JP6479115B1 - Power converter - Google Patents

Abstract

Provided is a power conversion device capable of suppressing smoke generation and burning even when a fuse portion is melted by an overcurrent. A power conversion device includes a power semiconductor element, an electrode wiring member, a housing, a fuse portion formed on the electrode wiring member, a cover member covering the fuse portion, The power semiconductor element 14, the electrode wiring member 13, and the sealing resin member 25 that seals the cover member 27 covering the fuse portion 16 in the housing 30 are provided. [Selection] Figure 3

Description

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

  In recent years, in the automobile industry, vehicles using a motor as a driving force source, such as hybrid cars and electric cars, have been actively developed. An inverter device for driving a motor supplies high-voltage driving power to the motor using a battery as a power source. In addition, resin-encapsulated power semiconductor devices are used for the inverter device, and in the field of power electronics, the power conversion device is increasingly important as a key device.

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

  If a relay that connects the battery and the motor drive circuit is connected in a short circuit state or if the connection is continued, the power conversion device smokes and burns due to a large current. Moreover, it is conceivable that the battery connected to the motor drive inverter device is damaged by the overcurrent exceeding the rating. In order to avoid such a situation, normally, when an overcurrent flows, a sensor that detects the overcurrent is used to control the switching of the power semiconductor element at high speed to cut off the current. However, even when the power semiconductor element is short-circuited, it is desired to more reliably prevent the above-described failure modes such as smoke.

  Specifically, for example, if an overcurrent cutoff fuse is inserted between the power semiconductor device and the battery, the overcurrent flowing between the motor drive inverter device and the battery can be prevented.

  However, chip-type overcurrent cutoff fuses are expensive. Therefore, there is a need for overcurrent blocking means that can reliably block an overcurrent that can flow to a battery when a power semiconductor element is short-circuited while being inexpensive. For example, in Patent Document 1 described below, a fuse portion is formed by cutting out an external connection electrode protruding outward from a semiconductor device and reducing the cross-sectional area.

JP 2005-175439 A

  However, in the technique of Patent Document 1, the fuse portion provided on the external connection electrode is exposed to the outside of the semiconductor device. Therefore, when the fuse portion is melted by an overcurrent, smoke may flow out of the device, and sparks may scatter around the device, causing the device to burn out due to a combustion reaction using the outside air.

  Therefore, there is a demand for a power conversion device that can suppress smoke generation and burning even if the fuse portion is melted by an overcurrent.

The power conversion device according to the present invention includes a power semiconductor element, an electrode wiring member connected to a main electrode of the power semiconductor element, a housing, and a fuse functioning as a fuse formed in the electrode wiring member. A sealing resin member that is a resin member that seals the cover member covering the fuse part, the cover member covering the fuse part, the power semiconductor element, the electrode wiring member, and the fuse part 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 lid member that has a through-hole penetrating to the outside and closes the through-hole is attached, and the lid member is separated from the through-hole when the fuse portion is torn or broken and opened. Raw Is shall.

  According to the power conversion device of the present invention, since the fuse portion is formed in the electrode wiring member, an expensive chip-type fuse is not provided, and the cost of the fuse portion can be reduced. Since the cover member covering the fuse portion is covered by the sealing resin member, it is possible to prevent the melted fuse portion member from being scattered outside. Moreover, since the fuse part can be shut off from the outside air by the sealing resin member, the progress of the combustion reaction due to the arc discharge generated at the time of fusing can be suppressed, and the smoke generated at the time of fusing leaks to the outside. Can be suppressed. Furthermore, when the fuse part is blown, the molten member that scatters can collide with the cover member so that it does not come into contact with the sealing resin member, so that the sealing resin member can be prevented from being damaged, and the sealing resin member The ability to suppress smoke and burnout can be maintained. Moreover, even when a spark or smoke is generated in the fuse portion, the cover member functions as a fire spread prevention plate, and the burnout and smoke generation of the power converter can be suppressed.

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 by the BB cross-section position of FIG. 1 which concerns on Embodiment 1 of this invention. It is sectional drawing of the power converter device cut | disconnected by 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 by 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 by 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 by the AA cross-section position of FIG. 1 which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
A power conversion apparatus 1 according to Embodiment 1 will be described with reference to the drawings. FIG. 1 is a plan view of the power conversion device 1 viewed from the opening side of the housing 30, and the sealing resin member 25 and the cover member 27 are made transparent and illustrated in order to explain the arrangement of each component. Absent. 2 is a cross-sectional view taken along the line BB in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line AA 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. 1 to 4 are schematic diagrams, and the dimensions of each member do not completely match between the drawings.

