JPH10313185A - Heat-dissipating method and device of electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a heat-dissipating method and a device, wherein heat released from electronic parts is transferred outside of an electronic equipment, so as to cool down the electronic equipment quickly without increasing it in temperature. SOLUTION: Thermal vias 24 are provided to a printed wiring board 22 provided inside a case 21 of an electronic equipment 2, so as to transfer heat released from an electronic part 23 to the rear surface of the printed wiring board 22. A heat-releasing unit 1 is equipped with a heat collector 12 which is provided to penetrate through the case 21 and to make its upper side thermally coupled with the thermal vias 24, a heat exchange frame 11 fixed to the outer side of the case 21, and one or more heat pipes 13 which transfer the heat of the heat collector 12 to the heat exchange frame 11. At this point, heat released from the electronic part 23 is transferred to the heat exchange frame 11 via the thermal vias 24, the heat collector 13, and the heat pipes 13 and dissipated through the heat exchange frame 11 by making a heat exchange with the outside air. Heat dissipation is carried out outside the case 21, so that the case 21 and its inside are restrained from rising in temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiating method and a heat radiating device for an electronic component mounted on a printed circuit board.

[0002]

2. Description of the Related Art In recent years, the performance of electronic devices such as personal computers has been improved, and the amount of heat generated by electronic components provided in the electronic devices has tended to increase. For this reason, if heat dissipation measures are not sufficient, the electronic equipment may be damaged due to thermal runaway. Various types of heat dissipation techniques for such electronic devices have been conventionally proposed. For example, there is a technology for circulating air inside and outside the electronic device using a cooling fan to cool the inside of the electronic device. Further, as described in Japanese Patent Application Laid-Open No. 8-102512, there is a technique in which heat generated in an electronic component is transferred to the outside of an electronic device by using a heat pipe to perform cooling.

FIG. 4 shows a technique described in the above-mentioned publication, in which a thermal via 102 in which a heat conductive member is filled in an opening penetrating in the thickness direction of a printed wiring board 101 is formed, and the surface of the thermal via 102 The electronic component 103 is mounted on the printed wiring board 101 in such a manner as to perform the above. Further, the heat pipe 104 is contacted with the back surface of the thermal via 102.
, And the other end of the heat pipe 104 is connected via a fixture 105 to a heat radiating member 106 such as an electronic device case or a chassis. In this configuration, heat generated in the electronic component 103 is transferred from the thermal via 102 to the heat pipe 105, and the heat pipe 105
The heat is transferred to the heat radiating member 106 directly or through the fixture, and is radiated to the outside from here.

[0004]

In such a conventional heat dissipation technique, the technique using the cooling fan described above makes it difficult to reduce the size of the electronic device due to the space for disposing the cooling fan, and also requires the cooling fan. Is a problem when the is driven. Further, in the technique shown in FIG. 4, heat generated in the electronic components is transmitted to the case or chassis of the electronic device, and heat is radiated by using the surface area thereof.
In some cases, the temperature is increased by the heat transmitted to the case or the chassis, and the temperature of a part of the electronic device is increased, which may cause a safety problem. Further, the radiant heat from the temperature-raised portion may increase the temperature inside the electronic device, and may increase the entire temperature including the inside of the electronic device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat radiation method and a heat radiation device capable of transferring heat generated from an electronic component to the outside of the electronic device and rapidly cooling the electronic device without increasing the temperature. It is in.

[0006]

According to the heat radiation method of the present invention, the heat of an electronic component is transferred to the back side of a printed circuit board via a thermal via provided on a printed wiring board provided in an electronic device. Further, heat is transferred to the outside of the electronic device case via a heat dissipation unit extending from the back side to the inside and outside of the electronic device case, and heat is radiated outside the electronic device case.

