JP2011155161A - Method of manufacturing heat sink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a heat sink excelling in work efficiency, low in manufacturing cost, and capable of reducing the size by reducing an interval between fins. <P>SOLUTION: This method of manufacturing a heat sink includes processes of: forming a laminated body 3 by laminating a plurality of flat plates 2a each having an adhesive 4 applied to one-side surface, and integrating them together by solidifying the adhesive 4; respectively mounting end faces of the respective flat plates 2a on a flat base plate 1 to fix the laminated body 3 on the base plate 1; and dissolving the adhesive 4 to be removed from among the flat plates 2a. The process of fixing the laminated body 3 on the base plate 1 may be a process of dividing the laminated body 3 into a plurality of small blocks 3' and thereafter fixing the small blocks 3' on the base plate 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a heat sink attached to an electrical component, an electronic component, a mechanical component, or the like.

  The heat sink is attached to an electrical component, an electronic component, a mechanical component, etc., and cools each component by dissipating heat. This heat sink is made of a material having a high thermal conductivity, for example, a metal such as aluminum or copper, or a ceramic having a high thermal conductivity such as AlN (aluminum nitride), and is designed to have a large heat radiation area, that is, a surface area. . As an example, the heat sink has a structure including protrusions called fins in order to secure a large heat radiation area. In order to realize the structure having the fins, the heat sink is mainly manufactured using an extrusion method, a caulking method, a cutting method, a casting method, a rolling method, a pressing method, or the like.

  The extrusion method is a method of obtaining a product with a desired shape through a die hole by applying a compressive force around the material placed in the container, and is particularly suitable when using a soft material such as aluminum or lead (non-patent Reference 1).

  The caulking method is a method in which a separately formed fin is crimped and fixed to a base plate.

  The cutting method is a method of creating fins by making a groove into a block-shaped material with a blade. It is particularly suitable when using a ceramic material that cannot be subjected to extrusion or caulking.

  Patent Document 1 exemplifies a method of manufacturing a heat sink using a casting method, a rolling method, and a pressing method. Specifically, the heat sink of Patent Document 1 has a shape in which a plurality of heat radiating plates (fins) are held parallel to each other by support columns, and in the case of casting, a pair of divided molds are combined. The molten metal is injected into the cavity to integrally form the support and the heat sink. On the other hand, a rolling method or a pressing method is used to form individual heat sinks, and a heat sink is manufactured by inserting a support column into a hole formed in each heat sink and fixing it with an adhesive.

Japanese Patent Laid-Open No. 11-340383

"Extrusion", edited by the Japan Institute of Metals, "Metal Handbook", page 1160, published on March 31, 1990

  Among the conventional examples described above, in the method of manufacturing a heat sink using the extrusion method, usable materials are limited to relatively soft materials, and at present, aluminum is mainly used as a heat sink material. . However, with this extrusion method, there is a limit to narrowing the gap between the fins, and currently about 10 mm is the limit. The heat radiation area is wider as the number of fins is larger, and the limit of the distance between the fins is the limit of the heat radiation area. Aluminum is a material having relatively high thermal conductivity, but has only about half the thermal conductivity of copper. On the other hand, copper having high thermal conductivity is insufficient in spreadability, so it is difficult to carry out the extrusion method using copper.

  According to the caulking method, the interval between the fins can be narrowed compared to the extrusion method, and an interval of about 4 mm can be realized. However, it is difficult to reduce the interval further. Further, the work of caulking the fins one by one is necessary, and the work is complicated, inefficient and low in manufacturing cost as compared with the extrusion method.

  In the cutting method, a material having a thermal expansion coefficient close to that of Si, such as AlN, is used. This is because if the heat expansion of the heat sink and the semiconductor mainly made of Si are the same, even if the heat sink is in direct contact with the semiconductor, cracks due to the difference in expansion do not occur in the semiconductor. This cutting method is particularly effective when it is difficult to carry out the extrusion method or the caulking method. However, since the cutting portion is discarded, the material cost is high, and the thickness of the fin (> 5 mm). There is a problem that the distance (5 mm) is limited.

  The casting method exemplified in Patent Document 1 has a great limitation on usable materials. In addition, when using a rolling method or a pressing method, as in the caulking method, a complicated operation of attaching the fins one by one to the support using holes and an adhesive is necessary, resulting in poor work efficiency and high manufacturing cost. .

