JPH098483A - Heat dissipating device of electronic device - Google Patents

Abstract

PURPOSE: To effectively dissipate heat released from a heat releasing electronic part mounted in an electronic device so as to protect other parts in the electronic device against an adverse effect caused by heat. CONSTITUTION: Heat dissipating fins 24a, 24b, and 24c are provided to the outer side 21 of a heat dissipating member 20 formed of material high in thermal conductivity, and furthermore heat dissipating fins 27a and 27b are also formed on the inner side 25 where a heat releasing electronic part 21 is installed. A shielding plane 36 is provided to a supporting plate 30 which holds the heat releasing electronic part 21 together with the heat dissipating member 20, confronting the fins 27a and 27b. As the fins are formed on both the sides of the heat dissipating member 20, heat released from the electronic part 14 is effectively dissipated, and the heat of the heat dissipating fins 27a and 27b is prevented from affecting the inward of a case 10 by the shielding effect of the shielding plane 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various kinds of electronic equipment such as on-vehicle audio equipment, and more particularly to a heat dissipation device for releasing heat from electronic parts such as power ICs.

[0002]

2. Description of the Related Art In an electronic device in which an electronic component that generates a large amount of heat is used, a heat dissipation device is used to release heat from the electronic component. FIG. 4 is a perspective view showing a conventional example of a heat dissipation device for escaping heat generated from an electronic component in a vehicle-mounted audio device. A heat dissipation member 2 is provided on one side surface of the housing 1. The heat dissipation 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 dissipation member 2, a plurality of heat dissipation fins (heat dissipation ribs) 2a protruding to the outside of the device are formed. Two electronic components 3 that generate a large amount of heat are mounted on a circuit board 4 installed in the housing 1. The electronic component 3 is a power IC that constitutes an audio amplifier, and one electronic component constitutes a 2-channel audio amplifier. The electronic component 3 is mounted on the circuit board 4 and installed on the inner surface 2 b of the heat dissipation member 2. A pair of support plates 5 formed of metal plates are installed so as to hold the electronic component 3, and both end portions of the support plates 5 are fixed to the heat dissipation member 2 with screws 6.

The electronic component 3 is installed in close contact with the inner surface 2b of the heat dissipation member 2, or silicone oil having a high thermal conductivity is applied between the electronic component 3 and the inner surface 2b, so that the heat from the electronic component 3 is generated. The heat is transmitted to the heat radiating member 2, and is mainly radiated to the outside of the device from the outer surface having the heat radiating fins 2a.

[0004]

In the heat dissipation device shown in FIG. 4, since the heat dissipation fins 2a are formed only on the outer surface of the heat dissipation member 2, the heat dissipation function of the heat dissipation member 2 is limited. For example, a power IC or the like that constitutes a 4-channel audio amplifier by itself has a very large amount of heat generation as compared with the conventional electronic component 3 shown in FIG. In a structure in which this kind of electronic component is installed on the inner surface of the heat dissipation member 2 and fixed by the support plate 5 as shown in FIG. 4, the amount of heat conducted from the electronic component to the heat dissipation member 2 is very large. The heat conducted to the heat radiating member 2 is radiated only from the outer surface on which the heat radiating fins 2a are formed, so that the heat radiating function is not sufficient and the heat tends to reach a state close to saturation in the heat radiating member 2.

When the amount of heat conducted to the heat radiating member 2 increases, the heat is radiated from the inner surface 2b of the heat radiating member 2 to the inside of the housing 1, or the air near the inner surface 2b is heated and convects into the housing. Therefore, the temperature inside the housing 1 rises. If the temperature inside the housing 1 becomes abnormally high, not only will other electronic components inside the housing 1 be adversely affected, but in the case of a vehicle-mounted audio device, for example, the tape loaded inside the housing 1 The magnetic tape in the cassette is affected by heat, causing a problem such as deterioration of the magnetic film, and further adversely affecting the magnetic head and the like.

The present invention has been made to solve the above-mentioned conventional problems and has been improved so that the heat radiation amount from the heat radiation member on which the electronic component is installed can be increased, and the heat radiated from the heat radiation member can be stored in other devices. An object of the present invention is to provide a heat dissipation device for an electronic device that does not adversely affect a recording medium such as an electronic component or a magnetic tape.

[0007]

According to the present invention, there is provided a heat dissipation device for an electronic device provided with a heat-generating electronic component and a heat dissipation member for releasing heat from the electronic component. On the side where the electronic component is installed, a radiating fin that protrudes in a region where the electronic component is not installed is provided, and a shielding surface is integrally formed with a support plate that holds the electronic component together with the radiating member. Are opposed to the heat radiation fins.

The support plate has a holding portion for sandwiching the electronic component with the heat radiating member, and a shield surface facing the heat radiating fin, and a heat radiating space is formed between the shield surface and the heat radiating member. Become. As shown in FIG. 1, the holding portion holds the electronic component between the heat radiating member and the inner surface of the heat radiating member, and the holding portion and the heat radiating member are connected by a screw, so that the electronic component can be connected to the inner surface of the heat radiating member and the holding portion. Will be in close contact with. Alternatively, the holding portion formed on the support plate has a concave portion surrounding the electronic component as in the conventional example shown in FIG. 4, and both end portions of the concave portion are fixed to the heat dissipation member by screwing or the like. Become.

Further, it is preferable that the shielding surface faces all of the heat dissipating fins provided on the side of the heat dissipating member on which the electronic parts are installed, and more preferably, the holding portion of the support plate and the shield surface. However, it covers almost the entire surface of the heat dissipation member.

Further, it is preferable that the supporting plate is bent so that the shielding surface is located farther from the heat radiating member than the holding portion. As a result, the heat dissipation space surrounded by the heat dissipation member and the shielding surface has a large volume. In this case, as shown in FIG. 3, it is preferable to provide a space δ between the shielding surface and the heat radiation fin.

Furthermore, a heat radiation space is formed between the support plate and the heat radiation member, and an opening for communicating the heat radiation space with the outside of the device is formed in the housing for housing the electronic component. It is possible to In this case, the opening includes the case formed in the heat dissipation member.

In the present invention, when the heat dissipation member is installed on one side surface of the housing and the outer surface of the heat dissipation member is exposed to the outside of the housing, the heat dissipation member is provided by the support plate. It is possible to have a structure in which the part and the internal space of the housing are divided. In this case, a heat dissipation space is formed between the heat dissipation member and the support plate, and the opening formed in the case allows the heat dissipation space to communicate with the outside of the case so that the inside of the case with the support plate as a boundary. It is possible to effectively prevent heat from being transmitted to.

[0013]

In the present invention, the heat radiation fin is provided on the side of the heat radiation member on which the electronic component is installed. Therefore, the heat transmitted from the electronic component to the heat dissipation member is easily dissipated from the side where the electronic component is installed. That is, since the radiation fins are formed on the side where the electronic parts are installed and the surface area is large, heat is easily radiated to the side where the electronic parts are installed, and it is easy to escape the heat by convection. . Therefore, it becomes possible to provide heat dissipation fins on both the front and back surfaces of the heat dissipation member, the amount of heat radiated from the heat dissipation member increases, and even in the case where an electronic component that generates a large amount of heat is used, Saturation of heat is less likely to occur, and a sufficient heat dissipation effect can be exhibited.

Further, the shield surface, which is a part of the support plate that holds the electronic component together with the heat dissipating member, extends to a position facing the heat dissipating fins of the heat dissipating member, and preferably this shield surface is the heat dissipating member. This is a structure that faces all the radiation fins provided on the electronic component installation side. Since the shielding surface faces the heat dissipating fins, it is possible to prevent the radiant heat to the electronic component installation side of the heat dissipating member from being shielded by the shield surface and to prevent the radiant heat from reaching other parts of the device. Further, even if the air in contact with the electronic component installation side of the heat dissipation member is heated, it is possible to prevent this air from being blocked by the shielding surface and reaching other parts in the device. Therefore, it is possible to prevent the other electronic components in the device, the magnetic head, and the magnetic tape from being adversely affected by heat.

Particularly, in the support plate, if the shield surface extends in the direction away from the heat dissipating member more than the holding portion in contact with the electronic component, the volume of the heat dissipating space between the heat dissipating member and the shield surface can be increased. . Therefore, convection in the heat dissipation space can be generated, and heat can be prevented from being trapped in the heat dissipation space. Further, by forming an opening in the housing and communicating the inside of the heat dissipation space with the outside of the device, the inside of the heat dissipation space can be ventilated and the heat dissipation effect can be enhanced.

That is, according to the present invention, the heat radiation member is provided with the heat radiation fins extending toward the electronic component installation side, so that the heat from the electronic component having a large heat generation amount can be effectively dissipated, and the heat is also generated in the device. Will not adversely affect other parts of the.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a heat dissipation device provided in an on-vehicle audio equipment as one embodiment of the present invention, and FIG. 2 shows a state in which the heat dissipation device of FIG. 1 is assembled. 1 is a front view shown in the direction of the arrow, and FIG. 3 shows a state in which the heat dissipation device of FIG. 1 is assembled.
It is sectional drawing of the II line.

FIG. 1 shows the rear part of the on-vehicle audio equipment, and the left side plate 11 and the rear side plate 12 of the housing 10 are shown. Although not shown, a nose portion is attached to the front of the housing 10, and various operation buttons and a display device are provided on the nose portion. Further, the housing 10 accommodates a tape drive unit in which a tape cassette is loaded, a disk drive unit in which an optical disc is loaded, and the like. Further, the housing 10 is provided with various electronic circuits such as a tuner. This in-vehicle electronic device is of a built-in audio amplifier type, and has a circuit board 1 installed in a housing 10.
3, electronic components that form an audio circuit are mounted.

A heat-generating electronic component 14 is mounted on the rear end of the upper surface of the circuit board 13. This electronic component 14
Is a power IC that constitutes a 4-channel audio amplifier. The electronic component 14 which constitutes one 4-channel audio amplifier is the conventional electronic component 3 shown in FIG.
The amount of heat generated is larger than that of. A plurality of lead terminals 14 a extend to the lower end of the electronic component 14. Each of the lead terminals 14a is inserted into the through hole 13a formed in the circuit board 13, and is soldered and connected to the conductive pattern formed on the back surface side of the circuit board 13.

A notch 12a is formed in the rear side plate 12 of the housing 10.
Is formed, and the heat dissipation member 20 is attached to the portion where the cutout 12a is formed. This heat radiation member 2
0 is formed of a metal material having a high thermal conductivity such as an aluminum alloy. The heat dissipation member 20 has an outer surface 2
1 is installed inside the rear side plate 12 in a state in which a part of 1 is exposed from the cutout portion 12a to the outer surface of the housing 10. Then, the left and right side portions 22 and 23 of the heat dissipation member 20 and the rear side plate 1
2 and 2 are fixed by a fixing screw (not shown).

Radiating fins 24a, 24b and 24c are formed on the outer surface 21 of the heat radiating member 20. Each of the heat radiation fins 24a, 24b, 24c is formed in a rib shape in the vertical direction at regular intervals. Heat dissipation member 2
Heat dissipation fins 24a, 24b formed on the outer surface 21 of
24 c is exposed to the outside of the housing 10 from the cutout portion 12 a of the rear side plate 12. On the inner surface 25 of the heat dissipation member 20, an installation plane 26 on which the electronic component 14 is installed is provided in the lower part on the left side of the drawing. One surface 14b of the electronic component 14
Are installed so as to be in close contact with the installation plane 26 or to face each other with a minimum gap.

On the inner surface 25, a plurality of radiating fins 27a are formed above the installation plane 26, and a plurality of radiating fins 27b are formed on the right side portion of the installation plane 26 in the figure. The radiating fins 27a have a vertical dimension excluding the installation plane 26, and the radiating fins 27b have a radiating member 2a.
It has a vertical dimension of almost zero height dimension. That is, the radiating fins 27a and 27b are the same as the radiating member 20.
In the inner surface 25 on the side where the electronic component 14 is installed, the electronic component 14 is provided in a region other than the installation plane 26 on which the electronic component 14 is installed. The radiation fins 27a and 2
7b has the same protruding height dimension from the inner surface 25,
This dimension is indicated by h. Further, in the heat dissipation member 20, a pair of female screw holes 2 are formed on the installation plane 26 with a space left and right.
8 is formed, and a pair of female screw holes 29 are formed in both left and right side portions 22 and 23.

A support plate 30 is attached to the inside of the heat dissipation member 20. The support plate 30 is formed by bending an iron plate such as a rolled steel plate. The support plate 30 holds the electronic component 14, and the heat radiated from the inner surface 25 of the heat dissipation member 20 causes an internal space B in the housing 10 (see FIG. 3).
Demonstrate the function to prevent the transmission to. Therefore, it is preferable that the heat dissipation member 20 is formed of a material having a lower thermal conductivity than the aluminum alloy, which is a material of the heat dissipation member 20, such as a rolled steel plate. Therefore, it is possible to form the support plate 30 with a material having an extremely low thermal conductivity such as a resin material. However, the effect of cooling the electronic component 14 can be enhanced by conducting the heat generated from the electronic component 14 not only to the heat dissipation member 20 side but also to the support plate 30 side to some extent. Therefore, as the material of the support plate 30, it is preferable to use an iron-based material such as a rolled steel plate having a certain degree of thermal conductivity rather than a resin material or the like.

However, it is also possible to form the support plate 30 with a material having an extremely high thermal conductivity such as an aluminum alloy plate. Since the support plate 30 has a smaller thickness than the heat dissipation member 20 and the support plate 30 is not provided with heat dissipation fins, even if a large amount of heat is transferred to the support plate 30, the support plate 30 causes the housing to move. The influence of the heat exerted on the internal space B of 10 is smaller than that of the heat dissipation member 20 in which the heat dissipation fins 27a and 27b are formed.

The left and right sides of the support plate 30 are provided on the heat radiating member 20.
It is bent to the side, and this part is fixed piece 31, 32
It has become. In addition, mounting holes 33 are provided in both fixing pieces 31 and 32.
Are formed. Both fixing pieces 31 and 32 are used for the heat dissipation member 2.
Installed on the inner surfaces of both sides 22 and 23 of the
A fixing screw 41 (see FIG. 2) is inserted into and screwed into the female screw hole 29, and the support plate 30 is fixed inside the heat dissipation member 20.

The support plate 30 is provided with a holding portion 34 which is bent so as to approach the heat radiation member 20.
In the state where the support plate 30 is attached to the heat dissipation member 20, the holding portion 34 is in close contact with the surface 14c of the electronic component 14 or faces the surface 14c with a minimum gap. The holding portion 34 has a pair of mounting holes 35 formed therein, and the fixing screw 42 inserted into the mounting hole 35 is formed in the female screw hole 2 formed in the heat dissipation member 20.
8 is screwed on. When the fixing screw 42 is tightened, the electronic component 14 is attached to the installation plane 2 of the heat dissipation member 20.
6 and the holding portion 34 of the support plate 30 are held and held, and the degree of contact between the surface 14b of the electronic component 14 and the installation plane 26 and the degree of contact between the surface 14c of the electronic component 14 and the holding portion 34 are Can be improved.

A portion of the support plate 30 where the holding portion 34 is not formed is a shielding surface 36. When the support plate 30 is attached to the heat dissipation member 20, the shielding surface 36 has the heat dissipation fins 27 a and 27 formed on the inner surface 25 of the heat dissipation member 20.
b. As shown in FIG. 2, the shielding surface 36 includes all the heat dissipation fins 27 formed on the inner surface 25 of the heat dissipation member 20.
a and 27b are opposed to each other, and the shielding surface 36 has a radiation fin 27.
It covers almost the entire area where a and 27b are formed.

The distance between the inner surface of the shield surface 36 and the inner surface 25 of the heat dissipation member 20 is indicated by H when the support plate 30 is attached to the heat dissipation member 20. As shown in FIG. 3, the distance H is larger than the rising height dimension h of each of the heat radiation fins 27a and 27b, and a distance δ is provided between the tips of the heat radiation fins 27a and 27b and the inner surface of the shielding surface 36. Is formed. Bending side plates 37 are provided on both sides of the shielding surface 36 of the support plate 30, but when the support plate 30 is attached to the heat dissipation member 20, both the folding side plates 37 are
It is located on both sides of the radiation fins 27a and 27b. Then, the inner surface 25, the shield surface 36, and the bent side plate 3 of the heat dissipation member 20.
The portion surrounded by 7 becomes the heat dissipation space A. The heat radiation fins 27a and 27b extend into the heat radiation space A.