Further, the heat radiating device of the present invention includes a printed wiring board mounted inside an electronic device case and having electronic components mounted on the surface thereof, and a heat radiating unit disposed inside and outside the case. The printed wiring board is provided with a thermal via for transferring heat generated in the electronic component to the back side of the printed wiring board, and the heat dissipation unit penetrates the case and has a thermal via on an inner surface thereof. And a heat exchange frame fixed to the outer surface of the case, and one or more heat pipes for transferring the heat of the heat collector to the heat exchange frame. It is characterized by the following. As one embodiment, in the electronic device case, a heat radiation window is opened at a position facing the thermal via, and the heat collector is disposed in the heat radiation window. A configuration is employed in which the heat pipe is closely connected to the thermal via, an outer surface of the thermal via is exposed to the outside of the case, and the exposed portion is connected to the heat pipe. Further, the heat exchange frame is fixed to a surface of the electronic device case, and has a configuration in which a number of heat radiation holes through which external air flows are opened.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a heat radiating unit used in a heat radiating device for performing the heat radiating method of the present invention. The heat radiating unit 1 includes a heat exchange frame 11 formed in a rectangular frame shape, a heat collector 12 disposed at a required position in the heat exchange frame 11, and a peripheral portion of the heat collector 12. It is configured to have a heat pipe 13 protruding in four directions from the surface and having a distal end connected to the heat exchange frame 11. The heat exchange frame body 11 is formed as a solid or hollow frame with a cross section, and screw insertion holes 14 for fixing are formed in the four corners in the thickness direction. In addition, the heat exchange frame 1
A plurality of heat radiating holes 15 penetrating the heat exchanging frame 11 in a plane direction are formed on each of the inner and outer side surfaces of the heat exchanging frame 11. And the outside surface, or in the case of a hollow, the inside and the outside are communicated and opened, respectively.

The heat collector 12 is made of a metal or the like having a high thermal conductivity, and has at least an upper surface formed flat and protruding above the upper surface of the heat exchange frame 11. Shape. The four ends of the heat collector 12 are connected to one end of the heat pipe 13 filled with a heat transfer member having an extremely high thermal conductivity, and the other end of the heat pipe 13 is connected to the other end. The heat exchange frame 11 is connected to opposing inner surfaces. In addition,
The heat pipe 13 may be constituted by a solid rod made of a metal material having high thermal conductivity.

FIG. 2 is a cross-sectional view before assembling a heat radiating device using the heat radiating unit 1, and FIG. 3 is a cross-sectional view of a main part in the assembled state. Electronic equipment 2 that dissipates heat
As shown in FIG. 2, a printed wiring board 22 is provided inside a case 21. The printed wiring board 22 is disposed along the bottom surface of the case 21 and is fixed by a fixing member (not shown). . Various electronic components 23 are mounted on the surface of the printed wiring board 22, and openings for penetrating the printed wiring board 22 in the thickness direction are provided at places where the electronic components 23 requiring heat radiation are mounted. A thermal via 24 filled with a heat conducting member such as a metal is formed in the opening. The thermal via 24 is closely contacted with the electronic component 23 on the upper surface, and the electronic component 23
Is configured to be able to transfer the heat generated in the above to the back side of the printed wiring board 22. On the bottom surface of the case 21 of the electronic device 2, a rectangular heat radiation window 25 is opened at a position facing the thermal via 24.

The heat dissipation unit 1 is attached to the electronic device 2 from the outside on the bottom surface of the case 21 with the heat collector 12 positioned at the heat dissipation window 25 on the bottom surface of the case 21. Then, it is fixed to the bottom surface of the case 21 by screws 16 inserted into the screw insertion holes 14 at the four corners. In this fixed state, the heat collector 12
The upper surface portion is positioned to enter the case 21 through the heat dissipation window 25, and the upper surface thereof is in close contact with the lower surface of the thermal via 24.

Therefore, in the heat dissipation device configured as described above, the heat generated in the electronic component 23 is
Through the printed wiring board 22 to the back side,
From here, heat is transferred to the heat collector 12. Then, the heat collected by the heat collector 12 is guided from the heat radiating window 25 to the outside of the case 22, and the heat pipes 1 on four sides of the heat collector 12 are formed.
The heat is transferred to four locations in the circumferential direction of the heat exchange frame 11 while being dispersed by the heat exchanger 3. At this time, part of the heat is radiated from the surface of the heat pipe 13. Further, the heat transmitted to the heat exchange frame 11 is exchanged with the air flowing through the large number of heat radiating holes 15 and is radiated to the atmosphere with high efficiency. Thus, heat of the electronic component 23 in the case 21 of the electronic device 2 is effectively radiated outside the case 21.

