JP3149648B2 - Semiconductor converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor converter having a semiconductor switching element in a main circuit formed of a bridge circuit, and a circuit of a driving circuit for sending a driving signal for causing the semiconductor switching element to perform a switching operation. The present invention relates to a configuration and a configuration of a wiring pattern used when a drive circuit is mounted on a printed wiring board.

[0002]

2. Description of the Related Art A semiconductor converter having a main circuit formed of a bridge circuit and having a semiconductor switching element for mutually converting DC and AC and supplying the load to a load is widely used as an inverter or the like in a power application field or the like. Already used in FIG. 3 shows a general circuit example of a three-phase inverter that converts DC into three-phase AC having a variable frequency as such a semiconductor converter. The three-phase inverter according to this example is
This is a semiconductor converter having a three-phase bridge circuit configuration and supplying a three-phase AC voltage to the motor 9 using a DC main power supply (Vd). The three-phase inverter includes an upper side circuit section 10 for controlling the high potential side of the three-phase AC voltage and a lower side circuit section 30 for controlling the low potential side of the three-phase AC voltage.

[0003] The upper side circuit section 10 includes a main circuit and a drive circuit. The main circuit of the circuit section 10 is configured U, V, transistors 20-22 of known bipolar as semiconductor switching elements provided respectively on each side of the W. The drive circuit of the circuit unit 10 includes an individual drive circuit 1 that individually sends out a drive signal for causing each of the transistors 20 to 22 to perform a switching operation.
4-16 (in the figure, denoted by the sign of D _U to D _W.) Is composed of. Each of the individual drive circuits 14 to 16 includes a DC auxiliary power supply 1
7 to 19 and a control signal (not shown) and the like are input.

The lower side circuit section 30 has substantially the same configuration as the upper side circuit section 10. The main circuit of the circuit unit 30 includes:
Semiconductor switches provided on each side of X, Y, Z
Well-known bipolar transistor 4 as a switching element
0-42. The drive circuit of the circuit unit 30 is
Each of the transistors 40 to 42 is constituted by individual driving circuits 34 to 36 (indicated by D _{X to} D _{Z in} the drawing) for individually transmitting driving signals for causing the transistors 40 to 42 to perform a switching operation. ing. Individual drive circuits 34-3
6, a common DC auxiliary power supply 37, a control signal (not shown) and the like are input from the outside.

In the three-phase inverter shown in FIG. 3 having this circuit configuration, a DC main power supply (Vd) is passed through a main circuit line 100 on the positive electrode side and a main circuit line 101 on the negative electrode side, and a DC main current (I _C ) is supplied. By the transistors 20 to 22 and 40 to 42 performs a switching operation, the DC-side main current (I _C) is the DC main power source (Vd)
Positive electrode → main circuit line 100 → transistors 20-22
Of the transistors → the motor 9 → the transistor of the transistors 40 to 42 → the main circuit line 101 → the negative electrode of the DC main power supply (Vd). Supply.

A three-phase inverter having such a circuit configuration is
It is often configured using two circuit boards as shown in FIG. That is, transistors 20 to 22 and 4
The main circuits 0 to 42 are formed on the main circuit board 3 on which the semiconductor chip 4 having these functions is mounted. The individual drive circuits 14 to 16 and 34 to 36 are configured on a drive circuit board 5 which is a circuit board on which these individual drive circuits are integrally mounted. The main circuit board 3 and the drive circuit board 5 are both housed inside a container configured with the case 1 and the base 2 having good thermal conductivity.
The main circuit board 3 and the drive circuit board 5 are interconnected by the internal connection leads 6. Further, a control signal and auxiliary power supplies 17 to 19 and 37 are supplied to the drive circuit board 5 from the outside via the external connection leads 7.

