Circuit body and power conversion device

Abstract

For a terminal protruding from a semiconductor device, there is no countermeasure for insulativity reduction and the like caused by outflow of a heat conduction member, and reliability of the device is reduced. A circuit body according to the present invention is provided with: a semiconductor device which is sealed with a sealing material, has a semiconductor element embedded therein, and has a heat dissipation surface formed on at least one surface thereof, said heat dissipation surface dissipating heat of the semiconductor element; a cooling member that is disposed so as to face the heat dissipation surface of the semiconductor device and that cools the semiconductor element; and a heat conduction member which is disposed between the semiconductor device and the cooling member and in which a terminal connected to the semiconductor element protrudes from at least one side surface of the semiconductor device. A first interval between the sealing material and the cooling member on the one side surface of the semiconductor device on which the terminal protrudes is narrower than a second interval between the sealing material and the cooling member on the other side surface of the semiconductor device on which the terminal does not protrude.

Description

Technical Field

[0001] The invention relates to a circuit body and a power conversion device. Background Art

[0002] The power conversion device based on the switching action of the semiconductor element has a high conversion efficiency and is therefore widely used in people's livelihood, vehicles, railways, substation equipment, etc. The semiconductor element generates heat when it is energized. Therefore, a cooling member for cooling the semiconductor element is provided, and a heat conduction member is arranged between the semiconductor device with the semiconductor element built in and the cooling member arranged opposite to the semiconductor device. The heat conduction member conducts the heat from the semiconductor element to the cooling member by closely contacting the semiconductor device and the cooling member. For the cooling of the semiconductor device, especially in vehicle-mounted applications, high reliability is sought to maintain heat dissipation.

[0003] Patent document 1 discloses a semiconductor module mounting structure, which surrounds a metal heat sink and forms a grease reservoir on the surface of a resin sealing portion. Even if the grease moves in the surface direction due to the expansion and contraction cycle in the thickness direction of the semiconductor module, it is difficult for external air to penetrate between the metal heat sink and the insulating sheet. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2005-310987 Summary of the invention Technical problem to be solved by the invention

[0005] In the semiconductor device described in Patent Document 1, no countermeasures are taken into consideration for the reduction in insulation due to the outflow of the heat conducting member for the terminals protruding from the semiconductor device, and thus the reliability of the device is reduced. Technical means for solving technical problems

[0006] The circuit body involved in the present invention includes: a semiconductor device, which is sealed by a sealing material and has a built-in semiconductor element, and at least one surface of which is formed with a heat dissipation surface for dissipating heat from the semiconductor element; a cooling member, which is arranged opposite to the heat dissipation surface of the semiconductor device and cools the semiconductor element; and a heat conduction member, which is arranged between the semiconductor device and the cooling member, and a terminal connected to the semiconductor element protrudes from at least one side surface of the semiconductor device, and a first interval between the sealing material and the cooling member on the one side surface of the semiconductor device where the terminal protrudes is narrower than a second interval between the sealing material and the cooling member on the other side surface of the semiconductor device where the terminal does not protrude. Effects of the Invention

[0007] According to the present invention, it is possible to provide a device having high reliability and capable of suppressing outflow of a heat conduction member. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a top view of the circuit body involved in embodiment. Figure 2 It is a cross-sectional view of the circuit body at line XX. Figure 3 It is a sectional stereoscopic view of the circuit body at line YY. Figure 4 It is a sectional stereoscopic view of the circuit body at line XX. Figure 5 It is a sectional stereoscopic view of the circuit body at line YY. Figure 6 It is a semi-transmissive top view of a semiconductor device. Figure 7 It is a circuit diagram of a semiconductor device. Figure 8 It is a cross-sectional view for explaining the manufacturing process of the circuit body (a) to (c). Fig. 9 It is a cross-sectional view for explaining the manufacturing process of the circuit body (d) to (f). Fig.10 It is a cross-sectional view of the circuit body taken along line XX in the comparative example. Fig.11 This is a cross-sectional view of the circuit body taken along line XX in Modification Example 1. Fig.12 (a) and (b) are cross-sectional views of the circuit body taken along line XX in Modification 2. Fig.13 (a)(b) are side views of the circuit body in Modification 3. Fig.14 This is a cross-sectional view of the circuit body taken along line XX in Modification 4. Fig.15 This is a cross-sectional view of the circuit body taken along line YY in Modification 5. Fig.16 It is a cross-sectional view of the circuit body taken along line YY in Modification Example 6. Fig.17 This is a circuit diagram of a power conversion device using a semiconductor device. Fig.18 It is a perspective view of the appearance of the power conversion device. Fig.19 It is a cross-sectional perspective view of the power conversion device taken along line XV-XV. DETAILED DESCRIPTION

[0009] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention, and are appropriately omitted and simplified for clarity of the description. The present invention may also be implemented in various other ways. Unless otherwise specified, each structural element may be singular or plural.

[0010] In order to facilitate understanding of the present invention, the positions, sizes, shapes, ranges, etc. of the various structural elements shown in the drawings may not represent actual positions, sizes, shapes, ranges, etc. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings.

[0011] When there are a plurality of components having the same or equivalent functions, different subscripts may be added to the same reference numerals for description. However, when there is no need to distinguish the plurality of components, the subscripts may be omitted for description.

[0012] Figure 1 It is a top view of the circuit body 400 according to the embodiment. The circuit body 400 is composed of the semiconductor device 300 and the cooling member 340 . Figure 1 In the illustrated example, the circuit body 400 is formed by arranging three semiconductor devices 300 in parallel.

