JP2018148164A - Power semiconductor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power semiconductor module incorporating multiple semiconductor elements, and capable of operating even if short circuit fault occurs in some of the semiconductor elements.SOLUTION: A power semiconductor module includes a semiconductor element, and a circuit breaking element connected in series therewith. The circuit breaking element has an insulator, and a metal layer provided thereon, where the metal layer includes a first portion and a second portion connected with external wiring, respectively, and a blowout portion. The first and second portions are provided while spaced apart from each other, and the blowout portion is connected, at both ends thereof, with the first and second portions. In the flow path of a current flowing through the semiconductor element and the circuit breaking element, the profile perpendicular to the current flow direction is smaller in the blowout portion than in the first and second portions.SELECTED DRAWING: Figure 3

Description

  The embodiment relates to a power semiconductor module including a plurality of semiconductor chips.

  Power converters such as converters and inverters are widely used in industrial applications such as traffic and distribution power equipment. Many of these power conversion devices are configured by using a power semiconductor module containing a plurality of semiconductor elements connected in parallel, and are turned on (conducting) and turned off (non-conductive) in accordance with a signal applied to the control gate of each semiconductor element. Power conversion is performed by a switch operation for switching between continuity).

  In these power conversion devices, for example, when some of the semiconductor elements connected in parallel are short-circuited for some reason, an excessive short-circuit current flows through the power semiconductor module. And if the protection function mounted in order to respond | correspond to such a failure mode detects a short circuit current, a power converter device will be stopped. Thereby, the risk of abnormal heat generation or breakage of equipment connected to the power conversion device can be reduced. However, as long as the short-circuited semiconductor element remains in the power semiconductor module, the power conversion device cannot be restarted. That is, the power semiconductor module contributes little to its reliability when viewed from the viewpoint of continuing operation of the power conversion device. Accordingly, there is a need for a power semiconductor module that can continue operation of the power conversion device even when a short-circuit failure occurs in a part of the semiconductor element and can realize redundancy of the system.

JP-A-9-70102 JP 2011-199940 A JP 2013-38864 A JP 2014-236530 A Japanese Patent Laying-Open No. 2015-23709

  The embodiment provides a power semiconductor module that incorporates a plurality of semiconductor elements and that can operate even when some of them are short-circuited.

  The power semiconductor module according to the embodiment includes a semiconductor element and a circuit breaker element connected in series to the semiconductor element. The circuit breaker element includes an insulator and a metal layer provided on the insulator. The metal layer includes a first part and a second part connected to an external wiring, and a fusing part. ,including. The first part and the second part are provided to be separated from each other, and the fusing part is connected to the first part and the second part at both ends thereof. In the flow path of the current flowing through the semiconductor element and the circuit breaker element, a cross section perpendicular to the direction in which the current flows is smaller than the first portion and the second portion in the fusing portion.

It is a schematic diagram which shows the power converter device which concerns on embodiment. It is a mimetic diagram showing a power semiconductor module concerning a 1st embodiment. 1 is a perspective view schematically showing a part of a power semiconductor module according to a first embodiment. It is a perspective view showing typically the circuit interruption element concerning a 1st embodiment. It is a schematic diagram which shows the characteristic of the circuit interruption element which concerns on 1st Embodiment. It is the schematic diagram which modeled the characteristic of the circuit interruption element which concerns on 1st Embodiment. It is a perspective view which shows typically the circuit interruption element which concerns on the modification of 1st Embodiment. It is a schematic diagram which shows the power converter device which concerns on the modification of 1st Embodiment. It is a schematic diagram which shows the power converter device which concerns on another modification of 1st Embodiment. It is a schematic diagram which shows the power converter device which concerns on 2nd Embodiment. It is a schematic diagram which shows the power converter device which concerns on the modification of 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. The same parts in the drawings are denoted by the same reference numerals, detailed description thereof will be omitted as appropriate, and different parts will be described. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.

