JP2010103372A - Electronic control device - Google Patents

Abstract

In an electronic control device, heat transferred from a heat generating component to a printed circuit board is reduced, and overheating of the printed circuit board is suppressed.
An electronic control device includes a printed circuit board (2) on which a heat generating component (3) is mounted and a casing (4) for housing the printed circuit board (2), and is interposed between the heat generating component (3) and the printed circuit board (2). And a heat conducting component 5 that contacts the housing 4 and transfers heat generated from the heat generating component 3 to the housing 4.
[Selection] Figure 2

Description

  The present invention relates to an electronic control device that includes a printed circuit board on which a heat generating component is mounted and a housing that accommodates the printed circuit board.

For example, a four-wheeled vehicle or a two-wheeled vehicle includes a printed circuit board on which heat-generating components such as a CPU (Central Processing Unit) and a device driver are mounted, and a housing that accommodates the printed circuit board. An electronic control device that performs electronic control of the mounted device is installed.
In such an electronic control device, it is necessary to dissipate heat generated from the heat generating components to the outside in order to obtain a good operating environment of various components including the heat generating components mounted on the printed circuit board.

  For example, in Patent Document 1, a cylindrical protruding portion protruding toward the inside is formed at a part of a housing (shield case), and the protruding portion is brought into contact with a heat generating component on a printed circuit board. A method for releasing heat generated from a heat generating component to a housing is disclosed.

  Patent Document 2 discloses a method of connecting a heat generating component to a housing (cover) through a heat radiating member, and releasing heat generated from the heat generating component to the housing through a heat radiating member fixed to the housing. (For example, refer to FIG. 6 of Patent Document 2).

In Patent Document 3 and Patent Document 4, an opening (through hole) is formed in the area of the printed circuit board on which the heat generating component is mounted, and a protruding portion protruding inward at a part of the housing is directly or A method is disclosed in which heat generated from a heat generating component is released to the housing by connecting to the heat generating component via a heat sink.
JP-A-10-190263 JP 2006-86536 A JP 2003-115681 A JP 2006-294754 A

By the way, even when the above heat dissipation measures are taken, since the heat generating component is directly mounted on the printed circuit board, the heat generated from the heat generating component is transferred to the printed circuit board. For this reason, the printed circuit board is heated by the heat generated from the heat-generating component.
Therefore, when a large number of heat-generating components are mounted on the printed circuit board or when the printed circuit board is thin, the printed circuit board becomes hot, and it is impossible to secure a good operating environment for various components mounted on the printed circuit board. There is a risk that restrictions may be imposed on the number of mounted heat generating components and the thickness of the printed circuit board.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce heat transferred from a heat-generating component to a printed circuit board and suppress overheating of the printed circuit board in an electronic control device.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention is an electronic controller provided with the printed circuit board in which a heat-emitting component is mounted, and the housing | casing which accommodates this printed circuit board, While being interposed between the said heat-generating component and the said printed circuit board, A configuration is adopted in which a thermal conductive component that is in contact with the casing and has a higher thermal conductivity than the printed board is provided.

  According to a second invention, in the first invention, the heat conducting component has a higher thermal conductivity than the printed circuit board.

  According to a third invention, in the first or second invention, a configuration is adopted in which the heat conducting component is in contact with the housing via a flexible heat conducting material.

  According to a fourth invention, in the third invention, the heat conducting component includes a recess for storing the heat conducting material.

  According to a fifth invention, in any one of the first to fourth inventions, the heat conducting component is interposed between the heat generating component and the printed circuit board at an interposed portion and the housing. The structure which has a contact part which is a site | part which contacts, and is equipped with an elastic body between the said interposed part and the said contact part is employ | adopted.

  According to a sixth aspect of the present invention, in the fifth aspect, the elastic body biases the contact portion toward the casing.

  In the present invention, “contact” does not mean only a state in which an object is connected by direct contact with the object, but includes a state in which the object and the object are connected via another object. Shall be.

According to the present invention, the heat conducting component that comes into contact with the housing is interposed between the heat generating component and the printed board. For this reason, conventionally, at least a part of the heat transferred from the heat generating component to the printed circuit board is transferred to the housing via the heat conductive component and radiated. Therefore, the heat transferred from the heat generating component to the printed circuit board can be reduced.
Therefore, according to the present invention, in the electronic control device, it is possible to reduce the heat transferred from the heat-generating component to the printed circuit board and suppress overheating of the printed circuit board.

  Hereinafter, an embodiment of an electronic control device according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

(First embodiment)
FIG. 1 is a cross-sectional view schematically showing a part of the electronic control device 1 of the present embodiment. FIG. 2 is a cross-sectional view of the electronic control device 1 of FIG. 1 as viewed from the side. As shown in these drawings, the electronic control device 1 includes a printed circuit board 2, a heat generating component 3, a housing 4, and a heat conductive bus bar 5 (heat conductive component).

