JP2019204855A - Heat dissipation structure - Google Patents

Abstract

To realize a heat dissipation structure capable of preventing a temperature of a housing from rising excessively to prevent burns.SOLUTION: A heat dissipation structure (20) comprises a heat transfer unit (10) between a cabinet (1) and a heating body (6). The heat transfer unit includes at least one thermal deformation member (2) having a heat deformation unit (22) at least partially made of a shape memory alloy. When reaching a transformation point, the thermal deformation unit deforms so that an air heat insulation layer (8) may be formed between the cabinet and the heating body.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heat dissipation structure that dissipates heat from a heating element used in an electronic device such as a mobile phone.

  In Patent Document 1, the heat generated from the heating element is efficiently spread in the surface direction with a heat diffusion film and then released to the casing (support), thereby suppressing the temperature of the casing from partially rising. A heat dissipating structure is disclosed.

JP 2010-171030 A (released on August 5, 2010)

  However, in the heat dissipation structure described in Patent Document 1, the heat generated by the heating element continues to be transmitted to the housing. For this reason, if the temperature of the heating element further rises and heat dissipation and heat diffusion cannot catch up, the temperature of the casing rises, and if a human body touches the casing, there is a risk of burns.

  An object of one embodiment of the present invention is to realize a heat dissipation structure that can prevent burns without excessively increasing the temperature of a housing.

  In order to solve the above problems, a heat dissipation structure according to an aspect of the present invention includes a housing, a heating element, and a heat transfer section disposed between the casing and the heating element. The heat transfer portion includes at least one heat deformation member having a heat deformation portion at least part of which is made of a shape memory alloy, and the heat deformation portion, when the temperature of the heat deformation portion reaches the transformation point, It deform | transforms so that an air heat insulation layer may be formed between a body and the said heat generating body.

  According to one aspect of the present invention, when the temperature of the thermally deformable portion of the thermally deformable member reaches the transformation point, the air insulation layer is formed between the housing and the heating element. The temperature drops. Therefore, according to the said one aspect | mode, the temperature of the said housing | casing does not rise too much and can implement | achieve the thermal radiation structure which can prevent a burn.

It is sectional drawing which shows an example of the thermal radiation structure concerning Embodiment 1. FIG. It is a perspective view which shows an example of the heat deformation member concerning Embodiment 1. FIG. (A) is a perspective view which shows the shape of the heat deformation member concerning Embodiment 1 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part more than a transformation point. It is a perspective view which shows the shape of the heat deformation member concerning Embodiment 1 when it is. (A) is sectional drawing which shows the movement of the heat | fever in the thermal radiation structure concerning Embodiment 1 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part transformed. It is sectional drawing which shows the movement of the heat | fever in the thermal radiation structure concerning Embodiment 1 when it is more than a point. It is a perspective view which shows an example of the heat deformation member concerning the modification 1 of Embodiment 1. FIG. It is sectional drawing which shows an example of the thermal radiation structure concerning Embodiment 2. (A) is sectional drawing which shows the shape of the heat-deformable member concerning Embodiment 3 when the temperature of a heat-deformation part is less than T1, (b) is the temperature of a heat-deformation part T1 or more, T2 It is sectional drawing which shows the shape of the heat-deformable member concerning Embodiment 3 when it is less than (c), (c) is the heat-deformable member concerning Embodiment 3 when the temperature of a heat-deformation part is T2 or more. It is sectional drawing which shows a shape. (A) is a perspective view which shows the shape of the heat deformation member concerning Embodiment 4 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part more than a transformation point. It is a perspective view which shows the shape of the heat deformation member concerning Embodiment 4 when it is. (A) is a perspective view which shows the shape of the heat deformation member concerning Embodiment 5 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part more than a transformation point. It is a perspective view which shows the shape of the heat deformation member concerning Embodiment 5 when it is. (A) is a perspective view which shows the shape of the heat deformation member concerning Embodiment 6 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part more than a transformation point. It is a perspective view which shows the shape of the heat deformation member concerning Embodiment 6 when it is. (A) is sectional drawing which shows the shape of the heat deformation member concerning Embodiment 6 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part more than a transformation point. It is sectional drawing which shows the shape of the heat deformation member concerning Embodiment 6 when it is. (A) is sectional drawing which shows the shape of the heat deformation member concerning Embodiment 7 when the temperature of a heat deformation part is lower than a transformation point, (b) is the temperature of a heat deformation part more than a transformation point. It is sectional drawing which shows the shape of the heat deformation member concerning Embodiment 7 when it is.

  An embodiment of the present invention will be described in detail. In the following embodiments, members having the same functions as those described above are denoted by the same reference numerals, and the description thereof will not be repeated.

Embodiment 1
FIG. 1 is a cross-sectional view showing an example of a heat dissipation structure 20 according to the present embodiment. In FIG. 1, as a heat dissipation structure 20 according to the present embodiment, a heat dissipation structure provided in a mobile phone is illustrated as an example. Hereinafter, the normal direction (vertical axis direction) of the substrate 7 shown in FIG. 1, in other words, the direction connecting the cabinet 1 and the heating element 6 is defined as the Z direction, and the thermal deformation member among the horizontal axis directions orthogonal to the Z direction. 2, the direction parallel to the fixed end 22a of the thermally deformable portion 22 is defined as the Y direction, and the horizontal axis direction orthogonal to the Y direction is defined as the X direction.

  As shown in FIG. 1, the heat dissipation structure 20 according to the present embodiment includes a cabinet 1 (housing), a heat transfer unit 10, a heating element 6, and a substrate 7. In FIG. 1, for convenience of illustration, only a part of the cabinet 1 is illustrated. The heating element 6 is disposed in a space surrounded by the cabinet 1. A heating element 6 of the mobile phone is mainly a CPU (Central Processing Unit) and is mounted on a substrate 7. The heat transfer unit 10 is disposed between the cabinet 1 and the heating element 6. The heat transfer unit 10 conducts heat generated from the heating element 6 to the cabinet 1. The heat transfer unit 10 includes a heat deformation member 2, a heat diffusion film 3, a sheet metal 4, and a heat conductive material layer 5.

  The heat conductive material layer 5 is provided between the heating element 6 and the sheet metal 4 in order to efficiently release the heat of the heating element 6 to the outside. In order to diffuse the heat of the heating element 6, the heat diffusion film 3 is attached to the surface of the sheet metal 4 opposite to the heat conductive material layer 5 with an adhesive (not shown). A thermal deformation member 2 is provided between the heat diffusion film 3 and the cabinet 1. The thermally deformable member 2 is formed using, for example, a shape memory alloy such as a Ni—Ti alloy. The entire heat deformation member 2 may be formed of a shape memory alloy, or only the heat deformation portion 22 described later may be formed of a shape memory alloy. Or only the part (in the case of this embodiment, fixed end 22a mentioned later) in the heat deformation part 22 which deform | transforms actually may be formed with the shape memory alloy.

  FIG. 2 is a perspective view showing an example of the thermally deformable member 2 according to the present embodiment. As shown in FIG. 2, in the present embodiment, a plurality of thermal deformation members 2 are provided between the thermal diffusion film 3 and the cabinet 1. FIG. 3A is a perspective view showing the shape of the thermal deformation member 2 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. It is a perspective view which shows the shape of the heat deformation member 2 concerning this embodiment when the temperature of the deformation | transformation part 22 is more than a transformation point.

  As shown in FIGS. 2 and 3 (a) and (b), the heat deformation member 2 has a fixing portion 21 and a heat deformation portion 22. The fixing | fixed part 21 is a frame which has a frame shape, for example. The fixing portion 21 is fixed to the heat diffusion film 3, for example, on the bottom surface 21 a of the fixing portion 21. A part of the thermal deformation portion 22 is fixed to the fixing portion 21. In the present embodiment, the thermal deformation portion 22 has, for example, a flap shape. One end of the thermally deformable portion 22 is a fixed end 22a and is fixed to one side of the frame.

  The heat-deformable member 2 has, for example, a quadrangular shape in which grooves 23 are formed along three sides. In the thermally deformable member 2, a portion surrounded by the groove portion 23 is the thermally deformable portion 22, and a portion outside the groove portion 23 surrounding the thermally deformable portion 22 is the fixed portion 21. The opposite end of the thermally deformable portion 22 to the groove portion 23 is a free end that is not fixed anywhere.

  As shown in FIG. 1, the heat-deformable member 2 is formed so that a part of the heat-deformable portion 22 contacts the cabinet 1 at a temperature lower than the transformation point (deformation temperature) of the shape memory alloy. As shown in FIG. 1 and FIG. 3A, the thermally deformable portion 22 stands in a state bent at a right angle to the Z direction with respect to the fixed portion 21 at a temperature lower than the transformation point (for example, a normal temperature). ing. For this reason, in this embodiment, the tip 22b (in other words, the end surface opposite to the fixed end 22a) of the thermal deformation portion 22 contacts the cabinet 1 at a temperature lower than the transformation point. As shown in FIG. 2, the heat deformable member 2 contacts the cabinet 1 so that the heat deformable portions 22 are arranged in the Y direction.

  On the other hand, as shown in FIG. 3B, when the temperature of the heat deforming portion 22 reaches the transformation point (threshold), the heat deforming portion 22 is interposed between the cabinet 1 and the heat generating element 6. Are deformed (fall down) in a direction away from the cabinet 1. When the temperature of the heat-deformed portion 22 reaches the transformation point, the heat-deformed portion 22 becomes horizontal with the fixed portion 21 by bending, for example, 90 degrees in the inclining direction indicated by the arrow about the fixed end 22a.

  FIG. 4A is a cross-sectional view showing the movement of heat in the heat dissipation structure 20 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. FIG. 5 is a cross-sectional view showing heat transfer in the heat dissipation structure 20 according to the present embodiment when the temperature of the heat-deformed portion 22 is equal to or higher than the transformation point. In FIG. 4A, heat conducted from the heating element 6 to the cabinet 1 via the heat transfer section 10 is indicated by an arrow indicated by a solid line. In FIG. 4B, the heat conducted from the heating element 6 to the heat transfer section 10 is indicated by an arrow indicated by a solid line, while the heat insulated by the air heat insulating layer 8 is indicated by an arrow indicated by a broken line. Yes.

  As shown to (a) of FIG. 4, in this embodiment, when the temperature of the heat deformation part 22 is lower than a transformation point, the heat of the heat generating body 6 is the heat conductive material layer 5, the sheet metal 4, and a thermal diffusion film. 3. Conducted to the cabinet 1 via the heat deformation member 2. At this time, the thermally deformable member 2 stands so that the tip 22 b of the thermally deformable portion 22 contacts the cabinet 1. For this reason, the heat of the heating element 6 can be efficiently conducted to the cabinet 1. The heat conducted to the cabinet 1 is dissipated into the air through the outer surface of the cabinet 1 in contact with the air. In this embodiment, at this time, heat is diffused in the surface direction (horizontal direction, X direction and Y direction) of the heat diffusion film 3 by the effect of the heat diffusion film 3 by setting the heat dissipation path in the Z-axis direction. The heat spot is prevented from being formed immediately above the heating element 6.

  However, if the temperature of the heating element 6 further rises and heat dissipation and heat diffusion cannot catch up, a high-temperature heat spot is formed immediately above the heating element 6, which may make the user feel uncomfortable. In some cases, the user may be burned.

  Therefore, in the present embodiment, the thermal deformation member 2 is provided between the cabinet 1 and the heating element 6 (more specifically, between the thermal diffusion film 3 and the cabinet 1). When the temperature of the thermal deformation part 22 is lower than the transformation point, a part of the thermal deformation part 22 comes into contact with the cabinet 1 and the temperature reaches the transformation point. Deforms in the direction of separation. For this reason, as shown in FIG. 4B, when the temperature of the thermally deformable portion 22 reaches the transformation point, the contact area between the thermally deformable member 2 and the cabinet 1 becomes 0 (zero). Thereby, the cross-sectional layer (air heat insulation layer 8) by air is formed between the thermal diffusion film 3 and the cabinet 1, and the heat conduction from the heat transfer part 10 to the cabinet 1 is suppressed. As a result, it is possible to reduce the temperature of the portion directly above the heating element 6 in the cabinet 1 and suppress the formation of a high-temperature heat spot. Therefore, according to this embodiment, it can prevent that the temperature of the cabinet 1 becomes high too much and a user gets burned.

  In addition, when the temperature of the heat-deformed portion 22 becomes lower than the transformation point (in other words, when the temperature of the heat-deformed portion 22 is no longer high), the reverse deformation occurs. That is, the thermally deformable portion 22 bends 90 degrees in the direction opposite to the arrow around the fixed end 22a from the lying state shown in FIG. The standing state shown in (a) of FIG. Thereby, since the heat deformation part 22 contacts with the cabinet 1 and the air heat insulation layer 8 is lost, the heat of the heating element 6 can be efficiently conducted to the cabinet 1.

  The transformation point of the shape memory alloy can be arbitrarily set. For example, the composition of the shape memory alloy may be changed so that the transformation point becomes a desired temperature. For example, as shown in Patent Document 1, when the temperature of the outer surface of the cabinet 1 exceeds 60 ° C., the cabinet 1 may cause a low-temperature burn when it is a housing of a small electronic device such as a form phone. The British national standard BS EN563 stipulates that “equipment surface temperature / contact time” that will cause low temperature burns is “43 ° C./8 hours, 48 ° C./10 minutes, 60 ° C./1 minute”. Therefore, the transformation point of the shape memory alloy is preferably set to 60 ° C. or lower, for example, and more preferably set to 50 ° C. or lower.

<Modification 1>
FIG. 5 is a perspective view showing an example of the thermally deformable member 2 according to this modification. The heat-deformable member 2 only needs to have a shape in which a part contacts the heat diffusion film 3 and another part contacts the cabinet 1. Therefore, as shown in FIG. 5, the heat-deformable member 2 may be formed in a rectangular shape that is long in the Y direction, for example. In other words, the thermal deformation portions 22 shown in FIG. 2 may be connected to one in the Y direction.

<Modification 2>
Further, in the present embodiment, when the thermal deformation portion 22 reaches the transformation point, the heat deformation portion 22 becomes horizontal with the fixing portion 21 by bending 90 degrees in the lying down direction indicated by the arrow with the fixing end 22a as an axis. And explained. However, in this embodiment, if the thermal deformation portion 22 is deformed so that the contact area between the thermal deformation member 2 and the cabinet 1 becomes 0 (zero), the bending angle is not limited to 90 degrees, but 90 degrees. It may be less.

[Embodiment 2]
FIG. 6 is a cross-sectional view showing an example of the heat dissipation structure 20 according to the present embodiment. As shown in FIG. 6, in the heat dissipation structure 20 according to the present embodiment, the bottom surface 21 a of the fixing portion 21 is fixed to the cabinet 1, and the tip 22 b of the heat deformation portion 22 contacts the heat diffusion film 3. Except for this, the heat dissipation structure 20 according to the first embodiment has the same configuration. Also in the present embodiment, when the temperature of the thermal deformation portion 22 reaches the transformation point, the thermal deformation portion 22 is interposed between the cabinet 1 and the heating element 6 and the air heat insulating layer 8 (see FIG. 4B). ) To form. More specifically, at this time, the thermal deformation portion 22 is deformed so as to form the air heat insulating layer 8 between the thermal deformation member 2 and the thermal diffusion film 3. As a result, the same effect as the heat dissipation structure 20 according to the first embodiment can be obtained.

  In addition, according to this embodiment, the bottom surface 21 a of the fixing portion 21 is fixed to the cabinet 1, so that the heat of the heating element 6 is transferred from the heat diffusion film 3 to the fixing portion 21 via the thermal deformation portion 22. Conducted and conducted from the fixed portion 21 to the cabinet 1. Therefore, according to the present embodiment, as in the first embodiment, the heat of the heating element 6 is conducted from the thermal diffusion film 3 to the thermal deformation portion 22 via the fixing portion 21, and from the thermal deformation portion 22 to the cabinet 1. Compared with the case where the heat conduction member 2 is conducted, the contact area between the thermal deformation member 2 and the cabinet 1 can be increased. Therefore, according to this embodiment, the heat conducted from the thermal diffusion film 3 to the thermal deformation portion 22 can be efficiently spread in the surface direction and then released to the cabinet 1. For this reason, according to this embodiment, compared with Embodiment 1, the local temperature rise of the cabinet 1 can be suppressed more.

  In the following embodiment, as in the first embodiment, the case where the bottom surface 21a of the fixing portion 21 is fixed to the heat diffusion film 3 will be described as an example. However, as in the present embodiment, the fixing portion 21 is described. Needless to say, the bottom surface 21a of the housing may be fixed to the cabinet 1. In the following description, the heat diffusion film 3 and the cabinet 1 can be read each other.

[Embodiment 3]
FIG. 7A is a cross-sectional view showing the shape of the thermally deformable member 2 according to the present embodiment when the temperature of the thermally deformable portion 22 is less than T1, and FIG. FIG. 7C is a cross-sectional view showing the shape of the thermally deformable member 2 according to the present embodiment when the temperature of the portion 22 is T1 or more and less than T2, and FIG. It is sectional drawing which shows the shape of the heat deformation member 2 concerning this embodiment when it is.

  As shown to (a)-(c) of FIG. 7, the thermal radiation structure 20 concerning this embodiment is provided with the several thermal deformation member 2 which has the thermal deformation part 22 using the shape memory alloy from which a transformation point differs. For example, the heat dissipation structure 20 according to the first embodiment has the same configuration. That is, in each embodiment mentioned above, the deformation temperature of each thermal deformation part 22 does not need to be the same temperature. The heat dissipating structure 20 according to the present embodiment includes a heat deformation member 2A made of a shape memory alloy having a transformation point of T1 degrees and a shape memory alloy having a transformation point of T2 degrees (where T1 <T2). The thermal deformation member 2B which consists of is provided. The structure of the thermally deformable members 2A and 2B is the same as that of the thermally deformable member 2 according to the first embodiment, for example. Hereinafter, the fixing part 21 and the thermal deformation part 22 of the thermal deformation member 2A are referred to as the fixing part 21A and the thermal deformation part 22A, and the fixing part 21 and the thermal deformation part 22 of the thermal deformation member 2B are referred to as the fixing part 21B and the thermal deformation part. 22B.

  As shown to (a) of FIG. 7, when the temperature of heat deformation part 22A * 22B is less than T1, neither heat deformation part 22A * 22B deform | transforms. For this reason, in this case, the heat-deformed portions 22 </ b> A and 22 </ b> B stand up so as to come into contact with the cabinet 1.

  On the other hand, as shown in FIG. 7B, when the temperature of the thermal deformation portions 22A and 22B is equal to or higher than T1 and lower than T2, the thermal deformation portion 22B is not deformed, but the thermal deformation portion 22A is deformed. For this reason, in this case, only the thermal deformation portion 22B stands up so as to come into contact with the cabinet 1, and the thermal deformation portion 22A is horizontal with, for example, the fixing portion 21A. Thereby, only the heat deformation member 2 </ b> B comes into contact with the cabinet 1. At this time, it is assumed that the number of the heat deformation members 2A and the number of the heat deformation members 2B are 1: 1, for example. In this case, the contact area between the thermally deformable member 2B and the cabinet 1 is half of the contact area between the thermally deformable members 2A and 2B and the cabinet 1 shown in FIG. As a result, heat conduction from the heating element 6 to the cabinet 1 is suppressed, and the surface temperature of the cabinet 1 is lowered.

  When the temperature of the heating element 6 further rises and the temperature of the thermal deformation portions 22A and 22B reaches T2 or more as shown in FIG. 7C, not only the thermal deformation portion 22A but also the thermal deformation portion 22B is deformed. . In this case, similarly to the thermally deformable portion 22A, the thermally deformable portion 22B is horizontal with the fixed portion 21B, for example. As a result, the contact area between the thermally deformable members 2A and 2B and the cabinet 1 becomes 0 (zero). Therefore, in this case, heat transfer can be further suppressed.

  As described above, according to the present embodiment, by providing a plurality of heat-deformable members 2A and 2B having the heat-deformable portions 22 using shape memory alloys having different transformation points as the heat-deformable member 2, the temperature becomes finer. Control can be performed.

[Embodiment 4]
FIG. 8A is a perspective view showing the shape of the thermal deformation member 2 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. It is a perspective view which shows the shape of the heat deformation member 2 concerning this embodiment when the temperature of the deformation | transformation part 22 is more than a transformation point.

  The portion where the thermal deformation portion 22 bends may be a portion between the fixed end 22a and the tip 22b instead of the fixed end 22a as in the first embodiment. As shown in FIGS. 8A and 8B, the heat dissipation structure 20 according to the present embodiment has a bent portion 22c at a portion between the fixed end 22a and the tip 22b. For example, it has the same configuration as the heat dissipation structure 20 according to the first embodiment.

  As shown in FIG. 8A, the shape of the heat-deformable member 2 when the temperature of the heat-deformable portion 22 is lower than the transformation point is the same as the shape of the heat-deformable member 2 shown in FIG. is there. However, in this embodiment, when the temperature of the thermal deformation portion 22 is equal to or higher than the transformation point, as shown in FIG. 8B, the portion ahead of the bent portion 22c (in other words, the bent portion 22c and the tip 22b Only the portion between the two is bent so as not to contact the cabinet 1.

  That is, in this embodiment, the fixed end 22a does not deform (bend) due to temperature. A portion between the fixed end 22a and the bent portion 22c stands up in a state of being bent at a right angle in the Z direction with respect to the fixed portion 21, regardless of the temperature of the thermal deformation portion 22. On the other hand, when the temperature of the thermally deformable portion 22 reaches the transformation point, the portion between the bent portion 22c and the tip 22b is in the lying down direction indicated by the arrow shown in FIG. For example, it bends 90 degrees and becomes horizontal with the fixed part 21. That is, in this embodiment, when the temperature of the heat-deformable part 22 reaches the transformation point, the heat-deformable part 22 is deformed so as to have an inverted L shape. As a result, the contact area between the heat-deformable member 2 and the cabinet 1 becomes 0 (zero).

  Therefore, according to the present embodiment, the same effect as the heat dissipation structure 20 according to the first embodiment can be obtained. In addition, the area of the thermally deformable portion 22 from the bent portion 22c to the tip 22b is smaller than the area of the thermally deformable portion 22 from the fixed end 22a to the tip 22b. For this reason, the load applied to the bent portion 22c when the bent portion 22c is bent is smaller than the load applied to the fixed end 22a when the fixed end 22a is bent. Therefore, according to this embodiment, compared with the case where the fixed end 22a is bent as in the first embodiment, metal fatigue due to deformation (bending) can be suppressed.

[Embodiment 5]
FIG. 9A is a perspective view showing the shape of the thermal deformation member 2 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. It is a perspective view which shows the shape of the heat deformation member 2 concerning this embodiment when the temperature of the deformation | transformation part 22 is more than a transformation point.

  The deformation (bending) part of the thermal deformation part 22 may be a plurality of places instead of a single place. The heat dissipation structure 20 according to the present embodiment has the same configuration as the heat dissipation structure 20 according to the first embodiment, for example, except for the following points.

  In the present embodiment, the thermally deformable portion 22 bends at two locations, that is, the fixed end 22a and the bent portion 22c at a temperature equal to or higher than the transformation point. As shown to (a) of FIG. 9, in this embodiment, when the temperature of the heat deformation part 22 is lower than a transformation point, it forms so that it may become a reverse L-shape.

  That is, in this embodiment, when the temperature of the heat-deformed portion 22 is lower than the transformation point, the portion between the fixed end 22a and the bent portion 22c is bent at a right angle in the Z direction with respect to the fixed portion 21. Is standing up. Further, at this time, the portion beyond the bent portion 22c is parallel to the fixing surface (bottom surface 21a) of the fixing portion 21 (in other words, parallel to the surface facing the heat-deformable member 2 and the heat diffusion film 3 in the cabinet 1). It is bent so as to surrender.

  For this reason, in this embodiment, when the temperature of the heat-deformed part 22 is lower than the transformation point, the upper surface (tip-side upper surface 22d) in the portion between the bent part 22c and the tip 22b of the heat-deformed part 22 is the cabinet. 1 is contacted. For this reason, according to this embodiment, compared with the case where the front-end | tip 22b of the thermal deformation part 22 is contacting the cabinet 1, the heat | fever of the heat generating body 6 can be more efficiently conducted to the cabinet 1. FIG. In addition to the above effects, the tip-side upper surface 22d can diffuse the heat of the cabinet 1 and further suppress local temperature rise of the cabinet 1.

  As shown in FIG. 9B, in this embodiment, the shape of the heat-deformable member 2 when the temperature of the heat-deformable portion 22 is equal to or higher than the transformation point is the heat-deformation shown in FIG. The shape of the member 2 is the same. For this reason, in this embodiment, when the temperature of the thermal deformation part 22 reaches the transformation point, the fixed end 22a and the bent part 22c are arranged so that the thermal deformation part 22 is parallel to the fixed surface (bottom surface 21a) of the fixed part 21. Each bend. Thereby, also in this embodiment, the same effect as Embodiment 1 can be acquired.

[Embodiment 6]
FIG. 10A is a perspective view showing the shape of the thermal deformation member 2 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. It is a perspective view which shows the shape of the heat deformation member 2 concerning this embodiment when the temperature of the deformation | transformation part 22 is more than an transformation point. FIG. 11A is a cross-sectional view showing the shape of the thermal deformation member 2 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. It is sectional drawing which shows the shape of the heat deformation member 2 concerning this embodiment when the temperature of the deformation | transformation part 22 is more than an transformation point.

  The heat dissipation structure 20 according to the present embodiment is the same as the heat dissipation structure 20 according to the first embodiment, for example, except for the following points. In the heat dissipation structure 20 according to the present embodiment, as shown in FIGS. 10A and 10B and FIGS. 11A and 11B, the thermally deformable portion 22 has a cylindrical shape. The thermal deformation portion 22 has an end on the bottom wall side of the side surface (circumferential surface) of the thermal deformation portion 22 such that the axial direction of the thermal deformation portion 22 is parallel to the fixing surface (bottom surface 21a) of the fixing portion 21. It is being fixed to the fixing | fixed part 21 by. More specifically, the thermally deformable portion 22 is fixed to the fixed portion 21 so that the axial direction of the thermally deformable portion 22 is parallel to one side of the fixed portion 21 made of a frame.

  Therefore, when the temperature of the thermal deformation portion 22 is lower than the transformation point, the thermal deformation portion 22 contacts the cabinet 1 at a part of the side surface of the thermal deformation portion 22 as shown in FIG. To do. On the other hand, as shown in (b) of FIG. 10 and (b) of FIG. 11, when the temperature of the thermal deformation part 22 reaches the transformation point (threshold), the thermal deformation part 22 is changed to (a) of FIG. As indicated by the arrows, the fixing portion 21 is deformed so as to be crushed toward the fixing surface (bottom surface 21a) side. In other words, the thermally deformable portion 22 shrinks so that the thickness of the thermally deformable portion 22 in the Z direction becomes small. As a result, the cabinet 1 and the heating element 6 are not in contact with each other, and the air heat insulating layer 8 is formed between the cabinet 1 and the heating element 6 (specifically, between the cabinet 1 and the heat-deformable member 2). The In addition, when the temperature of the heat deformation part 22 becomes lower than the transformation point, the thickness of the heat deformation part 22 returns to the original. That is, the thermally deformable portion 22 extends so that the thickness of the thermally deformable portion 22 increases.

  Therefore, according to the present embodiment, the same effect as that of the first embodiment can be obtained. In addition, according to the present embodiment, the thermal deformation portion 22 is not partially bent, but the thermal deformation portion 22 is deformed so that the thickness in the Z direction of the thermal deformation portion 22 is reduced. , Partial stress concentration can be suppressed. Therefore, according to the present embodiment, metal fatigue due to deformation (bending) can be reduced as compared with the case where the thermal deformation portion 22 is partially bent.

  In the present embodiment, the case where the thermal deformation portion 22 has a cylindrical shape is illustrated as an example, but the thermal deformation portion 22 may have a columnar shape.

[Embodiment 7]
12A is a cross-sectional view showing the shape of the thermal deformation member 2 according to the present embodiment when the temperature of the thermal deformation portion 22 is lower than the transformation point, and FIG. It is sectional drawing which shows the shape of the heat deformation member 2 concerning this embodiment when the temperature of the deformation | transformation part 22 is more than a transformation point.

  The heat dissipation structure 20 according to the present embodiment is the same as the heat dissipation structure 20 according to the first embodiment, for example, except for the following points. As shown in FIGS. 12A and 12B, the heat dissipating structure 20 according to the present embodiment has a heat deformation portion 22 formed in a rectangular parallelepiped. The thermal deformation part 22 is fixed to the fixing part 21 so that each side of the rectangular parallelepiped is parallel to each side of the fixing part 21 made of a frame in plan view.

  For this reason, when the temperature of the thermally deformable portion 22 is lower than the transformation point, the thermally deformable portion 22 has a fixed surface with the fixed portion 21 in the thermally deformable portion 22 as shown in FIG. Contacts the cabinet 1 on the opposite side. On the other hand, as shown in FIG. 12B, when the temperature of the thermal deformation portion 22 reaches the transformation point (threshold), the thermal deformation portion 22 is distorted in an oblique direction, so that the side surface becomes a parallelogram. It deforms as follows. Thereby, the thickness of the Z direction of the heat deformation part 22 becomes small, and the cabinet 1 and the heat generating body 6 do not contact. As a result, the air heat insulating layer 8 is formed between the cabinet 1 and the heating element 6 (specifically, between the cabinet 1 and the heat-deformable member 2). In addition, when the temperature of the heat-deformation part 22 becomes lower than the transformation point, the heat-deformation part 22 returns to its original thickness in the Z direction by returning the side surface to a rectangular shape.

  Therefore, according to the present embodiment, the same effect as that of the first embodiment can be obtained. Also in this embodiment, the thermally deformable portion 22 is not partially bent, but the thermally deformable portion 22 is deformed so that the thickness of the thermally deformable portion 22 in the Z direction is reduced. Stress concentration can be suppressed. Therefore, also in this embodiment, metal fatigue due to deformation (bending) can be reduced as compared with the case where the thermal deformation portion 22 is partially bent.

  In the present embodiment, when the temperature of the thermal deformation portion 22 is lower than the transformation point, the side surface of the thermal deformation portion 22 has a rectangular shape as an example. It may be in the shape.

[Summary]
The heat dissipation structure 20 according to the first aspect of the present invention includes a casing (cabinet 1), a heating element 6, and a heat transfer section 10 disposed between the casing and the heating element 6. The heat transfer section 10 includes at least one heat deformable member 2 having a heat deformable section 22 at least partially made of a shape memory alloy, and the heat deformable section 22 reaches the transformation point when the temperature of the heat deformable section 22 is reached. Then, it deform | transforms so that the air heat insulation layer 8 may be formed between the said housing | casing and the said heat generating body 6. FIG.

  According to said structure, when the temperature of the heat deformation part 22 of the said heat deformation member 2 reaches an transformation point, since the said air heat insulation layer 8 is formed between the said housing | casing and the said heat generating body 6, The temperature of the housing drops. For this reason, the temperature of the said housing | casing does not rise too much and a burn can be prevented.

  The heat dissipating structure 20 according to aspect 2 of the present invention is the heat dissipating structure 20 according to aspect 1, wherein the heat deformable member 2 has a part of the heat deformable part 22 when the temperature of the heat deformable part 22 is lower than the transformation point. It is formed so as to come into contact with the casing, and when the temperature of the thermal deformation section 22 reaches the transformation point, the thermal deformation section 22 may be deformed in a direction away from the casing.

  According to said structure, when the temperature of the said heat deformation part 22 reaches the said transformation point, the said heat deformation part 22 will be cut | disconnected from the said housing | casing, and the said heat insulation between the said housing | casing and the said heat generating body 6 will be carried out. Layer 8 can be formed.

  In the heat dissipation structure 20 according to the third aspect of the present invention, in the second aspect, the heat transfer unit 10 further includes a heat diffusion film 3, and a part of the heat deformation member 2 (fixing unit 21) It may be fixed to the diffusion film.

  According to said structure, according to the effect of the said heat | fever diffusion film 3, heat is spread | diffused in the surface direction of this heat | fever diffusion film 3, and it can prevent that a heat spot is made on the said heat generating body 6 directly.

  In the heat dissipation structure 20 according to the aspect 4 of the present invention, in the aspect 1, a part of the thermal deformation member 2 (fixing part 21) is fixed to the casing, and the heat transfer part 10 is The thermal deformation member 2 further includes a thermal diffusion film 3 such that a part of the thermal deformation member 2 contacts the thermal diffusion film 3 when the temperature of the thermal deformation portion 22 is lower than the transformation point. When the temperature of the thermal deformation portion 22 is formed and reaches the transformation point, the thermal deformation portion 22 may be deformed in a direction away from the thermal diffusion film 3.

