Power conversion device

Abstract

The present invention provides a power conversion device that makes the frame ground wire a simple structure. The power conversion device (10) includes: a semiconductor element (50); a control circuit substrate (60) having a control circuit (61) for controlling the semiconductor element (50); a resin housing (40) that accommodates the semiconductor element (50) and configures the control circuit substrate (60); and a conductive housing (20) that accommodates the resin housing (40). The power conversion device (10) has a conductive component (70) that electrically connects the control circuit substrate (60) and the housing (20). At least a portion of the conductive component (70) is buried in the resin housing (40).

Description

Technical Field

[0001] The present invention relates to an improved technology for a power conversion device. Background Art

[0002] A power conversion device installed in a hybrid vehicle or electric vehicle is placed between the battery and the motor, for example, to control the power stored in the battery and supply it to the motor. In such a power conversion device, the circuit board is electrically connected to a conductive housing to determine the circuit's reference potential. This housing functions as a frame ground. Various frame ground technologies have been proposed (e.g., Patent Document 1).

[0003] The circuit substrate disclosed in Patent Document 1 comprises a wiring substrate having circuit wiring incorporated therein, housed within a conductive housing. A portion of the outer peripheral end surface of the wiring substrate has a plated-side end portion plated with metal. The plated-side end portion, the circuit ground, and the housing are electrically connected via a conductive member. The conductive member is elastic and cantilevered to the inner wall of the housing. The free end of the conductive member elastically contacts the plated-side end portion.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-162083 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In the technology known from Patent Document 1, the structure of the frame ground is complicated and there is room for improvement.

[0009] An object of the present invention is to provide a technology capable of configuring a frame ground with a simple structure.

[0010] Means for solving problems

[0011] In the first aspect of the invention, there is provided a power conversion device comprising:

[0012] semiconductor components;

[0013] a control circuit substrate having a control circuit for controlling the semiconductor element;

[0014] a resin case that houses the semiconductor element and houses the control circuit substrate; and

[0015] A conductive housing that houses the resin casing.

[0016] The power conversion device is characterized in that:

[0017] The power conversion device includes a conductive member that electrically connects the control circuit substrate and the housing.

[0018] At least a portion of the conductive member is embedded in the resin case.

[0019] In the second aspect of the invention, one end portion of the conductive member is electrically connected to and fixed to the case.

[0020] In the third aspect of the invention, when the resin case is viewed toward the housing, the resin case has a rectangular structure, and the portion where the one end portion of the conductive member is fixed to the housing is an edge of the rectangular resin case.

[0021] In the fourth aspect of the invention, the other end portion of the conductive member is fixed to the control circuit substrate via a weld portion.

[0022] In the fifth aspect of the invention, the power conversion device further includes a fixing member that fixes the control circuit substrate to the resin case, and the fixing member is located near the welded portion.

[0023] In the sixth aspect of the invention, the conductive member is formed of a bus bar.

[0024] A portion of the bus bar including the other end portion is configured to be thinner than other portions.

[0025] Effects of the Invention

[0026] In the first aspect of the invention, at least a portion of the conductive component for the frame ground, which electrically connects the control circuit board to the housing, is embedded in the resin housing. For example, when the resin housing is molded, the conductive component can be integrally molded therewith. This allows the conductive component to be securely fixed to the resin housing, and a simple structure can be used to construct the frame ground. Furthermore, when assembling the power conversion device, there is no need to position the conductive component relative to the resin housing.

[0027] In the second aspect of the invention, the one end portion of the conductive member can be reliably fixed to the case.

[0028] In the third aspect of the invention, one end of the conductive component is fixed to the case at the edge of the rectangular resin housing. Therefore, regardless of the location of the conductive component, sufficient space inside the resin housing for housing the semiconductor element and for arranging the control circuit board can be ensured.

[0029] In the fourth aspect of the invention, the other end portion of the frame ground conductive member can be reliably and easily fixed to the control circuit substrate by a soldering process such as flow soldering.

