JP2000209846A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve utilization of an element and aim at cost reduction and miniaturization by equalizing share of current for each element uniform. SOLUTION: In this conversion device in each module type semiconductor element 201 are formed a planar beam lead 50 which connects electrically a penetrating part 26a of an envelope 26 with an IGBT chip 24 of a reference which is most distant from the penetrating part, and bypass parts 52a, 52b which connect the beam lead with IGBT chips 24a, 24b which are out of reference are formed. The bypass parts 52a, 52b branch from branching parts 51a, 51b, so as to have substantially the same inductance as a closed circuit which reaches the IGBT chips 24a, 24b which are out of reference from the branching parts 51a, 51b of the beam lead positioned above the out-of-reference IGBT chips, passing the IGBT chip 24s of reference. Thereby the inductances between the IGBT chips 24s, 24a, 24b are adjusted to be substantially identical in this power converting device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an IGBT (insulat).
ed gate bipolar transistor) or IEGT (injection
The present invention relates to a power converter including a modular semiconductor element including a plurality of power switching elements such as an enhanced gate transistor.

[0002]

2. Description of the Related Art Generally, a power switching element such as an IGBT or an IEGT is accommodated in a plurality of modules by connecting a plurality of element chips in parallel, and these modules are appropriately connected to a snubber circuit or the like to implement a power converter. It is configured. 7 is a configuration diagram of a main circuit in this type of power converter, FIG. 8 is a perspective view showing a schematic configuration of the power converter, and FIG. 9 is a perspective view showing a schematic configuration of each IGBT module. is there. 7 to 9, each IGBT module 20 is fixed on a cooling device 10 for heat radiation with bolts or the like. Each IGBT module 20
Has a flat electrode 23 on a main region of a metal plate 21 (heat conduction base) fixed on the cooling device 10 via an insulating plate 22, and an IGBT chip 24 and a freewheel diode chip 25 on the flat electrode 23. (Omitted in FIG. 9). An envelope 26 is mounted on the periphery of the metal plate 21. The envelope 26 is attached to each of the IGBT chips 24,
The flat electrode 23 and the insulating plate 22 are housed.

Each IGBT module 20 has an internal I
The emitter pad Ep of the GBT chip 24 is electrically connected to an external wiring conductor 31 such as copper via a flat beam lead 27 having a rectangular wave cross section. Similarly, the collector pad Cp of each IGBT chip 24 is flat. An external wiring conductor 3 such as copper through an electrode 23 and a flat beam lead 28
2 are electrically connected.

The wiring conductors 31 and 32 are connected to each IG.
While electrically connecting the BT modules 20 in parallel,
A snubber circuit including a snubber capacitor 35 and a diode module in which a snubber diode 33 is housed in an envelope 34 are connected.

[0005] Each IGBT module 20 is connected via a wire to a gate circuit 41 for supplying a gate signal to each IGBT chip 24 and a protection circuit 42 for detecting a voltage or current to perform a protection operation. ing.

[0006]

However, in the above-described power converter, when turning off, due to the parasitic inductance L and the parasitic resistance R on the circuit, the IGBT chips 20 connected in parallel are not equal. Current sharing and a large surge voltage are likely to occur.

For this reason, 1 in the IGBT chip 20
The maximum value of the energizing current per unit is set to a value lower than the design upper limit value with the IGBT chip 20 in which a large current flows unevenly in all the chips 20 as a standard. On the other hand, uneven current sharing tends to increase as the number of parallel IGBT chips 20 increases.

Therefore, when the number of parallel IGBT chips 20 is increased with the increase in capacity, the maximum value of the conduction current becomes considerably lower than the design upper limit value in the non-standard IGBT chip 20 through which a small current flows. , Reducing the utilization rate. Further, as the utilization rate decreases, the size of the module becomes larger than the size corresponding to the overall performance, so that the cost is unnecessarily increased.

The present invention has been made in view of the above circumstances, and provides a power conversion device capable of improving the utilization rate of elements by equalizing the current sharing among the elements and reducing the cost and size. The purpose is to:

[0010]

The invention corresponding to claim 1 is a power converter having a plurality of module-type semiconductor elements connected to each other, wherein each of the module-type semiconductor elements has a plate-like shape. A conductive base, an insulating substrate mounted on a central portion of one surface of the heat conductive base,
A planar electrode attached on the insulating substrate, a plurality of element chips bonded on the planar electrode, and the insulating substrate, the planar electrode and the element chips on a peripheral portion of the heat conduction base. An envelope mounted so as to surround, and a flat plate provided to penetrate the envelope and electrically connecting a penetrating portion of the envelope and a reference element chip farthest from the penetrating portion. Between the beam lead and the beam lead and the non-standard element chip, from the branch portion of the beam lead located above the non-standard element chip to the non-standard element chip through the standard element chip. The power converter includes a bypass section branched from the branch section and connected so as to have substantially the same inductance as a closed circuit.

