JP2019047550A - Electric power conversion device - Google Patents

Abstract

To provide an electric power conversion device which can inhibit smoking and burning even if a fuse part is melted by an excess current.SOLUTION: An electric power conversion device 1 includes: a power semiconductor device; an electrode wiring member 13; a housing 30; a fuse part 16 formed at the electrode wiring member 13; a cover member 27 which covers the fuse part 16; and a sealing resin member 25 which seals the power semiconductor device 14, the electrode wiring member 13, and the cover member 27 covering the fuse part 16 in the housing 30.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power converter in which a power semiconductor element is sealed by a resin member in a housing.

  In recent years, in the automobile industry, vehicles using a motor as a driving force source, such as hybrid vehicles and electric vehicles, have been actively developed. The inverter apparatus which drives a motor supplies the drive power of high voltage to a motor by using a battery as a power supply. In addition, resin-sealed power semiconductor devices are used as inverter devices, and in the field of power electronics, power converters are becoming increasingly important as key devices.

  Here, the power semiconductor element used for the inverter device is resin-sealed with other components. In such a power conversion device, when a short circuit failure occurs in an electronic component such as a power semiconductor element or a smoothing capacitor that constitutes a snubber circuit while power is supplied from a battery, an excessive short circuit current flows. For example, when the upper and lower arms of the inverter are shorted due to a malfunction of the gate drive circuit in the inverter control circuit, an overcurrent flows in the power semiconductor element, and a short circuit failure occurs.

  If a relay connecting the battery and the motor drive circuit is connected or continued in a short circuit condition, the power converter smokes and burns due to a large current. In addition, it is conceivable that a battery connected to the motor drive inverter device may be damaged due to the flow of the overcurrent exceeding the rating. In order to avoid such a situation, usually, when an overcurrent flows, a sensor for detecting an overcurrent is used to control the switching of the power semiconductor element at high speed to interrupt the current. However, even in the case where the power semiconductor element has a short circuit failure, it is desirable to more reliably prevent the failure mode such as smoke mentioned above.

  Specifically, for example, by inserting an overcurrent cutoff fuse between the power semiconductor device and the battery, it is possible to prevent the overcurrent flowing between the motor drive inverter device and the battery.

  However, chip-type overcurrent cutoff fuses are expensive. Therefore, there is a need for an overcurrent interrupting means that is inexpensive but can reliably shut off an overcurrent that can flow to the battery when the power semiconductor device has a short circuit failure. For example, in Patent Document 1 below, the fuse portion is formed by cutting the external connection electrode protruding to the outside from the semiconductor device and reducing the cross-sectional area.

JP, 2005-175439, A

  However, in the technique of Patent Document 1, the fuse portion provided in the external connection electrode is exposed to the outside of the semiconductor device. Therefore, when the fuse portion is melted and broken due to an excessive current, smoke may flow out of the apparatus, and sparks may be scattered around, and the apparatus may be burnt down due to a combustion reaction using the open air.

  Therefore, a power conversion device that can suppress smoke and burnout even if the fuse portion is melted and broken due to an overcurrent is desired.

  A power conversion device according to the present invention includes a power semiconductor device, an electrode wiring member connected to a main electrode of the power semiconductor device, a housing, and a fuse formed as a fuse formed in the electrode wiring member. A sealing resin member which is a resin member for sealing the inside of the casing, the cover member covering the fuse portion, the power semiconductor element, the electrode wiring member, and the cover member covering the fuse portion And.

