Power conversion device

Abstract

The purpose of the present disclosure is to provide a technique capable of uniformizing heat conduction in a heat sink surface. The power conversion device includes a semiconductor device, a cooler, a heat sink provided between the semiconductor device and the cooler, and a case covering an upper portion and a side portion of the semiconductor device. The semiconductor device includes a semiconductor element, an insulating side, a first circuit pattern and a second circuit pattern provided on an upper surface and a lower surface of the insulating side, respectively, and a sealing member. According to the present disclosure, the case is fixed to the cooler in a state in which the upper portion of the semiconductor is pressed toward the cooler side.

Description

Technical Field

[0001] This disclosure relates to power conversion devices. Background Technology

[0002] Various technologies have been proposed for power conversion devices incorporating semiconductor devices. For example, Patent Document 1 proposes a technology that involves placing a heat sink between the semiconductor device and a cooling plate (heat sink) to reduce the gap generated when the semiconductor device is fastened to the cooling plate and to improve the heat conduction between the semiconductor device and the cooling plate.

[0003] [Existing technical documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-149952 Summary of the Invention

[0006] [The technical problem that the invention aims to solve]

[0007] In the technology of Patent Document 1, since the semiconductor device is directly fastened to the cooling plate by screws, the pressing pressure applied from the semiconductor device to the cooling plate is concentrated around the periphery of the fastening portion. Therefore, the surface pressure applied from the semiconductor device to the heat sink becomes uneven, creating gaps between the semiconductor device and the heat sink. As a result, heat conduction within the heat sink surface becomes uneven, leading to a deterioration in the heat dissipation performance of the power conversion device. Furthermore, if the semiconductor element is enlarged as a countermeasure to reduce heat generation, it will make it difficult to miniaturize the semiconductor device and the power conversion device.

[0008] Therefore, this disclosure is made in response to the above problems, and its purpose is to provide a technique that can make heat conduction within the heat sink surface uniform.

[0009] Technical means for solving technical problems

[0010] The power conversion device disclosed herein comprises: a semiconductor device including a semiconductor element, an insulating layer, a first circuit pattern disposed on the upper surface of the insulating layer and electrically connected to the semiconductor element, a second circuit pattern disposed on the lower surface of the insulating layer, and a sealing member covering the semiconductor element, the insulating layer, and the first circuit pattern; a cooler; a heat sink disposed between the semiconductor device and the cooler; and a housing covering the upper and side portions of the semiconductor device, the housing being fixed to the cooler while the upper portion of the semiconductor device is pressed towards the cooler side.

[0011] Invention Effects

[0012] According to this disclosure, the housing is fixed to the cooler while pressing against the upper part of the semiconductor device towards the cooler side. This configuration enables uniform heat conduction within the heat sink surface.

[0013] The purpose, features, aspects and advantages of this disclosure will become clearer from the following detailed description and accompanying drawings. Attached Figure Description

[0014] Figure 1 A cross-sectional view showing the configuration of the power conversion device according to Embodiment 1.

[0015] Figure 2 This is a cross-sectional view showing the initial warped state of the semiconductor device according to Embodiment 1.

[0016] Figure 3 This is a cross-sectional view showing the initial warped state of the power conversion device according to Embodiment 1.

[0017] Figure 4 This is a cross-sectional view showing the state of the semiconductor device according to Embodiment 1 during operation.

[0018] Figure 5 This is a cross-sectional view showing the state of the associated device of the power conversion device according to Embodiment 1 when it is driven.

[0019] Figure 6 This is a cross-sectional view showing the state of the power conversion device according to Embodiment 1 during operation.

[0020] Figure 7 This is a cross-sectional view showing the structure of the power conversion device according to Embodiment 1.

[0021] Figure 8 This is a cross-sectional view showing the structure of the power conversion device involved in Embodiment 2.

[0022] Figure 9 This is a cross-sectional view showing the structure of the power conversion device involved in Embodiment 2.

[0023] Figure 10 This is a side view showing the structure of the power conversion device involved in Embodiment 3.

[0024] Figure 11 This is a perspective view showing the structure of the power conversion device involved in Embodiment 3.

[0025] Figure 12 This is a circuit diagram showing the structure of the semiconductor device involved in Embodiment 3.

[0026] Figure 13This is a side view showing the structure of the power conversion device involved in Embodiment 3.

[0027] Figure 14 A cross-sectional view showing the structure of the power conversion device according to Embodiment 4.

[0028] Figure 15 A cross-sectional view showing the structure of the power conversion device according to Embodiment 4.

