JP4656154B2 - Heat sink manufacturing method and heat sink - Google Patents

Description

  The present invention relates to a heat sink manufacturing method and a heat sink, and more particularly to a technique that can be used for cooling power modules (power device elements) such as automobiles, electric railways, home appliances, industrial machines, and electric power and can save space.

  Conventionally, various types of aluminum heat sinks such as an extruded material (die-cast material) heat sink, a corrugated fin brazed heat sink, and a plate fin brazed heat sink have been used to cool electric machines and electronic devices.

  In these conventional technologies, it is difficult to meet the demand for higher efficiency of the cooling device that should cope with the inevitable increase in density due to the recent reduction in thickness and size of electric and electronic devices. That is, it does not meet the demands for improving the heat dissipation performance with the same space volume and cooling conditions (cooling air volume, cooling air temperature), or reducing the size of the heat sink with the same heat dissipation performance.

Aluminum extruded material is one in which aluminum material passes through the extrusion mold and is extruded in a Tokoroten style.In the aluminum die-casting heat sink, the molten metal is filled into the mold cavity and is a kind of injection molding. As shown in FIG. 7, the manufactured heat sink 70 has a fin 71 that has a possible thickness of about 1.0 mm or more and cannot have a fine fin structure that can increase the heat transfer area to the air. Accordingly, the recent demand for higher performance cannot be satisfied as the heat transfer characteristics.
Further, with such a structure, when the fin 71 thickness remains the same and the fin pitch is narrowed to increase the heat radiation area, the pressure loss of the cooling air passing between the fins 71 increases. At the same time, there was a problem that the weight increased.
In addition, when the fin 71 is thinned to reduce the fin pitch, the fin efficiency, that is, the cooling efficiency is lowered.

As the corrugated fin brazing heat sink 80, a type in which an upright corrugated fin 82 is brazed to an aluminum plate 81 is illustrated as shown in FIG. In this structure, since the corrugated fins 82 are self-supporting, the thermal resistance is relatively large.
Furthermore, with such a structure, when the fin thickness remains the same and the fin pitch is narrowed to increase the heat radiation area, the pressure loss of the cooling air passing between the fins increases. there were.
Further, when the fin thickness is reduced and the fin pitch is narrowed, there is a problem that the fin efficiency, that is, the cooling efficiency is lowered.
Also, the fin height can be increased, or the fins can be stacked in several layers, but in this case, the heat conduction distance in the fin height direction becomes too long, resulting in no increase in performance and increased pressure loss. There was a problem.

  In order to improve the fin efficiency, as shown in FIG. 9, plate members 92 parallel to each other are erected on the surface of the base portion 91 and brazed, and between these plate members 92, 92, parallel to the surface of the base portion 91. A configuration in which the corrugated fins 93 are provided is also possible, but in this case, there are problems that the number of members increases, and positioning and assembling and joining of the plate member 92 and the fins 93 become difficult.

Further, when the base portion 91 and the plate material 92 are integrally formed and the fins 93 are inserted and joined between the plate materials 92, the accuracy of the interval dimension W0 between the plate materials 92 and the width dimension of the fins 93 is determined. If this is not sufficient, there is a problem that poor bonding occurs.
This is because it is difficult to ensure such dimensional accuracy at the time of joining the base portion 91 and the plate material 92 or at the time of manufacturing the fin 93, that is, if the interval between the plate materials 92 is equal to or smaller than the width of the fin 93 This is because insertion becomes impossible, and if it is too large, the fins 93 cannot be tightly fixed between the plate members 92 and cannot be tightly joined by brazing. As a result, there is a problem that they cannot be connected to such an extent that necessary heat conductivity can be obtained.

  In order to solve this problem, when the base portion 91 and the plate material 92 are separated from each other, and the plate material 92 and the fins 93 are joined to the base portion 91 at the same time, the base portion 91 and the plate material 92 are joined together. Since the heat conductivity is lower than that using an extruded material or a die-cast material in the attaching portion, there is a problem that sufficient cooling performance and fin efficiency cannot be obtained.

  The present invention has been made in view of the above circumstances, and intends to achieve the object of providing a heat sink that is easy to manufacture while maintaining a desired fin efficiency.

