JP2001077572A - Manufacture of heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the reliability of a heat sink in terms of water leakage and shorten the time for manufacturing the heat sink by positioning a core containing resin in a cavity formed by mating fixed hardware and movable hardware together. SOLUTION: A tapered portion 83a which is sloped toward the bottom of a hollow as it goes from the side end face toward the hollow is formed in either of fixed hardware 81 and movable hardware 82, and melted metal is poured along the tapered portion 83a. At this time, injected aluminum can be preventedfrom hitting directly against a core 27 by adjusting the slope of the tapered portion 83a formed in the fixed hardware 81, so that deformation and rupture of the core 27 made of resin material due to impact by melted aluminum can be prevented and thus a flow path formed in the heat sink can be prevented from being deformed. Subsequently, die cast molds 81 and 82 are removed, and then the workpiece is rapidly cooled. Thus the melted core 27 in resin can be suppressed more than ever.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heat sink for releasing and cooling heat generated from a device or an element, and more specifically to a gate turn-off thyristor (R) used for controlling the rotation of a large rotating machine. GT
O thyristor) and a method of manufacturing a heat sink for cooling a resistor.

[0002]

2. Description of the Related Art First, the structure of a heat sink as a cooling device will be described. FIG. 10 is a diagram schematically illustrating a main circuit portion, a water-cooling resistor, and a cooling water circulation system of a gate turn-off thyristor used for controlling the rotation speed of a large-sized rotating machine, for example. In the figure, 1 is a semiconductor element formed of a semiconductor, 2 is an anode pressed against the semiconductor element, 3 is a cathode pressed against the side opposite to the anode 2, 4 is an insulator formed of ceramic, 5 Is a main circuit heat sink for cooling heat generated from the semiconductor element, 6 is a bolt having a long shaft, 7 is a nut, 8 is a main circuit fastening upper plate, 9 is a main circuit fastening lower plate, and 10 is a main circuit fastening lower plate. This is a Teflon tube for flowing cooling water. 11 is a resistor made of metal, 12 is a heat sink for the resistor, 41 is a bolt, 42 is a nut, 13 is an upper plate for fastening the resistor, 14 is a lower plate for fastening the resistor, and 43 is a cooling water flowing therethrough. Teflon tube.

The main circuit heat sink 5 is laminated on the semiconductor element 1 above and below the semiconductor element 1 via the anode 2 and the cathode 3, and the semiconductor element 1 is laminated in three stages. The main circuit portion of the gate turn-off thyristor is clamped between the upper plate for tightening 8 and the lower plate for main circuit tightening 9. By applying a load in the axial direction of the bolt 6, a contact thermal resistance generated at a contact surface between the semiconductor element 1 and the anode 2 and the cathode 3, and a contact thermal resistance generated at a contact surface between the main circuit heat sink 5 and the anode 2 and the cathode 3 The contact thermal resistance has been reduced.

The resistor 11 and the resistor heat sink 12 are alternately laminated, and are
The water-cooled resistor portion is clamped between the resistor fastening upper plate 13 and the resistor fastening lower plate 14. By applying a load in the axial direction of the bolt 41, the resistor heat sink 1
The contact thermal resistance generated on the contact surface between the resistor 2 and the resistor 11 is reduced. 44 is a Teflon tube and a gate turn-off thyristor that connect the main circuit and the water-cooled resistor to allow cooling water to flow, and when a current flows back into the circuit, the current is bypassed to prevent destruction of other circuits. A regenerative circuit section (not shown) for performing the same has the same configuration.

Next, the operation will be described. When the gate turn-off thyristor and the resistor operate, the semiconductor element 1 generates heat in the main circuit portion, and the resistor 11 generates heat in the water-cooled resistor portion. Therefore, the semiconductor element 1 and the resistor 1
In order to prevent 1 from being destroyed by heat, it is necessary to release heat. First, in the main circuit portion, heat generated from the semiconductor element 1 is transmitted to the main circuit heat sink 5 and the cooling water via the anode 2 and the cathode 3. On the other hand, in the water-cooled resistor section, heat generated from the resistor 11 is transmitted to the cooling water via the resistor heat sink 12. The cooling water flows in the direction indicated by the arrow 45, passes through the main circuit heat sink 5 and the Teflon tube 10 of the main circuit portion, passes through the resistor heat sink 12 and the Teflon tube 43 through the Teflon tube 44, It flows out in the direction indicated by arrow 46. Dissipating heat generated from the semiconductor element 1 and the outside via the cooling water prevents the semiconductor element 1 and the resistor 11 from being broken.

FIG. 11 is a view for explaining a conventional method of manufacturing a heat sink. In the drawing, 47 is a heat sink body, 15 is an upper plate made of an aluminum brazing sheet, 16 is a lower plate made of an aluminum brazing sheet, 1
Reference numeral 7 denotes a cooling water passage, reference numeral 18 denotes a passage plate made of an aluminum brazing sheet having a cooling water passage 17 formed therein, and reference numeral 19 denotes a cooling water inlet / outlet. By joining the upper plate 15, the plurality of laminated flow passage plates 18, and the lower plate 16 together to form a single body, a flow passage through which the cooling water flows in the heat sink body 47 is formed.

A method for manufacturing the heat sink shown in FIG. 11 will be described. First, an aluminum brazing sheet having a brazing material (not shown) clad on a surface to be joined is prepared. Next, as shown in FIG. 11, for example, a flow path plate 18 formed by punching with a turret punch press or the like to form a cooling water circuit 17 and a cooling water inlet / outlet 19 is formed.
Create A plurality of flow path plates 18 are stacked,
The upper plate 15 and the lower plate 16 are overlapped and joined so as to form a lid of the laminated body.

FIG. 12 is a view for explaining a conventional method of manufacturing a heat sink. In the figure, 21 is a pipe-side fitting portion, 22 is a pipe-fitting portion, and 23 is a screw.
0. As a material of the pipe joint 20, for example, a material having higher hardness than aluminum as a material of the flow path plate 18 and having corrosion resistance to cooling water as a refrigerant may be used, and more specifically, austenitic stainless steel. Steel may be used. Examples of austenitic stainless steel include SUS304 (JIS standard). 2
Reference numeral 4 denotes a joint nut, and reference numeral 25 denotes a pipe.

For example, a linear brazing material having the same composition as the brazing material of the aluminum brazing sheet is wound around the outer periphery of the pipe joint 20, and the pipe side fitting portion 21 is inserted into the cooling water inlet / outlet 19. Here, since the cooling water inlet / outlet 19 is formed by laminating the channel plate 18 of an aluminum brazing sheet in which the cooling water inlet / outlet 19 is formed in advance by punching, it is naturally formed in a square shape. Therefore, the cooling water entrance 1
The pipe-side fitting portion 21 which is inserted into and fitted into the pipe 9 also has a square shape.

After temporarily assembling the upper plate 15, the lower plate 16, the plurality of flow passage plates 18, and the pipe joint 20 in this manner, the temperature is raised to about 600 ° C. in a nitrogen gas atmosphere using an atmosphere furnace or the like. Warm and braze all together. Here, the flux mixed into the brazing filler metal is, for example, non-corrosive KALF ₄ or K ₃ ALF
A fluoride-based flux containing the compound of No. ₆ as a main component is used.

The connection between the pipe joint 20 and the pipe 25 is made by inserting the pipe 25 into the pipe fitting section 22, fitting the pipe 25, and tightening the fitting with a fitting nut 24 which fits the screw section 23. Further, the tip end of the pipe 25 is plastically deformed, so that airtightness can be maintained.

[0012]

In the conventional method of manufacturing a heat sink, a plurality of flow path plates are superimposed. If there is a defect in the joint of the flow path plates, the heat sink is removed from the inner wall of the flow path formed inside the heat sink. Leakage may occur toward the side of the vehicle. Also, if cooling water leaks due to a defect in the joint part of the flow path plate, it is impossible to maintain the insulation state of the high voltage part, which may lead to a fatal accident,
It is necessary to check that no water leakage occurs. Specifically, the manufactured heat sink is immersed in water, and a high pressure is applied to a flow path through which the cooling water passes to perform a water leakage inspection. This inspection has a problem that it takes a long time of about ten and several minutes.

In addition, since the joint is brazed at the same time as the heat sink body 47, a jig for positioning the joint is required, and there is a problem that the temporary assembly is complicated and requires a long working time.

Further, in the brazing step, since a tunnel furnace in a nitrogen gas atmosphere is used, it takes a long time to complete the brazing. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method of manufacturing a heat sink that has high reliability against water leakage and that has a short manufacturing process time.

[0015]

SUMMARY OF THE INVENTION A method of manufacturing a heat sink according to the present invention is a method of manufacturing a heat sink having a flow path through which cooling water flows, wherein: (a) a fixing metal having a depression in a part thereof; A step (b) of combining the fixed mold and the movable mold such that a core having a resin is located in a cavity formed by combining a mold and a movable mold having a recess in a part thereof. A step of pouring and solidifying the molten metal into the cavity; and (c) a step of removing the fixed mold and the movable mold and taking out a solidified metal molding. (D) Inside the metal molding. A step of forming a flow path inside the metal molded product by removing the core.

A method of manufacturing a heat sink according to the present invention is characterized in that a metal is used for a core material of a core.

In the method of manufacturing a heat sink according to the present invention, the fixed mold includes a boss having a recess at the bottom of the recess, and the movable mold includes a boss having a recess at the bottom of the recess. After providing a pin having the same metal as the metal poured into each of the bosses of the movable mold, combining the fixed mold, the movable mold and the core so that the pin supports a core. Features.

According to a method of manufacturing a heat sink according to the present invention, a tapered portion is provided on one of a fixed die and a movable die, the tapered portion being inclined toward a bottom surface of the recess as it goes from the side end surface toward the recess, and the melt is formed along the tapered portion. Characterized in that the metal is poured.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a diagram for explaining a method of manufacturing a heat sink according to the present embodiment, and specifically, is a perspective view of a heat sink manufactured by the method according to the present embodiment. In the figures, FIGS.
The same reference numerals as in 2 denote the same or corresponding components. The heat sink shown in FIG. 1 can be used as any of a heat sink for a main circuit, a heat sink for a regenerative circuit, and a heat sink for a water-cooled resistor used for controlling the rotation speed of a large rotating machine. In the figure, reference numeral 26 denotes a heat sink body formed by die-casting aluminum, 29 denotes a flow path formed in the heat sink body 26, and 30 denotes a flow path 2
9 is a nipple serving as a joint for connecting to a Teflon tube (not shown), which is located at an end of the nipple 9.

Next, a method for manufacturing the heat sink will be described. FIG. 2 is a diagram for explaining a configuration of a core used when manufacturing the heat sink of the present embodiment. 2
Reference numeral 7 denotes a core made of resin and having heat resistance. The core 27 is manufactured by, for example, forming a firing chamber so as to correspond to the shape of the flow path 29 formed inside the heat sink body 26. As the resin, for example, PC
(Polycarbonate) or PPS (polysulfone).

3 and 4 are views for explaining a method of manufacturing the heat sink according to the present embodiment. FIG. 4A is a sectional view taken along the line AA of FIG. In the drawing, reference numeral 81 denotes a fixed mold having a depression 100 for forming the heat sink body 26 which is a molded product of a mold, and 82 denotes a heat sink body 26 which is a molded product of a metal. Is a movable mold having a cavity 101 for the die, and a die-cast mold having a cavity formed therein by matching the surface of the fixed mold 81 having the cavity with the surface of the movable mold 82 having the cavity. It is formed.

Reference numeral 83a denotes a tapered portion formed in the fixed mold 81 for pouring the molten aluminum into the mold, and 83b denotes a recess formed in the movable mold 82 for pouring the molten aluminum into the mold. The cross section of the dent 83b is trapezoidal, and the depth thereof is formed to be shallower as it goes from the side end surface to the dents 100 and 101 for forming the heat sink body 26. When the fixed mold 81 and the movable mold 82 are combined, the gate 83 which is a flow path for flowing the molten metal from the side surface of the die cast mold into the cavity inside the die cast mold by the tapered portion 83a and the recess 83b.
Is formed.

The amount of aluminum flowing into the cavity per unit time is determined by the width W (the length of the gate 83 in the lateral direction (the direction perpendicular to the direction in which metal flows)) and the thickness (the length of the taper 83a). Depth), the direction of inflow is the tapered portion 8
It can be adjusted by the inclination of 3a. In the present embodiment, an example is described in which the fixed mold 81 is provided with a tapered portion 83a and the movable mold 82 is provided with a recess 83b. However, the fixed mold 81 is provided with a recess 83b, and the movable mold 82 is provided with a tapered portion. 83a may be provided (not shown).

Reference numeral 84 denotes a recess provided on the fixing die 81 for fixing both ends of the core 27. The movable mold 82
A recess for fixing both ends of the core 27 is also formed on the side. Although not shown here, when the molten aluminum is poured into the mold, the fixed mold 81 and the movable mold 82
The fixed mold 81 or the movable mold 82 is provided with a groove and a pool for letting out the air stored in the cavity formed by combining them. Here, the pool corresponds to a space for efficiently releasing the air stored in the cavity when the molten aluminum is poured into the mold.

A method of manufacturing the heat sink according to the present embodiment will be described. First, after setting the end of the resin core 27 in the recess 84 in the fixed die 81 for die-casting, the surface of the fixed die 81 having the recess 100 and the recess 101 of the movable mold 82 are provided. The movable mold 82 is moved and closed so that the surface matches. As a result, the core having the resin is located in the cavity formed in the die casting mold.

Next, a molten metal (here, aluminum is described as an example) as a material of the heat sink is poured from the gate 83 at high speed and high pressure. The metal used as the material of the heat sink is, for example, aluminum, more specifically, A
DC12 (JIS standard) and the like.

Since the core 27 of the heat-resistant resin material is fixed at both ends by the recesses 84, the position is not shifted by injecting aluminum into the die-casting mold. Also, when pouring the molten aluminum into the mold, the aluminum is softened slightly by the injection of aluminum, but the injection of aluminum is completed in a short time, so the heat of the molten aluminum is rapidly taken away by the die-casting mold and the aluminum Solidifies to form the heat sink body 26.

As shown in FIG. 3 and FIG.
Since the tapered portion 83a formed on the fixed mold 81 is provided from the side end surface of the fixed mold 81 toward the depression of the fixed mold 81, the molten aluminum can be injected obliquely. At this time, the tapered portion 83a formed on the fixed die 81
By properly adjusting the inclination of the core, the injected aluminum can be prevented from directly hitting the core, thereby preventing the core 27 of the resin material from deforming and breaking due to the impact of the molten aluminum hitting. Accordingly, it is possible to prevent the flow path 29 formed inside the heat sink from being deformed.

Next, after removing the die-casting mold (that is, the fixed mold 81 and the movable mold 82), the aluminum molded product is rapidly cooled. Thereby, the dissolution of the core 27 of the resin material can be further suppressed. FIG. 5 is a diagram for explaining a method of manufacturing the heat sink according to the present embodiment.
Specifically, it is a perspective view showing an aluminum molded heat sink body 26 which is a solidified metal molded product after removing a die cast mold (that is, a fixed mold 81 and a movable mold 82). In the figure, reference numeral 28 denotes an end of the core. As shown in the figure, when the die casting mold is removed, the heat sink main body 26 in a state where the resin core 27 is cast into the aluminum heat sink main body 26 is formed.

