JP2012009498A - Heat radiation structure of heating unit and audio amplifier equipped with heat radiation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiation structure which is capable of effectively radiating heat from a heat source to an outside through a heat radiation plate, lightweight and easy to be formed.SOLUTION: A heat radiation structure (10) comprises: a metal section (11) which has one surface opposite to a heat source and another surface facing not in a direction toward the heat source; and a heat-conductive resin section (12) which is formed to protrude from the another surface in an outward direction but not toward the heat source and integrally molded with the metal section (11) by an outsert molding or an insert molding.

Description

  TECHNICAL FIELD The present invention relates to a heat dissipation structure of a device such as an electric circuit including an electronic component or an electric component that generates heat during operation, and more particularly, a heat dissipation structure and a heat dissipation structure of a device including a heat IC such as a power IC or a regulator such as an audio amplifier. It is related with the audio amplifier provided.

  It is common to mount various devices including an acoustic device on a vehicle, and an electronic circuit such as an audio amplifier, which is one of the main electrical elements of the acoustic device, includes components that generate heat such as a power IC and a regulator. Yes. Therefore, a heat dissipating mechanism is essential for ensuring the performance of electronic circuits including peripheral components and preventing destruction. As a heat dissipation mechanism, conventionally, heat is radiated using forced convection by heat conduction, an air cooling fan, or the like through a heat dissipation plate made of copper, aluminum or the like. At that time, it is necessary to cool the components disposed on the circuit board so that they can be maintained at a temperature lower than the heat resistant temperature.

Here, the following points are known as problems of the prior art using a heat sink such as copper or aluminum or a cooling fan.
-Copper has high thermal conductivity, but is expensive and heavy, making it unsuitable for general-purpose components.
・ Cooling fans tend to be noise sources, increase costs, and layout with good heat dissipation efficiency must be considered.
・ When using pure aluminum plate or aluminum die-casting as a heat dissipation material, (a) Pure aluminum has the second highest heat conductivity after copper, but it requires press forming, so the degree of freedom of shape is low and secondary processing is also possible. (B) Aluminum die casting has a high degree of freedom in shape, but because of the inclusion of impurities, it has lower thermal conductivity than pure aluminum. (C) Surface area to increase heat conduction and heat dissipation efficiency Since the volume needs to be increased, the weight is increased.

  Moreover, although metal materials, such as above-described copper and aluminum, are used as a material of a heat radiating member, utilization of resin is tried for the heat radiating member.

  For example, a metal material having a protrusion and a resin material are integrally formed by molding a resin on a metal substrate having holes (see Prior Art Document 1), and a plurality of resin heat sinks are bonded to the metal substrate. It is known to fix and form radiating fins (see Prior Art Document 2). In addition, the resin substrate and the heat radiating fin are integrally formed of resin (refer to the prior art document 3), the thermal conductive resin and the other member integrated with the heat conductive resin (refer to the prior art document 4), and It is also known to provide a heat conductive resin integrated so as to cover almost the whole of the heat dissipating fins disposed in contact with the heat conductive member (see Prior Art Document 5).

  Furthermore, a heat dissipation device (see Prior Art Document 6) that fixes the substrate and the heating element arranged on the substrate sandwiched between flat plates having fin-like portions, and a part of the heat dissipation member in contact with the heat generation member There is also known a heat radiating member (metal insert) (see Prior Art Document 7) provided with a heat radiating portion protruding from a member that fixes the heat radiating member.

  However, regarding the resin body described in Prior Art Document 1, the relationship with heat dissipation is not considered, and the sheet-like heat dissipating fins described in Prior Art Document 2 are arranged on the substrate at intervals. However, it is not easy to form the heat dissipation structure, and even if the heat dissipation structure described in the prior art document 3 is easy to form, the substrate and the heat sink constituting the heat dissipation structure are entirely formed of resin. There is a problem in that it is stably fixed to the heating element for a long time.

  Moreover, since the heat conductive molded object described in Prior Art Document 4 is formed integrally, the heat dissipation area is only the surface of the molded object, even though it is excellent in heat conductivity. The heat dissipation efficiency is not enough. Furthermore, in the heat sink described in Prior Art Document 5, the heat conductive resin is arranged and formed so as to cover the heat radiating fins, but the outer surface of the heat conductive resin is substantially flush with the outer surface of the heat radiating fins. Even if the thermal conductivity of the heat dissipation structure is improved by arranging and forming the conductive resin, the overall heat dissipation efficiency is greatly improved because the surface area of the entire heat dissipation structure is smaller than the surface area of the heat dissipation fin. Not.

  Furthermore, in the heat dissipating structure described in Prior Art Document 6, the heating element is sandwiched and fixed by the elasticity of the heat dissipating device made of resin, and the efficiency of heat conduction from the heating element to the heat dissipating device, the fixing strength, etc. Reliability is not enough. Further, in the heat dissipation structure described in Prior Art Document 7, the protrusion for improving the heat dissipation efficiency is formed from a metal element (metal insert), and the heat dissipation structure is not light.

JP 7-156194 A JP 2001-217359 A JP 2004-207690 A JP 2006-49878 A JP 2009-302302 A JP 2008-198835 A Japanese Utility Model Publication No. 5-66252

  In order to reduce the weight and reduce the cost of a heat dissipation structure using a heat sink made of heavy metal, which is heavy, it has been studied to form part of the heat dissipation structure with a resin having good thermal conductivity. . However, the reliability of the heat dissipation structure and the improvement of the heat dissipation efficiency are not enough, and further improvement of the heat dissipation efficiency and the freedom of processing of the heat dissipation structure, and the mounting position of the trunk, etc. under the seat depending on the vehicle type There was a problem in the ease of changing the shape and mounting angle of the heat dissipation structure.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a heat dissipation structure that can efficiently dissipate heat from a heat source (a heating element) to the outside from a heat radiating plate, and that is lightweight and easy to form, and an audio amplifier including the heat dissipation structure. And

  In order to solve the above-described problems, a heat dissipation structure according to the present invention is different from the heat source from a metal portion having a surface facing the heat source and another surface facing a direction different from the heat source, and the other surface. The metal part and the thermally conductive resin part integrally formed by outsert molding or insert molding are provided so as to protrude outward in the direction.

