Cooling structure for power conversion device

Abstract

To provide a cooling structure for a power conversion device that improves heat radiation performance of the power conversion device.SOLUTION: A cooling structure for a power conversion device 1 comprises: a plurality of semiconductor modules 2 that each have a semiconductor element built therein and have a heat radiation surface on at least one face; heat radiation members 3 that are thermally connected with the heat radiation surfaces of the semiconductor modules and have heat radiation fins 8; a frame 4 that supports the heat radiation members 3; and a cover 5 that covers the heat radiation members and the frame to form water channels passing through the heat radiation fins. The frame 4 is formed with openings 41 to which the heat radiation members 3 are fitted toward the frame 4, and the gap between the fitted heat radiation member 3 and the opening 41 is filled with seal members 12, 13. The heat radiation member 3 is joined to the cover 5 at the leading ends of the heat radiation fins 8, and is displaceable by a pressing force applied to the cover 5 toward the heat radiation surface of the semiconductor module 2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cooling structure for a power conversion device. [Background technology]

[0002] Power conversion devices that convert DC power and AC power mutually by the switching operation of semiconductor elements are widely used in electric vehicles, hybrid vehicles, etc. The semiconductor elements in the power conversion device generate heat due to their switching operation, and the cooling structure of the power conversion device is required to have high heat dissipation performance. In a semiconductor module containing a semiconductor element, a heat dissipation member that cools the heat generated by the semiconductor element is arranged in thermal connection with the heat dissipation surface of the semiconductor module. The heat dissipation member has heat dissipation fins, and a water channel that passes through the heat dissipation fins is formed as a cooling structure.

[0003] Patent document 1 discloses a cooling device for a semiconductor module in which the tip faces of a first cooling pin fin and a second cooling pin fin abut and undergo relative displacement in response to an input load, and in response to this displacement, a first base in contact with one side of the semiconductor module deforms, thereby reducing the gap between the semiconductor module and the first base.

[0004] Patent Document 2 discloses a cold plate comprising a base plate having a number of fins arranged in parallel, and a cover that covers the number of fins and defines an internal space between the base plate and the cover, in which the portion of the internal space facing the upper surfaces of the number of fins is provided with an uneven portion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-126117 A [Patent Document 2] JP 2019-160832 A Summary of the Invention [Problem to be solved by the invention]

[0006] The devices described in Patent Documents 1 and 2 were unable to improve the heat dissipation performance of the power conversion device. [Means for solving the problem]

[0007] The cooling structure for a power conversion device according to the present invention comprises a semiconductor module incorporating a semiconductor element and having a heat dissipation surface on at least one side, a heat dissipation member thermally connected to the heat dissipation surface of the semiconductor module and having heat dissipation fins, a frame supporting the heat dissipation member, and a cover covering the heat dissipation member and the frame and forming a water passage passing through the heat dissipation fins, wherein the frame has an opening through which the heat dissipation member is fitted toward the frame, and a sealing member is provided between the fitted heat dissipation member and the opening, and the heat dissipation member is joined to the cover at the tip of the heat dissipation fin and is configured to be displaceable toward the heat dissipation surface of the semiconductor module by a pressing force applied to the cover. Effect of the Invention

[0008] According to the present invention, it is possible to improve the heat dissipation performance of a power conversion device. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is an exploded perspective view of the power conversion device. [Diagram 2] FIG. 2 is a cross-sectional view of a power conversion device. [Diagram 3] 5(a) to 5(d) are cross-sectional views showing the assembly process of the power conversion device. [Figure 4] 1 is an enlarged cross-sectional view of a power conversion device according to a first modified example. [Diagram 5] 11 is an enlarged cross-sectional view of a power conversion device according to a second modified example. FIG. [Figure 6] 11 is an enlarged cross-sectional view of a power conversion device according to a third modified example. FIG. [Figure 7] 13 is an enlarged cross-sectional view of a power conversion device according to a fourth modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0011] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0012] FIG. 1 is an exploded perspective view of a power conversion device 1 according to an embodiment of the present invention. The power converter 1 includes a semiconductor module 2, a heat dissipation member 3, a frame 4, a cover 5, etc. In the example shown in Fig. 1, the power converter 1 includes six semiconductor modules 2 (21 to 26) arranged in parallel.

