Electronic control device

Abstract

To provide an electronic control device capable of efficiently cooling a plurality of heat-generating components including heat-generating components located at a distance from a fan's air blowing area without reducing a fan's performance.SOLUTION: The electronic control device includes an enclosure 1 provided with a first boss 6a and a second boss 6b, a circuit substrate 3, a first heat-generating component 4a, a second heat-generating component 4b, a plurality of heat-dissipating fins 8, and a fan 10. A first convex part 7a is provided on the inner surface of the enclosure 1. One end side of the first convex part is arranged in connection with the second boss. The other end side of the first convex part extends towards a third area C.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Vehicles such as automobiles are equipped with, for example, electronic control units (ECUs) for engine control, motor control, etc. Such in-vehicle electronic control devices usually include a circuit board on which heat-generating components are mounted. The heat-generating components are, for example, electronic components with a large amount of heat generation such as electronic circuits. In the above-described electronic control device, in order to protect the heat-generating components and the circuit board, it is necessary to accommodate the circuit board inside the housing. Therefore, it is important how to efficiently release the heat generated by the heat-generating components to the outside of the housing.

[0003] Patent Document 1 describes a cooling structure for heat-generating components, in which a cooling fan that blows air toward a metal plate of the housing is provided inside the housing, and the heat-generating components mounted on the circuit board and the metal plate of the housing are connected by a heat conductor. In the technology described in Patent Document 1, even when heat-generating components are arranged in locations that are difficult to cool with the original cooling fan, a cooling fan is additionally provided inside the housing separately from the original cooling fan so that the heat-generating components can be cooled efficiently and reliably.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology described in Patent Document 1, a cooling fan is arranged inside the housing in a state of facing the metal plate of the housing, and air is blown from this cooling fan so that the air hits the metal plate. For this reason, the flow of the air sent out from the cooling fan hits the metal plate and is forcibly bent, and due to this influence, the fan performance deteriorates, and there is a risk that the heat-generating components cannot be efficiently cooled. Further, the additional cooling fan is arranged inside the housing separately from the main body cooling fan attached to the intake hole of the housing. For this reason, foreign matters such as dust enter the housing from the intake hole of the housing, and this foreign matter is lifted by the cooling fan and adheres to the surfaces of the circuit board, heat-generating components, etc., which may adversely affect the operation of the electronic control device.

[0006] An object of the present invention is to provide an electronic control device capable of efficiently cooling a plurality of heat-generating components including heat-generating components arranged at positions away from the blowing region of the fan without deteriorating the fan performance.

Means for Solving the Problems

[0007] To solve the above problems, for example, the configuration described in the claims is adopted. This application includes a plurality of means for solving the above problems. If one of them is mentioned, it includes a housing provided with a plurality of bosses including a first boss and a second boss on the inner surface, a circuit board housed in the internal space of the housing, a first heat-generating component mounted on the circuit board and thermally connected to the housing via the first boss, a second heat-generating component mounted on the circuit board and thermally connected to the housing via the second boss, a plurality of heat-radiating fins formed on the outer surface of the housing, and a fan mounted on the outer surface of the housing and blowing air toward the heat-radiating fins. The electronic control device is provided with a first convex portion protruding toward the circuit board side on the inner surface of the housing. In the housing, when the region directly above the mounting position of the first heat-generating component is defined as the first region, the region directly above the mounting position of the second heat-generating component is defined as the second region, and the region between the first region and the fan in the blowing direction of the fan is defined as the third region, one end side of the first convex portion is arranged in a state of being connected to the second boss, and the other end side of the first convex portion extends toward the third region so as to transport the heat generated by the second heat-generating component to the third region.

Effect of the Invention

[0008] According to the present invention, it is possible to efficiently cool a plurality of heat-generating components including a heat-generating component arranged at a position away from the blowing region of the fan without degrading the fan performance. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0009]

Figure 1

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and for the sake of clarity of explanation, omissions and simplifications are made as appropriate. The present invention can be implemented in various other forms. Unless otherwise particularly limited, each component may be singular or plural. The positions, sizes, shapes, ranges, etc. of the respective components shown in the drawings may not represent the actual positions, sizes, shapes, ranges, etc. in order to facilitate the understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings.

[0011] <First Embodiment> FIG. 1 is a perspective view showing the appearance of an electronic control device according to the first embodiment, and FIG. 2 is a top view of the electronic control device shown in FIG. 1. Further, FIG. 3 is a sectional view taken along line I-I of the electronic control device shown in FIG. 2, and FIG. 4 is a sectional view taken along line II-II of the electronic control device shown in FIG. 2.

[0012] As shown in FIGS. 1 to 4, the electronic control device 100 includes a housing 1, a circuit board 3, a first heat-generating component 4a, a second heat-generating component 4b, a plurality of heat radiation fins 8, and a fan 10.

[0013] The housing 1 is formed in a rectangular shape in plan view. The housing 1 is composed of an upper housing 1a and a lower housing 1b. The upper housing 1a and the lower housing 1b are fixed by fastening members such as screws (not shown), for example. The upper housing 1a and the lower housing 1b are assembled so as to form a predetermined space inside the housing 1.