  In order to solve the above problems, an audio amplifier according to the present invention includes a component that is a heat source, a surface that is fixed so as to contact the component, and that faces the component and faces the component in a different direction. Heat dissipation comprising a metal part having a surface of the metal and a heat conductive resin part formed by protruding from the other surface in a direction different from that of the component and integrally formed by outsert molding or insert molding. And have a structure.

  As described above, in the present invention, the resin part for heat dissipation is integrally formed on the heat radiating plate by outsert molding or insert molding to increase the outer surface of the resin part, so that the resin from the heat source (heating element) can be obtained. Heat can be efficiently dissipated through the unit, and deterioration of the electronic circuit and the like due to excessive rise in temperature due to heat generation from the heat source (heating element) can be prevented.

  In the present invention, the heat dissipation structure can be reduced in weight by reducing the ratio of the metal heat dissipation plate to the heat dissipation structure and forming a part of the metal heat dissipation plate with a resin having good thermal conductivity. Furthermore, by forming the heat dissipation structure of the present invention by outsert molding or insert molding, the resin constituting a part of the heat dissipation structure can be easily processed, and the degree of freedom in designing the outer shape of the heat dissipation structure is improved.

(A), (b) shows the general-view figure and exploded perspective view of the audio amplifier provided with the thermal radiation structure of this invention. (A), (b), (c) shows the heat dissipation structure of the present invention and its cross-sectional view, wherein the resin part is outsert-molded with a vertical protrusion on the metal part. (A), (b), (c) shows the other heat dissipation structure of this invention and its sectional drawing, and the resin part was provided with the protrusion part of the vertical direction with respect to the metal part, and was outsert-molded. is there. (A), (b), (c) shows still another heat dissipation structure of the present invention and a cross-sectional view thereof, in which a resin part is insert-molded with a protrusion in the vertical direction with respect to a metal part. . (A), (b), (c) shows still another heat dissipation structure of the present invention and a cross-sectional view thereof, in which a resin part is insert-molded with a protrusion in the vertical direction with respect to a metal part. . FIG. 6 shows still another heat dissipation structure of the present invention, in which a resin part is provided with a protruding part in a lateral direction with respect to a metal part and is outsert molded. (A), (b) shows the further another heat dissipation structure of this invention, and the resin part is provided with the protrusion part of the horizontal direction with respect to the metal part, and is insert-molded. (A), (b) shows the further heat dissipation structure of this invention, and the resin part is provided with the pin-shaped protrusion part with respect to the metal part, and is outsert-molded. (A), (b) shows the further heat dissipation structure of this invention, and the resin part is provided with the pin-shaped protrusion part with respect to the metal part, and is insert-molded. (A), (b) shows the further heat dissipation structure of this invention, and is outsert-molded so that a resin part may protrude with respect to a metal part. (A), (b) shows the further another heat dissipation structure of this invention, and is insert-molded so that the resin part may protrude with respect to a metal part. (A), (b) shows the further heat dissipation structure of this invention, and is outsert-molded so that the resin part provided with the groove | channel may protrude with respect to a hollow metal part. (A), (b) shows the further another heat dissipation structure of this invention, and is insert-molded so that the resin part provided with the groove | channel may protrude with respect to a hollow metal part. (A) thru | or (d) show the other heat dissipation structure of this invention, and it is outsert-molded so that the resin part may protrude with respect to a part of metal part. (A) thru | or (e) shows other heat dissipation structure of this invention, insert-molded so that a resin part may protrude with respect to a metal part including a metal part in a resin part. is there. (A), (b) shows the further heat dissipation structure of this invention, and the heat dissipation structure arrange | positioned with respect to a flat-type heat dissipation part is outsert molding so that a resin part protrudes with respect to a metal part. It has been done. (A), (b) shows still another heat dissipation structure of the present invention, which is formed by outsert molding so that the resin part protrudes from a metal part whose upper and lower parts are curved outward. is there.

  Hereinafter, a heat dissipation structure according to the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

  FIG. 1A is a schematic view when an audio amplifier used in an audio device or the like mounted on a vehicle uses a heat dissipation structure according to the present invention, and FIG. 1B is an exploded perspective view of the audio amplifier. Is illustrated. For example, as shown in FIG. 1B, the audio amplifier 30 is closed by an upper lid 31 that covers an upper surface and one side surface of a circuit board 33 fixed to the housing 32, and the housing 32 and the upper lid 31. The heat dissipation structure 10 is provided on the side surface that is not present. Note that the heat dissipation structure 10 may be disposed in contact with the heat source 34. Moreover, the structure of the audio amplifier provided with the heat source 34 and described in FIGS. 1A and 1B is merely an example, and the shape and structure thereof can be changed as appropriate.

  The heat dissipation structure 10 is fixed to a heat source 34 such as a power IC installed on the circuit board 33, and heat from the heat source 34 is radiated to the surroundings through the heat dissipation structure 10. The heat dissipation structure 10 is usually about 100 mm × 20 to 50 mm, and the length may be about 200 to 300 mm.

  In order to effectively radiate heat from the heat radiating structure 10, a metal material having high thermal conductivity and a resin having good thermal conductivity are often used as the material of the heat radiating structure 10. Further, in order to efficiently dissipate the shape of the heat dissipation structure 10, the protruding portion of the heat dissipation structure 10 is formed in a fin shape, a pin shape, or the like so as to increase the surface area. Details of the heat dissipation structure 10 will be described with reference to FIGS.