[0013] The semiconductor device 300 is sealed by a sealing member 360 and contains semiconductor elements 155 and 157 described later. Terminals connected to the semiconductor elements 155 and 157 are led out from the sealing member 360 on the side of the semiconductor device 300. These terminals are connected to the capacitor module 500 (see Fig.17 ) and the positive terminal 315B and the negative terminal 319B, and the motor generators 192 and 194 connected to the AC circuit (see Fig.17 ) of the AC side terminal 320B and other power terminals through which large current flows. In addition, the terminals derived from the sealing member 360 on the side of the semiconductor device 300 are the lower arm gate terminal 325L, the collector sense terminal 325C, the emitter sense terminal 325E, the upper arm gate terminal 325U and other terminals. The circuit body 400 in which three semiconductor devices 300 are connected in parallel functions as a power conversion device, which converts direct current and alternating current through the switching action of the semiconductor elements 155 and 157. In addition, the number of semiconductor devices 300 possessed by the circuit body 400 is not limited to three, but is arbitrarily set according to various forms of the circuit body 400.

[0014] The cooling member 340 and the heat dissipation surface 301 of the semiconductor device 300 (see Figure 2) are arranged relative to each other, and cool the heat generated by the switching action of the semiconductor elements 155 and 157. Specifically, the cooling member 340 forms a flow path for the refrigerant to flow inside, and cools the heat generated by the semiconductor device 300 by the refrigerant flowing in the flow path. The refrigerant can be water, antifreeze obtained by mixing ethylene glycol in water, etc. The cooling member 340 is preferably aluminum with high thermal conductivity and light weight. It is manufactured by extrusion molding, forging, brazing, etc.

[0015] Figure 2 yes Figure 1 The cross-sectional view of the circuit body 400 at line XX is shown. Figure 3 yes Figure 1 The circuit body 400 is shown as a cross-sectional perspective view taken along line YY. The circuit body 400 includes a pressurizing mechanism for sandwiching and pressurizing the cooling members 340 provided on both sides of the semiconductor device 300. The pressurizing mechanism is not shown in the figure, but is a mechanism for pressing the semiconductor device 300 side by connecting the cooling members 340 on both sides with screws or the like.

[0016] like Figure 2 As shown, the first semiconductor element forming the upper arm circuit of the power conversion device includes an active element 155, a diode 156 (see the following Figure 6 , Figure 7 ). When the body diode of the active element 155 is used, the diode 156 can be omitted. The collector side of the first semiconductor element 155 is bonded to the second conductor plate 431. This bonding can use solder or sintered metal. The first conductor plate 430 is bonded to the emitter side of the first semiconductor element 155.

[0017] like Figure 3 As shown, as the second semiconductor element forming the lower arm circuit, it includes an active element 157, a diode 158 (refer to the following Figure 6 , Figure 7 The collector side of the second semiconductor element 157 is bonded to the fourth conductor plate 433. The third conductor plate 432 is bonded to the emitter side of the second semiconductor element 157.

[0018] In addition, Si, SiC, GaN, GaO, C, etc. can be used as active elements 155 and 157. Active elements 155 and 157 are, for example, power semiconductor elements such as IGBT (insulated gate bipolar transistor) and MOSFET (metal oxide semiconductor field effect transistor). When MOSFET is used as active element 155 and 157, diode 156 for upper arm and diode 158 for lower arm are not required.

[0019] The conductor plates 430, 431, 432, 433 are not particularly limited as long as they are made of materials with high electrical conductivity and thermal conductivity, but preferably use metal materials such as copper or aluminum materials, composite materials of metal materials and high thermal conductivity diamond, carbon, ceramics, etc. They can be used alone or plated with Ni, Ag, etc. to improve bonding with solder or sintered metal.

[0020] like Figure 2 , Figure 3 As shown, the conductor plates 430, 431, 432, 433 not only play a role of passing current, but also play a role of a heat conduction member that conducts the heat generated by the semiconductor elements 155, 156, 157, 158 to the cooling member 340. The conductor plates 430, 431, 432, 433 and the cooling member 340 have different potentials, so it is preferable to use insulating sheets 440, 441 between them. The semiconductor elements 155, 156, 157, 158, the conductor plates 430, 431, 432, 433, and the insulating sheets 440, 441 are sealed by the sealing material 360 by transfer molding to form the semiconductor device 300. In order to reduce the contact thermal resistance between the semiconductor device 300 and the cooling member 340, a heat conduction member 453 is arranged between the semiconductor device 300 and the cooling member 340.

[0021] The resin insulating layers 442 and 443 of the insulating sheets 440 and 441 are not particularly limited as long as they are made of a material that has adhesion to the heat sink, but preferably, they are made of an epoxy resin-based resin layer in which a powdered inorganic filler is dispersed. This is because the balance between adhesion and heat dissipation is better. The insulating sheets 440 and 441 may also be a single resin insulating layer, but it is preferred that the metal foil 444 is provided on the side in contact with the heat conduction member 453. In the transfer molding process, when the insulating sheets 440 and 441 are mounted on the mold, in order to prevent adhesion to the mold, a release sheet or metal foil 444 is provided on the contact surface between the insulating sheets 440 and 441 and the mold. Due to poor thermal conductivity, the release sheet needs to be peeled off in a process after transfer molding, but in the case of the metal foil 444, by selecting a metal with a high thermal conductivity such as copper or aluminum, it can be used without peeling off after transfer molding. When transfer molding is performed including the insulating sheets 440 and 441 , the end portions of the insulating sheets 440 and 441 are covered with the sealing material 360 , thereby achieving an effect of improving reliability.

[0022] The heat conducting member 453 is not particularly limited as long as it is a material with high thermal conductivity, but it is preferable to use a high thermal conductive material such as metal, ceramic, carbon material and a resin material in combination. This is because the resin material is filled between the high thermal conductive material and the high thermal conductive material, between the high thermal conductive material and the cooling member 340, and between the high thermal conductive material and the insulating sheets 440 and 441, so that the contact thermal resistance is reduced. The resin material is not particularly limited. For example, a material with good electrical insulation properties having a silicon-based resin as a main component is preferably used.

