JP2001015969A - Cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooling apparatus which can efficiently radiate heat by erecting fins on the heat receiving surface of the base plate of a heat sink. SOLUTION: In a cooling apparatus composed of a heat sink used for cooling the heating element 5 of an electronic device and a cooling fan, fins 10-b having the length corresponding to the height of the heating element 5 are provided at portions where the fins 10-b do not come into contact with the element 5 on the heat receiving surface 9-b of the base plate 9 of the heat sink used for the heating element 5 installed to the air blowing path of the cooling fan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for cooling a heating element by releasing heat generated from a heating element mounted on an electronic device such as a notebook personal computer to the outside. The present invention relates to a heat sink configured to directly dissipate heat and a configuration of a cooling fan for cooling the heat sink.

[0002]

2. Description of the Related Art CPs are used in electronic devices such as notebook personal computers (hereinafter referred to as portable personal computers).
An arithmetic element such as U is mounted. The processing speed of an arithmetic element has been increased by increasing the clock speed to 400 MHz or 500 MHz or increasing the degree of integration of semiconductors such as transistors in response to recent demands for high performance of electronic devices. However, when the processing speed of the arithmetic element is increased, the amount of heat generated also increases. If the amount of heat generated by the arithmetic element increases and the arithmetic element itself becomes high heat, the arithmetic element itself and other elements disposed around the arithmetic element are adversely affected by the adverse effect of the heat generating element (reliability is reduced). Receive. In order to prevent the adverse effect, it is necessary to release the heat generated by the heating element to the outside of the housing of the electronic device to cool the heating element. In recent years, the arithmetic element mounted on the electronic device is a heat sink for heat dissipation as a cooling device. It is becoming increasingly common to have The heat sink is generally formed of aluminum or copper having a good thermal conductivity. In addition, in the case where heat radiation is insufficient only by providing a heat sink, a cooling device having a cooling fan dedicated to the heat sink in addition to the heat sink is increasing. As a cooling device used for a conventional portable personal computer, for example, Japanese Patent Application Laid-Open No. 10-303
No. 580 discloses a system in which a cooling fan and a heat sink are combined. In the heat sink described in the above publication, fins are provided on one surface (hereinafter, referred to as a heat radiating surface) for radiating heat from the base plate in order to increase a heat radiating area of the heat generating element. It has a structure in which a heating element is brought into contact with the back surface of the surface (hereinafter, referred to as a heat receiving surface). The heat generated by the heat generating element is transmitted from the heat receiving surface of the heat sink to the heat sink, and is conducted (diffused) to the fins provided on the heat radiating surface via the inside of the heat sink having good thermal conductivity, and is released. Since this heat sink is installed in the air passage of the cooling fan, the heat released from the fins is released to the outside of the portable personal computer by the air flow of the cooling fan. That is, the heat radiation efficiency is increased by using the cooling fan as compared with the case where the heat from the fins is released outside the portable personal computer only by natural convection.

[0003]

However, in the heat sink provided in the cooling device described in Japanese Patent Application Laid-Open No. 10-303580, the fins are provided only on the heat radiation surface of the base plate. Therefore, depending on the shape of the fin, for example, the heat conduction distance to the tip of the fin becomes too long, so that heat may not be sufficiently transmitted to the tip of the fin. On the other hand, if the number of fins for releasing heat is not sufficient, the temperature of the entire heat sink rises due to insufficient heat radiation area. In the case of cooling a heating element using a fin having the above-described shape or a heat sink having the above-described number of fins, for example, in order to increase the heat release efficiency by receiving the air from a cooling fan with the fins. Even if it is configured, a good heat radiation effect cannot be obtained, and as a result, there is a problem that the heat radiation (heat exchange) efficiency of the heat sink is reduced.
SUMMARY OF THE INVENTION The present invention of claim 1 has been made to solve the above-described conventional problems, and provides a cooling device having good heat radiation efficiency by fins being erected on a heat receiving surface of a base plate of a heat sink. The purpose is to do. In the case of using the heat sink of claim 1 for a general low-profile heating element, the size of the fin used in the present invention can be set only up to the height of the heating element. Cannot set fins of any length with high heat dissipation efficiency.

