JP2020141047A - Heat sink and electronics - Google Patents

Abstract

To provide a heat sink capable of suppressing an increase in manufacturing costs and having excellent cooling performance, and an electronic device including the same.SOLUTION: A heat sink 1 comprises: a heat sink body 2 that includes a base plate 21 including a heating element mounting surface 211 on which a heating element is mounted and having a flat plate shape, and a plurality of pin fins 22 erected on a back surface 212 of the heating element mounting surface 211; and a flow path adjusting member 3 that is detachably attached to a gap 221 between the pin fins 22 and closes at least a part of the gap 221 between the pin fins 22.SELECTED DRAWING: Figure 3

Description

The present invention relates to heat sinks and electronic devices.

For example, in electronic devices such as power converters, heat sinks are used to cool heating elements such as semiconductor elements. As the heat sink, a so-called pin fin type heat sink in which a large number of pins are erected from a base plate having a flat plate shape may be used.

The pin fin type heat sink is usually manufactured by a method such as forging, casting, or cutting. The pins in the heat sink produced in this way are often arranged so that the distance between the pins is constant (for example, Patent Document 1).

However, from the viewpoint of further improving the cooling performance, it may be better that the distance between the pins differs depending on the position on the heat sink. For example, Patent Document 2 describes a heat radiating plate with a pin having a base plate and a plurality of comb-toothed heat radiating pin members joined to the base plate. The plurality of pins in the heat radiating pin member are arranged so as to increase the pin density of the portion corresponding to the back of the electronic component mounting position in the central portion of the base plate member and decrease the pin density of the peripheral portion thereof.

Japanese Unexamined Patent Publication No. 2014-82466 Japanese Unexamined Patent Publication No. 2015-226039

In order to improve the cooling performance of the heat sink, it is preferable to arrange the pins of the heat sink at the optimum positions according to the position where the heating element is mounted and the position where the refrigerant flows in and out. However, there are various aspects of the mounting position of the heating element on the heat sink. Therefore, for example, as in Patent Document 2, if the pin arrangement is changed according to the mounting position of the heating element, it is necessary to make various heat sinks having different pin arrangements, which may lead to an increase in manufacturing cost.

The present invention has been made in view of such a background, and an object of the present invention is to provide a heat sink which can suppress an increase in manufacturing cost and has excellent cooling performance and an electronic device provided with the heat sink.

One aspect of the present invention is a heat sink main body including a base plate having a flat plate shape and a plurality of pin fins erected on the back surface of the base plate.
A heat sink having a flow path adjusting member that is detachably attached to a gap between the pin fins and closes at least a part of the gap.

The flow path adjusting member of the heat sink is detachably attached to a gap between pin fins. Therefore, the position of the flow path adjusting member can be set according to the position where the heating element is mounted, the position where the refrigerant flows in and out, and the like. Then, by arranging the flow path adjusting member at an appropriate position according to the mounting position of the heating element or the like, the heating element can be efficiently cooled.

Further, since the flow path adjusting member of the heat sink can adjust the flow path of the refrigerant, it is not necessary to change the arrangement of the pin fins according to the mounting position of the heating element or the like. Therefore, according to the heat sink, the number of pin fin arrangement patterns can be reduced, and an increase in manufacturing cost can be suppressed.

As described above, the heat sink can suppress an increase in manufacturing cost and has excellent cooling performance.

FIG. 1 is an exploded perspective view of the heat sink according to the first embodiment. FIG. 2 is a bottom view of the heat sink according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is a perspective view of the flow path adjusting member exhibiting a substantially X shape in the first embodiment. FIG. 5 is a perspective view of the flow path adjusting member exhibiting a substantially zigzag shape in the second embodiment. FIG. 6 is an exploded perspective view of the electronic device according to the third embodiment. FIG. 7 is a top view of the electronic device according to the third embodiment. FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. FIG. 9 is a bottom view of the heat sink according to the third embodiment.

The heat sink body of the heat sink is made of a material having excellent thermal conductivity. The heat sink body may be made of, for example, aluminum, an aluminum alloy, copper, or a copper alloy.

