Electronic devices

Abstract

To improve the assemblability and mounting strength of a sealing material while ensuring the hermeticity of a casing by a sealing material, in a device equipped with a heat sink for individually dissipating heat from an integrated circuit component.SOLUTION: An electronic device 1 is configured such that a printed circuit board 7 on which an integrated circuit component 8 is mounted is housed in a housing 2, a heat sink 9 is thermally connected to the integrated circuit component 8, a fin 10 on the tip side of the heat sink 9 is exposed to the outside of the housing 2 through an opening 4a formed in the wall of the housing 2, and a sealing material 12 for sealing the gap between the heat sink 9 and the opening 4a is sandwiched between the heat sink 9 and the housing 2 in the thickness direction of the wall of the housing 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic device configured by housing a printed circuit board on which integrated circuit components are mounted within a housing. [Background technology]

[0002] For example, electronic devices such as an ECU (Electronic Control Unit) for an automobile are configured by accommodating an electronic circuit on a printed circuit board mounted with a CPU, ICs, transformers, capacitors, chip resistors, and other electronic components inside a metal housing, for example. In this type of electronic device, heat dissipation fins are integrally provided on the outer surface of the housing to dissipate heat, but more effective heat dissipation is required, especially for heat-generating components such as the CPU.

[0003] Conventionally, as shown in Patent Document 1, for example, a configuration has been considered in which an individual heat sink is provided for an integrated circuit component such as an LSI, which is a heat generating component among components mounted on a printed circuit board. In this configuration, an individual heat sink is connected to the top surface of the LSI on the printed circuit board via a thermally conductive sheet, and the top end side of the individual heat sink is exposed to the outside through an opening formed in the housing. This can improve the heat dissipation from the LSI. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-70383 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the electronic device is used outdoors, such as in a vehicle, the housing needs to be sealed to prevent water, moisture, dust, etc. from entering through gaps in the housing. In the above configuration, a gap is generated between the inner edge of the opening of the housing and the periphery of the side of the individual heat sink, so it is possible to add a sealant to the gap. However, when a sealant is simply provided between the inner edge of the opening of the housing and the periphery of the side of the individual heat sink, it is difficult to assemble the sealant and it is difficult to fix the sealant firmly, which causes problems such as the sealant easily peeling off or falling off.

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide an electronic device that is equipped with a heat sink that dissipates heat from individual integrated circuit components, and that can improve the assembly and mounting strength of the sealing material while ensuring the airtightness of the housing using the sealing material. [Means for solving the problem]

[0007] In order to achieve the above object, the electronic device of the present invention is configured by housing a printed circuit board (7) on which an integrated circuit component (8) is mounted within a housing (2), and a heat sink (9, 22, 32, 43, 56, 63) is thermally connected to the integrated circuit component, and fins (10, 23, 33, 44, 57, 64) at the tip side of the heat sink are exposed to the outside of the housing through an opening (4a) formed in the wall of the housing, and a sealant (12) for sealing the gap between the heat sink and the opening is provided between the heat sink and the housing, and is sandwiched in the thickness direction of the wall of the housing.

[0008] In the above configuration, the fins at the tip side of the heat sink thermally connected to the integrated circuit component are exposed to the outside of the housing through an opening formed in the wall of the housing, thereby dissipating heat well from the integrated circuit component. Unlike the case where the integrated circuit component is thermally connected to the housing, by providing a separate heat sink, it is possible to reduce the thickness of the TIM (Thermal Interface Material) when a gel-like thermal conductive material is interposed between the integrated circuit component and the heat sink, and high heat dissipation can be achieved.

[0009] The gap between the heat sink and the opening of the housing is sealed by the sealant, so that it is possible to prevent water, moisture, dust, etc. from entering the housing even when the housing is used outdoors. In this case, the sealant is provided between the heat sink and the housing in a form sandwiched in the thickness direction of the wall of the housing, so unlike the case where the gap in the wall direction is blocked, it is only necessary to place the sealant on one of the heat sink and the housing and then assemble the other, which makes assembly easy. Furthermore, once the sealant is assembled, it is easy to maintain the sandwiched state, which can eliminate problems such as falling off. As a result, in a device equipped with a heat sink that dissipates heat from individual integrated circuit components, it is possible to obtain the excellent effect of improving the assemblyability and mounting strength of the sealing material while ensuring the airtightness of the housing provided by the sealing material. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a vertical cross-sectional view illustrating a schematic configuration of an electronic device according to a first embodiment. [Diagram 2] Top view of electronic device [Diagram 3] FIG. 11 is a longitudinal sectional view showing a schematic configuration of an electronic device according to a second embodiment. [Figure 4] FIG. 13 is a longitudinal sectional view illustrating a schematic configuration of an electronic device according to a third embodiment. [Diagram 5] FIG. 13 is a vertical cross-sectional view illustrating a schematic configuration of an electronic device according to a fourth embodiment. [Figure 6]FIG. 13 is a vertical cross-sectional view illustrating a schematic configuration of an electronic device according to a fifth embodiment. [Figure 7] FIG. 13 is an enlarged longitudinal sectional view of a heat sink portion according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, several embodiments in which the present invention is applied to an electronic device, for example, an ECU for use in a vehicle, will be described with reference to the drawings. In each embodiment described below, the same reference numerals will be used for parts equivalent to those described in the preceding embodiment, and new illustrations and duplicated explanations will be omitted. In addition, in the drawings, hatching will be omitted as necessary even in cross-sectional views in order to make them easier to understand.

[0012] (1) First embodiment A first embodiment will be described with reference to Figs. 1 and 2. Fig. 1 shows a schematic configuration of an ECU for vehicle use as an electronic device 1 according to this embodiment. As shown in Fig. 1, the electronic device 1 is configured by accommodating a circuit board 3 constituting a control circuit for vehicle control and the like in a housing 2 having a thin, approximately rectangular box shape in the vertical direction in the figure. The housing 2 is composed of a thin rectangular box-shaped case 4 with an open bottom and a cover 5 that closes the bottom opening, and is configured by closely butting them together via a sealing material not shown. The case 4 and the cover 5 are made of metal such as aluminum or iron. As also shown in Fig. 2, a plurality of heat dissipation fins 6 are integrally provided on the upper surface, which is the outer surface of the case 4.

[0013] The circuit board 3 is configured by mounting an integrated circuit component 8, such as a CPU or other high heat generating component, and a number of other electronic components (not shown) on the upper surface of a printed circuit board 7, such as a multi-layer wiring board. Although not shown in detail, the integrated circuit component 8 is a well-known BGA type component having a number of solder balls in a grid pattern on the lower surface of a rectangular package, and is soldered to the printed circuit board 7, slightly to the left of the center in the figure. The other electronic components include, for example, transistors, capacitors, resistors, coils, etc. The circuit board 3 is attached to the upper surface of the cover 5, i.e., the bottom inside the housing 2.

[0014] The integrated circuit component 8 is provided with a metal, e.g., aluminum, heat sink 9 for dissipating heat from the package of the integrated circuit component 8. The mounting structure of the heat sink 9 will be described below. The heat sink 9 has a plate portion 9a of approximately the same size as the package of the integrated circuit component 8, and is integrally provided with a plurality of fins 10 extending upward from the plate portion 9a. The plate portion 9a of the heat sink 9 is placed on the upper surface of the package of the integrated circuit component 8 via a gel-like thermal conductive material 11 called TIM (Thermal Interface Material). For example, grease having a thermal conductivity of several W / mK or more is used as the thermal conductive material 11, and is applied to a thickness of, e.g., about 1 to 2 mm.

[0015] At this time, a rectangular opening 4a is formed in the upper wall of the case 4 at a position corresponding to above the integrated circuit component 8, through which the plate portion 9a and lower portions of the fins 10 of the heat sink 9 can pass vertically. As a result, the tip side of the fins 10 of the heat sink 9 is exposed to the outside of the housing 2 through the opening 4a formed in the upper wall of the case 4. In this embodiment, the fins 10 of the heat sink 9 are integrally provided with extending fin portions 10a that are parallel to the upper wall of the case 4 and bent like flanges on the outer sides in the front, rear, left and right directions in the figure.

[0016] The extending fin portion 10a is located at a position corresponding to the peripheral portion of the opening 4a of the case 4, and is provided at a position that is raised from the upper wall portion of the case 4 with a small gap, so as to form a rectangular frame shape as a whole. As shown in Fig. 1, a sealant 12 for sealing the gap between the heat sink 9 and the opening 4a is provided between the extending fin portion 10a and the upper surface of the case 4, in a form sandwiched in the thickness direction of the upper wall portion of the case 4, that is, in the vertical direction in the figure. The sealant 12 is made of, for example, a synthetic resin adhesive, and is provided, for example, at the peripheral portion of the opening 4a, so as to form a rectangular frame shape having a certain width when viewed from above, as shown in Fig. 2.

