JP3764267B2 - heatsink - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat sink for increasing a heat exchange area in various heat exchange devices, heat transfer devices, and the like, and more particularly to a heat sink that can be manufactured by a pressure casting method.
[0002]
[Prior art]
As is well known, a heat-related device such as a heat pipe is provided with a heat sink in order to increase a heat dissipation area or an endothermic area to improve heat exchange capability.
[0003]
An example of this is shown in FIGS. A heat sink 1 shown in FIG. 4 has a structure in which a plurality of flat fin bodies 2 which are parallel to each other are extended vertically upward from the upper surface of a flat base 3 and are extruded from, for example, an aluminum alloy. Manufactured by a molding method. Moreover, the heat sink 1 shown in FIG. 5 is the structure which changed the fin main body 2 into flat form, and was formed in the column shape, for example, is manufactured by the forge which used the copper alloy as a material.
[0004]
Here, the above-described extrusion molding and forging are methods in which the fin main body 2 and the base 3 are integrally processed from a single material. Therefore, as shown in FIG. 6, the fin main body that can be manufactured by this type of method. 2 has a minimum thickness (t) of about 2 mm, and the height (h) of the fin body 2 when the thickness (t) is set to 2 mm is limited to a maximum of about 20 mm. is there. Therefore, the ratio (C) between the thickness (t) and the height (h) of the fin body 2 in these manufacturing methods is expressed as C = h / t ≦ 20/2 = 10. Furthermore, the minimum pitch (p) between the fin bodies 2 is required to be 5 mm or more.
[0005]
Thus, in the conventional heat sink 1 obtained by the manufacturing method by extrusion molding or forging described above, the fin body 2 cannot be formed thin and high, and the fin body 2 provided for the surface area of the base 3 is provided. Since the number of sheets (number) is small, a sufficient heat exchange area could not be obtained.
[0006]
Thus, as a means for solving the above problems, a heat sink employing a pressure casting manufacturing method has been proposed, and this will be briefly described with reference to FIG. This type of heat sink 4 is a molten metal in which a plurality of rolled plates formed in advance in a predetermined shape are held substantially parallel to each other and, for example, about 2 mm of each lower end portion of the rolled plates is cast integrally. Is formed by pressure casting and integrated with the flat base 5.
[0007]
According to this pressure casting manufacturing method, since a ready-made rolled plate is adopted as the fin body 6, it is possible to achieve both the thinness and height in the fin body 6 and to set the pitch of each fin body 6 narrowly. As a result, the heat exchange area of the heat sink 4 can be increased as compared with the conventional one.
[0008]
[Problems to be solved by the invention]
However, in this type of heat sink 4, there is a possibility that the fin body 6 and the base 5 are loosened at the connecting portion, and the fin body 6 may come out of the base 5. This is because the load acting on the connecting portion between the fin body 6 and the base 5 increases in proportion to the height of the fin body 6, or the fin body 6 and the base 5 are originally separate members, This is because there is a limit even if the base 5 itself is formed thick and the insertion depth of the fin body 6 with respect to the base 5 is increased.
[0009]
In other words, conventionally, a heat sink having a thin and high fin body and sufficient strength has not been developed.
[0010]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a heat sink having a large heat exchange area and a strong configuration.
[0011]
[Means for Solving the Problem and Action]
In order to achieve the above object, the invention described in claim 1 is a material having a melting point lower than that of a material constituting the base, in the base provided so as to be able to transfer heat to the surface of the heat exchange target portion that generates or absorbs heat. is cast integrally with one end portion of the multiple fin using, in the heat sink being installed in an upright position their fins relative to the base, the connecting points between the fins of the base surface, and the base integrally formed of the same material, and is characterized in that the extension building protrusion triangular cross section toward the other end portion of the fin to the outer peripheral portion in a state that cast of the fins are provided.
[0012]
Therefore, according to the first aspect of the present invention, the base end portion of each fin is supported in the surface direction of the base in addition to the contact area between the base and the fin being increased by the protruding portion. The connection with the fins is strengthened, and as a result, the fins are reliably prevented from coming out of the base. In other words, the heat sink has a structure in which the connection between the base and the fins is strong. Note that by a protrusion with an acute angle, even if the pitch between the fins is narrow can be secured flat portion, the heat sink itself is not heavily over-time.
