Heat exchanger fixed structure

Abstract

To reduce the load on the soldering section of electronic components.SOLUTION: A heat sink fixing structure includes a heat sink 4 fixed to the body part 3A of the electronic component 3 whose leg 3B is connected to the substrate 2 by soldering, a flexible mounting part 1C provided in the equipment body 1 to which the substrate 2 is fixed, and a joining member 10 joining the heat sink 4 and the mounting part 1C.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heat sink fixing structure. [Background technology]

[0002] For example, Patent Document 1 discloses a structure in which an electronic component soldered to a substrate is fixed to a heat sink with screws, and the heat sink is then attached to the substrate and the metal housing sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-236185 Summary of the Invention [Problem to be solved by the invention]

[0004] Because it is difficult to achieve dimensional accuracy in the positions of the metal housing, the screw fixing points of the heat sink, and the board to which the electronic components are soldered, if the heat sink is fixed with a rigid structure, stress is likely to be placed on the soldering points of the electronic components to the board. When stress is placed on the soldering points, there is a risk of cracks occurring in those areas.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a heat sink fixing structure that can reduce the load on the soldered portions of electronic components. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one embodiment of the heat sink fixing structure of the present invention includes a heat sink fixed to a main body of an electronic component having legs connected to a substrate by soldering, a flexible mounting portion provided on the device main body to which the substrate is fixed, and a joining member that joins the heat sink and the mounting portion. [Effects of the Invention]

[0007] According to the present invention, the load on the soldered portion of the electronic component can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a heat sink fixing structure according to an embodiment. [Figure 2] FIG. 2 is a partially cutaway perspective view showing the heat sink fixing structure of the embodiment. [Figure 3] FIG. 3 is a cross-sectional view illustrating the heat sink fixing structure according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments. Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiments can be combined as appropriate.

[0010] 1 to 3, a heat sink fixing structure according to an embodiment is applied to, for example, an electronic device 100 mounted inside a vehicle cabin. The electronic device 100 is, for example, an AV (Audio Visual) integrated car navigation device.

[0011] The electronic device 100 includes a device body 1 , a substrate 2 , an electronic component 3 , a heat sink 4 , and a support member 5 .

[0012] The device body 1 is a housing that houses the circuit board 2, electronic components 3, heat sink 4, and support member 5, and has plate members that surround it in the up-down direction (X direction), left-right direction (Y direction), and front-back direction (Z direction). In FIG. 1, only one left-right side plate 1A and one top plate 1B are shown as plate members made of sheet metal, and other plate members are omitted. A display panel is provided as a plate member on the front side of the device body 1. The up-down direction (X direction) is also referred to as the vertical direction, and the plane formed by combining the up-down direction (X direction) and the front-back direction (Z direction) is referred to as the vertical plane. The left-right direction (Y direction) is also referred to as the horizontal direction, and the plane formed by combining the left-right direction (Y direction) and the front-back direction (Z direction) is referred to as the horizontal plane.

[0013] The substrate 2 is a printed circuit board formed in a plate shape, and the plate surface is arranged along a horizontal plane inside the device body 1. The substrate 2 is fixed with screws 6 to a plate member that is along the horizontal plane in the device body 1, such as a bottom plate or middle plate (not shown).

[0014] The electronic component 3 is an electronic device such as an integrated circuit (IC), and is composed of a rectangular main body 3A and leg portions 3B extending outward from the main body 3A. The leg portions 3B of the electronic component 3 are inserted into holes 2A in the substrate 2 and soldered with solder 7 (see FIG. 3). In this embodiment, the leg portions 3B of the electronic component 3 are inserted vertically through the holes 2A in the substrate 2, which is arranged along a horizontal plane.

