat deep tissue. It is a kind of electrotherapy using high frequency radio wave and the most frequently used among them is microwave (electromagnetic wave with a wavelength of 1m ~ 1cm). The effect obtained by this is a thermal effect on deep tissue. Diseases that can be adapted include inflammation of the musculoskeletal system, flank valves, acromegaly, and bruises, which are effective in reducing pain. As a method of heating tissue by resistance of body tissue when high-frequency electron radiation passes, tissue is warmed but not destroyed in medical diathermy. On the other hand, the tissue is destroyed in the surgical diathermy.

One of the most widely used fields besides the heating and drying of microwave energy is the field of plasma generation. Plasma is the Fourth State of Matter, which means a state in which electrons, ions, neutrons, and protons are mixed. In microwave (high-frequency) or high-frequency plasma generators, electrons are selectively energized to become high-energy states and collide with the source gas (neutrons) to dissociate more electrons, anions, cations, atoms, and molecules. Species, neutrons synthesized between various molecules and atoms, and active radicals in which neutrons are activated are generated. Depending on the species used in the plasma state, it is called chemically reactive plasma, ion beam plasma, electron beam plasma, reactive ion plasma. These activated radicals are used in many industries, such as semiconductor and display manufacturing, combustion, lighting, and chemical industries, because they allow the reactions to occur at high temperatures or even at low temperatures. In addition, the largest field among the fields related to the plasma generation field is the lighting field. In the case of plasma discharge lamps, unlike other conventional lighting sources such as incandescent lamps, fluorescent lamps, and metal halides, they are electrodeless, the brightest light source, have a long life, continuous white light, and can generate 140 lm / W light. There is an advantage. In the case of the semiconductor device plasma light source, it is a light source having a continuous spectrum of nearly 400-800 nm wavelength, which is a natural light source similar to sunlight, and is environmentally friendly and has a long lifetime. Since other light sources use electrodes, they are less energy efficient, contaminated, and corroded, resulting in shorter lifetimes. For example, about 70% of the source light amount is about 50,000 hours in the case of a semiconductor device plasma light source, but only about 20,000 hours in the case of a conventional high intensity discharge light source. Another advantage is that it is the highest efficiency light source that emits nearly 130-140 lm light flux per 1 W of power. Conventional plasma light sources are supplied with energy from a special inverter (electromagnetic ballast for electrodeless lamps) capable of low frequency (Low Frequency, 250KHz) oscillation, and plasma is generated, and the electrons in the plasma react with the gas enclosed in the lamp to generate ultraviolet rays. This ultraviolet light passes through the three-wavelength fluorescent material applied inside the lamp and is finally emitted as visible light, resulting in a long life and high efficiency illumination source. Table 1 summarizes the advantages and disadvantages of several existing lighting sources and AC semiconductor (low / high frequency) plasma lighting sources.

Lighting types Lighting
type life span
(hrs) magnitude
(klm) Energy efficiency
(lm / W) Chromaticity
Rendering Color temperature
(K) light on
time
(Sec) Re-light
time
(Sec) Incande-
scent Incandescent light 2,000 1,700 10-17 100 3,200 0.1 0.1 Fluore-
scent Fluorescent lamp 10,500 3,000 115 51-76 2,940-
6,430 0.3 0.1 LED LED 25,000 130 60 ~
100 30 6,000 0.1 0.1 HID (High intensity discharge) High brightness
Discharge lamp 20,000 25,000 65 ~
115 40-94 4,000 ~
5,400 60 480 AC (LF / RF) Plasma AC (low frequency / RF)
plasma 50,000 25,000 100 ~
140 70-94 4,000 ~
5,500 30 25

Table 1 shows the comparison between microwave (RF) and RF (high-frequency) plasma light sources and conventional light sources, and shows the superiority of plasma light sources.Usually, microwave (Microwave) and radio-frequency (Radio-Frequency) Etc., as described above, but separated according to the frequency band, but in some parts, these frequencies may be similar (for example, several hundred MHz frequency band, such as 300 MHz), in the present invention generalized to ultra-high frequency semiconductor do. The overall configuration of a conventional microwave application includes a magnetron, a waveguie, a circulator, a dummy load, a three stub-tuner, an applicator, and a plunger. Plunger (also called sliding short circuit) and power supply power. Each component of the existing microwave application is illustrated in FIG. 1.

The core generator of the conventional microwave is a magnetron, which is basically similar to a two-pole vacuum tube and has a structure in which hot electrons are emitted from a hot wire of a cathode. A high-voltage electric field is applied to the cylindrical outer anode and the inner cathode of pure copper, and a magnetic field perpendicular to the electric field is formed by permanent magnets installed above and below. Electrons protruding from the cathode are directed to the anode under the influence of the electric field and rotate inside the cylinder under the influence of the magnetic field. The electrons pass through vanes formed on the anode side, forming a high frequency electromagnetic field in the cavity resonator.

In the power supply, the AC voltage 220V is changed to a high voltage of 4000V or higher, and when the current flows in the magnetron, the microwave vibrates at a high frequency of 2.45GHz in the magnetron. When the microwave touches the irradiated object, the dipoles constituting the object rapidly change the arrangement direction of its axis by a high frequency electric field, and generate heat by frictional heat at this time. Therefore, only the insulator (dielectric) is heated because radio waves need to penetrate into the object.

