JP7652982B2 - Electronic control device and manufacturing method for electronic control device - Google Patents

Description

The present invention relates to an electronic control device and a method for manufacturing an electronic control device.

The control case in Patent Document 1 comprises a resin case that houses a circuit board on which electronic components are mounted, and a metal bracket that is fixed to the side of the case and is used to secure the case to other components.

JP 2004-179280 A

Incidentally, in an electronic control device, if a resin case is used as the case for accommodating an electronic circuit board, the weight of the electronic control device can be reduced and the cost of the case can be kept low.
However, a resin case generally has poorer heat dissipation properties than a metal case such as an aluminum die-cast case.
For this reason, in the case of electronic control devices that use plastic cases, if the amount of heat generated in the electronic circuit board increases as the electronic control device becomes smaller and its control functions are improved, the durability of the electronic components may be impaired.

The present invention has been made in consideration of the current situation, and its purpose is to provide an electronic control device and a method for manufacturing an electronic control device that can improve heat dissipation performance while using a resin case.

In one aspect, an electronic control device according to the present invention comprises a resin case that houses an electronic circuit board, a metallic heat dissipation member arranged to face a heat-generating portion of the electronic circuit board, and thermal grease arranged between the electronic circuit board and the metallic heat dissipation member, wherein the metallic heat dissipation member is formed in a plate shape, the resin case has a guide groove that holds the metallic heat dissipation member by inserting it into the resin case in a direction parallel to the electronic circuit board, and a notch that the metallic heat dissipation member held in the guide groove blocks from the inside of the resin case, and when the metallic heat dissipation member blocks the notch, the metallic heat dissipation member forms part of a wall portion of the resin case that surrounds the electronic circuit board, and the surface of the metallic heat dissipation member opposite the electronic circuit board is configured to be exposed to the outside of the resin case, and the metallic heat dissipation member has a hole that connects the inside and outside of the resin case, the hole opening in an area where the thermal grease is arranged.
In one aspect, a manufacturing method for an electronic control device according to the present invention is a manufacturing method for an electronic control device comprising an electronic circuit board housed in a resin case, the manufacturing method comprising a guide groove for inserting and holding the electronic circuit board and a plate-shaped metal heat dissipation member in a direction parallel to a board surface of the electronic circuit board, and a notch that is blocked from the inside of the resin case by the metal heat dissipation member held in the guide groove, the metal heat dissipation member facing a heat-generating portion of the electronic circuit board while held in the guide groove, and the manufacturing method for the electronic control device comprises the steps of: inserting the electronic circuit board and the metal heat dissipation member as a unit into the resin case along the guide groove; and filling heat dissipation grease between the electronic circuit board and the metal heat dissipation member housed in the resin case through a hole provided in the metal heat dissipation member that connects the inside and outside of the resin case.

According to the present invention, it is possible to improve heat dissipation performance while using a resin case.

1 is a perspective view showing an electronic control device according to a first embodiment; FIG. 2 is an exploded perspective view showing the electronic control device according to the first embodiment. FIG. 2 is an exploded perspective view showing the electronic control device of the first embodiment. 1 is a cross-sectional view showing an electronic control device according to a first embodiment. 4A to 4C are diagrams illustrating an assembly process of the electronic control device according to the first embodiment. FIG. 11 is a perspective view showing an electronic control device according to a second embodiment. FIG. 11 is an exploded perspective view showing an electronic control device according to a second embodiment. FIG. 11 is an exploded perspective view showing an electronic control device according to a second embodiment. FIG. 4 is a cross-sectional view showing an electronic control device according to a second embodiment. 13A to 13C are diagrams illustrating an assembly process of the electronic control device according to the second embodiment. FIG. 11 is a perspective view showing an electronic control device according to a third embodiment. FIG. 11 is an exploded perspective view showing an electronic control device according to a third embodiment. FIG. 11 is an exploded perspective view showing an electronic control device according to a third embodiment. FIG. 11 is a cross-sectional view showing an electronic control device according to a third embodiment. 13A to 13C are diagrams illustrating an assembly process of the electronic control device according to the third embodiment. FIG. 13 is a perspective view showing an electronic control device according to a fourth embodiment. FIG. 13 is an exploded perspective view showing an electronic control device according to a fourth embodiment. FIG. 13 is an exploded perspective view showing an electronic control device according to a fourth embodiment. FIG. 11 is a cross-sectional view showing an electronic control device according to a fourth embodiment. 13A to 13C are diagrams illustrating an assembly process of the electronic control device according to the fourth embodiment. FIG. 13 is a perspective view showing an electronic control device according to a fifth embodiment. FIG. 13 is an exploded perspective view showing an electronic control device according to a fifth embodiment. FIG. 13 is an exploded perspective view showing an electronic control device according to a fifth embodiment. FIG. 13 is a cross-sectional view showing an electronic control device according to a fifth embodiment. 13A to 13C are diagrams illustrating an assembly process of the electronic control device according to the fifth embodiment. 13A to 13C are diagrams illustrating the flow of heat dissipation grease in an electronic control device according to a fifth embodiment. 13 is a diagram showing an arrangement pattern of holes in an electronic control device according to a fifth embodiment. FIG. FIG. 13 is a perspective view showing an electronic control device according to a sixth embodiment. FIG. 13 is a perspective view showing an electronic control device according to a sixth embodiment. FIG. 13 is an exploded perspective view showing an electronic control device according to a sixth embodiment. FIG. 13 is an exploded perspective view showing an electronic control device according to a sixth embodiment. FIG. 13 is a cross-sectional view showing an electronic control device according to a sixth embodiment. 13A to 13C are diagrams illustrating an assembly process of the electronic control device according to the sixth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an electronic control device and a manufacturing method for an electronic control device according to the present invention will be described with reference to the drawings.
The electronic control device according to the present invention is, for example, an electronic control device of a non-waterproof structure mounted inside a vehicle interior, and performs four-wheel drive control, driving assistance control, and the like.