[0029] Figure 16 A cross-sectional view showing the structure of the power conversion device according to Embodiment 4.

[0030] Figure 17 A cross-sectional view showing the structure of the power conversion device according to Embodiment 4.

[0031] Figure 18 A cross-sectional view showing the structure of the power conversion device according to Embodiment 4.

[0032] Figure 19 A side view showing the structure of the power conversion device according to Embodiment 5.

[0033] Figure 20 A perspective view showing the structure of the power conversion device involved in Embodiment 5.

[0034] Figure 21 A block diagram illustrating the structure of the power conversion device according to Embodiment 6. Detailed Implementation

[0035] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The features described in the following embodiments are merely examples, and not all features are essential. Furthermore, in the following description, the same or similar symbols are used for the same constituent elements in multiple embodiments, and the description mainly focuses on different constituent elements. Additionally, the specific positions and directions of "upper," "lower," "left," "right," "surface," and "back side" in the following description need not necessarily correspond to the actual positions and directions in the implementation.

[0036] <Implementation Method 1>

[0037] Figure 1 This is a cross-sectional view showing the structure of the power conversion device according to Embodiment 1. Figure 1 The power conversion device includes a semiconductor device 11, a cooler 12, a heat sink 13, a housing 14, and screws 15.

[0038] The semiconductor device 11 includes a semiconductor element 11a, an insulating layer 11b, a first circuit pattern 11c, a second circuit pattern 11d, a terminal 11e, and a sealing component 11f.

[0039] The semiconductor element 11a involved in this embodiment 1 is an RC-IGBT (Reverse Conducting Insulated Gate Bipolar Transistor) in which a semiconductor switching element and a diode are disposed in a single chip. With this configuration, the number of chips can be reduced, thus enabling miniaturization of the semiconductor device 11 and the power conversion device.

[0040] However, the semiconductor element 11a is not limited to this and may include at least one of MOSFET (Metal Oxide Semiconductor Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), SBD (Schottky Barrier Diode), and PND (PN junction diode). In this specification, for example, at least one of A, B, ..., and Z means any one of more than one combination selected from the group consisting of A, B, ..., and Z.

[0041] In this embodiment 1, the material of the semiconductor element 11a includes wide-bandgap semiconductors such as silicon carbide (SiC), gallium nitride (GaN), and diamond. With this structure, the power loss of the semiconductor element 11a can be reduced, thereby achieving miniaturization of the semiconductor 11 and the power conversion device, or enabling high-density semiconductor device 11 or power conversion device. However, the material of the semiconductor element 11a is not limited to this, and may also include conventional silicon (Si).

[0042] The insulating layer 11b is made of materials such as resin and ceramic. The first circuit pattern 11c is a conductive component disposed on the upper surface of the insulating layer 11b, and the second circuit pattern 11d is a conductive component disposed on the lower surface of the insulating layer 11b. The first circuit pattern 11c is electrically connected to the terminals of the semiconductor element 11a through solder and bonding materials 11g such as silver.

[0043] Terminal 11e is electrically connected to at least one of semiconductor element 11a and first circuit pattern 11c via solder and bonding materials such as silver or aluminum wire 11h. Terminal 11e can be a conductive component, and the surface of terminal 11e can be plated with nickel (Ni) or tin (Sn).

[0044] The sealing member 11f covers the semiconductor element 11a, the insulating layer 11b, and the first circuit pattern 11c. In addition, the sealing member 11f according to Embodiment 1 also covers a portion of the terminal 11e, the bonding member 11g, and the aluminum wire 11h. The end of the terminal 11e and the lower part of the second circuit pattern 11d are exposed from the sealing member 11f. The material of the sealing member 11f includes, for example, epoxy resin.

[0045] Cooler 12 is a heat-conducting component, cooled by a fan or cooling water (not shown). The material of cooler 12 may include, for example, aluminum or copper.

[0046] The heat sink 13 is disposed between the second circuit pattern 11d of the semiconductor device 11 and the upper surface of the cooler 12, and is connected to both. In this embodiment 1, the material of the heat sink 13 includes, for example, graphite. The graphite heat sink 13 has the characteristics of high thermal conductivity and thin film fabrication, thus improving the heat dissipation of the power conversion device, which in turn helps to achieve miniaturization of the power conversion device.