[0015] The heat sink 4 dissipates heat from the electronic component 3 and is made of a material with high thermal conductivity, such as an aluminum alloy. The heat sink 4 has a heat transfer portion 4A and a heat dissipation portion 4B. The heat transfer portion 4A is formed in a plate shape so that it can be in contact with the outer surface of the main body portion 3A of the electronic component 3. In this embodiment, the heat transfer portion 4A is formed in a plate shape that extends in the vertical direction and has a vertical surface that is in contact with the vertical surface of the main body portion 3A. The heat transfer portion 4A is fixed in contact with the main body portion 3A by screws 8. Therefore, the heat from the main body portion 3A of the electronic component 3 is transferred to the heat transfer portion 4A. The heat dissipation portion 4B is provided continuous with the upper end of the heat transfer portion 4A. The heat dissipation section 4B has a horizontal section 4Ba that bends horizontally from the upper end of the heat transfer section 4A, a vertical section 4Bb that bends upward from the extended end of the horizontal section 4Ba, and fin sections 4Bc that extend horizontally from the middle of the extending vertical section 4Bb and from the extended end. Therefore, the heat dissipation section 4B dissipates heat transferred to the heat transfer section 4A from the horizontal section 4Ba, the vertical section 4Bb, and the fin sections 4Bc.

[0016] The support member 5 holds the electronic component 3 and is made of sheet metal. The support member 5 has a fixing portion 5A and a support portion 5B. The fixing portion 5A is formed into a plate shape by drawing so that it can contact the outer surface of the main body portion 3A of the electronic component 3. In this embodiment, the fixing portion 5A is formed into a plate shape extending in the vertical direction so as to have a vertical surface that contacts the vertical surface of the main body portion 3A. The fixing portion 5A is arranged to sandwich the main body portion 3A between the heat transfer portion 4A of the heat sink 4 and is fixed in contact with the main body portion 3A by screws 8 that secure the heat transfer portion 4A. The fixing portion 5A is also arranged facing the extended tip ends of the fin portions 4Bc of the heat sink 4, and defines a space portion 9 that penetrates in the front-rear direction to close the tip ends of the fin portions 4Bc. The support portions 5B bend and extend from both end portions of the fixing portion 5A so as to surround both sides of the main body portion 3A. The lower part of the support part 5B abuts against the horizontal surface of the substrate 2, and the lower end of the heat transfer part 4A of the heat sink 4 abuts against it. As a result, the support member 5 supports the main body part 3A and the heat sink 4 by having the substrate 2 bear the load acting on the main body part 3A of the electronic component 3 and the heat sink 4. Furthermore, because the support member 5 is made of sheet metal, heat from the main body part 3A of the electronic component 3 is transferred to it.

[0017] For the electronic device 100 configured in this manner, the heat sink fixing structure for fixing the heat sink 4 includes an attachment portion 1C provided on the device main body 1, a connection portion 5C provided on the support member 5, and a joining member 10 consisting of a screw that joins the heat sink 4, the attachment portion 1C, and the connection portion 5C.

[0018] The mounting portion 1C is the device main body 1 and is provided on the upper plate 1B in this embodiment. The mounting portion 1C is formed by stamping out the sheet metal of the upper plate 1B. The mounting portion 1C is configured in a tongue shape extending horizontally from the edge of an opening 1Ba formed in the upper plate 1B toward the inside of the opening 1Ba. The mounting portion 1C has a flexible flexible portion 1Ca formed by a notch 1Caa at its base extending from the edge of the opening 1Ba. The mounting portion 1C is elastically deformed and bent in the vertical direction by the flexible portion 1Ca, as shown by the two-dot chain line in FIG. 3. Furthermore, the mounting portion 1C has a through-hole 1Cb formed at its tip extending from the edge of the opening 1Ba, penetrating in the vertical direction. A screw, which is a joining member 10, is inserted through the through-hole 1Cb.

[0019] The connecting portion 5C is a support member 5 and is provided on the fixed portion 5A in this embodiment. The connecting portion 5C is formed from sheet metal together with the fixed portion 5A. The connecting portion 5C is configured in the shape of a tongue extending horizontally by bending the tip portion extending upward from the fixed portion 5A. A flexible flexible portion 5Ca is formed in the bent base portion of the connecting portion 5C by a notch 5Caa. The connecting portion 5C is elastically deformed and bent in the vertical direction by the flexible portion 5Ca, as shown by the two-dot chain line in FIG. 3. Furthermore, a screw hole 5Cb penetrating vertically is formed in the tip portion extending horizontally of the connecting portion 5C. A screw, which is a joining member 10, is screwed into the screw hole 5Cb.

[0020] A through-hole 4C is formed in the uppermost fin portion 4Bc of the heat sink 4, penetrating the heat sink 4 in the vertical direction. A screw, which is a joining member 10, is inserted through the through-hole 4C.

[0021] In this heatsink fixing structure, the upper end of the heatsink 4 is fixed to the device body 1 via the attachment portion 1C by the joining member 10. Therefore, the heatsink 4 fixed to the body 3A of the electronic component 3 is fixed to the device body 1 via the flexible attachment portion 1C. In addition, in the heatsink fixing structure, the upper end of the support member 5 is fixed to the device body 1 via the attachment portion 1C and the connection portion 5C by the joining member 10. Therefore, the support member 5 fixed to the body 3A of the electronic component 3 together with the heatsink 4 is fixed to the device body 1 via the flexible attachment portion 1C and the connection portion 5C.

[0022] It should be noted that, without being limited to the above-described embodiment, the mounting portion 1C may be provided on the side plate 1A instead of the top plate 1B. Furthermore, without being limited to the above-described embodiment, in the drawings, the X direction may be the horizontal direction, and the Y direction or Z direction may be the vertical direction.

[0023] Thus, the heat sink fixing structure of the embodiment includes a heat sink 4 fixed to the main body 3A of the electronic component 3 whose legs 3B are connected to the substrate 2 by soldering, a flexible mounting portion 1C provided on the device main body 1 to which the substrate 2 is fixed, and a joining member 10 that joins the heat sink 4 and the mounting portion 1C.

[0024] According to this heatsink fixing structure, the heatsink 4 fixed to the main body 3A of the electronic component 3 is joined to the device body 1, which fixes the board 2 to which the legs 3B of the electronic component 3 are soldered, via the flexure of the mounting portion 1C provided on the device body 1. Therefore, even if errors occur in the positional accuracy of the solder connection of the electronic component 3 to the board 2, the positional accuracy of the fixing of the heatsink 4 to the electronic component 3, or the positional accuracy of the fixing of the board 2 to the device body 1 during joining, the flexure of the mounting portion 1C can absorb these errors while joining the heatsink 4 to the device body 1. Therefore, the heatsink fixing structure of the embodiment can reduce the load on the soldered portion of the electronic component 3 due to the errors in the positional accuracy.

[0025] Furthermore, in the heat sink fixing structure of the embodiment, the attachment portion 1C has flexibility along the vertical direction in which the leg portions 3B of the electronic component 3 extend toward the board 2.

[0026] According to this heat sink fixing structure, cracks are likely to occur in the soldered portion when a load is applied in the direction in which leg portion 3B extends and is inserted into hole 2A in substrate 2, and by causing mounting portion 1C to bend in that direction, the load applied to the soldered portion in the direction in which cracks are likely to occur can be reduced. Therefore, the heat sink fixing structure of the embodiment can suppress the occurrence of cracks in the soldered portion.

[0027] In addition, the heat sink fixing structure of the embodiment includes a support member 5 that supports the main body portion 3A of the electronic component 3, and the support member 5 has a flexible connecting portion 5C that is joined to the mounting portion 1C together with the heat sink 4 by a joining member 10.

[0028] The support member 5 is fixed to the main body 3A of the electronic component 3. However, if there is an error in the positional accuracy of the solder connection of the electronic component 3 to the board 2, the positional accuracy of the fixation of the support member 5 to the electronic component 3, or the positional accuracy of the fixation of the board 2 to the device main body 1, a load may be placed on the soldered portion of the electronic component 3. In this regard, according to the heat sink fixing structure of the embodiment, the support member 5 is joined to the mounting portion 1C together with the heat sink 4 via the flexible connecting portion 5C by the joining member 10. Therefore, during joining, the above-mentioned error is absorbed by the bending of the connecting portion 5C and the mounting portion 1C, and the support member 5 together with the heat sink 4 can be joined to the device main body 1. Therefore, the heat sink fixing structure of the embodiment can reduce the load on the soldered portion of the electronic component 3 due to the above-mentioned positional accuracy error. Moreover, this heat sink fixing structure allows the joining member 10 to be used to join the mounting portion 1C and the connecting portion 5C, preventing an increase in the number of parts.

