JP2021068717A - Electronic control device - Google Patents

Abstract

To provide an electronic control device that can improve heat dissipation and productivity.SOLUTION: An electronic control device includes a bottomed tubular casing 2 with an opening 23 on one end side, a control board 6 inserted into the casing 2 through the opening 23, and a metal plate 4 fixed to the casing 2, and an opening side holding portion 26 that fixes a part of the metal plate 4 is provided on the opening 23 side of the casing 2, and the facing surface of the metal plate 4 with the control board 6 is arranged on the same surface as the facing surface of the opening side holding portion 26 with the control board 6, or on the control board 6 side.SELECTED DRAWING: Figure 3

Description

The present invention relates to an electronic control device.

The vehicle is equipped with an electronic control device such as an engine control unit or an automatic transmission control unit in the vehicle interior, the engine room, or the like. These electronic control devices are composed of, for example, a control board, a connector mounted on the control board, a housing for accommodating the control board, a seal member for ensuring waterproofness in the housing, and the like.

In recent years, with the increase in the functions of electronic control devices, the amount of heat generated by electronic components tends to increase more and more. Further, when the assembling process is complicated due to the increase in the number of parts constituting the electronic control device, the productivity is lowered. For this reason, it is important to increase the heat dissipation of the electronic control device and improve the productivity.

In the electronic control device of Patent Document 1, an electronic component is mounted and a circuit board in which a pair of metal members are coupled to predetermined positions on the front surface and the back surface is incorporated in a housing base. At that time, the circuit board is slid in the housing base, the end of the circuit board is inserted into the insertion hole of the partition wall separating the inside of the housing base and the opening for the connector, and the end of the circuit board is inserted in the opening for the connector. After a part is exposed, the housing cover is attached and fixed to the housing base. As a result, the front and back surfaces of the circuit board are held by the pair of metal members, and the heat generated from the electronic components is transferred to the housing and dissipated to the outside.

Japanese Unexamined Patent Publication No. 2014-093415

According to the technique described in Patent Document 1, the heat generated from the electronic component can be efficiently transferred to the housing by holding the front and back surfaces of the circuit board on the metal member. However, since the contact area between the metal member and the housing is limited, there is room for improving heat dissipation. Further, since the housing base, the housing cover, and the metal plate are separate parts, further improvement in productivity by integrating the parts is desired.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic control device capable of improving heat dissipation and productivity.

In order to solve the above problems, an electronic control device according to the present invention includes a bottomed tubular resin case having an opening on one end side, a control substrate inserted into the resin case through the opening, and the resin case. An electronic control device including a metal plate to be fixed, wherein an opening side holding portion for fixing one end of the metal plate is provided on the opening side of the resin case, and a control substrate of the metal plate is provided. The surface facing the opening side holding portion is arranged on the same surface as the surface facing the control board or on the control board side.

According to the present invention, heat dissipation and productivity can be improved.

It is external perspective view of the electronic control apparatus which concerns on 1st Example. It is explanatory drawing which shows the assembly procedure of the electronic control apparatus which concerns on 1st Example. It is a figure which compared the electronic control apparatus which concerns on 1st Example with a conventional electronic control apparatus. It is sectional drawing of the electronic control apparatus which concerns on 2nd Example. It is sectional drawing of the electronic control apparatus which concerns on 3rd Example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, for example, both heat dissipation and productivity of an electronic control device used in an engine control unit or an automatic transmission control unit mounted on an automobile are achieved.

Examples will be described with reference to FIGS. 1 to 3. FIG. 1 shows the appearance of the electronic control device 1. FIG. 2 shows an assembly procedure of the electronic control device 1.

The electronic control device 1 of this embodiment has a casing 2 as an example of a "resin case", a control board assembly 3 (see FIG. 2) housed in the casing 2, and a flat plate shape inserted and fixed to the casing 2. It is provided with a metal plate 4 (see FIG. 2).

The casing 2 is formed in a bottomed tubular shape having an opening 23 (see FIG. 2) on one end side. The casing 2 is injection molded from resin. As the material of the casing 2, it is preferable to use a lightweight resin having excellent heat resistance, such as PBT (Poly-Butylene-Terephetate), PA (Poly-Amide) 66, and PPS (Poly-Phynelene-Sulfide). Vehicle fixing portions 22 for fixing to a vehicle (not shown) are provided on both sides of the casing 2.

