Current detection printed board, voltage detection printed board, and current/voltage detector using same, and current detector and voltage detector

A current detection printed board includes: a board having a penetration hole that penetrates the board; and at least one wire that is formed in a coiled shape having both ends by penetrating the board along the periphery of the penetration hole and alternately connecting a front surface layer and a rear surface layer of the board, wherein, when a conductor, in which an AC current flows, is disposed to pass through the inside of the penetration hole, a current flowing in the wire is output through electromagnetic induction.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to a current detection printed board that is used to detect an alternating current flowing in a power transmission conductor used as voltage detection printed board that is used to detect an an alternating current (AC) power transmission path, to a AC voltage to be generated in the power transmission conductor, to a current/voltage detector using the same, and to a current detector and a voltage detector. In particular, the invention relates to a technology that uses high-frequency power as AC power.

2. Description of the Related Art

Like an impedance matching device or a high-frequency power supply device, there is known a device that detects AC power current and voltage and performs a control using the detected current and voltage. As an example, an impedance matching device will now be described.

FIG. 26is a block diagram of an example of a high-frequency power supply system that uses an impedance matching device.

The high-frequency power supply system is a system that performs a processing, such as plasma etching or plasma CVD, on a workpiece, such as a semiconductor wafer or a liquid crystal substrate. The high-frequency power supply system includes a high-frequency power supply device61, a transmission line62, an impedance matching device63, a load connection portion64, and a load65(plasma processing device65).

The high-frequency power supply device61is a device that outputs high-frequency power to the plasma processing device65as a load. Moreover, high-frequency power output from the high-frequency power supply device61is supplied to the plasma processing device65through the transmission line62having a coaxial cable, the impedance matching device63, and the load connection portion64having a shielded copper plate. In general, the high-frequency power supply device61outputs high-frequency power having a frequency of a radio frequency band (for example, a frequency of hundreds kHz or more).

The plasma processing device65is a device that performs a processing (etching or CVD) on a wafer or a liquid crystal substrate.

The impedance matching device63includes a matching circuit that has a variable impedance element (for example, a variable capacitor, a variable inductor, or the like) (not shown) therein. The impedance matching device63has a control function of changing impedance of the variable impedance element in the matching circuit to accomplish impedance matching between the high-frequency power supply device61and the load65.

In order to perform the above-described control, a current detector and a voltage detector are provided between an input terminal63aof the impedance matching device63and the matching circuit. The current detector and the voltage detector detect high-frequency current and high-frequency voltage output from the high-frequency power supply device61. Information of forward wave power or reflected wave power is obtained using the current and voltage detected by the detectors. Then, impedance of the variable impedance element is controlled using the obtained information to accomplish impedance matching.

FIG. 27is a schematic circuit diagram of a current detector80and a voltage detector90provided between the input terminal and a matching circuit67of the impedance matching device63. As shown inFIG. 27, a power transmission conductor66(for example, rod-shaped copper) serving as a power transmission path is provided between the input terminal63aand the matching circuit67. Then, the current detector80and the voltage detector90are provided on the power transmission conductor66.

The current detector80has a current transformer81, output wires82and83of the current transformer81, a current conversion circuit84, and an output wire85of the current conversion circuit84. In the current detector80, a current according to an AC current that flows in the power transmission conductor66flows in the current transformer81. This current is input to the current conversion circuit84through the output wires82and83and is converted into a predetermined voltage level. Then, the converted voltage is output from the output wire85of the current conversion circuit84.

The voltage detector90has a capacitor91, an output wire92of the capacitor91, a voltage conversion circuit93, and an output wire94of the voltage conversion circuit93. In the voltage detector90, a voltage according to an AC voltage generated in the power transmission conductor66is generated in the capacitor91. This voltage is input to the voltage conversion circuit93through the output wire92and is converted into a predetermined voltage level. Then, the converted voltage is output from the output wire94of the voltage conversion circuit93.

Subsequently, as described above, the information of forward wave power or reflected wave power is obtained using the current and voltage detected by the current detector80and the voltage detector90. The current detector80and the voltage detector90have a structure shown inFIGS. 28 and 29.

FIG. 28is a schematic exterior view of the current detector80and the voltage detector90.

FIGS. 29A to 29Care explanatory views illustrating the configuration of the current detector80and the voltage detector90shown inFIG. 28. Specifically,FIG. 29Ais a diagram showing the interior of a casing (indicated by a dotted line) ofFIG. 28in perspective view.FIG. 29Bis a diagram showing the vicinity of the current transformer81as viewed from the transverse side ofFIG. 29A.FIG. 29Cis a diagram showing the vicinity of the capacitor91as viewed from the transverse side ofFIG. 29A.

InFIGS. 28 and 29Ato29C, the power transmission conductor66and an insulator69covering the power transmission conductor66, not included in the current detector80and the voltage detector90, are shown for explanation. Further, inFIGS. 28 and 29Ato29C, for convenience, the same parts as those inFIG. 27are represented by the same reference numerals.

Hereinafter, the current detector80and the voltage detector90will be described with reference toFIGS. 28 and 29Ato29C.

InFIGS. 28 and 29Ato29C, the power transmission conductor66is, for example, a cylindrical copper rod. The periphery of the power transmission conductor66is covered with a hollow insulator69. Then, the power transmission conductor66and the insulator69pass through a casing71. Further, the current transformer81constituting the current detector80and the capacitor91constituting the voltage detector90are accommodated in the casing71.

In the current transformer81, a coated copper wire or the like is wound around a ring-shaped magnetic core (for example, a toroidal core or a ferrite core) to form a coiled wire. Then, the current transformer81is disposed such that the power transmission conductor66passes through the magnetic core. Accordingly, a current according to a current flowing in the power transmission conductor66flows in the coiled wire of the current transformer81.

The current flowing in the current transformer81is input to the current conversion circuit84through the output wires82and83that are connected to both ends of the coiled wire. Then, the current conversion circuit84converts the input current into a predetermined voltage level and outputs the converted voltage.

The capacitor91is formed by providing a ring-shaped conductor91b(for example, a copper ring) in the vicinity of the insulator69. The ring-shaped conductor91band a portion91afacing the power transmission conductor66function as electrodes of the capacitor. Accordingly, a voltage according to the voltage generated in the power transmission conductor66is generated in the capacitor91. The voltage generated in the capacitor91is input to the voltage conversion circuit93through the output wire92connected to the ring-shaped conductor91b. Then, the voltage conversion circuit93converts the input voltage into a predetermined voltage level and outputs the converted voltage.

Moreover, inFIGS. 28 and 29Ato29C, the output wire85of the current conversion circuit84and the output wire94of the voltage conversion circuit93are not shown. Further, in order to protect the current conversion circuit84and the voltage conversion circuit93from an influence of an electromagnetic wave, a common conductor cover72is provided to cover the current conversion circuit84and the voltage conversion circuit93.FIG. 28shows a state where the cover72is removed, in order to show the current conversion circuit84and the voltage conversion circuit93. Further, inFIGS. 29A to 29C, the cover72is not shown.

As described with reference toFIGS. 28 and 29Ato29C, the current detector80and the voltage detector90have the casing that covers the current transformer81, the capacitor91, and the like, in addition to the parts of the circuit diagram inFIG. 27. The casing is common to the current detector80and the voltage detector90according to the related art.

The current detector80and the voltage detector90described above can be used to other devices, such as the high-frequency power supply device61or the like. For example, in case of the high-frequency power supply device, the current detector and the voltage detector are provided at an output terminal of the high-frequency power supply device61. In this case, the current detector and the voltage detector are used to detect current and voltage required for controlling output forward wave power to have a set value.

The current detector and the voltage detector may detect current and voltage at the output terminal63bof the impedance matching device or the input terminal of the load65and may be used to control or analyze the detected current or voltage.

FIG. 30is a circuit diagram showing a case where the current detector80and the voltage detector90are provided between the matching circuit and the output terminal in the impedance matching device.

As shown inFIG. 30, the current detector80and the voltage detector90are provided on the power transmission conductor68between the matching circuit67and the output terminal63bin the impedance matching circuit. In this case, the current detector80and the voltage detector90detect current and voltage at the output terminal63bof the impedance matching circuit.

InFIG. 30, the same parts as those of the circuit diagram inFIG. 27are represented by the same reference numerals. Meanwhile, there is a difference in current and voltage at the input terminal63aand the output terminal63bof the impedance matching circuit. Accordingly, the current detector80and the voltage detector90have a structural difference in view of current resistance and voltage resistance. InFIG. 30, the same reference numerals are used regardless of the structural difference. For example, the output terminal63bof the impedance matching circuit has higher current and voltage than the input terminal63athereof. For this reason, when the current detector80and the voltage detector90are provided at the output terminal63bof the impedance matching circuit, it is necessary to extend an insulation length, compared with a case where the current detector80and the voltage detector90are provided at the input terminal63aof the impedance matching circuit. In order to extend the insulation length, a conductor having a large diameter is used as the power transmission conductor68or the insulator69covering the periphery of the power transmission conductor68has a large thickness. InFIG. 30, however, for convenience, the structural difference is not considered.

As shown inFIG. 30, when the current detector and the voltage detector are used in the impedance matching circuit, it is necessary to additionally provide a detector for detecting information of current and voltage for impedance matching on the input side of the impedance matching circuit.

Since the current transformer81constituting the current detector80is formed by winding the wire around the magnetic core, a variation in wiring interval or wiring strength may easily occur. For this reason, when a plurality of current detectors80are formed, a variation in detection value of the individual current detectors80may easily occur.

Further, a variation in shape of the output wires82and83of the current transformer81may easily occur, which may cause a variation in current detection value.

The inner diameter of the ring-shaped conductor91bconstituting the voltage detector90is substantially consistent with the outer diameter of the insulator69covering the periphery of the power transmission conductor66. The ring-shaped conductor91bis fitted into the insulator69. That is, the ring-shaped conductor91bis positioned by the insulator69. However, the insulator69may be thinned due to a secular change or the like. In this case, the position of the ring-shaped conductor91bmay be unstable, and a gap may occur between the power transmission conductor66and the insulator69. In this state, if an external force acts on the power transmission conductor66, the positional relationship between the power transmission conductor66and the ring-shaped conductor91bchanges. Then, a voltage detection value changes from an initial state (upon adjustment of the detector). Besides, since the position of the ring-shaped conductor91bis unstable, when a plurality of voltage detectors90are formed, a variation in detection value of the individual voltage detectors90may easily occur.

Further, a variation in shape of the output wire92of the ring-shaped conductor91bmay easily occur, which may cause a variation in voltage detection value.

That is, in case of the current detector80or the voltage detector90, when a plurality of detectors are formed, a variation in detection value of the individual detectors may easily occur.

Further, since the wire is wound around the core in the current transformer81constituting the current detector80, there is a self-resonant frequency by self inductance and line capacitance. However, since relative magnetic permeability of a magnetic material used for the core is large, the self-resonant frequency becomes low. For this reason, an upper limit of a detectable frequency band becomes low. That is, the detectable frequency band is limited.

In case of manufacturing the impedance matching device, when the current detector80and the voltage detector90are installed in the device, it is necessary to install the power transmission conductor66and the like simultaneously. However, there are many cases where the impedance matching device or the like is cramped. Accordingly, it may be difficult to install the power transmission conductor66and the like simultaneously due to interference with other parts. In addition, when the current detector80and the voltage detector90are removed for maintenance, since it is necessary to remove the power transmission conductor66and the like simultaneously, it may be difficult to remove the current detector80and the voltage detector90. For example, when the current detector80and the voltage detector90are disposed on the back side of the impedance matching device, it is necessary to remove the parts on the front side. At this time, in the configuration of the related art, since the volume of a portion to be removed becomes large, and thus it is necessary to remove more parts. As a result, a larger number of work steps are required.

SUMMARY OF THE INVENTION

An object of the invention is to provide a current transformer and a capacitor that can reduce a variation in current detection value or voltage detection value of individual detectors even though a plurality of detectors. Another object of the invention is to provide a current/voltage detector, and a current detector and a voltage detector that use the current transformer and the capacitor. Still another object of the invention is to improve maintenance.

According to a first aspect of the invention, there is provided a current detection printed board comprising: a board having a penetration hole that penetrates the board; and at least one wire that is formed in a coiled shape having both ends by penetrating the board along the periphery of the penetration hole and alternately connecting a front surface layer and a rear surface layer of the board, wherein, when a conductor, in which an AC current flows, is disposed to pass through the inside of the penetration hole, a current flowing in the wire is output through electromagnetic induction.

According to a second aspect of the invention, the wire may include: through holes formed at the penetrating portion of the board; and pattern wires formed on the front surface layer and the rear surface layer.

According to a third aspect of the invention, wherein, when a plurality of the wires are formed in the board, both ends or electrically identical portions of each wire may be electrically connectable to both ends or electrically identical positions of another wire.

According to a fourth aspect of the invention, there is provided a current detection printed board comprising: a board having a penetration hole that penetrates the board; and at least one wire that is formed in a coiled shape and has both ends by penetrating between a top conductive layer and a bottom conductive layer of the board along the periphery of the penetration hole and alternately connecting the top conductive layer and the bottom conductive layer of the board, and/or at least one wire that is formed in a coiled shape and has both ends by penetrating a part of layers of the board and alternately connecting a top conductive layer and a bottom conductive layer of the penetrating portion, wherein, when a conductor, in which an AC current flows, is disposed to pass through the inside of the penetration hole, a current flowing in the wire is output through electromagnetic induction.

According to a fifth aspect of the invention, the wire may include: through holes formed at the penetrating portion penetrating between the top conductive layer and the bottom conductive layer of the board or the part of layers of the board; and pattern wires formed on the top conductive layer and the bottom conductive layer of the penetrating portion.

According to a sixth aspect of the invention, when a plurality of the wires are formed in the board, both ends or electrically identical portions of each wire may be electrically connectable to both ends or electrically identical positions of another wire.

According to a seventh aspect of the invention, wherein the penetration hole may have a circular shape, and the wire may be formed in a circular shape along the periphery of the penetration hole.

According to an eighth aspect of the invention, wherein the AC current may be an AC current having a frequency of a radio frequency band.

According to a ninth aspect of the invention, there is provided a voltage detection printed board comprising: a board having a penetration hole that penetrates the board; and a wire that is formed along the periphery of the penetration hole, wherein, when a conductor, in which an AC voltage is generated, is disposed to pass through the penetration hole, the wire functions as an electrode of a capacitor by making a pair with a portion of the conductor facing the wire.

According to a tenth aspect of the invention, the wire may include: along the periphery of the penetration hole, a plurality of through holes penetrating the board; and pattern wires formed on a top conductive layer and a bottom conductive layer of the board so as to connect the through holes.

According to an eleventh aspect of the invention, the wire may include: along the periphery of the penetration hole, a plurality of through holes penetrating between the top conductive layer and the bottom conductive layer of the board or a part of layers of the board; and a pattern wire formed on at least one layer between the top conductive layer and the bottom conductive layer of the penetrating portion so as to connect the through holes.

According to a twelfth aspect of the invention, the through holes may have a circular shape, and the wire may be formed in a circular shape along the periphery of the penetration hole.

According to a thirteenth aspect of the invention, the AC voltage may be an AC voltage having a frequency of a radio frequency band.

According to a fourteenth aspect of the invention, there is provided a current/voltage detector that detects an AC current flowing in a power transmission conductor to be used as an AC power transmission path and an AC voltage generated in the power transmission conductor, the current/voltage detector comprising: a current detection printed board having a first penetration hole that penetrates the board, and including: at least one first wire that is formed in a coiled shape and has both ends by penetrating the board along the periphery of the first penetration hole and alternately connecting a front surface layer and a rear surface layer of the board; and a second wire for output that is connected to all or a part of both ends of the first wire, wherein when the power transmission conductor, in which an AC current flows, is disposed to pass through the first penetration hole, a current flowing in the first wire is output through electromagnetic induction; and a voltage detection printed board having a second penetration hole that penetrates the board, and including: a third wire that is formed along the periphery of the second penetration hole; and a fourth wire for output that is connected to a part of the third wire, wherein when the power transmission conductor, in which an AC voltage is generated, is disposed to pass through the second penetration hole, the third wire makes a pair with a portion of the power transmission conductor facing the third wire and functions as an electrode of a capacitor, and a voltage generated in the third wire is output from the fourth wire.

According to a fifteenth aspect of the invention, the first wire may include: through holes formed at the penetrating portion of the board; and pattern wires formed on the front surface layer and the rear surface layer.

According to a sixteenth aspect of the invention, the third wire may include: along the periphery of the second penetration hole, a plurality of through holes penetrating the board; and pattern wires formed on the front surface layer and the rear surface layer of the board to connect the through holes.

According to a seventeenth aspect of the invention, there is provided a current/voltage detector that detects an AC current flowing in a power transmission conductor to be used as an AC power transmission path and an AC voltage generated in the power transmission conductor, the current/voltage detector comprising: a current detection printed board having a first penetration hole that penetrates the board, and including: at least one first wire that is formed in a coiled shape and has both ends by penetrating between a top conductive layer and a bottom conductive layer of the board along the periphery of the first penetration hole and alternately connecting the top conductive layer and the bottom conductive layer of the board, and/or at least one wire that is formed in a coiled shape and has both ends by penetrating a part of layers of the board and alternately connecting a top conductive layer and a bottom conductive layer of the penetrating portion, and a second wire for output that is connected to all or a part of both ends of the first wire, wherein when the power transmission conductor, in which an AC current flows, is disposed to pass through the first penetration hole, a current flowing in the first wire is output through electromagnetic induction; and a voltage detection printed board having a second penetration hole that penetrates the board, and including: a third wire that is formed along the periphery of the second penetration hole; and a fourth wire for output that is connected to a part of the third wire, wherein when the power transmission conductor, in which an AC voltage is generated, is disposed to pass through the second penetration hole, the third wire makes a pair with a portion of the power transmission conductor facing the third wire and functions as an electrode of a capacitor, and a voltage generated in the third wire is output from the fourth wire.

