Electrical circuit body and power conversion device

Abstract

An electrical circuit body comprising: a semiconductor device containing a semiconductor element by sealing it with a sealing material and having a heat dissipation surface for dissipating heat from the semiconductor element, wherein the heat dissipation surface is formed on at least one surface; a cooling element arranged facing the heat dissipation surface of the semiconductor device and configured to cool the semiconductor element;and a thermal conducting element arranged between the semiconductor device and the cooling element, wherein a terminal connected to the semiconductor element projects from at least one side face of the semiconductor device, and a first distance between the sealing material and the cooling element on the one side face of the semiconductor device from which the terminal projects is narrower than a second distance between the sealing material and the cooling element on the other side face of the semiconductor device from which the terminal does not project.

Description

Technical field

[0001] The present invention relates to an electrical circuit body and a power conversion device. Background of the invention

[0002] A power conversion device that utilizes switching operation of a semiconductor element has high conversion efficiency and is therefore widely used for consumer use, in-vehicle use, railway use, transformation equipment, and the like. The semiconductor element generates heat when energized. Therefore, a cooling element for cooling a semiconductor element is provided, and a heat conducting element is disposed between the semiconductor device including the semiconductor element and the cooling element so as to face the semiconductor device. The heat conducting element conducts the heat generated by the semiconductor element to the cooling element by bringing the semiconductor device and the cooling element into close contact with each other. Cooling of a semiconductor device must have high reliability to maintain heat dissipation properties, especially in in-vehicle applications.

[0003] PTL 1 discloses a semiconductor module mounting structure in which a grease reservoir is formed on a surface of a resin sealing portion to surround a metal heat sink, and even if the grease moves in a surface direction due to an expansion / contraction cycle in a thickness direction of a semiconductor module, outside air is less likely to penetrate between the metal heat sink and an insulation sheet. Citation listPatent literature

[0004] PTL 1: JP 2005-310987 A Overview of the inventionTechnical problem

[0005] In the semiconductor device described in PTL 1, measures such as a reduction in insulation property due to the outflow of the heat conducting member with respect to the terminal protruding from the semiconductor device are not considered, and the reliability of the device is degraded. Solution to the problem

[0006] An electrical circuit body according to the present invention includes a semiconductor device containing a semiconductor element by sealing with a sealing material and having a heat dissipation surface for dissipating heat of the semiconductor element, wherein the heat dissipation surface is formed on at least one surface, a cooling element arranged facing the heat dissipation surface of the semiconductor device and configured to cool the semiconductor element, and a heat conducting element arranged between the semiconductor device and the cooling element, wherein a terminal connected to the semiconductor element protrudes from at least one side surface of the semiconductor device, and a first distance between the sealing material and the cooling element on the one side surface of the semiconductor device from which the terminal protrudes,is narrower than a second distance between the sealing material and the cooling element on the other side surface of the semiconductor device from which the terminal does not protrude. Advantageous effects of the invention

[0007] According to the present invention, a highly reliable device that suppresses the leakage of a heat conducting member can be provided. Short description of the drawings [ Fig. 1] Fig. 1 is a plan view of an electrical circuit body according to an embodiment. [ Fig. 2] Fig. 2 is a cross-sectional view along the line XX of the electric circuit body. [ Fig. 3] Fig. 3 is a perspective cross-sectional view taken along the line YY of the electric circuit body. [ Fig. 4] Fig. 4 is a perspective cross-sectional view taken along line XX of the electric circuit body. [ Fig. 5] Fig. 5 is a perspective cross-sectional view taken along the line YY of the electric circuit body. [ Fig. 6] Fig. 6 is a semi-transparent top view of the semiconductor device. [ Fig. 7] Fig. 7 is a circuit diagram of the semiconductor device. [ Fig. 8] The Fig. 8(a) to 8(c) are cross-sectional views for explaining the manufacturing steps of the electric circuit body. [ Fig. 9] The Fig. 9(d) to 9(f) are cross-sectional views for explaining manufacturing steps of the electric circuit body. [ Fig. 10] Fig. 10 is a cross-sectional view taken along line XX of an electric circuit body in a comparative example. [ Fig. 11] Fig. 11 is a cross-sectional view taken along line XX of an electric circuit body in a first modified example. [ Fig. 12] The Fig. 12(a) and Fig. 12(b) are cross-sectional views taken along line XX of an electric circuit body in a second modified example. [ Fig. 13] The Fig. 13(a) and Fig. 13(b) are side views of an electric circuit body in a third modified example. [ Fig. 14] Fig. 14 is a cross-sectional view taken along line XX of an electric circuit body in a fourth modified example. [ Fig. 15] Fig. 15 is a cross-sectional view taken along line YY of an electric circuit body in a fifth modified example. [ Fig. 16] Fig. 16 is a cross-sectional view along the line Y-Y of an electrical circuit body in a sixth modified example. Fig. 17] Fig. 17 is a circuit diagram of a power conversion device that uses a semiconductor device. Fig. 18] Fig. 18 is a perspective external view of the power conversion device. Fig. 19] Fig. 19 is a perspective cross-sectional view along the line XV-XV of the power conversion device. Description of Embodiments

[0008] ​​​Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are examples for describing the present invention and are omitted and simplified where appropriate for clarity of description. The present invention may be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] The positions, sizes, shapes, ranges, and the like of the components illustrated in the drawings may not represent the actual positions, sizes, shapes, ranges, and the like in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, and the like shown in the drawings.

[0010] In a case where there are multiple components with the same or similar functions, the description may be made using different indices for the same reference numerals. In a case where it is not necessary to distinguish between the multiple components, the description may be made with omitted indices.

[0011] Fig. 1 is a top view of an electrical circuit body 400 according to one embodiment.

[0012] The electrical circuit body 400 contains a semiconductor device 300 and a cooling element 340. In the Fig. In the example shown in Figure 1, the electrical circuit body 400 contains three semiconductor devices 300 present in parallel.

