JP2009272273A - Microwave processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for heating various objects to be heated at high efficiency by suitably arranging a plurality of power feed ports on a wall surface of a heating chamber and by optimizing frequency and phase differences of microwaves emitted from of respective power feed ports. <P>SOLUTION: The microwave processing apparatus includes oscillating sections 1a, 1c, power distribution sections 2a, 2c, amplification sections 4a-4d, a heating chamber 8 for housing the objects to be heated 9, power feed ports 5a-5d arranged on the wall surface of the heating chamber 8 and emitting microwaves, and phase variable sections 3a-3d inserted into a microwave propagation path. Reflective power from various objects to be heated is restrained to the minimum in order to achieve highly efficient heating by suitably controlling the phase differences and oscillating frequency of the microwaves emitted from the power feed ports 5a-5d. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a microwave processing apparatus including a microwave generation unit configured using a semiconductor element.

  This type of conventional microwave processing apparatus includes a semiconductor oscillation unit, a distribution unit that divides the output of the oscillation unit into a plurality of units, a plurality of amplification units that amplify the distributed outputs, and a recombination of the outputs of the amplification units. And a phase shifter between the distribution unit and the amplification unit (for example, Patent Document 1).

  The phase shifter is configured to switch the microwave pass line length according to the on / off characteristics of the diode. In addition, the synthesis unit can use two 90 degree and 180 degree hybrids, so that the output of the synthesis unit can be made two. By controlling the phase shifter, the power ratio of the two outputs can be changed, or the phase between the two outputs can be changed. Can be in phase or out of phase.

In addition, there is a conventional technique for detecting reflected power returning to the microwave generation unit from a heating chamber containing an object to be heated, and tracking an oscillation frequency at which the reflected power is minimized based on the reflected power signal ( Patent Document 2).
JP 56-132793 A JP-A-56-96486

  However, the microwaves radiated from the two outputs of the combining unit in the conventional configuration change the radiated power ratio and phase difference from the two radiating antennas arbitrarily and instantaneously by changing the phase by the phase shifter. However, it has been difficult to efficiently heat objects to be heated in various shapes, types, and quantities stored in a heating chamber to which microwaves are supplied by the radiation. In addition, when microwaves are supplied from a plurality of antennas, there is a problem that the reflected power varies due to the phase difference and the phase varies depending on the oscillation frequency.

  The present invention solves the above-described conventional problems, and optimally arranges a plurality of power feeding units having a function of radiating microwaves on the wall surface of the heating chamber, and shifts the phase of the microwaves to be supplied to each of them. A micro that corrects the reflected power to minimize the reflected power, improves detection accuracy, improves the reproducibility of detection results, and efficiently heats objects to be heated in various shapes, types, and quantities An object is to provide a wave generation processing apparatus.

In order to solve the above-described conventional problems, a microwave processing apparatus of the present invention includes a heating chamber that accommodates an object to be heated, an oscillation unit, and a power distribution unit that distributes and outputs the output of the oscillation unit to a plurality of units. A phase variable unit that varies at least one output phase of the power distribution unit, an amplification unit that amplifies the output of each of the power distribution unit and / or the phase variable unit, and an output of the amplification unit to the heating chamber A power supply unit to supply; a power detection unit that detects microwave power reflected from the respective power supply units in the direction of the amplification unit; and a control unit that controls an oscillation frequency of the oscillation unit and a phase amount of the phase variable unit; The control unit is a preliminary detection that detects a frequency at which microwave power reflected from the power supply unit in the direction of the amplification unit is minimized before the object to be heated is heat-treated in the heating chamber. Action And configured to perform the preliminary detection operation after controlling the phase variable unit to substantially match the phase difference of the microwaves supplied from the respective power supply units, and a plurality of power supply units. By controlling the phase difference and frequency of the microwave radiated from the chamber so that the reflected power is minimized, the microwave radiated into the heating chamber can be effectively absorbed by the heated object, and various shapes, types, and quantities Can be heated with high efficiency.

  The microwave processing apparatus of the present invention optimally arranges a plurality of power feeding units having a function of radiating microwaves on the wall surface of the heating chamber and optimizes the phase difference and frequency of the microwaves radiated from each power feeding unit. Therefore, it is possible to provide a microwave processing apparatus that heats an object to be heated of various shapes, types, and amounts with high efficiency.

