Electronic control device

Abstract

The present invention improves heat dissipation performance. This electronic control device comprises: a circuit substrate whereon a heat-generating component is mounted; a case housing the circuit substrate; and a heat sink connected to the case and made of a material having a higher thermal conductivity than the case. The case has a through-hole in a substrate-facing part facing the plane of the circuit substrate. The heat sink has: a fixed part fixed to the case; a heat contact part penetrating through the through-hole of the case; a case contact part positioned between the fixed part and the heat contact part; and a plate-like, non-contact part positioned between the fixed part and the case contact part. The heat contact part transfers heat from the heat-generating component directly or via a heat transfer member. The case contact part is in contact with a portion of the substrate-facing part. The non-contact part faces the substrate-facing part across a gap and, when the fixed part is fixed to the case, is elastically deformed.

Description

Electronic control unit

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

[0002] Generally, vehicles such as automobiles are equipped with a plurality of electronic control units (ECUs) for controlling various objects including the engine, power steering, brakes, airbags, etc. The electronic control units installed in vehicles have a structure in which a circuit board on which electronic components are mounted is housed inside a housing (see, for example, Patent Document 1).

[0003] The electronic control device described in Patent Document 1 includes a housing that houses a circuit board and a metal member for heat dissipation. The housing has a wall that faces the mounting location of an electronic component on the circuit board and is partially open. The metal member has a convex shape that penetrates the opening in the housing and a flange formed on the bottom side of the convex shape. The top of the convex shape contacts the position on the circuit board that corresponds to the mounting location of the electronic component, with a heat dissipation filler interposed therebetween. The flange contacts the wall portion of the housing around the opening, with a sealing filler interposed therebetween.

[0004] JP 2014-093414 A

[0005] However, in the electronic control device described in Patent Document 1, the upper surface of the flange of the metal member rests on the bottom surface of the housing. Therefore, it was necessary to design the heat dissipation clearance between the convex top of the metal member and the substrate, taking into account dimensional errors in the distance from the upper surface of the flange to the convex top, the parallelism of the upper surface of the flange, and variations in the thickness of the sealing filler. As a result, it was difficult to reduce the design value of the heat dissipation clearance, which hindered improvements in heat dissipation performance.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic control device capable of improving heat dissipation performance.

[0007] In order to solve the above problems and achieve the object of the present invention, an electronic control device according to one aspect of the present invention comprises a circuit board on which a heat-generating component is mounted, a case for accommodating the circuit board, and a heat sink connected to the case and made of a material with higher thermal conductivity than the case. The case has a through-hole in a board-facing portion facing the flat surface of the circuit board. The heat sink has a fixed portion fixed to the case, a thermal contact portion passing through the through-hole in the case, a case-contact portion located between the fixed portion and the thermal contact portion, and a plate-shaped non-contact portion located between the fixed portion and the case-contact portion. Heat is transferred to the thermal contact portion from the circuit board or the heat-generating component directly or via a heat transfer member. The case-contact portion contacts a portion of the board-facing portion. The non-contact portion faces the board-facing portion with a gap therebetween and elastically deforms when the fixed portion is fixed to the case.

[0008] According to the electronic control device having the above-described configuration, it is possible to improve the heat dissipation performance. Note that problems, configurations, and effects other than those described above will become clear from the following description of the embodiment.

[0009] 12. A perspective view of an electronic control device according to a first embodiment. An exploded perspective view of an electronic control device according to the first embodiment. A cross-sectional view taken along line A-A of FIG. 1. A perspective view of a heat sink according to the first embodiment. A cross-sectional view showing a state in which a thermal contact portion of the heat sink according to the first embodiment is in contact with an electronic component. A cross-sectional view showing a state in which a fixing portion of the heat sink is fixed to a case from the state shown in FIG. 5. A cross-sectional view of an electronic control device according to a second embodiment. A cross-sectional view showing a state in which a thermal contact portion of the heat sink according to the second embodiment is in contact with a circuit board. A cross-sectional view showing a state in which a fixing portion of the heat sink is fixed to a case from the state shown in FIG. 8. A perspective view of an electronic control device according to a third embodiment. A perspective view of a heat sink according to the third embodiment. A cross-sectional view showing a state in which a thermal contact portion of the heat sink according to the third embodiment is in contact with an electronic component. A cross-sectional view showing a state in which a fixing portion of the heat sink is fixed to a case from the state shown in FIG. 16. A perspective view of an electronic control device according to a fourth embodiment. A cross-sectional view of a heat sink according to the fourth embodiment. A cross-sectional view showing a state in which a thermal contact portion of the heat sink according to the fourth embodiment is in contact with an electronic component. A cross-sectional view showing a state in which a fixing portion of the heat sink is fixed to a case from the state shown in FIG. 16. A perspective view of an electronic control device according to a fifth embodiment. FIG. 14 is a perspective view of a heat sink according to a fifth embodiment. FIG. 15 is an exploded perspective view of an electronic control device according to a sixth embodiment. FIG. 16 is a perspective view of a heat sink according to a seventh embodiment. FIG. 17 is a perspective view of a heat sink according to an eighth embodiment. FIG. 18 is a perspective view of a heat sink according to a ninth embodiment. FIG. 19 is a perspective view of an electronic control device according to a tenth embodiment. FIG. 20 is a perspective view of a heat sink according to the tenth embodiment. FIG. 21 is a cross-sectional view of an electronic control device according to an eleventh embodiment.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are designated by the same reference numerals, and redundant description will be omitted.

[0011] 1. First Embodiment [Configuration of Electronic Control Device] First, the configuration of an electronic control device according to a first embodiment of the present invention will be described with reference to Figs. 1 to 3. Fig. 1 is a perspective view of the electronic control device according to the first embodiment. Fig. 2 is an exploded perspective view of the electronic control device according to the first embodiment. Fig. 3 is a schematic view of a cross section taken along line A-A shown in Fig. 1.

[0012] 1 to 3 is a vehicle electronic control device mounted on a vehicle that runs on liquid fuel such as gasoline or diesel. The electronic control device according to the present invention can also be widely applied to electronic control devices mounted on vehicles that run on hydrogen fuel, hybrid vehicles, electric vehicles, etc. Furthermore, the object controlled by the electronic control device is not limited to a specific object.

[0013] In the following description, in order to clarify the shapes and positional relationships of the various parts of the electronic control device 101, the thickness direction (height direction) of the electronic control device 101 is defined as the Z direction, and one of the two axial directions perpendicular to the Z direction is defined as the X direction and the other as the Y direction. The X direction, Y direction, and Z direction are perpendicular to each other.

[0014] As shown in FIGS. 1 to 3, the electronic control device 101 includes a circuit board 1, a connector 2, a case 3, and a heat sink 4.

[0015] The circuit board 1 is formed in the shape of a rectangular flat plate. The circuit board 1 has two sides that are approximately parallel to the X direction and two sides that are approximately parallel to the Y direction. The circuit board 1 is, for example, a printed wiring board, which is a rigid board that uses glass epoxy as a base material.

[0016] The circuit board 1 has mounting surfaces 1a and 1b, which are flat surfaces substantially perpendicular to the Z direction. The mounting surface 1a faces upward, and the mounting surface 1b faces downward. Wiring patterns of electric circuits are formed on the mounting surfaces 1a and 1b. Note that the circuit board according to the present invention may have wiring patterns formed on only one of the mounting surfaces.

[0017] As shown in Fig. 3, a connector 2 and electronic components 10 are mounted on a mounting surface 1a of the circuit board 1. The connector 2 is disposed on one side of the circuit board 1 that is substantially parallel to the X direction. The connector 2 electrically connects an electric circuit formed on the circuit board 1 to an external device (not shown). Examples of the external device include an electronic control unit, a camera, a sensor, an actuator, and the like that are mounted on a vehicle in addition to the present embodiment.

[0018] The connector 2 has terminals 21 and a housing 22 that supports the terminals 21. The terminals 21 are made of a conductive material such as metal. The terminals 21 are connected to the wiring pattern of the circuit board 1 by soldering or the like. The housing 22 is made of an insulating material such as resin. The connector 2 is manufactured by, for example, insert molding. The housing 22 is fitted into an opening 3f (described later) of the case 3.