In addition, the electronic control device of the present invention has an electronic circuit board housed in a resin case, and is equipped with a metal heat dissipation member arranged opposite the heat-generating portion of the electronic circuit board, and heat dissipation grease arranged between the electronic circuit board and the metal heat dissipation member.
In other words, the electronic control device according to the present invention employs a heat dissipation structure in which heat from heat-generating parts of an electronic circuit board is transferred to a metallic heat dissipation member via heat dissipation grease, and dissipated from the metallic heat dissipation member.
The above heat dissipation structure will be described in more detail below.

[First embodiment]
1 to 4 are diagrams showing an electronic control device 100A according to the first embodiment.
In detail, FIG. 1 is a perspective view of the electronic control device 100A, FIGS. 2 and 3 are exploded perspective views of the electronic control device 100A, and FIG. 4 is a cross-sectional view of the electronic control device 100A.
An electronic control device 100A according to the first embodiment will be described below with reference to FIGS. 1 to 4. FIG.

The electronic control device 100A includes an electronic circuit board 200 and a resin case 300 that houses the electronic circuit board 200.
The electronic circuit board 200 has a connector 210 and a heat generating component 220 such as a FET mounted on a surface 200A.

The resin case 300 is formed in a bag shape having an opening 301 .
In detail, the resin case 300 has a ceiling wall portion 302 which covers the upper surface on which the connector 210, heat-generating components 220, etc. of the electronic circuit board 200 are mounted, a bottom wall portion 303 which faces the rear surface 200B which is the lower surface of the electronic circuit board 200, left and right wall portions 304, 305 which rise from the left and right ends of the bottom wall portion 303 and connect to the ceiling wall portion 302, and a rear wall portion 306 which rises from the rear end of the bottom wall portion 303 and connects to the ceiling wall portion 302.

The opening 301 of the resin case 300 is covered with a resin cover 400 .
The resin cover 400 has a connector hole 410 formed therein.
After the electronic circuit board 200 is housed in the resin case 300, when the opening 301 of the resin case 300 is covered with the resin cover 400, the connector 210 is set to be inserted into the connector hole 410 and protrude to the outside.
The resin cover 400 is attached to the resin case 300 by snap fitting.

On the side opposite to the front surface 200A of the electronic circuit board 200 on which the heat generating components 220 are mounted, a metallic heat sink 500 as a metallic heat dissipation member is disposed opposite to the back surface 200B of the electronic circuit board 200 with a gap therebetween.
The metal heat sink 500 is a rectangular plate-like member made of steel, a copper alloy such as brass, aluminum, or the like.

Then, thermal grease 600 is placed between the metal heat sink 500 and the electronic circuit board 200 directly below the area where the heat generating component 220 is mounted (for example, directly below the outline of the solder land of the heat generating component 220).
In other words, the heat generated by the heat-generating component 220 is transferred to the metal heat sink 500 via the electronic circuit board 200 and the thermal grease 600, and is dissipated from the metal heat sink 500, thereby preventing the temperature of the heat-generating component 220 from rising.
The heat dissipation grease 600 is a hardening type heat dissipation grease, which is in a fluid grease form when the electronic control device 100A is assembled, and hardens at room temperature.

FIG. 5 shows a manufacturing method (in other words, an assembly process) of the electronic control device 100A shown in FIGS.
In assembling the electronic control device 100A, an electronic circuit board 200 on which the connector 210, heat generating components 220, etc. are mounted, a resin case 300, a resin cover 400, a metal heat sink 500, and heat dissipation grease 600 are prepared.

First, the thermal grease 600 is applied to the area of the rear surface 200B of the electronic circuit board 200 that is directly below the heat generating component 220.
Next, the metal heat sink 500 is fixed to the rear surface 200B of the electronic circuit board 200 with a predetermined gap therebetween so that the thermal grease 600 is sandwiched between the electronic circuit board 200 and the metal heat sink 500.

In other words, the electronic circuit board 200 and the metal heat sink 500 are fixed so that the back surface 200B of the electronic circuit board 200 and the front surface 500A of the metal heat sink 500 face each other with a gap between them, and the area of the gap directly below the heat-generating component 220 is filled with thermal grease 600.
The metal heat sink 500 can be fixed to the electronic circuit board 200 by a known method such as screw fastening with a spacer therebetween or snap fitting.

Then, after the process of stacking and integrating the electronic circuit board 200 and the metallic heat sink 500 with the thermal grease 600 sandwiched therebetween, the integrated electronic circuit board 200 and the metallic heat sink 500 are housed in the resin case 300.
Here, guide grooves 307 are integrally provided on the inner surfaces of the left and right wall portions 304, 305 of the resin case 300. The guide grooves 307 engage with the side edges of the electronic circuit board 200 and the metal heat sink 500 to guide the movement of the electronic circuit board 200 and the metal heat sink 500 in a direction parallel to the board surface of the electronic circuit board 200.

When storing the integrated electronic circuit board 200 and the metal heat sink 500 in the resin case 300, the integrated electronic circuit board 200 and the metal heat sink 500 are inserted into the resin case 300 from the opening 301 so that both side ends of the electronic circuit board 200 and the metal heat sink 500 engage with the guide grooves 307, and the electronic circuit board 200 and the metal heat sink 500 are held within the resin case 300.
Then, the electronic circuit board 200 and the metal heat sink 500 are pushed toward the rear wall portion 306, and the electronic circuit board 200 and the metal heat sink 500 are moved along the guide grooves 307 to the storage position.

Then, the opening 301 of the resin case 300 is covered with the resin cover 400, so that the electronic circuit board 200 and the metal heat sink 500 are sandwiched between the inner surface of the resin case 300 and the rear wall portion 306 of the resin case 300 and fixed inside the resin case 300, and then the heat dissipation grease 600 is allowed to harden.
When the heat generating component 220 is mounted on the rear surface 200B of the electronic circuit board 200, the gap between the heat generating component 220 and the metal heat sink 500 is filled with heat dissipation grease 600.

According to the electronic control device 100A of the first embodiment, the resin case 300 is used, and the heat generated by the heat generating component 220 is dissipated from the metal heat sink 500 via the heat dissipation grease 600.
Therefore, compared to a case where the metal heat sink 500 is not provided, the heat dissipation performance is improved, and the durability of the heat generating component 220 can be improved.

Furthermore, since electronic control device 100A uses resin case 300, the weight and cost of the case can be reduced.
Furthermore, since the electronic circuit board 200 and the metal heat sink 500 are integrated with the heat sink 600 sandwiched between them and then inserted into the resin case 300, the electronic circuit board 200 and the metal heat sink 500 can be stably assembled with the heat sink grease 600 filled in the desired area between the electronic circuit board 200 and the metal heat sink 500.

For example, if a metallic heat sink 500 is inserted into a resin case 300 and then an electronic circuit board 200 with thermal grease 600 applied thereto is inserted into the resin case 300, the thermal grease 600 may be peeled off by the metallic heat sink 500, and the adhesion of the thermal grease 600 to the rear surface 200B of the electronic circuit board 200 and the metallic heat sink 500 may be compromised.
Furthermore, after inserting the metal heat sink 500 and the electronic circuit board 200 into the resin case 300, when a filling nozzle is inserted into the gap between the metal heat sink 500 and the electronic circuit board 200 to fill the heat sink grease 600, it becomes necessary to position the filling nozzle with high precision and also to control the amount of application.

Furthermore, after the thermal grease 600 is applied by the filling nozzle, the applied state cannot be confirmed by visual inspection, making it difficult to obtain consistent quality.
Therefore, if the metal heat sink 500 and the electronic circuit board 200 are inserted into the resin case 300 and then the heat sink grease 600 is filled in, a large amount of capital investment is required in the manufacture of the electronic control device 100A, and the number of labor hours increases, resulting in an increase in the manufacturing cost of the electronic control device 100A.

In contrast, according to the assembly method shown in FIG. 5, the application of the thermal grease and confirmation of the applied state can be easily performed, and peeling off of the thermal grease when assembled to the resin case 300 can be prevented.
Therefore, it is possible to obtain stable heat dissipation performance while suppressing an increase in the manufacturing cost of the electronic control device 100A.

[Second embodiment]
The following describes a second embodiment that can easily and reliably fill in the heat dissipation grease while further increasing the heat dissipation efficiency compared to the electronic control device 100A of the first embodiment.
6 to 9 are diagrams showing an electronic control device 100B according to the second embodiment.

In detail, FIG. 6 is a perspective view of the electronic control device 100B, FIGS. 7 and 8 are exploded perspective views of the electronic control device 100B, and FIG. 9 is a cross-sectional view of the electronic control device 100B.
In addition, in Figs. 6 to 9 showing the electronic control device 100B according to the second embodiment, the same elements as those in the electronic control device 100A of the first embodiment are given the same reference numerals and detailed description thereof will be omitted.

The electronic control device 100B of the second embodiment, like the electronic control device 100A of the first embodiment, has a metal heat sink 500 arranged opposite the back surface 200B of the electronic circuit board 200, and is provided with a heat dissipation structure that transfers heat from the heat-generating component 220 to the metal heat sink 500 via heat dissipation grease 600 sandwiched between the metal heat sink 500 and the electronic circuit board 200.
On the other hand, the electronic control device 100B of the second embodiment differs from the electronic control device 100A of the first embodiment in that the shape of the resin case 300 is different and that the metal heat sink 500 has holes 501.
The hole 501 is provided penetrating the metallic heat sink 500 in the thickness direction so as to open into the area filled with the thermal grease 600 on the surface 500A of the metallic heat sink 500.

