JP2015015180A - Heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink capable of efficiently cooling, for example, a substrate which is disposed in an LED lighting device and on which LED light sources are scattered without using a fan.SOLUTION: A heat sink 8 is formed by disposing a heat-receiving bottom plate portion 23, and a plurality of plate-shaped radiation fins 24. The heat-receiving bottom plate portion 23 is disposed on a surface at a side opposite to an LED light source arrangement surface of a substrate on which a plurality of LED light sources are scattered, and thermally connected to the substrate. The radiation fin 24 is vertically disposed on a surface at a side opposite to the thermally-connected surface (basic end face 26) with the substrate of the heat-receiving bottom plate portion 23 through a clearance gap to each other, and the clearance gap of the radiation fin 24 is provided with a natural convection heat radiation function for releasing heat by allowing the air to flow by temperature difference of the air in the rising direction of the radiation fin 24. The heat-receiving bottom plate portion 23 and the radiation fin 24 are, for example, metallurgically and integrally formed, and a tongue ratio is 15 or more and 30 or less.

Description

  The present invention is applied to, for example, an LED lighting device including an LED (light emitting diode) light source, and relates to a heat sink for cooling the heat generated from the LED light source through the arrangement substrate.

  Conventionally, various heat sinks are used for cooling a heat generating electronic component such as an IC. The heat sink has a heat receiving surface that receives heat from the component to be cooled (heat generating component) and a heat radiating fin for radiating the heat received by the heat receiving surface. The method of forming the heat radiating fin is extrusion molding. Various things such as forging, cutting and raising, and metallurgy have been proposed (for example, see Patent Document 1).

JP-A-6-244327

  By the way, in recent years, various LED lighting devices using LED light sources have been proposed. In such LED lighting devices, a plurality of LED light sources are scattered (dispersed) on the LED light source arrangement surface of the substrate. Arrangement). When a plurality of LED light sources are scattered on the substrate in this manner, the substrate is heated almost uniformly over the entire substrate surface direction by the heat generated from the LED light sources. Therefore, a configuration for uniformly cooling a large-area substrate was not provided.

  That is, in the conventional heat sink, the heat receiving function that receives the heat of the heat source, the heat spread function that expands the heat from the heat source area, and the function that dissipates the heat to the air or the like are regarded as important components. In order to ensure the heat spread function, the thickness of the heat receiving plate portion forming the heat receiving surface of the heat sink is increased, and as a result, the weight of the heat sink is increased. However, in the LED heat sink for the LED lighting device, since the point light source is disposed in a relatively large area, the heat spread function is not important, and the thickness of the bottom plate portion of the heat sink is also functionally thin. The present inventor has thought that it is important to be sufficient, but rather lightweight.

  The present invention has been made to solve the above-mentioned problems, and the object thereof is to efficiently cool, for example, an LED light source interspersed substrate provided in an LED lighting device without using a fan or the like. The object is to provide a heat sink that can be reduced in weight.

  In order to achieve the above object, the present invention has the following configuration as means for solving the problems. That is, the first invention is a heat receiving bottom plate portion that is provided on the surface opposite to the LED light source arrangement surface of the substrate in which a plurality of LED light sources are arranged and is thermally connected to the substrate, A plurality of plate-like radiating fins provided on the surface opposite to the thermal connection surface with the substrate of the heat-receiving bottom plate portion, with a space between the radiating fins. It has a natural convection heat radiation function in which heat is dissipated by the flow of air due to the temperature difference of the air in the rising direction of the heat radiation fin, and the heat receiving bottom plate portion and the heat radiation fin are integrally formed thermally and structurally Thus, a configuration in which the tong ratio is formed to be 15 or more and 30 or less serves as means for solving the problem.

  The second invention is characterized in that, in addition to the structure of the first invention, a spacer is provided for maintaining the interval between adjacent heat dissipating fins.

  Further, in the third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, when the thickness of the heat receiving bottom plate portion is t and the diameter of the heat receiving bottom plate portion is D, t / D is 0. 2 or less, and the thickness of the radiating fin is 0.7 mm or less.