[0013] In the semiconductor device 300, the semiconductor elements 155 and 157 to be described later are integrated by sealing them with a sealing material 360. Terminals connected to the semiconductor elements 155 and 157 are led out of the sealing material 360 on the side surface of the semiconductor device 300. These terminals are power terminals through which a large current flows, such as a terminal 315B on the positive electrode side and a terminal 319B on the negative electrode side, which are connected to a capacitor module 500 (see Fig. 17) of a DC circuit, and an AC-side terminal 320B connected to motor generators 192 and 194 (see Fig. 17) of an AC circuit. In addition, the terminals led out from the sealing material 360 on the side surface of the semiconductor device 300 are terminals such as a lower arm gate terminal 325L, a collector sensing terminal 325C, an emitter sensing terminal 325E, and an upper arm gate terminal 325U. The electric circuit body 400, which is provided with three parallel semiconductor devices 300, functions as a power conversion device that converts a DC current and an AC current through switching operations of the semiconductor elements 155 and 157. Note that the number of semiconductor devices 300 included in the electric circuit body 400 is not limited to three and is arbitrarily determined according to various shapes of the electric circuit body 400.

[0014] The cooling element 340 is arranged so that it faces a heat dissipation surface 301 (see Fig. 2) faces the semiconductor device 300, and cools the heat generated by the switching operation of the semiconductor elements 155 and 157. Specifically, the cooling member 340 is formed with a flow path through which the coolant flows, and cools heat generated by the semiconductor device 300 by the coolant flowing through the flow path. Water, an antifreeze fluid in which ethylene glycol is mixed with water, or the like is used as the coolant. The cooling member 340 is preferably made of an aluminum-based material having high thermal conductivity and light weight. The cooling member 340 is manufactured by extrusion, forging, brazing, or the like.

[0015] Fig. 2 is a cross-sectional view along the line XX of the Fig. 1 shown electrical circuit body 400, and Fig. 3 is a perspective cross-sectional view along the line YY of the Fig. 1 shown electrical circuit body 400.

[0016] The electrical circuit body 400 includes a pressing mechanism configured to sandwich and pressurize the cooling elements 340 provided on both surfaces of the semiconductor device 300 from both surfaces. Although not shown, the pressing mechanism is, for example, a mechanism that couples the cooling elements 340 on both surfaces with screws or the like to pressurize the cooling elements 340 toward the semiconductor device 300 side.

[0017] As in Fig. 2, an active element 155 and a diode 156 are provided as first semiconductor elements constituting a circuit of an upper arm of the power conversion device (see the figures to be described later). Fig. 6 and Fig. 7). If a body diode of the active element 155 is used, the diode 156 can be omitted. A collector side of the first semiconductor element 155 is connected to a second circuit board 431. Solder or sintered metal can be used for this connection. A first circuit board 430 is connected to an emitter side of the first semiconductor element 155.

[0018] As in Fig. 3, an active element 157 and a diode 158 are provided as second semiconductor elements constituting a lower arm circuit (see the figures to be described later). Fig. 6 and Fig. 7). A collector side of the second semiconductor element 157 is connected to a fourth circuit board 433. A third circuit board 432 is connected to an emitter side of the second semiconductor element 157.

[0019] Note that Si, SiC, GaN, GaO, C, or the like can be used as the active elements 155 and 157. The active elements 155 and 157 are power semiconductor elements such as insulated gate bipolar transistors (IGBTs) and metal oxide semiconductor field-effect transistors (MOSFETs). When MOSFETs are used as the active elements 155 and 157, the upper arm diode 156 and the lower arm diode 158 are not required.

[0020] The printed circuit boards 430, 431, 432 and 433 are not particularly limited as long as they are materials with high electrical conductivity and thermal conductivity, but it is desirable to use a metal-based material such as a copper- or aluminum-based material, a composite material of a metal-based material and diamond, carbon, ceramic or the like with high thermal conductivity. These can be used alone, but can also be subjected to plating with Ni, Ag or the like to improve the bonding properties with solder or sintered metal.

[0021] As in the Fig. 2 and Fig. 3, the circuit boards 430, 431, 432, and 433, in addition to their function of supplying power, serve as a heat transfer element that transfers the heat generated by the semiconductor elements 155, 156, 157, and 158 to the cooling element 340. Since the circuit boards 430, 431, 432, and 433 and the cooling element 340 have different potentials, it is desirable to use insulating sheets 440 and 441 therebetween. The semiconductor elements 155, 156, 157, and 158, the circuit boards 430, 431, 432, and 433, and the insulating sheets 440 and 441 are sealed with a sealing material 360 by transfer molding to form a semiconductor device 300. In order to reduce the thermal contact resistance between the semiconductor device 300 and the cooling element 340, a heat conducting element 453 is arranged between the semiconductor device 300 and the cooling element 340.

[0022] The resin insulating layers 442 and 443 of the insulating sheets 440 and 441 are not particularly limited as long as they have adhesiveness with a heat sink, but an epoxy resin-based resin insulating layer in which a powdery inorganic filler is dispersed is desirable. This is because the balance between adhesiveness and heat dissipation property is good. The insulating sheets 440 and 441 can be a pure resin insulating layer, but it is desirable to provide a metal foil 444 on the side to come into contact with the heat conducting member 453. When the insulating sheets 440 and 441 are mounted on a die in the transfer molding step, a release sheet or a metal foil 444 is provided on a contact surface of the insulating sheets 440 and 441 with the die to prevent adhesion to the die.Since the release sheet has poor thermal conductivity, a step of peeling the release sheet is required after transfer molding. However, in the case of the metal foil 444, it can be used without peeling after transfer molding by selecting a copper- or aluminum-based metal with high thermal conductivity. When transfer molding is performed with the insulation sheets 440 and 441 included, the end portions of the insulation sheets 440 and 441 are covered with the sealing material 360, and therefore, there is an effect that improves reliability.