Next, the core 27 is removed. Thereby, the portion of the core 27 in the heat sink body 26 becomes hollow,
A flow path 29 for flowing the cooling water is formed. An example of a specific method for removing the core 27 will be described. First,
The heat sink body 26 is reheated so that the core 27 of the resin material is softened and pulled out from the heat sink body 26. Next, the heat sink main body 26 is immersed in a solvent, for example, methylene chloride, to dissolve the resin that cannot be removed. By doing this,
Channel 29 for flowing cooling water into heat sink body 26
Can be formed.

FIG. 6 is a diagram for explaining a method of manufacturing the heat sink according to the present embodiment, specifically, a method for mounting a nipple on the heat sink main body 26 from which the core 27 is removed. . In the figure, 28 is an O-ring for sealing, 30 is a nipple serving as a joint, and 48 is a threaded portion with a female thread. An internally threaded threaded portion 48 is machined to join the nipple 30 to form a joint as shown in FIG.
8 together with the nipple 30 to the heat sink body 26. The heat sink is completed by finishing grinding both surfaces of the heat sink body 26 with, for example, a milling machine. Although it has been described that the surface of the heat sink body 26 is ground after the nipple 30 is bonded to the heat sink body 26, the nipple 30 may be bonded after the surface is ground. Also, without using the O-ring 28, the screw 4
8 and the nipple 30 may be combined.

Next, the operation will be described. When the gate turn-off thyristor and the resistor operate, for example,
The semiconductor element generates heat in the main circuit portion, and the resistor generates heat in the water-cooled resistor portion. In order to prevent the semiconductor element and the resistor from being destroyed by heat, it is necessary to release heat.
Then, the heat generated by the heat sink is taken away and cooled. Specifically, the cooling water flowing inside the heat sink takes away the heat transmitted from the surface of the heat sink and releases the heat to the outside. The cooling water is nipple 3
Through a Teflon tube (not shown) connected to the core 0, it flows through the flow path 29 after the core is pulled out. Thus, the semiconductor element and the resistor are prevented from being destroyed.

As described above, according to the first embodiment, the flow path 29 through which the cooling water flows is different from the conventional one in which a plurality of members are joined, and the heat sink is integrally formed by die casting. Therefore, the cooling water does not leak from the inner wall of the flow path 29 toward the side surface of the heat sink body 26, so that a highly reliable heat sink can be obtained.

Further, the place where leakage may occur in the heat sink is only the connection between the heat sink body 26 and the nipple 30, so that the heat sink body 2
It is possible to determine whether or not there is a leak in the heat sink simply by examining whether or not water leaks at a portion where the nipple 30 and the nipple 30 are joined, so that the examination time can be shortened as compared with the related art. At this time, the water leakage inspection may be performed using a water leakage inspection machine using gas such as air. In particular, if the test is performed using a He leak detector using He as a gas, a helium gas having a smaller molecular structure than air can be used to perform a highly accurate airtight test, and the test time can be reduced to about 30 seconds or less. can do. A heat sink having high reliability against water leakage can be manufactured.
In addition, since the heat sink is integrally formed using die casting, which is a highly efficient processing method, the processing time can be significantly reduced as compared with the conventional manufacturing method using brazing.

Embodiment 2 FIG. 7 is a diagram for explaining the method for manufacturing the heat sink according to the present embodiment, and specifically, is a diagram for explaining the configuration of the core used for manufacturing the heat sink. In the figure, 31 is a spring-like metal,
Reference numeral 32 denotes a core in which an extensible spring-shaped metal 31 is embedded as a core material. The core 32 is a heat-resistant resin material in which an extensible spring-like metal 31 is embedded as a core material.
For example, it can be manufactured by injection molding using a resin containing PC (polycarbonate), PPS (polysulfone) or the like. The manufacturing method of the heat sink according to the present embodiment and the manufacturing method of the heat sink according to the first embodiment have no difference in the configuration of the manufacturing method except for the core.

When a heat sink is manufactured using the core 27 shown in FIG. 2, when the core of the resin material is removed from the heat sink, a large amount of the resin material of the core May be broken in the flow path 29, and a considerable amount of the core 27 may remain in the flow path 29. Therefore, in order to remove the resin material which is a residue of the core 27 stuck to the flow path 29. In addition, the dissolution time by the solvent increases,
This has led to an increase in solvent usage.

Therefore, by using the core 32 in which the extensible spring-like metal 31 is embedded, the resin material is cooled by the metal to which heat is easily transmitted, so that the resin material hardly sticks to the flow path 29. When the core 32 is removed from the heat sink, the force tends to be evenly distributed by the extensible spring-like metal 31, so that the core 32 breaks and the flow path 29
Can be prevented from remaining in the solvent, the dissolution time by the solvent can be shortened, and the amount of the solvent used can be reduced,
Manufacturing time can be reduced.

Embodiment 3 FIG. 8 is a diagram for explaining the method for manufacturing the heat sink according to the present embodiment, specifically, a diagram for explaining the configuration of the core used for manufacturing the heat sink. In the figure, 33 is a metal plate.
The metal plate 33 is a disc-shaped or square-shaped metal. Reference numeral 34 denotes a wire-shaped metal to which a plurality of metal plates 33 are attached, and reference numeral 35 denotes a core in which a wire-shaped metal 34 to which a plurality of metal plates 33 are attached as a core is embedded. The wire-shaped metal 34 to which the plurality of metal plates 33 are attached can be manufactured by, for example, joining the metal plate 33 and the wire-shaped metal by welding. The core 35 is made of a heat-resistant resin material in which a wire-like metal 34 having a plurality of metal plates 33 attached as a core material is embedded, for example, a resin containing PC (polycarbonate), PPS (polysulfone), or the like. Can be manufactured by injection molding. Note that the method of manufacturing the heat sink of the present embodiment and the method of manufacturing the heat sink of Embodiment 1
There is no difference in the structure of the manufacturing method other than the core.

When a heat sink is manufactured using the core 27 shown in FIG. 2, when the core of the resin material is removed from the heat sink, a large amount of the resin material of the core May be broken in the flow path 29, and a considerable amount of the core 27 may remain in the flow path 29. Therefore, in order to remove the resin material which is a residue of the core 27 stuck to the flow path 29. In addition, the dissolution time by the solvent increases,
This has led to an increase in solvent usage.

Therefore, by using a core 35 in which a wire-like metal 34 having a plurality of metal plates 33 attached is embedded, the resin material is cooled by the metal plate 33 and the metal 34, which are easy to transfer heat, and flows. It is hard to stick to road 29,
When the core 35 is removed from the heat sink, the forces are distributed evenly by the plurality of metal plates 33.
5 can be prevented from breaking and remaining in the flow path 29, so that the dissolving time by the solvent can be shortened, the amount of the solvent used can be reduced, and the manufacturing time can be shortened.

Embodiment 4 FIG. FIG. 9 is a diagram for explaining a method of manufacturing the heat sink according to the present embodiment. FIG.
FIG. 9A is a diagram illustrating a state in which a core is fixed between a movable mold and a fixed mold, and FIG. 9B is a diagram illustrating a state in which a pin is fitted to a boss described later. . In the figure, components denoted by the same reference numerals as those in FIG. 3 are the same or corresponding components. In the figure, 92 is a core, 88 is a fixed mold, 89 is a movable mold, 86 is a gate for pouring molten aluminum into the mold, 90 is a recess provided in the fixed mold and the movable mold. The provided boss 91 is a pin for preventing the core 92 from being tilted and inserted into the recess of the boss 90 having the recess. The pin 91 is made of, for example, zinc-plated aluminum, and stabilizes or fixes the position by supporting the core 92.

A method for manufacturing the heat sink according to the present embodiment will be described. First, a pin 91 is inserted into a recess of a boss 90 having a recess provided in the fixed mold 88 and the movable mold 89. At this time, the length of the pin 91 is previously set to an appropriate length so that the core 92 can be supported and the position can be stabilized or fixed.

Next, after setting the end of the core 92 of the resin material in the recess 84 in the fixed die 88 for die casting,
The surface of the fixed mold 88 having the depression 100 for forming the heat sink body 26 and the surface of the movable mold 89 having the depression 101 for forming the heat sink body 26 are closed together. As a result, the core having the resin is located in the cavity formed in the die casting mold, and the core 92 is supported by the pins 91. Next, the molten aluminum is transferred to a die casting mold comprising a fixed mold 88 and a movable mold 89 by a gate 86.
And the heat sink body 26 is formed integrally with the pins 91. The subsequent manufacturing method is the same as in the first embodiment.

In the present embodiment, the pin 91 supports the core 92 so that the molten aluminum is fixed to the fixed mold 88.
When flowing into the die-casting mold composed of the movable mold 89 and the movable mold 89, the core 92 of the resin material might be inclined. However, the core 92 of the resin material was not inclined, and the deformation of the flow path 29 was prevented. be able to.

Boss 90 and pin 91 with many depressions
Can be provided at random to support the core 92. However, the fixed mold 88 and the boss 90 having a recess provided in the movable mold 89 are used to fix the core 92 with the fixed mold 88 and the movable mold 89. It is particularly effective to support the same portion of the core 92 and to support the center of the core 92.

The zinc plating of the surface of the pin 91 allows the pin 91 to be welded to the aluminum die-cast material without any gap. As a result, the tip of the pin 91 that supports the core 92 and is in contact with the core 92 forms a part of the surface of the flow path 29 after the core is pulled out, but corresponds to the curved surface of the pin 91. The sides are integrated with the die-cast aluminum to maintain airtightness.
In the completed heat sink body 26, a hole is formed at a position where the boss 90 having the recess exists, but the boss 90 having the recess is arranged so that this hole is provided at the center of the surface of the heat sink body 26. A resistor that is sandwiched between heat sinks without the need for subsequent cutting (not shown)
If it is used as a positioning hole, it is not necessary to form a hole for positioning a resistor (not shown) sandwiched by the heat sink, so that the number of processing operations can be reduced.

[0047]

According to the method for manufacturing a heat sink according to the present invention, there is provided a method for manufacturing a heat sink having a flow path through which cooling water flows, wherein (a) a fixed mold having a recess in a part thereof; A step of combining the fixed mold and the movable mold so that a core having a resin is located in a cavity formed by combining a movable mold having a recess in a part thereof; (b) the cavity (C) removing the fixed mold and the movable mold, and taking out a solidified metal molded product; and (d) a core inside the metal molded product. Forming a flow path inside the metal molded product by removing water from the inner wall of the flow channel of the metal molded product. From the inner wall to the side It is not necessary to check whether the water, along with shortening the inspection time for the water leakage, it is possible to produce the heat sink has high reliability with respect to leakage.

In the method for manufacturing a heat sink according to the present invention, since a metal is used for the core of the core, the flow path is formed by extracting and removing the core, so that the core can be easily removed.

According to a method of manufacturing a heat sink according to the present invention, the fixed mold includes a boss having a recess at the bottom of the recess, and the movable mold includes a boss having a recess at the bottom of the recess. After providing a pin having the same metal as the metal poured into each of the bosses of the movable mold, since the fixed mold, the movable mold and the core are combined so that the pin supports a core, Since the core is supported by the pins in the cavity, the core is more firmly supported in the cavity, and the deformation of the flow path can be further suppressed.

In the method for manufacturing a heat sink according to the present invention, a tapered portion is provided on one of a fixed mold and a movable mold, the tapered portion being inclined toward a bottom surface of the recess in a direction from the side end surface toward the recess, and melting along the tapered portion. The molten metal is poured, so by appropriately adjusting the inclination of the tapered part, the poured metal can be prevented from directly hitting the core, which causes the molten metal to hit the core. This can prevent the core from being deformed and broken, and can prevent the formed flow path from being deformed.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method of manufacturing a heat sink according to a first embodiment.

FIG. 2 is a diagram illustrating a method of manufacturing the heat sink according to the first embodiment.

FIG. 3 is a diagram illustrating a method of manufacturing the heat sink according to the first embodiment.

FIG. 4 is a diagram illustrating a method of manufacturing the heat sink according to the first embodiment.

FIG. 5 is a diagram for explaining a method of manufacturing the heat sink according to the first embodiment.

FIG. 6 is a diagram for explaining the method for manufacturing the heat sink according to the first embodiment.

FIG. 7 is a view illustrating a method of manufacturing the heat sink according to the second embodiment.

FIG. 8 is a view illustrating a method of manufacturing the heat sink according to the third embodiment.

FIG. 9 is a view illustrating a method of manufacturing the heat sink according to the fourth embodiment.

FIG. 10 is a view for explaining a conventional method of manufacturing a heat sink.

FIG. 11 is a view for explaining a conventional method of manufacturing a heat sink.

FIG. 12 is a view for explaining a conventional method for manufacturing a heat sink.

[Explanation of symbols]

1 semiconductor element 2 anode
Reference Signs List 3 Cathode 4 Insulator 5 Main circuit heat sink 6 Bolt 7 Nut 8 Main circuit tightening upper plate 9 Main circuit tightening lower plate 10 Teflon tube 11 Resistor 12 Resistance heat sink 13 Resistance tightening upper plate 14 Resistance tightening Lower plate 15 upper plate
16 Lower plate 17 Cooling water channel 18 Channel plate
19 Cooling water inlet / outlet 20 Pipe joint 21 Pipe side fitting part
22 Pipe fitting part 23 Screw 24 Nut for fitting
25 piping 26 heat sink body 27 core
28 O-ring 29 Channel 30 Nipple 31 Spring-like metal 32 Core
33 Metal plate 34 Metal 35 Core
41 Bolt 42 Nut 43 Teflon tube 44 Teflon tube 47 Heat sink body 48 Screw part 81 Fixed die
82 Movable mold 83 Gate 86 Gate
88 Fixed mold 89 Movable mold 90 Boss
91 Pin 92 Core 84 Depression
100 dent 101 dent

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Nakaguchi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 5E322 AA07 FA01

Claims (4)

[Claims] 1. A method of manufacturing a heat sink having a flow path through which cooling water flows, comprising: (a) a fixed mold having a depression in a part thereof; and a movable mold having a depression in a part thereof. (B) a step of pouring a molten metal into the cavity and solidifying the same so that a core having a resin is located in a cavity formed by combining the two. c) removing the fixed mold and the movable mold and taking out a solidified metal molded product; and (d) removing a core inside the metal molded product and forming a flow path inside the metal molded product. Forming a heat sink. A method for manufacturing a heat sink, comprising: 2. The method according to claim 1, wherein the core has a metal core. 3. The fixed mold includes a boss having a recess at the bottom of the recess, the movable mold includes a boss having a recess at the bottom of the recess, and each of the boss of the fixed mold and the boss of the movable mold. 3. A fixed mold, the movable mold and a core are combined so that the pin supports a core after a pin having the same metal as a metal poured into the core is provided. The method for manufacturing a heat sink according to any one of the above. 4. A fixed mold or a movable mold having a tapered portion which is inclined toward the bottom from the side end surface toward the recess from the side end surface, and in which molten metal is poured along the tapered portion. The method for manufacturing a heat sink according to claim 1, wherein: