JPH08330480A - Heat sink with built-in fan motor - Google Patents

Abstract

PURPOSE: To provide a heat sink with a built-in fan where the replacement of a fan motor unit is easy even after attachment to an object to be cooled such as LSI, etc., and the setup in manufacture process is simple. CONSTITUTION: This heat sink is composed of a cover 2, a heat sink part 1, which has a flange la for heat radiation around, and a fan motor unit 3. The motor 3 built in the fan motor unit 3 is a one-bearing-type fan motor, and a magnet 8 is fixed to the side of the fan motor, and a coil 9 is fixed to the side of a board 10. The one-bearing-type fan motor is supported by a venturi 12. A fan motor unit 3 is caught between the cover 2 and the heat sink part 1, and the cover 2 is fixed to the heat sink part 1 by a screw, etc. The setup in manufacture process is easy, and the replacement of the fan motor unit is easy even after attachment to the object to be cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan motor built-in heat sink used for cooling an LSI such as a CPU.

[0002]

2. Description of the Related Art In recent years, a heat sink of a type having a fan motor built therein has been widely used in order to improve the cooling efficiency of an LSI or the like. This heat sink is made of a light metal and has a small fan motor in the center to increase the efficiency of thermal conductivity.

[0003]

FIG. 7 is a sectional view showing an example of a conventional thin fan built-in heat sink. The heat sink portion 35, in which a large number of jetty walls 35a are provided for heat dissipation, has a press-fitting hole 36 in the central portion. The housing portion 37 of the fan motor unit 38 is inserted into the press-fitting hole 36.
The fan motor unit 38 is attached to the heat sink portion 35 by press-fitting. In addition, when not using press fitting, it is attached with an adhesive or the like. Since the conventional thin heat sink with built-in fan has a structure in which the fan motor unit is fixed by press-fitting, bonding, etc., it is difficult to replace the fan when a problem occurs after fixing the attached fan motor unit. There was a drawback that the heat sink would be damaged if it was forcibly replaced.

Further, when a heat sink with a built-in fan motor is attached to an object to be cooled with an adhesive or a double-sided tape, it is more difficult to replace the fan motor unit. An object of the present invention is to easily replace a fan motor unit even after being attached to an object to be cooled such as an LSI,
Moreover, it is another object of the present invention to provide a heat sink with a built-in fan that is easier to assemble in the manufacturing process as compared with the conventional manufacturing method.

[0005]

In order to achieve the above object, a heat sink with a built-in fan according to the present invention comprises a heat sink having a jetty for radiating heat around it, and a fan motor unit in which a fan motor is supported by a venturi.
A lid member, the venturi of the fan motor unit is sandwiched between the heat sink and the lid member, and the lid member is attached to the heat sink with a screw or an engaging means, so that the heat sink, the fan motor unit, and the lid member are attached to each other. It is configured to be integrated. Further, in the above configuration, an elastic member is interposed between the lid member and the fan motor unit or between the heat sink and the fan motor unit to sandwich the fan motor unit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a heat sink with a built-in fan according to the present invention. Fan motor unit 3
Is fixed such that its upper surface is in contact with the lid 2 and its lower surface is in contact with the heat sink portion 1. A large number of jetties 1a for heat dissipation are provided around the heat sink portion 1. The fan motor unit 3 includes a fan 7 having a magnet 8 attached to the shaft 1.
This is a single-bearing type fan motor that is rotatably supported by the venturi 22. A circuit board mounting substrate 10 is attached to a venturi 22, and a coil 9 is fixed thereon. By passing an electric current through the coil 9, a magnetic field acts on the magnet 8 to rotate the fan 7. The object to be cooled is attached to the lower surface of the heat sink 1 with an adhesive or the like.

2A and 2B are views for explaining the details of the fan motor unit in FIG. 1. FIG. 2A is a front view showing a cross section of a portion excluding the venturi, and FIG. 2B is a plan view. The housing 1 is provided at the center of the bottom portion 16b of the venturi 16.
3 is fixed. The shaft 11 is rotatably supported in the housing 13 via a bearing 14. A stop ring 12 is locked at the end of the shaft 11 to prevent the shaft 11 from coming off.
The coil 9 has a triangular shape, and the fixed yoke 1 of the substrate 10 is provided.
It is mounted on top of 5. The venturi 16 has an annular portion 16a that is pressed against the lower surface of the lid 2, a bottom surface portion 16b that is pressed against the upper surface of the heat sink portion 1, and a connection portion 16 that connects the annular portion 16a and the bottom surface portion 16b.
It is composed of c, 16d and 16e.

FIG. 3 is an exploded perspective view of a heat sink with a built-in fan according to the present invention, which is an example in which an annular portion of a venturi has elasticity. The lid 18 has screw holes at four corners, and is attached to a heat sink portion 19 having a jetty 20 on the periphery by screws 4a, 4b, 4c and 4d. A hole 18d of a sufficient size that does not hinder the rotation of the fan 7 is opened in the center of the lid 18, and the periphery of the hole 18d has an equal angle (12
The grooves 18a, 18b and 18c are provided at 0 °. The annular portion 21d of the venturi 21 of the fan motor unit 17 has a wavy shape when viewed from the side, and
Protrusions 21a, 21b and 21c are planted at the positions corresponding to 8a, 18b and 18c and at the apex portions of the corrugated shape.

