WO2023243038A1 - Vehicle-mounted electronic control device - Google Patents

Abstract

The present invention improves heat dissipation performance. This vehicle-mounted electronic control device comprises a circuit board, a first cover, a second cover, and a heat-conductive member. The circuit board is mounted with an electronic component that generates heat and a connector component that transmits and receives signals. The first cover and the second cover are arranged on both sides of the circuit board in the thickness direction, and form a case that accommodates the circuit board. The heat-conductive member is interposed between the electronic component and the first cover. The first cover has a thick-walled portion that is formed thicker than the thickness of the other portions. The thick-walled portion has a heat-generating component facing portion where the heat of the electronic component is transferred through the heat-conductive member, and extends in a first direction toward one side of the first cover from the heat-generating component facing portion.

Description

Automotive electronic control unit

The present invention relates to a vehicle-mounted electronic control device.

In general, vehicles such as automobiles are equipped with a plurality of electronic control units (ECUs) to control various objects including engines, power steering, brakes, airbags, etc. An electronic control device mounted on a vehicle (hereinafter also referred to as "vehicle electronic control device") has a structure in which a circuit board on which electronic components are mounted is housed inside a housing (for example, Patent Document 1 ).

Japanese Patent Application Publication No. 2017-130514

In general, in-vehicle electronic control devices are often installed in the engine compartment. On the other hand, in recent years, more and more in-vehicle electronic control devices have been installed in vehicles in order to realize safe driving support and autonomous driving. Furthermore, the in-vehicle electronic control device may be installed in the vehicle interior in addition to the engine room.

However, when installing a vehicle-mounted electronic control device in a vehicle interior, the installation location is often a narrow space and a place where air does not easily flow. On the other hand, when an in-vehicle electronic control device functions as a control device, electronic components mounted thereon generate heat. If this heat generation temperature rises above the rated temperature of the electronic components, the in-vehicle electronic control device may not function properly, which may impede the safety of driving support and autonomous driving.

An object of the present invention is to provide an on-vehicle electronic control device that can improve heat dissipation performance.

In order to solve the above problems and achieve the objects of the present invention, the in-vehicle electronic control device of the present invention includes a circuit board, a first cover, a second cover, and a heat conductive member. Electronic components that generate heat and connector components that transmit and receive signals are mounted on the circuit board. The first cover and the second cover are arranged on both sides of the circuit board in the thickness direction, and form a case that accommodates the circuit board. The heat conductive member is interposed between the electronic component and the first cover. The first cover has a thick portion that is thicker than other portions. The thick portion has a heat generating component facing portion through which the heat of the electronic component is transmitted via the heat conductive member, and extends in a first direction toward one side of the first cover from the heat generating component facing portion.

According to the in-vehicle electronic control device configured as described above, heat dissipation performance can be improved.
Note that problems, configurations, and effects other than those described above will be made clear by the description of the embodiments below.

1 is a perspective view of an in-vehicle electronic control device according to a first embodiment of the present invention, viewed from an oblique direction. 2 is a schematic cross-sectional view taken along line AA shown in FIG. 1. FIG. FIG. 2 is a perspective view of an in-vehicle electronic control device according to a second embodiment of the present invention, viewed from an oblique direction. 4 is an enlarged view of a portion surrounded by a broken line E1 shown in FIG. 3. FIG. FIG. 7 is a perspective view of an in-vehicle electronic control device according to a third embodiment of the present invention, viewed from an oblique direction. 6 is a schematic cross-sectional view taken along line BB shown in FIG. 5. FIG. FIG. 7 is a perspective view of an in-vehicle electronic control device according to a fourth embodiment of the present invention, viewed from an oblique direction. 8 is a schematic cross-sectional view taken along line CC shown in FIG. 7. FIG. FIG. 7 is a perspective view of an in-vehicle electronic control device according to a fifth embodiment of the present invention, viewed from an oblique direction. FIG. 7 is a perspective view of an in-vehicle electronic control device according to a sixth embodiment of the present invention, viewed from an oblique direction. FIG. 7 is a perspective view of an in-vehicle electronic control device according to a seventh embodiment of the present invention, viewed from an oblique direction. 12 is an enlarged view of a portion surrounded by a broken line E2 shown in FIG. 11. FIG. FIG. 7 is a perspective view of an in-vehicle electronic control device according to an eighth embodiment of the present invention, viewed from an oblique direction. FIG. 2 is a temperature distribution diagram of a thermal fluid analysis result of an in-vehicle electronic control device in which two thick parts are close to each other. FIG. 7 is a perspective view of an in-vehicle electronic control device according to a ninth embodiment of the present invention, viewed from an oblique direction.

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

1. First Embodiment An on-vehicle electronic control device according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
FIG. 1 is an overall view of an in-vehicle electronic control device according to a first embodiment viewed from an oblique direction. FIG. 2 is a schematic cross-sectional view taken along line AA shown in FIG.

[In-vehicle electronic control unit]
An on-vehicle electronic control device 101 shown in FIGS. 1 and 2 is an electronic control device installed in a vehicle that runs using liquid fuel such as gasoline or diesel oil. The in-vehicle electronic control device according to the present invention is widely applicable to electronic control devices installed in vehicles such as vehicles that run using hydrogen as fuel, hybrid vehicles, and electric vehicles. Further, the object controlled by the on-vehicle electronic control device is not limited to a specific object.

In the following description, in order to clarify the shape and positional relationship of each part of the in-vehicle electronic control device 101, the thickness direction (height direction) of the in-vehicle electronic control device 101 will be referred to as the Z direction, and directions perpendicular to this Z direction will be described. Of the two axial directions, one direction is the X direction and the other direction is the Y direction. The X direction, Y direction, and Z direction are directions orthogonal to each other. Note that the Y direction corresponds to the first direction according to the present invention. Moreover, the X direction corresponds to the second direction according to the present invention.

As shown in FIGS. 1 and 2, the in-vehicle electronic control device 101 includes a circuit board 1 and a case 2 that houses the circuit board 1. The circuit board 1 has two mounting surfaces substantially perpendicular to the Z direction. That is, the thickness direction of the circuit board 1 is substantially parallel to the Z direction.

The circuit board 1 is formed into a rectangle. The circuit board 1 has two sides substantially parallel to the X direction and two sides substantially parallel to the Y direction. The circuit board 1 is constituted by a printed wiring board which is a rigid board using glass epoxy as a base material, for example. The circuit board 1 has mounting surfaces 1a and 1b that are planes substantially perpendicular to the Z direction. A wiring pattern is formed on the mounting surfaces 1a and 1b of the circuit board 1. Note that the circuit board according to the present invention may have a wiring pattern formed only on one mounting surface.

The circuit board 1 includes, as an example of electronic components, three connector components 11 (one is shown in FIG. 2), a first heat generating component 12, a second heat generating component (not shown), and a plurality of electronic components 13. has been implemented. Examples of the plurality of electronic components 13 include switching elements, resistance elements, capacitors, diodes, and the like.

Note that the number of connector components mounted on the circuit board 1 may be two or less, or four or more. Further, the number of heat generating components mounted on the circuit board 1 may be one or three or more.