In FIG. 3, the height dimension of the shielding surface 36 of the support plate 30 and the bending side plate 37 is indicated by L. This height dimension L
Is approximately the same as or slightly shorter than the distance between the inner surface of the ceiling plate 15 of the housing 10 and the upper surface of the circuit board 13, and therefore, the shield surface 36, the bending side plate 37, and the heat dissipation member 20.
The heat dissipation space A surrounded by the inner surface 25 and is completely isolated from the inner space B of the housing 10.

As shown in FIG. 1, in the heat dissipation space A, the circuit board 13 has an opening 13b formed by a round hole and an opening 13c formed by a rectangular cutout.
As shown in FIG. 3, the bottom plate 16 of the housing 10 is also formed with an opening 16a communicating with the openings 13b and 13c, and the ceiling plate 15 is also formed with an opening 15a. Inside the heat dissipation space A, the openings 13b, 13
It communicates with the outside of the housing 10, that is, the external space of the device through the openings c and 16a and the opening 15a.

Although the electronic component 14 has a very large amount of heat generation, the heat generated from the electronic component 14 is the surface 1
The outer surface 2 of the heat dissipating member 20 conducts from 4b to the heat dissipating member 20.
The heat radiation fins 24a, 24b, and 24c formed on the No. 1 radiate the heat to the external space of the housing 10. Heat dissipation member 2 at the same time
Heat is also radiated from the heat radiation fins 27a and 27b formed on the inner surface 25 of No. 0.

Since the heat radiation fins 27a and 27b are provided, the surface area of the inner surface 25 of the heat radiation member 27 is increased, so that the amount of heat generated from the inner surface 25 is increased. Although the heat from the inner surface 25 of the heat dissipation member 20 is radiated inward of the housing 10, the heat dissipation fins 27a and 27b are provided.
Since the shielding surface 36 faces the portion where the is formed, radiant heat is prevented from reaching the internal space B of the housing 10. Further, the air in contact with the radiating fins 27a and 27b is heated by the heat generated by the radiating fins 27a and 27b, and this heat convects in the radiating space A which is in a substantially sealed state. This convection of heat is blocked by the shield surface 36 and therefore does not reach the internal space B of the housing 10. Thus, in the heat dissipation member 20, not only the outer surface 21 but also the inner surface 25
The electronic components that produce a great heat dissipation effect and generate a large amount of heat
Therefore, it is possible to prevent the temperature rise of No. 4 from occurring. Then, the heat dissipation from the inner surface 25 is blocked by the shielding surface 36, so that the internal space B of the housing 10 can be prevented from being abnormally heated.

Next, when the support plate 30 is a metal plate such as a rolled steel plate, the heat from the electronic component 14 is conducted from the surface 14c to the holding portion 34 and is transferred into the support plate 30. Therefore, the support plate 30 also shares a certain amount of heat dissipation effect.
The heat of the support plate 30 is radiated into the heat dissipation space A, and the heat dissipation space A
Inside, heat on the side of the heat dissipation member 20 and heat from the side of the support plate 30 are dissipated. However, the heat in the heat dissipation space A is not limited to the openings 13b, 13c communicating with the heat dissipation space A,
It escapes to the outside of the casing 10 through 16a and the opening 15a.

The heat of the support plate 30 is generated by the internal space B of the housing 10.
Although it is also slightly diverged to the side, when the support plate 30 is an iron-based material of a rolled steel plate, since the thermal conductivity is appropriate, the effect of heat exerted on the internal space B is slight, and rather the support is supported. The shield surface 36 of the plate 30 mainly exhibits the function of preventing the heat in the heat dissipation space A from reaching the inner space B. Further, when the support plate 30 is made of a material having an extremely high thermal conductivity such as an aluminum alloy, heat from the support plate 30 easily reaches the internal space B, but the support plate 30 is a thin plate material. In addition, since the heat radiation fins are not provided, the influence of heat on the internal space B is not so large. In addition, an opening is formed in the housing 10,
Since the heat radiation space A has a structure in which it is constantly ventilated, the support plate 3
The heat from 0 is effectively released to the outside of the housing 10. Therefore, even if the support plate 30 is made of a material having a high thermal conductivity, it is possible to prevent the temperature of the support plate 30 from becoming abnormally high, and the influence on the internal space B becomes slight.