The control board assembly 3 is provided with a plurality of connectors 7 on one end side thereof. When a sealing material (not shown) or the like having adhesiveness is applied between each connector 7 and the casing 2 and the control board assembly 3 is assembled to the casing 2, each connector 7 is connected to the casing 2 via the sealing material or the like. The opening 23 of the is hermetically sealed. The sealing material may be applied when the electronic control device 1 is required to be waterproof. The curing type of the sealing material may be either thermosetting or humidity curing. By tightly sealing each connector 7 and the opening 23 of the casing 2 via a sealing material or the like, it is possible to prevent foreign matter, water, or the like from entering the inside of the electronic control device 1.

As shown in FIG. 2A, the control board 6 includes, for example, a printed wiring board 61 based on a glass epoxy resin or the like, and an electronic component 62 mounted on the printed wiring board 61. When connecting the electronic component 62 to the printed wiring board 61, for example, lead-free solder such as Sn-Cu solder, Sn-Ag-Cu solder, and Sn-Ag-Cu-Bi solder is used. Examples of the electronic component 62 include a microprocessor, a memory, other integrated circuits, a capacitor, a resistor, and the like. The electronic component 62 can be mounted on one side or both sides of the printed wiring board 61.

FIG. 2B shows the connector 7. The connector 7 is for connecting the control board 6 to another electronic circuit (not shown) in the vehicle. The connector 7 includes a connector terminal 72 for connecting the control board 6 and a vehicle-side harness (not shown), and a connector housing 71 for aligning and holding the connector terminals 72 at a predetermined pitch.

The connector housing 71 is integrally provided with an upper lid portion 711 projecting upward in FIG. 2 and a lower lid portion 712 projecting downward in FIG. 2. When the control board assembly 3 is assembled and fixed to the casing 2, the opening 23 of the casing 2 is covered by each of the lid portions 711 and 712.

The material of the connector terminal 72 is preferably copper or a copper alloy from the viewpoint of conductivity, miniaturization, and cost. As the material of the connector housing 71, for example, it is preferable to use a lightweight resin having excellent heat resistance, such as PBT (Poly-Butylene-Terethate), PA (Poly-Amide) 66, and PPS (Poly-Phyrene-Sulfide). ..

As shown in FIG. 2C, the connector terminal 72 and the control board 6 have a through-hole portion 63 of the control board 6 in which the connector terminal 72 is inserted, which is Sn-Cu solder, Sn-Ag-Cu solder, and Sn. Connect using lead-free solder such as -Ag-Cu-Bi solder. As a result, the connector 7 is attached to the control board 6, and the control board assembly 3 is manufactured. The type of the connector 7 may be either a surface mount type or a press-fit type.

As shown in FIG. 2D, a substrate accommodating space 21 is formed in the casing 2. A guide groove 24 is provided on the surface of the casing 2 facing the opening 23 (hereinafter referred to as the back surface) so that one end side of the control board 6 is inserted while sliding. A groove-shaped substrate mounting portion into which the control substrate 6 is inserted while sliding may be provided on the opening 23 side of the casing 2.

On the lower surface (hereinafter, bottom surface) in FIG. 2 of the casing 2, an opening side holding portion 26 for inserting and fixing one end (opening 23 side) of the metal plate 4 and the other end of the metal plate 4 are inserted. Is provided with a stepped portion 25 for inserting and fixing the metal. The opening side holding portion 26 is provided on the opening 23 side of the bottom surface of the casing 2. The step portion 25 is provided at the back surface side corner of the bottom surface of the casing 2. The step portion 25 is provided so that the inner surface of the casing 2 projects from the bottom surface over the guide groove 24.

The material of the metal plate 4 may be any of aluminum, aluminum alloy, iron or iron alloy from the viewpoint of heat dissipation. The metal plate 4 may be inserted into a mold when the casing 2 is resin-molded.

As shown in FIG. 2E, the casing is inserted into the substrate mounting portion 24 while sliding one end side of the control board 6 until one end side of the control board 6 abuts on the inner surface of the casing 2 and stops. The control board assembly 3 is mounted in 2.

FIG. 3 is a diagram comparing the electronic control device according to the first embodiment with the conventional electronic control device. FIG. 3A is a cross-sectional view of a conventional electronic control device, FIG. 3B is a cross-sectional view of the electronic control device according to the first embodiment, and FIG. 3C is a first embodiment. It is sectional drawing of the electronic control apparatus which concerns on one modification of the example, and FIG. 3D is a figure which compared the characteristic of each electronic control apparatus.

As shown in FIG. 3A, the opening side holding portion 126 of the conventional electronic control device has a tip surface and a view of the end portion (hereinafter, one end portion) on the opening 23 side of the casing 2 of the metal plate 4. Both the upper and lower sides (hereinafter, both front and back sides) of 3 are covered with resin. At this time, the surface of the metal plate 4 facing the control board 6 is arranged on the side opposite to the control board 6 (outside the casing 2) of the surface of the opening side holding portion 126 facing the control board 6. The clearance between the electronic component 62 mounted on the metal plate 4 side of the control board 6 and the metal plate 4 is a distance A.