[0023] The thermal conductivity of the heat conducting member 453 is about 5 to 8 W / (m·K). The method for measuring the thermal conductivity is not particularly limited. For example, the density, specific gravity, and thermal diffusivity of the heat conducting member 453 are measured and the thermal conductivity is calculated by density×specific gravity×thermal diffusivity.

[0024] The circuit body 400 undergoes a so-called hot-cold cycle, which repeats heating and cooling according to the switching operation of the semiconductor elements 155 and 157. Due to the hot-cold cycle, the semiconductor device 300 and the cooling member 340 have different thermal expansion coefficients, so there is a tendency for the heat conduction member 453 to be compressed and flow out of the semiconductor device 300.

[0025] like Figure 2 As shown, in the semiconductor device 300, the terminals 315B and 325C connected to the semiconductor elements 155, 156, 157, and 158 protrude from both sides of the semiconductor device 300. On the sealing material 360 on both sides of the semiconductor device 300 where the terminals 315B and 325C protrude, convex portions 454 and 455 are formed that protrude further than the surface of the heat dissipation surface 301 of the semiconductor device 300. The interval between the top of the convex portion 454 on the emitter side and the cooling member 340 is the first interval h1. Similarly, the interval between the top of the convex portion 455 on the collector side and the cooling member 340 is the first interval h1.

[0026] The thickness d of the heat conducting member 453 is the thickness of the semiconductor device 300 and the cooling member 340 in the stacking direction on the emitter side, and is the thickness of the semiconductor device 300 and the cooling member 340 in the stacking direction on the collector side. The heat conducting member 453 is arranged in a projection area 450 (see FIG. 4 ) including the conductor plates 430 and 432 in the stacking direction of the semiconductor device 300 and the cooling member 340. Figure 4 , Figure 5 ), but the thickness d of the heat conduction member 453 is at least the thickness of the portion arranged on the heat dissipation surface 301.

[0027] In addition, if Figure 3As shown, on the sealing material 360 on both sides of the semiconductor device 300 where the terminals 315B and 325C do not protrude, recesses 456 and 457 are formed that are more recessed than the surface of the heat dissipation surface 301 of the semiconductor device 300. The interval between the bottom of the recess 456 on the emitter side and the cooling member 340 is the second interval h2. Similarly, the interval between the bottom of the recess 457 on the collector side and the cooling member 340 is the second interval h2.

[0028] The first interval h1 between the top of the emitter-side protrusion 454 and the cooling member 340, or the first interval h1 between the top of the collector-side protrusion 455 and the cooling member 340 is less than the thickness d of the heat conduction member 453. Here, when the second interval h2 between the sealing material 360 and the cooling member 340 on the side of the semiconductor device 300 where the terminals 315B and 325C do not protrude is wider than the thickness d, the first interval h1 and the thickness d of the heat conduction member 453 may be equal.

[0029] The second interval h2 between the bottom of the recess 456 on the emitter side and the cooling member 340, or the second interval h2 between the bottom of the recess 457 on the collector side and the cooling member 340 is greater than the thickness d of the heat conduction member 453. Here, when the first interval h1 is narrower than the thickness d of the heat conduction member 453, the second interval h2 and the thickness d of the heat conduction member 453 may be equal.

[0030] Thus, in the circuit body 400, the first interval h1 between the sealing material 360 and the cooling member 340 on one side of the semiconductor device 300 where the terminal protrudes is narrower than the second interval h2 between the sealing material 360 and the cooling member 340 on the other side of the semiconductor device 300 where the terminal does not protrude. Thus, even if the semiconductor device 300 repeats expansion and contraction due to the hot and cold cycle, the heat conduction member 453 tends to extend toward the side where the terminal does not protrude, and does not tend to extend toward the side where the terminal protrudes. Therefore, when the hot and cold cycle is repeated, the heat conduction member 453 tends to extend toward the side where the terminal does not protrude, and in this case, there is an effect of filling the gap between the adjacent semiconductor devices 300 to further fix the semiconductor device 300. Then, since the heat conduction member 453 does not tend to extend toward the side where the terminal protrudes, if the extended heat conduction member 453 is attached to the terminal, it is possible to prevent the insulation between the terminals from being reduced due to migration phenomenon or the like.

[0031] Figure 4 yes Figure 1 The sectional perspective view of the circuit body 400 at the line XX shown in FIG. Figure 5 yes Figure 14 and 5. These are cross-sectional perspective views taken along the line YY of the circuit body 400. These cross-sectional perspective views show a state where the cooling member 340 and the heat conduction member 453 are removed from the circuit body 400, and show the emitter side of the semiconductor device 300.

[0032] The heat conducting member 453 is arranged to cover Figure 4 The heat dissipation surface 301 shown in FIG. 1 includes a projection area 450 of the conductor plates 430 and 432 in the stacking direction of the semiconductor device 300 and the cooling member 340. The heat dissipation surface 301 of the semiconductor device 300 is a surface including at least the projection area 450. Figure 4 As shown, on the sealing material 360 on the side of the semiconductor device 300 on the terminal 315B, 325C side, a convex portion 454 is formed outside the range of the heat dissipation surface 301, which protrudes more than the surface of the heat dissipation surface 301 of the semiconductor device 300. In the subsequent manufacturing process, the convex portion 454 is formed by providing a depression in the mold when forming the sealing material 360. The shape of the convex portion 454 is not particularly limited. For example, a trapezoid with a longer lower side is easy to manufacture. In addition, in order to ensure the insulation distance, it is preferred that there is a creepage distance of more than 1 mm between the line of the convex portion 454 on the projection area 450 side and the outer periphery of the insulating sheets 440, 441.

