WO2023089710A1

WO2023089710A1 - Electronic control device

Info

Publication number: WO2023089710A1
Application number: PCT/JP2021/042329
Authority: WO
Inventors: 諒秋葉; 義夫河合; 恵子上之
Original assignee: 日立Astemo株式会社
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2023-05-25

Abstract

This electronic control device is provided that may provide both heat radiation and endurance reliability. An electronic control device 100 includes a circuit board 4 having an electronic component 6 mounted thereon, a base 1, and a cover 2, the base 1 and cover 2 sandwich the circuit board 4 and form a housing that contains the circuit board 4 therein. The cover 2 includes a plurality of securing units 10a, 10b for securing the base 1, cover 2, and circuit board 2 integrally, and a stiffness reduction unit 9 for reducing the stiffness of the cover 2. This may reduce the stress on the cover 2 of the electronic control device 100 even if more screws are provided on the base 1, circuit board 4, and cover 2.

Description

electronic controller

The present invention relates to an electronic control device.

In recent years, with the increase in automatic driving and preventive safety functions, the functionality of in-vehicle electronic control devices is accelerating, and the amount of heat generated by electronic components (microcomputers, etc.) installed in electronic control devices is increasing. As means for suppressing the temperature rise of electronic components, a heat dissipation structure via a heat conductive material as disclosed in Patent Document 1 is known.

In Patent Document 1, a heat-generating element and a flexible heat-conducting member are arranged so as to sandwich a portion of the substrate on which the heat-generating element is mounted, and heat is dissipated to the housing through the heat-conducting member. A controller is disclosed.
Japanese Patent Application Laid-Open No. 2007-59608

An electronic control device is, for example, mounted in an automobile and used to control an engine, a transmission, a brake, a steering, etc., and includes a circuit board on which electronic components are mounted and a circuit board mounted and formed on the circuit board. It is generally composed of a connector that electrically connects an electric circuit and an external device, a base that accommodates the circuit board, and a cover that covers the circuit board accommodated in the base.

The circuit board and cover are held on the base by screws, for example. A thermally conductive material such as grease is placed between the electronic component and the base or between the circuit board and the base to suppress the temperature rise of the electronic component.

A fixed pedestal is provided near the center of the circuit board in the base or in the vicinity of electronic components that generate a large amount of heat. Heat dissipation performance can be improved.

However, on the other hand, since the pitch between the screws is narrowed, there is a risk that the deformation of the circuit board due to the difference in level during assembly will increase and the durability and reliability of the electronic control device will decrease.

An object of the present invention is to provide an electronic control device that can achieve both heat dissipation and durability reliability.

In order to achieve the above objectives, the present invention is configured as follows.

An electronic control device includes a circuit board on which electronic components are mounted, a base, and a cover, wherein the circuit board is sandwiched between the base and the cover to form a housing that accommodates the circuit board inside, The cover has a plurality of fixing portions for integrally fixing the base, the cover and the circuit board, and a rigidity reducing portion for reducing the rigidity of the cover.

According to the present invention, it is possible to provide an electronic control device that can reduce the stress generated in the cover even when the number of screw fixing points is increased, and can ensure both heat dissipation and durability reliability.

It is the figure which looked at the electronic control unit from the upper diagonal direction. It is the figure which looked at the electronic control unit from the downward diagonal direction. It is the figure which disassembled the electronic control unit, and saw from the upper direction. It is the figure which decomposed|disassembled the electronic control unit and looked at it from the downward diagonal direction. 1 is a plan view of a cover of an electronic control unit according to Embodiment 1 of the present invention; FIG. 1 is a perspective view of a cover of an electronic control unit according to Embodiment 1 of the present invention; FIG. FIG. 6 is a cross-sectional view taken along line XX of FIG. 5; It is a figure which shows the cover of the electronic control unit by Example 2 of this invention. FIG. 7 is a perspective view of a cover of an electronic control unit according to Embodiment 2 of the present invention; FIG. 9 is a cross-sectional view taken along line XX of FIG. 8; It is a figure which shows the cover of the electronic control unit by Example 3 of this invention. It is a perspective view of the electronic control unit by Example 3 of this invention. FIG. 12 is a cross-sectional view taken along line XX of FIG. 11; FIG. 4 is a diagram showing a cover of an electronic control unit according to Embodiment 4 of the present invention; FIG. 10 is a perspective view of a cover of an electronic control unit according to Embodiment 4 of the present invention; FIG. 15 is a cross-sectional view taken along line XX of FIG. 14; FIG. 10 is a diagram showing a cover of an electronic control unit according to Embodiment 5 of the present invention; FIG. 11 is a perspective view of a cover of an electronic control unit according to Example 5 of the present invention; FIG. 18 is a cross-sectional view taken along line XX of FIG. 17; FIG. 10 is a plan view of a cover of an electronic control unit according to Embodiment 6 of the present invention; FIG. 11 is a perspective view of an electronic control unit according to Example 6 of the present invention; FIG. 21 is a cross-sectional view taken along line YY of FIG. 20; FIG. 21 is a cross-sectional view along line XX of FIG. 20; FIG. 10 is a diagram showing a cover of an electronic control unit 100 according to Embodiment 7 of the present invention;

