Electronic device

Abstract

The present invention improves the heat dissipation performance of an electronic device. This electronic device comprises: a circuit board on which an electronic component that generates heat is mounted; a cooling member that has a cooling passage through which a cooling liquid passes, said cooling passage being formed in a size that includes a location facing the electronic component; and a thermal diffusion member that is positioned between the electronic component and the cooling passage. The thermal diffusion member transmits heat generated from the electronic component to the cooling passage side while diffusing the heat in a planar direction of a mounting surface of the circuit board, and has thermal diffusion directionality toward a direction destination region facing a side of the cooling passage that is further upstream than a region facing the electronic component.

Description

Electronic device

[0001] The present invention relates to an electronic device.

[0002] Generally, vehicles such as automobiles are equipped with a plurality of electronic control units (ECUs) to control various objects including engines, power steering, brakes, airbags, etc. The electronic control device mounted on the vehicle has a structure in which a circuit board on which electronic components are mounted is housed inside a housing.

[0003] The electronic components mounted on the circuit board of the electronic control device generate heat. If the generated heat temperature rises above the rated temperature of the electronic components, the electronic control device may not function properly. Therefore, it is desired to improve the heat dissipation performance of the electronic control device.

[0004] Patent Document 1 discloses a cooling device for cooling a heating element such as a switching element. The cooling device disclosed in Patent Document 1 is provided with a plurality of cooling fins and has a coolant flow path through which coolant flows. A notch is formed in the cooling fin at a position corresponding to at least the central portion of the heating element in the flow direction of the coolant. A chamber is formed in the coolant flow path by the notch of the cooling fin.

[0005] Japanese Patent Application Laid-Open No. 2009-188181

[0006] However, the cooling device described in Patent Document 1 has a structure in which heat diffuses radially around the element. Therefore, adjacent switching elements are likely to have heat interference, and a high-temperature region is generated between the switching elements. As a result, it is difficult to improve the cooling efficiency of the cooling device described in Patent Document 1, which hinders the improvement of the heat dissipation performance for the switching element (heating component).

[0007] An object of the present invention is to provide an electronic device capable of improving heat dissipation performance.

[0008] To solve the above problems and achieve the objectives of the present invention, an electronic device according to one aspect of the present invention comprises a circuit board on which heat-generating electronic components are mounted, a cooling member formed to include a position facing the electronic components and having a cooling passage through which a cooling liquid passes, and a heat diffusion member disposed between the electronic components and the cooling passage. The heat diffusion member diffuses the heat generated from the electronic components in the planar direction of the mounting surface of the circuit board and transmits it to the cooling passage side, and has a directivity of heat diffusion toward a target region facing the upstream side of the cooling passage rather than the region facing the electronic components.

[0009] The electronic device with the above configuration can improve heat dissipation performance. Other issues, configurations, and effects will be clarified by the following description of the embodiments.

[0010] This is a perspective view of the electronic device according to the first embodiment. This is an exploded perspective view of the electronic device according to the first embodiment. This is a perspective view of the cooling member in the electronic device according to the first embodiment with the first surface facing upwards. This is a cross-sectional view of the electronic device according to the first embodiment. This is a diagram showing the positional relationship between the cooling passage and the electronic component of the electronic device according to the first embodiment. This is a diagram showing the positional relationship between the heat diffusion member and the electronic component of the electronic device according to the first embodiment. This is a diagram showing the positional relationship between the heat diffusion member and the electronic component of the electronic device according to the second embodiment. This is a diagram showing the positional relationship between the heat diffusion member and the electronic component of the electronic device according to the third embodiment.

[0011] Embodiments of the present invention will now be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same function or configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0012] 1. First Embodiment [Configuration of Electronic Device] First, the configuration of the electronic device according to the first embodiment of the present invention will be described using Figures 1 to 4. Figure 1 is a perspective view of the electronic device according to the first embodiment. Figure 2 is an exploded perspective view of the electronic device according to the first embodiment. Figure 3 is a perspective view of the electronic device with the first surface of the cooling member facing upwards. Figure 4 is a cross-sectional view of the electronic device.

[0013] The electronic device 1 shown in Figure 1 is, for example, an electronic control device for vehicles installed in vehicles that run on liquid fuels such as gasoline or diesel. The electronic device according to the present invention is also widely applicable to electronic control devices for vehicles installed in vehicles such as vehicles that run on hydrogen fuel, hybrid vehicles, and electric vehicles.