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a heat sink that has good working efficiency and low manufacturing cost and can be miniaturized by reducing the interval between fins.

  The method of manufacturing a heat sink according to the present invention includes a step of laminating a plurality of flat plates each coated with an adhesive on one surface and solidifying the adhesive to form a laminated body, and a flat base plate And a step of fixing the laminated body on the base plate and a step of dissolving the adhesive and removing it from between the flat plates.

  The step of fixing the laminate on the base plate may be a step of fixing the small block on the base plate after dividing the laminate into a plurality of small blocks.

  Another heat sink manufacturing method of the present invention includes a step of winding a flat plate coated with an adhesive on one surface to form a wound body, and placing an end surface of the flat plate on a flat base plate. And a step of fixing the wound body on the base plate and a step of dissolving the adhesive and removing it from between the flat plates.

  The step of fixing the wound body on the base plate may be a step of fixing the coil body cut by cutting the wound body in a direction perpendicular to the longitudinal direction on the base plate.

  According to the present invention, since a plurality of fins can be arranged at very small intervals in the heat sink, it is possible to have a configuration having more fins in the same size heat sink. And the heat sink which has a comparable heat dissipation effect can be reduced in size compared with the past. Furthermore, a heat sink having a large number of fins can be easily manufactured with high work efficiency and low cost.

It is the schematic which shows the heat sink manufactured by the 1st Embodiment of this invention. It is a flowchart which shows the manufacturing method of the heat sink shown in FIG. It is a perspective view which shows the flat plate by which the adhesive agent was apply | coated to one side used for the manufacturing method of the heat sink shown in FIG. It is a perspective view which shows the laminated body on which the flat plate shown in FIG. 3 was laminated | stacked. It is a perspective view which shows the process of dividing the laminated body shown in FIG. It is a front view which shows the state which fixed the small block divided | segmented from the laminated body shown in FIG. 4 to the base board. It is a front view which shows the process of immersing the small block shown in FIG. 6 in the organic solvent. It is a flowchart which shows the manufacturing method of the heat sink of the 2nd Embodiment of this invention. It is the schematic which shows the heat sink manufactured by the 2nd Embodiment of this invention, (a) is a perspective view, (b) is sectional drawing. It is a perspective view which shows the elongate flat plate with which the adhesive agent was apply | coated to one surface used for the manufacturing method of the heat sink shown in FIG. It is a perspective view which shows the wound body by which the flat plate shown in FIG. 10 was wound. (A) is a perspective view which shows the process of cut | disconnecting the winding body shown in FIG. 11, (b) is a top view which shows the cut-out coil body. It is a perspective view which shows the process of grind | polishing the coil body shown in FIG.12 (b). (A) is a front view which shows the state which adhered the ground | polished coil body shown in FIG. 13 to the base board, (b) is the sectional drawing. (A) is a front view which shows the process of immersing the coil body shown in FIG. 14 in the organic solvent, (b) is the sectional drawing.

  Embodiments of the present invention will be described below with reference to the drawings.

  The heat sink manufactured by the present invention is attached to an electronic component, an electrical component, a mechanical component, and the like, and cools each component by dissipating heat transferred from each component to the outside. Specifically, as shown in FIG. 1, a plurality of fins 2 erected substantially vertically are fixed in parallel on one surface of a flat (planar) base plate 1. . The distance between the fins 2 of this heat sink is very small compared to the conventional case, for example, 1 mm.

  The manufacturing method of the heat sink by this invention is demonstrated with reference to the flowchart shown in FIG. First, as shown in FIG. 3, a flat plate 2a as a material for the fins 2 of the heat sink is prepared. The flat plate 2a is a metal having a high heat transfer property such as copper or aluminum, or a ceramic having a high heat transfer property such as aluminum nitride (AlN). As shown in FIG. 4, as many flat plates 2a as the number of fins 2 of a heat sink to be manufactured (see FIG. 1) are prepared and stacked to form a block-shaped laminate 3 (step S1). For example, a necessary number of flat plates 2a coated with the adhesive 4 are stacked on one surface, and the adhesive 4 is solidified while applying a certain pressure to be integrated. The adhesive 4 is soluble in an organic solvent 5 to be described later. For example, Amex X-2990A, 2990B (trade name) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. is used.