An embodiment of an electronic control device according to the present invention will be described below in detail with reference to the accompanying drawings.

In addition, in each figure, the same reference numerals indicate the same parts.

(Example 1)
1 to 4 are schematic configuration diagrams of an electronic control unit 100 to which the present invention is applied.

1 is a diagram of the electronic control unit 100 viewed obliquely from above, and FIG. 2 is a diagram of the electronic control unit 100 viewed obliquely from below. 3 and 4 are exploded perspective views of the electronic control unit 100, FIG. 3 is an exploded view of the electronic control unit 100 and viewed obliquely from above, and FIG. is an exploded view of the device viewed obliquely from below.

The electronic control unit 100 is, for example, mounted in an automobile and used to control the engine, transmission, brakes, steering, and the like. As shown in FIGS. 3 and 4, the circuit board 4 on which the electronic component 6 is mounted (mounted) and the electric circuit mounted on the circuit board 4 and formed on the circuit board 4 are electrically connected to an external device. A connector 3, a base 1 in which a circuit board 4 is housed, and a substantially quadrangular cover 2 for covering the circuit board 4 housed in the base 1. The circuit board 4 is sandwiched between the base 1 and the cover 2 to form a housing that accommodates the circuit board 4 inside.

2 to 4, the cover 2 is partially omitted and has a configuration described later.

In addition, a plurality of electronic components 6 are actually mounted on the circuit board 4 in addition to the electronic components 6 illustrated. The circuit board 4 and the cover 2 are integrally fixed to the base 1 by screws 7 or the like, for example. Between the electronic components 6 arranged on the circuit board 4 and the base 1 and between the electronic components 6 arranged on the circuit board 4 and the cover 2, a heat conductive material 5 such as grease is arranged. , the temperature rise of the electronic component 6 can be suppressed.

A fixed pedestal 8 is provided near the approximate center of the circuit board 2 in the base 1 or near the electronic component 6 that generates a large amount of heat, and the thickness of the heat conductive material caused by the dimensional variations of the circuit board 4, the base 1 and the cover 2. Variation can be suppressed, and heat dissipation performance can be improved.

On the other hand, since the pitch between the screws is narrowed, the deformation of the circuit board 4 due to the difference in level during assembly may increase, and the durability and reliability of the electronic control device 100 may decrease.

In Example 1 of the present invention, the configuration of the cover 2 is different from that of the prior art.

5, 6 and 7 are diagrams showing the cover 2 of the electronic control unit 100 according to the first embodiment. 5 is a plan view of the cover 2, FIG. 6 is a perspective view of the cover 2, and FIG. 7 is a sectional view taken along line XX of FIG.

As shown in FIGS. 5 to 7, four first fixing portions 10a are formed near the four corners of the substantially rectangular cover 2, and screws 7 are inserted into each of the first fixing portions 10a. A second fixing portion 10b is formed in the substantially central portion of the cover 2, and the screw 7 is also inserted into this second fixing portion 10b. A first fixing portion 10a and a second fixing portion 10b formed on the cover 2 support the head of the screw 7, and are formed with a bottom surface for fixing the head of the screw 7 and a mortar-shaped concave portion. there is In other words, each of the first fixing portion 10a and the second fixing portion 10b has a concave portion including a bottom surface for fixing the screw 7 and a side surface.