When the power supply powers the filament and the anode of the magnetron, the microwave generated from the magnetron is transmitted to the applicator via a waveguide, through a circulator and a 3-stub-tuner. do. The power of microwave energy emitted from the magnetron is absorbed by the irradiated object is called forward power (reflected power or incident wave power or traveling wave power), and the unabsorbed power is reflected power or reflected wave power. This is called. Since the reflected wave power can return and damage the magnetron, a circulator is used to change the direction of the reflected wave to protect it. The reflected wave energy is absorbed by the dummy rod through which the coolant flows and is emitted to the outside. To minimize reflections, a 3-stub tuner or plunger is used as a matcher.

1 illustrates an example of a plasma generating apparatus using microwaves. As illustrated in FIG. 1, in the conventional microwave application apparatus, the configuration is that the microwave generated from the magnetron undergoes a matching process through a waveguide, a circulator, a three stub-tuner, and a plunger. The energy is transferred to the applicator.

Other applications also have similar structures. The 3-stub tuner, isolator (circulator + dummy rod), and plunger can be omitted when the wavelength is calculated according to the frequency and the reflected wave is minimized by adjusting the waveguide length based on this. A typical example is a microwave oven used at home. In the case of the microwave of 2.45GHz, the magnetron has 1, 2, 3, 6 Kw output type, and the cooling method uses air cooling for low power and water cooling for high power. When more than 3Kw of energy is required, a plurality of magnetrons are combined and arranged. In the case of microwave at 915MHz, high power magnetron of 5 ~ 100 Kw exists and is mainly cooled by water cooling method.

As illustrated in FIG. 1, applications using microwaves are structurally complex, heavy and bulky. Therefore, there are many difficulties in applications requiring light and small short. Such fields include plasma sources for semiconductor manufacturing, lighting, and medical fields.

As mentioned above, in the conventional microwave application and process processing, the microwaveron, the circulator, the dummy rod, and the matching device for impedance tuning purpose make the microwave application bulky and heavy, and also mounted. There has been this difficult and time-consuming problem. Therefore, an object of the present invention is to remove the heavy and bulky microwave components as described above to facilitate the use.

In addition, in the past, microwaves are generated by one magnetron microwave, so that it is not easy to achieve large area and high uniformity. In addition, when applied using a plurality of multiple magnetrons, a power supply device and a waveguide using a waveguide, the above-mentioned bulky and heavy problems are serious and it is difficult to efficiently apply microwaves in various fields. In order to solve these problems, the present invention discloses a microwave system that can be efficiently and easily installed in various ways so as to achieve a desired process purpose by minimizing the microwave transmission device using an ultra-high frequency semiconductor module and a waveguide-coaxial cable conversion adapter. For the purpose of

Microwave system according to the present invention, a high frequency semiconductor module for oscillating microwave; An AC-DC conversion inverter converting the input AC power into DC to supply power to the semiconductor module; An automatic control board that regulates and supplies power and reduces or cuts off power when a reflected wave is generated; An applicator mounted with a plunger to minimize the reflected wave power to efficiently transmit microwaves, thereby supplying maximum power; A power supply device having a gateway for exchanging signals with an external device and connected to the applicator and a connector, a coaxial cable, and a coaxial conversion adapter to transmit microwaves; And an isolator inherent in the power supply device to diffract the reflected wave to protect the high frequency semiconductor module.

Preferably, the microwave system may further include a control algorithm in which the reflected wave power is minimized by modulating a frequency when the reflected wave power is inherent in the power supply device.

Preferably, the microwave system may further include a coaxial cable impedance tuner to minimize reflected wave power when reflected wave power occurs.

Microwave-generating high frequency semiconductor and its accessories such as transmission line, waveguide-coaxial switching adapter [Co-Axial Transition], impedance matching and circuit protection by coordination (tuning) algorithm through frequency modulation or coaxial cable impedance tuner In the system, it is possible to form a compact, lightweight and compact device, and to provide a microwave processing system that not only can easily perform microwave processing, but also can be easily installed to significantly improve the working efficiency. have.

In addition, according to the present invention, it is possible to easily configure and install a plurality of microwave oscillation apparatus, so that the microwave apparatus can be large-area or the installation and operation of a plurality of convenient applications can be performed. In the industrial field, there is an effect that can maximize the efficiency, economics, and convenience of the user for each industrial application processing.

1 is an exemplary configuration for explaining a plasma generating apparatus that is a conventional microwave application device.
Figure 2 is an exemplary view showing the components of the plasma generating apparatus of a conventional microwave application.
3 is a view showing that plasma is generated when each process condition is changed in a plasma generator using a conventional microwave.
Figure 4 is an illustration of a microwave oven using a conventional microwave.
5 is a structural diagram of a transmission line (coaxial cable) for microwave transmission.
6 is an exemplary view showing a configuration method in which a magnetron, a circulator, and a dummy rod are embedded in a power supply among components of a plasma generator that is a conventional microwave application device.
7 is an exemplary view showing a configuration method in which a magnetron, a circulator, a dummy rod, and a matching device are embedded in a power supply among components of a plasma generator, which is a conventional microwave application device.
Figure 8 is a component of the microwave generator according to the present invention, the magnetron, the circulator, the dummy rod embedded in the power supply after the waveguide-coaxial adapter (Co-Axial Adapter) and the coaxial cable An illustration showing how to connect to an applicator.
9 is a coaxial with a waveguide coaxial adapter after embedding a magnetron, a circulator, a dummy rod, and a matching device in a power supply among components of a plasma generator, a microwave application device according to the present invention. An illustration showing how to connect the cable to the applicator.
10 is an exemplary view showing a microwave application apparatus for generating a plasma using a semiconductor microwave oscillation apparatus, a transmission line, a transmission adapter according to the present invention.
11 is an exemplary view showing a microwave application apparatus and a plasma generation picture for generating a plasma using a semiconductor microwave oscillation apparatus, a transmission line, a transmission adapter according to the present invention.
FIG. 13 is an exemplary view showing a device configured to generate large-area plasma using a plurality of multiple semiconductor microwave power supplies, transmission lines, and transmission adapters according to the present invention; FIG.
14 is an exemplary view showing a large area plasma configuration by disposing a plurality of semiconductor microwave generators according to the present invention.
15 is an exemplary diagram illustrating a method of converting microwaves transmitted to a magnetron and a waveguide into a coaxial cable form using a coaxial-waveguide conversion adapter, and then collectively combining the coaxial rods of each linear plasma antenna and processing the same in parallel. .
Figure 16 branched the microwaves delivered to the magnetron and the waveguide using a waveguide splitter, and then converted them into a coaxial cable type using a coaxial-waveguide conversion adapter and then individually coaxial rods of each linear plasma antenna Exemplary diagram illustrating a method of processing by connecting in parallel or subset to connect in parallel.