[0030] In the fifth aspect of the invention, since the fixing member for fixing the control circuit substrate to the resin housing is located near the soldering portion, excessive external force is less likely to be applied to the soldering portion when the control circuit substrate vibrates or during the soldering process. Therefore, the reliability of the soldering portion can be improved.

[0031] In the sixth aspect of the invention, a portion of the busbar constituting the conductive member, including the other end portion, is thinner than the rest of the busbar. Therefore, during preheating of the busbar during welding processes such as flow soldering, heat is less likely to be dissipated from the busbar to the housing. As a result, weld quality is improved, resulting in better weld quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a cross-sectional view of the frame ground conductive member and its surroundings of the power conversion device according to the present invention.

[0033] Figure 2 yes Figure 1 A perspective view showing the assembled state of the heat sink, resin case, and control circuit board shown.

[0034] Figure 3 yes Figure 2 Magnified view of the 3 parts.

[0035] Figure 4 yes Figure 3 An exploded perspective view of the heat sink, resin case, and control circuit board shown.

[0036] Description of labels

[0037] 10: Power conversion device; 20: Case; 40: Resin casing; 50: Semiconductor element; 60: Control circuit substrate; 61: Control circuit; 70: Conductive component for frame ground; 70a: One end portion; 70b: Other end portion; 91: Fixing member. DETAILED DESCRIPTION

[0038] Hereinafter, a mode for carrying out the present invention will be described with reference to the accompanying drawings.

[0039] like Figure 1 As shown, the power conversion device 10 is disposed between a battery and a motor, for example, and is mounted in a hybrid vehicle or an electric vehicle to control the power stored in the battery and supply the power to the motor.

[0040] The power conversion device 10 includes: a bottomed housing 20 having conductivity; a conductive flat plate-shaped heat sink 30 located inside the housing 20 and overlapping the inner bottom surface 21; a rectangular resin case 40 integrally formed with the upper surface 31 of the heat sink 30 and housed in the housing 20; a semiconductor element 50 housed in the resin case 40; a control circuit substrate 60 (first substrate 60) disposed on the upper portion of the resin case 40; at least one first conductive member 70; and a plurality of second conductive members 80 (see FIG. 1 ). Figure 2 ).

[0041] The refrigerant flows through a refrigerant path 32 surrounded by the housing 20 and the radiator 30. That is, the radiator 30 also functions as a cover for the refrigerant path 32. The upper opening of the housing 20 is closed by the cover 22.

[0042] As described above, it is preferable that the heat sink 30 and the resin case 40 are an integrally molded product (for example, a die-molded product).

[0043] like Figure 1 and Figure 2 As shown, the resin case 40 is rectangular (including substantially rectangular and substantially square) when viewed toward the housing 20, i.e., rectangular when viewed from above. Furthermore, the resin case 40 is a frame-shaped member open in the vertical direction, and is composed of an outer frame peripheral wall 41 and a partition wall (not shown) that partitions the interior surrounded by the peripheral wall 41.

[0044] Like the resin case 40, the heat sink 30 has a rectangular shape (including a substantially rectangular or substantially square shape) when viewed toward the housing 20, that is, a rectangular shape when viewed from above. A flange 42 is integrally formed around the entire perimeter or a portion of the edge 41a (edge ​​41a of the peripheral wall 41) of the lower end of the resin case 40. This flange 42 extends outward from the edge 41a of the resin case 40 along the upper surface 31 of the heat sink 30. Furthermore, this flange 42 is integrally formed on the upper surface 31 of the heat sink 30 along with the resin case 40.

[0045] Multiple conductive, annular, flanged washers 43 are integrally provided on the flange 42. The heat sink 30 and flange 42 are secured to the inner bottom 21 of the housing 20 via multiple conductive fixing members 44 (first fixing members 44). Preferably, the heat sink 30 and flange 42 are secured to the housing 20 via the multiple fixing members 44 at at least four corners of the rectangular resin housing 40 in plan view. These multiple fixing members 44 are, for example, bolts inserted through the washers 43.

[0046] like Figure 1As shown, the semiconductor element 50 is a power semiconductor with high heat generation, such as an IGBT (insulated gate bipolar transistor), and is mounted on a semiconductor element substrate 51 (second substrate 51). The semiconductor element substrate 51 is provided (mounted) on the upper surface 31 of the heat sink 30. Therefore, the semiconductor element 50 can be cooled by the heat sink 30. For example, a power module is formed by combining the semiconductor element 50 with a freewheeling diode (circuit diode).

[0047] The control circuit substrate 60 includes a plurality of control circuits 61 for controlling the semiconductor element 50. Specifically, a plurality of control circuits 61 (switch control circuits 61) for controlling the switching of the semiconductor element 50 are provided on the board surface 60a of the control circuit substrate 60. For example, if the semiconductor element 50 is an IGBT, the switch control circuit 61 provided on the control circuit substrate 60 comprises a gate drive circuit for driving the gate of the IGBT.

[0048] And, as Figure 1 、 Figure 3 and Figure 4 As shown, the control circuit board 60 has at least one frame ground terminal 62 and a plurality of signal terminals 63 provided on its board surface 60a. The frame ground terminal 62 electrically connects the control circuit 61 to the housing 20 in order to determine a reference voltage (reference potential) for the control circuit 61. The plurality of signal terminals 63 electrically connect the control circuit 61 to the semiconductor device 50. The control circuit board 60 has a plurality of insertion holes 64 located between the frame ground terminal 62 and the plurality of signal terminals 63. These insertion holes 64 extend through each of the terminals 62 and 63.

[0049] The first conductive member 70 is a so-called "frame ground conductive member" that electrically connects the housing 20 and the control circuit board 60. More specifically, one end 70a of the first conductive member 70 is electrically connected to the housing 20, and the other end 70b is electrically connected to the frame ground terminal 62 of the control circuit board 60. Hereinafter, the first conductive member 70 will be referred to as the "frame ground conductive member 70," as appropriate.

[0050] The first conductive component 70 is a busbar (pin) formed from a conductive L-shaped member (e.g., a plate bent into an L-shape). More specifically, the first conductive component 70 comprises a horizontal plate portion 71 positioned on the flange 42 of the resin housing 40 and a vertical plate portion 72 extending upward from the end of the horizontal plate portion 71. At least a portion of the first conductive component 70, namely, the lower half of the vertical plate portion 72 and the horizontal plate portion 71, is embedded in the resin housing 40.

[0051] Specifically, the horizontal plate portion 71 is embedded in the flange 42 of the resin housing 40. However, the distal end portion 71a of the horizontal plate portion 71 is formed as an annular flat plate through which the fixing member 44 can be inserted, and the lower surface of the distal end portion 71a (the surface facing the upper surface 31 of the heat sink 30) is exposed from the resin housing 40. The distal end portion 71a constitutes one end portion 70a of the first conductive member 70.

[0052] The lower surface of the terminal portion 71a, which is exposed from the resin housing 40, overlaps and is electrically connected to the upper surface 31 of the heat sink 30. The terminal portion 71a, along with the flange 42 and the heat sink 30, is fixed to the housing 20 via the fixing member 44. As a result, the one end portion 70a of the first conductive member 70 is electrically connected and fixed to the housing 20.

[0053] The lower half 72a of the vertical plate portion 72 is embedded in the peripheral wall 41 of the resin case 40. The upper half 72b of the vertical plate portion 72, or the upper end portion 72b, protrudes upward from the upper portion of the resin case 40 (the upper end of the peripheral wall 41). The upper end portion 72b is the portion of the vertical plate portion 72 extending from the upper end (terminal end) to a position below the control circuit board 60. The upper end portion 72b constitutes the other end portion 70b of the first conductive member 70.

[0054] The upper end portion 72b is configured to be thinner (eg, narrower) than the lower half portion 72a. Therefore, a portion of the first conductive member 70 including at least the other end portion 70b is configured to be thinner than the other portions 71 and 72a.

[0055] The upper end portion 72b is inserted into the insertion hole 64 of the frame ground terminal 62 and is Figure 1 The solder portion 65 (also referred to as a solder part 65 or a solder layer 65 ) is fixed to the frame ground terminal 62 . As a result, the other end portion 70 b of the first conductive member 70 is fixed to the control circuit board 60 via the solder portion 65 .

[0056] like Figure 1 and Figure 3 As shown, the control circuit 61 is connected to the housing 20 via the frame ground terminal 62 , the first conductive member 70 , and the heat sink 30 , so that the voltage reference (reference potential) of the control circuit 61 can be determined using the housing 20 as the frame ground.

[0057] like Figure 3 and Figure 4 As shown, the plurality of second conductive components 80 are used to connect the control circuit substrate 60 and the semiconductor element 50 (see Figure 1) are so-called "control signal conductive members" electrically connected to the control circuit substrate 60. More specifically, one end portion (not shown) of a plurality of second conductive members 80 is electrically connected to the semiconductor element 50, and the other end portions 80a are electrically connected to the plurality of signal terminals 63 of the control circuit substrate 60. The number of second conductive members 80 is the same as the number of signal terminals 63. The second conductive members 80 are appropriately referred to as "control signal conductive members 80."

[0058] The plurality of second conductive components 80 all have the same structure and are each formed of a bus bar (pin) made of a conductive, elongated plate. The lower half of the second conductive component 80 is embedded in the resin housing 40. The upper half 80a, or the other end 80a, of the second conductive component 80 protrudes upward from the upper portion of the resin housing 40 (the upper end of the peripheral wall 41) and is thinner than the remaining portion of the second conductive component 80.

[0059] The other end portions 80 a are inserted into the insertion holes 64 of the signal terminals 63 and fixed to the signal terminals 63 via solder portions 65 (also referred to as soldering parts 65 or soldering layers 65 ).

[0060] like Figure 1 and Figure 2 As shown, the control circuit board 60 is fixed to the resin case 40 via fixing members 91 (second fixing members 91). The fixing members 91 are located near at least one of the welding portions 65. Specifically, the resin case 40 has a plurality of bosses 92 protruding upward from the upper end of the peripheral wall 41. The control circuit board 60 is fixed to the upper end surfaces of the bosses 92 via the fixing members 91. A plurality of through-holes 66 are formed at the four corners of the control circuit board 60, through which the fixing members 91 can be inserted. The fixing members 91 are formed by small screws that are threadedly fastened to the upper end surfaces of the bosses 92.

[0061] Based on the above description, the following is described.

[0062] like Figures 1 to 4 As shown, the power conversion device 10 includes:

[0063] semiconductor element 50;

[0064] a control circuit substrate 60 including a control circuit 61 for controlling the semiconductor element 50;

[0065] a resin housing 40 that houses the semiconductor element 50 and is provided with the control circuit substrate 60; and

[0066] The conductive housing 20 houses the resin case 40.

[0067] The power conversion device 10 includes a conductive member 70 (first conductive member 70 ) that electrically connects the control circuit substrate 60 and the housing 20 .

[0068] At least a portion of the conductive member 70 is embedded in the resin case 40 .

[0069] In this manner, at least a portion of the frame ground conductive component 70, which electrically connects the control circuit board 60 to the housing 20, is embedded in the resin housing 40. For example, when molding the resin housing 40, the conductive component 70 can be integrally molded therewith. This allows the conductive component 70 to be securely fixed to the resin housing 40, while also providing a simple structure for forming the frame ground. Furthermore, when assembling the power conversion device 10, there is no need to position the conductive component 70 relative to the resin housing 40.