The method of manufacturing a heat sink according to the present invention includes a comb-shaped member having a plurality of tooth portions having a predetermined thickness at predetermined intervals, and a plurality of corrugates having a predetermined height between each tooth portion and the tooth portions. A method of manufacturing a heat sink in which fins are arranged and a comb-shaped material and a corrugated fin are integrally joined by brazing, wherein the corrugated fin is divided into a plurality of parts between the tooth portions and the tooth portions. The above problem is achieved by heat-treating the corrugated fins and the corrugated fins between the corrugated fins with a spacer that presses the corrugated fins against the teeth, and then brazing the comb-shaped material and the corrugated fins. Solved.
The heat sink according to the present invention includes a comb-shaped member having a plurality of tooth portions having a predetermined thickness at predetermined intervals, and a plurality of corrugates having a predetermined height disposed between the tooth portions and the corrugation. And the corrugated fin is divided into two parts between one tooth part and another tooth part adjacent to the one tooth part, and the one tooth part and the other tooth part The above-mentioned problem has been solved by forming a gap between the corrugated fins divided into two .

  In the method of manufacturing a heat sink according to the present invention, the corrugated fin is divided into two parts (a plurality of divided parts) between the tooth parts, and a spacer is inserted between the corrugated fins. When heat treatment is performed with the fins pressed against the teeth, the comb-shaped material and the corrugated fins can be sufficiently bonded by brazing, thereby eliminating the bonding failure and obtaining sufficient heat conduction, It becomes possible to maintain a desired fin efficiency.

FIG. 5 shows an example of the heat sink structure of the present invention, and FIGS. 2 to 4 show the members of the brazed heat sink, which is the means of FIG. 5. Specifically, the heat sink of the present invention is shown in FIG. as shown in, the comb-shaped member 10 of the extruded material or die-cast material consists of a corrugated fin 17. As shown in FIG. 2, the comb-shaped member 10 has a shape in which a plurality of plate-like tooth portions 12 are provided in a parallel state and are suspended from a single base portion (heat receiving portion) 11. The corrugated fins 17 are a plurality of thin-walled panels subjected to corrugating as shown in FIG. 3, and the width dimension W2 thereof is the tooth portions 12 and the interval W1 and the corrugated fins provided between the tooth portions 12 and 12. It is set to be smaller than the value divided by the number of 17. As shown in FIG. 4, the spacer 19 has a plate shape bent in a V shape, and is elastically deformable so that the thickness expands in the direction of arrow A.

When manufacturing such a heat sink, two corrugated fins 17 are inserted into the gaps 14 between the respective tooth portions 12 and 12 in the comb-shaped material 10, and the tooth portions 12 are parallel between the corrugated fins 17 and 17. A plate-like spacer 19 is inserted into the state.
Then, as shown by an arrow A in FIG. 4, the corrugated fins 17 are pressed against the tooth portions 12 by the spacers 19. The core assembled in this way becomes an integral heat sink structure by brazing in the furnace in a brazing furnace while remaining integral.

  Further, since the comb-shaped extruded material 10 is made of aluminum or an aluminum alloy having good heat conductivity and the base portion 11 and the tooth portion 12 are integrated, a heat source is provided on the surface of the base portion 11 for cooling. In this case, heat treatment is performed while maintaining good heat conduction from the base portion 11 to the tooth portion 12 and being inexpensive, and the corrugated fins 17 are pressed against and contacted with the tooth portion 12 by the spacer 19. Therefore, it is possible to prevent the corrugated fins 17 and the tooth portions 12 from being sufficiently brazed and causing poor bonding. Thereby, a heat sink with good fin efficiency can be provided.

In the integrally brazed structure of the present invention, a heating element such as a semiconductor element is mounted on a flat part outside the base part 11 and used as a radiator. However, the heat transferred from the heating element to the base part 11 is suitable for heat transfer. The heat is efficiently transferred to the thin corrugated fin 17 that is transmitted to the tooth portion 12 having an area and is brazed tightly to the tooth portion 12, and finally the heat is released to the air passing through the corrugated fin 17. Will be.
In addition, in the integral brazing structure of the present invention, the thickness of the base portion 11, the thickness of the tooth portion 12, the thickness of the fin 17, the pitch of the fin 17, the fin through hole, the looping up of the looper, etc. are widened as necessary. Various combinations are possible.

