JP7129875B2 - Heat sink, manufacturing method thereof, and heat exchanger - Google Patents

Description

The present invention relates to a heat sink, its manufacturing method, and a heat exchanger.

A power converter such as an inverter or a converter has a semiconductor element for power conversion and a heat exchanger for cooling the semiconductor element. 2. Description of the Related Art For example, in a power conversion device mounted on a vehicle such as an automobile, a liquid-cooled heat exchanger is used in order to further improve cooling efficiency. A liquid-cooled heat exchanger has a heat sink and a jacket that forms a coolant flow path together with the heat sink. Moreover, the heat exchanger may be made of an aluminum material (including aluminum and an aluminum alloy; the same shall apply hereinafter) for the purpose of weight reduction.

This type of heat sink often includes pin fins in order to improve cooling performance while suppressing an increase in pressure loss when arranged in a coolant channel. For example, in Patent Document 1, a casing having a top wall and a bottom wall and having a cooling liquid flow path provided therein, and a radiator disposed in the cooling liquid flow path in the casing are provided. A liquid cooling system in which a heating element mounting portion is provided on either one of the outer surface of the top wall and the outer surface of the bottom wall, and the radiator has a substrate and a plurality of pin fins provided in a zigzag arrangement so as to protrude with respect to the substrate. A cooling system is described.

The radiator of Patent Document 1 has two types of pin fins with different heights. Of the two types of high and low pin fins, the cross-sectional shape of the high pin fin is a parallelogram, and one corner of the parallelogram faces the upstream side of the coolant flow direction in the coolant flow path, and the corner and the corner The corners located on the diagonal line similarly face the downstream side in the flow direction of the cooling liquid. Such a radiator includes: a first cutting process in which a base plate of the radiator is cut along a first straight line inclined to one side toward the downstream side in the cooling liquid flow direction in the cooling liquid flow path; and a second cutting process for cutting along a second straight line slanted to the other side.

In recent years, in order to cool the heat generating element more efficiently, a heat exchanger configured to directly mount the heat generating element on a heat sink has also been proposed (for example, Patent Document 2).

Japanese Unexamined Patent Application Publication No. 2016-4806 JP 2015-153925 A

In the radiator of Patent Document 1, in order to reduce the thermal resistance between the casing and the radiator, it is required to increase the flatness of the back surface of the pin fins, that is, the surface joined to the casing. However, in order to form high-pin fins in the heat sink of Patent Document 1, grooves having a depth equal to the height of the high-pin fins must be formed in either the first cutting process or the second cutting process. There is a need to. Therefore, depending on the cutting depth, the base plate may be distorted, and the flatness of the back surface of the pin fins may deteriorate. If the flatness of the back surface of the pin fins is low, a gap is likely to be formed between the casing and the radiator. As a result, there is a risk of causing an increase in thermal resistance between the casing and the radiator.

Similarly, when a heating element is mounted on a heat sink as in Patent Document 2, it is required to increase the flatness of the back surface of the pin fins from the viewpoint of reducing the thermal resistance between the heat sink and the heating element. . Further, when a heat generating element is mounted on a heat sink, a decrease in the flatness of the back surface of the pin fins may increase the thermal stress applied to the heat generating element.

Furthermore, since cutting is a processing method with relatively high processing costs and low processing efficiency, it is desirable to improve the production efficiency of heat sinks and reduce processing costs more than the manufacturing method of Patent Document 1. ing.

The present invention has been made in view of this background, and can be efficiently produced using an extruded profile, has a high flatness of the heating element mounting surface, and suppresses an increase in pressure loss while improving cooling performance. The object is to provide a heat sink that can be improved, a method for manufacturing the same, and a heat exchanger with the heat sink.

One aspect of the present invention is a base plate having a rectangular shape in plan view in the thickness direction and having a heating element mounting surface on which a heating element is mounted;
a plurality of fins arranged on the back surface of the heating element mounting surface of the base plate,
The fins are
Protruding from the base plate, arranged at intervals in a first direction parallel to one side of the outer peripheral edge of the base plate, and extending in a second direction orthogonal to the first direction a fin base;
a plurality of pins projecting from the fin base and spaced apart in the second direction;
the interval Wp between the pins in the second direction is narrower than the interval Wb between the fin bases in the first direction;
In the heat sink, the ratio Hb/Hp of the height Hb of the fin base to the height Hp of the pin satisfies 0<Hb/Hp<0.20.