[0070] Furthermore, the one end portion 70a of the conductive member 70 is electrically connected and fixed to the housing 20. Therefore, the one end portion 70a of the conductive member 70 can be reliably fixed to the housing 20.

[0071] Furthermore, when the resin housing 40 is viewed toward the housing 20, the resin housing 40 has a rectangular structure (see Figure 2 ), the portion where the one end portion 70a of the conductive component 70 is fixed to the box body 20 is the edge 41a of the rectangular resin housing 40 (that is, the flange 42 provided at the edge 41a).

[0072] In this manner, one end portion 70a of the conductive member 70 is fixed to the housing 20 at the edge 41a of the rectangular resin case 40. Therefore, regardless of the fixing position of the conductive member 70, sufficient space inside the resin case 40 for accommodating the semiconductor element 50 and sufficient space for arranging the control circuit board 60 can be ensured.

[0073] Furthermore, the other end portion 70b of the conductive member 70 is fixed to the control circuit board 60 via the soldering portion 65. Therefore, the other end portion 70b of the frame ground conductive member 70 can be reliably and easily fixed to the control circuit board 60 by a soldering process such as flow soldering.

[0074] The power conversion device 10 further includes a fixing member 91 (second fixing member 91) for fixing the control circuit board 60 to the resin case 40. The fixing member 91 is located near the soldering portion 65 (for example, near the soldering portion 65 to which the frame ground terminal 62 is fixed).

[0075] In this manner, since the fixing member 91 that fixes the control circuit board 60 to the resin case 40 is located near the soldered portion 65, when the control circuit board 60 vibrates or when the soldering process is performed, excessive external force is less likely to be applied to the soldered portion 65. Therefore, the reliability of the soldered portion 65 can be improved.

[0076] Furthermore, the conductive member 70 is composed of a bus bar.

[0077] A portion of the bus bar 70 (conductive member 70 ) including the other end portion 70 b is configured to be thinner than other portions 71 and 72 a .

[0078] Thus, a portion of the busbar constituting the conductive member 70, including the other end portion 70b, is thinner than the other portions 71 and 72a. Therefore, during preheating of the busbar during welding processes such as flow soldering, heat is less likely to be dissipated from the busbar to the housing 20. As a result, welding is performed more efficiently, improving the quality of the welded portion.

[0079] Industrial applicability

[0080] The present invention is suitable for a power conversion device mounted in a vehicle.

Claims

1. A power conversion device, comprising: semiconductor components; a control circuit substrate having a control circuit for controlling the semiconductor element; a resin housing that houses the semiconductor element and houses the control circuit substrate; and A conductive housing that houses the resin casing. The power conversion device is characterized in that: The power conversion device includes a conductive member that electrically connects the control circuit substrate and the housing. At least a portion of the conductive member is embedded in the resin housing. The power conversion device includes a conductive heat sink for cooling the semiconductor element. The heat sink and the resin housing are integrally formed. The heat sink is located inside the box and overlaps with the inner bottom surface. One end portion of the conductive member is fixed to the housing together with the heat sink by a fixing member, thereby being electrically connected and fixed to the housing.

2. The power conversion device according to claim 1, wherein: When the resin housing is viewed toward the box, the resin housing has a rectangular structure. The portion where the one end portion of the conductive member is fixed to the box is an edge of the rectangular resin case.

3. The power conversion device according to claim 1 or 2, characterized in that: The other end portion of the conductive member is fixed to the control circuit substrate via a soldered portion.

4. The power conversion device according to claim 3, wherein: The power conversion device further includes a fixing member that fixes the control circuit substrate to the resin case. The fixing member is located near the welding portion.

5. The power conversion device according to claim 3, wherein: The conductive component is composed of a bus bar, A portion of the bus bar including the other end portion is configured to be thinner than other portions.

6. The power conversion device according to claim 4, characterized in that The conductive component is composed of a bus bar, A portion of the bus bar including the other end portion is configured to be thinner than other portions.

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