[0023] 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 material with high thermal conductivity such as a metal, a ceramic, or a carbon-based material in combination with a resin material. This is because the resin material balances between the high thermal conductivity material and the high thermal conductivity material, between the high thermal conductivity material and the cooling member 340, and between the high thermal conductivity member and the insulation sheets 440 and 441, and the thermal contact resistance is reduced. The resin material is not particularly limited. For example, a material containing a silicone-based resin as a main component and having good electrical insulation properties is preferable.

[0024] The thermal conductivity of the heat-conducting member 453 is approximately 5 to 8 W / (mK). The method for measuring thermal conductivity is not particularly limited. For example, the density, specific gravity, and thermal diffusivity of the heat-conducting member 453 are measured to be obtained as density × specific gravity × thermal diffusivity.

[0025] The electrical circuit body 400 undergoes a so-called cooling / heating cycle that repeats heat generation and cooling according to the switching operation of the semiconductor elements 155 and 157. Since the thermal expansion coefficients of the semiconductor device 300 and the cooling element 340 are different due to this cooling / heating cycle, the heat conducting element 453 tends to be compressed and flow out to the outside of the semiconductor device 300.

[0026] As in Fig. As shown in FIG. 2, in the semiconductor device 300, terminals 315B and 325C connected to the semiconductor elements 155, 156, 157, and 158 protrude from both side surfaces of the semiconductor device 300. On the sealing material 360 on both side surfaces of the semiconductor device 300 from which the terminals 315B and 325C protrude, convex portions 454 and 455 protruding above the surface of the heat dissipation surface 301 of the semiconductor device 300 are formed. A distance between the top of the convex portion 454 on the emitter side and the cooling member 340 is a first distance h1. Similarly, a distance between the top of the convex portion 455 on the collector side and the cooling member 340 is the first distance h1.

[0027] The thickness d of the heat conducting element 453 is a thickness in the stacking direction of the semiconductor device 300 and the cooling element 340 on the emitter side, and is a thickness in the stacking direction of the semiconductor device 300 and the cooling element 340 on the collector side. The heat conducting element 453 is arranged on the heat dissipation surface 301, which contains a projection area 450 (see the Fig. 4 and Fig. 5) of the circuit boards 430, 432 in the stacking direction of the semiconductor device 300 and the cooling element 340, and the thickness d of the heat conducting element 453 is a thickness of at least one section arranged on the heat dissipation surface 301.

[0028] As in Fig. 3, concave portions 456 and 457, which are recessed from the surface of the heat-dissipating face 301 of the semiconductor device 300, are formed in the sealing material 360 on both side surfaces of the semiconductor device 300 from which the terminals 315B and 325C do not protrude. A distance between the bottom of the concave portion 456 on the emitter side and the cooling member 340 is a second distance h2. Similarly, a distance between the bottom of the concave portion 457 on the collector side and the cooling member 340 is the second distance h2.

[0029] The first distance h1 between the top of the convex portion 454 on the emitter side and the cooling member 340 or the first distance h1 between the top of the convex portion 455 on the collector side and the cooling member 340 is smaller than or equal to the thickness d of the heat conduction member 453. When the second distance h2 between the sealing material 360 and the cooling member 340 on the side surface of the semiconductor device 300 from which the terminals 315B and 325C do not protrude is wider than the thickness d, the first distance h1 and the thickness d of the heat conduction member 453 may be the same.

[0030] The second distance h2 between the bottom of the concave portion 456 on the emitter side and the cooling member 340 or the second distance h2 between the bottom of the concave portion 457 on the collector side and the cooling member 340 is greater than or equal to the thickness d of the heat conduction member 453. When the first distance h1 is narrower than the thickness d of the heat conduction member 453, the second distance h2 and the thickness d of the heat conduction member 453 may be the same.

[0031] As described above, in the electric circuit body 400, the first distance h1 between the sealing material 360 and the cooling member 340 on one side surface of the semiconductor device 300 from which the terminal protrudes is narrower than the second distance h2 between the sealing material 360 and the cooling member 340 on the other side surface of the semiconductor device 300 from which the terminal does not protrude. As a result, even if the semiconductor device 300 repeats expansion and contraction due to the cooling / heating cycle, the heat conducting member 453 is likely to leak to the side from which the terminal does not protrude, and is less likely to leak to the side from which the terminal protrudes.Therefore, when the cooling / heating cycle is repeated, the heat conducting member 453 is likely to leak to the side where the terminal does not protrude, in which case there is an effect of filling the gap between the adjacent semiconductor devices 300 and further fixing the semiconductor devices 300. Since the heat conducting member 453 is less likely to leak to the side where the terminal protrudes, it is possible to prevent the leaked heat conducting member 453 from adhering to the terminals and the insulation property between the terminals from deteriorating due to a migration phenomenon or the like.

[0032] Fig. 4 is a perspective cross-sectional view along the line XX of the Fig. 1 shown electrical circuit body 400, and Fig. 5 is a perspective cross-sectional view along the line YY of the Fig. 1. These perspective cross-sectional views show the emitter side of the semiconductor device 300 in a state in which the cooling element 340 and the heat conducting element 453 are removed from the electrical circuit body 400.

[0033] The heat conducting member 453 is arranged to cover the heat dissipation surface 301, which forms a projection area 450 of the circuit boards 430, 432 in the stacking direction of the semiconductor device 300 and the Fig. 4. The heat dissipation surface 301 of the semiconductor device 300 is a surface that includes at least the projection area 450. As shown in Fig. 4, on the sealing material 360 on the side surface of the semiconductor device 300 on the side of the terminals 315B and 325C, a convex portion 454 protruding from the surface of the heat-dissipating surface 301 of the semiconductor device 300 is formed outside the area of ​​the heat-dissipating surface 301. In a manufacturing step to be described later, the convex portion 454 is formed by providing a concave portion in the die when forming the sealing material 360. The shape of the convex portion 454 is not particularly limited. For example, a trapezoid with a long bottom is easy to manufacture. In addition, to ensure the insulation distance, it is desirable to have a creepage distance of greater than or equal to 1 mm between the area along the convex portion 454 on the side of the projection region 450 and the outer peripheries of the insulation sheets 440 and 441.