The heat sink main body has a base plate having a flat plate shape, and a plurality of pin fins erected on the back side surface of the base plate. The heat sink body can be manufactured, for example, by forging or cutting.

A heating element mounting surface on which the heating element is mounted is provided on one surface of the base plate in the thickness direction. The heating element mounted on the heating element mounting surface may be, for example, a semiconductor element constituting a power conversion circuit or the like.

A plurality of pin 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 arrangement of the pin fins can take various forms, but from the viewpoint of increasing the degree of freedom in the arrangement of the heating element, it is preferable that the plurality of pin fins are arranged at equal intervals. In this case, since the number of pins per unit area on the back surface of the heating element mounting surface is constant, the pins arranged directly under the heating element regardless of the mounting position of the heating element on the heating element mounting surface. The number can be increased sufficiently. Therefore, in this case, the degree of freedom in arranging the heating element can be increased without impairing the cooling performance.

Further, each pin fin may have a columnar shape or a square columnar shape. The above-mentioned "cylindrical column" includes a columnar shape having a circular cross-sectional shape in a cross section parallel to the plate surface of the base plate, a columnar shape having an elliptical shape, and a columnar shape having an oval shape. Further, the "square columnar" includes a columnar having a square cross-sectional shape, a columnar having a rectangular shape, a columnar having a rhombus, a columnar having a parallelogram, and the like.

The pin fins preferably have a square columnar shape. In this case, in a state where the flow path adjusting member is attached to the gap between the pin fins, the displacement and vibration of the flow path adjusting member can be suppressed more effectively.

A flow path adjusting member is detachably attached to the gap between the pin fins. The flow path adjusting member may be arranged so as to completely close the gap formed between the adjacent pin fins, or may be arranged so as to close a part of the gap.

The flow path adjusting member is preferably made of the same metal as the insulator or the heat sink body. That is, for example, when the heat sink body is made of aluminum, the flow path adjusting member is preferably made of an insulator or aluminum. Further, for example, when the heat sink body is made of an aluminum alloy, it is preferable that the flow path adjusting member is made of an insulator or the same aluminum alloy as the heat sink body. In this case, it is possible to prevent the formation of a local battery between the heat sink main body and the flow path adjusting member, and suppress the electrolytic corrosion of the heat sink main body and the flow path adjusting member.

The shape of the flow path adjusting member can be appropriately set according to the arrangement of the pin fins. For example, a first straight line portion in which the gap between the pin fins extends in a first direction and a second straight line portion extending in a second direction different from the first direction. When formed in a grid pattern with the above, the flow path adjusting member is connected to the first closed portion arranged in the first straight line portion and the first closed portion, and is arranged in the second straight line portion. It is preferable to have a second closed portion. That is, it is preferable that the flow path adjusting member has a substantially L-shaped portion including a first closed portion and a second closed portion.

In this case, the heat sink body 2 can hold the first closed portion between the pin fins adjacent to each other in the second direction, and can hold the second closed portion between the pin fins adjacent to each other in the first direction. As a result, the displacement of the flow path adjusting member due to the pressure received from the refrigerant or the like can be suppressed in both the first direction and the second direction, and the flow path adjusting member can be easily held at a desired position.

From the same viewpoint, the flow path adjusting member includes a third closing portion extending in the first direction from the connecting portion between the first closing portion and the second closing portion, and the second closing portion from the connecting portion. It is more preferable to have a fourth closed portion extending in the direction of. That is, it is preferable that the flow path adjusting member has a substantially X-shaped portion including a first closed portion, a second closed portion, a third closed portion, and a fourth closed portion.

In this case, for example, when the flow path adjusting member is pressed in the second direction by the pressure received from the refrigerant or the like, the first closed portion extending from the connecting portion to one side in the first direction and the other side The flow path adjusting member can be supported by two closing portions with the extending third closing portion. Similarly, when the flow path adjusting member is pressed in the first direction by the pressure received from the refrigerant or the like, it extends from the connecting portion to the second closing portion extending to one side in the second direction and to the other side. The flow path adjusting member can be supported by the two closing portions with the fourth closing portion.

As described above, according to the flow path adjusting member having a substantially X-shaped portion, each of the four closed portions extending from the connecting portion can be held by the pin fins around the connecting portion. As a result, the displacement of the flow path adjusting member can be suppressed more effectively.

The heating element mounted on the heat sink may be directly bonded to the heating element mounting surface, or another member may be interposed between the heating element mounting surface and the heating element. Members that can intervene between the heating element mounting surface and the heating element include, for example, a circuit board in which metal plates are bonded to both sides of a ceramic plate, or a relatively soft material such as pure aluminum, which exerts thermal stress. There is a stress relaxation plate to relax.

When a circuit board is provided between the heating element mounting surface and the heating element, the circuit board can be directly joined on the heating element mounting surface. That is, the heat sink includes a back metal layer bonded to the heating element mounting surface of the base plate, a ceramic plate laminated on the back metal layer, and a circuit metal layer laminated on the ceramic plate. You may have a circuit board provided with.

When joining the circuit board to the heating element mounting surface of the heat sink body, a method such as brazing or diffusion joining is used. Since the heat sink body and the circuit board are heated by these methods, the heat sink body and the circuit board during the bonding are thermally expanded as compared with those before the bonding. At this time, by joining the heat sink body and the circuit board with the flow path adjusting member removed from the heat sink body, the heat sink body can be thermally expanded without being restrained by the flow path adjusting member. As a result, the generation of strain due to thermal expansion can be suppressed.

Then, by cooling these after the bonding between the heat sink body and the circuit board is completed, the heat sink body and the circuit board can be contracted without being restrained by the flow path adjusting member, and the waviness of the circuit metal layer can be reduced. it can. As a result, deterioration of the flatness of the circuit board can be suppressed, and the heating element can be mounted more easily.

An electronic device can be configured by mounting the heating element on the heating element mounting surface of the heat sink and accommodating the pin fins in the jacket. Such electronic devices
With the heat sink of the above aspect,
A jacket including a bottom wall portion facing the pin fins and a peripheral wall portion arranged around the bottom wall portion and facing the base plate.
A refrigerant flow path composed of a space surrounded by the base plate and the jacket,
It has a heating element arranged on the heating element mounting surface.

In the electronic device of the above aspect, it is preferable that the flow path adjusting member is arranged so as to guide the refrigerant into the gap between the pin fins arranged directly under the heating element. The pin fins arranged directly under the heating element are more likely to transfer heat from the heating element than the pin fins arranged at a position away from directly under the heating element. Therefore, more refrigerant can flow through the pin fins arranged directly under the heating element, and the heat of the pin fins can be removed more efficiently. As a result, the heating element can be cooled more efficiently.

In the electronic device, it is preferable that the heat sink is detachably held on the jacket. In this case, for example, when a defect occurs in the heating element, the heat sink, or the jacket, the heat sink can be removed from the jacket and the defective component can be easily replaced.

(Example 1)
Examples of the heat sink will be described with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 3, the heat sink 1 includes a base plate 21 having a heating element mounting surface 211 on which the heating element is mounted and having a flat plate shape, and a plurality of heat sinks erected on the back surface 212 of the heating element mounting surface 211. The heat sink body 2 provided with the pin fins 22 and the gap 221 between the pin fins 22 are detachably attached to each other, and as shown in FIGS. 2 and 3, at least a part of the gap 221 between the pin fins 22 is closed. It has a road adjusting member 3. Hereinafter, the configuration of the heat sink 1 of this example will be described in detail.

As shown in FIG. 1, the heat sink main body 2 of this example has a base plate 21 and pin fins 22. The heat sink main body 2 may be composed of, for example, a 6000 series aluminum alloy such as JIS A6063 alloy or a 3000 series aluminum alloy such as JIS A3003 alloy.

As shown in FIG. 1, the base plate 21 has a rectangular shape in a plan view when viewed from the thickness direction. The dimensions of the base plate 21 in the vertical direction (long side direction) and the horizontal direction (short side direction) are not particularly limited. For example, the base plate 21 of this example has a vertical dimension (long side direction) of 100 mm and a horizontal direction (short side direction) of 90 mm.