According to a second aspect of the present invention, there is provided a fin having an arbitrary length as described above, wherein a portion of a heat receiving surface of a base plate of a heat sink, which is in contact with a heating element, is formed as a convex portion or a concave portion. It is an object of the present invention to provide a cooling device capable of erecting a fin having an arbitrary length as a shape portion on a heat receiving surface of a base plate of a heat sink. The size of the cooling fan mounted on the cooling fan according to the first or second aspect of the present invention has been limited with the recent miniaturization of portable personal computers and the like. Therefore, when the cooling fan having the limited size as described above is used, it is impossible to expect a large air volume. In such a situation, how the air of the cooling fan of a limited size can be sent to a heat-radiating component such as the heat-generating element and the heat sink by reducing the loss improves the heat-radiating effect. Is an important factor for A third object of the present invention is to provide a cooling device capable of sending air from a cooling fan to a heat sink with reduced loss by providing a top plate and side walls that cover the heat sink in a duct shape. . In addition, the joining portion for joining the heat sink provided with the duct and the cooling fan used in the present invention of claim 3 to the cooling fan causes air loss when air leakage occurs when the cooling fan blows air. It is necessary to have a closed structure to prevent leakage. However, in order for the duct portion and the cooling fan to have a sealed structure without air leakage, it is required that each of the duct portion and the cooling fan have high component accuracy. In addition, when each of the duct portion and the cooling fan does not have sufficient component precision, a close contact member or the like is required at the joint portion so as to eliminate air leakage. According to a fourth aspect of the present invention, the top plate and the side wall that cover the heat sink in a duct shape are formed integrally with the housing of the cooling fan, so that the heat sink and the cooling fan have a high airflow loss while maintaining a small loss of airflow. An object of the present invention is to provide a cooling device that does not require component precision, does not leak air, and does not require a close contact member for joining.

[0005]

According to a first aspect of the present invention, there is provided a cooling apparatus comprising: a heat sink for cooling a heat generating element of an electronic device; and a cooling fan for blowing air to the heat sink. Wherein the heat sink comprises: a base plate arranged such that a heat receiving surface is in contact with a heat generating surface of a heat generating element; and fins provided on a heat radiating surface of the base plate. A fin having a length corresponding to the height of the heating element is provided at a position on the heat receiving surface where the heating element is avoided. According to a second aspect of the present invention, in the portion where the heat receiving surface of the base plate is in contact with the heat generating surface of the heat generating element, the length of the fin provided on the heat receiving surface is adjusted by adjusting the length of the heat generating element. Alternatively, a concave portion is provided. According to a third aspect of the present invention, the heat sink includes a base plate and fins,
A duct for taking in or exhausting the cooling fan is formed by the side wall, the top plate, and the circuit board surface on which the heating element is installed, which is covered by the side wall and the top plate. The invention of claim 4 is characterized in that the duct is formed integrally with a housing surrounding the cooling fan.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on illustrated embodiments. FIG. 1 is a perspective view showing a configuration of a portable personal computer as an example of an electronic device to which the cooling device of the present invention is applied. FIG. 2 is a perspective view showing an example of a configuration of an electronic component and a heat radiation component mounted on a portable personal computer. FIG. 3 is a partially enlarged view of the heating element and the heat sink in FIG. In the portable personal computer shown in FIG.
A display unit 1 provided with a display element such as the above is mounted so as to be rotatable about a tilt shaft 2a on a main body unit 2 provided with a keyboard 3 as input means. As shown in FIG. 2, a circuit board 4 for realizing the performance of the device is provided inside the main body 2, and on the circuit board 4, an element that generates heat represented by a CPU (hereinafter, a heating element 5). ) Are implemented. An exhaust port 8 for discharging heat emitted from the heating element 5 is provided on a side surface of the main body 2. FIG.
As shown in FIG. 3, in order to easily release the heat generated from the heating element 5, the heat sink 6 is provided directly on the upper surface (heating surface) 5 a of the heating element 5 or attached to the upper surface 5 a of the heating element 5. In contact with each other via the heat conducting member 13.
Here, the heat radiation area is increased and the heat sink 6
The heat generating element 5 itself mounted on the circuit board 4 uses a cooling device configured to combine a cooling fan 7 for removing heat transmitted to the outside and discharging the heat to the outside through an exhaust port 8 provided on the side surface of the housing. In addition, other elements standing upright around the heating element 5 are prevented from being affected by the heating element 5. The heat sink 6 is made of a material having good thermal conductivity such as aluminum or copper.
A plate-shaped, rod-shaped, or pin-shaped fin 10 is provided on the plate 9 adjacently at a predetermined interval. The heat sink 6 has a shape that can be formed from an extruded material or a die cast material. As a wing of the cooling fan 7, an axial flow of a type in which wind flows linearly along a direction orthogonal to the rotation surface of the wing, or a flat type in which the flow of wind is refracted by 90 ° before and after passing through the cooling fan 7 A cooling fan is used. As described above, in the cooling device including the heat sink 6 and the cooling fan 7 as components, heat is efficiently transmitted to the entire heat sink 6, and the cooling fan 7 does not lose the blown air and the heat radiation like the heating element 5 and the heat sink 6 does. It is important to feed the parts to improve the cooling effect.

Next, a cooling device according to a first embodiment of the present invention will be described. FIG. 4 is a perspective view of a heat sink in the cooling device according to the first embodiment of the present invention, and FIG.
FIG. 6 is a partially enlarged view of the heat sink of FIG.
FIG. 7 is a bottom view of the heat sink of FIG. 7, and FIG. 7 is a cross-sectional view of the heat sink of FIG. In the heat sink 6 of the present embodiment, fins 10-a are provided at regular intervals on a heat radiation surface 9-a, which is one surface of the base plate 9. This is described in JP-A-10-30358.
The configuration is the same as the conventional configuration described in Japanese Patent Publication No. 0, or the general configuration shown in FIGS. However, in the conventional configuration described in JP-A-10-303580 and the like,
The back surface (heat receiving surface 9-b) of the one surface (heat radiating surface 9-a)
However, it is constituted by a uniformly flat surface so that good surface contact with the upper surface 5a of the heating element 5 or the heat conducting member 13 can be achieved. For this reason, the heat transmitted from the upper surface 5a of the heating element 5 to the base plate 9 is conducted (diffused) toward the tip of the fin 10 standing upright as shown in FIG. Depending on the shape, for example, the heat conduction distance to the tip of the fin becomes too long, so that heat may not be sufficiently transmitted to the tip of the fin. On the other hand, if the number of fins for releasing heat is not sufficient, the temperature of the entire heat sink rises due to insufficient heat radiation area. In the case of using a heat sink having the fin shape or the number of fins described above to cool the heating element, even if the fin receives the air from the cooling fan to increase the heat release efficiency, good heat dissipation is achieved. The effect cannot be obtained, and as a result, the heat radiation (heat exchange) efficiency of the heat sink may be reduced. Therefore, in the present embodiment, not only the heat radiation surface 9-a of the base plate 9 but also the heat receiving surface 9-b is located at a position that does not interfere with the upper surface 5a of the heat element 5, Are provided with fins 10-b having a length corresponding to. Thus, in this embodiment,
By providing the fins 10-b on the heat receiving surface 9-b, the dead space of the heat sink 6 can be effectively used, and the heat conduction path and the heat radiation area can be increased. Can be improved.

Next, a cooling device according to a second embodiment of the present invention will be described. FIG. 8 is a sectional view of the heat sink according to the second embodiment of the present invention. The fins 10-a and 10-b which are respectively provided upright on the upper and lower surfaces of the base plate 9 constituting the heat sink of FIG. 8 are ideally shaped so as to maximize the heat radiation effect (heat radiation area, heat conduction distance). Etc. are appropriate). However, the heat receiving surface 9-
The shape of the fins 10-b erected on b is restricted from being structurally set only within a height determined by the sum of the element height of the heating element 5 and the thickness of the heat conducting member 13. Therefore, in the present embodiment, the height of the fin 10-b is adjusted by providing the convex portion 14 at a portion of the heat receiving surface 9-b which contacts the heat generating element 5 and receives heat. As described above, in the present embodiment, the convex portion 14
Is provided, the length of the fin 10-b can be made any length, and a desired fin shape can be obtained, so that the heat conduction (diffusion) path and the heat radiation area can be further increased. As a result, the heat radiation effect can be improved. When the height of the fin 10-b is adjusted to be short, a concave portion may be provided instead of the convex portion 14.

Next, a cooling device according to a third embodiment of the present invention will be described. FIG. 9 is a perspective view of a cooling device according to a third embodiment of the present invention, and FIG. 10 is a cross-sectional view of the cooling device of FIG. In the present embodiment, fins 10-a are provided on the side surface of the heat sink 6 so as to efficiently flow the air blown by the cooling fan 7 over the surfaces of the heat sink 6 and the heating element 5.
And a side wall 11 having a side wall height slightly longer than the total length or the total length of 10-b, and a heat radiation surface 9- On the side a, a top plate 12 is added so as to cover the upper edge 11a of the side wall 11, so that the heating elements 5
The duct connected to the intake or exhaust port of the cooling fan 7 is formed together with the circuit board 4 which is the installation surface of the cooling fan 7. In the present embodiment, the duct formed by the side wall 11, the top plate 12, and the circuit board 4 is divided into two upper and lower air passages.
On the side, a rectangular cylindrical air passage formed by the base plate 9, the side wall 11, and the top plate 12 is formed.
On the other hand, on the heat receiving surface 9-b side of the base plate 9, the base plate 9, the side wall 11, and the circuit board 4
To form a rectangular tubular air passage. As described above, in the present embodiment, since the ventilation from the cooling fan 7 flows through the respective ventilation paths without loss such as leakage by providing the duct, the amount of air passing through the surface of the heat sink 6 to which heat is transmitted is reduced. The heat radiation effect of the heating element 5 can be improved.