[0014] FIG. 5 is a bottom view of the upper housing included in the electronic control device shown in FIG. 1. As shown in FIG. 5, a first boss 6a, a second boss 6b, and a first convex portion 7a are provided on the lower surface of the upper housing 1a. The lower surface of the upper housing 1a corresponds to the inner surface of the housing 1. The first boss 6a, the second boss 6b, and the first convex portion 7a are all provided in a state of protruding from the lower surface of the upper housing 1a toward the circuit board 3 side. The upper housing 1a is preferably formed of a metal material having excellent thermal conductivity, such as aluminum or an aluminum alloy. The upper housing 1a is, for example, a casting obtained by aluminum die casting. In that case, it is desirable to form the upper housing 1a of ADC12. Note that the upper housing 1a is not limited to aluminum or the like, and for example, cost reduction can be achieved by forming it of sheet metal such as iron, or weight reduction can be achieved by forming it of a non-metallic material such as a resin material. Similarly, the lower housing 1b can be formed of sheet metal such as iron or a non-metallic material such as a resin material in addition to aluminum or the like.

[0015] One or a plurality of connectors 9 and Ethernet (registered trademark) terminals (not shown) are arranged on one side of the housing 1. In the present embodiment, as an example, two connectors 9 are arranged on one side of the housing 1. The connector 9 is a connector for electrically connecting to an external device (not shown), that is, a connector for external connection. An insertion portion 12 for inserting the connector 9 is formed in the housing 1, and a part of the connector 9 is arranged so as to face the outside of the housing 1 through the insertion portion 12. The insertion portion 12 is formed by a hole or notch or the like through which the connector 9 can be inserted. Further, a stepped portion 14 for forming the insertion portion 12 is integrally formed on the upper housing 1a of the housing 1. The stepped portion 14 is formed in a state of protruding from the upper surface of the upper housing 1a. The connector 9 is connected to a wiring pattern (not shown) formed on the circuit board 3. Between the electronic control device 100 and an external device (not shown), power supply or transmission and reception of various signals are performed via the connector 9 and the Ethernet terminal.

[0016] The circuit board 3 is housed in the internal space of the housing 1. The internal space of the housing 1 is a space surrounded by the upper housing 1a and the lower housing 1b. At the corner of the upper housing 1a, there is provided a boss 2 (Figs. 3 and 4) protruding toward the circuit board 3 side. The boss 2 is integrally formed with the upper housing 1a. The circuit board 3 is fixed to the boss 2 of the housing 1 by screws (not shown). The circuit board 3 is composed of, for example, a glass epoxy substrate formed of an organic material such as epoxy resin. The circuit board 3 is preferably formed of FR4 (Flame Retardant Type 4) material, but may also be composed of a metal core substrate having a metal material as a base material. The circuit board 3 can be a single-layer board or a multilayer board.

[0017] A plurality of heat-generating components including semiconductor elements such as microcomputers are mounted on the circuit board 3. The plurality of heat-generating components are mounted on the upper surface of the circuit board 3 and are electrically and mechanically connected to the circuit board 3 by a bonding material such as solder. In the present embodiment, as an example of the plurality of heat-generating components mounted on the circuit board 3, the first heat-generating component 4a and the second heat-generating component 4b are cited, but the number of heat-generating components mounted on the circuit board 3 may be three or more. Also, passive elements such as capacitors (not shown) are mounted on the circuit board 3. Further, a wiring pattern (not shown) for electrically connecting the heat-generating component 4 etc. and the connector 9 etc. is formed on the circuit board 3.

[0018] The first heat-generating component 4a is composed of a semiconductor package in which a semiconductor element (semiconductor chip) such as a microcomputer or a CPU (central processing unit) is encapsulated with resin. As the package structure of the first heat-generating component 4a, BGA (Ball Grid Array) is preferable. The main heat dissipation path of the first heat-generating component 4a is the path via the upper surface of the first heat-generating component 4a. The first heat-generating component 4a has a heat spreader or the like for promoting heat dissipation of the semiconductor element that is the heat-generating body, and this heat spreader or the like is arranged in a state of being exposed on the upper surface of the first heat-generating component 4a. For this reason, the amount of heat dissipated by the first heat-generating component 4a is greater in the path of dissipating heat upward by the heat spreader or the like than in the path of dissipating heat to the circuit board 3 via the solder balls.

[0019] On the first heat-generating component 4a, a first heat-conducting material 5a and a first boss 6a are provided. As the first heat-conducting material 5a, various types of materials such as grease-like, gel-like, and sheet-like can be used. Generally used heat-conducting materials are grease-like heat-conducting materials. More specifically, they are heat-curing resins with adhesiveness, semi-curing resins with low elasticity, etc. The first heat-conducting material 5a contains fillers with good heat conductivity formed by metals, carbon, ceramics, etc. The first heat-conducting material 5a is preferably formed of a material having flexibility that can be deformed with respect to deformation, vibration due to the heat of the circuit board 3, and tolerances during manufacturing. Specifically, for example, it is preferable to form the first heat-conducting material 5a of a semi-curing resin using a silicon-based resin containing ceramic fillers. The first heat-conducting material 5a thermally connects the first heat-generating component 4a and the first boss 6a by being laminated on the above-described heat spreader with a predetermined thickness. The first boss 6a is formed in a square shape according to the outer shape of the first heat-generating component 4a. Further, the first boss 6a is provided convexly on the lower surface of the upper housing 1a in order to fill the gap between the first heat-generating component 4a and the upper housing 1a in the thickness direction (height direction) of the housing 1. Thereby, the heat generated by the first heat-generating component 4a is transmitted to the upper housing 1a of the housing 1 via the first heat-conducting material 5a and the first boss 6a. Also, the heat of the first heat-generating component 4a transmitted to the upper housing 1a is configured to be released to the outside of the housing 1 by convective heat transfer by the air blown from the fan 10 between the heat-radiating fins 8.