  The heat dissipation structure of the present invention is shown in FIGS. This heat dissipation structure is outsert molded so that the resin portion protrudes from the metal portion. 2 (a) is an external view, FIG. 2 (b) is a cross-sectional view as viewed from the direction of arrows A1-A1 in FIG. 2 (a), and FIG. 2 (c) is as viewed from the direction of arrows A2-A2. It is sectional drawing containing the cross section of the fin-shaped protrusion part 121. FIG.

  In the heat dissipation structure 10 shown in FIGS. 2A to 2C, the resin portion 12 is integrated with the metal portion 11 by outsert molding. As shown in the cross-sectional views of the heat dissipation structure 10 (FIGS. 2B and 2C), the hole 113 of the metal part is filled with the resin 12 and formed on the back surface 111 of the metal part by outsert molding. The resin part 12 provided with the back surface part 122 of the resin part and the protruding part 121 of the resin part is formed.

  As shown in FIG. 2B, the hole 113 of the metal part 11 corresponding to the adjacent fin-shaped protrusion 121 is formed in the vertical direction of the fin-shaped protrusion 121 in FIG. 2A (in FIG. 2B). , The positions are shifted from each other in the depth direction of the figure). Also, in the cross-sectional view of FIG. 2C, the holes 113 of the metal part 11 corresponding to the adjacent fin-like protruding parts 121 are similarly displaced from each other in the vertical direction of the figure.

  The back surface portion 111 of the metal portion and the front surface 112 of the metal portion are sandwiched between the back surface portion 122 of the resin portion and the protruding portion 121 of the resin portion connected via the resin portion filled in the hole 113 of the metal portion, and the metal portion 11 and the resin part 12 are firmly fixed. Further, the protrusion 121 of the resin portion is formed as a fin-like protrusion having a groove in the vertical direction in appearance.

  From the heat dissipating structure 10 that is in direct contact with the heat generating part (refer to the heat source (power IC or the like) 34 in FIG. 1B), through the metal part 11 and the protruding part 121 of the resin part 12, the outside of the heat dissipating structure 10. Heat is efficiently dissipated in the direction (outward of the fin-like protrusions 121 of the resin part 12: the arrow direction in FIG. 2A). As a heat release path, there is a path through the resin in the direction in which the fin-like protrusion 121 of the heat-conductive resin part 12 protrudes. Since the air around the surface of the fin-shaped protrusion 121 has a lower thermal conductivity than the resin portion 12, the heat conduction and heat dissipation through the air are relatively small.

  In the heat dissipation structure shown in FIG. 2, the weight can be reduced as compared with the case where the entire heat dissipation structure is made of metal such as aluminum. Since the heat dissipating structure can be formed by outsert molding, it is easy to form and can easily cope with a change in the shape of the heat dissipating structure. By forming this heat dissipation structure by outsert molding, unlike aluminum and aluminum die casting, it is possible to punch out from more than 3 directions, and relatively complicated shapes can be formed, which is necessary for aluminum die casting. There was no need for additional parts and secondary processing.

  In the part where the heat dissipation structure 10 is in direct contact with the heat generating part, a metal part 11 having higher thermal conductivity than the resin part 12 is disposed, and the resin part 12 having good thermal conductivity is used as a heat dissipation path from the metal part 11 to the outside. The resin part 12 provided with the fin-like protrusion part 121 improved in the above was used. For this reason, the heat dissipation characteristics of the heat dissipation structure are equivalent or improved as compared with the conventional structure in which the entire heat dissipation structure is made of metal such as aluminum.

  Another heat dissipation structure of the present invention is shown in FIGS. This heat dissipation structure is outsert-molded so that the resin part protrudes from the metal part, and the metal part and the resin part are integrated. 3 (a) is an external view of the heat dissipation structure, FIG. 3 (b) is a cross-sectional view as viewed from the direction of arrows B1-B1 in FIG. 3 (a), and FIG. 3 (c) is a cross-sectional view of FIG. It is sectional drawing containing the cross section of the shape protrusion part 121 seen from the arrow direction of B2-B2.

  In the heat dissipation structure of FIG. 3, the height of the protrusion 121 of the resin portion 12 protruding from the metal portion 11 is the same as the height of the fin-like protrusion 121 of the heat dissipation structure 10 shown in FIGS. Low compared. Further, the protruding portion 121 of the resin portion is integrally formed with the groove 124 in the vertical direction in appearance.

  In the heat dissipation structure of FIG. 3, as shown in FIG. 3B, the hole 113 of the metal part is filled with the resin 12 and formed on the back surface 111 of the metal part, as in the heat dissipation structure of FIG. The metal portion 11 is sandwiched and fixed by the resin portion 12 including the back surface portion 122 of the resin portion and the protruding portion 121 of the resin portion.

  As shown in FIG. 3 (b), the hole 113 of the metal part 11 corresponding to the adjacent fin-shaped protrusion 121 is in the vertical direction of the fin-shaped protrusion 121 of FIG. 3 (a) (in FIG. 3 (b)). , The positions are shifted from each other in the depth direction of the figure). Further, in the cross-sectional view of FIG. 3C, the holes 113 of the metal part 11 corresponding to the adjacent fin-like protrusions 121 are similarly displaced from each other in the vertical direction of the figure.

  In the heat dissipation structure shown in FIGS. 3A to 3C, the height of the protruding portion 121 is lower than that in FIG. 2B, and the external surface area of the resin portion 12 in contact with the outside air is relatively small. The heat dissipation efficiency is relatively small. Therefore, the heat dissipation effect of the protrusion 121 is small compared to FIG. If the maximum temperature of the circuit element or the like can be kept below the limit temperature even if the heat generation amount from the heat source is relatively small and the heat dissipation effect is somewhat small, the volume of the heat dissipation structure can be obtained using the heat dissipation structure of FIG. Can be reduced.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so that the resin portion protrudes from the metal portion, and the metal portion and the resin portion are integrated. 4A is an external view of the heat dissipation structure, FIG. 4B is a cross-sectional view as viewed from the direction of arrows C1-C1 in FIG. 4A, and FIG. 4C is a view of FIG. It is sectional drawing containing the cross section of the fin-shaped protrusion part 121 seen from the arrow direction of C2-C2.