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

<Case 30>
The housing 30 is formed in a bottomed cylindrical shape, and has a role of a frame for casting the sealing resin member 25. In the following description, “inside”, “inside”, “outside”, and “outside” mean the inside or outside of the housing 30. “Vertical direction” means the direction in which the cylindrical portion of the casing 30 extends, and “lateral direction” means the direction in which the bottom of the casing 30 extends.

  The bottom part of the housing 30 is constituted by a metal heat sink 12. The heat sink 12 has a role of radiating heat generated in the power semiconductor element 14 to the outside. For the heat sink 12, for example, a material having a thermal conductivity of 20 W / (m · K) or more such as aluminum or an aluminum alloy is used. The heat sink 12 is formed in a rectangular flat plate shape. The inner surface portion of the heat sink 12 facing the member on the power semiconductor element 14 side is provided with a flat element facing protrusion 12a that protrudes inward, and the inner surface of the element facing protrusion 12a is the power semiconductor element. It contacts the 14 side member. 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 radiates heat from these fins 19 toward the outside air. It may be water-cooled.

  The cylindrical portion of the housing 30 is configured by an insulating case 11. The insulating case 11 is formed using an arbitrary resin material having high insulating properties and thermoplasticity, for example, a resin material such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyether ether ketone (PEEK). The

<Power Semiconductor Element 14 and 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 an element mold resin 20 which is a resin member to form a packaged semiconductor element module 29. Yes. The control lead frame 21 connected to the control terminal of the power semiconductor element 14 is also sealed with the element mold resin 20. The electrode lead frame 13 and the control lead frame 21 protrude outward from the element mold resin 20. The element mold resin 20 is preferably made of a hard resin having a Young's modulus of several GPa in order to protect internal elements and wiring. For example, an epoxy resin is used.

  The power semiconductor element 14 is a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The power semiconductor element 14 may be another type of switching element such as a power IGBT (Insulated Gate Bipolar Transistor) in which diodes are connected in antiparallel. The power semiconductor element 14 is used, for example, in an inverter circuit or a converter circuit that drives equipment such as a vehicle driving motor, 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 the main electrode is provided 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 a current flowing between the main electrodes may be provided as the control terminal.

  The drain terminal is connected to the positive electrode lead frame 13a, and the source terminal is connected to the negative electrode lead frame 13b via the electrode wiring member 15a. Since a large current flows through the electrode wiring member 15a, the electrode wiring member 15a is formed by processing, for example, a gold / silver / copper / aluminum plate material, a wire bond, or a ribbon bond. 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 by, for example, wire bonds such as gold, copper, and aluminum, or ribbon bonds 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 connecting portions of the electrode lead frames 13 a and 13 b connected to the main electrode of the power semiconductor element 14 are arranged on the heat sink 12 side of the power semiconductor element 14. The surface opposite to the heat sink 12 of the electrode connection portion of the electrode lead frame 13a 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 the conductive bonding material 17. The surface of the electrode connecting portion of the negative electrode lead frame 13b opposite to the heat sink 12 is joined to one end of an electrode wiring member 15a formed in an L shape by a conductive joining material 17. The source terminal on the surface opposite 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 a material having good conductivity and high thermal conductivity, such as solder, silver paste, or conductive adhesive.

  The surface on the heat sink 12 side of the electrode connection portions of the electrode lead frames 13a and 13b is not covered with 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 protruding portion 12a of the heat sink 12 through an insulating member 18 formed in a sheet shape. Heat generated by the power semiconductor element 14 is transmitted to the heat sink 12 via the electrode connecting portions of the electrode lead frames 13a and 13b 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 of W / (m · K), and an insulating silicon resin, epoxy resin, urethane resin, or the like. It is comprised with the adhesive agent, grease, or insulating sheet which consists of these resin materials. Furthermore, the insulating member 18 can 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 regulate 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 protrusion 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 protrusion 20a, and the insulation and heat transfer properties of the insulating member 18 can be managed. it can. For example, in a low withstand voltage vehicle using a 12V battery, the creepage distance necessary to ensure a predetermined 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 protrusion 20a of the element mold resin 20 can be shortened, and the power conversion device 1 can be thinned. When the insulating member 18 is a material having rigidity and a small change in thickness due to pressing, the thickness of the insulating member 18 can be managed, and thus the protrusion 20a of the element mold resin 20 may not be provided.