  In the prior art, in the heat sink 70, it is difficult to reduce the diameter or thickness of the fin 71 for transferring heat to the air, the frame or lattice of the extruded profile, and the height of the pin and fin. Yes, there are some technical limitations. In the heat sink 80, thin fins similar to those of the present invention can be used, but a portion corresponding to the tooth portion 12 of the present invention that efficiently transfers heat from the base portion is missing, and the fin 82 is self-supporting. Therefore, it is difficult to make the fins 82 tall, and it is difficult to apply them except as a compact heat sink.

  In the present invention, the interval between the teeth 12 of the comb-shaped material 10 is designed to be slightly smaller than the width dimension of the corrugated fins 17 + the width of the spacer, so that the teeth 12 and the teeth of the comb-shaped extruded material 10 are connected to each other as shown in FIG. The corrugated fins 17 can be easily inserted into W1 between the portions 12, and after that, the spacers 19 are inserted between the corrugated fins 17 and 17, and the elasticity of the spacers 19 allows the corrugated fins 17 to If the comb-shaped extrudate 10 and the corrugated fins 17 are lightly pressed, the close contact between the tooth portions 12 and the corrugated fins 17 becomes complete. By performing the heat treatment in this state, it is possible to join the fin and the tooth portion 12 without poor bonding.

Then, as shown in FIG. 5, remove the spacers 19 after completion of the heat treatment as comprising SUS plate or the like, between and how the corrugated fin 17 shall be the structure in which gap 14 is present.
The gap 14 can also be used as an air passage when used as a radiator during brazing in a furnace. In this case, since the flow velocity of the air inside the gap 14 is higher than the flow velocity of the air between the corrugated fins 17, the warm air between the corrugated fins 17 is sucked out toward the gap 14, thereby further cooling effect. Can have.

  Further, in the present invention, as shown in FIG. 6, in the comb-shaped member 10, the tip portions of the adjacent tooth portions 12 are integrally connected to each other to form the second base portion 13, whereby the base portion is formed. A heat source can be arrange | positioned to the surface and the back surface of the part 11 and the base part 13, and double-sided cooling can be performed.

  According to the heat sink manufacturing method and the heat sink of the present invention, the corrugated fin is divided into two parts between the tooth part and the tooth part, and a spacer is inserted between the corrugated fins. When heat treatment is performed with the fins pressed against the teeth, the comb-shaped material and the corrugated fins can be sufficiently bonded by brazing, thereby eliminating the bonding failure and obtaining sufficient heat conduction, There is an effect that the desired fin efficiency can be maintained.

Hereinafter, an embodiment of a manufacturing method and a heat sink heatsink will be described with reference to the drawings.

FIG. 1 is a front view (a) and a bottom view (b) showing a heat sink of this embodiment , and FIGS. 2 to 4 are front views showing members of the heat sink in FIG.
The heat sink of this embodiment is configured to include a comb-shaped member 10, a corrugated fin 17, and a spacer 19.

As shown in FIG. 2, the comb-shaped member 10 has a shape in which a plurality of plate-like tooth portions 12 are provided in parallel to each other so as to be suspended from a single base portion (heat receiving portion) 11. 12 is an integral member made of an extruded material or a die-cast material.
A heat source (cooled part) (not shown) is arranged on the flat part of the outer surface of the base part (heat receiving part) 11. As this heat source, power modules (power device elements) such as MOSFETs (Metal Oxide Silicon Field Effect Transistors), IGBTs (Insulated Gate Bipolar Transistors), and IPMs (Intelligent Power Modules) can be applied.
The size of the base portion 11 in plan view is set to be substantially equal to the contour size of these power modules.
The dimension between the tooth parts 12, 12 is set as indicated by W1 in FIG.

