JPH07297583A - Heat sink equipped with fan - Google Patents

Abstract

PURPOSE:To obtain a heat sink which is equipped with a fan and capable of effectively dissipating much heat released from a high heat releasing device restraining undesirable vibrational noises. CONSTITUTION:A heat sink is provided with a heat sink main body 10 which is formed of material high in thermal conductivity and equipped with heat dissipating fins 11, 11,... and a lid 20 which is formed of material high in thermal conductivity covering the upside of the heat sink main body 10 for the formation of air ducts 12, 12,.... Furthermore, a cooling fan which enables air to be sucked in or discharged out through an air inlet 21 provided to the lid 20 to forcibly introduce cooling air into the air ducts 12, 12,... and an elastic body 40 which is high in thermal conductivity and flexibility and interposed between the upsides of the heat dissipating fins 11 and the bearing part of the lid 20 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink with a fan.

[0002]

2. Description of the Related Art As shown in FIG. 13, a conventional heat sink with a fan has a heat sink body 10 made of a material having a good heat conductivity such as aluminum, a lid 20 for covering the upper surface of the heat sink body 10, and a cooling body. It consists of a fan 30.

The heat sink body 10 has a plurality of pin-shaped radiating fins 11, 11 ... Standing over substantially the entire upper surface, leaving a space for accommodating the cooling fan 30 in the central portion thereof. It is mounted on the upper surface of the element.

The lid 20 is provided to guide the cooling air blown out from the cooling fan 30 to the radiation fins 11, 11 ... Side, and as shown in FIG.
The introduction hole 21 is opened at a site corresponding to the mounting position of the.
Further, screw 60 fixing holes 50 for fixing the screws 60 to the upper surface of the heat sink body 10 are provided at the four corners of the lid body 20.

Therefore, when the cooling fan 30 is driven with the lid 20 mounted on the heat sink body 10, the cooling air flows from the introduction hole 21 to the radiation fins 1.
1, 11 ... Is forcedly introduced into the ventilation passage 12 formed between them, and heat is exchanged with each radiating fin 11 while passing through the ventilation passage 12 and exiting to the side to cool the heat sink body 10. Be seen.

[0006]

By the way, when the amount of heat generated by the high heat generating element is increased, it is necessary to further improve the heat radiation effect. In the conventional example, the heat sink body 10 is used.
In order to improve the heat radiation effect of the cooling fan 30, the cooling fan 30 is enlarged or the rotation speed of the cooling fan 30 is increased. However, there is a limit to the increase in size of the cooling fan 30, and there is a drawback in that noise is generated when the rotation speed of the cooling fan 30 is improved.

Further, as shown in FIG. 15, the heat sink body 10 has a drawback that when the upper surface of the heat radiation fin 11 and the lid 20 are brought into contact with each other, the heat sink body 10 is in a point contact state and the noise becomes louder. there were.

The present invention has been made to solve the above drawbacks, and an object of the present invention is to provide a heat sink with a fan having a high heat dissipation effect.

[0009]

According to the present invention, the above object is to provide a plurality of radiation fins 11, 11 as shown in FIG.
The heat sink body 10 formed of a material having excellent heat conductivity, and the ventilation path 1 in the heat sink body 10.
The heat sink body 10 for forming 2, 12, ...
2 made of a material with excellent thermal conductivity that covers the upper surface of the
0, a cooling fan 30 that sucks or exhausts air from an introduction hole 21 formed in the lid 20, and forcibly introduces cooling air into the ventilation passages 12, 12, ..., The upper surface of the radiation fin 11 and the lid 20. This is achieved by providing a heat sink with a fan, which has a heat conductive elastic body 40 formed of a material having excellent heat conductivity and flexibility interposed between the abutting portion and the contact portion.

[0010]

In the heat sink with fan of the present invention, the open portion of the upper surface of the heat sink body 10 is closed by the lid 20, and the ventilation passages 12 are formed between the radiation fins 11, 11.

The heat sink body 10 is made of a material having good heat conductivity, and the heat generated from the high heat generating element 60 is transferred to the heat sink body 10 and cooled by the cooling air forcedly introduced from the cooling fan 30.

Here, the velocity of the cooling air forcedly introduced into the heat sink body 10 is the highest near the introduction hole 21,
Since the temperature gradually decreases toward the discharge port, high heat exchange efficiency can be expected in the vicinity of the introduction hole 21.

The present invention has been made in view of the above points, and positively conducts heat between the heat radiation fins 11 and the lid body 20 and functions as a member for forming the ventilation passage 12 of the lid body 20. In addition, it is used as a cooling element.

That is, in the heat sink with fan according to the present invention, the heat conductive elastic body 40 is provided between the upper surface of the heat radiation fin 11 and the lid 20 covering the upper surface of the heat radiation fin 11.
Is interposed, and the contact area between the upper surface of the radiation fin 11 and the lid 20 is enlarged.

As a result, the radiating fins 11 are cooled by the cooling air and the heat transfer cooling by the lid 20, thus improving the overall cooling efficiency. Further, the upper surface of the radiation fin 11 and the lid 2
By preventing point contact with 0, vibration generated by rotation of the cooling fan 30 is absorbed by the heat conductive elastic body 40, and unpleasant noise is prevented.

