JP2009004558A - Heat sink constituted of channel-shaped fin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat sink which is lightweight and superior in heat radiation as a radiator for radiating heat generated by electrical components of various electronic equipment, and the like. <P>SOLUTION: The heat sink comprises channel-shaped fins 2 each formed by bending one metal plate into a channel shape and a heat-conduction substrate 3 jointed to the reverse surfaces of the bottom plates 4 of closed portions of the plurality of channel-shaped fins 2, wherein the plurality of channel-shaped fins 2 are disposed in parallel at intervals and side walls 7 of those channel-shaped fins 2 are arrayed in parallel in a fixed direction, the fins being applicable to the heat-conduction substrate 3, even when the heat-conduction substrate having a curved surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat sink that is a heat radiating body for dissipating heat generated from electric parts such as various electronic devices, and in particular, by adopting a U-shaped fin, heat transfer efficiency from a heat transfer substrate to the heat radiating fin. It is to provide a heat sink that is light, lightweight and has good heat dissipation efficiency.

  In recent years, various electronic components have become increasingly denser and smaller in size, and the amount of heat generated per unit area generated from these electronic components has increased. Heat sinks that dissipate the heat are also becoming more sophisticated. Is now required. In addition, electrical components that are becoming smaller and lighter are required to have better performance and lighter weight. As such a heat sink, there is a heat sink by a metal extrusion technique. However, it is difficult to manufacture a large heat sink, and it is difficult to manufacture fins having a complicated structure. Also, thin fins are difficult to extrude, and it is difficult to deal with electrical parts that are becoming lighter. Furthermore, the extrusion method heat sink has a high die and is difficult to apply to various types of electrical products.

  Further, heat sinks made of corrugated fins manufactured by bending metal thin plates are also employed (Japanese Patent Laid-Open Nos. 8-130274 and 8-320194). Since the corrugated fin has a hermetically sealed portion at the top (on the opposite side when the heat transfer substrate side is the bottom plate), the heat of the air heated by the fin is poor and the heat dissipation is not good. Further, since the corrugated fin has a constant shape, there is a problem that the area of the joint surface with the heat transfer substrate cannot be freely taken.

  A heat radiating fin having a U-shaped heat radiating fin is also known (Japanese Patent Application No. 10-126075). In this case, a large number of U-shaped fins are stacked, and heat transfer resistance is generated in each overlapped portion, so heat transfer efficiency is not good. A fin having a structure in which a thin plate is punched into a U-shape is also known as a heat radiating fin (Japanese Patent Laid-Open No. 2003-174129). Therefore, the heat transfer efficiency is poor.

  Various types of mechanical joining means have been tried in joining the heat transfer substrate and the heat radiating fins (for example, Japanese Patent Laid-Open Nos. 11-340392 and 2003-174129). In these mechanical joinings, there is a problem that the heat transfer substrate is distorted at the time of joining, the smoothness of the heat transfer substrate is deteriorated, and the heat transfer from the heating element to the heat transfer substrate is deteriorated.

JP-A-8-320194 (page 1-2, FIG. 1). JP-A-8-130274 (page 1-2, FIG. 1). Japanese Patent Laid-Open No. 10-126075 (page 1-2, FIG. 1). Japanese Patent Laying-Open No. 2003-174129 (page 1-2, FIG. 1). JP-A-11-340392 (page 1-2, FIG. 1).

  An object of the present invention is to provide a heat sink made of a thin metal plate and made of a fin that is lightweight and has a large heat dissipation effect. Another object of the present invention is that the heat dissipating fins are formed from parallel side walls of a thin metal plate, and the upper portion (opposite side to the heat transfer substrate) has an open structure. It is an object of the present invention to provide a heat sink with good heat dissipation and a good structure. Another object of the present invention is to provide a heat sink having a structure in which a large bonding area between the heat transfer substrate and the heat radiating fins can be taken, and having high heat transfer efficiency from the heat transfer substrate to the heat radiating fins. It is another object of the present invention to provide a heat sink that has a simple structure, can be a fin with high productivity, and is inexpensive. The present invention also provides a heat sink having good adhesion between the heating element and the heat transfer substrate by joining the heat transfer substrate and the heat radiating fin so as not to cause processing strain or thermal distortion. Is to provide. Furthermore, the present invention provides a heat sink that is lightweight and has a large heat dissipation effect even when the heating element is a curved surface.

The present invention has been made to achieve the above object, and the heat sink of the present invention has the following characteristics. The present invention relates to a heat transfer substrate in which a U-shaped fin formed by bending a single metal plate into a U-shape and a back side surface of a bottom plate that is a closed portion of a plurality of U-shaped fins are joined. When,
And a plurality of U-shaped fins spaced apart and arranged on a heat transfer substrate so that their side walls are parallel and face in a certain direction. The present invention also provides a curved shape in which a U-shaped fin formed by bending a single metal plate into a U-shape and a back side surface of a bottom plate that is a closed portion of a plurality of U-shaped fins are joined. A heat transfer board, and these U-shaped fins are arranged in a fixed direction on the heat transfer board at intervals and arranged in the normal direction of the curved surface of the heat transfer board. . The present invention also relates to the heat sink in which the U-shaped fin and the heat transfer substrate are bonded with an adhesive. Further, the present invention relates to the side wall of the U-shaped fin, and relates to the heat sink including a side wall that rises after shrinking in the width direction from the bottom plate at a rising portion from the bottom plate toward the open portion. The present invention also relates to the heat sink in which the side wall is bent at the apex of the side wall of the U-shaped fin. Further, in the present invention, the U-shaped fins are opened so as to expand upward, and the side walls of these U-shaped fins are arranged in the normal direction of the curved surface of the heat transfer substrate. It relates to the heat sink.

  An object of the present invention is to provide a heat sink with good heat dissipation. A heat sink, also called a heat sink or radiator, is a component that is attached to a machine or electrical component that generates heat, and is intended to lower the temperature of the heating element by radiating heat. It has the structure where the fin which is a body is attached to the heat-transfer board | substrate.

The heat transfer substrate is a metal plate that serves to transfer heat of the heating element to the fins while being bonded to the heat radiating fins to fix the fins. The heat transfer substrate does not necessarily have to be a flat surface, and can take a curved surface or other shapes along the structure of the surface of the heating element. The material of the heat transfer substrate is preferably made of a metal having good heat transfer properties such as aluminum or an alloy thereof, copper or an alloy thereof.

  The heating element is an electrical component that generates heat when used, such as a semiconductor element such as a CPU or LED, or a lamp such as a halogen lamp, and the heat sink of the present invention generates heat by dissipating the heat of these heating elements by the radiation fins. The purpose is to suppress the temperature rise of the body.

  The heat dissipating fin of the present invention comprises a U-shaped fin. The U-shaped fin is a heat radiating fin having a structure in which a single metal plate is bent into a U-shape. In the heat sink of the present invention, a plurality of U-shaped fins are arranged in parallel in a fixed direction at intervals, and the heat transfer substrate and the back side surface of the bottom plate which is a closed portion of the fins are joined. Thus, by having a U-shaped shape, a fin can be easily manufactured from a thin plate structure, and a thin and lightweight fin can be manufactured. Furthermore, since the U-shaped fin has a wide bottom, a large bonding area with the heat transfer substrate can be obtained. Moreover, since the upper part is an open shape, the dissipating property of the air heated by the fins is improved.