[0013] The semiconductor module 2 is mounted on a substrate 6. On the substrate 6, electronic components other than the semiconductor module 2, positioning holes, fixing bosses, and the like are mounted, but are not shown in FIG. The semiconductor module 2 contains a semiconductor element sealed with a sealing material. Both sides of the semiconductor module 2 are heat dissipation surfaces that dissipate heat generated by the switching operation of the semiconductor element, and thermally conductive members 7 (see FIG. 2) such as thermally conductive grease or a thermally conductive sheet are provided on both sides of the semiconductor module 2.

[0014] The heat dissipation member 3 is thermally connected to the heat dissipation surface of the semiconductor module 2 and has heat dissipation fins 8. The heat dissipation member 3 is provided with six heat dissipation members 31 to 36 corresponding to the six semiconductor modules 21 to 26. The frame 4 has openings 41 formed therein, and the heat dissipation member 3 is supported by fitting the heat dissipation member 3 into the openings 41. The openings 41 have six openings 41 formed therein, each of which fits into one of the six heat dissipation members 31 to 36. The cover 5 covers the heat dissipation member 3 and the frame 4 to form a water passage passing through the heat dissipation fins 8. Details of the cover 5 will be described later with reference to FIG. 2. The shape of the heat dissipation fins 8 is not limited and may be a cylindrical pin fin or another shape.

[0015] 1, the lower side of the substrate 6 is not shown in an exploded perspective view, but similar to the upper side, a heat dissipation member 3 having heat dissipation fins 8 is thermally connected to the lower heat dissipation surface of the semiconductor module 2. The heat dissipation member 3 is fitted into an opening 41 formed in the frame 4, and a cover 5 is provided to cover the heat dissipation member 3 and the frame 4, forming a lower water channel that passes through the heat dissipation fins 8. The lower water channel and the upper water channel are connected by a connecting portion 10, and cooling water is circulated by a pump (not shown).

[0016] The semiconductor module 2 may incorporate not only one semiconductor element but also multiple semiconductor elements. In this case as well, one heat dissipation surface is set for the multiple semiconductor elements, and one heat dissipation member 3 is provided corresponding to this heat dissipation surface. The semiconductor module 2 may also be divided into multiple parts. In this case as well, one heat dissipation surface is set for the multiple semiconductor modules 2, and one heat dissipation member 3 is provided corresponding to this heat dissipation surface.

[0017] Furthermore, the power conversion device 1 shows an example in which six semiconductor modules 2 (21 to 26) are arranged in parallel on one cover 5, but the number of semiconductor modules 2 is arbitrary. Also, in this embodiment, an example in which the heat dissipation members 3 are arranged on both sides of the semiconductor module 2 will be described, but the heat dissipation members 3 may be arranged on one side of the semiconductor module 2. In this case, a housing or mounting member is arranged on the other side of the semiconductor module 2, and the other side of the semiconductor module 2 is fixed to this housing or mounting member by a fixing member.

[0018] Fig. 2 is a cross-sectional view of the power converter 1 in this embodiment. This cross-sectional view is taken along the line A-A' in Fig. 1, and illustrates a state in which a heat dissipation member 3, a frame 4, a cover 5, etc. are attached to both sides of a semiconductor module 2.

[0019] As shown in Fig. 2, the upper cover 5 and the upper frame 4 are bonded at the bonding portion 66 with an adhesive or the like, and the lower cover 5 and the lower frame 4 are also bonded with an adhesive or the like, so that each is kept watertight. This forms a water channel that covers the heat dissipation member 3 and the frame 4. An inlet pipe 58 that serves as an inlet for the cooling water is installed in the lower water channel W1, and an outlet pipe 59 that serves as an outlet for the cooling water is installed in the upper water channel W2. In addition, the connecting portion 10 is connected in a watertight state by the second seal member 13, and connects the lower water channel W1 and the upper water channel W2.

[0020] The cooling water is supplied from the inlet pipe 58, passes through the heat dissipation fins 8 of the lower water passage W1, passes through the connecting portion 10, is supplied to the upper water passage W2, passes through the heat dissipation fins 8 in the upper water passage W2, and is discharged from the outlet pipe 59. The flow of the cooling water is one example and is not limited to this.

[0021] An opening 41 into which the heat dissipation member 3 is fitted is formed in the frame 4. A first seal member 12 is provided between the inner periphery of the opening 41 and the outer periphery of the heat dissipation member 3, and after the heat dissipation member 3 is fitted, the gap between the heat dissipation member 3 and the opening 41 is sealed by the first seal member 12 to maintain watertightness. The first seal member 12 is an elastic member such as rubber, and an O-ring, for example, can be used.

[0022] The cover 5 includes a fixed portion 51 to which a pressing force is applied, a pressing portion 52 joined to the tip of the heat dissipation fin 8, and an elastic portion 53 provided between the fixed portion 51 and the pressing portion 52. The cover 5 is a plate-like member having high heat transfer performance, such as aluminum, with the fixed portion 51 formed in the convex portion, the pressing portion 52 formed in the concave portion, and the elastic portion 53 formed in the inclined portion connecting the fixed portion 51 in the convex portion and the pressing portion 52 in the concave portion.

[0023] The fixing portion 51 is provided with a fixing member 11, which is shown in a simplified manner. In the example of FIG. 2, the fixing portion 51 is set between each of the semiconductor modules 2 arranged in parallel, and further at both ends of the power conversion device 1, but the fixing member 11 is provided on each fixing portion 51. A pressing force is applied to the fixing portion 51 by the fixing member 11. The fixing member 11 fixes the heat dissipation member 3, the frame 4, the cover 5, etc., which are assembled on both sides of the semiconductor module 2, from both sides. The fixing member 11 is, for example, a bolt that penetrates from the upper cover 5 to the lower cover 5 and is fastened with a nut. In this case, the bolt penetrates the water channel, the frame 4, and the substrate 6, but is provided so as to ensure watertightness of the water channel and insulation from the substrate 6. The fixing member 11 is not limited to being fastened with a bolt, and a compressive force may be applied from the outside of the cover 5 by a leaf spring or the like. In addition, in order to adjust the pressing force from the fixing member 11, a spacer may be provided between the stacked frames 4, substrates 6, etc.

[0024] The inside of the pressing portion 52 (the side of the water channels W1, W2) is joined to the tip of the heat dissipation fin 8 with brazing material 81 or the like. The elastic portion 53 has higher elasticity or deformation performance than the fixed portion 51 and the pressing portion 52, and the pressing force applied to the fixed portion 51 urges the pressing portion 52, in other words, the heat dissipation member 3 joined to the pressing portion 52, toward the heat dissipation surface of the semiconductor module 2.

[0025] The heat dissipation member 3 is fitted into the opening 41 of the frame 4 via a first seal member 12. The first seal member 12 is an elastic member such as rubber, and the pressing force applied to the fixing portion 51 allows the heat dissipation member 3 to be displaced toward the heat dissipation surface of the semiconductor module 2.

[0026] 3(a) to 3(d) are cross-sectional views showing an assembly process of the power conversion device 1 in the embodiment. For ease of understanding, the drawings will be described based on an enlarged view of a part of the power conversion device 1, which corresponds to region B indicated by a dashed line in FIG. 2.

[0027] 3(a), in step 1, the inside of the pressing portion 52 of the cover 5 and the tip of the heat dissipation fin 8 are joined with brazing material 81 or the like. For the joining, a material with high thermal conductivity is preferably used, and joining by brazing or ultrasonic waves is preferable, but the joining method is not limited to these. By joining the heat dissipation member 3 to the cover 5, heat transfer from the tip of the heat dissipation fin 8 to the cover is promoted, and the heat dissipation performance of the power conversion device 1 is improved.

[0028] Next, in step 2, as shown in FIG. 3(b), the cover 5 to which the heat dissipation member 3 is joined and the frame 4 are brought close to each other with the opening 41 formed thereon, and then the heat dissipation member 3 is fitted into the opening 41. Prior to this fitting, a first seal member 12 such as an O-ring is installed on the side surface of the base of the heat dissipation member 3 joined to the cover 5, and a second seal member 13 such as an O-ring is installed on the connection portion 10 between the lower water channel and the upper water channel. In addition, an adhesive or the like is applied in advance to the adhesive portion 66 between the frame 4 and the cover 5. The frame 4 is formed with an opening 41 into which the heat dissipation member 3 is fitted toward the frame 4. In other words, the opening 41 of the frame 4 is formed so that the heat dissipation member 3 can be attached and detached toward the cover 5 side.

[0029] Then, the frame 4 is brought close to the cover 5, and the heat dissipation member 3 is fitted to the inner peripheral surface of the opening 41 via the first seal member 12. This fitting closes the opening 41, and the frame 4 and the cover 5 are bonded together at the adhesive portion 66, maintaining watertightness. Although not shown, the frame 4 and the cover 5 on the lower side of the power conversion device 1 are also similarly formed with the cover 5 to which the heat dissipation member 3 is joined, and the frame 4 is brought close to each other, the heat dissipation member 3 is fitted into the opening 41, and the frame 4 and the cover 5 are bonded together at the adhesive portion 66.

[0030] 3(c), in step 3, the heat dissipation member 3 is brought into contact with the heat dissipation surfaces on both sides of the multiple semiconductor modules 2 mounted on the substrate 6 via the heat conductive member 7, and the connecting parts 10 are connected via the second seal member 13. Specifically, the substrate 6 on which the semiconductor modules 2 are mounted is placed on the lower frame 4 on which the heat dissipation member 3 is fitted, and then the upper frame 4 on which the heat dissipation member 3 is fitted is placed on the substrate 6. Note that in the figure, the semiconductor modules 2 are shown with different thicknesses assuming that there is variation in the thickness of the semiconductor modules 2.

[0031] Next, in step 4, as shown in FIG. 3(d), the fixing member 11 is placed on the fixing portion 51 of the cover 5, and the heat dissipation member 3, the frame 4, the cover 5, etc., which are assembled on both sides of the semiconductor module 2, are fixed from both sides. By this fixing, the pressing force applied to the fixing portion 51 of the cover 5 is transmitted to the pressing portion 52 via the elastic portion 53, and the heat dissipation member 3 joined to the inside of the pressing portion 52 is pressed toward the semiconductor module 2. The heat dissipation member 3 is supported by the frame 4 via the first seal member 12 so as to be displaceable toward the heat dissipation surface of the semiconductor module 2. That is, the heat dissipation member 3 joined to the cover 5 can be pressed down toward the heat dissipation surface of the semiconductor module 2 by the elasticity of the elastic portion 53 of the cover 5, and the heat dissipation member 3 itself is supported by the frame 4 via the first seal member 12, so that it can be displaced toward the heat dissipation surface of the semiconductor module 2.

[0032] The amount of displacement of the heat dissipation member 3 is determined by the balance of the pressing force from the fixing member 11, the reaction force of the elastic portion 53, and the reaction forces from the semiconductor module 2 and the heat conductive member 7, i.e., the surface pressure. By making the pressing force larger than a predetermined value, the elastic portion 53 deforms and the heat dissipation member 3 is displaced until the surface pressure of the semiconductor module 2 reaches a predetermined value, even in a semiconductor module 2 with a relatively thin thickness. This reduces the influence of variations in the thickness of the semiconductor module 2, and significantly improves the heat dissipation performance of the power conversion device 1. The effects of this embodiment are described below.

[0033] According to this embodiment, the tips of the heat dissipation fins 8 and the cover 5 are joined by brazing, ultrasonic waves, or the like, which promotes heat transfer from the tips of the heat dissipation fins 8 to the cover 5. This expands the effective heat dissipation area of ​​the cover 5 that contributes to heat dissipation to the cooling water, improving heat dissipation performance.

[0034] Furthermore, when joining the tips of the heat dissipation fins 8 and the cover 5, if the heat dissipation member 3 and the semiconductor module 2 are assembled together before joining, there is a risk that the high temperature during joining may exceed the heat resistance temperature of the semiconductor module 2. In this embodiment, the tips of the heat dissipation fins 8 and the cover 5 are joined before the semiconductor module 2 is assembled, so there is no need to consider the heat resistance temperature of the semiconductor module 2 during joining. Then, after joining, the first seal member 12 is installed on the side of the base of the heat dissipation member 3 and fitted into the inner peripheral surface of the opening 41, thereby improving assembly while ensuring watertightness.