[0017] 1, in this embodiment, locking claw portions 13 (only one shown) that lock onto the edge of the opening 4a on the underside of the case 4 when the heat sink 9 is assembled are integrally provided on the outer surfaces of the midpoints of the fins 10 on both the left and right ends of the heat sink 9. The locking claw portion 13 is shaped so that when the heat sink 9 is inserted into the opening 4a from above, the fin 10 passes through the inner wall of the opening 4a while bending, and at the position where it passes through the opening 4a, it locks onto the underside of the upper wall of the case 4. The heat sink 9 can be obtained by casting or pressing.

[0018] Next, the operation of the above configuration will be described. When assembling the electronic device 1 having the above configuration, the printed circuit board 7 on which the integrated circuit components 8 and the like are mounted is mounted on the cover 5, and then the case 4 is mounted so as to cover the cover 5. At this time, the thermally conductive material 11 is applied in advance to the upper surface of the package of the integrated circuit components 8. Alternatively, after the case 4 is mounted, the thermally conductive material 11 is applied to the upper surface of the package of the integrated circuit components 8 through the opening 4a.

[0019] Thereafter, a sealant 12 is applied around the opening 4a on the top surface of the case 4, and the heat sink 9 is inserted through the opening 4a, and the plate portion 9a is connected to the package of the integrated circuit component while compressing the thermally conductive material 11. At the same time, the sealant 12 is sandwiched between the extending fin portion 10a of the heat sink 9 and the periphery of the opening 4a of the case 4, and the locking claw portion 13 is locked to the underside of the edge of the opening 4a of the case 4, thereby obtaining the electronic device 1.

[0020] In the above configuration, the fins 10 at the tip side of the heat sink 9 thermally connected to the integrated circuit component 8 are exposed to the outside of the housing 2 through the opening 4a formed in the upper wall of the case 4, thereby allowing good heat dissipation from the integrated circuit component 8. Unlike the case where the integrated circuit component 8 is thermally connected to the housing 2, the provision of a separate heat sink 9 makes it possible to reduce the thickness of the thermally conductive material 11 interposed between the integrated circuit component 8 and the heat sink 9, thereby achieving high heat dissipation.

[0021] The gap between the heat sink 9 and the opening 4a of the case 4 is sealed by the sealant 12, so that it is possible to prevent water, moisture, dust, and the like from entering the housing 2 even when the housing 2 is used outdoors. In this case, the sealant 12 is provided between the heat sink 9 and the case 4 in a form sandwiched in the thickness direction of the wall of the case 4, so unlike the case where the gap in the wall direction is blocked, it is only necessary to place the sealant 12 on the case 4 and then assemble the heat sink 9, which makes assembly easy. In addition, once the sealant 12 is assembled, the sealant 12 is pressurized and the sandwiched state is easily maintained, so that the problem of the sealant 12 falling off can be eliminated.

[0022] Thus, according to this embodiment, while being equipped with a heat sink 9 that dissipates heat from the integrated circuit components 8 individually, it is possible to obtain the excellent effect of improving the assembly property and mounting strength of the sealing material 12 while ensuring the airtightness of the housing 2 by the sealing material 12.

[0023] Particularly in this embodiment, the heat sink 9 is provided with the extending fin portion 10a, and the seal material 12 is sandwiched between the outer surface of the upper wall portion of the case 4 and the extending fin portion 10a. This allows the sealant 12 to be easily sandwiched between the case 4 and the extending fin portion 10a, simplifies assembly of the sealant 12, and provides high mounting strength. In this embodiment, the heat sink 9 is provided with the locking claws 13, which allows the heat sink 9 to be easily and reliably positioned relative to the case 4 and prevents the heat sink 9 from shifting out of position after assembly.

[0024] (2) Second embodiment 3 shows an electronic device 21 according to a second embodiment, which differs from the first embodiment in the shape of a heat sink 22. That is, in this embodiment as well, the heat sink 22 integrally includes a plate portion 22a that is placed on the upper surface of the package of the integrated circuit component 8 via a thermally conductive material 11, and a plurality of fins 23 that extend upward from the plate portion 22a and are exposed through the opening 4a. In this embodiment, an extending fin portion 23a for sandwiching the sealant 12 between the upper surface of the case 4 and the fin 23 extends in a form that branches from the middle of the upwardly extending fin 23. A locking claw portion 24 is also provided on the heat sink 22.

[0025] In this embodiment, the heat sink 22 can be assembled in the same manner as in the first embodiment. As in the first embodiment, the heat sink 22 that individually dissipates heat from the integrated circuit components 8 is provided, and the sealant 12 can be easily attached to the housing 2 while ensuring the hermeticity of the housing 2. Once the sealant 12 is attached, the sandwiched state of the sealant 12 is easily maintained, and the problem of the sealant 12 falling off can be eliminated. Furthermore, the heat dissipation area of ​​the fins 23 can be made larger than in the first embodiment, and the heat dissipation effect can be improved.

[0026] (3) Third embodiment FIG. 4 shows an electronic device 31 according to a third embodiment, which differs from the first embodiment in the shape of the heat sink 32 and the arrangement of the sealant 12. That is, in this embodiment as well, the heat sink 32 integrally includes a plate portion 32a that is placed on the upper surface of the package of the integrated circuit component 8 via the thermally conductive material 11, and a plurality of fins 33 that extend upward from the plate portion 32a and are exposed through the opening 4a. In this embodiment, the fins 33 are branched from the middle and are integrally provided with an extending fin portion 33a that extends horizontally and sandwiches the sealant 12 between the lower surface of the upper wall portion, which is the inner surface of the case 4. In this embodiment, the heat sink 32 is integrally provided with a locking claw portion 34 that is locked to the upper surface of the edge of the opening 4a.

[0027] In obtaining the electronic device 31 having the above configuration, the printed circuit board 7 on which the integrated circuit components 8 and the like are mounted is assembled onto the cover 5, and then the heat sink 32 is placed via the thermally conductive material 11, and thereafter, the sealing material 12 is applied around the periphery of the opening 4a on the underside of the case 4, and the case 4 is assembled so as to cover the cover 5. At this time, the upper part of the heat sink 32 passes relatively through the opening 4a from bottom to top, and at that time, the locking claws 24 are locked to the upper surface side of the edge of the opening 4a of the case 4.

[0028] According to the third embodiment, similarly to the first and second embodiments, the heat sink 32 that individually dissipates heat from the integrated circuit components 8 is provided, and the sealant 12 can be easily attached and the strength of the attachment can be improved while ensuring the hermeticity of the housing 2. In addition, once the sealant 12 is attached, the sandwiched state of the sealant 12 can be easily maintained, so that the problem of the sealant 12 falling off can be eliminated. Furthermore, compared to the first embodiment, the heat dissipation area of ​​the fins 33, i.e., the area of ​​the portion exposed on the upper surface side of the case 4, can be made larger, and the heat dissipation effect can be improved.

[0029] (4) Fourth embodiment 5 shows an electronic device 41 according to a fourth embodiment, which differs from the first embodiment in the following respects. That is, in this embodiment, a second heat dissipation fin portion 42 that stands up to a short height is integrally provided on the upper surface of the upper wall portion of the case 4, positioned so as to surround the opening 4a. Meanwhile, a heat sink 43 that is thermally connected to the integrated circuit component 8 via the thermally conductive material 11 integrally includes a plate portion 43a and a plurality of fins 44 that extend upward from the plate portion 43a and are exposed through the opening 4a.

[0030] In this embodiment, the fin 44 is provided with an extending fin portion 44a extending integrally therewith for sandwiching the sealant 12 between the fin 44 and the upper surface of the case 4. The extending fin portion 44a extends horizontally in the circumferential direction to form a rectangular frame shape as a whole at a height position slightly higher than the second heat dissipation fin portion 42, and furthermore, the outer tip portion 44b is provided in a shape that is slightly bent downward, that is, so-called key-shaped. The heat sink 43 is also provided with a locking claw portion 45. The sealant 12 is provided in a shape that is sandwiched between the extending fin portion 44a and a portion of the upper surface of the case 4 including the second heat dissipation fin portion 42 in the thickness direction of the upper wall of the case 4, that is, in the vertical direction in the figure.

[0031] According to the fourth embodiment, as in the first to third embodiments, the heat sink 43 that individually dissipates heat from the integrated circuit components 8 is provided, and the sealant 12 can be easily attached and attached with good strength while ensuring the hermeticity of the housing 2. After the sealant 12 is attached, the sealant 12 can be easily kept sandwiched, and the problem of the sealant 12 falling off can be eliminated. Furthermore, since the sealant 12 is arranged in a so-called labyrinth shape, the seal length of the sealant 12 can be secured long, and the effect of preventing the sealant 12 from falling off is also high, and the sealability can be improved compared to the first embodiment. The heat dissipation area of ​​the extended fin portion 44a is increased, and the heat dissipation of the heat sink 43 can be improved.

[0032] (5) Fifth embodiment FIG. 6 shows the configuration of an electronic device 51 according to a fifth embodiment, and the differences from the first embodiment and the like will be described below. That is, in this embodiment, another electronic component 52 is mounted on the printed circuit board 7 adjacent to the integrated circuit component 8 on the right side in the figure. The electronic component 52 is a low heat-resistant component such as a memory. At this time, a rectangular block-shaped protrusion 53 is integrally formed on the lower surface side, which is the inner surface of the upper wall of the case 4, located above the electronic component 52, that is, to the right of the opening 4a. The package of the electronic component 52 is thermally connected to the protrusion 53 via a thermally conductive gel 54 made of, for example, TIM, thereby dissipating heat from the case 4.

[0033] Furthermore, a third heat dissipation fin portion 55 is integrally provided on the case 4, which is positioned so as to surround the opening 4a and rises at a height slightly lower than that of the heat dissipation fin portion 6. Meanwhile, a heat sink 56 thermally connected to the integrated circuit component 8 via the thermal conductive material 11 integrally includes a plate portion 56a and a plurality of fins 57 extending upward from the plate portion 56a and exposed through the opening 4a.

[0034] An extension fin portion 57a ​​is integrally provided at the upper end of the fin 57 to sandwich the sealant 12 between the third heat dissipation fin portion 55 of the case 4. The extension fin portion 57a ​​extends horizontally in the circumferential direction to form a rectangular frame shape as a whole at a height position slightly higher than the third heat dissipation fin portion 55, and furthermore, the outer tip portion 57b is bent slightly downward, that is, is provided to form a so-called key shape. As a result, the sealant 12 is sandwiched between the extension fin portion 57a ​​of the heat sink 56 at a position separated from the tip side, i.e., upward, from the upper wall portion of the case 4. The heat sink 56 is also provided with a locking claw portion 58.

[0035] According to the fifth embodiment, similarly to the first to fourth embodiments, the heat sink 56 for individually dissipating heat from the integrated circuit components 8 is provided, and the sealant 12 can be easily attached and has good mounting strength while ensuring the hermeticity of the housing 2. Also, the problem of the sealant 12 falling off can be eliminated. Furthermore, since the sealant 12 is arranged in a so-called labyrinth shape, the seal length of the sealant 12 can be secured long, and the effect of preventing the sealant 12 from falling off can be improved, resulting in improved sealing performance.

[0036] In addition, since the sealing position of the sealant 12 is located above the top surface of the case 4, good heat dissipation from the case 4 can be ensured even if the thermal conductivity of the sealant 12 is poor. In particular, even if the electronic component 52 is disposed near the integrated circuit component 8, the heat dissipation path and heat dissipation area from the electronic component 52 can be ensured without being blocked by the sealant 12, and good heat dissipation from the electronic component 52 can also be achieved.

[0037] (6) Sixth embodiment and other embodiments 7 shows a main part of an electronic device 61 according to the sixth embodiment, which differs from the fifth embodiment in the following respects. That is, in this embodiment, other electronic components 52 such as a memory are mounted on a printed circuit board 7 adjacent to the integrated circuit component 8 on the right side in the figure, and are thermally connected to a protrusion 53 on the bottom surface of the case 4 via a thermally conductive gel 54 made of, for example, TIM, to dissipate heat from the case 4. In this case, in addition to the heat dissipation fins 6, a fourth heat dissipation fin 62 is provided on the case 4 at a height slightly lower than the heat dissipation fins 6, located on the right side of the opening 4a in the figure. No heat dissipation fins are present on the left side and in front and behind the opening 4a in the figure.

[0038] On the other hand, the heat sink 63, which is thermally connected to the integrated circuit component 8 via the thermal conductive material 11, integrally comprises a plate portion 63a and a plurality of fins 64 extending upward from the plate portion 63a and exposed through the opening 4a. Of the fins 64, the one on the right side in the figure is integrally provided at its upper end with an upper extending fin portion 64a for sandwiching the sealant 12 between it and the fourth heat dissipation fin portion 62 of the case 4. The fins 64 on the left side and the front and rear in the figure are integrally provided with lower extending fin portions 64b that branch off midway through the fin 64 and for sandwiching the sealant 12 between it and the upper surface of the case 4.

