WO2019159576A1

WO2019159576A1 - Electronic control device

Info

Publication number: WO2019159576A1
Application number: PCT/JP2019/000636
Authority: WO
Inventors: 裕二朗金子; 河合　義夫; 尭之福沢
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2018-02-13
Filing date: 2019-01-11
Publication date: 2019-08-22
Also published as: JP2021068717A

Abstract

Provided is an electronic control device that enables improvement in heat dissipation and productivity. This electronic control device comprises: a bottomed tubular casing 2 having 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, wherein an opening-side retaining portion 26 for fixing a part of the metal plate 4 is provided on the opening 23 side of the casing 2, and the surface, of the metal plate 4, that faces the control board 6 is located flush with, or on the control board 6 side with respect to, the surface, of the opening-side retaining portion 26, that faces the control board 6.

Description

Electronic control unit

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 passenger compartment or engine room. These electronic control devices are composed of, for example, a control board, a connector mounted on the control board, a casing that accommodates the control board, a sealing member that ensures waterproofness in the casing, and the like.

In recent years, with the increase in functions of electronic control devices, the amount of heat generated by electronic components tends to increase more and more. Furthermore, when the assembly process becomes complicated as the number of parts constituting the electronic control device increases, productivity decreases. 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 the 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 connector opening, and the circuit board is inserted in the connector opening. 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 heat generated from the electronic components is transmitted to the casing to be radiated to the outside.

JP 2014-093415 A

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. Furthermore, since the housing base, the housing cover, and the metal plate are separate components, further improvement in productivity by component integration is desired.

The present invention has been made in view of the above problems, and an object thereof 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 cylindrical resin case having an opening on one end side, a control board inserted into the resin case from the opening, and the resin case. An electronic control device comprising a fixed metal plate, 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 the control board of the metal plate Is disposed on the same surface or on the control substrate side with respect to the surface of the opening side holding portion facing the control substrate.

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

1 is an external perspective view of an electronic control device according to a first embodiment. It is explanatory drawing which shows the assembly procedure of the electronic control apparatus which concerns on 1st Example. It is the figure which compared the electronic control apparatus which concerns on 1st Example with the 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, an automatic transmission control unit, and the like mounted on an automobile are made compatible.

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

The electronic control device 1 according to the present embodiment includes 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 that is insert-fixed to the casing 2. And a metal plate 4 (see FIG. 2).

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

The control board assembly 3 is provided with a plurality of connectors 7 on one end side thereof. When a sealing material (not shown) 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. The opening 23 is sealed liquid-tightly. The sealing material may be applied when the electronic control device 1 needs to be waterproof. The curing type of the sealing material may be either heat curing or humidity curing. By sealing each connector 7 and the opening 23 of the casing 2 in a liquid-tight manner via a sealing material or the like, it is possible to prevent foreign matter or water from entering the electronic control device 1.

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

FIG. 2 (b) 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 terminal 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. When the control board assembly 3 is assembled and fixed to the casing 2 by these

cover portions

711 and 712, the opening 23 of the casing 2 is covered.

The material of the connector terminal 72 is preferably copper or a copper alloy from the viewpoint of conductivity, miniaturization, and cost. For the material of the connector housing 71, it is preferable to use a resin that is light and excellent in heat resistance, such as PBT (Poly-Bene-Terephthalate), PA (Poly-Amide) 66, PPS (Poly-Phenylene-Sulphide). .

As shown in FIG. 2 (c), the connector terminal 72 and the control board 6 are connected to the through-hole portion 63 of the control board 6 into which the connector terminal 72 is inserted by Sn—Cu solder, Sn—Ag—Cu solder, 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 connector 7 may be either a surface mount type or a press fit type.

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

On the lower surface (hereinafter referred to as the bottom surface) in FIG. 2 of the casing 2, an opening side holding portion 26 that insert-fixes one end portion (opening portion 23 side) of the metal plate 4 and the other end portion of the metal plate 4. And a step 25 for fixing the insert. The opening side holding part 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 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 protrudes from the bottom surface to the guide groove 24.

The material of the metal plate 4 may be 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 board mounting portion 24 while sliding the one end side of the control board 6 until the one end side of the control board 6 comes into contact with the inner surface of the casing 2 and stops. The control board assembly 3 is installed in the board 2.

FIG. 3 is a diagram comparing the electronic control device according to the first embodiment with a conventional electronic control device. 3A is a sectional view of a conventional electronic control device, FIG. 3B is a 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 an example, FIG.3 (d) is the 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 is a front end surface of the end portion (hereinafter referred to as one end portion) on the opening portion 23 side of the casing 2 of the metal plate 4 and the figure. The upper and lower surfaces (hereinafter referred to as front and back surfaces) in 3 are covered with resin. At this time, the surface of the metal plate 4 facing the control board 6 is disposed on the side opposite to the control board 6 (outside of the casing 2) than the face 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. 3 (b), the opening side holding portion 26 of the electronic control apparatus according to the first embodiment has a front end surface and a lower surface in FIG. Covered with resin. At this time, the surface of the metal plate 4 facing the control substrate 6 is disposed on the same surface as the surface of the opening side holding portion 26 facing the control substrate 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). Thereby, the metal plate 4 can be brought close to the control board 6. Therefore, in the process of radiating the heat generated from the electronic component 62 to the atmosphere through the metal plate 4, as shown in FIG. 3D, the heat dissipation of the electronic control device of FIG. It is superior to the heat dissipation of the conventional electronic control device a). In addition, you may arrange | position a heat conductive material between the electronic component 62 and the metal plate 4 according to a use environment.