The point closest to each of the first fixing portions 10a by the screws 7 of the cover 2 is the second fixing portion 10b formed in the central portion of the cover 2, and the first fixing portion 10a and the second fixing portion 10b, an elliptical opening 9 is formed in the vicinity of the first fixing portion 10a, and an opening 9 is formed in the vicinity of the second fixing portion 10b.

Since there are four first fixing parts 10a around the second fixing part 10b, four openings 9 are formed around the second fixing part 10b.

As shown in FIGS. 5 to 7, the opening 9 is formed in the vicinity of the first fixing portion 10a and the second fixing portion 10b of the cover 2, so that the first fixing portion 10a and the second fixing portion 10b are separated from each other. The rigidity of the cover 2 between the fixed portions 10b can be lowered, and the stress generated in the cover 2 can be reduced.

Therefore, it is possible to provide an electronic control device with high durability and reliability in which the cover 2 is unlikely to be damaged even when environmental temperature changes, vibrations, etc. are taken into consideration.

In other words, according to the first embodiment, the stress generated in the cover 2 can be reduced even when the number of screw fixing points is increased, so that the electronic control device 100 that can ensure both heat dissipation and durability reliability of the electronic control device 100 is provided. can do.

Although the opening 9 has an elliptical shape in the illustrated example, it is not limited to an elliptical shape, and may have another shape such as a circular shape.
(Example 2)
Next, Example 2 of the present invention will be described.

8, 9 and 10 are diagrams showing the cover 2 of the electronic control unit 100 according to the second embodiment. 8 is a plan view of the cover 2, FIG. 9 is a perspective view of the cover 2, and FIG. 10 is a sectional view taken along line XX of FIG.

Other configurations in the second embodiment are the same as those in the first embodiment.

Embodiment 2 shown in FIGS. 8, 9 and 10 is characterized in that the opening 9 is replaced with a thin portion 11 in contrast to Embodiment 1.

As a result, the second embodiment can obtain the same effect as the first embodiment, and the rigidity of the cover 2 can be reduced. In addition, since the second embodiment can prevent contamination and water from entering the electronic control unit 100 as compared with the first embodiment, it is possible to prevent the electronic control unit 100 from being damaged by them.

(Example 3)
Next, Example 3 of the present invention will be described.

11, 12 and 13 are diagrams showing the cover 2 of the electronic control unit 100 according to the third embodiment. 11 is a plan view of the cover 2, FIG. 12 is a perspective view of the cover 2, and FIG. 13 is a sectional view taken along line XX of FIG.

Other configurations in the third embodiment are the same as those in the first embodiment.

Embodiment 3 shown in FIGS. 11, 12 and 13 is characterized in that the thin portions 11 of the four first fixing portions 10a are replaced with crank portions 12 in contrast to the second embodiment. As shown in FIG. 13, the crank portion 12 in the third embodiment projects toward the upper surface of the cover 2, has a U-shaped cross section, and connects the first fixing portion 10a and the second fixing portion 10b. It is a portion extending in a direction perpendicular to the straight line.

The third embodiment can obtain the same effects as the second embodiment, and can reduce the rigidity of the cover 2 .

In addition, in Example 3, by replacing the thin portion 11 of Example 2 with the crank portion 12, the cover 2 is more easily deformed than in Example 2, so that the stress can be further reduced, and the electronically controlled There is an effect that the endurance reliability of the device 100 can be improved.

The third embodiment also includes an example in which the thin portion 11 is not formed in the vicinity of the second fixing portion 10b.

In addition, Example 3 also includes an example in which the opening 9 is formed in the vicinity of the second fixing portion 10b.

In the illustrated example, one crank portion 12 is formed on a straight line connecting the first fixing portion 10a and the second fixing portion 10b, but at least one crank portion 12 is formed. A plurality of crank portions 12 are formed and edges are also good.

(Example 4)
Next, Example 4 of the present invention will be described.

14, 15 and 16 are diagrams showing the cover 2 of the electronic control unit 100 according to the fourth embodiment. 14 is a plan view of the cover 2, FIG. 15 is a perspective view of the cover 2, and FIG. 16 is a sectional view taken along line XX of FIG.