[0033] like Figure 5 As shown, a concave portion 456 that is more recessed than the surface of the heat dissipation surface 301 of the semiconductor device 300 is formed on the sealing material 360 on the side of the semiconductor device 300 where the terminals 315B and 325C do not protrude. In the subsequent manufacturing process, the concave portion 456 is formed by providing a convex portion on the mold when forming the sealing material 360. The shape of the concave portion 456 is not particularly limited. For example, a trapezoid with a shorter lower side is easy to manufacture. In addition, in order to ensure the insulation distance, it is preferred that there is a creepage distance of more than 1 mm between the line of the concave portion 456 on the side of the projection area 450 and the outer periphery of the insulating sheets 440 and 441.

[0034] Figure 6 FIG. 3 is a semi-transmissive top view of the semiconductor device 300 . Figure 7 is a circuit diagram of the semiconductor device 300 . like Figure 6 , Figure 7As shown, the positive side terminal 315B is output from the collector side of the upper arm circuit, and the positive side terminal 315B is connected to the positive side of the battery or capacitor. The upper arm gate terminal 325U is output from the gate of the active element 155 of the upper arm circuit. The negative side terminal 319B is output from the emitter side of the lower arm circuit, and the negative side terminal 319B is connected to the negative side of the battery or capacitor, or GND. The lower arm gate terminal 325L is output from the gate of the active element 157 of the lower arm circuit. The AC side terminal 320B is output from the collector side of the lower arm circuit and connected to the motor. In the case of neutral point grounding, the lower arm circuit is connected to the negative side of the capacitor instead of GND.

[0035] The emitter sense terminal 325E of the upper arm is output from the emitter of the active element 155 of the upper arm circuit, and the emitter sense terminal 325E of the lower arm is output from the emitter of the active element 157 of the lower arm circuit. The collector sense terminal 325C of the upper arm is output from the collector of the active element 155 of the upper arm circuit, and the collector sense terminal 325C of the lower arm is output from the collector of the active element 157 of the lower arm circuit.

[0036] In addition, the conductor plate (emitter side of the upper arm circuit) 430 and the conductor plate (collector side of the upper arm circuit) 431 are arranged above and below the active element 155 and the diode 156 of the semiconductor element (upper arm circuit). The conductor plate (emitter side of the lower arm circuit) 432 and the conductor plate (collector side of the lower arm circuit) 433 are arranged above and below the active element 157 and the diode 158 of the semiconductor element (lower arm circuit).

[0037] The semiconductor device 300 of this embodiment has a structure in which two arm circuits of an upper arm circuit and a lower arm circuit are integrated into one power module, that is, a 2-in-1 structure. In addition, a structure in which a plurality of upper arm circuits and lower arm circuits are integrated into one module can also be used. In this case, the number of output terminals from the semiconductor device 300 can be reduced and miniaturization can be achieved.

[0038] Figure 8 (a)~ Figure 8 (c) Fig. 9 (d) to (f) are cross-sectional views for explaining the manufacturing process of the circuit body 400. A cross-sectional view taken along line XX is shown on the left side of each figure, and a cross-sectional view of one semiconductor device 300 taken along line YY is shown on the right side.

[0039] Figure 8(a) is a solder connection process and a wire bonding process. The collector side of the semiconductor element 155 and the cathode side of the semiconductor element 156 are connected to the second conductor plate 431, and the gate electrode, emitter electrode, and collector electrode of the semiconductor element 155 are connected to the gate terminal 325U, emitter sense terminal 325E, and collector sense terminal 325C of the upper arm by wire bonding. In addition, the emitter side of the semiconductor element 155 and the anode side of the semiconductor element 156 are connected to the first conductor plate 430 to manufacture the circuit body 310 on the upper arm side. Similarly, the collector side of the semiconductor element 157 and the cathode side of the semiconductor element 158 ​​are connected to the fourth conductor plate 433, and the gate electrode, emitter electrode, and collector electrode of the semiconductor element 157 are connected to the gate terminal 325L, emitter sense terminal 325E, and collector sense terminal 325C of the lower arm by wire bonding. Furthermore, the emitter side of the semiconductor element 157 and the anode side of the semiconductor element 158 ​​are connected to the third conductor plate 432 to manufacture the circuit body 310 on the lower arm side. Figure 8 (a) shows only the circuit diagram 310 on the upper arm side, and does not show the circuit diagram 310 on the lower arm side.

[0040] Figure 8 (b)~ Figure 8 (c) is a transfer molding process. In the transfer molding process, the transfer molding device 601 includes a spring 602 and a mold 603, and also includes a mechanism for vacuum adsorbing the insulating sheets 440 and 441 and a vacuum degassing mechanism. Figure 8 As shown in (b), the insulating sheets 440 and 441 are temporarily placed in a mold 603 preheated to a constant temperature of 175°C, and the insulating sheets 440 and 441 are held by vacuum adsorption. Then, the circuit body 310 preheated to 175°C is set in the mold 603 at a position away from the insulating sheets 440 and 441.

[0041] Then, if Figure 8 As shown in (c), the upper and lower molds 603 are clamped. At this time, the insulating sheets 440, 441 and the conductor plates 430, 431 are pressurized and in close contact by the spring 602. Next, the mold cavity is evacuated. If the vacuuming is completed to below the specified air pressure, the seal is further squeezed to completely clamp the upper and lower molds 603. At this time, the insulating sheets 440, 441 are in contact with the circuit body 310. In the vacuum state, the insulating sheets 440, 441 are in contact with the circuit body 310 and are in close contact due to the pressure of the spring 602, so that they can be in close contact without being involved in the gap. Then, the sealing material 360 is injected into the mold cavity. In addition, the ends around the insulating sheets 440, 441 are buried in the sealing material 360.