[0019] The electronic component 10 is disposed approximately in the center of the mounting surface 1a of the circuit board 1. The electronic component 10 is an electronic component that incorporates an arithmetic circuit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The electronic component 10 has a processor such as an IC (Integrated Circuit) chip or a semiconductor chip. IC chips and semiconductor chips are high-performance components that operate at processing speeds of several hundred MHz to several GHz, and therefore generate a lot of heat. The electronic component 10 corresponds to the heat-generating component according to the present invention.

[0020] 1 and 2, the case 3 is formed, for example, from a resin material into a hollow rectangular parallelepiped shape and houses the circuit board 1. The case 3 has an upper plate portion 3a and a lower plate portion 3b that face each other in the Z direction, a left plate portion 3c and a right plate portion 3d that face each other in the X direction, and a back plate portion 3e having a flat surface that is approximately perpendicular to the Y direction.

[0021] The case 3 has an opening 3f facing the back plate portion 3e in the Y direction. A housing 22 of the connector 2 connected to the circuit board 1 is fitted into the opening 3f. A seal member (not shown) is interposed between the case 3 and the housing 22. The seal member seals the joint between the case 3 and the housing 22.

[0022] Support ridges 31 are formed on the inner surfaces of the left plate 3c, right plate 3d, and back plate 3e of the case 3. The support ridges 31 have grooves extending horizontally. Three edges of the circuit board 1 on which the connector 2 is not disposed engage with the grooves of the support ridges 31. The circuit board 1, with the connector 2 connected, is inserted into the case 3 through the opening 3f. At this time, two edges of the circuit board 1 that are approximately parallel to the Y direction slide along the grooves of the support ridges 31. The circuit board 1 is then supported by the support ridges 31 and the housing 22 of the connector 2 inside the case 3.

[0023] The upper plate portion 3a of the case 3 faces the mounting surface 1a of the circuit board 1 in the Z direction. The upper plate portion 3a corresponds to the board-facing portion of the present invention. The upper plate portion 3a has a through hole 32 and a seat portion 33. The through hole 32 is located approximately in the center of the upper plate portion 3a. The through hole 32 is formed in a circular shape. The through hole 32 faces the electronic component 10 mounted on the circuit board 1 in the Z direction (see FIG. 3). Note that the through hole of the present invention is not limited to a circular shape, and any shape such as a rectangle, another polygon, or an ellipse can be used.

[0024] The seating portion 33 protrudes substantially perpendicularly from the outer surface of the upper plate portion 3a. The seating portion 33 is formed in a circular ring shape surrounding the through-hole 32. A case contact portion 412 (see FIG. 6 ), which will be described later, of the heat sink 4 comes into contact with the seating portion 33. Note that the seating portion according to the present invention is not limited to a circular ring shape, and any shape, such as a rectangular or polygonal frame shape, can be used.

[0025] The left and right plate portions 3c, 3d each have a bracket 35. The bracket 35 on the right plate portion 3d is shown in Figures 1 and 2. Each bracket 35 protrudes substantially perpendicularly from the left and right plate portions 3c, 3d. The bracket 35 is formed in a plate shape having a flat surface substantially perpendicular to the Z direction.

[0026] Each bracket 35 has a screw through hole 35a. A screw 8 (see FIG. 6) passes through the screw through hole 35a. Each bracket 35 is fixed to the vehicle body (vehicle) using the screw 8. A fixing portion 43 (described later) of the heat sink 4 is fixed to each bracket 35 using the screw 8. Each bracket 35 also has an engaging claw 35b (see FIG. 6) with which the fixing portion 43 of the heat sink 4 engages. The engaging claw 35b protrudes from the upper surface of each bracket 35.

[0027] (Configuration of Heat Dissipator) Next, the configuration of the heat dissipator 4 will be described with reference to Fig. 4. Fig. 4 is a perspective view of the heat dissipator 4.

[0028] 4, the heat sink 4 is formed by bending an elastically deformable metal plate. Examples of the metal that constitutes the heat sink 4 include aluminum and alloys primarily containing aluminum.

[0029] The heat sink 4 has a heat sink base 41, two legs 42, and two fixing portions 43. The heat sink base 41 is formed in the shape of a generally rectangular plate that is long in the X direction. The two legs 42 are continuous with both ends of the heat sink base 41 in the X direction. The two fixing portions 43 are continuous with the ends of the two legs 42 opposite the heat sink base 41 side.

[0030] The heat dissipation base 41 has upper and lower surfaces that are flat surfaces substantially perpendicular to the Z direction. The lower surface of the heat dissipation base 41 faces the upper plate portion 3a (see FIG. 2) of the case 3. The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412, and a non-contact portion 413.

[0031] The thermal contact portion 411 is located approximately in the center of the heat dissipation base 41. The thermal contact portion 411 is formed in a cylindrical shape with a bottom that protrudes approximately perpendicularly from the lower surface of the heat dissipation base 41. The thermal contact portion 411 has a circular bottom and a peripheral wall portion that is continuous with the periphery of the bottom. The peripheral wall portion of the thermal contact portion 411 is formed in a tapered shape with a diameter that decreases toward the bottom.

[0032] The thermal contact portion 411 passes through the through-hole 32 of the case 3. The bottom of the thermal contact portion 411 is located inside the case 3. A heat transfer member 6 is interposed between the bottom of the thermal contact portion 411 and the top surface of the electronic component 10. The heat transfer member 6 is, for example, thermal grease. Heat generated in the electronic component 10 is transferred to the thermal contact portion 411 of the heat sink 4 via the heat transfer member 6, and is dissipated mainly from the heat dissipation base 41.

[0033] The bottom of the thermal contact portion 411 may be in contact with the top surface of the electronic component 10. In this case, the heat generated in the electronic component 10 is directly transferred to the thermal contact portion 411 of the heat sink 4 and is dissipated mainly from the heat dissipation base 41.

[0034] The case contact portion 412 of the heat dissipation base 41 is a portion on the underside of the heat dissipation base 41 that comes into contact with the seating portion 33 of the case 3 (see FIG. 6 ). Therefore, the case contact portion 412 is an annular region that corresponds to the seating portion 33. The case contact portion 412 comes into contact with the seating portion 33 and closes the through-hole 32 of the case 3.

[0035] The non-contact portions 413 of the heat dissipation base 41 are plate-shaped portions between the case contact portions 412 and the two legs 42 (see FIG. 6 ). That is, the non-contact portions 413 are plate-shaped portions corresponding to both sides of the heat dissipation base 41 in the X direction. The non-contact portions 413 are elastically deformable. The plate-shaped non-contact portions 413 face the upper plate portion 3 a of the case 3 with a gap therebetween.

[0036] The non-contact portion 413 has two tapered portions 414. The tapered portions 414 gradually shorten the length of the non-contact portion 413 in the Y direction toward the two leg portions 42 (fixed portions 43). Therefore, the length of the non-contact portion 413 in the Y direction on the two leg portions 42 (fixed portions 43) side is shorter than the length of the non-contact portion 413 in the Y direction on the case contact portion 412 side. The length of the non-contact portion 413 in the Y direction corresponds to the widthwise length of the non-contact portion 413 according to the present invention.

[0037] The non-contact portion 413 has two tapered portions 414, which facilitates elastic deformation of the two leg portions 42 (fixing portion 43) of the non-contact portion 413. Furthermore, elastic deformation of the heat dissipation base 41 near the case contact portion 412 can be suppressed, thereby suppressing stress applied to the electronic component 10 via the thermal contact portion 411.

[0038] The two legs 42 protrude downward from both ends in the X direction of the heat dissipation base 41. The two legs 42 are formed in the shape of plates having flat surfaces that are approximately perpendicular to the X direction. The two legs 42 face the outer surfaces of the left and right plate portions 3 c, 3 d of the case 3.

[0039] The two fixing portions 43 protrude in the X direction from the lower ends of the two legs 42. The two fixing portions 43 are formed in the shape of plates having flat surfaces that are approximately perpendicular to the Z direction. The two fixing portions 43 do not face the heat dissipation base 41 in the Z direction. The lower surfaces of the two fixing portions 43 face the upper surfaces of the two brackets 35 of the case 3.

[0040] The two fixing portions 43 each have a screw through hole 43a. A screw 8 (see FIG. 6) passes through the screw through hole 43a. The two fixing portions 43, together with the two brackets 35 of the case 3, are fixed to the vehicle body using the screws 8. This allows the shape of the case 3 to be simpler than when the two fixing portions 43 of the heat sink 4 are fixed to portions separate from the brackets 35.

[0041] [Work for Mounting the Heat Sink] Next, the work for mounting the heat sink 4 to the case 3 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a cross-sectional view showing a state in which the thermal contact portion 411 of the heat sink 4 is in contact with the electronic component 10. Fig. 6 is a cross-sectional view showing a state in which the fixing portion 43 of the heat sink 4 is fixed to the bracket 35 of the case 3.

[0042] Before attaching the heat sink 4 to the case 3, the worker connects the housing 22 of the connector 2 to the case 3. As a result, the circuit board 1 integrated with the connector 2 is placed inside the case 3. The electronic component 10 mounted on the circuit board 1 faces the through-hole 32 of the case 3. Next, the worker attaches the heat transfer member 6 to the top surface of the electronic component 10.

[0043] Even if the heat transfer member 6 is attached to the upper surface of the electronic component 10 in advance, it does not interfere with the case 3 when the circuit board 1 is inserted into the case 3. Therefore, the heat transfer member 6 may be attached to the upper surface of the electronic component 10 before the circuit board 1 is inserted into the case 3.

[0044] Next, as shown in Fig. 5, the worker inserts the thermal contact portion 411 of the heat sink 4 into the through-hole 32 of the case 3. As a result, the bottom of the thermal contact portion 411 comes into contact with the electronic component 10 via the heat transfer member 6. In addition, the case contact portion 412 of the heat sink 4 comes into contact with the seating portion 33 of the case 3. At this time, the non-contact portion 413 of the heat sink 4 faces the upper plate portion 3a of the case 3 at a predetermined distance (approximately the same distance as the height of the seating portion 33). In addition, the fixing portion 43 of the heat sink 4 faces the bracket 35 of the case 3 at an appropriate distance.

[0045] Next, the worker engages the fixing portion 43 with the engaging claw 35b of the bracket 35. This temporarily secures the fixing portion 43 to the bracket 35. Next, as shown in FIG. 6 , the worker secures the fixing portion 43 to the bracket 35 using the screw 8. In this embodiment, the fixing portion 43 and the bracket 35 are fastened together to the vehicle body to secure the fixing portion 43 to the bracket 35. This completes the installation of the heat sink 4 to the case 3. At this time, since the fixing portion 43 is temporarily secured to the bracket 35, the worker can easily secure the fixing portion 43 using the screw 8.

[0046] When the fixing portion 43 is fixed to the bracket 35 using the screw 8, the non-contact portion 413 of the heat sink 4 elastically deforms from the case contact portion 412 as the fixing portion 43 is displaced downward (toward the bracket 35). At this time, the dimensional tolerance in the Z direction from the upper surface of the non-contact portion 413 to the lower surface of the fixing portion 43 (hereinafter referred to as the "heat sink-side dimensional tolerance") and the dimensional tolerance in the Z direction of the bracket 35 (hereinafter referred to as the "case-side dimensional tolerance") are absorbed by the elastic deformation of the case contact portion 412. Therefore, the distance from the bottom of the thermal contact portion 411 to the upper surface of the electronic component 10 (hereinafter referred to as the "heat sink clearance") can be designed without considering the heat sink-side dimensional tolerance or the case-side dimensional tolerance.

[0047] Furthermore, the non-contact portion 413 faces the upper plate portion 3a of the case 3 with a gap therebetween. Therefore, the heat dissipation clearance can be determined without considering the flatness of the non-contact portion 413 of the heat sink 4 or the flatness of the upper plate portion 3a of the case 3. In this way, the electronic control device 101 can reduce the dimensional tolerances that need to be considered when determining the heat dissipation clearance, thereby allowing the design value of the heat dissipation clearance to be reduced. This makes it possible to reduce the thickness of the heat transfer member 6 and the thermal resistance. As a result, the heat dissipation performance of the heat sink 4 can be improved.

[0048] Furthermore, the gap between the non-contact portion 413 and the upper plate portion 3a can increase the area of ​​the heat sink 4 that is exposed to air. This improves the heat dissipation performance of the heat sink 4. Furthermore, when a force is applied to the non-contact portion 413, the non-contact portion 413 elastically deforms, so the heat dissipation clearance does not change. As a result, stress can be prevented from being applied to the circuit board 1 and the electronic component 10.

[0049] 2. Second Embodiment [Configuration of Electronic Control Device] An electronic control device according to a second embodiment will now be described with reference to Figs. 7 to 9. Fig. 7 is a cross-sectional view of the electronic control device according to the second embodiment. Fig. 8 is a cross-sectional view showing a state in which the thermal contact portion of the heat sink according to the second embodiment is in contact with a circuit board. Fig. 9 is a cross-sectional view showing a state in which the fixing portion of the heat sink is fixed to a case.

[0050] 7 to 9, the electronic control device 102 according to the second embodiment includes a circuit board 1, a connector 2, a case 3, and a heat sink 4. The electronic control device 102 differs from the electronic control device 101 according to the first embodiment in the position of the electronic components 10 mounted on the circuit board 1. Therefore, the position of the electronic components 10 will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0051] The circuit board 1 has a mounting surface 1a, which is a flat surface facing upward, and a mounting surface 1b, which is a flat surface facing downward. A connector 2 is mounted on the mounting surface 1a of the circuit board 1. An electronic component 10 is mounted on the mounting surface 1b of the circuit board 1.

[0052] The electronic component 10 is disposed in the approximate center of the mounting surface 1b of the circuit board 1. The through hole 32 of the case 3 faces the approximate center of the mounting surface 1a of the circuit board 1 in the Z direction. The approximate center of the mounting surface 1a is an area that overlaps with the electronic component 10 mounted on the mounting surface 1b in the Z direction.

[0053] The thermal contact portion 411 of the heat sink 4 passes through the through hole 32 of the case 3. A heat transfer member 6 is interposed between the bottom of the thermal contact portion 411 and approximately the center of the mounting surface 1 a of the circuit board 1. Heat generated in the electronic component 10 is transferred to the thermal contact portion 411 of the heat sink 4 via the circuit board 1 and the heat transfer member 6, and is dissipated mainly from the heat dissipation base 41.

[0054] The bottom of the thermal contact portion 411 may be in contact with the mounting surface 1 a of the circuit board 1. In this case, the heat generated in the electronic component 10 is transferred to the thermal contact portion 411 of the heat sink 4 via the circuit board 1, and is dissipated mainly from the heat dissipation base 41.

[0055] The electronic control device 102 of the second embodiment can also achieve the same effect as the electronic control device 101 of the first embodiment. That is, in the second embodiment, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4, the flatness of the upper plate portion 3 a of the case 3, etc. Therefore, the electronic control device 102 can reduce the design value of the heat dissipation clearance, and can improve the heat dissipation performance of the heat sink 4.

[0056] 3. Third Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a third embodiment will be described below with reference to Fig. 10 and Fig. 11. Fig. 10 is a perspective view of the electronic control device according to the third embodiment. Fig. 11 is a perspective view of a heat sink according to the third embodiment.

[0057] 10 and 11, an electronic control device 103 according to the third embodiment includes a circuit board 1 (see FIG. 12), a connector 2, a case 3, and a heat sink 4A. The electronic control device 103 differs from the electronic control device 101 according to the first embodiment in the heat sink 4A. Therefore, the configuration of the heat sink 4A will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0058] (Configuration of the Heat Dissipator) The heat dissipator 4A is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4A include aluminum and alloys primarily containing aluminum. The heat dissipator 4A has a heat dissipation base 41, two legs 42, and two fixing portions 43.

[0059] The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412 (see FIG. 12), and a non-contact portion 413. The non-contact portion 413 has two tapered portions 414 and two deformed end portions 415.

[0060] The two deformed ends 415 are located on both sides of the case contact portion 412 (see FIG. 12) in the X direction. Furthermore, the two deformed ends 415 are located closer to the case contact portion 412 (see FIG. 12) in the non-contact portion 413 than the two tapered portions 414. The two deformed ends 415 are formed by bending the non-contact portion 413 into a generally mountain-like shape that protrudes upward (opposite the upper plate portion 3a of the case 3). The two deformed ends 415 are continuous in the Y direction. In other words, the ridges of the two deformed ends 415 extend in the Y direction.

[0061] [Work for Mounting the Heat Dissipator] Next, the work for mounting the heat dissipator 4A to the case 3 will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a cross-sectional view showing a state in which the thermal contact portion 411 of the heat dissipator 4A is in contact with the electronic component 10. Fig. 13 is a cross-sectional view showing a state in which the fixing portion 43 of the heat dissipator 4A is fixed to the bracket 35 of the case 3.

[0062] Before attaching the heat sink 4A to the case 3, the worker connects the housing 22 of the connector 2 to the case 3. Next, the worker attaches the heat transfer member 6 to the top surface of the electronic component 10. The heat transfer member 6 may be attached to the top surface of the electronic component 10 before inserting the circuit board 1 into the case 3.

[0063] Next, as shown in Fig. 12, the worker inserts the thermal contact portion 411 of the heat sink 4A into the through-hole 32 of the case 3. As a result, the bottom of the thermal contact portion 411 comes into contact with the electronic component 10 via the heat transfer member 6. In addition, the case contact portion 412 of the heat sink 4A comes into contact with the seating portion 33 of the case 3. At this time, the non-contact portion 413 of the heat sink 4A faces the upper plate portion 3a of the case 3 at a predetermined distance (approximately the same distance as the height of the seating portion 33). In addition, the fixing portion 43 of the heat sink 4A faces the bracket 35 of the case 3 at an appropriate distance.

[0064] Next, the worker engages the fixing portion 43 with the engaging claw 35b of the bracket 35. This temporarily fastens the fixing portion 43 to the bracket 35. Next, as shown in FIG. 13 , the worker uses the screw 8 to fasten the fixing portion 43 to the bracket 35. This attaches the heat sink 4A to the case 3.

[0065] When the fixing portion 43 is fixed to the bracket 35 with the screw 8, the fixing portion 43 is displaced downward (toward the bracket 35), and the non-contact portion 413 of the heat sink 4A elastically deforms from the deformation end portion 415. This reduces the variation in the position of the starting point of elastic deformation of the non-contact portion 413. As a result, it is possible to reduce the variation in the amount of deformation in the two non-contact portions 413 located on both sides of the heat sink base 41 in the X direction.

[0066] Furthermore, the two deformed ends 415 can suppress displacement of the center in the X direction relative to the two deformed ends 415. This allows the design value of the heat dissipation clearance to be reduced, thereby reducing the thickness of the heat transfer member 6. As a result, thermal resistance can be reduced, and the heat dissipation performance of the heat sink 4A can be stabilized. Furthermore, because the deformed ends 415 are formed in a generally mountain-like shape, the length of the flat portion of the deformed end 416 in the Y direction is shortened, thereby increasing the elastic force of the non-contact portion 413. This suppresses the deterioration of the elastic force of the non-contact portion 413 over time and the plastic deformation of the non-contact portion 413.

[0067] In the third embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4A, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device 103 can reduce the design value of the heat dissipation clearance, and the heat dissipation performance of the heat sink 4A can be improved.

[0068] 4. Fourth Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a fourth embodiment will be described below with reference to Fig. 14 and Fig. 15. Fig. 14 is a perspective view of the electronic control device according to the fourth embodiment. Fig. 15 is a perspective view of a heat sink according to the fourth embodiment.

[0069] 14 and 15, the electronic control device 104 according to the fourth embodiment includes a circuit board 1 (see FIG. 16), a connector 2, a case 3, and a heat sink 4B. The electronic control device 104 differs from the electronic control device 101 according to the first embodiment in the heat sink 4B. Therefore, the configuration of the heat sink 4B will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0070] (Configuration of the Heat Dissipator) The heat dissipator 4B is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4B include aluminum or an aluminum-based alloy. The heat dissipator 4B has a heat dissipation base 41, two legs 42, and two fixing portions 43.

[0071] The heat dissipation base 41 has a thermal contact portion 411 and a non-contact portion 413. The non-contact portion 413 has two tapered portions 414 and two deformed end portions 416.

[0072] The two deformed ends 416 are located on both sides of the case contact portion 412 (see FIG. 16 ) in the X direction. Furthermore, the two deformed ends 416 are located closer to the case contact portion 412 (see FIG. 16 ) in the non-contact portion 413 than the two tapered portions 414. The two deformed ends 416 are formed by bending the non-contact portion 413 into a generally valley-like shape that is convex downward (toward the upper plate portion 3a of the case 3). The two deformed ends 416 are continuous in the Y direction. In other words, the valley lines of the two deformed ends 416 extend in the Y direction.

[0073] The tops of the two deformed ends 416 are formed in a rectangular plane extending in the Y direction. The tops of the two deformed ends 416 contact the upper plate 3a of the case 3. Therefore, the tops of the two deformed ends 416 correspond to the case contact portions according to the present invention. That is, the two deformed ends 416 also serve as the case contact portions. The length (height) of the two deformed ends 416 in the Z direction is longer than the length (height) of the seating portion 33 of the case 3 in the Z direction. Therefore, the heat dissipation base 41 of the heat sink 4B does not contact the seating portion 33.

[0074] [Work for Mounting the Heat Sink] Next, the work for mounting the heat sink 4B to the case 3 will be described with reference to Figs. 16 and 17. Fig. 16 is a cross-sectional view showing a state in which the thermal contact portion 411 of the heat sink 4B is in contact with the electronic component 10. Fig. 17 is a cross-sectional view showing a state in which the fixing portion 43 of the heat sink 4B is fixed to the bracket 35 of the case 3.

[0075] Before attaching the heat sink 4B to the case 3, the worker connects the housing 22 of the connector 2 to the case 3. Next, the worker attaches the heat transfer member 6 to the top surface of the electronic component 10. The heat transfer member 6 may be attached to the top surface of the electronic component 10 before inserting the circuit board 1 into the case 3.

[0076] Next, as shown in FIG. 16 , the worker inserts the thermal contact portion 411 of the heat sink 4B into the through-hole 32 of the case 3. As a result, the bottom of the thermal contact portion 411 comes into contact with the electronic component 10 via the heat transfer member 6. In addition, the two deformed end portions 416 of the heat sink 4B come into contact with the upper plate portion 3a of the case 3. At this time, the non-contact portion 413 of the heat sink 4B other than the two deformed end portions 416 faces the upper plate portion 3a of the case 3 at a predetermined distance (approximately the same distance as the height of the two deformed end portions 416). In addition, the fixing portion 43 of the heat sink 4B faces the bracket 35 of the case 3 at an appropriate distance.

[0077] Next, the worker engages the fixing portion 43 with the engaging claw 35b of the bracket 35. This temporarily fastens the fixing portion 43 to the bracket 35. Next, as shown in FIG. 17 , the worker uses the screw 8 to fasten the fixing portion 43 to the bracket 35. This attaches the heat sink 4B to the case 3.

[0078] When the fixing portion 43 is fixed to the bracket 35 with the screw 8, the fixing portion 43 is displaced downward (toward the bracket 35), and the non-contact portion 413 of the heat sink 4B elastically deforms from the deforming end portion 416. This reduces the variation in the position that serves as the starting point of elastic deformation of the non-contact portion 413. As a result, it is possible to reduce the variation in the amount of deformation in the two non-contact portions 413 located on both sides of the heat sink base 41 in the X direction.