  Specifically, the thickness of each flat plate 2a is the same as the thickness of each fin 2 of the heat sink to be manufactured, and the interval between the flat plates 2a is the same as the interval between the fins 2 of the heat sink to be manufactured. The thickness of each flat plate 2a is in the range of about several tens of μm to several mm, and can be appropriately selected in consideration of the use environment. The adhesive 4 is made of resin and has a layer thickness of about 1 μm to 10 mm. Since the layer thickness of the adhesive 4 is the distance between the fins 2 of the heat sink after completion, it is appropriately selected in consideration of the use environment of the product. Although not shown, spherical spacers (plastic sphere, ceramic sphere, etc.) having a uniform particle diameter may be mixed in the adhesive 4, and in this case, the particle diameter of the spacer is the thickness of the adhesive 4, that is, the fins. The interval between the two is accurately defined. As the bonding method, a method such as natural solidification or heat solidification may be appropriately selected according to the characteristics of the adhesive 4 to be used. Note that the pressure applied when the adhesive 4 is solidified is set to a level that does not break the spacers in the adhesive 4.

  Next, as shown in FIG. 5, the laminated body 3 is cut | disconnected according to the planar dimension of the fin 2 of the heat sink to manufacture (step S2). Cutting is performed by a method using a tool suitable for the characteristics of the material of the flat plate 2a among super steel blades, GC (green carbon) grindstones, diamond grindstones, wire saws, metal band saws, and the like. In the example shown in FIG. 5, one laminated body 3 is cut so as to be divided into eight to obtain eight small blocks 3 ′.

  As shown in FIG. 6, the end face of each flat plate 2a of the small block 3 'formed by cutting the laminated body 3 is placed on and fixed to the base plate 1 (step S3). The small block 3 ′ is fixed to the base plate 1 by a method suitable for the characteristics of the material of the flat plate 2 a and the base plate 1 among soldering, brazing, adhesion, and the like. However, bonding with the same adhesive as the adhesive 4 is not preferable because there is a high possibility of peeling when immersed in the organic solvent 5 described later. A fixing method using a metal such as soldering or brazing is preferable in that there is no possibility of peeling when immersed in the organic solvent 5 and high thermal conductivity is obtained. The base plate 1 may be made of the same material as the flat plate 2a. Even when the base plate 1 is made of a material different from that of the flat plate 2a, the base plate 1 is preferably made of a material having high thermal conductivity.

  As shown in FIG. 7, the small block 3 ′ and the base plate 1 fixed and integrated are immersed in an organic solvent 5. At this time, the resin adhesive 4 interposed between the flat plates 2a is dissolved and removed by the organic solvent 5 (step S4). As a result, the adhesive 4 is removed, and the plurality of fins 2 (flat plates 2a) are arranged on the base plate 1 side by side with a predetermined interval (corresponding to the layer thickness of the adhesive 4). Become. Then, the heat sink shown in FIG. 1 is completed by pulling up from the organic solvent 5 and drying it (step S5). As the organic solvent 5, alcohol such as IPA (isopropyl alcohol), acetone, NMP (N-methyl-pyrrolidone) or the like is used according to the material of the adhesive 4.

  In the example described above, the laminated body 3 is formed using the flat plate 2a larger than the planar shape of the fin 2 of the heat sink to be manufactured, and the laminated body 3 is divided into a plurality of small pieces for manufacturing a plurality of heat sinks. Block 3 'is produced. However, the laminated body 3 is formed using the flat plate 2a having the same size as the planar shape of the fin 2 of the heat sink to be manufactured, and the laminated body 3 is fixed to the base plate 1 without being divided to manufacture one heat sink. You may make it do.

  According to the present invention, since the plurality of fins 2 can be arranged at a very small interval (for example, less than 1 mm), when the size of the heat sink is the same, a configuration having a larger number of fins than in the past is adopted. The heat dissipation effect (cooling effect) can be enhanced. Moreover, when manufacturing a heat sink having a similar heat dissipation effect, the heat sink can be made smaller than before. In addition, when manufacturing a heat sink with a large number of fins, the individual fins can be fixed together, instead of being individually attached to the base plate, and the adhesive can be removed in a batch, facilitating manufacturing. The work efficiency is high and the manufacturing cost can be kept low.