Next, the productivity of the casing 2 will be described. The electronic control device in FIG. 3A has a structure in which the front end surface and both front and back surfaces of one end portion of the metal plate 4 are covered with resin. Therefore, when the casing 2 is resin-molded with a mold, the opening side holding portion A step formed at the inner edge of 126 becomes an undercut. For this reason, it is necessary to divide the mold after the casing 2 is resin-molded, 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 substrate 6 is arranged on the same surface as the surface of the opening side holding portion 26 facing the control substrate 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 (the upper surface in FIG. 2) of one end of the metal plate 4 is not covered with resin, the resin and the metal plate 4 of the opening side holding portion 26 are not covered. The contact area is reduced and the waterproof reliability is inferior to that of the electronic control device of FIG.

Therefore, as shown in FIG. 3C, for example, a thin portion 41 having a thinner plate thickness than other portions of the metal plate 4 may be formed at one end of the metal plate 4. Accordingly, 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 C (C = B). Therefore, the metal plate 4 is brought close to the control board 6 and the contact area between the resin of the opening side holding portion 26 and the metal plate 4 can be made wider than the electronic control device of FIG. Can be improved.

The thin portion 41 may be formed by cutting out the control board 6 side of the metal plate 4. Thereby, it becomes easy to fill the resin of the opening side holding part 26 to the control board 6 side of the thin part 41. As a result, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 increases, the metal plate 4 can be more firmly fixed, and the waterproof reliability can be improved.

According to the present embodiment, the surface of the metal plate 4 facing the control substrate 6 is arranged on the same surface as the surface of the opening side holding portion 26 facing the control substrate 6. The metal plate 4 can be brought close to the control board 6 and the heat dissipation of the control board 6 can be improved while improving the productivity at the time of resin molding.

Furthermore, 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.

Furthermore, 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 the following embodiments including the present embodiment, differences from the first embodiment will be mainly described.

FIG. 4A is a cross-sectional view of an electronic control device according to the second embodiment, and FIG. 4B is a cross-sectional view of an 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 when the casing 2 is molded with resin. Thereby, at least a part of the through hole 42 is embedded in the resin of the opening side holding part 26. As a result, the adhesion 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 more firmly fixed. With respect to the stress generated by environmental temperature change or vibration, The resin of the opening side holding part 26 is hardly peeled off, and the adhesion reliability is improved.

Further, as shown in FIG. 4B, a thin portion 41 having a thickness thinner than other portions of the metal plate 4 is formed at one end of the metal plate 4, and the thin portion 41 has a through-hole. A hole 42 may be formed. Moreover, the thin portion 41 may be formed by cutting out the control board 6 side of the metal plate 4. Thereby, it becomes easy to fill the thin portion 41 and the through hole 42 with the resin of the opening side holding portion 26, the contact area between the resin of the opening side holding portion 26 and the metal plate 4 is increased, and the metal plate is more firmly formed. 4 can be fixed.

A third embodiment will be described with reference to FIG.

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

As shown in FIG. 5A, a bent portion 43 that is bent toward the side opposite to the control substrate 6 may be formed at one end of the metal plate 4. Thereby, the contact | adherence area of resin of the opening part side holding | maintenance part 26 and the metal plate 4 can be increased, improving the rigidity of the metal plate 4. FIG.

The distal end surface of the bent portion 43 may be covered with a part of the opening side holding portion 26. Thereby, the contact | adherence area of resin of the opening part side holding | maintenance part 26 and the metal plate 4 can be increased.

Further, as shown in FIG. 5 (b), the bent portion 43 may be formed with a through hole 44 that penetrates the thickness of the metal plate 3. The through-hole 44 may be filled with at least a part of the resin of the opening side holding portion 26 when the casing 2 is molded with resin. Thereby, 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 part 26 and the metal plate 4 increases, and the metal plate 4 can be fixed more firmly.

As mentioned above, although the embodiment of the electronic control device according to the present invention has been described in detail, the present invention is not limited to each of the above-described embodiments, and does not depart from the spirit of the present invention described in the claims. Thus, various design changes can be made.

The above embodiments are described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Moreover, the structure of another Example can also be added to the structure of a certain Example. Moreover, you may add, delete, or replace another structure about a part of structure of each Example.

Further, the technical features included in each of the embodiments described above are not limited to the combinations specified in the claims, and can be combined as appropriate.

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

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

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

Claims

An electronic control device comprising a bottomed cylindrical resin case having an opening on one end side, a control board inserted into the resin case from the opening, and a metal plate fixed to the resin case,
On the opening side of the resin case, an opening side holding portion that fixes one end of the metal plate is provided,
An electronic control device in which a surface of the metal plate facing the control board is disposed on the same surface or the control board side with respect to a surface of the opening side holding portion facing the control board.
The electronic control device according to claim 1, wherein the metal plate is insert-fixed to the resin case.
3. The electronic control device according to claim 2, wherein a thin-walled portion having a thinner plate thickness than other portions of the metal plate is formed at one end of the metal plate.
The electronic control device according to claim 3, wherein a through hole in which at least a part is embedded in the opening side holding portion is formed in the thin portion.
The electronic control device according to claim 3, wherein the thin portion is formed by cutting out the control board side of the metal plate.
The electronic control device according to claim 2, wherein a bent portion is formed at one end portion of the metal plate and is bent toward the opposite side of the control board.
The electronic control device according to claim 6, wherein a through-hole in which at least a part is embedded in the opening side holding portion is formed in the bent portion.
The electronic control device according to claim 6, wherein a distal end surface of the bent portion is covered with a part of the opening side holding portion.
The electronic control device according to claim 1, wherein a guide groove into which the control board is inserted while sliding is provided on an inner surface of the resin case.
The electronic control device according to any one of claims 1 to 9, wherein a resin thin film is formed on a surface of the metal plate.