  According to the power conversion device of the present invention, the fuse portion is formed in the electrode wiring member, so that an expensive chip type fuse is not provided, and the cost of the fuse portion can be reduced. Since the cover member that covers the fuse portion is covered by the sealing resin member, it is possible to prevent the member of the fuse portion that has been fused from scattering to the outside. In addition, since the fuse portion can be shut off from the outside air by the sealing resin member, it is possible to suppress the progress of the combustion reaction due to the arc discharge generated at the time of melting, and smoke generated at the time of melting is leaked to the outside Can be suppressed. Furthermore, when the fuse portion is melted and broken, the scattering melting member can be made to collide with the cover member and not be in contact with the sealing resin member, so that damage to the sealing resin member can be suppressed, and the sealing resin member It is possible to maintain the suppression of smoke and burnout caused by In addition, even when sparks and smoke are generated in the fuse portion, the cover member functions as a fire spread prevention plate, and it is possible to suppress burning and smoking of the power conversion device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view of the power converter device which concerns on Embodiment 1 of this invention. It is sectional drawing of the power converter device cut | disconnected in the BB cross-sectional position of FIG. 1 which concerns on Embodiment 1 of this invention. It is sectional drawing of the power converter device cut | disconnected in the AA cross-section position of FIG. 1 which concerns on Embodiment 1 of this invention. It is a perspective view of the cover member and fuse part which concern on Embodiment 1 of this invention. It is a schematic diagram for demonstrating the current density of the fuse part which concerns on Embodiment 1 of this invention. It is a schematic diagram explaining the variation of the shape of the fuse part which concerns on Embodiment 1 of this invention. It is a schematic diagram explaining the variation of the shape of the fuse part which concerns on Embodiment 1 of this invention. It is sectional drawing of the power converter device cut | disconnected in the AA cross-section position of FIG. 1 which concerns on Embodiment 2 of this invention. It is sectional drawing of the power converter device cut | disconnected in the AA cross-section position of FIG. 1 which concerns on Embodiment 3 of this invention. It is sectional drawing of the power converter device cut | disconnected in the AA cross-section position of FIG. 1 which concerns on Embodiment 4 of this invention.

Embodiment 1
A power conversion device 1 according to a first embodiment will be described with reference to the drawings. FIG. 1 is a plan view of the power conversion device 1 as viewed from the opening side of the housing 30, and the sealing resin member 25 and the cover member 27 are illustrated as being transparent in order to explain the arrangement of the components. Absent. FIG. 2 is a cross-sectional view taken along the line B-B in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line A-A in FIG. FIG. 4 is a perspective view of the cover member 27 and the fuse portion 16 as viewed obliquely from the opening side of the housing 30. FIG. 1 to 4 are schematic views, and the dimensions of the respective members do not completely match between the drawings.

  The power conversion device 1 includes various components such as the power semiconductor element 14, the electrode wiring member 13 connected to the main electrodes of the power semiconductor element 14, the housing 30, and the power semiconductor element 14 in the housing 30. And a sealing resin member 25 which is a resin member for sealing.

<Case 30>
The housing 30 is formed in a cylindrical shape with a bottom and has a role of a frame for casting the sealing resin member 25. In addition, below, when only saying "inside""inside" or "outside""outside" shall mean the inside or the outside of the housing | casing 30. FIG. The “longitudinal direction” refers to the direction in which the cylindrical portion of the housing 30 extends, and the “lateral direction” refers to the direction in which the bottom of the housing 30 extends.

  The bottom of the housing 30 is constituted by a metal heat sink 12. The heat sink 12 has a role of radiating the heat generated in the power semiconductor element 14 to the outside. The heat sink 12 is made of, for example, a material having a thermal conductivity of 20 W / (m · K) or more, such as aluminum and aluminum alloy. The heat sink 12 is formed in a rectangular flat shape. On the inner surface of the heat sink 12 facing the member on the power semiconductor element 14 side, there is provided a flat element facing protrusion 12a projecting inward, and the inner surface of the element facing protrusion 12a is a power semiconductor element Abuts against the member on the 14 side. On the outer surface of the heat sink 12, as shown in FIG. 2, a plurality of flat fins 19 arranged at intervals are provided. The fins 19 are in contact with the outside air, and the heat sink 12 dissipates heat from the fins 19 toward the outside air. In addition, it may be water-cooled.

  The cylindrical portion of the housing 30 is constituted by the insulating case 11. The insulating case 11 is formed using any resin material having high insulating property and thermoplasticity, for example, resin materials such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), and polyetheretherketone (PEEK). Ru.

<Power Semiconductor Element 14, Electrode Wiring Member 13>
In the present embodiment, the power semiconductor element 14 and the electrode lead frame 13 as the electrode wiring member 13 are sealed with the element mold resin 20 which is a resin member to form a packaged semiconductor element module 29. There is. The control lead frame 21 connected to the control terminal of the power semiconductor element 14 is also sealed by the element mold resin 20. The electrode lead frame 13 and the control lead frame 21 protrude outward from the element mold resin 20. As the element mold resin 20, a hard resin having a Young's modulus of several GPa is preferably used in order to protect the elements and the wiring inside. For example, an epoxy resin is used.