  According to said structure, when the temperature of the said heat deformation part 22 reaches the said transformation point, the said heat deformation part 22 will be cut | disconnected from the said heat | fever diffusion film 3, and the above-mentioned between the said housing | casing and the said heat generating body 6 will be described. The air insulation layer 8 can be formed. Moreover, according to said structure, while the effect of the said heat | fever diffusion film 3 can prevent that a heat | fever is spread | diffused in the surface direction of this heat | fever diffusion film 3, and a heat spot can be formed on the said heat generating body 6 directly. Compared with the said aspect 3, the local temperature rise of the said housing | casing can be suppressed more.

  In the heat dissipation structure 20 according to the fifth aspect of the present invention, in any one of the first to fourth aspects, the heat transfer section 10 is a heat deformable section using a shape memory alloy having a different transformation point as the heat deformable member 2. You may provide the some heat deformation member (thermal deformation member 2A * 2B) which has (thermal deformation part 22A * 22B).

  According to said structure, temperature control can be performed more finely.

  In the heat dissipation structure 20 according to the sixth aspect of the present invention, in any one of the first to fifth aspects, the thermal deformation portion 22 has a flap shape in which one end (fixed end 22a) is fixed. When the temperature of 22 reaches the transformation point, from one end to the end opposite to the one end (tip 22b) so as to form an air heat insulating layer 8 between the casing and the heating element 6. You may bend in at least one place between.

  According to said structure, when the temperature of the said heat deformation part 22 reaches the said transformation point, the said heat deformation part 22 will bend, and the said air heat insulation layer 8 will be provided between the said housing | casing and the said heat generating body 6. FIG. Can be formed.

  The heat dissipation structure 20 according to the seventh aspect of the present invention is the heat dissipation structure 20 according to any one of the first to fifth aspects, wherein the thermal deformation portion 22 is configured such that when the temperature of the thermal deformation portion 22 reaches the transformation point, You may deform | transform so that the thickness of the said heat deformation part 22 of the direction (Z direction) connecting the heat generating body 6 may become small.

  According to said structure, when the temperature of the said heat deformation part 22 reaches the said transformation point, the said thickness of the said heat deformation part 22 will become small, and the said air between the said housing | casing and the said heat generating body 6 will be carried out. The heat insulation layer 8 can be formed. Moreover, according to said structure, partial stress concentration can be suppressed and the metal fatigue by a deformation | transformation can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

1 Cabinet (housing)
2, 2A, 2B Thermal deformation member 3 Thermal diffusion film (heat transfer part)
4 Sheet Metal 5 Thermal Conductive Material Layer 6 Heating Element 7 Substrate 8 Air Thermal Insulation Layer 10 Heat Transfer Part 20 Heat Dissipation Structure 21, 21A, 21B Fixed Part 21a Bottom Surface 22, 22A, 22B Thermal Deformation Part 22a Fixed End 22b Tip 22c Bent Part 22d Top end side upper surface 23 Groove

Claims (7)

A housing, a heating element, and a heat transfer section disposed between the casing and the heating element,
The heat transfer part includes at least one heat deformation member having a heat deformation part at least part of which is made of a shape memory alloy,
The heat-dissipating structure is characterized in that when the temperature of the heat-deformable part reaches the transformation point, the heat-deformable part is deformed so as to form an air heat insulating layer between the casing and the heating element.   The thermally deformable member is formed such that a part of the thermally deformable portion is in contact with the housing when the temperature of the thermally deformable portion is lower than the transformation point, and the temperature of the thermally deformable portion is The heat dissipation structure according to claim 1, wherein when the transformation point is reached, the thermal deformation portion is deformed in a direction away from the housing. The heat transfer part further includes a heat diffusion film,
The heat radiating structure according to claim 2, wherein a part of the heat deformable member is fixed to the heat diffusion film. A part of the thermal deformation member is fixed to the housing,
The heat transfer part further includes a heat diffusion film,
The thermal deformation member is formed so that a part of the thermal deformation member is in contact with the thermal diffusion film when the temperature of the thermal deformation portion is lower than the transformation point, and the temperature of the thermal deformation portion is 2. The heat dissipation structure according to claim 1, wherein when the transformation point is reached, the thermal deformation portion is deformed in a direction away from the thermal diffusion film.   The heat transfer section includes a plurality of heat deformable members having heat deformable sections using shape memory alloys having different transformation points as the heat deformable members. The heat dissipation structure according to item. The thermal deformation part has a flap shape with one end fixed,
When the temperature of the heat-deformed portion reaches the transformation point, a space between the one end and the end opposite to the one end is formed so as to form an air insulation layer between the housing and the heating element. The heat dissipation structure according to any one of claims 1 to 5, wherein the heat dissipation structure is bent at at least one location.   When the temperature of the thermally deformable portion reaches the transformation point, the thermally deformable portion is deformed so that the thickness of the thermally deformable portion in a direction connecting the casing and the heating element is reduced. The heat dissipation structure according to any one of claims 1 to 5.

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