According to an eighteenth aspect of the invention, the first wire may include: through holes formed at the penetrating portion penetrating between the top conductive layer and the bottom conductive layer of the board or the part of layers of the board; and pattern wires formed on the top conductive layer and the bottom conductive layer of the penetrating portion.

According to a nineteenth aspect of the invention, the third wire may include: along the periphery of the penetration hole, a plurality of through holes penetrating between the top conductive layer and the bottom conductive layer of the board or a part of layers of the board; and a pattern wire formed on at least one layer between the top conductive layer and the bottom conductive layer of the penetrating portion so as to connect the through holes.

According to a twentieth aspect of the invention, when a plurality of the first wires are formed in the board, both ends or electrically identical portions of each wire may be electrically connectable to both ends or electrically identical positions of another wire.

According to a twenty-first aspect of the invention, the first penetration hole provided in the current detection printed board and the second penetration hole provided in the voltage detection printed board may be substantially coaxially located.

According to a twenty-second aspect of the invention, the current/voltage detector may further comprise: a first conversion circuit that converts the current output from the second wire of the current detection printed board into a predetermined voltage level; a fifth wire that outputs the voltage converted by the first conversion circuit; a second conversion circuit that converts the voltage output from the fourth wire of the voltage detection printed board into a predetermined voltage level; and a sixth wire that outputs the voltage converted by the second conversion circuit.

According to a twenty-third aspect of the invention, the first conversion circuit may be provided on the current detection printed board, and the second conversion circuit may be provided on the voltage detection printed board.

According to a twenty-fourth aspect of the invention, the current/voltage detector may further comprises: a conductor casing that fixes the current detection printed board and the voltage detection printed board therein, wherein the casing may have: on an axis passing through the first penetration hole provided in the current detection printed board and the second penetration hole provided in the voltage detection printed board, a penetration hole through which the power transmission conductor passes; an opening through which a magnetic flux acting on the first wire passes; an opening that allows the third wire and the power transmission conductor to be not shielded; an opening through which the fifth wire is led to the outside; and an opening through which the sixth wire is led to the outside, and wherein the casing may be configured to cover the current detection printed board and the voltage detection printed board, excluding the openings.

According to a twenty-fifth aspect of the invention, the casing may include: a first casing that fixes the current detection printed board; a second casing that fixes the voltage detection printed board; a first cover that covers the first casing; and a second cover that covers the second casing, and the first casing and the second casing are disposed such that both sides thereof overlap each other.

According to a twenty-sixth aspect of the invention, a shield member that reduces the amount of an electromagnetic wave entering from a side of the first wire into a side of the first conversion circuit may be provided in at least one of the first casing and the first cover.

According to a twenty-seventh aspect of the invention, a shield member that reduces the amount of an electromagnetic wave entering from a side of the third wire into a side of the second conversion circuit may be provided in at least one of the second casing and the second cover.

According to a twenty-eighth aspect of the invention, the first casing and the second casing may be formed in a single body.

According to a twenty-ninth aspect of the invention, the casing may include a fixing unit that substantially fixes the relative position between the power transmission conductor, and the current detection printed board and the voltage detection printed board.

According to a thirtieth aspect of the invention, the AC power may be AC power having a frequency of a radio frequency band.

According to a thirty-first aspect of the invention, there is provided a current detector that detects an AC current flowing in a power transmission conductor to be used as an AC power transmission path, the current detector comprising: a current detection printed board having a first penetration hole that penetrates the board, and including: at least one first wire that is formed in a coiled shape and has both ends by penetrating the board along the periphery of the first penetration hole and alternately connecting a front surface layer and a rear surface layer of the board, and a second wire for output that is connected to all or a part of both ends of the first wire, wherein when the power transmission conductor, in which an AC current flows, is disposed to pass through the first penetration hole, a current flowing in the first wire is output through electromagnetic induction.

According to a thirty-second aspect of the invention, there is provided a current detector that detects an AC current flowing in a power transmission conductor to be used as an AC power transmission path, the current detector comprising: a current detection printed board having a first penetration hole that penetrates the board, and including: at least one first wire that is formed in a coiled shape and has both ends by penetrating between a top conductive layer and a bottom conductive layer of the board along the periphery of the penetration hole and alternately connecting the top conductive layer and the bottom conductive layer of the board, and/or at least one first wire that is formed in a coiled shape and has both ends by penetrating a part of layers of the board and alternately connecting a top conductive layer and a bottom conductive layer of the penetrating portion; and a second wire for output that is connected to all or a part of both ends of the first wire, wherein when the power transmission conductor, in which an AC current flows, is disposed to pass through the first penetration hole, and a current flowing in the first wire is output through electromagnetic induction.

According to a thirty-third aspect of the invention, the current detector may further comprise: a first conversion circuit that converts the current output from the second wire of the current detection printed board into a predetermined voltage level; and a third wire that outputs the voltage converted by the first conversion circuit.

According to a thirty-fourth aspect of the invention, the first conversion circuit may be provided on the current detection printed board.

According to a thirty-fifth aspect of the invention, the current detector may further comprise: a conductor casing that fixes the current detection printed board therein, wherein the casing has: on an axis passing through the first penetration hole provided in the current detection printed board; a penetration hole through which the power transmission conductor passes; an opening through which a magnetic flux acting on the first wire passes; and an opening through which a third wire is led to the outside, and wherein the casing is configured to cover the current detection printed board, excluding the openings.

According to a thirty-sixth aspect of the invention, the casing may include: a first casing that fixes the current detection printed board; and a first cover that covers the first casing.

According to a thirty-seventh aspect of the invention, a shield member that reduces the amount of an electromagnetic wave entering from the first wire into the first conversion circuit may be provided in at least one of the first casing and the first cover.

According to a thirty-eighth aspect of the invention, the casing may include a fixing unit that substantially fixes the relative position between the power transmission conductor and the current detection printed board.

According to a thirty-ninth aspect of the invention, the AC power may be AC power having a frequency of a radio frequency band.

According to a fortieth aspect of the invention, there is provided a voltage detector that detects an AC voltage generated in a power transmission conductor to be used as an AC power transmission path, the voltage detector comprising: a voltage detection printed board having a first penetration hole that penetrates the board, and including a first wire that is formed along the periphery of the first penetration hole, and a second wire for output that is connected to a part of the first wire, wherein when the power transmission conductor, in which an AC voltage is generated, is disposed to pass through the first penetration hole, the first wire functions as an electrode of a capacitor by making a pair with a portion of the power transmission conductor facing the first wire, and a voltage generated in the first wire is output from the second wire.

According to a forty-first aspect of the invention, the voltage detector may further comprise a first conversion circuit that converts the voltage output from the second wire of the voltage detection printed board into a predetermined voltage level; and a third wire that output the voltage converted by the first conversion circuit.

According to a forty-second aspect of the invention, the first conversion circuit may be provided on the voltage detection printed board.

According to a forty-third aspect of the invention, the voltage detector may further comprise a conductor casing that fixes the voltage detection printed board therein, wherein the casing may have: on an axis passing through the first penetration hole provided in the voltage detection printed board; a penetration hole through which the power transmission conductor passes; an opening that allows the first wire and the power transmission conductor to be not shielded, and an opening through which the third wire is led to the outside; and the casing may be configured to cover the voltage detection printed board, excluding the openings.

According to a forty-fourth aspect of the invention, the casing may include: a first casing that fixes the voltage detection printed board; and a first cover that covers the second casing.

According to a forty-fifth aspect of the invention, a shield member that reduces the amount of an electromagnetic wave entering from a side of the first wire into a side of the first conversion circuit may be provided in at least one of the first casing and the first cover.

According to a forty-sixth aspect of the invention, the casing may include a fixing unit that substantially fixes the relative position between the power transmission conductor and the voltage detection printed board.

According to a forty-seventh aspect of the invention, wherein the AC power may be AC power having a frequency of a radio frequency band.

According to the first and fourth aspects of the invention, since the coiled wire is formed in the printed board, the printed board can have a function of a current transformer.

According to the second and fifth aspects of the invention, since the through holes and pattern wires form the coiled wire, unlike the related art, there is no case where a self-resonant frequency or a degree of coupling of the current transformer changes due to a variation in winding internal or winding strength. For this reason, when a plurality of current detection printed boards are formed, a variation in current detection value of the individual current detection printed boards can be reduced.

According to the seventh aspect of the invention, when the conductor, in which the AC current flows, is disposed to pass through the penetration hole, a cylindrical (a circular shape in section) conductor is preferably used as the conductor. Further, since a magnetic flux is generated around the conductor, the magnetic flux can efficiently pass through the wire having the coiled shape.

Like the eighth aspect of the invention, in case of an AC current having a frequency of a radio frequency band, a variation in winding interval or winding strength may have a large effect on the current detection value. However, according to the current detection printed board having the configuration of the invention, even though an AC current having a frequency of a radio frequency band is adopted, an influence thereof can be suppressed to the minimum.

According to the ninth aspect of the invention, the wire that is formed along the penetration hole provided in the board functions as an electrode of the capacitor. Therefore, the printed board can have a voltage detection function.

According to the tenth and eleventh aspects of the invention, with the through holes and the pattern wires, a ring-shaped wire that functions as an electrode of the capacitor can be formed in the printed board. Therefore, when a plurality of voltage detection printed boards are formed, a variation in voltage detection value of the individual voltage detection printed boards can be reduced.

Further, the wire has a feature in that the through holes are utilized, as well as the pattern wires. That is, only with the pattern wires, the ring-shaped wire does not have a thickness enough to functioning as an electrode of the capacitor. For this reason, with the through holes, the thickness of the ring-shaped wire can be made large.

According to the twelfth aspect of the invention, when the conductor, in which the AC voltage is generated, is disposed to pass through the penetration hole, a cylindrical (a circular shape in section) conductor is preferably used as the conductor. Further, in case of the circular shape, an inter-electrode distance of the capacitor is likely to be kept constant, and a variation in detection value can be reduced.

Like the thirteenth aspect of the invention, in case of an AC voltage having a frequency of a radio frequency band, a structural variation may have a large effect on the voltage detection value. However, according to the voltage detection printed board having the configuration of the invention, even though an AC voltage having a frequency of a radio frequency band is adopted, an influence thereof can be suppressed to the minimum.

According to the fourteenth and seventeenth aspects of the invention, current detection can be performed by the current detection printed board, and voltage detection can be performed by the voltage detection printed board. Further, according to the thirty-first and thirty-second aspects of the invention, current detection can be performed by the current detection printed board. In addition, according to the fortieth aspect of the invention, voltage detection can be performed by the voltage detection printed board.

According to the twenty-first aspect of the invention, at least portions of the power transmission conductor penetrating the current/voltage detector can be formed in a linear shape (for example, a cylindrical shape). That is, since it is necessary to form the power transmission conductor in a complex shape, manufacturing of the power transmission conductor can be simplified.

According to the twenty-third aspect of the invention, the second wire and the fourth wire can be formed by pattern wires (as occasion demands, including through holes). Accordingly, a variation in detection value due to a variation in shape of the wire or the like can be reduced. Further, the number of assembling steps can be reduced.

Further, the effects of the thirty-fourth aspect of the invention are the same as the effects about the second wire. In addition, the effects of the forty-second aspect of the invention are the same as the effects about the fourth wire.

According to the twenty-fourth aspect of the invention, the printed boards are shielded, excluding the openings required for the current detection printed board and openings required for the voltage detection printed board. Therefore, an influence of an electromagnetic wave on the printed boards can be reduced as small as possible.

Further, the effects of the thirty-fifth aspect of the invention are the same as the effects about the current detection printed board. In addition, the effects of the forty-third aspect of the invention are the same as the effects about the voltage detection printed board.

According to the twenty-sixth aspect of the invention, an influence of an electromagnetic wave on the first conversion circuit can be reduced as small as possible. Further, the effects of the thirty-seventh aspect of the invention are the same as the above-described effects.

According to the twenty-seventh aspect of the invention, an influence of an electromagnetic wave on the second conversion circuit can be reduced as small as possible. Further, the effects of the forty-fifth aspect of the invention are the same as the above-described effects.

According to the twenty-eighth aspect of the invention, for example, the first casing and the second casing are formed in a signal body such that the first penetration hole provided in the current detection printed board and the second penetration hole provided in the voltage detection printed board are substantially coaxially located. Therefore, the number of steps of substantially coaxially locating the first penetration hole and the second penetration hole can be removed.

According to the twenty-ninth aspect of the invention, the relative position between the power transmission conductor, and the current detection printed board and the voltage detection printed board can be kept substantially constant. Further, according to the thirty-eighth aspect of the invention, the relative position between the power transmission conductor and the current detection printed board can be kept substantially constant. In addition, according to the forty-sixth aspect of the invention, the relative position between the power transmission conductor and the voltage detection printed board can be kept substantially constant.

Like the thirtieth aspect of the invention, in case of an AC power having a frequency of a radio frequency band, a variation in winding interval or winding strength has a large effect on the current detection value. Further, a structural variation has a large effect on the voltage detection value. However, according to the current/voltage detector having the configuration of the invention, even though an AC power having a frequency of a radio frequency band is adopted, an influence thereof can be suppressed to the minimum.

Further, the effects of the thirty-ninth aspect of the invention are the same as the effects about current detection. In addition, the effects of the forty-seventh aspect of the invention are the same as the effects about voltage detection.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the details of the invention will be described with reference to the drawings.

(1) Current Detection Printed Board

FIGS. 1A to 1Dare diagrams showing an example of a current detection printed board1according to the invention.

Specifically,FIG. 1Ais a plan view of the current detection printed board1(as viewed from the above).FIG. 1Bis a schematic view of a portion (a portion A surrounded by a dotted line) ofFIG. 1Aon magnified scale.FIG. 1Cis a diagram showing linear expansion for simplification ofFIG. 1B.FIG. 1Dshows a wire of the current detection printed board1whenFIG. 1Cis viewed from the side. Moreover, as regards the wire shown inFIG. 1D, portions that are not typically viewed are shown in perspective view for explanation.

As shown inFIGS. 1A to 1D, the current detection printed board1is provided with a penetration hole101that penetrates a board. A wire10(hereinafter, referred to as a coiled wire10) that is formed in a coiled shape is provided along the periphery of the penetration hole101. The coiled wire10is formed in a coiled shape having both ends by alternately connecting a front surface121and a rear surface122of the board while penetrating the board. Portions of the wire penetrating the board are formed by through holes11and wires of the front surface and the rear surface of the board are formed by pattern wires12and13.

Moreover, inFIGS. 1B and 1C, portions indicated by dotted lines represent pattern wires of the rear surface of the board. These portions are in perspective view, and thus indicated by dotted lines. Output wires21and22are connected to both ends10aand10bof the coiled wire10. The output wires are connected to output terminals23and24.

In this example, the board having a double-sided structure (hereinafter, referred to a double-sided board) is used. Accordingly, the pattern wires are formed on a front surface layer and a rear surface layer of one insulator member110.

The coiled wire10is an example of a coiled first wire of the invention, and the output wires21and22are examples of the second wire of the invention.

FIG. 2is a diagram showing a case where a power transmission conductor66, in which an AC current flows, and an insulator69covering the power transmission conductor66are disposed to pass through the penetration hole101provided in the current detection printed board1. Moreover, for simplification, the wire is not shown. Further, in this embodiment and the following embodiments, a case where the current detection printed board or a voltage detection printed board described below is provided between an input terminal and a matching circuit67of an impedance matching device63.

In case of the current detection printed board1shown inFIG. 1, as shown inFIG. 2, when the power transmission conductor66, in which an AC current flows, is disposed to pass through the penetration hole101, a current flows in the coiled wire10by electromagnetic induction. That is, the printed board can have a current transformer. Specifically, a current transformer can be formed in the current detection printed board1.

Accordingly, the portions of the coiled wire10correspond to the current transformer81in the circuit diagram shown inFIG. 27.

With this configuration, the portions of the coiled wire10are formed by the through holes and the pattern wires, and thus there is almost no variation in shape or position. Accordingly, there is almost no variation in winding interval or winding strength. Therefore, when a plurality of current detection printed boards1are formed, a variation in current detection value of the individual current detection printed boards1can be reduced.

As described below, a current conversion circuit51corresponding to the current conversion circuit84shown inFIG. 27may be provided on the current detection printed board1ofFIG. 1. In this case, the output terminals23and24shown inFIG. 1are not required, and the output wires21and22of the coiled wire10are directly connected to the current conversion circuit51.

The insulator member110of the board is formed of, for example, glass epoxy. Relative magnetic permeability of the insulator member110of the board is smaller than a magnetic material. For this reason, a self-resonant frequency may be higher, compared with a case where a current transformer is formed by winding a wire around a magnetic material uses as a core, like the related art. Accordingly, an upper limit of a detectable frequency band is higher than the related art.

FIGS. 3A to 3Eare diagrams showing another example of the current detection printed board1according to the invention.

Specifically,FIG. 3Ais a plan view of the current detection printed board1.FIG. 3Bis a schematic view of a portion (a portion B surrounded by a dotted line) ofFIG. 3Aon magnified scale.FIG. 3Cis a diagram showing linear expansion for simplification ofFIG. 3B.FIG. 3Dshows a wire of the current detection printed board1whenFIG. 3Cis viewed from the side.FIG. 3Eshows the wire of the current detection printed board1paying emphasis on the output wire21as viewed from the side. Moreover, as regards the wire shown inFIGS. 3A to 3E, portions that are not typically viewed are shown in perspective view for explanation. In addition, for convenience, the current detection printed board1, through holes11, pattern wires12and13, and the like are represented by the same reference numerals as those inFIGS. 1A to 1D.

The current detection printed board1shown inFIGS. 3A to 3Eis specifically the same as the current detection printed board1shown inFIGS. 1A to 1D, except that the board has a multilayer structure, and the coiled wire10is formed between inner layers.

Moreover, in this specification, insulator materials constituting the board having a multilayer structure (hereinafter, referred to as a multilayer board) are appropriately called a first insulator material, a second insulator material, a third insulator material, in sequence from the upper portion of the drawings. Further, conductive layers to be formed between the individual insulator materials of the board are appropriately called a first conductive layer, a second conductive layer, a third conductive layer, . . . . Further, a conductive layer to be formed at the front surface of the board is called a front surface layer, and a conductive layer to be formed at the rear surface of the board is called a rear surface layer.

Moreover, although the double-sided board has the front surface layer and the rear surface layer and may be called a multilayer board, since only one insulator material exists, there are no conductive layers to be formed between the individual insulator materials of the board.

In the example ofFIGS. 3A to 3E, the insulator materials of the board include three insulator materials of a first insulator material111, a second insulator112, and a third insulator material113. Then, a first conductive layer131is formed between the first insulator material111and the second insulator material112, and a second conductive layer132is formed between the second insulator material112and the third insulator material113. Further, a front surface layer can be formed on a front surface121(a surface on the first insulator material) of the board. In addition, a rear surface layer can be formed on a rear surface122(a lower surface of the third insulator material). In the example ofFIGS. 3A to 3E, the rear surface layer of the board is not provided.

For this reason, inFIGS. 3A to 3E, the coiled wire10is formed between the first conductive layer131and the second conductive layer132. Accordingly, the coiled wire10can have a structure that cannot be viewed from the outside of the board. In this case, portions of the coiled wire10correspond to the current transformer81of the circuit diagram shown inFIG. 27.

Further, as shown inFIG. 3E, the output wire21of the coiled wire10is formed by a pattern wire21aconnected to one end10aof the coiled wire10formed in the first conductive layer131, a through hole21b, and a pattern wire21C formed on the front surface of the board. The output wire21is connected to the output terminal23. The output wire22of the coiled wire10is the same as the output wire21, and thus the description thereof will be omitted.

Moreover, as described below, the current conversion circuit51corresponding to the current conversion circuit84shown inFIG. 27may be formed on thee current detection printed board1ofFIGS. 3A to 3E. In this case, the output terminals23and24shown inFIGS. 3A to 3Eare not required, and thus the output wires21and22of the coiled wire10are directly connected to thee current conversion circuit51.

FIGS. 4A and 4Bare diagram showing another example of the coiled wire10. For example, as shown inFIG. 4A, the coiled wire10may be formed between the front surface layer of the board and the second conductive layer132. Moreover, inFIG. 4A, since the rear surface layer is not provided on the rear surface122of the board, the coiled wire10is formed by alternately connecting the front surface layer as a top conductive layer of the board and the second conductive layer132as a bottom conductive layer of the board.

Further, as shown inFIG. 4B, the coiled wire10may be formed between the front surface layer as a top conductive layer and the rear surface layer as a bottom conductive layer of the board. Moreover, inFIG. 4B, likeFIGS. 1A to 1D, the coiled wire10is formed by alternately connecting the front surface layer and the rear surface layer of the board.

In general, a through hole is one for connection between layers by forming a penetration hole between the layers of the board and providing a conductive layer (for example, copper) in the penetration hole. Moreover, the term ‘between the layers’ may mean ‘between all layers’ or ‘between some layers’.

The through hole is a type of inserting a lead line. However, the through hole only for connection between the layers is particularly called a via hole. Then, the via hole includes a penetration via hole that forms a penetration hole from the front surface of the board to the rear surface thereof, and an interstitial via hole that forms a penetration hole only between specific layers. Further, the interstitial via hole includes a blind via in which a hole is viewed from one surface of the board, as shown inFIG. 4A, and a buried via in which a hole is not viewed from both surfaces of the board, as shown inFIGS. 3A to 3E.

The example shown inFIGS. 3A to 3Eand4uses a so-called four-layered board (four conductive layers including the front surface layer and the rear surface layer), but is not intended to limit the invention. For example, a multilayer board, such as a three-layered board, a six-layered board, or an eight-layered board, may be used.

FIG. 5is diagram showing another example of the current detection printed board1according to the invention. The current detection printed board1shown inFIG. 5is different from that ofFIG. 1in that two coiled wires10-1and10-2are provided in the current detection printed board1. Specifically, a first coiled wire10-1that is disposed near the outside of the current detection printed board1and a second coiled wire10-2that is disposed closer to the penetration hole101than the first coiled wire10-1does are provided in the current detection printed board1. Further, the first coiled wire10-1and the second coiled wire10-2are formed by through holes and pattern wires, likeFIGS. 1B and 1C. For this reason, the descriptions thereof will be omitted. Of course, the multilayer board shown inFIGS. 3A to 3Emay be used. Here, the description thereof will be omitted.

As described above, in the current detection printed board1shown inFIG. 5, since the two coiled wires10-1and10-2are provided, various kinds of current transformers can be formed in one current detection printed board1. This example will be described with reference toFIG. 6.

FIG. 6is a connection diagram of the current detection printed board1shown inFIG. 5.

As shown inFIG. 5, output terminals23-1and24-1are connected to both ends10-1aand10-1bof the first coiled wire10-1. Further, output terminals23-2and24-2are connected to both ends10-2aand10-2bof the second coiled wire10-2. In this case, with the connection shown inFIG. 6, various kinds of current transformers can be formed in one current detection printed board1. Moreover, inFIG. 6, ‘x’ means non-connection to other terminals.

Specifically, in case of connection (a) inFIG. 6, a current transformer using the first coiled wire10-1is formed in the current detection printed board1.

In case of connection (b) inFIG. 6, a current transformer using the second coiled wire10-2is formed in the current detection printed board1.

In case of connection (c) inFIG. 6, if the output terminal23-2and the output terminal24-1are connected to each other, a current transformer when the first coiled wire10-1and the second coiled wire10-2are connected in series to each other is formed. Therefore, in this case, a current transformer having larger inductance can be formed, compared with the cases (a) and (b) inFIG. 6.

In addition, like connection (d) inFIG. 6, if the output terminal23-1and the output terminal23-2are connected to each other, and the output terminal24-1and the output terminal24-1are connected to each other, a current transformer when the first coiled wire10-1and the second coiled wire10-2are connected in parallel with each other.

FIG. 7is a diagram showing another example of the current detection printed board1according to the invention. In the current detection printed board1, likeFIG. 5, the first coiled wire10-1and the second coiled wire10-2are provided in one current detection printed board1. The current detection printed board1ofFIG. 7is different from that ofFIG. 5in that the first coiled wire10-1and the second coiled wire10-2are disposed to have a double helix structure. Further, inFIG. 7, likeFIG. 5, various kinds of current transformers can be formed in one current detection printed board1. Moreover, inFIGS. 5 and 7, for ease discrimination of the wires, the positions of the output terminals are shifted from each other, but the invention is not limited thereto. Various kinds of position relationship may be adopted.

As shown inFIG. 7, the first coiled wire10-1and the second coiled wire10-2can be arranged to have a double helix structure. Alternatively, many arrangement examples may be considered, in addition to the example shown inFIG. 7.

FIGS. 8A to 8Eare diagrams showing the arrangement examples of the first coiled wire10-1and the second coiled wire10-2.FIGS. 8A to 8Eschematically show the sections of the first coiled wire10-1and the second coiled wire10-2and show various arrangement examples. Moreover, the first coiled wire10-1and the second coiled wire10-2are shifted from each other with respect to a backward direction as viewed from the paper. Since portions that are not typically viewed are shown in perspective view for explanation, the wires may seem to overlap each other.

For example,FIG. 8Ashows an example where the first coiled wire10-1and the second coiled wire10-2are formed in the same conductive layer. In this case, the pattern wire of the first coiled wire10-1is longer than that of the second coiled wire10-2. Of course, the pattern wire of the second coiled wire10-2may be longer than that of the first coiled wire10-1.

FIG. 8Bshows an example where the first coiled wire10-1and the second coiled wire10-2are formed in the same conductive layer, likeFIG. 8A. However, the pattern wires of the first coiled wire10-1and the second coiled wire10-2have the same length.

FIG. 8Cshows an example where the through hole of the second coiled wire10-2is formed further towards the inside than the first coiled wire10-1, and the pattern wire of the second coiled wire10-2is formed in a conductive layer inside the first coiled wire10-1.

FIG. 8Dshows an example where the through hole of the second coiled wire10-2is formed further towards the inside than the first coiled wire10-1, and the pattern wire of the second coiled wire10-2is formed in a conductive layer outside the first coiled wire10-1.

FIG. 8Eshows an example where the through hole of the second coiled wire10-2is formed further towards the outside than the first coiled wire10-1, and the pattern wire of the second coiled wire10-2is formed in a conductive layer inside the first coiled wire10-1.

In addition, various modifications can be considered and easily considered from the above examples, and thus the descriptions thereof will be omitted. Moreover, as shown inFIGS. 8A and 8B, when the pattern wires of the first coiled wire10-1and the second coiled wire10-2are formed in the same conductive layer, a double-sided board can be used.

InFIGS. 8A to 8E, as the current detection printed board1is viewed in plan view, the through holes and the pattern wires of the first coiled wire10-1and the second coiled wire10-2are shifted from each other. With this configuration, various arrangement examples can be made. Alternatively, as shown inFIG. 8C, if the through hole of the second coiled wire10-2is formed further towards the inside than the through hole of the first coiled wire10-1, and the pattern wire of the second coiled wire10-2is formed further towards the inside than the pattern wire of the first coiled wire10-1, as viewed in plan view, the pattern wires of the first coiled wire10-1and the second coiled wire10-2may be partially overlap each other. Of course, the relationship between the first coiled wire10-1and the second coiled wire10-2may be reversed.

