JP3748733B2 - Heat dissipation device for electronic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to various electronic devices such as in-vehicle audio devices, and more particularly to a heat dissipation device for electronic devices for releasing heat generated by electronic components such as power transistors.
[0002]
[Prior art]
In an electronic device using an electronic component that generates a large amount of heat, a heat dissipation device is used to release heat from the electronic component. FIG. 3 is a perspective view showing a conventional example of a heat radiating device for releasing heat generated from an electronic component in an in-vehicle acoustic device.
[0003]
A heat radiating member 2 is provided on one side surface of the housing 1. The heat dissipating member 2 is called a heat sink and is made of a metal material having a high thermal conductivity such as an aluminum alloy. On the outer surface of the heat radiating member 2, a plurality of heat radiating fins (heat radiating ribs) 2a projecting to the outside of the device are formed. Two electronic components 3 having a large amount of heat generation are mounted on a circuit board 4 installed in the housing 1. The electronic component 3 is a power IC constituting an audio amplifier, and one electronic component constitutes a two-channel audio amplifier. The electronic component 3 is installed on the inner surface 2 b of the heat dissipation member 2 in a state of being mounted on the circuit board 4. A pair of holders 5 formed of metal plates are installed so as to hold the electronic component 3, and fixing portions 5 a and 5 a at both ends of the holder 5 are fixed to the heat radiating member 2 by screws 6. .
[0004]
The electronic component 3 is installed in close contact with the inner surface 2b of the heat radiating member 2, or silicon oil having a high thermal conductivity is applied between the electronic component 3 and the inner surface 2b, and the heat from the electronic component 3 is radiated from the heat radiating member 2. The heat is transmitted to the outside of the device mainly from the outer surface having the radiation fins 2a.
[0005]
[Problems to be solved by the invention]
However, since the above-described conventional heat radiating device is configured to hold the electronic component 3 by screwing both end portions of the holder 5 to the heat radiating member 2, there are the following problems.
[0006]
First, since it is necessary to screw the holder 5 for each electronic component 3, the number of screws 6 (fixing members) increases in proportion to the number of electronic components 3, and the assembly work becomes complicated. .
[0007]
Secondly, in the above-described conventional configuration, the holder 5 has the fixing portion 5a extending in the width direction, so that a mounting area for one electronic component 3 is required to be wide in the left-right direction. Therefore, it is difficult to arrange a plurality of electronic components 3 adjacent to each other.
[0008]
Third, the adhesion between the electronic component 3 and the heat dissipation member 2 differs depending on the tightening torque of the screws 6 and 6. For example, if the tightening torque is small, the adhesion between the electronic component and the heat radiating member 2 becomes too weak, and if the tightening torque is too large, the electronic component 3 may be excessively stressed and the electronic component may be damaged.
[0009]
The present invention is for solving the above-described conventional problems, and can dissipate an electronic component on a heat radiating member without performing a screw tightening operation, and can stabilize the adhering force. The purpose is to provide.
Another object of the present invention is to provide a heat dissipation device for an electronic component in which a large number of electronic components can be arranged adjacent to each other.
[0010]
[Means for Solving the Problems]
In the present invention, a heat generating electronic component, a heat radiating member having an installation plane to which a heat radiating surface of the electronic component is applied, and a holder for supporting a back surface opposite to the heat radiating surface of the electronic component are provided in the apparatus body. In the heat dissipation device for electronic equipment
The holder is integrally formed with a metal plate with a support surface facing the heat radiating member with a space therebetween, and an elastically deformable extension provided at the tip of the support surface. Supported by a substrate on which electronic components are mounted,
The heat radiating member is provided with a pressing portion that extends to a position spaced apart from the installation plane by a predetermined distance, and the extension portion of the holder is pressed toward the installation plane by the pressing portion, whereby the electronic component is The heat radiation surface of the electronic component is brought into close contact with the installation plane by being pressed by a support surface .