  One metal plate constituting the U-shaped fin is made of a metal having good heat conductivity such as aluminum or an alloy thereof, copper or an alloy thereof. The thickness d of the thin plate is preferably 0.05 mm to 2 mm, more preferably 0.1 mm to 1.0 mm, and most preferably 0.15 mm to 0.3 mm. As the thickness increased, the amount of air passing between them decreased, and when it was too thin, the temperature at the tip of the fin decreased, and experimental results showed that these ranges were preferable. The width w of the bottom plate of the U-shaped fin is preferably 2 mm to 15 mm, more preferably 3 mm to 10 mm, and most preferably 4 mm to 7 mm. Although it is preferable that the gap between the fins is wide, it is preferable that the number of fins is large. The height h of the U-shaped fin is preferably 5 mm to 50 mm, more preferably 10 mm to 40 mm, and most preferably 15 mm to 30 mm. The height of the fin is limited in terms of structure, and if it is too high or too low, the thermal efficiency is poor, and these ranges are desirable as a result of experiments. The interval p between the side walls of the U-shaped fins arranged in parallel is preferably 2 mm to 15 mm, more preferably 3 mm to 10 mm, and most preferably 4 mm to 7 mm. These are also for the same reason as in the case of the width w of the bottom plate of the fin. As described above, these ranges are ranges in which it is confirmed that the heat dissipation effect is large as a result of experiments. The length and width of the heat sink as a whole are determined by the amount of heat to be radiated, heat dissipation performance such as an allowable temperature rise, and the space allocated to the heat sink in terms of the dimensions of the heating element and the device design.

  The shape of the U-shaped fin of the present invention is not necessarily limited to that in which the side wall rises at a right angle from the bottom. In the rising portion of the U-shaped fin toward the open portion, the side wall may be once reduced in the width direction from the bottom plate of the closed portion and then risen toward the open portion. By adopting such a shape, the heat transfer area from the heat transfer substrate at the bottom can be increased, and the heat of the heat transfer substrate can be easily transferred to the fins.

  As another shape of the U-shaped fin of the present invention, a structure in which a thin metal plate on the side wall is bent at the apex of the side wall of the U-shaped fin can be taken. By adopting such a structure, the height of the fin is limited, but it is suitable when it is desired to increase the surface area of the fin. It is preferable that the direction of bending is the same for all side walls. The angle of bending is preferably 1 degree or more and less than 90 degrees, more preferably 10 degrees or more and 60 degrees or less.

  The heat sink of the present invention is characterized in that a plurality of U-shaped fins are arranged in parallel in a certain direction with a space between the heat transfer substrates, and the back side surface of the bottom plate of the closed portion is joined to the heat transfer substrate. To do. When the heating element is a flat plate, the heat transfer substrate of the present invention is also a flat plate along the heating element. The side walls of the plurality of U-shaped fins are arranged in parallel with the plurality of side walls of the U-shaped fins. By arranging in parallel in this way, the flow of air heated by the fins is directed in a certain direction, and the convection effect is improved. As described above, it is desirable that the side wall intervals between the plurality of U-shaped fins are uniform on the side walls arranged in parallel with a space therebetween. This is because the heat transfer substrate can be uniformly cooled.

  If the heat transfer from the heating element is not uniform and is locally high in the heat transfer board, increase the number of U-shaped fins in that part and close the side wall spacing in that part. You can also. By doing so, the heat sink as a whole can be cooled uniformly.

  When the heating element is a curved surface, the heat transfer substrate of the present invention is also preferably curved along the heating element. The plurality of U-shaped fins can be arranged in the normal direction of the curved surface of the heat transfer substrate. As a result, the air flow heated by the fins is evenly dissipated toward the entire curved surface, and the convection effect is improved. In this case, the U-shaped fins are opened so as to spread slightly outward, and a plurality of side walls of the U-shaped fins are arranged in the normal direction of the curved surface of the heat transfer substrate. The convection effect of the air heated by the radiating fin is further improved.

  The U-shaped fin and the heat transfer substrate in the present invention are preferably surface-treated with a heat-resistant black paint such as black alumite treatment. This is because the heat dissipation coefficient is increased by the black surface treatment.