  The printed board 2 is a multilayer wiring board on which a wiring pattern is formed, and a plurality of electronic components including a heat generating component 3 such as a CPU (Central Processing Unit) and a device driver are mounted thereon.

  The heat generating component 3 is a component that generates heat when energized, such as a CPU (Central Processing Unit) or a device driver, as described above, and is electrically and physically connected to the printed circuit board 2 by a plurality of leads 3a.

The housing 4 accommodates the printed circuit board 2 therein, and has a support mechanism (not shown) that fixes the positional relationship between the housing 4 and the printed circuit board 2.
The printed circuit board 2 is supported by such a support mechanism, whereby the component mounting surface (front and back surfaces) of the printed circuit board 2 and the housing 4 are separated from each other by a certain distance.
The housing 4 is formed by pressing, cutting, or die casting a metal material such as zinc, aluminum, or copper.

The electronic control device 1 according to the present embodiment is interposed between the heat generating component 3 and the printed circuit board 2 and contacts the housing 4, thereby transferring heat generated from the heat generating component 3 to the housing 4. It has a heat conducting bus bar 5 that heats.
More specifically, the heat conduction bus bar 5 is a crank-shaped plate member including an interposition part 5a, a contact part 5b, and a connection part 5c, and the interposition part 5a is interposed between the heat generating component 3 and the printed board 2. The contact portion 5b is in contact with the housing 4 and the connecting portion 5c connects the interposed portion 5a and the contact portion 5b. The heat conduction bus bar 5 is made of a metal material such as copper or stainless steel, and has a heat conductivity higher than that of the printed circuit board 2.

When assembling the electronic control unit 1, the heat conduction bus bar 5 is fixed to the printed circuit board 2 via an adhesive or the like, and the heat generating component 3 is disposed on the interposition part 5 a of the heat conduction bus bar 5. For this reason, in order to make arrangement | positioning of the heat-emitting component 3 easy, as shown in FIG. 2, it is preferable that the connection direction of the interposition part 5a with respect to the connection part 5c differs from the connection direction of the contact part 5b.
Accordingly, when the heat generating component 3 is disposed on the interposition part 5a, the contact part 5b can be prevented from interfering with work.

  In the electronic control device 1 having such a configuration, at least a part of the heat generated from the heat generating component 3 that is transmitted in the direction of the printed circuit board 2 is transmitted to the housing 4 via the heat conduction bus bar 5. Heated and dissipated.

According to the electronic control device 1 of the present embodiment as described above, the heat conduction bus bar 5 that is in contact with the housing 4 is interposed between the heat generating component 3 and the printed board 2. Therefore, conventionally, at least a part of the heat transferred from the heat generating component 3 to the printed circuit board 2 is transferred to the housing 4 through the heat conduction bus bar 5 and radiated. Therefore, the heat transferred from the heat generating component 3 to the printed circuit board 2 can be reduced.
Therefore, according to the electronic control device 1 of the present embodiment, the heat transferred from the heat generating component 3 to the printed circuit board 2 can be reduced, and overheating of the printed circuit board 2 can be suppressed.

Further, according to the electronic control device 1 of the present embodiment, the heat conduction bus bar 5 has a higher heat conductivity than the printed circuit board 2.
For this reason, of the heat generated from the heat generating component 3, most of the heat transferred in the direction of the printed circuit board 2 is transferred to the housing via the heat conduction bus bar 5 and is radiated. Therefore, the heat transferred from the heat generating component 3 to the printed circuit board 2 can be further reduced, and overheating of the printed circuit board 2 can be further suppressed.

Further, in the heat conduction bus bar 5 provided in the electronic control device 1 of the present embodiment, the interposition part 5a is disposed between the heat generating component 3 and the printed board 2, the contact part 5b is in contact with the housing 4, and the connecting part 5c has the shape which connects the interposition part 5a and the contact part 5b.
For this reason, the space for installing the interposition part 5a on the printed circuit board 2 is not required separately, and the space for installing the heat conduction bus bar 5 is hardly required.
Therefore, the heat conduction bus bar 5 can be installed without affecting the layout of the electronic components on the printed circuit board 2.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the description of the second embodiment, the description of the same parts as in the first embodiment will be omitted or simplified.

FIG. 3 is a cross-sectional view of the electronic control device 1A according to the present embodiment as viewed from the same side as in FIG. As shown in this figure, in the electronic control unit 1A of the present embodiment, the heat conduction bus bar 5 is in contact with the housing 4 via the grease 6 (a flexible heat conduction material).
The heat conduction bus bar 5 includes a recess 5d in the contact portion 5b. The grease 6 is stored in the recess 5 d of the heat conduction bus bar 5.