  A power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is used as the power semiconductor element 14. The power semiconductor element 14 may use another type of switching element such as a power IGBT (Insulated Gate Bipolar Transistor) in which diodes are connected in reverse parallel. The power semiconductor element 14 is used, for example, in an inverter circuit and a converter circuit for driving an apparatus such as a motor for driving a vehicle, and controls a rated current of several amperes to several hundred amperes. As a material of the power semiconductor element 14, silicon (Si), silicon carbide (SiC), gallium nitride (GaN) or the like may be used.

  The power semiconductor element 14 is formed in a rectangular flat chip shape, a drain terminal as a main electrode is provided on the surface on the heat sink 12 side, and a main electrode on the surface of the housing 30 opposite to the heat sink 12 Source terminals are provided. A gate terminal as a control terminal is provided on the surface of the housing 30 opposite to the heat sink 12. A sensor terminal or the like for detecting the current flowing between the main electrodes may be provided as the control terminal.

  The drain terminal is connected to the electrode lead frame 13a on the positive electrode side, and the source terminal is connected to the electrode lead frame 13b on the negative electrode side via the electrode wiring member 15a. Since a large current flows in the electrode wiring member 15a, the electrode wiring member 15a is formed of, for example, a processed plate of gold, silver, copper, or aluminum, wire bonding, or ribbon bonding. The gate terminal and the sensor terminal are connected to the control lead frame 21 via the control wiring member 15b. The control wiring member 15b can be formed, for example, by wire bonding of gold, copper, aluminum or the like or ribbon bonding of aluminum.

  The electrode lead frames 13a and 13b on the positive electrode side and the negative electrode side are formed in a flat plate shape. The electrode connection portions of the electrode lead frames 13 a and 13 b connected to the main electrodes of the power semiconductor element 14 are disposed closer to the heat sink 12 than the power semiconductor elements 14. The surface on the opposite side to the heat sink 12 of the electrode connection portion of the electrode lead frame 13 a on the positive electrode side is joined to the drain terminal of the surface on the heat sink 12 side of the power semiconductor element 14 by a conductive bonding material 17. The surface of the electrode connection portion of the electrode lead frame 13b on the negative electrode side opposite to the heat sink 12 is bonded to one end of an L-shaped electrode wiring member 15a by a conductive bonding material 17. The source terminal of the surface on the opposite side to the heat sink 12 of the power semiconductor element 14 is bonded to the other end of the electrode wiring member 15 a by the conductive bonding material 17. The conductive bonding material 17 is made of, for example, a material having high conductivity and high thermal conductivity, such as solder, silver paste, or a conductive adhesive.

  The surface on the heat sink 12 side of the electrode connection portion of the electrode lead frames 13 a and 13 b is not covered by the element mold resin 20 and is exposed to the outside of the semiconductor element module 29. The exposed portions of the electrode lead frames 13a and 13b are in contact with the inner surface of the element facing projection 12a of the heat sink 12 through the insulating member 18 formed in a sheet shape. The heat generation of the power semiconductor element 14 is transmitted to the heat sink 12 through the electrode connection portions of the electrode lead frames 13 a and 13 b and the insulating member 18. The insulating member 18 is made of a material having high thermal conductivity and high electrical insulation. Therefore, the insulating member 18 has, for example, a thermal conductivity of several W / (m · K) to several tens W / (m · K), and is insulating, such as silicon resin, epoxy resin, urethane resin, etc. The adhesive, the grease or the insulating sheet made of the resin material of Furthermore, the insulating member 18 can also be configured by combining a resin material with another material having a low thermal resistance such as a ceramic substrate or a metal substrate and having an insulating property.

  Further, in order to define the thickness of the insulating member 18, a protrusion 20 a is provided on the heat sink 12 side of the element mold resin 20. By pressing the projections 20a of the element mold resin 20 against the heat sink 12, the thickness of the insulating member 18 can be defined by the height of the projections 20a, and the insulation and heat conductivity of the insulating member 18 can be managed. it can. For example, in a low voltage system car using a 12V battery, a creeping distance required to secure a predetermined insulation withstand voltage is about 10 μm. Therefore, in the case of a low withstand voltage automobile, the thickness required for insulation can be reduced, so that the protrusions 20 a of the element mold resin 20 can be shortened, and the power converter 1 can be thinned. In the case where the insulating member 18 is a material that has rigidity and a small change in thickness due to pressing, the thickness of the insulating member 18 can be controlled, so the protrusions 20 a of the element mold resin 20 may be omitted.

  The distance between the electrode lead frames 13a and 13b sealed in the element mold resin 20 and the heat sink 12 can be controlled by the protrusions 20a, and the gaps are formed on the electrode lead frame 13b on the negative electrode side described later. The distance between the fuse portion 16 and the heat sink 12 can be controlled, and the thermal conductivity and insulation between the two can be managed.

  The electrode lead frame 13a on the positive electrode side protrudes from the element mold resin 20 and then extends laterally along the inner surface of the heat sink 12 with a gap from the inner surface of the heat sink 12, and then bent, It extends in the longitudinal direction to the side away from the opening 12 (the opening side of the housing 30). The portion extending in the lateral direction with a space from the inner surface of the heat sink 12 is referred to as the positive electrode side lateral extending portion 13a1, and the portion extending in the longitudinal direction away from the heat sink 12 is the positive electrode It is referred to as a side longitudinal extension 13a2. The distance between the positive electrode side lateral extension 13a1 and the heat sink 12 corresponds to the sum of the thickness of the insulating member 18 and the height of the element facing protrusion 12a of the heat sink 12. The fuse part 16 mentioned later is formed in the horizontal direction extended part 13a1 by the side of a positive electrode.

  The positive electrode side longitudinal extension 13a2 is joined to the positive electrode external connection terminal 10a inserted and outsert in the insulating case 11 by welding or soldering. The external connection terminal 10a on the positive electrode side is joined to the vertical direction extending portion 13a2 on the positive electrode side, and a portion extending in the vertical direction and a portion extending in the lateral direction toward the outside of the housing 30 have. The part which protrudes from the housing | casing 30 outside is connected to other apparatuses, such as a positive electrode of DC power supply.

  The electrode lead frame 13b on the negative electrode side also protrudes from the element mold resin 20, and then forms a gap with the inner surface of the heat sink 12 and extends along the inner surface of the heat sink 12; A negative electrode side longitudinal extending portion 13b2 extending to the side away from the heat sink 12 is provided. The length of the positive electrode side lateral extension 13a1 is longer than the negative electrode side lateral extension 13b1 to form the fuse portion 16.

  The longitudinal extension 13b2 on the negative electrode side is joined to the external connection terminal 10b on the negative electrode side inserted and outsert in the insulating case 11 by welding or soldering. The external connection terminal 10b on the negative electrode side is joined to the vertical extension 13b2 on the negative electrode side, with a portion extending in the vertical direction and a portion extending in the lateral direction toward the outside of the housing 30. have. The portion protruding from the housing 30 to the outside is connected to another device such as the negative electrode of the DC power supply.

  The electrode lead frames 13a and 13b and the external connection terminals 10a and 10b use a metal such as copper or copper alloy having good conductivity and high thermal conductivity, and a large current of several amps to several hundreds of amps flows . The surfaces of the electrode lead frames 13a and 13b may be plated with a metal material such as Au, Ni, or Sn.

  The control lead frame 21 protrudes from the sealing resin member 25 on the opening side of the housing 30 and is connected to a control device that controls the on / off of the power semiconductor element 14.

<Fuse section 16>
The electrode wiring member 13 is formed with a fuse portion 16 functioning as a fuse. In the present embodiment, the fuse portion 16 is formed in a portion of the electrode lead frame 13 (in the present example, the laterally extending portion 13a1 on the positive electrode side) which protrudes outward from the element mold resin 20. By forming the fuse portion 16 on the electrode lead frame 13, there is no need for an additional member, and the cost can be reduced. In this example, since the fuse portion 16 is formed in the laterally extending portion of the electrode lead frame 13, the direction (height direction) in which the electrode lead frame 13 is separated from the heat sink 12 to form the fuse portion 16. Can be suppressed, and the height of the power converter 1 can be suppressed. Further, since the fuse portion 16 is formed on the electrode lead frame 13a on the positive electrode side, the current can be interrupted on the upstream side of the power semiconductor element 14. Therefore, even when a circuit abnormality of the power semiconductor element 14 occurs, such as a short circuit between the power semiconductor element 14 and the housing 30, the current can be cut off on the upstream side to prevent an overcurrent.