  In the heat dissipation structure shown in FIGS. 4A to 4C, a protrusion 121 of the resin part is provided so as to cover a part of the back surface 111 of the metal part, the surface 112 of the metal part, and the side part 115 of the metal part. Resin portion 12 is formed. The metal portion 11 is sandwiched by the surface portion 126, the side surface portion 127, and the back surface portion 122 of the resin portion 12 formed so as to cover a part of the back surface 111 of the metal portion, the surface 112 of the metal portion, and the side surface portion 115 of the metal portion. Therefore, the metal part 11 and the resin part 12 are firmly fixed.

  Further, in the C2-C2 direction of FIG. 4A, the upper and lower end portions are sandwiched between the both side surface portions 127 and the back surface portion 122 of the resin portion 12. Further, the protrusion 121 of the resin portion is formed as a fin-like protrusion having a groove in the vertical direction in appearance.

  The heat dissipating structure in FIG. 4 is the same as the heat dissipating structure in FIG. 2 in terms of the length of the short side and the long side, the height of the fin-like protrusion, and the thickness of the metal part 11. If the heat conduction to the resin part is approximately the same, the heat dissipation effect can be predicted to be approximately the same.

  In addition, by forming this heat dissipation structure by insert molding, unlike aluminum and aluminum die-casting, it is possible to perform die-cutting from more than three directions, so that relatively complicated shapes can be formed, which is necessary for aluminum die-casting. The additional part which was was unnecessary.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so that the resin portion protrudes from the metal portion, and the metal portion and the resin portion are integrated. 5 (a) is an external view of the heat dissipation structure, FIG. 5 (b) is a cross-sectional view as viewed from the direction of arrows D1-D1 in FIG. 5 (a), and FIG. 5 (c) is a cross-sectional view of FIG. It is sectional drawing containing the cross section of the protrusion part 121 seen from the arrow direction of D2-D2.

  Also in the heat dissipation structure shown in FIGS. 5A to 5C, the resin portion 12 is formed on the metal portion 11 as an integral structure by insert molding. Even in this heat dissipation structure, the surface portion 126, the side surface portion 127, and the back surface portion 122 of the resin portion 12 formed to cover a part of the back surface 111 of the metal portion, the surface 112 of the metal portion, and the side surface portion 115 of the metal portion, Since the metal part 11 is clamped, the metal part 11 and the resin part 12 are firmly fixed.

  Further, in the direction D2-D2 in FIG. 5A, the upper and lower end portions are sandwiched between the both side surface portions 127 and the back surface portion 122 of the resin portion 12. Further, the protrusion 121 of the resin portion is formed as a fin-like protrusion having a groove in the vertical direction in appearance. Further, the protruding portion 121 of the resin portion is integrally formed with the groove 124 in the vertical direction in appearance.

  In the heat dissipation structure of FIG. 5, the height of the protruding portion 121 of the resin portion 12 protruding from the metal portion 11 is compared with the height of the fin-like protruding portion 121 of the heat dissipation structure shown in FIGS. And low. Therefore, the external surface area of the resin part 12 in contact with the outside air of the heat dissipation structure of FIG. 5 is relatively small, and the heat dissipation efficiency is relatively small. Therefore, the heat dissipation effect including the protrusion 121 is small compared to the heat dissipation structure of FIG.

  Still another heat dissipation structure of the present invention is shown in FIG. This heat dissipation structure is outsert-molded so that the resin portion protrudes from the metal portion, and the protrusion 121 of the resin portion is formed as a fin-like protrusion having a lateral groove in appearance. Is done.

  6 is not shown, and although the groove forming direction is different from the heat dissipation structure of FIG. 2 (vertical direction in FIG. 2 and horizontal direction in FIG. 6), the cross section of the heat dissipation structure in FIG. As shown in the figure, the resin portion 12 is filled with the resin 12 by the outsert molding, and has a resin portion back surface portion 122 formed on the metal portion back surface 111 and a resin portion protrusion 121. Part 12 is formed.

  Further, the back surface portion 111 of the metal portion and the front surface 112 of the metal portion are sandwiched between the back surface portion 122 of the resin portion and the protruding portion 121 of the resin portion connected through the resin portion filled in the hole 113 of the metal portion. The metal part 11 and the resin part 12 are firmly fixed.

  Further, in the heat dissipating structure of FIG. 6, as shown in FIG. 2B, the holes 113 of the metal part 11 corresponding to the adjacent fin-like protruding parts 121 are positioned with respect to each other as in the heat dissipating structure of FIG. The positions of the fin-shaped protrusions 121 in FIG. 6 are shifted from each other in the left-right direction.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so that the resin portion 12 protrudes from the metal portion. 7 (a) and 7 (b) show an overview of different heat dissipation structures.

  7 (a) and 7 (b), the grooves are formed in a different direction from the heat dissipating structure in FIG. 5 (vertical direction in FIG. 5 and horizontal direction in FIG. 7). 5, the metal portion 11 is sandwiched by the resin portion 12 formed so as to cover a part of the back surface 111 of the metal portion, the front surface 112 of the metal portion, and the side surface portion 115 of the metal portion. The metal part 11 and the resin part 12 are firmly fixed. Further, the protrusion 121 of the resin portion is formed as a fin-like protrusion having a groove in the lateral direction in appearance.

  Further, the protrusion 121 formed on the surface of the resin part 12 in FIG. 7B is lower than the fin-like protrusion 121 formed on the surface of the resin part 12 in FIG. Since the surface area of 121 in contact with the outside air is small, its heat dissipation effect is relatively small.

[Simulation analysis of heat conduction effect of heat dissipation structure]
While changing the material of the element which comprises a thermal radiation structure, changing the shape of the thermal radiation fin, the simulation analysis was conducted about the heat conduction effect of the thermal radiation structure by simulation, and the analysis result of Table 1 was obtained. In the comparative example, the heat dissipation fin is integrally formed by aluminum die casting as the heat dissipation structure, and in the analysis examples 1 to 5, the heat dissipation structure is formed by outsert molding of resin using an aluminum plate as a metal part. .

  About comparative example and analysis examples 1-5, heat dissipation structure is 45 mm in height and 250 mm in length, the shape (vertical groove, horizontal groove) of a radiation fin, the height (high and low) of a radiation fin, and the number of radiation fins And the thickness was set as shown in Table 1, and the analysis of heat conduction was performed. The thermal conductivity of the aluminum die casting, the aluminum plate, and the resin portion is 160 W / m · ° C., 160 W / m · ° C., and 20 W / m · ° C., respectively. And the result about the effectiveness of the heat dissipation effect of the analysis examples 1-5 was obtained from the analysis result of the maximum temperature of the aluminum plate and outsert resin of Table 1.

The heat dissipation structures of the comparative example and analysis examples 1 to 5 are as follows.
(A) In the comparative example, a heat radiating plate and a heat radiating fin are integrally formed by aluminum die casting, and a vertical radiating fin is provided.
(B) Analytical Examples 1 to 5 correspond to the heat dissipation structure shown in FIGS. 2, 3 and 6, and as the heat dissipation structure, resin heat dissipation fins are outserted on the aluminum plate of the metal member for heat dissipation. Molded.
Analysis Example 1 includes a long (long) heat radiation fin in the vertical direction.
Analysis Example 2 includes a low (short) heat radiation fin in the vertical direction.
Analysis Example 3 includes low (short) radiating fins in the lateral direction.
Analysis Example 4 includes a relatively large number of low (short) heat dissipation fins in the lateral direction.
Analysis Example 5 includes a high (long) heat radiation fin in the lateral direction.

The following conclusions were obtained from the analysis results of heat conduction.
-Although the maximum temperature of the aluminum plate (metal part) of the heat dissipation structure of analysis examples 1 to 5 and the outsert resin having good thermal conductivity is the same, both are lower than the maximum temperature of the aluminum plate of the comparative example.
In the analysis examples 1 and 2 in which the resin radiating fins are formed in the vertical direction, the surface area of the radiating fins is increased by increasing the height of the resin radiating fins, and the heat transfer surface with the outside is increased. The maximum temperature of both the heat-dissipating aluminum plate and resin heat-dissipating fins tends to decrease.

  In the analysis example 3 in which the resin radiating fins are formed in the horizontal direction (longitudinal direction), the resin contributing to heat conduction is compared with the analysis example 2 in which the resin radiating fins having the same height are formed in the vertical direction. The cross-sectional area of the heat-radiating fins (area perpendicular to the heat transfer direction) increases, and the temperature of both the heat-dissipating aluminum plate and resin fin tends to decrease compared to the case where the heat-radiating fins are arranged vertically. .

  -Comparison between Analysis Example 3 and Analysis Example 4 increases the number of rows of heat dissipating fins arranged in the lateral direction, increases the surface area of the heat dissipating fins, and increases the heat transfer surface with the outside air. The maximum temperature of both aluminum plates and resin radiating fins tends to decrease.

  ・ Comparing Analysis Example 3 and Analysis Example 5, increasing the height of the heat dissipating fins (the length of the heat dissipating fins) arranged in the lateral direction and increasing the surface area increases the heat transfer surface with the outside. Both the aluminum plate of the heat dissipation structure and the resin heat dissipation fin tend to decrease in temperature.

  Therefore, when the amount of heat generated by the power element that is the heat source is larger, it is possible to suppress the rise in the maximum temperature of the aluminum plate of the heat dissipation structure and the resin heat dissipation fin by increasing the height of the fin. is there. Further, in analysis examples 3 to 5 in which the resin radiating fins are formed in the horizontal direction, the height of the resin radiating fins is increased and the number of rows of the resin radiating fins is increased. The effect of lowering the maximum temperature of aluminum plate and resin heat radiation fins is high.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is outsert molded so that the resin portion 12 protrudes from the metal portion 11. FIG. 8A is an external view of the heat dissipation structure, and FIG. 8B is a cross-sectional view including the cross section of the pin-shaped protrusion 121 as viewed from the direction of arrows E-E in FIG. is there.

  In the heat dissipation structure shown in FIGS. 8A and 8B, the resin part 12 is formed on the metal part 11 in an integral structure by outsert molding. In this heat dissipation structure, as shown in the cross-sectional view of FIG. 8B, the back surface of the resin portion connected via the resin portion filled in the hole 113 of the metal portion, as in the heat dissipation structure of FIG. The back surface 111 of the metal part and the front surface 112 of the metal part are sandwiched between the part 122 and the protruding part 121 of the resin part, and the metal part 11 and the resin part 12 are firmly fixed.

  Further, the protrusion 121 of the resin portion has a structure in which pin-like protrusions 121 are two-dimensionally arranged in appearance. Therefore, the cross-sectional view seen from the arrow direction perpendicular to EE in FIG. 8A is the same as the cross-sectional view seen from the arrow direction EE of the heat dissipation structure of FIG.