[0047] The housing 14 covers the upper and sides of the semiconductor 11, and the material of the housing 14 includes, for example, an insulating material. The housing 14 is fixed to the cooler 12 by screws 15 while the upper part of the semiconductor device 11 is pressed towards the cooler 12. Alternatively, the housing 14 may be fixed to the cooler 12 by adhesive or the like without screws 15.

[0048] In the prior art, because the semiconductor device is directly fastened to the cooling plate by screws, a large axial force is applied directly to the semiconductor device, and the pressing pressure applied from the semiconductor device to the cooling plate is concentrated around the periphery of the fastening portion. As a result, uneven warping deformation of the semiconductor device and excessive deformation of the heat sink occur, creating gaps between the semiconductor device and the heat sink, leading to uneven heat conduction within the heat sink surface.

[0049] In this regard, according to the power conversion device of Embodiment 1, the housing 14 presses against the upper part of the semiconductor device 11 towards the cooler 12, which can suppress the direct application of large axial forces to the semiconductor device and the heat sink. Therefore, the surface pressure applied from the semiconductor device 11 to the heat sink 13 can be uniformized, thereby making the heat conduction within the surface of the heat sink 13 uniform, thus improving the heat dissipation performance of the power conversion device. As a result, it helps to achieve miniaturization of the power conversion device.

[0050] Furthermore, in this embodiment 1, a flange 14a protruding outward is provided in the housing 14, and the flange 14a is fixed to the cooler 12 by screws 15. With this configuration, it is easy to align the left-right direction of the housing 14 with the in-plane direction of the upper surface of the cooler 12. This allows for uniformity of the surface pressure applied from the semiconductor device 11 to the heat sink 13, thereby uniformizing the in-plane heat conduction of the heat sink 13 and improving the heat dissipation performance of the power conversion device.

[0051] Furthermore, for the actual product, the semiconductor device 11, particularly the second circuit pattern 11d exposed from the sealing member 11f, at room temperature before the semiconductor device 11 is driven, exhibits conditions such as... Figure 2 The warping situation shown is referred to as "initial warping" (hereinafter, this warping is recorded as "initial warping"). In the case of initial warping, in order to uniformize the heat conduction within the surface of the heat sink 13, the surface pressure applied from the semiconductor device 11 to the heat sink 13 must be averaged.

[0052] Therefore, in this embodiment 1, the semiconductor device 11 is pressed by the housing 14, causing the compression amount of the heat sink 13 pressed by the semiconductor device 11 to become greater than the warpage amount before the semiconductor device 11 is driven. Here, the compression amount of the heat sink 13 is the maximum deformable amount of the heat sink 13, which can be expressed as the product of the thickness of the heat sink 13 and the compression ratio of the heat sink 13. Based on this configuration, as... Figure 3 As shown, the heat sink 13 can absorb the warping of the semiconductor device 11 before it is driven, and thus can uniformize the surface pressure applied from the semiconductor device 11 to the heat sink 13.

[0053] To ensure good heat dissipation of the power conversion device, it is necessary to consider not only the initial warp but also the warp changes during the operation of the power conversion device. Figure 4 This illustrates the warping when the power conversion device is driven, and... Figure 2 Compared to the initial warp, the degree of warp becomes smaller.

[0054] Figure 5 The diagram illustrates a situation where the recovery amount of the heat sink 13 is less than the difference between the warpage amount before and during operation of the semiconductor device 11. In this case, a gap 51 is formed between the second circuit pattern 11d and the heat sink 13, thus worsening the heat dissipation of the power conversion device.

[0055] Therefore, in this embodiment 1, the recovery amount of the heat sink 13 becomes greater than the warp change, which is the difference between the warp amount before and during the driving of the semiconductor 11. Based on this configuration, as... Figure 6 As shown, the gap 51 between the second circuit pattern 11d and the heat sink 13 can be suppressed, thus improving the heat dissipation of the power conversion device.

[0056] As described above, in order to increase the resilience of the heat sink 13, a material with a good resilience rate is selected for the heat sink 13, and the thickness of the heat sink 13 must be increased. However, if the thickness of the heat sink 13 is increased, the thermal resistance of the heat sink 13 increases, resulting in reduced heat dissipation. Therefore, it is preferable to minimize the warpage of the semiconductor device 11 as much as possible. Next, a structure for reducing the warpage of the semiconductor device 11 will be described.

[0057] When the semiconductor device 11 is driven, the semiconductor element 11a generates heat, which is transferred to the structural components of the semiconductor device 11 and raises their temperature. Therefore, in order to suppress the amount of warpage of the semiconductor device 11 from before driving (i.e., at room temperature) to during driving (i.e., at high temperature), it is important to ensure that the coefficients of linear expansion of the structural components of the semiconductor device 11 are consistent. Among the structural components of the semiconductor device 11, the structural components with a large volume proportion and high elasticity are the insulating layer 11b, the first circuit pattern 11c, the second circuit pattern 11d, and the sealing component 11f. Therefore, ensuring that the coefficients of linear expansion of these components are consistent is effective in suppressing the amount of warpage.

[0058] Among them, the structural component whose volume ratio is most easily increased within the semiconductor device 11 is the sealing component 11f. Therefore, it is preferable to make the coefficient of linear expansion of the sealing component 11f close to the coefficients of linear expansion of the first circuit pattern 11c, the second circuit pattern 11d, and the sealing component 11f, which have a greater influence on warpage.

[0059] Therefore, in this embodiment 1, when the coefficient of linear expansion of the insulating layer 11b is α1, the coefficient of linear expansion of the sealing member 11f is α2, and the coefficient of linear expansion of at least one of the first circuit pattern 11c and the second circuit pattern 11d is α3, α1≤α2≤α3 holds true. With this configuration, the warpage of the semiconductor device 11 can be suppressed, thereby easily satisfying the condition that the recovery amount of the heat sink 13 is greater than the warpage of the semiconductor device 11. As a result, the thickness of the heat sink 13 can be made thinner, improving the heat dissipation of the power conversion device, which in turn helps to achieve miniaturization of the power conversion device.

[0060] Next, other structures for reducing the warpage of the semiconductor device 11 will be described. Generally, the coefficients of linear expansion and elastic modulus of the first circuit pattern 11c and the second circuit pattern 11d are greater than those of other structural components within the semiconductor device 11. Therefore, if the volume density of the second circuit pattern 11d below the semiconductor device 11 increases, the warpage of the semiconductor device 11 is more likely to increase. Furthermore, the first circuit pattern 11c has the function of dispersing the heat generated by the semiconductor element 11a in the horizontal direction and suppressing heat retention between the semiconductor element 11a and the insulating layer 11b, which generally has low thermal conductivity, leading to deterioration in heat dissipation. Therefore, simply thinning the first circuit pattern 11c may result in deterioration of the heat dissipation of the power conversion device.

[0061] Therefore, in this embodiment 1, the thickness of the first circuit pattern 11c located on the semiconductor element 11a side becomes greater than the thickness of the second circuit pattern 11d located on the cooler 12 side. With this structure, not only can the warpage of the semiconductor device 11 be suppressed, but the heat dissipation of the power conversion device can also be improved.

[0062] In this embodiment 1, as Figure 7 As shown, the width of the heat sink 13 is smaller than the width of at least one of the first circuit pattern 11c and the second circuit pattern 11d, and when viewed from above, the semiconductor element 11a can also be disposed inside the outer edge of the heat sink 13. With this configuration, the heat sink 13 is located within the coverage area of ​​the semiconductor element 11a, that is, directly below the semiconductor element 11a, thus maintaining the heat dissipation performance of the power conversion device. Furthermore, since the amount of compression and recovery required for the heat sink 13 can be reduced, the thickness of the heat sink 13 can be made thinner, thereby improving the heat dissipation performance of the power conversion device.

[0063] In this embodiment 1, the surface pressure obtained by dividing the pressure applied from the housing 14 to the semiconductor device 11 by the area of ​​the heat sink 13 can be greater than the surface pressure necessary to deform the heat sink 13 corresponding to the warpage of the semiconductor device 11 before it is driven. That is, the surface pressure applied from the housing 14 to the heat sink 13 can also be greater than the surface pressure necessary to generate the compression required to absorb the initial warpage of the heat sink 13. With this configuration, the surface pressure applied from the semiconductor device 11 to the heat sink 13 can be uniformized, improving the heat dissipation performance of the power conversion device.

[0064] <Implementation Method 2>

[0065] Figure 8This is a cross-sectional view showing the structure of the power conversion device according to Embodiment 2. In Embodiment 2, the housing 14 includes a body 14b and a spring 14c as an elastic member. The body 14b contains, for example, resin and has insulating properties. The spring 14c is disposed on the body 14b and is used to press the upper part of the semiconductor device 11 toward the cooler 12 side.

[0066] Generally, since power conversion devices handle high voltages, it is essential to ensure the insulation distance between conductive components at different potentials. In this embodiment 2, by employing an insulating body 14b and a spring 14c, it is easier to ensure the insulation distance between the semiconductor device 11 and other devices, thereby increasing the design freedom of the power conversion device and contributing to its miniaturization.

[0067] like Figure 9 As shown, the spring 14c can also be partially embedded in the body 14b. Such a housing 14 can be manufactured by injection molding the body 14b onto the spring 14c. With this structure, since the spring 14c is covered by the insulating body 14b, it is easier to ensure the insulation distance, thereby increasing the design freedom of the power conversion device and helping to achieve miniaturization of the power conversion device.

[0068] Furthermore, the housing 14 can be configured such that the restoring force of the spring 14c changes non-linearly with respect to the displacement of the spring 14c. For example, it can be configured such that the graph representing the relationship between displacement and restoring force is curved, so that the increase in the restoring force of the spring 14c gradually increases or decreases as the displacement of the spring 14c increases. With such a structure, the controllability of the pressure on the heat sink 13 can be improved, thereby improving the heat dissipation of the power conversion device, and consequently, contributing to the miniaturization of the power conversion device.

[0069] <Implementation Method 3>

[0070] Figure 10 This is a side view showing the structure of the power conversion device according to Embodiment 3. Figure 11 It is a three-dimensional diagram representing its structure.

[0071] In this embodiment 3, a housing 14 presses against the upper part of a plurality of semiconductor devices 11 toward the cooler 12. With this structure, compared to providing a housing 14 for each semiconductor device 11, the space required for the housing 14 can be reduced, and since the number of screws 15 used to fix the housing 14 to the cooler 12 is reduced, miniaturization of the power conversion device can be achieved.

[0072] Furthermore, the semiconductor element 11a of each of the plurality of semiconductor devices 11 may also include a first semiconductor element and a second semiconductor element. For example... Figure 11 As shown, in each of the plurality of semiconductor devices 11, terminals 11e, such as control terminals of the first semiconductor element, can protrude from the first side 11f1 of the sealing member 11f, and terminals 11e, such as control terminals of the second semiconductor element, can also protrude from the second side 11f2 of the sealing member 11f, which is opposite to the first side 11f1. Furthermore, the plurality of semiconductor devices 11 can be arranged adjacent to sides other than the first side 11f1 and the second side 11f2. Thus, by employing semiconductor devices 11 with terminals 11e extending from the sealing member 11f in two directions, and by arranging the semiconductor devices 11 side-by-side in a direction perpendicular to the first side 11f1 and the second side 11f2 of the terminals 11e, miniaturization of the power conversion device can be achieved.

[0073] Thus, by arranging the terminals 11e of the first semiconductor element and the second semiconductor element on opposite surfaces, as... Figure 10 As shown, the length L between the opposing inner walls of the housing 14 can be shortened. When the length L of the housing 14 is long, the rigidity of the housing 14 decreases and it is prone to deformation. If the thickness of the housing 14 is increased to improve its rigidity, the power conversion device will become larger. In contrast, according to the above structure, the length L of the housing 14 can be shortened. Therefore, according to this viewpoint, the power conversion device can also be miniaturized.

[0074] The first semiconductor element and the second semiconductor element included in the semiconductor element 11a in each semiconductor device 11 can be as follows: Figure 12 The high-side semiconductor element 11a1 and the low-side semiconductor element 11a2 shown have a 2-in-1 wiring structure. With this structure, the control terminals of the high-side semiconductor element 11a1 and the low-side semiconductor element 11a2 can be efficiently configured as terminals 11e, thereby enabling miniaturization of the power conversion device.

[0075] In addition, Figure 10 In this embodiment, a heat sink 13 is provided for each semiconductor device 11, but it is not limited to this. For example, as... Figure 13 As shown, a heat sink 13 can also be disposed between multiple semiconductor devices 11 and the cooler 12. With such a structure, since heat is diffused horizontally within the heat sink 13, the heat dissipation of the power conversion device can be improved, which in turn helps to achieve miniaturization of the power conversion device.

[0076] It should be noted that the above-described embodiment 3 can be applied to any one of embodiments 1 and 2.

[0077] <Implementation Method 4>

[0078] Figure 14 This is a cross-sectional view showing the structure of the power conversion device according to Embodiment 4. In Embodiment 4, a protrusion 11f3 protruding toward the cooler 12 is provided on the sealing member 11f, and a fitting hole 12a that fits into the protrusion 11f3 is provided on the cooler 12. With this structure, by improving the accuracy of the mounting positions of the semiconductor device 11 and the heat sink 13, the heat dissipation effect of the heat sink 13 can be obtained efficiently, and the heat dissipation performance of the power conversion device can be improved.