Next, a cooling device according to a fourth embodiment of the present invention will be described. FIG. 11 is a perspective view of a cooling device according to a fourth embodiment of the present invention, and FIG. 12 is a cross-sectional view of the cooling device of FIG. In this embodiment, the housing of the cooling device including the heat sink provided with the duct and the cooling fan described in the third embodiment is integrated. Specifically, in the cooling device of the third embodiment, the side plate 11 is configured to also function as a side housing of the cooling fan 7, and the top plate 12 is configured to also function as a top cover of the cooling fan 7.
The side plates 11 located on both sides of the cooling fan 7 are integrally formed with a back cover (casing) 7 a of the cooling fan 7. As described above, in the present embodiment, since the heat sink 6 having the duct and the cooling fan 7 are integrated with each other, the joint between the intake and exhaust ports is eliminated, so that it is possible to prevent air from leaking from the joint. Therefore, a contact member for preventing air from leaking from the joint portion, and the heat sink 6
The airflow of the cooling fan 7 passing through the heat sink 6 can be maximized without increasing the dimensional accuracy of the cooling fan 7.

[0011]

As described above, according to the first aspect of the present invention, the number of fins for sufficiently transmitting the heat of the heating element can be increased while effectively utilizing the dead space. The heat radiation area can be increased, and the heat radiation effect of the heating element can be improved. According to the second aspect of the present invention, since an optimal fin shape having high heat radiation efficiency can be obtained, the heat radiation effect of the heating element can be improved. According to the third aspect of the present invention, since the amount of air passing through the surface of the heat sink to which the heat has been transmitted increases, the heat radiation effect of the heating element can be improved. According to the fourth aspect of the present invention, the number of heat dissipating components can be reduced, and the air from the cooling fan can be sent to the heat sink without loss, so that the heat dissipating effect of the heat generating element can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a portable personal computer as an example of an electronic device using a cooling device of the present invention.

FIG. 2 is a perspective view showing a configuration of an electronic component and a heat radiation component mounted on the portable personal computer.

FIG. 3 is a partially enlarged view of a heating element and a heat sink in FIG. 2;

FIG. 4 is a perspective view of a heat sink in the cooling device according to the first embodiment.

FIG. 5 is a partially enlarged view of the heat sink of FIG. 4;

FIG. 6 is a bottom view of the heat sink of FIG. 4;

FIG. 7 is a cross-sectional view of the heat sink of FIG. 4 taken along the plane AA.

FIG. 8 is a sectional view of a heat sink according to a second embodiment of the present invention.

FIG. 9 is a perspective view of a cooling device according to a third embodiment of the present invention.

FIG. 10 is a sectional view of the cooling device of FIG. 9;

FIG. 11 is a perspective view of a cooling device according to a fourth embodiment of the present invention.

FIG. 12 is a cross-sectional view of the cooling device of FIG.

FIG. 13 is a structural diagram of a heat sink in a conventional cooling device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Display part, 2 ... Body part, 2a ... Tilt axis, 3 ... Keyboard, 4 ... Circuit board, 5 ...
Heating element, 6 heat sink, 7 cooling fan, 8 exhaust port, 9 base plate, 9-a
... heat radiation surface, 9-b ... heat receiving surface, 10, 10-a,
10-b: Fin, 11: Side wall, 12: Top plate, 13: Heat conductive member, 14: Convex part

Claims (4)

[Claims] 1. A cooling device comprising: a heat sink used to cool a heat generating element of an electronic device; and a cooling fan for blowing air to the heat sink. And a fin provided on the heat radiating surface of the base plate, wherein the heat receiving surface of the base plate has a length corresponding to the height of the heat generating element at a position avoiding the heat generating element. A cooling device comprising fins. 2. A portion where the heat receiving surface of the base plate is in contact with the heat generating surface of the heating element is provided with a fin provided on the heat receiving surface and a convex or concave portion for adjusting the height of the heating element. The cooling device according to claim 1, wherein a shape portion is provided. 3. The base plate and the fins constituting the heat sink are covered by a side wall and a top plate, and the side wall, the top plate, and the circuit board surface on which the heat generating element is installed are used to draw air from the cooling fan or fins. 3. A duct for exhausting air is formed.
The cooling device according to claim 1. 4. The cooling device according to claim 3, wherein the duct is formed integrally with a housing surrounding the cooling fan.