JP2000227820A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide structure fitted to a thin casing, which cools the temperature of a heating element to a prescribed one and suppresses the rise of the temperature on the surface of the casing, by installing a heat radiation board on the inner wall face of the casing or a keyboard rear face or integrally forming the heat radiation board with the inner wall face of the casing and supplying the blow-out air of a fan to the heat radiation board. SOLUTION: Heat generated in a CPU 1 is transmitted to a heat radiation board 11 installed on a casing wall face and a keyboard rear face through flexible heat transmission members 2 and 3, is diffused in the face direction of the heat radiation board 11 in the heat radiation board 11 and it is radiated to outside air. At that time, the cooling wind of a fan 16 is given to the radiation board 11 and the heat radiation board 11 is cooled. Since the fan 16 is installed near the inner end part of a casing, fresh outside air around the casing can be supplied to the radiation board 11. Even if the arranging position of the fan 16 is not near the CPU 1 but near the inner end part of the casing, heat is diffused to the end part of the casing by the heat radiation board 11 and effective cooling by the fan 16 is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for an electronic device containing a wiring board, a keyboard, a fan, and the like having a heating element mounted in a housing, and a cooling device for maintaining the heating element at a predetermined temperature. About.

[0002]

2. Description of the Related Art A prior art is disclosed in Japanese Patent Application Laid-Open No. Hei 8-286783, in which a heat sink is installed at the bottom inside a first housing on which a heating element is mounted. It conducts heat to the bottom surface and spreads heat on the housing surface to radiate heat. Japanese Patent Application No. 7-11288 (reference) discloses an example in which a fan is accommodated in a housing to cool a heating element.

[0003]

In an electronic device represented by a portable personal computer or the like, there is a tendency that the heat generation of the element is improved due to the improvement of the performance, and the housing size is reduced in thickness and weight.

In the example of Japanese Patent Application Laid-Open No. 8-286783, since the surface of the housing is a heat radiating surface, the heat radiating area is limited to the size of the housing. In other words, when performing natural cooling without using a fan, the upper limit of the amount of heat radiation is uniquely determined,
It becomes impossible to operate the element above the limit of the amount of heat radiation. Therefore, as the performance of the element increases, it becomes difficult to cool the heat generating element (since the surface temperature of the housing increases and the operator feels uncomfortable), thereby hindering the performance of the electronic device.
On the other hand, in the example of Japanese Patent Application No. 7-11288, a fan is housed horizontally to reduce the size of the housing.

[0005] However, when the amount of heat generation increases with the performance of the element, a fan must be arranged near the heat generation element in order to effectively supply cooling air to the heat generation element. There is a problem that can be severely restricted. For example, when the heating element is mounted at a position distant from the end of the housing, if the fan is installed in the vicinity of the heating element, the heated air inside the housing will be supplied to the heating element. That is, no consideration has been given to cooling the heating element by supplying fresh outside air whose temperature has not risen.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cooling device that cools a heating element to a predetermined temperature by supplying fresh outside air whose temperature has not risen in response to an increase in the amount of heat generated by the apparatus accompanying an improvement in processing performance of an electronic apparatus. An object of the present invention is to provide a structure suitable for a thin housing that suppresses a rise in body surface temperature.

[0007]

Means for Solving the Problems In a housing containing a wiring board on which a heating element is mounted, a keyboard, a heat dissipation member of the heating element, and the like, on the inner wall surface of the housing or on the back of the keyboard, the heating element is connected via a heat dissipation member. A heat sink connected thermally was installed, a fan was arranged near the end of the housing, and the heat sink was installed so that the cooling air of the fan was applied to the heat sink.

That is, the heat generated by the heat generating member in the electronic device housing is transmitted to the heat radiating plate provided on the inner wall surface of the housing and the back of the keyboard via the heat radiating member connected to the heat generating member, and radiated by the heat radiating plate. After being diffused in the plane direction of the plate, the heat is radiated to the outside air. At this time, a cooling air of a fan is applied to the heat sink to cool the heat sink. Since the heat sink is installed on the housing wall, a large area is used to obtain high heat dissipation performance,
The heating element and the heat radiating plate can be connected regardless of the position of the heating element on the wiring board.

On the other hand, since the radiator plate itself is cooled by the fan, an increase in the temperature of the radiator plate, that is, a rise in the surface temperature of the housing in contact with the radiator plate is suppressed. At this time, since the fan is installed near the inner end of the housing, fresh air around the housing can be supplied to the heat sink. Since the heat of the heating element is transported to the vicinity of the fan via the radiator plate, even if the fan is not installed in the vicinity of the heating element (regardless of the positional relationship between the heating element and the fan), the heating element is not affected by fresh air. The heat can be dissipated.

