JP2013254925A - Electronic circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit device capable of efficiently radiating heat generated by an electronic component involving heat generation to the exterior of the device.SOLUTION: An electronic circuit device includes: a multilayer circuit board 10 where a predetermined wiring pattern 11a is formed on a surface layer 11; an electronic component 11b mounted on the wiring pattern 11a and involving heat generation; and a housing 20 housing the multilayer circuit board 10. The multilayer circuit board 10 has a ground pattern 13b provided in an inner layer 13, and the ground pattern 13b is conductively connected with the wiring pattern 11a through a through hole (a connection part) 14 and is formed extending to the exterior of the surface layer 11 so that a necessary part X contacts with a side wall part 23 (the housing 20). The side wall part 23 (the housing 20) has a function that radiates heat transmitted from the electronic component 11b to the side wall part 23 (the housing 20) through the wiring pattern 11a, the through hole 14, and the ground pattern 13b.

Description

  The present invention relates to an electronic circuit device having a multilayer circuit board on which a wiring pattern capable of mounting an electronic component that generates heat is formed.

  Conventionally, as this type of electronic circuit device, for example, one described in Patent Document 1 below is known. The electronic circuit device described in Patent Document 1 includes a multilayer circuit board on which a connector and electronic components are mounted on a wiring pattern, and a notch formed so as to expose a part of the connector to the outside. And a metal casing mounted on the multilayer circuit board so as to accommodate other parts of the connector excluding a part of the connector and the electronic parts. In this case, the electronic parts are separated from the metal casing. Is mounted on a multilayer circuit board.

JP 2009-205944 A

By the way, when the electronic component provided in the electronic circuit device described in Patent Document 1 is an electronic component that generates heat, the electronic component that generates heat is disposed so as to be separated from the casing. Because the heat generated from the electronic components is simply transferred to the wiring pattern, the heat generated from the electronic components that generate heat cannot be efficiently radiated to the outside of the device (outside the housing). There was a problem, and there was room for further improvement in this respect.
Accordingly, an object of the present invention is to provide an electronic circuit device that can efficiently dissipate heat generated from an electronic component that generates heat to the outside of the device in order to cope with the above-described problems.

  The present invention includes a multilayer circuit board having a predetermined wiring pattern formed on a surface layer, an electronic component with heat generation mounted on the wiring pattern, and a housing for housing the multilayer circuit board. Has a grounding pattern provided in its inner layer, and the grounding pattern is electrically connected to the wiring pattern through a connecting portion, and extends to the outside of the surface layer so that the required portion abuts the housing. The housing has a function of dissipating heat from the electronic component to the housing through the wiring pattern, the connection portion, and the ground pattern. .

  Further, according to the present invention, the casing and the ground pattern are formed of different metal materials, and the ground pattern or the ground pattern by contact of different metals between the required portion of the ground pattern and the casing. Corrosion prevention means for preventing corrosion of the casing is provided.

  Further, the present invention is characterized in that the required part has a tongue-like shape, and the required part and the casing are in surface contact.

  In the invention, it is preferable that the housing is provided with a recessed portion that comes into contact with the electronic component.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic circuit apparatus which can achieve an initial objective and can efficiently radiate the heat | fever emitted from the electronic component with a heat_generation | fever to the exterior of an apparatus can be provided.

1 is a cross-sectional view of an electronic circuit device according to an embodiment of the present invention. The figure which shows the side wall part of a housing | casing when it sees from the arrow A direction by the embodiment. Sectional drawing of the electronic circuit apparatus by the modification of the embodiment. Sectional drawing of the electronic circuit apparatus by the other modification of the embodiment. Sectional drawing of the electronic circuit apparatus by the other modification of the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. In FIG. 1, the electronic circuit device according to the present embodiment is mainly composed of a multilayer circuit board 10 and a housing 20.

  The multilayer circuit board 10 includes a hard surface layer 11 located on the front surface side in FIG. 1, a hard back layer 12 located on the back surface side in FIG. 1, and a soft material located between the surface layer 11 and the back layer 12. The inner layer 13 is fixed to the housing 20 using an appropriate fixing means.

  A predetermined wiring pattern 11a is formed on the surface of the surface layer 11, and an electronic component 11b that generates heat is mounted on the wiring pattern 11a. As the shape of the electronic component 11b, a shape such as a four-way lead flat package (QFP) or a ball grid array (BGA) can be applied.

  The inner layer 13 located in the intermediate portion of the multilayer circuit board 10 includes a soft insulating substrate 13a and a ground pattern 13b made of a copper foil pattern provided on the entire back surface of the insulating substrate 13a. Thus, in this example, the multilayer circuit board 10 is configured to have the ground pattern 13b provided on the inner layer 13 thereof.

  In FIG. 1, reference numeral 14 denotes a conductive through hole provided so as to penetrate all of the surface layer 11, the inner layer 13 and the back layer 12. The through hole 14 includes a ground pattern 13b, a wiring pattern 11a, and the like. Are provided so as to be conductively connected.