As shown in FIG. 3B, the opening side holding portion 26 of the electronic control device according to the first embodiment has a front end surface of one end of the metal plate 4 and a lower surface (hereinafter, back surface) in FIG. It is covered with resin. At this time, the surface of the metal plate 4 facing the control board 6 is arranged on the same surface as the surface of the opening side holding portion 26 facing the control board 6. The clearance between the electronic component 62 mounted on the metal plate 4 side of the control board 6 and the metal plate 4 is a distance B (B <A). As a result, the metal plate 4 can be brought close to the control board 6. Therefore, in the process of dissipating the heat generated from the electronic component 62 to the atmosphere through the metal plate 4, as shown in FIG. 3 (d), the heat dissipation of the electronic control device of FIG. 3 (b) is shown in FIG. It is superior to the heat dissipation of the conventional electronic control device of a). A heat conductive material may be arranged between the electronic component 62 and the metal plate 4 depending on the usage environment.

Next, the productivity of the casing 2 will be described. Since the electronic control device of FIG. 3A has a structure in which the tip surface and both front and back surfaces of one end of the metal plate 4 are covered with resin, the opening side holding portion is formed when the casing 2 is resin-molded with a mold. The step formed on the inner edge of 126 is an undercut. Therefore, it is necessary to divide the mold after resin molding the casing 2, which complicates the mold structure and the resin molding process.

On the other hand, in the electronic control device of FIG. 3B, the surface of the metal plate 4 facing the control board 6 is arranged on the same surface as the surface of the opening side holding portion 26 facing the control board 6. Therefore, the mold structure and the resin molding process can be simplified, and the productivity of the casing 2 is improved.

Next, waterproof reliability will be described. In the electronic control device of FIG. 3B, since one surface (upper surface in FIG. 2) of one end of the metal plate 4 is not covered with resin, the resin of the opening side holding portion 26 and the metal plate 4 The contact area with the metal becomes smaller, and the waterproof reliability becomes inferior to that of the electronic control device shown in FIG. 3 (a).

Therefore, as shown in FIG. 3C, for example, a thin portion 41 having a thickness thinner than that of the other portion of the metal plate 4 may be formed at one end of the metal plate 4. As a result, the clearance between the electronic component 62 mounted on the metal plate 4 side of the control board 6 and the metal plate 4 becomes a distance C (C = B). Therefore, while the metal plate 4 is close to the control board 6, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 can be made wider than that of the electronic control device of FIG. 3 (b), and the waterproof reliability can be improved. Can be improved.

The thin-walled portion 41 may be formed by cutting out the control substrate 6 side of the metal plate 4. As a result, the resin of the opening side holding portion 26 can be easily filled on the control substrate 6 side of the thin wall portion 41. As a result, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 is increased, the metal plate 4 can be fixed more firmly, and the waterproof reliability can be improved.

According to this embodiment, the surface of the metal plate 4 facing the control board 6 is arranged on the same surface as the surface of the opening side holding portion 26 facing the control board 6, so that the casing 2 is molded. It is possible to improve the heat dissipation of the control board 6 by bringing the metal plate 4 closer to the control board 6 while increasing the productivity at the time of resin molding.

Further, since the metal plate 4 is insert-fixed to the casing 2, the productivity of the casing 2 can be improved as compared with the case where the casing 2 is composed of a plurality of separate parts.

Further, since the guide groove 24 into which the control board 6 is inserted while sliding is formed on the inner surface of the casing 2, the control board 6 can be inserted into the casing 2 while being guided by the guide groove 24.

The second embodiment will be described with reference to FIG. In each of the following examples including this embodiment, the differences from the first embodiment will be mainly described.

FIG. 4A is a cross-sectional view of the electronic control device according to the second embodiment, and FIG. 4B is a cross-sectional view of the electronic control device according to one modification of the second embodiment.

As shown in FIG. 4A, a through hole 42 that penetrates the thickness of the metal plate 4 may be formed at one end of the metal plate 4. The through hole 42 is filled with at least a part of the resin of the opening side holding portion 26 at the time of resin molding of the casing 2. As a result, at least a part of the through hole 42 is embedded in the resin of the opening side holding portion 26. As a result, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 is increased, the metal plate 4 can be fixed more firmly, and the stress generated by changes in the environmental temperature, vibration, or the like can be resisted. The resin of the opening side holding portion 26 is less likely to be peeled off, and the adhesion reliability is improved.