[0010]

1 and 2 show an embodiment of the present invention. FIG. 1 is a perspective view of an electronic apparatus according to the present embodiment.
Is installed. On the main wiring board 12, a sub-wiring board 6 on which an element having a particularly large amount of heat generation (hereinafter referred to as CPU) such as a CPU (Central Processing Unit) is mounted. Further, a fan 16 is installed on the bottom surface near the back inside the housing 100. Here, the fan 16 is arranged so that the fan intake surface comes to the notch 17 provided in the main wiring board 12.

FIG. 2 is a sectional view. The electronic device according to the present embodiment includes a sub-wiring board 6 on which the CPU 1 is mounted, a sub-wiring board 6, a main wiring board 12 on which a plurality of elements (not shown) are mounted, a housing 100 containing a keyboard 14, and the like.
Consists of A heat sink 11 is laid on the bottom of the housing 100. It is desirable that the heat radiating plate 11 has an area as large as possible. If necessary, the heat radiating plate 11 may be provided with substantially the same area as the bottom surface of the housing and further up to the rear surface of the housing. Further, the heat radiating plate 11 may also be used as the housing 100 by forming the housing 100 itself from a high heat conductive material such as an Mg alloy.

The CPU 1 is mounted on a sub-wiring board 6 and is thermally connected to a metal block 13 attached to a radiator plate 11 via a flexible heat conductive member (for example, a mixture of Si rubber and a filler such as aluminum oxide) 2. Connected to. The sub-wiring board 6 is connected to the main wiring board 12 via a connector 15.
Attached to. The back surface of the sub-wiring board 6 on which the CPU 1 is mounted is connected to the base plate 5 of the keyboard 14 via the flexible heat conductive member 3. The keyboard base plate 5 is made of metal and also functions as a heat sink.

A fan 16 is installed on the bottom surface near the end inside the housing 100. The fan 16 has a radiator plate 161 formed integrally with a fan case.
Reference numeral 161 is in thermal contact with the heat radiating plate 11 installed on the bottom surface of the housing via a highly thermally conductive sheet, grease, or the like. The fan 16 is installed such that the axis of rotation of the fan is substantially perpendicular to the bottom surface of the housing. Therefore, since a fan having a diameter larger than the thickness (height) of the housing can be mounted, high cooling performance can be obtained.

The fan 16 is connected to the main wiring board 12.
Are arranged such that the fan intake surface comes to the notch 17 provided in the groove. With this arrangement, the fan intake surface and the exhaust portion are isolated by the wiring board. That is, a space formed between the main wiring board 12 and the keyboard base plate 5 (fan intake surface side) and a space formed between the main wiring board 12 and the housing bottom surface (fan exhaust section side). And the exhaust from the fan does not re-enter the intake side.

In the space formed between the main wiring board 12 and the keyboard base plate 5, an air inlet 101 outside the housing is provided on the side of the housing, and the air flows roughly in the direction of the arrow in the figure. . The fan 16 may be provided with a space between the fan 16 and the heat sink 11 without providing the heat sink 161.

The heat generated by the CPU 1 is transferred to the heat radiating plates 11 and 5 provided on the wall surface of the housing and the back of the keyboard via the flexible heat conducting members 2 and 3, and the heat radiating plates 11 and 5 cause the surfaces of the heat radiating plates to face each other. After being diffused in the direction, the heat is radiated to the outside air. At this time, the cooling air of the fan 16 is applied to the heat radiating plate 11 to cool the heat radiating plate. Since the heat radiating plates 11 and 5 are installed on the wall surface of the housing 100, high heat radiation performance is obtained by utilizing a large area, and the CPU and the sub-wiring board 6 on which the CPU 1 is mounted regardless of the position on the main wiring board 12. A heat sink can be connected. On the other hand, since the radiator plate 11 is cooled by the fan 6, the rise of the temperature of the radiator plate 11, that is, the surface temperature of the housing 100 with which the radiator plate 11 is in contact is suppressed.

At this time, since the fan 16 is installed near the inner end of the housing, fresh outside air around the housing can be supplied to the heat sink. Even if the position of the fan 16 is not near the CPU 1 but near the inner end of the housing, the heat dissipation plate 11 diffuses heat to the end of the housing, so that the fan 16 can effectively cool the fan.

In order to increase the heat diffusion effect of the heat radiating plate 11, it is more effective to form a heat transport member such as a heat pipe integrally with the heat radiating plate 11. According to the present embodiment,
It is possible to suppress a rise in the temperature of the housing surface, especially the surface on the bottom surface side where the CPU 1 faces, and to cool the CPU 1 effectively.