  That is, this means that the ground pattern 13 b is conductively connected to the wiring pattern 11 a through the through hole 14. The through hole 14 corresponds to the connecting portion in claim 1 of the claims.

  On the other hand, in FIG. 1, the inner layer 13 portion extending toward the side wall portion described later of the housing 20 is provided so as to protrude outside the surface layer 11 and the back layer 12 so as to form a substantially tongue shape. Yes. Then, 13 ground pattern portions extending toward the side wall portion (hereinafter, the 13 ground pattern locations are defined as required portions X of the ground pattern 13) abut (contact) the housing 20 (the side wall portion). In this way, it is extended to the outside of the surface layer 11 and the back layer 12.

  Specifically, the required portion X of the ground pattern 13b is exposed to the outside of the surface layer 11 and the back layer 12, and the required portion X of the ground pattern 13b serving as the exposed portion has a substantially tongue-like shape. And is in contact with the side wall portion of the housing 20 in a state of being bent at a substantially right angle along the thickness direction of the multilayer circuit board 10.

  The casing 20 is made of a metal material such as aluminum, is formed in a substantially box shape that accommodates the multilayer circuit board 10, and has a front wall portion 21 and a bottom wall portion 22 that are substantially parallel to the multilayer circuit board 10. And a side wall portion 23 having a standing wall shape connecting the front wall portion 21 and the bottom wall portion 22, and the side wall portion 23 is bent so as to be substantially parallel to the side wall portion 23 as shown in FIG. It is configured to abut (surface contact) with the required portion X of the ground pattern 13b.

  Further, in this case, the housing 20 has a function of radiating heat from the electronic component 11b that generates heat to the side wall portion 23 (housing 20) through the wiring pattern 11a, the through hole 14, and the ground pattern 13b. doing. That is, during the operation of the electronic component 11b, heat generated from the electronic component 11b is sequentially transmitted from the wiring pattern 11a → the through hole 14 → the ground pattern 13b → the side wall portion 23 (housing 20) to the outside of the device (housing) 20).

  As described above, in the present embodiment, the multilayer circuit board 10 in which the predetermined wiring pattern 11a is formed on the surface layer 11, the electronic component 11b with heat generation mounted on the wiring pattern 11a, and the housing for housing the multilayer circuit board 10. The multilayer circuit board 10 has a ground pattern 13b provided on the inner layer 13, and the ground pattern 13b is electrically connected to the wiring pattern 11a through a through hole (connecting portion) 14 and the required The portion X is extended to the outside of the surface layer 11 so as to contact the side wall portion 23 (housing 20). The side wall portion 23 (housing 20) includes the wiring pattern 11a, the through hole 14 and the ground pattern 13b. Therefore, it has a function of radiating heat from the electronic component 11b to the side wall portion 23 (housing 20).

  Therefore, during operation of the electronic component 11b, heat generated from the electronic component 11b is sequentially transmitted from the wiring pattern 11a → the through hole 14 → the ground pattern 13b → the side wall portion 23 (housing 20) to the outside of the apparatus (housing). Since the heat emitted from the electronic component 11b that generates heat can be efficiently radiated (dissipated) to the outside of the device (outside the housing 20), the electronic component 11b It is possible to provide an electronic circuit device that does not cause a rise in temperature.

  In the present embodiment, the required portion X of the ground pattern 13b has a tongue-like shape, and the required portion X and the side wall portion 23 (housing 20) are in surface contact, so that the ground pattern 13b and the housing 20 are in contact with each other. Therefore, the heat generated from the electronic component 11b that generates heat can be dissipated more efficiently to the outside of the apparatus (outside the housing 20).

  Further, when the ground pattern 13b (required portion X) is in surface contact with the housing 20 (side wall portion 23), the housing 20 is grant-connected in a state having the grounding area. In addition, since a ground having a relatively large area can be said to be a stable ground, there is an advantage that generation of radiation noise (electromagnetic waves) to the outside of the housing 20 can be suppressed as much as possible.

  In the present embodiment, the ground pattern 13b and one side wall portion 23 are in surface contact, but the ground pattern 13b (required portion X) is, for example, in four directions (upper, lower, left, and right) of the multilayer circuit board 10. When the multilayer circuit board 10 is provided so as to protrude from the periphery, two or more of the four required portions X and the four side wall portions 23 provided in the housing 20 are brought into surface contact with each other. Also good.

  Moreover, although this embodiment demonstrated the example which the required part X of the ground pattern 13b formed with the copper foil pattern contact | abuts directly to the side wall part 23 (casing 20) formed with aluminum, Thus, in the case where the housing 20 and the ground pattern 13b are formed of different metal materials, as shown in FIG. 3 as a modified example of the present embodiment, the required portion X of the ground pattern 13b. A thin plate-like metal plate 30 formed by tin plating, nickel plating, or the like may be interposed between the side wall portion 23 and the side wall portion 23 (housing 20).