[0079] In addition, such as Figure 15 As shown, a groove 12b can also be provided on the cooler 12 to define the position of the heat sink 13 in the in-plane direction. The inner wall of the groove 12b can restrict the movement of the heat sink 13 in the in-plane direction. With this structure, not only can the accuracy of the mounting position of the heat sink 13 be improved, but the heat dissipation performance of the power conversion device can also be improved.

[0080] In addition, such as Figure 16 As shown, an opening 13a can also be provided on the heat sink 13, configured so that the protrusion 11f3 of the sealing member 11f passes through the opening 13a. With this structure, the accuracy of the mounting position of the heat sink 13 can be improved, and the heat dissipation performance of the power conversion device can be improved.

[0081] In addition, such as Figure 17 As shown, an opening 13a can also be provided on the heat sink 13, and a protrusion 12c passing through the opening 13a can be provided on the cooler 12. With this structure, the ease of installation of the heat sink 13 and the accuracy of the mounting position of the heat sink 13 can be improved.

[0082] In addition, such as Figure 18 As shown, a fitting hole 11f4 for engaging with the protrusion 12c of the cooler 12 can also be provided on the sealing member 11f. With this structure, the accuracy of the installation of the sealing member 11f and the heat sink 13, as well as the accuracy of the mounting position of the semiconductor device 11 and the heat sink 13, can be improved.

[0083] Furthermore, the above-described embodiment 4 can be applied to any one of embodiments 1-3.

[0084] <Implementation Method 5>

[0085] Figure 19 This is a side view showing the structure of the power conversion device according to Embodiment 5. Figure 20 It is a three-dimensional diagram showing its structure. Figure 19 and Figure 20 The structure is described in Embodiment 3. Figure 10 and Figure 11 A control board 16 was added to the existing structure.

[0086] The control substrate 16 is a substrate used to control the semiconductor device 11 and is directly fixed (fastened) to the housing 14. With this structure, since there is no need for a dedicated fixing component for fixing the control substrate 16, space can be saved and miniaturization of the power conversion device can be achieved.

[0087] In addition, such as Figure 20 As shown, numerous fixing points 14d, such as screw fastening points for fixing the control board 16, can be provided on the housing 14. Therefore, the amplitude of the control board 16 can be suppressed when the power conversion device vibrates, and stable driving of the power conversion device can be achieved.

[0088] Furthermore, the above-described embodiment 5 can be applied to any one of embodiments 1-4.

[0089] <Implementation Method 6>

[0090] The power conversion device described in Embodiment 6 can be applied to the power conversion devices described in Embodiments 1 to 5 above. The power conversion device described in Embodiment 6 is not limited to a specific power conversion device; the following description explains the application of the power conversion device described in Embodiment 6 to a three-phase inverter.

[0091] Figure 21 This is a block diagram illustrating the structure of a power conversion system employing the power conversion device 200 described in Embodiment 6. For example... Figure 21 The power conversion system shown includes a power supply 100, a power conversion device 200, and a load 300. The power supply 100 is a DC power supply, providing DC power to the power conversion device 200. The power supply 100 can be composed of various power sources, such as a DC system, solar cells, or batteries, or it can be composed of a rectifier circuit or an AC / DC converter connected to an AC system. Alternatively, the power supply 100 can also be composed of a DC / DC converter that converts the DC power output from a DC system into a predetermined power.

[0092] The power conversion device 200 is a three-phase inverter connected between the power supply 100 and the load 300. The power conversion device 200 converts the DC power supplied by the power supply 100 into AC power and provides AC power to the load 300. Figure 21As shown, the power conversion device 200 includes: a main conversion circuit 201 that converts DC power into AC power and outputs it; a drive circuit 202 that outputs drive signals for driving each switching element of the main conversion circuit 201; and a control circuit 203 that outputs control signals to the drive circuit 202 for controlling the drive circuit.

[0093] Load 300 is a three-phase motor driven by AC power provided by power conversion device 200. Furthermore, load 300 is not limited to a specific application and can be a motor used in various electrical devices, such as motors in hybrid vehicles, electric vehicles, railway vehicles, elevators, or air conditioning equipment.