[0034] As in Fig. 5, the concave portion 456, which is recessed from the surface of the heat-dissipating face 301 of the semiconductor device 300, is formed in the sealing material 360 on the side surface of the semiconductor device 300 from which the terminals 315B and 325C do not protrude. In a manufacturing step to be described later, the concave portion 456 is formed by providing a convex portion in the die when molding the sealing material 360. The shape of the concave portion 456 is not particularly limited. For example, a trapezoid with a short bottom is easy to manufacture. In addition, to ensure the insulation clearance, it is desirable to have a creepage distance of greater than or equal to 1 mm between the region along the concave portion 456 on the side of the projection region 450 and the outer peripheries of the insulation sheets 440 and 441.

[0035] Fig. 6 is a semi-transparent top view of the semiconductor device 300. Fig. 7 is a circuit diagram of the semiconductor device 300.

[0036] As in the Fig. 6 and Fig. As shown in Figure 7, the positive electrode side terminal 315B is output from the collector side of an upper arm circuit and is connected to one side of the positive electrode 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. A negative electrode side terminal 319B is output from an emitter side of the lower arm circuit and is connected to one side of the negative electrode 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. An AC side terminal 320B is output from the collector side of the lower arm circuit and is connected to a motor.When a neutral point is grounded, the lower arm circuit is not connected to GND but to the negative electrode side of the capacitor.

[0037] The upper arm emitter sense terminal 325E is output from the emitter of the active element 155 of the upper arm circuit, and the lower arm emitter sense terminal 325E is output from the emitter of the active element 157 of the lower arm circuit. The upper arm collector sense terminal 325C is output from the collector of the active element 155 of the upper arm circuit, and the lower arm collector sense terminal 325C is output from the collector of the active element 157 of the lower arm circuit.

[0038] Furthermore, a printed circuit board (emitter side of the upper arm circuit) 430 and a printed circuit board (collector side of the upper arm circuit) 431 are arranged above and below the active element 155 and the diode 156 of the power semiconductor element (upper arm circuit). A printed circuit board (emitter side of the lower arm circuit) 432 and a printed circuit board (collector side of the lower arm circuit) 433 are arranged above and below the active element 157 and the diode 158 of the power semiconductor element (lower arm circuit).

[0039] The semiconductor device 300 of the present embodiment has a 2-in-1 structure, which is a structure in which two-arm circuits of the upper arm circuit and the lower arm circuit are integrated into one module. Furthermore, a structure in which multiple upper arm circuits and lower arm circuits are integrated into one module may be employed. In this case, the number of output terminals of the semiconductor device 300 can be reduced, and the size can be reduced.

[0040] The Fig. 8(a) to 8(c) and the Fig. 9(d) to 9(f) are cross-sectional views for explaining a manufacturing step of the electric circuit body 400. A cross-sectional view taken along line XX is shown on the left side of each drawing, and a cross-sectional view of a semiconductor device 300 taken along line YY is shown on the right side of each drawing.

[0041] Fig. 8(a) illustrates a soldering connection step and a wire bonding step. The collector side of the semiconductor element 155 and the cathode side of the semiconductor element 156 are connected to the second circuit board 431, and the gate electrode, emitter electrode, and collector electrode of the semiconductor element 155 are connected to the gate terminal 325U, the emitter sense terminal 325E, and the collector sense terminal 325C of the upper arm, respectively, by wire bonding. Furthermore, the emitter side of the semiconductor element 155 and the anode side of the semiconductor element 156 are connected to the first circuit board 430 to form 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 circuit board 433, and the gate electrode, emitter electrode, and collector electrode of the semiconductor element 157 are connected to the gate terminal 325L, the emitter sense terminal 325E, and the collector sense terminal 325C of the lower arm, respectively, 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 circuit board 432 to form the circuit body 310 on the lower arm side. In FIG. Fig. However, in Fig. 8(a), only the circuit body 310 on the upper arm side is shown, and the circuit body 310 on the lower arm side is not shown.

[0042] The Fig. 8(b) to 8(c) show a step of transfer molding.

[0043] In the transfer molding step, a transfer molding device 601 includes a spring 602 and a die 603, and further includes a mechanism for vacuum adsorption of the insulation sheets 440 and 441 and a vacuum degassing mechanism. As shown in Fig. As shown in Figure 8(b), the insulation sheets 440 and 441 are temporarily placed in a die 603 that has been preheated to a constant temperature state of 175°C, and the insulation sheets 440 and 441 are held by vacuum adsorption. The circuit body 310, preheated to 175°C in advance, is placed in the die 603 at a position away from the insulation sheets 440 and 441.

[0044] Next, as in Fig. As shown in Figure 8(c), the upper and lower dies 603 are clamped. At this time, the insulation sheets 440 and 441 and the circuit boards 430 and 431 are pressurized and brought into close contact with each other by the spring 602. Next, the cavity of the die is evacuated. When the vacuum exhaustion is completed to a predetermined atmospheric pressure or less, the package is further compressed, and the upper and lower dies 603 are completely clamped. At this time, the insulation sheets 440 and 441 and the circuit body 310 are in contact with each other. In a vacuum state, the insulation sheets 440 and 441 and the circuit body 310 come into contact with each other and come into close contact with each other by the pressure application of the spring 602, so that they can be brought into close contact with each other without introducing any voids. Then the sealing material is injected 360 into the die cavity.Note that the peripheral end portions of the insulation sheets 440 and 441 are embedded in the sealing material 360.

[0045] Here, in the die 603, as shown in a cross-sectional view along the line XX, the concave portions 604 and 605 further include convex portions 606 and 607, as shown in a cross-sectional view along the line YY. As described with reference to Fig. 2, the concave portions 604 and 605 form the convex portions 454 and 455 that protrude from the surface of the heat dissipation surface 301 of the semiconductor device 300. As described with reference to Fig. 3, the convex portions 606 and 607 form the concave portions 456 and 457 recessed from the surface of the heat-dissipating surface 301 of the semiconductor device 300. After that, the semiconductor device 300 sealed with the sealing material 360 is removed from the transfer molding device 601, and post-curing is performed at 175°C for 2 or more hours.

[0046] Fig. 9(d) shows the semiconductor device 300 removed from the transfer molding apparatus 601. In the semiconductor device 300, the convex portions 454 and 455 protruding from the heat-dissipating surface 301 are formed on the side surface of the semiconductor device 300 from which the terminal protrudes. Furthermore, the concave portions 456 and 457 recessed from the surface of the heat-dissipating surface 301 are formed on the side surface from which the terminal does not protrude.

[0047] Fig. Figure 9(e) illustrates one step of the application. The heat-conducting element 453 is applied to the cooling element 340.

[0048] Fig. 9(f) shows a close contact / curing step. The cooling member 340, to which the heat conducting member 453 is applied, is brought into close contact with the semiconductor device 300. Then, the cooling member 340 is pressed against the semiconductor device 300 via the heat conducting member 453, and the heat conducting member 453 is cured to manufacture the electric circuit body 400. As a result, the distance between the convex portions 454 and 455 and the cooling member 340 and the distance between the concave portions 456 and 457 and the cooling member 340 are set to the values ​​described with reference to FIG. Fig. 2 and Fig. 3 described distances.

[0049] Fig. 10 is a cross-sectional view taken along line XX of an electric circuit body 400 in a comparative example. This comparative example shows an example of a case where the present embodiment is not applied, for comparison with the present embodiment.

[0050] As in Fig. As shown in FIG. 10, a distance between the sealing material 360 of the semiconductor device 300 and the cooling member 340 on the side surface of the semiconductor device 300 is the same as a distance between the heat dissipation surface 301 of the semiconductor device 300 and the cooling member 340. Therefore, there is a possibility that the heat conducting member 453 is compressed and flows out from the side surface of the semiconductor device 300 by the cooling / heating cycle. If the heat conducting member 453 flows out to the terminal protruding side, the flowed-out heat conducting member 453 adheres to the terminal, thereby deteriorating the insulation property between the terminals due to the migration phenomenon or the like.

[0051] In the present embodiment, as described with reference to the Fig. 2 and Fig. 3, the first distance h1 between the sealing material 360 and the cooling member 340 on one side surface of the semiconductor device 300 from which the terminal protrudes is narrower than the second distance h2 between the sealing material 360 and the cooling member 340 on the other side surface of the semiconductor device 300 from which the terminal does not protrude. As a result, the heat conducting member 453 is suppressed from leaking to the side where the terminal protrudes.

[0052] Fig. Fig. 11 is a cross-sectional view taken along line XX of an electric circuit body 400 in a first modified example. Note that a cross-sectional view taken along line YY of the electric circuit body 400 is similar to that of Fig. 3 is similar.

[0053] At the Fig. 2, the convex portions 454 and 455 are formed on the sealing material 360 on a side surface of the semiconductor device 300 from which the terminal protrudes. In the first modified example, as shown in Fig. As shown in FIG. 11, the convex portions 458 and 459 facing the sealing material 360 are formed at the end portion of the cooling member 340 on the outer side of the heat dissipation surface 301. The first distance h1, which is a distance between the top of the convex portions 458 and 459 and the sealing material 360, is narrower than the thickness d of the heat conducting member 453. To ensure the insulation properties, it is desirable that the area along the inner side of the convex portions 458 and 459 of the cooling member 340 be separated from the outer peripheries of the insulation sheets 440 and 441 by more than or equal to 1 mm. The configuration shown in the first modified example also has an effect similar to that of the embodiment. Moreover, it is not necessary to form the concave portions 604 and 605 of the die 603 in the step of transfer molding, and the manufacturability of the die 603 is improved.

[0054] The Fig. 12(a) and Fig. 12(b) are cross-sectional views along line XX of an electric circuit body 400 in a second modified example. Fig. 12(a) is an overall view and Fig. Fig. 12(b) is a partially enlarged view. Note that a cross-sectional view along the line YY of the electric circuit body 400 is different from that of Fig. 3 is similar.

[0055] At the Fig. 2, the convex portions 454 and 455 formed on the sealing material 360 are formed to a height at which the tops do not reach the cooling member 340, but in the second modified example as shown in Fig. 12(a), the convex portions 460 and 461 are formed to be higher in the direction of the cooling member 340 than the heat dissipation surface 301, and to cover the end portion of the cooling member 340 in the stacking direction of the semiconductor device 300 and the cooling member 340 from the outside. As shown in Fig. As shown in Fig. 12(b), at the end portion of the cooling member 340, a distance between the convex portion 460 of the sealing material 360 and the cooling member 340 is a first distance h1. The first distance h1 between a region along the inner side of the convex portions 460 and 461 provided at the end portion of the sealing material 360 and a region along the outer side of the cooling member 340 is narrower than the thickness d of the heat conducting member 453. The configuration shown in the second modified example also has an effect similar to that of the embodiment. Furthermore, since the heat conducting member 453 is less likely to flow out to the outside, the thickness d of the heat conducting member 453 can be reduced, the thermal resistance is improved, and an excellent heat dissipation property is achieved.

[0056] The Fig. 13(a) and Fig. 13(b) are side views of an electric circuit body 400 in a third modified example. Fig. 13(a) is a side view of a terminal side corresponding to the right side of Fig. 4 corresponds, seen from, and Fig. 13(b) is a side view of the other terminal side corresponding to the left side of Fig. 4. Note that a cross-sectional view along the line YY of the electric circuit body 400 is similar to that of Fig. 3 is similar.

[0057] At the Fig. 4, the convex portion 454 having a uniform height is formed along the side surface on the terminal side of the semiconductor device 300. In the third modified example, as shown in FIGS. Fig. 13(a) and Fig. As shown in FIG. 13(b), a plurality of convex portions 454 are formed corresponding to positions of a plurality of terminals provided on a terminal side, which is a side surface of the semiconductor device 300. Since the plurality of convex portions 454 are located on the projection surface of the terminal, even if the heat conducting member 453 flows from between the convex portions 454 and 454 to the outside of the semiconductor device 300, it can be prevented from adhering to the terminal. The configuration shown in the third modified example also has an effect similar to that of the embodiment. Note that, although only one surface (emitter side) of the semiconductor device 300 has been shown and described, convex portions may similarly be formed on the other surface (collector side) according to the position of each terminal.

[0058] Furthermore, the configuration described in the third modified example can be applied to the first modified example and the second modified example. That is, the convex portions 458 and 459 formed facing the sealing material 360 at the end portion of the cooling member 340 on a side surface of the semiconductor device 300 from which the terminal protrudes can respectively form convex portions corresponding to the positions of the terminals. Further, the convex portions 460 and 461 formed on the sealing material 360 on a side surface of the semiconductor device 300 from which the terminal protrudes can form convex portions corresponding to the positions of the terminals at a height at which they cover the end portion of the cooling member 340 from the outside.

[0059] Fig. Fig. 14 is a cross-sectional view taken along line XX of an electric circuit body 400 in a fourth modified example. Note that a cross-sectional view taken along line YY of the electric circuit body 400 is similar to that of Fig. 3 is similar.

[0060] At the Fig. 2, the convex portions 454 and 455 are formed on the sealing material 360, but in the fourth modified example as shown in Fig. As shown in FIG. 14, the convex portions 462 and 463 are formed on the sealing material 360, and the concave portions 464 and 465 are formed in the sealing material 360 between the convex portions 462 and 463 and the heat dissipation surface 301. The distance between the convex portions 462 and 463 and the cooling member 340 is set to a first distance h1. The first distance h1 is narrower than the thickness d of the heat conducting member 453. The configuration shown in the fourth modified example also has an effect similar to that of the embodiment.Moreover, the heat conducting member 453 is retained in the concave portions 464 and 465 of the sealing material 360 before the heat conducting member 453 flows out to the outside by the cooling / heating cycle, and as a result, the heat conducting member 453 is less likely to flow to the outside, so that the heat conducting member 453 can be effectively prevented from adhering to the terminal.

[0061] Furthermore, the configuration described in the third modified example can also be applied to the fourth modified example. That is, the convex portions 462 and 463 and the concave portions 464 and 465 formed on the sealing material 360 on a side surface of the semiconductor device 300 from which the terminal protrudes can be formed respectively according to the positions of the terminals.

[0062] Fig. Fig. 15 is a cross-sectional view taken along line YY of an electric circuit body 400 in a fifth modified example. Note that a cross-sectional view taken along line XX of the electric circuit body 400 may be the same as that shown in Fig. 2, and that other first to fourth modified examples may be applied.

[0063] At the Fig. 3, the concave portions 456 and 457 are formed in the sealing material 360, but in the fifth modified example as shown in Fig. As shown in FIG. 15, the convex portions 466 and 467 are formed on the sealing material 360 on the outside of the concave portions 456 and 457. In other words, the convex portions 466 and 467 are formed on the sealing material 360, and the concave portions 456 and 457 are further formed between the convex portions 466 and 467 and the heat dissipation surface 301. The distance between the bottom portions of the concave portions 456 and 457 and the cooling member 340 is set to a second distance h2. The second distance h2 is wider than the thickness d of the heat conduction member 453. The distance between the top surfaces of the convex portions 466 and 467 and the cooling member 340 is narrower than the second distance h2. The configuration shown in the fifth modified example also has an effect similar to that of the embodiment.Moreover, the heat conducting member 453 is retained in the concave portions 456 and 457 of the sealing material 360 before flowing out by the cooling / heating cycle, and even if the heat conducting member 453 has a low viscosity, there is an effect of preventing the heat conducting member from flowing out to the outside.

[0064] Fig. Fig. 16 is a cross-sectional view along line YY of an electric circuit body 400 in a sixth modified example. Note that a cross-sectional view along line XX of the electric circuit body 400 may be the same as that shown in Fig. 2, and that other first to fourth modified examples may be applied.

[0065] At the Fig. 3, the concave portions 456 and 457 are formed in the sealing material 360, but in the sixth modified example as shown in Fig. As shown in Fig. 16, the concave portions 470 and 471 are formed at the end portion of the cooling member 340. A distance between the bottom portions of the concave portions 470 and 471 and the sealing material 360 is set to a second distance h2. The second distance h2 is wider than the thickness d of the heat conduction member 453. The configuration shown in the sixth modified example also has an effect similar to that of the embodiment. Moreover, the heat conduction member 453 is retained between the concave portions 470 and 471 of the cooling member 340 and the sealing material 360 before it flows out through the cooling / heating cycle, and even if the heat conduction member 453 has a low viscosity, there is an effect of preventing the heat conduction member from flowing out to the outside.

[0066] Fig. 17 is a circuit diagram of the power conversion device 200 using the semiconductor device 300.