With the projections 21a, 21b and 21c of the annular portion 21d fitted in the grooves 18a, 18b and 18c of the lid 18, the lid 18 is fitted to the heat sink portion 19a.
Since the fan motor unit 17 is assembled, the fan motor unit 17 will not be displaced after the assembly. Further, in the assembled state, the wave shape of the wave shape is deformed to be small and the annular portion 21d is pressed against the lower surface of the lid 18, so that the annular portion 21d has repulsive habit and the fan motor unit 17 Is securely fixed between the lid 18 and the heat sink portion 19. The lid 18 and the heat sink portion 19 are made of aluminum, and the venturi 21 is made of resin or the like.

FIG. 4 is a cross-sectional view showing another embodiment of the elastic member, which is an example provided between the lid and the fan motor unit. In this embodiment, the annular portion 22a of the venturi 22 of the fan motor unit 25 is not wavy, but the annular portion 2
Protrusions 23 are provided at a plurality of locations on 2a. The fan motor unit 25 is sandwiched between the lid 24 and the heat sink 26.
4, the upper portion of the protrusion 23 abuts the lower surface of the lid 24, and the vicinity of the protrusion of the annular portion 22a bends downward as shown in FIG. Therefore, a repulsive force is generated in the annular portion 22a, and the fan motor unit 25 is sandwiched between the lid 24 and the heat sink 26 by the elastic force.

FIG. 5 is a sectional view showing still another embodiment of the elastic member, which is an example provided between the heat sink and the fan motor unit. Two rising portions 27a and 27b are provided on the bottom portion 27c of the venturi 27. The rising portions 27a and 27b are pressed against the upper surface of the heat sink portion, and a repulsive force is generated on the bottom surface portion 27c. FIG. 6 is a sectional view showing another embodiment of the engaging means for the heat sink and the lid. Flange portions 32a and 32b are provided on the periphery of the lid 32, and projections 32c and 32d are provided at the tip end portions of the flange portions 32a and 32b. On the other hand, locking portions 30a and 30b are provided on the outermost jetty of the heat sink portion 30.

When the fan motor unit 31 is sandwiched, the flange portions 32a and 32b of the lid 32 are fitted and pushed into the jetty of the heat sink portion 30 to push the protrusion 32.
c and 32d are locked to the locking portions 30a and 30b. In the embodiments shown in FIGS. 4, 5 and 6, the means for determining the position of the fan motor unit in a state of being sandwiched by the elastic member (the grooves 18a, 18b and 18c shown in FIG. 3 and the projections) is used. 21a, 21b and 21c) of the same function is taken.

[0013]

As described above, the present invention comprises the heat sink, the fan motor unit and the lid member, and the fan motor unit is sandwiched between the heat sink and the lid member and attached by screws or engaging means. Since the heat sink, the fan motor unit and the lid member are integrated, the following various effects can be obtained. The fan motor unit can be manufactured in the same manner as a normal fan motor manufacturing method, and there is no need to change the manufacturing line. You can check the quality of the fan motor unit separately before installing it in the heat sink. In the conventional heat sink with a built-in fan, it is difficult to replace the fan motor unit after the heat sink is attached to the heat sink, so it is not possible to judge whether the heat sink is built in or not. The heat sink with a built-in fan can be easily incorporated in the manufacturing process.
In addition, the fan motor unit can be easily replaced after being attached to the object to be cooled.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a heat sink with a built-in fan according to the present invention.

2A and 2B are views for explaining the details of the fan motor unit in FIG. 1, in which FIG. 2A is a front view showing a cross section of a portion excluding a venturi, and FIG. 2B is a plan view.

FIG. 3 is an exploded perspective view of a heat sink with a built-in fan according to the present invention.

FIG. 4 is a sectional view showing another embodiment of the elastic member.

FIG. 5 is a sectional view showing still another embodiment of the elastic member.

FIG. 6 is a cross-sectional view showing another embodiment of the engaging means for the heat sink and the lid.

FIG. 7 is a partial cross-sectional view for explaining a conventional heat sink.

[Explanation of symbols]

1, 19, 26, 30, 35 ... Heat sink part 2, 18, 24, 32 ... Lid 3, 17, 25, 28, 31, 38 ... Fan motor unit 4a, 4b, 4c, 4d ... Screw 7 ... Fan 8 ... Magnet 9 ... Coil 10 ... Substrate 11 ... Shaft 12 ... Stop ring 13, 37 ... Housing 14 ... Bearing 15 ... Fixed yoke 16, 21, 22, 27 ... Venturi 20 ... Jetty 23 ... Projection 36 ... Press-fit hole

Claims (2)

[Claims] 1. A heat sink having a jetty for radiating heat around, a fan motor unit supporting a fan motor with a venturi, and a lid member. The venturi of the fan motor unit includes a heat sink and a lid member. A heat sink with a built-in fan motor, characterized in that the heat sink, the fan motor unit and the lid member are integrated by sandwiching the lid member and attaching the lid member to the heat sink with screws or engaging means. 2. The fan according to claim 1, wherein an elastic member is interposed between the lid member and the fan motor unit or between the heat sink and the fan motor unit to sandwich the fan motor unit. Heat sink with built-in motor.