  A first invention includes a heating chamber that accommodates an object to be heated, an oscillation unit, a power distribution unit that distributes and outputs the output of the oscillation unit, and a phase that varies at least one output phase of the power distribution unit A variable unit, an amplifying unit that amplifies the output of each of the power distribution unit and / or the phase variable unit, a power supply unit that supplies the output of the amplifying unit to the heating chamber, and a micro that reflects from each power supply unit toward the amplification unit A power detection unit that detects wave power, and a control unit that controls the oscillation frequency of the oscillation unit and the phase amount of the phase variable unit, and the control unit is a stage before heat-treating the object to be heated contained in the heating chamber. The preliminary detection operation is performed to detect the frequency at which the microwave power reflected from the power feeding unit in the direction of the amplification unit is minimized, and the phase variable unit is controlled so that the phase difference of the microwaves supplied from the respective power feeding units is determined. After roughly matching, reserve The pre-detection operation is performed by matching the phase differences of the microwaves radiated from the plurality of power supply units, thereby improving the reproducibility of the detection results and radiating from the plurality of power supply units. The microwave phase difference and frequency can be controlled reliably, and the microwaves radiated to the heating chamber can be efficiently absorbed by the object to be heated, so that objects to be heated of various shapes, types, and quantities can be obtained. It can be heated with high efficiency.

  In particular, the second invention is configured to select the center frequency of the oscillation frequency band of the oscillation unit as a frequency that substantially matches the phase difference of the microwaves supplied from the respective power supply units of the first invention. Yes, by performing the preliminary detection operation by matching the phase difference of the microwaves radiated from a plurality of power supply units at the center of the frequency band to be used, the reproducibility of the detection result is improved, and the microwaves radiated from the plurality of power supply units The phase difference and frequency of waves can be controlled reliably, and the microwaves radiated into the heating chamber are efficiently absorbed by the object to be heated. Can be heated.

  According to the third aspect of the invention, in particular, in the preliminary detection operation for detecting the frequency at which the microwave power reflected from the power feeding unit of the first aspect of the invention in the direction of the amplification unit is minimized, according to the frequency of the output microwave of the oscillation unit, It is configured to correct and control the phase amount of the phase variable unit, and the microwaves radiated from a plurality of power supply units are corrected by correcting the phase difference of the microwaves radiated from the plurality of power supply units to be shifted depending on the propagating frequency. Preliminary detection operation under the correct conditions to keep the phase difference of the same and keep constant, improve the detection accuracy and enhance the reproducibility to efficiently absorb the microwave radiated into the heating chamber to the heated object It is possible to heat objects to be heated in various shapes, types and amounts with high efficiency.

According to a fourth aspect of the present invention, there is provided a heating chamber that accommodates an object to be heated, an oscillation unit, a power distribution unit that distributes and outputs the output of the oscillation unit, and a phase that varies at least one output phase of the power distribution unit A variable unit, an amplifying unit that amplifies the output of each of the power distribution unit and / or the phase variable unit, a power supply unit that supplies the output of the amplifying unit to the heating chamber, and a micro that reflects from each power supply unit toward the amplification unit A power detection unit that detects wave power, and a control unit that controls the oscillation frequency of the oscillation unit and the phase amount of the phase variable unit, and the control unit is a stage before heat-treating the object to be heated contained in the heating chamber. The preliminary detection operation is performed to detect the frequency at which the microwave power reflected from the power supply unit in the direction of the amplification unit is minimum. In the preliminary detection operation, the phase of the microwave to be supplied at each power supply unit input position is approximately Matched detection This is the first configuration, and based on the detection operation results that match the phase difference of microwaves radiated from multiple power feeding units at the position closest to the heating chamber radiation with the same microwave propagation conditions Reproducibility is improved, and the phase difference and frequency of microwaves radiated from multiple power supply units can be reliably controlled, and the microwaves radiated into the heating chamber are efficiently heated. It can be absorbed by objects, and heated objects of various shapes, types, and quantities can be heated with high efficiency.