  The protrusion 20a can manage the distance between the electrode lead frames 13a and 13b sealed in the element mold resin 20 and the heat sink 12, and is formed on the electrode lead frame 13b on the negative electrode side described later. The interval between the fuse portion 16 and the heat sink 12 can be managed, and the thermal conductivity and insulation between them 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 space from the inner surface of the heat sink 12, and then bends, It extends in the vertical direction on the side away from 12 (the opening side of the housing 30). A portion extending in the lateral direction with a space from the inner surface of the heat sink 12 is referred to as a laterally extending portion 13a1 on the positive electrode side, and a portion extending in the vertical direction on the side away from the heat sink 12 is defined as the positive electrode. This is referred to as a longitudinal extension 13a2 on the side. The distance between the laterally extending portion 13a1 on the positive electrode side and the heat sink 12 corresponds to the total distance of the thickness of the insulating member 18 and the height of the element facing protruding portion 12a of the heat sink 12. A fuse portion 16 to be described later is formed in the laterally extending portion 13a1 on the positive electrode side.

  The vertical extension 13a2 on the positive electrode side is joined to the positive 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 extension 13a2 on the positive electrode side and extends in the vertical direction, and a portion that extends in the horizontal direction toward the outside of the housing 30. have. A portion protruding from the housing 30 to the outside is connected to another device such as a positive electrode of a DC power source.

  The negative electrode lead frame 13b also protrudes from the element mold resin 20, and is spaced apart from the inner surface of the heat sink 12, and extends along the inner surface of the heat sink 12. A negative electrode side longitudinally extending portion 13b2 extending to the side away from the heat sink 12. The length of the laterally extending portion 13a1 on the positive electrode side is longer than that of the laterally extending portion 13b1 on the negative electrode side in order to form the fuse portion 16.

  The longitudinally extending portion 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 portion 13b2 on the negative electrode side, and a portion extending in the vertical direction and a portion extending in the horizontal direction toward the outside of the housing 30. have. A portion protruding from the housing 30 to the outside is connected to another device such as a negative electrode of a DC power source.

  The electrode lead frames 13a and 13b and the external connection terminals 10a and 10b are made of metal such as copper or copper alloy having good conductivity and high thermal conductivity, and a large current of several amperes to several hundred amperes 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 on / off of the power semiconductor element 14.

<Fuse part 16>
The electrode wiring member 13 has a fuse portion 16 that functions as a fuse. In the present embodiment, the fuse portion 16 is formed in a portion of the electrode lead frame 13 protruding outward from the element mold resin 20 (in this example, the laterally extending portion 13a1 on the positive electrode side). By forming the fuse portion 16 in the electrode lead frame 13, no additional member is required, 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 electrode lead frame 13 is away from the heat sink 12 (height direction) for forming the fuse portion 16. It is possible to prevent the power converter device 1 from becoming taller. Further, since the fuse portion 16 is formed in 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, it is possible to cut off the current upstream so that no overcurrent occurs.

  The fuse portion 16 is constituted by a portion of the electrode wiring member 13 having a smaller cross-sectional area than the front and rear portions in the current flow direction. That is, the fuse section 16 has a smaller cross-sectional area than the fuse section 16 than the front (upstream) and rear (downstream) portions in the current flow direction. 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 smaller cross-sectional area than the front and rear becomes large, and the fuse portion 16 locally rises in temperature and blows. This cuts off the overcurrent. 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 other portions of the electrode lead frame 13 or may be made of a different material. Although not limited to this, the fuse portion 16 is stamped from a flat plate made of copper or a copper alloy having a thickness of about 0.5 mm to 1.5 mm, similarly to the other portions of the electrode lead frame 13. Can be formed.

  The shape of the fuse part 16 may be any shape as long as the cross-sectional area is reduced. For example, as shown in FIGS. 6 and 7, the cross-sectional area may be reduced by providing a notch on one side or both sides, or providing a through hole on the inside. The shape of the notch or the through hole may be an arbitrary shape such as a triangle, a pentagon, a trapezoid, a rhombus, a parallelogram, a circle, and an ellipse in addition to a rectangle. The number of notches or through holes is not limited to one, and a plurality of notches or through holes may be provided. A plurality of notches or through holes may be alternately arranged in a staggered manner or irregularly at different positions in the length direction of the wiring. A 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 that 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 the portion of the housing 30 (in this 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. Therefore, the fuse portion 16 is covered with 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 parallelepiped box shape having an opening on the heat sink 12 side, and the front side (upstream side) of the fuse part 16 is formed on two side surfaces facing each other. A cover through hole 27a through which the laterally extending portion 13a1 penetrates and a cover through hole 27b through which the laterally extending portion 13a1 on the rear side (downstream side) of the fuse portion 16 penetrates are provided. Each cover through hole 27a, 27b is closed by a laterally extending portion 13a1. Therefore, the space formed by the cover member 27 and the heat sink 12 is sealed. 4A is a perspective view of the cover member 27 and the electrode lead frame 13a in an exploded state, and FIG. 4B on the right side of FIG. 4 is the cover member 27 for the electrode. 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 insulating properties and high rigidity. Moreover, you may comprise the cover member 27 with a material with high heat conductivity. The cover member 27 may be made of a resin material such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or polyether ether ketone (PEEK), and is made of alumina, aluminum hydroxide, zirconia, aluminum nitride, silicon nitride. Or a ceramic material such as The cover member 27 is made of, for example, a metal material such as Cu, Al, Fe, Cu alloy, Al alloy, or Fe alloy when insulation with the electrode lead frame 13a, the fuse portion 16, and the heat sink 12 can be secured. 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 adhesion, welding, caulking, or the like.