  In the present invention, the heat transfer substrate and the U-shaped fin are preferably bonded by an adhesive. Adhesive bonding does not require a high temperature so that the heat transfer board is distorted, and does not apply excessive force to the heat transfer board or the heat radiation fins and does not distort the material. It becomes a stable heat transfer board and heat dissipation fin. Adhesive bonding is a method of bonding to the bonding surface through a substance having adhesiveness, a method of interposing a low melting point metal such as solder, and a method of bonding via an adhesive in a narrow sense made of inorganic or organic substances There is. A tape-like adhesive such as an adhesive tape can also be used. Such an adhesive inclusion desirably has heat conductivity. As the organic adhesive, a type of adhesive called a heat conductive adhesive or heat transfer cement is used. As the main component of the organic adhesive, a silicone type, an epoxy type, an acrylic type, a urethane type, etc. that can withstand a high temperature of 120 ° C. to 150 ° C. are used. As these heat conductive fillers, metals having good thermal conductivity such as copper, nickel, silver, gold, and aluminum, alloys and compounds thereof, or aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, silicon oxide, silicon carbide, etc. Ceramic powder, carbon powder such as carbon black, graphite and diamond, and powder in a fibrous form are used and mixed with a main agent such as epoxy.

  According to the present invention, it is possible to provide a heat sink having a large heat dissipation effect despite being thin and lightweight. In addition, the heat sink of the present invention can have a structure in which air heated by the heated side wall can be easily removed because the heat dissipating fins are formed of parallel side walls of thin metal plates and the upper part has an open structure. Moreover, since the heat sink of this invention is a structure which can take the joining area of a heat-transfer board | substrate and a radiation fin large, it can be set as the heat sink with the sufficient heat-transfer efficiency from a heat-transfer board | substrate to a radiation fin. The heat sink of the present invention is a U-shaped heat radiation fin with a simple structure and has a simple structure. Therefore, the heat sink is easy to manufacture and the cost is low. Further, in the present invention, when the heat transfer substrate and the heat radiating fin are bonded, an adhesive is used to bond the heat transfer substrate so as not to cause processing strain or thermal distortion, thereby generating the heating element and the heat transfer substrate. It becomes a heat sink with good adhesion. Further, in the present invention, since the heat transfer substrate and the U-shaped fin are bonded by an adhesive, workability when bonding a large number of fins to the heat transfer substrate as in the present invention is good. Moreover, in the heat sink of this invention, since the height of a fin and the space | interval of a parallel part can be taken freely, the heat sink corresponding to various electric equipments is easy to manufacture. Moreover, since the heat sink of the present invention can be structured to increase the area of the bottom plate without changing the surface area of the fins, the heat transfer area is increased and the thermal resistance is reduced. Further, even when the heating element is a curved surface, it becomes a heat radiating fin along that, and in that case, it can be a fin with good heat radiating efficiency.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings. FIG. 1 is a perspective view showing an example of a heat sink manufactured by the present invention. The heat sink 1 has U-shaped fins 2a, 2b, 2c, 2d,... Formed by bending a single metal thin plate into a U-shape, with the open side of the side faced in a certain direction and spaced apart. Are arranged in parallel. The heat transfer substrate 3 and the back side surface 8 of the bottom plate 4 of the fin closed portion are joined by an adhesive layer 5. A heating element 6 is tightly bonded to the heat transfer substrate 3. In the present invention, a plurality of U-shaped fins 2a, 2b, 2c, 2d,... Are arranged in parallel at intervals, and the side walls 7a-1, 7a-2 of these U-shaped fins are arranged. 7b-1, 7b-2, 7c-1, 7c-2,... Are arranged in parallel.

