KR102267544B1 - Microwave System - Google Patents

Abstract

A microwave system for generating microwaves includes: a plurality of multiple high-frequency semiconductor power supplies for oscillating microwaves; a plurality of transmission lines and a transmission adapter for transmitting power from the power supply; a plurality of powered applicators; a communication gateway for measuring and feeding back forward power and reflected wave power among the power supplied to each applicator from the plurality of power supply devices; a display device displaying the forward power and the reflected wave power; a plurality of external multiple monitors displaying the forward power, reflected wave power, and a matching process curve; a central control computer that sets and transmits a power value that the user wants to be supplied from each power supply device, receives the measured forward power and reflected wave power, and transmits it to the display device, and compares and reviews the corresponding values; and a central automatic control computer that accurately and automatically controls the power value and transmits and operates it to a microwave application device through a communication device and a communication protocol.

Description

Microwave System

The present invention relates to a microwave system, and more particularly, a high-frequency semiconductor that generates microwaves, a transmission line that is an accessory 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 the frequency (f) bandwidth is from 300 MHz to 30 GHz (wavelength standard: 1 cm - 1 m). 1 MHz < f (frequency) < 300 MHz is called Radio Frequency. f (frequency) < 1 MHz is called low frequency. In general, microwaves (ultra-high frequency) and radio waves (Radio-Frequency) are divided and named according to frequency bands as described above, but in some parts, since there are cases where these frequencies have similar bands (e.g. For frequency bands of hundreds of MHz, such as 300 MHz), in the present invention, it is generally referred to as microwave or high frequency. When a semiconductor device generates microwaves or high frequencies, it is called Solid State Microwave (SSMW) or Solid State Radio-Frequency (SSRF).

Microwaves have the property of being completely reflected when they touch the metal. However, when a non-metal dielectric is irradiated with microwaves, it penetrates into the dielectric, rotates and vibrates polar molecules in the molecule, and generates heat by internal friction. This heat causes the microwave irradiated object to be heated. A typical example of using this closely in real life is the microwave oven.

Devices using microwaves are next-generation industrial technologies that can dramatically reduce working time, process costs, energy, and labor costs. The industrial application fields of microwaves are very wide, and the applications in the food field include heating, drying, thawing, sterilization, and cooking. In particular, when microwave energy is irradiated to food, it penetrates the surface of the food and heats the inside very quickly, so that it has a minimal effect on the taste, smell, texture, and nutritional value of the food. As for other industrial applications, existing industries include rubber processing, paper fabric dyeing, fixing and drying, and wood drying, while new business groups include military use, semiconductor and display production, electronic product production process, medical use, etc. have.

Microwaves can also be used in the field of medical devices. High-frequency diathermy (high-frequency diathermy, 高周波療法) is a type of medical device that uses microwaves and is used to heat deep tissues. It is a type of electrotherapy using high-frequency radio waves, and the most frequently used among them is microwave (electromagnetic wave with a wavelength of 1m to 1cm) therapy. As an effect obtained by this, the thermal effect with respect to deep tissue is mentioned. Diseases to which it can be adapted include inflammation of the musculoskeletal system, spondylolisthesis, shoulder syndrome, bruises, and the like, and are effective in relieving pain associated with these. When high-frequency electromagnetic radiation passes through, it is a method of heating the tissue by the resistance of the body tissue. In medical diathermy, the tissue is warmed but not destroyed. On the other hand, in electrocoagulation [surgical diathermy] tissue is destroyed.

One of the most widely used fields other than heating and drying of microwave energy is the field of plasma generation. Plasma is the fourth state of matter (The Fourth State of Matter), which means a state in which electrons, ions, neutrons, protons, etc. are mixed. In a microwave (ultra-high frequency) or high-frequency plasma generator, electrons selectively obtain energy and become a high-level energy state, collide with the source gas (neutron), and more and more electrons, anions, cations, various atoms, and molecules dissociated from proto-molecules Species, neutrons synthesized between various molecules and atoms, and active radicals in which each neutron is activated are generated. Depending on which species is used in the plasma state, they are called chemically reactive plasma, ion beam plasma, electron beam plasma, or reactive ion plasma. Since these activated radicals can cause reactions that are possible at high temperatures to occur even at low temperatures, they are being applied in numerous industrial fields such as semiconductor and display manufacturing, combustion, lighting, and chemical industries. 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 existing lighting sources such as incandescent lamps, fluorescent lamps, and metal halide, it is electrodeless, the brightest light source, has a long lifespan, is continuous white light, and can generate light with an intensity of 140 lm/W. There are advantages. In the case of such a semiconductor device plasma light source, it is a light source having a continuous spectrum of almost 400 to 800 nm wavelength, and is a natural light source almost similar to sunlight, environmentally friendly and has a long lifespan. Since other existing light sources use electrodes, energy efficiency is low and their lifespan is short due to contamination and corrosion, whereas plasma light sources have a long lifespan because they are electrodeless. For example, about 70% of the source light comes out and the time it takes to reach it is about 50,000 hours in the case of a plasma light source of a semiconductor device, but only 20,000 hours in the case of an existing high intensity discharge lamp. Another advantage is that it is the most efficient light source emitting almost 130-140 lm of light flux per 1W of output. The conventional plasma light source generates plasma by receiving energy from a special inverter (electronic ballast for electrodeless lamp) capable of oscillating low frequency (250KHz band), and the electrons in the plasma react with the gas enclosed in the lamp to generate ultraviolet rays. This UV light passes through the three-wavelength fluorescent material applied to the inside of the lamp and is finally emitted as visible light to become a long-life, high-efficiency lighting source. Table 1 summarizes the comparison of advantages and disadvantages of other existing lighting sources and AC semiconductor device (low/high frequency) plasma lighting sources.

Lighting Types light source
type life span
(hrs) magnitude
(klm) energy efficiency
(lm/W) chromaticity
Rendering color temperature
(K) light on
time
(Sec) light up again
time
(Sec) Incand-
scented incandescent lamp 2,000 1,700 10-17 100 3,200 0.1 0.1 Fluore-
scented 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 (ultra high frequency) and RF (high frequency) plasma illumination sources and conventional illumination sources and the superiority of plasma illumination sources.

In general, microwaves (ultra-high frequency) and radio waves (Radio-Frequency) are divided and named according to frequency bands as described above, but in some parts, since there are cases where these frequencies have similar bands (e.g. For example, a frequency band of several hundred MHz, such as 300 MHz), in the present invention, it is generally referred to as a very high frequency semiconductor. The overall configuration of the conventional microwave application device includes a magnetron, a waveguide, a circulator, a dummy load, a three-stub-tuner, an applicator (applicator), a plunger ( Plunger) [this is also called a sliding short circuit] and the power supply power (Power). Each component of the conventional microwave application device is illustrated in FIG. 1 .

The core generator of the conventional microwave is a magnetron, which is basically similar to a dipole vacuum tube, and has a structure in which hot electrons are emitted from the hot wire of the cathode. A high-voltage electric field is applied to the cylindrical outer anode and inner cathode of pure copper, and a magnetic field perpendicular to the electric field is formed by the permanent magnets installed above and below. The electrons protruding from the cathode go 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 the vanes formed on the anode side and form a high-frequency electromagnetic field in the cavity resonator.

When the electric current flows through the magnetron by changing the AC voltage of 220V to 4000V or higher in the power supply, a microwave that vibrates at a high frequency of 2.45GHz is created in the magnetron. When the microwave hits the object to be irradiated, the dipole constituting the object rapidly changes the direction of its axis arrangement by the high-frequency electric field, and heat is generated by frictional heat at this time. Therefore, only the insulator (dielectric) is heated because radio waves need to penetrate into the object.

When power is supplied to the filament and anode of the magnetron from the power supply, the microwave generated from the magnetron is transmitted to the applicator through the waveguide, the circulator, and the 3-stub-tuner. do. The power absorbed by the irradiated object by the energy of the microwave oscillated from the magnetron is called forward power, and the power that is not absorbed is called reflected power or reverse power. it is said Since the reflected wave power may return and damage the magnetron, a circulator that changes the direction of the reflected wave is used to protect it, and the energy of the reflected wave is absorbed by the dummy rod through which the cooling water flows and is emitted to the outside. Use a 3-stub tuner or plunger as a matcher to minimize reflected waves.

1 shows an example of a plasma generating apparatus using microwaves. As illustrated in FIG. 1, the conventional microwave application device has a configuration in which microwaves generated from a magnetron go through a matching process through a waveguide, a circulator, a 3-stub-tuner and a plunger, and an applicator ( The energy is transmitted to the applicator.

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

As illustrated in FIG. 1 , an application device using microwaves is structurally complex, heavy, and has a large breakage. Therefore, there are many difficulties in application fields that require light, thin, and compact. Such fields include plasma sources for semiconductor manufacturing, lighting, and medical fields.

As described above, in the case of a conventional microwave application device and process processing, the volume of the microwave application device increases due to the existing magnetron generating microwaves, a circulator, a dummy load, and a matching device for impedance tuning purposes. There has been this difficult and time-consuming problem. Accordingly, an object of the present invention is to facilitate use by removing the heavy and bulky microwave components as described above.

Also, conventionally, since microwaves are oscillated by one magnetron microwave, it has not been easy to achieve a large area and high uniformity. In addition, when a microwave transmission device using a plurality of multiple magnetrons, a power supply device, and a waveguide is used, the above-described bulky and heavy problems are serious, making it difficult to efficiently apply microwaves in various fields. In order to solve these problems, in the present invention, a microwave transmission device using a high frequency semiconductor module and a waveguide-coaxial cable conversion adapter is made light, thin and compact, and a microwave system that can be installed efficiently in various ways so that the user can achieve the desired process purpose is intended to

A microwave system according to the present invention includes: a plurality of multi-frequency semiconductor power supplies for oscillating microwaves; a plurality of transmission lines and a transmission adapter for transmitting power from the power supply; a plurality of powered applicators; a communication gateway for measuring and feeding back forward power and reflected wave power among the power supplied to each applicator from the plurality of power supply devices; a display device displaying the forward power and the reflected wave power; a plurality of external multiple monitors displaying the power values and a matching process curve; a central control computer that sets and transmits a power value that the user wants to be supplied from each power supply device, receives the measured forward power and reflected wave power, and transmits it to the display device, and compares and reviews the corresponding values; and a central automatic control computer that accurately and automatically controls the power value and transmits and operates it to a microwave application device through a communication device and a communication protocol.

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Preferably, the microwave system may further include a tuning control algorithm for minimizing reflected wave power by modulating a frequency when reflected wave power is generated by being embedded in the plurality of power supply devices.

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

Preferably, the applicator is equipped with a plunger to minimize reflected wave power to transmit microwaves.

Preferably, the power supply device and the applicator may be connected to a connector and a coaxial cable transmission line to transmit microwaves.

Preferably, the power supply device and the applicator may be connected to a connector and a coaxial conversion adapter to transmit microwaves.

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Impedance matching and circuit protection by high-frequency semiconductors that generate microwaves and their accessories, transmission line, waveguide-coaxial conversion adapter [Co-Axial Transition], matching (tuning) algorithm through frequency modulation or coaxial cable impedance tuner In the system, it is possible to form a compact device that is light and has a small volume, and it is possible to simply perform a microwave process, as well as to provide a microwave treatment system that can significantly improve work efficiency by easy installation of such a device. have.

In addition, according to the present invention, since a plurality of microwave oscillators can be easily configured and installed, it is possible to increase the area of the microwave device or to install and operate a plurality of simple applications, so that various applications such as plasma, lighting, medical care, heating, and extraction are possible. There is an effect of maximizing the user's efficiency, economy, and convenience for processing each industrial application in the industrial field.

1 is an exemplary configuration diagram for explaining a plasma generator that is a conventional microwave application device.
Figure 2 is an exemplary view showing the components of a plasma generator that is a conventional microwave application device.
3 is a view showing that plasma is generated when each process condition is changed in a plasma generating apparatus using a conventional microwave.
4 is an exemplary view of a microwave oven using a conventional microwave.
5 is a structural diagram of a transmission line (coaxial cable) for transmitting microwaves.
6 is an exemplary view showing a configuration method in which a magnetron, a circulator, and a dummy load are embedded in a power supply among components of a plasma generator, which is a conventional microwave application device.
7 is an exemplary diagram 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.
8 is a waveguide-coaxial (cable) conversion adapter (Co-Axial Adapter) and a coaxial cable after embedding a magnetron, a circulator, and a dummy rod among the components of a plasma generator which is a microwave application device according to the present invention in the power supply. An example diagram showing the configuration method to connect to the applicator (application device).
9 shows a magnetron, a circulator, a dummy rod, and a matching device among the components of a plasma generating device that is a microwave application device according to the present invention embedded in the power supply, and then the waveguide-coaxial (cable) conversion adapter (Co-Axial Adapter) and coaxial Example diagram showing how to connect the cable to the applicator (application device).
10 is an exemplary view showing a microwave application device for generating plasma using a semiconductor microwave oscillation device, a transmission line, and a transmission adapter according to the present invention.
11 is an exemplary view showing a microwave application device for generating plasma using a semiconductor microwave oscillation device, a transmission line, and a transmission adapter according to the present invention and a photo of plasma generation.
13 is an exemplary view showing a device configured to enable large-area plasma generation using a plurality of multi-semiconductor microwave power supplies, transmission lines, and transmission adapters according to the present invention;
14 is an exemplary view illustrating a large-area plasma configuration by arranging a plurality of semiconductor microwave generators according to the present invention.
15 is an exemplary diagram illustrating a method of processing by converting the microwave transmitted to the magnetron and the waveguide into a coaxial cable form using a coaxial-waveguide conversion adapter, and then connecting the coaxial rods of each linear plasma antenna as a whole and connecting them in parallel .
16 shows the microwaves transmitted to the magnetron and the waveguide after branching the microwaves using a waveguide splitter, and then converting it to a coaxial cable form using a coaxial-waveguide conversion adapter. Then, the coaxial rods of each linear plasma antenna are individually connected to each other. An example diagram showing how to connect or subset in parallel and process them.

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

This embodiment is provided to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the shape of elements in the drawings may be exaggerated to emphasize a clearer description. It should be noted that the same members in each drawing are sometimes shown with the same reference numerals. In addition, detailed descriptions of well-known functions and configurations that are determined to unnecessarily obscure the gist of the present invention will be omitted.

1 is a top view and a side view of a microwave application device. The overall composition of the microwave application device is a magnetron (Magnetron; 111), a waveguide (Waveguie; 112), a circulator (113), a 3-stub-tuner (3stub-tuner; 115), an applicator (Applicator; 117), sliding short It is composed of a 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 (Magnetron; 111), the microwave generated from the magnetron passes through the waveguide, the circulator (113), and the 3-stub-tuner (3 stub-tuner; 115). It is transmitted to the applicator (Applicator, applicator; 117).

A 3-stub tuner is a device with three metal rods in a waveguide or cavity resonator, and is a matching device that maximizes the transmission of microwaves without reflection. A plunger or a sliding short circuit (SSC) is also an additionally mounted device for matching in order to minimize reflected waves. Sometimes a 4-stub is used instead of a 3-stub. In addition, either manual tuning is performed by manually adjusting each stub, or automatic tuning is performed by the matching algorithm. The automatic matching machine is composed of a stub, a diode, an integrated automatic control board, and a motor drive unit, so that the load impedance is matched by giving o. The matching is described in more detail as follows. In general, when combining two circuits, if the impedance viewed from the output terminal of the first circuit to the input terminal of the same circuit is Z1=R1+jX1, and the input impedance of the second circuit is Z2=R2+jX2, the conjugate between the two impedances (共役) relationship, that is, R1=R2, X1=-X2, the condition of minimum loss and maximum output is obtained. Here, the first circuit is a matching device, and the second circuit is an applicator. That is, the matching is a method for transmitting the maximum output in the signal transmission path. The principle of matching is that the signal source has an internal resistance and for maximum output transmission, the load must be equal to the signal source's impedance. Where active components are included, the input and output impedances are quite different. However, the input impedance needs to be matched to the signal source, and the output load needs to be matched to the output impedance. Power amplifiers and many active components deviate from the basic principles because of the limitations imposed by internal power dissipation and linearity requirements. The output load impedance should be optimally selected with matching impedance to achieve maximum output transmission under these limiting conditions. There are several types of matching methods such as matching by a conductor rod, matching by a conductive plate window in the waveguide, matching by an anti-reflection termination circuit, matching by a tapered waveguide, and matching by a transformer (/4 impedance converter). have. As illustrated in FIG. 2, in the case of a 3-stub tuner, a conductive rod is inserted into the waveguide from the wide side of the waveguide to match. If a reflected wave exists in the waveguide, the reflected wave is canceled by the electromagnetic field generated by the conductive rod. The plunger matching method is a matching method by means of the conductor plate window in the waveguide. It is a method of inserting obstacles such as a conductor plate at a right angle to the observation in the waveguide at a distance, and selecting an appropriate distance to the load for matching. 1 and 2 are cases in which the 3-stub tuner matching method and the plunger matching method are mixed.