  According to the fifth aspect of the invention, in particular, in the preliminary detection operation for detecting the frequency at which the microwave power reflected in the direction of the amplification unit from the power feeding unit of the fourth invention is minimized, according to the frequency of the output microwave of the oscillation unit, The phase amount of the phase variable section is corrected and controlled so that the phase difference at each power feed section input position is kept constant. The frequency at which the phase difference of the microwaves radiated from a plurality of power feed sections propagates The microwaves radiated to the heating chamber are realized by correcting the deviation due to the detection conditions, realizing the detection operation under the correct conditions to keep the phase difference at multiple power feeding unit input positions constant, improving the detection accuracy, and improving the reproducibility. Can be efficiently absorbed by the object to be heated, and the object to be heated of various shapes, types and amounts can be heated with high efficiency.

  In a sixth aspect of the invention, in particular, one of the microwave supply paths to the heating chamber of the fourth or fifth aspect of the invention is used as a reference path, and the control unit has a phase difference with a relative value with respect to the reference path. The control of the phase difference control of microwaves radiated from a plurality of power feeding parts is clarified, the detection accuracy and reproducibility can be improved, and the microwaves radiated to the heating chamber can be controlled. The object to be heated can be efficiently absorbed, and the object to be heated of various shapes, types, and amounts can be heated with high efficiency.

  According to a seventh aspect of the invention, in particular, the control unit according to any one of the fourth to sixth aspects includes means for detecting and storing a relative phase difference with respect to a reference path of a microwave supply path to a plurality of heating chambers. It is possible to acquire and save information to correct the unique microwave supply path variation in each microwave processing device, and to clarify the reference for the phase difference control of microwaves radiated from multiple power supply units. Therefore, the detection accuracy and reproducibility can be improved, the microwave radiated to the heating chamber can be efficiently absorbed by the heated object, and the heated object with various shapes, types, and quantities is highly efficient. Can be heated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a configuration diagram of a microwave processing apparatus according to the first embodiment of the present invention.

  In FIG. 1, the microwave generation unit includes oscillation units 1 a and 1 c configured using semiconductor elements, power distribution units 2 a and 2 c that distribute the outputs of the oscillation units 1 a and 1 c, and outputs of the power distribution units 2 a and 2 c. Amplifying units 4a to 4d configured using semiconductor elements to be amplified, power feeding units 5a to 5d for radiating microwave output amplified by the amplifying units 4a to 4d into a heating chamber 8 to be described later, and power distribution units 2a and 2c And phase variable units 3a to 3d that are inserted into a microwave propagation path connecting the amplifiers 4a to 4d and generate an arbitrary phase difference between input and output, and microwave propagation that connects the amplifiers 4a to 4d and the power feeding units 5a to 5d The power detectors 6a to 6d that detect the microwave reflected power that is inserted into the path and reflects from the power feeding units 5a to 5d in the direction of the amplifiers 4a to 4d, and the reflected power that is detected by the power detectors 6a to 6d It is constituted by a control unit 7 for controlling the phase of the oscillation frequency and the phase variable parts 3a~3d of the oscillator 1a, 1c in accordance with the.

  Further, the microwave processing apparatus of the present invention has a heating chamber 8 having a substantially rectangular parallelepiped structure for storing an object to be heated, and the heating chamber 8 is opened and closed to store a wall surface made of a metal material and the object to be heated 9. The microwave to be supplied is confined inside by an opening / closing door (not shown) and a mounting table on which the object to be heated 9 is mounted. The microwave outputs generated by the oscillating units 1 a and 1 c are propagated, and power feeding units 5 a to 5 d that radiate and supply the heating chamber 8 are arranged on the wall surface that constitutes the heating chamber 8. In the present embodiment, a configuration is shown in which the power feeding units 5a to 5d are arranged at substantially the center of each wall surface. The arrangement of the power supply unit is not limited to the present embodiment, and a plurality of power supply units may be provided on any wall surface, and power is supplied to adjacent surfaces such as the right wall surface and the bottom wall surface that are not opposed surfaces. The part may be configured.