  Furthermore, in a fourth aspect of the invention, in addition to the configuration of the first, second, or third aspect, the heat receiving bottom plate has a disk shape or a donut-shaped disk shape in which a through hole is formed in a central portion of the circular shape. The heat dissipating fins are provided radially from the center of the heat receiving bottom plate.

  Furthermore, the fifth invention is characterized in that, in addition to the configuration of any one of the first to fourth inventions, the bottom plate portion for heat reception and the heat radiation fin are integrally formed metallurgically by brazing. Features.

  The heat sink of the present invention is formed having a heat receiving bottom plate portion and a plurality of plate-like heat radiating fins, and the heat receiving bottom plate portion includes an LED light source arrangement surface of a substrate on which a plurality of LED light sources are arranged. Is provided on the opposite surface and is thermally connected to the substrate, and the radiating fins are spaced apart from each other on the surface opposite to the thermal connection surface of the bottom plate for heat reception with the substrate. Although it is provided, the tong ratio (the height of the radiating fins / the interval between the radiating fins) is formed to be 15 or more and 30 or less. With the natural convection heat radiation function that heat is released by the air flowing due to the temperature difference of the air in the rising direction of the heat radiation fin, it is possible to efficiently dissipate substantially uniform heat over the entire substrate surface of the LED light source mounting substrate. .

  In other words, if the spacing between the radiating fins is too narrow, the air flow that flows through the spacing between the radiating fins cannot be generated satisfactorily. If the spacing between the radiating fins is too wide, the number of radiating fins is reduced, and the heat sink is dissipated. Since the efficiency is deteriorated, the present inventor can achieve an excellent effect of improving the flow of air flowing between the radiating fins and increasing the heat transfer area by increasing the number of radiating fins. As a result, it was found that the above-mentioned effect can be exhibited by setting the tongue ratio to 15 or more and 30 or less.

  Based on this study, the heat sink is formed with a tong ratio of 15 or more and 30 or less, and the conventional heat sink is formed to dissipate the heat of a heat generating component such as an electronic component such as an IC, Whereas the configuration for uniformly cooling the substrate was not provided, the present invention provides a heat of the substrate in which a plurality of LED light sources are scattered and heated almost uniformly throughout the substrate surface direction. Can be uniformly dissipated through the heat receiving substrate, and can be efficiently dissipated.

  In addition, the heat sink can be reduced in weight by providing no fins and the like, and the heat receiving bottom plate portion and the heat radiating fins are integrally formed thermally and structurally, thereby making the heat receiving bottom plate portion. The heat radiation fins are connected to each other so that a large thermal resistance does not occur between them, heat is easily transmitted, and the above-described good characteristics can be exhibited. In particular, the heat sink of the present invention can be manufactured more easily and the cost can be further reduced by integrally forming the bottom plate for heat reception and the heat radiating fins by metallurgical integration. it can.

  Therefore, by applying the heat sink of the present invention to an LED lighting device formed by arranging a plurality of LED light sources on a substrate, an LED lighting device that is easy to manufacture, can be reduced in weight, and cost can be reduced. In particular, the heat sink of the present invention can be more easily manufactured by metallurgically integrally forming the heat receiving bottom plate and the heat radiation fin by brazing, and even more. The cost can be reduced.

  In addition, since the heat sink of the present invention is formed to have a tong ratio as high as 15 or more, since the distance between the radiation fins is narrow and the height of the radiation fins is high, there is a problem that adjacent radiation fins may touch each other. Although it may occur, it is possible to prevent such a trouble from occurring by providing a spacer that maintains the interval between adjacent heat radiation fins.

  Furthermore, by forming the thickness of the heat radiating fins to 0.7 mm or less, the tong ratio can be easily formed to 15 or more and 30 or less. The thickness of the bottom plate for heat reception is t, and the diameter of the bottom plate for heat reception is D. In this case, by forming t / D to an appropriate value of 0.2 or less, the heat received by the bottom plate for heat reception from the LED light source mounting substrate can be easily transferred to the heat radiation fin, and the heat radiation efficiency can be improved. Further, the heat sink can be further reduced in weight by forming the radiating fins and the bottom plate for heat reception thin.