Another aspect of the present invention is a heat exchanger comprising a jacket that holds the heat sink,
The jacket is
a bottom wall portion disposed facing the fins of the heat sink;
a peripheral wall portion erected from an outer peripheral edge portion of the bottom wall portion and holding a base plate of the heat sink;
a coolant flow path composed of a space surrounded by the base plate, the bottom wall portion, and the peripheral wall portion;
a coolant introduction port arranged in the peripheral wall portion at a position facing a fin arranged at one end in the first direction among the plurality of fins;
a coolant outlet facing the fin arranged at the other end of the plurality of fins in the first direction in the peripheral wall portion and arranged at a position different from the coolant inlet in the second direction; , in a heat exchanger.

Still another aspect of the present invention is a method for manufacturing the heat sink of the above aspect, wherein the base plate and the base plate protrude from the base plate and have a plate shape and are spaced apart from each other in a direction perpendicular to the extrusion direction by extrusion molding. Produce an extruded profile with a plurality of fin planned parts arranged with a gap,
In the method of manufacturing a heat sink, the plurality of pre-finned portions are cut along a straight line extending in a direction different from the extrusion direction to form the fins.

The heat sink has a base plate having a heating element mounting surface, and a plurality of fins provided on the back surface of the heating element mounting surface of the base plate. Each fin also has a fin base protruding from the base plate and a plurality of pins protruding from the fin base. Further, the distance Wp between the pins, the distance Wb between the fin bases, and the ratio Hb/Hp of the height Hb of the fin base to the height Hp of the pins satisfy the above specific relationship. Thereby, the cooling performance of the heat sink can be enhanced while suppressing an increase in pressure loss.

The heat sink can be manufactured by the manufacturing method of the above aspect, that is, by a method of manufacturing an extruded profile having a base plate and a portion to be fins by extrusion, and then cutting the portion to be fins. In this manufacturing method, a fin having a fin base portion and a pin can be formed by cutting the fin-planned portion while the tool is separated from the base plate. Therefore, according to the manufacturing method of the aspect described above, it is possible to reduce the distortion of the base plate during the cutting process, thereby improving the flatness of the heating element mounting surface.

Moreover, according to the manufacturing method of the aspect described above, since the gaps between the fin bases can be formed by extrusion, the number of times of cutting can be reduced as compared with the conventional heat sink. Therefore, the heat sink can be produced with high efficiency.

1 is a perspective view of a heat sink in Example 1. FIG. 1 is a plan view of a heat sink in Example 1. FIG. 3 is a partial cross-sectional view taken along line III-III of FIG. 2; FIG. FIG. 3 is a partial cross-sectional view taken along line IV-IV of FIG. 2; 1 is a perspective view of an extruded profile in Example 1. FIG. FIG. 10 is a partial cross-sectional view showing a main part of a heat sink in Example 2; FIG. 11 is a perspective view of a heat exchanger in Example 3; FIG. 11 is an exploded perspective view of a heat exchanger in Example 3; FIG. 11 is a plan view of a heat exchanger in Example 3;

The heat sink may be made of an aluminum material. As the aluminum material forming the heat sink, for example, A1000 series aluminum, A3000 series alloys, A5000 series alloys, A6000 series alloys, etc. can be employed, but the aluminum material is not limited to these aluminum materials.

The base plate of the heat sink has a rectangular shape when viewed from the thickness direction. Here, the concept of "rectangular shape" includes rectangles, squares, and shapes with rounded corners in these shapes.

One surface of the base plate in the thickness direction is provided with a heating element mounting surface on which the heating element is mounted. The heat generating element mounted on the heat generating element mounting surface may be, for example, a semiconductor element or the like that constitutes a power conversion circuit. Also, the semiconductor element may be directly mounted on the heating element mounting surface, or a circuit board may be interposed between the heating element mounting surface and the heating element. As the circuit board, for example, a laminate board or the like in which metal plates are bonded to both sides of a ceramic plate can be used.

A plurality of fins are arranged on the other surface of the base plate in the thickness direction, that is, on the back surface of the heating element mounting surface. The plurality of fins are spaced apart from each other in a first direction parallel to one side of the outer peripheral edges in a plan view of the base plate in the thickness direction. The thickness of the fins, ie the outer dimension of the fins in the first direction, can be, for example, 1.0-3.0 mm.

The interval Wb between the fin bases can be, for example, 0.9-3.0 mm, preferably 1.0-2.4 mm. The interval Wb between the fin bases is a value determined by the shape of the die used for extrusion in the manufacturing method of the above aspect. If the interval Wb between the fin bases is made narrower than 0.9 mm, the thickness of the portion of the die corresponding to the space between the fin bases becomes excessively thin, which may lead to deterioration in the durability of the die.