  The amplifying units 4a to 4d constitute a circuit with a conductor pattern formed on one surface of a dielectric substrate made of a low dielectric loss material, and each semiconductor is operated in order to operate a semiconductor element that is an amplifying element of each amplifying unit satisfactorily. Matching circuits are arranged on the input side and output side of the element, respectively. The power distribution units 2a and 2c may be in-phase distributors that do not cause a phase difference between outputs such as a Wilkinson distributor, or may have a phase difference between outputs such as a branch line type or a rat race type. It may be the resulting distributor. The power distribution units 2a and 2c propagate approximately half of the microwave power input from the oscillation units 1a and 1c to the respective outputs.

  The phase variable units 3a to 3d are configured using a variable capacitance element whose capacitance changes according to the applied voltage, and each phase variable range is a range from 0 degrees to about 180 degrees. As a result, the phase difference of the microwave power output from the phase variable units 3a to 3d can be controlled in the range of 0 degree to ± 180 degrees. The power detection units 6a to 6d extract the power of so-called reflected waves of microwaves reflected in the direction of the amplification units 4a to 4d from the power supply units 5a to 5d. The power coupling degree is, for example, about 40 dB, and the reflected power is about Extract the electric energy of 1/10000. The power signals are rectified by a detection diode (not shown), smoothed by a capacitor (not shown), and the output signal is input to the control unit 7.

  Based on the heating condition of the object to be heated directly input by the user or the heating information obtained from the heating state of the object to be heated during heating and the detection information from the power detectors 6a to 6d, the control unit 7 The driving power supplied to each of the oscillators 1a and 1c and the amplifiers 4a to 4d, which are constituent elements of the generator, and the voltage supplied to the phase variable parts 3a to 3d are controlled and stored in the heating chamber 8. The object 9 is heated optimally.

  About the microwave processing apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the object to be heated 9 is stored in the heating chamber 8, the heating condition is input from an operation unit (not shown), and the heating start key is pressed. In response to the control output signal of the control unit 7 that has received the heating start signal, the microwave generation unit starts its operation. The control means 7 operates a drive power supply (not shown) to supply power to the oscillation units 1a and 1c.

  At this time, the initial oscillation frequency of the oscillation units 1a and 1c is supplied with a voltage signal set to 2400 MHz, for example, and oscillation starts. When the oscillating units 1a and 1c are operated, their outputs are distributed approximately ½ each by the power distributing units 2a and 2c, resulting in four microwave power signals. Thereafter, the drive power supply is controlled to operate the amplification units 4a to 4d. The microwave power signals are output to the power feeding units 5 a to 5 d through the amplification units 4 a to 4 d and the power detection units 6 a to 6 d that operate in parallel, and are radiated into the heating chamber 8.

When 100% of the microwave power supplied into the heating chamber 8 is absorbed by the object to be heated, the reflected power from the heating chamber 8 becomes 0 W. Depending on the type, shape, and amount of the object to be heated, Impedance changes, and microwave reflected power propagating in the direction from the power supply units 5a to 5d to the amplification units 4a to 4d is generated due to misalignment with the microwave power supply side. The power detectors 6 a to 6 d detect the microwave reflected power and send a detection signal proportional to the reflected power amount to the control unit 7.

  The control unit 7 controls the oscillation units 1a and 1c and the phase variable units 3a to 3d and detects them by the power detectors 6a to 6d before the heat treatment of the object 9 accommodated in the heating chamber 8. Preliminary detection operation is performed to determine the oscillation frequency and phase difference for minimizing the reflected power and to determine the heat treatment conditions. In the preliminary detection operation, the control unit 7 matches the phase differences of the microwaves radiated from the plurality of power supply units, and the oscillation frequency of the oscillation units 1a and 1c is increased from 2400 MHz to 1 MHz, for example, to 2500 MHz which is the upper limit of the frequency variable range. By operating the power detectors 6a to 6d at the same time, the power detectors 6a to 6d detect the microwave power reflected from the power supply units 5a to 5d in the direction of the amplifiers 4a to 4d, thereby obtaining oscillation frequency information that minimizes the reflected power. be able to.