In the invention according to claim 2, the lid 20
In addition, a cylindrical narrowed portion 22 is provided in the introduction hole 21 of the lid body 20 to narrow down the cooling air forcedly introduced into the ventilation passage 12,
Increase wind speed. As a result, the radiation fins 11, 11, ...
In addition to increasing the heat dissipation effect of, the cooling effect of the lid 20 increases.

In the third aspect of the invention, the heat conductive elastic body 40 is formed in a sheet shape, and the heat conductive elastic body 40 is attached to the heat radiation fins 11, 11 ,.
Is fastened to the upper surface of the lid and the lid 20.

Further, in the invention as set forth in claim 4, by fixing the heat conductive elastic body 40 to the lid body 20 in advance, the heat conductive elastic body 40 is formed between the upper surface of the heat radiation fin 11 and the lid body 20. Installation work to intervene becomes easy.

[0019]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. First, an embodiment of the present invention is shown in FIGS. The heat sink with fan is the heat sink body 10
The cover 20 covers the upper surface of the heat sink body 10, the cooling fan 30, and the heat conductive elastic body 40 interposed between the heat sink body 10 and the lid 20.

The heat sink body 10 is made of a material having a good heat transfer property such as aluminum, and has a plurality of leads 61,
It is fixed to the high heat generating element 60 provided with 61 ... Using a heat conductive compound or an adhesive. The heat sink body 10 has a plurality of pin-shaped heat radiation fins 11, 11 ...
Screw holes 13 for attaching the lid 20 are provided at the four corners.

The lid 20 is formed of a material having a good heat transfer property such as aluminum, and has a flat plate portion 23 having an introduction hole 21 formed at the center thereof, and a peripheral portion of the introduction hole 21 protruding from the back surface of the flat plate portion 23. And a cylindrical narrowed portion 22. This lid 2
0 closes the upper surface of the heat sink body 10 in the flat plate portion 23, and forms a ventilation path having the flat plate portion 23 as a ceiling surface in the gap between the heat radiation fins 11, 11 ,. Note that FIG.
Reference numeral 24 denotes an insertion hole through which a fixing screw 60 or the like screwed into the screw hole is inserted.

The cooling fan 30 is a heat sink body 10.
It is installed in the central part of. The cooling fan 30 is rotationally driven in a direction in which the cooling air is drawn into the ventilation passage 12 from the introduction hole 21 formed in the lid 20, and the cooling air is cooled by the throttle portion 22.
The wind speed of the heat sink is increased and introduced into the ventilation passage 12, and the heat sink body 10 is exchanged with the heat radiation fins 11, 11 ...
Exhausted from the side.

The heat conductive elastic body 40 has heat conductivity and flexibility, and is preferably made of a material having excellent performance such as adhesiveness and flame retardancy, for example, silicon rubber, etc., formed in a sheet shape, and a heat sink. The upper surface of the main body 10, more specifically, the heat radiation fins 11, 11 ... In addition,
In FIG. 1, reference numeral 41 denotes an opening 41 corresponding to the narrowed portion 22 on the lid 20 side, and 42 denotes an insertion hole 42 such as a screw 60.

With the above configuration, the heat sink body 10
When the screw 60 or the like is tightened in a state where the heat conductive elastic body 40 is sandwiched between the cover 20 and the lid 20, as shown in FIG. It deforms following the irregularities on the back surface of the body 20. As a result, the contact area between the two is expanded, the thermal resistance value is lowered, and further, the metal contact between the lid 20 and the heat sink body 10 is prevented, and the vibration generated by the rotation of the cooling fan 30 is thermally conducted. It is absorbed by the elastic body 40, and an unpleasant sound is prevented. Furthermore, since the heat conductive elastic body 40 absorbs the vibration of the cooling fan 30, the screws 6 caused by the vibration are absorbed.
Looseness such as 0 is prevented.

In this embodiment, the heat conductive elastic body 40 is formed of one sheet material, but as shown in FIG. 4, in order to save the material of the heat conductive elastic body 40, The heat conductive elastic body 40 may be formed in a lattice shape by thinning out a portion that does not contact the upper surface of the heat radiation fin 11.

Further, as shown in FIGS. 5 and 6, in order to prevent the cooling air from passing through the ventilation passages 12, 12, ... Without contributing to cooling, the radiation fins 11, 11, .. A plurality of auxiliary pins 43, 43 ... on the grid
May be formed on the heat conductive elastic body 40.

Next, a second embodiment of the present invention is shown in FIG. In this embodiment, the heat conductive elastic bodies 40, 40, ... Are integrally formed with the lid body 20, and the work of inserting the heat conductive elastic body 40 is unnecessary. The fins 11 are arranged in a dotted pattern on the upper surface of the fin 11. In this case, as shown in FIG. 8, the heat conductive elastic body 40 is rounded downward so that the height error of the radiation fin 11 can be absorbed and the upper surface of the radiation fin 11 can be deformed. It is desirable to make it have a cross-sectional shape.