According to a second aspect of the present invention, in the power converter according to the first aspect, the bypass portion is a conductive member connected to a non-standard element chip through the beam lead. A power converter including a block portion and a convex portion having a substantially U-shaped cross section that accommodates an upper portion of the conductive block portion and connects an upper end portion of the conductive block portion and the beam lead.

Further, the invention according to claim 3 is the power conversion device according to claim 1, wherein the bypass unit has a coil shape.

According to a fourth aspect of the present invention, in the power converter according to the first aspect, the beam lead portion has a slope whose height decreases from the through portion toward the reference element chip. A power conversion device including a conductive block portion that connects the slope portion and a non-standard element chip as the bypass portion.

According to a fifth aspect of the present invention, in the power converter of the fourth aspect, the beam lead portion has a step-like step portion instead of the slope portion. It is.

According to a sixth aspect of the present invention, there is provided a power converter having a plurality of module-type semiconductor elements connected to each other, wherein a power supply side emitter connection terminal and a reference terminal farthest from the emitter connection terminal. A flat-plate-shaped emitter-side bus connected between the emitter electrode of the module-type semiconductor element via an emitter-side slope portion whose height decreases from the emitter connection terminal toward the reference module-type semiconductor element; Arranged in parallel with the emitter-side bus, the height between the collector connection terminal on the power supply side and the collector electrode of the reference module type semiconductor element decreases from the collector connection terminal toward the reference module type semiconductor element. A collector bus having a flat plate shape connected through a collector-side slope portion, and An inductance substantially the same as a path from the branch portion of the slope on the emitter side located above the non-reference emitter electrode to the emitter electrode of the reference module type semiconductor device, between the emitter electrode of the outside modular semiconductor device and the emitter electrode of the outside reference semiconductor device. So as to have a flat-plate-shaped emitter-side bypass portion branched from the branch portion of the emitter-side slope portion and connected, and between the collector-side slope portion and the collector electrode of the non-standard module-type semiconductor element. To have substantially the same inductance as the path from the branch portion of the collector-side slope portion located above the non-reference collector electrode to the collector electrode of the reference module type semiconductor element,
A power converter comprising: a collector-side bypass portion having a flat plate shape that is branched from a branch portion of the collector-side slope portion and connected. (Operation) Therefore, the invention corresponding to claim 1 is provided with the means as described above, so that the through portion of the envelope and the reference farthest from the through portion in each modular semiconductor element of the power converter. A flat plate-shaped beam lead for electrically connecting the element chip and a reference element chip from a branch portion of the beam lead located above the non-reference element chip between the beam lead and the non-reference element chip. By providing a bypass portion branched from the branch portion and connected so as to have substantially the same inductance as the closed circuit that reaches the non-standard element chip through the same, the inductance between each device chip is adjusted to be substantially the same. Therefore, the current sharing among the elements can be equalized, the utilization rate of the elements can be improved, and the cost and size can be reduced.

According to a second aspect of the present invention, as the bypass portion, the conductive block portion penetrating the beam lead and connected to the non-standard element chip and the upper portion of the conductive block portion are accommodated. In addition, since a projection having a substantially U-shaped cross section for connecting the upper end of the conductive block portion and the beam lead is provided, the area occupied in the lateral direction can be reduced in addition to the action corresponding to claim 1. .

Further, according to the invention corresponding to claim 3, since the bypass portion has a coil shape, the same operation as the operation corresponding to claim 1 can be achieved.

According to a fourth aspect of the present invention, the beam lead portion has a slope portion whose height decreases from the penetrating portion toward the reference element chip, and the bypass portion has a slope portion and the reference portion. Since the conductive block portion for connecting with the outside element chip is provided, the same operation as the operation according to the first aspect can be achieved, and the lateral direction can be achieved similarly to the operation according to the second aspect. Occupied area can be reduced, and the inductance can be increased, but the shape can be simplified as compared with the invention corresponding to claim 2.