[0020] The second heat-generating component 4b is constituted by a semiconductor package in which a semiconductor element such as a microcomputer or a CPU is encapsulated with resin in the same manner as the first heat-generating component 4a. As the package structure of the first heat-generating component 4a, BGA is preferable. The second heat-generating component 4b has a heat spreader or the like in the same manner as the first heat-generating component 4a. Therefore, the main heat dissipation path of the second heat-generating component 4b is the path passing through the upper surface of the second heat-generating component 4b.

[0021] On the second heat generating component 4b, a second heat transfer material 5b and a second boss 6b are provided. The second heat transfer material 5b thermally connects the second heat generating component 4b and the second boss 6b. Since the details of the second heat transfer material 5b are the same as those of the first heat transfer material 5a described above, the description thereof is omitted. The second boss 6b is formed in a quadrangular shape according to the outer shape of the second heat generating component 4b. Further, the second boss 6b is provided in a convex shape on the lower surface of the upper housing 1a in order to fill the gap between the second heat generating component 4b and the upper housing 1a in the thickness direction of the housing 1. Thereby, the heat generated by the second heat generating component 4b is transmitted to the upper housing 1a of the housing 1 via the second heat transfer material 5b and the second boss 6b.

[0022] Note that, among the first heat generating component 4a and the second heat generating component 4b, the semiconductor element included in at least one of the heat generating components may be a semiconductor element such as a gigabit Ethernet IC (integrated circuit), a memory IC, or a power supply IC. Further, among the first heat generating component 4a and the second heat generating component 4b, the package structure of at least one of the heat generating components may be, for example, a QFP (Quad Flat Package) or a QFN (Quad Flat Non - leaded package). That is, the package structure of the first heat generating component 4a or the second heat generating component 4b is not limited to a specific structure.

[0023] The first convex portion 7a is formed as a convex protrusion on the lower surface of the upper housing 1a. Here, the arrangement of the first convex portion 7a will be described with reference to FIGS. 2 and 5. The first convex portion 7a linearly extends long in a direction (the left - right direction in FIG. 2) intersecting the plurality of heat - radiating fins 8. In the longitudinal direction of the first convex portion 7a, one end side of the first convex portion 7a is arranged in a state of being connected to the second boss 6b as shown in FIG. 5. In other words, one end side of the first convex portion 7a is arranged at a position continuous with the second boss 6b. The other end side of the first convex portion 7a extends toward the region between the fan 10 and the first heat - generating component 4a. As described above, the first convex portion 7a is integrally formed on the upper housing 1a by casting such as die - casting. However, the first convex portion 7a may be made as a separate member from the upper housing 1a, for example, a member made of a heat pipe, a vapor chamber, or a metal material with high thermal conductivity such as Cu or Al, and this member may be attached to the upper housing 1a.

[0024] The plurality of heat - radiating fins 8 are formed on the upper surface of the upper housing 1a. The upper surface of the upper housing 1a corresponds to the outer surface of the housing 1. The heat - radiating fins 8 are integrally formed with the upper housing 1a when the upper housing 1a is constituted by a casting. However, the heat - radiating fins 8 may be made as a separate member from the upper housing 1a and attached to the upper housing 1a. This also applies to the first boss 6a and the second boss 6b.

[0025] The fan 10 is an air-cooling fan and blows air in the F direction in FIG. 1. The fan 10 is mounted on the upper surface of the upper housing 1a. Therefore, there is no risk that foreign matters such as dust inside the housing 1 will be lifted by the air blown by the fan 10. The first convex portion 7a described above is disposed on the side opposite to the fan 10 in the thickness direction of the upper housing 1a. Therefore, no matter what shape or arrangement the first convex portion 7a has, the presence of the first convex portion 7a will not obstruct the air blown from the fan 10. The fan 10 is disposed closer to one side of the housing 1 where the connector 9 is disposed. Specifically, the fan 10 is disposed at a position adjacent to the stepped portion 14. Thereby, the fan 10 is disposed in the vicinity of the connector 9. By disposing the fan 10 in the vicinity of the connector 9 in this way, the connector 9 and the fan 10 can be easily wired and the wiring length can be shortened. Among the plurality of heat radiation fins 8 formed on the upper surface of the upper housing 1a, some of the heat radiation fins 8 are formed shorter than the other heat radiation fins 8 so as not to interfere with the mounting position of the fan 10. Also, a plurality of heat radiation fins 8 are disposed in the air blowing direction F of the fan 10. These heat radiation fins 8 are disposed along the air blowing direction F of the fan 10. Therefore, the air sent out from the fan 10 flows between the heat radiation fins 8.

[0026] The fan 10 can be regarded as a refrigerant circulation device for circulating air as a refrigerant. The fan 10 is preferably a centrifugal fan or a blower fan. The fan 10 which is a centrifugal fan or a blower fan is configured to bend the sucked air by 90° inside the fan and exhaust it. Therefore, by mounting the fan 10 in close contact with the upper surface of the upper housing 1a, it is possible to contribute to the reduction of the height of the electronic control device 100. However, the fan 10 is not limited to a centrifugal fan or a blower fan, and may be, for example, an axial flow fan. In that case, it is advisable to provide an appropriate gap between the upper surface of the upper housing 1a and mount the axial flow fan so that air can be sent out from the axial flow fan between the heat radiation fins 8.

[0027] Here, the upper housing 1a is defined by dividing it into a plurality of regions. As shown in FIGS. 2 to 4, the upper housing 1a has a first region A, a second region B, and a third region C. These regions are divided by the mounting positions and the air blowing directions of the first heat generating component 4a, the second heat generating component 4b, and the fan 10. Specifically, the first region A is the region directly above the mounting position of the first heat generating component 4a. The heat radiation fins 8 existing in the first region A are cooled by the air sent out from the fan 10. That is, the first region A is configured to dissipate heat by forced air cooling. The second region B is the region directly above the mounting position of the second heat generating component 4b. The heat radiation fins 8 existing in the second region B are configured to dissipate heat mainly by natural air cooling. The third region C is the region between the first region A and the fan 10 in the air blowing direction F (FIG. 1) of the fan 10.

[0028] The first region A is located in the air blowing direction F of the fan 10. Therefore, the first region A has a higher heat dissipation effect than the second region B. In order to improve the heat dissipation efficiency of the electronic control device 100, it is preferable that the heat generation amount of the first heat generating component 4a is larger than the heat generation amount of the second heat generating component 4b.

[0029] Regarding the arrangement of the first convex portion 7a described above, when described in terms of regions, it is as follows. First, one end side of the first convex portion 7a is arranged at a position adjacent to the second region B. Also, the other end side of the first convex portion 7a extends toward the third region C. That is, the first convex portion 7a extends from the second region B toward the third region C. Thereby, the heat generated by the second heat generating component 4b is transported to the third region C through the first convex portion 7a. Therefore, regarding the heat of the second heat generating component 4b transported to the third region C through the first convex portion 7a, it is possible to actively dissipate heat by convective heat transfer using the air sent out from the fan 10 toward the third region C.

[0030] Furthermore, the third region C is located between the fan 10 and the first region A, i.e., on the upstream side of the first region A, in the air blowing direction F of the fan 10. Therefore, the air sent out from the fan 10 is supplied to the third region C in a cold state before taking the heat of the first heat generating component 4a and being warmed, i.e., as cold air. Thus, the temperature gradient becomes large between the second region B located directly above the second heat generating component 4b and the third region C receiving the air blowing (cold air) from the fan 10, and the heat transfer in the first convex portion 7a is promoted by this temperature gradient. Therefore, the heat of the second heat generating component 4b can be efficiently released to the outside of the housing 1. On the other hand, the air sent out from the fan 10 is supplied to the first region A located directly above the first heat generating component 4a. Therefore, the heat of the first heat generating component 4a can be efficiently released to the outside of the housing 1.

[0031] In addition, in FIG. 2, as a preferable example for efficiently performing heat transport from the second region B to the third region C, the other end side of the first convex portion 7a is arranged in a state of crossing the third region C, but it is not limited to this, and the other end of the first convex portion 7a may be arranged in the third region C or in front of the third region C. That is, the first convex portion 7a only needs to extend toward the third region C so as to transport the heat generated by the second heat generating component 4b to the third region C. When the other end of the first convex portion 7a is arranged in front of the third region C, the first convex portion 7a does not exist in the third region C, and a free space is secured on the circuit board 3 directly below the third region C. Therefore, on the circuit board 3, electronic components (for example, tall components, etc.) necessary for operating the first heat generating component 4a can be arranged near the first heat generating component 4a by using the above free space.

[0032] Also, in FIG. 2, the first convex portion 7a is formed in a straight line shape, but it is not limited to this, and the first convex portion 7a may be partially bent so as not to interfere with low-profile electronic components such as capacitors. Also, the protruding dimension of the first convex portion 7a with respect to the lower surface of the upper housing 1a may be partially increased or decreased.

[0033] The plurality of heat dissipation fins 8 are formed on the upper surface of the upper housing 1a as described above. Each heat dissipation fin 8 is arranged at regular intervals in a direction orthogonal to the air blowing direction F of the fan 10. The heat dissipation fin 8 preferably forms a linear flow path through which air can be blown from the fan 10 toward the first region A. For this reason, in the present embodiment, each heat dissipation fin 8 is formed parallel to the air blowing direction F of the fan 10. As a result, the air sent out from the fan 10 smoothly flows along the heat dissipation fins 8 so as to pass through the third region C and the first region A in order. Therefore, the first heat generating component 4a can be cooled without degrading the fan performance.

[0034] Note that the shape and size of the heat dissipation fin 8 are not limited to the shapes and sizes shown in FIGS. 1 and 2 and can be arbitrarily changed. Modification examples of the shape of the heat dissipation fin 8 and the like will be described in detail later. Here, the region forced-air-cooled by the air blowing from the fan 10 is defined as the forced-air-cooled region D, and the region that surrounds the mounting position of the second heat generating component 4b and is naturally air-cooled is defined as the natural-air-cooled region E. In such a case, the forced-air-cooled region D is a region including the first region A and the third region C, and the natural-air-cooled region E is a region including the second region B.

[0035] The interval between the heat dissipation fins 8 in the forced-air-cooled region D is preferably the same as or narrower than the interval between the heat dissipation fins 8 in the natural-air-cooled region E. The reason is as follows. First, if the interval between the heat dissipation fins 8 in the forced-air-cooled region D is narrowed, a larger heat dissipation area can be ensured by the heat dissipation fins 8, so that the amount of heat dissipated in the forced-air-cooled region D can be increased. On the other hand, if the interval between the heat dissipation fins 8 in the natural-air-cooled region E is narrowed, it becomes difficult for air due to natural convection to enter the back side of the heat dissipation fins 8 (the side closer to the upper surface of the upper housing 1a). Therefore, in order to dissipate heat efficiently in both the forced-air-cooled region D and the natural-air-cooled region E, the interval between the heat dissipation fins 8 in the forced-air-cooled region D is preferably the same as or narrower than the interval between the heat dissipation fins 8 in the natural-air-cooled region E.