  When the fuse part 16 is melted, the molten member that scatters is allowed to collide with the cover member 27 and can be prevented from coming into contact with the sealing resin member 25, and the sealing resin member 25 can be prevented from being damaged. The performance of suppressing smoke generation and burning by the stop resin member 25 can be maintained. Moreover, even when a spark or smoke is generated in the fuse portion 16, the cover member 27 functions as a fire spread prevention plate, and the power conversion device 1 can be prevented from being burned out and smoked.

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

<Sealing resin member 25>
The sealing resin member 25 is a resin member that seals the power semiconductor element 14, the electrode wiring member 13, and the cover member 27 covering 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. For example, a resin material having high rigidity and high thermal conductivity is used for the sealing resin member 25. The sealing resin member 25 may be made of, for example, an epoxy resin, a silicon resin, a urethane resin, PPS, PEEK, or ABS containing a heat conductive filler. The Young's modulus of the sealing resin member 25 is preferably 1 MPa to 50 GPa and the thermal conductivity is 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 outer side of the cover member 27 covering the fuse portion 16 is covered by the sealing resin member 25, it is possible to prevent the melted member of the fuse portion 16 from being scattered outside the cover member 27. Since the space inside the cover member 27 can be blocked from outside air, it is possible to suppress the progress of the combustion reaction due to arc discharge generated at the time of fusing, and it is possible to suppress the smoke generated at the time of fusing from leaking to the outside. .

Embodiment 2. FIG.
Next, the power converter device 1 which concerns on Embodiment 2 is demonstrated. The description of the same components as those in the first embodiment is 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 the AA cross-sectional position of FIG.

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

  Unlike the first embodiment, the housing 30 (heat sink 12) has a recess 12b that is recessed on the side away from the fuse portion 16 in a portion covered by the cover member 27. The recess 12b is formed in a rectangular parallelepiped shape in accordance with the shape of the cover member 27. In addition, the recessed part 12b may be formed in arbitrary shapes, such as a column shape, if it is covered with the cover member 27.

  According to this configuration, the size of the sealed space by the cover member 27 can be widened by providing the recess 12b. Moreover, the space | interval of the fuse part 16 and the heat sink 12 can be expanded, and it can suppress that the electrode wiring member 13 and the heat sink 12 are short-circuited by the member of the fuse part 16 fuse | melted.

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

Embodiment 3 FIG.
Next, the power converter device 1 according to Embodiment 3 will be described. The description of the same components as those in the first embodiment is 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 inside the cover member 27 is partially different. FIG. 9 is a cross-sectional view of power conversion device 1 according to the present embodiment, cut at the AA cross-sectional position of FIG.

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

  Unlike the first embodiment, the space covered by the cover member 27 is filled with an arc extinguishing agent 26 that has an arc extinguishing action of arc discharge generated when the fuse portion 16 is melted. According to this configuration, even after the fuse portion is blown, it is possible to suppress the energization from being continued by arc discharge, and to quickly cut off the current after the blow. Therefore, damage to the power semiconductor element 14 and the sealing resin member 25 can be suppressed.

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

  When the arc extinguishing agent 26 is made of silicon resin, the Young's modulus may be made lower than that of the sealing resin member 25. For example, the Young's modulus of the silicon resin is on the order of several tens of MPa (megapascals) (for example, a value between 10 MPa and 30 MPa). For example, a rubber material, silicon rubber, or silicon gel may be used. According to this configuration, when the fuse portion 16 is melted, the molten member that scatters into a plurality of spherical lumps can be held in the soft silicon resin. Therefore, it is possible to prevent the energization path from being maintained by the melted member after fusing, and to suppress a short circuit between the electrode wiring member 13 and the heat sink 12.

