KR101356582B1 - Filter for RF Power Signal and RF Power Supply Comprising the Filter - Google Patents

Abstract

The present invention discloses a filter for a radio frequency power device and a high frequency power device including the filter. The filter for a high frequency power device of the present invention includes a planar spiral inductor formed through a thick film deposition process on a ceramic or metal substrate having excellent heat dissipation characteristics, and a capacitor electrically connected to the inductor to perform a filtering operation. In addition, a power signal of a desired frequency band may be filtered from a high frequency power signal having a magnitude of several amps (A) or more. The filter of the present invention not only provides excellent heat dissipation characteristics because it is formed on the substrate having excellent heat dissipation without adhesive of other foreign substances, and is formed of a conductive metal layer of a thick film, so that the low Q index of a conventional inductor having a flat spiral shape Can solve the problem.

High Frequency Power Supplies, Filters, Inductors

Description

Filter for high frequency power device and high frequency power device having the filter {Filter for RF Power Signal and RF Power Supply Comprising the Filter}

The present invention is applied to a high frequency power device for supplying high frequency power (Radio Frequency) power for the purpose of generating heat or plasma to remove unnecessary harmonic components included in the process of generating a high frequency power signal. And a high frequency power device including the filter.

High frequency (Radio Frequency) power device is a device that supplies power by providing a signal (power source) having a high frequency of several MHz or more to the load side, unlike a general power supply device that supplies direct current or commercial AC power. Such high frequency power devices are used in various fields.

For example, a capacitively coupled parallel plate plasma apparatus is an example. In a capacitively coupled parallel plate plasma apparatus, a pair of parallel plate electrodes are disposed in a chamber in a vacuum state and the inside of the chamber is filled with a gas for plasma. The high frequency power device provided outside the chamber supplies high frequency power to the plate electrode to form a high frequency electric field between both electrodes. The high frequency electric field excites the gas filled in the vacuum chamber into the plasma state. The capacitively coupled parallel plate plasma apparatus is used in a plasma etching apparatus for etching a metal film or a deposition apparatus for depositing a metal film.

In another example, a high frequency power unit is also used in a high frequency melting furnace. By causing a high frequency current to flow through a coil wound around the outer circumferential surface of the furnace, an electromagnetic field is generated in the furnace. The electromagnetic fields heat objects in the furnace by dielectric heating or induction heating.

1 schematically illustrates a power supply system using such a high frequency power device. The power supply system 100 includes a high frequency power device 110, a transmission line 130 formed of a coaxial cable, and an impedance matching unit 150. ) And load 170. The melting furnace or the plasma apparatus corresponds to the load 170.

 The high frequency power signal output from the high frequency power device 110 is supplied to the load 170 through the impedance matching unit 150. The impedance matching unit 150 matches the impedance of the high frequency power device 110 with the impedance of the load 170 so that the supply power of the high frequency power device 110 is transferred to the load 170 as it is. However, the power supply system 100 may not include the impedance matching unit 150 in some cases.

The high frequency power device 110 includes a signal generator 111 for generating a high frequency signal including a high frequency oscillator, a signal amplifier 113 for amplifying the high frequency signal generated by the signal generator 111 to a desired power level, and In addition, the signal amplifier 113 includes a filter 115 for removing noise components included in the amplified signal.

The signal generated by the signal generator 111 is amplified to a desired power level by the signal amplifier 113. However, in this process, harmonic components, which are unwanted frequency components other than the fundamental frequency generated by the signal generator 111, are amplified together. Such harmonics are removed by the filter unit 115.

The filter unit 115 may include a plurality of band rejection filters (BRFs) or notch filters for sequentially removing secondary harmonics, tertiary harmonics, and quaternary harmonics among the signals output from the signal amplifier 113. Or a Notch Filter (BPF) or a Band Pass Filter (BPF) for filtering only source frequency components.

In these filters, an analog filter by a combination of an inductor and a capacitor is used. However, it is to remove the noise from the high frequency amplified signal of current of several amperes (A), so it can be applied to the analog filter or the integrated circuit chip for electronic equipment that processes small signal of several microamps or less. Of course, the applied semiconductor filter cannot be used.

One of the important considerations in filter design for high frequency power supplies is that a lot of heat is generated during the filtering process, which is especially necessary for inductors with weak physical properties.

A typical inductor is usually an inductor in which a copper wire is wound in a solenoid solid shape, a planar spiral inductor produced by a semiconductor process, or a solenoid type micro three-dimensional inductor by MEMS (Microelectromechanical Systems) technology. Inductors are primarily used for small signal processing and cannot be used in high frequency power devices. Even in the solenoid type made of winding copper wires, there is a problem of disconnection due to heat generated during the processing of the high frequency power signal. In order to solve this problem, a method of manufacturing a coil in which a wire is inserted into a separate solenoid tube filled with coolant for cooling has been proposed.

Recently, a coil of a type in which a copper plate having a two-dimensional spiral shape is bonded on a synthetic resin substrate has been proposed. However, since the heat dissipation characteristics of the synthetic resin substrate and the like are limited, a problem arises in that the copper plate is peeled from the synthetic resin substrate by the heat generated during the filtering process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a filter for a high frequency power device that is used in a high frequency power device for supplying power and effectively removes noise from a high frequency power signal while effectively dissipating heat generated in a filtering process, and a high frequency power device including the filter. In providing.

In order to achieve the above object, a filter for a high frequency power device provided in a high frequency power device to remove harmonic components except for a source frequency of a high frequency signal includes a substrate and a predetermined inductance as a physical metal vapor deposition on the upper surface of the substrate. It includes a flat spiral inductor to provide a. Here, the metal layer includes a plurality of first thin films having a tensile residual stress, and a second thin film alternately and repeatedly deposited with the first thin film having a compressive residual stress.

The high frequency power device includes a signal generator for generating a high frequency signal including a high frequency oscillator, a signal amplifier for amplifying the high frequency signal generated by the signal generator to a desired power level, and a signal amplified by the signal amplifier. And a filter unit for extracting the high frequency source frequency component, and the filter of the present invention is included in the filter unit.

The filter may include a terminal portion, which is the metal layer spaced apart from the inductor, a capacitor provided between one end of the inductor and the terminal portion, and a connection lead, which is a conductive metal connecting the other end of the inductor and the terminal portion. It may further include.

Furthermore, the filter may further include a ground layer formed on the bottom surface of the substrate by physical vapor deposition of the metal layer and serving as an electrical reference node. However, the reference node is not necessarily formed on one surface of the substrate.

When the metal layer forming the inductor, the terminal portion, or the ground layer is formed of copper (Cu), the metal layer is formed on the top surfaces of the alternately repeatedly deposited first and second thin films to prevent oxidation of copper. It may further include.

The filter for a high frequency power device according to the present invention has excellent heat dissipation characteristics because it is formed on the substrate having excellent heat dissipation without adhesive of other foreign substances, and thus is separated from the substrate by heat generated by a planar spiral inductor having a current of several amps or more. No problem arises.

In addition, since the filter for a high frequency power device according to the present invention is formed of a conductive metal layer of a thick film, it is possible to solve a problem such as a low Q index of a conventional inductor having a flat spiral shape.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the drawings.

The filter for a high frequency power device of the present invention is an analog filter that can be applied to the filter unit 115 of FIG. 1, and may have any filtering characteristic as long as it filters a specific frequency band component by a combination of a capacitor and an inductor. The filter unit 115 of FIG. 1 may naturally include components other than the filter of the present invention described below in order to separate a desired signal from a high frequency power signal or to remove unnecessary components.

The filter of the present invention is characterized by maximizing its inductor characteristics and heat dissipation characteristics by forming a thick film by depositing a conductive metal on the substrate by a physical vapor deposition method. The filter 200 of the present invention illustrated in FIGS. 2 to 5 is an example of various filters according to the present invention, and is an example in which one inductor 203 and a capacitor 207 are connected in parallel.

2 and 3, the filter 200 of the present invention includes a substrate 201, a planar spiral inductor 203 formed by being deposited on the substrate 201, and a terminal part for input or output of a high frequency power signal. 205 and a capacitor 207 provided between the terminal portion 205 and one end 203-1 of the inductor 203. In addition, a connection lead 209 which is a conductive metal in the form of an air bridge for electrically connecting the other end 203-3 and the terminal portion 205 of the inductor 203 is provided.

On the bottom surface of the substrate 201, a ground layer 211 is formed as an electrical reference node or ground of the filter 200. However, the electrical reference node of the filter 200 is not necessarily formed on the substrate 201, but may be provided on one side of the high frequency power device 110 in which the substrate 201 is installed.

According to another embodiment of the present invention, the connection line 209 connects the via hole provided at the other end 203-3 of the inductor 203 and the via hole provided at one side of the terminal unit 205 to form a substrate ( 201) may be provided on the bottom surface.

2 is an electric circuit diagram showing an equivalent filter 200 shown in FIG. 2, and it can be seen that one inductor 203 and a capacitor 207 are connected in parallel. According to the circuit diagram, one end 203-1 of the inductor 203 is shown as an input terminal and the terminal unit 205 is shown as an output terminal. In contrast, the terminal unit 205 becomes an input terminal and one end of the inductor 203 ( 203-1) may be an output terminal.

In addition to the general synthetic resin, the substrate 201 may use a ceramic material or a metal material having excellent heat dissipation characteristics. The substrate 201 of FIGS. 2 to 5 shows a substrate of ceramic material. However, when the substrate 201 is an electrically conductive metal or other electrically conductive material, an insulating layer for electrical insulation must be provided between the substrate 201, the inductor 203, the terminal portion 205, and the ground layer 211. .

For example, the insulating layer (not shown) may use the ceramic coating layer or the method of forming the ceramic layer described in another patent application No. 10-2008-0114777 of the applicant. According to this, the insulating layer (not shown) forms a coating film selected from silicon oxide (SiO 2), aluminum oxide (Al 2 O 3), aluminum nitride (AlN), and silicon nitride (Si 3 N 4) by physical vapor deposition (PVD). can do. In addition, when the substrate 201 is made of aluminum (Al) or magnesium (Mg), the insulating layer (not shown) may be coated with a film treatment method such as plasma electrolytic oxidation (PEO), which oxidizes the outer surface of the substrate 201. It may be formed by. Alternatively, the insulating layer (not shown) is an insulating material represented by silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium dioxide (ZrO ₂ ), inorganic pigments (RO) of 10nm to 10㎛ size The ceramic powder, which is a powder of), may be formed by coating and firing by the method of screen printing, jet spraying or electrostatic coating.

The inductor 203, the terminal portion 205, and the ground layer 211 are conductive metal layers 301 and 305 formed of a thick film by a magnetron sputtering method for physical vapor deposition, and may be formed by the same deposition process and etching process. . Since it is directly deposited on the substrate 201 having excellent heat dissipation properties without any other adhesive material, the heat generated from the inductor 203 or the like during the filtering process is effectively transferred to the substrate 201 to dissipate heat, so that the inductor 203 is peeled off. No problems shall arise.

The material of the metal layers 301 and 305 may be a conductive metal, and copper (Cu) is generally used.

The thickness of the entire metal layers 301 and 305 may be generally determined as the thickness of the metal layer 301 forming the inductor 203 due to process reasons or the like. The thickness of the metal layer 301 forming the inductor 203 is considered by the electric resistance value of the inductor 203, the Q index affected by the resistance value, the strength of the current flowing through the inductor 203, the desired inductance strength, and the like. However, in the case of a high frequency power device, it may be a thick film having a thickness of about 100 μm or more in a width of several millimeters. In other words, since the metal layer 301 is deposited as a thick film, it is possible to significantly reduce the electrical resistance value of the inductor 203 itself, which prevents the problem of lowering the Q index of the planar spiral inductor, thereby reducing the inductor 203. Reduce losses and improve filter characteristics

The conductive metal layers 301 and 305 formed of the thick film may use a magnetron sputtering method for high speed / high density deposition, which is disclosed in the applicant's other patents 10-0870971. According to this, the metal layers 301 and 305 may be formed by alternately repeatedly depositing the first thin film and the second thin film having a thickness of 1 nanometer to 10 micrometer as shown in FIG. 4 according to the residual stress. 4 shows that the first thin film 401 is deposited first on the substrate 201, the second thin film 403 may be deposited before the first thin film 401.

The first thin film 401 is a film having a characteristic of tensile residual stress, and is formed by sputtering by a direct current pulse or alternating plasma generated by supplying a direct current pulse or alternating current to a magnetron sputter deposition source. The second thin film 403 is a film having a characteristic of compressive residual stress, and is formed by sputtering by DC plasma generated by supplying DC power to a sputter deposition source.

When the metal layers 301 and 305 are formed of copper (Cu), alternately repeatedly deposited first to prevent oxidation of the surface and to improve adhesion to the connection lead 209 or the capacitor 207 to be soldered. Antioxidation films 303 and 307 may be formed on the top surfaces of the thin film 401 and the second thin film 403. The anti-oxidation films 303 and 307 may be made of a metal material that prevents the oxidation of copper and improves the adhesion of the soldering solder. For example, gold (Au) may be formed by plating or sputtering. .

As described above, since the inductor 203 and the terminal portion 205 formed of the thick metal layer 301 are physically vapor deposited on the substrate 201 by sputtering, the adhesion to the substrate 201 is excellent and the inductor 203 is excellent. The heat generated at) may be easily released through the substrate 201.

Hereinafter, the manufacturing method of the filter 200 of the present invention will be described with reference to FIG. Referring to FIG. 5A, metal layers 301 and 305 of copper (Cu) are deposited on both surfaces of the substrate 201 as a thick film. As described above, the metal layers 301 and 305 may be formed by alternately repeatedly depositing the first thin film 401 having tensile residual stress and the second thin film 403 having compressive residual stress. As described above, the metal layers 301 and 305 deposited on both sides of the substrate 201 may use the magnetron sputtering apparatus for thick film deposition, which is disclosed in Patent Application No. 10-2009-0035878, in addition to the Applicant Patent No. 10-0870971. Can be. This sputtering apparatus revolves and rotates the substrate 201 mounted on the substrate fixing part in the sputtering chamber. The first thin film 401 and the second thin film 403 are sequentially deposited while the substrate 201 in opposition sequentially faces the deposition source for forming the first thin film 401 and the second thin film 403. Is formed, and at the same time, the rotation of the substrate 201 can form the metal layers 301 and 305 on both surfaces thereof.

When the deposition of the metal layers 301 and 305 is performed, an inductor may be formed on the metal layer 301 deposited on the upper surface of the substrate 201 through a lithography and etching process as shown in FIG. 5B. 203 and the terminal portion 205 are formed.

When the inductor 203, the terminal portion 205, and the ground layer 211 are provided by FIGS. 5A and 5B, the filter 200 may be soldered by soldering the capacitor 207 and the connection lead 209 in a subsequent process. ) Is completed.

The manufacturing method of the filter 200 according to the example of FIG. 2 has been described above with reference to FIG. 5. As described above, the filter 200 of the present invention is not limited to the electrical circuit diagram of FIG. 2 and may be provided in various ways.

For example, a plurality of filters having different filtering frequency bands may be formed on the substrate. Here, each filter may be presented in series cascaded to provide a multi-stage filtering process for the high frequency power signal input from the amplifying stage to finally output a power signal of a desired high frequency band.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

1 is a block diagram showing a power supply system using a conventional high frequency power device;

2 is a perspective view of a filter for a high frequency power device according to an embodiment of the present invention;

3 is a cross-sectional view taken along the line A-A of FIG.

4 is a cross-sectional view showing a detailed configuration of the metal layer of FIG.

FIG. 5 is a manufacturing process diagram provided to explain a method for manufacturing a filter for a high frequency power device of FIG. 2.

Description of the Related Art

201: substrate 203: inductor

203-1: One end of the inductor 205: Terminal part

207: capacitor 209: connecting lead

211: ground layer 301, 305: metal layer

303, 307: antioxidant film

Claims (8)

In the high frequency power unit filter provided in the high frequency power unit to remove the harmonic components except the source frequency of the high frequency signal, Board; A conductive metal layer physically vapor-deposited with a thick film of 100 μm or more on an upper surface of the substrate, the inductor having a planar spiral shape providing a predetermined inductance; And A ground layer serving as an electrical reference node as the metal layer formed on a lower surface of the substrate, The metal layer is formed of copper and a plurality of first thin films having a tensile residual stress and a plurality of second thin films formed of copper and having a compressive residual stress are alternately repeatedly deposited to form the thick film, and alternately repeating A filter for a high frequency power device, characterized in that it further comprises an antioxidant film formed on the uppermost surfaces of the deposited first thin film and the second thin film to prevent oxidation of copper. The method of claim 1, A terminal unit which is the metal layer formed to be spaced apart from the inductor; A capacitor provided between one end of the inductor and the terminal portion; And And a connection lead which is a conductive metal connecting between the other end of the inductor and the terminal portion. delete delete A signal generator for generating a high frequency signal including a high frequency oscillator, a signal amplifier for amplifying the high frequency signal generated by the signal generator to a desired power level, and a source frequency of the high frequency included in the signal amplified by the signal amplifier It includes a filter unit for extracting the components, The filter unit, Board; A conductive metal layer physically vapor-deposited with a thick film of 100 μm or more on an upper surface of the substrate, the inductor having a planar spiral shape providing a predetermined inductance; And A ground layer serving as an electrical reference node as the metal layer formed on a lower surface of the substrate, The metal layer is formed of copper and a plurality of first thin films having a tensile residual stress and a plurality of second thin films formed of copper and having a compressive residual stress are alternately repeatedly deposited to form the thick film, and alternately repeating A filter for a high frequency power device, characterized in that it further comprises an antioxidant film formed on the uppermost surfaces of the deposited first thin film and the second thin film to prevent oxidation of copper. The method of claim 5, The filter unit, A terminal unit which is the metal layer formed to be spaced apart from the inductor; A capacitor provided between one end of the inductor and the terminal portion; And And a connection lead which is a conductive metal connecting between the other end of the inductor and the terminal portion. delete delete

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