  FIG. 2 shows a cross-sectional view of an example of a U-shaped fin according to the present invention. The U-shaped fins 2a, 2b, 2c,... Shown in this figure are formed from the bottom plates 4a, 4b, 4c,... To the side walls 7a-1, 7a-2, 7b-1, 7b-2, 7c- 1, 7 c-2,... Stand upward at a right angle, and the upper part is open. The plurality of U-shaped fins 2 are desirably arranged in parallel with a constant interval p. The U-shaped fin 2 has a fin thickness d. The thickness of the fin means the thickness of the side walls 7a and 7b, and the bottom plate 4 is usually the same, but the thickness of the bottom plate can be changed. The distance q between the side walls 7a-1 and 7a-2 of the U-shaped fin 2 is preferably substantially equal to the interval p at which the plurality of U-shaped fins are arranged in parallel. The width w of the back side surface 8 of the bottom plate 4 joined to the heat transfer substrate 3 is substantially equal to q + 2d in this figure.

  FIG. 3 is a sectional view showing another example of the U-shaped fin of the present invention. The case where the rising part of the side wall of the U-shaped fin of the present invention from the bottom plate toward the open part is formed of a side wall rising after being reduced in the width direction from the bottom plate of the closed part is illustrated. FIG. A shows a case where the side walls 13a and 13b rise from the bottom plate 12 of the U-shaped fin 11 to the inside at an angle α. In FIG. B, an example in which the rising angle α from the bottom plate 15 of the U-shaped fin 14 to the inside of the side walls 16a and 16b is close to zero is included in the present invention. In these drawings, the width w to be joined to the heat transfer substrate on the back side of the bottom plates 12 and 15 is w> q + 2d. Even with such a structure, the heat transfer width w can be increased while keeping the distance p between the sidewalls of adjacent U-shaped fins constant, so that the heat transfer area can be increased and the heat transfer efficiency can be improved. It was.

  FIG. 4 is a sectional view showing another example of the U-shaped fin of the present invention. When using the U-shaped fins of the present invention, the height of the heat sink may be limited due to the limitations on the size of the device. In such a case, there is a case where it is desired to reduce the height without changing the surface area of the fin as a heat sink of the heat sink so much. As such an application example, a case where a sheet metal is bent at the apexes of the side walls 22a and 22b of the U-shaped fin 21 is illustrated. The direction of bending is preferably bent in a certain direction as shown in FIG. A structure in which the side walls 26a and 26b of the U-shaped fin 25 face outward from the inside (FIG. B) or inwardly can also be adopted.

  FIG. 5 is a sectional view showing an example of the heat sink 31 when the heat transfer substrate is a curved surface. This is a case where the heating element 32 has a curved surface and the heat transfer substrate 33 has a curved surface. The back side of the bottom plates 35a, 35b, 35c, 35d,... Of the U-shaped fins 34a, 34b, 34c, 34d,... By the adhesive layers 36a, 36b, 36c, 36d,. The heat transfer substrate 33 is joined. In this figure, the side walls 37a-1, 37a-2, 37b-1, 37b-2, 37c-1, 37c-2, 37d-1, 37d-2,. The case of standing in the direction perpendicular to the base 35 is illustrated. Further, center lines a, b, c, d,... Between the sidewalls of these U-shaped fins are arranged in the normal direction of the curved surface of the heat transfer substrate 32.

  FIG. 6 is a sectional view showing a heat sink 41 which is another example in the case where the heat transfer substrate is a curved surface. This is a case where the heating element 42 has a curved surface and the heat transfer substrate 43 has a curved surface. The back side of the bottom plates 45a, 45b, 45c, 45d,... Of the U-shaped fins 44a, 44b, 44c, 44d,. , 46d,... Are joined to the heat transfer substrate 43. Each of the U-shaped fin side walls 47a-1, 47a-2, 47b-1, 47b-2, 47c-1, 47c-2, 47d-1, 47d-2,. Are arranged in the normal direction of the curved surface. 5 and 6 show the case where the surface of the heat transfer substrate has a semicircular curved surface, other curved surfaces such as a cylinder and an ellipse may be used.