Further, in the invention according to claim 5, the beam lead portion has a step-like step portion instead of the slope portion, so that the same effect as that of claim 4 can be obtained. Can be.

According to a sixth aspect of the present invention, since each bus and each bypass adjust the inductance between the module-type semiconductor elements to be substantially the same, the turn-off between the module-type semiconductor elements is prevented. Current sharing can be equalized, the utilization rate of the element can be improved, and the cost and size can be reduced.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a first embodiment of the present invention. The same reference numerals are given and the detailed description is omitted, and different portions are mainly described here. In the following respective embodiments, the duplicated description will be omitted in the same manner.

[0022] That is, a semiconductor device module 20 ₁ according to the present embodiment is to achieve uniform inductance L and resistance R, in particular FIG. 1 (a), (b)
As shown in FIG. 7, a flat beam lead 50 is provided penetrating through the envelope 26, and electrically connects the penetrating portion 26a of the envelope 26 and the reference IGBT chip 24s farthest from the penetrating portion 26a. , Beam lead 50 and non-standard IG
Non-standard IGBT between BT chips 24a and 24b
Beam lead 50 located above chips 24a and 24b
IGBT chip 24 from branch portions 51a and 51b of
IGBT chips 24a, 24b outside the reference
Are provided with bypass portions 52a and 52b that are branched from the branch portions 51a and 51b and connected so as to have substantially the same inductance L and resistance R as the closed circuit reaching.

Here, for example, when three IGBT chips 24s, 24a, 24b are arranged in a direction in which the three IGBT chips 24s, 24a, 24b are sequentially separated from the penetrating portion 26a, the bypass portions 52a, 52b are shown in FIG.
As shown in (b), the IGBT closest to the penetrating portion 26a
The width, thickness, length, and material are set so as to have the maximum resistance and inductance (4L + 4R) with the chip 24b and the medium resistance and inductance (2L + 2R) with the center IGBT chip 24a. And the shape and the like are designed. However, the total inductance and resistance (6L + 6R) of the closed circuit are equal to the respective IGBT chips 24s and 24s.
a and 24b are substantially the same.

According to the above configuration, the bypass unit 5
2a, 52b are IGBT chips 24s, 24a, 24
Since the inductance L and the resistance R between b are adjusted to be substantially the same, the current sharing between the respective IGBT chips can be equalized at the time of turn-off, and the utilization rate of the element chips can be improved, and the cost and size can be reduced. Can be planned. (Second Embodiment) FIG. 2 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a second embodiment of the present invention.

The module type semiconductor device 20 ₂ according to the present embodiment is a variant of the first embodiment, there is provided along the bypass section in the vertical direction, specifically shown in FIG. 2 As described above, the emitter pads Ep of the IGBT chips 24a and 24b outside the standard penetrate through the beam lead 50.
The metal blocks 53a, 53b connected above, the upper portions of the metal blocks 53a, 53b are accommodated, and the upper ends of the metal blocks 53a, 53b and the beam lead 50 are connected.
And a convex portion 54a, 54b having a substantially U-shaped cross-section for connecting the two.

Here, the metal block portions 53a and 53b and the convex portions 54a and 54b are formed by the non-standard IGBTs 24a and
The height (length) is changed based on the arrangement of the IGBT chips 24s, 24a and 24b, and the height (length) is changed based on the arrangement of the IGBT chips 24s, 24a and 24b. Dimensions, materials, shapes, etc. are designed.

According to the above configuration, in addition to the effects of the first embodiment, the occupied area in the horizontal direction can be reduced. (Third Embodiment) FIG. 3 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a third embodiment of the present invention.

The module type semiconductor device 20 ₃ according to the present embodiment is a modification of the second embodiment, the bypass portion be those formed coiled electrode 55a, at 55b, specifically, beam Lead 50 and each IG other than the standard
Coiled electrodes 55a and 55b are provided between the BT chips 24a and 24b to individually connect them.

Here, the coiled electrodes 55a and 55b are
The number of turns and the diameter of the coil are changed based on the arrangement of the IGBT chips 24a and 24b. As described above, the total inductance L and resistance R of the closed circuit are substantially the same between the IGBT chips 24s, 24a and 24b. It is formed as follows.

With the above configuration, the same effects as in the second embodiment can be obtained. Note that the same effects can be obtained even when the present embodiment is applied to a pressure contact type package. (Fourth Embodiment) FIG. 4 is a schematic diagram showing a configuration of a modular semiconductor device applied to a power converter according to a fourth embodiment of the present invention.

The semiconductor device module 20 ₄ according to the present embodiment is a modification of the second embodiment, the convex portion 54a of the bypass portion, there is omitted the 54b, specifically, the inclined surface portion A plurality of metal block portions 56a and 56b are provided between the beam lead 50a having the 55 and the IGBT chips 24a and 24b other than the reference to connect them.

Here, each of the metal block portions 56a, 56b
And the slope portion 55 of the beam lead 50a is connected to each IGBT 2
The heights are changed based on the layout of the IGBT chips 24s, 24a, and 24b. The shape and the like are designed.

With the above configuration, the same effects as those of the second embodiment can be obtained, and the inductance can be increased, but the shape can be simplified. In addition,
In the present embodiment, as shown in FIG. 5, a modular semiconductor element 2 having a beam lead 50b having a step portion 57 having a step shape instead of the slope portion 55 of the beam lead 50a.
Be modified to 0 _5, it is needless to say it is possible to obtain the same effect. (Fifth Embodiment) FIG. 6 is a schematic diagram showing a partial configuration of a power converter according to a fifth embodiment of the present invention.

This embodiment is different from the above-described embodiments, and shows a connection structure of each module type semiconductor element. Specifically, as shown in FIG. 6, a power supply (for example, a smoothing capacitor or the like) side is used. Between the emitter connection terminal 60e and the emitter electrode 20sE of the reference module type semiconductor device 20s farthest from the emitter connection terminal 60e, the height decreases from the emitter connection terminal 60e toward the reference module type semiconductor device 20s. A flat emitter-side bus (b) connected via an emitter-side slope 61e
us-bar) 62e and the collector-side terminal 62c, and the collector-side terminal 60c between the power supply-side collector connection terminal 60c and the collector electrode 20sC of the reference module-type semiconductor element 20s. A flat-plate-shaped collector-side bus 62c connected via a collector-side slope 61c whose height decreases toward the element 20s, the emitter-side slope 61e and the emitter electrodes 2 of the non-standard modular semiconductor elements 20a and 20b.
0aE and 20bE, the non-standard emitter electrode 20
emitter side slope 61e located above aE, 20bE
A flat plate that is branched from the branch portions 63a and 63b of the emitter-side inclined portion 61e and connected so as to have substantially the same inductance L as the path from the branch portions 63a and 63b to the emitter electrode 20sE of the reference modular semiconductor element 20s. The emitter-side bypass portions 64a, 64b having a shape and the collector-side slope portions 61c and the collector electrodes 20aC, 20bC of the non-standard module type semiconductor elements 20a, 20b are located above the non-standard collector electrodes 20aC, 20bC. Branch portions 65a, 65 of collector-side slope portion 61c
b of the collector-side slope portion 61c so as to have substantially the same inductance L as the path from the base electrode b to the collector electrode 20sC of the reference modular semiconductor device 20s.
a, and a collector side bypass portion 66a, 66b having a flat plate shape and branched from and connected to the collector side.

Here, the emitter-side bus 62e, the emitter-side bypass portions 64a and 64b, and the collector-side bus 6
2c and the collector-side bypass sections 66a, 66b
They have parallel plate shapes.

As described above, the buses 62e and 62c and the bypass portions 64a-b and 66a-b connect the total inductance L and resistance R in the closed circuit between the emitter connection terminal 60e and the collector connection terminal 60c to each module. The width, thickness, length, material, shape, and the like are designed to be substantially the same among the mold semiconductor elements 20s, 20a, and 20b.

According to the above configuration, each bus 62
e, 62c and the bypass portions 64a-b, 66a-b adjust the inductance L and the resistance R between the module-type semiconductor elements 20s, 20a, 20b to be substantially the same, so that each module-type semiconductor element is turned off. The current sharing between the semiconductor elements can be equalized, the utilization rate of the elements can be improved, and the cost and size can be reduced.

The emitter-side bus 62e and the emitter-side bypass portions 64a and 64b, and the collector-side bus 62
c and the collector-side bypass sections 66a and 66b have a parallel plate shape and current flow in opposite directions. Therefore, the emitter-side bus 62e and the bypass sections 64a to 64b
, And the mutual inductance between the collector-side bus 62c and the bypass portions 66a and 66b can be reduced, so that a reduction in surge voltage can be expected.

In this embodiment, first to fourth
Even if the configuration is modified to be combined with any one of the embodiments, the effects of both the present embodiment and the applied embodiment can be obtained. In addition, the present invention can be implemented with various modifications without departing from the scope of the invention.

[0040]

As described above, according to the present invention, there is provided a power conversion device capable of improving the utilization rate of the elements by equalizing the current sharing among the elements, reducing the cost and reducing the size. it can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a modular semiconductor element applied to a power converter according to a fourth embodiment of the present invention.

FIG. 5 is a schematic view showing a modified configuration in the embodiment.

FIG. 6 is a schematic diagram showing a partial configuration of a power conversion device according to a fifth embodiment of the present invention.

FIG. 7 is a configuration diagram of a main circuit in a conventional power converter.

FIG. 8 is a perspective view showing a schematic configuration of a conventional power converter.

FIG. 9 is a perspective view showing a schematic configuration of each conventional IGBT module.

[Explanation of symbols]

_{20 1 ~20 5, 20s, 20a} , 20b ... semiconductor device module L ... inductance R ... resistance 26 ... envelope 26a ... through portion 24s, 24a, 24b ... IGBT chips 50, 50a, 50b ... beam leads 51a, 51b ... Branch portions 52a, 52b. Bypass portions 53a, 53b, 56a, 56b .... Metal block portions 54a, 54b .. Protrusion portions 55.

Claims (6)

[Claims] 1. A power converter having a plurality of module-type semiconductor elements connected to each other, wherein each of the module-type semiconductor elements has a plate-like heat conduction base and a central part on one surface of the heat conduction base. An insulating substrate attached to the; a planar electrode stuck on the insulating substrate; a plurality of element chips bonded on the planar electrode; and the insulating substrate on a peripheral portion of the heat conductive base; An envelope attached so as to surround the planar electrode and each of the element chips; and a reference element chip which is provided through the envelope and which is the farthest from the penetrating portion of the envelope and the penetrating portion. A flat beam lead electrically connecting the reference chip and the reference element chip from a branch portion of the beam lead positioned above the non-reference element chip between the beam lead and the non-reference element chip. Through so as to have a closed circuit and substantially the same inductance leading to the reference outside of the element chip, the power conversion device characterized by comprising a bypass unit that connects branched from the branch portion. 2. The power conversion device according to claim 1, wherein the bypass unit includes a conductive block connected to a non-standard element chip through the beam lead, and a conductive block connected to the conductive block. A power conversion device, comprising: a projection having a substantially U-shaped cross section that accommodates an upper portion and connects an upper end portion of the conductive block portion and the beam lead. 3. The power converter according to claim 1, wherein the bypass unit has a coil shape. 4. The power conversion device according to claim 1, wherein the beam lead portion has a slope portion whose height decreases from the penetrating portion toward the reference element chip. A power converter, comprising: a conductive block portion that connects between the slope portion and a non-standard element chip. 5. The power conversion device according to claim 4, wherein the beam lead portion has a step-like step portion instead of the slope portion. 6. A power converter having a plurality of module-type semiconductor elements connected to each other, comprising: an emitter connection terminal on a power supply side; and an emitter electrode of a reference module-type semiconductor element furthest from the emitter connection terminal. A flat-plate-shaped emitter-side bus connected between the emitter connection terminals via an emitter-side slope portion whose height decreases from the emitter connection terminal toward the reference module-type semiconductor element, and arranged in parallel with the emitter-side bus; A connection is made between the collector connection terminal on the power supply side and the collector electrode of the reference module type semiconductor device via a collector side slope portion whose height decreases from the collector connection terminal toward the reference module type semiconductor device. A flat-plate-shaped collector-side bus, and the emitter-side slope and the non-standard module type semiconductor element. Between the emitter electrode and the emitter electrode, the emitter has a substantially same inductance as a path from a branch portion of the slope on the emitter side located above the non-reference emitter electrode to an emitter electrode of the reference module type semiconductor element. A flat plate-shaped emitter-side bypass portion branched from the branch portion of the side slope portion and connected to the collector-side bypass portion between the collector-side slope portion and the collector electrode of the non-standard module type semiconductor element; A flat plate-shaped branch connected from the branch portion of the collector-side slope portion so as to have substantially the same inductance as the path from the branch portion of the located collector-side slope portion to the collector electrode of the reference modular semiconductor device. A power converter comprising: a collector-side bypass unit.