[0014] Furthermore, the electronic device according to the present invention is not limited to an in-vehicle electronic control device. Also, the object controlled by the electronic device according to the present invention is not limited to a vehicle. Moreover, the electronic device according to the present invention is not limited to controlling an object.

[0015] In the following explanation, in order to clarify the shape and positional relationships of each part of the electronic device 1, the thickness direction (height direction) of the electronic device 1 will be defined as the Z direction, and of the two axes perpendicular to the Z direction, one direction will be defined as the X direction and the other as the Y direction. The X, Y, and Z directions are mutually orthogonal directions.

[0016] As shown in Figures 1 to 3, the electronic device 1 comprises a water-cooled housing 2, a first circuit board 3, second circuit boards 4A and 4B, a first cover 5, a second cover 6, and a heat diffusion member 8 (see Figure 3).

[0017] The water-cooled enclosure 2 comprises a frame 21 and a cooling member 22. The frame 21 is formed in the shape of a rectangular frame that is elongated in the X direction. The material of the frame 21 can be, for example, resin, metal, or a casting such as aluminum die-cast.

[0018] The cooling member 22 has a cooling passage 24 through which the coolant flows, an inlet portion 25, and an outlet portion 26. The cooling member 22 also has a plurality of connector through holes 27. The plurality of connector through holes 27 are located near the cooling passage 24 and are aligned in the X direction.

[0019] As shown in Figure 2, the cooling passage 24 is formed in a flat, approximately U-shape. One plane of the cooling passage 24 faces the first circuit board 3 in the Z direction. The other plane of the cooling passage 24 faces the second circuit boards 4A and 4B in the Z direction. The cooling passage 24 consists of an inlet-side passage portion 24a, an outlet-side passage portion 24b, and a bent portion 24c.

[0020] The inlet-side passage 24a and the outlet-side passage 24b are formed in a straight line extending in the X direction. The inlet-side passage 24a and the outlet-side passage 24b are adjacent in the Y direction. The bent section 24c is an arch-shaped passage and is connected to one end of the inlet-side passage 24a and one end of the outlet-side passage 24b. The bent section 24c connects the inlet-side passage 24a and the outlet-side passage 24b. The other ends of the inlet-side passage 24a and the outlet-side passage 24b are close to one side of the frame 21 that extends in the X direction.

[0021] The inlet section 25 is connected to the other end of the inlet-side passage section 24a. The outlet section 26 is connected to the other end of the outlet-side passage section 24b. The coolant enters the inlet-side passage section 24a from the inlet section 25, passes through the bend section 24c, and flows through the outlet-side passage section 24b. At this time, the coolant is heated by heat generated from the electronic components 33 mounted on the first circuit board 3 and the electronic components 41 mounted on the second circuit boards 4A and 4B. The heated coolant exits to the outside through the outlet section 26.

[0022] The inlet section 25 and the outlet section 26 are connected to a circulation pump (not shown) and a radiator (not shown). The radiator cools the coolant that exits the outlet section 26. The circulation pump sends the coolant cooled by the radiator to the inlet section 25. As a result, the coolant circulates within the cooling passage 24.

[0023] The first circuit board 3 is formed in the shape of a rectangular flat plate that is elongated in the X direction. The first circuit board 3 is a printed wiring board that is a rigid substrate, for example, using glass epoxy as the base material. The first circuit board 3 has a mounting surface 3a which is a plane substantially perpendicular to the Z direction. The mounting surface 3a of the first circuit board 3 faces one of the planes of the cooling passage 24. In addition, the circuit board according to the present invention may have both planes as mounting surfaces.

[0024] Multiple connectors 31, multiple connection connectors 32, and multiple electronic components 33 are mounted on the mounting surface 3a of the first circuit board 3. The multiple connectors 31 are arranged along one side extending in the X direction and one side extending in the Y direction of the first circuit board 3. The multiple connectors 31 electrically connect the electrical circuit formed on the first circuit board 3 to external equipment (not shown). Examples of external equipment other than those in this embodiment include electronic control devices, cameras, sensors, actuators, etc., which are mounted on vehicles.