(First embodiment)
Drawing 1 is a mimetic diagram showing power converter 1 concerning an embodiment. The power converter 1 is, for example, a DC / AC converter that converts DC power into three-phase AC. The power conversion device 1 converts DC power input to the input terminals A ₁ and A ₂ into three-phase AC power, and supplies it to a load 10 such as an AC motor connected to the output terminals B _{1 to} B ₃ .

As shown in FIG. 1, the power conversion device 1 includes a conversion phase 20 that outputs AC power to output terminals B _{1 to} B ₃ , respectively. The conversion phase 20 has one power semiconductor module 30 on each of the input terminal A ₁ side and the input terminal A ₂ side. AC power is output to each of the output terminals B _{1 to} B ₃ by a switching operation for alternately turning on and off the two power semiconductor modules 30 arranged in the conversion phase 20. And the power converter device 1 outputs 3 phase alternating current power by mutually shifting the phase of the alternating current output from each conversion phase 20 120 degree | times.

Figure 2 is a schematic diagram showing a transformation phase 20 to output the AC power to the output terminal B _1. As shown in the figure, the conversion phase 20 includes two power semiconductor modules 30 connected in series between the input terminals A ₁ and A ₂ . The output terminal B ₁ outputs a potential between the two power semiconductor modules 30. Each power semiconductor module 30 includes a plurality of semiconductor elements 40 and a plurality of circuit interrupting elements 50. The plurality of semiconductor elements 40 are connected in parallel, and one circuit interruption element 50 is connected in series to each semiconductor element 40. The number of semiconductor elements 40 and circuit interruption elements 50 arranged in the module is the same.

For example, if the input terminal A ₁ is a positive terminal, the circuit breaker element 50 is disposed on the low voltage side of the semiconductor element 40. Hereinafter, the “arrangement” in this specification is not limited to the spatial arrangement of each component, but also means a circuit arrangement. The distinction between the two will be apparent by considering the description and the related figures.

  The semiconductor element 40 is, for example, a power MOS transistor or an IGBT (Insulating gate Bipolar Transistor). The circuit breaker element 50 is disposed, for example, on the source electrode side of the NMOS transistor or on the emitter electrode side of the N-channel IGBT.

For example, in the power semiconductor module 30 arranged on the input terminal A ₁ side, when one of a plurality of semiconductor elements 40 connected in parallel fails and the source-drain or emitter-collector is short-circuited, the power Even if a control signal for turning off the semiconductor module 30 is input, the failed semiconductor element 40 is held in a conductive state. When the power semiconductor module 30 arranged on the input terminal A ₂ side is turned on, the current flows between the input terminals A ₁ and A ₂ through the conversion phase 20 without flowing to the load 10 side.

Such a short-circuit current flows evenly to the semiconductor elements 40 connected in parallel in the healthy power semiconductor module 30, but in the power semiconductor module 30 including the failed semiconductor element 40, it concentrates on the short-circuited semiconductor element 40. At this time, faulty circuit breaking element 50 connected in series to the semiconductor element 40 is, with its semiconductor element 40, between the output terminal B _1, and, the power semiconductor module 30 that is arranged at the input terminal A ₂ side Disconnect the connection between. For example, the metal wiring in the path of the current flowing through the circuit breaker element 50 and the semiconductor element 40 has a part where the current density is higher in the circuit breaker element 50 than in other parts. And the circuit interruption | blocking element 50 is fuse | melted in a part with a high current density by a short circuit current, and isolate | separates the semiconductor element 40 from a circuit. Thus, it is possible to cut off the short-circuit current flowing between the input terminals A ₁ and A _2.

Further, in the power semiconductor module 30 arranged on the input terminal A ₂ side, when one of the semiconductor elements 40 is short-circuited, a current path between the semiconductor element 40 and the input terminal A ₂ is a circuit. The short-circuit current that is disconnected between the input terminals A ₁ and A ₂ is cut off by the cut-off element 50.