[0094] The power conversion device 200 will now be described in detail. The main conversion circuit 201 includes switching elements and freewheeling diodes (not shown). For example, the freewheeling diodes may be integrated into the switching elements. By switching the switching elements, the main conversion circuit 201 converts the DC power supplied by the power supply 100 into AC power and supplies AC power to the load 300. The specific circuit structure of the main conversion circuit 201 can take many forms. In this embodiment 6, the main conversion circuit 201 is a two-level three-phase full-bridge circuit, which can be composed of six switching elements and six freewheeling diodes connected in reverse parallel to each switching element. The semiconductor device 11 described in embodiments 1 to 5 is used as the switching element of the main conversion circuit 201. Of the six switching elements, every two switching elements are connected in series to form upper and lower arms, and each upper and lower arm constitutes a phase (U phase, V phase, W phase) of the full-bridge circuit. Furthermore, the output terminals of each upper and lower arm, i.e., the three output terminals of the main conversion circuit 201, are connected to the load 300.

[0095] The drive circuit 202 generates drive signals for driving the switching elements of the main conversion circuit 201 and provides them to the control electrodes of the switching elements of the main conversion circuit 201. Specifically, the drive circuit 202 outputs drive signals to the control electrodes of each switching element to turn the switching element on and to turn the switching element off, based on control signals from the control circuit 203 (described later). When it is necessary to keep the switching element on, the drive signal is a voltage signal greater than the threshold voltage of the switching element (on signal); when it is necessary to keep the switching element off, the drive signal is a voltage signal less than the threshold voltage of the switching element (off signal).

[0096] Control circuit 203 controls the switching elements of main conversion circuit 201 to provide the desired power to load 300. Specifically, control circuit 203 calculates the on-time (conduction time) of each switching element of main conversion circuit 201 based on the power to be provided to load 300. For example, control circuit 203 can use pulse width modulation (PWM) control to control main conversion circuit 201 to calculate the time, where the PWM modulates the on-time of the switching elements according to the voltage to be output. Then, control circuit 203 outputs control commands (control signals) to drive circuit 202, causing it to output on signals for switching elements that should be turned on at each time point and off signals for switching elements that should be turned off. Drive circuit 202 outputs on or off signals to the control electrodes of each switching element as drive signals according to the control signals.

[0097] In the power conversion device 200 according to Embodiment 6, since the power conversion devices according to Embodiments 1 to 5 are applied, the heat conduction within the heat sink surface can be made uniform, thereby improving the heat dissipation performance of the power conversion device 200.

[0098] In this embodiment 6, an example of applying the power conversion device described in embodiments 1 to 5 to a two-level three-phase inverter is given. However, this embodiment 6 is not limited to this and can be applied to various power conversion devices. Although the power conversion device described in this embodiment 6 is a two-level power conversion device, it can also be a three-level or multi-level power conversion device. Furthermore, when providing power to a single-phase load, the above-described power conversion device can also be applied to a single-phase inverter. In addition, when providing power to DC loads, the above-described power conversion device can also be applied to a DC / DC converter or an AC / DC converter.

[0099] Furthermore, the power conversion device involved in this embodiment 6 is not limited to the case where the load is an electric motor. For example, it can also be used as a power supply device for a discharge machining machine, a laser machining machine, an electromagnetic induction heater, or a contactless power supply system, and can also be used as a power regulator for a solar power generation system or an energy storage system.

[0100] Furthermore, various implementation methods and variations can be freely combined, and various implementation methods and variations can be appropriately modified or omitted.

[0101] The above description is exemplary in all respects and not restrictive. It can be understood that numerous variations not shown in the examples are conceivable.

[0102] [Label Explanation]

[0103] 11 Semiconductor device, 11a Semiconductor element, 11a1 High-side semiconductor element, 11a2 Low-side semiconductor element, 11b Insulating layer, 11c First circuit pattern, 11d Second circuit pattern, 11e Terminal, 11f Sealing component, 11f1 First side surface, 11f2 Second side surface, 11f3 Protrusion, 11f4 Fitting hole, 12 Cooler, 12a Fitting hole, 12b Groove, 12c Protrusion, 13 Heat sink, 13a Opening, 14 Housing, 14b Body, 14c Spring, 16 Control board, 200 Power conversion device, 201 Main conversion circuit, 202 Drive circuit, 203 Control circuit.

Claims

1. A power conversion device, characterized in that, include: A semiconductor device, the semiconductor device comprising semiconductor elements; Insulating layer; A first circuit pattern is disposed on the upper surface of the insulating layer and is electrically connected to the semiconductor element. A second circuit pattern is disposed on the lower surface of the insulating layer; and a sealing component, the sealing component covering the semiconductor element, the insulating layer and the first circuit pattern; Cooler; A heat sink, disposed between the semiconductor device and the cooler; and A housing that covers the upper and sides of the semiconductor device. The housing is fixed to the cooler while the upper part of the semiconductor device is pressed towards the cooler side.