  The thin metal plate 30 is sandwiched (provided) between the required portion X of the ground pattern 13b and the side wall portion 23 (housing 20), and the ground pattern 13b or the housing by contact (contact) of different metals. It has a function to prevent corrosion of the body 20. The metal plate 30 corresponds to the corrosion preventing means in claim 2 of the claims.

  Further, in the present embodiment, an example in which the front wall portion 21 provided in the housing 20 has a flat shape has been described. However, as another modified example of the present embodiment, for example, as illustrated in FIG. You may provide the 1st hollow part 41 which consists of a substantially recessed shape which contact | abuts the electronic component 11b in the (housing | casing 20). At this time, the bottom wall portion 41a located at the bottom of the first recess 41 is configured to contact the electronic component 11b. In addition, the 1st hollow part 41 is corresponded to the hollow part in Claim 4 of a claim.

  In this case, during operation of the electronic component 11b, heat generated from the electronic component 11b is transferred from the wiring pattern 11a → the through hole 14 → the ground pattern 13b → the side wall 23 (housing 20), and the electronic component 11b. Because heat is radiated to the outside of the apparatus (outside of the casing 20) using another heat dissipation path that is transmitted from the (package of the electronic component 11b) to the first recess 41 provided in the casing 20. Thus, more effective heat dissipation is possible (heat dissipation is possible at a position relatively close to the electronic component 11b which is a heat source). In addition, you may interpose heat conductive members (not shown), such as a heat conductive sheet, between the electronic component 11b and the 1st hollow part 41 as needed.

  In addition, as shown in FIG. 5, when the through hole 14 is electrically connected to the wiring pattern 11a provided in the surface layer 11 and the other wiring pattern 12a provided in the back layer 12. In addition, the bottom wall portion 22 provided in the housing 20 may be provided with a second recess portion 42 having a substantially inverted concave shape that comes into contact with the other wiring pattern 12a. In this case, the upper wall portion 42a located on the upper side of the second depression 42 is configured to abut against the other wiring pattern 12a (back layer 12).

  In this case, during operation of the electronic component 11b, the heat generated from the electronic component 11b is not only the heat dissipation path and the other heat dissipation path, but also the wiring pattern 11a → through hole 14 → other wiring pattern 12a → second. Since heat is also radiated to the outside of the apparatus (outside of the housing 20) using the path of the recess 42 (housing 20), more effective heat radiation is possible (from the electronic component 11b as a heat source). Heat dissipation is possible at a relatively close position). In addition, you may interpose a heat conductive member (not shown), such as a heat conductive sheet, between the wiring pattern 12a (back layer 12) and the 2nd hollow part 42 as needed.

  In the case of the configuration shown in FIG. 5, the multilayer circuit board 10 on which the electronic component 11 is mounted is sandwiched between the first depression 41 and the second depression 42, and thus the multilayer circuit board 10. Can be stably held inside the housing 20.

  In the present embodiment, an example in which the casing 20 is formed of a metal material such as aluminum has been described. However, the casing 20 generates heat through the wiring pattern 11a, the through hole 14, and the ground pattern 13b. Any material that can dissipate heat from the electronic component 11b to the housing 20 to the outside of the device (outside of the housing 20) can be adopted. For example, the housing 20 is made of a ceramic material, a resin material, You may form with glass fiber.

DESCRIPTION OF SYMBOLS 10 Multilayer circuit board 11 Surface layer 11a Wiring pattern 11b Electronic component 12 Back layer 13 Inner layer 13a Insulating substrate 13b Grounding pattern 14 Through hole (connection part)
20 Housing 21 Front wall 22 Bottom wall 23 Side wall 30 Metal plate (corrosion prevention means)
41 1st hollow part (hollow part)
41a Bottom wall portion 42 Second depression 42a Upper wall portion X Required portion

Claims (4)

A multilayer circuit board having a predetermined wiring pattern formed on the surface layer;
An electronic component with heat generation mounted on the wiring pattern;
A housing for housing the multilayer circuit board,
The multilayer circuit board has a ground pattern provided in an inner layer thereof,
The ground pattern is conductively connected to the wiring pattern through a connection portion, and is extended to the outside of the surface layer so that a required portion is in contact with the housing.
The electronic circuit device, wherein the casing has a function of radiating heat from the electronic component to the casing through the wiring pattern, the connection portion, and the ground pattern. The housing and the ground pattern are formed of different metal materials,
Corrosion prevention means for preventing corrosion of the ground pattern and the housing due to contact of different metals is provided between the required portion of the ground pattern and the housing. Item 2. An electronic circuit device according to Item 1. 3. The electronic circuit device according to claim 1, wherein the required portion has a tongue-like shape, and the required portion and the housing are in surface contact. The electronic circuit device according to any one of claims 1 to 3, wherein the housing is provided with a recessed portion that comes into contact with the electronic component.

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