[0011]
In this invention, when the pressing part provided in the heat radiating member presses the holder, the heat radiating surface of the electronic component is brought into close contact with the installation plane of the heat radiating member. Therefore, the electronic component can be brought into close contact with the heat radiating member without screwing the heat radiating member and the holder. In addition, since the adhesion force between the electronic component and the heat dissipation member is determined by the dimensional accuracy of the space between the installation surface of the heat dissipation member and the pressing portion, the adhesion force between the electronic component and the heat dissipation member is stabilized and excessive stress is applied to the electronic component. There is nothing.
[0012]
Further, the holder, the is provided with a pair of side plates bent toward the heat radiating member from both sides of the bearing surfaces, the electronic component from the three directions by the bearing surface and the side plate of the holder It is preferable that it is enclosed .
[0013]
In the present invention, since the electronic component can be brought into close contact with the heat radiating member by elastic force, the adhesion between the electronic component and the heat radiating member is stabilized.
[0014]
In addition, a support portion that is opposed to the base end portion on the mounting side of the electronic component with a gap is provided, and the heat dissipation member is inserted and mounted between the electronic component and the support portion. In this case, the holder can be inserted into a position where the holder is pressed by the pressing portion.
[0015]
If comprised in this way, attachment of a heat radiating member can be completed by inserting a heat radiating member from the upper direction of an electronic device, and an electronic component can be stuck to a heat radiating member.
[0016]
The device main body is provided with a plurality of electronic components and holders that support the respective electronic components arranged side by side, and the pressing portion of the electronic component is configured to be able to press each of the plurality of holders. It is preferable that they are provided along the alignment direction.
[0017]
When the structure to be closer contact several electronic components to the heat radiating member thus the pressing unit, a number can be arranged close to the electronic component to each other, requires only a smaller space required for the arrangement.
[0018]
If the lead portion extending from the electronic component is soldered to the circuit board, the electronic component is pressed against the heat radiating member by the pressing portion even when the mounting positions of the plurality of electronic components vary slightly. Sometimes, the variation in the position can be absorbed by the deformation of the lead portion.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings.
FIG. 1 is a partial perspective view showing an in-vehicle electronic device as an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the electronic device when FIG. 1 is viewed from the + Y direction.
[0020]
FIG. 1 shows a side portion of an in-vehicle electronic device 10, and a left side plate 11 </ b> A of a housing 11 appears. Although not shown in FIG. 1, a nose portion is attached to the front (+ Y direction) of the housing 11A, and various operation buttons, a display device, and the like are provided on the nose portion. The housing 11 houses a tape drive unit in which a tape cassette is loaded, a disk drive unit in which an optical disk is loaded, and the like. Furthermore, the housing 11 is provided with various electronic circuits such as a tuner and a TV receiver. The in-vehicle electronic device 10 is an audio amplifier built-in type, and electronic components constituting an audio circuit, a power supply circuit, and the like are mounted on a circuit board 13 installed in the housing 11.
[0021]
On the left end (−X side) of the circuit board 13, exothermic electronic components 14, 15 and 16 are mounted. For example, the electronic component 15 is a power transistor constituting a 4-channel audio amplifier, and the electronic components 14 and 16 are power FETs constituting a power circuit.
[0022]
A single electronic component 15 constituting a four-channel audio amplifier generates more heat than other electronic components. Since the electronic device 10 with built-in audio amplifier is a multi-function type having various devices such as a tape drive unit, a disk drive unit, a tuner, and a TV receiver as described above, the power consumption is large. Therefore, the amount of heat generated by the electronic components 14 and 16 such as power FETs constituting a power supply circuit for supplying power to these various devices also increases.
[0023]
Lead terminals 14a, 15a and 16a extend at the base ends of the electronic components 14, 15 and 16, respectively. Each lead terminal 14a, 15a, 16a is inserted into a plurality of through holes 13a formed in the circuit board 13, and soldered to a conductive pattern formed on the back side of the circuit board 13. These electronic components 14, 15 and 16 are mounted on the circuit board 13 in a line in the Y direction shown in the figure.