  The fuse portion 16 is constituted by a portion of the electrode wiring member 13 whose cross-sectional area is smaller than that of the front and rear portions in the current flow direction. That is, the fuse portion 16 has a smaller cross-sectional area than the portions on the front side (upstream side) and the rear side (downstream side) in the flow direction of the current than the fuse portion 16. As shown in FIG. 5, when an overcurrent flows through the electrode lead frame 13, the current density of the fuse portion 16 having a cross-sectional area smaller than that of the front and back becomes larger, and the temperature of the fuse portion 16 locally rises and melts off. Cut off the over current. The fuse portion 16 is made of gold, silver, copper, or aluminum having high electrical conductivity. The fuse portion 16 may be made of the same material as that of the other part of the electrode lead frame 13, or a different material may be used. Although not limited to this, the fuse portion 16 punches out a flat plate made of copper or copper alloy having a thickness of about 0.5 mm to 1.5 mm as the other parts of the electrode lead frame 13 It can be formed by

  The shape of the fuse portion 16 may be any shape as long as it reduces the cross-sectional area. For example, as shown in FIGS. 6 and 7, notches may be provided on one side or both sides, or through holes may be provided on the inner side to reduce the cross-sectional area. The shape of the notch or the through hole may be any shape other than a rectangle, such as a triangle, a pentagon, a trapezoid, a rhombus, a parallelogram, a circle, and an ellipse. The number of notches or through holes is not limited to one, and may be plural. Also, the plurality of notches or through holes may be alternately staggered or irregularly arranged at different positions in the longitudinal direction of the wiring. The plurality of through holes may be arranged in either the width direction or the length direction of the wiring.

<Cover member 27>
A cover member 27 which covers the fuse portion 16 is provided. A space is provided between the fuse portion 16 and the cover member 27. In the present embodiment, the cover member 27 covers a portion of the housing 30 (in the present example, the heat sink 12) facing the fuse portion 16 in addition to the fuse portion 16. That is, the heat sink 12 side of the cover member 27 is a cover opening 27 c that opens to the heat sink 12, and the cover opening 27 c is closed by the inner surface of the heat sink 12. Thus, the fuse portion 16 is covered by the cover member 27 and the inner surface of the heat sink 12. As shown in FIG. 4, the cover member 27 is formed in a rectangular box shape having an opening on the heat sink 12 side, and on the two side surfaces facing each other, the cover member 27 is on the front side (upstream side) A cover through hole 27a through which the portion of the laterally extending portion 13a1 penetrates and a cover through hole 27b through which the portion of the laterally extending portion 13a1 behind the fuse portion 16 (downstream side) penetrates are provided. Each cover through hole 27a, 27b is closed by the laterally extending portion 13a1. Thus, the space formed by the cover member 27 and the heat sink 12 is sealed. 4A is a perspective view of a state in which the cover member 27 and the electrode lead frame 13a are disassembled, and FIG. 4B on the right side of FIG. It is a perspective view of the state attached to lead frame 13a, and shows lead frame 13a for electrodes with a dashed dotted line.

  The cover member 27 is made of a material having an insulating property and high rigidity. Further, the cover member 27 may be made of a material having a high thermal conductivity. The cover member 27 may be made of a resin material such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK), and alumina, aluminum hydroxide, zirconia, aluminum nitride, silicon nitride And the like, and may be made of a ceramic material such as The cover member 27 is made of, for example, a metal material such as Cu, Al, Fe, a Cu alloy, an Al alloy, a Fe alloy or the like if insulation with the electrode lead frame 13a, the fuse portion 16 and the heat sink 12 can be ensured. May be

  In order to seal the space formed by the cover member 27 and the heat sink 12, the cover member 27 may be fixed to the heat sink 12 and the electrode lead frame 13a by bonding, welding, caulking or the like.

  When the fuse portion 16 is melted and cut, the scattering melting member is caused to collide with the cover member 27 to suppress contact with the sealing resin member 25 and damage to the sealing resin member 25 can be suppressed. The ability to suppress smoke and burnout by the resin stopping member 25 can be maintained. In addition, even when sparks or smoke are generated in the fuse portion 16, the cover member 27 functions as a fire spread prevention plate, and it is possible to suppress burning and smoking of the power conversion device 1.

  The space inside the cover member 27 may be filled with air, or may be vacuum or an inert gas such as nitrogen or argon.