The connector component 11 is an electronic component that allows the circuit board 1 to transmit electrical signals generated by the circuit board 1 to external equipment, and for the circuit board 1 to receive electrical signals generated by external equipment. Examples of external devices that exchange electrical signals with the on-vehicle electronic control device 101 include electronic control devices, cameras, sensors, actuators, etc. that are mounted on a vehicle other than those in this embodiment.

The three connector components 11 are mounted on one end of the circuit board 1 in the Y direction. The three connector parts 11 are arranged at predetermined intervals in the X direction. A portion of each connector component 11 projects laterally from one of the two sides of the circuit board 1 parallel to the X direction.

A harness (not shown) is connected to the three connector parts 11. The harness is a wiring bundle for electrically connecting the circuit board 1 and external equipment. A harness has a structure in which a metal wire, which is a conductor for making an electrical connection, is covered with a protective coating, which is an insulator.

The first heat generating component 12 is arranged approximately at the center of the mounting surface 1a. The first heat generating component 12 is, for example, an electronic component having a built-in arithmetic circuit such as a CPU (Central Processing Unit) called a microcomputer or a GPU (Graphics Processing Unit). The first heat generating component 12 includes a processor such as an IC (integrated circuit) chip or a semiconductor chip. Since IC chips and semiconductor chips are highly functional components that operate at processing speeds of several hundred MHz to several GHz, they generate a lot of heat. That is, the first heat generating component 12 is an electronic component that generates heat. The power consumption of the first heat generating component 12, which is such a highly functional component, is extremely high and may reach several tens of W.

The amount of heat generated by the first heat generating component 12, which is an electronic component having an arithmetic function, is greater than the amount of heat generated by the other electronic components 13. Therefore, in this embodiment, an electronic component having an arithmetic function is defined as a heat generating component. The heat generating component according to the present invention is not limited to what is called a microcomputer, and may be, for example, a memory that communicates with a microcomputer.

The first heat generating component 12 is connected to the case 2 via the heat conductive member 6 in order to radiate the heat generated by itself. The thermally conductive member 6 is made of, for example, a thermally conductive resin, and more specifically, made of TIM (Thermal Interface Material). The heat conductive member 6 is sandwiched between the first heat generating component 12 and the case 2. Further, the heat conductive member 6 is in close contact with both the first heat generating component 12 and the case 2. By arranging the heat conductive member 6 in this manner, the heat generated by the first heat generating component 12 can be efficiently transmitted to the case 2.

A second heat generating component (not shown) is arranged at a position shifted in the X direction from the first heat generating component 12 on the mounting surface 1a. The second heat generating component is connected to the case 2 via a heat conductive member (not shown). A heat conductive member (not shown) is in close contact with both the second heat generating component and the case 2.

The case 2 is formed into a hollow rectangular parallelepiped shape. The case 2 protects the circuit board 1 housed therein from dust, water, and shock. The case 2 includes a first cover 3 and a second cover 4 that face each other in the Z direction. The first cover 3 forms the top and side surfaces of the case 2 . The second cover 4 forms the lower surface of the case 2 .

The first cover 3 is made of a metal material. The metal constituting the first cover 3 is preferably aluminum or an alloy mainly composed of aluminum. However, the material constituting the first cover 3 is not limited to metal, and may be resin. The first cover 3 faces one mounting surface of the circuit board 1 .

The first cover 3 has a substantially rectangular top plate 3a and three side plates 3b, 3c, and 3d continuous to three sides of the top plate 3a. The top plate 3a faces the mounting surface 1a of the circuit board 1. The side plates 3b and 3c face each other in the X direction. A connector opening 3e is formed on the side surface of the first cover 3 facing the side plate 3d.

As shown in FIG. 2, a partition piece 31, a first heat dissipation pedestal 32, and a second heat dissipation pedestal (not shown) are provided on the surface of the top plate 3a that faces the mounting surface 1a of the circuit board 1. ing. The partition piece 31 partitions the mounting surface 1a of the circuit board 1 into a region where the three connector components 11 are mounted, and a region where the first heat generating component 12, the plurality of electronic components 13, etc. are mounted.

The first heat dissipation pedestal 32 faces the first heat generating component 12 mounted on the mounting surface 1a of the circuit board 1. The first heat radiation pedestal portion 32 is a substantially square protrusion. The outer shape of the surface of the first heat dissipating pedestal 32 that faces the mounting surface 1 a of the circuit board 1 is larger than the outer shape of the upper surface of the first heat generating component 12 .

The above-mentioned heat conductive member 6 is interposed between the first heat dissipation pedestal 32 and the first heat generating component 12. The heat of the first heat generating component 12 is transmitted from the first heat radiation pedestal 32 to the first cover 3. Note that in the first cover according to the present invention, the first heat dissipation pedestal 32 may not be provided, and the heat conductive member 6 may be brought into contact with the surface of the top plate 3a that faces the mounting surface 1a.

The second heat dissipation pedestal faces the second heat generating component mounted on the mounting surface 1a of the circuit board 1. A heat conductive member (not shown) is interposed between the second heat radiation pedestal and the second heat generating component. The heat of the first heat generating component 12 is transmitted to the first cover 3 from the second heat radiation pedestal.

An opening step 33 is formed in the top plate 3a from the partition piece 31 to the side opening to avoid interference with the three connector components 11. The opening step portion 33 forms one of the two sides of the top plate 3a that are parallel to the X direction. The opening step 33 and the partition piece 31 form a connector opening 3e that exposes the three connector components 11.

The top plate 3a has two thick parts 341 and 351 that are thicker than other parts. The thick portions 341 and 351 are formed into a substantially rectangular shape having short sides substantially parallel to the X direction. That is, the thick portions 341 and 351 extend in the Y direction.

One end portion of the thick portion 341 in the Y direction overlaps with the first heat radiation pedestal portion 32 in the Z direction. Therefore, one end portion of the thick portion 341 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12 via the first heat dissipation pedestal portion 32 and the heat conductive member 6. The heat of the first heat generating component 12 is transmitted to the heat generating component facing portion of the thick portion 341 via the first heat radiating pedestal portion 32 and the heat conductive member 6. The other end of the thick portion 341 in the Y direction reaches the connector opening 3e, which is one of the side portions of the first cover 3. The other end of the thick portion 341 in the Y direction is continuous with the opening step portion 33.

One end of the thick portion 351 in the Y direction overlaps the second heat dissipation pedestal (not shown) in the Z direction. Therefore, one end portion of the thick portion 351 in the Y direction is a heat generating component facing portion that faces a second heat generating component (not shown) via the second heat dissipation pedestal portion and the heat conductive member. The heat generating component facing portion of the thick portion 351 is a portion to which heat of the second heat generating component (not shown) is transmitted via the second heat radiating pedestal portion and the heat conductive member. The other end of the thick portion 351 in the Y direction reaches the connector opening 3e, which is one of the side portions of the first cover 3. The other end of the thick portion 351 in the Y direction is continuous with the opening step portion 33.

The top plate 3a has a high ceiling part 36 that makes the internal space of the case 2 higher than other parts. On the mounting surface 1a of the circuit board 1, an electronic component (not shown) that is taller than other electronic components is mounted on a portion of the top plate 3a facing the high ceiling portion 36. Thereby, the first cover 3 does not interfere with tall electronic components mounted on the circuit board 1.