[0042] Here, in the mold 603, as shown in the cross-sectional view along the line XX, the concave portions 604 and 605 also include convex portions 606 and 607 as shown in the cross-sectional view along the line YY. Figure 2 As described above, the recessed portions 604 and 605 form the convex portions 454 and 455 that protrude further than the surface of the heat dissipation surface 301 of the semiconductor device 300. Figure 3 As described above, the protrusions 606 and 607 form the recesses 456 and 457 that are recessed from the surface of the heat dissipation surface 301 of the semiconductor device 300. After that, the semiconductor device 300 sealed with the sealing material 360 is taken out from the transfer molding device 601 and post-cured at 175° C. for more than 2 hours.

[0043] Fig. 9 (d) shows the semiconductor device 300 taken out from the transfer molding device 601. In the semiconductor device 300, convex parts 454 and 455 protruding further than the heat dissipation surface 301 are formed on the side surface of the semiconductor device 300 where the terminal protrudes. In addition, concave parts 456 and 457 recessed further than the surface of the heat dissipation surface 301 are formed on the side surface where the terminal does not protrude. Fig. 9 (e) is a coating step in which the heat conduction member 453 is coated on the cooling member 340 .

[0044] Fig. 9 (f) is a close contact and curing step. The cooling member 340 coated with the heat conduction member 453 is brought into close contact with the semiconductor device 300. Then, the cooling member 340 is pressed onto the semiconductor device 300 via the heat conduction member 453, and the heat conduction member 453 is cured to manufacture the circuit body 400. Thus, the intervals between the convex portions 454, 455 and the cooling member 340, and the intervals between the concave portions 456, 457 and the cooling member 340 are set to the reference Figure 2 , Figure 3 The interval described.

[0045] Fig.10 XX is a cross-sectional view of a circuit body 400 in a comparative example. This comparative example shows an example in which the present embodiment is not applied, for comparison with the present embodiment. like Fig.10 As shown, the interval between the sealing material 360 of the semiconductor device 300 and the cooling member 340 on the side of the semiconductor device 300 is the same as the interval between the heat dissipation surface 301 of the semiconductor device 300 and the cooling member 340. Therefore, due to the hot and cold cycle, the heat conduction member 453 is compressed, and the heat conduction member 453 may flow out from the side of the semiconductor device 300. In the case where the heat conduction member 453 protrudes to the side where the terminal protrudes, the protruding heat conduction member 453 adheres to the terminal, and the insulation between the terminals is reduced due to the jump phenomenon and the like.

[0046] In this embodiment, as shown in FIG. 2, Figure 3 As described above, the first distance h1 between the sealing material 360 and the cooling member 340 on one side of the semiconductor device 300 where the terminal protrudes is narrower than the second distance h2 between the sealing material 360 and the cooling member 340 on the other side of the semiconductor device 300 where the terminal does not protrude. This prevents the heat conduction member 453 from protruding toward the side where the terminal protrudes.

[0047] Fig.11 is a cross-sectional view of the circuit body 400 at line XX in Modification 1. In addition, the cross-sectional view of the circuit body 400 at line YY is similar to Figure 3 same. Figure 2 In the embodiment shown in FIG. 1 , convex portions 454 and 455 are formed on the sealing material 360 on one side of the semiconductor device 300 where the terminal protrudes. Fig.11 As shown, at the end of the cooling member 340 outside the heat dissipation surface 301, convex portions 458 and 459 are formed opposite to the sealing material 360. The interval between the top of the convex portions 458 and 459 and the sealing material 360, that is, the first interval h1, is narrower than the thickness d of the heat conduction member 453. In order to ensure insulation, it is preferred that the inner side of the convex portions 458 and 459 of the cooling member 340 is more than 1 mm away from the outer periphery of the insulating sheets 440 and 441. The structure shown in Modification Example 1 also has the same effect as the embodiment. In addition, it is not necessary to form the concave portions 604 and 605 of the mold 603 in the transfer molding process, and the manufacturability of the mold 603 is improved.

[0048] Fig.12 (a) Fig.12 (b) is a cross-sectional view of the circuit body 400 in the second modification example taken along line XX. Fig.12 (a) is the overall picture, Fig.12 (b) is a partial enlarged view. In addition, the cross-sectional view of the circuit body 400 at the YY line is Figure 3 same.

[0049] Figure 2 In the embodiment shown in FIG. 1 , the convex portions 454 and 455 formed on the sealing material 360 are formed so that their tops do not reach the height of the cooling member 340. However, in the second modification, as shown in FIG. Fig.12 As shown in (a), in the stacking direction of the semiconductor device 300 and the cooling member 340, convex portions 460 and 461 are formed which are higher than the heat dissipation surface 301 in the direction of the cooling member 340 and cover the end of the cooling member 340 from the outside. Fig.12As shown in (b), at the end of the cooling member 340, the interval between the convex portion 460 of the sealing material 360 and the cooling member 340 is a first interval h1. The first interval h1 between the inner line of the convex portions 460 and 461 provided at the end of the sealing material 360 and the outer line of the cooling member 340 is narrower than the thickness d of the heat conduction member 453. The structure shown in the second modification also has the same effect as the embodiment. In addition, the heat conduction member 453 is not easy to flow out, so the thickness d of the heat conduction member 453 can be made thinner, the thermal resistance is improved, and the heat dissipation is excellent.

[0050] Fig.13 (a) Fig.13 (b) is a side view of the circuit body 400 in the third modification. Fig.13 (a) is equivalent to Figure 4 A side view of one terminal on the right side. Fig.13 (b) is equivalent to Figure 4 The side view of the circuit body 400 is viewed from the other terminal side on the left. Figure 3 same.