  As described above, in the power semiconductor module 30, even if a part of the plurality of semiconductor elements 40 connected in parallel is short-circuited, the semiconductor element 40 that has failed is separated from the circuit by the circuit interrupting element 50, and the other normal Switching operation can be continued by the semiconductor element 40. And the power converter device 1 can continue operation | movement, without stopping, if the fall of the output of the power semiconductor module 30 containing the failed semiconductor element 40 is in a tolerance | permissible_range.

FIG. 3 is a perspective view schematically showing a part of the power semiconductor module 30. The power semiconductor module 30 further includes, for example, a mounting substrate (not shown) and copper patterns 31 and 33 provided thereon. For example, the copper pattern 31 is connected to the input terminal A ₁ on the positive electrode side, and the semiconductor elements 40 are arranged side by side on the copper pattern 31. The copper pattern 33 is connected to, for example, the output terminal B ₁ , and the circuit breaker element 50 is arranged side by side on the copper pattern 33. The semiconductor element 40 and the circuit interruption element 50 are mounted on the copper patterns 31 and 33, for example, by a bonding material such as solder.

  The semiconductor element 40 is, for example, an IGBT, and has an emitter electrode 41 and a gate pad 43 on the surface thereof. The collector electrode on the back side is connected to the copper pattern 31 via, for example, solder. The circuit breaker element 50 includes an insulator 50a and a metal layer 50b provided on the surface thereof. The insulator 50 a is, for example, a ceramic substrate such as glass or alumina, and electrically insulates the metal layer 50 b from the copper pattern 33. The metal layer 50b includes, for example, copper, a copper alloy, aluminum, or an aluminum alloy.

  As shown in FIG. 3, the metal layer 50 b is connected to the emitter electrode 41 of the semiconductor element 40 via, for example, a metal wire 35. Further, the metal layer 50 b is connected to the copper pattern 33 via, for example, a metal wire 37.

  FIG. 4 is a perspective view schematically showing the circuit breaker element 50. The metal layer 50 b provided on the surface of the insulator 50 a has a first part 53, a second part 55, and a fusing part 57. For example, the first portion 53 is connected in series to the semiconductor element 40 via the metal wire 35. The second portion 55 is provided apart from the first portion 53 and is connected to the copper pattern 33 via the metal wire 37. The fusing part 57 is provided between the first part 53 and the second part 55, and both ends thereof are connected to the first part 53 and the second part 55, respectively.

  The fusing part 57 is provided so that the current density is higher than that of the first part 53 and the second part 55. That is, the flow path of the current flowing through the semiconductor element 40 and the circuit breaker element 50 is provided such that a cross section perpendicular to the direction in which the current flows is smaller than the first portion 53 and the second portion 55 in the fusing portion 57.

As shown in FIG. 4, the fusing part 57 is provided in a bar shape extending in a direction from the first part 53 toward the second part 55, for example. The fusing part 57 has a cross-sectional area S in a cross section orthogonal to the direction of the current _ID flowing from the first part 53 to the second part 55, for example. In addition, fusing part 57 has a length L along the direction of current _ID .

  FIG. 5 is a schematic diagram illustrating the characteristics of the circuit breaker element 50. For example, at time t = 0, the semiconductor element 40 is short-circuited, and the current, the amount of heat generation, and the temperature of the fusing part 57 when the short-circuit current exceeding the rated value flows through the circuit-breaking element 50 connected in series are represented with time. ing.

As shown in FIG. 5, the current and the amount of heat generated by the fusing part 57 increase with time. Thereafter, as the temperature rises due to heat generation in the fusing part 57, the resistance value increases, the current starts to decrease, and the heat generation amount also decreases. In contrast, the temperature of the fusing unit 57 monotonically increases from room temperature T _R. And when the temperature of the fusing part 57 reaches its melting point Tm, the fusing part 57 is melted, and the current path between the first part 53 and the second part 55 is interrupted.