[0067] The power conversion device 200 includes inverter circuit units 140 and 142, an inverter circuit unit 43 for auxiliary equipment, and a capacitor module 500. The inverter circuit units 140 and 142 include a plurality of semiconductor devices 300 that are connected to form a three-phase bridge circuit. In a case where the current capacity is large, additional semiconductor devices 300 are connected in parallel, and the parallel connection is performed for each phase of the three-phase inverter circuit, thereby responding to an increase in the current capacity. In addition, it is also possible to respond to an increase in the current capacity by connecting in parallel the active elements 155 and 157 and the diodes 156 and 158, which are semiconductor elements included in the semiconductor device 300.

[0068] The inverter circuit unit 140 and the inverter circuit unit 142 have the same basic circuit configuration and substantially the same control method and operation. Since the basic circuit operation of the inverter circuit unit 140 and the like is well known, a detailed description thereof is omitted here.

[0069] As described above, the upper arm circuit includes the upper arm active element 155 and the upper arm diode 156 as semiconductor switching elements, and the lower arm circuit includes the lower arm active element 157 and the lower arm diode 158 as semiconductor switching elements. The active elements 155 and 157 perform a switching operation in response to a drive signal output from one or the other of the two drive circuits constituting the drive circuit 174, and convert DC power supplied from the battery 136 into three-phase AC power.

[0070] 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. As shown in Fig. As shown in Figure 7, the cathode electrodes of diodes 156 and 158 are electrically connected to the collector electrodes of active elements 155 and 157, respectively, and the anode electrodes are electrically connected to the emitter electrodes of active elements 155 and 157, respectively. As a result, the current flows in the forward direction from the emitter electrode to the collector electrode of the upper-arm active element 155 and the lower-arm active element 157. The active elements 155 and 157 are, for example, IGBTs.

[0071] Note that a metal oxide semiconductor field effect transistor (MOSFET) can be used as the active element, in which case the diode 156 for the upper arm and the diode 158 for the lower arm are not required.

[0072] The positive electrode side terminal 315B and the negative electrode side terminal 319B of each of the upper and lower arm series circuits are each connected to a DC terminal for the capacitor terminal of the capacitor module 500. AC power is generated at the connecting portion of the upper arm circuit and the lower arm circuit, and the connecting portion of the upper arm circuit and the lower arm circuit of each of the upper and lower arm series circuits is 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 connected to the AC output terminal of the power conversion device 200, and the generated AC power is supplied to a stator winding of the motor generator 192 or 194.

[0073] The control circuit 172 generates a timing signal for controlling the switching timing of the upper arm active element 155 and the lower arm active element 157 based on input information from a controller, a sensor (e.g., the current sensor 180), or the like on the vehicle side. The driver circuit 174 generates a drive signal for causing the upper arm active element 155 and the lower arm active element 157 to perform the switching operation based on the timing signal output from the control circuit 172. Note that reference numerals 181, 182, and 188 denote connectors.

[0074] The series circuits of an upper and lower arm include a temperature sensor (not shown), and temperature information of the series circuits of an upper and lower arm is input to the microcomputer. Voltage information on the positive DC electrode side of the series circuits of an upper and lower arm is input to the microcomputer. The microcomputer performs overtemperature detection and overvoltage detection based on these pieces of information and stops the switching operation of all the active elements 155 for the upper arm and the active elements 157 for the lower arm when overtemperature or overvoltage is detected, thus protecting the series circuits of the upper and lower arms from overtemperature or overvoltage.

[0075] Fig. 18 is a perspective exterior view of the Fig. 17 shown power conversion device 200, and Fig. 19 is a perspective cross-sectional view taken along the line XV-XV of the Fig. 18 shown power conversion device 200.

[0076] The power conversion device 200 includes a casing 12 formed by a lower casing 11 and an upper casing 10 and formed in a substantially rectangular parallelepiped shape. An electrical circuit body 400, a capacitor module 500, and the like are housed in the casing 12. The electrical circuit body 400 has a cooling flow path flowing to the cooling element 340, and a cooling water inflow pipe 13 and a cooling water outflow pipe 14 communicating with the cooling flow path protrude from a side surface of the casing 12. A top of the lower casing 11 is opened, and the upper casing 10 is attached to the lower casing 11 while the opening of the lower casing 11 is closed. The upper casing 10 and the lower casing 11 are formed of an aluminum alloy or the like and are fixed while being sealed with respect to the outside.The upper housing 10 and the lower housing 11 may be integrated. Since the housing 12 has a simple rectangular parallelepiped shape, it facilitates mounting on a vehicle or the like and simplifies production.

[0077] A connector 17 is attached to a side surface of the housing 12 in the longitudinal direction, and an AC terminal 18 is connected to the connector 17. Furthermore, a connector 21 is provided on a surface from which the cooling water inflow pipe 13 and the cooling water outflow pipe 14 are led out.

[0078] As in Fig.19, the electrical circuit body 400 is housed in the casing 12. The control circuit 172 and the drive circuit 174 are arranged above the electrical circuit body 400, and the capacitor module 500 is housed on the DC terminal side of the electrical circuit body 400. The power conversion device 200 can be thinned and the degree of freedom in installation on the vehicle is improved by disposing the capacitor module at the same height as the electrical circuit body 400. The AC-side terminal 320B of the electrical circuit body 400 penetrates the current sensor 180 and is connected to the connector 188. In addition, the positive electrode side terminal 315B and the negative electrode side terminal 319B, which are DC terminals of the semiconductor device 300, are connected to the terminals 362A and 362B, respectively.362B on the positive and negative electrode side of the capacitor module 500.

[0079] The above-described embodiment has the following operational effect. (1) An electric circuit body 400 includes: a semiconductor device 300 that includes semiconductor elements 155 and 157 by sealing with a sealing material 360 and has a heat dissipation surface 301 for dissipating heat from the semiconductor elements 155 and 157, the heat dissipation surface 301 being formed on at least one surface; a cooling member 340 disposed facing the heat dissipation surface 301 of the semiconductor device 300 and configured to cool the semiconductor elements 155 and 157; and a heat conduction member 453 disposed between the semiconductor device 300 and the cooling member 340. 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 distance h1 between the sealing material 360 and the cooling element 340 on one side surface of the semiconductor device 300 from which the terminal protrudes is narrower than a second distance h2 between the sealing material 360 and the cooling element 340 on the other side surface of the semiconductor device 300 from which the terminal does not protrude. As a result, it is possible to suppress the leakage of the heat conducting element and provide a highly reliable device.