If the microwave is reflected back from the applicator without being absorbed, the reflected microwave can cause fatal damage to the magnetron. In this case, it changes the direction of the reflected wave to protect the magnetron, and the redirected reflected wave is a dummy load. Load; 123), the energy is absorbed. Cooling water is supplied to the dummy rod to dissipate the absorbed heat to the outside. The power propagated in the propagation direction of the microwave oscillated from the magnetron is called forward power, and the power returned without being absorbed by the applicator is reflected power (reflected power). electric power) or countercurrent wave power. Since the reflected wave that is not matched and the microwave returns to is transmitted as it is, it damages the expensive magnetron 111. Therefore, the direction of the reflected wave is changed separately by the magnet built into the circulator 113, and then the dummy rod 123 ) to be absorbed by the absorbent in the The dummy rod 123 that absorbs heat, the magnetron 111 that generates heat, and the power supply module or power supply 121 are cooled by supplying air or cooling water so that the temperature does not rise, and reflected wave energy absorbed by the cooling water is emitted to the outside. In order to measure the forward power and the reflected wave power, a directional coupler is sometimes installed between the circulator and the 3-stub tuner. Two microwave-measuring ports are made in the waveguide to measure forward power with the port facing the applicator, and the other is positioned in the opposite direction, that is, toward the magnetron, to measure reflected wave power.

An assembly diagram of a plasma generator using microwaves is illustrated in FIG. 2 . 3 shows pictures of plasma generated using such microwaves. The pictures of plasma generated at each pressure are exemplified by changing the pressure, which is an important process variable.

An exemplary view of a home cooker using microwaves to heat and cook or defrost food is shown in FIG. 4 . In this case, the load impedance was calculated and designed, and the Since it is an application device, the device is simple compared to the application field of plasma.

A waveguide, a conduit through which microwaves are transmitted, is any structure that confines, guides, and propagates waves. Mainly, it refers to a hollow conductive metal tube made to propagate electromagnetic waves. The waveguide is applied to high-power, low-loss, millimeter wave systems, and as an example of use, it is used to transmit electromagnetic waves such as radar, satellite repeater, broadcast radio wave transmission or heating, and plasma generation as described above. is used for The structural form of the waveguide is a metal conductor (copper, brass, aluminum, etc.) that surrounds the electromagnetic waveguide space, and the thickness of the conductor must be sufficiently secured to be about 1-3 mm for mechanical strength. make it double

The frequencies of microwaves allowed by the International Radio Association for industrial, scientific, and medical fields (Industrial, Scientific, Medial: ISM) other than the communication frequencies mainly used for communication are 2.45GHz and 915MHz (0.915GHz). In the case of 2.45GHz microwave, the waveguide dimensions used 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) is mainly used, and in the case of 915MHz, the WR-975 (internal size: 247.65 x 43.18 mm) waveguide is used. As such, the size of the waveguide is usually determined according to the frequency of the microwave. Waveguides vary from WR-2300 (internal size: 584.2 x 292.1 mm; operating frequency 0.32 to 0.49 GHz) to WR-3 (internal size: 0.86 x 0.43 mm; operating frequency 217 to 333 GHz). The larger the used frequency, the smaller the internal size of the waveguide.

In the microwave oscillator, for the transmission of microwave energy, which is an irradiation part, an electric wire cannot be used because it radiates microwaves to the outside, and a metal hollow pipe called a waveguide is usually used. The waveguide is classified into a rectangular or circular waveguide and a ridge-type waveguide having a complex shape depending on the cross-sectional shape. Rectangular waveguides are generally used, and circular and ridge-type waveguides are used for special purposes.

In general, a waveguide that transmits microwaves is in the form of a square tube and transmits microwaves having a spreading characteristic by confinement in the square tube, and is usually made of brass or copper with good conductivity. Therefore, the square waveguide becomes heavy and large when installing a process or device using microwaves, and assembling becomes difficult. In particular, even in the case of low power, the installation is difficult and application is limited because the device is heavy and heavy. An example of a plasma generating device using such a microwave delivery device (see FIGS. 1 and 2 ) is illustrated in FIG. 6 .

For microwave transmission, there is a coaxial cable (coaxial tube) in addition to the waveguide. As the frequency increases, the problem is that the wave easily escapes to the outside. In the case of a frequency of 60Hz or higher, a closed waveguide is used to reduce the wave's escape to the outside. As a closed waveguide method, there are a coaxial cable (Co-Axial Cable), a metal waveguide (Metallic WaveGuide), and a strip line method. A coaxial cable is a system that surrounds the inner conductor with an insulator and shields the outer conductor so that a higher frequency signal can be transmitted than a general power transmission line or wire (a cable made by twisting two twisted wires). It is a form to reduce the wave escaping out of the cable due to the external conductor.

A coaxial cable is a transmission line with a central conductor supported by polyethylene on the central axis of a pipe made of conductors, and is used to transmit the output signal of the power monitor. Coaxial cables are combustible and easy to handle, but the power tolerance of microwave transmission energy is small. In the case of a low loss coaxial cable with an impedance of 50 ohm, the maximum allowable power of microwave transmission energy is 330 Watt (outer diameter 10mm) ~ 520 Watt (outer diameter 15mm) in the case of a frequency of 2.45 GHz, and in the case of a frequency of 915 MHz, 330 Watt (outer diameter) 10mm) ~ 520Watt (outer diameter 15mm) and 580 Watt (outer diameter 10mm) ~ 900Watt (outer diameter 15mm). Coaxial cables are used for high-frequency heating devices, but not for microwave heating devices with high power of 300 ~ 500 W or more.