[0025] Multiple connection connectors 32 are arranged along the other side of the first circuit board 3 that extends in the X direction. The multiple connection connectors 32 pass through multiple connector through holes 27 in the cooling member 22 and are connected to multiple connection connectors (not shown) mounted on the second circuit boards 4A and 4B. As a result, the first circuit board 3 is electrically connected to the second circuit boards 4A and 4B.

[0026] The multiple electronic components 33 consist of a first electronic component 33A, a second electronic component 33B, and a third electronic component 33C. The electronic components 33A to 33C are arranged approximately in the center of the mounting surface 3a of the first circuit board 3. The electronic components 33A to 33C are, for example, SoCs (System on Chip) and correspond to the heat-generating electronic components according to the present invention.

[0027] The second circuit boards 4A and 4B are arranged with a gap between them in the X direction. The second circuit boards 4A and 4B are each formed in the shape of a long rectangular plate in the Y direction. The second circuit boards 4A and 4B are printed wiring boards that are rigid substrates, for example, using glass epoxy as the base material. The second circuit boards 4A and 4B have mounting surfaces 4a which are planes substantially perpendicular to the Z direction (see Figure 4). The mounting surfaces 4a of the second circuit boards 4A and 4B face the other plane of the cooling passage 24.

[0028] On the mounting surface 4a of the second circuit boards 4A and 4B, electronic components 41 (see Figure 4) and a plurality of connection connectors (not shown) are mounted. The electronic components 41 generate heat. The plurality of connection connectors are arranged along one side of the second circuit boards 4A and 4B that extends in the X direction. The plurality of connection connectors 32 of the first circuit board 3 are connected to the plurality of connection connectors.

[0029] The first cover 5 is formed in the shape of a rectangular flat plate that is elongated in the X direction. The material of the first cover 5 can be, for example, resin, metal, or a casting such as aluminum die-cast. The first cover 5 is fixed to the frame 21 and covers the plane of the first circuit board 3 opposite to the mounting surface 3a.

[0030] The second cover 6 is formed in the shape of a rectangular flat plate that is elongated in the X direction. The material of the second cover 6 can be, for example, resin, metal, or a casting such as aluminum die-cast. The second cover 6 is fixed to the frame 21 and covers the plane opposite to the mounting surface 4a of the second circuit boards 4A and 4B.

[0031] As shown in Figures 3 and 4, the heat diffusion member 8 is positioned between the cooling member 22 and the multiple electronic components 33. The heat diffusion member 8 is formed in the shape of a roughly rectangular flat plate. A heat conduction member 9 is interposed between the heat diffusion member 8 and the multiple electronic components 33. The heat conduction member 9 is, for example, thermal grease. The heat generated in the multiple electronic components 33 is transferred to the heat diffusion member 8 via the heat conduction member 9.

[0032] The heat diffusion member 8 is a so-called vapor chamber. In a vapor chamber, a cooling medium sealed in a confined space undergoes repeated phase changes, diffusing heat from a heat source. The heat diffusion member 8 has a hollow, flat plate-shaped housing, a wick structure housed inside the housing, and a cooling medium impregnated into the wick structure. The wick structure has a porous capillary structure.

[0033] The cooling medium of the heat diffusion member 8 turns into vapor when heated and diffuses from the wick structure into the housing. At this time, the heat from the multiple electronic components 33, which are heat sources, is diffused by the heat diffusion member 8 and transferred to the cooling member 22. The vaporized cooling medium tends to move towards areas with a larger porosity in the wick structure. Therefore, the heat diffusion member 8 has directionality in diffusing the heat generated by the multiple electronic components 33.

[0034] [Positional relationship between cooling passage and electronic components] Next, the positional relationship between the cooling passage 24 and the electronic components 33A to 33C in the cooling member 22 will be explained using Figure 5. Figure 5 is a diagram showing the positional relationship between the cooling passage 24 and the electronic components 33A to 33C.

[0035] As shown in Figure 5, the electronic components 33A to 33C are positioned in the Z direction opposite to the cooling passage 24. The first electronic component 33A is opposite the end of the inlet-side passage 24a of the cooling passage 24 on the bent portion 24c side. The second electronic component 33B is opposite the end of the outlet-side passage 24b of the cooling passage 24 on the bent portion 24c side. The third electronic component 33C is opposite the end of the outlet-side passage 24b of the cooling passage 24 on the outlet portion 26 side.

[0036] The first electronic component 33A is positioned upstream of the cooling passage 24 compared to the second electronic component 33B. The second electronic component 33B is positioned upstream of the cooling passage 24 compared to the third electronic component 33C. Electronic components 33A to 33C are each positioned so that their entirety faces the cooling passage 24. However, the electronic components according to the present invention may be positioned so that only a portion of them faces the cooling passage.

[0037] The first electronic component 33A and the second electronic component 33B are adjacent in the Y direction. In other words, the first electronic component 33A and the second electronic component 33B are adjacent laterally when viewed from the direction in which the coolant flows through the inlet-side passage 24a and the outlet-side passage 24b (X direction). The second electronic component 33B and the third electronic component 33C are adjacent in the X direction. In other words, the second electronic component 33B and the third electronic component 33C are adjacent in the direction in which the coolant flows through the inlet-side passage 24a and the outlet-side passage 24b.

[0038] [Positional relationship between heat diffusion member and electronic components] Next, the positional relationship between the heat diffusion member 8 and the electronic components 33A to 33C will be explained using Figure 6. Figure 6 is a diagram showing the positional relationship between the heat diffusion member 8 and the electronic components 33A to 33C.

[0039] As shown in Figure 6, the heat diffusion member 8 is formed in a roughly rectangular shape, sized to face the multiple electronic components 33A to 33C. The heat diffusion member 8 has a target region 81. The target region 81 has a larger porosity of pores in the wick structure than other regions. Therefore, the heat diffusion member 8 diffuses heat toward the target region 81.

[0040] The target region 81 is located upstream of the cooling passage 24, relative to the multiple electronic components 33A to 33C. In other words, the target region 81 is located upstream of the first electronic component 33A, which is the furthest upstream of the electronic components 33A to 33C, relative to the first electronic component 33A. As a result, the heat diffusion member 8 actively diffuses the heat generated by the multiple electronic components 33A to 33C to the region of the cooling passage 24 where the water temperature is lower, thereby dissipating the heat. Consequently, the heat dissipation efficiency of the heat generated by each electronic component 33A to 33C can be improved.

[0041] Furthermore, the target region 81 is adjacent to each of the electronic components 33A to 33C. Specifically, electronic component 33A is adjacent to the target region 81 in the X direction. The third electronic component 33C is adjacent to the target region 81 in the Y direction. The second electronic component 33B is adjacent to the target region 81 in an oblique direction consisting of components in the X and Y directions. This prevents thermal interference between adjacent electronic components (for example, the first electronic component 33A and the second electronic component 33B) when the heat diffusion member 8 diffuses the heat generated by each of the electronic components 33A to 33C toward the target region 81.

[0042] 2. Second Embodiment [Configuration of Electronic Device] The following describes the electronic device 1A according to the second embodiment. The electronic device 1A has the same configuration as the electronic device 1 according to the first embodiment described above. The difference between the electronic device 1A and the electronic device 1 according to the first embodiment is the heat diffusion member 8A. Therefore, the heat diffusion member 8A and the positional relationship between the heat diffusion member 8A and the electronic components 33A to 33C will be explained here using Figure 7. Figure 7 is a diagram showing the positional relationship between the heat diffusion member 8A and the electronic components 33A to 33C.

[0043] As shown in Figure 7, the heat diffusion member 8A is formed in a substantially rectangular shape, sized to face the multiple electronic components 33A to 33C and the bent portion 24c of the cooling passage 24. The heat diffusion member 8A has a first targeting region 82A, a second targeting region 82B, and a third targeting region 82C. The targeting regions 82A to 82C have a larger porosity of pores in the wick structure than the other regions. Therefore, the heat diffusion member 8 diffuses heat toward the targeting regions 82A to 82C.

[0044] The first targeting region 82A is located upstream of the cooling passage 24, relative to the multiple electronic components 33A to 33C. In other words, the first targeting region 82A is located upstream of the first electronic component 33A, which is the furthest upstream of the electronic components 33A to 33C, relative to the first electronic component 33A. As a result, the heat diffusion member 8A actively diffuses the heat generated by the multiple electronic components 33A to 33C to the region of the cooling passage 24 where the water temperature is lower, thereby dissipating the heat. Consequently, the heat dissipation efficiency of the heat generated by each electronic component 33A to 33C can be improved.

[0045] The second target area 82B faces the upstream side of the cooling passage 24 with respect to the second electronic component 33B and the third electronic component 33C. That is, the second target area 82B is on the upstream side of the cooling passage 24 with respect to the second electronic component 33B and faces the downstream side of the cooling passage 24 with respect to the first electronic component 33A. Thereby, the heat diffusion member 8A actively diffuses the heat generated in the second electronic component 33B to a region where the water temperature in the cooling passage 24 is low for heat dissipation. As a result, the heat dissipation performance of the heat generated in the second electronic component 33B can be improved.

[0046] The third target area 82C faces the upstream side of the cooling passage 24 with respect to the third electronic component 33C. That is, the third target area 82C is on the upstream side of the cooling passage 24 with respect to the third electronic component 33C and faces the downstream side of the cooling passage 24 with respect to the second electronic component 33B. Thereby, the heat diffusion member 8A actively diffuses the heat generated in the third electronic component 33C to a region where the water temperature in the cooling passage 24 is low for heat dissipation. As a result, the heat dissipation performance of the heat generated in the third electronic component 33C can be improved.

[0047] Furthermore, the plurality of target areas 82A to 82C do not face the plurality of electronic components 33A to 33C. Thereby, when the heat diffusion member 8 diffuses the heat generated in each of the electronic components 33A to 33C toward the target area 81, it is possible to prevent adjacent electronic components (for example, the first electronic component 33A and the second electronic component 33B) from having heat interference.

[0048] 3. Third Embodiment [Configuration of Electronic Device] Hereinafter, the electronic device 1B according to the third embodiment will be described. The electronic device 1B has the same configuration as the electronic device 1 according to the first embodiment described above. The difference between the electronic device 1B and the electronic device 1 according to the first embodiment is the heat diffusion member 8B. Therefore, here, the heat diffusion member 8B and the positional relationship between the heat diffusion member 8B and the electronic components 33A to 33C will be described with reference to FIG. 8. FIG. 8 is a diagram showing the positional relationship between the heat diffusion member 8B and the electronic components 33A to 33C.

[0049] As shown in Figure 8, the heat diffusion member 8B is formed in a substantially rectangular shape, sized to face the multiple electronic components 33A to 33C and the bent portion 24c of the cooling passage 24. The heat diffusion member 8B has a first non-directed region 83A, a second non-directed region 83B, and a third non-directed region 83C. The non-directed regions 83A to 83C have a smaller porosity of pores in the wick structure than the other regions. Therefore, the heat diffusion member 8B diffuses heat in a direction away from the non-directed regions 83A to 83C.

[0050] The first non-directed region 83A is located downstream of the first electronic component 33A in the cooling passage 24 and faces the region adjacent to the first electronic component 33A. As a result, the heat diffusion member 8B actively diffuses the heat generated by the first electronic component 33A to the upstream side of the cooling passage 24, i.e., to the region in the cooling passage 24 where the water temperature is lower, thereby dissipating the heat. Consequently, the heat dissipation efficiency of the heat generated by the first electronic component 33A can be improved.

[0051] The second non-directed region 83B is located downstream of the second electronic component 33B in the cooling passage 24 and faces the region adjacent to the second electronic component 33B. As a result, the heat diffusion member 8B actively diffuses the heat generated by the second electronic component 33B to the upstream side of the cooling passage 24, i.e., to the region in the cooling passage 24 where the water temperature is lower, thereby dissipating the heat. Consequently, the heat dissipation efficiency of the heat generated by the second electronic component 33B can be improved.

[0052] The third non-directed region 83C is located downstream of the third electronic component 33C in the cooling passage 24 and faces the region adjacent to the third electronic component 33C. As a result, the heat diffusion member 8B actively diffuses the heat generated by the third electronic component 33C to the upstream side of the cooling passage 24, i.e., to the region in the cooling passage 24 where the water temperature is lower, thereby dissipating the heat. Consequently, the heat dissipation efficiency of the heat generated by the third electronic component 33C can be improved.

[0053] Furthermore, upstream of the third electronic component 33C in the cooling passage 24, there is a region facing the second electronic component 33B. However, a second non-directed region 83B is located between the second electronic component 33B and the third electronic component 33C in the heat diffusion member 8B. Therefore, thermal interference between the second electronic component 33B and the third electronic component 33C can be prevented.

[0054] The embodiments of the electronic device of the present invention, including their effects, have been described above. However, the electronic device of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention as described in the claims.