[0080] The present invention is not limited to the above-described embodiments, and other modes conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention as long as the characteristics of the present invention are not impaired. Furthermore, the above-described embodiment and various modified examples can be combined. List of reference symbols 10 upper housing 11 lower housing 13 Cooling water inlet pipe 14 Cooling water drain pipe 17, 21, 181, 182, 188 connectors 18 AC connection 43, 140, 142 Inverter circuit unit 155 first semiconductor element (active element of the upper arm circuit) 156 first semiconductor element (diode of the upper arm circuit) 157 second semiconductor element (active element of the lower arm circuit) 158 second semiconductor element (diode of the lower arm circuit) 172 control circuit 174 driver circuit 180 current sensor 192, 194 Motor generator 200 power conversion device 300 semiconductor devices 301 heat dissipation surface 315B connection on the positive electrode side 319B Connection on the negative electrode side 320B AC-side connection 325E Emitter measurement connection 325L Lower arm gate connector 325C collector measuring connection 325U Upper arm gate connector 340 cooling element 360 sealing material 400 electrical circuit body 420 circuit board 430 first circuit board (emitter side of the upper arm circuit) 431 second circuit board (collector side of the upper arm circuit) 432 third circuit board (emitter side of the lower arm circuit) 433 fourth circuit board (collector side of the lower arm circuit) 440 first insulation sheet (emitter side) 441 second insulation sheet (collector side) 442 first resin insulating layer (emitter side) 443 second resin insulation layer (collector side) 444 Metal foil 450 Projection area of ​​circuit board 453 Heat conducting element 454, 460, 462, 466 convex section of the sealing material on the emitter side 455, 461, 463, 467 convex section of the sealing material on the collector side 456, 464 concave section of the sealing material on the emitter side 457, 465 concave section of the sealing material on the collector side 458 convex section of the cooling element on the emitter side 459 convex section of the cooling element on the collector side 470 concave section of the cooling element on the emitter side 471 concave section of the cooling element on the collector side 500 capacitor module 601 injection molding device 602 spring QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2005-310987 A

[0004]

Claims

[1] Electrical circuit body comprising: a semiconductor device containing a semiconductor element by sealing with a sealing material and having a heat dissipation surface for dissipating heat of the semiconductor element, the heat dissipation surface being formed on at least one surface; a cooling element arranged facing the heat dissipation surface of the semiconductor device and configured to cool the semiconductor element; and a heat conducting element arranged between the semiconductor device and the cooling element, where a terminal connected to the semiconductor element protrudes from at least one side surface of the semiconductor device, and a first distance between the sealing material and the cooling element on the one side surface of the semiconductor device from which the terminal protrudes is narrower than a second distance between the sealing material and the cooling element on the other side surface of the semiconductor device from which the terminal does not protrude. [2] The electrical circuit body according to claim 1, wherein the first distance is less than or equal to a thickness of the heat conducting member, and when the second distance is wider than the thickness of the heat conducting member, the first distance is equal to the thickness of the heat conducting member. [3] The electrical circuit body according to claim 1, wherein the second distance is greater than or equal to a thickness of the heat conducting member, and when the first distance is narrower than the thickness of the heat conducting member, the second distance is equal to the thickness of the heat conducting member. [4] Electrical circuit body according to claim 1, wherein a convex portion projecting from a surface of the heat dissipation surface on which sealing material is formed on the one side surface of the semiconductor device from which the terminal projects, and a distance between the convex portion and the cooling element is the first distance. [5] The electric circuit body according to claim 4, wherein the convex portion is formed at a height at which it covers an end portion of the cooling member from the outside. [6] The electric circuit body according to claim 5, wherein a concave portion is formed in the sealing material between the convex portion and the heat dissipating surface. [7] Electrical circuit body according to claim 1, wherein 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 from which the terminal protrudes, and a distance between the convex portion and the cooling element is the first distance. [8] Electrical circuit body according to one of claims 4 to 7, wherein the connection contains multiple connections, and a plurality of the convex portions are formed corresponding to positions of the plurality of terminals. [9] Electrical circuit body according to one of claims 4 to 7, wherein a concave portion recessed from the heat dissipation surface in which sealing material is formed on the other side surface of the semiconductor device from which the terminal does not protrude, and a distance between the concave portion and the cooling element is the second distance. [10] The electric circuit body according to claim 9, wherein a convex portion is formed on the sealing material on the other side surface of the semiconductor device on the outside of the concave portion. [11] Electrical circuit body according to one of claims 4 to 7, wherein a concave portion is formed at one end portion of the cooling member on the other side surface of the semiconductor device from which the terminal does not protrude, and a distance between the concave portion and the sealing material is the second distance. [12] An electrical circuit body according to any one of claims 1 to 7, wherein the thermal conductivity of the heat conducting element is 5 to 8 W / (mK). [13] Electrical circuit body according to one of claims 1 to 7, wherein the semiconductor device includes a circuit board connected to the semiconductor element, and the semiconductor device includes an insulating sheet between the circuit board and the heat-conducting element. [14] Electrical circuit body according to claim 9, wherein the heat dissipation surface is formed on both surfaces of the semiconductor element, the cooling element is arranged on both surfaces of the semiconductor device facing the heat-emitting surface, and the heat conducting element is arranged on both surfaces between the semiconductor device and the cooling element. [15] A power conversion device comprising the electric circuit body according to any one of claims 1 to 7, wherein DC power is converted into AC power.