  The semiconductor power module 30 is designed, for example, to operate the protection circuit and stop the operation when the time tr elapses after a short-circuit current exceeding 10 times its rated current starts to flow. Therefore, if the time when the temperature of the fusing part 57 reaches the melting point Tm is ts, the fusing part 57 is preferably provided so that ts <tr. Thereby, the semiconductor element 40 that has failed before the protection circuit operates can be separated from the circuit, and the operation of the power semiconductor module 30 can be continued. The rated current of the semiconductor power module 30 is set to, for example, (maximum allowable current of the semiconductor element 40) × (number of parallel semiconductor elements 40). Here, the maximum allowable current means, for example, the maximum current that can be continuously passed through the semiconductor element 40.

  For example, the semiconductor element 40 may not operate normally due to thermal runaway when a current 10 times the maximum allowable current flows. Therefore, the protection circuit is designed to stop the semiconductor power module 30 within a time tr from when the maximum allowable current starts to flow until an operation failure occurs. When the semiconductor element 40 is made of silicon, the time tr is designed to be about 10 μsec, for example. When the semiconductor element 40 is made of silicon carbide (SiC), the time tr is designed to be about 5 μs, for example.

FIG. 6 is a schematic diagram illustrating the modeled characteristics of the circuit breaker element 50. The current i and the heat generation amount Q of the fusing part 57 are generated in a step shape at time t = 0, and are constant with respect to the time t. In this case, the resistance of the fusing part 57 uses a predetermined temperature value and is constant regardless of the temperature T. For example, when copper is used as a material, a resistance value of T = 1000 ° C. is used. As a result, the temperature change amount ΔT of the fusing unit 57 (= _{T-T R)} is calculated using the following equation (1), increases from room temperature _{T R} linearly with time t.

Here, Q _T (= Q × t) is the cumulative calorific value, C is the heat capacity, r is the specific resistance, ρ is the density, and c is the specific heat.

  As shown in Expression (1), the temperature change amount ΔT of the fusing part 57 is expressed as a function having the current i and the time t as variables, and depends on the specific resistance r, density ρ, specific heat c, and cross-sectional area S of the material. To do. Here, the length L of the fusing part 57 is canceled in the equation. Therefore, ideally, it can be understood that the cross-sectional area S becomes a parameter for increasing the temperature if the material constituting the fusing part 57 is designated. Moreover, when the cross-sectional area of the fusing part 57 changes in the direction in which the current flows, the cross-sectional area S when approximating a rectangular parallelepiped as shown in FIG. 4 is used.

Furthermore, the cross-sectional area (S / i) per unit current is expressed by the following equation (2).

Here, t = tr, as ΔT = _{Tm-T R,} can be determined the upper limit of the cross-sectional area S of the fusion portion 57.

Example 1
For example, in the case where the semiconductor element 40 is a power semiconductor element made of silicon and the material of the fusing part 57 is copper or a copper alloy, the unit is calculated as tr = 10 μsec, Tm = 1085 ° C., TR = 25 ° C. The cross-sectional area S per current is 14 × 10 ⁻⁶ mm ² / A. That is, when a current of 1 A flows through the fusing part 57 having a cross-sectional area of 14 × 10 ⁻⁶ mm ² , the temperature reaches a melting point of 1085 ° C. in 10 μs after the short-circuit current starts to flow. Therefore, by setting the cross-sectional area S to a short-circuit current × 14 × 10 ⁻⁶ mm ² or less, the fusing part 57 can be formed so as to be blown within 10 μsec from the start of the short-circuit current flow.