As described above, in this configuration, heat generated inside the electronic device 2 is transmitted to the outside of the case 21 and is radiated outside the case 21, so that heat is accumulated inside the electronic device 2. Case 2 disappears
Part 1 is not heated, and the temperature inside the electronic device 2 does not rise due to radiant heat from the heated part. Further, the heat radiation unit 1 is a case 21
Fixed to the bottom surface of the electronic device, the appearance of the electronic device is not impaired, and the heat exchange frame 11 of the heat radiating unit 1 also functions as a leg of the electronic device 2. Since the flow of air through the heat radiation hole 15 on the side surface of the eleventh side can be secured, the heat exchange efficiency, that is, the heat radiation efficiency is not reduced.

In the above embodiment, the heat collector and the heat exchange frame are formed in a rectangular shape. However, the heat collector and the heat exchange frame may be formed in an arbitrary shape such as a polygon or a circle in accordance with the shape of the electronic device case. Can be formed. The means for fixing the heat radiating unit to the case is not limited to a screw, but may be an engaging structure using a hook member or an adhesive structure.
Also, the number of heat pipes and the dimensions of the heat collector and the heat exchange frame can be set to appropriate numbers and dimensions according to the amount of heat required to release heat.

[0015]

As described above, according to the present invention, the heat generated by the electronic components mounted on the printed wiring board is transferred to the back side of the printed wiring board by the thermal via provided on the printed wiring board, Since heat is transferred to the outside of the electronic device case and radiated through the heat dissipation unit provided over the inside and outside of the electronic device case on the side, heat is not accumulated inside the electronic device or the case, It is possible to prevent a part of the electronic device from being heated, and to perform a suitable heat radiation without increasing the internal temperature of the electronic device due to the radiant heat of the heated portion. Also, since no cooling fan is required,
There is no obstacle to miniaturization of electronic devices and no noise problem.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat dissipation unit used in a heat dissipation device of the present invention.

FIG. 2 is a sectional view of the heat radiating device in a state before the heat radiating unit of FIG. 1 is mounted.

FIG. 3 is a sectional view of a main part of a heat radiating device constituted by the heat radiating unit of FIG. 1;

FIG. 4 is a partial cross-sectional view illustrating an example of a conventional heat dissipation technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat dissipation unit 2 Electronic device 11 Heat exchange frame 12 Heat collector 13 Heat pipe 15 Heat dissipation hole 21 Case 22 Printed wiring board 23 Electronic component 24 Thermal via 25 Heat dissipation window

Claims (5)

[Claims] 1. A heat radiation method for mounting an electronic component on a printed wiring board contained in an electronic device, and dissipating heat generated by the electronic component to the outside of an electronic device case. The heat of the electronic component is transferred to the back side of the printed circuit board through the thermal via provided in the electronic device case, and further, the electronic device case is extended through a heat dissipating unit extending from the back surface to inside and outside of the electronic device case. A method of dissipating heat to the outside of the electronic device case and dissipating heat outside the electronic device case. 2. The heat from the Searbia is collected by a heat collector provided inside and outside of the electronic device case, and is transferred from the heat collector to a heat exchange frame disposed around the heat exchanger via a heat pipe. 2. The heat radiating method for an electronic device according to claim 1, wherein the heat exchanging is performed by exchanging heat with external air in the heat exchanging frame. 3. A printed wiring board, which is provided in a case of an electronic device and has electronic components mounted on a surface thereof, and a heat radiating unit disposed over the inside and outside of the case. A thermal via is provided for transmitting heat generated by the component to the back side of the printed wiring board, and the heat radiating unit penetrates the case and has a heat collector thermally coupled to the thermal via on an inner surface thereof. A heat exchange frame fixed to an outer surface of the case; and one or more heat pipes for transferring heat of the heat collector to the heat exchange frame. apparatus. 4. A heat radiating window is provided in the case at a position facing the thermal via, and the heat collector is disposed in the heat radiating window, and the heat collector has an inner surface formed in the thermal via. 4. The heat radiating device for an electronic device according to claim 3, wherein the heat pipe is connected to the case, and the heat pipe is connected to the exposed portion. 5. The electronic device according to claim 3, wherein the heat exchanging frame is fixed to a surface of the electronic device case, and has a plurality of heat radiation holes through which external air flows. Heat dissipation device.