Further, as shown in FIG.
Since a gap δ is formed between the a and 27b and the shielding surface 36, the heat generated by the radiation fins 27a and 27b is generated by the shielding surface 3
6 is not directly conducted to the support plate 30.
It is possible to prevent the temperature from rising.

As an embodiment of the present invention, it is preferable that an opening is formed to connect the heat radiation space to the outside of the housing. However, depending on the amount of heat generated by the electronic component 14, the opening may be omitted. Since the heat from the radiation fins 27a and 27b is shielded by the shield surface 36, an effect can be expected in that the influence of heat on the internal space B can be reduced.

The openings are formed on the circuit board 13 as shown in the figure.
The heat dissipation member 20 is not limited to the one formed on the housing 10 or the housing 10.
It is also possible to directly form the opening in the. The present invention also provides
The present invention is not limited to audio equipment for vehicles, but can be applied to other electronic equipment. The heat-generating electronic component is not limited to the power IC, and may be a large transistor that generates a large amount of heat or a resistor that has a high resistance value.

[0038]

As described above, in the present invention, since the heat dissipation member is provided with the heat dissipation fin extending to the electronic component installation side, the heat dissipation effect to the electronic component installation side can be expected, and the heat dissipation effect of the heat dissipation member can be enhanced. . Moreover, the heat radiated from the heat dissipation member to the electronic component side can be shielded by the support plate, and the influence of the heat on the electronic components and other components in other parts of the device can be prevented. Further, since the support plate can exhibit both the function of holding the electronic component and the function of shielding the heat from the heat dissipation member, it is not necessary to provide a separate component for shielding the heat.

Further, in the support plate, by arranging the shield surface in the direction away from the heat dissipation member rather than the holding portion of the electronic component, the volume of the heat dissipation space surrounded by the shield surface and the heat dissipation member can be increased, and the space inside the heat dissipation space can be increased. A large cooling effect due to convection of heat can be expected.

Further, by forming an opening in the housing which communicates with the heat radiation space, heat between the heat radiation member and the support plate can be released to the outside of the device, and the heat from the heat radiation member and the support plate can be released. Can be effectively diverged.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a heat dissipation device for an electronic device according to an embodiment of the present invention,

FIG. 2 shows a state in which the heat dissipation device shown in FIG. 1 is assembled.
II front view shown from the direction of the arrow

3 is a cross-sectional view taken along the line III-III of FIG. 1 showing a state where the heat dissipation device shown in FIG. 1 is assembled;

FIG. 4 is a perspective view showing a heat dissipation device of a conventional electronic device,

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Housing 13 Circuit board 13b, 13c Opening 15a, 16a Opening 14 Electronic component 14a Lead terminal 20 Radiating member 24a, 24b, 24c Radiating fin 26 Installation plane 27a, 27b Radiating fin 30 Support plate 34 Holding part 36 Shielding surface A Heat dissipation space

Claims (3)

[Claims] 1. A heat dissipating device for an electronic device, comprising: a heat-generating electronic component; and a heat dissipating member that dissipates heat from the electronic component, wherein an electronic component is installed on the side of the heat dissipating member on which the electronic component is installed. A radiating fin that protrudes in a region where no component is installed is provided, and a shielding surface is integrally formed on a support plate that holds the electronic component together with the radiating member, and the shielding surface faces the radiating fin. A heat dissipation device for electronic devices characterized by being. 2. The heat dissipation of an electronic device according to claim 1, wherein the support plate is bent and formed such that the shielding surface extends to a position apart from the heat dissipating member more than a holding portion holding the electronic component. apparatus. 3. A heat radiating space is formed between the support plate and the heat radiating member, and an opening for communicating the heat radiating space and the outside of the device is formed in the housing for housing the electronic component. A heat dissipation device for an electronic device according to claim 1.