  In the heat dissipation structure of FIG. 8, the heat dissipation structure 10 that is in contact with the heat generating portion as an integral structure is connected to the outside of the heat dissipation structure 10 via the pin-shaped protrusions 121 of the metal portion 11 and the resin portion 12 ( Heat is dissipated to the outside of the pin-shaped protrusion 121 of the resin portion 12. As a heat release path, there is only a path through the resin in the protruding direction of the pin-shaped protruding portion 121 of the heat-conductive resin portion 12.

  Therefore, as compared with the fin-like protrusions 121 of the heat dissipation structure in FIG. 2, any space in the vertical direction or the horizontal direction between the pin-like protrusions 121 is not connected with a resin having good thermal conductivity. In other words, since the space between the pin-shaped protrusions 121 is not connected with a resin having good thermal conductivity, the pin-shaped protrusion 121 of the heat dissipation structure of FIG. The heat dissipation efficiency is low compared to the entire protrusion.

  Still another heat radiation structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so that the resin portion protrudes from the metal portion. FIG. 9A is an external view of the heat dissipation structure, and FIG. 9B is a cross-sectional view as seen from the direction of arrows F-F in FIG.

  Further, as shown in FIG. 9B, the surface portion 126 of the resin portion 12 formed to cover a part of the back surface 111 of the metal portion, the surface 112 of the metal portion, and the side surface portion 115 of the metal portion, the side surface portion. Since the metal part 11 is clamped by the 127 and the back surface part 122, the metal part 11 and the resin part 12 are firmly fixed.

  The heat dissipating structure in FIG. 9 is one in which pin-shaped protrusions 121 are two-dimensionally arranged in appearance. Furthermore, the heat release path is only the path through the resin in the direction in which the pin-shaped protrusion 121 of the heat-conductive resin part 12 protrudes. Therefore, as compared with the fin-like protrusions 121 of the heat dissipation structure in FIG. 3, neither the vertical or horizontal spaces between the pin-like protrusions 121 are connected by the heat conductive resin. Compared with the whole fin-shaped protrusion part of FIG. 3, the thermal conductivity of the entire pin-shaped protrusion part 121 is relatively low.

  Still another heat dissipation structure of the present invention is shown in FIGS. 10 (a) and 10 (b). This heat dissipation structure is outsert-molded so as to protrude by the thickness direction of the resin portion 12 with respect to the normal direction of the surface (plane) of the metal portion 11. FIG. 10A is an external view of the heat dissipation structure, and FIG. 10B is a cross-sectional view seen from the direction of arrows G-G in FIG.

  As shown in FIG. 10 (b), the back surface portion 111 of the metal portion and the front surface portion 126 of the resin portion are connected through the resin portion filled in the hole 113 of the metal portion. The surface 112 of the metal part is clamped, and the metal part 11 and the resin part 12 are firmly fixed. Further, the heat from the metal part 11 is dissipated from the surface part 126 of the resin part where the resin part 12 is in contact with the outside air via the resin part 12 of the thermal good conductor. The heat dissipation efficiency improves as the thickness of the resin portion 12 increases. In addition, compared with the heat dissipation structure of FIG. 2, since the protrusion part 121 is not formed in the resin part 12, the heat dissipation efficiency is low.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so as to protrude by the thickness direction of the resin portion 12 with respect to the normal direction of the surface (plane) of the metal portion 11. Fig.11 (a) is an external view of a thermal radiation structure, FIG.11 (b) is sectional drawing seen from the arrow direction of HH of Fig.11 (a).

  Further, as shown in FIG. 11, the back surface portion 122 of the resin portion, the side surface portion 127 of the resin portion, and the resin portion formed so as to cover a part of the back surface 111 of the metal portion, the front surface 112 and the side surface portion 115 of the metal portion. The metal part 11 and the resin part 12 are firmly fixed.

  Furthermore, the heat from the metal part 11 is dissipated from the surface part 126 of the resin part in which the resin part 12 is in contact with the outside air through the resin part 12 of the thermal good conductor. The heat dissipation efficiency improves as the thickness of the resin portion 12 increases. In addition, compared with the heat dissipation structure of FIG. 4, since the protrusion part 121 is not formed in the resin part 12, the heat dissipation efficiency is low.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is outsert molded so that the resin portion protrudes from the metal portion. FIG. 12A is an external view of the heat dissipation structure, and FIG. 12B is a cross-sectional view seen from the direction of arrows I-I in FIG.

  In the heat dissipation structure shown in FIGS. 12A and 12B, the resin portion 12 is integrated with the metal portion 11 by outsert molding. Moreover, in the cross section of FIG.12 (b), the cross section of the metal part 11 is a square hollow body. Furthermore, as illustrated in the cross-sectional view of FIG. 12B, the back surface portion 122 of the resin portion and the resin portion connected via the resin portion filled in the hole 113 of the hollow box-shaped metal portion 11. The protrusion part 121 sandwiches the back surface 111 of the metal part and the front surface 112 of the metal part, and the metal part 11 and the resin part 12 are firmly fixed.

  Further, as shown in the cross-sectional view of FIG. 12B, the resin portion 12 having unevenness is disposed on one side surface of the metal portion 11 and the concave portion of the surface 112. In this heat dissipation structure, a groove is formed in the resin portion 12 along the longitudinal direction of the metal portion 11.

  The resin portion 12 is formed in a layered manner on one side surface and the surface of the metal portion 11, but may be formed in a layered shape on both side surfaces and the surface of the metal portion 11, and formed in a layered shape only on the surface of the metal portion 11. May be. Furthermore, the groove formed in the resin part 12 may be formed in a direction perpendicular to the longitudinal direction of the metal part 11, and the direction of the groove formed in the side surface and the surface may be different.

  The heat dissipation structure of FIG. 12 is a heat dissipation structure that includes a protrusion 121 that is shorter than the length of the fin-shaped protrusion 121 of the heat dissipation structure of FIG. 2. Therefore, the heat dissipation surface area of the protrusion 121 is small and the heat dissipation efficiency is low. Relatively small. However, the heat dissipation structure shown in FIG. 12 can dispose the resin part 12 for heat dissipation not only on the surface of the hollow metal part 11 but also on the side surface, thereby improving the heat dissipation efficiency.