FIG. 3 shows another embodiment. This embodiment is an example of an electronic device having a structure similar to that of the embodiment shown in FIG. 2, in which a fan 16 is installed on the base plate 5 of the keyboard 14 and the base plate 5 is cooled by the fan. This embodiment is applied to a case where a CPU having a large heat value is installed between the wiring board and the keyboard, or a case where the surface temperature of the keyboard, which is often touched by the operator, is desired to be particularly low. Suitable. FIG. 3 shows the latter example.

In this embodiment, the configuration is almost the same as that of FIG. 2 except that the fan 16 is installed on the base plate 5 of the keyboard 14. A space (fan exhaust unit side) formed between the main wiring board 12 and the keyboard base plate 5 by the wiring board inside the housing, and the main wiring board 12
And a space (fan intake surface side) formed between the main wiring board 12 and the housing bottom radiating plate 11.
And an air inlet 101 outside the housing in a space formed between
Is provided.

The air flows roughly in the direction of the arrow in the figure, cools the keyboard base plate 5, and suppresses the temperature rise on the keyboard surface. FIG. 3 shows an example in which the temperature rise on the keyboard surface is suppressed.
(Shown in FIG. 2) can also be applied to the suppression of temperature rise. That is,
A radiator plate corresponding to the keyboard base plate 5 may be provided on the inner wall surface of the palm rest 20, and may have the same configuration as that of FIG.

As shown in FIG. 4, an air inlet 101 may be provided on the bottom of the housing just below the intake surface of the fan 16 in order to reduce the flow resistance on the fan intake side. By providing the air inlet at the bottom of the housing just below the intake surface of the fan 16 as compared with the case where the air inlet is provided at the side of the housing, the opening area can be increased, and the air from the inlet can flow inside the housing. Since the air is drawn into the fan without bending, the flow resistance on the fan suction side is reduced.

FIG. 5 shows another embodiment. This embodiment is an electronic device having a structure similar to that of the embodiment shown in FIG. 2, and is suitable for suppressing an increase in the surface temperature of the keyboard (or palm rest) and the bottom surface of the housing. 2 differs from the embodiment of FIG. 2 in the direction of intake and exhaust of the fan. That is, the inside of the housing is formed by the wiring board between the main wiring board 12 and the keyboard base plate 5 (on the side of the fan intake surface) and between the main wiring board 12 and the bottom of the housing. An air exhaust port 102 to the outside of the housing is provided in a space formed between the main wiring board 12 and the heat sink 11 on the bottom surface of the housing.

The air flows roughly in the direction of the arrow in the figure, and the air whose temperature has risen in the space formed between the main wiring board 12 and the keyboard base plate 5 is exhausted to cool the keyboard base plate 5 (keyboard surface). Temperature rise). At the same time, a radiator plate 161 provided on the fan 16 thermally connected to the radiator plate 11 installed at the bottom of the housing.
Is cooled. That is, since the heat transferred to the bottom heatsink 11 is removed via the heatsink 161, the rise in the surface temperature of the bottom surface of the housing is also suppressed.

In the present embodiment, the air whose temperature has increased in the space formed between the main wiring board 12 and the keyboard base plate 5 is blown to the radiator plate 161.
An air inlet for the outside air of the housing may be provided in a space formed between the main wiring board 12 and the keyboard base plate 5, and fresh air may be blown to the heat sink 161. In this case, the air inlet and the air outlet 102 are provided on different housing surfaces (for example, the side surface and the back surface) so that the exhausted air is not sucked into the housing again. With this structure,
The heat sink 161 is cooled more effectively, and the rise in the surface temperature of the bottom surface of the housing is further suppressed.

In the embodiments shown in FIGS. 1 to 5, the CPU 1
Although the example in which is mounted on the sub-wiring board 6 has been described, the same configuration can be applied to the case where the device is directly mounted on the main wiring board 12 without using the sub-wiring board.

[0027]

According to the present invention, it is possible to effectively cool the heating element and to suppress a rise in the temperature of the housing surface.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electronic device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a sectional view of an electronic device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an electronic device according to a third embodiment of the present invention.

FIG. 5 is a sectional view of an electronic device according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CPU, 5 ... Keyboard base plate, 6, 12 ... Wiring board, 11 ... Heat sink, 16 ... Fan, 100 ... Housing, 1
01 ... intake port.

Claims (1)

[Claims] 1. A heating element, a keyboard, a fan, a heat radiating member thermally connected to the heat generating element, a heat radiating plate thermally connected to the heat radiating member, and the like, which are mounted on a wiring board and constitute an electronic circuit. An electronic device comprising a housing, wherein the heat radiating plate is installed on the inner wall surface of the housing or the back of the keyboard, or the heat radiating plate is formed integrally with the inner wall surface of the housing so that air blown by a fan is supplied to the heat radiating plate. An electronic device, comprising: