JP3509630B2 - Heat sink manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink which is a component of a cooling device for cooling a semiconductor element such as a gate turn-off thyristor (GTO) used for rotation control of a large rotating machine or a resistor, and a method of manufacturing the same. It is about.

[0002]

2. Description of the Related Art First, the role of a cooling device will be described with reference to the drawings. FIG. 18 is a configuration diagram schematically showing a configuration of a main circuit unit (thyristor) of a gate turn-off thyristor and a water cooling resistor used for controlling the rotation speed of a large rotating machine, and a cooling water circulation system. In the figure, 1 is a semiconductor element formed of a semiconductor, 2 is an anode pressed against the semiconductor element 1,
Reference numeral 3 is a cathode pressed against the side opposite to the anode 2, 4 is an insulator made of ceramics, 5 is a heat sink for a main circuit for cooling the heat generated from the semiconductor element 1, 6 is a bolt, 7
Is a nut, 8 is an upper plate for tightening the main circuit, 9 is a lower plate for tightening the main circuit, and 10 is a fluororesin (polytetrafluoroethylene:
It is a tube made of Teflon (trade name).

The semiconductor element 1 is sandwiched by a heat sink 5 for a main circuit via an anode 2 and a cathode 3 to be laminated, and further sandwiched by an upper plate 8 for main circuit tightening and a lower plate 9 for main circuit tightening and bolted. By tightening with 6 and the nut 7, pressure is applied in the axial direction, and the contact thermal resistance generated between the surfaces of the main circuit heat sink 5 and the anode 2 and the cathode 3 is reduced.

Further, 11 to 14 are water-cooled resistors,
11 is a heat sink for resistance, 12 is a metal resistor, 1
3 is an upper plate for resistance tightening, and 14 is a lower plate for resistance tightening. The water-cooled resistor section is similar to the main circuit section in that the resistor 6 and the resistor heat sink 11 are alternately sandwiched between the bolt 6 and the nut 7.
By tightening by applying pressure in the axial direction, it has a stack structure.

Although not shown in the drawings, there is a regenerative circuit as a semiconductor element in the device for preventing current from flowing backward in the circuit to prevent destruction of other circuits. Similarly, a heat sink is used for the regenerative circuit. A resistor having a stack structure that is in pressure contact with the semiconductor element sandwiched therebetween is configured. In this way, the heat sink is installed for the purpose of preventing the element and the resistor from being destroyed by heat generation.

Next, the operation will be described. When the cooling water flows into the main circuit heat sink 5 through the inflow port, the cooling water passes through the other main circuit heat sinks 5 in the stack structure to deprive the semiconductor device 1 of heat generation, and then the resistance is passed through the tube 10. Flows into the resistor heat sink 11. In the resistor, as in the main circuit, another heat sink for resistance 11
Pass through, take away heat from the resistor and flow out.

Next, the structure of the conventional heat sink will be described. FIG. 19 is an exploded view showing the structure of a conventional heat sink proposed by the inventors by the specification of Japanese Patent Application No. 9-239681. In the figure, 100 is a heat sink body, 15 is an upper plate made of an aluminum brazing sheet, 16 is a lower plate also made of an aluminum brazing sheet, 17 is a refrigerant passage, and 18 is an aluminum brazing sheet having a refrigerant passage 17 formed therein. It is a flow path plate. The heat sink body 100 is configured by the upper plate 15, the lower plate 16, and the flow path plate 18 formed by laminating a plurality of sheets. Reference numeral 19 is a refrigerant inlet / outlet port.

Next, a method of manufacturing the above-described conventional heat sink will be described. FIG. 20 is a diagram showing a structure and a manufacturing method of a conventional heat sink.
Reference numeral 0 is a pipe joint, 21 is a pipe side fitting portion, 22 is a pipe fitting portion, 23 is a screw, 24 is a joint nut, and 25 is a pipe. First, as shown in FIG. 20, an aluminum brazing sheet having a brazing material clad on the side to be joined is punched by a turret punch press or the like to form a refrigerant passage 17 and a refrigerant inlet / outlet 19. The plate 18 is created. Next, a plurality of the flow path plates 18 are laminated, and the upper plate 15 and the lower plate 16 are further stacked so as to form a lid of this laminated body. Next, 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,
The pipe side fitting portion 21 is inserted into the refrigerant inlet / outlet port 19. Since the refrigerant inlet / outlet port 19 appears by laminating the aluminum brazing sheets in which the refrigerant inlet / outlet port 19 is formed by punching in advance, it naturally has a rectangular shape. Therefore, the pipe side fitting portion 2 that is inserted and fitted into the refrigerant inlet / outlet port 19
1 also has a square shape. The material of the pipe joint 20 is austenitic stainless steel (for example, SUS304) having a hardness higher than that of aluminum and having corrosion resistance to cooling water that is a refrigerant.

After temporarily assembling the upper plate 15, the lower plate 16, the flow path plate 18, and the pipe joint 20 in this way, the temperature is raised to 600 ° C. in a nitrogen gas atmosphere by using an atmosphere furnace or the like, And brazing. Here, as the flux mixed in the brazing material, a non-corrosive fluoride-based flux containing a compound of KAlF ₄ or K ₃ AlF ₆ as a main component is used.

Further, the pipe joint 20 and the pipe 25 are connected by inserting the pipe 25 into the pipe fitting portion 22, fitting it, and tightening it with a joint nut 24 that fits the screw portion 23. In addition, by plastically deforming the tip of the pipe 25,
Watertightness can be maintained.

[0011]

Since the conventional heat sink is constructed as described above, there are many joints, and if there is a defect in even one place, the cooling water leaks to the high voltage portion,
Since there is a possibility of causing a fatal accident, it is necessary to apply high pressure in the inspection process and submerge in water for a long time for inspection, which causes a problem of high inspection cost. Further, since the joints are brazed at the same time, the joints must be positioned by a jig, which takes a long time for temporary assembly and the brazing is N
_Since a tunnel furnace with _two atmospheres is used, there is a problem that it takes a long time to complete the brazing and the throughput becomes long. On the other hand, as a manufacturing method having fewer joints than the above-described manufacturing method of the heat sink, a usual casting method in which a sand mold is used and a pipe is put in and aluminum is poured into the sand mold is considered. However, when a heat sink is manufactured by such a method, a lot of "voids" are generated in aluminum that is the heat sink body,
Therefore, there is a problem that the adhesion between the aluminum and the pipe is not sufficient and the performance as a heat sink cannot be exhibited. In addition, a manufacturing method (die-cast molding) in which a molten metal is poured into the mold at high speed and high pressure using a mold is also considered, but when a heat sink is manufactured by such a method, However, there is a problem that the pipe is often crushed or deformed, and a heat sink having a desired flow path shape cannot be efficiently obtained.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a high-performance heat sink which has high reliability against water leakage, low manufacturing cost.

[0013]

[0014]

[0015]

A method for manufacturing a heat sink according to the present invention comprises a pipe in which a flow path for cooling water is bent , and the pipe is used for thermal expansion of the pipe.
Secure it to a holder equipped with a means to prevent buckling due to
With the pipe as a core, the heat sink body is integrally formed by die casting around the pipe ,
Melt the heat sink body material into the die cast mold
When flowing in, the mainstream of the heat sink body material is
It was designed so as not to hit the pipe .

[0016] A method of manufacturing a heat sink of the present invention means to prevent bending the seat is spring mechanism.

[0017]

[0018] In the method of manufacturing heat sinks of the present invention, in the above-mentioned method is for fixing the inclination of the pipe at the time of die casting.

Further, the method of the heat sink production present invention, in the above-mentioned method, the spacer to suppress the inclination pipe to the die-casting mold is provided, which are integrally molded heat sink body is cast by the spacer.

[0020] In the method of manufacturing heat sinks of the present invention, in the above-mentioned method, in which the pipe is made of stainless steel or aluminum.

[0021] In the method of manufacturing heat sinks of the present invention, in the above-mentioned method, the outer peripheral surface of the pipe, in which were plated to react with heatsink body material during die casting.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, the first embodiment of the present invention will be described. 1 is a first embodiment of the present invention.
FIG. 6 is a diagram showing a heat sink for a water-cooled resistor used for controlling the rotation speed of a large-sized rotating machine according to FIG. In the figure, 26 is a heat sink body die-cast from aluminum, 27 is a pipe that serves as a flow path, and 30 is a nipple that is joined to the end of the pipe 27 as a joint, and is a fluororesin (polytetrafluoro) that serves as a flow path. Ethylene: trade name
It is connected to a tube (not shown) made of Teflon.

Next, a method of manufacturing the heat sink will be described. As shown in FIG. 2, the pipe 27 is bent so as to correspond to the flow path shape. In this case, in this embodiment, the pipe material is made of stainless steel (SUS304) or pure aluminum material (A1100), and has an outer diameter of 12 mm and a wall thickness of 1.0 to 1.6 mm. Next, FIG.
As shown in (a), at both ends of the pipe 27, the pipe 27
Insert a holder 50 for preventing molten aluminum from flowing into the inside, and as shown in FIG. 2 (b),
It is put in a die-cast fixed mold 81 as a core, and the mold is closed by a movable mold 82 (see FIG. 3) having a similar shape, and as shown in FIG. 3, molten aluminum (ADC12 in this embodiment). Pour into the die casting mold 80 at high speed and high pressure. Here, FIG. 3 is a cross-sectional view of the die-casting mold 80 as viewed from the side surface direction, and is a cross-sectional view taken along the line BB as viewed in the direction of arrow A in FIG. Reference numeral 81 is a fixed mold, 82 is a movable mold, 27 is a pipe, and 50 is a holder. At this time, the pipe 27 is held by the die-casting mold 80 through the holder 50, and before the molten aluminum melt flows into the pipe 27, the molten aluminum flown in the holder 50 portion is solidified and the inside of the pipe is No defects occur when plugged with molten aluminum. As a result, a heat sink having the shape shown in FIG. 4 and having the pipe 27 cast into the aluminum heat sink body 26 is completed. Next, the nipple 30 which becomes a joint as shown in FIG. 1 is joined. The nipple 30 is an austenitic stainless steel (for example, SUS303 or SUS304) in this embodiment.
Or iron-based materials are used. After joining the nipple 30, both sides are finished with a milling machine, etc.
Completed as a heat sink for water-cooled resistor shown in.

In operation, a tube (not shown) through which cooling water flows is connected to the nipple 30, the cooling water flows through the pipe 27, and the resistance sandwiched between both surfaces of the heat sink body 26 by heat transfer and heat conduction. Cool the body (not shown). The cooling water heated by cooling is the other nipple 3
It flows out from 0 through a tube.

As described above, according to the present embodiment, since the flow paths are completely independent, only the leak at the joint between the nipple and the pipe need be inspected. Moreover, since die casting, which is a highly efficient processing method for integrally molding the pipe and the heat sink body, is performed, assembly is not required, and the processing time can be significantly shortened compared to the conventional brazing type. In addition, since die casting is performed using the holder, there is no problem of closing the inside of the pipe with the molten aluminum.

Embodiment 2. In the first embodiment, FIG.
As shown in (a), the pipe 27 is fixed to the die-cast fixed mold 81 via the holder 50.
The gap between the fixed mold 81 and the movable mold 82 can be sufficiently controlled so that the molten aluminum does not flow into the inside of 7,
Further, if there is no problem that burrs on the die split surface appear on the pipe portion, the pipe 27 may be directly fixed to the die-cast fixed die 83 as shown in FIG.

Embodiment 3. Next, a third embodiment of the present invention
Will be explained. FIG. 6 is a diagram showing a pipe according to the third embodiment of the present invention. In the present embodiment, the final heat sink has the same appearance as the first and second embodiments, but the manufacturing method is different. Figure 6
As shown in (a), the nipple 30 that serves as a joint is previously joined to the pipe 27 that serves as a flow path by welding, brazing, or the like, and the state shown in FIG. 6B is finished. In this way, the flow path is completed before die casting,
Next, a holder (not shown) is attached to the thread portion of the nipple 30, and the pipe 2 is attached in the same manner as in the first embodiment.
7, the nipple 30 and the holder are placed as a core in a die casting mold, and molten aluminum (ADC12 in the present embodiment) is poured at high speed and high pressure. As a result, as shown in FIG. 1, a heat sink having a structure in which the pipe 27 with the nipple 30 joined thereto is cast into the heat sink body 26 made of aluminum is completed.

As described above, according to the third embodiment, since the nipple 30 is joined first, the leak test can be carried out at the stage where the pipe 20 and the nipple 30 are joined, and the leakage test is performed at this stage. Except for this, the yield of the heat sink obtained after die casting is close to 100%. Further, as compared with the case where the nipple 30 is joined after die-cast molding, less material is wasted when leakage occurs, so that the yield is improved.

In this embodiment, the holder is attached to the screw part of the nipple 30. However, similar to the second embodiment, if the gap between the fixed mold and the movable mold can be managed sufficiently. , The holder is not necessary.

Fourth Embodiment Next, a fourth embodiment of the present invention
Will be explained. FIG. 7 is a diagram illustrating a method of manufacturing a heat sink according to the fourth embodiment of the present invention, and is a diagram showing a structure around the pipe when the pipe 28 is inserted as a core into a die casting mold and cast. In the figure, 28 is a pipe made of a material such as stainless steel, for example, SUS304, which is bent, and 50 is used in the die-casting mold when die-casting using the pipe 28 as a core. A holder for fixing the pipe 28, and this holder 50 is made of a material (in the present embodiment, SKD11) having a linear expansion coefficient similar to that of the mold material (SKD). Reference numeral 60 denotes a spring washer provided in the holder 50, which functions as a spring mechanism that absorbs thermal expansion of the pipe 28 material heated during die casting. Reference numeral 70 denotes a partition plate for preventing molten aluminum that has flowed through the gap of the holder 50 from entering the inside of the pipe 28. Although this partition plate 70 is shown in the present embodiment, it is not always necessary unless the molten aluminum flows into the pipe 28, and even if it is omitted, there is no essential problem.

At the time of die-cast molding, high temperature molten aluminum is poured into the mold, and the pipe 28 serving as the core touches the high temperature molten aluminum and becomes instantly hot. On the other hand, since the mold has a large heat capacity, it cannot be instantly heated, and the pipe 28 expands and expands, but the mold hardly expands.
Large thermal stress is generated in the pipe 28. Without the spring washer 60, the pipe 28 would buckle and deform due to the thermal stress. When the spring washer 60 is provided as in the present embodiment, the displacement of the spring washer 60 absorbs the expansion of the pipe and prevents the pipe from buckling and deforming.

In this embodiment, the stainless steel pipe 2 is used.
Although the example according to No. 8 is shown, the same effect can be obtained with an aluminum pipe.

As described above, the spring washer 60 for absorbing the expansion of the pipe 28 during die casting is provided, and the spring washer 60 is housed in the pipe 2
By providing the holder 50 capable of holding 8 the deformation of the pipe due to buckling can be prevented, and a heat sink having a desired flow path shape can be obtained.

Embodiment 5. Next, a fifth embodiment of the present invention
Will be explained. FIG. 8 is a diagram illustrating a method of manufacturing a heat sink according to a fifth embodiment of the present invention, and is a diagram showing a structure around the pipe when the pipe 28 is put into a die-casting die as a core and cast. In the figure, 28 is a pipe which is made of stainless steel and is bent, and 50 is a holder for fixing the pipe 28 in a die-casting mold when die-casting using the pipe 28 as a core. The holder 50 is made of a material (in the present embodiment, SKD11) having a linear expansion coefficient similar to that of the mold material (SKD). 61 is this holder 5
It is a coiled spring that is provided inside 0 and acts as a spring mechanism that absorbs thermal expansion of the pipe 28 material heated during die casting. Reference numeral 70 denotes a partition plate for preventing molten aluminum that has flowed through the gap of the holder 50 from entering the inside of the pipe 28. Although this partition plate 70 is shown in the present embodiment, it is not always necessary as long as molten aluminum does not flow into the pipe 28, and there is no problem if it is omitted.

Even with such a structure, the same effect as when the above-mentioned spring washer 60 is used is exhibited. That is, as long as the spring mechanism is a spring mechanism, the component contained in the holder 50 to absorb the elongation may be a disc spring, and is not a limitation.

In the above fourth and fifth embodiments, too,
Similar to the third embodiment, the nipple may be first joined to the pipe, and then the spring washer 60 or the spiral spring may be housed in the end of the nipple to provide a holder capable of holding the nipple.

Sixth Embodiment Next, Embodiment 6 of the present invention
Will be explained. FIG. 9 is a diagram illustrating a method of manufacturing a heat sink according to a sixth embodiment of the present invention, and is a diagram showing a structure around the pipe when the pipe 28 is put in a die-casting mold as a core and cast. In the figure, 28 is a pipe made of a material such as stainless steel, for example, SUS304, which is bent, and 51 is used in the die-casting mold when die-casting using the pipe 28 as a core. A holder for holding and fixing the pipe 28, and this holder is made of a heat-resistant resin material (polysulfone: PPS in this embodiment).

At the time of die casting, the high temperature molten aluminum is poured into the mold, and the pipe 28 serving as the core touches the high temperature molten aluminum and instantly becomes hot. On the other hand, since the mold has a large heat capacity, it cannot be instantly heated, and the pipe 28 expands and expands, but the mold hardly expands.
Large thermal stress is generated in the pipe 28. Normally, this thermal stress causes the pipe 28 to buckle and deform, but in the present embodiment, since the holder 51 is made of a heat-resistant resin material, the holder 51 itself becomes hot to some extent, It softens and deforms, and this deformation causes the pipe 2
Since the extension of No. 8 is absorbed, the pipe 28 does not buckle and deform.

As described above, by providing the holder for absorbing the elongation of the pipe 28 due to the heat at the time of die casting, it is possible to prevent the deformation due to the buckling of the pipe and to obtain the heat sink having the desired flow path shape. To be

In the sixth embodiment, as in the third embodiment, the nipple is first joined to the pipe, and then the nipple is held by the holder made of the resin material capable of absorbing the thermal expansion. You may

Embodiment 7. Next, a seventh embodiment of the present invention
Will be explained. FIG. 10 is a cross-sectional view of a die-casting mold relating to a method for manufacturing a heat sink according to a seventh embodiment of the present invention, as viewed from the side. In the figure, 84 is a fixed die-cast mold, 85 is a movable die-cast mold, 86 is a die-cast mold, and 87 is a gate of the die-cast mold 86 into which molten aluminum flows. Direction) is a gate shape with no pipes on the extension line. The appearance of the heat sink is the same as that of the first to sixth embodiments, but the manufacturing method is different in the present embodiment.

Similar to the method of manufacturing the heat sink of the fifth embodiment, both ends of the pipe 28 bent so as to correspond to the shape of the flow path are inserted into the holder 50 together with the coiled springs 61, as shown in FIG. Movable mold 85 of the same shape is inserted as a core into the fixed die-cast mold 84.
The mold is closed with, and the molten aluminum (ADC12 in this embodiment) is fast-pressed into the die-cast mold 86.
Pour into. At this time, since the gate 87 of the mold is shaped such that the main flow of the molten aluminum does not directly hit the pipe 28, the pipe 28 is not deformed by the fluid inertia force of the molten aluminum even if the flow rate of the molten aluminum is high. As a result, a heat sink having a desired flow path shape, which has the same shape as that of FIG. 4 and is cast into the aluminum heat sink body without deformation of the pipe, can be obtained. In the following, a heat sink is completed by joining a nipple as a joint to the end of the pipe.

As described above, according to the present embodiment, the shape of the gate flow path is such that the main stream of molten aluminum does not directly hit the pipe, so that the pipe is not deformed. This improves the yield of the heat sink.

In the present embodiment, the shape of the gate channel of the die-casting mold is further changed from the manufacturing method shown in the fifth embodiment so that the main stream of molten aluminum does not directly hit the pipe. First Embodiment
Also for the manufacturing methods shown in 4 and 6, the heat sink may be manufactured with the same gate flow path shape.

Embodiment 8. Next, an eighth embodiment of the present invention
Will be explained. FIG. 11 is a diagram for explaining a heat sink manufacturing method according to an eighth embodiment of the present invention.
Reference numeral 88 is a die-cast fixed die, 89 is a die-cast movable die, and 90 and 91 are protrusions for preventing inclination. In the die-casting mold according to the present embodiment, as in the case of the seventh embodiment, the gate flow path is shaped so that the main stream of the molten aluminum does not directly collide with the pipe. Protrusions for preventing the inclination of the pipe are provided, and protrusions for preventing the inclination are also provided for the movable mold having the same shape. Using such a mold, a heat sink is manufactured by a similar method. In the seventh embodiment, the shape of the gate flow path is such that the main stream of the molten aluminum does not directly hit the pipe, so the pipe is not deformed, but the molten aluminum flows obliquely along the pipe. Could tilt. In the present embodiment, as shown in FIG. 11, since the projections 90 and 91 for preventing tilt are provided in the die casting mold, the pipe 28 is not tilted and deformation can be prevented. Further, as a result, the completed heat sink has a recessed hole corresponding to the protrusions 90 and 91 at the center, but in the present embodiment, this is a hole for positioning a resistor (not shown) sandwiched by the heat sink. Is used as.

As described above, according to the present embodiment, since the fixed mold 88 and the movable mold 89 are provided with the projections 90 and 91 for preventing tilt, the pipe 28 is prevented from tilting. As a result, a heat sink having uniform thermal characteristics on the upper and lower surfaces can be obtained, the yield of the heat sink can be improved, and the loss cost can be reduced. Further, it is not necessary to form a hole for positioning a resistor (not shown) sandwiched between heat sinks, and the processing cost can be reduced.

In addition, in the present embodiment, the die-casting mold shown in the seventh embodiment is further provided with a protrusion for preventing inclination in the die-casting mold, but it is used in the first to sixth embodiments. For the die-casting die, the same tilt-preventing protrusion as in the present embodiment may be provided in the die-casting die.

Ninth Embodiment Next, Embodiment 9 of the present invention
Will be explained. FIG. 12 is a diagram for explaining a heat sink manufacturing method according to a ninth embodiment of the present invention.
A pipe fixing spacer 92 is made of, for example, an aluminum material (A1100 in the present embodiment). The die-casting mold according to the present embodiment is similar to that shown in the eighth embodiment in that projections 90 and 91 for preventing the inclination of the pipe are provided in the die-casting mold, and further, as shown in FIG.
As shown in FIG. 2, a pipe fixing spacer 92 is provided in the die cast fixed mold 88 so as to be fixed to the protrusion 90 in the fixed mold. Although not shown here, the movable mold 89 is also provided with a similar spacer, and such a mold is used to cast the spacer 92 together to integrally mold the heat sink body and the pipe. In the eighth embodiment, even if the protrusions 90 and 91 are provided in the mold, depending on the size of the heat sink, they are not sufficient to support the pipe 28 and may tilt. In the present embodiment, FIG.
As shown in FIG. 2, since the pipe fixing spacer 92 is fixed to the protrusion 90 provided in the die cast fixing mold 88, the pipe 28 does not tilt and is deformed even with a large heat sink. It can be prevented.

As described above, according to the present embodiment, since the spacer 92 for preventing tilt is provided in the fixed mold 88 and the movable mold 89 and the spacer 92 is cast, the pipe 28 tilts. Disappears. As a result, a heat sink having uniform thermal characteristics on the upper and lower surfaces can be obtained, the yield of the heat sink can be improved, and the loss cost can be reduced.

In addition, in the present embodiment, a pipe fixing spacer is further provided in the die-casting metal mold shown in the eighth embodiment, but the die used in the first to seventh embodiments is used. For cast mold,
A pipe fixing spacer similar to that of the present embodiment may be provided in the die casting mold.

Embodiment 10. Next, a tenth embodiment of the present invention will be described. FIG. 13 is a diagram showing a heat sink according to the tenth embodiment of the present invention. In the figure, 26 is a heat sink body formed by aluminum die casting, 2
Reference numeral 8 denotes a stainless steel, for example, austenitic stainless steel SUS304, a bent pipe, and 31 denotes a nipple made of austenitic stainless steel, for example, SUS303 in the present embodiment.
In the present embodiment, a pipe material bent so as to correspond to the shape of the flow path is put as a core in a die-casting mold, and molten aluminum (ADC12 in the present embodiment) is poured at high speed and high pressure to form a pipe 28. Is molded into a heat sink body 26 made of aluminum, and then the nipple 31 is joined to the pipe portion protruding from the heat sink body 26 by TIG welding.

The present embodiment is characterized in that stainless steel is used for the material of the pipe 28. Therefore, since the pipe of the present embodiment has poor heat conduction, the nipple 31 is tied.
When G welding is performed, the heat sink body 26 is removed from the pipe 28.
The amount of heat transferred to the aluminum heat sink body 26 can be reduced, and the aluminum heat sink body 26 can be prevented from melting or deforming. Further, since the pipe of this embodiment is made of highly rigid stainless steel, the pipe is unlikely to be deformed even when the molten aluminum flows into the mold at high speed and high pressure. Also, the nipple 31 that serves as a joint
Since the material and the pipe material 28 serving as a flow path are similar materials, there is no potential difference in electrolytic corrosion, and electrolytic corrosion does not easily occur, so that the material has corrosion resistance. Further, since the material of the pipe 28 and the material of the nipple 31 are also strong in corrosion resistance, it is possible to prevent corrosion due to the cooling water in use, and to avoid water leakage.

Eleventh Embodiment Next, an eleventh embodiment of the present invention will be described. 14 is a diagram showing a heat sink according to an eleventh embodiment of the present invention. In the figure, 26 is a heat sink body molded by aluminum die casting, and 29 is a heat sink body.
Is a pipe made of an aluminum material such as A1100 and bent, 32 is an iron-based material,
For example, in this embodiment, the nipple is made of a material such as SKD11 or SUS304. This nipple 32
The nipple 3 to facilitate positioning during brazing.
2 has a shape such that the brazing filler metal fits into the outer periphery 32a. 40 is a linear aluminum brazing material. In the present embodiment, a pipe material bent so as to correspond to the flow path shape is put as a core in a die-casting mold, and molten aluminum (ADC12 in the present embodiment) is poured at high speed and high pressure to form a pipe 29. Is molded into the heat sink body 26, and then the nipple 32 is inserted into the pipe portion protruding from the heat sink body 26. Then, the linear aluminum brazing material 40 is wound around the outer periphery of the nipple 32 to form a fluoride flux. Are brazed together and joined. At the time of brazing, care is taken not to melt or deform the heat sink body 26, and heating / bonding is performed.

The present embodiment is characterized in that aluminum is used as the material of the pipe 29. Therefore, the pipe of the present embodiment has a good thermal conductivity, so that the performance as a sheet sink is good. However, the wall thickness is required so that the pipe is not deformed. Also, by using an aluminum material as the material of the pipe 29, if the nipple 32 is removed,
The heat sink body 26 and the pipe material 29 are the same material,
Easy to recycle. Further, there is no difference in electrolytic corrosion potential between the pipe 29 and the heat sink body 26, and it is possible to prevent cracks from running on the outer peripheral surface of the pipe due to crevice corrosion or the like.

In the above embodiment, as shown in FIG. 15, a linear aluminum brazing material 40 is provided at the overlapping portion of the pipe 29 made of an aluminum material (A1100) and the nipple 32 made of a ferrous material. Alternatively, the heat sink body 26 made of an aluminum material may be formed by die-casting after winding and brazing with a fluoride-based flux to bond them together. At the time of die-cast molding, the nipple 32 is kept in contact with the die-casting mold so as not to remelt the aluminum brazing portion, and the temperature of the brazing portion is controlled so as not to rise above the melting temperature.

Twelfth Embodiment Next, a twelfth embodiment of the present invention will be described. FIG. 16 is a diagram showing a pipe according to the twelfth embodiment of the present invention. In the present embodiment, the outer periphery of the pipe 27 bent to correspond to the shape of the flow path is coated with a metal film 41 having a good affinity for aluminum to a thickness of, for example, 10 μm by a plating process or the like, and this plating is performed. A heat sink shape in which the pipe 27 is cast into the heat sink body by inserting the pipe 27 into the die cast mold as a core and pouring molten aluminum (ADC12 in the present embodiment) into the mold at high speed and high pressure. To mold. After that, after inserting the nipple into the pipe portion protruding from the heat sink body, TIG welding is performed and joining is performed as in the tenth embodiment. At this time, the nipple may be joined by aluminum brazing as in the eleventh embodiment.

Thus, in this embodiment, the pipe 2
Metal film 4 with good affinity for aluminum on the outer circumference of 7 materials
Since 1 is covered by a plating process etc., when molten hot aluminum flows into the mold at high speed and high pressure, reaction layers such as intermetallic compounds and diffusion layers are instantly between the flowing aluminum and the plating layer. When formed, the adhesion strength is increased, the contact thermal resistance between the pipe and the heat sink body is reduced, and the heat exchange capacity of the heat sink is improved.

FIG. 17 (a) shows that a pipe made of SUS304 is plated with aluminum (ADC1) without plating.
2) is cut into a workpiece and its cross section (SUS30
It is the photograph which observed the interface of 4 pipes and aluminum ADC12) by SEM. As shown in FIG. 17 (a), it can be seen that cracks are generated here and there at the interfaces, and thermal contact is not good. FIG. 17B shows a heat sink manufactured by casting tin (Sn) -plated aluminum (ADC12) on the outer circumference of a pipe made of SUS304, and cutting the heat sink to obtain a cross section (SUS304 pipe and aluminum ADC12). It is the photograph which observed the interface) by SEM. As shown in FIG. 17B, the aluminum ADC 12
It can be seen that a reaction layer is formed between and the Sn-plated SUS304 pipe. Also, although not shown,
A similar effect is obtained by zinc (Zn) plating. In this case, when the galvanized film, which has a lower melting point than aluminum and is relatively hard to oxidize, is present on the outer peripheral portion of the pipe, contact with the hot aluminum melt causes a partial melting in a short time to form a reaction layer. It is considered that this improves the thermal contact.

As described above, since the outer circumference of the pipe material is covered with tin plating or zinc plating, which has a good affinity with aluminum which is the material of the heat sink body, when molten hot aluminum flows at high speed and high pressure, the plating is performed. Part of the layer is melted, a reaction layer such as intermetallic compound is instantly formed, the adhesion strength is increased, the contact thermal resistance between the pipe and the heat sink body is reduced, and as a result, the heat exchange capacity of the heat sink Has the effect of improving.

[0060]

[0061]

[0062]

As described above , according to the method of the present invention , in the method of manufacturing the heat sink in which the cooling water circulates, the pipe in which the cooling water flows is bent. The above pipe is used for thermal expansion of the pipe.
Secure it to a holder equipped with a means to prevent buckling due to
With the pipe as a core, the heat sink body is integrally formed by die casting around the pipe ,
Melt the heat sink body material into the die cast mold
When flowing in, the mainstream of the heat sink body material is
Since it does not collide with the pipe, it can be prevented from being deformed due to buckling, and at the same time , the heat sink body material
May directly hit the pipe and cause deformation of the pipe.
Therefore, a heat sink having a desired flow path shape can be obtained.

Further, in the above method, since the means for preventing buckling is the spring mechanism, it is possible to easily absorb the thermal expansion of the pipe material and prevent deformation due to buckling.

[0064]

Further, in the above method, since the inclination of the pipe is fixed at the time of die casting, the inclination of the pipe can be prevented, so that a heat sink having a desired flow path shape can be obtained.

Further, in the above method, since the spacer for suppressing the inclination of the pipe is provided in the die casting mold, and the heat sink body is integrally molded by casting together with the spacer,
Since the inclination of the pipe can be prevented, a heat sink having a desired flow path shape can be obtained.

Further, in the above method, since the pipe is made of stainless steel or aluminum, when the pipe is made of stainless steel, deformation of the pipe is unlikely to occur, and melting and deformation of the heat sink body during nipple welding can be prevented. There is. Also, when the pipe is made of aluminum, a high-performance sheet sink having good thermal conductivity can be obtained. Also, if the nipple is removed, the heat sink body and the pipe material are made of the same material, which has the effect of facilitating recycling.

Further, in the above method, since the outer peripheral surface of the pipe is plated so as to react with the heat sink body material during die casting, the contact heat resistance between the pipe and the heat sink body is reduced, and the heat exchange of the heat sink is performed. Ability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a heat sink according to a first embodiment of the present invention.

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

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

FIG. 4 is a perspective view showing a heat sink body in which a pipe is cast by die casting according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a method of manufacturing a heat sink according to the second embodiment of the present invention.

FIG. 6 is a diagram showing a method of manufacturing a heat sink according to the third embodiment of the present invention.

FIG. 7 is a diagram showing a method of manufacturing a heat sink according to the fourth embodiment of the present invention.

FIG. 8 is a diagram showing a method of manufacturing a heat sink according to a fifth embodiment of the present invention.

FIG. 9 is a diagram showing a method of manufacturing a heat sink according to a sixth embodiment of the present invention.

FIG. 10 is a diagram showing a method of manufacturing a heat sink according to a seventh embodiment of the present invention.

FIG. 11 is a diagram showing a method of manufacturing a heat sink according to an eighth embodiment of the present invention.

FIG. 12 is a diagram showing a method of manufacturing a heat sink according to a ninth embodiment of the present invention.

FIG. 13 is a diagram showing a method of manufacturing a heat sink according to the tenth embodiment of the present invention.

FIG. 14 is a diagram showing a method of manufacturing a heat sink according to an eleventh embodiment of the present invention.

FIG. 15 is a diagram showing another method for manufacturing the heat sink according to the eleventh embodiment of the present invention.

FIG. 16 is a diagram showing a pipe according to a twelfth embodiment of the present invention.

FIG. 17 is a photograph of a microscope observing the interface between the pipe and the aluminum heat sink body when tin plating is applied to the outer peripheral surface of a stainless steel pipe and when tin plating is not applied.

FIG. 18 is a configuration diagram schematically showing a configuration of a main circuit unit (thyristor) of a gate turn-off thyristor and a water cooling resistor used for controlling the rotation speed of a large-sized rotating machine, and a cooling water circulation system.

FIG. 19 is an exploded view of the structure of a conventional heat sink.

FIG. 20 is a diagram showing a structure and a manufacturing method of a conventional heat sink.

[Explanation of symbols]

1 semiconductor element, 2 anode, 3 cathode, 4 insulator,
5 Heat sink for main circuit, 6 bolts, 7 nuts,
8 Main circuit tightening upper plate, 9 Main circuit tightening lower plate, 10
Tube, heat sink for 11 resistors, 12 resistors,
13 Resistance tightening upper plate, 14 Resistance tightening lower plate, 15
Upper plate, 16 Lower plate, 17 Refrigerant flow path, 18 Flow path plate, 1
9 refrigerant inlet / outlet, 20 pipe joint, 21 pipe side fitting part, 22 pipe fitting part, 23 screw, 24 joint nut, 25 pipe, 26 heat sink body, 27, 2
8,29 Pipe, 30, 31, 32 Nipple, 32
a outer periphery of nipple, 40 aluminum brazing material, 41 plated layer, 50 holder, 51 resin holder, 60 spring washer, 61 spiral spring, 70 partition plate, 80,86 die cast mold, 81,83,8
4,88 Fixed mold, 82,85,89 Movable mold, 8
7 gates, 90, 91 protrusions, 92 spacers, 10
0 Heat sink body.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Kashiba 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Masaharu Moriyasu 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi (56) Reference JP-A-7-307423 (JP, A) JP-A-7-290226 (JP, A) JP-A-3-142057 (JP, A) JP-A-10-85921 (JP , A) Actual Kaihei 6-48949 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22D 19/00 H01L 23/34-23/473

Claims (6)

(57) [Claims] 1. A method of manufacturing a heat sink in which cooling water circulates, wherein a flow path through which the cooling water flows is bent.
It constituted by has been subjected pipe, the pipe, the pipe
For holders equipped with means to prevent buckling due to thermal expansion of
Fix it, use the pipe as a core, and integrally mold the heat sink body around the pipe by die casting .
Heat sink melted into the die-cast mold
When flowing in the body material,
A method for manufacturing a heat sink, characterized in that the main stream is prevented from colliding with the pipe . 2. A means for preventing buckling, heat sink manufacturing method according to claim 1, characterized in that a spring mechanism. 3. The heat sink manufacturing method according to claim 1 or 2, wherein the fixing the tilt pipe during die casting. 4. The spacer of suppressing the inclination of the pipe provided on the die-casting mold, in any of claims 1 <br/> to 3, characterized in that integrally formed heat sink body is cast by the spacer A method for manufacturing the heat sink described. 5. A pipe claims 1, characterized in that it is constructed of stainless steel or aluminum 4
A method for manufacturing a heat sink according to any one of 1. The outer peripheral surface of 6. Pipe, heat sink manufacturing method according to any one of claims 1 to 5, characterized in that performing the plating of reacting with the heatsink body material during die casting.