The second cover 4, like the first cover 3, is made of a metal material. The metal constituting the second cover 4 is preferably aluminum, an aluminum-based alloy, or an iron alloy containing carbon. However, the material constituting the second cover 4 is not limited to metal, and may be resin.

The second cover 4 is made of a bent member whose side surface is approximately L-shaped when viewed from the X direction. The second cover 4 is connected to the first cover 3 using screws (not shown) or the like. The second cover 4 includes a cover body 41 that forms the bottom surface of the case 2, and a support piece 42 that stands up substantially perpendicularly from the cover body 41. The cover body 41 faces the mounting surface 1b of the circuit board 1 in the Z direction.

The support piece 42 is a plate having a plane substantially perpendicular to the Y direction. The upper ends of the support pieces 42 abut against the bottom surfaces of the portions of the three connector components 11 that protrude laterally from the circuit board 1 . Thereby, the three connector components 11 can be stably supported by the circuit board 1 and the second cover 4.

[Heat dissipation of in-vehicle electronic control unit]
Next, heat radiation of the on-vehicle electronic control device 101 will be explained.

When the in-vehicle electronic control device 101 starts operating, electronic components such as the first heat-generating component 12 mounted on the circuit board 1 generate heat, and the temperature of the in-vehicle electronic control device 101 rises. The heat generated by the first heat generating component 12 reaches the first cover 3 via the heat conductive member 6. The heat that has reached the first cover 3 is conducted to the lower temperature side of the first cover 3.

Here, the side portion of the first cover 3 has the lowest temperature. In particular, heat around the connector component 11 is radiated through the harness. Therefore, the temperature of the connector opening 3e is often the lowest among the side parts of the first cover 3. Therefore, most of the heat that reaches the first cover 3 through the heat conductive member 6 from the first heat generating component 12 is transmitted through the connector opening 3e (the side of the first cover 3 where the connector component 11 is arranged). ) is conducted in the direction (Y direction).

The thick portions 341 and 351 can increase the amount of heat transfer of the first cover 3. The temperature increase width ΔTj of the first heat generating component 12 in the process of increasing the temperature of the first heat generating component 12 (second heat generating component) is expressed by the following equation (1). Here, R is thermal resistance, Q is calorific value, e is emissivity, t is time, and C is heat capacity.

Equation (1) shows that increasing the heat capacity C leads to a reduction in the temperature rise width ΔTj. The heat capacity C is expressed by the following equation (2). However, m is weight and c is specific heat.

The in-vehicle electronic control device 101 according to the present embodiment achieves an increase in the heat capacity C by locally increasing the heat capacity (weight) of the first cover 3. Equation (1) shows the range of temperature rise during the transition period when the temperature changes. On the other hand, the heat dissipation ability during the steady period after which the temperature becomes constant is based on the ability during the transition period. Therefore, forming the thick portions 341 and 351 on the first cover 3 is effective both during the transition period and the steady period of temperature change.

Further, the thick portions 341 and 351 extend toward the connector opening 3e. Thereby, it is possible to increase the amount of heat conduction of the first cover 3. The amount of heat transferred in an object is expressed by the following equation (3). However, dQ is the amount of heat transfer, ΔT is the temperature gradient, and dA is the cross-sectional area of the portion where heat is transferred.

In other words, the larger the temperature difference, the greater the amount of heat conduction. Furthermore, the larger the cross-sectional area of the portion through which heat is transferred, the greater the amount of heat conduction. Therefore, by providing the thick portions 341 and 351 extending toward the connector opening 3e, the heat of the first heat generating component 12 (second heat generating component) can be efficiently radiated. Then, the temperature of the first heat generating component 12 (second heat generating component) can be reduced.

In this way, the in-vehicle electronic control device 101 according to the first embodiment can improve the heat dissipation performance of the heat generated by the first heat generating component 12 (second heat generating component). By using the in-vehicle electronic control device 101, safer driving support and automatic driving can be realized.

Further, the thick portions 341 and 351 of the in-vehicle electronic control device 101 according to the first embodiment are continuous with the opening step portion 33. Thereby, the heat transmitted through the thick portions 341 and 351 can efficiently reach the connector opening 3e. As a result, the heat dissipation performance of the first cover 3 (vehicle electronic control device 101) can be improved.

Note that a gap may be formed between the thick portions 341 and 351 and the opening step portion 33. In this case, by providing the thick portions 341 and 351, the amount of heat conduction of the first cover 3 can be increased. Furthermore, by shortening the length of the thick portions 341 and 351 in the Y direction, the weight of the first cover 3 can be reduced.

Furthermore, the direction in which the thick portion according to the present invention extends is not limited to the direction toward the connector opening. The thick portion according to the present invention may extend in any direction as long as it is directed toward the side (edge) of the first cover. The temperature of the side portion is lower than that of the portion facing the heat generating component. Therefore, if the thick portion extends in the direction toward the side portion of the first cover, heat dissipation performance can be improved. However, it is preferable that the thick portion extends toward the side where the temperature is relatively low.

2. Second Embodiment An on-vehicle electronic control device according to a second embodiment of the present invention will be described below with reference to FIGS. 3 and 4.
FIG. 3 is an overall view of the in-vehicle electronic control device according to the second embodiment viewed from an oblique direction. FIG. 4 is an enlarged view of a portion surrounded by a broken line E1 shown in FIG.

[In-vehicle electronic control unit]
As shown in FIG. 3, a vehicle-mounted electronic control device 102 according to the second embodiment has the same configuration as the vehicle-mounted electronic control device 101 according to the first embodiment. The in-vehicle electronic control device 102 includes a circuit board 1 (see FIG. 2) and a case 202 that accommodates the circuit board 1.

The case 202 is composed of a first cover 302 and a second cover 4 that face each other in the Z direction. The first cover 302 differs from the first cover 3 according to the first embodiment in thick portions 342 and 352. Therefore, the thick portions 342 and 352 will be explained here, and the same components as the first cover 3 will be given the same reference numerals and the explanation will be omitted.

The thick portions 342 and 352 are formed into a substantially rectangular shape with short sides substantially parallel to the X direction. That is, the thick portions 342 and 352 extend in the Y direction.

One end of the thick portion 342 in the Y direction overlaps with the first heat dissipation pedestal 32 (see FIG. 2) in the Z direction. Therefore, one end portion of the thick portion 342 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12 via the first heat dissipating pedestal portion 32 and the heat conductive member 6 (see FIG. 2). The heat of the first heat generating component 12 is transmitted to the heat generating component facing portion of the thick portion 342 via the first heat radiating pedestal portion 32 and the heat conductive member 6 (see FIG. 2). The other end of the thick portion 342 in the Y direction is continuous with the opening step portion 33 .

As shown in FIG. 4, the thick portion 342 has a tapered portion 342a whose length in the X direction becomes shorter toward the connector opening 3e in the Y direction. As a result, the cross-sectional area B perpendicular to the Y-direction at the other end of the thick part 342 in the Y direction is the cross-sectional area A perpendicular to the Y-direction at one end of the thick part 342 in the Y direction (the part facing the heat generating component). (Cross-sectional area A>Cross-sectional area B).