[0029] Furthermore, in the heatsink fixing structure of the embodiment, the heatsink 4 (the uppermost fin portion 4Bc) is sandwiched between the mounting portion 1C and the connecting portion 5C, and the joining member 10, which is a screw, is inserted from the mounting portion 1C through the heatsink 4 and screwed into the screw hole 5Cb of the connecting portion 5C. By configuring the heatsink fixing structure of the embodiment in this way, it is possible to prevent cracks from occurring in the heatsink 4 due to forming screw holes in a low-rigidity heatsink 4 made of an aluminum alloy or the like. Moreover, in the heatsink fixing structure of the embodiment, by sandwiching and joining the heatsink 4 between the mounting portion 1C and the connecting portion 5C, it is possible to form screw holes in the heatsink 4 and join it to the mounting portion 1C, and simultaneously bring the heatsink 4 into contact with the mounting portion 1C, thereby ensuring heat dissipation performance.

[0030] In the heat sink fixing structure of the embodiment, the connecting portion 5C is flexible in the up-down direction in which the leg portion 3B of the electronic component 3 extends toward the board 2.

[0031] As described above, cracks are likely to occur in the soldered portion when a load is applied in the direction in which leg portion 3B extends and is inserted into hole 2A of substrate 2, and by causing connection portion 5C to bend in that direction, the load applied to the soldered portion in the direction in which cracks are likely to occur can be reduced. Therefore, the heat sink fixing structure of the embodiment can suppress the occurrence of cracks in the soldered portion.

[0032] In the heat sink fixing structure of the embodiment, the main body 3A of the electronic component 3 is fixed by sandwiching it between the heat sink 4 and the support member 5, and a space 9 is provided between the heat sink 4 and the support member 5, penetrating in a predetermined direction.

[0033] According to the heat sink fixing structure of this embodiment, the space 9 penetrating in a predetermined direction is used as a flow path for heat dissipation, thereby improving the heat dissipation effect.

[0034] In the heatsink fixing structure of the embodiment, when joining the heatsink 4 and the mounting portion 1C, a gap is provided between the heatsink 4 and the mounting portion 1C as shown by the dashed line in Fig. 3, and they are joined by joining member 10 to eliminate this gap. Also, in the heatsink fixing structure of the embodiment, when joining the heatsink 4 and the connecting portion 5C, a gap is provided between the heatsink 4 and the connecting portion 5C, and they are joined by joining member 10 to eliminate this gap. With this heatsink fixing structure, by being configured in this way, it is possible to increase the absorption rate of dimensional errors.

[0035] In addition, in the heatsink fixing structure of the embodiment, the joining direction of the joining members 10 is along the vertical direction intersecting with the plate surface of the substrate 2. According to this heatsink fixing structure, the joining direction of the joining members 10 is aligned with the direction in which the substrate 2 is likely to bend, thereby increasing the absorption rate of dimensional errors. [Explanation of symbols]

[0036] 1. Device body 1C Mounting part 2 boards 3. Electronic Components 3A Main body 3B Legs 4 Heat sink 5 Support member 5C Connection 9 Space section 10 Joint material

Claims

1. a heat sink fixed to a body of an electronic component having legs connected to a substrate by soldering; a flexible mounting portion provided on a device body to which the substrate is fixed; a joining member that joins the heat sink and the mounting portion; Including, a support member for supporting the main body of the electronic component, the support member including a flexible connecting portion joined to the mounting portion by the joining member together with the heat sink; Heatsink fixed structure.

2. The heat sink fixing structure according to claim 1 , wherein the mounting portion has flexibility along a direction in which the leg portion of the electronic component extends toward the board.

3. 3. The heat sink fixing structure according to claim 1, wherein the heat sink is sandwiched between the mounting portion and the connecting portion, and the joining member is inserted from the mounting portion through the heat sink and joined to the connecting portion.

4. 4. The heat sink fixing structure according to claim 1, wherein the main body of the electronic component is fixed by sandwiching it between the heat sink and the support member, and a space extending in a predetermined direction is provided between the heat sink and the support member.

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