  According to the electronic control apparatus 1A of the present embodiment having such a configuration, since the heat conduction bus bar 5 is in contact with the housing 4 via the grease 6, for example, the dimensional accuracy of the housing 4 and the heat conduction bus bar 5 is achieved. Even if it is not high, the heat conduction bus bar 5 and the housing 4 can be brought into contact with each other.

  Further, according to the electronic control unit 1A of the present embodiment, since the heat conduction bus bar 5 includes the recess 5d for storing the grease 6, the grease is provided between the contact portion 5b of the heat conduction bus bar 5 and the housing 4. 6 can be securely clamped and the heat conducting bus bar 5 and the housing 4 can be reliably brought into contact with each other.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the description of the third embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

FIG. 4 is a cross-sectional view of the electronic control device 1B of the present embodiment as viewed from the same side as in FIG. As shown in this figure, in the electronic control device 1B of the present embodiment, the contact portion 5b of the heat conduction bus bar 5 and the connecting portion 5c are in contact via a leaf spring 5e (elastic body). That is, the electronic control device 1B of the present embodiment includes the leaf spring 5e between the interposition part 5a and the contact part 5b.
The leaf spring 5e is in contact with the contact portion 5b and the connecting portion 5c so as to urge the contact portion 5b toward the housing 4.

According to the electronic control device 1B of this embodiment having such a configuration, for example, when the electronic control device 1B is assembled, the leaf spring 5e contracts even when the housing 4 presses the heat conduction bus bar 5. Thus, it is possible to suppress the stress from acting on the printed circuit board 2.
Further, after assembly of the electronic control unit 1B, the contact portion 5b of the heat conduction bus bar 5 is urged toward the housing 4 by the leaf spring 5e, so that the heat conduction bus bar 5 is securely attached to the housing 4. It becomes possible to make it contact.

  The preferred embodiment of the electronic control device according to the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the said embodiment, the structure which uses the heat conductive bus bar 5 as a heat conductive component of this invention was demonstrated.
However, the present invention is not limited to this, and is interposed between the heat generating component 3 and the printed circuit board 2 and is in contact with the housing 4 to transmit heat generated from the heat generating component 3 to the housing 4. Any component that can be heated can be used as a heat conductive component.

Moreover, in the said 2nd Embodiment, the structure which uses the grease 6 as a soft heat conductive material of this invention was demonstrated.
However, the present invention is not limited to this, and it is also possible to use silicon gel or a heat transfer sheet as a soft heat conductive material.

Moreover, in the said 3rd Embodiment, the structure which uses the leaf | plate spring 5e as an elastic body of this invention was demonstrated.
However, the present invention is not limited to this, and a coil spring or rubber can be used as the elastic body.
In addition, when using rubber | gum as an elastic body, it is preferable to select a thing with the high heat conductivity as much as possible so that the heat transfer of the heat conduction bus bar 5 may not be prevented.

Further, for example, the surface of the heat conduction bus bar 5 may be covered with an insulating material while avoiding the region in contact with the heat generating component 3 and the region in contact with the housing 4 or the grease 6.
Accordingly, even if the lead 3a of the heat generating component 3 is in contact with the heat conduction bus bar 5, it is possible to prevent the lead 3a and the heat conduction bus bar 5 from being short-circuited.

It is sectional drawing which showed typically a part of electronic control apparatus in 1st Embodiment of this invention. It is sectional drawing which looked at the electronic controller in 1st Embodiment of this invention from the side of FIG. It is sectional drawing which looked at the electronic control apparatus in 2nd Embodiment of this invention from the side of FIG. It is sectional drawing which looked at the electronic control apparatus in 3rd Embodiment of this invention from the side of FIG.

Explanation of symbols

  1, 1A, 1B ... Electronic control device, 2 ... Printed circuit board, 3 ... Heat generating component, 4 ... Case, 5 ... Heat conduction bus bar (heat conduction component), 5a ... Interposition part, 5b ... ... contact part, 5c ... connecting part, 5d ... concave part, 5e ... leaf spring (elastic body), 6 ... grease (heat conduction material)

Claims (6)

An electronic control device comprising a printed circuit board on which a heat generating component is mounted, and a housing for housing the printed circuit board,
An electronic control comprising: a heat conduction component that is interposed between the heat generating component and the printed circuit board, contacts the housing, and transfers heat generated from the heat generating component to the housing. apparatus.   The electronic control device according to claim 1, wherein the heat conducting component has a higher thermal conductivity than the printed circuit board.   The electronic control device according to claim 1, wherein the heat conducting component is in contact with the housing via a flexible heat conducting material.   The electronic control device according to claim 3, wherein the heat conducting component includes a recess for storing the heat conducting material.   The heat conducting component has an interposition portion that is a portion interposed between the heat generating component and the printed board, and a contact portion that is a portion that contacts the housing, and the interposition portion, The electronic control device according to claim 1, further comprising an elastic body between the contact portion. The electronic control device according to claim 5, wherein the elastic body biases the contact portion toward the housing.

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