In this embodiment, the shape of the heat conductive elastic body 40 is not limited to that shown in FIG. 7, and as shown in FIG. It may be fixed, and further, the heat conductive elastic body 40 formed in a lattice shape as shown in FIG. 10 may be fixed to the lid body 20.

Further, as shown in FIG. 11, the auxiliary pin 4
The thermal conductive elastic body 40 on which the lids 3, 3 ...
It may be fixed at 0. Next, a third embodiment is shown in FIG.

In this embodiment, a plurality of radiation fins 11 and 11,
And a heat sink body 10 formed of a material having excellent heat conductivity, and a material having excellent heat conductivity that covers the upper surface of the heat sink body 10 to form an air passage in the heat sink body 10. And a lid 20 that is
The upper surfaces of the radiating fins 11, 11, ... And the abutting portion of the lid 20 are joined by solder 70.

With the above structure, the heat sink main body 10 and the lid body 20 are joined together by the solder 70, that is, the solder body 70 is fixed to the radiating fins 11, 11 ,. And transform. As a result, the contact area between the two is expanded, the thermal resistance value is lowered, and further, the metal contact between the lid 20 and the heat sink body 10 is prevented, and the unpleasant noise generated by the rotation of the cooling fan 30 is prevented.

As a method of fixing with solder, it is desirable to use cream solder in consideration of workability and the like, and the surface of the lid 20 or the heat sink body 10 (radiation fin 1
Cream solder is applied to the upper surface of Nos. 1, 11 ..., After that, the applied product is placed in a reflow oven for soldering.

Since the inside of the reflow furnace is at a high temperature during soldering, the cooling fan 30 is mounted after the soldering in order to avoid deformation.

[0034]

As is apparent from the above description, according to the present invention, it is possible to efficiently dissipate the high heat generated by the high heat generating element and suppress unpleasant vibration noise.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a diagram showing details of FIG. 1, in which (a) is a top view,
(B) is AA sectional drawing.

FIG. 3 is a view in which a heat conductive elastic body is interposed between a top surface of a heat radiation fin and a lid body.

4A and 4B are views showing a modified example of FIG. 2, in which FIG. 4A is a top view and FIG. 4B is a sectional view taken along line BB.

FIG. 5 is a diagram showing another modified example of FIG. 2, (a)
Is a top view and (b) is a sectional view taken along line CC.

FIG. 6 is an exploded view of FIG.

FIG. 7 is a diagram showing a second embodiment of the present invention, (a)
Is a top view and (b) is a side view of (a).

FIG. 8 is a view showing attachment of a heat conductive elastic body,
(A) is a figure which shows the state which mounted the heat conductive elastic body on the upper surface of a radiation fin, (b) is a figure which shows the state which pressed the heat conductive elastic body with a screw etc. FIG.

9A and 9B are views showing a modified example of the second embodiment of the present invention, in which FIG. 9A is a top view and FIG. 9B is a top view of FIG. 9A.

10A and 10B are views showing a modified example of FIG. 9, in which FIG. 10A is a side view and FIG. 10B is a sectional view taken along line DD.

FIG. 11 is a diagram showing another modification of FIG. 9,
(A) is a top view and (b) is a side view.

FIG. 12 is a diagram showing a third embodiment of the present invention,
(A) is a top view and (b) is a EE sectional view.

FIG. 13 is a view showing a conventional example, (a) is a top view,
(B) is a FF sectional view.

14A and 14B are views showing a conventional lid, in which FIG. 14A is a top view and FIG. 14B is a side view of FIG.

FIG. 15 is a diagram showing a contact state between a lid and a radiation fin.

[Explanation of symbols]

 10 heat sink main body 11 radiating fins 12 ventilation path 20 lid 21 introduction hole 30 cooling fan 40 thermal conductive elastic body

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 23/467

Claims (4)

[Claims] 1. A heat sink body (10) comprising a plurality of heat radiation fins (11, 11, ...) And formed of a material having excellent thermal conductivity, and an air passage (12) formed in the heat sink body (10). To cover the upper surface of the heat sink body (10), the lid body (20) is made of a material having excellent thermal conductivity, and the introduction hole (21) formed in the lid body (20) sucks or exhausts air. A cooling fan (30) for forcibly introducing cooling air into the ventilation passages (12, 12 ...), and an upper surface of the heat radiation fins (11, 11 ...) And a contact portion of the lid body (20). A heat sink with a fan having a heat conductive elastic body (40) formed of a material having excellent heat conductivity and flexibility. 2. The introduction hole (21) of the lid (20) includes:
2. The heat sink with a fan according to claim 1, further comprising a cylindrical throttle portion (22) for narrowing cooling air forcedly introduced into the ventilation passages (12, 12 ...) And increasing the wind speed. 3. The heat sink with a fan according to claim 1, wherein the heat conductive elastic body (40) is formed into a single sheet shape. 4. The heat conductive elastic body (40) includes a lid body (2).
The heat sink with a fan according to claim 1 or 2, which is fixed to (0).