The amount of heat conduction of the thick portion 342 decreases as it moves toward the connector opening 3e side in the Y direction (away from the heat generating component facing portion). Therefore, even if the cross-sectional area B is reduced, the heat dissipation performance does not deteriorate significantly. Therefore, in this embodiment, the cross-sectional area B is made small while taking into account the desired radiation performance. This makes it possible to ensure the desired radiation performance and reduce the weight of the thick portion 342 (the entire first cover 302).

As shown in FIG. 3, one end of the thick portion 352 in the Y direction overlaps with the second heat dissipation pedestal (not shown) in the Z direction. Therefore, one end portion of the thick portion 352 in the Y direction is a heat generating component facing portion that faces a second heat generating component (not shown) via the second heat radiating pedestal portion and a heat conductive member (not shown). The heat of the second heat generating component is transmitted to the heat generating component facing portion of the thick portion 352 via the second heat radiating pedestal and the heat conductive member. The other end of the thick portion 352 in the Y direction is continuous with the opening step portion 33 .

The thick portion 352 has a tapered portion 352a whose length in the X direction becomes shorter toward the connector opening 3e in the Y direction. As a result, the cross-sectional area perpendicular to the Y-direction at the other end of the thick portion 352 in the Y-direction is larger than the cross-sectional area perpendicular to the Y-direction at one end of the thick portion 352 in the Y-direction (the portion facing the heat generating component). small.

In this way, according to the in-vehicle electronic control device 102 according to the second embodiment, it is possible to both reduce the weight of the first cover 302 and improve heat dissipation performance. Furthermore, when the first cover 302 is molded by casting using a metal mold (mold), by forming the tips of the thick parts 342 and 352 to be thin, the first cover 302 can be released from the mold. can improve sex. As a result, the quality of the first cover 302 can be improved.

Note that the cross-sectional area B of the thick portion according to the present invention is not limited to being smaller than the cross-sectional area A. The cross-sectional area B of the thick portion according to the present invention can be appropriately set depending on the desired radiation performance. For example, the cross-sectional area B of the thick portion according to the present invention may be greater than or equal to the cross-sectional area A. (Cross-sectional area A≦Cross-sectional area B). However, it is not preferable to increase the weight of the thick portion (the entire first cover) in order to slightly improve radiation performance. Therefore, it is preferable that the cross-sectional area B is equal to or less than the cross-sectional area A.

Further, the thick portion according to the present invention may have a tapered portion whose length (height) in the Z direction becomes shorter (lower) toward the connector opening 3e side in the Y direction. Also in this case, the cross-sectional area B can be made smaller than the cross-sectional area A. Note that when the cross-sectional area B is made smaller than the cross-sectional area A, it is not limited to providing a tapered portion, and for example, a thick portion having a T-shaped shape when viewed from the Z direction may be provided.

3. Third Embodiment An on-vehicle electronic control device according to a third embodiment of the present invention will be described below with reference to FIGS. 5 and 6.
FIG. 5 is an overall view of the in-vehicle electronic control device according to the third embodiment viewed from an oblique direction. FIG. 6 is a schematic cross-sectional view taken along line BB shown in FIG.

[In-vehicle electronic control unit]
As shown in FIG. 5, the vehicle-mounted electronic control device 103 according to the third embodiment has the same configuration as the vehicle-mounted electronic control device 101 according to the first embodiment. The in-vehicle electronic control device 103 includes a circuit board 1 (see FIG. 6) and a case 203 that accommodates the circuit board 1.

The case 203 is composed of a first cover 303 and a second cover 4 that face each other in the Z direction. The first cover 303 differs from the first cover 3 according to the first embodiment in thick portions 343 and 353. Therefore, the thick parts 343 and 353 will be explained here, and the same components as the first cover 3 will be given the same reference numerals and the explanation will be omitted.

The thick portions 343 and 353 are formed into a substantially rectangular shape with short sides substantially parallel to the X direction. That is, the thick portions 343 and 353 extend in the Y direction.

One end of the thick portion 343 in the Y direction overlaps the first heat dissipation pedestal 32 (see FIG. 2) in the Z direction. Therefore, one end portion of the thick portion 343 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12 via the first heat dissipating pedestal portion 32 and the heat conductive member 6 (see FIG. 2). The heat of the first heat generating component 12 is transmitted to the heat generating component facing portion of the thick portion 343 via the first heat radiating pedestal portion 32 and the heat conductive member 6. The other end of the thick portion 343 in the Y direction is continuous with the opening step portion 33 .

As shown in FIG. 6, the first heat generating component 12 has a built-in heat generating chip 12a which is a component that generates heat. The length L1 of the thick portion 343 in the X direction is longer than the length L2 of the heat generating chip 12a in the X direction. Thereby, the heat generated by the heat generating chip 12a of the first heat generating component 12 can be efficiently transmitted to the thick portion 343.

Note that in order to efficiently transfer the heat generated in the first heat generating component 12 to the thick wall portion 343, the length L1 of the thick wall portion 343 in the X direction must be greater than or equal to the length L2 of the heat generating chip 12a in the X direction. Bye. Further, since the thick portion 343 extends in the Y direction, the length of the thick portion 343 in the Y direction is longer than the length of the heat generating chip 12a in the Y direction.

One end of the thick portion 353 in the Y direction overlaps the second heat dissipation pedestal (not shown) in the Z direction. Therefore, one end portion of the thick portion 353 in the Y direction is a heat generating component facing portion that faces a second heat generating component (not shown) via the second heat radiating pedestal portion and a heat conductive member (not shown). The heat of the second heat generating component is transmitted to the heat generating component facing portion of the thick portion 353 via the second heat radiating pedestal and the heat conductive member. The other end of the thick portion 353 in the Y direction is continuous with the opening step portion 33 .

The second heat generating component has a built-in heat generating chip (not shown) which is a component that generates heat. The length of the thick portion 343 in the X direction is longer than the length of the heat generating chip (not shown) in the X direction. Thereby, the heat generated by the heat generating chip of the second heat generating component can be efficiently transmitted to the thick portion 343.

In this manner, according to the in-vehicle electronic control device 103 according to the third embodiment, the heat generated in the first heat generating component 12 (heat generating chip 12a) can be efficiently transferred to the thick portion 343. Moreover, the heat generated in the heat generating portion of the second heat generating component can be efficiently transmitted to the thick wall portion 343. As a result, heat dissipation performance can be improved.

4. Fourth Embodiment An on-vehicle electronic control device according to a fourth embodiment of the present invention will be described below with reference to FIGS. 7 and 8.
FIG. 7 is an overall view of the in-vehicle electronic control device according to the fourth embodiment viewed from an oblique direction. FIG. 8 is a schematic cross-sectional view taken along line CC shown in FIG.

[In-vehicle electronic control unit]
As shown in FIG. 7, the vehicle-mounted electronic control device 104 according to the fourth embodiment has the same configuration as the vehicle-mounted electronic control device 101 according to the first embodiment. The in-vehicle electronic control device 104 includes a circuit board 1 (see FIG. 8) and a case 204 that accommodates the circuit board 1.

The case 204 is composed of a first cover 304 and a second cover 4 that face each other in the Z direction. The first cover 304 differs from the first cover 3 according to the first embodiment in thick portions 344 and 354. Therefore, here, the thick portions 344 and 354 will be explained, and the same components as the first cover 3 will be given the same reference numerals and the explanation will be omitted.

The thick portions 344 and 354 are formed into a substantially rectangular shape with short sides substantially parallel to the X direction. That is, the thick portions 344 and 354 extend in the Y direction.

As shown in FIGS. 7 and 8, the intermediate portion of the thick portion 344 in the Y direction overlaps with the first heat radiation pedestal portion 32 in the Z direction. Therefore, the intermediate portion of the thick portion 343 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12 via the first heat dissipating pedestal portion 32 and the heat conductive member 6. The heat of the first heat generating component 12 is transmitted to the heat generating component facing portion of the thick portion 344 via the first heat radiating pedestal portion 32 and the heat conductive member 6.

One end of the thick portion 344 in the Y direction is located on the side opposite to the connector opening 3e in the Y direction (on the side plate 3d side) with respect to the heat generating component facing portion. Therefore, the thick portion 344 extends from the heat generating component facing portion toward the side plate 3d. A tapered portion 344a whose length in the X direction becomes shorter toward the side plate 3d is formed at one end of the thick portion 344 in the Y direction.

The other end of the thick portion 344 in the Y direction is continuous with the opening step portion 33. At the other end of the thick portion 344 in the Y direction, a tapered portion 344b whose length in the X direction becomes shorter toward the connector opening 3e is formed.

The intermediate portion of the thick portion 354 in the Y direction overlaps with the second heat dissipation pedestal portion (not shown) in the Z direction. Therefore, the intermediate portion of the thick portion 354 in the Y direction is a heat generating component facing portion that faces a second heat generating component (not shown) via the second heat dissipation pedestal and a heat conductive member (not shown). The heat of the second heat generating component is transmitted to the heat generating component facing portion of the thick portion 354 via the second heat radiating pedestal and the heat conductive member.

One end of the thick portion 354 in the Y direction is located closer to the side plate 3d in the Y direction than the heat generating component facing portion. Therefore, the thick portion 354 extends from the heat generating component facing portion toward the side plate 3d. A tapered portion 354a is formed at one end of the thick portion 354 in the Y direction, the length of which decreases in the X direction toward the side plate 3d.

The other end of the thick portion 354 in the Y direction is continuous with the opening step portion 33. At the other end of the thick portion 354 in the Y direction, a tapered portion 354b whose length in the X direction becomes shorter toward the connector opening 3e is formed.

In this way, the thick portions 344 and 354 of the in-vehicle electronic control device 104 according to the fourth embodiment extend from the respective heating component opposing portions to both sides in the Y direction. Thereby, heat dissipation performance can be improved.

5. Fifth Embodiment Hereinafter, an on-vehicle electronic control device according to a fifth embodiment of the present invention will be described using FIG. 9.
FIG. 9 is an overall view of the in-vehicle electronic control device according to the fifth embodiment viewed from an oblique direction.

[In-vehicle electronic control unit]
As shown in FIG. 9, the vehicle-mounted electronic control device 105 according to the fifth embodiment has the same configuration as the vehicle-mounted electronic control device 101 according to the first embodiment. The in-vehicle electronic control device 105 includes a circuit board 1 (see FIG. 8) and a case 205 that accommodates the circuit board 1.

The case 205 is composed of a first cover 305 and a second cover 4 (not shown) that face each other in the Z direction. The first cover 305 differs from the first cover 3 according to the first embodiment in thick portions 345 and 355. Therefore, here, the thick portions 345 and 355 will be explained, and components common to the first cover 3 will be given the same reference numerals and explanations will be omitted.

The thick portions 345 and 355 are formed into a substantially rectangular shape with short sides substantially parallel to the X direction. That is, the thick portions 345 and 355 extend in the Y direction.

One end of the thick portion 345 in the Y direction overlaps the first heat dissipation pedestal 32 (see FIG. 2) in the Z direction. Therefore, one end portion of the thick portion 345 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12 via the first heat radiation pedestal portion 32 and the heat conductive member 6 (see FIG. 2). The heat of the first heat generating component 12 is transmitted to the heat generating component facing portion of the thick portion 345 via the first heat radiating pedestal portion 32 and the heat conductive member 6. The other end of the thick portion 345 in the Y direction is continuous with the opening step portion 33 .

The thick portion 345 has an end surface 345a on the side opposite to the connector opening 3e in the Y direction. The position of this end surface 345a in the Y direction is the same as the position of the end surface of the first heat radiation pedestal 32 on the side opposite to the connector opening 3e side in the Y direction. Thereby, the thick portion 345 can be made smaller while ensuring heat dissipation performance. As a result, the weight of the first cover 305 can be reduced without impairing heat dissipation performance.

One end of the thick portion 355 in the Y direction overlaps with the second heat dissipation pedestal (not shown) in the Z direction. Therefore, one end portion of the thick portion 355 in the Y direction is a heat generating component facing portion that faces a second heat generating component (not shown) via the second heat radiating pedestal portion and a heat conductive member (not shown). The heat of the second heat generating component is transmitted to the heat generating component facing portion of the thick portion 355 via the second heat radiating pedestal and the heat conductive member. The other end of the thick portion 355 in the Y direction is continuous with the opening step portion 33 .

The thick portion 355 has an end surface 355a on the side opposite to the connector opening 3e side in the Y direction. The position of this end surface 355a in the Y direction is the same as the position of the end surface of the second heat radiation pedestal (not shown) on the side opposite to the connector opening 3e in the Y direction. Thereby, the thick portion 345 can be made smaller while ensuring heat dissipation performance. As a result, the weight of the first cover 305 can be reduced without impairing heat dissipation performance.

In this way, according to the in-vehicle electronic control device 105 according to the fifth embodiment, the weight of the first cover 305 can be reduced without impairing the heat dissipation performance.

6. Sixth Embodiment Hereinafter, an in-vehicle electronic control device according to a sixth embodiment of the present invention will be described using FIG. 10.
FIG. 10 is an overall view of the in-vehicle electronic control device according to the sixth embodiment viewed from an oblique direction.

[In-vehicle electronic control unit]
As shown in FIG. 10, a vehicle-mounted electronic control device 106 according to the sixth embodiment has the same configuration as the vehicle-mounted electronic control device 101 according to the first embodiment. The in-vehicle electronic control device 106 includes a circuit board 1 (see FIG. 8) and a case 206 that houses the circuit board 1.

The case 206 is composed of a first cover 306 and a second cover 4 (not shown) that face each other in the Z direction. The first cover 306 differs from the first cover 3 according to the first embodiment in thick portions 346 and 356. Therefore, here, the thick portions 346 and 356 will be explained, and the same components as the first cover 3 will be given the same reference numerals and the explanation will be omitted.

The thick portions 346 and 356 are formed into a substantially rectangular shape with short sides substantially parallel to the X direction. That is, the thick portions 346 and 356 extend in the Y direction.

The intermediate portion of the thick portion 346 in the Y direction overlaps with the first heat dissipation pedestal portion 32 (not shown) in the Z direction. Therefore, the intermediate portion of the thick portion 346 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12 via the first heat dissipation pedestal portion 32 and the heat conductive member 6 (not shown). The heat of the first heat generating component 12 is transmitted to the heat generating component facing portion of the thick portion 346 via the first heat radiating pedestal portion 32 and the heat conductive member 6.