<Sealing resin member 25>
The sealing resin member 25 is a resin member for sealing the cover member 27 covering the power semiconductor element 14, the electrode wiring member 13, and the fuse portion 16 in the housing 30. The sealing resin member 25 is not filled in the sealed space inside the cover member 27 and covers the outside of the cover member 27. In the present embodiment, the sealing resin member 25 is configured to seal the semiconductor element module 29 in the housing 30. The sealing resin member 25 also seals other components such as the insulating member 18 and the external connection terminals 10 a and 10 b in the housing 30. The sealing resin member 25 is made of, for example, a resin material having high rigidity and high thermal conductivity. The sealing resin member 25 may be made of, for example, an epoxy resin containing a thermally conductive filler, a silicon resin, a urethane resin, PPS, PEEK, or ABS. The Young's modulus of the sealing resin member 25 may be 1 MPa to 50 GPa, and the thermal conductivity may be 0.1 W / (m · K) to 20 W / (m · K). By sealing each component with the sealing resin member 25, vibration resistance and environmental resistance can be improved.

  Since the outside of the cover member 27 covering the fuse portion 16 is covered by the sealing resin member 25, it is possible to prevent the member of the fused portion 16 from scattering to the outside of the cover member 27. Since the space inside the cover member 27 can be shielded from the outside air, it is possible to suppress the progress of the combustion reaction due to the arc discharge generated at the time of melting, and to suppress the smoke generated at the time of melting being leaked to the outside .

Second Embodiment
Next, the power conversion device 1 according to the second embodiment will be described. Description of the same components as those of the above-described first embodiment will be omitted. The basic configuration of the power conversion device 1 according to the present embodiment is the same as that of the first embodiment, but the configuration of the heat sink 12 is partially different. FIG. 8 is a cross-sectional view of the power conversion device 1 according to the present embodiment cut at a cross-sectional position along the line A-A in FIG.

  Similar to the first embodiment, a cover member 27 that covers the fuse portion 16 is provided. The cover member 27 covers a portion of the housing 30 (in this example, the heat sink 12) facing the fuse portion 16 in addition to the fuse portion 16.

  Unlike the first embodiment, the housing 30 (heat sink 12) has a recess 12 b recessed toward the side away from the fuse portion 16 in the portion covered by the cover member 27. The recess 12 b is formed in a rectangular parallelepiped shape in accordance with the shape of the cover member 27. The recess 12 b may be formed into any shape such as a cylindrical shape as long as it is covered by the cover member 27.

  According to this configuration, the size of the sealed space by the cover member 27 can be expanded by providing the recess 12 b. Further, the distance between the fuse portion 16 and the heat sink 12 can be increased, and a short-circuit between the electrode wiring member 13 and the heat sink 12 can be suppressed by the fused member of the fuse portion 16.

  Note that the housing 30 (heat sink 12) may have a protruding portion that protrudes toward the fuse portion 16 in a portion covered by the cover member 27. Also in this case, a space is provided between the protrusion and the fuse portion 16. The distance between the fuse portion 16 and the heat sink 12 can be adjusted appropriately.

Third Embodiment
Next, the power conversion device 1 according to the third embodiment will be described. Description of the same components as those of the above-described first embodiment will be omitted. The basic configuration of power conversion device 1 according to the present embodiment is the same as that of the first embodiment, but the inner configuration of cover member 27 is partially different. FIG. 9 is a cross-sectional view of the power conversion device 1 according to the present embodiment cut at the cross-sectional position along the line A-A of FIG. 1.

  Similar to the first embodiment, a cover member 27 that covers the fuse portion 16 is provided. The cover member 27 covers a portion of the housing 30 (in this example, the heat sink 12) facing the fuse portion 16 in addition to the fuse portion 16.

  Unlike the first embodiment, the space covered by the cover member 27 is filled with an arc extinguishing agent 26 which has an arc extinguishing action of the arc discharge generated when the fuse portion 16 is fused. According to this configuration, it is possible to suppress the continuation of the energization by the arc discharge even after the fuse portion is fused, and to interrupt the current promptly after the fusion. Therefore, damage to the power semiconductor element 14, the sealing resin member 25 and the like can be suppressed.

  The arc extinguishing agent 26 is silicon, sand such as silica sand, gas such as sulfur hexafluoride (SF6), or silicon resin such as silicone rubber or silicone gel.

  When the arc extinguishing agent 26 is a silicone resin, the Young's modulus may be lower than that of the sealing resin member 25. For example, the Young's modulus of the silicone resin is on the order of several tens of MPa (megapascals) (for example, a value between 10 MPa and 30 MPa), and for example, a rubber material, silicone rubber, silicone gel may be used. According to this configuration, it is possible to immerse and hold a plurality of spherical members in the form of spherical lumps that are scattered when the fuse portion 16 is melted and broken. Therefore, after melting, while maintaining that an electricity supply path is maintained can be prevented by the fuse | melted member, it can suppress that the electrode wiring member 13 and the heat sink 12 short-circuit.