In order to fully understand the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Embodiment of the present invention may be modified in various forms, the scope of the invention should not be construed as limited to the embodiments described in detail below.

This embodiment is provided to more completely explain the present invention to those skilled in the art. Therefore, the shape of the elements in the drawings and the like may be exaggerated to emphasize a more clear description. It should be noted that the same members in each drawing are sometimes indicated by the same reference numerals. In addition, detailed description of well-known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention will be omitted.

   1 is a top and side view of a microwave application. The overall configuration of the microwave application consists of a magnetron (111), a waveguide (112), a circulator (113), a 3-stub-tuner (115), an applicator (117), sliding short circuit 119, a power supply or power 121 that regulates and supplies power to the marnetron. That is, when power is supplied to the filament and the anode of the magnetron (111) from the power, the microwave generated from the magnetron passes through the waveguide, the circulator (113), the 3-stub tuner (3 stub-tuner; 115) It is delivered to an applicator.

A three-stub tuner is a device with three metal rods in a waveguide or cavity resonator, which is a matching device that allows microwaves to be transmitted without reflection. The plunger or sliding short circuit (SSC) is also an additional device for matching to minimize reflected waves. Sometimes 4- stubs are used instead of 3-stubs. In addition, manual tuning of each stub may be performed by manual tuning, or automatic tuning may be performed using a matching algorithm. The automatic matcher consists of a stub, a diode, an integrated automatic control board, and a motor drive unit, which match the load impedance. The more detailed description of matching is as follows. In general, when two circuits are combined, when the input terminal of the same circuit is seen at the output terminal of the first circuit and the impedance of Z1 = R1 + jX1 is set, and the input impedance of the second circuit is Z2 = R2 + jX2, the airspace is between the two impedances. If there is a relationship (i), that is, R1 = R2 and X1 = -X2, a condition of loss minimum and output maximum is obtained. The first circuit is a matcher and the second circuit is an applicator. That is, matching is a method for transmitting the maximum output in the signal transmission path. The principle of matching is that the signal source has internal resistance and the load must be equal to the impedance of the signal source for maximum output transmission. Where active elements are included, the input impedance and output impedance are quite different. However, the input impedance needs to match the signal source, and the output load must match the output impedance. Power amplifiers and many active devices deviate from the basic principle because of the limitations imposed by internal power loss and linearity requirements. The output load impedance should be chosen optimally by matching the impedance to ensure maximum output transfer under these constraints. There are several types of matching methods: matching by conductor rod, matching by conductor plate window in waveguide, matching by non-reflective termination circuit, matching by taper waveguide, matching by transformer (/ 4 impedance converter). have. As illustrated in FIG. 2, in the case of the 3-stub tuner, the conducting rod is inserted into the waveguide at the wide side of the waveguide to match. When the reflected wave is present in the waveguide, the reflected wave is canceled by the electromagnetic field caused by the conductor rod. The plunger matching method is a matching method based on the conductor plate window in the waveguide. The plunger matching method inserts obstacles such as the conductor plate at a right angle to the observation in the waveguide, and selects a suitable distance to the load. 1 and 2 show a case where a 3-stub tuner matching method and a plunger matching method are mixed.

 If the microwaves are reflected back from the applicator without being absorbed, the reflected microwaves can cause catastrophic damage to the magnetrons, in which case they divert the reflected waves to protect the magnetrons. The energy is absorbed in the load (123). The dummy rod is supplied with cooling water to release the absorbed heat to the outside. The power propagated in the traveling direction of the microwave generated from the magnetron is called forward power, or the power returned without being absorbed by the applicator is the reflected power. This is called electrostatic or backflow power. If the reflected wave that is not matched and the microwave is returned as it is, it damages the expensive magnetron 111, so that the reflected wave is separately converted by the magnet inherent in the circulator 113, and then the dummy rod 123 Absorb in the absorber so that it disappears. The dummy rod 123 that absorbs heat, the magnetron 111 that generates heat, and the power supply module or power supply 121 cool by supplying air or cooling water so that the temperature does not rise, and the reflected wave energy absorbed in the cooling water. Is emitted to the outside. In order to measure the forward power and the reflected wave power, a directional coupler may be installed between the circulator and the 3 stub tuner. In the waveguide, two microwave measuring ports are made, one for measuring the forward power with the direction of the port pointing to the applicator, and the other for measuring the reflected wave power in the opposite direction, that is, toward the magnetron.