  Furthermore, by forming the bottom plate portion for heat reception into a disk shape or a donut type disk shape in which a through hole is formed in the center portion of the circular shape, and providing the radiation fins radially around the center portion of the bottom plate portion for heat reception, For example, it is possible to efficiently dissipate the heat of the LED light source-arranged substrate formed in a donut-shaped disk shape in which a through hole is formed in the disk-shaped or circular center part, and the through-hole is formed in the disk-shaped or circular center part. The present invention can be applied as a heat radiating device of an LED lighting device formed by using an LED light source provided substrate formed in a formed donut disk shape.

FIG. 2 is a schematic perspective view (a) showing a first embodiment of the heat sink according to the present invention and a schematic explanatory view (b) for explaining the operation thereof. It is explanatory drawing for demonstrating the spacer provided in the heat sink of an Example. It is a perspective view of the heat sink of 2nd Example. It is a perspective view which expands and shows a part of heat sink of 2nd Example. It is a typical perspective view which abbreviate | omits the one part structure and shows the heat sink of 3rd Example. It is sectional explanatory drawing which shows the example of the LED lighting apparatus to which the heat sink of 3rd Example is applied. It is an enlarged view of A area | region of FIG. It is the perspective explanatory view which looked at the LED lighting apparatus shown in FIG. 6 from the B direction of FIG. It is the figure which looked at the LED illuminating device shown in FIG. 6 from the C direction of FIG. It is typical sectional drawing for demonstrating the thermal radiation operation | movement by the LED lighting apparatus shown in FIG. It is sectional explanatory drawing which shows the structure of the heat sink of another Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1A is a schematic perspective view showing an embodiment of a heat sink according to the present invention. As shown in the figure, the heat sink 8 of the present embodiment has a heat receiving bottom plate portion 23 and a plurality of radiating fins 24. In the drawing, the formation site of the heat receiving bottom plate portion 23 is easily understood. Therefore, the surface of the heat receiving bottom plate portion 23 is shaded. The heat receiving bottom plate portion 23 is formed of a plate having a donut-shaped disk shape in which a through hole 22 is formed in a circular central portion, and the thickness thereof is uniformly formed at 3 mm. The diameter of the heat receiving bottom plate portion 23 is Is formed to 250 mm, for example.

  The heat-receiving bottom plate portion 23 is an LED light source arrangement of a substrate on which a plurality of LED light sources are scattered (see, for example, the substrate 3 on which the LED light sources 6 are scattered as shown in FIG. 9). It is provided on the surface opposite to the installation surface and is thermally connected to the substrate, and the base end surface 26 (the lower surface in the drawing) of the heat receiving bottom plate portion 23 is the thermal connection surface with the substrate. And the heat receiving surface from the substrate.

  Each radiating fin 24 is formed in a uniform plate shape having a thickness of 0.5 mm, and is spaced from each other on the surface opposite to the base end surface 26 (upper surface in the figure) of the heat receiving bottom plate portion 23 by, for example, 5 mm. And is provided radially with the center of the bottom plate 23 for heat receiving as the center. Each radiating fin 24 is formed to have a narrower width from the heat-receiving bottom plate portion 23 toward the front end side.

The heat receiving bottom plate portion 23 is formed of an aluminum plate, and the heat radiating fins 24 are formed of a clad material in which a silicon film is formed on the surface of the aluminum plate, and the heat receiving bottom plate portion 23 and the heat radiating fins 24. Are integrally formed metallurgically by brazing, and are integrally formed thermally and structurally. The thermal conductivity of aluminum is 250~270W / m ² ℃, conventionally, as compared to the thermal conductivity of the commonly used aluminum die-cast alloy is less than 200 W / m ² ° C. for a heat sink formed Since the heat conductivity is high, good heat transfer is performed through the heat receiving bottom plate 23 and the heat radiation fins 24, and a good heat radiation effect can be achieved. Further, the heat sink 8 of this embodiment has a weight of about 1 kg and is lightweight.

  The detailed method for integrally forming the heat receiving bottom plate portion 23 and the heat radiating fins 24 is not particularly limited. For example, the heat radiating fins 24 are provided on the upper side of the heat receiving bottom plate portion 23 and temporarily assembled. However, it can be easily formed by placing it in a furnace, and in this case, since the silicon-rich layer of the clad material melts in the furnace and then solidifies when cooled, it is easily formed integrally. be able to.

  Further, the heat sink 8 of the present embodiment is formed with a tong ratio of 15 or more and 30 or less. As shown by an arrow A in FIG. It has a natural convection heat radiation function in which heat is dissipated by the flow of air due to the temperature difference of the air (in the vertical direction in FIG. 1B).

  Further, in the present embodiment, a spacer 40 that maintains the interval between adjacent heat radiating fins 24 is provided over the entire circumference of the heat sink 8. The spacer 40 is provided at a position on the distal end side of the radiating fin 24. Thus, when the spacer 40 is provided on the distal end side of the radiating fin 24, compared to the case where the spacer 40 is provided on the proximal end side of the radiating fin 24. The effect of preventing the mechanical deformation or the like of the heat sink 8 from being maintained by maintaining the distance between the heat radiating fins 24 can be exhibited even better (structurally stronger), and the heat conduction efficiency is also improved. The spacer 40 is preferably provided on the tip side of the radiating fin 24.

  In this embodiment, the spacer 40 is formed by a member different from the heat radiating fins 24 and is formed in a ring shape over the entire circumference of the heat sink 8. For example, as shown in FIG. Alternatively, a notch 39 may be formed in the heat dissipating fin 24 and at least a part of the notch 39 may be bent toward the adjacent heat dissipating fin 24 to form the spacer 40. 2 shows the formation of the spacers 40 by means of the rectangular radiating fins 24 for easy understanding of the drawing. For example, the heat receiving bottom plate portion 23 is formed in a rectangular shape as in a second embodiment to be described later. As shown in the figure, the shape of the radiating fins 24 can also be rectangular.

  As shown in FIG. 2, when the spacer 40 is formed using the notch 39 formed in each radiating fin 24, the notch 39 is formed at the same position in the adjacent radiating fin 24, and the notch is formed. When the tongue piece formed by the formation is simply bent at a right angle to form the spacer 40, the tip of the spacer 40 enters the notch 39 of the adjacent radiating fin 24 as shown in FIG. May not be constant.

  Therefore, for example, as shown in FIGS. 2A and 2B, the front end of the spacer 40 is bent along the surface of the adjacent radiating fin 24, or as shown in FIG. The angle θ of 40 may be bent to an angle different from 90 ° (here, θ <90 °). Further, as shown in FIG. 2D, if the positions of the notches 39 of the adjacent radiating fins 24 are different from each other, at least a part of the formation of the notches 39 is simply bent at a right angle to form the spacer 40. It can also be.

  Next, a second embodiment of the heat sink according to the present invention will be described. In the second embodiment and each embodiment described later, the same reference numerals are assigned to the same name portions as those in the first embodiment, and the duplicate description is omitted or simplified.

  As shown in FIG. 3, the heat sink 8 of the second embodiment has a heat receiving bottom plate portion 23 formed of a rectangular plate and a surface opposite to the base end surface 26 of the heat receiving bottom plate portion 23. The spacers 40 have rectangular plate-like heat dissipating fins 24 that are provided to be spaced from each other, and the spacers 40 that maintain the distance between the adjacent heat dissipating fins 24 form notches 39 in the heat dissipating fins 24. The tongue piece formed by this is bent to the side of the adjacent radiating fin 24 (see FIG. 4).

