JP2017042783A - Method for manufacturing heat radiation substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a heat radiation substrate by which a fin can be formed with a good accuracy.SOLUTION: A method for manufacturing a heat radiation substrate D2 comprising a base 1 of which at least one of front and rear faces is partially provided with a heat radiation part 2, and plural fins 21 which are integrally formed with the heat radiation part 2 of the base 1 and provided upright with respect to the base 1. The method includes: a raw material preparation process in which an intermediate molding W1, in which a formation part 15 is provided corresponding to the heat radiation part 2 and a non-formation part 16 is provided corresponding to parts other than the heat radiation part, is prepared; and a forging process in which the fins 21 are formed on the formation part 15 in the intermediate molding W1. In the forging process, the fins 21 are formed by plastically deforming the formation part 15 by die forging while suppressing the non-formation part 16 without deformation thereof.SELECTED DRAWING: Figure 2B

Description

  The present invention relates to a method for manufacturing a heat dissipation board in which a heat sink is provided on a part of a base, and a related technique.

  As a casing of a power control unit (PCU) for controlling the driving of a hybrid vehicle or an electric vehicle, or a panel casing for a heat exchanger (IGBT cooler), a base and a plurality of fins in a part of the base A heat dissipating board provided with a (heat sink) is well known.

  For example, Patent Documents 1 and 2 disclose a heat dissipation board in which a heat sink constituted by an aluminum alloy forged product or the like is attached to a base constituted by an aluminum alloy die cast product or a forged product.

JP 2012-105369 A JP 2013-254787 A

  However, in the heat dissipating substrates shown in Patent Documents 1 and 2, when the heat sink is attached to the base with an adhesive, there is a problem that the heat dissipating performance may be deteriorated because the adhesive has low thermal conductivity. In addition, when a heat sink is attached to the base by heat treatment such as fusion welding or brazing welding, the dimensional accuracy of the heat sink or base decreases due to thermal distortion during heating. If it does so, the attachment accuracy of the heat sink with respect to a base will also fall, and the subject that heat dissipation performance will fall generate | occur | produces.

  Furthermore, since a work of attaching a heat sink to the base is necessary, the number of manufacturing steps is increased accordingly, making it difficult to manufacture, resulting in a decrease in production efficiency and an increase in cost.

  On the other hand, in recent years, a technique has been proposed in which a heat dissipation substrate in which a heat sink (a plurality of fins) is integrally formed on a base is manufactured by forging.

  However, the heat sink part (heat dissipating part) has a complicated shape in which a large number of fins are formed at narrow intervals, while the part other than the heat sink of the base (base main body part) is only scattered by convex parts such as a base. It is a simple shape. For this reason, when manufacturing a heat dissipation board by forging, it is difficult to adjust the punch load because the degree of processing between the base body and the heat dissipation part is greatly different and the volume balance is poor. There arises a problem that it is very difficult to mold with high accuracy. Furthermore, since the overall size of the heat dissipation substrate is larger than that of the heat dissipation portion, the overall size of the forging die is increased and the punch load is also increased. For this reason, there is a problem that the burden on the fin forming portion in the forging die is increased, and the die life is shortened. Further, since the base body portion having a simple shape and a plurality of fins having a complicated shape coexist, a discharge mechanism (knockout mechanism) for ejecting the molded product from the mold after molding becomes complicated. As a result, the configuration of the mold itself becomes complicated, and there is a problem that the mold production cost (cost) increases.

  The present invention has been made in view of the above-described problem, and a heat dissipation board capable of efficiently and inexpensively manufacturing a heat dissipation board excellent in heat dissipation performance, in which a plurality of fins are formed integrally with a base with high accuracy. An object is to provide a manufacturing method and related technology.

  In order to achieve the above object, the present invention comprises the following arrangement.

[1] A heat dissipation provided with a base in which at least one of the front and back surfaces is partially provided with a heat dissipation portion, and a plurality of fins that are integrally formed with the heat dissipation portion of the base and are erected with respect to the base A method for manufacturing a substrate, comprising:
As a forming material of the heat dissipation substrate, a material preparation step of preparing an intermediate molded body provided with a molding portion corresponding to the heat dissipation portion and provided with a non-molding portion corresponding to a portion other than the heat dissipation portion;
Including a forging step of forming the fin in the forming portion of the intermediate formed body,
In the forging step, the fin is formed by plastically deforming the molded part by die forging while suppressing the non-molded part without being deformed.

  [2] The method for manufacturing a heat dissipation board as recited in the aforementioned Item 1, wherein the thickness of the molded part in the intermediate molded body is formed to be thicker than the thickness of the non-molded part.

[3] The forging die used in the forging step includes a die and a punch,
A fin forming hole for forming the fin on the restraining surface of the punch is provided,
The preceding item 1 or 2, wherein when the punch is driven into the intermediate formed body installed on the die, the fin is formed by backward extrusion that causes a metal material constituting the forming portion to flow into the fin forming hole. The manufacturing method of the thermal radiation board | substrate of description.