One end of the thick portion 346 in the Y direction is located on the side plate 3d, which is the opposite side from the connector opening 3e. The side plate 3d corresponds to the other side according to the present invention. Further, the other end of the thick portion 346 in the Y direction is continuous with the opening step portion 33.

The intermediate portion of the thick portion 356 in the Y direction overlaps with the second heat dissipation pedestal portion (not shown) in the Z direction. Therefore, the intermediate portion of the thick portion 356 in the Y direction is a heat generating component facing portion that faces the second heat generating component via the second heat dissipation pedestal and a heat conductive member (not shown). The heat of the second heat generating component is transmitted to the heat generating component facing portion of the thick portion 356 via the second heat radiating pedestal and the heat conductive member.

One end of the thick portion 356 in the Y direction is located on the side of the side plate 3d that is opposite to the connector opening 3e in the Y direction of the top plate 3a. Further, the other end of the thick portion 356 in the Y direction is continuous with the opening step portion 33 .

A thick connection portion 366 is provided on the top plate 3a. The thick connection portion 366 is formed into a substantially rectangular shape extending in the X direction. One end of the connection thick portion 366 in the X direction is continuous with the other end of the thick portion 346 in the Y direction. The other end of the connection thick part 366 in the X direction is continuous with the other end of the thick part 356 in the Y direction. The connector opening 3e side of the connection thick portion 366 in the Y direction is continuous with the opening step 33.

In this way, the thick portions 346 and 356 of the in-vehicle electronic control device 105 according to the sixth embodiment extend from the respective heating component opposing portions to both sides in the Y direction. Both ends of the thick portions 346 and 356 in the Y direction reach both ends of the top plate 3a in the Y direction. Thereby, heat dissipation performance can be improved.

Furthermore, when manufacturing the first cover 306 by casting, the connector opening 3e side in the Y direction of the thick portions 346, 356 or the side opposite to the connector opening 3e side is molded to form a gate portion. (mold). Thereby, the fluidity of the metal during casting can be improved. Furthermore, variations in the temperature of the first cover 306 during the cooling process during casting can be suppressed. As a result, blowholes can be suppressed and the quality of the first cover 306 can be improved.

7. Seventh Embodiment Hereinafter, an on-vehicle electronic control device according to a seventh embodiment of the present invention will be described using FIGS. 11 and 12.
FIG. 11 is an overall view of the in-vehicle electronic control device according to the seventh embodiment viewed from an oblique direction. FIG. 12 is an enlarged view of a portion surrounded by a broken line E2 shown in FIG. 11.

[In-vehicle electronic control unit]
As shown in FIG. 11, a vehicle-mounted electronic control device 107 according to the seventh embodiment has the same configuration as the vehicle-mounted electronic control device 106 according to the sixth embodiment. The in-vehicle electronic control device 107 includes a circuit board 1 (see FIG. 8) and a case 207 that houses the circuit board 1.

The case 207 is composed of a first cover 307 and a second cover 4 (not shown) that face each other in the Z direction. The first cover 307 differs from the first cover 306 according to the sixth embodiment in that it has a plurality of heat radiation fins 377. Therefore, here, the plurality of radiation fins 377 will be explained, and the same components as the first cover 306 will be given the same reference numerals and the explanation will be omitted.

As shown in FIGS. 11 and 12, a plurality of heat radiation fins 377 are provided on the top plate 3a. The plurality of radiation fins 377 are provided in a portion of the top plate 3a other than the high ceiling portion 36. That is, the plurality of radiation fins 377 are also provided in the thick portions 346 and 356. The plurality of radiation fins 377 are formed in a plate shape having a plane substantially perpendicular to the X direction and extending in the Y direction.

Both ends of each radiation fin 377 in the Y direction are chamfered by cutting the corners diagonally. Thereby, sharp parts can be eliminated from the plurality of radiation fins 377, and safety can be improved. The length of the plurality of radiation fins 377 in the Z direction is set to be equal to or less than the length of the high ceiling section 36 in the Z direction. Thereby, there is no need to increase the installation space for the on-vehicle electronic control device 107.

Note that if there is no restriction on the length in the Z direction in the installation space of the in-vehicle electronic control device, the length in the Z direction of the plurality of radiation fins 377 can be set to a value longer than the length in the Z direction of the high ceiling section 36. can do. Further, if there is no restriction on the length in the Z direction in the installation space of the in-vehicle electronic control device, a plurality of radiation fins may be provided in the high ceiling portion 36.

Further, the heat radiation fin according to the present invention is not limited to being formed in a plate shape having a plane substantially perpendicular to the X direction. The heat dissipation fin according to the present invention can have a shape capable of dissipating heat, such as a plate shape having a plane substantially perpendicular to the Y direction, a plate shape having a curved surface, or a rod shape. Further, the heat dissipation fin according to the present invention may be provided only in the thick portion.

According to the in-vehicle electronic control device 107 according to the seventh embodiment, since it has a plurality of heat radiation fins 377, when installed in a place where there is air convection, it is possible to obtain a heat radiation effect due to air convection. As a result, the heat dissipation performance can be improved more than the first cover 306 according to the sixth embodiment.

8. Eighth Embodiment An on-vehicle electronic control device according to an eighth embodiment of the present invention will be described below with reference to FIGS. 13 and 14.
FIG. 13 is an overall view of the in-vehicle electronic control device according to the eighth embodiment viewed from an oblique direction. FIG. 14 is a temperature distribution diagram of a thermal fluid analysis result of a vehicle-mounted electronic control device in which two thick parts are close to each other.

[In-vehicle electronic control unit]
As shown in FIG. 13, an in-vehicle electronic control device 108 according to the eighth embodiment has the same configuration as the in-vehicle electronic control device 106 according to the sixth embodiment. The on-vehicle electronic control device 108 includes a circuit board 1 (see FIG. 8) and a case 208 that houses the circuit board 1.

The case 208 is composed of a first cover 308 and a second cover 4 (not shown) that face each other in the Z direction. The first cover 308 is the same as the first cover 306 according to the sixth embodiment. The thick parts 346 and 356 of the first cover 308 are formed into a substantially rectangular shape having short sides substantially parallel to the X direction. That is, the thick portions 346 and 356 extend in the Y direction.

A connector component (not shown), a first heat generating component 12A, and a second heat generating component 12B are mounted on the circuit board of the in-vehicle electronic control device 108. The first heat generating component 12A and the second heat generating component 12B are lined up at an appropriate distance in the X direction. The first heat generating component 12A and the second heat generating component 12B have a processor such as an IC (integrated circuit) chip or a semiconductor chip, and are electronic components that generate heat.

The intermediate portion of the thick portion 346 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12A via a first heat dissipation pedestal and a heat conductive member (not shown). The heat of the first heat generating component 12A is transmitted to the heat generating component facing portion of the thick portion 346 via the first heat radiating pedestal and the heat conductive member.

The intermediate portion of the thick portion 356 in the Y direction is a heat generating component facing portion that faces the second heat generating component 12B via a second heat dissipating pedestal and a heat conductive member (not shown). The heat of the second heat generating component 12B is transmitted to the heat generating component facing portion of the thick portion 356 via the second heat radiating pedestal and the heat conductive member. The distance between the thick portions 346 and 356 in the X direction is set to a predetermined distance. Preferably, the predetermined distance is set to 1 mm or more.