[0024]
As shown in FIGS. 1 and 2, the electronic components 14, 15 and 16 are supported from the back side by holders 21, 22 and 23. Each holder 21, 22, and 23 is formed by punching and pressing a thin metal plate. Although the holders 21, 22, and 23 have different sizes in the width direction, the configuration is the same. Therefore, the holder 21 that is mounted on the electronic component 14 will be mainly described below.
[0025]
The back surface (surface on the + X side) facing the inside of the housing of the electronic component 14 is supported by the support surface 21 a of the holder 21. Side plates 21b and 21b are bent on both sides of the support surface 21a. Also, holding pieces 21c and 21c for holding the heat radiation surface (the surface on the -X side) of the electronic component 14 are formed at the front edge portions of the side plates 21b and 21b by bending. In the holder 21, a bifurcated extension 21d is provided at the upper end (+ Z side) of the support surface 21a, and the extension 21d can be elastically deformed. The extension 21 d protrudes above the electronic component 14 when mounted on the substrate 13. Further, a pressurizing portion 21e protruding in the back surface direction (the X direction in the figure) of the electronic component 14 is formed on the support surface 21a as a bulge (embossed).
[0026]
At the lower end of the holder 21, leg portions 21f, 21f extending downward from the side plates 21b, 21b are integrally formed, and a part thereof is support pieces 21g, 21g extending further downward. The support pieces 21g and 21g are formed with convex portions 21h and 21h that are bent outwardly in a U-shape. The support pieces 21g and 21g are respectively inserted into holding holes 13b and 13b drilled in the circuit board 13 to the side of the through hole 13a. When the support pieces 21g and 21g are inserted into the holding holes 13b and 13b from above, the convex portions 21h and 21h forcibly pass through the holding holes 13b and 13b. The holder 21 is attached so as not to be easily detached from the substrate 13 by being hooked on the lower surface of the substrate.
[0027]
As shown in FIG. 1, a cutout portion 11B is formed in the left side plate 11A of the housing 11, and a heat dissipation member 30 is attached to the cutout portion 11B. The heat radiating member 30 is made of a metal material having a high thermal conductivity such as an aluminum alloy.
[0028]
The heat radiating member 30 shown in FIG. 1 has an L-shaped cross section, and a plurality of rib-shaped heat radiating fins are formed on the outer and upper surfaces thereof. Further, a pressing portion 31 extending inward of the apparatus main body is integrally formed on the surface facing the electronic components 14, 15 and 16. On the inner surface of the heat dissipating member 30, an installation plane 32 is formed below the pressing portion 31 so that the heat dissipating surfaces of the electronic components 14, 15 and 16 are in close contact with each other. The said pressing portion 31 is provided by opening the installation plane 32 and spacing, insertion groove 31a is formed between the inner surface and the pressing portion 31 of the heat dissipating member 30. As shown in FIG. 1, the pressing portion 31 can hold the extension parts 21 d, 22 d, 23 d of all the holders 21, 22, 23 and the electronic components 14, 15, 16 and the holders 21, 22, 23. It is formed so as to extend long along the alignment direction (Y direction).
[0029]
As shown in FIG. 1, the installation plane 32 is provided with a plurality of insertion holes 32a, 32b, 32c,... That secure air in and out between the inside and the outside of the electronic device 10. It is possible to increase the heat dissipation effect by allowing air to flow inside and outside 30.
[0030]
As shown in FIG. 2, a locking portion 33 that protrudes forward (−X direction) is formed at the lower end portion of the heat dissipation member 30. As shown in FIG. 1, U-shaped attachment grooves 34 and 34 are formed at both ends of the heat dissipation member 30.