The difference between a transmission line and a waveguide is that a transmission line (including a coaxial line) propagating by a TEM mode can also be viewed as a waveguide, but in general, propagation of radio waves by a TEM mode is not called a waveguide. In other words, only propagation by TE mode (Transverse Electric Field/Wave) and TM mode (Transverse Magnetic Field/Wave, transverse magnetic field) is mainly used as a waveguide. The shape of the transmission line is composed of two or more conductors, and it is a structure in which the two conductors are isolated by a dielectric. In the energy transfer method, energy is transferred in the form of a reciprocating current/voltage wave flowing through two conductors. When viewed in the form of electromagnetic waves, the radio wave is transmitted as a TEM wave, and is due to the transmission of a current wave or a voltage wave. Since there is no cut-off frequency, it can operate from direct current to very high frequencies, and it is applied to low power and somewhat low frequencies, but it is inefficient in the ultra-high frequency band due to the skin effect and dielectric loss. Coaxial cable is a kind of transmission line, and in general, 2-wire parallel cable has a defect in that the effective resistance of the conductor increases at high frequencies due to the skin effect. To compensate for this, the coaxial cable was developed, and its form is 5 is the same. Looking at the coaxial cable structure in detail, two cylindrical conductors and dielectrics share a central axis, the inner conductor is used for actual signal transmission, and the outer conductor is a mesh-shaped shield made of aluminum/copper. ) (braided or foil paper), and it is made by filling the gap with dielectric/insulator (polyethylene, etc.) and separating it. At the outermost part, the outer sheath is surrounded by a cable jacket (vinyl, polyethylene, etc.).

The advantage of the coaxial cable is that it is a transmission line with a shielded structure where external interference hardly affects, and since there is no cutoff frequency like a waveguide, it can be used from direct current (DC) to microwaves and millimeter waves. Currently, it is possible to go over 50 in short distances. However, over several GHz bands, the loss is large depending on the distance, so a waveguide structure is used. The smaller the outer diameter is, the higher the high frequency can be used, but the power that can be carried is limited, and there is a difficulty in manufacturing. The propagation mode generally operates in the TEM mode. It is used in long-distance telephone network, CATV, video transmission, premises information communication network, etc.

Coaxial cable connectors are BNC, TNC, FT-type, N-type, F-type, and miniature type (SMA, SMB, SMC). Coaxial cable is usually used as a transmission line at frequencies below UHF, but even in microwave circuits above that, the inner conductor uses silver plating on the steel wire so that the signal flows through the silver-plated part of the conductor surface, resulting in a skin effect in the microwave band. To lower the loss due to the insulator, a material such as Teflon is used as an insulator to lower the dielectric loss.

In the case of using low-power microwaves, there is a method of reducing the volume and weight by using a coaxial cable instead of a waveguide. The plasma generating apparatus using microwaves illustrated in FIG. 6 will be described as an example. If the magnetron (referred to as 'M'), circulator (referred to as 'C'), and dummy rod (referred to as 'D') are outside, they occupy a separate space. It is installed inside the supply device for integration and unification. In this way, significant spatial reduction is possible, and the power supply to the magnetron is directly connected from the inside, and the copper wire is small and easy to install, such as sharing the cooling line. 3 If the stub-tuner (matcher or matcher) is manual, the stub must be operated for matching, so place it outside. In the case of the auto tuner, as illustrated in FIG. 7 , the stubs are automatically adjusted to match the impedance. In this case, the tuner can be positioned inside the power supply.

In the case of FIGS. 6 and 7 , it is inconvenient to use a waveguide to connect from the isolator (the sum of the circulator and the dummy rod is referred to as an isolator) to the applicator. In order to solve this part, the present invention discloses a method of converting a microwave waveguide transmission method to a coaxial cable transmission method. That is, if a waveguide-coaxial (cable) conversion adapter (Co-Axial Adapter) for converting a waveguide into a coaxial cable is used, the microwave can be transmitted by finally connecting to the applicator 117 using a coaxial cable instead of the waveguide.

In this case, there is an advantage in that the installation space is additionally reduced and the installation can be facilitated. 8 and 9 respectively show a case where the tuner is outside the power supply (FIG. 6) and when the tuner is inside the power supply (FIG. 7), a case where a waveguide-coaxial cable conversion adapter is installed and used in a simplified manner It is also an example. 8 and 9 show an embodiment in which a waveguide-coaxial cable conversion adapter is connected to the waveguide flange of the tuner to convert to a coaxial cable, and the waveguide-coaxial cable conversion adapter is used again to connect to the applicator and use. That is, it is a method to use by connecting the tuner -> waveguide-coaxial cable conversion adapter -> coaxial cable -> coaxial cable-waveguide conversion adapter. The difference between FIG. 8 and FIG. 9 is a case where the tuner is embedded in the power supply box ( FIG. 9 ) and a case where the tuner is external to the power supply box ( FIG. 8 ). As described above, in the present invention, the microwave device is simplified by using a waveguide-coaxial cable conversion adapter (Co-Axial Adapter) and a coaxial cable. In addition, the present invention includes a method for facilitating installation by embedding the isolator and the matching device in the power supply and connecting them with a coaxial cable.

Microwave applications can be greatly simplified if the device is configured using methods such as pre-designing and characterizing the length for accurate impedance matching so that a 3-stub tuner and isolator are not required in the microwave path. have. In addition to these cases, especially in the case of plasma generation, a tuner (matcher) should 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 as a substitute for the conventional three-stub type tuner (Figs. 1 to 2, 7 to see Fig. 9). The present invention includes a method of using a matching impedance in the form of a plunger.

In addition, instead of using a conventional magnetron and a tuner (matching device), a semiconductor ultra-high frequency generation module is used as a substitute for this conventional method, and the generation frequency is modulated and tuned (FVTM), or a coaxial tuner or plunger is used as an applicator. In the case of fusion with and matching impedance, microwave equipment can be used much more simply. The present invention includes an applicator method equipped with such a frequency modulation method (FVTM) or a plunger type matching method. A detailed method for this will be described later.