In the resin case 300 of the second embodiment, a rectangular cutout 308 is formed in the bottom wall 303 , extending from the opening 301 toward the rear wall 306 , with the direction from the opening 301 toward the rear wall 306 being the longitudinal direction.
When the metal heat sink 500 is inserted into the resin case 300, the metal heat sink 500 covers the cutout 308 from the inside, so that the metal heat sink 500 forms part of the bottom wall portion 303 of the resin case 300.
In other words, the back surface 500B of the metal heat sink 500, which is the surface opposite the electronic circuit board 200, is exposed to the outside of the resin case 300 at the cutout 308, and the front surface 500A of the metal heat sink 500, which is the surface facing the electronic circuit board 200, is exposed to the inside of the resin case 300.

As a result, the heat from the heat-generating component 220 transferred to the metal heat sink 500 is dissipated to the outside of the resin case 300 from the metal heat sink 500 exposed to the outside of the resin case 300 at the cutout 308 .
Therefore, the electronic control device 100B of the second embodiment has higher heat dissipation efficiency than the electronic control device 100A of the first embodiment in which heat is dissipated from the metal heat sink 500 to the inside of the resin case 300.

Here, in the electronic control device 100B of the second embodiment, as in the electronic control device 100A of the first embodiment, it is possible to adopt an assembly method in which heat dissipation grease 600 is applied to the electronic circuit board 200, and then the electronic circuit board 200 and the metal heat dissipation plate 500 are integrated with the heat dissipation grease 600 sandwiched between them, and the integrated electronic circuit board 200 and the metal heat dissipation plate 500 is inserted into the resin case 300.
However, in the electronic control device 100B of the second embodiment, after the electronic circuit board 200 and the metal heat sink 500 are assembled into the resin case 300, the heat sink 600 can be filled between the electronic circuit board 200 and the metal heat sink 500 (or between the heat-generating component 220 and the metal heat sink 500) using the holes 501 provided in the metal heat sink 500.

FIG. 10 shows a manufacturing method (in other words, an assembly process) of the electronic control device 100B shown in FIGS.
In the electronic control device 100B of the second embodiment, guide grooves 307 for guiding the movement of the electronic circuit board 200 and the metal heat sink 500 are also integrally formed on the inner surfaces of the left and right wall portions 304, 305 of the resin case 300.

First, the electronic circuit board 200 and the metal heat sink 500 are engaged with the guide groove 307 and inserted into the resin case 300 , and the electronic circuit board 200 and the metal heat sink 500 are placed opposite each other inside the resin case 300 .
At this time, the notch 308 is formed to include the area directly below the heat-generating component 220 so that a hole 501 is provided in the portion of the metal heat sink 500 exposed to the outside of the resin case 300 by the notch 308.
From the viewpoint of the filling property of the thermal grease 600, the diameter of the hole 501 is preferably 1.5 mm or more.

After inserting the electronic circuit board 200 and the metal heat sink 500 into the interior of the resin case 300, a filling nozzle for the thermal grease 600 is inserted into the hole 501 provided in the metal heat sink 500 exposed at the cutout 308, and the thermal grease 600 is filled and hardened in the area sandwiched between the electronic circuit board 200 and the metal heat sink 500, specifically, in the area directly below the heat-generating component 220.
Here, in the electronic circuit board 200 that has been subjected to this manufacturing process, the holes 501 are closed with the hardened heat dissipation grease 600 .

According to the electronic control device 100B of the second embodiment, when inserting the electronic circuit board 200 and the metal heat sink 500 into the resin case 300, there is no need to fix and integrate the metal heat sink 500 to the electronic circuit board 200, and the electronic circuit board 200 and the metal heat sink 500 can be inserted individually into the resin case 300.
Therefore, the number of steps and parts required for integrating the electronic circuit board 200 and the metal heat sink 500 can be reduced.

Furthermore, the metal heat sink 500 is exposed to the outside of the resin case 300 at the cutout 308, and heat can be dissipated directly from the metal heat sink 500 to the outside of the resin case 300, so that the heat from the heat-generating component 220 can be dissipated efficiently.
Furthermore, when filling the gap between the electronic circuit board 200 and the metal heat sink 500 with the heat dissipation grease 600, the heat dissipation grease 600 can be filled through the holes 501 that open into the filling area, so that the heat dissipation grease 600 can be filled easily and reliably.

For example, when filling the gap between the electronic circuit board 200 and the metal heat sink 500 with the thermal grease 600 by inserting a filling nozzle, it is necessary to position the nozzle, and it is difficult to reliably fill the required areas with the thermal grease 600.
In contrast, when filling the thermal grease 600 through the hole 501 provided in the metal heat sink 500, there is no need to position the filling nozzle, and the thermal grease 600 spreads around the hole 501 as the center, so that the thermal grease 600 can be easily filled into the required area.

[Third embodiment]
Below, we will explain the third embodiment, which employs a manufacturing method in which heat dissipation grease 600 is filled through holes 501 provided in a metal heat dissipation plate 500, as in the second embodiment, but changes the method of assembling the metal heat dissipation plate 500 to the resin case 300.

11 to 14 are diagrams showing an electronic control device 100C according to the third embodiment, where FIG. 11 is an oblique view of the electronic control device 100C, FIGS. 12 and 13 are exploded oblique views of the electronic control device 100C, and FIG. 14 is a cross-sectional view of the electronic control device 100C.
In addition, in Figures 11 to 14 which show the electronic control device 100C according to the third embodiment, the same elements as those in the electronic control device 100A of the first embodiment or the electronic control device 100B of the second embodiment are given the same symbols and detailed descriptions are omitted.

In the third embodiment, the rear wall 306 side of the bottom wall 303 of the resin case 300 is an opening 309, and a guide groove 310 is provided for inserting a metallic heat sink 500 from the rear wall 306 side. By inserting the metallic heat sink 500 along the guide groove 310, the opening 309 is blocked by the metallic heat sink 500.
In addition, a snap-fit claw 311 is provided at the rear end of the bottom wall portion 303 to prevent the metal heat sink 500 from falling out and to hold the metal heat sink 500 in the inserted state, and a fitting hole 502 into which the snap-fit claw 311 fits is provided in the metal heat sink 500.

In other words, after inserting the metal heat sink 500 along the guide groove 310 from the rear wall portion 306 side, the snap-fit claws 311 of the resin case 300 are fitted into the fitting holes 502 of the metal heat sink 500, whereby the metal heat sink 500 is fixed in a position blocking the opening 309 of the bottom wall portion 303.
Here, the opening 309 is formed to include the area directly below the heat-generating component 220, and a hole 501 for filling with thermal grease 600 is formed in the portion of the metal heat sink 500 that is exposed to the outside by the opening 309.

FIG. 15 shows a manufacturing method (in other words, an assembly process) of the electronic control device 100C shown in FIGS.
The electronic circuit board 200 is inserted into the resin case 300 from the opening 301 of the resin case 300 along the guide groove 307 .
Finally, the opening 301 of the resin case 300 is closed by the resin cover 400 , so that the resin case 300 is sandwiched between the resin cover 400 .

On the other hand, as described above, the metal heat sink 500 is inserted along the guide groove 310 from the rear wall 306 side of the resin case 300 and fixed in the inserted position by fitting the snap fit claws 311 into the fitting holes 502.
The electronic circuit board 200 and the metal heat sink 500 are disposed opposite each other within the resin case 300 with a gap therebetween.
Next, thermal grease 600 is filled between the electronic circuit board 200 and the metallic heat sink 500 through the holes 501 of the metallic heat sink 500 exposed in the opening 309, and is then allowed to harden.

According to the electronic control device 100C of the third embodiment, the same actions and effects as those of the second embodiment are achieved.
Furthermore, according to the electronic control device 100C of the third embodiment, even if the heat-generating component 220 is positioned on the opposite side of the electronic circuit board 200 from the side on which the connector 210 is mounted (in other words, closer to the rear wall portion 306), heat dissipation performance can be ensured with a metal heat sink 500 of the minimum required size, and the weight and cost increases due to the larger size of the metal heat sink 500 can be suppressed.

[Fourth embodiment]
A fourth embodiment will be described below in which the resin case 300 is integrally molded with the metal heat sink 500 by insert molding.
16 to 19 are diagrams showing an electronic control device 100D of the fourth embodiment, with FIG. 16 being a perspective view of the electronic control device 100D, FIGS. 17 and 18 being exploded perspective views of the electronic control device 100D, and FIG. 19 being a cross-sectional view of the electronic control device 100D.
In addition, in Figures 16 to 19 which show the electronic control device 100D according to the fourth embodiment, the same elements as those in the electronic control device 100A of the first embodiment or the electronic control device 100B of the second embodiment are given the same symbols and detailed descriptions are omitted.

The resin case 300 in the electronic control device 100D of the fourth embodiment is integrally formed with the metal heat sink 500 by insert molding.
Here, the metal heat sink 500 is inserted so as to cover the window-like opening 312 provided in the area directly below the heat generating component 220 in the bottom wall portion 303 of the resin case 300 .
Therefore, the metal heat sink 500 is exposed to the outside of the resin case 300 at the opening 312 .

Furthermore, in the portion of the metal heat sink 500 exposed to the outside of the resin case 300 , in other words, in the area directly below the heat generating component 220 , a hole 501 for filling with heat dissipating grease 600 is provided.
When the electronic circuit board 200 is inserted into the resin case 300 from the opening 301 along the guide groove 307, the electronic circuit board 200 and the metal heat sink 500 face each other with a gap between them, and the metal heat sink 500 is positioned directly below the heat-generating component 220 mounted on the electronic circuit board 200.

FIG. 20 shows a manufacturing method (in other words, an assembly process) for the electronic control device 100D shown in FIGS.
Since the resin case 300 is integrally provided with the metal heat sink 500, the task of inserting the metal heat sink 500 into the resin case 300 is not required when assembling the electronic control device 100D.

When the electronic circuit board 200 is inserted into the resin case 300 from the opening 301 along the guide groove 307, the electronic circuit board 200 and the metal heat sink 500 face each other with a gap therebetween.
Here, the area directly below the heat-generating component 220 in the gap between the electronic circuit board 200 and the metal heat sink 500 is filled with heat sink grease 600 through a hole 501 provided in the metal heat sink 500 exposed at the opening 312 in the bottom wall portion 303 of the resin case 300, and then allowed to harden.

The electronic control device 100D of the fourth embodiment has the same functions and effects as the electronic control device 100B of the second embodiment.
Furthermore, according to the electronic control device 100D of the fourth embodiment, the resin case 300 is integrally provided with the metal heat sink 500 by insert molding, so that the assembly labor required to attach the metal heat sink 500 to the resin case 300 can be reduced, and airtightness can be easily ensured at the joint between the metal heat sink 500 and the resin case 300, and the strength of the resin case 300 can be improved.

[Fifth embodiment]
Below, we will explain the fifth embodiment of the electronic control device 100E, which differs from the second embodiment of the electronic control device 100B in that two holes 501 are provided in the metal heat dissipation plate 500 and that a convex portion (in other words, a protrusion or enclosure portion) is formed on the metal heat dissipation plate 500 to limit the flow area of the thermal grease 600.

21 to 24 are diagrams showing an electronic control device 100E of the fifth embodiment, with FIG. 21 being a perspective view of the electronic control device 100E, FIGS. 22 and 23 being exploded perspective views of the electronic control device 100E, and FIG. 24 being a cross-sectional view of the electronic control device 100E.
In addition, in Figs. 21 to 24 showing the electronic control device 100E according to the fifth embodiment, the same elements as those in the electronic control device 100B according to the second embodiment are given the same reference numerals and detailed description thereof will be omitted.

In the electronic control device 100E of the fifth embodiment, a ring-shaped protrusion 510 is provided on the surface 500A of the metal heat sink 500 so as to surround a rectangular area serving as a filling area for the heat dissipation grease 600, in other words, so as to surround an area including the opening end of the hole 501.
The protrusion 510 can be formed by adhering a frame-shaped member to the surface 500 A of the metal heat sink 500 , or can be provided integrally with the metal heat sink 500 .

In the embodiment shown in FIG. 22, the area surrounded by the protrusion 510, that is, the area filled with the thermal grease 600, is rectangular in shape with the insertion direction of the electronic circuit board 200 as the longitudinal direction.
However, the filling area of the thermal grease 600 is set according to the shape of the heat-generating component 220 and its orientation in the mounted state, and is not limited to a rectangular shape with the insertion direction of the electronic circuit board 200 as the longitudinal direction.

Furthermore, a first hole 501A is provided at the center of one longitudinal end of the rectangular region surrounded by the convex portion 510, and a second hole 501B is provided at the center of the other longitudinal end.
That is, the metal heat sink 500 has a first hole 501A provided at one end of the area surrounded by the protrusion 510, and a second hole 501B provided at the other end of the area.
Here, either the first hole 501A or the second hole 501B is used for filling with the thermal grease 600, and the other is used for checking the filling state of the thermal grease 600.

FIG. 25 shows a manufacturing method (in other words, an assembly process) for the electronic control device 100E shown in FIGS.
First, the electronic circuit board 200 and the metallic heat sink 500 are inserted into the resin case 300 by engaging them with the guide grooves 307 , so that the electronic circuit board 200 and the metallic heat sink 500 face each other inside the resin case 300 .

Thereafter, of the two holes 501A, 501B provided in the metal heat sink 500 exposed in the cutout 308, for example, a filling nozzle for the thermal grease 600 is inserted into the first hole 501A, and the thermal grease 600 is filled.
FIG. 26 is a diagram showing the flow of the thermal grease 600 when the thermal grease 600 is filled from the first hole 501A.
When the thermal grease 600 filled from the first hole 501A flows toward the second hole 501B and reaches the second hole 501B, the thermal grease 600 overflows (in other words, leaks out) from the second hole 501B to the outside of the resin case 300.

In other words, when filling the thermal grease 600 through the first hole 501A, if the thermal grease 600 overflows from the second hole 501B, this indicates that the thermal grease 600 has been filled (in other words, applied) at least between the first hole 501A and the second hole 501B.
Therefore, by appropriately setting the positional relationship between the first hole 501A and the second hole 501B, it is possible to appropriately control the amount and filling range of the thermal grease 600 to be filled, for example by stopping the filling operation of the thermal grease 600 when the thermal grease 600 overflows from the second hole 501B.
Here, the overflow of thermal grease 600 from second hole 501B can be detected by visual inspection by an operator or by a board appearance inspection device.

It is apparent that various patterns can be adopted for the arrangement of the holes 501 when the holes 501 are provided in the metal heat sink 500.
FIG. 27 shows an example in which two holes 501 are provided in a metal heat sink 500, with a first hole 501A and a second hole 501B being arranged at both diagonal corners of a rectangular area surrounded by a convex portion 510.

In addition, one hole 501 for filling the thermal grease 600 can be provided, and multiple holes 501 for checking the flow state of the thermal grease 600 can be provided.
For example, three holes 501 can be arranged in a straight line, with two of the holes 501 being for confirmation, and the center hole can be used for filling and both ends for confirmation.

Furthermore, the holes 501 are not limited to being arranged in a straight line, and three or more confirmation holes 501 may be provided to surround the filling hole 501 .
For example, a filling hole 501 can be provided in the center of a rectangular filling area, and confirmation holes 501 can be provided at each of the four corners.

Also, instead of surrounding the filled area of thermal grease 600 with a convex portion 510, it may be surrounded by a concave portion (in other words, a groove portion), or the bottom of the filled area may be made deeper (in other words, recessed) than the surrounding unfilled area.
In addition, when no protrusion 510 surrounding the filling area of the thermal grease 600 is provided and the surface 500A of the metal heat sink 500 onto which the thermal grease 600 is applied is formed flat, multiple holes 501 can be provided.
Conversely, it is also possible to provide only one hole 501 in a metal heat sink 500 having a protrusion 510 surrounding the filling area of the heat dissipation grease 600 .

Sixth Embodiment
Below, we will explain the sixth embodiment of the electronic control device 100F, in which the metal heat sink 500 also serves as a bracket for mounting the resin case 300, in other words, the mounting bracket is integrally provided with the metal heat sink 500.

28-32 are diagrams showing an electronic control device 100F of the sixth embodiment, where FIGS. 28 and 29 are oblique views of the electronic control device 100F, FIGS. 30 and 31 are exploded oblique views of the electronic control device 100F, and FIG. 32 is a cross-sectional view of the electronic control device 100F.
In addition, in Figs. 28 to 32 showing an electronic control device 100F according to the sixth embodiment, the same elements as those in the above-described embodiments are given the same reference numerals and detailed description thereof will be omitted.

In the electronic control device 100F of the sixth embodiment, the resin case 300 is attached to another member using an attachment bracket 700, which is a processed sheet metal part.
Furthermore, the resin case 300 has a window-like opening 312 in the area of the bottom wall portion 303 directly below the heat-generating component 220 .

The bracket 700 has a heat dissipation section 701 which is fitted into the opening 312 and is formed in a shallow box shape that opens toward the outside of the resin case 300 .
The bottom wall portion 701 a of the heat dissipation portion 701 is provided with one or more holes 701 b for filling with the heat dissipation grease 600 .

When the bracket 700 is attached to the resin case 300 , the bottom wall portion 701 a of the heat dissipation portion 701 faces the electronic circuit board 200 directly below the heat generating component 220 of the electronic circuit board 200 .
The gap between the bottom wall portion 701 a and the electronic circuit board 200 is filled with thermal grease 600 through the holes 701 b, so that heat from the heat-generating components 220 is transferred to the bottom wall portion 701 a via the thermal grease 600 .
In other words, the heat dissipation portion 701 (more specifically, the bottom wall portion 701a) constitutes a metallic heat dissipation member.

Furthermore, the bracket 700 has a pair of mounting portions 702 a and 702 b that are provided parallel to the bottom wall portion 303 of the resin case 300 .
The mounting portions 702a, 702b extend from a pair of side walls 701c, 701d of the heat dissipation portion 701 along the bottom wall 303 of the resin case 300 toward the walls 304, 305 of the resin case 300, and protrude outward from the walls 304, 305.

A mounting hole 702c is provided at the tip of the mounting portions 702a, 702b, and the resin case 300 (in other words, the electronic control device 100F) is attached to another member by a bolt inserted through this mounting hole 702c.
The mounting portions 702a and 702b are provided with tongue portions 703a and 703b that rise up along the walls 304 and 305, respectively.
The tongue portions 703a and 703b have an engagement hole 703c.

The walls 304 and 305 of the resin case 300 are provided with guide grooves 704 a and 704 b into which the tongue pieces 703 a and 703 b are inserted from the bottom wall 303 side of the resin case 300 toward the top wall 302 .
Each of the guide grooves 704a, 704b is constituted by a pair of convex portions, and an engaging convex portion 704c that protrudes from the wall portions 304, 305 is formed between the pair of convex portions.

Here, when the tongue portions 703a, 703b are inserted into the guide grooves 704a, 704b from the bottom wall portion 303 side of the resin case 300, the engaging protrusions 704c engage with the engaging holes 703c of the tongue portions 703a, 703b, thereby fixing the bracket 700 to the resin case 300.
When the bracket 700 is fixed at a position where the engaging protrusions 704 c engage with the engaging holes 703 c of the tongue portions 703 a and 703 b , the heat dissipating portion 701 of the bracket 700 is fitted into the opening 312 of the bottom wall portion 303 of the resin case 300 .

The shape and fixing method of the bracket 700 are not limited to those shown in FIGS.
For example, the fixing method of the metal heat sink 500 in the electronic control device 100B of the second embodiment can be adopted, and mounting portions 702a, 702b can be integrally formed on the metal heat sink 500 to serve as a bracket for mounting the resin case 300.

FIG. 33 shows a manufacturing method (in other words, an assembly process) for the electronic control device 100F shown in FIGS.
In manufacturing the electronic control device 100F, first, the electronic circuit board 200 and the bracket 700, which also serves as a metal heat dissipation member, are attached to the resin case 300.
Next, the thermal grease 600 is filled between the bottom wall portion 701 a and the electronic circuit board 200 using the holes 701 b provided in the bottom wall portion 701 a of the heat dissipation portion 701 of the bracket 700 .