  The arc extinguishing agent 26 may not be filled in the entire inner space of the cover member 27. For example, when the arc extinguishing agent 26 is made of silicon resin, the silicon 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 for the arc extinguishing agent 26, the heat dissipation of the fuse part 16 when an overcurrent flows decreases, the temperature rise rate increases, and the period until the fuse part 16 is blown out is increased. It can be shortened.

Embodiment 4 FIG.
Next, the power converter device 1 which concerns on Embodiment 4 is demonstrated. The description of the same components as those in the first embodiment is 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 AA cross-sectional position of FIG.

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

  Unlike the first embodiment, the housing 30 (heat sink 12) has a through-hole 28 penetrating to the outside in a portion covered with the cover member 27. A lid member 31 that closes the through hole 28 is attached.

  The through hole 28 is formed in a rectangular parallelepiped shape according to the shape of the cover member 27, and penetrates the inner side and the outer side of the heat sink 12 in the vertical direction. The lid member 31 is fixed to the outer end portion 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, and prevents moisture from entering from the outside. The lid member 31 is made of a member different from the heat sink 12, and may be made of a thin film metal material such as Cu or Al, or a resin material such as PPS, PEEK, or ABS.

  The lid member 31 may be formed of a water repellent filter made of a resin material such as polytetrafluoroethylene (PTFE).

  When the fuse part 16 is torn due to an overcurrent, the lid member 31 is separated from the heat sink 12 by the energy due to the fuse part 16 breaking or the scattered fuse part 16 or a part of the lid member 31 is damaged. An opening is made. At this time, since the fuse part 16 that has been melted and scattered is discharged to the outside of the power converter 1, damage to the power converter 1 can be prevented, and a stable interruption effect can be obtained.

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

[Other Embodiments]
Finally, other embodiments of the present invention will be described. Note that the configuration of each embodiment described below is not limited to being applied independently, and can be applied in combination with the configuration of other embodiments as long as no contradiction arises.

(1) In each of 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 with the element mold resin 20 which is a resin member; The case 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 are not 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 that are 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 that is sealed with the sealing resin member 25.

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

(3) In each of the above-described embodiments, the case where the power conversion device 1 includes one power semiconductor element 14 (switching element) has been described 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 positive electrode wiring member and the negative electrode wiring member, and the fuse portion 16 may be formed in the positive electrode electrode member or the negative electrode wiring member. A series circuit of two switching elements is a bridge circuit connected in parallel between the positive electrode side electrode wiring member and the negative electrode side electrode wiring member. The fuse part 16 may be provided. A part or all of the power semiconductor element 14 may be a diode.

(4) In each of the embodiments described above, 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 blocked by the inner surface of the heat sink 12. The case where it has come off has been 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 over the entire circumference.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

DESCRIPTION OF SYMBOLS 1 Power converter, 13 Electrode wiring member, 14 Power semiconductor element, 16 Fuse part, 20 Element mold resin, 25 Sealing resin member, 26 Arc extinguishing agent, 27 Cover member, 28 Through-hole, 29 Semiconductor element module, 30 Case, 31 Lid member

Claims (8)

A power semiconductor element;
An electrode wiring member connected to the main electrode of the power semiconductor element;
A housing,
A fuse portion functioning as a fuse formed in the electrode wiring member;
A cover member covering the fuse part;
Semiconductor elements the power, e Bei and a sealing resin member is a resin member for sealing the electrode wiring member, and the cover member covering the fuse unit in the housing,
In addition to the fuse portion, the cover member covers a portion of the housing that faces the fuse portion,
The casing has a through hole penetrating to the outside in a portion covered by the cover member, and a lid member that closes the through hole is attached,
The lid member is a power conversion device in which when the fuse portion is torn, the lid member is separated from the through-hole or broken to generate an opening . The power semiconductor element and the electrode lead frame as the electrode wiring member are a semiconductor element module sealed with an element mold resin which is a resin member,
The power converter according to claim 1, wherein the fuse portion is formed in a portion of the electrode lead frame that protrudes outward from the element mold resin.   3. The power converter according to claim 1, wherein the fuse portion is configured by a portion of the electrode wiring member having a cross-sectional area smaller than that of a portion before and after the current flow direction.   The power conversion according to any one of claims 1 to 3, wherein a space covered by the cover member is filled with an arc extinguishing agent having an arc extinguishing action of arc discharge generated when the fuse portion is melted. apparatus.   The power converter according to claim 4, wherein the arc-extinguishing agent is a silicon resin.   The power conversion device according to claim 5, wherein the silicone 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 case is formed in a bottomed cylindrical shape whose bottom is constituted by a metal heat sink,
The power conversion device according to any one of claims 1 to 7 , wherein the cover member covers a portion of the heat sink that faces the fuse portion in addition to the fuse portion.

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