JPH06290972A - Reactor manufacture on metallic printed board and inverter device using same reactor - Google Patents

Abstract

PURPOSE:To mount a reactor on a board, on which a power element is placed, in order to miniaturize and lighten an inverter device. CONSTITUTION:A reactor is composed of an insulating board 110 and a ring- shaped core 112, a plurality of rectangular patterns 111 arranged to the insulating board 110 at regular intervals and wires 113 each connecting one rectangular pattern 111 and another rectangular pattern 111 separated from one rectangular patterns 111 by a fixed number of patterns. The core 112 is disposed adjacent to a plurality of the rectangular patterns 111 of the insulating board 110, one rectangular pattern 111 on the ring inside of the core 112 and the wires 113 are arranged so as to cross core 112, and connected to an other rectangular pattern 111 on the ring outside of the core 112 separated by a fixed number of patterns, and the process is repeated, thus winding coils consisting of the patterns 111 and the wires 113 on the ring-shaped core 112.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor used as a filter for an inverter.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram of a conventional inverter device and its connection diagram. In the figure, 50 is an AC input power source, 51 is an inverter device, 52 is a motor, and 14-1.
Reference numeral 9 is a diode for converting alternating current to direct current, 53 is a smoothing capacitor, 2 to 7 are switching elements for PWM modulating direct current, and 8 to 13 are connected in antiparallel to the switching elements 2 to 7 to process a reactive current. The feedback diodes 101 to 103 for performing are the potentials VUN, VVN, VWN of the output lines U, V, W with respect to the potential stabilization point N.

FIG. 8 is a diagram showing voltage waveforms when the switching elements 2 to 7 of the conventional inverter device shown in FIG. 7 are switching, and correspond to VUN, VVN and VWN in FIG. Further, 54 is an output U, V, and
It is the neutral point potential of W, and VC = (VUN + VVN + VWN) /
Expressed as 3. The voltage change dV / dt becomes a noise source, but the noise due to the voltage change between the outputs U, V, W causes normal mode noise, and the output U with respect to the potential stable point such as the earth E or the DC voltage bus P, N. , V, W neutral voltage changes cause common mode noise.
Hereinafter, the common mode noise countermeasure filter will be mainly described.

FIG. 9 is a sectional view of a main circuit portion of a conventional inverter device. In the figure, 1 is a switching element 2
7 and main circuit elements such as feedback diodes 8 to 13 (hereinafter,
A main circuit board on which main circuit elements 2 to 13 are mounted,
Reference numeral 46 is a cooling fin that transfers the heat of the main circuit elements 2 to 13 to the outside air, and 59 is an insulating layer that electrically insulates between the main circuit elements 2 to 13 and the cooling fin 46. Reference numeral 49 is a casing of the inverter device, and the cooling fins 46 are fixed to the casing 49, but the cooling fins 46 and the casing 49 are electrically connected.

FIG. 10 is an equivalent circuit diagram showing a path of common mode noise in the main circuit of the conventional inverter device shown in FIG. In the figure, 55 is the main circuit board 1.
The stray capacitance Ci between the cooling fin 46 and the cooling fin 46 is a stray capacitance Cc of the output wiring with respect to the earth E, and 57 is the winding of the motor 52 and the frame (the frame is connected to the earth E).
The stray capacitance Cm, 58 between them is the in-phase current io represented by i = C · dV / dt. The potential stabilization point N and the neutral point P ₁ of the AC input line have the same potential with respect to the carrier frequency of PWN. The voltage of Vc54 is applied to the neutral point P _{3 of the} output lines U, V, W with respect to this potential stabilization point. In addition, P ₃ is grounded E through stray capacitance Cc56 and stray capacitance Cm57.
Connected to.

In FIG. 9, the insulating layer 59 needs to be electrically insulated, but thermally, the heat generated by the main circuit elements 2 to 13 needs to be efficiently transmitted to the cooling fins 46, so that the thickness thereof is large. It is thin and has a large area. Therefore, the stray capacitance Ci55 in the meantime becomes considerably large. The neutral point P ₂ of the main circuit elements _{2 to} 13 is connected to the output line U,
Since it has the same potential as the neutral point P ₃ of V and W, Ci55 is represented in the equivalent circuit diagram as shown in FIG. Also, the housing 4
Since 9 receives the potential change of the main circuit elements 2 to 13 directly through Ci 55, there is a danger of electric shock if a person touches the housing 49. Therefore, the housing 49 is grounded E for safety.
, The equivalent circuit of FIG. 10 is obtained.

As shown in FIG. 10, the stray capacitance Ci55,
Common-mode voltage Vc5 on the stairs with respect to Cc56 and Cm57
Since 4 is added, a common-mode current io58 represented by i = C · dV / dt flows through the power supply line to cause common-mode noise, and an input common-mode current (zero-phase current) sensor,
That is, an adverse effect occurs such that the earth leakage breaker operates even if no grounding accident has occurred.

In order to reduce this common mode current io58,
When i = C · dV / dt, there are a method of reducing C and a method of reducing the voltage change rate dV / dt. Hereinafter, a method of reducing the voltage change dV / dt will be described.

FIG. 11 is a diagram showing a common mode filter for smoothing changes in the common mode voltage Vc54 and its connection diagram. Reference numeral 60 denotes an in-phase reactor in which three output lines are wound around one core in the same direction and operates only for an in-phase voltage, and only a component whose current sum does not become zero operates as a reactor. 62 ~
A capacitor 64 is connected to the DC voltage bus N. 61
Is a voltage clamp diode for clamping the resonance voltage at the resonance frequency of the in-phase reactor 60 and the capacitors 62 to 64 to VDC of the DC voltage buses P and N.

FIG. 12 shows this in-phase filter on an equivalent circuit diagram. In the figure, 65 is an in-phase reactor on the equivalent circuit, and 66 is a capacitor on the equivalent circuit. As shown in the figure, this filter operates on the common-mode voltage Vc54 on the stairs, and smoothes the potential change of the common-mode voltage applied to Cc56 and Cm57 of the output line, so that i
o58 is reduced. At this time, the output common-mode filter operates at the neutral point of the output lines U, V, W, and does not work at the neutral point P _{2 of} the main circuit element, that is, the potential of the main circuit board 1 in FIG. Therefore, as shown in the equivalent circuit of FIG.
io58 due to i55 is not reduced.

FIG. 13 is a block diagram showing the case where a differential filter for smoothing the differential voltage change of the output lines U, V and W is used. In the figure, reference numerals 70 to 72 are differential reactors, and 73 to 75 are capacitors, which together form an LC filter.

FIG. 14 is a physical wiring diagram of the inverter main circuit unit with the common mode filter shown in FIG. Output lines U, V, and W are output from the main circuit board 1 in which the main circuit elements 2 to 13 are incorporated, and are connected to the inverter output through the in-phase reactor 60, the capacitors 62 to 64, and the voltage clamp diode 61. Both ends of the voltage clamp diode 61 are connected to the smoothing capacitor 53.

FIG. 15 shows an equivalent circuit when wiring is performed as shown in FIG. As shown in FIG.
Since the wiring from the main circuit board 1 to the capacitors 62 to 64 via the in-phase reactor 60 becomes long, the wiring inductance L ₁ 76 in the normal mode exists, and the wiring from the voltage clamp diode 61 to the smoothing capacitor 53 is also provided. Since it becomes longer, the wiring inductance L ₂ 78 exists.

FIG. 16 shows the wiring inductance L in FIG.
Line voltage when there is ₁ 76, FIG. 17 shows voltage clamp diode 61 when there is wiring inductance L ₂ 78.
The voltage waveforms at both ends of are shown. In FIG. 16, when the wiring is short, the wiring inductance L ₁ 76 is small, and since L ₀ is the in-phase reactor, the line voltage hardly resonates with the capacitors 62 to 64, but when the wiring is long, the wiring inductance L ₁ 76 exists. Therefore, the waveform becomes as shown in the figure below, and the desired voltage is not applied to the motor 52.

Further, when the wiring inductance L ₂ 78 is present, the resonance voltage exceeds VDC as shown in FIG. 17, whereby the clamp of the line voltage to VDC becomes ineffective, and the peak value of the line voltage exceeds VDC. In addition, breakdown voltage breakdown of the diode will occur.

FIG. 18 shows another part of the inverter device.
The case where a reactor is used is shown. A power factor improving reactor 79 is inserted between the rectifying diodes 14 to 19 and the smoothing capacitor 53 to smooth the AC input current waveform.

FIG. 19 is a view showing a manufacturing member and a manufacturing process of the conventional in-phase reactor 60. In the figure, 42 is a core, 45 is a winding composed of three phases, and 80 is a core 42.
Is a case for protecting the coil from the winding 45. The core 42 is wrapped in a case 80, and the winding 45 is wound around the case 80 to manufacture the in-phase reactor 60. Further, when the in-phase reactor 60 is composed of one large coil, the coil is wound in multiple turns and stray capacitance exists between the input and output, so that the reactance value decreases at high frequencies and it becomes ineffective as a reactor. Also, when the reactor is wound multiple times, the winding heats up due to copper loss, and iron loss occurs from the core because it operates at high frequency, but since the winding is wound, heat dissipation is poor and the core The temperature rises. Due to this temperature rise of the core, the reactance value of the coil is reduced and the magnetic saturation is likely to occur. As a countermeasure, it is necessary to increase the size of the core, which leads to an increase in cost and an increase in size of the device.

[0018]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Since it is configured as described above, there are the following problems. In the coil winding method, if multiple windings are made on one large coil, inter-wire stray capacitance exists at the overlapping points, and at high frequencies, it will not operate as a reactor. When the reactor is manufactured by the conventional method, heat is contained in the reactor, the reactance value is lowered, and magnetic saturation easily occurs.

Further, since the conventional inverter device is constructed as described above, it has the following problems. Since the reactor has a certain thickness and cannot be surface-mounted on the main circuit board and is placed separately, the wiring from the voltage clamp diode to the smoothing capacitor becomes long. As a result, the voltage across the voltage clamp diode rises, the line voltage cannot be clamped to the DC bus voltage, and the withstand voltage of the clamp diode is exceeded, which may destroy the diode. In addition, since the reactor cannot be surface-mounted on the main circuit board and is placed separately, there is a leak reactance due to the wiring length in the in-phase filter circuit, and the line voltage resonates and the desired voltage cannot be obtained. Further, as prior arts for reducing the size and thickness of the reactor and surface-mounting it on the same substrate, there are, for example, Japanese Patent Laid-Open Nos. 3-135371 and 3-135373, but it is small for use in an inverter device. A reactor that is thin and can be used with a line withstand voltage of 600 V is needed.

[0020]

According to a first aspect of the present invention, there is provided a reactor in which an insulating thin film is formed on a metal substrate and a conductive thin film is used to form a pattern on the printed circuit board, a ring-shaped iron core, and the iron core. Crossing the ring, a plurality of strip patterns arranged at a predetermined interval on the metal printed circuit board, a bonding pad provided on the land portion of the strip pattern, and one strip pattern. A wire that connects the other strip-shaped pattern separated by a predetermined number, and an insulating material that insulates the ring-shaped iron core and the strip-shaped pattern, into the strip-shaped patterns of the metal printed board. The iron cores are arranged in close proximity to each other via an insulating material, and one strip-shaped pattern inside the ring of the iron core is connected to one end of the wire, or a bonding pad is connected. , The wire is arranged so as to straddle the iron core, and the wire is connected to another strip-shaped pattern on the outside of the ring of the iron core separated by a predetermined number, or connected via a bonding pad, By repeating the above, the coil composed of the pattern and the wire is wound around the ring-shaped iron core.

The in-phase reactor according to the second aspect of the present invention is the first aspect.
In the reactor according to the invention, a coil composed of the pattern and the wire is wound around the ring-shaped iron core in a plurality of phases in the same direction for each phase to provide a common-mode reactor that operates only for a common-mode voltage.

A third aspect of the present invention is an inverter device comprising a plurality of switching elements for receiving electric power from a direct current power source and converting direct current into alternating current. The second aspect is that a plurality of switching elements are mounted on a metal printed board. An in-phase filter including the in-phase reactor of the invention is provided on the output side of the switching element.

[0023]

In the reactor and the in-phase reactor according to the first and second aspects of the present invention, the ring-shaped iron core is arranged close to a plurality of strip-shaped patterns of the metal printed circuit board having good thermal conductivity, and one of the inner sides of the ring of the iron core is arranged. One of the strip-shaped patterns and one end of the wire are connected, the wire is arranged so as to straddle the iron core, and the strip-shaped pattern is connected to another one of the strip-shaped outer sides of the iron core separated by a predetermined number, which is By repeating the coil consisting of the pattern and the wire around the ring-shaped iron core by repeating, stray capacitance between wires is less likely to exist, it can operate as a reactor even at high frequency, and the heat of the wire Since the heat is radiated from the metal printed circuit board and the heat is less likely to stay inside, the reactance value is less likely to decrease, and magnetic saturation is less likely to occur.

A third aspect of the present invention is an inverter device comprising a plurality of switching elements for receiving electric power from a direct current power source and converting direct current into alternating current. The second aspect is that a plurality of switching elements are mounted on a metal printed circuit board. Since the common mode filter including the common mode reactor according to the invention is provided on the output side of the switching element, the wiring length can be short,
Since the line voltage does not resonate due to leakage reactance, and the wiring length from the clamp diode to the smoothing capacitor is short, the voltage across the clamp diode rises because the line voltage cannot be clamped to the DC bus voltage. Also, the breakdown voltage of the clamp diode is not exceeded and the diode is not destroyed.

[0025]

【Example】

Example 1. The first and second inventions will be described with reference to the drawings. 1A and 1B are manufacturing examples of an in-phase reactor according to an embodiment of the second invention. FIG. 1A is a plan view of the reactor, and FIG. 1B is a sectional view of the reactor showing an AA cross section of FIG.
In the figure, 110 is an insulating substrate such as a metal printed circuit board on which an insulating thin film is formed on a metal substrate having good thermal conductivity, and a conductive thin film is used to form a pattern thereon, 111 is a pattern on the insulating substrate 110, 112 Is an insulating coated ring-shaped core, 113 is a wire (for U phase, V phase, W phase), 114 is a ring-shaped core 112 and pattern 111
An insulating material such as an under resist, which is inserted between and. The reactor of this embodiment includes an insulating substrate 110, a ring-shaped core 112, a plurality of strip-shaped patterns 111 arranged at predetermined intervals on the insulating substrate 110 so as to cross the ring of the core 112, and one strip-shaped pattern 111. Another strip pattern 111 separated from the strip pattern 111 by a predetermined number
And an insulating substrate 110, which is composed of a wire 113 connecting
Of the insulating material 11 near the plurality of strip-shaped patterns 111 of
The core 112 is arranged via 4 and the core 11 is provided for each of the three phases.
2 one strip-shaped pattern on the inner side of the ring is connected to one strip-shaped pattern 111 on one side of the wire 113, and the wire 113 is arranged so as to straddle the core 112. The coil composed of the pattern 111 and the wire 113 is wound around the ring-shaped core 112 by connecting to the ring 111 and repeating this.

FIG. 2 is a comparison diagram of the reactor of the present invention and the conventional reactor. In the coil of this invention,
Since each wire 113 needs only a short distance, it does not need to be covered, and an outer diameter of about 0.3 mm is sufficient.
Moreover, since the pattern 111 is a pattern of a metal substrate,
About 0.5 mm is sufficient. In addition, the insulation distance for providing the withstand voltage of 600 V necessary for use in the inverter device is sufficient if the wires 113 are filled with silicon gel or the like, and the distance between the wires 113 is about 1 mm. 0.8 mm if coated
The degree is enough.

The inductance L of the coil is represented by the following equation, where n is the number of turns and 1 is the magnetic path length. L∝n ² / l From the above formula, the smaller the magnetic path length l, the larger the inductance L, and the more turns n wound around the small core (core with a small window area), the more efficiently the inductance L can be manufactured. it can. The conventional coil is inefficient because it uses a large-diameter skin-covering wire, so that the window area is large, and therefore a large number of turns must be wound around a core having a long magnetic path length. In the conventional coil manufacturing example, a heat-resistant vinyl electric wire AWG26 having an outer diameter of 2.
2 mm is required. Further, in the conventional coil, it is difficult to dissipate heat, so the core wire becomes thick, and since vinyl is used to withstand pressure, the jacket becomes thick. In addition, the thicker the jacket, the worse the heat dissipation, which may lead to a vicious circle in which the core wire must be thicker. Further, in the above description, an example of an in-phase reactor manufactured by winding coils for three phases of U-phase, V-phase and W-phase for each phase is shown, but in the case of a single phase, only one phase is considered. Just do it.

Example 2. Although the example in which the insulating material is interposed between the pattern and the core has been described in the first embodiment, it is also possible to use a core coated with an insulating coating.

Example 3. FIG. 3 is a manufacturing example of the reactor in one embodiment of the present invention. Although the reactor is manufactured on the insulating substrate 110 as in the first embodiment,
The bonding pad 115 is interposed between the pattern 113 on the insulating substrate 110 in FIG. 1 and the wire 113.

Example 4. In the first embodiment, the insulating substrate 110
Although an insulating thin film is applied on a metal substrate with good thermal conductivity and a metal printed circuit board on which a pattern is formed with a conductive thin film is used, the same effect can be obtained by using a DBC (Direct Bonding Copper) or the like. You can get it.

Example 5. FIG. 4 is a plan view of the main circuit board according to the third embodiment of the present invention and corresponds to the circuit diagram of FIG. In the figure, 20 and 21 are in-phase reactors, which correspond to 60 in FIG. 14 and are configured by connecting two in series. 22
˜27 are diodes, which correspond to 61 in FIG. 28
-30 are capacitors and correspond to 62-64 in FIG.
Reference numeral 31 is a bonding pad for wire bonding, 32 is a wire, and 33 is a pattern on the main circuit board 1.

Since the winding of the reactor of the present invention is formed by the thin wire 32 and the pattern 33, the number of turns can be increased even with a small core, and the reactor can be efficiently manufactured. FIG. 5 is a comparison diagram of the stray capacitance of the reactor, and FIG. 5 (a) shows the case of one conventional reactor.
(B) is a case of two reactors of the present invention. Since the reactor of the present invention uses a small core,
Two capacitors are used in series as compared with the conventional one, but as shown in FIG. 5B, the capacitance between the lines is halved due to the series connection. Therefore, by connecting in series, the high frequency characteristics of the reactor are improved as compared with the conventional case. In addition, since the wiring of the main circuit element and the reactor can be shortened, the leakage reactances L ₁ 76, L ₂ 78 and the like in FIG. 10 can be reduced, and a filter with good characteristics can be formed.

In the above description, the case where the reactor of the present invention is used as the in-phase reactor has been described, but the power factor improving reactor 79 of FIG. 18 can be mounted on the main circuit board as shown in FIG. 6, and in this case. But Figure 18
By dividing the reactor 79 of 2 into 40 and 41,
The inductance value can be increased and the stray capacitance can be reduced, and the heat dissipation can be improved.

[0034]

As described above, according to the present invention, since the components such as the reactor are arranged on the same substrate as the main circuit element, a reactor having a small leakage reactance and a stray capacitance can be formed, and the heat dissipation is good. It is possible to obtain a filter with good characteristics.

Further, by using the reactor according to the present invention, a reactor having a small leakage reactance and a small stray capacitance can be formed, and the core of the reactor is adhered onto an insulating substrate such as a metal substrate having a good heat dissipation property. Since the generated heat is efficiently dissipated, a small and thin inverter device having a filter with good characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a manufacturing example of a reactor according to an embodiment of the present invention.

FIG. 2 is a comparison diagram of a reactor according to an embodiment of the present invention and a conventional reactor.

FIG. 3 is a manufacturing example of a reactor according to an embodiment of the present invention.

FIG. 4 is a plan view of a main circuit board of an inverter device using the reactor of the present invention.

FIG. 5 is a comparison diagram of stray capacitances of a reactor according to an embodiment of the present invention and a conventional reactor.

FIG. 6 shows another embodiment of the present invention in which a power factor improving reactor is mounted on a main circuit board.

FIG. 7 is a block diagram of a conventional inverter device and a connection diagram thereof.

FIG. 8 is an explanatory diagram of voltage waveforms during switching of the conventional inverter device.

FIG. 9 is a sectional view of a main circuit portion of a conventional inverter device.

FIG. 10 is an equivalent circuit diagram showing a path of common mode noise in a conventional inverter device.

FIG. 11 is a common-mode filter for smoothing changes in common-mode voltage and a connection diagram thereof.

FIG. 12 is an equivalent circuit diagram showing a path of common mode noise of an inverter with a common mode filter.

FIG. 13 is a configuration diagram when a differential filter is used.

FIG. 14 is a substantial wiring diagram of a conventional inverter main circuit unit with an in-phase filter.

FIG. 15 is an equivalent circuit diagram of FIG.

16 is a voltage waveform of FIG.

FIG. 17 is a voltage waveform of FIG.

FIG. 18 is a circuit diagram when the present invention is used in another portion of the inverter device.

FIG. 19 is a view showing a manufacturing member and a manufacturing process of a conventional in-phase reactor.

[Explanation of symbols]

 1 Main Circuit Board 2-7 Switching Element 8-13 Feedback Diode 14-19 Rectifier Diode 20, 21 Core 31 Bonding Pad 32 Wire 33 Pattern 51 Inverter Device 53 Smoothing Capacitor 60 In-Phase Reactor 61 Voltage Clamp Diode 62-64 Capacitor 70-72 Differential reactor 73 to 75 Capacitor 76, 78 Wiring inductance 77 Reactor line capacity 79 Reactor for power factor improvement 110 Insulating substrate 111 Pattern on insulating substrate 112 Core 113 Wire 114 Insulating material

Claims (3)

[Claims] 1. A metal printed circuit board on which an insulating thin film is formed on a metal substrate, and a pattern is formed on the metal thin film with a conductive thin film, a ring-shaped iron core, and a ring of the iron core.
A plurality of strip-shaped patterns arranged at a predetermined interval on the metal printed circuit board, a bonding pad provided on a land portion of the strip-shaped pattern, and another strip-shaped pattern separated from one strip-shaped pattern by a predetermined number. A wire connecting one of the strip-shaped patterns, and an insulating material for insulating the ring-shaped iron core and the strip-shaped pattern, in proximity to the plurality of strip-shaped patterns of the metal printed board,
The iron core is arranged through the insulating material, one strip-shaped pattern inside the ring of the iron core is connected to one end of the wire, or is connected through a bonding pad, so that the wire straddles the iron core. Arranged, connected to another strip-shaped pattern outside the ring of the iron core separated by a predetermined number, or connected through a bonding pad, by repeating this, the pattern and the ring-shaped iron core A reactor for a switching device, in which a coil made of a wire is wound. 2. A ring-shaped iron core is wound with coils of the pattern and the wire for a plurality of phases in the same direction for each phase to form a common-mode reactor that operates only for common-mode voltage. The reactor according to claim 1. 3. The in-phase reactor according to claim 2, wherein in an inverter device including a plurality of switching elements which receives power from a DC power source and converts direct current into alternating current, on a metal printed board on which the plurality of switching elements are mounted. An inverter device characterized in that a common-mode filter including a switch is provided on the output side of the switching element.