In order to avoid the conventional method of using a magnetron that oscillates microwaves as in the case of FIGS. 1 to 9, recently, a semiconductor device is used instead of a magnetron to oscillate microwaves, and the semiconductor microwave (Solid-State Micro-) Wave: SSMW) method. The semiconductor used at this time is a silicon-based laterally diffused metal oxide semiconductor [Laterally Diffused-Metal Oxide Semiconducotor LDMOS] Field-Effective Transistor (FET).

Fig. 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 used in the past. Since the semiconductor microwave generating module requires the supply of DC power, the AC-DC conversion inverter 225 is included in order 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 . Also, 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). There are Analog, Profibus, CanOpen, or Modbus RS232/RS485 methods for communicating with the outside. When the semiconductor microwave module does not properly match during operation, a reflected wave is generated and a cooling line 131 is installed to cool it. In the case of air cooling, a fan is installed without the need to supply cooling water, and the air supplied from the fan contains heat and is discharged to the outside of the power supply, so installation is relatively easy. However, when the reflected wave power is large, it is safe to install a cooling water line because it generates a lot of heat 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 delivering them to the applicator. As illustrated in FIG. 10, the microwave generated by the high-frequency semiconductor module is transmitted to the applicator through a connector attached to the power supply end, a coaxial cable, and a coaxial cable-waveguide conversion adapter. of the isolator 227 is possible, and when a reflected wave is generated, the semiconductor microwave generator module 223 is 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 and used. 11 illustrates plasma generation by a single linear antenna using a semiconductor microwave generator. Microwaves are generated from the semiconductor microwave generation power supply 121 and connected to a linear plasma antenna through a connector (coaxial) -> coaxial cable -> connector (coaxial) and transmitted. 11 shows that the energy of microwaves is transmitted to generate plasma.

11 illustrates plasma generation by a single linear antenna using a semiconductor microwave generator. Microwave is generated from the semiconductor microwave generator power supply 121 and is transmitted by connecting to a linear plasma antenna through a connector (coaxial) -> coaxial cable -> connector (coaxial). FIG. 11 shows that the energy of microwaves is transferred by this method to generate plasma. As illustrated in FIG. 11, when using the semiconductor ultra-high frequency generation module and the frequency modulation tuning method, compared to the conventional method of connecting a microwave generated from a magnetron with a waveguide flange, and using an isolator, a tuner, etc. It can be seen that it is much lighter, thinner and smaller and easier to install.

A microwave generator using such a semiconductor device has the following advantages. (1) 1 ~ Maximum allowable output (For example, the maximum allowable power is about 300 ~ 500Watt depending on the outer diameter of the coaxial cable with impedance matching) Accurate power adjustment is possible in 1W units. (2) Frequency is 50MHz up and down of 2450MHz, that is, frequency modulation of 2450MHZ 50MHz (2400 ~ 2500 MHz range) is possible. (3) Longer lifespan than the magnetron method. (4) It is possible to embed a small isolator inside the power supply, and when a reflected wave is generated, the generator circuit is protected through immediate automatic reduction and interruption of the supplied power. (5) Small in volume and light in weight. (6) Accurate measurement of incident wave power and reflected wave power is possible. (6) Ripple is small and power transmission efficiency is high. (7) (There is a need to cover a large area, etc.) In the case of an industrial application that requires a plurality of applicators, it is possible to achieve the user's purpose by optimizing it in various ways by making it light, thin and compact.

In the case of using a coaxial cable, although it is applied in the low power area of 300 ~ 500 Watt or less, a method to improve this point is expected, and microwave transmission is possible even at higher power. In addition, even before a coaxial cable with a high maximum power tolerance comes out or another transmission method comes out, depending on the field of application, the microwave transmission device oscillated from each high-frequency semiconductor module is separated and installed into a plurality (refer to FIGS. 13 and 14). By distributing and transmitting microwaves of appropriate power (energy) required by the device, as well as individually controlling each high-frequency semiconductor power module, it is possible to fine-tune the application device. Accordingly, the present invention features and includes a transmission method and apparatus using such a 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 field of electromagnetic wave is arbitrarily divided by the frequency, and the frequency is the number of times the wave vibrates in 1 second. The unit of frequency is Hz, and 1 Hz means that the wave vibrates once per second. The relationship between frequency (f), wavelength (), and speed of light (C) is as follows.

= C/f(1)

That is, the shorter the wavelength, the higher the frequency, and the longer the wavelength, the lower the frequency. Here, the speed of light C is 2.99792458*10 ⁸ m/s.

According to the wavelength, electromagnetic waves are divided into gamma rays, x-rays, ultraviolet rays, visible rays, infrared rays, microwaves, and radio waves from the shortest region. That is, microwaves are radio waves with a lower frequency and longer wavelength than light, but have a higher frequency and shorter wavelength among radio waves, and are used in various industrial fields such as radar, navigation, communication and heating, plasma, and the like, as described above. A transmission (tansmission) length Li for impedance matching is as follows.

Li = / 4 (2)

A microwave transmission adapter is manufactured by the above-described transmission length. Even when a semiconductor device is used to oscillate microwaves, reflected waves may be generated due to impedance mismatch. In a microwave device using a semiconductor device, since the frequency of the semiconductor device can be changed in a certain range, impedance matching can be performed by modulating the frequency according to (Equation 1) and (Equation 2), and in the present invention, impedance matching method. That is, the present invention is characterized in that the reflected wave is minimized by an algorithm that adjusts, tunes and matches the frequency when the applicator and the impedance do not match or when the Li does not match. That is, when it is generated and output from the semiconductor module, since it is possible to modulate the frequency, matching is possible through such frequency modulation, and this is called 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 not using a conventional tuner (matcher). In this case, microwave equipment is much simpler and easier can be used

In addition, in the case of connecting the semiconductor microwave power supply device and the applicator with a coaxial cable, additional tuning (matching) can be performed using a coaxial impedance adjusting device between them, and this can be performed using the 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. 12 . It is installed between the semiconductor microwave generator 121 and the applicator 117 and is connected by a coaxial cable. The 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, and thereby the impedance of the coaxial impedance tuner 228 is automatically or manually adjusted to minimize the reflected wave. In the case of automatic tuning, it is revealed that installation is possible in the microwave power supply device 121 . The present invention includes a coaxial impedance tuning method in addition to the frequency modulation tuning method.