[4] A forging die used in the forging step includes a molding die provided corresponding to the molding part and a suppression die provided corresponding to the non-molding part,
The manufacturing of the heat dissipation substrate according to any one of the preceding items 1 to 3, wherein, in the forging step, the fin is formed on the molded portion by the molding die while the non-formed portion is suppressed by the suppression die. Method.

[5] The inhibition die is configured to be relatively retractable in a direction opposite to the restraining direction with respect to the molding die,
The forging die includes deterring force applying means for applying a deterring force in the restraining direction of the deterring die,
5. The method for manufacturing a heat dissipation substrate according to item 4, wherein in the forging step, the non-molded portion is inhibited via the inhibition die by the inhibition force of the inhibition force applying means.

[6] The forging die used in the forging step includes a molding die provided corresponding to the molding part,
The outer periphery of the mold is provided with a surplus escape recess,
6. The method for manufacturing a heat dissipation board according to any one of the preceding items 1 to 5, wherein surplus metal material generated in the forging process is allowed to flow into the recess and the recess.

  [7] The method for manufacturing a heat dissipation board according to any one of items 1 to 6, wherein the intermediate formed body is manufactured by forging in the material preparation step.

[8] A heat dissipation comprising a base in which at least one of the front and back surfaces is partially provided with a heat radiating portion, and a plurality of fins that are integrally formed with the heat radiating portion of the base and are erected with respect to the base. A forging die for forming a substrate,
A mold for forming the fins, which is provided corresponding to the heat dissipation portion of the heat dissipation substrate;
A forging die provided with a suppressing means provided to correspond to a portion other than the heat radiating portion of the heat radiating substrate and for suppressing a portion other than the heat radiating portion.

[9] The suppression means includes
A deterrent mold configured to be relatively retractable in a direction opposite to the constraint direction with respect to the mold;
The forging die according to the preceding item, comprising deterrence applying means for applying deterrence to the deterring die in a restraining direction.

[10] A die and a punch are provided,
10. The forging die according to 8 or 9 above, wherein the punch and the inhibition die are provided.

  [11] The forging die according to any one of the aforementioned items 8 to 10, wherein a surplus escape recess is provided on the outer periphery of the molding die.

[12] A heat dissipation comprising a base in which at least one of the front and back surfaces is partially provided with a heat dissipating part, and a plurality of fins that are integrally formed with the heat dissipating part of the base and are erected on the base A substrate,
A heat dissipation board, wherein a surplus wall is integrally provided on the base along the outer periphery of the heat dissipation portion.

  According to the method for manufacturing a heat dissipation board of the invention [1], since the manufactured heat dissipation board is integrally formed with fins (heat sinks) on the base, a separate heat sink is attached to the base and the adhesive has low thermal conductivity. Compared with a heat dissipation board attached by heat treatment such as welding, it is possible to suppress the decrease in thermal conductivity and the occurrence of thermal distortion, maintain high dimensional accuracy and obtain sufficient heat dissipation performance Can do. Furthermore, since the fins are integrally formed on the base, the number of manufacturing steps is small, and the production efficiency can be improved and the cost can be reduced. Further, since a plurality of fins having a dense and complicated shape are formed by partial forging, the fins can be formed with a load that is small enough to form the fins. For this reason, excessive pressure is not applied to the metal material in the forging die, deformation can be prevented and the dimensional accuracy can be further improved, and a large load is applied to the fin forming part of the forging die. In addition, it is possible to prevent early forging of the forging die and to improve the life of the die and reduce the cost more reliably. Furthermore, because of partial forging, the mold can be formed in a simple structure, and the cost can be further reduced.

  According to the manufacturing method of the heat dissipation board of the invention [2], since the metal material for forming the fin can be sufficiently secured, the fin with high dimensional accuracy can be more reliably formed.

  According to the manufacturing method of the heat dissipation board of the invention [3], since the fin is formed by backward extrusion, a fin having a small cross-sectional area such as a pin fin can be reliably formed with high accuracy.

  According to the manufacturing method of the heat dissipation substrate of the invention [4], the non-molded portion of the intermediate molded body can be suppressed to a stable state, and therefore the processing accuracy of fins and the like can be further improved.

  According to the manufacturing method of the heat dissipation board of the invention [5], the non-molded portion of the intermediate molded body can be suppressed with an appropriate pressure, so that the processing accuracy of fins and the like can be further improved.

  According to the method for manufacturing a heat dissipation board of the invention [6], it is possible to prevent the material pressure from partially rising excessively, thereby preventing harmful deformation of the base, fins, etc., and ensuring a high-quality heat dissipation board. Can be manufactured.

  According to the method for manufacturing a heat dissipation board of the invention [7], the intermediate molded body and the heat dissipation board can be manufactured by a series of forging processes, so that the production efficiency can be improved.

  According to the forging dies of the inventions [8] to [11], since the above-described method invention can be carried out, the same effects as the above-described method invention can be obtained.

  According to the heat dissipation substrate of the invention [12], it can be obtained by carrying out the above method invention.

FIG. 1A is a cross-sectional view showing a primary forming forging die used in a method for manufacturing a heat dissipation board according to an embodiment of the present invention in an open state. FIG. 1B is a cross-sectional view showing the forging die for primary forming according to the embodiment in a closed state. FIG. 2A is a cross-sectional view showing the forging die for secondary forming used in the manufacturing method of the embodiment in an open state. FIG. 2B is a cross-sectional view showing the forging die for secondary forming according to the embodiment in a closed state. FIG. 3A is a perspective view of the intermediate molded body used in the manufacturing method of the embodiment as viewed from the surface side. FIG. 3B is a perspective view of the intermediate molded body of the embodiment as viewed from the back side. FIG. 4A is a perspective view of the heat dissipation board manufactured by the manufacturing method of the embodiment as viewed from the back side. FIG. 4B is an enlarged plan view showing a heat radiating portion in the heat radiating substrate of the embodiment. FIG. 5 is a sectional view showing the periphery of a forming die in a punch of a forging die for secondary forming that is a first modification of the present invention. FIG. 6A is an enlarged cross-sectional view showing the periphery of a molded portion of an intermediate molded body used in the manufacturing method of the second modified example of the present invention. FIG. 6B is an enlarged cross-sectional view showing the periphery of a forming die of a forging die for secondary forming used in the manufacturing method of the second modified example. FIG. 7A is a perspective view of a heat dissipation board as a third modification of the present invention viewed from the back side. FIG. 7B is an enlarged plan view showing a heat radiating part in the heat radiating board of the third modified example.

  The heat dissipation substrate W2 manufactured by the manufacturing method according to the embodiment of the present invention is configured by a forged product. That is, in the manufacturing method of this embodiment, die forging as primary formation (1F) is performed on a rectangular plate-shaped forging material W as shown in FIG. 1A, and a primary molded product (1F as shown in FIG. 1B). Product). Subsequently, as shown in FIGS. 2A and 2B, die forging as secondary molding (2F) is performed on the intermediate molded body W1 as the primary molded product to produce a secondary molded product (2F product). The secondary molded product is employed as the heat dissipation substrate W2 of the present embodiment.

  In this embodiment, as the forging material W used for the primary forming, a wrought material, for example, a material obtained by cutting a flat bar (flat plate) shaped extruded material, a material obtained by cutting a plate-like rolled material, a continuous cast bar, What was cut | disconnected and carried out the horizontal upsetting process in the substantially flat form etc. can be used suitably. Furthermore, as the material of the material W, an aluminum alloy (Al alloy), a copper alloy, or the like can be used. In particular, Al alloys such as alloy numbers A1100, A6063, and A3003 can be preferably used.

  As shown in FIGS. 3A and 3B, an intermediate molded body (primary molded product) W <b> 1 as a molding material for secondary molding includes a rectangular plate-like base 1. On the surface side of the base 1, a plurality of large and small truncated cone-shaped bases 11 are integrally formed so as to protrude from the surface side (upward), and a mounting base 12 having a flat upper surface is provided on the surface side (upward) ) Are integrally formed so as to protrude. Further, on the back surface side of the base 1, a molding portion 15 having a rectangular shape in plan view is formed integrally with the mounting base 12 so as to protrude on the back surface side (downward). Here, in the present embodiment, the non-molded portion 16 is configured by a portion other than the molded portion 15 of the intermediate molded body W1, that is, the entire area on the front surface side of the intermediate molded body W1 and the outer portion of the molded portion 15 on the back surface side. ing.

  As shown in FIG. 4A and FIG. 4B, a plurality of pin fins 21 aligned vertically and horizontally are perpendicular to the base 1 on the back surface side of the heat dissipation substrate W2 as a secondary molded product, except for the outer periphery of the molded portion 15. It is integrally formed so as to protrude (stand up) in the direction. Further, a surplus wall 22 continuous in the circumferential direction is integrally formed on the back surface side of the heat dissipation substrate W2 so as to surround the plurality of pin fins 21 at a portion corresponding to the outer periphery of the molding portion 15.

  Moreover, the part corresponding to the said non-molding part 16 in the thermal radiation board | substrate W2 is equipped with the substantially same shape with respect to the intermediate molded object W1. For example, the pedestal 11 and the mounting base 12 in the non-molded portion 16 of the intermediate molded body W1 have the pedestal 11 and the mounting base 12 having substantially the same shape in the same position also in the heat-radiating substrate W2 after the secondary molding. In the present embodiment, the pedestal 11 is for mounting other components, and the mounting base 12 is for mounting a heating element (heating element) such as a reactor, a converter, an inverter, or an IGBT.