In addition, in an electronic control device 100F equipped with a bracket 700 that also serves as a metal heat dissipation member, a plurality of holes 701b can be opened in a bottom wall portion 701a of the heat dissipation portion 701 of the bracket 700, at least one of which can be used as a hole for inserting a filling nozzle for the heat dissipation grease 600, and at least one of which can be used to check the filling status.
In addition, a convex portion surrounding the filling area of the thermal grease 600 can be provided on the surface of the bottom wall portion 701 a facing the electronic circuit board 200 .

The technical ideas described in the above embodiments can be used in any suitable combination as long as no contradiction occurs.
Furthermore, although the contents of the present invention have been specifically described with reference to preferred embodiments, it is obvious that a person skilled in the art can adopt various modified embodiments based on the basic technical concept and teachings of the present invention.

For example, a metallic heat dissipation member such as metallic heat sink 500 may include heat dissipation fins.
Moreover, the metal heat sink 500 can be fixed to the resin case 300 by bonding.
Furthermore, if the electronic circuit board 200 has multiple heat-generating components 220 (in other words, multiple heat-generating sites), the thermal grease 600 can be filled individually into each area of the heat-generating components 220, or the thermal grease 600 can be filled into one area that includes multiple heat-generating components 220.

100A-100F: Electronic control device, 200: Electronic circuit board, 220: Heat generating component (heat generating part), 300: Resin case, 400: Resin cover, 500: Metal heat sink (metal heat sink), 501: Hole, 600: Heat dissipation grease

Claims (8)

An electronic control device,
A resin case that houses an electronic circuit board;
a metal heat dissipation member disposed so as to face a heat generating portion of the electronic circuit board;
a heat dissipation grease disposed between the electronic circuit board and the metal heat dissipation member;
Equipped with
The metal heat dissipation member is formed in a plate shape,
The resin case is
a guide groove for inserting and holding the metal heat dissipation member into the resin case in a direction parallel to the electronic circuit board;
a notch that is closed from the inside of the resin case by the metal heat dissipation member held in the guide groove;
having
a surface of the metal heat dissipation member opposite to the electronic circuit board is exposed to the outside of the resin case, and the metal heat dissipation member forms a part of a wall portion of the resin case that surrounds the electronic circuit board by closing the cutout with the metal heat dissipation member;
The metal heat dissipation member has a hole that communicates between the inside and the outside of the resin case, the hole opening in an area where the heat dissipation grease is disposed.
Electronic control unit. 2. The electronic control device according to claim 1 ,
The metal heat dissipation member has a plurality of the holes.
Electronic control unit. 2. The electronic control device according to claim 1 ,
The metal heat dissipation member has a convex portion or a concave portion provided on a surface on which the heat dissipation grease is applied so as to surround an area including an opening end of the hole.
Electronic control unit. 4. The electronic control device according to claim 3 ,
The metal heat dissipation member has, as the holes, a first hole provided at one end of an area surrounded by the protrusions or the recesses and a second hole provided at the other end of the area.
Electronic control unit. 5. The electronic control device according to claim 4,
When the heat dissipation grease is filled between the electronic circuit board and the metallic heat dissipation member housed in the resin case through the first hole, the heat dissipation grease is configured to leak out of the resin case through the second hole when the heat dissipation grease is filled within a predetermined filling range.
Electronic control unit. 2. The electronic control device according to claim 1 ,
The metal heat dissipation member also serves as a bracket for mounting the resin case.
Electronic control unit. A method for manufacturing an electronic control device having an electronic circuit board housed in a resin case, comprising the steps of:
The resin case is
a guide groove into which the electronic circuit board and the plate-shaped metal heat dissipation member are inserted and held in a direction parallel to a board surface of the electronic circuit board, and a notch that is closed from an inside of the resin case by the metal heat dissipation member held in the guide groove,
the metal heat dissipation member is held in the guide groove and faces a heat generating portion of the electronic circuit board;
The method for manufacturing the electronic control device includes:
a step of inserting the electronic circuit board and the metal heat dissipation member together into the resin case along the guide groove;
a step of filling a gap between the electronic circuit board and the metal heat dissipation member housed in the resin case with thermal grease through a hole provided in the metal heat dissipation member that communicates between the inside and outside of the resin case;
A manufacturing method of an electronic control device comprising the steps of: A method for manufacturing an electronic control device according to claim 7, comprising the steps of:
The metal heat dissipating member has a convex portion or a concave portion on a surface on which the heat dissipating grease is applied, the convex portion or the concave portion being provided so as to surround an area including an open end of the hole, and the hole has a first hole provided at one end of the area surrounded by the convex portion or the concave portion and a second hole provided at the other end of the area,
The step of filling the thermal grease includes:
filling the thermal grease between the electronic circuit board and the metal heat dissipation member through the first hole;
a step of checking for leakage of the thermal grease from the second hole to the outside of the resin case;
A method for manufacturing an electronic control device , comprising :

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