In addition, in the present invention, as another matching method, separate from the conventional method such as a 3-stub tuner (or 4-stub tuner) or a new matching method such as the above-mentioned frequency modulation, a plunger is combined with an applicator to manually Alternatively, a method in which registration can be performed automatically is disclosed. The applicator 117 can be connected in the form of a waveguide or coaxial cable, and a plunger 119 is installed behind the applicator 117 to be tuned and used. The plunger 119 can also be a waveguide type or a coaxial cable type.

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

In addition, in the present invention, when an instantaneous reflected wave is generated, in order to protect the microwave generating device from it, the isolator provided with a cooling line that protects the high frequency semiconductor module by diffracting the reflected wave is miniaturized and is embedded in the high frequency semiconductor power supply device. characterized in that

The concept of a plurality of semiconductor microwave generators is shown in FIG. 13 . A plurality of power modules (referred to as power supply, Power Module, PoM; 121) are installed, and an applicator (application device) is applied to each module. Each applicator may be an applicator as part of an overall applicator, or it may be an entirely separate and independent applicator. As illustrated in FIG. 10 , each power supply module has a respective control board, and a communication system capable of communicating with an external light exists. Therefore, it is possible to centrally control each power module in the Personal Computer PC (501) system or PLC (Programmable Logic Controller; 501). For communication with the outside, there are Modbus RS232 / RS485 methods when using a PC, and Profibus or CanOpen methods when using PLC. 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 the set value to find it. After each module is executed, the measured forward power and reflected wave power 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 set values, compares and analyzes them, determines whether the desired specifications of the application device are met, and instructs the next command according to the optimization algorithm. Typically, a human machine display (HMI) display 505 is installed in 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 a micro-application device, which may be dangerous due to leakage, is installed in an isolated space, each of the plurality of power modules using a multi-monitor (507) in a separate control room through the remote interface device The forward power, reflected wave power, and matching process trajectory curve are monitored on the Smith Chart. Through the above method, the microwave application device can be made lighter, thinner and smaller, and since the microwave can be branched and used, it has a great advantage that it can be applied in various ways suitable for various purposes of the user at the same time.

An example of a device for transmitting microwaves using the plurality of semiconductor micro power modules described above is representatively illustrated in FIG. 14 . It is a very difficult field to generate a large-area plasma to maintain uniformity. In particular, a large-area plasma source for processing 12-inch or larger wafers or 5th to 8th generation LCDs is absolutely necessary. It is very difficult to make uniform large-area plasma using one microwave power supply and one applicator. In addition, when generating and using the shape of each reaction chamber, gas flow pattern, gas inlet, and radicals, it is necessary to control and supply plasma according to process conditions such as the shape of the radical distributor, and one large-area source It is almost impossible to match the desired uniformity and throughput (response speed). Therefore, there is a need for a method to make one large element by dividing it into multiple sources and configuring it. As shown in Figure 14, the power of each power module is supplied to a coaxial rod wrapped in each insulator to form a linear plasma, but a plurality of these linear plasma antennas are installed to combine and configure a plasma source to form a large area. It constitutes a plasma (Large Area Plasma). In this case, since it is necessary to connect and use a plurality of power supply devices, there is a disadvantage in that it is complicated and expensive to configure the entire device. As a method to improve this, it is possible to transmit microwaves by a method of collectively processing linear plasma antennas in parallel and connecting them to a single coaxial rod (see Fig. 15), or a method of dividing and parallel processing into a small number and connecting them (see Fig. 16). Do.

In the present invention, a new method and only some examples of a semiconductor microwave generating method and apparatus are disclosed, and individual applications such as plasma are to be specified in more detail as a separate invention and applied separately.

In addition to the method of using a plurality of high-frequency semiconductor power modules as in the case of the example of FIG. 14, a separate method of oscillating and transmitting microwaves using a conventional magnetron is also possible. In the case of a multi-linear plasma source composed of several coaxial antennas (see FIG. 14), it is also possible to individually connect each microwave device to each coaxial rod. That is, in this case, as illustrated in FIG. 9, the final waveguide-coaxial cable conversion in each of several microwave power supplies with a magnetron, an isolator, a tuner (both ends are in the form of a waveguide), and a waveguide-coaxial cable conversion adapter. It is a method of connecting each coaxial cable through the connector of the adapter and connecting one-to-one to each coaxial rod of the linear plasma source. Therefore, in this case, each magnetron, isolator, tuner, and waveguide-coaxial cable conversion adapter must be connected to each coaxial rod and used. There are disadvantages.

In order to improve the above problems, it is possible to process the coaxial antennas of the linear plasma to be transmitted by using a single power supply device, a magnetron and a waveguide in parallel. In this case, the microwave transmitted to the magnetron and the waveguide is converted into a coaxial cable or coaxial rod form using a coaxial (cable)-waveguide conversion adapter, and then the coaxial rod of each linear plasma is connected in parallel to process it. This method is illustrated in FIG. 15 . When a vacuum is required to generate plasma, the O-ring or metal gasket for vacuum is arranged on the surface of the coaxial rod arrangement plate to maintain the vacuum state. In addition, in order to minimize the influence of the metal rod on the application process (eg, generation of process contaminants), the metal rod is surrounded by an insulating material and a material such as quartz or sapphire that can transmit microwaves. In addition, if necessary, a vacuum sealing adapter or the like is installed to maintain a vacuum at both ends of the metal rod and the insulating material.