  The arc extinguishing agent 26 may not be filled in all of the inner space of the cover member 27. For example, when the arc extinguishing agent 26 is a silicone resin, the silicone resin may be filled only between the fuse portion 16 and the heat sink 12.

  When a material having a low thermal conductivity is used as the arc extinguishing agent 26, the heat dissipation of the fuse portion 16 decreases when an overcurrent flows, the temperature increase rate increases, and the period until the fuse portion 16 is melted is determined. It can be shortened.

Fourth Embodiment
Next, a power converter 1 according to Embodiment 4 will be described. Description of the same components as those of the above-described first embodiment will be omitted. The basic configuration of the power conversion device 1 according to the present embodiment is the same as that of the first embodiment, but the configuration of the heat sink 12 is partially different. FIG. 10 is a cross-sectional view of the power conversion device 1 according to the present embodiment cut at the cross-sectional position along the line A-A in FIG.

  Similar to the first embodiment, a cover member 27 that covers the fuse portion 16 is provided. The cover member 27 covers a portion of the housing 30 (in this example, the heat sink 12) facing the fuse portion 16 in addition to the fuse portion 16.

  Unlike the first embodiment, the housing 30 (heat sink 12) has a through hole 28 penetrating to the outside at a portion covered by the cover member 27. A lid member 31 for closing the through hole 28 is attached.

  The through hole 28 is formed in a rectangular parallelepiped shape in accordance with the shape of the cover member 27 and penetrates the inside and the outside of the heat sink 12 in the longitudinal direction. The lid member 31 is fixed to the outer end of the inner peripheral surface of the through hole 28. The lid member 31 is fixed to the heat sink 12 by adhesion, welding, caulking or the like to prevent moisture from invading from the outside. The lid member 31 is made of a member different from the heat sink 12, and may be made of, for example, a thin film of a metal material such as Cu or Al, or a resin material such as PPS, PEEK, or ABS.

  The lid member 31 may be configured of a water repellent filter made of a resin material such as poly tetra fluoro ethylene (PTFE).

  When the fuse portion 16 is torn by the overcurrent, the lid member 31 is separated from the heat sink 12 due to the energy due to the rupture of the fuse portion 16 or the scattered fuse portion 16 or a part of the lid member 31 is broken. There is an opening. Under the present circumstances, since the fuse part 16 which melted and scattered is discharged | emitted to the exterior of the power converter device 1, the damage of the power converter device 1 can be prevented and the stable interruption | blocking effect can be acquired.

  As in the third embodiment, the arc extinguishing agent 26 may be filled in the space formed by the cover member 27, the heat sink 12, and the lid member 31.

Other Embodiments
Finally, other embodiments of the present invention will be described. The configuration of each embodiment described below is not limited to one applied individually, and may be applied in combination with the configuration of the other embodiments as long as no contradiction arises.

(1) In the above embodiments, the semiconductor element module 29 in which the power semiconductor element 14 and the electrode lead frame 13 as the electrode wiring member 13 are sealed by the element mold resin 20 which is a resin member The case where it has been described has been described as an example. However, the embodiment of the present invention is not limited to this. That is, the power semiconductor element 14 and the electrode wiring member 13 may not be sealed by the element mold resin 20 and may not be packaged. That is, the power semiconductor element 14, the electrode wiring member 13 and the like in a state not sealed in the element mold resin 20 may be sealed in the housing 30 by the sealing resin member 25. In this case, the electrode wiring member 13 may be a bus bar or the like, and the fuse portion 16 may be formed in a portion of the electrode wiring member on the positive electrode side or the negative electrode side sealed in the sealing resin member 25.

(2) In each of the above embodiments, the fuse portion 16 has been described as an example being formed on the electrode lead frame 13a (laterally extending portion 13a1) on the positive electrode side. However, the embodiment of the present invention is not limited to this. That is, the fuse portion 16 may be formed at any part of the electrode wiring member 13 which is connected to the main electrode of the power semiconductor element 14 and sealed in the sealing resin member 25. For example, the fuse portion 16 may be the lateral extension 13b1 of the electrode lead frame 13b on the negative electrode side, the longitudinal extension 13a2 on the positive electrode side, the longitudinal extension 13b2 on the negative electrode side, or the positive electrode side or the negative electrode side The external connection terminals 10a and 10b may be formed.