[0035] Furthermore, by making the first seal member 12 out of an elastic member such as rubber, it is possible to absorb any misalignment between the heat dissipation member 3 and the opening 41 during assembly. Since the first seal member 12 is deformable in response to the relative displacement between the outer periphery of the heat dissipation member 3 and the inner periphery of the opening 41, it is possible to absorb any misalignment within the allowable range of the minimum amount of crushing required to make the opening 41 watertight.

[0036] Furthermore, in this embodiment, the heat dissipation member 3 joined to the cover 5 is pressed against the heat dissipation surface of the semiconductor module 2 by the elasticity of the elastic portion 53 of the cover 5 and the displacement of the first seal member 12. If this embodiment is not applied, for example, if the heat dissipation member 3 is fixed integrally to the frame 4, an excessive force is applied to the semiconductor module 2 due to manufacturing variations in the semiconductor module 2, and the semiconductor module 2 is damaged. On the other hand, if the semiconductor module 2 is thin, the thermal resistance between the heat dissipation surface of the semiconductor module 2 and the heat dissipation member 3 becomes large, and the heat dissipation performance of the power conversion device 1 is deteriorated. A power conversion device 1 in which a plurality of semiconductor modules 2 are provided in parallel also has a similar problem due to the variation in the thickness of the semiconductor modules 2. According to this embodiment, even if the thickness of the semiconductor module 2 varies, the surface pressure on the semiconductor module 2 is kept uniform, and the contact thermal resistance of the heat dissipation surface of the semiconductor module 2 and the heat conductive member 7 can be kept low. Furthermore, even if the heat dissipating member 3 is displaced, the tips of the heat dissipating fins 8 and the cover 5 are joined together, so the thickness of the water passage does not change and the flow of the cooling water is not impeded.

[0037] The thickness of the elastic portion 53 of the cover 5 may be thinner than other portions of the cover 5. By making the thickness thinner, the amount of elastic deformation of the elastic portion 53 increases, and the range in which the elastic portion 53 can accommodate variations in the thickness of the semiconductor modules 2 can be increased. As a result, when a plurality of semiconductor modules 2 are provided in parallel, even if the thicknesses of the plurality of semiconductor modules 2 vary greatly, each heat dissipation member 3 deforms up and down according to the variations in the thickness of the semiconductor modules 2, so that the surface pressure on the semiconductor modules 2 is kept uniform, and the contact thermal resistance of the heat dissipation surface of the semiconductor modules 2 and the heat conductive member 7 can be kept low.

[0038] (Variation 1) Fig. 4 is an enlarged cross-sectional view of the power conversion device 1 in the modified example 1. This enlarged cross-sectional view corresponds to the cross section along the line A-A' in Fig. 1, and corresponds to the region B indicated by the dashed line in Fig. 2, as in Fig. 3(d). The same reference numerals are used to designate the same parts as in Fig. 3(d), and their description will be simplified.

[0039] 4, in Modification 1, the elastic portion 53 of the cover 5 has a bellows structure. By making the elastic portion 53 have a bellows structure, the amount of elastic deformation of the elastic portion 53 increases.

[0040] According to variant example 1, the range in which the semiconductor module 2 can accommodate thickness variations can be increased, the surface pressure on the heat dissipation surface of the semiconductor module 2 can be maintained, and the contact thermal resistance with the heat dissipation surface and the thermal conductive member 7 can be kept low.

[0041] (Variation 2) Fig. 5 is an enlarged cross-sectional view of the power conversion device 1 in the modified example 2. This enlarged cross-sectional view corresponds to the cross section along the line A-A' in Fig. 1, and corresponds to the region B indicated by the dashed line in Fig. 2, as in Fig. 3(d). The same reference numerals are used to designate the same parts as in Fig. 3(d), and their description will be simplified.

[0042] 5, in the second modification, a groove 54 for positioning the heat dissipating fin 8 is provided inside the pressing portion 52 of the cover 5. The tip of the heat dissipating fin 8 is fitted into the groove 54 and joined.