FIG. 15 is a temperature distribution diagram of the thermal fluid analysis results when the two thick parts 346A and 356A of the first cover 308A are close to each other by less than 1 mm in the X direction. As shown in FIG. 15, when the distance between the thick portions 346A and 356A in the X direction is less than 1 mm, thermal interference occurs between the two heat generating components 12A and 12B. As a result, the heat dissipation performance of the first cover 308A deteriorates.

The in-vehicle electronic control device 108 according to the eighth embodiment sets the distance between the thick portions 346 and 356 in the X direction to 1 mm or more. This makes it possible to improve heat dissipation performance while avoiding thermal interference between the heat generating components 12A and 12B. Note that three or more thick parts of the heat generating component according to the present invention may be provided. In that case, the distance between each of the plurality of thick parts is set to 1 mm or more.

9. Ninth Embodiment Hereinafter, an on-vehicle electronic control device according to a ninth embodiment of the present invention will be described using FIG. 15.
FIG. 15 is an overall view of the in-vehicle electronic control device according to the ninth embodiment viewed from an oblique direction.

[In-vehicle electronic control unit]
As shown in FIG. 15, a vehicle-mounted electronic control device 109 according to the ninth embodiment has the same configuration as the vehicle-mounted electronic control device 101 according to the first embodiment. The in-vehicle electronic control device 109 includes a circuit board 1 (not shown) and a case 209 that accommodates the circuit board 1.

The case 209 is composed of a first cover 309 and a second cover 4 (not shown) that face each other in the Z direction. The first cover 309 differs from the first cover 3 according to the first embodiment in thick portions 349 and 359. Therefore, here, the thick portions 349 and 359 will be explained, and components common to the first cover 3 will be given the same reference numerals and explanations will be omitted.

The thick portions 349 and 359 are formed into a substantially rectangular shape with short sides substantially parallel to the X direction. That is, the thick portions 349 and 359 extend in the Y direction.

As shown in FIG. 15, the intermediate portion of the thick portion 349 in the Y direction overlaps with the first heat dissipation pedestal (not shown) in the Z direction. Therefore, the intermediate portion of the thick portion 349 in the Y direction is a heat generating component facing portion that faces the first heat generating component 12A via the first heat dissipation pedestal and a heat conductive member (not shown). The heat of the first heat generating component 12A is transmitted to the heat generating component facing portion of the thick portion 349 via the first heat radiating pedestal and the heat conductive member.

One end of the thick portion 349 in the Y direction is located on the side plate 3d, which is the opposite side to the connector opening 3e. The other end of the thick portion 349 in the Y direction is continuous with the opening step portion 33 . Two slits 349a and a slit 349b are formed in the thick portion 349. The two slits 349a extend from one end of the thick portion 349 in the Y direction to the portion facing the heat generating component. The slit 349b extends from the other end of the thick portion 349 in the Y direction to the portion facing the heat generating component.

The intermediate portion of the thick portion 359 in the Y direction overlaps with the second heat dissipation pedestal portion (not shown) in the Z direction. Therefore, the intermediate portion of the thick portion 359 in the Y direction is a heat generating component facing portion that faces the second heat generating component 12B via the second heat dissipating pedestal and a heat conductive member (not shown). The heat of the second heat generating component 12B is transmitted to the heat generating component facing portion of the thick portion 359 via the second heat radiating pedestal and the heat conductive member.

One end of the thick portion 359 in the Y direction is located on the side plate 3d, which is the opposite side to the connector opening 3e. The other end of the thick portion 359 in the Y direction is continuous with the opening step portion 33 . A slit 359a is formed in the thick portion 359. The slit 359a extends from one end of the thick portion 349 in the Y direction to the portion facing the heat generating component.

Slits 349a, 349b, and 359a are provided in the thick parts 349 and 359 of the in-vehicle electronic control device 109 according to the ninth embodiment. Thereby, the cross-sectional area of the portion through which heat is transmitted can be increased, and the heat of the first heat generating component 12A and the second heat generating component 12B can be efficiently radiated. Further, the surface area of the thick portions 349 and 359 can be increased. As a result, when the in-vehicle electronic control device 109 is installed in a place where air convection exists, it is possible to obtain a heat dissipation effect due to air convection. Therefore, heat dissipation performance can be further improved.

10. Summary As described above, the in-vehicle electronic control device 101 includes the circuit board 1 , the case 2 that houses the circuit board 1 , and the heat conductive member 6 . On the circuit board 1, a first heat generating component 12 (electronic component that generates heat) and a connector component 11 (connector) that transmits and receives signals are mounted. The case 2 is formed from a first cover 3 and a second cover 4 arranged on both sides of the circuit board 1 in the thickness direction. The heat conductive member 6 is interposed between the first heat generating component 12 and the first cover 3. The first cover 3 has a thick portion 341 that is thicker than other portions. The thick portion 341 extends in the Y direction (first direction) from the heat generating component facing portion where the heat of the first heat generating component 12 is transmitted via the heat conductive member 6 toward one side of the first cover 3 .
Thereby, the amount of heat conduction can be increased. Then, the heat generated in the first heat generating component 12 and reaching the first cover 3 via the heat conductive member 6 can be conducted in the direction toward one side of the first cover 3. As a result, the heat of the first heat generating component 12 can be efficiently radiated. Therefore, the heat dissipation performance of the first cover 3 (vehicle electronic control device 101) can be improved.

The first cover 3 of the vehicle-mounted electronic control device 101 described above forms a connector opening 3e that exposes the connector component 11. One side of the first cover 3 is a connector opening 3e.
Thereby, the heat reaching the first cover 3 from the first heat generating component 12 can be conducted to the connector opening 3e, which has the lowest temperature among the side parts (edges) of the first cover 3. As a result, the amount of heat conduction of the first cover 3 can be increased.

The first cover 3 of the vehicle-mounted electronic control device 101 described above has an opening step 33 that forms a connector opening 3e. The thick portion 341 is continuous with the opening step portion 33.
Thereby, the heat transmitted through the thick portion 341 can efficiently reach the connector opening 3e. As a result, the heat dissipation performance of the first cover 3 (vehicle electronic control device 101) can be improved.

The first cover 3 of the vehicle-mounted electronic control device 101 described above has an opening step 33 that forms a connector opening 3e. A gap may be formed between the thick portion 341 and the opening step portion 33.
Thereby, the amount of heat conduction of the first cover 3 can be increased, and the weight of the first cover 3 can be reduced.

The first cover 302 of the vehicle-mounted electronic control device 102 described above has a thick portion 342. The cross-sectional area B of the thick portion 342 perpendicular to the Y direction (first direction) on one side of the first cover 302 is less than or equal to the cross-sectional area A of the thick portion 342 facing the heat generating component perpendicular to the Y direction. be.
This makes it possible to both reduce the weight of the first cover 302 and improve heat dissipation performance.