  In this heat dissipation structure, only a part of the surface of the metal part 11 is covered with the resin part 12, but the ratio of the surface of the metal part 11 covered with the resin part 12 is changed, and the color of the resin part 12 is changed or changed appropriately. By combining a plurality of colors, the appearance and pattern of the heat dissipation structure 10 can be variously changed. Therefore, when the heat dissipation structure 10 is arranged in a vehicle trunk or the like, the heat dissipation structure 10 having a good appearance can be formed without any additional parts.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so that the resin portion protrudes from the metal portion. FIG. 13A is an external view of the heat dissipation structure, and FIG. 13B is a cross-sectional view as seen from the direction of arrows JJ in FIG.

  In the heat dissipation structure shown in FIGS. 13A and 13B, the resin portion 12 is integrated with the metal portion 11 by insert molding. Moreover, in the cross section of FIG.13 (b), the cross section of the metal part 11 is a square hollow body. Further, as shown in FIG. 13, the metal portion 11 and the resin portion 12 are sandwiched between the back surface portion 122 and the surface portion 126 of the resin portion 12 formed so as to cover both side surfaces and the surface 112 of the metal portion. It is firmly fixed.

  Further, as illustrated in FIGS. 13A and 13B, the resin portions 12 having unevenness are disposed on both side surfaces of the metal portion 11 and the concave portions of the surface 112. The direction of grooves formed on the upper surface (groove in the long side direction) and both side surfaces (grooves in the short side direction) of FIG. 13A are different, but the same direction (long side direction or short side of the metal part). (Side direction) grooves may be formed, or grooves may be formed only on the upper surface.

  Furthermore, since the degree of freedom of processing of the resin part 12 of the heat dissipation structure in FIG. It can be easily changed and the design can be improved. Further, the appearance and pattern of the heat dissipation structure 10 can be variously changed by appropriately changing the color of the resin portion 12 or combining a plurality of colors. Therefore, when the heat dissipation structure 10 is arranged in a vehicle trunk or the like, the heat dissipation structure 10 having a good appearance can be formed without any additional parts.

  Still another heat dissipation structure of the present invention is shown in FIGS. This heat dissipation structure is outsert molded so that the resin portion protrudes from a part of the metal portion. In any of FIGS. 14A to 14D, the heat-dissipating resin portion 12 is disposed only in the vicinity of the portion near the heat source of the metal portion 11 (see FIG. 1B).

  Here, FIG. 14A arranges the resin part 12 having the fin-like protrusion 121 as the heat-dissipating resin part 12, and FIG. 14B protrudes to the surface as the heat-dissipating resin part 12. The resin part 12 in which the part 121 and the groove part 124 are formed is arranged, and FIG. 14C arranges the resin part 12 having the pin-like protruding part 121 as the heat-dissipating resin part 12, and FIG. Is a resin part 12 having a thickness disposed as the resin part 12 for heat dissipation.

  Although not shown in FIGS. 14A to 14D, the resin portion back surface 122 and the resin portion protrusion 121 are connected via a resin portion formed in the hole 113 of the metal portion. The back surface 111 of the metal part and the front surface 112 of the metal part are sandwiched, and the metal part 11 and the resin part 12 are firmly fixed.

  14A to 14D, the heat radiating resin portion 12 is disposed only on a part of the surface of the heat radiating metal portion 11, and is generally compared with the thermal conductivity of the metal portion 11. Thus, the thermal conductivity of the resin portion 12 is low. Therefore, the heat dissipation efficiency by the resin part 12 of the heat dissipation structure of FIG. 14 is lower than that of the heat dissipation structure of FIG. 2, FIG. 3, FIG. 8 and FIG. .

  However, even if the heat generation amount from the heat source is relatively small and the heat dissipation effect is somewhat small, if the maximum temperature of the circuit element or the like can be kept below the limit temperature, the heat dissipation structure of FIG. The volume of the structure can be reduced.

  Still another heat dissipating structure of the present invention is shown in FIGS. This heat dissipation structure is insert-molded so that the metal part is included in a part of the resin part and the resin part protrudes from the metal part. 15A is a fin-like protrusion 121, FIG. 15C is a protrusion 121 and a groove 124, FIG. 15D is a pin-like protrusion 121, and FIG. 15E is a thick resin. The unit 12 is provided. In any of the heat dissipation structures, the metal part 11 is disposed only in the vicinity of the part closest to the heat source of the resin part 12.

  FIG.15 (b) is sectional drawing seen from the arrow direction of KK of Fig.15 (a). Further, as shown in FIG. 15B, the metal part 11 and the resin part 12 are firmly fixed by being sandwiched by the resin part 12 formed so as to cover the surface 112 and both side parts 115 of the metal part. ing.

  Moreover, in the heat dissipation structure described in FIGS. 15A and 15C, the metal part 11 is formed only in the vicinity of the part closest to the heat source, and generally the thermal conductivity of the metal part 11 is used. Since the thermal conductivity of the resin part 12 is lower than that of the resin part 12, the metal part 11 is formed over the entire back surface part 122 of the resin part 12, respectively corresponding to FIGS. 5, 6, 9 and 11. The effect is relatively lower than the heat dissipation efficiency of the heat dissipation structure.

  However, even if the heat generation amount from the heat source is relatively small and the heat dissipation effect is somewhat small, if the maximum temperature of the circuit element or the like can be kept lower than the limit temperature, the heat dissipation structure of FIG. The volume of the structure can be reduced.