Each fin protrudes from the base plate and has a fin base extending in a second direction perpendicular to the first direction, and a plurality of pins protruding from the fin base. That is, each fin has a comb-like shape in which a plurality of pins are connected via the fin base. The width of the pin, ie the distance between the end faces of the pin in the second direction, can be, for example, 1.0-4.0 mm, preferably 1.1-3.9 mm. Further, the height Hp of the pin, that is, the distance from the base plate to the tip of the pin can be, for example, 4.0 to 10.0 mm, preferably 5.0 to 7.0 mm.

The distance Wp between the pins can be, for example, 0.7-2.5 mm, preferably 0.8-1.8 mm. The interval Wp between the pins is a value determined by the machining diameter of the tool used for cutting in the manufacturing method of the above aspect. If the interval Wb between the pins is made narrower than 0.7 mm, the machining diameter of the tool becomes excessively small, which may lead to deterioration of the durability of the tool.

The cross-sectional shape of the pin in the direction of projection is preferably square, rectangular or parallelogram. These cross-sectional shapes can be easily formed by cutting a plate-like fin-provisioned portion. Therefore, the production efficiency of the heat sink can be further improved.

The pin may have a constant thickness over the entire range in the height direction when viewed from the second direction, that is, the extending direction of the fin base, or may have a thickness depending on the position in the height direction. may have changed. The shape of the pin viewed from the second direction is determined by the shape of the hole of the die used for extrusion. Therefore, the shape of the pin viewed from the second direction can be relatively freely set.

The shape of the pin when viewed from the second direction may be, for example, a tapered shape that tapers from the root of the fin base toward the tip. By increasing the thickness of the root in this manner, the thermal resistance between the base plate and the pin can be further reduced. Further, by reducing the thickness of the tip of the pin, which has a lower temperature than the base of the pin and has a low cooling efficiency, it is possible to avoid a decrease in cooling performance and increase the flow passage cross-sectional area of the coolant. As a result, the cooling performance can be further improved while suppressing the increase in pressure loss more effectively.

The spacing Wp between the pins in the second direction is narrower than the spacing Wb between the fin bases in the first direction. Accordingly, it is possible to suppress an increase in pressure loss when the heat sink is arranged in the coolant channel. If the interval Wp between the pins is equal to or greater than the interval Wb between the fin bases, the pressure loss may increase.

Also, the ratio Hb/Hp of the height Hb of the fin base to the height Hp of the pin satisfies 0<Hb/Hp<0.20. In this way, by projecting the fin base slightly from the base plate, when the coolant passes between the pins, the fin base disturbs the flow of the coolant in the vicinity of the base plate, thereby stirring the coolant. . As a result, the development of the temperature boundary layer of the coolant on the base plate can be suppressed, and the cooling performance can be further improved.

When the value of Hb/Hp is 0, that is, when the space between the pins is flush with the base plate, when the coolant passes between the pins, the flow of the coolant in the vicinity of the base plate It does not have the effect of disturbing the Therefore, a temperature boundary layer, that is, a layer of coolant having a temperature relatively close to the temperature of the base plate tends to develop on the base plate. In this case, the relatively low-temperature coolant flowing away from the base plate is blocked by the temperature boundary layer, making it difficult to contact the base plate. As a result, the cooling performance may deteriorate.

When the value of Hb/Hp is 0.20 or more, the flow resistance tends to increase when the coolant passes between the pins. Therefore, in this case, there is a risk of causing an increase in pressure loss.

From the viewpoint of further improving cooling performance while suppressing an increase in pressure loss, the thickness of the fins is 1.5 mm to 2.5 mm, the width of the pins is 1.1 to 1.6 mm, and the distance between the pins is Wp is 0.8 to 1.8 mm, the interval Wb between the fin bases is 1.0 to 2.4 mm, and the ratio Wp/Wb of the interval Wp between the pins to the interval Wb between the fin bases is 0<Wp /Wb<0.80 is preferably satisfied.

The heat sink can constitute a heat exchanger by combining with a jacket. the jacket has a bottom wall portion positioned facing the fins of the heat sink;
a peripheral wall portion erected from the outer peripheral edge portion of the bottom wall portion and holding the base plate of the heat sink;
a coolant flow path consisting of a space surrounded by the base plate, the bottom wall and the peripheral wall;
a coolant introduction port arranged in the peripheral wall at a position facing the fin arranged at one end in the first direction among the plurality of fins;
a coolant outlet in the peripheral wall facing the fin arranged at the other end in the first direction among the plurality of fins and arranged at a position different from the coolant inlet in the second direction; ing.

By arranging the coolant inlet and the coolant outlet so as to face the fins, the coolant flowing from the coolant inlet can be guided between the pins. Between the pins are fin bases that project slightly from the base plate, as described above. Therefore, the fin base agitates the coolant that is about to pass between the pins, and the development of the temperature boundary layer can be suppressed.

Further, by arranging the coolant outlet at a position shifted from the coolant inlet in the second direction, the coolant flowing from the coolant inlet can flow not only in the first direction but also in the second direction. Thereby, the heat exchange efficiency between the heat sink and the coolant can be further enhanced.

As a result, the heat exchanger can improve cooling performance while suppressing an increase in pressure loss.

Further, when the cross-sectional shape of the pin is square, rectangular, or parallelogram, by arranging the coolant outlet at a position shifted from the coolant inlet in the second direction, A coolant flow can be formed in the direction toward the corners present on the side surfaces of the pin. Thereby, the cooling performance can be improved and the pressure loss of the heat exchanger can be further reduced.

From the viewpoint of further enhancing the above-described effects, the coolant inlet is arranged at a position facing one end of the fins in the second direction, and the coolant outlet is arranged at a position facing the other end of the fins in the second direction. It is preferable that That is, the coolant inlet port is arranged at one of the corners of the coolant channel, and the coolant outlet port is arranged at a corner opposite to the corner where the coolant inlet port is arranged. In this case, the flow of the coolant is formed in the entire coolant channel, and the efficiency of heat exchange between the heat sink and the coolant can be further enhanced. As a result, the cooling performance of the heat exchanger can be further improved.

(Example 1)
An embodiment of the heat sink will be described with reference to the drawings. As shown in FIGS. 1 and 2, the heat sink 1 has a rectangular shape in plan view in the thickness direction, and includes a base plate 2 having a heat generating element mounting surface 21 on which a heat generating element is mounted, and and a plurality of fins 3 arranged on the back surface of the heating element mounting surface 21 . The fin 3 has a fin base 31 protruding from the base plate 2 and a plurality of pins 32 protruding from the fin base 31 .

As shown in FIGS. 2 and 3 , the fin bases 31 are spaced apart from each other in a first direction X parallel to one side of the outer peripheral edge of the base plate 2 . Further, the fin base 31 extends in a second direction Y perpendicular to the first direction X, as shown in FIGS. 2 and 4 . The pins 32 provided on each fin 3 are spaced apart in the second direction Y. As shown in FIG.

Further, the interval Wp (see FIG. 4) between the pins 32 in the second direction Y is narrower than the interval Wb (see FIG. 3) between the fin bases 31 in the first direction X, and the height Hp (see FIG. 4) of the pins 32 ) to the height Hb of the fin base 31 satisfies 0<Hb/Hp<0.20. The configuration of the heat sink 1 of this example will be described in more detail below.

The heat sink 1 of this example is made of an aluminum material. The dimensions of the base plate 2 of the heat sink 1 are not particularly limited. For example, the base plate 2 of this example has a rectangular shape with long sides of 150 mm and short sides of 110 mm. Although not shown in the drawing, a heating element mounting surface 21 is provided in the center of one plate surface of the base plate 2 . Further, as shown in FIGS. 1 and 2, a plurality of fins 3 are arranged on the rear surface of the heating element mounting surface 21 . The periphery of the plurality of fins 3 on the back surface of the heating element mounting surface 21 constitutes a flange surface 22 for attachment to the jacket.

As shown in FIG. 2, the fin bases 31 of this example are spaced apart from each other in a first direction X, which is a direction parallel to the long side of the base plate 2 when viewed from the thickness direction. It extends in the second direction Y, which is parallel to the short sides. That is, the heat sink 1 of this example has a plurality of fin bases 31 arranged side by side in the longitudinal direction of the base plate 2 and extending in the lateral direction.

The length and thickness of the fin base 31 are not particularly limited. For example, the length of the fin base 31 in this example is 90 mm, and the thickness A of the fin base 31, that is, the outer dimension of the fin base 31 in the first direction X is 2.0 mm. The distance Wb between the fin bases 31 shown in FIG. 3, that is, the distance between the fin bases 31 adjacent to each other in the second direction Y is 2.4 mm, and the height of the fin bases 31 shown in FIG. The thickness Hb is 0.50 mm.

As shown in FIGS. 2 and 4 , each fin base 31 has a plurality of pins 32 spaced apart from each other in the second direction Y, that is, the extending direction of the fin base 31 . The pin 32 of this example has a square prism shape. The height Hp of the pins 32 shown in FIG. The width B of the pin 32 is 1.5 mm. Note that, as shown in FIG. 3 , the thickness of the pin 32 in the first direction X is 2.0 mm, which is equal to the thickness A of the fin base 31 .

The heat sink 1 of this example can be produced by the following method. First, an extruded shape comprising a base plate 2 and a plurality of pre-finned portions 30 protruding from the base plate 2 and having a plate shape and spaced apart from each other in a direction perpendicular to the extrusion direction E by extrusion molding. A material 10 is produced (see FIG. 5). The spacing between the fin-proposed portions 30 and between the fin-proposed portions 30 is the same as the thickness A of the fin bases 31 and the spacing Wb between the fin bases 31, respectively. Further, the height of the pre-fin portion 30 is the same as the height Hp of the pin 32 .

After extrusion, if desired, the extruded profile 10 may be cut to desired lengths.

Next, the plurality of pre-finned portions 30 are cut along straight lines extending in a direction different from the extrusion direction E to form the fins 3 . In this example, cutting is performed along a straight line extending in a direction perpendicular to the extrusion direction E. As shown in FIG. Thereby, slits are formed in the pre-finned portion 30 and the pre-finned portion 30 can be partitioned into a plurality of pins 32 by the slits. The width of the slit to be formed by cutting is the same as the interval Wp between the pins 32 . The depth of the slit is the same as the value obtained by subtracting the height Hb of the fin base 31 from the height Hp of the pin 32 .

In this example, slits are formed in the pre-finned portion 30 during cutting, and unnecessary pre-finned portions 30 existing at the front end portion 301 and the rear end portion 302 in the extrusion direction E are removed. As a result, a flange surface 22 for bonding to the jacket 5 is formed around the plurality of fins 3 . As described above, the heat sink 1 shown in FIG. 1 can be obtained.

The heat sink 1 of this example has a base plate 2 having a heating element mounting surface 21 and a plurality of fins 3 provided on the back surface of the heating element mounting surface 21 of the base plate 2 . Each fin 3 has a fin base 31 protruding from the base plate 2 and a plurality of pins 32 protruding from the fin base 31 . Further, the distance Wp between the pins 32 in the heat sink 1, the distance Wb between the fin bases 31, and the ratio Hb/Hp of the height Hb of the fin bases 31 to the height Hp of the pins 32 satisfy the above specific relationship. As a result, the cooling performance of the heat sink 1 can be enhanced while suppressing an increase in pressure loss.

In addition, the heat sink 1 having the fins 3 is produced by extruding the extruded profile 10 having the base plate 2 and the fin-planned portions 30, and then cutting the fin-planned portions 30, as described above. It can be produced by In this manufacturing method, the fin 3 having the fin base 31 and the pin 32 is formed by cutting the pre-fin portion 30 while the tool is separated from the base plate 2 during cutting. can be done. Therefore, the distortion of the base plate 2 during cutting can be reduced, and the flatness of the heating element mounting surface 21 can be improved. By mounting a heating element on the heating element mounting surface 21 of the heat sink 1, the contact thermal resistance between the heating element and the heat sink 1 can be reduced.

Moreover, according to the manufacturing method of the above aspect, since the gaps between the fin bases 31 can be formed by extrusion, the number of times of cutting can be reduced as compared with the conventional heat sink 1 . Therefore, the heat sink 1 can be produced with high efficiency.

In this example, an example of the heat sink 1 in which the interval Wb between the fin bases 31, the interval Wp between the pins 32, the thickness A of the fin bases 31, and the width B of the pins 32 in the second direction Y are all the same will be described. However, these values may differ depending on the position on the base plate 2. FIG. For example, the interval Wb between the fin bases 31 of some of the fins 3 may be different from the interval Wb between the fin bases 31 of the remaining fins 3 . Similarly, the interval Wp between the pins 32 of some pins 32 among the plurality of pins 32 may be set to a value different from the interval between the pins 32 of the remaining pins 32 .

(Example 2)
In this example, a heat sink 102 having pins 34 with a tapered shape when viewed from a first direction is described. Note that, of the reference numerals used in the present and subsequent examples, the same reference numerals as those of the previously-described embodiments indicate the same components as those of the previously-described embodiments unless otherwise specified.