The thick portion 342 of the first cover 302 described above is formed into a substantially rectangular shape extending in the Y direction (first direction) and the X direction (second direction) orthogonal to the Y direction and the height direction. The thick portion 342 has a tapered portion 342a whose length in the X direction becomes shorter toward one side of the first cover 302.
Thereby, the cross-sectional area B can be made smaller than the cross-sectional area A. Further, the cross-sectional area of the thick portion 342 can be gradually reduced in accordance with the amount of heat conduction that decreases as it goes in the Y direction.

The thick portion 342 described above may have a tapered portion whose height decreases toward one side of the first cover 302.
Thereby, the cross-sectional area B can be made smaller than the cross-sectional area A. Further, the cross-sectional area of the thick portion 342 can be gradually reduced in accordance with the amount of heat conduction that decreases as it goes in the Y direction.

The length L1 in the X direction (second direction) of the thick portion 343 of the first cover 303 described above is equal to or greater than the length L2 in the X direction of the heat generating chip 12a, which is the heat generating portion built into the first heat generating component 12. It is.
Thereby, the heat generated by the heat generating chip 12a of the first heat generating component 12 can be efficiently transmitted to the thick portion 343.

The thick portion 344 of the first cover 304 described above extends from the heat generating component facing portion to the side opposite to the connector opening 3e (one side of the first cover 304).
Thereby, heat dissipation performance can be improved.

The first cover 306 described above has a thick portion 346. The end of the thick portion 346 opposite to the connector opening 3e (one side of the first cover 306) is connected to the side of the side plate 3d opposite to the connector opening 3e (the other side). ) located in
Thereby, heat dissipation performance can be improved.

The thick portion of the first cover 307 described above has radiation fins 377 .
Thereby, when installed in a place where there is air convection, it is possible to obtain a heat dissipation effect due to air convection. As a result, the heat dissipation performance of the first cover 307 can be improved.

A first heat generating component 12A and a second heat generating component 12B (a plurality of electronic components) are mounted on the circuit board of the above-mentioned in-vehicle electronic control device 108. The thick portions 346 and 356 of the first cover 308 are provided for the heat generating components 12A and 12B (each electronic component).
Thereby, the amount of heat conduction can be increased according to the number of heat generating components. The heat generated by the heat generating components 12A and 12B and reaching the first cover 308 can be conducted in a direction toward one side of the first cover 308, respectively. As a result, the heat of the heat generating components 12A, 12B can be efficiently radiated. Therefore, the heat dissipation performance of the first cover 308 (vehicle electronic control device 101) can be improved.

A gap of 1 mm or more is formed between the adjacent thick parts 346 and 356 of the first cover 308 described above.
This makes it possible to improve heat dissipation performance while avoiding thermal interference between the heat generating components 12A and 12B.

The thick portion 349 of the first cover 309 described above has slits 349a and 349b extending in the Y direction (first direction).
Thereby, the cross-sectional area of the portion through which heat is transmitted can be increased, and the heat of the first heat generating component 12A can be efficiently radiated. Further, the surface area of the thick portion 349 can be increased, and a heat dissipation effect due to air convection can be obtained.

The embodiments of the in-vehicle electronic control device of the present invention have been described above, including their effects. However, the in-vehicle electronic control device of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention as set forth in the claims.

Furthermore, the embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace some of the configurations of each embodiment with other configurations.

For example, in the first embodiment described above, the heat generated from the first heat generating component 12 is transmitted to the thick portion 341 via the first heat radiating pedestal 32 and the heat conductive member 6. However, the first cover according to the present invention may have a configuration in which the heat dissipation pedestal is not provided. In this case, heat generated from the heat generating component is transmitted to the thick portion via the heat conductive member.

1... Circuit board, 1a, 1b... Mounting surface, 2, 202, 203, 204, 205, 206, 207, 208, 209... Case, 3... First cover, 3a... Top plate, 3b, 3c, 3d... Side Face plate, 3e... Connector opening, 4... Second cover, 6... Heat conductive member, 11... Connector parts, 12, 12A... First heat generating component, 12a... Heat generating chip, 12B... Second heat generating component, 13... Electronic Parts, 31... Partition piece, 32... First heat dissipation pedestal part, 33... Step part for opening, 36... High ceiling part, 41... Cover body, 42... Support piece, 101, 102, 103, 104, 105, 106, 107, 108, 109... Vehicle electronic control device, 302, 303, 304, 305, 306, 307, 308, 308A, 309... First cover, 341, 342, 343, 344, 345, 346, 346A, 349, 351, 352, 353, 354, 355, 356, 359...thick part, 342a, 344a, 344b, 352a, 354a, 354b...tapered part, 345a, 355a...end surface, 349a, 349b, 359a...slit, 366...connection Thick part, 377...radiating fin

Claims (14)

1. A circuit board on which electronic components that generate heat and connector components that transmit and receive signals are mounted;
   a first cover and a second cover that are arranged on both sides of the circuit board in the thickness direction and form a case that accommodates the circuit board;
   a heat conductive member interposed between the electronic component and the first cover;
   The first cover has a thick part that is thicker than other parts,
   The thick portion has a heat generating component facing portion through which heat of the electronic component is transmitted via the heat conductive member, and extends in a first direction from the heat generating component facing portion toward one side of the first cover. In-vehicle electronic control unit.
2. the first cover defines a connector opening that exposes the connector component;
   The vehicle-mounted electronic control device according to claim 1, wherein one side portion of the first cover is the connector opening.
3. The first cover has an opening step that forms the connector opening,
   The vehicle-mounted electronic control device according to claim 2, wherein the thick portion is continuous with the opening step portion.
4. The first cover has an opening step that forms the connector opening,
   The vehicle-mounted electronic control device according to claim 2, wherein a gap is formed between the thick portion and the opening step portion.
5. A cross-sectional area of the thick portion on one side of the first cover perpendicular to the first direction is less than or equal to a cross-sectional area of the thick portion facing the heat generating component perpendicular to the first direction. Item 1. The in-vehicle electronic control device according to item 1.
6. The thick portion is formed in a substantially rectangular shape extending in the first direction and a second direction perpendicular to the first direction and the height direction, and as it goes toward one side of the first cover, the thick portion extends in the second direction. The vehicle-mounted electronic control device according to claim 5, further comprising a tapered portion that shortens the length in the direction.
7. The vehicle-mounted electronic control device according to claim 5, wherein the thick portion has a tapered portion that decreases in height toward one side of the first cover.
8. The length of the thick portion in the first direction and the second direction perpendicular to the thickness direction is greater than or equal to the length in the second direction of a heat generating portion built into the electronic component. in-vehicle electronic control unit.
9. The vehicle-mounted electronic control device according to claim 1, wherein the thick portion extends from the heat generating component facing portion to a side opposite to one side of the first cover.
10. The in-vehicle electronic device according to claim 9, wherein an end of the thick portion opposite to one side of the first cover is located on the other side opposite to the one side of the first cover. Control device.
11. The vehicle-mounted electronic control device according to claim 1, wherein the thick portion has a heat radiation fin.
12. A plurality of the electronic components are mounted on the circuit board,
    The vehicle electronic control device according to claim 1, wherein the thick portion is provided for each electronic component.
13. The vehicle-mounted electronic control device according to claim 12, wherein a gap of 1 mm or more is formed between the adjacent thick parts.
14. The vehicle electronic control device according to claim 1, wherein the thick portion has a slit extending in the first direction.

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