InFIGS. 5 and 7, an example where the two coiled wires10are provided in one current detection printed board1has been illustrated, but the number of coiled wires is not limited thereto. For example, three or more coiled wires10may be provided in one current detection printed board1. Of course, with this configuration, the number of combinations of the coiled wires10to be formed in one current detection printed board1can be increased. Further, as described below, when the current conversion circuit51is provided on the current detection printed board1, the same can be applied. In this case, as described above, the wires may be connected near both ends of the coiled wires10or may be connected in the current conversion circuit51. That is, both ends of each wire or positions electrically identical to both ends thereof are electrically connectable to both ends of another wire or positions electrically identical to both ends thereof.

Next, the effects of a case where a plurality of coiled wires10are provided in the current detection printed board1, as shown inFIGS. 5 and 7, will be described.

In general, a coil (also referred to as an inductor) has a frequency characteristic, and the characteristic changes according to a frequency to be used. Specifically, a detection level of a current is low in a region where a frequency is low. For this reason, the coil is used in a region where a frequency is high. However, an excessively high frequency causes resonance. A frequency at the time of resonance is referred to as a resonant frequency. Near the resonant frequency, a change in detection level of a current is excessively large, and thus it is unsuitable for current detection. For this reason, schematically, a detectable frequency band is limited. That is, a usable frequency has an upper limit and a lower limit.

If inductance of the coil becomes large, the detectable frequency band goes toward a lower frequency. Meanwhile, if inductance of the coil becomes small, the detectable frequency band goes toward a higher frequency. For this reason, it is necessary to select inductance of the coiled wire10to an appropriate value using a frequency of an AC current flowing in the power transmission conductor66.

The above-described high-frequency power supply device61outputs different frequencies of high-frequency power according to the uses. For example, a frequency of 2 MHz, 13.56 MHz, or the like is used according to the uses. For this reason, since it is necessary to select inductance of the coiled wire10according to the frequencies. Accordingly, if various kinds of current transformers can be formed in one current detection printed board1, convenience can be increased. For example, if both the current transformer for 2 MHz and the current transformer for 13.56 MHz can be formed, it is unnecessary to prepare the current detection printed boards1for the individual frequencies. Therefore, kinds of products can be reduced.

Like the examples shown inFIGS. 1A to 1DandFIGS. 3A to 3E, when the coiled wire10is a simplex wound wire, there is a limit to increase the number of turns. Then, there is also a limit to increase inductance. Here, in case of serial connection indicated by (c) ofFIG. 6, inductance of the coiled wire10can be increased, and thus the detectable frequency band can be made low.

(2) Voltage Detection Printed Board

FIGS. 9A to 9Dare diagrams showing an example of a voltage detection printed board2according to the invention.

Specifically,FIG. 9Ais a plan view of the voltage detection printed board2.FIG. 9Bis a schematic view of a portion (a portion C surrounded by a dotted line) ofFIG. 9Aon magnified scale.FIG. 9Cis a diagram showing linear expansion for simplification ofFIG. 9B.FIG. 9Dshows a wire of the voltage detection printed board2whenFIG. 9Cis viewed from the side. Moreover, as regards the wire shown inFIG. 9D, portions that are not typically viewed are shown in perspective view for explanation.

As shown inFIGS. 9A to 9D, the voltage detection printed board2has a penetration hole201that penetrates a board, and a ring-shaped wire30that is provided in the vicinity of the penetration hole201. The ring-shaped wire30is formed by, along the periphery of the penetration hole201, providing a plurality of through holes31that penetrate the board and patterns wires32and33that connect the through holes to a front surface221and a rear surface222of the board. For this reason, the individual through holes are provided between the pattern wires32and33of the front surface of the rear surface of the board. Further, the thickness of each of the through holes is formed to have the substantially same thickness as the thickness of the board. In such a manner, the ring-shaped30is obtained.

Moreover, inFIGS. 9B and 9C, the pattern wires32and33of the front surface and the rear surface of the board overlap each other. Further, an output wire40is connected to the ring-shaped wire30.

In the voltage detection printed board2inFIGS. 9A to 9D, when a power transmission conductor66, in which an AC voltage is generated, is disposed to pass through the penetration hole201, the ring-shaped wire30and a portion of the power transmission conductor66facing the ring-shaped wire30function as electrodes of a capacitor. That is, the printed board can have a function as the electrodes of the capacitor. Accordingly, portions of the ring-shaped wire30correspond to the electrode91bof the capacitor of the circuit diagram inFIG. 27.

With this configuration, the portions of the ring-shaped wire30are formed by the through holes31or the pattern wires32and33. Accordingly, there is almost no variation in shape or position. Therefore, when a plurality of voltage detection printed boards2are formed, a variation in voltage detection value of the individual voltage detection printed boards2can be reduced.

Moreover, as described below, a voltage conversion circuit53corresponding to the voltage conversion circuit93shown inFIG. 27may be provided on the voltage detection printed board2ofFIGS. 9A to 9D. In this case, an output terminal41shown inFIGS. 9A to 9Dis not required, and thus the output wire40of the ring-shaped wire30is directly connected to the voltage conversion circuit53.

Moreover, the ring-shaped wire30is an example of a third wire of the invention (a first wire in the case of a voltage detector), and the output wire40is an example of a fourth wire of the invention (a second wire in the case of a voltage detector).

FIGS. 10A to 10Eare diagrams showing another example of the voltage detection printed board2according to the invention.

Specifically,FIG. 10Ais a plan view of the voltage detection printed board2.FIG. 10Bis a schematic view of a portion (a portion D surrounded by a dotted line) ofFIG. 10Aon magnified scale.FIG. 10Cis a diagram showing linear expansion for simplification ofFIG. 10B.FIG. 10Dshows a wire of the voltage detection printed board2whenFIG. 10Cis viewed from the side.FIG. 10Eshows the wire of the voltage detection printed board2paying emphasis on the output wire40as viewed from the side. Moreover, as regards the wire shown inFIGS. 10A to 10E, portions that are not typically viewed are shown in perspective view for explanation. In addition, for convenience, the voltage detection printed board2, through holes31, pattern wires32and33, and the like are represented by the same reference numerals as those inFIGS. 9A to 9D.

The voltage detection printed board2shown inFIGS. 10A to 10Eis specifically the same as the voltage detection printed board2shown inFIGS. 9A to 9D, except that the board has a multilayer structure, and the ring-shaped wire30is formed between inner layers. This is the same asFIGS. 3A to 3E, and the description thereof will be omitted.

For this reason, inFIGS. 10A to 10E, the ring-shaped wire30is formed between a first conductive layer231and a second conductive layer232. Accordingly, the ring-shaped wire30may not be viewed. Further, in this case, the portions of the ring-shaped wire30correspond to the electrode91bof the capacitor of the circuit diagram inFIG. 27.

The ring-shaped wire30is formed by pattern wires40aconnected to one end30aof the ring-shaped wire30formed in the first conductive layer231, through holes40b, and pattern wires40cformed on the front surface of the board40c, as shown inFIG. 10E. The output wire40is connected to an output terminal41.

Moreover, unlike the above description, as shown inFIGS. 11A and 11B, the ring-shaped wire30may be formed.

FIGS. 11A and 11Bshow another example of the ring-shaped wire30.

FIG. 11Ashows an example where an additional pattern wire for connecting the through holes is provided between a top conductive layer and a bottom conductive layer at penetration portions of the through holes31. In this example, four pattern wires of a pattern wire34, a pattern wire35, a pattern wire36, and a pattern wire37are provided in sequence from the upper portion of the board. As such, three or more pattern wires may be provided.

FIG. 11Bshows an example where a pattern wire38is provided in only one layer between the top conductive layer and the bottom conductive layer at the penetration portions of the through holes31. As such, only one pattern wire may be provided.

Accordingly, a pattern wire may be provided in at least one layer between the top conductive layer and the bottom conductive layer at the penetration portions of the through holes so as to connect the through holes. In this case, the portions of the ring-shaped wire30correspond to the electrode91bof the capacitor of the circuit diagram inFIG. 27.

FIGS. 12A to 12Care schematic exterior views of a current/voltage detector3according to a third embodiment of the invention. Specifically,FIG. 12Ais a schematic exterior view three-dimensionally showing the current/voltage detector3.FIG. 12Bis a schematic exterior view of a conductor casing as viewed from the side.FIG. 12Cis a diagram when the conductor casing ofFIG. 12Bis removed.

As shown inFIG. 12A, like the related art, the current/voltage detector3has a structure in which a power transmission conductor66can penetrate a casing. Moreover, the power transmission conductor66and an insulator69surrounding the power transmission conductor66are not included in the current/voltage detector3but are just shown for explanation. Further, the insulator69insulates the power transmission conductor66and the current/voltage detector3. For this reason, an actual length of the insulator69is shorter than the length of the insulator69shown in the drawing, but it is shown likeFIG. 12Afor simplification of the drawing. The same is applied to other drawings (for example,FIG. 17).

As shown inFIG. 12C, the current detection printed board1and the voltage detection printed board2are accommodated in the casing. For this reason, a current that flows in the power transmission conductor66passing through the casing can be detected by the current detection printed board1, and a voltage that is generated in the power transmission conductor66can be detected by the voltage detection printed board2.

That is, in the example shown inFIG. 12B, a left portion of the current/voltage detector3corresponds to a current detector310and a right portion thereof corresponds to a voltage detector320. Moreover, the casing is formed of a conductor, such as aluminum or the like. Then, the current detector310corresponds to the current detector80shown inFIG. 27, and the voltage detector320corresponds to the voltage detector90shown inFIG. 27.

FIGS. 13A and 13Bare diagrams showing the schematic configuration of the current/voltage detector3shown inFIGS. 12A to 12C. Specifically,FIG. 13Ais a diagram showing the configuration of the current/voltage detector3.FIG. 13Bis a schematic view showing when individual parts ofFIG. 13Aare assembled. Moreover, inFIGS. 13A and 13B, the shapes of the individual parts are schematic. For example, a penetration hole through which the power transmission conductor66passes or an opening through which a magnetic flux passes is provided in the casing or the board, but it is not shown in the drawings. Further, inFIGS. 13A and 13B, portions that are not viewed from the outside are schematically indicated by dotted lines.

As shown inFIG. 13A, the current/voltage detector3has a casing main body300, and the current detection printed board1, the voltage detection printed board2, a current detector cover301, and a voltage detector cover302that are fixed to the casing main body300. Of course, parts, such as screws or beads, for fixing the above-described constituents, but they are regarded as portions of the constituents and are not shown for simplification of explanation. Further, as indicated by an arrow inFIG. 13A, if the constituents are fixed to the casing main body300, as shown inFIG. 13B, the current detection printed board1and the voltage detection printed board2are fixed in the casing main body300, and the current detection printed board1and the voltage detection printed board2are covered with the covers301and302, respectively.

Moreover, in the casing main body300, a portion where the current detection printed board1is fixed is an example of a first casing of the invention, and a portion where the voltage detection printed board2is fixed is an example of a second casing of the invention (a first cover in the case of a voltage detector). Further, the current detector cover301is an example of a first cover of the invention, and the voltage detector cover302is an example of a second cover of the invention (a first cover in the case of a voltage detector).

That is, like the related art, the current detection printed board1and the voltage detection printed board2are disposed in the casing. The casing main body300is common to the current detection printed board1and the voltage detection printed board2. Then, if the current detection printed board1is fixed on the front surface of the casing main body300, the voltage detection printed board2is fixed on the rear surface thereof. Accordingly, the current detection printed board1and the voltage detection printed board2are accommodated in separate spaces, respectively. Therefore, there is almost no mutual interference between the current detection printed board1and the voltage detection printed board2, and detection accuracy increases.

Next, other parts than the current detector cover301and the voltage detector cover302will be specifically described.

FIGS. 14A to 14Care diagrams of the casing main body300. Specifically,FIG. 14Ais a diagram as viewed from a side on which the current detection printed board1is fixed.FIG. 14Bis a cross-sectional view of a side surface of the casing main body300.FIG. 14Cis a diagram as viewed from a side on which the voltage detection printed board2is fixed.

FIGS. 15A and 15Bare diagrams three-dimensionally showing the casing main body300. Specifically,FIG. 15Ais a diagram as viewed from the side on which the current detection printed board1is fixed, andFIG. 15Bis a diagram as viewed from the side on which the voltage detection printed board2.

FIGS. 16A and 16Bare diagrams when the current detection printed board1and the voltage detection printed board2are mounted on the casing main body300in a state where the current detector cover301and the voltage detector cover302are not mounted. Specifically,FIG. 16Ais a diagram of the current detection printed board1side.FIG. 16Bis a diagram of the voltage detection printed board2side.

As shown inFIGS. 14A to 16B, a through hole303and concave portions311,312,321, and322are provided in the casing main body300. Accordingly, the power transmission conductor66and the insulator69covering the power transmission conductor66pass through the casing main body, and the current detection printed board1and the voltage detection printed board2are accommodated in the casing main body. Moreover, the current detection printed board1is accommodated on a side where the concave portions311and312are provided, and the voltage detection printed board2is accommodated on a side where the concave portions321and322are provided.

Four board fixing portions315are provided at four corners of the concave portion311, and the current detection printed board1is fixed to the portions. This is to allow the current detection printed board1to float with respect to the bottom surface of the concave portion311such that the coiled wire provided in the current detection printed board1does not come into contact with the casing.

Similarly, four board fixing portions324are provided at four corners of the concave portion321such that the voltage detection printed board2floats with respect to the bottom surface of the concave portion321.

For example, unlikeFIGS. 3A to 3E, when the coiled wire10of the current detection printed board1is not formed on the rear surface layer of the board, the board fixing portions315provided at the four corners of the concave portion311can be removed. Then, the height of the bottom surface of the concave portion311can be the same as the height of the bottom surface of the concave portion312. For this reason, the structure of the casing main body300can be simplified. Similarly, for example, unlikeFIGS. 10A to 10E, when the ring-shaped wire30of the voltage detection printed board2is not formed in the rear surface layer of the board, the board fixing portions324provided at the four corners of the concave portion321can be removed, and thus the height of the bottom surface of the concave portion321can be the same as the height of the bottom surface of the concave portion322. For this reason, the structure of the casing main body300can be simplified.

Further, on the current detection printed board1side of the casing main body300, a first shield portion313that shields a magnetic flux is provided in the vicinity of the penetration hole.

Next, the current detection printed board1and the voltage detection printed board2will be respectively described.

(Description of Current Detection Printed Board1)

The coiled wire10of the current detection printed board1is the same as that of the current detection printed board1inFIGS. 1A to 1D, but the output wires21and22are connected to the current conversion circuit51in forms of the pattern wires. The current conversion circuit51corresponds to the current conversion circuit84shown inFIG. 27.

Accordingly, unlike the current detection printed board1inFIG. 1, the coiled wire10and the current conversion circuit51are provided on the same board. Further, the output wire52connected to the current conversion circuit51extends towards the outside of the casing through a wire opening316. Moreover, the current conversion circuit51has an output terminal to which the output wire52is connected. In addition, the output wire52may be partially a pattern wire or may be overall a wire other than the pattern wire.

In the casing main body, a second shield portion314is provided at a corresponding position between the coiled wire10of the current detection printed board1and the current conversion circuit51. For this reason, the current detection printed board1has a shape having a partially narrower width according to the second shield portion314.

Moreover, the current conversion circuit51is an example of a first conversion circuit of the invention, and the output wire52is an example of a fifth wire of the invention (a third wire in the case of a current detector).

(Description of Voltage Detection Printed Board2)

The ring-shaped wire30of the voltage detection printed board2is the same as the voltage detection printed board2inFIGS. 1A to 1D, but the output wire40is connected to the voltage conversion circuit53in forms of the pattern wire. The voltage conversion circuit53corresponds to the voltage conversion circuit93inFIG. 27.

Accordingly, unlike the voltage detection printed board2inFIG. 1, the ring-shaped wire30and the voltage conversion circuit53are provided on the same board. Further, the output wire54connected to the voltage conversion circuit53extends towards the outside of the casing through a wire opening325. Moreover, the voltage conversion circuit53has an output terminal to which the output wire54is connected. In addition, the output wire54may be partially a pattern wire or may be overall a wire other than the pattern wire.

In the casing main body, a third shield portion323is provided at a corresponding position between the ring-shaped wire30of the voltage detection printed board2and the voltage conversion circuit53. For this reason, the voltage detection printed board2has a partially narrower width according to the third shield portion323.

Moreover, the voltage conversion circuit53is an example of a second conversion circuit of the invention (a first conversion circuit in the case of a voltage detector), and the output wire54is an example of a sixth wire of the invention (a third wire in the case of a voltage detector).

Next, the effects of the casing will be described.

(i) Effects of Current Detection Opening317

FIG. 17is a cross-sectional view showing a case where the power transmission conductor66and the insulator69covering the power transmission conductor66penetrate the current/voltage detector3.FIG. 17shows a state where the current detector cover301and the voltage detector cover302are mounted. Moreover, the board fixing portions315and324shown inFIGS. 14A to 14Cand the like are not shown. Further, the current detection printed board1and the voltage detection printed board2are partially omitted. In addition, as shown inFIG. 17, a penetration hole, through which the power transmission conductor66and the insulator69covering the power transmission conductor66passes, is provided in the current detector cover301and the voltage detector cover302.

If a current flows in the power transmission conductor66, a magnetic flux occurs around the conductor. The magnetic flux acts on the coiled wire10provided in the current detection printed board1, such that a current flows in the coiled wire10. Then, the current flowing in the coiled wire10is detected, thereby recognizing the current flowing in the power transmission conductor66. For this reason, if the power transmission conductor66and the current detection printed board1are shielded by the conductor casing, the magnetic flux does not act on the current detection printed board1, and thus the current cannot be detected. Accordingly, an opening317, through which the magnetic flux generated around the conductor is introduced into the casing, is provided in the casing. The opening317is formed by a gap between the first shield portion313and the current detector cover301.

(ii) Effects of Second Shield Portion314

An electromagnetic wave is generated by an AC current flowing in the power transmission conductor66. Since the electromagnetic wave has an effect on a circuit characteristic, it is necessary to prevent the electromagnetic wave from entering the current conversion circuit51, if possible. For this reason, the second shield portion314is provided in the casing, thereby realizing an electromagnetic shield effect and keeping a good circuit characteristic of the current conversion circuit51.

Moreover, the second shield portion314is formed by narrowing the board width. This is to shield an electromagnetic wave passing through the inside of the board. That is, the reason why the second shield portion314having a narrower board width is formed is that, when the second shield portion314is provided to cover the upper portion of the board, without narrowing the board width, an electromagnetic wave passes through the portions of the board, and thus an electromagnetic shield effect becomes weak.

FIGS. 18A and 18Bshow an example of an application of the second shield portion314.

As shown inFIGS. 14A to 16B, since only with the second shield portion314of the casing main body300, a gap occurs in the output wires21and22of the coiled wire10, electromagnetic shield may not be sufficient. In this case, as shown inFIG. 18A, a shield portion317for burying the gap may be provided in the current detector cover301. In such a manner, the gap in the output wires21and22is almost removed, and thus an electromagnetic shield effect increases.

Further, as shown inFIG. 18B, instead of the second shield portion314, a shield portion318may be provided in the current detector cover301.

Moreover, as for the third shield portion323of the voltage detection printed board2side, the same one as the shield portion317or the shield portion318provided in the current detector cover301may be provided in the voltage detector cover302, thereby increasing an electromagnetic shield effect. This is the same asFIGS. 18A and 18B, and the description thereof will be omitted.

As described above, as for the current detection and voltage detection sides, the casing main body300is formed as a single body. For this reason, as described above, current detection and voltage detection can be performed in separate spaces, and the outputs can be converted into voltage levels using the individual conversion circuits. Therefore, there is almost no mutual interference, and thus detection accuracy can be improved.

FIGS. 19A and 19Bshow a current/voltage detector3aas a modification of the current/voltage detector3. However, a current detector cover301aand a voltage detector cover302aare not shown. InFIGS. 19A and 19B, the current detection printed board1is as shown inFIGS. 1A to 1D, and the voltage detection printed board2is as shown inFIGS. 9A to 9D. That is, the current conversion circuit51is not provided in the current detection printed board1, and the voltage conversion circuit53is not provided in the voltage detection printed board2. A casing main body300ahaving a shape for the current detection printed board1and the voltage detection printed board2is used. For this reason, the output of the current detection printed board1is output outside the casing by output wires25and26, not pattern wires. Further, the output of the voltage detection printed board2is output outside the casing by an output wire42, not a pattern wire. Moreover, the output wires25and26are connected to a current conversion circuit51that is separately provided, and the output wire42is connected to the voltage conversion circuit53that is separately provided.

(4) Current Detector and Voltage Detector

In the above description, the current detector310and the voltage detector320are formed as a single body. However, the invention is not limited thereto, but the current detector310and the voltage detector320may be separately provided. Here, the same reference numerals asFIGS. 12A to 12Care used.

FIG. 20is a diagram showing an example where the current detection printed board1and the voltage detection printed board2are accommodated in separate casings, thereby forming the current detector310and the voltage detector320separately. As shown inFIG. 20, if the current detector310and the voltage detector320are provided separately and disposed such that both sides overlap each other, the same effects as the current detector and the voltage detector formed as a single body can be obtained.

FIG. 21is a diagram showing an application when the current detector310and the voltage detector320are provided separately. As shown inFIG. 21, the current detector310and the voltage detector320may overlap each other in different directions, not in the same direction. Moreover, as shown inFIG. 21, if the penetration holes303provided in the individual detectors are coaxially located, the power transmission conductor66can be linear, and thus the structure can be simplified. Further, ease of assembling can be realized.

Although an example where the detector is provided at the input terminal63aof the impedance matching device has been described in the above description, the invention is not limited thereto. For example, the detector may be provided at an output terminal of the high-frequency power supply device61or may be provided at the output terminal63bof the impedance matching device. Moreover, as described above, there is a difference in current and voltage at the input terminal63aand the output terminal63b(the same as the input terminal of the load65) of the impedance matching device. For this reason, when the detector is provided at the output terminal63bof the impedance matching device or the input terminal of the load65, in order to extend an insulation distance, it is preferable to use a power transmission conductor68having a large diameter or an insulator69covering the periphery of the power transmission conductor68in consideration of the difference. Further, the detector may be used for other systems other than the high-frequency power supply system.

Although a case where the current detector310is disposed near the input and the voltage detector320is disposed at the back of the current detector310has been described in the above description, as shown inFIG. 22, the voltage detector320may be disposed near the input.

Although an example where the current detector310and the voltage detector are used together has been described in the above description, either the current detector310or the voltage may be used.

(5) Fixing Method

When the outer diameter of the insulator69and the inner diameter of the penetration hole provided in the casing main body300are substantially consistent with each other, the insulator69and the current/voltage detector3can be fixed. However, actually, the insulator69having an outer diameter smaller than the inner diameter of the penetration hole may be used. In this case, a gap occurs between the insulator69and a casing main body305. As such, if the gap exists, when the power transmission conductor66and the current/voltage detector3are mounted on the impedance matching device63, the relative position therebetween may not be constant according to mounting devices. In this case, when a plurality of devices are formed, a variation in detection value of the individual devices occurs. For this reason, when the gap is large, it is preferable to keep the relative position between the power transmission conductor66and the current/voltage detector3constant.

FIG. 23is a diagram showing a fixing method of the insulator69. As shown inFIG. 23, a concave portion is provided in the insulator69, and the current detector cover301and the voltage detector cover302are fitted into the concave portion. With this configuration, the insulator69can be fixed by the current detector cover301and the voltage detector cover302. Then, even though the outer diameter of the insulator69is smaller than the inner diameter of the penetration hole303, the relative position between the power transmission conductor66, and the current detection printed board1and the voltage detection printed board2can be substantially kept constant.

As described inFIG. 20and the like, the fixing method can be applied to a case where the current detector310and the voltage detector320are provided separately.

FIG. 24is a diagram showing a fixing method of the insulator69when only the current detector310is used separately. Moreover, inFIG. 24, the casing main body of the current detector310is used as the casing main body305. Further, in case of the voltage detector320, the same method can also be adopted. Here, the description thereof will be omitted.

As shown inFIG. 20, when the current detector310and the voltage detector320are double-barreled, likeFIG. 23, the insulator69can be fixed by the current detector cover301and the voltage detector cover302. However, when either the current detector301or the voltage detector302is used, either an upper cover or a lower cover does not exist (as viewed from the paper). Then, the insulator69may not be stably fixed. In this case, as shown inFIG. 24, in order to stabilize the insulator, a mounting part306for fixing the insulator69may be provided at the lower portion of the casing main body305(as viewed from the paper). The mounting part306is fitted into the concave portion provided in the insulator69and is mounted on the casing main body305by beads or the like (not shown). Of course, the invention is not limited to the examples shown inFIGS. 23 and 24. For example, the shape of the mounting part306may be changed.

FIG. 25is a diagram showing a case where the sizes of the power transmission conductor66and the insulator69are suited to the size of the current/voltage detector3in the current/voltage detector3shown inFIG. 23. Moreover, in the example ofFIG. 24, the same method can also be adopted. Here, the description thereof will be omitted.

LikeFIG. 23, when the insulator39is fixed to the current/voltage detector3, in order to improve maintenance, as shown inFIG. 25, the sizes of the power transmission conductor66and the insulator69may be suited to the size of the current/voltage detector3, such that the power transmission conductor66and the insulator69can be removed from the current/voltage detector3. With this configuration, maintenance can be improved. Moreover, inFIG. 25, though not shown, a connection portion for connection to anther conductor is provided in the power transmission conductor66. Moreover, the current detector cover301, the voltage detector cover302, and the mounting part306ofFIGS. 23 to 25are an example of a fixing unit of the invention.

Although an example where high-frequency power having a frequency (for example, a frequency of hundreds kHz or more) of a radio frequency band is used has been described in the above description, AC power having a frequency lower than the frequency of the radio frequency band may be used. Meanwhile, in case of the high frequency, such as the frequency of the radio frequency band, it is necessary to shield the electromagnetic wave using the second shield portion314and the third shield portion323in the casing. Accordingly, when the frequency of AC power is low and an influence of the electromagnetic wave is negligible, the second shield portion314and the fourth shield portion323may not be provided. Besides, since characteristics are different according to the frequencies to be used, it is preferable to use a casing suitable for the characteristic.

Although a case where the power transmission conductors66and68are a cylindrical copper rod, that is, has a circular shape in section has been described in the above description, the invention is not limited thereto. For example, a conductor having an elliptical shape or a rectangular shape in section may be used. Further, although a case where the penetration hole101of the current detection printed board1and the penetration hole201of the voltage detection printed board2have a circular shape has been described, the invention is not limited thereto. For example, an elliptical shape or a rectangular shape may be used.

As described above, there exist various kinds of the current detection printed board, the voltage detection printed board, and the detectors using the same. Therefore, other combinations than those described above can be made.