As shown in FIG. 6, the heat sink 102 of this example includes a base plate 2, a heating element mounting surface 21 provided on one plate surface of the base plate 2, and a plurality of heating element mounting surfaces 21 provided on the back surface of the heating element mounting surface 21. of fins 303 and. Each fin 303 has a fin base 33 and a plurality of pins 34 arranged on the fin base 33 . The pin 34 of this example has a tapered shape that tapers from a root 341 to the fin base 33 toward a tip 342 in plan view in the second direction Y. As shown in FIG. Others are the same as the first embodiment.

By making the root 341 of the pin 34 thicker than the tip 342 of the pin 34 as in this example, heat can be easily conducted from the fin base 33 to the pin 34 . Thereby, the thermal resistance between the base plate 2 and the pins 34 can be further reduced. Further, by reducing the thickness of the tip 342, which has a lower temperature than the base 341 of the pin 34 and has low cooling efficiency, the cross-sectional area of the coolant flow path can be widened while avoiding a decrease in cooling performance. As a result, according to the heat sink 102 of this example, it is possible to more effectively suppress an increase in pressure loss and further improve the cooling performance. In addition, the heat sink 102 of this example can have the same effects as those of the first example.

(Example 3)
This example is an example of a heat exchanger 4 having a heat sink 1 . As shown in FIGS. 7 and 8 , the heat exchanger 4 of this example has a heat sink 1 and a jacket 5 that holds the heat sink 1 . As shown in FIG. 8, the jacket 5 includes a bottom wall portion 51 arranged to face the fins 3 of the heat sink 1 and an outer peripheral edge portion of the bottom wall portion 51 to hold the base plate 2 of the heat sink 1 . and a peripheral wall portion 52 that

As shown in FIGS. 8 and 9 , the refrigerant flow path 41 of the heat exchanger 4 is composed of a space surrounded by the base plate 2 , the bottom wall portion 51 and the peripheral wall portion 52 . In addition, the peripheral wall portion 52 has a refrigerant introduction port 521 for introducing the refrigerant into the refrigerant flow path 41 from the outside of the heat exchanger 4 and a refrigerant outlet port for discharging the refrigerant from the refrigerant flow path 41 to the outside of the heat exchanger 4. 522 are provided.

As shown in FIG. 9 , the coolant introduction port 521 is arranged at a position facing the fin 3 a arranged at one end in the first direction X among the plurality of fins 3 . The coolant outlet port 522 faces the fin 3 b arranged at the other end in the first direction X among the plurality of fins 3 and is arranged at a position different from the coolant inlet port 521 in the second direction Y.

The jacket 5 of this example is made of an aluminum material, and has a bottomed box shape composed of a bottom wall portion 51 and a peripheral wall portion 52 . As shown in FIG. 8 , a stepped portion 523 for holding the base plate 2 of the heat sink 1 is formed on the top surface of the peripheral wall portion 52 . The flange surface 22 of the base plate 2 is arranged on the stepped portion 523 . The space between the peripheral wall portion 52 and the base plate 2 is liquid-tightly sealed. The peripheral wall portion 52 and the base plate 2 may be joined by, for example, a brazing material, an adhesive, or the like. In addition, by placing a sealing material such as an O-ring between the peripheral wall portion 52 and the base plate 2 and fastening the heat sink 1 to the jacket 5 with a fastening member such as a bolt, the gap between the peripheral wall portion 52 and the base plate 2 is reduced. may be sealed in a liquid-tight manner.

As shown in FIG. 9, the coolant introduction port 521 of this example is specifically arranged at a position facing one end of the fin 3a in the second direction Y. As shown in FIG. Also, the coolant outlet port 522 is arranged at a position facing the other end in the second direction Y of the fin 3b. That is, the coolant inlet port 521 is arranged at one of the corners of the coolant channel 41, and the coolant outlet port 522 is arranged at a corner opposite to the corner where the coolant inlet port 521 is arranged. .

Since the heat exchanger 4 of this example is arranged such that the refrigerant inlet 521 and the refrigerant outlet 522 face the fins 3, the refrigerant flowing from the refrigerant inlet 521 can be guided between the pins 32. can be done. Between the pins 32 are the fin bases 31 slightly protruding from the base plate 2 as described above. Therefore, the fin base portion 31 agitates the coolant that is about to pass between the pins 32, thereby suppressing the development of the temperature boundary layer.