  Next, a third embodiment of the heat sink according to the present invention will be described. As shown in FIG. 5, the heat sink 8 of the third embodiment is formed in substantially the same manner as the first embodiment, and the third embodiment is different from the first embodiment in that the heat sink 8 The shape of the fin 24 is different from that of the heat dissipating fin 24 in the first embodiment. Further, in the heat radiating fins 24 of the heat sink 8 of the third embodiment, a plurality of through holes 25 are formed at intervals from each other in the region from the center to the tip in the rising direction. In FIG. 5, the illustration of the spacer 40 is omitted.

  The heat sink 8 of the third embodiment can be applied to, for example, the LED lighting device 1 as shown in FIGS. 6 to 9, and the arrangement position thereof is as shown in FIGS. The substrate (LED light source disposed substrate) 3 is opposite to the LED light source disposed surface 5. Hereinafter, the LED lighting device 1 to which the heat sink 8 of the third embodiment is applied will be briefly described.

  The LED lighting device 1 includes a donut-shaped disk-shaped substrate 3 in which a substantially circular through hole 2 is formed, and a cylindrical portion 4 provided in a manner of penetrating the through hole 2 of the substrate 3. The cylindrical portion 4 has a cylindrical portion 4a protruding from one surface (lower side in FIG. 6) of the substrate 3 and a cylindrical portion 4b protruding from the opposite surface (upper surface in FIG. 6). 3 protrudes from both sides. The cylindrical portion 4b is formed of a resin member and has characteristics such as light weight, mechanical strength, and difficulty in transferring heat. The power source 11 of the LED light source 6 can be stored in the cylinder of the cylindrical portion 4 (4b).

  In addition, as shown in FIG. 9, a plurality of (for example, 99) LED light sources 6 are disposed on the LED light source disposition surface 5 of the substrate 3 at intervals with each other. By providing the heat sink 8 of the third embodiment on the side of the substrate surface 7 opposite to the arrangement surface 5, the heat sink 8 is provided so as to cover the outer periphery of the cylindrical portion 4b, and the base end surface 26 of the heat sink 8 (FIG. 7) is thermally connected to the substrate 3 to radiate the heat of the LED light source 6. A resin cover member 32 is provided on the outer peripheral side of the heat sink 8, and a plurality of slits 31 are formed in the cover member 32 at intervals, and the slits 31 are intervals between the heat radiation fins 24 of the heat sink 8. It is formed corresponding to the formation position.

  As shown in FIGS. 6 and 8, the cylindrical portion 4 b has one end side in the cylindrical axis direction (Z-axis direction in the figure) protruding ahead of the tip of the heat sink 8, and the protruding cylindrical portion 4 b side. A slit-like vent 9 is formed in the peripheral wall portion. In addition, the cylindrical portion 4b has a circular shape in the cross-sectional shape (XY cross-sectional shape) of the cylindrical hole, but the cylindrical portion 4b has a portion where the vent hole 9 is formed at the tip side (in FIG. 6). Having a region where the diameter continuously decreases toward the upper side) and a region where the diameter decreases stepwise, the diameter of the tip is formed smaller than the diameter in the region where the heat sink 8 is disposed, A base 30 for attaching the LED lighting device 1 to the attachment location is formed at the tip of the cylindrical portion 4b.

  Here, the base 30 is formed to a size specified in, for example, JIS base E39, and the LED lighting device 1 having a high wattage of 50 W or more (depending on the performance of the LED light source, about 300 W) as a corresponding lighting device. Even in the case of forming the LED lighting device, it is possible to reduce the weight by reducing the weight of the heat sink 8 of the third embodiment. Therefore, it is possible to reduce the risk of falling of the LED lighting device 1 against an earthquake, and it is possible to improve the workability at the time of construction and enable one person to work.

  The cylindrical portion 4a is provided so as to protrude from the LED light source arrangement surface 5 side of the substrate 3, and its protruding length is, for example, about 7 cm, and the protruding tip portion (the other end side of the cylindrical portion 4 in the cylinder axis direction). ) To the peripheral edge of the substrate 3, a transparent cover member 12 is formed. The transparent cover member 12 is provided so as to cover the LED light source arrangement surface 5 with a space from the LED light source arrangement surface 5, and the cylindrical body 15 is integrated with the transparent cover member 12 inside the transparent cover member 12. Provided.

  In addition, the cylindrical part 4a is provided inside the cylindrical body 15 with a space from the cylindrical body 15, and the cylindrical part 4a and the cylindrical body 15 are connected via a connecting plate portion 27, so that the cylindrical part is provided. 4a, the cylindrical body 15, and the transparent cover member 12 are integrally formed of, for example, a transparent resin. An opening 10 is formed at the protruding tip of the cylindrical portion 4a, and the diameter of the opening 10 and the cylindrical inner diameter of the cylindrical portion 4a are formed to be 30 mm or more (for example, 80 mm).

  In this LED lighting device 1, as shown in FIG. 7, the contact portion between the lower surface (base end surface 26) of the heat receiving bottom plate portion 23 of the heat sink 8 and the peripheral edge portion of the transparent cover member 12 is a sealing member. An O-ring 33 is provided, an O-ring 34 as a seal member is provided at a contact portion between the bottom plate 23 of the heat sink 8 and the cylinder 15, and the LED covered with the transparent cover member 12 and the cylinder 15 is provided. The light source 6 is formed in a liquid-tight and air-tight manner so that water does not enter the region where the light source 6 is disposed.

  The cylindrical wall of the cylindrical portion 4a is formed to increase in thickness from the opening 10 side to the substrate 3 side. However, the contact portion side of the cylindrical portion 4a with the bottom plate 23 is connected to the contact portion side. A groove portion 35 having an opening is formed over the entire circumference of the cylindrical portion 4a so that the contact area between the cylindrical portion 4a and the bottom plate 23 of the heat sink 8 is reduced. It is comprised so that heat may not be easily transmitted to the site | part 4a side.

  In this LED lighting device 1, when heat is generated by driving the LED light source 6 and the temperature of the substrate 3 rises, heat is transferred from the substrate 3 to the heat receiving bottom plate portion 23 of the heat sink 8, and further, heat is transferred to the radiation fins 24. The heat is radiated from the radiation fins 24. Further, when the temperature of the substrate 3 rises due to the heat of the LED light source 6, an upward airflow is generated in the space between the heat radiation fins 24 of the heat sink 8, and as shown by an arrow A in FIG. The air that has entered the base end side (interval between the fins 23 on the base end side) flows to the front end side of the heat sink 8 along the outer wall surface side of the cylindrical portion 4 and is led out from the front end side to the outside. Consists of composition. Since the through holes 25 are formed in the fins 24, air flows through the holes 25, and the air is more likely to flow through the heat sink 8.

  On the other hand, when the temperature of the air in the cylinder of the cylindrical part 4 rises due to the rise in the temperature of the power supply 11 stored in the cylindrical part 4, as shown by the arrow B in FIG. Ascending airflow is generated in the tube, and air having a temperature lower than that of the air in the cylinder is introduced from the outside into the cylinder of the cylindrical part 4 through the opening 10 of the cylindrical part 4. By being derived, the power source 11 is cooled.

  In addition, as shown in FIG. 7, the LED lighting device 1 is provided with a heat insulating layer 13 on the outer peripheral wall of the cylindrical portion 4 b surrounded by the heat sink 8. As indicated by an arrow C in FIG. 10, air passes along the outer peripheral side of the cylindrical portion 4 from the tip portion where the opening 10 is formed to the tip portion of the heat sink 8. An air passage 14 is formed. As shown in FIG. 7, the air passage 14 is connected to the air passage 14a, the air passage 14b, and the air passages 14a and 14b so as to communicate with each other. The plate portion 27 is formed to have a plurality of through holes 16 formed at intervals.

  The present invention is not limited to the above embodiments, and can take various forms. For example, in the third embodiment, the through holes 25 are formed in the radiating fins 24 of the heat sink 8, but the holes 25 may be omitted. Further, the hole 25 may be formed in the first and second embodiments.

  In each of the above embodiments, the thickness of the heat-receiving bottom plate portion 23 is 3 mm, the thickness of the radiating fins 24 is 0.5 mm, and the interval between the radiating fins 24 is 5 mm. The thickness of the fin 24 and the space | interval of the radiation fin 24 are not specifically limited, It sets suitably. In addition, in order to make the tongue ratio of the heat sink 8 15 or more and 30 or less and to reduce the weight of the heat sink 8, the thickness of the heat receiving bottom plate portion 23 is 5 mm or less (for example, the diameter of the heat receiving bottom plate portion 23 is 250 mm). t / D is preferably an appropriate thickness capable of maintaining a mechanical strength of 0.02 or less), and the thickness of the radiating fin 24 is preferably formed to an appropriate thickness capable of maintaining a mechanical strength of 0.7 mm or less, It is preferable that the space | interval of the radiation fin 24 shall be about 5-10 mm.

  Furthermore, in the said Example, although the plate-shaped radiation fin 24 was integrally formed by brazing in the plate-shaped heat-receiving bottom-plate part 23, other than brazing, welding by soldering, such as laser welding, friction resistance, etc. It may be formed metallurgically and integrally by other methods. For example, as shown in FIG. 11, the heat receiving bottom plate portion 23 and the radiation fins 24 may be formed by bending a plate such as an aluminum clad and integrally forming adjacent plates by metallurgy. Good.

  Furthermore, the material for forming the heat sink 8 is not particularly limited, and is appropriately set. The heat receiving bottom plate portion 23 and the heat radiating fins 24 are made of, for example, aluminum or an aluminum alloy, magnesium, a magnesium alloy, or thermal conductivity. The resin can be formed.

  Further, in the first and third embodiments, the heat receiving bottom plate portion 23 has a shape having the through hole 22, but the heat receiving bottom plate portion 23 may have a disk shape in which the through hole 22 is not formed. It is good also as a shape. In addition, when setting it as a disk shape, it is preferable to provide the radiation fin 24 radially centering on the center part.

  Since the heat sink of the present invention can dissipate substantially uniform heat on the substrate surface with a simple configuration, it can be used, for example, as a heat dissipating means for LED lighting devices in the household and industrial fields.

DESCRIPTION OF SYMBOLS 1 LED lighting apparatus 2 Through-hole 3 Substrate 4 (4a, 4b) Cylindrical part 5 LED light source arrangement surface 6 LED light source 7 Substrate surface 8 Heat sink 9 Vent 10 Open 11 Power supply 12 Transparent cover member 13 Heat insulation layer 14 Air passage 15 Cylindrical body 16 Through hole 23 Heat receiving bottom plate part 24 Radiation fin 26 Base end face 39 Notch 40 Spacer

Claims (5)

  A heat receiving bottom plate portion provided on a surface opposite to the LED light source arrangement surface of a substrate on which a plurality of LED light sources are arranged and thermally connected to the substrate, and the substrate of the heat receiving bottom plate portion And a plurality of plate-like heat dissipating fins provided on the surface opposite to the thermal connection surface with a space between each other, and the space between the heat dissipating fins is the air in the rising direction of the heat dissipating fins. It has a natural convection heat radiation function in which heat is dissipated by the flow of air due to the temperature difference, and the heat receiving bottom plate portion and the heat radiation fin are integrally formed thermally and structurally, and the tong ratio is 15 or more A heat sink characterized by being formed to 30 or less.   The heat sink according to claim 1, wherein a spacer is provided to maintain an interval between adjacent radiating fins.   When the thickness of the bottom plate for heat receiving is t and the diameter of the bottom plate for receiving heat is D, t / D is formed to be 0.2 or less, and the thickness of the radiating fin is formed to be 0.7 mm or less. The heat sink according to claim 1 or 2, characterized by the above.   The heat-receiving bottom plate has a disk shape or a donut-shaped disk shape in which a through hole is formed in the center of the circular shape, and the heat radiating fins are provided radially around the center of the heat-receiving bottom plate. The heat sink according to claim 1, claim 2, or claim 3.   The heat sink according to any one of claims 1 to 4, wherein the heat-receiving bottom plate portion and the heat radiation fin are integrally formed metallurgically by brazing.

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