[0051] Figure 4 In the embodiment shown in FIG. 1 , a convex portion 454 having a uniform height is formed along the side surface of the terminal side of the semiconductor device 300. Fig.13 (a) Fig.13 As shown in (b), a plurality of convex portions 454 are formed corresponding to the positions of a plurality of terminals provided on one side surface of the semiconductor device 300, i.e., the terminal side. The plurality of convex portions 454 are located on the projection surface of the terminals, so even if the heat conduction member 453 flows out of the semiconductor device 300 from between the convex portions 454 and the convex portions 454, it can be prevented from adhering to the terminals. The structure shown in the modification example 3 also has the same effect as the embodiment. In addition, only one side (emitter side) of the semiconductor device 300 is illustrated and described, but convex portions can also be formed on the other sides (collector side) in the same manner corresponding to the positions of the terminals.

[0052] In addition, the structure shown in Modification 3 can be applied to Modification 1 and Modification 2. That is, at the end of the cooling member 340 on one side of the semiconductor device 300 where the terminal protrudes, the convex parts 458 and 459 formed opposite to the sealing material 360 can be formed as convex parts corresponding to the positions of the respective terminals. In addition, on the sealing material 360 on one side of the semiconductor device 300 where the terminal protrudes, the convex parts 460 and 461 formed to a height covering the end of the cooling member 340 from the outside can be formed as convex parts corresponding to the positions of the respective terminals.

[0053] Fig.14is a cross-sectional view of the circuit body 400 at line XX in Modification 4. Figure 3 same. Figure 2 In the embodiment shown in FIG. 1 , convex portions 454 and 455 are formed on the sealing material 360. However, in the modification example 4, as shown in FIG. Fig.14 As shown, convex portions 462 and 463 are formed on the sealing material 360, and concave portions 464 and 465 are formed on the sealing material 360 between the convex portions 462 and 463 and the heat dissipation surface 301. Then, the interval between the convex portions 462 and 463 and the cooling member 340 is set to the first interval h1. The first interval h1 is narrower than the thickness d of the heat conduction member 453. The structure shown in the modification example 4 also has the same effect as the embodiment. In addition, before the heat conduction member 453 flows out to the outside due to the cold and hot cycle, the heat conduction member 453 is accumulated in the concave portions 464 and 465 of the sealing material 360, as a result, the heat conduction member 453 is not easy to flow out to the outside, so that the heat conduction member 453 can be effectively prevented from being attached to the terminal.

[0054] The structure shown in Modification 3 can be applied to Modification 4. That is, the protrusions 462 and 463 and the recesses 464 and 465 formed on the sealing material 360 on one side of the semiconductor device 300 where the terminal protrudes can be formed to correspond to the positions of the terminals.

[0055] Fig.15 is a cross-sectional view of the circuit body 400 at line YY in Modification Example 5. In addition, the cross-sectional view of the circuit body 400 at line XX can be Figure 2 The same as above, or Modification 1 to Modification 4 can be applied.

[0056] Figure 3 In the embodiment shown in FIG. 1 , recesses 456 and 457 are formed on the sealing material 360. However, in the fifth modification, as shown in FIG. Fig.15 As shown, convex parts 466 and 467 are formed on the outer side of the concave parts 456 and 457 and on the sealing material 360. In other words, the convex parts 466 and 467 are formed on the sealing material 360, and the concave parts 456 and 457 are formed between the convex parts 466 and 467 and the heat dissipation surface 301. The interval between the bottom of the concave parts 456 and 457 and the cooling member 340 is set to the second interval h2. The second interval h2 is wider than the thickness d of the heat conduction member 453. The interval between the top of the convex parts 466 and 467 and the cooling member 340 is narrower than the second interval h2. The structure shown in this modification example 5 also has the same effect as the embodiment. In addition, it has the following effect: the heat conduction member 453 is accumulated in the concave parts 456 and 457 of the sealing material 360 before flowing out due to the cold and hot cycle, and even the heat conduction member 453 with a low viscosity can be prevented from flowing out to the outside.

[0057] Fig.16 is a cross-sectional view of the circuit body 400 at line YY in Modification Example 6. In addition, the cross-sectional view of the circuit body 400 at line XX can be Figure 2 The same as above, or Modification 1 to Modification 4 can be applied.

[0058] Figure 3 In the embodiment shown in FIG. 1 , recesses 456 and 457 are formed on the sealing material 360. However, in the modification 6, as shown in FIG. Fig.16 As shown, recesses 470 and 471 are formed at the end of the cooling member 340. The interval between the bottom of the recesses 470 and 471 and the sealing material 360 is set to the second interval h2. The second interval h2 is wider than the thickness d of the heat conduction member 453. The structure shown in the modification example 6 also has the same effect as the embodiment. And it has the following effect: before the heat conduction member 453 flows out due to the cold and hot cycle, it will accumulate between the recesses 470 and 471 of the cooling member 340 and the sealing material 360, and even the heat conduction member 453 with a low viscosity can be prevented from flowing out to the outside.

[0059] Fig.17 2 is a circuit diagram of a power conversion device 200 using a semiconductor device 300 . The power conversion device 200 includes inverter circuit units 140, 142, an inverter circuit unit 43 for auxiliary machines, and a capacitor module 500. The inverter circuit units 140 and 142 have a plurality of semiconductor devices 300, and a three-phase bridge circuit is formed by connecting them. In the case of a large current capacity, the semiconductor devices 300 are further connected in parallel, and these parallel connections are performed corresponding to each phase of the three-phase inverter circuit, so that the increase in current capacity can be coped with. In addition, by connecting the active elements 155, 157, diodes 156, 158 as semiconductor elements built into the semiconductor device 300 in parallel, it is also possible to cope with the increase in current capacity.

[0060] The inverter circuit unit 140 and the inverter circuit unit 142 have the same basic circuit configuration, and their control methods and operations are also basically the same. The outline of the circuit operation of the inverter circuit unit 140 and the like is well known, so a detailed description thereof will be omitted here.

[0061] As described above, the upper arm circuit includes the upper arm active element 155 and the upper arm diode 156 as semiconductor elements for switching, and the lower arm circuit includes the lower arm active element 157 and the lower arm diode 158 as semiconductor elements for switching. The active elements 155 and 157 receive a drive signal output from one or the other of the two drive circuits constituting the drive circuit 174 to perform a switching operation, and convert the DC power supplied from the battery 136 into a three-phase AC power.

[0062] As described above, the upper arm active element 155 and the lower arm active element 157 include a collector electrode, an emitter electrode, and a gate electrode. The upper arm diode 156 and the lower arm diode 158 include two electrodes, a cathode electrode and an anode electrode. Figure 7 As shown, the cathode electrodes of the diodes 156 and 158 are electrically connected to the collector electrodes of the active elements 155 and 157, respectively, and the anode electrodes of the diodes 156 and 158 are electrically connected to the emitter electrodes of the active elements 155 and 157, respectively. As a result, the current flows from the emitter electrodes of the active elements 155 for the upper arm and the active elements 157 for the lower arm toward the collector electrodes in a clockwise direction. The active elements 155 and 157 are, for example, IGBTs.

[0063] Alternatively, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) may be used as an active element. In this case, the upper arm diode 156 and the lower arm diode 158 are unnecessary.

[0064] The positive terminal 315B and the negative terminal 319B of each upper and lower arm series circuit are respectively connected to the DC terminal for capacitor connection of the capacitor module 500. The connection parts of the upper arm circuit and the lower arm circuit respectively generate AC power, and the connection parts of the upper arm circuit and the lower arm circuit of each upper and lower arm series circuit are connected to the AC side terminal 320B of each semiconductor device 300. The AC side terminal 320B of each semiconductor device 300 of each phase is respectively connected to the AC output terminal of the power conversion device 200, and the generated AC power is supplied to the stator winding of the motor generator 192 or 194.

[0065] The control circuit 172 generates a timing signal for controlling the switching timing of the active element 155 for the upper arm and the active element 157 for the lower arm based on input information from a control device or a sensor (e.g., a current sensor 180) on the vehicle side. The drive circuit 174 generates a drive signal for switching the active element 155 for the upper arm and the active element 157 for the lower arm based on the timing signal output from the control circuit 172. In addition, 181, 182, and 188 are connectors.

[0066] The upper and lower arm series circuits include a temperature sensor (not shown), and the temperature information of the upper and lower arm series circuits is input to the microcomputer. In addition, the voltage information of the DC positive side of the upper and lower arm series circuits is input to the microcomputer. Based on this information, the microcomputer performs over-temperature detection and over-voltage detection. When over-temperature or over-voltage is detected, the microcomputer stops the switching action of all the active elements 155 for the upper arm and the active elements 157 for the lower arm to protect the upper and lower arm series circuits from over-temperature or over-voltage.

[0067] Fig.18 yes Fig.17 The external perspective view of the power conversion device 200 is shown in FIG. Fig.19 yes Fig.18 The power conversion device 200 is a cross-sectional perspective view taken along line XV-XV shown in FIG.

[0068] The power conversion device 200 is composed of a lower shell 11 and an upper shell 10, and has a housing 12 formed in a roughly rectangular shape. The interior of the housing 12 accommodates a circuit body 400, a capacitor module 500, etc. The circuit body 400 has a cooling flow path flowing to the cooling member 340, and a cooling water inlet pipe 13 and a cooling water outlet pipe 14 connected to the cooling flow path protrude from one side of the housing 12. The upper side of the lower shell 11 is open, and the upper shell 10 is installed on the lower shell 11 by blocking the opening of the lower shell 11. The upper shell 10 and the lower shell 11 are formed of aluminum alloy, etc., and are sealed and fixed relative to the outside. The upper shell 10 and the lower shell 11 can be integrally formed. By setting the housing 12 to a simple rectangular shape, it is easy to install on a vehicle, etc., and it is also easy to produce.

[0069] The connector 17 is mounted on one side surface in the longitudinal direction of the housing 12, and the AC terminal 18 is connected to the connector 17. In addition, a connector 21 is provided on the surface from which the cooling water inflow pipe 13 and the cooling water outflow pipe 14 are led out.

[0070] like Fig.19 As shown, the circuit body 400 is housed in the housing 12. The control circuit 172 and the drive circuit 174 are arranged above the circuit body 400, and the capacitor module 500 is housed on the DC terminal side of the circuit body 400. By arranging the capacitor module at the same height as the circuit body 400, the power conversion device 200 can be made thinner, and the degree of freedom of installation in the vehicle can be improved. The AC side terminal 320B of the circuit body 400 passes through the current sensor 180 and is connected to the connector 188. In addition, the positive side terminal 315B and the negative side terminal 319B as the DC terminal of the semiconductor device 300 are respectively connected to the positive / negative terminals 362A and 362B of the capacitor module 500.

[0071] According to the above-described embodiment, the following effects can be obtained. (1) A circuit body (400) includes: a semiconductor device (300) sealed with a sealing material 360 and having semiconductor elements 155 and 157 built therein, and having a heat dissipation surface 301 formed on at least one surface thereof for dissipating heat from the semiconductor elements 155 and 157; a cooling member 340 disposed opposite to the heat dissipation surface 301 of the semiconductor device 300 and cooling the semiconductor elements 155 and 157; and a heat conduction member 453 disposed between the semiconductor device 300 and the cooling member 340, wherein a terminal connected to the semiconductor elements 155 and 157 protrudes from at least one side surface of the semiconductor device 300, and a first interval h1 between the sealing material 360 and the cooling member 340 on one side surface of the semiconductor device 300 where the terminal protrudes is narrower than a second interval h2 between the sealing material 360 and the cooling member 340 on another side surface of the semiconductor device 300 where the terminal does not protrude. Thus, outflow of the heat conduction member can be suppressed, and a device with high reliability can be provided.

[0072] The present invention is not limited to the above-mentioned embodiments, and other modes that can be considered within the technical concept of the present invention are also included in the scope of the present invention as long as the characteristics of the present invention are not impaired. In addition, a structure combining the above-mentioned embodiments and a plurality of modified examples is also possible. Description of symbols

[0073] 10 Upper shell 11 Lower housing 13 Cooling water inlet pipe 14 Cooling water outflow pipe 17, 21, 181, 182, 188 connectors 18 communication terminals 43, 140, 142 inverter circuit 1551st semiconductor element (upper arm circuit active element) 1561st semiconductor element (upper arm circuit diode) 157 Second semiconductor element (lower arm circuit active element) 158 Second semiconductor element (lower arm circuit diode) 172 Control Circuit 174 drive circuit 180 Current Sensor 192, 194 Electric generator 200 Power conversion device 300 Semiconductor devices 301 heat dissipation surface 315B positive terminal 319B Negative terminal 320B AC side terminal 325E Emitter Sense Terminals 325L Lower arm gate terminal 325C Collector Sense Terminal 325U Upper arm gate terminal 340 Cooling Components 360 Sealing Materials 400 Circuit Body 420 Conductor Plate 430 1st conductor plate (emitter side of upper arm circuit) 431 Second conductor plate (upper arm circuit collector side) 432 The third conductor plate (emitter side of lower arm circuit) 433 4th conductor plate (lower arm circuit collector side) 440 1st insulating sheet (emitter side) 441 Second insulation sheet (collector side) 442 1st resin insulation layer (emitter side) 443 Second resin insulation layer (collector side) 444 metal foil 450 Projected area of ​​the conductor plate 453 Heat transfer components 454, 460, 462, 466: convex portion of sealing material on emitter side 455, 461, 463, 467 Convex portion of sealing material on collector side 456, 464 Recessed portion of sealing material on emitter side 457, 465 Recessed portion of sealing material on collector side 458 Convex portion of cooling member on emitter side 459 Convex portion of cooling member on collector side 470 Recessed portion of cooling member on emitter side 471 Recessed portion of cooling member on collector side 500 Capacitor Module 601 Transfer Molding Device 602 Spring.

Claims

1. A circuit body, characterized in that: include: A semiconductor device, the semiconductor device being sealed by a sealing material and having a built-in semiconductor element, and having at least one surface formed with a heat dissipation surface for dissipating heat from the semiconductor element; a cooling member disposed opposite to the heat dissipation surface of the semiconductor device and cooling the semiconductor element; as well as a heat conduction member disposed between the semiconductor device and the cooling member, A terminal connected to the semiconductor element protrudes from at least one side surface of the semiconductor device. A first distance between the sealing material and the cooling member on the one side surface of the semiconductor device where the terminal protrudes is narrower than a second distance between the sealing material and the cooling member on the other side surface of the semiconductor device where the terminal does not protrude.

2. The circuit body according to claim 1, characterized in that: When the first interval is less than or equal to the thickness of the heat conduction member and the second interval is wider than the thickness of the heat conduction member, the first interval and the thickness of the heat conduction member are equal.

3. The circuit body according to claim 1, characterized in that: When the second interval is equal to or larger than the thickness of the heat conduction member and the first interval is narrower than the thickness of the heat conduction member, the second interval and the thickness of the heat conduction member are equal.

4. The circuit body according to claim 1, characterized in that: A convex portion protruding from the surface of the heat dissipation surface is formed on the sealing material on the one side surface of the semiconductor device where the terminal protrudes, The interval between the protrusion and the cooling member is the first interval.

5. The circuit body according to claim 4, characterized in that: The convex portion is formed to have a height that covers the end portion of the cooling member from the outside.

6. The circuit body according to claim 5, characterized in that: A recessed portion is formed in the sealing material between the raised portion and the heat dissipation surface.

7. The circuit body according to claim 1, characterized in that: A convex portion facing the sealing material is formed at an end portion of the cooling member on the one side surface of the semiconductor device where the terminal protrudes, The interval between the protrusion and the cooling member is the first interval.

8. The circuit body according to any one of claims 4 to 7, characterized in that: The terminal comprises a plurality of terminals, The protrusions are formed in plurality corresponding to the positions of the plurality of terminals.

9. The circuit body according to any one of claims 4 to 7, characterized in that: forming a recessed portion that is more recessed than the heat dissipation surface on the sealing material at the other side surface of the semiconductor device where the terminal does not protrude, The interval between the recessed portion and the cooling member is the second interval.

10. The circuit body according to claim 9, characterized in that: A convex portion is formed on the sealing material outside the concave portion and on the other side surface of the semiconductor device.

11. The circuit body according to any one of claims 4 to 7, characterized in that: A recess is formed at an end of the cooling member on the other side surface of the semiconductor device where the terminal does not protrude. The interval between the recessed portion and the sealing material is the second interval.

12. The circuit body according to any one of claims 1 to 7, characterized in that: The thermal conductivity of the thermally conductive member is 5 to 8 W / (m·K).

13. The circuit body according to any one of claims 1 to 7, characterized in that: The semiconductor device includes a conductive plate bonded to the semiconductor element. The semiconductor device includes an insulating sheet between the conductor plate and the heat conduction member.

14. The circuit body according to claim 9, characterized in that: The heat dissipation surface is formed on both sides of the semiconductor element, The cooling member is arranged on both sides facing the heat dissipation surface of the semiconductor device. The heat conduction member is located between the semiconductor device and the cooling member and is disposed on both surfaces.

15. A power conversion device, characterized in that: A circuit body according to any one of claims 1 to 7, which converts direct current into alternating current.

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