[0079] Furthermore, because displacement in the X direction toward the center can be suppressed relative to the two deformed ends 416, it is possible to reduce the design value of the heat dissipation clearance and reduce the thickness of the heat transfer member 6. As a result, it is possible to reduce thermal resistance and stabilize the heat dissipation performance of the heat sink 4B. Furthermore, because the deformed end 416 is formed in a generally valley shape, the length of the flat portion of the deformed end 416 in the Y direction is shortened, thereby increasing the elastic force of the non-contact portion 413. This suppresses the deterioration of the elastic force of the non-contact portion 413 over time and the plastic deformation of the non-contact portion 413.

[0080] In the fourth embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4B, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device 104 can reduce the design value of the heat dissipation clearance, and the heat dissipation performance of the heat sink 4B can be improved.

[0081] In the fourth embodiment described above, the two valley-shaped deformed ends 416 contact the upper plate 3a of the case 3. However, the heat sink according to the present invention may be configured so that the two valley-shaped deformed ends do not contact the upper plate 3a of the case 3. In this case, the height of the two valley-shaped deformed ends is set lower than the height of the seat 33. This allows the heat sink base to have a case contact portion that contacts the seat 33. Note that even if the two valley-shaped deformed ends do not contact the upper plate 3a of the case 3, the same effect as in the fourth embodiment described above can be obtained. Furthermore, since the heat sink in this case has a case contact portion, it can block the through hole 32 of the case 3.

[0082] 5. Fifth Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a fifth embodiment will be described below with reference to Fig. 18 and Fig. 19. Fig. 18 is a perspective view of the electronic control device according to the fifth embodiment. Fig. 19 is a perspective view of a heat sink according to the fifth embodiment.

[0083] 18 and 19 , an electronic control device 105 according to the fifth embodiment includes a circuit board 1 (not shown), a connector 2, a case 3, and a heat sink 4C. The electronic control device 105 differs from the electronic control device 101 according to the first embodiment in the heat sink 4C. Therefore, the configuration of the heat sink 4C will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0084] (Configuration of the Heat Dissipator) The heat dissipator 4C is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4C include aluminum or an aluminum-based alloy. The heat dissipator 4C has a heat dissipation base 41, two legs 42, and two fixing portions 43.

[0085] The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412 (not shown), and a non-contact portion 413. The non-contact portion 413 has two tapered portions 414 and two notched portions 417.

[0086] The two notches 417 are located in the areas where the two tapered portions 414 are formed in the non-contact portion 413. The notches 417 are grooves that penetrate the non-contact portion 413 and are formed in a roughly C-shape that is convex on the side opposite to the thermal contact portion 411. The notches 417 are made up of a linear portion that extends in the X direction and two linear portions that extend along the tapered portions 414.

[0087] The two cutouts 417 facilitate elastic deformation of the two non-contact portions 413 located on both sides of the heat dissipation base 41. The cutouts according to the present invention may be any cutouts that facilitate elastic deformation of the non-contact portions, and may, for example, thin the non-contact portions.

[0088] Furthermore, the two notches 417 are formed in a generally C-shape that protrudes on the side opposite to the thermal contact portion 411, and are therefore spaced apart from the thermal contact portion 411. As a result, the two notches 417 prevent the electric heat of the heat sink 4C from being blocked at a position close to the thermal contact portion 411. As a result, the two notches 417 can facilitate elastic deformation of the non-contact portion while ensuring the heat dissipation performance of the heat sink 4C.

[0089] In the fifth embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4C, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device 105 can reduce the design value of the heat dissipation clearance, and the heat dissipation performance of the heat sink 4C can be improved.

[0090] 6. Sixth Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a sixth embodiment will be described below with reference to Fig. 20. Fig. 20 is an exploded perspective view of the electronic control device according to the sixth embodiment.

[0091] As shown in Fig. 20, the electronic control device 106 according to the sixth embodiment includes a circuit board 1, a connector 2, a case 3A, and a heat sink 4C. The electronic control device 106 has a configuration similar to that of the electronic control device 105 according to the fifth embodiment (see Fig. 18). The electronic control device 106 differs from the electronic control device 105 in the case 3A. Therefore, the configuration of the case 3A will be described here, and a description of the configuration common to the fifth embodiment will be omitted.

[0092] The case 3A is formed, for example, from a resin material into a hollow rectangular parallelepiped shape. The case 3A houses the circuit board 1. The case 3A has an upper plate 3a, a lower plate 3b, a left plate 3c, a right plate 3d, a back plate 3e, and an opening 3f. Support protrusions 31 are formed on the inner surfaces of the left plate 3c, the right plate 3d, and the back plate 3e of the case 3A.

[0093] The upper plate portion 3a has a through hole 32. The seating component 7 is press-fitted and fixed into the through hole 32. The seating component 7 may be fixed to the upper plate portion 3a using an adhesive, or may be fixed to the upper plate portion 3a using other fixing methods such as fixing using a screw or caulking.

[0094] The seating component 7 is formed in a cylindrical shape. One axial end (upper end) of the seating component 7 protrudes substantially perpendicularly from the upper plate portion 3a. The case contact portion 412 (not shown) of the heat sink 4C contacts the one axial end (upper end) of the seating component 7. The thermal contact portion 411 of the heat sink 4C passes through the axial hole of the seating component 7. Therefore, the thermal contact portion 411 essentially passes through the through-hole 32 of the upper plate portion 3a of the case 3A. Because the seating component 7 is a separate component from the upper plate portion 3a, the height by which the seating component 7 protrudes from the upper plate portion 3a can be easily adjusted.

[0095] In the sixth embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4C, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device 106 can reduce the design value of the heat dissipation clearance, and the heat dissipation performance of the heat sink 4C can be improved.

[0096] 7. Seventh Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a seventh embodiment will be described below with reference to Fig. 21. Fig. 21 is a perspective view of a heat sink according to the seventh embodiment.

[0097] The electronic control device according to the seventh embodiment includes a circuit board 1 (not shown), a connector 2 (not shown), a case 3 (not shown), and a heat sink 4D. The electronic control device according to the seventh embodiment differs from the electronic control device 101 according to the first embodiment in the heat sink 4D. Therefore, the configuration of the heat sink 4D will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0098] 21, the heat sink 4D is formed by bending an elastically deformable metal plate. The metal constituting the heat sink 4D can be, for example, aluminum or an alloy primarily containing aluminum. The heat sink 4D has a heat sink base 41, two legs 42, and two fixing portions 43.

[0099] The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412 (not shown), and a non-contact portion 413. The non-contact portion 413 has two tapered portions 414 and two deformed end portions 415.

[0100] The two deformed ends 415 are located on both sides of the thermal contact portion 411 (case contact portion 412) in the X direction. The two deformed ends 415 are also located on the thermal contact portion 411 (case contact portion 412) side of the two tapered portions 414 in the non-contact portion 413. The two deformed ends 415 are formed into a generally mountain-like shape that convex upward (opposite the upper plate portion 3a of the case 3) by bending the non-contact portion 413. The two deformed ends 415 extend along the Y direction.

[0101] The deforming end 415 has two slits 415a. The two slits 415a are arranged side by side at an appropriate distance in the Y direction. The two slits 415a cut out the deforming end 415 in the X direction, making the corners (ridges) of the deforming end 415 discontinuous. The two slits 415a make it easier for the non-contact portion 413 to elastically deform. As a result, when two slits 415a are formed in the two deforming end portions 415, displacement in the X direction toward the center of the two deforming end portions 415 can be suppressed more effectively than when the two deforming end portions 415 do not have slits 415a.

[0102] In this embodiment, two slits 415a are formed in one deformed end portion 415. However, in the heat dissipation body according to the present invention, one or three or more slits may be formed in one deformed end portion. The length (width) of the slit in the Y direction can be set arbitrarily. Furthermore, when multiple slits are formed in one deformed end portion, the lengths of the slits in the Y direction may be different.

