Circuit device and electromechanical integrated unit

Abstract

The present invention effectively dissipates heat from a circuit board of a circuit device. A circuit device (1) is provided with: a circuit board (2) that includes a circuit component (25) for driving a motor; a case (3) that accommodates the circuit board (2); and a heat transfer member (4) that is accommodated in the case (3) and is thermally connected to the circuit board (2). The case (3) includes a peripheral wall section (32) and a heat sink (34) coupled to the peripheral wall section (32). At least a portion of the circuit board (2) is positioned between the heat sink (34) and the heat transfer member (4). The heat transfer member (4) is thermally connected to the heat sink (34) and at least a portion of the circuit board (2).

Description

Circuit device and electromechanical integrated unit

[0001] The present disclosure relates to a circuit device and an electromechanical integrated unit.

[0002] Patent Document 1 discloses a device equipped with a circuit board for driving a motor. This device includes a support member for transferring heat from a heat generating element included in the circuit board to a heat sink, and the support member is in contact with the surface of the heat generating element facing the heat sink.

[0003] JP 2017-123700 A

[0004] In the above-mentioned conventional techniques, there are cases where heat transfer from the circuit board to the heat sink is insufficient.

[0005] An object of the present disclosure is to provide a circuit device and an electromechanical integrated unit that can effectively dissipate heat from a circuit board.

[0006] A circuit device according to one aspect of the present disclosure includes a circuit board including circuit components for driving a motor, a case that houses the circuit board, and a heat transfer member housed within the case and thermally connected to the circuit board. The case includes a peripheral wall and a heat sink coupled to the peripheral wall. At least a portion of the circuit board is located between the heat sink and the heat transfer member. The heat transfer member is thermally connected to the heat sink and at least the portion of the circuit board.

[0007] An electromechanical integrated unit according to one aspect of the present disclosure includes the circuit device and a motor device connected to the case of the circuit device.

[0008] FIG. 1 is a perspective view showing an electromechanical integrated unit according to one embodiment. FIG. 2 is an exploded perspective view showing a circuit device included in the electromechanical integrated unit. FIG. 3 is a bottom view showing a main portion of the circuit device. FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3. FIG. 5 is an exploded perspective view showing further main portions of the circuit device. FIG. 6 is an exploded perspective view showing a circuit device included in an electromechanical integrated unit according to a first modified example. FIG. 7 is a bottom view showing the main portion of the circuit device. FIG. 8 is a cross-sectional view taken along line B-B in FIG. 7. FIG. 9 is a cross-sectional view taken along line C-C in FIG. 7. FIG. 10 is an exploded perspective view showing further main portions of the circuit device. FIG. 11A is a perspective view showing a heat transfer member included in an electromechanical integrated unit according to a second modified example, and FIG. 11B is another perspective view showing the heat transfer member. FIG. 12 is a perspective view showing an electromechanical integrated unit according to a third modified example. FIG. 13 is a cross-sectional view of a circuit device included in an electromechanical integrated unit according to a fourth modified example. FIG. 14 is a cross-sectional view of a circuit device included in an electromechanical integrated unit according to a fifth modified example. Fig. 15 is a cross-sectional view of a circuit device provided in an electromechanical integrated unit according to a sixth modified example, Fig. 16 is a cross-sectional view of a circuit device provided in an electromechanical integrated unit according to a seventh modified example, and Fig. 17 is a cross-sectional view of a circuit device provided in an electromechanical integrated unit according to an eighth modified example.

[0009] The circuit device and electromechanical integrated unit of the present disclosure will be described below with reference to the accompanying drawings. The drawings referred to in the following embodiments are all schematic diagrams. Therefore, the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0010] 1. Embodiments (1) Overall Structure of Electromechanical Integrated Unit Fig. 1 shows the entire electromechanical integrated unit 9 of one embodiment. The electromechanical integrated unit 9 of one embodiment integrally includes a circuit device 1 and a motor device 8 driven by the circuit device 1. The circuit device 1 and the motor device 8 are mechanically and electrically connected. The circuit device 1 supplies power to the motor device 8, and drives the motor device 8 with the supplied power. The circuit device 1 controls the operation of the motor device 8 by controlling the power supplied to the motor device 8.

[0011] (2) Circuit Device Fig. 2 shows a circuit device 1 according to one embodiment. The circuit device 1 includes a circuit board 2, a case 3 that houses the circuit board 2, and a heat transfer member 4. The heat transfer member 4 is housed in the case 3 and is thermally connected to the circuit board 2.

[0012] (2-1) Circuit Board The circuit board 2 includes a substrate 20 and a plurality of circuit components 25 (see FIGS. 4 and 5) mounted on the substrate 20. The substrate 20 is a thick, flat substrate, and has a first surface 20A and a second surface 20B facing opposite sides in the thickness direction.

[0013] The first surface 20A and the second surface 20B are both flat, but are not limited to this. Either or both of the first surface 20A and the second surface 20B may be uneven.

[0014] The first surface 20A of the substrate 20 faces a heat sink 34 (described later) included in the case 3. The second surface 20B of the substrate 20 faces a bottom wall 33 (described later) included in the case 3.

[0015] The plurality of circuit components 25 includes elements of a drive circuit and elements of a control circuit. The drive circuit elements include, for example, field effect transistors (hereinafter abbreviated as "FETs") or insulated gate bipolar transistors (hereinafter abbreviated as "IGBTs"). The control circuit elements include, for example, a microcontroller unit (hereinafter abbreviated as "MCU"). The plurality of circuit components 25 are mounted on the first surface 20A of the substrate 20.

[0016] In one embodiment, the plurality of circuit components 25 are mounted only on the first surface 20A of the substrate 20, but this is not limiting. The plurality of circuit components 25 may also be mounted on both the first surface 20A and the second surface 20B of the substrate 20.

[0017] (2-2) Case As shown in Fig. 2, the case 3 includes a peripheral wall portion 32, a bottom wall portion 33, and a heat sink 34. The peripheral wall portion 32 and the bottom wall portion 33 are integrally formed using a thermally conductive material. The thermally conductive material forming the peripheral wall portion 32 and the bottom wall portion 33 is, for example, aluminum, but is not limited to this. The heat sink 34 is formed separately from the peripheral wall portion 32 and the bottom wall portion 33 using a thermally conductive material. The thermally conductive material forming the heat sink 34 is, for example, aluminum, but is not limited to this.

[0018] The peripheral wall portion 32 has a rectangular frame-like outer shape. The peripheral wall portion 32 includes a pair of side walls 321, 322 that face each other. A notch 323 is formed in the edge of the side wall 321, facing the heat sink 34 relative to the peripheral wall portion 32 (hereinafter referred to as the "first direction D1"). Similarly, a notch 324 is formed in the edge of the side wall 322, facing the first direction D1. The notches 323, 324 are each recessed in the direction in which the peripheral wall portion 32 faces the heat sink 34 (hereinafter referred to as the "second direction D2").

[0019] The first orientation D1 and the second orientation D2 are opposite to each other. In other words, the first orientation D1 is the orientation in which the opening 320 is positioned relative to the bottom wall portion 33 of the case 3, and the heat sink 34 is positioned relative to the bottom wall portion 33 of the case 3. In other words, the second orientation D2 is the orientation in which the bottom wall portion 33 is positioned relative to the opening 320 of the case 3, and the bottom wall portion 33 is positioned relative to the heat sink 34 of the case 3.

[0020] The bottom wall portion 33 is formed integrally with the rectangular frame-shaped peripheral wall portion 32 so as to close the opening on the first side of the peripheral wall portion 32. The peripheral wall portion 32 and the bottom wall portion 33 may be formed separately. The peripheral wall portion 32 and the bottom wall portion 33 form a cylindrical case body 31 with a bottom.

[0021] The heat sink 34 includes a flat lid portion 345 coupled to the peripheral wall portion 32, and a plurality of fins 346 protruding in a first direction D1 from the lid portion 345. The plurality of fins 346 protrude in the first direction D1 from the lid portion 345 in parallel to one another.

[0022] The lid portion 345 of the heat sink 34 is coupled to the peripheral wall portion 32 so as to close the opening 320 on the second side of the peripheral wall portion 32. In other words, the heat sink 34 is coupled to the case body 31 so as to close the opening 320 of the case body 31, which is a cylindrical case with a bottom.

[0023] 4, the lid portion 345 is provided with a connection portion 348. The connection portion 348 is a portion that is thermally connected to the circuit board 2. The connection portion 348 is configured as a protrusion that protrudes from the lid portion 345 in the second direction D2.

[0024] The connection portion 348 of the heat sink 34 is thermally connected to at least one circuit component 25 mounted on the circuit board 2. In one embodiment, the connection portion 348 is thermally connected to a plurality of circuit components 25 mounted on the circuit board 2.

[0025] A thermally conductive member 51 is disposed between the connection portion 348 of the heat sink 34 and at least one circuit component 25 of the circuit board 2. The thermally conductive member 51 contacts the connection portion 348 of the heat sink 34 and also contacts a plurality of circuit components 25 (e.g., a plurality of circuit components 25 configured with FETs or IGBTs). The connection portion 348 is thermally connected to the plurality of circuit components 25 via the thermally conductive member 51.

[0026] The thermally conductive member 51 may be, for example, in the form of a sheet. The thermally conductive member 51 may not be disposed between the connection portion 348 of the heat sink 34 and at least one circuit component 25 of the circuit board 2.

[0027] 2 to 5, the heat transfer member 4 is made of a thermally conductive material and is formed separately from the case body 31 and the heat sink 34. The thermally conductive material forming the heat transfer member 4 is, for example, aluminum, but is not limited to this.

[0028] The heat transfer member 4 includes a member body 48 and a connection portion 45 provided on the member body 48. The member body 48 is a portion that is thermally connected to the heat sink 34. The connection portion 45 is a portion that is thermally connected to the circuit board 2.

[0029] The member main body 48 includes a first portion 481 having a long plate shape, a second portion 482 protruding in a first direction D1 from a first longitudinal end of the first portion 481, and a third portion 483 protruding in the first direction D1 from a second longitudinal end of the first portion.

[0030] In one embodiment, the first portion 481, the second portion 482, and the third portion 483 are integrally formed, but are not limited to this. The second portion 482 may be formed separately from the first portion 481, and the third portion 482 may be formed separately from the first portion 481.

[0031] For example, if the first portion 481, the second portion 482, and the third portion 483 are formed separately from one another, the second member 482 and the third member 483, each of which is a spacer formed of a thermally conductive material in a cylindrical or polygonal columnar shape, can be mechanically and thermally connected to the first member 481, which is formed of a thermally conductive material. The second member 482 and the third member 483 can be thermally and mechanically connected to the first portion 481 by an appropriate connecting means. The connecting means is, for example, screw fastening.

[0032] The tip portion 482A of the second portion 482 is bent at a right angle to form an L-shape. Similarly, the tip portion 483A of the third portion 483 is bent at a right angle to form an L-shape. The right angle here includes not only a right angle in the strict sense, but also an angle that can be considered a right angle. The direction in which the tip portion 482A of the second portion 482 bends and extends is opposite to the direction in which the tip portion 483A of the third portion 483 bends and extends.

[0033] In one embodiment, the connection portion 45 of the heat transfer member 4 is configured as a part of the first portion 481. The connection portion 45 has a shape that protrudes in the first direction D1 further than the other part of the first portion 481. In other words, the other part of the first portion 481 is the part of the first portion 481 excluding the connection portion 45.

[0034] The connection portion 45 is thermally connected to the substrate 20 of the circuit board 2. The connection portion 45 is thermally connected to a region on the second surface 20B of the substrate 20 that is located behind at least one circuit component 25. In one embodiment, the connection portion 45 is thermally connected to a region on the second surface 20B of the substrate 20 that is located behind a plurality of circuit components 25 (e.g., a plurality of circuit components 25 configured with FETs or IGBTs).

[0035] A thermally conductive member 52 is disposed between the connection portion 45 of the heat transfer member 4 and the substrate 20. The thermally conductive member 52 is in contact with the connection portion 45 of the heat transfer member 4 and also with the substrate 20. The connection portion 45 is thermally connected to a plurality of circuit components 25 (e.g., a plurality of circuit components 25 configured with FETs or IGBTs) via the thermally conductive member 52 and the substrate 20.

[0036] The thermally conductive member 52 may be, for example, in the form of a sheet. The thermally conductive member 52 may not be disposed between the connecting portion 45 of the heat transfer member 4 and the substrate 20.

[0037] The second portion 482 and the third portion 483 of the heat transfer member 4 are mechanically and thermally connected to the heat sink 34. Specifically, the tip portion 482A of the second portion 482 contacts a surface 345A of the lid portion 345 of the heat sink 34 in the second direction D2, and is mechanically and thermally connected to the surface 345A of the lid portion 345. It is preferable that the tip portion 482A of the second portion 482 directly contacts the lid portion 345, but a thermally conductive member may be interposed between the tip portion 482A of the second portion 482 and the lid portion 345.

[0038] Similarly, the tip portion 483A of the third portion 483 contacts the surface 345A of the lid portion 345 of the heat sink 34 in the second direction D2, and is mechanically and thermally connected to the surface 345A of the lid portion 345. It is preferable that the tip portion 483A of the third portion 483 directly contact the lid portion 345, but a thermally conductive member may be interposed between the tip portion 483A of the third portion 483 and the lid portion 345.

[0039] (2-4) Integrated Product The circuit board 2 and the heat transfer member 4 are joined to the heat sink 34 to form the integrated product 7 shown in Figures 2 to 4. In the integrated product 7, the circuit board 2 including the substrate 20 and the plurality of circuit components 25 is sandwiched between the heat sink 34 and the heat transfer member 4. The circuit board 2 is located between the heat sink 34 and the heat transfer member 4, which is mechanically and thermally connected to the heat sink 34.

[0040] The circuit device 1 of one embodiment is formed by joining the case 3 to the integrated piece 7 (see FIG. 2 ). With the case 3 joined to the integrated piece 7, the protruding portion 482A of the second portion 482 included in the heat transfer member 4 is inserted into the notch 323 in the side wall 321 of the case 3, and the protruding portion 483A of the third portion 483 included in the heat transfer member 4 is inserted into the notch 324 in the side wall 322 of the case 3. It is preferable that the protruding portion 482A of the second portion 482 fits into the notch 323 of the case 3, and the protruding portion 483A of the third portion 483 fits into the notch 324 of the case 3.

[0041] 1, the motor device 8 includes a motor case 82 that forms the outer shell of the motor device 8, and a motor 84 housed in the motor case 82. The motor case 82 is formed using a thermally conductive material. The thermally conductive material forming the motor case 82 is, for example, aluminum, but is not limited to this.

[0042] The motor case 82 is mechanically connected to the case 3 that forms the outer shell of the circuit device 1. In one embodiment, the motor case 82 is thermally connected to the case 3 of the circuit device 1. It is preferable that the motor case 82 be in direct contact with the case 3 of the circuit device 1, but a thermally conductive member may be interposed between the motor case 82 and the case 3 of the circuit device 1.

[0043] The motor 84 is electrically connected to the circuit board 2 housed in the circuit device 1. The motor 84 is driven to rotate by power supplied from the circuit device 1.

[0044] (4) Effects In the electromechanical integrated unit 9 according to the embodiment described above, the heat sink 34 has a connection portion 348 that is thermally connected to the circuit board 2 and a portion that is thermally connected to the heat transfer member 4. Therefore, the paths that thermally connect the circuit board 2 and the heat sink 34 include a first path that directly connects the circuit board 2 to the heat sink 34 without passing through the heat transfer member 4, and a second path that connects the circuit board 2 to the heat sink 34 via the heat transfer member 4. The first path is a path for transferring heat from the front side of the circuit board 2 to the heat sink 34, and the second path is a path for transferring heat from the back side of the circuit board 2 to the heat sink 34. The first path and the second path are independent of each other. In the electromechanical integrated unit 9 according to the embodiment, heat can be effectively transferred from the circuit board 2 to the heat sink 34 through two paths, one on the front side and one on the back side.

[0045] Therefore, according to the electromechanical integrated unit 9 of the embodiment, heat can be effectively dissipated from the circuit board 2 to the outside via the heat sink 34 .

[0046] 2. Modifications The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as in the modifications listed below, as long as the object of the present disclosure can be achieved. In the following description of the modifications, the same components as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0047] 6 to 10 show an integrated element 7 included in a mechanically and electrically integrated unit 9 according to a first modification. In the first modification, the circuit board 2 included in the circuit device 1 includes a first circuit board 21 and a second circuit board 22. The first circuit board 21 and the second circuit board 22 are configured separately from each other and are electrically connected to each other.

[0048] The first circuit board 21 and the second circuit board 22 are positioned parallel to each other. Here, "parallel" includes not only parallel in the strict sense but also a state that can be considered parallel. The first circuit board 21 is positioned in the first direction D1 relative to the second circuit board 22. The distance between the first circuit board 21 and the heat sink 34 is shorter than the distance between the second circuit board 22 and the heat sink 34.

[0049] The first circuit board 21 is a circuit board that constitutes a power circuit for supplying power for driving the motor. The first circuit board 21 includes a substrate 210 and at least one circuit component 25 mounted on the substrate 210. The substrate 210 is a thick, flat substrate having a first surface 210A and a second surface 210B that face opposite each other in the thickness direction.

[0050] The first surface 210A and the second surface 210B are both flat, but are not limited to this. Either or both of the first surface 210A and the second surface 210B may be uneven.

[0051] The first surface 210A of the substrate 210 faces in a first direction D1, in other words, faces the heat sink 34. The second surface 210B of the substrate 210 faces in a second direction D2, in other words, faces the second circuit board 22.

[0052] At least one circuit component 25 mounted on the first circuit board 21 is, for example, a FET. In the first modification, a plurality of circuit components 25 are mounted on the first surface 210A of the substrate 210.

[0053] The second circuit board 22 is a circuit board that constitutes a control circuit for operating the power circuit. The second circuit board 22 includes a substrate 220 and at least one circuit component 25 mounted on the substrate 220. The substrate 220 is a thick, flat substrate having a first surface 220A and a second surface 220B that face opposite each other in the thickness direction. Both the first surface 220A and the second surface 220B are flat, but this is not a limitation. One or both of the first surface 220A and the second surface 220B may not be flat.

[0054] The first surface 220A of the substrate 220 is a surface facing the first direction D1. The first surface 220A faces the first circuit board 21, or in other words, faces the heat sink 34. The second surface 210B of the substrate 210 is a surface facing the second direction D2, or in other words, faces the bottom wall 33 of the case 3.

[0055] At least one circuit component 25 mounted on the second circuit board 22 is, for example, an MCU. In the first modification, the circuit component 25, which is an MCU, is mounted in the center of the first surface 220A of the board 220.

[0056] The heat transfer member 4 is thermally connected to the first circuit board 21, and also to the second circuit board 22. That is, the heat transfer member 4 is thermally connected to the first circuit board 21 and the second circuit board 22.

[0057] The heat transfer member 4 includes a member body 48, and a first connection portion 41 and a second connection portion 42 provided on the member body 48. The first connection portion 41 is a portion that is thermally connected to the first circuit board 21, and the second connection portion 42 is a portion that is thermally connected to the second circuit board 22.

[0058] In the first modified example, the first connecting portion 41 and the second connecting portion 42 of the heat transfer member 4 are each configured as a part of the first portion 481. The first connecting portion 41 and the second connecting portion 42 are positioned side by side in a direction perpendicular to the longitudinal direction of the first portion 481 and are continuous with each other.

[0059] The first connection portion 41 is thermally connected to the substrate 210 of the first circuit board 21. The first connection portion 41 is thermally connected to a region of the second surface 210B of the substrate 210 that is on the back side of at least one circuit component 25. In the first modified example, the first connection portion 41 is thermally connected to a region of the second surface 210B of the substrate 210 that is on the back side of a plurality of circuit components 25 (for example, a plurality of circuit components 25 configured with FETs or IGBTs).

[0060] A thermally conductive member 53 is disposed between the first connection portion 41 of the heat transfer member 4 and the substrate 210 of the first circuit board 21. The thermally conductive member 53 is in contact with the first connection portion 41 of the heat transfer member 4 and also with the substrate 210 of the first circuit board 21. The first connection portion 41 is thermally connected to a plurality of circuit components 25 (e.g., a plurality of circuit components 25 configured with FETs or IGBTs) via the thermally conductive member 53 and the substrate 210.

[0061] The thermally conductive member 53 may be, for example, in a sheet shape. The thermally conductive member 53 may not be disposed between the first connection portion 41 of the heat transfer member 4 and the substrate 210 of the first circuit board 21.

[0062] The second connection portion 42 is thermally connected to the circuit components 25 included in the second circuit board 22. A thermally conductive member 54 is disposed between the second connection portion 42 of the heat transfer member 4 and the circuit components 25 of the second circuit board 22. The thermally conductive member 54 is in contact with the second connection portion 42 of the heat transfer member 4 and also with the circuit components 25 of the second circuit board 22. The second connection portion 42 is thermally connected to the circuit components 25 (e.g., circuit components 25 configured in an MCU) via the thermally conductive member 54.

[0063] The thermally conductive member 54 may be, for example, in the form of a sheet. The thermally conductive member 54 may not be disposed between the second connection portion 42 of the heat transfer member 4 and the circuit components 25 of the second circuit board 22.

[0064] In the first modified example, the first circuit board 21, the second circuit board 22, and the heat transfer member 4 are joined to the heat sink 34 to form the integrated body 7. In the integrated body 7, the first circuit board 21 is sandwiched between the heat sink 34 and the heat transfer member 4, and the heat transfer member 4 is sandwiched between the first circuit board 21 and the second circuit board 22. The first circuit board 21 is positioned in a first direction D1 relative to the heat transfer member 4, and the second circuit board 22 is positioned in a second direction D2 relative to the heat transfer member 4.

[0065] In the electromechanical integrated unit 9 of the first modified example including the above-described integrated element 7, heat is transferred from the first circuit board 21 to the heat sink 34 via two paths. The two paths are independent of each other.

[0066] Of the two paths, one path is a path in which heat is transferred directly from at least one circuit component 25 of the first circuit board 21 to the heat sink 34 without passing through the heat transfer member 4. The other path is a path in which heat is transferred from the substrate 20 of the first circuit board 21 to the heat sink 34 via the heat transfer member 4. The path of heat transfer from the second circuit board 22 to the heat sink 34 is a path in which heat is transferred to the heat sink 34 via the heat transfer member 4.

[0067] Therefore, according to the electromechanical integrated unit 9 of the embodiment, heat can be effectively dissipated from the first circuit board 21 and the second circuit board 22 to the outside via the heat sink 34 .

[0068] 11A and 11B show the heat transfer member 4 included in the electromechanical integrated unit 9 of the second modified example. The basic configuration of the electromechanical integrated unit 9 of the second modified example is the same as that of the first modified example. In the following description of the second modified example, the same components as those of the first modified example are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0069] The heat transfer member 4 is thermally connected to the first circuit board 21 and the second circuit board 22, similarly to the first modified example.

[0070] The heat transfer member 4 includes a member body 48 , a first connecting portion 41 , a second connecting portion 42 , and a heat insulating portion 43 provided on the member body 48 .

[0071] The first connecting portion 41 and the second connecting portion 42 of the heat transfer member 4 are positioned side by side in a direction perpendicular to the longitudinal direction of the member body 48. A heat insulating portion 43 is provided between the first connecting portion 41 and the second connecting portion 42. The direction in which the first connecting portion 41 and the second connecting portion 42 are aligned is perpendicular to the first direction D1 and also perpendicular to the second direction D2.

[0072] The heat insulating portion 43 is a portion that inhibits heat conduction between the first connection portion 41 and the second connection portion 42. In the second modified example, the heat insulating portion 43 is configured as a gap 430 provided in the member main body 48. The gap 430 is a slit-shaped gap that is provided linearly extending in the longitudinal direction of the member main body 81.

[0073] The void 430 is provided in the first portion 481. The void 430 penetrates the first portion 481. The direction in which the void 430 penetrates and the direction in which the first connecting portion 41 and the second connecting portion 42 are arranged are perpendicular to each other. It is not essential that the void 430 penetrate the first portion 418; it may not penetrate. Furthermore, the heat insulating portion 43 does not have to be the void 430. For example, the heat insulating portion 43 may include a porous portion in which a large number of pores are formed. The heat insulating portion 43 may include a heat insulating member disposed between the first connecting portion 41 and the second connecting portion 42.

[0074] In the electromechanical integrated unit 9 of the second modified example including the heat transfer member 4 described above, heat is transferred from the first circuit board 21 to the heat sink 34 and from the second circuit board 22 to the heat sink 34 through the heat transfer member 4 including the first connecting portion 41 and the second connecting portion 42. In addition, in the electromechanical integrated unit 9 of the second modified example, the heat transfer member 4 is provided with the heat insulating portion 43, which prevents heat generated on the first circuit board 21 from being transferred to the second circuit board 22 and also prevents heat generated on the second circuit board 22 from being transferred to the first circuit board 21.

[0075] Therefore, according to the second modified electromechanical integrated unit 9, heat can be effectively dissipated from the first circuit board 21 to the outside via the heat sink 34, and heat can be effectively dissipated from the second circuit board 22 to the outside via the heat sink 34.

[0076] 12 shows a third modified example of the electromechanical integrated unit 9. The electromechanical integrated unit 9 of the third modified example further includes a heat insulating member 61.

[0077] The heat insulating member 61 is disposed between the motor case 82, which forms the outer shell of the motor device 8, and the case 3, which forms the outer shell of the circuit device 1. The heat insulating member 61 is a member formed into a rectangular flat plate using a heat insulating material. The heat insulating material forming the heat insulating member 61 is, for example, fluororesin, but is not limited to this. The fluororesin used as the heat insulating material is, for example, polytetrafluoroethylene (hereinafter abbreviated as "PTFE"). Polyetheretherketone (hereinafter abbreviated as "PEEK") or polyimide (hereinafter abbreviated as "PI") can also be used as the heat insulating material. The heat insulating member 61 is disposed to inhibit heat conduction between the motor device 8 and the circuit device 1.

[0078] The heat insulating member 61 may be in direct contact with the motor case 82, or another member may be interposed between the heat insulating member 61 and the motor case 82. Similarly, the heat insulating member 61 may be in direct contact with the case 3 of the circuit device 1, or another member may be interposed between the heat insulating member 61 and the case 3 of the circuit device 1.

[0079] In the electromechanical integrated unit 9 of the third modified example that includes the above-described heat insulating member 61, heat generated in the motor device 8 is prevented from being transmitted to the heat sink 34 through the peripheral wall 32 of the circuit device 1. This prevents heat generated in the motor device 8 from being transmitted to the circuit board 2 through the peripheral wall 32 of the circuit device 1 and the heat sink 34. The heat generated in the motor device 8 can be dissipated via an appropriate structure that fixes the motor device 8 within the mechanism.

[0080] (4) Fourth Modification Fig. 13 shows a cross section of the circuit device 1 included in the electromechanical integrated unit 9 of the fourth modification. The basic configuration of the electromechanical integrated unit 9 of the fourth modification is the same as that of the first modification. In the following description of the fourth modification, the same components as those of the first modification are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0081] The electromechanical integrated unit 9 of the fourth modified example further includes a heat insulating member 62 included in the circuit device 1. The heat insulating member 62 is disposed between the peripheral wall portion 32, which constitutes a part of the case 3 of the circuit device 1, and the heat sink 34, which constitutes another part of the case 3. The heat insulating member 62 is formed using a heat insulating material. The heat insulating material for the heat insulating member 62 may be, for example, a fluororesin, but is not limited thereto. Examples of fluororesins used as the heat insulating material include PTFE, PEEK, and PI. The heat insulating member 62 is disposed to inhibit heat conduction between the peripheral wall portion 32 and the heat sink 34. The heat insulating member 62 is formed, for example, in a rectangular ring shape, but may have other shapes. For example, the heat insulating member 62 may not be a ring-shaped member that is continuous around the entire circumference, but may be divided at least at one point around the entire circumference.

[0082] In the fourth modified example of the mechanically and electrically integrated unit 9, the second part 482 and the third part 483 included in the heat transfer member 4 are mechanically and thermally connected to the heat sink 34, but it is preferable that they are not mechanically connected to the peripheral wall portion 32, and it is also preferable that they are not thermally connected to the peripheral wall portion 32.

[0083] The heat insulating member 62 may be in direct contact with the peripheral wall portion 32, or another member may be interposed between the heat insulating member 62 and the peripheral wall portion 32. Similarly, the heat insulating member 62 may be in direct contact with the heat sink 34, or another member may be interposed between the heat insulating member 62 and the heat sink 34.

[0084] In the electromechanical integrated unit 9 of the fourth modified example including the heat insulating member 62, the heat generated in the motor device 8 is prevented from being transmitted to the heat sink 34 through the peripheral wall 32 of the circuit device 1. Therefore, the heat generated in the motor device 8 is prevented from being transmitted to the circuit board 2 through the peripheral wall 32 and the heat sink 34 of the circuit device 1.

[0085] (5) Fifth Modification Fig. 14 shows a cross section of the circuit device 1 included in the electromechanical integrated unit 9 of the fifth modification. The basic configuration of the electromechanical integrated unit 9 of the fifth modification is the same as that of the first modification. In the following description of the fifth modification, the same components as those of the first modification are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0086] A portion of the peripheral wall 32 included in the circuit device 1 of the fifth modification is configured with a heat insulating structure 325 that has a lower thermal conductivity than the other portions of the peripheral wall 32. The heat insulating structure 325 is a porous structure 326 in which a large number of pores are formed. The peripheral wall 32 of the fifth modification can be manufactured, for example, by forming only a portion of the peripheral wall 32 into the porous structure 326 when forming the aluminum peripheral wall 32 using a 3D printer.

[0087] The heat insulating structure 325 is formed at the end of the peripheral wall portion 32 in the first direction D1, but may be formed in another portion of the peripheral wall portion 32. The heat insulating structure 325 preferably has a ring-shaped shape that is continuous around the entire circumference of the peripheral wall portion 32, but may also have a shape that is divided at least at one point around the entire circumference of the peripheral wall portion 32.

[0088] In the fifth modification, the portion of the peripheral wall 32 that is located inside the porous structure 326 is configured with a non-porous solid structure 327. The solid structure 327 preferably has a ring-shaped shape that is continuous around the entire circumference of the peripheral wall 32, but may also have a shape that is divided at least at one point around the entire circumference of the peripheral wall 32.

[0089] In the electromechanical integrated unit 9 of the fifth modified example that includes the porous structure 326, heat generated in the motor device 8 is prevented from being transmitted to the heat sink 34 through the peripheral wall 32 of the circuit device 1. This prevents heat generated in the motor device 8 from being transmitted to the circuit board 2 through the peripheral wall 32 of the circuit device 1 and the heat sink 34. Furthermore, since part of the peripheral wall 32 is made of the porous structure 326, the weight of the peripheral wall 32 is reduced. Additionally, in the electromechanical integrated unit 9 of the fifth modified example that includes the solid structure 327, the solid structure 327 is located more inward than the porous structure 326, which more reliably prevents foreign matter from entering the case 3.

[0090] (6) Sixth Modification Fig. 15 shows a cross section of the circuit device 1 included in the electromechanical integrated unit 9 of the sixth modification. The basic configuration of the electromechanical integrated unit 9 of the sixth modification is the same as that of the fifth modification. In the following description of the sixth modification, the same components as those of the fifth modification are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0091] In the circuit device 1 of the sixth modified example, the positional relationship between the porous structure 326 that constitutes part of the peripheral wall portion 32 and the solid structure 327 adjacent to the porous structure 326 is different from that of the fifth modified example.

[0092] In the sixth modification, the portion of the peripheral wall 32 that is outside the porous structure 326 is configured with a solid structure 327. The solid structure 327 preferably has a shape that is continuous in an annular shape around the entire circumference of the peripheral wall 32, but may also have a shape that is interrupted at least in one location around the entire circumference of the peripheral wall 32. The peripheral wall 32 of the sixth modification can also be manufactured by, for example, molding only a portion of the peripheral wall 32 into the porous structure 326 when molding the aluminum peripheral wall 32 using a 3D printer.

[0093] In the electromechanical integrated unit 9 of the sixth modified example, the solid structure 327 is positioned so as to cover the porous structure 326 from the outside, thereby more reliably preventing foreign matter from entering the case 3.

[0094] (7) Seventh Modification Fig. 16 shows a cross section of the circuit device 1 included in the electromechanical integrated unit 9 of the seventh modification. The basic configuration of the electromechanical integrated unit 9 of the seventh modification is the same as that of the fifth modification. In the following description of the seventh modification, the same components as those of the fifth modification are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0095] In the circuit device 1 of the seventh modification, the peripheral wall portion 32 does not include the solid structure 327 adjacent to the porous structure 326. That is, in the seventh modification, the porous structure 326 constituting part of the peripheral wall portion 32 is formed in a range from the inner end to the outer end of the peripheral wall portion 32.

[0096] The peripheral wall portion 32 of the seventh modified example can also be manufactured by, for example, molding only a portion of the peripheral wall portion 32 into a porous structure 326 when molding an aluminum peripheral wall portion 32 using a 3D printer.

[0097] (8) Eighth Modification Fig. 17 shows a cross section of the circuit device 1 included in the electromechanical integrated unit 9 of the eighth modification. The basic configuration of the electromechanical integrated unit 9 of the eighth modification is the same as that of the first modification. In the following description of the eighth modification, the same components as those of the first modification are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0098] The heat sink 34 included in the circuit device 1 of the eighth modification includes a first heat dissipation portion 341 , a second heat dissipation portion 342 , and a heat insulating portion 343 .

[0099] The first heat dissipation portion 341 is a portion of the heat sink 34 to which the heat transfer member 4 is mechanically and thermally connected. A first portion 481 and a second portion 482 of the heat transfer member 4 are mechanically and thermally connected to the first heat dissipation portion 341. The first heat dissipation portion 341 is configured as a part of the lid portion 345. A connection portion 348 of the heat sink 34 protrudes from the first heat dissipation portion 341 in the second direction D2.