  As shown in FIG. 3, the corrugated fins 17 are a plurality of thin panels subjected to corrugation processing in which an aluminum plate or an aluminum alloy plate is corrugated by roller molding, press processing, or the like. , 12 is set to be smaller than 1/2 of the interval W1. The corrugated fins 17 are obtained by heat-treating a brazing sheet having a surface with an aluminum brazing material having a thickness of about 10% and brazing the teeth 12. As the brazing material on the surface of the corrugated fins 17, an Al—Si alloy, another Al eutectic alloy, or the like can be applied.

As shown in FIG. 4, the spacer 19 is formed into a plate shape obtained by bending an aluminum plate or an aluminum alloy plate into a V shape, and is a spring-like one that can be elastically deformed so that the thickness expands in the direction of arrow A. Is done. The spacer 19 is made of an aluminum plate or an aluminum alloy plate having the same material and structure as the corrugated fins 17, and a brazing material is provided on the surface as described above, or a brazing material is provided. Good.
The thickness dimension of the spacer 19 is set larger than the interval W4 between the corrugated fins 17 and 17 when the corrugated fins 17 and 17 are joined to the tooth portions 12 and 12 without the spacer 19.

When manufacturing such a corrugated fin, in the comb-shaped material 10, two corrugated fins 17, 17 are inserted into the gap 14 between the respective toothed portions 12, 12, and the toothed portion is interposed between the corrugated fins 17, 17. A plate-like spacer 19 is inserted in a state parallel to 12. Then, as shown by an arrow A in FIG. 4, the corrugated fins 17 are pressed against the tooth portions 12 by the spacers 19.
Here, at least the corrugated fin 17 is made of an aluminum plate or an aluminum alloy plate, and an Al-based brazing material is provided on the surface in contact with the tooth portion 12 and the spacer 19. Since the brazing filler metal can be provided, the teeth 12, the corrugated fins 17, and the spacers 19 are joined by the heat treatment.
The core assembled in this way becomes an integral heat sink structure by brazing in the furnace in a brazing furnace while remaining integral.

  Further, since the comb-shaped extruded material 10 is made of aluminum or an aluminum alloy having good heat conductivity and the base portion 11 and the tooth portion 12 are integrated, a heat source is provided on the surface of the base portion 11 for cooling. In this case, since the heat conduction from the base portion 11 to the tooth portion 12 is maintained and the corrugated fins 17 are pressed against and contacted with the tooth portion 12 by the spacer 19, The fins 17 and the tooth portions 12 are sufficiently brazed to prevent poor bonding.

In the heat sink having the integrally brazed structure of the present embodiment, a heating element such as a power module is mounted on the flat part outside the base part 11 and used as a radiator, but the heat transferred from the heating element to the base part 11 is The heat is efficiently transferred to the thin corrugated fins 17 which are transmitted to the teeth 12 having an appropriate heat transfer cross-sectional area and are brazed tightly to the teeth 12, and finally pass through the corrugated fins 17. Heat will be released to the air. At this time, heat can be transmitted from the base portion 11 to the corrugated fins 17 even through the spacer 19 made of aluminum, and the spacer 19 can have a rectifying action for adjusting the direction of the cooling air in the heat sink. As a result, the flow of cooling air is stabilized, and the cooling efficiency can be improved. Thereby, since a desired cooling efficiency can be obtained, it is possible to reduce the size of the heat sink and save space.

In this embodiment , the interval W1 between the teeth 12 and 12 of the comb-shaped member 10 is set slightly smaller than the double corrugated fin 17 width dimension W2 + spacer width dimension, and as shown in FIG. The corrugated fins 17 are easily inserted into W1 between the tooth portions 12 of the comb-shaped extruded material 10 and the spacers 19 are inserted between the corrugated fins 17 and 17 thereafter. If the comb-shaped extrudate 10 and the corrugated fin 17 are lightly pressed from the mountain direction of the corrugated fins 17, the close contact between the tooth portions 12 and the corrugated fins 17 is completed. By performing the heat treatment in this state, it is possible to join the fin and the tooth portion 12 without poor bonding.

Embodiments of a heat sink manufacturing method and a heat sink according to the present invention will be described below with reference to the drawings.
FIG. 5 is a front view showing the heat sink of the present embodiment.

