JP3635984B2 - Power converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power conversion device that includes a reactor, a power conversion circuit configured by a series connection circuit of power semiconductor elements, and a control circuit that drives the power conversion circuit, and is formed by integrating them.
[0002]
[Prior art]
FIG. 4 is a schematic exploded configuration diagram showing a conventional example of a step-down chopper device that is typical as this type of power conversion device.
5 is a schematic cross-sectional configuration diagram of the step-down chopper device shown in FIG. 4, and FIG. 6 is a circuit configuration diagram of the step-down chopper device having the configuration shown in FIG.
[0003]
In the schematic exploded view shown in FIG. 4, the reactor 10 includes a flat plate coil conductor 11 shaped like a spiral as shown in the figure, a magnetic plate 12 covering one plane of the flat plate coil conductor 11, and the flat plate coil conductor 11. As shown in the figure, a magnetic plate 13 having a through hole at the center is integrally formed. Further, the semiconductor substrate 20 has a series connection circuit of a MOSFET 21a and a MOSFET 21b as power semiconductor elements. The configured power conversion circuit 21 and a control circuit 22 for driving the power conversion circuit 21 are mounted. Further, an insulating plate 31 having a through hole in the central portion between the reactor 10 and the semiconductor substrate 20 as shown in the figure. Has been inserted.
[0004]
The reactor 10, the insulating plate 31, and the semiconductor substrate 20 shown in FIG. 4 are stacked as shown in the schematic cross-sectional configuration diagram shown in FIG. 5, and as shown in the cross-sectional configuration diagram, the outer peripheral portion and the internal gap of the flat coil conductor 11 are stacked. The part is filled with an insulator 14.
[0005]
Furthermore central end of the flat coil conductor 11 shown in FIG. 4 ₍₁ part code M), the connection point between MOSFET21a and MOSFET21b (reference numeral M ₂ parts), the magnetic material plate 13, insulating plate 31 of each of the through- They are connected via connection conductors (not shown) that pass through the holes.
[0006]
Accordingly, FIG. 4, step-down chopper apparatus shown in FIG. 5 becomes such circuit configuration shown in FIG. 6, the external DC power supply across the series connection circuit (reference numeral P _i, N _i portion) between MOSFET21a and MOSFET21b 1, a load 2 is connected between the outer peripheral end of the reactor 10 (reference P _o ) and the negative terminal (reference N _i ) of the external DC power supply 1, and the control circuit 22 causes a MOSFET 21 a to be connected. By alternately turning on and off the MOSFET 21b, a DC voltage stepped down from the DC voltage of the external DC power supply 1 can be supplied to the load 2.
[0007]
[Problems to be solved by the invention]
In the circuit configuration of the conventional step-down chopper device shown in FIG. 6, the capacitor 3 serves to smooth the voltage across the load 2. The capacitor 3 is composed of the reactor 10, the semiconductor substrate 20, and the insulating plate 31. Must be installed outside the integrated structure, which is a factor in increasing the size and cost of the entire power conversion device such as a step-down chopper device.
An object of the present invention is to solve the above-described problems and provide a power converter such as a small-sized and low-cost step-down chopper device.
[0008]
[Means for Solving the Problems]
The power conversion device according to the present invention includes a flat plate coil conductor having an outer peripheral portion and an internal gap filled with an insulator and shaped in a spiral shape, a first magnetic plate covering one plane of the flat plate coil conductor, A reactor formed by integrating a second magnetic plate having a through hole in the central portion covering the other flat surface of the flat coil conductor, and a module formed of a series connection circuit of power semiconductor elements A power conversion circuit, a control circuit that is formed in the same module as the power conversion circuit, is connected to one end of the series connection circuit, and has a through hole in the center. An electrode plate having substantially the same outer peripheral shape as the reactor, and a first insulating plate inserted between the electrode plate and the power conversion circuit and having a through hole in the center and the same outer peripheral shape as the reactor And the electrode plate Inserted between the serial reactors, and has a through hole in the center portion and a second insulating plate of the same outer peripheral shape as the reactor, the center of the intermediate connection point of the series connection circuit the flat coil conductor The ends are connected to each other through the respective through holes.
[0009]
According to the present invention, the power conversion device can be made more compact by making the power conversion device positively using the stray capacitance interposed between the plate coil conductor and the electrode plate laid close to each other. The price can be reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic exploded configuration diagram showing an embodiment of a step-down chopper device that is typical as a power conversion device of the present invention.
FIG. 2 is a schematic cross-sectional configuration diagram of the step-down chopper device shown in FIG.
Further, FIG. 3 is an equivalent circuit configuration diagram of the step-down chopper device shown in FIG.
1 to 3, components having the same functions and structures as those of the conventional apparatus shown in FIGS. 4 to 6 are denoted by the same reference numerals.
[0011]