  Still another heat dissipating structure of the present invention is shown in FIGS. FIG. 16A is a schematic view of the heat dissipation structure, and FIG. 16B is a cross-sectional view seen from the direction of arrows L-L in FIG. This heat dissipating structure is a heat dissipating structure for a structure in which a power IC or the like serving as a heat source is disposed flat on a circuit board and heat can not be effectively dissipated even if the heat dissipating plate is disposed in a direction perpendicular to the substrate.

  Here, when the heat radiating plate (metal portion 11) has a curved portion, the efficiency of heat conduction decreases at a portion where the shape changes sharply, such as the curved portion, and heat stays. Therefore, heat is not efficiently dissipated from the heat dissipation structure, heat is not sufficiently dissipated from the heat source, and there is a problem that heat dissipation efficiency is lowered. In the heat dissipation structure of FIG. 16, in order to solve the above problems, a layered resin portion 12 with good thermal conductivity is formed in the vicinity of the curved portion 117 of the metal portion 11.

  Further, the lower surface of the flat part 116 of the metal part is brought into plane contact with a heat source such as a power IC placed flat on the circuit board, so that heat is effectively conducted from the heat source to the metal part 11. Thereafter, heat is conducted from the flat part 116 of the metal part to the tip part 118 of the metal part through the bent part 117 of the metal part, and heat is radiated from all surfaces of the metal part including the surface of the flat part 116 of the metal part. To do.

  However, the bent portion 117 of the metal part has a lower thermal conductivity than the flat part of the metal part. Therefore, in order to prevent a decrease in thermal conductivity at the bent portion 117 of the metal portion, and to further improve the thermal conductivity of the bent portion 117, the vicinity of the bent portion includes the bent portion 117 of the metal portion. Resin portions were formed in layers on the front and back surfaces and both side surfaces of the metal portion.

  Then, as can be seen from the cross-sectional view of FIG. 16B, the cross-sectional area of the heat conduction path from the flat part 116 of the metal part to the tip part 118 via the bent part 117 is increased, and the heat absorbed from the heat source is increased. The heat can be effectively dissipated to the tip 118 of the metal part and further to the outside air without the heat staying at the bent part 117 of the metal part.

  The heat dissipation structure of FIG. 16 is an effective structure as a heat dissipation structure when the surface of the heat source is parallel to the horizontal direction. Moreover, since the front end portion 118 of the heat radiating plate can be extended within the space where the heat radiating structure is provided and the surface area of the heat radiating plate can be increased, the heat radiating efficiency can also be improved.

  FIG. 17 shows still another heat dissipation structure of the present invention. FIG. 17A is a schematic view of the heat dissipation structure, and FIG. 17B is a cross-sectional view seen from the direction of arrows M-M in FIG. This heat dissipation structure includes a metal part that is in contact with the heat source at both upper and lower ends and protrudes outward in the middle part, and has an inner surface and an outer surface of the convex raised parts of the upper and lower metal parts. This is a heat dissipation structure in which the resin part is formed in layers by outsert molding.

  The heat transmitted from the heat source to the metal part is further dissipated outward through a layered resin part formed on the surface of the metal part. Further, heat conduction from the upper end portion of the metal portion to the lower end portion or from the lower end portion of the metal portion to the upper end portion is increased by the layered resin portions formed on the front and back surfaces of the bent portion of the metal portion. Effectively through the road. As a result, heat conduction in the longitudinal direction and the vertical direction of the metal part is performed without stagnation, and heat from the heat source can be effectively radiated to the outside.

DESCRIPTION OF SYMBOLS 10 Heat dissipation structure 11 Metal part 111 The back surface of a metal part 112 The surface of a metal part 113 The hole of a metal part 114 The side edge part of a metal part 115 The side part of a metal part 116 The flat part of a metal part 117 The bending part of a metal part 118 Tip portion 12 Resin portion 121 Projection portion of resin portion 122 Back surface portion of resin portion 123 Resin injection hole 124 Groove portion of resin portion 125 Recess portion of resin portion 126 Surface portion of resin portion 127 Side surface portion of resin portion 30 Audio amplifier 31 Upper lid 32 Housing Body 33 Circuit board 34 Heat source (power IC, etc.)

Claims (12)

  A metal part having a surface facing the heat source and another surface facing in a direction different from the heat source, and protruding from the other surface in a direction different from the heat source, the metal part and outsert molding or insert A heat dissipating structure provided with a heat conductive resin part integrally formed by molding.   The heat dissipation structure according to claim 1, wherein the metal part has a flat plate shape.   The heat dissipation structure according to claim 1, wherein the resin portion is formed on two or more surfaces or side surfaces of the metal portion.   The heat dissipation structure according to claim 1, wherein a plurality of grooves are formed on a surface of the resin portion.   The heat dissipation structure according to claim 4, wherein the groove is formed in a vertical direction or a horizontal direction on a surface of the resin portion.   The heat radiating structure according to claim 4, wherein the resin portion includes a plurality of fin-like protrusions serving as side walls of the groove.   The heat dissipation structure according to claim 1, wherein a plurality of pin-shaped protrusions are formed on a surface of the resin portion.   The heat dissipation structure according to claim 1, wherein the metal part includes a concave part on the surface of which the resin part is disposed.   The flat metal part includes a curved part, and the resin part is formed in layers on the upper and lower surfaces and the side surface of the flat metal part near the curved part including the curved part. 2. The heat dissipation structure according to 2.   The heat dissipation structure according to claim 1, wherein the resin portion is formed only in the vicinity of the heat source.   The heat dissipation structure according to any one of claims 1 to 7, wherein the metal portion is formed only in the vicinity of the heat source. The heat source components,
A metal part that is fixed so as to be in contact with the component and that has a surface facing the component and another surface that faces in a different direction from the component, and projects from the other surface in a direction different from the component. A heat dissipation structure comprising the metal part and a thermally conductive resin part integrally molded by outsert molding or insert molding;
An audio amplifier characterized by comprising:

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