[0103] In the seventh embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4D, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device of the seventh embodiment can reduce the design value of the heat dissipation clearance, and can improve the heat dissipation performance of the heat sink 4D.

[0104] 8. Eighth Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to an eighth embodiment will be described below with reference to Fig. 22. Fig. 22 is a perspective view of a heat sink according to the eighth embodiment.

[0105] The electronic control device according to the eighth embodiment includes a circuit board 1 (not shown), a connector 2 (not shown), a case 3 (not shown), and a heat sink 4E. The electronic control device according to the eighth embodiment differs from the electronic control device 101 according to the first embodiment in the heat sink 4E. Therefore, the configuration of the heat sink 4E will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0106] (Configuration of the Heat Dissipator) As shown in Figure 22, the heat dissipator 4E is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4E include aluminum or an alloy primarily containing aluminum. The heat dissipator 4E has a heat dissipation base 41, two legs 42, and two fixing portions 43.

[0107] The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412 (not shown), and a non-contact portion 413. The non-contact portion 413 has two tapered portions 414, two deformed end portions 418, and two openings 413a.

[0108] The two deformed ends 418 are located on both sides of the thermal contact portion 411 (case contact portion 412) in the X direction. The two deformed ends 415 also serve as the ends of the two tapered portions 414 in the non-contact portion 413 on the thermal contact portion 411 (case contact portion 412) side. Each deformed end 415 is formed from two mountain-shaped portions that convex upward (opposite the upper plate portion 3a of the case 3). The two deformed ends 418 extend along the Y direction.

[0109] The two openings 413a are formed in a generally trapezoidal shape by cutting out a large portion of the non-contact portion 413. The openings 413a are composed of two linear portions extending in the X direction and two linear portions extending along the tapered portion 414. The two openings 413a cut out the flat portion of the non-contact portion 413 and the intermediate portions in the Y direction of the two deformed ends 418. As a result, the non-contact portion 413 is formed in a generally V-shape when viewed from above as a whole. The size of the openings formed in the non-contact portion 413 can be set as desired.

[0110] In the heat sink 4E of this embodiment, the non-contact portion 413 is formed in a substantially V-shape, which facilitates elastic deformation of the non-contact portion 413. Furthermore, the deforming end portion 418 is formed from two mountain-shaped portions, which prevents or suppresses deformation of the narrow deforming end portion 418 when the non-contact portion 413 elastically deforms. As a result, the two deforming end portions 418 can suppress displacement of the center portion in the X direction relative to the two deforming end portions 418.

[0111] In the eighth embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4E, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device of the eighth embodiment can reduce the design value of the heat dissipation clearance, and can improve the heat dissipation performance of the heat sink 4E.

[0112] 9. Ninth Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a ninth embodiment will be described below with reference to Fig. 23. Fig. 23 is a perspective view of a heat sink according to the ninth embodiment.

[0113] The electronic control device according to the ninth embodiment includes a circuit board 1 (not shown), a connector 2 (not shown), a case 3 (not shown), and a heat sink 4F. The electronic control device according to the ninth embodiment differs from the electronic control device 101 according to the first embodiment in the heat sink 4F. Therefore, the configuration of the heat sink 4F will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0114] (Configuration of the Heat Dissipator) As shown in Figure 23, the heat dissipator 4F is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4F include aluminum or an alloy primarily containing aluminum. The heat dissipator 4F has a heat dissipation base 41, two legs 42, and two fixing portions 43.

[0115] The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412 (not shown), and a non-contact portion 413. The non-contact portion 413 has two tapered portions 414, two deformed end portions 415, and two case contact portions 419.

[0116] The two deformed ends 415 are located on both sides of the thermal contact portion 411 (case contact portion 412) in the X direction. The two deformed ends 415 also serve as the ends of the two tapered portions 414 of the non-contact portion 413 on the thermal contact portion 411 (case contact portion 412) side. The two deformed ends 415 are formed by bending the non-contact portion 413 into a generally mountain-like shape that convex upward (opposite the upper plate portion 3a of the case 3). The two deformed ends 415 extend along the Y direction.

[0117] The two case contact portions 419 are located between the two deformed end portions 415 and the thermal contact portion 411. The two case contact portions 419 are formed by bending the non-contact portion 413, so as to have a generally valley-like shape that is convex downward (toward the upper plate portion 3a of the case 3). The two case contact portions 419 are continuous in the Y direction. Each case contact portion 419 is continuous with each deformed end portion 415 in the X direction. That is, one inclined surface of the case contact portion 419 forms the same plane as one inclined surface of the deformed end portion 415.

[0118] The tops of the two case contact portions 419 are formed in a rectangular plane extending in the Y direction. The tops of the two case contact portions 419 contact the upper plate portion 3a (see FIG. 2) of the case 3. Therefore, the length (height) of the two case contact portions 419 in the Z direction is longer than the length (height) of the seating portion 33 (see FIG. 2) of the case 3 in the Z direction. Therefore, the heat dissipation base 41 of the heat dissipator 4F does not contact the seating portion 33.

[0119] When the fixing portion 43 of the heat dissipation body 4F is fixed to the bracket 35, the fixing portion 43 is displaced downward (toward the bracket 35), and the non-contact portion 413 of the heat dissipation body 4F elastically deforms from the deforming end portion 415. This reduces the variation in the position that serves as the starting point of elastic deformation of the non-contact portion 413. As a result, it is possible to reduce the variation in the amount of deformation in the two non-contact portions 413 located on both sides of the heat dissipation base 41 in the X direction.

[0120] In the ninth embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4F, the flatness of the upper plate portion 3a of the case 3, etc. Therefore, the electronic control device of the ninth embodiment can reduce the design value of the heat dissipation clearance, and can improve the heat dissipation performance of the heat sink 4F.

[0121] 10. Tenth Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to a tenth embodiment will be described below with reference to Fig. 24 and Fig. 25. Fig. 24 is a perspective view of the electronic control device according to the tenth embodiment. Fig. 25 is a perspective view of a heat sink according to the tenth embodiment.

[0122] 24 and 25 , an electronic control device 107 according to the tenth embodiment includes a circuit board 1 (not shown), a connector 2, a case 3B, and a heat sink 4G. The electronic control device 107 differs from the electronic control device 101 according to the first embodiment in the components mounted on the circuit board 1, the case 3B, and the heat sink 4G. Therefore, the configuration of the components mounted on the circuit board 1, the case 3B, and the heat sink 4G will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0123] A connector 2, a first electronic component, a second electronic component, a third electronic component, and a fourth electronic component are mounted on a mounting surface 1a (see FIG. 1) of the circuit board 1. The first to fourth electronic components generate heat. The first to fourth electronic components correspond to heat-generating components according to the present invention.

[0124] The first electronic component is the same as the electronic component 10 according to the first embodiment (see FIG. 3). The first electronic component is arranged in approximately the center of the mounting surface 1a (see FIG. 3) of the circuit board 1. The second and third electronic components are arranged at one end of the mounting surface 1a in the X direction. The second and third electronic components are lined up at an appropriate distance in the Y direction. The second and third electronic components are smaller than the first electronic component. The fourth electronic component is arranged at the other end of the mounting surface 1a (see FIG. 1) in the X direction. When viewed from the Z direction, the fourth electronic component has a rectangular shape that is longer in the Y direction.

[0125] 24, the case 3B is formed, for example, from a resin material into a hollow rectangular parallelepiped shape. The case 3B houses the circuit board 1 (not shown). The case 3B has an upper plate 3a, a lower plate 3b, a left side plate 3c, a right side plate 3d, a back plate 3e, and an opening 3f.

[0126] The upper plate portion 3a corresponds to the board-facing portion according to the present invention. The upper plate portion 3a has a first through hole, a second through hole, a third through hole, a fourth through hole, and a seating portion. The first through hole is located approximately in the center of the upper plate portion 3a. The first through hole is the same as the through hole 32 according to the first embodiment and is formed in a circular shape. The first through hole faces the first electronic component mounted on the circuit board 1 in the Z direction.