Other configurations in the fourth embodiment are the same as those in the first embodiment.

　In the fourth embodiment shown in FIGS. 14, 15 and 16, the opening 9 is not formed in contrast to the first embodiment. A side surface portion 13 is formed on the outer periphery of the screw 7 in the first fixing portion 10a and the second fixing portion 10b, and a plurality of slit-like openings 9a are formed in the side surface portion 13.

As a result, in the fourth embodiment, the same effect as in the first embodiment can be obtained. Since the generated stress can be further reduced, the endurance reliability of the electronic control unit 100 can be improved.

In the illustrated example, eight slit-shaped openings 9a are formed in the side surface portion 13, but the number is not limited to eight, and one or more slit-shaped openings 9a may be formed. In other words, the slit-shaped opening 9a may be formed in a part of the side surface portion 13 .

(Example 5)
Next, Example 5 of the present invention will be described.

17, 18 and 19 are diagrams showing the cover 2 of the electronic control unit 100 according to the fifth embodiment. 17 is a plan view of the cover 2, FIG. 18 is a perspective view of the cover 2, and FIG. 19 is a sectional view taken along line XX of FIG.

Other configurations in the fifth embodiment are the same as those in the first embodiment.

In Example 5 shown in FIGS. 17, 18 and 19, unlike Example 1, the opening 9 is not formed, and unlike Example 4, the first fixing portion 10a and the second fixing portion 10b are formed. A substantially fan-shaped opening 9b is formed in the side surface portion 13 of the outer periphery of the screw 7 at .

A substantially fan-shaped opening 9b is formed in the straight side portion 13 connecting the first fixing portion 10a to the nearest second fixing portion 10b (formed in the central portion of the cover 2). formed. Accordingly, one opening 9b is formed in the first fixing portion 10, and four openings 9b are formed in the second fixing portion 10b.

As a result, in the fifth embodiment, in addition to obtaining the same effect as in the fourth embodiment, the rigidity of the portion where the greatest stress is generated can be lowered, and the stress generated in the cover 2 can be further reduced. can improve the durability and reliability of

(Example 6)
Next, Example 6 of the present invention will be described.

20, 21, 22 and 23 are diagrams showing the cover 2 of the electronic control unit 100 according to the sixth embodiment. 20 is a plan view of the cover 2, FIG. 21 is a perspective view of the cover 2, FIG. 22 is a cross-sectional view along the line YY of FIG. 20, and FIG. 23 is a view along the line XX of FIG. It is a sectional view.

Other configurations in the sixth embodiment are the same as in the first embodiment.

In Example 6 shown in FIGS. 20, 21, 22 and 23, unlike Example 1, the opening 9 is not formed. An opening 9bb extending to the vicinity of the screw 7 is formed on the side surface of the fixing portion 10b side. Therefore, the opening 9bb is formed of a first slit-shaped opening extending in the circumferential direction of the screw 7 and a second slit-shaped opening extending in the diametrical direction of the screw 7 .

When the opening 9bb is viewed from above the cover 2, the length M1 of the first opening, which is the portion of the slit 15 extending in the circumferential direction of the screw 7, and the second opening, which is the portion of the screw 7 extending in the diametrical direction. By setting the length M2 to 1/20 or less of the wavelength of the maximum noise generated by the electronic component 6, the risk of noise outflow and intrusion can be reduced.

An opening 9bb is formed on a straight line connecting the first fixing part 10a and the nearest second fixing part 10b (formed in the central part of the cover 2).

Therefore, one opening 9bb is formed in the first fixing portion 10, and four openings 9bb are formed in the second fixing portion 10b.

Further, the distance N (slit width) between the cover 2 and the screw 7 in the opening 9bb having the first opening and the second opening shown in FIG. , the distance T between the connector 3 and the base 1 and the distance U between the connector 3 and the cover 2 shown in FIG. , a highly reliable electronic control unit 100 can be realized.

As a result, in Example 6, in addition to obtaining the same effects as in Example 5, the risk of noise outflow and intrusion can be reduced, and contaminant intrusion can be suppressed.

Even if the distance N is set narrower than any one of the distance S, the distance T, and the distance U, it is possible to suppress entry of contaminants from the opening 9bb.

(Example 7)
Next, Embodiment 7 of the present invention will be described.

