Power conversion device

Abstract

The power conversion device of the present invention includes a plurality of semiconductor packages and a heat dissipation component that is in thermal contact with the plurality of semiconductor packages. The heat dissipation component includes a plurality of heat dissipation fins and a fin base on which the plurality of heat dissipation fins are formed. The power conversion device also includes a frame that can displace and hold the fin base, and a flow path cover that presses the fin base toward the plurality of semiconductor packages. The flow path cover has a convex pressing portion that abuts against the front end of the heat dissipation fin among the plurality of heat dissipation fins that is at a distance of more than a predetermined distance from both ends of the arrangement direction of the plurality of semiconductor packages.

Description

Technical Field

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

[0002] Power conversion devices require high efficiency, miniaturization, and excellent heat dissipation. Patent Document 1 discloses a semiconductor device characterized by comprising: a plate-shaped semiconductor module having a first main surface and a second main surface facing opposite sides; a first heat dissipation member thermally coupled to the first main surface; a second heat dissipation portion having a plate-shaped base arranged parallel to and thermally coupled to the second main surface; and a circuit portion disposed on the second main surface side of the semiconductor module, the base being disposed between the circuit portion and the semiconductor module, defining a connection path for configuring a connection member, the connection member being used to provide an electrical connection between the circuit portion and the semiconductor module.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-028401 Summary of the Invention

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

[0007] In the invention described in Patent Document 1, there is room for improvement in heat dissipation performance.

[0008] Technical solutions to solve technical problems

[0009] The power conversion device according to the first aspect of the present invention includes: a plurality of semiconductor packages; and a heat dissipation member in thermal contact with the plurality of semiconductor packages, the heat dissipation member including a plurality of heat dissipation fins and a fin base on which the plurality of heat dissipation fins are formed, the power conversion device further including: a frame for displaceably holding the fin base; and a flow path cover for pressing the fin base toward the plurality of semiconductor packages, the flow path cover having a convex pressing portion, the pressing portion abutting against the front end of one of the plurality of heat dissipation fins at a distance greater than a predetermined distance from both ends of the plurality of semiconductor packages in the arrangement direction.

[0010] Invention Effects

[0011] According to the present invention, the heat dissipation component can also more easily contact the semiconductor package in the central part, thereby improving heat dissipation. Attached Figure Description

[0012] Figure 1 This is an exploded perspective view of the power conversion device.

[0013] Figure 2This is a cross-sectional view of the power conversion device in Embodiment 1.

[0014] Figure 3 This is a cross-sectional view of the power conversion device in Variation Example 1.

[0015] Figure 4 This is a cross-sectional view of the power conversion device in Variation Example 2.

[0016] Figure 5 This is a cross-sectional view of the power conversion device in Embodiment 2.

[0017] Figure 6 This is a cross-sectional view of the power conversion device in Embodiment 3. Detailed Implementation

[0018] —Implementation Method 1—

[0019] The following reference Figures 1-2 The following describes Embodiment 1 of the power conversion device.

[0020] Figure 1 This is an exploded perspective view of the power conversion device 1. The power conversion device 1 includes an insulating plate 8, a heat dissipation component 3, a frame 4, and a flow path cover 5. Furthermore, although in... Figure 1 Not shown from the perspective of the image, but a semiconductor package 2 is provided at the lower part of the insulating plate 8. Additionally, the TIM (Transformer Insulator) described later is omitted from this figure. The flow path cover 5 is formed of aluminum, copper, stainless steel, etc. The frame 4 and the flow path cover 5 are joined by brazing, laser welding, adhesives, etc. The insulating plate 8 is made of insulating materials such as ceramics and resin.

[0021] The heat dissipation component 3 includes a fin base 31, multiple heat dissipation fins 32, and a flange 33. The heat dissipation component 3 also includes a protrusion 34, which will be described later. Figure 1 Not shown from the perspective of the image. The fin base 31 is thermally connected to the heat dissipation surface of the semiconductor package 2, which is a heat dissipation component, via the insulating plate 8. In addition, although the heat dissipation fins 32 are shown as cylindrical needles, they can also be other shapes, and the shape of the heat dissipation fins 32 is not limited.

[0022] The frame 4 has the same number of openings 41 as the heat dissipation components 3, and the heat dissipation components 3 are fitted into these openings 41. Details regarding the state in which the heat dissipation components 3 are fitted into the openings 41 will be provided in [reference needed]. Figure 2 As explained later. The flow path cover 5 covers the heat dissipation component 3 and the frame 4, thus forming a closed space. This closed space will be referred to as the refrigerant flow path below. The flow path cover 5 has an inlet pipe 93 and an outlet pipe 94, through which the refrigerant flows from the inlet pipe 93 towards the outlet pipe 94, i.e., from left to right in the diagram. The refrigerant passes through the heat dissipation fins 32, thereby allowing heat to be efficiently transferred from the heat dissipation fins 32 to the refrigerant. Detailed information about the flow path cover 5 will be provided in [reference needed].Figure 2 This will be explained later.

[0023] Figure 2 This is a cross-sectional view of the power conversion device 1. Figure 2 yes Figure 1 Sectional view II-II, shown in a section perpendicular to the refrigerant flow direction. The area surrounded by heat dissipation member 3, frame 4, and flow path cover 5 is the refrigerant flow path 90. Figure 2 In the semiconductor package 2, an insulating plate 8 with TIM 81 on both sides is provided between the semiconductor package 2 and the heat dissipation component 3. The heat dissipation component 3 includes a fin base 31, multiple heat dissipation fins 32, a flange portion 33, and a protrusion 34. A sealing component 85 is provided between the flange portion 33 and the frame 4. The sealing component 85 is a flexible component such as an adhesive or a rubber elastic material.

[0024] The fin base 31 is displaceably configured relative to the frame 4 and the flow path cover 5. A pressing part 52 is formed convexly on the flow path cover 5; when fastened by the fastening member 12, the pressing part 52 deforms, applying pressure to the heat dissipation fins 32. The pressing part 52 is provided with... Figure 2 The image shows approximately the center of the semiconductor package 2. This "center of the center" can also be described as a position located at or above a predetermined distance from both ends of the semiconductor package 2's arrangement direction. Due to the presence of this pressing part 52, pressure can be applied evenly to multiple semiconductor packages 2.

[0025] Figure 2 A TIM81 is disposed between the semiconductor package 2 and the heat sink 3, but this is not a necessary component. Adhesives, soldering, brazing, sintering, etc., can be used to replace the TIM81, or the semiconductor package 2 and the heat sink 3 can be directly joined. The insulating plate 8 protrudes laterally in the figure to ensure creepage distance. TIM81, or Thermal Interface Material, is composed of thermally conductive silicone grease, gap-filling materials, etc. The flange 33 of the heat sink 3 is located at the overlap between the fin base 31 and the frame 4, and is connected to the frame 4 via a sealing member 85.

[0026] The protrusion 34 is the area of ​​the fin base 31 that protrudes downwards in the figure. By providing the protrusion 34, a space 34V is formed between the flange 33 and the insulating plate 8. Therefore, when forming the refrigerant flow path 90, even if the flange 33 is deformed by a large force from the flow path cover 5 and the frame 4, as long as its deformation converges within the space 34V, the flange 33 will not contact the insulating plate 8. If the deformed flange 33 contacts the insulating plate 8, a large load may cause the insulating plate 8 to break, specifically, it may cause cracks. Therefore, it can be said that the presence of the flange 33 helps to prevent the insulating plate 8 from breaking.

[0027] The pressing part 52 is disposed in the forming area of ​​the heat dissipation fins 32. Figure 2 The approximate central portion as seen from the perspective of the heat sink 32. By setting the lateral length of the pressing part 52 in the figure to less than half the total length of the area where the heat sink fins 32 are formed, the pressure applied to the heat sink fins 32 will be shifted towards the central portion, making it easier to apply pressure to the semiconductor package 2 in the central portion. Without the pressing part 52, since only the two ends of the heat sink fins 32 are fixed, it is difficult to apply pressure to the central portion, resulting in insufficient contact between the semiconductor package 2 located near the center and the heat dissipation member 3, which may lead to insufficient heat dissipation.

[0028] The flange portion 33 is made thinner, making it more prone to deformation when fastened to the fastener 11 using the fastening member 12. For example, the flange portion 33 is thinner than the protrusion 34. Therefore, the active deformation of the flange portion 33 reduces warping in other parts of the heat sink 3, especially the central part. Furthermore, because the flange portion 33 is more easily deformable, the displacement of the heat sink fins 32 relative to the frame 4 is increased, improving the fit to package tolerances.

[0029] According to the above-described implementation method 1, the following effects can be obtained.

[0030] (1) The power conversion device 1 includes a plurality of semiconductor packages 2 and a heat dissipation member 3 in thermal contact with the plurality of semiconductor packages 2. The heat dissipation member 3 includes a plurality of heat dissipation fins 32 and a fin base 31 on which the plurality of heat dissipation fins 32 are formed. The power conversion device 1 also includes a frame 4 for displaceably holding the fin base 31 and a flow path cover 5 for pressing the fin base 31 toward the plurality of semiconductor packages 2. The flow path cover 5 has a convex pressing portion 52 that abuts against the front end of the heat dissipation fin 32 of the plurality of heat dissipation fins 32 at a predetermined distance from both ends of the plurality of semiconductor packages 2 in the arrangement direction. Therefore, the heat dissipation member 3 can also more easily contact the central semiconductor package 2, thereby improving heat dissipation performance.

[0031] (2) Multiple semiconductor packages 2 are in thermal contact with the heat dissipation member 3 via an insulating plate 8. The fin base 31 has a flange 33 that overlaps with the frame 4 in the thickness direction, and a protrusion 34 that protrudes further toward the insulating plate 8 than the flange 33 and abuts against the insulating plate 8. This prevents damage to the insulating plate 8.

[0032] (3) The length of the pressing part 52 along the arrangement direction is less than 1 / 2 of the total length of the area where the multiple heat dissipation fins 32 are formed. If the pressing part 52 is too long, for example, covering the entire width of the heat dissipation fins 32, the whole thing will be pressed down, resulting in a weakening of the pressing force in the central part. Therefore, the length of the pressing part 52 is preferably less than approximately 1 / 2 of the total length of the area where the multiple heat dissipation fins 32 are formed.

[0033] (4) The pressing part 52 is located approximately in the center of the flow path cover 5 in the arrangement direction. Therefore, it is possible to clearly see the central part where the pressing force weakens when only the two ends are fixed.

[0034] (5) The thickness of the flange portion 33 is made thinner than that of the protrusion portion 34. Therefore, the flange portion 33 actively deforms, thereby reducing the warping of other parts of the heat dissipation component 3, especially the warping of the central part.

[0035] Figure 3 This is a cross-sectional view of the power conversion device 1 in Modified Example 1. (Compared to the one in Embodiment 1) Figure 2 The difference lies in that the sealing member 85 is changed to a fixed sealing member 85a. The fixed sealing member 85a is a metal joint formed by brazing filler metal or the like. However, the fixed sealing member 85a is not a necessary component, and friction stir welding or fusion welding can also be used. In Embodiment 1, a highly flexible sealing member 85 is used, but since the flange portion 33 is deformable, the displacement of the heat dissipation fins 32 can be ensured even when a fixed sealing member 85a is used.

[0036] According to this modified example, the following effects can be achieved.

[0037] (6) The flange 33 is metal-joined with the frame 4. Therefore, the number of components in the power conversion device 1 can be reduced.

[0038] (Variation Example 2)

[0039] Figure 4 This is a cross-sectional view of the power conversion device 1 in Modified Example 2. It is different from the one in Embodiment 1. Figure 2 The difference lies in that the heat dissipation component 3 does not have a flange 33 and a protrusion 34, but instead has a sealing groove 86. The sealing groove 86 is equipped with a sealing component 87. The sealing component 87 is, for example, an O-ring.

[0040] According to this modified example, the following effects can be achieved.

[0041] (7) At least one of the fin base 31 and the frame 4 has a sealing groove 86 for configuring the sealing member 85. The fin base 31 and the frame 4 are axially sealed via the sealing member 87. Therefore, there is no need to apply liquid sealing material, thus simplifying the manufacturing process. In addition, the fins can still move in the axially sealed state, thus ensuring adaptability to package thickness tolerances.

[0042] In addition, in this modified example, the sealing groove 86 is provided on the heat dissipation member 3, but the sealing groove 86 can also be provided on the frame 4, or the sealing groove 86 can be provided on both the heat dissipation member 3 and the frame 4.

[0043] —Implementation Method 2—

[0044] Reference Figure 5Embodiment 2 of the power conversion device will be described below. In the following description, the same reference numerals are used for the same components as in Embodiment 1, and the main differences will be explained. Points not specifically described are the same as in Embodiment 1. The main difference between this embodiment and Embodiment 1 is that the semiconductor package is mounted on a printed circuit board.

[0045] Figure 5 This is a cross-sectional view of the power conversion device 1A in Embodiment 2. It differs from that in Embodiment 1. Figure 2 The difference lies in the addition of a printed circuit board 800. The printed circuit board 800 has a wiring pattern 810 forming the inverter circuit. The wiring pattern 810 is formed on multiple layers along the surface of the printed circuit board 800. Furthermore, the printed circuit board 800 has through-holes 820 that are electrically and thermally connected to the wiring pattern 810. The through-holes 820 are holes extending along the thickness direction of the printed circuit board 800, and a metal film is formed inside the holes. Additionally, the semiconductor package 2 in this embodiment is used for the inverter circuit and is connected to the printed circuit board 800 via wiring (not shown).

[0046] Each semiconductor package 2 includes a semiconductor element 201, a first conductor 202, a second conductor 203, and a molding resin 204. A bonding member, such as solder, is provided between the semiconductor element 201 and the first conductor 202 and the second conductor 203. The molding resin 204 covers the semiconductor element 201, the first conductor 202, and the second conductor 203, but the upper end face of the first conductor 202 and the lower end face of the second conductor 203 are exposed. Therefore, the heat generated by the semiconductor element 201 is dissipated above the semiconductor element 201 via the first conductor 202 and the insulating plate 8 to the heat dissipation member 3, and below the semiconductor element 201 via the second conductor 203 to the printed circuit board 800.

[0047] According to the above-described embodiment 2, the following effects can be obtained.

[0048] (8) The power conversion device 1A includes a printed circuit board 800 having multiple wiring patterns 810 forming inverter circuits. Multiple semiconductor packages 2 are mounted on the printed circuit board 800 in a row. Therefore, low inductance of the printed circuit board 800 can be achieved. In addition, the power conversion device 1A including the printed circuit board 800 can be miniaturized and is easy to install.

[0049] —Implementation Method 3—

[0050] Reference Figure 6 Embodiment 3 of the power conversion device will be described below. In the following description, the same reference numerals are used for the same components as in Embodiment 2, and the main differences will be explained. Points not specifically described are the same as in Embodiment 2. The main difference between this embodiment and Embodiment 2 is that both sides of the semiconductor package 2 are cooled.

[0051] Figure 6 This is a cross-sectional view of the power conversion device 1B in Embodiment 3. Compared to Embodiment 2... Figure 5 The difference lies in the fact that the lower part of the printed circuit board 800 also has a structure for heat dissipation using a refrigerant. That is, Figure 6 The structure of the upper part, including the semiconductor package 2, is the same as in Embodiment 2. In the following text, the surface above the semiconductor package 2 in the illustration is referred to as the first surface 2a, and the surface below the illustration is referred to as the second surface 2b. The second surface 2b is also referred to as the surface opposite to the first surface 2a.

[0052] The power conversion device 1B includes two identical heat dissipation components 3, namely, a first heat dissipation component 3a and a second heat dissipation component 3b. The power conversion device 1B also includes two identical frames 4, namely, a first frame 4a and a second frame 4b. Furthermore, the power conversion device 1B includes two identical flow path covers 5, namely, a first flow path cover 5a and a second flow path cover 5b. The first heat dissipation component 3a, the first frame 4a, and the first flow path cover 5a form a flow path for refrigerant to dissipate heat emitted from the first surface 2a of the semiconductor package 2. The second heat dissipation component 3b, the second frame 4b, and the second flow path cover 5b form a flow path for refrigerant to dissipate heat emitted from the second surface 2b of the semiconductor package 2.

[0053] According to the above-described embodiment 3, the following effects can be obtained.

[0054] (9) A plurality of semiconductor packages 2 have a first surface 2a and a second surface 2b opposite to the first surface 2a. A heat dissipation member 3 includes a first heat dissipation member 3a for dissipating heat emitted from the first surface 2a and a second heat dissipation member 3b for dissipating heat emitted from the second surface 2b. A frame 4 includes a first frame 4a in contact with the first heat dissipation member 3a and a second frame 4b in contact with the second heat dissipation member 3b. A flow path cover 5 includes a first flow path cover 5a in contact with the first heat dissipation member 3a and the first frame 4a, and a second flow path cover 5b in contact with the second heat dissipation member 3b and the second frame 4b. The second surface 2b of the plurality of semiconductor packages 2 is in thermal contact with the second heat dissipation member 3b via a printed circuit board 800. Therefore, the semiconductor packages 2 can be cooled from both sides.

[0055] The above-described embodiments and modifications can be combined separately. Various embodiments and modifications have been described above, but the present invention is not limited to these. Other embodiments conceivable within the scope of the inventive concept are also included within the scope of the present invention.

[0056] Label Explanation

[0057] 1, 1A, 1B: Power conversion devices

[0058] 2: Semiconductor Packaging

[0059] 3: Heat dissipation components

[0060] 4: Framework

[0061] 5: Flow path cover

[0062] 8: Insulation board

[0063] 31: Fin base

[0064] 32: Heat dissipation fins

[0065] 33: Flange portion

[0066] 34: Protrusion

[0067] 52: Pressing part

[0068] 86: Sealing groove

[0069] 201: Semiconductor Components

[0070] 800: Printed substrate

[0071] 810: Wiring pattern

[0072] 820: Through hole.

Claims

1. A power conversion device, characterized in that, include: Multiple semiconductor packages; as well as Heat dissipation components that are in thermal contact with the plurality of semiconductor packages, The heat dissipation component includes multiple heat dissipation fins and a fin base on which the multiple heat dissipation fins are formed. The power conversion device further includes: A frame that can be displaced to hold the fin base; as well as The fin base is pressed toward the flow path cover of the plurality of semiconductor packages. The flow path cover has a convex pressing part that abuts against the front end of one of the plurality of heat dissipation fins that is at a distance greater than a predetermined distance from both ends of the plurality of semiconductor packages in the arrangement direction.

2. The power conversion device as described in claim 1, characterized in that, The plurality of semiconductor packages are in thermal contact with the heat dissipation component via an insulating plate. The fin base has a flange portion that overlaps with the frame in the plate thickness direction, and a protrusion portion that protrudes further toward the insulating plate than the flange portion and abuts against the insulating plate.

3. The power conversion device as described in claim 1, characterized in that, The length of the pressing portion along the arrangement direction is less than 1 / 2 of the total length of the area where the plurality of heat dissipation fins are formed.

4. The power conversion device as described in claim 1, characterized in that, The pressing part is located approximately at the center of the arrangement direction in the flow path cover.

5. The power conversion device as described in claim 2, characterized in that, The flange portion is made thinner than the protrusion portion.

6. The power conversion device as described in claim 5, characterized in that, The flange is metal-jointed to the frame.

7. The power conversion device as claimed in claim 1, characterized in that, At least one of the fin base and the frame has a groove for sealing material. The fin base and the frame are sealed axially by the sealing material.

8. The power conversion device as claimed in claim 1, characterized in that, It also includes a printed circuit board having multiple wiring patterns forming the inverter circuitry. The plurality of semiconductor packages are arranged in a row and mounted on the printed substrate.

9. The power conversion device as described in claim 8, characterized in that, The plurality of semiconductor packages have a first side and a second side opposite to the first side. The heat dissipation component includes a first heat dissipation component for dissipating heat released from the first surface and a second heat dissipation component for dissipating heat released from the second surface. The frame includes a first frame that contacts the first heat dissipation component and a second frame that contacts the second heat dissipation component. The flow path cover includes a first flow path cover that contacts the first heat dissipation component and the first frame, and a second flow path cover that contacts the second heat dissipation component and the second frame. The second side of the plurality of semiconductor packages is in thermal contact with the second heat dissipation member via the printed substrate.

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