[0031]
As shown in FIG. 1, the both sides of the cut portion 11B of the left side plate 11A of the housing 11, a portion of the bent mounting piece 11C of the left side plate 11A, 11C and 11C ', 11C' are formed, respectively Has been. Female threaded holes 11a, 11a corresponding to U-shaped mounting grooves 34, 34 formed at both ends of the heat radiating member 30 are formed in the mounting pieces 11C, 11C. A plurality of pedestal portions 11E are formed on the lower edge portion of the cutout portion 11B by bending a part of the left side plate 11A to the inside of the housing 11. The substrate 13 is mounted in the housing 11 while being placed on the pedestal 11E.
[0032]
Further, at the lower edge of the notch portion 11B, a support portion (support piece) 11F is provided by extending a part of the left side plate 11A as it is. As shown in FIG. 2, the support portion 11 </ b> F is provided in front of the base end portion of each electronic component 14, 15, 16 mounted on the substrate 13. A locking projection 11G protruding in the direction of the electronic components 14, 15, 16 is formed on the support portion 11F.
[0033]
Next, a method for attaching the heat radiating member 30 will be described.
The lead terminals 14a, 15a, 16a of the electronic components 14, 15, 16 are inserted into the through holes 13a of the substrate 13, and the support pieces of the holders 21, 22, 23 are inserted into the holding holes 13b of the substrate 13. The lead terminals 14 a, 15 a, 16 a and the holders 21, 22, 23 are fixed to the substrate 13 by soldering on the back surface of the substrate 13. In this state, the substrate 13 is installed on the pedestal portion 11E and fixed in the housing 11 by screwing or the like.
[0034]
The heat dissipating member 30 is mounted in the notch 11B from a position just above the left side plate 11A or slightly outwardly from the housing 11 as shown in FIG.
[0035]
The lower end portion of the heat dissipation member 30 is inserted between the base end portions of the electronic components 14, 15, and 16 and the support portion 11 </ b> F facing the front thereof. When the heat dissipating member 30 is inserted from the chain line state of FIG. 2 into the solid line state, the engaging portion 33 formed at the lower end of the heat dissipating member 30 is below the engaging convex portion 11G formed so as to protrude from the support portion 11F. Hang on. Moreover, the lower end part of the heat radiating member 30 is pinched | interposed between the electronic components 14, 15, 16 and the support part 11F, and the heat radiating member 30 is hold | maintained.
[0036]
In the process of inserting the heat dissipation member 30 into the state shown by the solid line in FIG. 2, the extension 21 d at the upper end of the holder 21 and the extensions 22 d and 23 d of the other holders 22 and 23 are pressed against the pressing portion 31 of the heat dissipation member 30. Is inserted into the insertion groove 31a inside. The extension portions 21d, 22d, and 23d all protrude above the electronic components 14, 15, and 16, but the extension portions 21d, 22d, and 23d are forcibly pressed in the −X direction by the pressing portion 31. It is. Therefore, the back surfaces of the electronic components 14, 15, and 16 are pressed in the direction of the heat dissipation member 30 by the pressing portions 21 e, 22 e, and 23 e of the holders 21, 22, and 23 due to the deformation elastic force of the extension portions 21 d, 22 d, and 23 d. The heat radiation surfaces of the electronic components 14, 15, and 16 are brought into close contact with the installation plane 32 of the heat radiation member 30.
[0037]
Even if the mounting positions of the electronic components 14, 15, 16 are slightly varied, the lead terminals 14 a, 15 a, 16 a of the electronic components 14, 15, 16 are deformed, and the electronic components 14, 15, 16 are The posture is changed so as to be in close contact with the installation plane 32.
[0038]
When the heat dissipating member 30 is inserted in the solid line state of FIG. 2, the heat dissipating member 30 is fitted to the electronic components 14, 15, 16 and the holders 21, 22, 23, and the electronic components 14, 15, 16 It is held without moving by clamping with the support portion 11F. In this state, a connecting screw is inserted from the outside into the mounting grooves 34 and 34 formed on both sides of the heat radiating member 30 and screwed into the female screw holes 11a and 11a of the left side plate 11A. The plate 11A is connected and fixed to each other.