The present embodiment is different from the above-described heat sink manufacturing method and heat sink configuration in that the heat sink has no spacer 19. Other corresponding components are denoted by the same reference numerals and description thereof is omitted.

In the manufacturing method of the heat sink in the present embodiment, instead of the aluminum spacer 19 shown in FIG. 4A, for example, a SUS one having the same shape as the spacer 19 or a SUS made in FIG. As shown in b), it is possible to use a spacer 21 composed of spacer members 21a and 21a facing each other with a taber surface in the thickness direction.
The spacers 19 and 21 made of SUS are coated with BN (boron nitride) on the surface thereof.

  Thereby, the corrugated fins 17 and 17 are inserted between the tooth portions 12 and 12 of the comb-shaped member 10, and the spacer 19 or the spacer 21 made of SUS is inserted. In the spacer 21, after inserting between the tooth parts 12 and 12, spacer member 21a, 21a moves to the arrow B direction shown in FIG. 4, respectively. Thereby, the thickness dimension of the spacer 21 increases in the arrow A direction, and the corrugated fins 17 can be pressed and brought into close contact with the tooth portion 12 in the same manner as the spacer 19 described above. In this state, heat treatment is performed, and the corrugated fins 17 and the tooth portions 12 are brazed and joined in the same manner.

  After brazing by heat treatment, the spacers 19 and 21 made of SUS are removed. At this time, since SUS and aluminum do not react, the SUS spacers 19 and 21 can be easily removed. Moreover, it becomes possible to remove more easily by BN apply | coated to the surface. Thus, the gap 14 is present between the corrugated fins 17 and 17.

  Further, in the present embodiment, the same effects as those of the first embodiment can be obtained, and a gap 14 is present between the corrugated fins 17 and 17 as shown in FIG. 14 can be used as an air passage when used as a radiator. In this case, the air flow rate in the gap 14 is higher than the air flow rate between the corrugated fins 17. A further cooling effect can be obtained by a so-called ejecting effect in which warm air in the air is sucked out to the gap 14 side.

Note that the comb-shaped member 10 may have a configuration in which the tip portions of the adjacent tooth portions 12 are integrally connected to each other to form the second base portion 13 .

In this case, a power device for controlling the inverter is disposed on the flat portion on the outer surface of the base portion 11, and a voltage converter (converter) is disposed on the flat portion on the outer back surface of the base portion 13. 11 and a heat source can be arranged on the front surface and the back surface of the base portion 13 to perform double-sided cooling.

It is the front view (a) and bottom view (b) which show one form of a heat sink . It is a front view which shows the member of a heat sink. It is a front view which shows the member of a heat sink. It is a front view which shows the member of a heat sink. It is a front view which shows embodiment of the heat sink which concerns on this invention. It is a front view which shows one form of a heat sink . It is a front view which shows the conventional heat sink. It is a front view which shows the conventional heat sink. It is a front view which shows the conventional heat sink.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Comb material 11 Base part 12 Tooth part 13 Base part 14 Gap | interval 17 Corrugated fins 19 and 21 Spacer 21a Spacer member

Claims (2)

A comb-shaped material having a plurality of teeth with a predetermined thickness at a predetermined interval, and a plurality of corrugated fins having a predetermined height and corrugated between each tooth and the teeth are brazed. A heat sink manufacturing method in which a comb-shaped member and a corrugated fin are integrally bonded,
The comb corrugated fins are divided into a plurality of portions between the tooth portions, and the comb-shaped members are heat-treated in a state where a spacer for pressing the corrugated fins against the tooth portions is inserted between the corrugated fins. And a method of manufacturing a heat sink, characterized by brazing corrugated fins and removing the spacers after brazing.   A comb-shaped member having a plurality of tooth portions with a predetermined thickness at a predetermined interval, and a plurality of corrugated fins each having a predetermined height disposed between the tooth portions and corrugated. The corrugated fin is divided into two parts between one tooth part and another tooth part adjacent to the one tooth part, and divided into two parts between the one tooth part and the other tooth part. A heat sink, wherein a gap is formed between the corrugated fins.

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