By the way, in the conventional three-phase inverter,
The drive circuit board 5 is often configured as shown in FIG. That is, the drive circuit board 5 uses a double-sided printed wiring board, and the individual drive circuits 14 to 16 and the individual drive circuits 34 to 36 are both mounted on the front surface 5 a side of the drive circuit board 5. Incidentally, in the individual drive circuits 14 to 16, the respective ground potentials are connected to the respective emitters of the transistors 20 to 22 included in the upper side circuit unit 10. For this purpose, the wiring patterns 11 to 13 on which the individual drive circuits 14 to 16 are mounted are formed as separate wiring patterns on the conductor on the foil-shaped surface 5a side of the double-sided printed wiring board. At that time, the individual drive circuit 1
The wiring patterns 11 and 12 for the wires 4 and 15 are integrally formed including the terminal portions connected to the connection leads 6 and 7. However, the wiring pattern 1 for the individual drive circuit 16
Reference numeral 3 designates a portion connected to a terminal portion connected to the connection leads 6 and 7, which is structurally separated as a wiring pattern 51. The wiring pattern 51 is formed using the foil-like conductor of the back surface 5b of the double-sided printed wiring board.

In the individual drive circuits 34 to 36, the respective ground potentials are connected to a line 45 to which the respective emitters of the transistors 40 to 42 provided in the lower side circuit section 30 are connected together. This line 45
This is a common ground potential line for defining a ground potential that is a common reference potential on the negative electrode side. For this purpose, the individual drive circuits 34 to 36 are mounted on the common wiring pattern 31. The wiring pattern 31 is formed using a foil-like conductor on the front surface 5a of the double-sided printed wiring board. At this time, the wiring pattern 31 is
The portion connected to the terminal portion connected to the wiring 7 is formed as a wiring pattern 52 so as to be structurally separated. The wiring pattern 52 is formed using a conductor on the side of the foil-shaped back surface 5b of the double-sided printed wiring board.

That is, the drive circuit board 5 of the conventional example shown in FIG. 5 has wiring patterns on both surfaces 5a and 5b. However, since the double-sided printed wiring board is used, the distance between the individual drive circuits 14 to 16 and the distance between the individual drive circuits 14 to 16 and the individual drive circuits 34 to 36 combined by the wiring pattern 31 are different. The necessary electrical insulation is well maintained.

By the way, 3 provided with the circuit configuration shown in FIG.
The phase inverter converts the DC main power supply (Vd) into three-phase AC, so that the transistors 20 to 22 on the upper side and the transistors 40 to 42 on the lower side alternately perform a switching operation according to a cycle corresponding to the control signal. I do. that time,
In general, each of the transistors 20 to 22 on the upper side performs a switching operation with a time difference corresponding to an electrical angle of 120 ° to make the three-phase alternating current a balanced three-phase alternating current. Also, each of the transistors 40 to
The same operation is performed during 42. Further, a group of transistors 20 to 22 on the upper side and a transistor 40 on the lower side
Between the groups of .about.42, the opposing transistors, for example, the transistor 20 and the transistor 40, need to perform a switching operation with a time difference corresponding to an electrical angle of 180.degree. is there.

[0011]

One of the most important things in configuring a semiconductor converter is to prevent malfunction of each semiconductor switching element. If the semiconductor switching element malfunctions, an arm short circuit occurs and an excessive current flows, which may lead to a serious accident such as destruction of the semiconductor switching element or a driven device such as an electric motor. Because.

In recent years, due to the development of semiconductor technology, the frequency of malfunctions of the semiconductor switching element caused by the semiconductor switching element itself has been extremely reduced, and the reliability of the semiconductor conversion device has been improved. However, besides the semiconductor switching element, there may be several things that can cause a malfunction in the semiconductor switching element. One of them is derived from the configuration of the drive circuit board. In a three-phase inverter, the emitter potential of transistors 20 to 22 is
2, and changes at different timings according to the above-described switching operations of 40 to 42. For this reason, in the drive circuit board provided in the three-phase inverter, the potential of each wiring pattern connected to the emitters of the transistors 20 to 22 constantly fluctuates.

In the case of the configuration of the drive circuit board 5 provided in the above-described conventional three-phase inverter, the individual drive circuit 1
Attention is particularly paid to the wiring pattern 13 on which the wiring 6 is mounted and the wiring pattern 51 electrically connected thereto. That is, as shown in FIG.
This is because the wiring pattern 52 and the wiring pattern 51 have portions opposed to each other with the wiring pattern 12 sandwiching the insulating substrate of the double-sided printed wiring board. Since these opposing portions have the same configuration as the capacitor, there is a relatively large value of parasitic capacitance. The high frequency current is
It easily flows through this large value of parasitic capacitance. Therefore, when the potential of the emitter of the transistor 22 fluctuates sharply, a high-frequency current may flow from the wiring patterns 13 and 51 into the wiring patterns 31 and 12 via the parasitic capacitance. The transistors 21 and 40 to 42 driven by the individual driving circuits 15 and 34 to 36 mounted on the wiring patterns 12 and 31, respectively,
A malfunction may occur.

The wiring pattern 31 is longer than the wiring patterns 11 to 13 because the individual driving circuits 34 to 36 are integrally mounted thereon. The wiring pattern 52 is the wiring pattern 31.
In this case, the wiring pattern is longer than the wiring pattern 31 because it is necessary to connect the wiring pattern to the terminal portion connected to the connection leads 6 and 7. Incidentally, the wiring pattern 52a for the common ground potential line 45 is also formed in the wiring pattern 52. This wiring pattern 52a, as shown in FIG.
Is formed so as to surround the region of the wiring pattern 52. The ground potential line 45 applies a common reference potential to the individual drive circuits 34 to 36 and is also electrically connected to the emitters of the transistors 40 to 42 and the negative side of the auxiliary power supply 37. Therefore, the main circuit line 101 and the emitters of the transistors 40 to 42 are electrically connected to the ground potential line 45.

For this reason, a part of the DC-side main current (I _C ) is shunted from the main circuit line 101 to the ground potential line 4.
It also flows to 5. In particular, if it contains high-frequency components in the DC side main current (I _C), for the inductance of the main circuit line 101, ratio shunted to ground line 45 of the high-frequency component is increased. FIG. 6 shows a main part of the ground potential line 45 together with its peripheral circuits. The above will be described in detail with reference to FIG. FIG.
As shown in the figure, when the transistor 41 is turned on, the main circuit line 101 to which the emitter of the transistor 41 is connected receives a direct current (I _CY ) flowing toward the negative side of the direct current main power supply (Vd). Flow begins. Immediately after the transistor 41 is turned on, the value of the DC-side main current (I _CY ) sharply increases, so that the ratio of the high-frequency component is extremely large. The main circuit line 101 has a parasitic inductance (L) between a portion of the main circuit line 101 where the emitter of the transistor 41 is connected and a portion where the emitter of the transistor 40 is connected.
1) always exists even if it is not intended. The presence of this parasitic inductance (L1) causes a shunt (I _l1 ) to flow to the ground potential line 45 as described _below . That is, the shunt (I _l1 ) is determined by the main circuit line 101 → the connection point with the emitter of the transistor 41 → the ground potential line 45 → the connection point with the emitter of the transistor 40 → the main circuit line 1
01, flows through the ground potential line 45. This shunt (I _l1 ) generates a high-frequency voltage in the parasitic inductance (L2, L3, L4, etc.) of the ground potential line 45. For this reason, a circuit element having a ground potential connected between them (a circuit element (not shown) constituting the individual drive circuits 34 and 35) causes a difference in the ground potential. If there is a difference in the ground potential, there is a possibility that the original function of the ground potential may not be fulfilled, whereby the circuit element may malfunction. In this case, since the individual drive circuits 34 and 35 transmit an erroneous drive signal, a feared malfunction may occur in the transistors 40 and 41. This also applies to the individual drive circuit 36 for the transistor 42.

In view of the above problems, it is an object of the present invention to review a wiring pattern of a drive circuit board used for a semiconductor converter such as an inverter and to provide a semiconductor converter with less malfunction.

[0017]