That is, in the schematic exploded view shown in FIG. 1, the reactor 10 includes a flat coil conductor 11 shaped like a spiral as shown in the figure, a magnetic plate 12 covering one plane of the flat coil conductor 11, and a flat coil conductor. 11 is formed integrally with a magnetic plate 13 having a through hole at the center as shown in the figure, and a series connection circuit of MOSFET 21a and MOSFET 21b as power semiconductor elements is formed on the semiconductor substrate 20. And a control circuit 22 for driving the power conversion circuit 21 are mounted. Furthermore, as shown in the drawing, the electrode plate 23 has a through hole in the center and has substantially the same outer peripheral shape as the reactor 10. end (code N _O unit) is connected MOSFET 21, to one end of the series connection circuit of the 21b (code N _i part), also the electrode plate 23 and the semiconductor substrate 2 As shown in the figure, an insulating plate 24 having a through hole at the center is inserted between the electrode plate 23 and the reactor 10, and the center between the electrode plate 23 and the reactor 10 as shown in the figure. An insulating plate 31 having a through hole in the part and having the same outer peripheral shape as that of the reactor 10 is inserted.
[0012]
The reactor 10, the insulating plate 31, the electrode plate 23, the insulating plate 24, and the semiconductor substrate 20 shown in FIG. 1 are stacked as shown in the schematic cross-sectional configuration diagram shown in FIG. An insulator 14 is filled in the outer peripheral portion and the internal gap portion of the conductor 11.
[0013]
Furthermore central end of the flat coil conductor 11 shown in FIG. 1 ₍₁ part code M), and a connection point between MOSFET21a and MOSFET21b (code M ₂ parts), the magnetic plate 13, insulating plate 31, the electrode plate 23 The insulating plates 24 are connected via connection conductors (not shown) that pass through the through holes.
[0014]
Accordingly, FIG. 1, the step-down chopper device of the configuration shown in FIG. 2 becomes such circuit configuration shown in FIG. 3, the external DC power supply across the series connection circuit (reference numeral P _i, N _i portion) between MOSFET21a and MOSFET21b 1 DC voltage is supplied from the outer peripheral edge portion of the reactor 10 (reference numeral P _o portion), the negative terminal of the external DC power source 1 end of (code N _i part) the same potential of the electrode plate 23 (code N _O unit ), And the control circuit 22 alternately turns on and off the MOSFET 21a and the MOSFET 21b, so that a DC voltage stepped down from the DC voltage of the external DC power supply 1 can be supplied to the load 2.
[0015]
At this time, as shown in FIG. 2, the stray capacitance C _S interposed between the laminated flat plate coil conductors 11 and the electrode plates 23 functions to smooth the voltage across the load 2. In recent years, it has become possible to smooth the voltage across the load 2 with only the stray capacitance C _S by using a high-speed power semiconductor element constituting the power converter.
[0016]
【The invention's effect】
According to the present invention, as described above, by making a power conversion device that positively utilizes the stray capacitance interposed between the laminated flat plate coil conductor and the electrode plate, the power conversion device can be made smaller and less expensive. For example, it is a power conversion device suitable as an internal power source of a mobile phone or the like.
Although an example of a step-down chopper device has been described as the power conversion device of the present invention, it can also be applied to a step-up chopper device or the like.
[Brief description of the drawings]
FIG. 1 is a schematic exploded configuration diagram of a power conversion device showing an embodiment of the present invention. FIG. 2 is a schematic cross-sectional configuration diagram of FIG. 1. FIG. 3 is an equivalent circuit configuration diagram of FIG. FIG. 5 is a schematic cross-sectional configuration diagram of FIG. 4. FIG. 6 is a circuit configuration diagram of FIG. 4.
DESCRIPTION OF SYMBOLS 1 ... DC power supply, 2 ... Load, 3 ... Capacitor, 10 ... Reactor, 11 ... Flat coil conductor, 12, 13 ... Magnetic board, 20 ... Semiconductor substrate, 21 ... Power conversion circuit, 21a, 21b ... MOSFET, 22 ... Control circuit, 23 ... electrode plate, 24, 31 ... insulating plate.

Claims (1)

An outer peripheral portion and an internal gap are filled with an insulator, and a spirally shaped flat coil conductor, a first magnetic plate covering one flat surface of the flat coil conductor, and the other flat surface of the flat coil conductor A reactor formed by integrating a second magnetic plate having a through hole in the central portion to be covered;
A power conversion circuit formed as a module and configured by a series connection circuit of power semiconductor elements;
A control circuit that is formed in the same module as the power conversion circuit and drives the power conversion circuit;
An electrode plate connected to one end of the series connection circuit and having a through hole in the center and substantially the same outer shape as the reactor;
A first insulating plate that is inserted between the electrode plate and the power conversion circuit and has a through hole in the center and has the same outer peripheral shape as the reactor;
The inserted between the electrode plates and the reactor, and a second insulating plate of the same outer peripheral shape as the reactor and has a through hole in the center portion,
A power conversion device comprising: an intermediate connection point of the series connection circuit and a central end portion of the flat coil conductor connected through the respective through holes.

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