Further, by arranging the refrigerant outlet port 522 at a position shifted from the refrigerant inlet port 521 in the second direction Y, the refrigerant flowing in from the refrigerant inlet port 521 flows not only in the first direction X but also in the second direction Y. can be made In particular, the coolant inlet port 521 of this example is arranged at a position facing one end of the fin 3a in the second direction Y, and the coolant outlet port 522 is arranged at a position facing the other end of the fin 3b in the second direction Y. It is Therefore, the flow of the coolant is formed in the entire coolant channel 41, and the heat exchange efficiency between the heat sink 1 and the coolant can be enhanced.

Furthermore, by setting the cross-sectional shape of the pin 32 to any one of a square, a rectangle, and a parallelogram, the coolant flow in the direction toward the corners 321 (see FIG. 2) existing on the side surface of the pin 32 in the coolant channel 41. Can form a flow. Thereby, while improving cooling performance, the pressure loss of the heat exchanger 4 can be reduced more.

As a result, the heat exchanger 4 can improve cooling performance while suppressing an increase in pressure loss.

(Experimental example 1)
In this example, pressure loss and cooling performance are evaluated by thermal fluid analysis simulation when the dimensions of the fin base 31 and the pin 32 in the heat sink 1 are variously changed. The structural model used for the analysis includes the spacing Wb between the fin bases 31, the spacing Wp between the pins 32, the height Hb of the fin bases 31, the height Hp of the pins 32, the thickness A of the fin bases 31, and in the second direction Y Example 3 is the same as Example 3 except that the width Hp of the pin 32 is set to the value shown in Table 1.

Among the structural models shown in Table 1, the fins 3 of models 1, 5, 9, 13, and 17 are not partitioned into a plurality of pins 32 by slits, and have a plate shape. Further, the fin of the model 31 does not have the fin base 31 and the pin 32 protrudes from the base plate 2 .

Specifically, the physical property values used for the analysis are as follows.
Refrigerant: 50% ethylene glycol aqueous solution (temperature 20°C, density 1057.4 kg/m ³ , viscosity 8.8 × 10 ^-4 Pa·s, specific heat 3349.2 K/(kg·K), thermal conductivity 0.411 W /(m・K))
・Refrigerant temperature: 20°C
・Refrigerant flow rate: 10 L/min
・The amount of heat generated by the heating element: 100W

In the thermal fluid analysis, six heat generating elements are arranged on the heat generating element mounting surface 21 of each structural model, and the coolant is flowed through the coolant flow paths 41 . Then, the value of the pressure loss ΔP [kPa] and the value of the thermal resistance Rth [K/W] in the steady state are calculated. The value of the pressure loss ΔPa is a value obtained by subtracting the pressure of the refrigerant at the refrigerant outlet port 522 from the refrigerant pressure at the refrigerant inlet port 521 . Also, the value of the thermal resistance Rth [K/W] is a value calculated by the following formula using the maximum temperature Tmax [° C.] of the heating element mounting surface 21 .
Rth = (Tmax-20)/100

Table 1 shows the value of ΔP and the value of Rth in each structural model. In the evaluation of pressure loss, when the value of ΔP is 60.0 kPa or less, the symbol "A" is displayed in the "evaluation" column, and when the value is greater than 60.0 kPa and 66.0 kPa or less, the symbol "B" is higher than 66.0 kPa. The symbol "C" is indicated when Then, the cases of symbols "A" and "B" in which the value of ΔP was 66.0 kPa or less were judged to be acceptable because the increase in pressure loss could be suppressed.

In the evaluation of the cooling performance, when the value of Rth is 0.155 K / W, the symbol "A" is displayed in the "evaluation" column, and when it exceeds 0.155 K / W and is 0.175 K / W or less, the symbol "B", 0 The symbol "C" is given when higher than 0.175 K/W. The cases of symbols "A" and "B" having an Rth value of 0.175 K/W or less were judged to be acceptable because they had excellent cooling performance.

In the "Comprehensive evaluation" column, the symbol "A" is given when both the pressure loss and cooling performance are "A", one of the pressure loss and cooling performance is "B", and the other is "A" or The symbol "B" is given for "B", and the symbol "C" is given for at least one of pressure loss and cooling performance "C".

Comparing the structural models shown in Table 1 in which the spacing Wb between the fin bases 31 is the same, the structural model in which the fins 3 are provided with slits and divided into a plurality of pins 32 is the fin 3 having no slits. It can be understood that the thermal resistance tends to be smaller than that of In the structural model in which the fins 3 are provided with slits, the interval Wp between the pins 32 is narrower than the interval Wb between the fin bases 31, and the ratio of the height Hb of the fin bases 31 to the height Hp of the pins 32 is Hb/ A structural model in which Hp satisfies 0<Hb/Hp<0.20 can suppress an increase in pressure loss ΔP compared to a structural model that does not satisfy these conditions.

Therefore, the interval Wp between the pins 32 is narrower than the interval Wb between the fin bases 31, and the ratio Hb/Hp of the height Hb of the fin bases 31 to the height Hp of the pins 32 is 0<Hb/Hp<0.20. According to the heat sink 1 that fills, it is possible to improve the cooling performance while suppressing an increase in pressure loss.

Among these structural models, in particular, the thickness A of the fin base 31 is 1.5 mm to 2.5 mm, the width B of the pins 32 is 1.1 to 1.6 mm, and the interval Wp between the pins 32 is 0.5 mm. 8 to 1.8 mm, the interval Wb between the fin bases 31 is 1.0 to 2.4 mm, and the ratio Wp/Wb of the interval Wp between the pins 32 to the interval Wb between the fin bases 31 is 0<Wp/ Structural models 6, 10, and 11 that satisfy Wb<0.80 can further reduce thermal resistance and pressure loss than structural models that do not satisfy any of these conditions.

Therefore, the thickness A of the fin base 31 is 1.5 mm to 2.5 mm, the width B of the pin 32 is 1.1 to 1.6 mm, and the interval Wp between the pins 32 is 0.8 to 1.8 mm. The interval Wb between the fin bases 31 is 1.0 to 2.4 mm, and the ratio Wp/Wb of the interval Wp between the pins 32 to the interval Wb between the fin bases 31 is 0<Wp/Wb<0.80. The heat sink 1 that satisfies can further improve the cooling performance.

The heat sink 1, the manufacturing method thereof, and the heat exchanger 4 according to the present invention are not limited to the embodiments and experimental examples described above, and may be modified as appropriate without departing from the scope of the present invention. can.

Reference Signs List 1, 102 heat sink 2 base plate 21 heating element mounting surface 3, 303 fins 31, 33 fin base 32, 34 pins

Claims (5)

a base plate having a rectangular shape in plan view in the thickness direction and having a heating element mounting surface on which the heating element is mounted;
a plurality of fins arranged on the back surface of the heating element mounting surface of the base plate,
The fins are
Protruding from the base plate, arranged at intervals in a first direction parallel to one side of the outer peripheral edge of the base plate, and extending in a second direction orthogonal to the first direction a fin base;
a plurality of pins projecting from the fin base and spaced apart in the second direction;
the interval Wp between the pins in the second direction is narrower than the interval Wb between the fin bases in the first direction;
A heat sink wherein a ratio Hb/Hp of the height Hb of the fin base to the height Hp of the pin satisfies 0<Hb/Hp<0.20. The thickness of the fin is 1.5 mm to 2.5 mm, the width of the pin in the second direction is 1.1 to 1.6 mm, and the interval Wp between the pins is 0.8 to 1.8 mm. The interval Wb between the fin bases is 1.0 to 2.4 mm, and the ratio Wp/Wb of the interval Wp between the pins to the interval Wb between the fin bases is 0<Wp/Wb<0.80. The heat sink of claim 1, filling. A heat exchanger comprising the heat sink according to claim 1 or 2 and a jacket holding the heat sink,
The jacket is
a bottom wall portion disposed facing the fins of the heat sink;
a peripheral wall portion erected from an outer peripheral edge portion of the bottom wall portion and holding a base plate of the heat sink;
a coolant flow path composed of a space surrounded by the base plate, the bottom wall portion, and the peripheral wall portion;
a coolant introduction port arranged in the peripheral wall portion at a position facing a fin arranged at one end in the first direction among the plurality of fins;
a coolant outlet facing the fin arranged at the other end of the plurality of fins in the first direction in the peripheral wall portion and arranged at a position different from the coolant inlet in the second direction; , a heat exchanger. The coolant inlet is arranged at a position facing one end of the fin in the second direction, and the coolant outlet is arranged at a position facing the other end of the fin in the second direction. Item 4. The heat exchanger according to item 3. A method for manufacturing a heat sink according to claim 1 or 2,
By extrusion molding, an extruded profile including the base plate and a plurality of pre-finned portions protruding from the base plate and having a plate shape and spaced apart from each other in a direction perpendicular to the extrusion direction is manufactured. ,
A method of manufacturing a heat sink, wherein the fins are formed by cutting the plurality of pre-finned portions along a straight line extending in a direction different from the extrusion direction.

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