According to the present invention, there are provided the following objects: 1) a bridge circuit configuration having at least two upper sides and at least two lower sides of the bridge circuit configuration ; a main circuit semiconductor switching elements are provided respectively, are mounted on the wiring pattern by a foil-like conductor printed wiring board has, as described above to drive to cause the semiconductor switching element to perform the switching operation, each of the semiconductor an apparatus and a driving circuit for chromatic individual drive circuits provided in correspondence with the switching element, the individual drive circuit, define a dedicated reference potential pieces
With another criteria potential line separately, wherein the drive circuit, e Bei co Tsumoto quasi potential line defining a common reference potential for each individual by the drive circuit of the upper edge or the lower edge, No, respectively Re its pieces by criteria potential line, it is a formed by connecting in one position with respect to co Tsumoto quasi potential line of the corresponding side configuration, or 2) has a 3-phase bridge circuit configuration, the three-phase bridge times
A main circuit semiconductor switching element is provided in each of the upper sides of each side and the lower side of the road configuration, it is mounted on the wiring pattern by a foil-like conductor printed wiring board has, the semiconductor switching elements as to drive in order to perform a switching operation, it has a separate driver circuit provided in correspondence to each of the semiconductor switching elements
An apparatus and a driving circuit for the individual drive circuits, the individual criteria potential line define a dedicated reference potential
It provided separately, wherein the drive circuit, e Bei co Tsumoto quasi potential line defining a common reference potential for each individual <br/> another driving circuit of the upper edge or the lower edge, their respective the individual by criteria potential line, be formed by connecting in one position with respect to co Tsumoto quasi potential line of the corresponding edge structure, it is achieved by.

[0018]

In the present invention, As mentioned above,
Road is the upper or lower sidePiecesSeparate drive circuitEveryCommon group
Specify the quasi-potentialCommon groupEquipped with a quasi-potential line, and
Semiconductor switching element on each of the upper and lower sides
Each individual drive circuit that drives the
Specify the rankIndividual groupQuasi-potential lineIndividuallyBe prepared
And the individualSeparate groupThe quasi-potential line is the corresponding sideCommon group of
It should be connected to the quasi-potential line at one place.
As a result, the DC main power supply (Vd) is
DC main current (I_C )
OfCommon groupWhen flowing through the quasi-potential line,Another
BaseThe potentials of the quasi-potential lines areCommon groupConnected to quasi-potential line
The potential of the point that was hit. This potential isSeparate groupAssociate
It is uniform in the potential line. This enables individual drive
No difference in reference potential in circuit
You. As a result, the difference of the reference potential in the individual drive circuit
Cause an incorrect drive signal to be sent from the individual drive circuit.
The issue is cancelled.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. Reference Example; FIG. 1, the three-phase inverter according to Embodiment of this invention, is an explanatory view showing a configuration of a driving circuit board. Since the three-phase inverter according to the present embodiment has the same circuit configuration as the conventional example described above with reference to FIG. 3, the description of the circuit operation will be omitted. The three-phase inverter according to the present embodiment includes a main circuit board 3 having the same configuration as that described above with reference to FIG. 4 and individual driving circuits 14 to 16 and 34 to
And the drive circuit board 5 according to the present embodiment, which is integrally mounted.

In the drive circuit board 5 of the present embodiment shown in FIG. 1, the independent wiring patterns 11 to 13 for the individual drive circuits 14 to 16 are all connected to the connection leads 6 and 7.
The surface 5a of the substrate 5 including the terminal portion connected to the
Formed on the side. Accordingly, the wiring pattern 51 provided in the conventional example does not exist. In addition, the individual driving circuit 3
The common wiring pattern 31 for 4 to 36 is also formed integrally on the surface 5a side of the substrate 5 including the portion provided in the wiring pattern 52 in the conventional example. As a result, the terminal portions connected to the connection leads 6 and 7 and the wiring pattern 52a for the ground potential line 45 are also formed on the surface 5a side of the substrate 5. Therefore, these wiring patterns 11 to 13 and 31 do not have any portions which are in a positional relationship facing each other across the insulating substrate of the double-sided printed wiring board as in the conventional example.

As described above, since the wiring patterns facing each other are not formed, the wiring patterns 11 to 11 are formed.
The value of the parasitic capacitance formed between 13 and 31 is extremely small. For this reason, the value of the high-frequency noise current flowing through the different wiring patterns through the parasitic capacitance between the wiring patterns becomes extremely small. As a result, the occurrence of malfunction of the individual drive circuits 15 and 34 to 36 caused by the high frequency noise current and the possibility of malfunction of the transistors 21 and 40 to 42 are greatly reduced. Therefore, a very reliable 3
A phase inverter can be realized.