2 illustrates an assembly diagram of a plasma generator using microwaves. 3 shows photographs of plasma generated using such microwaves. Changes in pressure, an important process variable, illustrate the generation of plasma at each pressure.

An illustration of a home cooker using microwaves to heat or cook food is shown in FIG. 4. In this case, the load impedance is calculated and designed and Applied devices are simpler than plasma applications.

A waveguide, which is a channel through which microwaves are transmitted, is an arbitrary structure that traps, guides, and propagates waves. It refers mainly to the hollow conductor metal tube which makes electromagnetic waves propagate. Waveguides are applied to high-power, low-loss, millimeter wave systems, etc. As examples of use, waveguides can be used to transmit electromagnetic waves such as radars, satellite repeaters, broadcasting radio waves or heating, and plasma generation. To be used. The structure of the waveguide is a metal conductor (copper, brass, aluminum, etc.) that surrounds the electromagnetic waveguide space, and should be sufficiently secured with a conductor thickness of 1 to 3 mm for mechanical strength, and the number of skin penetration depths in the application frequency range. Make it double.

The frequencies of microwaves allowed for industrial, scientific, and medical fields (Industrial, Scientific, Medial: ISM) other than those used by the International Radio Association for communication are 2.45 GHz and 915 MHz (0.915 GHz). Waveguides used for 2.45 GHz microwave are WR-284 (internal size: 72.14 x 34.04 mm), WR-340 (internal size: 86.36 x 43.18 mm), WR-430 (internal size: 109.22 x 54.61 mm) For 915 MHz, the WR-975 (internal size: 247.65 x 43.18 mm) waveguide is used. As such, the size of the waveguide is typically determined according to the frequency of the microwave. Waveguides range from WR-2300 (internal size: 584.2 x 292.1 mm; frequency of use 0.32-0.49 GHz) to WR-3 (internal size: 0.86 x 0.43mm; frequency of use 217-333 GHz). The higher the frequency used, the smaller the internal wave height of the waveguide.

In the microwave oscillator, the transmission of microwave energy, which is an irradiation part, cannot be used because the electric wire radiates microwaves to the outside, and a metal hollow pipe commonly referred to as a waveguide is used. Waveguides are rectangular or circular waveguides according to the cross-sectional shape, and ridge waveguides of complex shape. Commonly used are rectangular waveguides, and circular and ridge waveguides are used for special purposes.

In general, a waveguide that transmits microwaves is in the form of a square tube and traps the microwave having the propagating property in the square tube and is usually made of brass or copper with good conductivity. Therefore, such a square waveguide is heavy, large, and difficult to assemble in the installation of a microwave process or apparatus. In particular, even in the case of low power, the installation is limited due to the heavy and heavy equipment. An example of a plasma generator using such a microwave delivery device (see FIGS. 1 and 2) is illustrated in FIG. 6.

Microwave transmissions include coaxial cables (coaxial tubes) in addition to waveguides. The problem is that the wave easily escapes to the outside as the frequency increases. For frequencies above 60 Hz, a closed waveguide is used to reduce the wave exiting to the outside. Closed waveguides include co-axial cables, metallic waveguides, and strip lines. Coaxial cable is used for shielding the outer conductor with the insulator around the inner conductor so that it can send higher frequency signals than the regular power transmission line or wire (twisted wire twisted pair). It is a form to reduce the wave coming out of the cable by the external conductor.

Coaxial cable is a transmission line having a center conductor supported by polyethylene on a pipe central axis made of a conductor, and used for output signal transmission of a power monitor. Coaxial cables are flammable and easy to handle, but have a small power allowance for microwave transmission energy. For low loss coaxial cable with an impedance of 50 ohms, the maximum power allowance for microwave transmission energy is between 330 Watts (10 mm outside) and 520 Watts (15 mm outside) for frequencies 2.45 GHz and 330 Watts (for outside frequencies 915 MHz). 10mm) ~ 520Watt (outer diameter 15mm) and 580 Watt (outer diameter 10mm) ~ 900Watt (outer diameter 15mm). Coaxial cable is used for high frequency heating devices, but not for high power over 300 ~ 500W for microwave heating devices.

The difference between the transmission line and the waveguide is that the transmission line propagating in the TEM mode (including the coaxial line) can be seen as a waveguide, but in general, the propagation transmission in the TEM mode is not called a waveguide. In other words, the waveguide is used mainly for propagation in the TE mode (Transverse Electric Field / Wave) and the TM mode (Transverse Magnetic Field / Wave). The shape of the transmission line consists of two or more conductors, two conductors separated by a dielectric. In the energy transfer method, energy is transferred in the form of a reciprocating current / voltage wave flowing through two conductors. The propagation form is transmitted as a TEM wave when viewed in the form of electromagnetic waves, and is transmitted by a current wave or a voltage wave. Since there is no cutoff frequency, it can operate from DC to very high frequency, and it is applied to low power and somewhat low frequency, but it is inefficient due to skin effect and dielectric loss in ultra high frequency band. Coaxial cable is a type of transmission line. In general, two-wire parallel cable has a defect that increases the effective resistance of wire at high frequency due to skin effect. Coaxial cable was developed to compensate for this. Same as FIG. Looking at the above coaxial cable structure in detail, two cylindrical conductors and dielectrics share a central axis, the inner conductor is used for the actual signal transmission, and the outer conductor is a mesh-shaped shield made of aluminum / copper. (Braided or foiled), separated by filling them with a dielectric / insulator (polyethylene etc.). On the outermost side, the outer jacket is surrounded by a cable jacket (vinyl, polyethylene, etc.).

 An advantage of the coaxial cable is that the transmission line has a shielded structure with little influence from external interference, and since there is no cutoff frequency like a waveguide, it can be used from direct current (DC) to microwave and millimeter wave. At present, short distances of up to about 50 are possible. However, more than a few GHz band, the loss is large depending on the distance, the waveguide structure is used, the smaller the outer diameter, the higher the frequency can be used, the power that can be carried is limited, there is a difficulty in manufacturing. Propagation mode generally operates in TEM mode. It is used in long distance telephone network, CATV, video transmission, local area communication network, etc. (commonly used below 1GHz).

Coaxial cable connector uses BNC, TNC, FT-type, N-type, F-type, miniature type (SMA, SMB, SMC). Coaxial cables are commonly used as transmission lines at frequencies below UHF, but even in microwave circuits above, internal conductors use silver plating on steel wires so that signals flow through the silver plated portion of the conductor surface. Due to the low loss, the dielectric material is used to reduce the dielectric loss, such as Teflon.

In the case of using low-power microwave, there is a method of reducing the volume, weight, and the like by using a coaxial cable instead of the waveguide. Referring to the plasma generating apparatus using a microwave illustrated in Figure 6 as an example. When the magnetron (called 'M'), circulator (called 'C'), and dummy rod (called 'D') are outside, they occupy a separate space. It is installed inside the feeder to integrate and unify. In this way, it is possible to considerably reduce the space, and to connect the power supply to the magnetron directly from the inside, and to share the cooling line, there is an advantage that the copper wire is small and easy to install. The 3 stub-tuner (matcher or matcher) is located outside because it must be matched only when the stub is operated. In the case of the auto tuner, as shown in FIG. 7, the stubs are automatically adjusted to match the impedance, so in this case it is possible for the tuner to be placed into the power supply.

In FIG. 6 and FIG. 7, it is inconvenient to connect the isolator (the sum of the circulator and the dummy rod is called an isolator) to the applicator using a waveguide. In order to solve such a part, the present invention discloses a method of converting a microwave waveguide transmission method into a coaxial cable transmission method. That is, when a waveguide-coaxial adapter is used to convert the waveguide into a coaxial cable, a coaxial cable may be used instead of the waveguide to finally connect to the applicator 117 to transmit microwaves.

In this case, there is an additional advantage that the installation space is reduced and can be easily installed. 8 and 9 respectively show the case where the tuner is installed outside the power supply (FIG. 6) and when the tuner is inside the power supply (FIG. 7) by simply installing a waveguide-coaxial cable conversion adapter. This is an illustration. 8 and 9 show an embodiment in which the waveguide-coaxial cable switching adapter is connected to the waveguide flange of the tuner to convert to a coaxial cable and then connected to an applicator using the waveguide-coaxial cable switching adapter. That is, it is a method of connecting a tuner-> waveguide-coaxial cable adapter-> coaxial cable-> coaxial cable-waveguide converter. The difference between FIG. 8 and FIG. 9 is the case where the tuner is inherent in the power supply box (FIG. 9) and in the case outside the power supply box (FIG. 8). As described above, the present invention is characterized by simplifying the microwave device using a waveguide-coaxial adapter and a coaxial cable. In addition, the present invention also includes a method of integrating the isolator and matching device in the power supply to facilitate installation by coaxial cable.

Microwave applications can be greatly simplified if the device is constructed using methods such as pre-designing and specifying lengths for accurate impedance matching so that 3-stub tuners and isolators are not needed in the path through which the microwaves are delivered. have. In addition to these cases, especially in the case of plasma generation, a tuner (matcher) must be used for impedance matching. As a method of not using the conventional tuner 115, there is a method in which the plunger 119 is fused with the applicator 117 to replace the conventional three stub type tuner (FIGS. 1 to 2 and 7 to 7). 9). The present invention includes a method of matching impedance in the form of a plunger.

In addition, instead of using a conventional magnetron and a tuner, a semiconductor ultra-high frequency generation module is used instead of the conventional method, and the frequency is modulated and tuned (FVTM), or a coaxial tuner or plunger is used. In combination with, the microwave equipment can be used much simpler when used with matching impedances. The present invention includes an applicator method equipped with such a frequency modulation method (FVTM) or a plunger type matching method. Detailed method thereof will be described later.

In order to avoid the method of using a magnetron that oscillates a conventional microwave as in the case of FIGS. 1 to 9, the microwave is oscillated using a semiconductor device instead of a magnetron. Wave: SSMW). The semiconductor used in this case is a silicon-based, lateral-diffused-metal oxide semiconducotor LDMOS field-effect transistor (FET).

10 illustrates a plasma generator using a semiconductor microwave power supply. The semiconductor microwave generator is a method of oscillating microwaves using a semiconductor instead of a magnetron. Since the semiconductor microwave generation module requires the supply of a DC power supply, the semiconductor microwave generation module includes an AC-DC conversion inverter 225 to convert the AC input power 231 supplied to the power supply 121 into DC, and the inverter includes a power control board ( Power is supplied to the control board 221 and the semiconductor microwave generating module 223. In addition, in order to set and control the microwave power to be supplied, the power control board exchanges signals with the outside through a communication gateway (GateWay 233). External communication methods include Analog, Profibus, CanOpen, or Modbus RS232 / RS485. In operation, when the matching is not properly performed in the semiconductor microwave module, a reflection wave is generated, and a cooling line 131 is installed to cool it. In the case of air cooling, it is relatively easy to install because only the fan is installed without air supply and the air supplied from the fan bears heat and is discharged to the outside of the power supply. However, when the reflected wave power is large, it is safe to install a coolant line because heat generation is large and can be fatal to the microwave semiconductor device.

10 illustrates a method of generating microwaves by the high frequency semiconductor module embedded up to the cooling water line and transmitting the same to the applicator. As illustrated in FIG. 10, the microwaves generated by the high frequency semiconductor module are transmitted to the applicator via a connector, a coaxial cable, and a coaxial cable-waveguide conversion adapter attached to the power supply stage. The small isolator 227 may be embedded in the microwave power supply 121, and when the reflected wave is generated, the semiconductor microwave generator module 223 may be protected through an immediate automatic reduction and interruption of the supplied power. Although the cooling line of the isolator is not illustrated in FIG. 10, the cooling line 131 supplied to the semiconductor microwave generator module 223 may be shared or separately installed. 11 illustrates plasma generation by one linear antenna using a semiconductor microwave generator. Microwaves are generated from the semiconductor microwave generating power supply 121 and connected to the linear plasma antenna via the connector (coaxial)-> coaxial cable-> connector (coaxial) for transmission. In FIG. 11, the energy of microwaves is transferred to show that plasma is generated.

11 illustrates plasma generation by one linear antenna using a semiconductor microwave generator. Microwaves are generated from the semiconductor microwave generating power supply 121 and connected to the linear plasma antenna via the connector (coaxial)-> coaxial cable-> connector (coaxial) for transmission. It is shown in FIG. 11 that the energy of microwaves is transmitted and plasma is generated by this method. As illustrated in FIG. 11, in the case of using a semiconductor ultra-high frequency generating module and a frequency modulation tuning method as compared to a method of connecting a microwave generated from a conventional magnetron with a waveguide flange and connecting an isolator, a tuner, or the like, an application device It can be seen that it is much thinner and simpler to install.

The microwave generator using the semiconductor device has the following advantages. (1) 1 ~ maximum allowable output (e.g. maximum allowable power is about 300 ~ 500Watt depending on the coaxial cable whose impedance is matched). (2) The frequency is up to 2450MHz, 50MHz, that is, 2450MHZ 50MHz frequency range (2400 ~ 2500MHz) is possible. (3) It has longer life than magnetron method. (4) It is possible to have a small isolator inside the power supply and to protect the generator circuit through immediate automatic reduction and interruption of the supplied power in case of reflected wave. (5) It is small in volume and light in weight. (6) Accurate measurement of incident wave power and reflected wave power. (6) Low ripple and high power transmission efficiency. (7) For industrial applications that require multiple applicators (such as the need to cover large areas), this can be achieved by minimizing the size of the applicator and installing it in various ways to achieve the user's purpose.

In the case of using coaxial cable, although it is applied in the low power range of 300 to 500 Watt or less, this will be improved, and microwave transmission can be performed at higher power. In addition, even before a coaxial cable having a high maximum power allowance or another transmission method is released, a plurality of microwave transmission devices oscillated in each high frequency semiconductor module are separately installed and installed according to the application field (see FIGS. 13 and 14). It is possible to fine tune the application by individually distributing and transmitting microwaves of the appropriate power (energy) required by the device, as well as individually adjusting each high frequency semiconductor power module. Therefore, the present invention features and includes a transmission scheme and apparatus using the plurality of microwave power supplies, transmission lines, and adapters.

Microwave refers to a region of electromagnetic waves with a frequency (frequency) of 300 MHz to 30 GHz and a wavelength of 1 cm to 1 m. The area of the electromagnetic wave is arbitrarily divided by the frequency, which is the number of times the wave vibrates for 1 second. The frequency unit is expressed in Hz, and 1Hz indicates that the wave vibrates once in one second. The relationship between the frequency f, the wavelength, and the speed C of light is as follows.

              = C / f (1)

In other words, the shorter the wavelength, the higher the frequency and the longer the electromagnetic wave the lower the frequency. Where the speed C of light is 2.99792458 * 10 ⁸ m / s.

According to the wavelength, electromagnetic waves are classified into gamma rays, x-rays, ultraviolet rays, visible rays, infrared rays, microwaves, radio waves, etc. from the shortest region, and in general, infrared rays or more are called radio waves. In other words, although microwaves have a lower frequency and longer wavelength than light, microwaves have a higher frequency and shorter wavelength, and are used in various industrial fields such as radar, navigation, communication and heating, and plasma as described above. The transmission length Li for impedance matching is as follows.

              Li = / 4 (2)

 The microwave transmission adapter is manufactured according to the above transmission length. Even when a semiconductor device is used to oscillate microwaves, reflected waves may be generated due to impedance mismatch. In the microwave device using the semiconductor element, since the frequency of the semiconductor element can be changed within a certain range, impedance matching can be performed by modulating the frequency according to (Equation 1) and (Equation 2). Impedance matching method. That is, the present invention is characterized in that the reflected wave is minimized by an algorithm for adjusting and tuning the frequency when the applicator and the impedance are not matched or the Li is not matched to match. That is, when generated and output from the semiconductor module, it is possible to modulate the frequency so that it can be matched through such frequency modulation, which is referred to as a frequency variation tuning method (FVMM). In summary, the present invention discloses a microwave system equipped with an impedance matching method in the form of frequency modulation (FVTM) as a method that does not use a conventional tuner (matcher), in which case the microwave equipment is further simplified and easily Can be used.

In addition, when a coaxial cable is connected between a semiconductor microwave power supply device and an applicator, a coaxial impedance adjusting device can be further tuned (co-axed), which is used as a coaxial or coaxial impedance tuner method (Co-Axial). Impedance Tuning Method). An example of installation of the coaxial impedance tuner 228 using this method is illustrated in FIG. It is installed between the semiconductor microwave generator 121 and the applicator 117 is connected by a coaxial cable. Coaxial impedance tuner 228 is configured to change the impedance, which can be adjusted manually or automatically. That is, the magnitude of the reflected wave measured by the microwave detection sensor is displayed on the power supply device 121, thereby adjusting and tuning the impedance of the coaxial impedance tuner 228 to minimize the reflected wave by automatically or manually adjusting the impedance. In the case of automatic tuning, it is revealed that the microwave power supply 121 can be installed inherently. The present invention includes a coaxial impedance tuning method in addition to the frequency modulation tuning method.

In addition, in the present invention, in addition to the conventional matching method such as a 3-stub tuner (or 4-stub tuner) or a new matching method such as the frequency modulation, etc., another coupling method is a combination of the plunger and the passive. Or a method in which matching can be made automatically. Applicator 117 can be connected in the form of a waveguide or coaxial cable, it can be used by tuning the plunger 119 behind the applicator 117. The plunger 119 can also be a waveguide type or a coaxial cable method.

In summary, the present invention includes a method of minimizing reflected waves by impedance matching using frequency modulation tuning, coaxial impedance tuner 228 or plunger 119.

In addition, in the present invention, when an instantaneous reflected wave is generated, an isolator having a cooling line for diffusing the reflected wave to protect the high frequency semiconductor module in order to protect the microwave generator therefrom is made smaller in the high frequency semiconductor power supply. Characterized in that.

A concept of a plurality of semiconductor microwave generators is illustrated in FIG. 13. A plurality of power modules (denoted by power supply, Power Module, PoM; 121) are installed, and an applicator (application) is applied to each module. Each applicator can be a partial applicator of the entire applicator or a completely separate and independent applicator. As illustrated in FIG. 10, each power supply module has each control board, and there is a communication system capable of communicating with an external lamp. Therefore, it is possible to centrally control each power module from a Personal Computer PC (501) system or a PLC (Programmable Logic Controller) 501. In case of using PC, Modbus RS232 / RS485 type is used. In case of PLC, Profibus or CanOpen type is used. The central control computer system 501 sets a desired power value for each power module 121, and each power module executes the optimization of the power of this setting value. The forward power and the reflected wave power measured after each module is executed are transmitted to the central control computer system 501 through the communication gateway 233. The central control computer system 501 receives these data values, displays them with the setting values, and compares and analyzes them to determine whether they meet the desired specifications of the application. Typically, the HMI (Human Machine DIsplay) display 505 is installed on the central control computer system 501 itself installed next to the micro application device to monitor the operation status of each power module 121 in the field. When micro applications that are dangerous due to leakage problems are installed in an isolated space, each of the plurality of power modules can be controlled by using a multi-monitor (507) in a separate control room through a remote interface device. The forward power, reflected wave power, and matching process trajectory curves are monitored on a Smith chart. Through the above method, the microwave application device can be made lighter and shorter, and the branched microwave can be used at the same time, so that it can be applied in various ways appropriately for various purposes of the user.

An example of a device for transmitting microwaves using the plurality of semiconductor micro power modules is representatively illustrated in FIG. 14. Generating large area plasma to maintain uniformity is a very difficult field. In particular, a large-area plasma source is needed to process 12-inch or larger wafers or LCDs of 5-8 generations or larger. It is very difficult to make a large area plasma uniform using one microwave power supply and one applicator. In addition, in the case of generating and using the shape of each reaction chamber, the flow pattern of the gas, the gas inlet, and the radical, it is necessary to control and supply the plasma in accordance with the process processing conditions such as the shape of the radical distributor, and one large area source It is almost impossible to achieve the desired uniformity and throughput. Therefore, there is a need for a method of dividing this into multiple sources to make one large source. As shown in FIG. 14, power of each power module is supplied to coaxial rods wrapped in each insulator to form a linear plasma, but a plurality of such linear plasma antennas are installed to combine and configure a plasma source to provide a large area. A plasma is composed of a large area plasma. In this case, since a plurality of power supplies must be connected and used, it is disadvantageous that the entire device is complicated and expensive. In order to improve this, microwaves can be transmitted either by linearly processing linear plasma antennas in parallel and connecting them to one coaxial rod (see Fig. 15), or by connecting them in parallel and parallel processing (see Fig. 16). Do.

In the present invention, only a new method and some examples of the semiconductor microwave generating method and apparatus are disclosed, and the individual application such as plasma is specifically described in detail as a separate invention and separately filed.

In addition to the method of using a plurality of high-frequency semiconductor power modules as in the example of FIG. 14, a separate method of oscillating and transmitting microwaves using a conventional magnetron is possible. In the case of multiple linear plasma sources (see FIG. 14) composed of several coaxial antennas, it is also possible to individually connect each microwave device to each coaxial rod. That is, in this case, as shown in Figure 9, the final waveguide-to-coaxial cable switch is applied to each of the several microwave power supplies incorporating a magnetron, an isolator, a tuner (in both ends of the waveguide form), and a waveguide-coaxial cable adapter. It is connected to each coaxial cable through the connector of the adapter and connected to each coaxial rod of the linear plasma source one-to-one. Therefore, in this case, it is complicated and expensive to configure the whole device because each coaxial rod has to use a plurality of power supply devices each including magnetron, isolator, tuner, and waveguide-coaxial cable switching adapter. There are disadvantages.

In order to solve the above problems, it is possible to use a single power supply, a magnetron and a waveguide, and process coaxial antennas of a linear plasma to receive microwaves in parallel. In this case, the microwaves transmitted to the magnetron and the waveguide are converted into coaxial cables or coaxial rods using a coaxial (cable) -waveguide conversion adapter, and the coaxial rods of each linear plasma are connected in parallel. This method is illustrated in FIG. 15. When a vacuum is required to generate a plasma, an O-ring or a metal gasket for vacuum is disposed on the surface of the coaxial rod array plate to maintain a vacuum state. In addition, in order to minimize the impact of the metal rod on the application process (process pollutant generation, etc.), the material is wrapped around the metal rod with a material such as quartz or sapphire that can pass microwaves. If necessary, a vacuum sealing adapter or the like is installed so as to maintain a vacuum at both ends of the metal rod and the insulating material.

In the above method, the microwaves generated in one magnetron are connected in the order of waveguide-> waveguide-coaxial cable conversion adapter-> coaxial cable-> coaxial rod antenna to collect a plurality of antennas of a flat plasma element, and the final coaxially connected in parallel. It is connected to the rod and delivered. Apart from this method, it is possible to branch the waveguide using a waveguide splitter and then connect it to the coaxial rods of the respective linear plasma antennas or to the coaxial rods partially paralleled. That is, in this case, a waveguide-> waveguide splitter-> a plurality of waveguides-coaxial cable conversion adapter-> a plurality of coaxial cables-> a plurality of coaxial rod antennas. 16 illustrates a case of connecting to a parallel assembled coaxial rod. However, in this case, since only one power is used, it is difficult to individually control and control the power supplied to each linear plasma, and thus the linear plasma electron temperature and electron density. It is possible to use a coaxial cable splitter instead of the waveguide splitter as one of the methods separate from the above method. That is, the method of connecting the microwave generated from one magnetron to the waveguide-> waveguide-coaxial cable conversion adapter-> coaxial cable-> coaxial cable splitter-> a plurality of coaxial cables-> a plurality of coaxial rod antennas, As described above, various modifications and equivalent other embodiments are possible.

In the present invention, a method of using a coaxial cable or a waveguide is mentioned, but a microwave includes a strip line method or other method as a transmission line method, and each line method according to the type of transmission line. And employing a suitable adaptation adapter.

In summary, in the present invention, microwaves generated by using one high-power and magnetron as described above are connected to an application device in a manner of multiple distribution using a switching adapter, a coaxial cable, and a splitter to easily transmit microwaves. It also includes how to do it.

As described above, the present invention is characterized by a microwave application device for transmitting it through the microwave generated by the high-frequency semiconductor device and the transmission line and the adapter. In this way, the weight and volume are smaller and easier to install. In addition, it is possible to transmit and adjust the uniformity, large area and fine microwave energy in a variety of fields by separating and installing a plurality. In addition, in the present invention, even if the microwave is generated and used using a conventional magnetron, the microwave is easily and individually subdivided or collectively paralleled by using a waveguide-coaxial cable switching adapter and a splitter. Disclosed is a method of delivery.

The embodiments are merely exemplary, and it will be apparent to those skilled in the art that various modifications and equivalent other embodiments are possible.

Therefore, it will be understood that the present invention is not limited to the forms mentioned in the above detailed description. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims. It is also to be understood that the present invention includes all modifications, equivalents and substitutions within the spirit and scope of the invention as defined by the appended claims.

111: magnetron 112: waveguide
113: Circulator 115: 3-Stub Tuner
117: applicator 119: plunger or sliding short circuit
121: microwave power supply 131: cooling line
151: coaxial cable 153: connector
155: coaxial cable and waveguide conversion adapter
156: metal coaxial rod
157: insulating material such as quartz, sapphire or tempered glass
159: vacuum sealing adapter of metal rod and insulation
171: plasma 173: antenna
175: coaxial rod array plate for plasma generation
181: Microwave Splitter
161: [wafer etc. substrate] 165: holder with cooling line
221: automatic control board 223: semiconductor microwave generating module
225: AC-DC switching inverter 231: power supply
233: External communication gateway 501: PC or PLC automatic control system
503: CPU or Cotroller Board 505: HMI Display
507: multi monitor

Claims (3)

A high frequency semiconductor module for oscillating microwaves;
An AC-DC conversion inverter converting the input AC power into DC to supply power to the semiconductor module;
An automatic control board that regulates and supplies power and reduces or cuts off power when a reflected wave is generated;
An applicator mounted with a plunger to minimize the reflected wave power to efficiently transmit microwaves, thereby supplying maximum power;
A power supply device having a gateway for exchanging signals with an external device and connected to the applicator and a connector, a coaxial cable, and a coaxial conversion adapter to transmit microwaves; And
Isolator inherent in the power supply device to diffract the reflected wave to protect the high frequency semiconductor module
Microwave system comprising a.
The method of claim 1,
And a control algorithm for minimizing the reflected wave power when the reflected wave power is inherent in the power supply.
The method of claim 1,
And a coaxial cable impedance tuner to minimize reflected wave power when reflected wave power occurs.

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