In the above method, the microwave generated from one magnetron is connected in the order of waveguide -> waveguide-coaxial cable conversion adapter -> coaxial cable -> coaxial rod antenna, and a plurality of antennas of the line flat plasma source are assembled and the final coaxial connected in parallel. It is a method of transmitting by connecting to a rod. Separately from this method, it is possible to branch the waveguide using a waveguide splitter and then connect it individually to the coaxial rod of each linear plasma antenna or to connect it to a partially parallel set coaxial rod. That is, in this case, it is a method of connecting the waveguide -> waveguide splitter -> multiple waveguides-coaxial cable conversion adapter -> multiple coaxial cables -> multiple coaxial rod antennas. A case of connecting to a parallel set of coaxial rods is exemplified in FIG. 16 . 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 the electron temperature and electron density of each linear plasma. It is possible to use a coaxial cable splitter instead of a method using a waveguide splitter as one of methods other than the above method. That is, the microwave generated from one magnetron is connected to the waveguide -> waveguide-coaxial cable conversion adapter -> coaxial cable -> coaxial cable splitter -> multiple coaxial cables -> multiple coaxial rod antennas, and in the present invention, It is pointed out that other embodiments that are variously modified and equivalent as described above are possible.

In the present invention, a method using a coaxial cable (Co-Axial Cable) or a waveguide has been mentioned, but the microwave transmission line method includes a Strip Line method or other method, and each line method according to the type of transmission line This includes the adoption of a conversion adapter suitable for

In summary, in the present invention, as described above, microwaves generated using one high power and a magnetron are multiplied by using a conversion adapter, coaxial cable, and splitter, etc. including how to

As described above, the present invention features a microwave application device that transmits microwaves generated by a high-frequency semiconductor device and a transmission line and an adapter. Through this method, the weight and volume are smaller and the installation is easy. In addition, it is possible to transmit and control fine microwave energy with good uniformity and large area in various fields by separately installing and transmitting a plurality of them. In addition, in the present invention, even when generating and using microwaves using a conventional magnetron, microwaves are more easily individually, subset-parallel, or collective set-parallel processing using a waveguide-coaxial cable conversion adapter and a splitter. A method of delivery has been disclosed.

The embodiments are merely exemplary, and those of ordinary skill in the art to which the present invention pertains will appreciate that various modifications and equivalent other embodiments are possible therefrom.

Therefore, it will be well understood that the present invention is not limited to the form mentioned in the above detailed description. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims. Moreover, it is to be understood that the present invention covers all modifications, equivalents and substitutions falling within the spirit and scope of the invention as defined by the appended claims.

When each symbol is defined with respect to the configuration of the processing apparatus using microwaves according to the present invention shown in the accompanying drawings, it is as follows.
111: magnetron (Magnetron)
112: Waveguide (Waveguie)
113: Circulator
115 : 3-stub-tuner
117: Applicator
119: Plunger or Sliding Short Circuit
121: microwave power supply (Microwave Power)
131: Cooling Line
151: Co-Axial Cable
153: Connector
155: Coaxial cable and waveguide conversion adapter (Co-Axial Transition Adapter)
156: metal coaxial bar
157: insulating material such as quartz, sapphire or tempered glass
159: metal rod and insulating material vacuum sealing adapter
171 : Plasma
173: Antenna
175: coaxial rod arrangement plate for plasma generation
181: Microwave Splitter (Splitter)
161: [Wafer, etc.] Substrate
165: Wafer Holder with Cooling Line
221: automatic control board (Control Board)
223: semiconductor microwave generating module
225: AC-DC conversion inverter
231: power supply
233: Gateway for External Communication
501: PC or PLC automatic control system
503: CPU or Cotroller Board
505 : HMI (Human-Machine-Interface) Display
507 : Multi-Monitor (Mult-Monitor)

Claims (15)

delete delete delete delete delete delete a plurality of microwave generators;
a plurality of communication gateways mounted on each of the plurality of microwave generators and measuring and feeding back forward power and reflected wave power of the plurality of microwave generators; and
Controlling the plurality of microwave generators to form a uniform large-area plasma source by comparing the measured forward power and reflected wave power of the plurality of microwave generators with a set value and setting the power value of each of the plurality of microwave generators including a central control computer that
Each of the plurality of microwave generators,
a high-frequency semiconductor power supply device for supplying power;
a coaxial cable for transmitting the power of the power supply device; and
and an applicator to which the power is supplied via the coaxial cable.
8. The method of claim 7,
The microwave system further comprising a tuning control algorithm for minimizing the reflected wave power by modulating the frequency when the reflected wave power is generated within the high frequency semiconductor power supply device.
8. The method of claim 7,
Each of the plurality of microwave generators,
The microwave system further comprising a coaxial cable impedance tuner connected to the coaxial cable and configured to minimize reflected wave power by adjusting the impedance of the coaxial cable when reflected wave power is generated.
8. The method of claim 7,
Each of the plurality of microwave generators,
The microwave system further comprising a plunger mounted on the applicator to minimize the reflected wave power.
8. The method of claim 7,
Each of the plurality of microwave generators,
and a connector connecting the coaxial cable to the high frequency semiconductor power supply and the applicator.
8. The method of claim 7,
Each of the plurality of microwave generators,
The microwave system further comprising a coaxial conversion adapter for connecting the high frequency semiconductor power supply and the applicator.
8. The method of claim 7,
The microwave system further comprising a plurality of multiple monitors externally displaying the forward reflection power, reflected wave power, and matching process curve of each of the plurality of microwave generators. delete delete

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