[0039]
In this heat radiating device, even if the holders 21, 22, 23 and the heat radiating member 30 are not fixed to each other with screws, the electronic components 14, 15, 16 and the heat radiating member 30 are securely adhered to each other with an appropriate force. Moreover, since the screwing space of the holders 21, 22, 23 and the heat radiating member 30 is not necessary, the electronic components 14, 15, 16 can be arranged adjacent to each other.
[0040]
In addition, heat dissipation of each electronic component 14, 15 and 16 is applied between the heat radiation surface of each electronic component 14, 15, 16 and the installation plane 32 of heat dissipation member 30 by applying silicon oil or the like having high thermal conductivity. Can be performed more efficiently.
[0041]
【The invention's effect】
According to the present invention described in detail above, the heat radiating member and the heat radiating surface of the electronic component can be reliably adhered with an appropriate force. Therefore, the adhesion between the heat dissipation member and the electronic component does not become insufficient, or excessive stress does not act on the electronic component.
[0042]
In addition, the heat radiating member can be fixed by simply inserting the heat radiating member into the notch or the like of the device main body (housing) from above or slightly obliquely above, and the heat radiating member and the electronic component can be brought into close contact with each other. Simple.
[0043]
In addition, when a plurality of heat generating electronic components are provided, the interval between the electronic components can be reduced.
[Brief description of the drawings]
FIG. 1 is a partial perspective view showing an in-vehicle electronic device as an embodiment of the present invention;
2 is a cross-sectional view of the electronic device when FIG. 1 is viewed from the + Y direction;
FIG. 3 is a perspective view showing a conventional example of a heat dissipation device for releasing heat generated from an electronic component in an on-vehicle acoustic device;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Electronic equipment 11A Left side plate 11B Notch part 11F Support part 14,15,16 Electronic component 21,22,23 Holder 21d, 22d, 23d Extension part 21e Pressurization part 30 Heat radiation member 31 Pressing part 32 Installation plane

Claims (5)

An electronic device in which a heat-generating electronic component, a heat-dissipating member having an installation plane on which a heat-dissipating surface of the electronic component is applied, and a holder that supports a back surface opposite to the heat-dissipating surface of the electronic component are provided on the device body In the heat dissipation device of
The holder is integrally formed with a metal plate with a support surface facing the heat radiating member with a space therebetween, and an elastically deformable extension provided at the tip of the support surface. Supported by a substrate on which electronic components are mounted,
The heat dissipating member is provided with a pressing portion extending to a position spaced apart from the installation plane by a predetermined distance, and the extension portion of the holder is pressed toward the installation plane by the pressing portion, whereby the electronic component is supported by the support portion. A heat dissipating device for an electronic device , wherein the heat dissipating surface of the electronic component is brought into close contact with the installation plane by being pressed by a surface . Said holder, said pair of side plates bent toward the heat radiating member from both sides of the bearing surfaces is provided, the electronic component is surrounded in three directions by the bearing surface and the side plate of the holder and it has claim 1 heat radiator of an electronic apparatus according.   A support portion that is opposed to the base end portion on the mounting side of the electronic component with a space therebetween is provided, and the heat radiating member is inserted and attached between the electronic component and the support portion. The heat dissipation device for an electronic device according to claim 1, wherein the holder is inserted into a position where the holder is pressed by the pressing portion.   The device body is provided with a plurality of electronic components and holders that support the electronic components arranged side by side. The heat dissipating device for an electronic device according to claim 1, wherein the heat dissipating device is disposed along the heat dissipating device. The heat dissipation device for an electronic device according to any one of claims 1 to 4, wherein a pressing portion that presses the back surface of the electronic component is formed on the support surface of the holder so as to protrude.

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