  A pure aluminum plate (JISA1100) having a thickness of 0.2 mm, a width of 60 mm, and a length of 41.8 mm is bent at a right angle, the height h is 18 mm, the width w for joining to the heat transfer substrate is 5.6 mm, and between the side walls Six U-shaped fins having a distance q of 5.2 mm were manufactured. These U-shaped fins were black-anodized by surface treatment. A pure aluminum plate (JISA1100) having a thickness of 2 mm, a width of 60 mm, and a length of 60 mm was used as a heat transfer substrate, and black anodized by surface treatment. The distance p between the sidewalls of the six U-shaped fins adjacent to the six U-shaped fins on this heat transfer substrate is 5.2 mm, and the open side of the side faces in a certain direction as shown in FIG. Were arranged in parallel at intervals. And the heat transfer substrate and these U-shaped fins are made of a high thermal conductive adhesive whose main agent is an epoxy resin, the filler is nickel, and the thermal conductivity when cured is 1.0 W / m ° C. or more. Joined, one heat sink was made. In this heat sink, a platinum ceramic heater was used as a heating element, and bonded with a heat conductive double-sided adhesive tape. The heat sink obtained had a thermal resistance of 4.8 ° C./W and very good heat conductivity.

  The heat sink manufactured by the present invention is used as an electric component that dissipates heat generated from various electronic devices and electric devices such as lamps.

The perspective view which shows the example of the heat sink of this invention. Sectional drawing which shows the example of the U-shaped fin in this invention. Sectional drawing which shows the other example of the U-shaped fin in this invention. Sectional drawing which shows the other example of the U-shaped fin in this invention. Sectional drawing which shows the example of the heat sink of this invention in case a heat-transfer board | substrate is a curved surface. Sectional drawing which shows the other example of the heat sink of this invention in case a heat-transfer board | substrate is a curved surface.

Explanation of symbols

1: heat sink, 2: U-shaped fin, 3: heat transfer board, 4: bottom plate,
5: Adhesive layer, 6: Heating element, 7: Side wall, 8: Back side.
11: U-shaped fin, 12: Bottom plate, 13: Side wall,
14: U-shaped fin, 15: Bottom plate, 16: Side wall.
21: U-shaped fin, 22: Side wall,
25: U-shaped fin, 26: Side wall.
31: heat sink, 32: heating element, 33: heat transfer board,
34: U-shaped fin, 35: Bottom plate, 36: Adhesive layer, 37: Side wall.
41: heat sink, 42: heating element, 43: heat transfer board,
44: U-shaped fin, 44: Bottom plate, 45: Adhesive layer, 46: Side wall.

Claims (6)

A U-shaped fin formed by bending a single metal plate into a U-shape;
A heat transfer substrate to which the back side surface of the bottom plate, which is a closed portion of the plurality of U-shaped fins, is joined;
A heat sink comprising: a plurality of U-shaped fins spaced apart and arranged on the heat transfer substrate so that their side walls are parallel and face in a certain direction. A U-shaped fin formed by bending a single metal plate into a U-shape;
A heat transfer substrate having a curved shape to which the back side surface of the bottom plate, which is a closed portion of the plurality of U-shaped fins, is joined;
A heat sink comprising: the U-shaped fins arranged in a fixed direction on the heat transfer substrate at intervals, and arranged in a normal direction of a curved surface of the heat transfer substrate.   The heat sink according to claim 1 or 2, wherein the U-shaped fin and the heat transfer substrate are bonded by an adhesive.   The heat sink according to claim 1 or 2, comprising a side wall that rises after shrinking in the width direction from the bottom plate at a rising portion from the bottom plate toward the open portion with respect to the side wall of the U-shaped fin.   The heat sink according to claim 1 or 2, wherein the side wall is bent at the apex of the side wall of the U-shaped fin. The heat sink according to claim 2, wherein the U-shaped fins are opened so as to spread upward, and the respective side walls of the U-shaped fins are arranged in the normal direction of the curved surface of the heat transfer substrate.

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