2. The power conversion device as described in claim 1, characterized in that, By pressing the housing against the semiconductor device, the compression of the heat sink by the semiconductor device is greater than the warpage of the semiconductor device before it is driven.

3. The power conversion device as described in claim 1, characterized in that, The recovery amount of the heat sink is greater than the difference between the warp amount before the semiconductor device is driven and the warp amount during the drive, i.e., the warp change.

4. The power conversion device as described in claim 1, characterized in that, When the coefficient of linear expansion of the insulating layer is α1, the coefficient of linear expansion of the sealing component is α2, and the coefficient of linear expansion of at least one of the first circuit pattern and the second circuit pattern is α3, α1≤α2≤α3 holds true.

5. The power conversion device as described in claim 1, characterized in that, The thickness of the first circuit pattern is greater than the thickness of the second circuit pattern.

6. The power conversion device as described in claim 1, characterized in that, The width of the heat sink is less than the width of at least one of the first circuit pattern and the second circuit pattern; When viewed from above, the semiconductor element is disposed inside the outer edge of the heat sink.

7. The power conversion device as claimed in claim 1, characterized in that, The surface pressure obtained by dividing the pressure applied from the housing to the semiconductor device by the area of ​​the heat sink is greater than the surface pressure required to deform the heat sink in accordance with the warp amount before the semiconductor device is driven.

8. The power conversion device as claimed in claim 1, characterized in that, The enclosure includes: The body, which is insulating; and An elastic member is disposed on the body and is used to press the upper part of the semiconductor device toward the cooler side.

9. The power conversion device as described in claim 8, characterized in that, The elastic component is partially embedded in the body.

10. The power conversion device as claimed in claim 8, characterized in that, The restoring force of the elastic component changes nonlinearly relative to the displacement change of the elastic component.

11. The power conversion device as claimed in claim 1, characterized in that, One of the housings presses against the upper part of the plurality of semiconductor devices toward the cooler side.

12. The power conversion device as claimed in claim 11, characterized in that, One of the heat sinks is disposed between the plurality of semiconductor devices and the cooler.

13. The power conversion device as claimed in claim 11, characterized in that, Each of the plurality of semiconductor devices comprises a high-side semiconductor element and a low-side semiconductor element having a 2-in-1 wiring structure.

14. The power conversion device as claimed in claim 11, characterized in that, Each of the plurality of semiconductor devices includes a first semiconductor element and a second semiconductor element. In each of the plurality of semiconductor devices, the terminals of the first semiconductor element protrude from a first side of the sealing member, and the terminals of the second semiconductor element protrude from a second side of the sealing member opposite to the first side. The plurality of semiconductor devices are arranged so that the sides other than the first side and the second side are arranged adjacent to each other.

15. The power conversion device as claimed in claim 1, characterized in that, A protrusion is provided on the sealing component that protrudes toward the cooler; A fitting hole is provided on the cooler to fit the protrusion.

16. The power conversion device as claimed in claim 1, characterized in that, A slot is provided on the cooler to determine the in-plane position of the heat sink.

17. The power conversion device as claimed in claim 15, characterized in that, An opening is provided on the heat sink; The protrusion of the sealing member passes through the opening.

18. The power conversion device as claimed in claim 1, characterized in that, An opening is provided on the heat sink; A protrusion passing through the opening is provided on the cooler.

19. The power conversion device as claimed in claim 18, characterized in that, The sealing component is provided with a fitting hole that engages with the protrusion of the cooler.

20. The power conversion device as claimed in claim 1, characterized in that, It also includes a control substrate fixed to the housing and used to control the semiconductor device.

21. The power conversion device according to any one of claims 1-20, characterized in that, The heat sink is made of graphite.

22. The power conversion device according to any one of claims 1-20, characterized in that, The semiconductor element includes an RC-IGBT.

23. The power conversion device according to any one of claims 1-20, characterized in that, The semiconductor element is made of a wide-bandgap semiconductor.

24. The power conversion device according to any one of claims 1-20, characterized in that, include: A main conversion circuit having the semiconductor device, and converting and outputting the input power; A driving circuit that outputs a driving signal to the semiconductor device for driving the semiconductor device; as well as A control circuit is provided, which outputs a control signal to the drive circuit for controlling the drive circuit.

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