[0013]
Further, in the invention described in claim 2, the protrusion is a fin that is 15% or more larger than a structure in which the fin is installed in a standing state on a portion other than the protrusion on the surface of the base. It has a contact area.
[0014]
Therefore, according to the invention of claim 2, since the contact area between the base and each fin is sufficiently ensured, the strength of the connecting portion between the base and each fin is further improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific example according to the present invention will be described with reference to FIG. The example shown here is an example employing a flat fin body. A plurality of fin bodies 8 are attached to the upper surface of the base 7 in FIG. 1 so as to extend vertically upward, and the base 7 and the fin bodies 8 constitute a heat sink 9. As an example, the base 7 is a substantially square or rectangular plate having a thickness of about 1 to 3 mm, and is formed by casting Cu or a Cu alloy.
[0016]
On the other hand, the fin main body 8 forms a flat plate having a thickness (t) of 1.5 mm and a height (h1) of 20 mm as an example. As a material for the fin body 8, a rolled material made of Al or an Al alloy is employed. The ratio (C) between the thickness (t) and the height (h) in the fin body 8 is expressed as C = h / t ≦ 20 / 0.5 = 40. The pitch (p) between the fin bodies 8 is set to 2 mm.
[0017]
On the other hand, the left and right side portions of the upper surface portion of the base 7 sandwiching the fin main bodies 8 are raised upward along the side surfaces of the fin main bodies 8, and these portions are formed as protruding portions 10. On the other hand, in the upper surface portion of the base 7, portions other than the protruding portions 10, that is, portions between the protruding portions 10 are flat portions 20 having the same thickness. In addition, the insertion depth of the fin main body 8 with respect to the base 7 is set to 1 to 2 mm from the flat portion 20.
[0018]
The protrusion 10 is, for example, a protrusion having a triangular cross section facing each other with the fin body 8 interposed therebetween. Moreover, in this specific example, the height (h2) of the protrusion 10 with respect to the flat portion 20 of the base 7 is a contact area with the fin main body 8 as compared with the configuration in which the fin main body 8 is attached to the flat portion 20 in an upright state. Is set at a height increased by about 15%. In other words, the contact area between the protruding portion 10 and each fin body 8 is about 15% larger than the configuration in which the fin body 8 is attached to the flat portion 20 in an upright state. In this manner, the fin body 8 is supported by the outer peripheral portion of the base end portion being covered with the protruding portion 10 formed integrally from the same material as the base 7.
[0019]
Here, as other combinations of the material of the base 7 and the material of the fin body 8, Al—Mg, Al—graphite, Al—carbon fiber, and the like can be given. Among these, it is preferable to select a material having as high a thermal conductivity as possible and a good so-called castability. Further, the surface of the fin main body 8 may be plated with Zn, Sn, or the like, and according to this, compatibility with the molten metal forming the base 7 is improved.
[0020]
Therefore, according to the heat sink 9 configured as described above, the substantial area cast into the base 7 of each fin body 8 is increased by about 15% compared to the conventional case, Since the base end portion is supported from the lateral direction in FIG. 1, the connection between both members is strengthened, and the fin main body 8 is reliably prevented from coming out of the base 7. In addition, since the manufacturing method which attaches the fin main body 8 which consists of rolling materials to the base 7 by pressure casting is employ | adopted, since the fin main body 8 can be comprised thinly and highly, and pitch (p) can be set narrowly, as a whole The heat exchange area becomes larger. Therefore, the heat sink 9 having a strong configuration and a large heat exchange area can be obtained.
[0021]
Here, as a manufacturing method of the heat sink 9, more specifically, as a method of attaching the fin main body 8 and the base 5, for example, a conventionally known pressure casting manufacturing method can be used. That is, as shown in FIG. 2, the upper ends of the plurality of fin bodies 8 are held by the upper mold 11 (movable mold 11) with the above pitch and posture. In that case, the lower end part of each fin main body 8 is hold | maintained so that about 1-2 mm may protrude into the internal space of the lower mold | type 12 (fixed mold | type 12). This dimension is the insertion depth of the fin body 8 with respect to the base 7 described above. In addition, the bottom of the upper mold 11 is provided with a recess having a shape that follows the protrusion 10.
[0022]
On the other hand, the bottom surface portion of the lower mold 12 is formed on a flat surface. Further, the fixed mold 12 is provided with a pressure punch 14 configured to press a molten metal 13 which is a material of the base 7 upward from below in FIG. Then, from the above state, as shown in FIG. 3, the pressure punch 14 is moved in the direction of the arrow toward the movable mold 11 to apply pressure to the molten metal 13. In that case, about 1 to 2 mm at the lower end of each fin body 8 is inserted into the molten metal 13. When the lower end portion of the fin body 8 comes into contact with the molten metal 13 of Cu, the surface of the fin body 8 is melted because the melting point of Al is lower than the melting point of Cu. And if the material of the molten metal 13 and the fin main body 8 solidifies together, the base 7 and the fin main body 8 will be connected integrally.
[0023]
Furthermore, if the cooling / cleaning process etc. which follow a usual way are performed, work will be completed. As a result, it is possible to obtain a heat sink 9 in which there are almost no void defects in the base 7 and the base 7 and the fin body 8 are firmly connected. That is, in the heat sink 9 of this specific example, the base end portion of the fin body 8 is embedded in the base 7 and extends from the surface of the base 7 toward the upper end portion of the fin body 8 so as to cover the base end portion. The protrusion 10 is formed integrally with the base 7.
[0024]
In the above specific example, a flat fin body is illustrated, but the present invention is not specifically limited to the above, and the shape of the fin body may be, for example, a thin plate curved in a wave shape, a cylindrical shape, or a prismatic shape. . Note that the fin body is not limited to a rolled material, and a fin body formed by cutting or a casting can be employed .
[0025]
【The invention's effect】
As is apparent from the above description, according to the first aspect of the present invention, the outer peripheral portion of the fin is formed integrally with the fin on the surface of the base by the same material as the base. state and impact out of the triangular cross-section Ru extending toward the fin other end portion is provided with, since the material of the fins using a material having lower melting point than the base material, as compared with the conventional The connection strength between the fin and the base can be improved. In other words, a heat sink having a large heat exchange area and a strong structure can be obtained.
[0026]
Moreover, in invention of Claim 2, compared with the structure which attached the fin to the part other than the protrusion part in the surface of a base in the standing state, a protrusion part has a contact area with a fin larger 15% or more. Therefore, the strength of the connecting portion between the base and each fin body can be further improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a specific example of a heat sink according to the present invention.
FIG. 2 is a schematic view showing a state before pressurization in the manufacturing method of the specific example.
FIG. 3 is a schematic view showing a state during pressurization in the manufacturing method.
FIG. 4 is a schematic view showing a conventional heat sink.
FIG. 5 is a schematic view showing another example of a conventional heat sink.
FIG. 6 is a schematic diagram showing the relationship between the thickness and height of a fin body in a conventional heat sink.
FIG. 7 is a cross-sectional view showing a heat sink manufactured by a pressure casting method.
[Explanation of symbols]
7 ... Base, 8 ... Fin body, 9 ... Heat sink, 10 ... Projection, 120 ... Flat part.

Claims (2)

In the base provided so that heat can be exchanged on the surface of the heat exchange target portion that generates heat or absorbs heat, one end portion of the multiple fin with lower melting point material than the material constituting the base is cast integrally with their In the heat sink assembled in an upright state with respect to the base,
The base is integrally formed with the same material as that of the base at the connection portion with the fin on the surface of the base, and extends in a triangular cross section toward the other end of the fin with the outer periphery of the fin cast. A heat sink characterized in that a protruding part is provided.   The protrusion has a contact area with the fin that is 15% or more larger than a configuration in which the fin is mounted in an upright state on a portion of the surface of the base other than the protrusion. The heat sink according to claim 1.

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