[0100] The second heat dissipation portion 342 is a portion of the heat sink 34 to which the peripheral wall portion 32 is mechanically and thermally connected. The second heat dissipation portion 342 is configured as a part of the lid portion 345. The second heat dissipation portion 342 is positioned so as to surround the entire periphery of the first heat dissipation portion 341. The second heat dissipation portion 342 is configured as the outer peripheral edge portion of the lid portion 345.

[0101] The heat insulating portion 343 is a portion of the heat sink 34 that is provided between the first heat dissipation portion 341 and the second heat dissipation portion 342. The heat insulating portion 343 has a lower thermal conductivity than the first heat dissipation portion 341 and the second heat dissipation portion 342. The heat insulating portion 343 preferably has a ring-shaped shape that is continuous around the entire circumference of the lid portion 345, but may also have a shape that is divided at least at one point around the entire circumference of the lid portion 345.

[0102] The heat insulating portion 343 is a porous portion 344 having many pores formed therein. The heat sink 34 of the eighth modification can be manufactured by, for example, molding only a portion of the lid portion 345 into the porous portion 344 when molding the lid portion 345 made of aluminum using a 3D printer.

[0103] In the electromechanical integrated unit 9 of the eighth modified example including the heat insulating portion 343, the heat generated in the motor device 8 is prevented from being transmitted to the first heat dissipation portion 341 of the heat sink 34 through the peripheral wall portion 32 of the circuit device 1. Therefore, the heat generated in the motor device 8 is prevented from being transmitted to the circuit board 2 through the heat sink 34.

[0104] The above-described embodiments and various modified examples based on the accompanying drawings are merely examples of the present disclosure. The present disclosure is not limited to the above-described embodiments and various modified examples. Various modifications other than these embodiments and various modified examples are possible depending on the design, etc., as long as they do not deviate from the technical concept of the present disclosure. Furthermore, the configurations of the various modified examples can also be appropriately combined and applied.

[0105] 3. Summary As described above based on the embodiment and various modified examples, the circuit device (1) of the first aspect includes a circuit board (2) including circuit components (25) for driving a motor, a case (3) that houses the circuit board (2), and a heat transfer member (4) housed in the case (3) and thermally connected to the circuit board (2). The case (3) includes a peripheral wall portion (32) and a heat sink (34) coupled to the peripheral wall portion (32). At least a portion of the circuit board (2) is located between the heat sink (34) and the heat transfer member (4). The heat transfer member (4) is thermally connected to the heat sink (34) and at least a portion of the circuit board (2).

[0106] According to this embodiment, heat is transferred from the circuit board (2) to the heat sink (34) via the heat transfer member (4) located on the opposite side of the circuit board (2) from the heat sink (34). Therefore, heat can be transferred from the circuit board (2) to the heat sink (34) via multiple paths, and heat can be effectively dissipated from the circuit board (2) to the outside via the heat sink (34).

[0107] In the circuit device (1) of the second aspect, the peripheral wall portion (32) of the first aspect has an opening (320). The heat sink (34) is coupled to the peripheral wall portion (32) so as to close the opening (320).

[0108] According to this aspect, by combining the peripheral wall portion (32) and the heat sink (34), the case (3) that houses the circuit board (2) can be configured compactly.

[0109] In the circuit device (1) of the third aspect, in the first or second aspect, the circuit board (2) includes a first circuit board (21) and a second circuit board (22). The first circuit board (21) is located between a heat sink (34) and a heat transfer member (4). The heat transfer member (4) is located between the first circuit board (21) and the second circuit board (22). The heat transfer member (4) is thermally connected to the heat sink (34) and the first circuit board (21).

[0110] According to this aspect, heat is transferred from the first circuit board (21) to the heat sink (34) via the heat transfer member (4) located on the opposite side of the first circuit board (21) from the heat sink (34). Therefore, heat transfer from the first circuit board (21) to the heat sink (34) can be performed via multiple paths, and heat can be effectively dissipated from the first circuit board (21) to the outside via the heat sink (34).

[0111] In the circuit device (1) of the fourth aspect, in the third aspect, the first circuit board (21) is a circuit board that constitutes a power circuit for supplying power for driving a motor, and the second circuit board (22) is a circuit board that constitutes a control circuit for operating the power circuit.

[0112] According to this embodiment, heat can be effectively dissipated from the power circuit to the outside via the heat transfer member (4) and the heat sink (34).

[0113] In the circuit device (1) of the fifth aspect, in the third or fourth aspect, the heat transfer member (4) is thermally connected to the heat sink (34), the first circuit board (21), and the second circuit board (22).

[0114] According to this aspect, both heat dissipation from the first circuit board (21) to the outside and heat dissipation from the second circuit board (22) to the outside can be effectively performed via the heat transfer member (4) and the heat sink (34).

[0115] In the circuit device (1) of the sixth aspect, in any one of the third to fifth aspects, the heat transfer member (4) includes a first connection portion (41) thermally connected to the first circuit board (21), a second connection portion (42) thermally connected to the second circuit board (22), and a heat insulating portion (43) provided between the first connection portion (41) and the second connection portion (42).

[0116] According to this aspect, both heat dissipation from the first circuit board (21) to the outside and heat dissipation from the second circuit board (22) to the outside can be effectively performed via the heat transfer member (4) and the heat sink (34). In addition, the influence of heat generated by the first circuit board (21) on the second circuit board (22) can be suppressed, and the influence of heat generated by the second circuit board (22) on the first circuit board (21) can be suppressed.

[0117] In the circuit device (1) of the seventh aspect, in the sixth aspect, the heat insulating portion (43) is a gap (430) provided in the heat transfer member (4).

[0118] According to this aspect, the influence of heat generated by the first circuit board (21) on the second circuit board (22) and the influence of heat generated by the second circuit board (22) on the first circuit board (21) can be effectively suppressed by a simple structure in which a gap (430) is provided in the heat transfer member (4).

[0119] The circuit device (1) of an eighth aspect is the circuit device (1) of any one of the first to seventh aspects, further comprising a heat insulating member (62) arranged between the peripheral wall portion (32) and the heat sink (34).

[0120] According to this aspect, the heat generated in the motor device (8) is prevented from being transmitted to the circuit board (2) through the peripheral wall (32) and the heat sink (34) of the circuit device (1).

[0121] In the circuit device (1) of the ninth aspect, in any one of the first to eighth aspects, a part of the peripheral wall portion (32) is configured with a heat insulating structure (325) having a lower thermal conductivity than other parts of the peripheral wall portion (32).

[0122] According to this aspect, the heat generated in the motor device (8) is prevented from being transmitted to the circuit board (2) through the peripheral wall (32) and the heat sink (34) of the circuit device (1).

[0123] In the circuit device (1) of the tenth aspect, in the ninth aspect, the heat insulating structure (325) is a porous structure (326).

[0124] According to this aspect, the heat generated in the motor device (8) is prevented from being transmitted to the circuit board (2) through the peripheral wall portion (32) and the heat sink (34) of the circuit device (1) by a simple structure in which part of the peripheral wall portion (32) is made into a porous structure (326).

[0125] In the circuit device (1) of the eleventh aspect, in any one of the first to tenth aspects, the heat sink (34) includes a first heat dissipation portion (341) thermally connected to the heat transfer member (4), a second heat dissipation portion (342) thermally connected to the peripheral wall portion (32), and an insulating portion (343) provided between the first heat dissipation portion (341) and the second heat dissipation portion (342).

[0126] According to this aspect, the heat generated in the motor device (8) is prevented from being transmitted to the circuit board (2) through the heat sink (34).

[0127] In the circuit device (1) of the twelfth aspect, in the eleventh aspect, the heat insulating portion (343) is a porous portion (344).

[0128] According to this aspect, the heat generated in the motor device (8) is prevented from being transmitted to the circuit board (2) through the heat sink (34) by a simple structure in which part of the heat sink (34) is made into a porous portion (344).

[0129] The electromechanical integrated unit (9) of the thirteenth aspect comprises a circuit device (1) of any one of the first to twelfth aspects and a motor device (8) connected to the case (3) of the circuit device (1).

[0130] According to this embodiment, heat is transferred from the circuit board (2) to the heat sink (34) via the heat transfer member (4) located on the opposite side of the circuit board (2) from the heat sink (34). Therefore, heat can be transferred from the circuit board (2) to the heat sink (34) via multiple paths, and heat can be effectively dissipated from the circuit device (1) to the outside via the heat sink (34).

[0131] The electromechanical integrated unit (9) of the fourteenth aspect is the thirteenth aspect, further comprising a heat insulating member (61) disposed between the motor device (8) and the circuit device (1).

[0132] According to this aspect, the heat generated in the motor device (8) is prevented from being transmitted to the circuit board (2) through the heat sink (34) by a simple structure in which a heat insulating member (61) is disposed between the motor device (8) and the circuit device (1).

[0133] REFERENCE SIGNS LIST 1 Circuit device 2 Circuit board 21 First circuit board 22 Second circuit board 25 Circuit component 3 Case 32 Peripheral wall 325 Heat insulating structure 326 Porous structure 34 Heat sink 341 First heat dissipation section 342 Second heat dissipation section 343 Heat insulating section 344 Porous section 4 Heat transfer member 41 First connection section 42 Second connection section 43 Heat insulating section 430 Air gap 61 Heat insulating member 62 Heat insulating member 8 Motor device 9 Electromechanical integrated unit

Claims

1. a circuit board including circuit components for driving the motor; a case that houses the circuit board; a heat transfer member housed in the case and thermally connected to the circuit board, the case includes a peripheral wall portion and a heat sink coupled to the peripheral wall portion; At least a portion of the circuit board is located between the heat sink and the heat transfer member, the heat transfer member is thermally connected to the heat sink and to at least the portion of the circuit board. circuit device.

2. The peripheral wall portion has an opening, and the heat sink is coupled to the peripheral wall portion so as to close the opening. The circuit device of claim 1.

3. The circuit board includes a first circuit board and a second circuit board, the first circuit board is located between the heat sink and the heat transfer member; the heat transfer member is located between the first circuit board and the second circuit board; the heat transfer member is thermally connected to the heat sink and the first circuit board. The circuit device of claim 1.

4. the first circuit board is a circuit board that configures a power circuit for supplying power for driving a motor, The second circuit board is a board circuit that configures a control circuit for operating the power circuit. The circuit device of claim 3.

5. the heat transfer member is thermally connected to the heat sink, the first circuit board, and the second circuit board. The circuit device of claim 3.

6. the heat transfer member includes a first connection portion thermally connected to the first circuit board, a second connection portion thermally connected to the second circuit board, and a heat insulating portion provided between the first connection portion and the second connection portion. The circuit device of claim 3.

7. The heat insulating portion is a gap provided in the heat transfer member. The circuit device of claim 6.

8. The heat sink further includes a heat insulating member disposed between the peripheral wall portion and the heat sink. The circuit device of claim 1.

9. A portion of the peripheral wall portion is configured with a heat insulating structure having a lower thermal conductivity than the other portion of the peripheral wall portion. The circuit device of claim 1.

10. The heat insulating structure is a porous structure. The circuit device of claim 9.

11. The heat sink includes a first heat dissipation portion thermally connected to the heat transfer member, a second heat dissipation portion thermally connected to the peripheral wall portion, and a heat insulating portion provided between the first heat dissipation portion and the second heat dissipation portion. The circuit device of claim 1.

12. The heat insulating portion is a porous portion. The circuit device of claim 11.

13. A circuit device according to any one of claims 1 to 12; a motor device connected to the case of the circuit device, Integrated electromechanical unit.

14. a heat insulating member disposed between the motor device and the circuit device; The electromechanical integrated unit according to claim 13.