[0055] Furthermore, the embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those comprising all the described configurations. It is also possible to replace parts of the configuration of one embodiment with those of another embodiment, and to add configurations from other embodiments to the configuration of one embodiment. Additionally, it is possible to add, delete, or replace parts of the configuration of each embodiment with those of other embodiments.

[0056] The heat diffusion members 8 and 8A according to the first and second embodiments described above have only a target region, and the heat diffusion member 8B according to the third embodiment has only a non-target region. However, the heat diffusion member according to the present invention may have both a target region and a non-target region.

[0057] Furthermore, the heat diffusion member according to the present invention is not limited to one piece, but may be divided into multiple pieces. For example, the heat diffusion member 8A according to the second embodiment has multiple targeting regions 82A to 82C. However, the heat diffusion member according to the present invention may be composed of three heat diffusion members, each having one targeting region. In other words, the electronic device of the present invention may be equipped with a heat diffusion member for each electronic component.

[0058] In this specification, although terms such as "parallel" and "orthogonal" are used, these do not mean only strictly "parallel" and "orthogonal," but may also refer to states that are "approximately parallel" or "approximately orthogonal," which include "parallel" and "orthogonal" and are within a range in which they can perform their functions.

[0059] 1, 1A, 1B... Electronic device, 2... Water-cooled enclosure, 3... First circuit board, 4A, 4B... Second circuit board, 5... First cover, 6... Second cover, 8, 8A, 8B... Heat diffusion member, 9... Heat conduction member, 21... Frame, 22... Cooling member, 24... Cooling passage, 24a... Inlet side passage, 24b... Outlet side passage, 24c... Bent section, 25... Inlet section, 26... Outlet section, 27... Connector through hole, 31... Connector, 32... Connection connector, 33... Electronic component, 33A... First electronic component, 33B... Second electronic component, 33C... Third electronic component, 41... Electronic component, 81... Target area, 82A... First target area, 82B... Second target area, 82C... Third target area, 83A...First non-direction destination area, 83B...Second non-direction destination area, 83C...Third non-direction destination area

Claims

1. An electronic device comprising: a circuit board on which heat-generating electronic components are mounted; a cooling member formed to include a position facing the electronic components and having a cooling passage through which a cooling liquid passes; and a heat diffusion member disposed between the electronic components and the cooling passage, wherein the heat diffusion member diffuses the heat generated from the electronic components in the planar direction of the mounting surface of the circuit board and transmits it to the cooling passage side, and has a directional heat diffusion towards a target region facing the upstream side of the cooling passage rather than the region facing the electronic components.

2. The electronic device according to claim 1, wherein the heat diffusion member comprises a housing on a flat plate with a hollow interior, a wick structure housed inside the housing and having a porous capillary structure, and a cooling medium impregnated into the wick structure, wherein when the cooling medium is heated, it turns into vapor and diffuses from the wick structure into the housing, forming a vapor chamber.

3. The electronic device according to claim 2, wherein the porosity of the wick structure in the directed region is greater than that of at least a portion of the region facing the electronic component or the region facing the cooling passage downstream of that region.

4. The electronic device according to claim 2, wherein the heat diffusion member has a non-directed target region that is downstream of the cooling passage and faces the region facing the electronic component, and the porosity of the pores of the wick structure is smaller in the non-directed target region than in at least a portion of the region facing the electronic component or the region that is upstream of the cooling passage and faces that region.

5. The electronic device according to claim 1, wherein the electronic component comprises a first electronic component and a second electronic component, and the first electronic component and the second electronic component are adjacent to each other laterally when viewed from the upstream and downstream directions of the cooling passage.

6. The electronic device according to claim 5, wherein the cooling passage has an inlet-side passage portion, an outlet-side passage portion which is at least a part of which is adjacent to the inlet-side passage portion, and a bent portion which connects the inlet-side passage portion and the outlet-side passage portion, the first electronic component is positioned opposite the inlet-side passage portion, and the second electronic component is positioned opposite the outlet-side passage portion.

7. An electronic device comprising: a circuit board on which heat-generating electronic components are mounted; a cooling member formed to include a position facing the electronic components and having a cooling passage through which a cooling liquid passes; and a heat diffusion member disposed between the electronic components and the cooling passage, wherein the heat diffusion member transmits the heat generated from the electronic components to the cooling passage side while diffusing it in the planar direction of the mounting surface of the circuit board.

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