[0036] As described above, in the first embodiment, the first convex portion 7a is provided on the lower surface of the upper housing 1a. One end side of the first convex portion 7a is arranged in a state of being connected to the second boss 6b, and the other end side of the first convex portion 7a extends from the second region B toward the third region C so as to transport the heat generated by the second heat generating component 4b to the third region C. Thereby, both the first heat generating component 4a arranged in the blowing region (forced air cooling region D) of the fan 10 and the second heat generating component 4b arranged at a position away from the blowing region of the fan 10 can be efficiently cooled without degrading the fan performance. Further, by being able to efficiently cool the second heat generating component 4b arranged at a position away from the blowing region of the fan 10, the degree of freedom in arranging the second heat generating component 4b on the circuit board 3 can be increased.

[0037] Further, in the first embodiment, the first heat generating component 4a and the first boss 6a are connected by the first heat transfer material 5a, and the second heat generating component 4b and the second boss 6b are connected by the second heat transfer material 5b. Thereby, the heat generated by the first heat generating component 4a can be efficiently transmitted to the upper housing 1a via the first heat transfer material 5a and the first boss 6a. Similarly, the heat generated by the second heat generating component 4b can be efficiently transmitted to the upper housing 1a via the second heat transfer material 5b and the second boss 6b.

[0038] <Second Embodiment> FIG. 6 is a diagram showing a cross-sectional state of the electronic control device according to the second embodiment at the position of the I-I line in FIG. 2, and FIG. 7 is a diagram showing a cross-sectional state of the electronic control device according to the second embodiment at the position of the II-II line in FIG. 2. As shown in FIGS. 6 and 7, the electronic control device 100 according to the second embodiment is different in that a heat transfer member 11 is provided between the circuit board 3 and the first convex portion 7a as compared with the configuration (FIGS. 3 and 4) of the first embodiment described above. The heat transfer member 11 is a member that thermally connects the first convex portion 7a and the circuit board 3. On the upper surface of the circuit board 3, a metal portion not covered by a resist or the like is exposed, and the heat transfer member 11 is in contact with this metal portion.

[0039] The heat transfer member 11 may be formed of a grease-like heat conductive material similar to the heat conductive material 5 described above, or may be formed of a gasket or the like in which a conductive non-woven fabric is wound around a sponge material. The heat transfer member 11 preferably has flexibility (elasticity) in addition to heat conductivity. Since the heat transfer member 11 has flexibility, the heat transfer member 11 can be surely brought into close contact with both the first convex portion 7a and the circuit board 3. In addition, deformation, vibration, and manufacturing tolerances of the circuit board 3 due to heat can be absorbed by the deformation of the heat transfer member 11.

[0040] As shown in FIG. 8, the heat transfer member 11 may be formed continuously linearly along the longitudinal direction of the first convex portion 7a, or may be formed in a dot shape at intervals along the longitudinal direction of the first convex portion 7a as shown in FIG. 9. In the configuration in which the heat transfer member 11 is formed linearly, a wide contact area of the heat transfer member 11 with respect to the circuit board 3 and the first convex portion 7a can be ensured. Therefore, the heat of the circuit board 3 can be efficiently transmitted to the first convex portion 7a. In the configuration in which the heat transfer member 11 is formed in a dot shape, it is possible to flexibly cope even when it is necessary to divide the heat transfer member 11 into small parts due to the mounting density of the circuit board 3. The width of the heat transfer member 11 is preferably the same as the width of the first convex portion 7a in order to ensure a wide contact area. However, the width of the heat transfer member 11 may be narrower than the width of the first convex portion 7a. The width of the heat transfer member 11 refers to the dimension of the heat transfer member 11 in the short direction of the first convex portion 7a, and the width of the first convex portion 7a refers to the dimension in the short direction of the first convex portion 7a.

[0041] In FIG. 9, the intervals of the heat transfer members 11 in the longitudinal direction of the first convex portion 7a may be at a constant interval or may vary depending on the location. Also, the sizes of the respective heat transfer members 11 arranged in the longitudinal direction of the first convex portion 7a may be of a constant size or may vary depending on the location.

[0042] In the second embodiment, by providing the heat transfer member 11 between the first convex portion 7a and the circuit board 3, heat from other heat generating components (not shown) and the circuit board 3, excluding the first heat generating component 4a and the second heat generating component 4b, can be easily conducted to the first convex portion 7a through the heat transfer member 11. Therefore, the heat dissipation performance of the electronic control device 100 can be improved. In addition, deformation, vibration due to the heat of the circuit board 3, and manufacturing tolerances can be absorbed by the deformation of the heat transfer member 11. For this reason, an electronic control device 100 having high reliability can be provided.

[0043] <Third Embodiment> FIG. 10 is a top view of the electronic control device according to the third embodiment, and FIG. 11 is a bottom view of the upper housing included in the electronic control device shown in FIG. 10. As shown in FIGS. 10 and 11, the electronic control device 100 according to the third embodiment has a different shape of the first convex portion 7a compared to the configuration (FIGS. 2 and 5) of the first embodiment described above. In the longitudinal direction of the first convex portion 7a, one end side (the left side in FIG. 11) of the first convex portion 7a is arranged in a state of being connected to two sides of the second boss 6b. Further, the first convex portion 7a is formed so that its width gradually narrows from the second region B toward the third region C so as not to interfere with the first boss 6a. In addition, the other end side of the first convex portion 7a extends from the second region B toward the third region C in the same manner as in the first embodiment described above. In addition, the other end side of the first convex portion 7a is arranged in a state of crossing the third region C.

[0044] In the third embodiment, by arranging one end side of the first convex portion 7a to be connected to two sides of the second boss 6b, compared with the configuration of the first embodiment described above, the heat of the second heat-generating component 4b can be efficiently transferred from the second boss 6b to the first convex portion 7a. Further, since one end side of the first convex portion 7a is formed wide, the area of the first convex portion 7a becomes wider compared with the configuration of the first embodiment. For this reason, the thermal resistance when transporting the heat of the second heat-generating component 4b to the third region C is reduced. Therefore, it becomes easier to transport the heat of the second heat-generating component 4b to the third region C through the first convex portion 7a. Thus, the heat dissipation performance of the electronic control device 100 can be improved.

[0045] In addition, in FIG. 11, one end side of the first convex portion 7a is arranged to be connected to two sides of the second boss 6b, but it is not limited thereto, and one end side of the first convex portion 7a may be arranged to be connected to three sides or four sides of the second boss 6b. Further, the shape of the first convex portion 7a may be any shape as long as one end side of the first convex portion 7a is connected to two or more sides of the second boss 6b and the other end side of the first convex portion 7a does not interfere with the first boss 6a. Also, in terms of improving the heat dissipation performance of the electronic control device 100, the larger the size of the first convex portion 7a, the more preferable.

[0046] <Fourth Embodiment> FIG. 12 is a top view of the electronic control device according to the fourth embodiment. As shown in FIG. 12, the electronic control device 100 according to the fourth embodiment has different orientations of the plurality of heat dissipation fins 8 compared with the configuration (FIG. 2) of the first embodiment described above. This will be described in detail below.

[0047] First, among the plurality of heat dissipation fins 8 formed on the upper surface of the upper housing 1a, the heat dissipation fins 8a arranged on the first region A side are arranged in a direction along the air blowing direction of the fan 10, similar to the first embodiment. In contrast, the heat dissipation fins 8b arranged on the second region B side are arranged at an angle different from that of the heat dissipation fins 8a arranged on the first region A side. Further, the heat dissipation fins 8b arranged in the vicinity of the second region B are arranged at an angle different from that of the heat dissipation fins 8a toward the forced air cooling region D which is the air blowing region of the fan 10. Also, including the heat dissipation fins 8b arranged in the vicinity of the second region B, the heat dissipation fins 8b arranged in the natural air cooling region E are arranged in a direction orthogonal to the air blowing direction F (FIG. 1) of the fan 10. In other words, in FIG. 12, the heat dissipation fins 8a arranged on the first region A side are arranged vertically, and the heat dissipation fins 8b arranged on the second region B side are arranged horizontally.

[0048] In the fourth embodiment, by arranging the heat dissipation fins 8b arranged in the vicinity of the second region B at an angle different from that of the heat dissipation fins 8a toward the forced air cooling region D including the third region C, the distribution of the heat transmitted from the second heat generating component 4b to the upper housing 1a spreads along the heat dissipation fins 8b toward the forced air cooling region D side. Therefore, the heat of the second heat generating component 4b can be efficiently transported to the forced air cooling region D. Also, by arranging all the heat dissipation fins 8b arranged in the natural air cooling region E, including the heat dissipation fins 8b arranged in the vicinity of the second region B and the heat dissipation fins 8b arranged at positions adjacent to the forced air cooling region D, uniformly horizontally as shown in FIG. 12, the heat dissipation performance of the heat generating components (including the second heat generating component 4b) mounted in the natural air cooling region E can be improved.

[0049] In addition, in FIG. 12, all the heat dissipation fins 8b arranged in the natural air cooling region E are arranged horizontally, but not limited to this. Only the heat dissipation fins 8b arranged near the second region B may be arranged horizontally, or only the heat dissipation fins 8b arranged at a position adjacent to the forced air cooling region D may be arranged horizontally. Further, the direction of the heat dissipation fins 8b is not limited to a direction orthogonal to the blowing direction F of the fan 10, and it is sufficient that the heat dissipation fins 8b are formed toward the forced air cooling region D.

[0050] <Fifth Embodiment> FIG. 13 is a top view of the electronic control device according to the fifth embodiment. FIG. 14 is a cross-sectional view taken along line IV-IV of the electronic control device shown in FIG. 13, and FIG. 15 is a cross-sectional view taken along line V-V of the electronic control device shown in FIG. 13. FIG. 16 is a bottom view of the upper housing included in the electronic control device shown in FIG. 13. As shown in FIGS. 13 to 16, the electronic control device 100 according to the fifth embodiment is different in that a second convex portion 7b is provided on the housing 1 as compared with the configuration (FIGS. 1 to 5) of the first embodiment described above. The second convex portion 7b is provided on the bottom surface of the upper housing 1a. Further, the second convex portion 7b is provided in a state of protruding from the bottom surface of the upper housing 1a toward the circuit board 3 side. That is, the second convex portion 7b is formed as a convex-shaped protrusion on the bottom surface of the upper housing 1a. The second convex portion 7b is formed in a shape bent at a right angle as shown in FIG. 16, that is, an L shape.

[0051] One end side of the second convex portion 7b is arranged in a state of being connected to the second boss 6b. In other words, the second convex portion 7b is arranged at a position continuous with the second boss 6b. One end side of the first convex portion 7a is connected to one side of the second boss 6b, and one end of the second convex portion 7b is connected to the other side of the second boss 6b located on the opposite side. That is, a part of the first convex portion 7a and a part of the second convex portion 7b are arranged to be continuous via the second boss 6b. Thereby, the heat transmitted from the second heat generating component 4b to the second boss 6b can be dissipated to both the first convex portion 7a and the second convex portion 7b.

[0052] The other end side of the second convex portion 7b extends to the downstream side of the first region A in the air blowing direction (FIG. 1) of the fan 10. Thereby, the other end side of the second convex portion 7b can be directly cooled by the air blown from the fan 10. Further, the other end of the second convex portion 7b is disposed at a position farther from the fan 10 than the third region C and the first region A. Further, as shown in FIG. 13, the distance L1 between the closest point of the second convex portion 7b to the fan 10 and the fan 10 is longer than the distance L2 between the closest point of the first convex portion 7a to the fan 10 and the fan 10. Thereby, when air is sent out from the fan 10, the other end side of the first convex portion 7a can be preferentially cooled over the other end side of the second convex portion 7b. Further, as shown in FIG. 14, in the air blowing direction F of the fan 10, the first convex portion 7a and the first boss 6a are arranged with a first interval G1 therebetween, and the second convex portion 7b and the first boss 6a are arranged with a second interval G2 therebetween. Thereby, interference between the heat of the second heat generating component 4b transported through the first convex portion 7a and the second convex portion 7b to the forced air cooling region and the heat of the first heat generating component 4a mounted in the first region A within the forced air cooling region can be suppressed.

[0053] In the fifth embodiment, by providing the second convex portion 7b on the lower surface of the upper housing 1a, the heat dissipation path for releasing the heat of the second heat generating component 4b is increased. Further, the other end side of the second convex portion 7b is cooled by the air blown by the fan 10. For this reason, the temperature gradient becomes large between one end of the second convex portion 7b located in the vicinity of the second region B and the other end of the second convex portion 7b located in the forced air cooling region, and the heat transfer in the second convex portion 7b is promoted by this temperature gradient. Therefore, the heat of the second heat generating component 4b can be efficiently transported to the forced air cooling region side.

[0054] Note that the second convex portion 7b is formed integrally with the upper housing 1a by casting such as die casting, like the first convex portion 7a, but is not limited thereto. The second convex portion 7b may be formed as a separate member from the upper housing 1a, for example, a member made of a heat pipe, a vapor chamber, or a metal material having high thermal conductivity such as Cu or Al, and this member may be attached to the upper housing 1a.

[0055] <Sixth Embodiment> FIG. 17 is a top view of the electronic control unit according to the sixth embodiment. As shown in FIG. 17, the electronic control unit 100 according to the sixth embodiment has different orientations of the plurality of heat radiation fins 8 formed on the upper surface of the upper housing 1a as compared with the configuration (FIG. 13) of the above-described fifth embodiment, among the plurality of heat radiation fins 8 arranged in the air blowing direction of the fan 10. Specifically, among the plurality of heat radiation fins 8 arranged in the air blowing direction of the fan 10, a predetermined heat radiation fin 8c is inclined with respect to the air blowing direction of the fan 10 so as to extend the air blowing region (forced air cooling region D) of the fan 10 toward the second region B. Further, the interval between adjacent heat radiation fins 8c in the direction orthogonal to the air blowing direction of the fan 10 gradually increases as the distance from the fan 10 increases. Further, focusing on each heat radiation fin 8c, one end of the heat radiation fin 8c is arranged in the third region C, and the other end of the heat radiation fin 8c is arranged on the natural air cooling region side (the right side in FIG. 17) than one end of the heat radiation fin 8c due to the inclination of the heat radiation fin 8c itself.

[0056] In the sixth embodiment, due to the inclination of the heat dissipation fins 8c arranged in the air blowing direction of the fan 10, the air blowing area of the fan 10 is expanded toward the second area B side, so that the housing 1 can be forced air-cooled over a wider range. In addition, since the area of the second convex portion 7b arranged in the air blowing area of the fan 10 increases, compared with the fifth embodiment described above, the heat of the heat generating components (including the second heat generating component 4b) mounted in the natural air cooling area can be efficiently transported to the forced air cooling area D. Further, the heat dissipation fins 8c are formed obliquely at an angle from a third area C located near the air outlet of the fan 10. For this reason, most of the air sent out between the fan 10 and the heat dissipation fins 8c can flow to a position deviating from directly above the mounting position of the first heat generating component 4a. As a result, on the downstream side of the first area A in the air blowing direction of the fan 10, not only the air heated by taking away the heat of the first heat generating component 4a but also the cooled air sent out from the fan 10 can flow. Therefore, the other end side of the second convex portion 7b can be efficiently cooled by the air blowing from the fan 10. In addition, interference between the heat of the second heat generating component 4b transported to the forced air cooling area D through the second convex portion 7b and the heat of the first heat generating component 4a mounted in the first area A within the forced air cooling area D can be suppressed.

[0057] <Seventh Embodiment> FIG. 18 is a top view of the electronic control device according to the seventh embodiment, and FIG. 19 is a cross-sectional view taken along line III-III of the electronic control device shown in FIG. 18. As shown in FIGS. 18 and 19, compared with the configuration of the first embodiment described above (FIGS. 2 and 4), the electronic control device 100 according to the seventh embodiment is different in that a third convex portion 7c is provided on the upper housing 1a of the housing 1. The third convex portion 7c is provided on the upper surface of the upper housing 1a together with the heat radiation fins 8. The third convex portion 7c protrudes on the side opposite to the first convex portion 7a in the thickness direction of the upper housing 1a. The protruding dimension of the third convex portion 7c with respect to the upper surface of the upper housing 1a is set to be the same as the protruding dimension of the heat radiation fins 8. Further, the third convex portion 7c extends from the vicinity of the second region B to in front of the third region C. More specifically, in the longitudinal direction of the third convex portion 7c, one end of the third convex portion 7c (the right end in FIG. 18) is disposed at substantially the same position as one end of the first convex portion 7a, and the other end of the third convex portion 7c is disposed in the immediate vicinity of the third region C so as not to impede the air blowing of the fan 10. Further, the third convex portion 7c is formed along the first convex portion 7a. Note that the direction and shape of the third convex portion 7c are not limited to the examples shown in FIGS. 18 and 19, and can be changed as necessary. For example, by setting the protruding dimension of the third convex portion 7c to be larger than the protruding dimension of the heat radiation fins 8, the efficiency of heat transport by the third convex portion 7c may be increased.

[0058] In the seventh embodiment, by providing the third convex portion 7c on the upper housing 1a, the cross-sectional area for transporting the heat of the second heat generating component 4b to the third region C becomes larger than the case where only the first convex portion 7a is provided. Thereby, since the thermal resistance when transporting the heat of the second heat generating component 4b to the third region C is reduced, the heat dissipation performance of the electronic control device 100 can be improved. Further, although the third convex portion 7c extends from the vicinity of the second region B to in front of the third region C, it is not provided in the third region C. For this reason, heat transport by the third convex portion 7c is possible without adversely affecting the air blowing of the fan 10 (without degrading the fan performance). Therefore, the heat dissipation performance of the second heat generating component 4b can be improved while maintaining the heat dissipation performance of the first heat generating component 4a.

[0059] Note that the present invention is not limited to the above-described embodiments and includes various modifications. For example, in the above-described embodiments, the present invention has been described in detail for easy understanding of the content, but the present invention is not necessarily limited to having all the configurations described in the above-described embodiments. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Further, it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Also, for part of the configuration of each embodiment, it is possible to delete it, add another configuration, or replace it with another configuration.

Description of Reference Numerals

[0060] 1... housing, 3... circuit board, 4a... first heat-generating component, 4b... second heat-generating component, 5a... first heat transfer material, 5b... second heat transfer material, 6a... first boss, 6b... second boss, 7a... first convex portion, 7b... second convex portion, 7c... third convex portion, 8, 8a, 8b, 8c... heat dissipation fins, 9... connector, 10... fan, 11... heat transfer member, 100... electronic control device, A... first region, B... second region, C... third region, F... air flow direction, G1... first interval, G2... second interval

Claims

1. A housing having a plurality of bosses including a first boss and a second boss provided on an inner surface thereof; A circuit board housed in the internal space of the housing; A first heat generating component mounted on the circuit board and thermally connected to the housing via the first boss; A second heat generating component mounted on the circuit board and thermally connected to the housing via the second boss; A plurality of heat dissipation fins formed on an outer surface of the housing; A fan mounted on the outer surface of the housing and blowing air toward the heat dissipation fins; An electronic control device comprising: On the inner surface of the housing, a first convex portion protruding toward the circuit board side is provided; In the housing, when the region directly above the mounting position of the first heat generating component is defined as a first region, the region directly above the mounting position of the second heat generating component is defined as a second region, and the region between the first region and the fan in the blowing direction of the fan is defined as a third region, One end side of the first convex portion is arranged in a state of being connected to the second boss; The other end side of the first convex portion extends toward the third region so as to transport heat generated by the second heat generating component to the third region Electronic control device.

2. One end side of the first convex portion is arranged so as to be connected to at least two sides of the second boss The electronic control device according to claim 1.

3. On the inner surface of the housing, a second convex portion protruding toward the circuit board side is further provided; One end side of the second convex portion is arranged in a state of being connected to the second boss; The other end side of the second convex portion extends to the downstream side of the first region in the blowing direction of the fan The electronic control device according to claim 1.

4. A part of the first convex portion and a part of the second convex portion are arranged to be continuous via the second boss The electronic control device according to claim 3.

5. The distance between the closest point of the second convex portion to the fan and the fan is longer than the distance between the closest point of the first convex portion to the fan and the fan The electronic control device according to claim 3.

6. In the blowing direction of the fan, the first convex portion and the first boss are arranged with a first interval therebetween, and the second convex portion and the first boss are arranged with a second interval therebetween The electronic control device according to claim 3.

7. Further comprising a heat transfer member that thermally connects the first convex portion and the circuit board The electronic control device according to claim 1.

8. Of the plurality of heat dissipation fins formed on the outer surface of the housing, a predetermined heat dissipation fin arranged in the blowing direction of the fan is inclined with respect to the blowing direction of the fan so as to extend the blowing region of the fan toward the second region side. The electronic control device according to claim 1.

9. The housing is provided with a third convex portion protruding on the side opposite to the first convex portion. The third convex portion extends from the vicinity of the second region to the front of the third region. The electronic control device according to claim 1.

10. The heat generation amount of the first heat generating component is larger than the heat generation amount of the second heat generating component. The electronic control device according to claim 1.

11. A connector for external connection is arranged on one side of the housing. The fan is arranged in the vicinity of the connector. The electronic control device according to claim 1.

12. The fan is a centrifugal fan or a blower fan. The electronic control device according to claim 1.

13. The first heat generating component and the first boss are connected by a first heat transfer material. The second heat generating component and the second boss are connected by a second heat transfer material. The electronic control device according to claim 1.

14. Of the plurality of heat dissipation fins formed on the outer surface of the housing, the heat dissipation fins arranged in the vicinity of the second region are arranged at an angle different from that of the heat dissipation fins arranged on the first region side toward the blowing region of the fan. The electronic control device according to claim 1.

15. The heat dissipation fins arranged in the vicinity of the second region are arranged in a direction perpendicular to the blowing direction of the fan. The electronic control device according to claim 14.

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