[0022] In the description reference example so far, has been explained by the drive circuit board 5 configured by using the both surfaces printed wiring board, is not limited to Re this. That is, in a three-phase inverter having an individual drive circuit for driving each transistor provided in a main circuit having a three-phase bridge circuit configuration, a printed circuit board used as a drive circuit board may be a single-sided printed circuit board. Even in the case of a multilayer printed wiring board, a three-phase inverter with very few malfunctions can be realized if the wiring patterns for mounting the individual drive circuits are arranged so that the wiring patterns facing each other are not provided. Of course.

Further, in the description of the reference examples so far ,
Has been described as a three-phase inverter using transistors of the bipolar type according to a known NPN type semi conductor switching element, it is not limited to Re this. The same operation and effect can be obtained even when an appropriate type of voltage-driven transistor such as a PNP-type bipolar transistor, a MOSFET, an IGBT, or an appropriate type of thyristor is used as the semiconductor switching element. .

It should be noted also in the description of Example ever, the wiring pattern 52a for ground potential line 45, the peripheral portion of the wiring pattern 52, has been to be formed so as to surround a region of the wiring pattern 52, is not limited to is this. When a double-sided or multi-layer printed wiring board is used, the wiring pattern 52a is separated from the wiring pattern 52 and formed on a conductor on a different layer from the conductor on which the wiring pattern 52 is formed, for example, on the back surface 5b side. May be done. In this case, for example, it is preferable that the wiring pattern 52a has the same shape as the wiring pattern 52 except for the terminal portion, and is formed to face the wiring pattern 52, for example. Accordingly, the wiring pattern 52a can reduce the values of the parasitic inductance and the resistance that cause the fluctuation of the ground potential by increasing the cross-sectional area of the conductor.

[0025] Example; FIG. 2 is an explanatory diagram showing together with the peripheral circuit configuration of the ground potential line of a main part of the three-phase inverter according to an embodiment of the invention corresponding to claim 1.
As shown in FIG. 2, the three-phase inverter according to the present embodiment separately supplies the ground potential, which is the reference potential on the negative electrode side, to the individual drive circuits 34 and 35 that transmit drive signals to the transistors 40 and 41 on the lower side. Individual ground potential lines 46 and 47 for defining
It has. Further, wiring patterns (not shown) corresponding to the individual ground potential lines 46 and 47 are formed on the drive circuit board 5 provided in the three-phase inverter of this example. These individual ground potential lines 46 and 47 are connected to the ground potential line 4 at one of the connection lines 46a and 47a, respectively.
5 is connected. Although not shown in FIG. 2, the individual drive circuit 36 for sending a drive signal to the transistor 42 on the lower side is also formed with an individual ground potential line. Connected to the ground potential line 45 by the individual driving circuit 3
This is the same as in the case of 4,35.

As described above, the individual driving circuits 34 to 36
In the driving circuit of the present example the individual ground line of each dedicated individual is provided, the DC-side main current supplied to the main circuit of a three-phase inverter from the DC main power source (Vd) (I _C)
[In FIG. 2, only the split flow (I _l1 ) is shown. ]
Flows through the ground potential line 45, the ground potentials of the individual ground potential lines 46, 47 and the like are changed to the connection lines 46a, 47
It becomes the potential of the common ground potential line 45 at the point connected by a or the like. This potential is applied to the individual ground potential line 4
6, 47, etc. may be different from each other, but are uniform inside the same individual ground potential lines 46, 47, etc. As a result, even if a difference in the ground potential occurs due to the shunt flowing through the parasitic inductance (L2, L3, L4) or the like of the ground potential line 45, the internal of each individual drive circuit 46, 47, etc. Does not cause a difference in ground potential. Therefore, it is possible to prevent the individual drive circuits 46, 47 and the like from transmitting an erroneous drive signal due to the difference in the ground potential inside the individual drive circuits 46 and 47 and the like.

[0027] In the description up to now, in Example,
The case where a bipolar transistor of the NPN type is used as the semiconductor switching element has been described as an example. However, in the case of using a PNP transistor or the like in at least the upper side circuit portion, the three-phase inverter has the same potential for the emitters of the transistors provided in the upper side circuit portion. By providing a dedicated individual reference potential line for setting the emitter potential for each circuit, it is possible to reduce the occurrence of malfunctions in the individual drive circuit.

Furthermore, in the description so far that in Example, a semiconductor conversion device has been that the inverter,
It is not limited to this. That is, as long as the converter is a semiconductor converter including a semiconductor switching element in a main circuit having a bridge circuit configuration, a converter for converting AC to DC may be used.

[0029]

In the semiconductor converter according to the present invention,
Is, as explained above, Connection with reference potential
For individual drive circuits that require
Dedicated and dedicated reference potential such as ground potentialIndividualGroup
Set a reference potential lineThe corresponding side of the upper or lower side
To one common reference potential lineEspecially
Thus, the reference potential in the individual drive circuit can be made uniform. this
That the reference potential in the individual drive circuit is not uniform
Malfunction of individual drive circuit due to
Becomes

Further, the semiconductor converter as described in the section can be applied to, for example, an inverter for controlling an electric motor by supplying an alternating voltage of a variable frequency to the electric motor, thereby reducing malfunction of the individual drive circuit. By doing so, the reliability is improved, and there is an effect that it is possible to eliminate the danger of a major accident such as arm short-circuit.

[Brief description of the drawings]

Figure 1 is an explanatory diagram showing a configuration of a driving circuit board of the three-phase inverter according to Embodiment of the invention this

FIG. 2 is an explanatory diagram showing a configuration of a ground potential line of a main part of a three-phase inverter according to an embodiment of the present invention, corresponding to claims 1 and 2 , together with peripheral circuits.

FIG. 3 is a circuit diagram showing a general circuit configuration of a three-phase inverter.

FIG. 4 is a sectional view showing a general configuration of a three-phase inverter.

FIG. 5 is an explanatory diagram showing a configuration of a conventional drive circuit board for a three-phase inverter.

FIG. 6 is an explanatory diagram showing a configuration of a ground potential line of a main part of a conventional three-phase inverter together with peripheral circuits.

FIG. 7 is an explanatory diagram showing an arrangement of a main part of a wiring pattern of a ground potential line provided in a drive circuit board of a conventional three-phase inverter.

[Explanation of symbols]

 5 Drive Circuit Board 5a Surface 11 Wiring Pattern 12 Wiring Pattern 13 Wiring Pattern 14 Individual Drive Circuit 15 Individual Drive Circuit 16 Individual Drive Circuit 31 Wiring Pattern 34 Individual Drive Circuit 35 Individual Drive Circuit 36 Individual Drive Circuit 45 Reference Potential Line 46 Reference Potential Line 47 Reference potential line

Claims (2)

(57) [Claims] [Claim 1, further comprising a bridge circuit configuration, the bridge times
At least two upper sides of the road configuration, a main circuit semiconductor switching element is provided in each of the at least two lower sides, is mounted on the wiring pattern by a foil-like conductor printed wiring board has the to drive in order to perform the switching operation to the semiconductor switching element, a device equipped with a drive circuit that have a separate driver circuit provided in correspondence to each of the semiconductor switching elements, wherein the individual drive circuit, comprising individual separate group <br/> quasi potential line you define a dedicated reference potential, wherein the driving circuit, co-defines the common reference potential for each of the upper side or the lower side pieces by driving circuit Tsumoto e Bei quasi potential line, their respective of individual-specific criteria potential lines, one for co Tsumoto quasi potential line of the corresponding side
A semiconductor converter characterized by being connected at a point. 2. A has a three-phase bridge circuit configuration, the 3 Ive
A main circuit semiconductor switching element is provided in each of the respective sides of the upper sides and the lower side of the ridge circuitry, is mounted on the wiring pattern by a foil-like conductor printed wiring board has, the semiconductor switching to drive in order to perform the switching operation to the device, an apparatus and a driving circuit for chromatic individual drive circuits provided in correspondence with each of the semi <br/> conductor switching element, the individual drive circuit comprises individually separate group <br/> quasi potential line you define a dedicated reference potential, wherein the driving circuit, defines the common reference potential for each of the upper side or the lower side pieces by driving circuit e Bei co Tsumoto quasi potential line, their respective of individual-specific criteria potential lines, one for co Tsumoto quasi potential line of the corresponding side
A semiconductor converter characterized by being connected at a point.