Further, a through hole 213 penetrating in the thickness direction is provided at a corner portion of the base plate 21 of this example. The base plate 21 is configured so that, for example, a fastening member such as a bolt can be inserted into the through hole 213 and the heat sink 1 and a peripheral device such as a jacket can be mechanically fastened via the fastening member.

As shown in FIG. 3, a heating element mounting surface 211 is provided on one plate surface in the thickness direction of the base plate 21. Specifically, the heating element mounting surface 211 of this example is arranged at the center of the base plate 21 in a plan view viewed from the thickness direction. Further, around the heating element mounting surface 211, an outer frame portion 214 protruding from the heating element mounting surface 211 on the side opposite to the pin fin 22 is provided. The thickness of the base plate 21 on the heating element mounting surface 211 is 0.4 mm, and the thickness of the outer frame portion 214 is 4 mm. The base plate 21 does not have to have the outer frame portion 214. Further, the thickness of the base plate 21 and the thickness of the outer frame portion 214 on the heating element mounting surface 211 are not limited to this example, and can be changed as appropriate.

As shown in FIG. 3, the circuit board 4 is arranged on the heating element mounting surface 211 of the heat sink 1 of this example. The circuit board 4 has a back surface metal layer 41 joined on the heating element mounting surface 211, a ceramic plate 42 laminated on the back surface metal layer 41, and a circuit metal layer 43 laminated on the ceramic plate 42. are doing. As a method of joining the base plate 21 and the back surface metal layer 41, for example, a method such as brazing or diffusion joining can be adopted. The base plate 21 of this example and the back surface metal layer 41 are joined by diffusion bonding. Although not shown in the figure, the heating element is mounted on the circuit metal layer 43.

The back surface metal layer 41 and the circuit metal layer 43 may be made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy. Further, the thickness of the back surface metal layer 41 and the circuit metal layer 43 can be appropriately set from the range of 0.1 to 1.0 mm, for example. The back surface metal layer 41 and the circuit metal layer 43 of this example are specifically made of copper and each have a thickness of 0.7 mm.

A ceramic plate 42 is interposed between the back surface metal layer 41 and the circuit metal layer 43. The ceramic plate 42 may be made of, for example, an oxide-based ceramic such as alumina or a nitride-based ceramic such as aluminum nitride or silicon nitride. Specifically, the ceramic plate 42 of this example is made of silicon nitride and has a thickness of 0.32 mm.

As shown in FIGS. 2 and 3, a plurality of pin fins 22 having a square columnar shape are erected on the back surface 212 of the heating element mounting surface 211 of the base plate 21. The pin fin 22 of this example has a rhombus shape with a side of 3.3 mm in a cross section parallel to the heating element mounting surface 211 of the base plate 21.

Further, as shown in FIG. 2, the pin fins 22 are arranged so that the side surfaces 222 face each other at a distance from each other. As a result, between the pin fins 22, a first straight line portion 221a that exhibits a linear shape extending in the first direction D1 and a first direction D1 in a plan view seen from the thickness direction of the base plate 21. Is formed with a grid-like gap 221 having a second straight line portion 221b extending in a different second direction D2.

The angle formed by the first direction D1 and the short side of the base plate 21 in this example is 34 °, and the angle formed by the first direction D1 and the second direction D2 is 68 °. That is, the first straight line portion 221a extends in a direction inclined by 34 ° with respect to the short side of the base plate 21, and the second straight line portion 221b extends in a direction inclined by 68 ° with respect to the first straight line portion 221a. It is set up. The angle formed by the first direction D1 and the short side of the base plate 21 is not limited to the embodiment of this example. Further, the second direction D2 may have any angle as long as it is different from the first direction D1.

The width of the gap 221 between the pin fins 22 is not particularly limited, but can be appropriately set from, for example, a range of 0.5 to 2.0 mm. The pin fins 22 of this example are arranged so that the width of the gap 221 with the adjacent pin fins 22 is 0.9 mm in both the first direction and the second direction. That is, the widths of the first straight line portion 221a and the second straight line portion 221b in the heat sink main body 2 of this example are both 0.9 mm.

A flow path adjusting member 3 is detachably attached to the gap 221 between the pin fins 22. As shown in FIGS. 2 and 4, the flow path adjusting member 3 of this example is connected to the first closed portion 31 arranged in the first straight portion 221a and the first closed portion 31, and is connected to the second straight portion 221b. It has a second closed portion 32 arranged. Further, as shown in FIG. 4, the flow path adjusting member 3 has a third closing portion 34 extending in the first direction from the connecting portion 33 between the first closing portion 31 and the second closing portion 32 and the connecting portion. It has a fourth closed portion 35 extending from 33 in the second direction. That is, the cross-sectional shape of the flow path adjusting member 3 of this example is substantially X-shaped.

As shown in FIG. 3, the height of the flow path adjusting member 3 of this example is the same as the height of the pin fin 22. Further, as shown in FIG. 2, the thickness of the first closed portion 31 to the fourth closed portion 35 is the same as the width of the gap 221 between the pin fins 22. Therefore, the flow path adjusting member 3 of this example can completely close the gap 221 between the pin fins 22 when inserted into the gap 221 between the pin fins 22.

In the heat sink 1 of this example, as shown in FIG. 2, four flow path adjusting members 3 are arranged at the center of the back surface 212 of the base plate 21, but the arrangement and number of the flow path adjusting members 3 are different. It may be appropriately set according to the position where the heating element is mounted, the position where the refrigerant flows in, the position where the refrigerant flows out, and the like.

Although not shown in the figure, for example, when the inflow position of the refrigerant and the outflow position of the refrigerant face each other, the flow path adjusting member 3 can be arranged at a position facing the inflow position of the refrigerant. In this case, the refrigerant flowing from the inflow position of the refrigerant is distributed sideways by the flow path adjusting member 3, and the bias of the refrigerant flow in the heat sink 1 can be reduced.

Next, the action and effect of the heat sink 1 of this example will be described. As shown in FIG. 1, the flow path adjusting member 3 of the heat sink 1 is detachably attached to the gap 221 between the pin fins 22. Therefore, the flow path adjusting member 3 can be mounted at an appropriate position according to the position where the heating element is mounted, the position where the refrigerant flows in, the position where the refrigerant flows out, and the like. Then, by arranging the flow path adjusting member 3 at an appropriate position according to the mounting position of the heating element or the like, the heating element can be efficiently cooled.

Further, since the heat sink 1 can adjust the flow path of the refrigerant by the flow path adjusting member 3, it is not necessary to change the arrangement of the pin fins 22 according to the mounting position of the heating element or the like. Therefore, according to the heat sink 1, the number of arrangement patterns of the pin fins 22 can be reduced, and an increase in manufacturing cost can be suppressed.

As described above, the heat sink 1 can suppress an increase in manufacturing cost and has excellent cooling performance.

As shown in FIG. 2, the gap 221 between the pin fins 22 in the heat sink main body 2 of this example is different from the first straight line portion 221a which has a linear shape extending in the first direction D1 and the first direction D1. It is formed in a grid pattern including a second straight line portion 221b extending in the second direction D2 and exhibiting a straight line shape. Further, as shown in FIGS. 2 and 4, the flow path adjusting member 3 is connected to the first closed portion 31 arranged in the first straight line portion 221a and the first closed portion 31, and is arranged in the second straight line portion 221b. It has a second closed portion 32 and the like.

Further, the flow path adjusting member 3 has a third closing portion 34 extending in the first direction D1 from the connecting portion 33 between the first closing portion 31 and the second closing portion 32, and a second direction from the connecting portion 33. It has a fourth closed portion 35 extending to D2. That is, the flow path adjusting member 3 of this example has a substantially X-shaped portion including a first closed portion 31, a second closed portion 32, a third closed portion 34, and a fourth closed portion 35.

As shown in FIG. 2, the first closed portion 31 and the third closed portion 34 are held between adjacent pin fins 22 in the second direction D2. Further, the second closed portion 32 and the fourth closed portion 35 are held between adjacent pin fins 22 in the first direction D1.

Therefore, for example, when the flow path adjusting member 3 is pressed in the second direction D2 by the pressure received from the refrigerant or the like, the first closed portion 31 extending from the connecting portion 33 to one side in the first direction D1. The flow path adjusting member 3 can be supported by two closing portions with the third closing portion 34 extending to the other side. Similarly, when the flow path adjusting member 3 is pressed in the first direction D1 by the pressure received from the refrigerant or the like, the second closing portion 32 extending from the connecting portion 33 to one side in the second direction D2 The flow path adjusting member 3 can be supported by two closing portions with the fourth closing portion 35 extending to the other side.

As described above, according to the flow path adjusting member 3 having a substantially X-shaped portion, each of the four closed portions 31, 32, 34, and 35 extending from the connecting portion 33 is formed around the connecting portion 33. It can be held by the pin fins 22. As a result, the misalignment of the flow path adjusting member 3 can be suppressed more effectively.

The heat sink 1 includes a back metal layer 41 bonded on the heating element mounting surface 211 of the base plate 21, a ceramic plate 42 laminated on the back metal layer 41, and a circuit metal layer 43 laminated on the ceramic plate 42. It has a circuit board 4 provided with and. In producing the heat sink 1 of this example, the heat sink body 2 and the circuit board 4 may be joined in a state where the flow path adjusting member 3 is removed from the heat sink body 2. As a result, the heat sink body 2 can be thermally expanded without being restrained by the flow path adjusting member 3. As a result, the generation of strain due to thermal expansion can be suppressed.

Then, by cooling these after the bonding between the heat sink main body 2 and the circuit board 4 is completed, the heat sink main body 2 and the circuit board 4 are contracted without being restrained by the flow path adjusting member 3, and the circuit metal layer 43 Waviness can be reduced. As a result, deterioration of the flatness of the circuit board can be suppressed, and the heating element can be mounted more easily.

(Example 2)
In this example, as an example of another aspect of the flow path adjusting member, the configuration of the flow path adjusting member 302 will be described with reference to FIG. Of the codes used in the examples after this example, those having the same code as those used in the above-mentioned examples indicate the same components and the like as those in the above-mentioned examples unless otherwise specified.

The flow path adjusting member may take various forms other than the substantially X-shape shown in FIG. For example, as shown in FIG. 5, the flow path adjusting member 302 may have a substantially zigzag shape in which the first closed portion 31 and the second closed portion 32 are alternately connected via the connecting portion 33. The flow path adjusting member 302 of this example may be used in combination with the flow path adjusting member 3 shown in FIG. 4, or the flow path adjusting member 302 of this example may be used alone. The flow path adjusting member 302 of this example is configured so as to be detachably attached to the gap 221 (see FIG. 2) between the pin fins 22 like the flow path adjusting member 3 of FIG. Therefore, the heat sink 1 provided with the flow path adjusting member 302 of this example can exert the same action and effect as that of the first embodiment.

(Example 3)
This example is an example of an electronic device 5 provided with a heat sink 1. As shown in FIG. 6, the electronic device 5 of this example has a heat sink 1 and a jacket 6. As shown in FIGS. 6 and 8, the jacket 6 has a bottom wall portion 61 facing the plurality of pin fins 22 and a peripheral wall portion 62 arranged around the bottom wall portion 61 and facing the base plate 21. are doing. As shown in FIG. 8, a refrigerant flow path 63 composed of a space surrounded by the base plate 21 and the jacket 6 is formed between the base plate 21 and the jacket 6. Further, the heating element 7 is arranged on the heating element mounting surface 211 of the base plate 21. Then, as shown in FIG. 9, the flow path adjusting member 3 is arranged so as to guide the refrigerant into the gap 221 between the pin fins 22 arranged directly below the heating element 7.

The jacket 6 of this example is made of an aluminum material, and as shown in FIGS. 6 and 8, the bottom wall portion 61 and the four peripheral wall portions 62 (62a) arranged on the outer peripheral edge portion of the bottom wall portion 61. It has a bottomed box shape consisting of ~ 62d). The above-mentioned "aluminum material" includes aluminum and aluminum alloys.

The base plate 21 of the heat sink 1 is placed on the top surface 621 of the peripheral wall portion 62. As shown in FIG. 7, of the four peripheral wall portions 62a to 62d, two peripheral wall portions 62a and 62c extend in a direction parallel to the long side of the base plate 21, and the remaining two peripheral wall portions 62b , 62d extend in a direction parallel to the short side of the base plate 21. The lengths of the peripheral wall portions 62b and 62d arranged along the short sides of the base plate 21 are shorter than the lengths of the peripheral wall portions 62a and 62c arranged along the long sides.

The top surface 621 of the peripheral wall portion 62 is provided with a groove portion 622 (see FIG. 8) extending along the inner peripheral edge of the peripheral wall portion 62. As shown in FIGS. 6 and 8, an O-ring 623 is held in the groove. The O-ring 623 is interposed between the base plate 21 and the peripheral wall portion 62, and can tightly seal the gap between the two.

Further, as shown in FIG. 6, a fastening hole 624 for fastening the base plate 21 is provided on the outer side of the groove portion 622. The fastening hole 624 is arranged at the same position as the through hole of the base plate 21 placed on the peripheral wall portion 62. In the jacket 6 of this example, as shown in FIG. 6, the heat sink 1 is inserted through the bolt 625 by inserting the bolt 625 as a fastening member into the through hole 213 of the base plate 21 and the fastening hole 624 of the peripheral wall portion 62. It can be held detachably.

The pin fins 22 and the flow path adjusting member 3 of the heat sink 1 are arranged in the refrigerant flow path 63 including the space surrounded by the base plate 21, the bottom wall portion 61, and the peripheral wall portion 62. As shown in FIG. 8, a gap 611 is formed between the bottom wall portion 61, the bottom wall portion 61, and the tip 222 of the pin fin 22. The gap 611 between the bottom wall portion 61 and the pin fins 22 is preferably narrower than the gap 221 between the pin fins 22. In this case, it is possible to prevent the refrigerant from flowing into the gap 611 between the bottom wall portion 61 and the pin fin 22. As a result, the refrigerant can flow more easily into the gap 221 between the pin fins 22, and the cooling performance can be improved.

As shown in FIGS. 6 to 8, the jacket 6 of this example has a refrigerant introduction port 631 that supplies a refrigerant from the outside of the electronic device 5 to the refrigerant flow path 63, and a refrigerant from the refrigerant flow path 63 to the outside of the electronic device 5. It has a refrigerant outlet 632 and a refrigerant outlet 632. The refrigerant introduction port 631 is provided at the center of the peripheral wall portion 62a arranged along one long side of the base plate 21 among the four peripheral wall portions 62. Further, the refrigerant outlet 632 is provided at the center of the peripheral wall portion 62c facing the peripheral wall portion 62a having the refrigerant introduction port 631.

A circuit board 4 is bonded to the heating element mounting surface 211 of the heat sink 1 of this example. As shown in FIG. 7, the circuit board 4 has two circuit metal layers 43 extending in a direction parallel to the long side of the base plate 21 and arranged at intervals from each other. Further, three heating elements 7 arranged at intervals in the direction parallel to the long side of the base plate 21 are joined to each circuit metal layer 43. Specifically, the heating element 7 of this example is a semiconductor element. Each semiconductor element has a square shape. In the following, for convenience, the heating element 7 arranged in the upper left of FIG. 7 is referred to as a first heating element 7a, and the second heating element 7b and the third heating element 7c are sequentially turned counterclockwise from the first heating element 7a. , The fourth heating element 7d, the fifth heating element 7e, and the sixth heating element 7f.

As shown in FIG. 9, the flow path adjusting member 3 of this example is arranged so that the refrigerant is less likely to flow between the heating elements 7 adjacent to each other in the long side direction of the base plate 21. More specifically, the flow path adjusting member 3 in the heat sink 1 of this example has a side 71 (see FIG. 7) parallel to the short side of the base plate 21 in each heating element 7 and the refrigerant introduction port 631 side of this side 71. It is arranged along the line segment 72 connecting the ends of the. As a result, the refrigerant flowing in from the refrigerant introduction port 631 can be guided to the gap 221 between the pin fins 22 arranged directly under the heating element 7.

The effect of improving the cooling performance by arranging the flow path adjusting member 3 as in this example can be compared by, for example, the following thermo-fluid simulation.

First, a structural model of the electronic device 5 of this example is prepared, and a 50% ethylene glycol aqueous solution as a refrigerant is supplied from the refrigerant introduction port 631. The temperature of the refrigerant is 60 ° C., and the flow rate of the refrigerant is 10 L / min. Then, the temperature of the heating element 7 in the steady state is calculated when the calorific value of each of the heating elements 7a to 7f is 100 W.

Table 1 shows the temperature of each heating element 7 when the flow path adjusting member 3 is arranged as in this example, and the temperature of each heating element 7 when the flow path adjusting member 3 is not arranged.

As shown in Table 1, by guiding the refrigerant directly under the heating element 7 by the flow path adjusting member 3, the temperature of the heating element 7 can be lowered as compared with the case where the flow path adjusting member 3 is not attached. From these results, it can be understood that the cooling performance can be further improved by guiding the refrigerant directly under the heating element 7 by the flow path adjusting member 3.

The aspects of the heat sink 1 and the electronic device 5 of the present invention are not limited to the embodiments of Examples 1 to 3, and the configurations can be appropriately changed as long as the gist of the present invention is not impaired. For example, in Examples 1 to 3, the heat sink main body 2 provided with the square columnar pin fins 22 is shown, but the shape of the pin fins 22 is not limited to this, and the flow path adjusting member 3 is attached. I wish I could.

As described above, the arrangement of the flow path adjusting member 3 can be appropriately set according to the position of the heating element 7, the position of the refrigerant introduction port 631, the position of the refrigerant outlet port 632, and the like. For example, when the flow velocity of the refrigerant is uneven without the flow path adjusting member 3, by arranging the flow path adjusting member 3 in the portion where the flow velocity of the refrigerant is high, the uneven flow velocity is suppressed and the entire heat sink 1 is used. Can also be cooled uniformly.

The flow path adjusting member 3 may be arranged at a desired position when the heat sink 1 is attached to the electronic device 5. In the state of the heat sink 1 alone, the flow path adjusting member 3 may be arranged at any position. Further, in the state of the heat sink 1 alone, the flow path adjusting member 3 may be removed from the heat sink main body 2. In any case, if the flow path adjusting member 3 is arranged at a desired position when it is attached to the electronic device 5, the effect of improving the cooling performance can be exhibited.

1 Heat sink 2 Heat sink body 21 Base plate 211 Heating element mounting surface 212 Back 22 Pin fins 221 Gap 3 Flow path adjusting member

Claims (5)

A heat sink main body having a base plate having a heating element mounting surface on which a heating element is mounted and having a flat plate shape, and a plurality of pin fins erected on the back surface of the heating element mounting surface.
A heat sink having a flow path adjusting member that is detachably attached to a gap between the pin fins and closes at least a part of the gap. The gap is a lattice having a first straight line portion extending in a first direction and a second straight line portion extending in a second direction different from the first direction. The flow path adjusting member is formed in a shape, and the flow path adjusting member is connected to a first closed portion arranged in the first straight line portion and a second closed portion arranged in the second straight line portion. The heat sink according to claim 1, further comprising. The flow path adjusting member extends from the connecting portion between the first closing portion and the second closing portion to the third closing portion extending in the first direction and from the connecting portion in the second direction. The heat sink according to claim 2, further comprising a fourth closed portion. The heat sink includes a circuit board including a back surface metal layer bonded on the heating element mounting surface, a ceramic plate laminated on the back surface metal layer, and a circuit metal layer laminated on the ceramic plate. The heat sink according to any one of claims 1 to 3. The heat sink according to any one of claims 1 to 4,
A jacket including a bottom wall portion facing the pin fins and a peripheral wall portion arranged around the bottom wall portion and facing the base plate.
A refrigerant flow path composed of a space surrounded by the base plate and the jacket,
Having a heating element arranged on the heating element mounting surface,
The flow path adjusting member is an electronic device arranged so as to guide a refrigerant into a gap between the pin fins arranged directly under the heating element.

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