(3) In each said embodiment, the case where the power converter device 1 provided the one semiconductor element 14 (switching element) for electric power was demonstrated as an example. However, the embodiment of the present invention is not limited to this. That is, the power conversion device 1 may be provided with a plurality of power semiconductor elements. For example, two switching elements may be connected in series between the electrode wiring member on the positive electrode side and the electrode wiring member on the negative electrode side, and the fuse portion 16 may be formed in the electrode wiring member on the positive electrode side or the negative electrode side. In addition, a series circuit of two switching elements is a bridge circuit in which a plurality of sets are connected in parallel between the electrode wiring member on the positive electrode side and the electrode wiring member on the negative electrode side. , And the fuse unit 16 may be provided. Further, part or all of the power semiconductor element 14 may be a diode.

(4) In each of the above embodiments, the heat sink 12 side of the cover member 27 is the cover opening 27 c that opens to the heat sink 12 side, and the cover opening 27 c is closed by the inner surface of the heat sink 12. The case of peeling was described as an example. However, the embodiment of the present invention is not limited to this. That is, the heat sink 12 side of the cover member 27 is not open, and the cover member 27 may cover the fuse portion 16 all around.

  In the present invention, within the scope of the invention, each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted.

Reference Signs List 1 power converter, 13 electrode wiring member, 14 power semiconductor element, 16 fuse portion, 20 element mold resin, 25 sealing resin member, 26 arc extinguishing agent, 27 cover member, 28 through hole, 29 semiconductor element module, 30 Housing, 31 lid

A power conversion device according to the present invention includes a power semiconductor device, an electrode wiring member connected to a main electrode of the power semiconductor device, a housing, and a fuse formed as a fuse formed in the electrode wiring member. A sealing resin member which is a resin member for sealing the inside of the casing, the cover member covering the fuse portion, the power semiconductor element, the electrode wiring member, and the cover member covering the fuse portion If, Bei example, said cover member, in addition to the fuse unit, covers a portion of the housing that is opposite to the fuse portion, wherein the housing, the portion covered by the cover member A cover member is attached to the outer side, and a cover member for closing the through hole is attached, and the cover member is separated from the through hole when the fuse portion is torn, or is broken when the opening is opened Is raw Is shall.

Claims (11)

Power semiconductor elements,
An electrode wiring member connected to the main electrode of the power semiconductor element;
And
A fuse portion formed on the electrode wiring member and functioning as a fuse;
A cover member covering the fuse portion;
And a sealing resin member which is a resin member for sealing the cover member covering the power semiconductor element, the electrode wiring member, and the fuse portion in the casing. The power semiconductor element and the electrode lead frame as the electrode wiring member are a semiconductor element module sealed by an element mold resin which is a resin member,
The power conversion device according to claim 1, wherein the fuse portion is formed in a portion of the electrode lead frame protruding outward from the element mold resin.   The power conversion device according to claim 1 or 2, wherein the fuse portion is configured by a portion of the electrode wiring member whose cross-sectional area is smaller than portions before and after a current flow direction.   The power conversion according to any one of claims 1 to 3, wherein the space covered by the cover member is filled with an arc-extinguishing agent having an arc-extinguishing action of an arc discharge generated when the fuse portion is fused. apparatus.   The power converter according to claim 4, wherein the arc extinguishing agent is a silicone resin.   The power converter according to claim 5, wherein the silicon resin has a Young's modulus lower than that of the sealing resin member.   The power converter according to claim 5 or 6, wherein Young's modulus of the silicon resin is on the order of several tens of megapascals.   The power conversion device according to any one of claims 1 to 7, wherein the cover member covers a portion of the housing facing the fuse portion in addition to the fuse portion.   The power conversion device according to claim 8, wherein the housing has a recess recessed toward the side away from the fuse portion in a portion covered by the cover member.   The power conversion device according to claim 8, wherein the housing has a through hole penetrating to the outside in a portion covered by the cover member, and a lid member for closing the through hole is attached. The housing is formed in a bottomed cylindrical shape in which a bottom portion is formed of a metal heat sink,
The power conversion device according to any one of claims 1 to 10, wherein the cover member covers a portion of the heat sink facing the fuse portion in addition to the fuse portion.

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