  Next, a second embodiment of the heat sink manufacturing method of the present invention will be described with reference to the flowchart of FIG. In the present embodiment, as shown in FIG. 9, the heat sink having a circular planar shape is manufactured, and the wound body 6 is formed instead of the stacked body 3. Is different. Since other processes are substantially the same as those in the first embodiment, the description thereof is omitted.

  In this embodiment, as shown in FIG. 10, a long flat plate 2a having an adhesive 4 applied on one surface is prepared, and as shown in FIG. 11, the long flat plate 2a is wound and wound. The body 6 is formed (step S6). The number of windings 6 (the number of times the flat plate 2a is wound) is half the number of fins 2 of the heat sink to be manufactured. The long flat plate 2a is long enough to wind the flat plate 2a by the number of turns that is half the number of the fins 2, and has a winding body 6 having a size that matches the planar shape of the base plate 1. Is formed in such a length that can be formed.

  Then, as shown in FIG. 12, the wound body 6 is cut into a ring shape in a direction perpendicular to the longitudinal direction, and the coil body 6 'is cut out (step S7). Further, as necessary, as shown in FIG. 13, the cut-out coil body 6 'is polished using the polishing board 7 or the like (step S8). The height of the coil body 6 'after cutting out and polishing the wound body 6 is made to coincide with the height of the fin 2 of the heat sink to be manufactured. However, step S8 can be omitted if the coil body 6 'can be brought to a desired height and an acceptable surface roughness can be obtained without polishing.

  After that, as shown in FIG. 14, the flat plate end surface 2a of the coil body 6 'is placed on and fixed to the base plate 1 (step S9). As shown in FIG. 15, the coil body 6 ′ and the base plate 1 fixed and integrated are immersed in an organic solvent 5, and the resin adhesive 4 interposed between the flat plates 2 a is used. Then, the organic solvent 5 is dissolved and removed (step S10). And the heat sink shown in FIG. 9 is completed by pulling up from the organic solvent 5 and making it dry (step S11). These steps S9 to S11 can be performed by the same method as steps S3 to S5 of the first embodiment described above.

  The above description relates to an example of manufacturing a heat sink having a circular planar shape. However, when manufacturing a heat sink having a rectangular planar shape, a rectangular wound body 6 may be manufactured. The flat plate 2a may be wound around the core.

  In the above-described example, the long wound body 6 is formed using the flat plate 2a having a width larger than the height of the fin 2 of the heat sink to be manufactured, and the wound body 6 is cut in a direction perpendicular to the longitudinal direction. Thus, the coil body 6 ′ is produced. However, the wound body 6 is formed using the flat plate 2a having the same width as the height of the fin 2 of the heat sink to be manufactured, and the wound body 6 is fixed to the base plate 1 without being cut and the heat sink is attached. You may make it manufacture.

  According to this embodiment, in addition to being able to exhibit the effects of the present invention described above, the step of laminating the plurality of flat plates 2a is unnecessary, and the step of applying the adhesive 4 to one surface of the flat plate 2a is performed once. Therefore, the manufacturing efficiency is good and the manufacturing cost can be kept low.

DESCRIPTION OF SYMBOLS 1 Base plate 2 Fin 2a Flat plate 3 Laminate 3 'Small block 4 Adhesive 5 Organic solvent 6 Winding body 6' Coil body 7 Polishing board

Claims (4)

Laminating a plurality of flat plates coated with an adhesive on one surface and solidifying the adhesive to form a laminated body,
Placing each end face of each flat plate on a flat base plate, and fixing the laminate on the base plate;
Dissolving the adhesive and removing it from between the flat plates;
A method for manufacturing a heat sink.   The heat sink according to claim 1, wherein the step of fixing the laminated body on the base plate is a step of fixing the small block on the base plate after dividing the laminated body into a plurality of small blocks. Manufacturing method. A step of winding a flat plate coated with an adhesive on one surface to form a wound body;
Placing the end face of the flat plate on a flat base plate, and fixing the wound body on the base plate;
Dissolving the adhesive and removing it from between the flat plates;
A method for manufacturing a heat sink.   The step of fixing the wound body on the base plate is a step of fixing the coil body cut by cutting the wound body in a direction perpendicular to the longitudinal direction on the base plate. The manufacturing method of the heat sink as described.

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