FIG. 24 is a diagram showing the cover 2 of the electronic control unit 100 according to the seventh embodiment.

Embodiment 7 shown in FIG. 24 differs from Embodiment 6 in that the pitch between the screws 7 in the plurality of first fixing portions 10a and third fixing portions 10b′ arranged on the outer peripheral side of the electronic control unit 100 is 100 mm or less. , the risk of noise leakage from between the base 1 and the cover 2 is reduced. The first fixing portions 10a are arranged at the four corners of the base 2, while the third fixing portions 10b' have the same shape as the first fixing portions 10a and are located on the outer peripheral side of the base 2. , and between the first fixing portions 10a arranged at the four corners.

Therefore, in the example shown in FIG. 24, four third fixing portions 10b' are formed on the base 2. As shown in FIG.

In the example shown in FIG. 24, the third fixing portion 10b' closest to the first fixing portion 10a at the right corner shown at the bottom of the cover 2 is the third fixing portion 10b' formed at the bottom of the cover 2. It is fixed part 10b'.

In addition, with respect to the distance between the first fixing portion 10a at the right corner and the third fixing portion 10b' formed at the bottom, the first fixing portion 10a at the right corner and the right end side of FIG. Since the distance from the third fixing portion 10b' formed in the central portion of the circular first fixing portion 10a is approximately the same, the area of the circular arc on the peripheral side of the circular first fixing portion 10a is approximately half the area. A U-shaped opening 9c is provided.

The openings 9c of the plurality of first fixing portions 10a and the plurality of third fixing portions 10b' are formed at positions facing the second fixing portion 10b formed in the central portion of the base 2. ing.

As a result, in the seventh embodiment, approximately Since the L-shaped opening 9c is arranged, both the stress generated in the second fixing portion 10b by the first fixing portion 10a and the third fixing portion 10b' can be reduced. Durability reliability can be further improved.

The

openings

9, 9a, 9b, 9bb, 9c, the thin portion 11, and the crank portion 12 described above can be collectively referred to as rigidity reduction portions that reduce the rigidity of the cover 2.

Also, the first fixing part 10a, the second fixing part 10b and the third fixing part 10b' can be generically called fixing parts for fixing the base 1, the board circuit 4 and the cover 2.

Also, in either or both of the cover 2 and the base 1, the thermal emissivity of at least a portion including the position where the heat conductive material 5 is arranged and the back surface thereof can be 0.6 or higher.

Further, when a plurality of electronic components 6 are arranged on the circuit board 4, the thermal conductivity of the thermal conductive material 5 arranged on the electronic component 6 with a large maximum heat generation is It is preferable to set the thermal conductivity to be higher than the thermal conductivity of the thermally conductive material 5 disposed on the electronic component 6 having a smaller maximum amount of heat generation than the component 6 .

Also, the electronic component 6 is soldered to the circuit board 4 . The Young's modulus of the thermal conductive material 5 disposed on the electronic component 6 having a short solder life compared to the electronic component 6 soldered to the circuit board 4 has a long solder life. is preferably smaller than the Young's modulus of the thermally conductive material 5 arranged at .

In addition, in either or both of the base 1 and the cover 2, it is preferable that the fixing base 8 for screwing in the center of the base 1 is the same height as the other screwing bases of the base 1 or higher. .

DESCRIPTION OF SYMBOLS 1... Base, 2... Cover, 3... Connector, 4... Circuit board, 5... Thermally conductive material, 6... Electronic component, 7... Screw, 8... Fixing

pedestal

9, 9a, 9b, 9bb, 9c... Opening part 10a... First fixing part 10b... Second fixing part 10b'... Third fixing part 11 Thin portion 12 Crank portion 13 Side portion 14 Upper surface of cover 15 Slit M Slit length N Upper surface of cover and screws distance between, S... distance between base and cover, T... distance between connector and base, U... distance between connector and cover, 100... electronic control unit