  Here, in the present embodiment, the heat radiating portion (heat sink) 2 is configured by the portion where the plurality of pin fins 21 of the heat radiating substrate W2 are formed.

  Next, a forging mold D1 for primary molding for forming the intermediate molded body W1 of the present embodiment and a method for manufacturing the intermediate molded body W1 using the mold D1 will be described in detail.

  1A and 1B are sectional views showing a forging die D1 for primary molding for producing an intermediate molded body (primary molded product) W1. As shown in both figures, the forging die D1 for primary forming includes a punch 3 as an upper die and a die 4 as a lower die.

  The upper surface of the die 4 is formed with a constraining recess 40 that is formed in a shape corresponding to the shape of the outer peripheral surface of the intermediate molded body W1 and opens upward. Further, on the inner peripheral surface of the constraining concave portion 40, a base molding concave portion 41 and a mounting base molding concave portion 42 for molding the base 11 and the mounting base 12 of the intermediate molded body W1 are formed, respectively.

  Here, in the present embodiment, the inner peripheral surface of the constraining recess 40 of the die 4 is configured as a constraining surface.

  On the other hand, the punch 3 is disposed above the die 4 so as to correspond to the constraining recess 40, and can be driven up and down in the vertical direction by a driving means (not shown). The lower end portion of the punch 4 is formed in a shape that can be accommodated in the constraining recess 40 of the die 4, and the lower end portion of the die 4 is moved into the constraining recess 40 by lowering the punch 3 from the raised position. It can be driven with a load.

  Further, a knockout pin 46 is provided at a required portion of the die 4. For example, a knockout pin accommodation hole 45 penetrating in the vertical direction is formed on the bottom surface of the base molding recess 41 at an appropriate position, and at the end portion (such as the right end portion in FIGS. 1A and 1B) on the bottom surface of the restraint recess 40, Knockout pin accommodation holes 45 penetrating in the vertical direction are formed, and the knockout pins 46 are accommodated in the accommodation holes 45 so as to protrude upward. The knockout pin 46 protrudes immediately after molding by driving of a driving means (not shown) so that the intermediate molded body W1 as a primary molded product is pushed up and released from the constraining recess 40 of the die 4 and discharged. It has become.

  Further, on the lower end surface (restraint surface) of the punch 3, a molding part molding concave part 35 for molding the molding part 15 of the intermediate molded body W <b> 1 is formed corresponding to the mounting base molding concave part 42 of the die 4.

  Using the forging die D1 for primary forming having the above-described configuration, the intermediate forming body W1 is obtained by performing primary forming on the forging material W. That is, as shown in FIG. 1A, the forging material W is loaded and set in the constraining recess 40 of the die 4 with the punch 3 raised. In the case where the forging material W is an aluminum alloy, for example, the heating temperature is set to 400 ° C. to 550 ° C. Further, the temperature (die temperature) of the punch 3 and the die 4 is set to about 200 ° C.

  Then, the punch 3 is lowered and driven into the constraining recess 40 of the die 4. As a result, as shown in FIG. 1B, the forged material W is clamped by the punch 3 and the die 4 to plastically flow a required portion of the metal material (metal) constituting the forged material W, and the base forming recess 41 and the mounting base The base 11 and the mounting base 12 are molded by filling the molding recess 42, and the molding part 15 is molded by filling the molding part molding recess 35 with a metal material. After the intermediate molded body W1 as the primary molded product is formed in this way, the punch 3 is raised, while the knockout pin 46 protrudes upward to push up the intermediate molded body W1, so that the intermediate molded body W1 restrains the die 4. It is discharged from the recess 40.

  In the present embodiment, the primary forming by the primary forming forging die D1 corresponds to the material preparation step.

  Next, a forging die D2 for secondary forming for forming the heat dissipation substrate W2 of the present embodiment and a method for manufacturing the heat dissipation substrate W2 using the die D2 will be described in detail.

  2A and 2B are cross-sectional views showing a forging die D2 for secondary molding for manufacturing a heat dissipation substrate (secondary molded product) W2. As shown in both figures, the forging die D2 for secondary forming includes a punch 5 as an upper die and a die 6 as a lower die.

  The die 6 has substantially the same configuration as the die 4 of the forging die D1 for primary forming. That is, a constraining recess 60 is formed on the upper surface of the die 6, and in the constraining recess 60, a pedestal receiving recess 61 corresponding to the pedestal forming recess 41 and the mounting base forming recess 42 of the primary forming forging die D 1. And the mounting base accommodation recessed part 62 is formed, respectively. In the present embodiment, the inner peripheral surface of the constraining recess 60 of the die 6 is configured as a constraining surface.

  Furthermore, a knockout pin 66 is disposed in a required portion of the die 6 so as to protrude through a knockout pin accommodation hole 65.

  On the other hand, the punch 5 is provided with an anvil 51 that can be moved up and down by a driving means (not shown). On the lower surface side of the anvil 51, a restraining die 53 is attached so as to be slidable in the vertical direction via a punch holder 52, and is configured to be able to rise upward (retracting direction) with respect to the anvil 51. The inhibition mold 53 is formed with an opening 54 that accommodates and arranges a molding mold 55 described later. The opening 54 of the restraining die 53 penetrates vertically and is formed at a position corresponding to the molding portion 15 of the intermediate molded body W1 set in the constraining recess 60 of the die 6. Furthermore, the part except the opening part 54 in the lower surface (suppression surface) of the suppression mold | type 53 is arrange | positioned corresponding to the non-molding part 16 of the surface side in the intermediate molded body W1.

  A spring 7 such as a compression coil spring is interposed between the restraining die 53 and the anvil 51 so that the restraining force of the restraining die 53 can be applied by the elastic force (repulsive force) of the spring 7 as will be described later. It has become. Here, in the present embodiment, the spring 7 constitutes a deterrence applying unit, and the deterring die 53 and the deterring force applying unit constitute a deterring unit.

  In the present invention, the deterring force applying means is not limited to the spring 7, and any means can be used as long as it can apply an appropriate pressure. Examples of the deterrence imparting means other than the spring include a gas cushion and a knockout mechanism possessed by the press.

  A molding die 55 is fixed on the lower surface side of the anvil 51 so as to move up and down in synchronization with the anvil 51. The molding die 55 is inserted into the opening 54 of the restraining die 53 so that the lower surface of the molding die 56 is exposed below the restraining die 53. The forming die 55 is formed with a plurality of fin forming holes 56 having a circular cross section that open on the lower surface and penetrate in the vertical direction. A knockout pin 57 is accommodated in each fin forming hole 56 so as to be slidable in the vertical direction.

  When the punch 5 (anvil 51) is lowered during molding described later, the restraining die 53 among the punches 5 hits the non-molded portion 16 of the intermediate molded body W1, and the descent stops and the anvil 51 (molding die) continues to descend. 55) is relatively raised (retracted).

  On the other hand, since the molding die 55 descends in synchronization with the anvil 51, when the punch 5 descends, the molding part 15 of the intermediate molded body W1 can be pressurized by the molding die 55 with a sufficient molding load. .

  Needless to say, the fin forming hole 56 of the forming die 55 is used for forming the pin fin 21 by flowing a metal material during forming. At the time of molding, the tip surface (lower end surface) of the knockout pin 57 functions as a molding surface for molding the tip surface of the pin fin 21. Therefore, at the time of molding, the knockout pin 57 is disposed at a position where the lower end surface thereof is retracted (raised) by the length of the pin fin 21 with respect to the lower end surface of the molding die 55. Further, the knockout pin 57 is advanced (lowered) by a driving means (not shown) immediately after molding, so that the pin fin 21 protrudes downward from the fin molding hole 56 and is released.

  Here, in the present embodiment, the lower surface of the mold 55 is configured as a constraining surface of the punch 5.

  Note that the pin fin 21 can be formed by back pressure forging. For example, the knockout pin 57 is biased downward by a biasing means such as a spring. Immediately before molding, the knockout pin 57 has its lower end surface disposed at or near the lower end opening position of the fin molding hole 56, and while molding, the knockout pin 57 is retracted (raised) by the flow pressure of the metal material. The metal material is caused to flow into the fin forming hole 56. As a result, resistance (back pressure) can be applied to the metal material flowing into the fin forming hole 56 in the direction opposite to the inflow direction (downward direction), and the pin fin 21 can be formed with high accuracy by preventing the lack of thickness. be able to.

  Further, a surplus escape portion 58 is formed on the outer periphery of the molding die 55 on the lower surface side of the restraining die 53 so that surplus metal material generated during molding is accommodated in the surplus recess portion 58. Yes.

  Using the forging die D2 for secondary molding having the above configuration, the intermediate molded body W1 is subjected to secondary molding to obtain the heat dissipation substrate W2. That is, as shown in FIG. 2A, with the punch 5 raised, the intermediate molded product W1 as the primary molded product is put into the constraining recess 60 of the die 6 and set. In this case, the base 11 and the mounting base 12 of the intermediate molded body W1 are respectively stored in the base receiving recess 61 and the mounting base receiving recess 62 of the die 6. The heating temperature of the intermediate molded body W1 is set to 250 ° C to 600 ° C. Further, the temperature (die temperature) of the punch 5 and the die 6 is set to about 300 ° C. However, the secondary forming can be performed by cold forging instead of hot forging.

  In this state, the punch 5 is lowered and driven into the constraining recess 60 of the die 6. 2B, the lower surface of the inhibition mold 53 of the punch 5 hits the non-molded portion 16 (portion other than the molded portion 15) on the upper surface side (back surface side) of the intermediate molded body W1, and the descent stops. Rises (retreats) relative to the mold 55 that continues to descend. And with the rise, the spring 7 is compressed, and the inhibition mold 53 inhibits the non-molded portion 16 of the intermediate molded body W1 by the repulsive force. Thus, since the non-molding part 16 of the intermediate molded body W1 is restrained by the restraining die 53 by the elastic force of the spring 7, it is possible to prevent an excessive pressure from being applied to the non-molding part 16 during molding. Therefore, it is possible to fix the position of the non-molded portion 16 in a stable state without plastic deformation.

  On the other hand, the forming die 55 of the punch 5 is lowered together with the anvil 51 and pressurizes the forming portion 15 of the intermediate formed body W1 with a sufficient forming load, so that the forming portion 15 is plastically deformed. As a result, the metal material constituting the molding portion 15 is plastically flowed and flows into the fin molding hole 56 of the molding die 55 to mold the pin fins 21, thereby manufacturing the heat dissipation substrate W <b> 2 as a secondary molded product. Further, during this molding, surplus metal material generated around the molding portion 15 is allowed to escape into the recess 58 and the material pressure in the mold is prevented from excessively rising.

  Thereafter, the punch 5 is raised. When the punch is raised, the knockout pin 57 of the punch 5 is advanced (lowered) and the pin fin 21 is protruded from the fin forming hole 56, and the knockout pin 66 of the die 6 is advanced (raised), and the heat dissipation substrate W2 is pushed up. And is discharged from the constraining recess 60 of the die 6.

  In the heat dissipation substrate W2 (forged raw material) manufactured in this way, the surplus wall 22 is erected so as to surround the outer periphery of the pin fin 21, but in this embodiment, the surplus wall 22 is provided as necessary. It is cut and removed by machining and shipped as a heat dissipation board product. In the present invention, it is also possible to configure the heat dissipation substrate as a final product with all or part of the surplus wall 22 remaining. For example, a part of the surplus wall 22 is used as a flow path wall through which a coolant flows, or the surplus wall 22 is used as a pedestal for mounting other parts, thereby allowing the heat dissipation substrate W2 to leave the surplus wall 22 remaining. Can be configured as a final product.

  In the present embodiment, secondary forming by the secondary forming forging die D2 corresponds to the forging step. Further, the restraining direction of the punch 5 such as the inhibition die 53 and the forming die 55 in the secondary forging die D2 is downward, and the restraining direction of the die 6 is upward.

  As described above, according to the method for manufacturing a heat dissipation board of the present embodiment, the pin fins 21 (heat sinks) are integrally formed on the base 1, so that a separate heat sink is used as a base with an adhesive having low thermal conductivity. Compared to bonding, heat dissipation performance can be improved, and compared to the case where a separate heat sink is attached by heat treatment such as welding, the occurrence of thermal distortion can be suppressed and high dimensional accuracy is maintained. be able to.

  Further, in the present embodiment, heat radiation is divided into overall forging (primary molding) in which the main part is molded except for the pin fins 21 (heat sink) having a dense shape and partial forging (secondary molding) in which the heat sink part is molded. The substrate W2 is manufactured. The intermediate molded body W1 manufactured by the primary molding does not include a pin fin (heat sink) having a dense and complicated shape, and there is no large deviation in the processing degree as a whole, and the volume balance is good. For this reason, in the primary molding, the punch load can be adjusted appropriately, and the intermediate molded body W1 can be molded with a substantially uniform pressure in a balanced manner as a whole, and the intermediate molded body W1 with high dimensional accuracy can be manufactured. Furthermore, a uniform load with a good balance can be applied to the entire area of the mold, and it is possible to prevent a problem that an excessive load is partially applied to the mold D1, and to prevent early forging of the forged mold D1. The mold life can be improved and the cost can be reduced.

  Further, in the secondary molding, only the dense and complicated heat sink portion (the plurality of pin fins 21) is molded by partial forging. Therefore, the pin fin 21 can be molded with a relatively small load that can be molded. it can. Therefore, an excessive load is not applied to the fin forming portion of the molding die 55 during the secondary molding, and the early forging die D2 can be prevented from being damaged. Similar to the forging die D1 for the next molding, the die life can be improved and the cost can be reduced.

  In the present embodiment, a surplus escape portion 58 is formed on the outer periphery of the forming die 55 of the forging die D2 for secondary forming, and surplus metal material generated during the secondary forming is filled into the recess portion 58. By doing so, it is possible to prevent the material pressure from partially rising excessively. For this reason, it is possible to prevent deformation of the base 1 and the pin fins 21 in the molded product (heat radiating substrate W2), and it is possible to manufacture a higher quality heat radiating substrate W2.

  Further, in the forging die D2 for secondary molding, the non-molded portion 16 of the intermediate molded body W1 is restrained by the spring force of the spring 7 through the restraint die 23. It is possible to reliably prevent deformation of the non-molded portion 16 such as the base 1 without applying a load. Furthermore, since the non-molded portion 16 of the intermediate molded body W1 can be restrained with an appropriate pressure by the restraining die 23, the intermediate molded body W1 can be held in a stable state and secondary molding can be performed with high accuracy.

  Further, since the molding part 15 of the intermediate molded body W1 as a molding material for secondary molding is raised and formed thick, when the fin 21 is molded by pressurizing the molding part 15, the metal for fin molding Sufficient material can be secured and the fins 21 can be reliably formed.

  Moreover, in this embodiment, since the primary shaping | molding and the secondary shaping | molding are performed by a series of forging processes, the thermal radiation board | substrate W2 can be manufactured efficiently.

  In the above embodiment, the intermediate formed body W1 used for the secondary forming is formed by forging. However, the intermediate formed body W1 does not necessarily need to be formed by forging. In the present invention, the intermediate molded body W1 may be formed of any molded product, for example, a die-cast molded product.

  Moreover, in the said embodiment, although the case where the surplus relief part 58 formed in the punch 5 of the forging die D2 for secondary forming was formed in the suppression die 53 was described as an example, the present invention is not limited to this. In the present invention, the excess relief portion 58 may be formed on the outer periphery of the mold 55. For example, as shown in FIG. 5, a concave step portion may be formed on the outer periphery of the molding die 55, and the extra thickness relief recess portion 58 may be configured by the concave step portion. Of course, from the viewpoint of operational reliability, it is preferable to form a surplus escape portion 58 on the inner periphery of the inhibition die 53 as in the mold D2 of the above embodiment shown in FIGS. 2A and 2B. That is, as shown in FIG. 5, the metal material M flowing into the surplus escape recess 58 at the time of molding is preferentially filled from the outside of the surplus escape recess 58. In addition, if the excess thickness relief recess 58 is formed, the metal material is likely to enter the gap S between the outer peripheral surface of the molding die 55 and the suppression mold 53, and burrs are likely to occur in the gap S. Then, due to the influence of the burr, the sliding operation of the restraining mold 53 with respect to the molding die 55 is hindered, and a sliding failure (operation failure) may occur. For this reason, as shown in the embodiment of FIG. 2A and FIG. 2B, it is preferable to form the excess thickness relief recess 58 on the inner periphery of the suppression die 53.

  Moreover, in the said embodiment, although the shaping | molding part 15 of the intermediate molded body W1 is built up and it protrudes upwards, it is not necessary to form the molding part 15 of the intermediate molded body W1 thickly. For example, as shown in FIG. 6A, the molded portion 15 of the intermediate molded body W1 can be formed flat so as to be flush with other regions. In this case, as shown in FIG. 6B, when the punch 5 is driven by secondary molding, the tip surface (lower end surface) of the molding die 55 is disposed below the upper surface of the base 1 in the heat dissipation substrate W2, The lower end position (base position) of the fin 21 on the heat radiating substrate W <b> 2 is disposed below the upper surface of the base 1. Even if it is such a shape, it can be used without difficulty as a heat dissipation board product by appropriately dealing with a design change or the like.

  Moreover, in the said embodiment, although the pin fin 21 is formed in the heat sink (heat radiating part) 2 of the thermal radiation board | substrate W2, in the present invention, the shape of the fin 21 is not specifically limited. For example, in the present invention, as shown in FIGS. 7A and 7B, a plurality of plate-like or blade-like plate fins 21 may be formed in parallel on the heat radiation portion 2 of the heat radiation substrate W2.

  In the above-described embodiment, the case where the closed forging that hardly generates burrs is used as an example of the primary molding and the secondary molding has been described as an example. However, the present invention is not limited thereto, and in the present invention, primary molding and / or As secondary forming, burr out forging such as semi-sealing forging or non-sealing forging may be used.

  In the above embodiment, in the secondary molding, the entire region of the non-molded portion 16 of the intermediate molded body W1 is suppressed by the mold. However, the present invention is not limited to this, and in the present invention, the non-molded portion 16 is subjected to the secondary molding. Only a part of the non-molded part 16 may be suppressed and the remaining part of the non-molded part 16 may be set in an open state without being suppressed. Further, when suppressing the non-molded portion 16 of the intermediate molded body W, it is not always necessary to suppress the non-molded portion 16 with a mold such as a depressing mold, and it should be suppressed using a depressing jig different from the mold. Anyway. In this case, the suppression means is constituted by the suppression jig.

  In the above embodiment, the fins 21 are formed by rearward extrusion in the secondary molding. However, the present invention is not limited to this, and in the present invention, fin forming holes are formed on the die (lower mold) side. The fins may be formed by forward extrusion.

  Furthermore, in the said embodiment, although the fin 21 is formed in the back surface side of the thermal radiation board | substrate W2, it is not restricted to it, In this invention, you may form a fin in the surface side of a thermal radiation board | substrate, In addition, fins may be formed on both the back side and the back side.

  In the present invention, when the intermediate formed body W1 is manufactured by die forging as in the above embodiment, the primary forming and the secondary forming may be performed by one (one) forging device. It is good, and it may be performed by a separate mold apparatus. That is, the primary and secondary which are provided with two or more mold stages of a primary forging mold and a secondary forging mold, and the punches of both molds are moved up and down by one press mechanism. A continuous molding die device may be used, the forging die for primary molding and the forging die for secondary molding are independent, and each punch is moved up and down by separate press mechanisms. The primary forming and the secondary forming may be performed separately by using a table forging device.

  The method for manufacturing a heat dissipation board of the present invention can be suitably used when manufacturing a heat dissipation board for a power control unit for controlling driving of a hybrid vehicle or an electric vehicle, a heat dissipation board for a heat exchanger panel, and the like.

1: Base 15: Deformation part 16: Non-deformation part 2: Heat radiation part 21: Pin fin (plate fin)
22: surplus wall 5: punch 53: deterring die 55: mold 56: fin forming hole 58: surplus escaping recess 6: die 7: spring (suppressing force applying means)
D2: Forging die for secondary molding M: Metal material W1: Intermediate molded body (molding material)
W2: Heat dissipation board

Claims (12)

Manufacture of a heat dissipation board comprising a base in which at least one of the front and back surfaces is partially provided with a heat dissipation portion, and a plurality of fins that are integrally formed with the heat dissipation portion of the base and are erected with respect to the base A method,
As a forming material of the heat dissipation substrate, a material preparation step of preparing an intermediate molded body provided with a molding portion corresponding to the heat dissipation portion and provided with a non-molding portion corresponding to a portion other than the heat dissipation portion;
Including a forging step of forming the fin in the forming portion of the intermediate formed body,
In the forging step, the fin is formed by plastically deforming the molded part by die forging while suppressing the non-molded part without being deformed.   The method for manufacturing a heat dissipation substrate according to claim 1, wherein a thickness of the molded part in the intermediate molded body is formed to be thicker than a thickness of the non-molded part. The forging die used in the forging step includes a die and a punch,
A fin forming hole for forming the fin on the restraining surface of the punch is provided,
2. The fin is formed by backward extrusion that causes a metal material constituting the forming portion to flow into the fin forming hole when the punch is driven into the intermediate formed body placed on the die. The manufacturing method of the thermal radiation board of 2. The forging die used in the forging step includes a molding die provided corresponding to the molding part, and a suppression die provided corresponding to the non-molding part,
The heat dissipation substrate according to any one of claims 1 to 3, wherein, in the forging step, the fin is formed on the molding portion by the molding die while the non-molding portion is suppressed by the suppression die. Production method. The inhibition mold is configured to be relatively retractable in a direction opposite to the constraint direction with respect to the molding mold,
The forging die includes deterring force applying means for applying a deterring force in the restraining direction of the deterring die,
The method of manufacturing a heat dissipation substrate according to claim 4, wherein, in the forging step, the non-molded portion is inhibited via the inhibition die by the inhibition force of the inhibition force applying means. The forging die used in the forging step includes a molding die provided corresponding to the molding part,
The outer periphery of the mold is provided with a surplus escape recess,
The method for manufacturing a heat dissipation substrate according to any one of claims 1 to 5, wherein excess metal material generated in the forging step is allowed to flow into the recess and the recess.   The method for manufacturing a heat dissipation substrate according to any one of claims 1 to 6, wherein the intermediate formed body is manufactured by forging in the material preparation step. Forming a heat dissipating board comprising a base partially provided with a heat dissipating part on at least one of the front and back surfaces, and a plurality of fins integrally formed on the heat dissipating part of the base and standing on the base A forging die for
A mold for forming the fins, which is provided corresponding to the heat dissipation portion of the heat dissipation substrate;
A forging die provided with a suppressing means provided to correspond to a portion other than the heat radiating portion of the heat radiating substrate and for suppressing a portion other than the heat radiating portion. The deterring means is
A deterrent mold configured to be relatively retractable in a direction opposite to the constraint direction with respect to the mold;
The forging die according to claim 8, further comprising deterrence applying means for applying a deterring force in the restraining direction to the deterring die. With dies and punches,
The forging die according to claim 8 or 9, wherein the punch is provided with the forming die and the restraining die.   The forging die according to claims 8 to 10, wherein a surplus escape recess is provided on an outer periphery of the molding die. A heat dissipating board comprising a base partially provided with a heat dissipating part on at least one of the front and back surfaces, and a plurality of fins that are integrally formed with the heat dissipating part of the base and are erected on the base. And
A heat dissipation board, wherein a surplus wall is integrally provided on the base along the outer periphery of the heat dissipation portion.

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