JP2017034111A - heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink which deals with increase of the heating power of a heating element and properly cools the heating element.SOLUTION: A heat sink 100 includes a base 10 and a fin unit 20. The base 10 is thermally connected to a heating element. The fin unit 20 has a plurality of fins 22 and is detachably attached to the base 10. The base 10 comprises: a base body part 11 made of a first material and thermally connected to the heating element and the fin unit 20; and a base side engaging part 12 which is made of a second material having a thermal expansion coefficient lower than that of the first material and engages with a fin side engaging part 24 formed at the fin unit 20.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heat sink.

  Various electronic devices and electrical devices are provided with a heat sink for radiating heat generated by a heating element such as a semiconductor element. Conventionally, a heat sink including a base on which a heating element is fixed and a fin that is detachably attached to the base has been proposed (see Patent Document 1).

JP 2008-41684 A

  The heat sink described in Patent Document 1 can cope with an increase in the amount of heat generated by the heating element by adjusting the number of fins. However, since this heat sink is attached to the base by fitting the fin into the groove formed in the base, if the base becomes hot due to the heat transferred from the heating element, The formed grooves are also large, and the fins can be removed from the base. When the fins are removed, the heat dissipation performance of the heat sink is lowered, so that the heating element cannot be accurately cooled.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a heat sink that can cope with an increase in the amount of heat generated by the heating element and that can accurately cool the heating element.

  In order to solve the above problems, a heat sink according to an aspect of the present invention includes a base that is thermally connected to a heating element, and a fin unit that has at least one fin and is detachably attached to the base. . The base is formed of the first material, and is formed of the first portion thermally connected to the heating element and the fin unit, and the second material having a lower coefficient of thermal expansion than the first material, and is formed in the fin unit. A second portion that engages with the engaging portion.

  Note that any combination of the above-described constituent elements, and those obtained by replacing the constituent elements and expressions of the present invention with each other among methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the heat sink which can respond to the increase in the emitted-heat amount of a heat generating body, and can cool a heat generating body exactly can be provided.

It is a perspective view which shows the heat sink which concerns on embodiment. It is a disassembled perspective view which shows the heat sink which concerns on embodiment. It is a top view of a base and a fin unit. 4A and 4B are sectional views of the heat sink. FIGS. 5A and 5B are views showing a state when the fin unit is attached to the base. FIGS. 6A and 6B are views showing a state when the fin unit is attached to the base. FIGS. 7A and 7B are views showing a state when the fin unit is attached to the base.

  Hereinafter, the same or equivalent components and members shown in the respective drawings are denoted by the same reference numerals, and repeated descriptions thereof are omitted as appropriate. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. Also, in the drawings, some of the members that are not important for describing the embodiment are omitted.

  1 and 2 show a heat sink 100 according to an embodiment. FIG. 1 is a perspective view of the heat sink 100. FIG. 2 is an exploded perspective view of the heat sink 100. The heat sink 100 radiates heat generated by a heating element such as an LSI. The heat sink 100 includes a base 10, a fin unit 20, and a heat transfer member 30. Hereinafter, the side on which the fin unit 20 is attached to the base 10 will be described as the upper side.

  The base 10 is thermally connected to the heating element. The heat transfer member 30 is provided between the base 10 and the fin unit 20. The fin unit 20 is detachably attached to the base 10 with the heat transfer member 30 interposed therebetween. The heat generated by the heating element is transmitted in the order of the base 10, the heat transfer member 30, and the fin unit 20, and is mainly radiated in the fin unit 20.

  FIG. 3 is a top view of the base 10 and the fin unit 20. 4A and 4B are cross-sectional views of the heat sink 100. FIG. 4A corresponds to the cross-sectional view taken along line AA in FIG. 3, and FIG. 4B corresponds to the cross-sectional view taken along line BB in FIG. 4A and 4B show a state where the fin unit 20 is attached to the base 10.

  The fin unit 20 includes a base 21 and a plurality of fins 22. The base portion 21 includes a base body portion 23 and a fin side engagement portion 24. The base main body 23 is a substantially rectangular member in plan view, and is formed of a material having a relatively high thermal conductivity such as aluminum.

  The fin side engaging portion 24 is provided below the base main body portion 23. The fin-side engagement portion 24 is a hook-shaped member, and includes a first portion 24a extending downward, a second portion 24b extending from the lower end of the first portion 24a in a direction substantially orthogonal to the first portion 24a, and a second portion. And a third portion 24c protruding upward from the portion 24b. The fin side engaging portion 24 may be formed integrally with the base main body portion 23 or may be formed separately from the base main body portion 23 and then coupled to the base main body portion 23.

  The plurality of fins 22 are provided on the upper side of the base main body 23. The plurality of fins 22 are elongated plate-like members, and are formed of a material having a relatively high thermal conductivity such as aluminum or copper. The plurality of fins 22 may be formed integrally with the base portion 21 or may be combined with the base portion 21 after being formed separately from the base portion 21.

  The base 10 includes a base main body portion 11 and a base side engaging portion 12. The base body 11 is thermally connected to the heating element. The base main body 11 is a rectangular member in plan view, and is formed of a material having a relatively high thermal conductivity such as aluminum or copper. The base main body 11 may be formed of the same material as the base main body 23 of the fin unit 20 or may be formed of a material different from the base main body 23.

  The base side engaging portion 12 is fixed to the base main body portion 11. In the present embodiment, the base-side engaging portion 12 is accommodated in the concave portion 11a formed in the base main body portion 11, and is fixed there. The base side engaging portion 12 is a box-shaped member and is formed of a material having a lower coefficient of thermal expansion than the base main body portion 11. Thereby, the thermal deformation of the base side engaging part 12 is suppressed. Preferably, the base side engaging portion 12 is formed of a material that hardly undergoes thermal deformation with heat generated by the heating element. For example, the base side engaging part 12 is formed of ceramics. On the upper surface of the base side engaging portion 12, a first opening 12a for the fin side engaging portion 24 to enter the base side engaging portion 12 and the tip of the fin side engaging portion 24 (ie, the third portion 24c). ) Is formed in the second opening 12b.

  The heat transfer member 30 is fixed to the upper surface of the base body 11. The heat transfer member 30 is a substantially rectangular member in plan view, and an opening 30a is formed at a position corresponding to the fin side engaging portion 24 and the base side engaging portion 12 in the vertical direction.

  In the present embodiment, the heat transfer member 30 includes an elastic member 31 and a heat transfer sheet 32. The elastic member 31 is a substantially rectangular member in plan view, and is formed of an elastic material such as sponge or rubber. The elastic member 31 has an opening corresponding to the opening 30a.

  The heat transfer sheet 32 is a sheet-like member and is wound around the elastic member 31. In a state where the fin unit 20 is attached to the base 10, the heat transfer sheet 32 contacts the base main body 23 in addition to the base main body 11. That is, the heat transfer sheet 32 is thermally connected to both the base main body 11 and the base main body 23. Therefore, the heat transferred from the heating element to the base 10 (particularly the base main body 11) is transferred to the fin unit 20 via the heat transfer sheet 32 and is mainly radiated in the fins 22.

  5 to 7 show a state where the fin unit 20 is attached (or removed) to the base 10. 5 (a), 6 (a), and 7 (a) correspond to FIG. 4 (a). FIGS. 5B, 6B, and 7B correspond to FIG. 4B. The flow of attaching and detaching the fin unit 20 to the base 10 will be described with reference to FIG. 4 in addition to FIGS.

  From the state where the fin unit 20 is removed from the base 10 as shown in FIGS. 5A and 5B, the fin unit 20 is moved downward to approach the base 10. When the fin unit 20 is brought close to the base 10 while crushing the heat transfer member 30, the fin side engaging portion 24 enters the base side engaging portion 12 from the first opening 12a as shown in FIGS. 6 (a) and 6 (b). To do.

  As shown in FIGS. 7A and 7B, the fin unit 20 is rotated 90 degrees with the vertical direction as the rotation axis while the fin unit 20 is pressed against the base 10 side. The third portion 24c of the fin-side engagement portion 24 faces the second opening 12b in the vertical direction.

  When the pressing of the fin unit 20 against the base 10 side is stopped, the fin unit 20 is urged away from the base 10 by the elastic force of the heat transfer member 30. Then, as shown in FIGS. 4A and 4B, the third portion 24 c of the fin-side engagement portion 24 is caught by the second opening 12 b of the base-side engagement portion 12. Further, the second portion 24 b of the fin side engaging portion 24 is pressed against the base side engaging portion 12. In this way, the fin side engaging portion 24 and the base side engaging portion 12 are engaged, and the fin unit 20 is attached to the base 10.

  When the fin unit 20 is removed from the base 10 (that is, when the engagement between the fin side engaging portion 24 and the base side engaging portion 12 is disengaged), the flow is opposite to that when mounting. That is, the fin unit 20 is removed from the base 10 in the flow of FIG. 4 → FIG. 7 → FIG. 6 → FIG.

  According to the heat sink 100 according to the embodiment described above, the fin unit 20 is detachably attached to the base 10. Thereby, even when the heat generation amount of the heating element increases or when the temperature of the environment in which the heating element is used is different from the assumption (for example, when it is used in an environment that is hotter than expected), that is, the heat sink 100 is required. Even if the cooling performance is changed, it can be dealt with by replacing the fin unit 20 while keeping the base 10 fixed to the heating element with screws, adhesive or the like. For example, the cooling performance can be changed by replacing the fin unit 20 having the number of fins corresponding to the heat generation amount. In addition, according to the heat sink 100 according to the embodiment, the base 10 includes a base main body portion 11 that transmits heat from the heating element to the fin unit 20, and a base side engagement portion 12 that engages with the fin unit 20. ,including. The base side engaging portion 12 is formed of a material having a lower coefficient of thermal expansion than the base main body portion 11. Therefore, compared with the case where the base side engaging part 12 is formed of the same material as the base main body part 11, thermal deformation of the base side engaging part 12 when the temperature of the heat sink 100 (particularly the base 10) is increased is suppressed. Is done. Therefore, even if the temperature of the heat sink 100 becomes high, the engagement between the base side engaging portion 12 and the fin side engaging portion 24 can be maintained. That is, even if the temperature of the heat sink 100 becomes high, the fin unit 20 is removed from the base 10. Since it does not come off, the heat sink 100 can accurately cool the heating element. That is, according to the heat sink 100 according to the embodiment, it is possible to provide a heat sink 100 that can cope with an increase in the amount of heat generated by the heat generating element and can accurately cool the heat generating element.

  Further, in the heat sink 100 according to the embodiment, the fin side engaging portion 24 and the base side engaging portion 12 are engaged by the biasing force of the heat transfer member 30. Here, even if the fin-side engagement portion 24 and the base-side engagement portion 12 are slightly deformed due to thermal expansion, the third portion 24c is still inserted into the second opening 12b by the urging force of the heat transfer member 30. The second portion 24b is also pressed against the base side engaging portion 12. In other words, according to the heat sink 100 according to the embodiment, even when the fin side engaging portion 24 and the base side engaging portion 12 are thermally deformed, their engagement can be maintained.

  In the heat sink 100 according to the embodiment, the tip of the hook-like fin-side engagement portion 24 is caught by the opening of the base-side engagement portion 12 by the urging force of the heat transfer member 30, and the fin-side engagement portion 24 and the base The side engaging portion 12 is engaged. That is, the fin unit 20 can be attached to the base 10 relatively easily. Thereby, the time which replacement | exchange of the fin unit 20 can be shortened, and the cost of replacement work can be reduced. Moreover, since the structure of the engaging portion is relatively simple, each engaging portion and thus the heat sink 100 can be manufactured at a relatively low cost.

  The configuration of the heat sink according to the embodiment has been described above. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements, and such modifications are also within the scope of the present invention. Also, combinations of the embodiments are possible. Hereinafter, a modification is shown.

(Modification 1)
In the embodiment, the case where the fin unit 20 includes a plurality of fins 22 has been described, but the present invention is not limited thereto. The fin unit 20 may include only one fin 22. That is, the fin unit 20 only needs to include at least one fin 22.

(Modification 2)
In the embodiment, the case where one fin unit 20 is attached to one base 10 has been described, but the present invention is not limited to this. A plurality of fin units 20 may be attached to one base 10. In this case, the number of fins 22 included in each fin unit 20 may not be the same.

(Modification 3)
Although not particularly mentioned in the embodiment, when the fin side engaging portion 24 is formed separately from the base main body portion 23 and then coupled to the base main body portion 23, the fin side engaging portion 24 is It may be formed of a material having a lower coefficient of thermal expansion than the base main body 23. For example, the fin side engaging portion 24 may be formed of ceramics. In this case, in addition to the base-side engagement portion 12, the fin-side engagement portion 24 is hardly thermally deformed by the heat generated by the heating element, so that the base-side engagement portion 12 and the fin-side engagement portion 24 are highly engaged. Strength can be maintained.

(Modification 4)
In the embodiment, the case where the heat transfer member 30 includes the elastic member 31 and the heat transfer sheet 32 has been described, but the present invention is not limited thereto. The heat transfer member 30 only needs to have high thermal conductivity and elasticity, and may be formed of, for example, rubber containing silicon.

(Modification 5)
In the embodiment, when the hook-shaped fin-side engagement portion 24 is hooked on the opening of the base-side engagement portion 12, the fin-side engagement portion 24 and the base-side engagement portion 12 are detachably engaged, Although the case where the unit 20 is detachably attached to the base 10 has been described, the present invention is not limited to this. The base 10 may have a hook-shaped engaging portion, and the fin-side engaging portion 24 may have an opening through which the hook is caught. Further, the fin side engaging portion 24 and the base side engaging portion 12 may have other structures as long as they can be detachably engaged.

  DESCRIPTION OF SYMBOLS 10 Base, 11 Base main-body part, 12 Base side engaging part, 20 Fin unit, 21 Base part, 22 Fin, 23 Base part main part, 24 Fin side engaging part, 30 Heat transfer member, 31 Elastic member, 32 Heat transfer sheet 100 Heat sink.

Claims (3)

A base thermally connected to the heating element;
A fin unit having at least one fin and detachably attached to the base;
The base is
A heat transfer section thermally connected to the heating element and the fin unit;
A heat sink comprising: a base side engagement portion that is formed of a material having a lower thermal expansion coefficient than the heat transfer portion and engages with a fin side engagement portion formed in the fin unit. A heat transfer member that is provided between the base and the fin unit and that thermally connects them;
When the fin unit is attached to the base, the heat transfer member is elastically deformed by being sandwiched between the base and the fin unit,
2. The heat sink according to claim 1, wherein the fin-side engagement portion and the base-side engagement portion are configured to be engaged by receiving an urging force due to elastic deformation from the heat transfer member. .   The heat sink according to claim 2, wherein the heat transfer member includes an elastic member and a heat transfer sheet that is wound around the elastic member and thermally connects the base and the fin unit.

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