For example, the rated current of the power semiconductor module 30 in which eight semiconductor elements 40 having the maximum allowable current 30A are connected in parallel is 240A. When the time tr elapses after the current of 2400 A, which is 10 times the rated current, starts to flow, the power semiconductor module 30 stops its operation. In this case, even if a current 10 times as large as the maximum allowable current flows in each of the semiconductor elements 40, the cross-sectional area S is 14 × 10 ⁻⁶ (mm ² / A) × so that the fusing portion 57 is not blown. It may be 300 (A) = 42 × 10 ⁻⁴ (mm ² ) or more. On the other hand, the short-circuit current that flows intensively in the failed semiconductor element 40 is 2400 A, and the corresponding cross-sectional area S is 14 × 10 ⁻⁶ (mm ² / A) × 2400 (A) = 33.6 ×. 10 ⁻³ (mm ² ). Accordingly, the cross-sectional area S may be 42 × 10 ⁻⁴ mm ² or more and 33.6 × 10 ⁻³ mm ² or less. Here, if the thickness of the metal layer 50b is 0.1 mm, the width of the fusing part 57 may be 0.042 mm or more and 0.336 mm or less.

(Example 2)
For example, when the semiconductor element 40 is a power semiconductor element made of silicon and the material of the fusing part 57 is aluminum or an aluminum alloy, the upper limit of the cross-sectional area S of the fusing part 57 is tr = 10 μsec, Tm = 660. Calculated as ° C, T _R = 25 ° C. As a result, the upper limit of the cross-sectional area S is short-circuit current × 26 × 10 ⁻⁶ mm ² . The fusing part 57 having a cross-sectional area S equal to or smaller than this reaches 660 ° C., which is the melting point of aluminum, within 10 μsec from the occurrence of the short-circuit current, and is cut off. For example, the short-circuit current is set to 10 times the rated current of the power semiconductor module 30.

  By using aluminum or an aluminum alloy as the material of the metal layer 50b, it can be melted at a temperature lower than that of copper or a copper alloy. As a result, the temperature of the power semiconductor module 30 when the fusing part 57 is blown can be suppressed, the influence on the devices arranged around the device can be reduced, and the insulating seal filled in the module can be reduced. It is also possible to suppress deterioration of the stopping material.

(Example 3)
For example, when the semiconductor element 40 is a power semiconductor element made of silicon carbide (SiC), the upper limit of the cross-sectional area S of the fusing part 57 is calculated with tr = 5 μsec. For example, when the material of the fusing part 57 is copper or a copper alloy, the cross-sectional area S is 10 × 10 ⁻⁶ mm ² / A or less. Moreover, when the material of the fusing part 57 is aluminum or an aluminum alloy, the cross-sectional area S becomes a short circuit current × 18 × 10 ⁻⁶ mm ² or less.

  FIG. 7 is a perspective view schematically showing a circuit breaker element 60 according to a modification of the embodiment. Circuit breaker element 60 includes an insulator 60a and a metal layer 60b provided on the surface thereof. The insulator 60a is, for example, a ceramic substrate such as glass or alumina, and the metal layer 60b includes, for example, copper, copper alloy, aluminum, or aluminum alloy.

  The metal layer 60b has a first portion 63, a second portion 65, and fusing portions 67a to 67c. The first portion 63 and the second portion 65 are provided to be separated from each other. The fusing parts 67a to 67c are provided between the first part 63 and the second part 65, and both ends thereof are connected to the first part 63 and the second part 65, respectively. In this example, three fusing parts 67a to 67c are arranged, but the embodiment is not limited to this. For example, four or more fusing parts may be disposed between the first part 63 and the second part 65.

In the fusing parts 67a to 67c, each cross section orthogonal to the direction of the current _ID flowing from the first part 63 to the second part 65 has a cross-sectional area S1 to S3. The fusing parts 67a to 67c are formed such that the sum of the cross-sectional areas S1 to S3 is equal to or less than the value of the cross-sectional area S calculated using the equation (2). For example, when the semiconductor element 40 is a power semiconductor element made of silicon and the material of the metal layer 60b is copper or a copper alloy, the sum of the cross-sectional areas S1 to S3 per unit current is short circuit current × 14 × 10. ^{It is -6} (mm < ^{2 >} ) or less. Also in the case of the material shown in Example 2, 3, the sum total of cross-sectional area S1-S3 is below the upper limit shown in each.

  In the circuit interruption element 60, for example, when any one of the fusing parts 67a to 67b is blown, a short-circuit current flowing through the other two becomes large, and the fusing parts are sequentially blown. Therefore, in the circuit breaker element 60, the current path between the first portion 63 and the second portion 65 can be more reliably cut off, and the reliability of the power semiconductor module 30 can be improved. .

  FIG. 8 is a schematic diagram showing a power conversion device 2 according to a modification of the first embodiment. FIG. 8 shows the conversion phase 20 including two power semiconductor modules 70. The power semiconductor module 70 includes a semiconductor element 40 connected in parallel and a circuit breaker element 50 connected in series to each semiconductor element 40. Further, a circuit breaker element 60 may be arranged in place of the circuit breaker element 50.

For example, if the input terminal A ₁ is a positive terminal and the input terminal A ₂ is a negative terminal, the circuit breaker element 50 is disposed on the high voltage side of the semiconductor element 40. That is, if the semiconductor element 40 is an NMOS transistor, the circuit interruption element 50 is disposed on the drain electrode side. If the semiconductor element 40 is an N-channel IGBT, the circuit breaker element 50 is disposed on the collector electrode side.

  As described above, the circuit breaker element 50 may be arranged on either the high voltage side or the low voltage side of the semiconductor element 40 by separating the semiconductor element 40 connected in series to the circuit from the circuit. For this reason, it can be advantageously arranged in a limited space in the module, which contributes to miniaturization of the module.

FIG. 9 is a schematic diagram illustrating a power conversion device 3 according to another modification of the first embodiment. FIG. 9 shows the conversion phase 20 including two power semiconductor modules 80. The power semiconductor module 80 includes semiconductor elements 40 connected in parallel, and circuit interruption elements 50 _H and 50 _L connected in series to each semiconductor element 40.

As shown in FIG. 9, two circuit breaker elements 50 _H and 50 _L are arranged for one semiconductor element 40. The circuit interruption elements 50 _H and 50 _L are arranged on the high voltage side and the low voltage side of the semiconductor element 40, respectively. The total number of circuit breaker elements 50 _H and 50 _L arranged in the module is twice that of the semiconductor element 40. The circuit interruption elements 50 _H and 50 _L have the same configuration as the circuit interruption element 50 or 60, for example.

In this example, the metal layer is blown in both circuit breaker elements 50 _H and 50 _L , and semiconductor element 40 is isolated from the circuit on both the high voltage side and the low voltage side. For example, when the current path is cut off in one of the circuit breaker elements 50 _H and 50 _L , the electric energy held inside the semiconductor element 40 is released through the other. The current generated thereby melts the fusing part 57 in the other of the circuit breaker elements 50 _H and 50 _L , and the failed semiconductor element 40 is completely separated from the circuit. As a result, another circuit connected to the semiconductor element 40, for example, a gate control circuit (not shown) can be protected.

  As described above, in this embodiment, the semiconductor element 40 that has caused the short-circuit fault can be separated from the circuit by using the circuit breaker element 50 or 60 having a simple configuration that does not include the active region. As a result, the switching operation can be continued in the power semiconductor modules 30, 70 and 80 including the semiconductor element 40 in which the short circuit failure has occurred. As a result, the redundancy of the power conversion system composed of these power semiconductor modules can be improved. That is, it is possible to improve the reliability of the power conversion devices 1, 2, and 3 incorporating each power semiconductor module from the viewpoint of continued operation.

  Instead of the circuit breaker elements 50 and 60, for example, a configuration using an existing current limiting fuse or an automotive fuse may be considered. These are adapted to the rated voltage of industrial power converters such as in-vehicle and traffic systems where improvement in reliability is strongly desired. However, existing fuses are too large to be placed in the module. Further, when a configuration is adopted in which the semiconductor element is arranged outside the module and connected to the semiconductor element by wiring, the parasitic inductance increases and the switching speed of the power semiconductor module is limited. Therefore, using these existing fuses is not practical. On the other hand, the circuit breaker elements 50 and 60 according to the present embodiment can be manufactured using a metal film forming method such as sputtering and a semiconductor process such as photolithography, and the size can be reduced. . And the circuit interruption | blocking elements 50 and 60 can be arrange | positioned on the mounting board | substrate in a power semiconductor module, or an empty space.

  Moreover, in the existing fuse, it is necessary to arrange an arc extinguishing material in order to suppress the persistence of the arc after fusing. On the other hand, in the circuit interruption element 60, it is possible to reduce the electric current which flows through each by arrange | positioning the several fusing part 67a-67c, and to suppress an arc. Thereby, it is possible to reduce or eliminate the arc extinguishing material.

(Second embodiment)
FIG. 10 is a schematic diagram showing the power conversion device 4 according to the second embodiment. FIG. 10 shows a conversion phase 20 including two power semiconductor modules 90. The power semiconductor module 90 includes semiconductor elements 40 a and 40 b and a circuit interruption element 50.

  As shown in FIG. 10, the circuit breaker element 50 is connected in series to the semiconductor elements 40a and 40b connected in parallel. That is, when one of the semiconductor elements 40a and 40b causes a short circuit failure and a short circuit current flows through the power semiconductor module 90, the circuit breaker element 50 separates the two semiconductor elements 40a and 40b from the circuit. Thereby, the power semiconductor module 90 can continue the switching operation. And the power converter device 4 can continue the operation | movement, if the output fall of the power semiconductor module 90 is in a tolerance | permissible_range.

  The number of circuit breaker elements 50 arranged in the power semiconductor module 90 is one half of the total number of semiconductor elements 40a and 40b. For example, such a configuration is effective when the total number of semiconductor elements 40a and 40b disposed inside the module is large relative to the size of the module. That is, by reducing the number of circuit breaker elements 50, the power semiconductor module 90 can be downsized and its manufacturing cost can be reduced.

  Note that the number of semiconductor elements 40 connected in series to the circuit breaker element 50 may be three or more. That is, when the plurality of semiconductor elements 40 are separated from the circuit by the single circuit breaker element 50, it is sufficient that the output drop of the power semiconductor module 90 is within an allowable range. In this example, since the current flowing through one circuit breaker element 50 in the normal state is the number of semiconductor elements 40 connected in series to the circuit breaker element 50, the lower limit of the cross-sectional area S of the fusing part 57 is one semiconductor element 40. The cross-sectional area S when one circuit breaker element 50 is connected to is multiplied by the number of semiconductor elements 40 connected in series. On the other hand, the upper limit of the cross-sectional area S of the fusing part 57 is the same as the cross-sectional area S when one circuit breaker element 50 is connected to one semiconductor element 40.

FIG. 11 is a schematic diagram showing a power conversion device 5 according to a modification of the second embodiment. FIG. 11 shows a conversion phase 20 including two power semiconductor modules 95. The power semiconductor module 95 includes a semiconductor element 40a, 40b and the circuit breaking element ₅₀ H, 50 _L.

As shown in FIG. 11, the circuit breaking element 50 _H and 50 _L are respectively connected in series with the parallel connected semiconductor elements 40a and the semiconductor element 40b. Circuit breaking element 50 _H is arranged on the high voltage side of the semiconductor elements 40a and 40b, the circuit breaking element 50 _L is disposed on the low voltage side of the semiconductor elements 40a and 40b. I.e., one of the semiconductor elements 40a and 40b is caused a short circuit fault, when the short-circuit current flows to the power semiconductor module 90, the circuit breaking element 50 _H and 50 _L are completely two semiconductor elements 40a and 40b from the circuit To separate. Thereby, the power semiconductor module 90 can continue the switching operation. In the power semiconductor module 90, another circuit (not shown) connected to the semiconductor elements 40a and 41b can be protected.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1-5 ... Power converter device, 10 ... Load, 20 ... Conversion phase, 30, 70, 80, 90, 95 ... Power semiconductor module, 31, 33 ... Copper pattern, 35, 37 ... Metal wire, 40, 40a, 40b ... semiconductor device, 41 ... emitter electrode, 43 ... gate pad, 50, 50 _{H, 50} L, 60 ... circuit breaking element, 50a, 60a ... insulator, 50b, 60b ... metal layer, 53, 63 ... first portion, 55,65 ... second portion, 57,67A～67c ... fusion portion, _{A 1,} A 2 _... input terminal, _B 1 .about.B 3 _... output terminal, S, S1 to S3 ... sectional area

Claims (10)

A semiconductor element;
A circuit breaker element connected in series to the semiconductor element;
With
The circuit breaker element has an insulator, and a metal layer provided on the insulator,
The metal layer includes a first part and a second part respectively connected to external wiring, and a fusing part.
The first part and the second part are provided spaced apart from each other;
The fusing part is connected to the first part and the second part at both ends thereof,
In the flow path of the current that flows through the semiconductor element and the circuit breaker element, a cross section perpendicular to the direction in which the current flows is smaller than the first part and the second part in the fusing part. The power semiconductor module according to claim 1, wherein the metal layer includes copper or a copper alloy, and when the rated current is IMAX,
The power semiconductor module in which the area of the cross section in the fusing part is IMAX × 10 × 14 × 10 ⁻⁶ mm ² or less. A plurality of the semiconductor elements connected in parallel;
A plurality of the circuit breaker elements connected in series to each of the semiconductor elements;
With
When the parallel number of the semiconductor elements is N,
The power semiconductor module according to claim 2, wherein an area of the cross section of the fusing part is (IMAX × 10 / N) × 14 × 10 ⁻⁶ mm ² or more. The circuit breaker element has a plurality of the fusing parts,
3. The power semiconductor module according to claim ² , wherein a total area of the cross sections is IMAX × 10 × 14 × 10 ⁻⁶ mm ² or less. The power semiconductor module according to claim 1, wherein the metal layer includes aluminum or an aluminum alloy, and when the rated current is IMAX,
The power semiconductor module in which the area of the cross section in the fusing part is IMAX × 10 × 26 × 10 ⁻⁶ mm ² or less. A plurality of the semiconductor elements connected in parallel;
A plurality of the circuit breaker elements connected in series to each of the semiconductor elements;
With
When the parallel number of the semiconductor elements is N,
The power semiconductor module according to claim 5, wherein an area of the cross section of the fusing part is (IMAX × 10 / N) × 26 × 10 ⁻⁶ mm ² or more. The circuit breaker element has a plurality of the fusing parts,
6. The power semiconductor module according to claim 5, wherein a total area of the cross sections is IMAX × 10 × 26 × 10 ⁻⁶ mm ² or less.   The power semiconductor module according to any one of claims 1 to 7, wherein the circuit breaker element is disposed on at least one of a low voltage side and a high voltage side of the semiconductor element. Including a plurality of the semiconductor elements,
The power semiconductor module according to claim 1, wherein the circuit breaker element is connected in series to two or more semiconductor elements connected in parallel. A semiconductor element;
A circuit interrupting element connected in series to the semiconductor element and capable of interrupting a current flowing through the semiconductor element;
With
The metal wiring in the path of the current flowing through the circuit breaker element and the semiconductor element has a portion where the current density is higher than other portions in the circuit breaker element,
The circuit breaker element is a power semiconductor module that separates the semiconductor element by fusing a portion having the high density by the current.