Claims

a circuit board on which electronic components are mounted;
a base;
a cover;
with
sandwiching the circuit board between the base and the cover to form a housing containing the circuit board;
The electronic control device according to claim 1, wherein the cover has a plurality of fixing portions for integrally fixing the base, the cover and the circuit board, and a rigidity reduction portion for reducing the rigidity of the cover.
In the electronic control device according to claim 1,
The cover has a substantially quadrilateral shape, and the plurality of fixing portions are composed of four first fixing portions formed near the four corners of the cover and a second fixing portion formed substantially in the center of the cover. The reduced-rigidity portions are in the vicinity of each of the four first fixing portions and in the vicinity of the second fixing portion, each of the four first fixing portions and the second fixing portion An electronic control device, comprising: an opening formed in a straight line connecting with a fixed part.
In the electronic control device according to claim 1,
The cover has a substantially quadrilateral shape, and the plurality of fixing portions are composed of four first fixing portions formed near the four corners of the cover and a second fixing portion formed substantially in the center of the cover. The reduced-rigidity portions are in the vicinity of each of the four first fixing portions and in the vicinity of the second fixing portion, each of the four first fixing portions and the second fixing portion An electronic control device, characterized in that it is a thin portion formed in a straight line connecting with a fixed portion.
In the electronic control device according to claim 1,
The cover has a substantially quadrilateral shape, and the plurality of fixing portions are composed of four first fixing portions formed near the four corners of the cover and a second fixing portion formed substantially in the center of the cover. The electronic control device according to claim 1, wherein the reduced-rigidity portion is a crank portion formed in the vicinity of each of the four first fixed portions.
In the electronic control device according to any one of claims 2, 3 and 4,
The base and the cover are not in contact with each other, and the circuit board is integrally fixed between the base and the cover by screws inserted into the first fixing portion and the second fixing portion. An electronic control unit characterized by
In the electronic control device according to claim 5,
The electronic control device, wherein the first fixing portion and the second fixing portion are formed with a concave portion having a bottom surface for fixing the screw and a side surface.
In the electronic control device according to claim 1,
The cover has a substantially quadrilateral shape, and the plurality of fixing portions are composed of four first fixing portions formed near the four corners of the cover and a second fixing portion formed substantially in the center of the cover. wherein each of the first fixing portion and the second fixing portion has a recess formed by a bottom surface and a side surface for fixing a screw, and the reduced rigidity portion includes the side surface of the first fixing portion and the second An electronic control device characterized by being an opening formed in the side surface of the second fixing portion.
In the electronic control device according to claim 7,
The electronic control device, wherein the opening is formed of a first slit-shaped opening extending in a circumferential direction of the screw and a second slit-shaped opening extending in a diametrical direction of the screw.
In the electronic control device according to claim 8,
The circuit board has a connector for electrically connecting the circuit board to the outside, and the slit widths of the first opening and the second opening correspond to the distance between the base and the connector. , the distance between the cover and the connector, or the distance between the base and the cover.
In the electronic control device according to claim 9,
The electronic control device, wherein slit lengths of the first opening and the second opening are 1/20 or less of a wavelength of maximum noise generated by the electronic component mounted on the circuit board.
In the electronic control device according to claim 1,
An electronic control device, wherein one of the plurality of fixed portions is arranged near the center of the housing.
In the electronic control device according to claim 8,
a third fixing portion having the same shape as the first fixing portion and arranged on the outer peripheral side of the cover, wherein the screw between the first fixing portion and the third fixing portion; The electronic control device, wherein the minimum pitch between the screws is 100 mm or less.
In the electronic control device according to claim 1,
A heat-conducting material is disposed between the electronic component mounted on the circuit board and the base and between the electronic component mounted on the circuit board and the cover. The electronic control device, wherein the heat emissivity of at least a portion of the position where the heat conductive material is arranged and the back surface of the heat conductive material is 0.6 or more.
In the electronic control device according to claim 13,
A plurality of the electronic components are arranged on the circuit board, and the thermal conductivity of the thermal conductive material arranged on the electronic component with a large maximum heat generation is compared to the electronic component with a large maximum heat generation. and a thermal conductivity higher than that of the thermally conductive material arranged in the electronic component having a small maximum heat generation amount.
Any electronic control device according to claim 13,
The electronic component is soldered to the circuit board, and the Young's modulus of the thermal conductive material disposed on the electronic component with a short solder life compared to the electronic component with a long solder life is the electronic component with a long solder life. An electronic control device, wherein the Young's modulus of the thermally conductive material disposed on the part is smaller than that of the thermally conductive material.