Further, as shown in FIG. 4B, a thin-walled portion 41 having a thickness thinner than that of the other portion of the metal plate 4 is formed at one end of the metal plate 4, and the thin-walled portion 41 penetrates. Holes 42 may be formed. Moreover, the thin-walled portion 41 may be formed by cutting out the control substrate 6 side of the metal plate 4. As a result, the resin of the opening side holding portion 26 can be easily filled in the thin wall portion 41 and the through hole 42, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 increases, and the metal plate becomes stronger. 4 can be fixed.

The third embodiment will be described with reference to FIG.

FIG. 5A is a cross-sectional view of the electronic control device according to the third embodiment, and FIG. 5B is a cross-sectional view of the electronic control device according to one modification of the third embodiment.

As shown in FIG. 5A, a bent portion 43 bent toward the side opposite to the control substrate 6 may be formed at one end of the metal plate 4. As a result, it is possible to increase the contact area between the resin of the opening side holding portion 26 and the metal plate 4 while increasing the rigidity of the metal plate 4.

The tip surface of the bent portion 43 may be covered with a part of the opening side holding portion 26. As a result, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 can be increased.

Further, as shown in FIG. 5B, a through hole 44 that penetrates the thickness of the metal plate 3 may be formed in the bent portion 43. The through hole 44 may be filled with at least a part of the resin of the opening side holding portion 26 at the time of resin molding of the casing 2. As a result, at least a part of the through hole 44 is embedded in the resin of the opening side holding portion 26. As a result, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 is increased, and the metal plate 4 can be fixed more firmly.

Although the embodiment of the electronic control device according to the present invention has been described in detail above, the present invention is not limited to each of the above embodiments and does not deviate from the spirit of the present invention described in the claims. Therefore, various design changes can be made.

Each of the above-described embodiments has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, other configurations may be added, deleted, or replaced with respect to a part of the configurations of each embodiment.

Further, the technical features included in each of the above-described examples are not limited to the combinations specified in the claims, and can be appropriately combined.

For example, in the electronic control device of the above-described embodiment, the surface of the metal plate 4 facing the control board 6 is arranged on the same surface as the surface of the opening side holding portion 26 facing the control board 6. Not limited to this, the surface of the metal plate 4 facing the control board 6 may be arranged on the control board 6 side with respect to the surface of the opening side holding portion 26 facing the control board 6. As a result, the metal plate 4 can be brought closer to the control board 6.

Further, for example, the metal plate 4 may be arranged so as to face the high heating element having the largest heat generation amount among the electronic components 62 mounted on the control board 6.
Further, in order to improve heat radiation, a thin film of resin may be formed on the surface of the metal plate 4. The thickness of the resin is preferably such that the heat dissipation efficiency due to heat radiation exceeds the deterioration of heat dissipation due to thermal resistance. It also contributes to improving the adhesion with the resin case.

1: Electronic control device, 2: Casing, 4: Metal plate, 6: Control board, 23: Opening, 24: Guide groove, 26: Opening side holding part, 41: Thin wall part, 42: Through hole, 43: Bent part, 44: Through hole

Claims (10)

An electronic control device including a bottomed tubular resin case having an opening on one end side, a control substrate inserted into the resin case through the opening, and a metal plate fixed to the resin case.
On the opening side of the resin case, an opening side holding portion for fixing one end of the metal plate is provided.
An electronic control device in which the surface of the metal plate facing the control board is the same as the surface of the opening side holding portion facing the control board, or is arranged on the control board side. The metal plate is insert-fixed to the resin case.
The electronic control device according to claim 1. A thin portion having a thickness thinner than that of the other portion of the metal plate is formed at one end of the metal plate.
The electronic control device according to claim 2. The thin-walled portion is formed with a through hole in which at least a part is embedded in the opening-side holding portion.
The electronic control device according to claim 3. The thin-walled portion is formed by cutting out the control substrate side of the metal plate.
The electronic control device according to claim 3. At one end of the metal plate, a bent portion bent toward the side opposite to the control substrate is formed.
The electronic control device according to claim 2. A through hole is formed in the bent portion so that at least a part thereof is embedded in the opening side holding portion.
The electronic control device according to claim 6. The tip surface of the bent portion is covered with a part of the opening side holding portion.
The electronic control device according to claim 6. A guide groove into which the control board is inserted while sliding is provided on the inner surface of the resin case.
The electronic control device according to claim 1. A resin thin film is formed on the surface of the metal plate.
The electronic control device according to any one of claims 1 to 9.

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