[0043] According to the second modification, the tip of the heat dissipating fin 8 is fitted and joined in the groove 54, so that the fluctuation of the relative position with respect to the opening 41 of the frame 4 can be reduced when assembling with the frame 4, improving the ease of assembly. Also, the heat transfer from the tip of the heat dissipating fin 8 to the cover 5 is further promoted, the effective heat dissipation area contributing to heat dissipation to the cooling water is enlarged, and the heat dissipation performance is improved. Also, by limiting the joining location to the groove 54, the amount of brazing material can be reduced when joining by brazing, and an increase in flow resistance due to the flow of the brazing material 81 between the heat dissipating fins 8 can be suppressed.

[0044] (Variation 3) Fig. 6 is an enlarged cross-sectional view of the power conversion device 1 in the modified example 3. This enlarged cross-sectional view corresponds to the cross section along the line A-A' in Fig. 1, and corresponds to the region B indicated by the dashed line in Fig. 2, as in Fig. 3(d). The same reference numerals are used to designate the same parts as in Fig. 3(d), and their description will be simplified.

[0045] 6, in the third modification, a protrusion 82 is provided at the tip of the heat dissipation fin 8, and a groove 54 is provided on the surface to which the protrusion 82 of the heat dissipation fin 8 is joined inside the pressing portion 52 of the cover 5. Then, the protrusion 84 of the heat dissipation fin 8 is fitted into and joined to the groove 54 of the cover.

[0046] According to the third modification, the projections 82 at the tips of the heat dissipating fins 8 are fitted and joined into the grooves 54, so that the fluctuation in the relative position with respect to the opening 41 of the frame can be reduced when the fins are assembled to the frame 4, improving the ease of assembly. Also, the heat transfer from the tips of the heat dissipating fins 8 to the cover 5 is promoted, the effective heat dissipation area contributing to the heat dissipation to the cooling water is enlarged, and the heat dissipation performance is improved. Also, by limiting the joining points to the grooves 54, the amount of brazing material can be reduced when joining by brazing, and an increase in flow resistance due to the inflow of brazing material between the heat dissipating fins 8 can be suppressed. In addition, the same effect can be obtained by providing a groove at the tip of the heat dissipation fin 8 and a protrusion on the inside of the pressing portion 52 of the cover 5, and joining the protrusion by fitting it into the groove, in contrast to the configuration of variant example 3.

[0047] (Variation 4) Fig. 7 is an enlarged cross-sectional view of the power conversion device 1 in the modified example 4. This enlarged cross-sectional view corresponds to the cross section along the line A-A' in Fig. 1, and corresponds to the region B indicated by the dashed line in Fig. 2, as in Fig. 3(d). The same reference numerals are used to designate the same parts as in Fig. 3(d), and their description will be simplified.

[0048] 7, in the fourth modification, a groove 55 for holding the brazing material 81 is formed inside the pressing portion 52 of the cover 5. The groove 55 has a width that allows the brazing material 81 to be held by capillary action, and the shape thereof is not limited.

[0049] According to the fourth modification, when the tip of the heat dissipation fin 8 and the inside of the pressing portion 52 are joined by brazing, an appropriate amount of brazing material 81 can be held by capillary action, and excess brazing material 81 is prevented from flowing out between the heat dissipation fins 8. This prevents the flow of cooling water from being impeded, and prevents a decrease in the heat dissipation performance of the power conversion device 1.

[0050] According to the embodiment described above, the following advantageous effects can be obtained. (1) The cooling structure of the power conversion device 1 includes a semiconductor module 2 incorporating a semiconductor element and having a heat dissipation surface on at least one side, a heat dissipation member 3 thermally connected to the heat dissipation surface of the semiconductor module 2 and having heat dissipation fins 8, a frame 4 supporting the heat dissipation member 3, and a cover 5 covering the heat dissipation member 3 and the frame 4 to form water channels W1, W2 passing through the heat dissipation fins 8, the frame 4 has an opening 41 into which the heat dissipation member 3 is fitted toward the frame 4, and a seal member 12 is provided between the fitted heat dissipation member 3 and the opening 41, the heat dissipation member 3 is joined to the cover 5 at the tip of the heat dissipation fin 8, and is configured to be displaceable toward the heat dissipation surface of the semiconductor module 2 by a pressing force applied to the cover 5. This improves the heat dissipation performance of the power conversion device.

[0051] The present invention is not limited to the above-described embodiment, and other embodiments that are conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention as long as they do not impair the characteristics of the present invention. In addition, the above-described embodiment may be combined with a number of modified examples. [Explanation of symbols]

[0052] 1...power conversion device, 2, 21-26...semiconductor module, 3, 31-36...heat dissipation member, 4...frame, 5...cover, 6...substrate, 8...heat dissipation fin, 10...connecting portion, 11...fixing member, 12...first sealing member, 13...second sealing member, 41...opening, 51...fixing portion, 52...pressing portion, 52...elastic portion, 54, 55...groove portion, 58...inlet pipe, 59...outlet pipe, 66...adhesive portion, 81...soldering material, 82...projection portion, W1, W2...water channel.

Claims

1. a semiconductor module incorporating a semiconductor element and having a heat dissipation surface on at least one side thereof; a heat dissipation member having heat dissipation fins and thermally connected to the heat dissipation surface of the semiconductor module; a frame supporting the heat dissipation member; and a cover covering the heat dissipation member and the frame to form a water passage passing through the heat dissipation fins; an opening into which the heat dissipation member is fitted toward the frame is formed in the frame, and a gap between the fitted heat dissipation member and the opening is sealed with a seal member; The heat dissipation member is joined to the cover at the tip of the heat dissipation fin, and is configured to be displaceable toward the heat dissipation surface of the semiconductor module by a pressing force applied to the cover.

2. The cooling structure for a power conversion device according to claim 1, The cover has an elastic portion that biases the cover toward the heat dissipation surface by the pressing force applied to the cover.

3. The cooling structure for the power conversion device according to claim 2, The cover is formed of a plate-like member, A cooling structure for a power conversion device, wherein the elastic portion has a thickness thinner than a thickness of the cover.

4. The cooling structure for the power conversion device according to claim 2, The cooling structure for a power conversion device, wherein the elastic portion has a bellows structure.

5. The cooling structure for a power conversion device according to claim 1, the cover includes a fixed portion to which the pressing force is applied, a pressing portion joined to a tip of the heat dissipation fin, and an elastic portion provided between the fixed portion and the pressing portion, The elastic portion urges the pressing portion toward the heat dissipation surface by the pressing force applied to the fixing portion.

6. The cooling structure for a power conversion device according to claim 1, The sealing member is provided between the inner periphery of the opening and the outer periphery of the heat dissipation member, and is an elastic member that causes the heat dissipation member to be displaced toward the heat dissipation surface of the semiconductor module due to the pressing force.

7. The cooling structure for a power conversion device according to claim 1, The cover has a surface to which the tips of the heat dissipation fins are joined, and a groove into which the tips of the heat dissipation fins are fitted is formed in the surface of the cover.

8. The cooling structure for a power conversion device according to claim 1, The cover has a surface to which the tips of the heat dissipation fins are joined, and a groove for holding brazing material is formed on the surface of the cover.

9. The cooling structure for a power conversion device according to claim 1, The heat dissipation fin has a protrusion at its tip, A cooling structure for a power conversion device, wherein the cover has a groove on a surface to which the tip of the heat dissipation fin is joined, and the protrusion of the heat dissipation fin is fitted into the groove of the cover.

10. The cooling structure for a power conversion device according to any one of claims 1 to 9, The semiconductor modules are provided in parallel in plurality, the cover covers the plurality of semiconductor modules; the frame is formed with openings into which the heat dissipation members provided corresponding to the heat dissipation surfaces of the semiconductor modules are fitted, The cooling structure for a power conversion device is configured so that each of the heat dissipation members is displaceable toward the heat dissipation surface of each of the semiconductor modules by a pressing force applied to the cover.

11. The cooling structure for a power conversion device according to any one of claims 1 to 9, The semiconductor module includes heat dissipation surfaces formed on both sides of the semiconductor element, the heat dissipation members are disposed on both sides of the semiconductor module so as to face the heat dissipation surface, The frame is disposed on both sides to support a heat dissipation member, The cover is a cooling structure for a power conversion device that covers the heat dissipation member and the frame and forms water channels passing through the heat dissipation fins on both sides.

Images