[0127] The second through hole and the third through hole are located at one end of the upper plate portion 3a in the X direction. The second through hole and the third through hole are aligned at an appropriate distance in the Y direction. The second through hole and the third through hole are formed in a circular shape. The second through hole faces a second electronic component mounted on the circuit board 1 in the Z direction. The third through hole faces a third electronic component mounted on the circuit board 1 in the Z direction.

[0128] The fourth through hole is located at the other end of the upper plate portion 3a in the X direction. The fourth through hole is formed in a rectangular shape that is long in the Y direction. The fourth through hole faces a fourth electronic component mounted on the circuit board 1 in the Z direction. The seating portion of the upper plate portion 3a is formed in a rectangular frame shape that surrounds the first to fourth through holes. A case contact portion (described later) of the heat sink 4G comes into contact with the seating portion of the upper plate portion 3a.

[0129] (Configuration of the Heat Dissipator) As shown in Figure 25, the heat dissipator 4G is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4G include aluminum and alloys primarily containing aluminum. The heat dissipator 4G has a heat dissipation base 41, two legs 42, and two fixing portions 43.

[0130] The heat dissipation base 41 has a first thermal contact portion 411 a , a second thermal contact portion 411 b , a third thermal contact portion 411 c , a fourth thermal contact portion 411 d , a case contact portion (not shown), and a non-contact portion 413 .

[0131] The first thermal contact portion 411a is located approximately in the center of the heat dissipation base 41. The first thermal contact portion 411a is the same as the thermal contact portion 411 according to the first embodiment. The first thermal contact portion 411a passes through a first through-hole in the case 3B. The bottom of the first thermal contact portion 411a is located inside the case 3B. A thermally conductive member is interposed between the bottom of the first thermal contact portion 411a and the top surface of the first electronic component. The thermally conductive member is, for example, thermal grease. Heat generated in the first electronic component is transferred to the first thermal contact portion 411a of the heat sink 4G via the thermally conductive member and is dissipated mainly from the heat dissipation base 41.

[0132] The second thermal contact portion 411b and the third thermal contact portion 411c are disposed at one end in the X direction of the heat dissipation base 41. The second thermal contact portion 411b and the third thermal contact portion 411c are arranged side by side at an appropriate distance in the Y direction.

[0133] The second thermal contact portion 411b and the third thermal contact portion 411c are formed in a cylindrical shape with a bottom that protrudes approximately perpendicularly from the lower surface of the heat dissipation base 41. The second thermal contact portion 411b and the third thermal contact portion 411c have a circular bottom and a peripheral wall portion that is continuous with the periphery of the bottom. The peripheral wall portions of the second thermal contact portion 411b and the third thermal contact portion 411c are formed in a tapered shape with a diameter that decreases toward the bottom.

[0134] The second thermal contact portion 411b passes through a second through-hole in the case 3B. The bottom of the second thermal contact portion 411b is located inside the case 3B. A thermally conductive member is interposed between the bottom of the second thermal contact portion 411b and the top surface of the second electronic component. Heat generated in the second electronic component is transferred to the second thermal contact portion 411b of the heat sink 4G via the thermally conductive member and is dissipated mainly from the heat dissipation base 41.

[0135] The third thermal contact portion 411c passes through a third through-hole in the case 3B. The bottom of the third thermal contact portion 411c is located inside the case 3B. A thermally conductive member is interposed between the bottom of the third thermal contact portion 411c and the top surface of the third electronic component. Heat generated in the third electronic component is transferred to the third thermal contact portion 411c of the heat sink 4G via the thermally conductive member and is dissipated mainly from the heat dissipation base 41.

[0136] The fourth thermal contact portion 411d is disposed at the other end of the heat dissipation base 41 in the X direction. The fourth thermal contact portion 411d is formed in the shape of a rectangular tube with a bottom that protrudes substantially perpendicularly from the underside of the heat dissipation base 41. The fourth thermal contact portion 411d has a rectangular bottom that is long in the Y direction and four peripheral wall portions that are continuous with the periphery of the bottom. The four peripheral wall portions are formed in a tapered shape that reduces the internal space toward the bottom.

[0137] The fourth thermal contact portion 411d passes through a fourth through-hole in the case 3B. The bottom of the fourth thermal contact portion 411d is located inside the case 3B. A thermally conductive member is interposed between the bottom of the fourth thermal contact portion 411d and the top surface of the fourth electronic component. Heat generated in the fourth electronic component is transferred to the fourth thermal contact portion 411d of the heat sink 4G via the thermally conductive member and is dissipated mainly from the heat dissipation base 41.

[0138] The case contact portion of the heat dissipation base 41 is the portion on the underside of the heat dissipation base 41 that comes into contact with the seating portion of the case 3B. Therefore, the case contact portion of the heat dissipation base 41 is a rectangular frame-shaped region that corresponds to the seating portion of the case 3B. The case contact portion comes into contact with the seating portion and blocks the first to fourth through holes of the case 3B.

[0139] The non-contact portion 413 of the heat dissipation base 41 is the portion between the case contact portion 412 and the two legs 42. The non-contact portion 413 faces the upper plate portion 3a of the case 3B with a gap therebetween.

[0140] The non-contact portion 413 has two tapered portions 414 and two deformed end portions 415. The tapered portions 414 gradually shorten the length of the non-contact portion 413 in the Y direction toward the two leg portions 42 (fixed portions 43).

[0141] The two deformed ends 415 are located on both sides of the thermal contact portion 411 (case contact portion) in the X direction. The two deformed ends 415 are located closer to the thermal contact portion 411 in the non-contact portion 413 than the two tapered portions 414. The two deformed ends 415 are formed into a generally mountain-like shape that convex upward (opposite the upper plate portion 3a of the case 3) by bending the non-contact portion 413. The two deformed ends 415 are continuous in the Y direction.

[0142] The electronic control device 107 according to the tenth embodiment has a plurality of heat-generating components (first to fourth electronic components). The heat sink 4G of the electronic control device 107 has first to fourth thermal contact portions 411a to 411d to which heat is transferred from the plurality of heat-generating components, respectively. This allows the heat generated by the plurality of heat-generating components to be efficiently dissipated.

[0143] In the tenth embodiment as well, the heat dissipation clearance can be designed without considering the dimensional tolerance of the heat sink side, the dimensional tolerance of the case side, the flatness of the non-contact portion 413 of the heat sink 4G, the flatness of the upper plate portion 3a of the case 3B, etc. Therefore, the electronic control device 107 can reduce the design value of the heat dissipation clearance, and the heat dissipation performance of the heat sink 4G can be improved.

[0144] 11. Eleventh Embodiment [Configuration of Electronic Control Device] The configuration of an electronic control device according to an eleventh embodiment will be described below with reference to Fig. 26. Fig. 26 is a cross-sectional view of the electronic control device according to the eleventh embodiment.

[0145] 26 , an electronic control device 108 according to the eleventh embodiment includes a circuit board 1, a connector 2 (not shown), a case 3C, and a heat sink 4H. The electronic control device 108 differs from the electronic control device 101 according to the first embodiment in the case 3C and the heat sink 4H. Therefore, the configurations of the case 3C and the heat sink 4H will be described here, and a description of the configuration common to the first embodiment will be omitted.

[0146] 26, the case 3C is formed, for example, from a resin material into a hollow rectangular parallelepiped shape. The case 3C houses the circuit board 1 (not shown). The case 3C has an upper plate 3a, a lower plate 3b, a left plate 3c, a right plate 3d, a back plate 3e, and an opening 3f.

[0147] The upper plate portion 3a corresponds to the board-facing portion according to the present invention. The upper plate portion 3a has a through-hole 32, a seat portion 33, and two engagement claws 36. The two engagement claws 36 protrude substantially perpendicularly from both ends of the upper plate portion 3a in the X direction. The two engagement claws 36 each extend in the Y direction. The two engagement claws 36 engage with the heat sink 4H.

[0148] In the eleventh embodiment, the left side plate portion 3c and the right side plate portion 3d do not have the bracket 35 according to the first embodiment. However, the left side plate portion 3c and the right side plate portion 3d according to the eleventh embodiment may each have the bracket 35. In this case, the bracket 35 does not have the engaging claw 35b. In other words, the heat sink 4H is not fastened together with the bracket 35.

[0149] (Configuration of Heat Dissipator) As shown in Fig. 26, the heat dissipator 4H is formed by bending an elastically deformable metal plate. Examples of the metal constituting the heat dissipator 4H include aluminum and alloys mainly containing aluminum.

[0150] The heat sink 4H has a heat dissipation base 41. The heat dissipation base 41 is formed in the shape of a substantially rectangular plate that is long in the X direction. The heat dissipation base 41 has upper and lower surfaces that are flat surfaces that are substantially perpendicular to the Z direction. The lower surface of the heat dissipation base 41 faces the upper plate portion 3a of the case 3C. The heat dissipation base 41 has a thermal contact portion 411, a case contact portion 412, and a non-contact portion 413. The thermal contact portion 411 and the case contact portion 412 are the same as in the first embodiment.

[0151] The non-contact portions 413 form both ends of the heat dissipation base 41 in the X direction. The ends of the non-contact portions 413 in the X direction engage with the engaging claws 36 of the case 3C. This fixes the heat dissipation body 4H to the case 3C. Therefore, the ends of the non-contact portions 413 in the X direction correspond to the fixing portions according to the present invention. The non-contact portions 413 face the upper plate portion 3a of the case 3 with a gap therebetween.

[0152] [Work for Mounting the Heat Sink] Next, the work for mounting the heat sink 4H to the case 3C will be described. Before mounting the heat sink 4H to the case 3C, the worker connects the housing 22 of the connector 2 to the case 3C. Next, the worker mounts the heat transfer member 6 on the top surface of the electronic component 10.

[0153] Next, the worker inserts the thermal contact portion 411 of the heat sink 4H into the through-hole 32 of the case 3C. As a result, the bottom of the thermal contact portion 411 comes into contact with the electronic component 10 via the heat transfer member 6. In addition, the case contact portion 412 of the heat sink 4H comes into contact with the seating portion 33 of the case 3C. At this time, the non-contact portion 413 of the heat sink 4H faces the upper plate portion 3a of the case 3C at a predetermined distance (approximately the same distance as the height of the seating portion 33).

[0154] Next, the worker engages the end of the non-contact portion 413 with the engaging claw 36 of the upper plate 3 a of the case 3 C. This fixes the end of the non-contact portion 413 to the upper plate 3 a of the case 3 C. As a result, the heat sink 4 H is attached to the case 3 C.

[0155] When the end of the non-contact portion 413 is fixed to the upper plate portion 3a, the end of the non-contact portion 413 is displaced downward (toward the upper plate portion 3a), causing the non-contact portion 413 to elastically deform from the case contact portion 412. At this time, the dimensional tolerance of the heat sink 4H in the X direction (hereinafter referred to as the "heat sink-side dimensional tolerance") and the dimensional tolerance of the engaging claw 36 in the Z direction (hereinafter referred to as the "case-side dimensional tolerance") are absorbed by the elastic deformation of the non-contact portion 413. Therefore, the heat dissipation clearance can be designed without considering the heat sink-side dimensional tolerance or the case-side dimensional tolerance.

[0156] Furthermore, the non-contact portion 413 faces the upper plate portion 3a of the case 3C with a gap therebetween. Therefore, the heat dissipation clearance can be determined without considering the flatness of the non-contact portion 413 of the heat sink 4H or the flatness of the upper plate portion 3a of the case 3C. In this way, the electronic control device 108 can reduce the dimensional tolerances that need to be considered when determining the heat dissipation clearance, thereby reducing the design value of the heat dissipation clearance. As a result, the heat dissipation performance of the heat sink 4H can be improved.

[0157] Furthermore, the gap between the non-contact portion 413 and the upper plate portion 3a can increase the area of ​​the heat sink 4H that is exposed to air. This improves the heat dissipation performance of the heat sink 4H. Furthermore, when a force is applied to the non-contact portion 413, the non-contact portion 413 elastically deforms, so the heat dissipation clearance does not change. As a result, stress can be prevented from being applied to the circuit board 1 and the electronic component 10.

[0158] The above describes the embodiments of the electronic control device of the present invention, including their effects. However, the electronic control device of the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention as defined in the claims.

[0159] Furthermore, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.

[0160] In this specification, the words "parallel" and "orthogonal" are used, but these do not mean only "parallel" and "orthogonal" in the strict sense, but also include "parallel" and "orthogonal" and may also mean a "substantially parallel" or "substantially orthogonal" state within a range in which the functions can be exerted.

[0161] DESCRIPTION OF SYMBOLS 1...circuit board, 1a, 1b...mounting surface, 2...connector, 3, 3A, 3B, 3C...case, 3a...upper plate portion (substrate facing portion), 3b...lower plate portion, 3c...left side plate portion, 3d...right side plate portion, 3e...back plate portion, 3f...opening, 4, 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H...heat sink, 6...heat transfer member, 7...seating component, 10...electronic component, 21...terminal, 22...housing, 31...support ridge portion, 32...through hole, 33...seating portion, 35...bracket, 35a...screw through hole, 35b, 36...engaging claw, 41...heat dissipation base, 42...leg portion, 43...fixing portion, 43a...screw through hole, 101, 102, 103, 104, 105, 106, 107, 108...Electronic control device, 411...Thermal contact portion, 411a...First thermal contact portion, 411b...Second thermal contact portion, 411c...Third thermal contact portion, 411d...Fourth thermal contact portion, 412, 419...Case contact portion, 413...Non-contact portion, 413a...Opening portion, 414...Tapered portion, 415, 416, 418...Deformed end portion, 415a...Slit, 417...Notched portion

Claims

1. An electronic control device comprising: a circuit board on which a heat-generating component is mounted; a case that houses the circuit board; and a heat sink connected to the case and made of a material with a higher thermal conductivity than the case, wherein the case has a through hole in a board-facing portion that faces the flat surface of the circuit board, and the heat sink has: a fixing portion fixed to the case; a thermal contact portion that passes through the through hole in the case and to which heat is transferred from the circuit board or the heat-generating component directly or via a heat transfer member; a case contact portion located between the fixing portion and the thermal contact portion and in contact with a part of the board-facing portion; and a plate-shaped non-contact portion located between the fixing portion and the case contact portion, facing the board-facing portion with a gap therebetween, and elastically deforming when the fixing portion is fixed to the case.

2. An electronic control device according to claim 1, wherein the non-contact portion has a deformed end portion that serves as a base end portion for elastic deformation, and the deformed end portion is formed by bending so as to be convex toward the board-facing portion side or the side opposite to the board-facing portion side.

3. The electronic control device according to claim 2, wherein the deformed end portion has at least one slit that makes the corner portion discontinuous.

4. An electronic control device according to claim 1, wherein the case has a seat protruding from the periphery of the through-hole in the board-facing portion, and the case contact portion contacts the seat.

5. The electronic control device according to claim 4, wherein the seating portion is a cylindrical part that fits into the through hole.

6. The electronic control device according to claim 1, wherein the non-contact portion has a notch that penetrates or is thinned in the thickness direction.

7. The electronic control device according to claim 6, wherein the notch is formed in a substantially C-shape that is convex on the side opposite to the thermal contact portion.

8. An electronic control device as described in claim 1, wherein, when the direction perpendicular to the direction toward the fixed part in the non-contact part is defined as the width direction, the length of the non-contact part in the width direction on the fixed part side is shorter than the length of the non-contact part in the width direction on the thermal contact part side.

9. The electronic control device according to claim 8, wherein the non-contact portion has a tapered portion whose length in the width direction gradually decreases toward the fixed portion.

10. The electronic control device according to claim 1, wherein the case contact portion is formed by bending the heat sink so that it is convex toward the board-facing portion.

11. The electronic control device according to claim 1, wherein the fixing portion is fixed to the vehicle together with the case using screws.

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