[0039] As a result, a portion of the sealant 12 is sandwiched between the upper extending fin portion 64a of the heat sink 63 and the fourth heat dissipation fin portion 62 at a position spaced from the top wall portion of the case 4 toward the tip side, i.e., upward. The remaining portion of the sealant 12 is sandwiched between the lower extending fin portion 64b of the heat sink 63 and the upper surface of the case 4. This allows heat from the electronic component 52 to be effectively dissipated mainly from the fourth heat dissipation fin portion 62.

[0040] According to the sixth embodiment, similarly to the first to fifth embodiments, the heat sink 63 for dissipating heat from the integrated circuit components 8 individually is provided, and the sealant 12 can be easily attached and has good mounting strength while ensuring the hermeticity of the housing 2. Also, the problem of the sealant 12 falling off can be eliminated. In this case, since the sealing position of the sealant 12 is separated upward from the upper surface of the case 4 at the fourth heat dissipation fin portion 62, the heat dissipation from the electronic components 52 can be improved even if the thermal conductivity of the sealant 12 is poor.

[0041] In the above-mentioned embodiments, the CPU is given as a specific example of an integrated circuit component, but the present invention can also be applied to other heat-generating components such as a power supply IC. Of course, the specific configurations of the overall structure of the housing, the shape and structure of the heat sink, the shape and structure of the fins and the extended fin portion, etc. can be modified in various ways. The materials of the heat conductive material and the sealing material can also be modified in various ways. In addition, the present invention can be applied not only to ECUs for vehicles, but also to electronic devices in general in which a circuit board is arranged in a housing, and the applications thereof can be agricultural machinery, construction machinery, generators, etc.

[0042] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0043] In the drawings, 1, 21, 31, 41, 51, and 61 indicate electronic devices, 2 indicates a housing, 4 indicates a case, 4a indicates an opening, 6, 42, 55, and 62 indicate heat dissipation fin portions, 7 indicates a printed circuit board, 8 indicates an integrated circuit component, 9, 22, 32, 43, 56, and 63 indicate heat sinks, 10, 23, 33, 44, 57, and 64 indicate fins, 10a, 23a, 33a, 44a, 57a, 64a, and 64b indicate extending fin portions, 11 indicates a thermally conductive material, 12 indicates a sealing material, 13, 24, 34, 45, and 58 indicate locking claw portions, 52 indicates an electronic component, and 54 indicates a thermally conductive gel.

Claims

1. An electronic device comprising a housing (2) housing a printed circuit board (7) on which an integrated circuit component (8) is mounted, A heat sink (9, 22, 32, 43, 56, 63) is thermally connected to the integrated circuit component, and a fin (10, 23, 33, 44, 57, 64) on the tip side of the heat sink is exposed to the outside of the housing through an opening (4a) formed in the wall of the housing, A sealant (12) for sealing a gap between the heat sink and the opening is sandwiched between the heat sink and the housing in a thickness direction of a wall of the housing, The heat sink is provided with an extending fin portion (10a, 23a, 33a, 44a, 57a, 64a, 64b) parallel to a wall of the housing, the extending fin portion being positioned corresponding to the peripheral portion of the opening of the housing, while a heat dissipating fin portion (42, 55, 62) is provided on an outer surface of the wall of the housing; The electronic device, wherein the sealing material is sandwiched between the heat dissipation fin portion or an inner surface of the wall portion of the housing and an extending fin portion of the heat sink.

2. The electronic device according to claim 1 , wherein at least a portion of the sealing material is sandwiched between the extending fin portion of the heat sink and the heat dissipation fin portion of the housing at a position spaced from the wall portion of the housing toward the tip side of the heat dissipation fin portion of the housing.

3. An electronic device comprising a housing (2) housing a printed circuit board (7) on which an integrated circuit component (8) is mounted, A heat sink (9, 22, 32, 43, 56, 63) is thermally connected to the integrated circuit component, and a fin (10, 23, 33, 44, 57, 64) on the tip side of the heat sink is exposed to the outside of the housing through an opening (4a) formed in the wall of the housing, a sealant (12) for sealing a gap between the heat sink and the opening is provided between the heat sink and the housing, the sealant being sandwiched in a thickness direction of a wall of the housing; The electronic device includes a heat sink having a locking claw portion (13, 24, 34, 45, 58) that locks onto the edge of the opening of the housing.

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