  However, since the electrical line length from the oscillation units 1a and 1c to the input portions of the power feeding units 5a to 5d varies due to the length of the propagation line and the variation of components connected on the way, the phase variable units 3a to 3d Even if the control is adjusted to 0 degree, the phase shifts at the input positions of the power feeding units 5a to 5d. For this reason, the control of the phase variable sections 3a to 3d is controlled so that the phase difference is the same at the input portions of the power feeding sections 5a to 5d that have the same microwave propagation conditions and are closest to the heating chamber radiation. Correct the variation. Since the variation in the electrical line length varies depending on the frequency, if the correction value is determined at the center frequency of the oscillation frequency band to be used, for example, 2450 MHz, the deviation width is reduced with respect to the frequency variation. Furthermore, if the phase amount of the phase variable units 3a to 3d is corrected and controlled according to the oscillation frequencies of the oscillation units 1a and 1c, detection operation under more correct conditions can be realized, detection accuracy can be improved, and reproducibility can be improved. It is done.

  The control unit 7 first obtains oscillation frequency information that minimizes the reflected power under the condition in which the phase differences of the microwaves radiated from the plurality of power supply units are matched, and the phase difference is varied based on this condition. Continue the preliminary detection operation under conditions. In order to set a predetermined phase difference between the microwaves radiated from a plurality of power supply units, a path from the plurality of microwave supply paths to the heating chamber to the power supply unit 5a, for example, is used as a reference path, and the input of the power supply unit 5a The relative phase difference of the input part of the power feeding units 5b to 5d with respect to the part is controlled. By the relative control with the reference path, the supply conditions of the microwaves radiated from the power supply units 5a to 5d can be clarified, and the detection accuracy and reproducibility can be improved. Further, similarly to the detection operation in which the phase differences of the radiating microwaves are made to coincide with each other, the phase amounts of the phase variable units 3a to 3d are corrected and controlled in accordance with the oscillation frequencies of the oscillation units 1a and 1c. It is possible to correct that the phase difference of the microwaves radiated from the power feeding units 5a to 5d is shifted depending on the propagating frequency, realize the detection operation under the correct conditions, improve the detection accuracy, and improve the reproducibility.

  By repeatedly performing the above operations, the control unit 7 obtains information on the reflected power with respect to the oscillation frequencies of the oscillation units 1a and 1c and the phase differences of the phase variable units 3a to 3d in which the phase difference setting position and the relative control target are clarified. Thus, the preliminary detection operation can be completed.

  The control unit 7 controls the oscillation units 1a and 1c and the phase variable units 3a to 3d under the conditions of the oscillation frequency and the phase difference at which the reflected power is minimized so that an output corresponding to the input heating condition can be obtained. To control the oscillation output. Microwaves having an oscillation frequency according to the control of the control unit 7 are converted into electric power according to the control in the amplification units 4a to 4d, supplied to the input units of the power supply units 5a to 5d with a control-designated phase difference, and further heated. Radiated into the chamber 8.

By operating in this way, the detection operation can be performed accurately even for heated objects of various shapes, sizes, and quantities, the reproducibility of the detection results is improved, and the reflected power is minimized. High-efficiency heating can be started under the conditions, and it is possible to prevent the semiconductor elements provided in the amplifying units 4a to 4d from excessively generating heat due to reflected power, and to avoid thermal destruction.

  Next, how to deal with variations in the electrical line length of each microwave processing apparatus will be described.

  In order to cope with the variation of each microwave processing apparatus, it is necessary to have a unique correction value for correcting each phase difference control for each apparatus. In addition, it is necessary to update this unique correction value when a part is replaced due to a failure or the like. Such a correction value is detected and stored for each microwave processing apparatus. The inherent correction value detected for each microwave processing apparatus is measured under a reproducible load condition, for example, without an object to be heated. For detection, for example, a microwave of 2400 MHz is radiated to the heating chamber 8 from the power supply unit 5a of the reference path and the power supply unit 5b that obtains the inherent correction value, and the phase difference that minimizes the reflected power of the power detection unit 6a is obtained. A deviation from the design value of the condition becomes a specific correction value of each microwave processing apparatus.

  Similarly, if the frequency is changed to detect up to 2500 MHz which is the upper limit of the frequency variable range, and the same detection is performed on the power feeding units 5c and 5d, the unique correction values are obtained.

  By storing this unique correction value and correctly correcting the phase difference control standards for microwaves radiated from multiple power supply units, detection accuracy and reproducibility can be improved, and microwaves radiated into the heating chamber can be efficiently used. Therefore, the object to be heated can be absorbed efficiently, and the object to be heated of various shapes, types and amounts can be heated with high efficiency.

  As described above, the microwave processing apparatus according to the present invention can optimize the phase difference and the frequency of the microwaves radiated from each of the power supply units while optimally arranging the plurality of power supply units on the wall surface of the heating chamber. Therefore, the present invention can also be applied to uses such as a heating device using a dielectric heating as typified by a microwave oven, a garbage processing machine, or a microwave power source of a plasma power source as a semiconductor manufacturing device.

Configuration diagram of microwave processing apparatus according to Embodiment 1 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1c Oscillation part 2a, 2c Power distribution part 3a-3d Phase variable part 4a-4d Amplification part 5a-5d Power supply part 6a-6d Power detection part 7 Control part 8 Heating chamber 9 Heated object

Claims (7)

A heating chamber that accommodates an object to be heated; an oscillation unit; a power distribution unit that distributes and outputs the output of the oscillation unit; and a phase variable unit that varies at least one output phase of the power distribution unit; An amplifying unit that amplifies the output of each of the power distribution unit and / or the phase variable unit, a feeding unit that supplies the output of the amplifying unit to the heating chamber, and a reflection from the respective feeding unit toward the amplifying unit A power detection unit for detecting microwave power; and a control unit for controlling the oscillation frequency of the oscillation unit and the phase amount of the phase variable unit;
The controller performs a pre-detection operation for detecting a frequency at which the microwave power reflected from the power supply unit toward the amplification unit is minimized before the object to be heated housed in the heating chamber is heat-treated. A microwave processing apparatus configured to perform the preliminary detection operation after controlling the phase variable unit to substantially match the phase difference of the microwaves supplied from the respective power feeding units. The microwave processing apparatus according to claim 1, wherein a center frequency of an oscillation frequency band of the oscillation unit is selected as a frequency that substantially matches a phase difference of the microwaves supplied from the respective power supply units. In the preliminary detection operation for detecting the frequency at which the microwave power reflected from the power supply unit in the direction of the amplification unit is minimized, the phase amount of the phase variable unit is corrected and controlled according to the frequency of the output microwave of the oscillation unit. The microwave processing apparatus according to claim 1 to be performed. A heating chamber that accommodates an object to be heated; an oscillation unit; a power distribution unit that distributes and outputs the output of the oscillation unit; and a phase variable unit that varies at least one output phase of the power distribution unit; An amplifying unit that amplifies the output of each of the power distribution unit and / or the phase variable unit, a feeding unit that supplies the output of the amplifying unit to the heating chamber, and a reflection from the respective feeding unit toward the amplifying unit A power detection unit for detecting microwave power; and a control unit for controlling the oscillation frequency of the oscillation unit and the phase amount of the phase variable unit;
The controller performs a pre-detection operation for detecting a frequency at which the microwave power reflected from the power supply unit toward the amplification unit is minimized before the object to be heated housed in the heating chamber is heat-treated. A microwave processing apparatus configured as described above, wherein in the preliminary detection operation, detection is performed first by substantially matching the phases of microwaves supplied at the input positions of the power feeding units. In the preliminary detection operation for detecting the frequency at which the microwave power reflected from the power supply unit in the direction of the amplification unit is minimized, the phase amount of the phase variable unit is corrected and controlled according to the frequency of the output microwave of the oscillation unit. The microwave processing apparatus according to claim 4, wherein the phase difference at each of the power feeding unit input positions is kept constant. 6. The configuration according to claim 4, wherein one of the microwave supply paths to the heating chamber having a plurality is used as a reference path, and the control unit controls the phase difference with a relative value with respect to the reference path. Microwave processing device. The said control part has a structure which detects and memorize | stores the relative phase difference with respect to the said reference | standard path | route of the microwave supply path | route to the said heating chamber which has multiple, The structure of any one of Claim 4 to 6 characterized by the above-mentioned. Microwave processing equipment.

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