JP2016111167A - Lamination unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency of a power card in a lamination unit configured by laminating a plurality of power cards each accommodating a semiconductor element therein and a plurality of coolers.SOLUTION: A cooler 3b of a lamination unit comprises a main body 30 and a pair of metal plates 13a and 13b. In the main body 30, openings 32a and 32b communicating to a passage Ps are provided at positions opposite to power cards 5 at both sides. Each of the metal plates closes the opening via a gasket. A plurality of fins 14a and 14b are provided on a surface of the metal plate closer to the passage, and the other side of the surface is in contact with the power card 5. A rib 31 is provided in a center of the main body 30 in an integration direction of the passage Ps. The fins of the metal plates 13a and 13b include notches 15 through which the rib 31 is passed. Between the rib 31 and the fins 14a and 14b, elastic members 33a and 33b are held by the notches 15.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a stacked unit in which a plurality of power cards and a plurality of coolers are stacked.

  A stacked unit is known in which a plurality of power cards containing a semiconductor element and a plurality of coolers are stacked, and the power cards are in contact with both sides of at least one cooler. Such a stacked unit can efficiently cool by integrating a large number of semiconductor elements. Such a laminated unit is employed in, for example, an inverter that supplies power to a traveling motor in an electric vehicle (for example, Patent Document 1).

JP2013-121236A

  The applicant of the present application has devised a laminated unit that employs a characteristic cooler (Japanese Patent Application No. 2014-189299, filed on September 17, 2014, unpublished at the time of application). The cooler is composed of a main body and a pair of metal plates. The main body is formed with a flow path through which the refrigerant flows in a direction crossing the stacking direction, and the main body is provided with an opening that communicates with the flow path on the surface facing each of the power cards on both sides. Yes. Each metal plate closes each opening. Each metal plate is provided with a plurality of fins extending along the flow direction of the refrigerant on the flow path side surface, and the opposite surface is in contact with the power card. This lamination unit is pressurized in the lamination direction, and the opening on both sides of the main body of the cooler is sealed with a gasket and a pair of metal plates by the pressure.

  In this cooler, a metal plate is used at a portion in contact with the power card, but the main body separate from the metal plate can be made of a material other than metal, for example, a resin. On the other hand, if there is a gap between the tip of the fin extending from one metal plate and the tip of the fin extending from the other metal plate inside the main body due to the intersection of the parts, the refrigerant is a gap between the flat surfaces of the fins. Since it is easier to flow through the gap, there is a risk that the loss in cooling efficiency will increase. This specification provides the technique which reduces the loss in the cooler of the said lamination | stacking unit which the applicant of this application devised.

  The laminated units targeted by the technology disclosed in this specification are as follows. The stacked unit is a device in which a plurality of power cards containing semiconductor elements and a plurality of coolers are stacked. A power card is in contact with both sides of at least one cooler. The at least one cooler includes a main body and a pair of metal plates. The main body has a flow path through which the refrigerant flows in a direction intersecting the stacking direction. The main body is provided with an opening communicating with the flow path at a position facing each of the power cards on both sides. Each of the pair of metal plates closes each opening of the main body via a gasket. Each metal plate is provided with a plurality of fins extending along the flow direction of the refrigerant on the flow path side surface, and the opposite surface is in contact with the power card. The laminated unit is pressurized in the laminating direction so that the openings on both sides of the main body are sealed with a pair of metal plates. The main body of the cooler of the laminated unit disclosed in the present specification is provided with at least one rib crossing the flow path. The at least one rib extends in a direction parallel to the pair of metal plates and intersecting the refrigerant flow direction. The rib extends from one of the opposing inner surfaces of the flow path to the other. Furthermore, the tips of the plurality of fins provided in each of the pair of metal plates are opposed to each other in the flow path, and the notches through which the ribs described above are provided are provided in the plurality of fins of each metal plate. An elastic member is sandwiched between the rib and the plurality of fins at the notch.

  In the notch, the rib and the elastic member close the gap between the tip of the fin extending from one metal plate and the tip of the fin extending from the other metal plate. Therefore, the refrigerant flowing between the tips of the fins is guided to the gap between the flat surfaces of the fins. According to said structure, the quantity of the refrigerant | coolant which flows along the flat surface of a fin can be increased, and cooling efficiency improves. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a perspective view of the lamination | stacking unit of an Example. It is a top view which shows the layout in the case of the power converter using the lamination | stacking unit of an Example. It is a disassembled perspective view of a cooler. It is sectional drawing of the cooler cut by the XY plane in a figure.

  The laminated unit of the embodiment will be described with reference to the drawings. FIG. 1 shows a perspective view of the laminated unit 2. The laminated unit 2 of the embodiment is a main component of a power converter mounted on an electric vehicle. The power converter includes a voltage converter that boosts the direct current of the battery, and an inverter that converts the boosted direct current into alternating current and supplies the alternating current to the traveling motor. The voltage converter and the inverter include a large number of switching elements (semiconductor elements) that generate a large amount of heat. The stacked unit 2 is a unit that efficiently cools these many switching elements together.

  As shown in FIG. 1, the stacked unit 2 is a unit in which a plurality of power cards 5 and a plurality of coolers 3 a to 3 e are stacked. The direction of the X axis in the figure corresponds to the stacking direction. The same applies to the subsequent drawings.

  A cooler is in contact with both sides of each power card 5. The three coolers 3b to 3d have the same structure, and the power card 5 is in contact with both surfaces of the coolers 3b to 3d. In the coolers 3a and 3e at both ends in the stacking direction, the power card 5 is in contact with only one surface. Therefore, the coolers 3a and 3e at both ends in the stacking direction have a slightly different structure from the coolers 3b to 3d. However, the coolers 3a to 3e are common in that they have a flow path through which the refrigerant flows in the Y-axis direction in the drawing. As will be described in detail later, the coolers 3a to 3e have through holes penetrating in the stacking direction at both ends in the Y-axis direction in the figure, and are supplied from a supply pipe 91 provided in the cooler 3a. The refrigerant reaches the cooler 3e at the other end in the stacking direction through one through hole. The refrigerant is a liquid, typically water or LLC (Long Life Coolant). The refrigerant absorbs heat from the adjacent power card 5 while passing through each of the coolers 3a to 3e, and is discharged from a discharge pipe 92 provided in the cooler 3a through the other through hole.

  The structure of the cooler 3b, one of the three coolers 3b to 3d with which the power card 5 is in contact with both sides will be outlined. The cooler 3 b includes a resin main body 30 and a pair of metal plates 13. As will be described in detail later, the main body 30 has a flow path through which the refrigerant passes, and an opening that communicates with the flow path is provided on the surface facing the power card 5. Each of the pair of metal plates 13 closes the respective openings with a gasket interposed therebetween. The flow path of the main body 30 is sealed by the pair of metal plates 13 and a gasket described later. The coolers 3c and 3d have the same structure as the cooler 3b. The coolers 3a and 3e have a flow path formed therein, an opening is provided on the surface facing the power card 5, and the opening is sealed with a metal plate and a gasket. It is the same as 3b-3d. The cooler 3a located at one end in the stacking direction is that the outermost surface of the stacking unit 2 is closed, and the supply pipe 91 and the discharge pipe 92 are provided on the outer surface. And different. The cooler 3e located at the other end in the stacking direction is different from the coolers 3b to 3d in that the outermost surface of the stacking unit 2 is blocked.

  FIG. 2 is a plan view showing a component layout of the power converter 100 in which the laminated unit 2 is incorporated. The stacked unit 2 is accommodated between the inner wall of the housing 80 of the power converter 100 and the support 82. A leaf spring 83 is inserted between the stacked unit 2 and the support 82. The laminated unit 2 is held by the leaf spring 83 while being pressed in the laminating direction. As will be described in detail later, the watertightness between the opening of the main body 30 and the metal plate 13 is maintained by pressurization in the stacking direction. Further, the pressure in the stacking direction increases the adhesion between the coolers 3a to 3e and the power card 5, and the heat transfer efficiency from the power card 5 to the coolers 3a to 3e is enhanced. In addition to the multilayer unit 2, the housing 80 accommodates a capacitor element 81 and a reactor 84. Some capacitor elements 81 and reactors 84 are components of the voltage converter, and the remaining capacitor elements are used as smoothing capacitors that suppress pulsation of the output current of the voltage converter. In addition, the housing 80 accommodates a substrate, a current sensor, and the like for controlling the switching element accommodated in the power card 5, but these are not shown.

  Next, the cooler 3b is demonstrated about the coolers 3b-3d with which the power card 5 is contacting on both sides. The coolers 3c and 3d have the same structure as the cooler 3b. Details of the structure of the coolers 3a and 3e are omitted.

  FIG. 3 shows an exploded perspective view of the cooler 3b. In FIG. 3, the power cards 5 located on both sides in the stacking direction of the cooler 3b are drawn with phantom lines. As described above, the cooler 3b includes the resin main body 30, the pair of metal plates 13a and 13b, the gaskets 12a and 12b, and the elastic members 33a and 33b. The main body 30 has a flow path Ps through which a refrigerant flows. The main body 30 is provided with openings 32a and 32b at positions facing the power cards 5 on both sides. The openings 32a and 32b communicate with the internal flow path Ps. Reference numeral 93 indicates a groove for weight reduction. Although not visible in FIG. 3, a groove for weight reduction is also provided on the opposite side surface of the main body 30. Thus, although the main body 30 has a complicated shape, the main body 30 can be made at low cost by injection molding of resin. Moreover, since the main body 30 is made of resin, it is lightweight.

  One opening 32a of the main body 30 is closed by the metal plate 13a with the gasket 12a interposed therebetween. The other opening 32b is closed by the metal plate 13b with the gasket 12b interposed therebetween. The pair of metal plates 13 a and 13 b face each other with the main body 30 interposed therebetween. A plurality of fins 14 a are provided on the surface 13 a 1 facing the flow path side of the metal plate 13 a, and the opposite surface 13 a 2 is in contact with the power card 5. A plurality of fins 14 b are provided on the surface 13 b 1 facing the flow path side of the metal plate 13 b, and the opposite surface 13 b 2 is in contact with another power card 5. The fins 14a of the metal plate 13a and the fins 14b of the metal plate 13b are disposed in the refrigerant flow. The heat of the power card 5 is absorbed by the refrigerant through the metal plates 13a and 13b and the fins 14a and 14b provided on them. The cooler 3b has a main body 30 made of a resin having a low thermal conductivity. However, the cooler 3b is provided with the metal plates 13a and 13b in a portion where one surface is in contact with the power card 5 and the other surface is in contact with the refrigerant. The performance is secured.

  The main body 30 is horizontally long in the Y-axis direction, and cylindrical portions 35 extending in the stacking direction are provided at both ends in the Y-axis direction. A through hole 34 extending in the stacking direction is formed inside the cylindrical portion 35. The refrigerant that has entered from the through hole 34a of the one cylinder part 35a flows in the Y-axis direction through the flow path Ps and exits from the through hole 34b of the other cylinder part 35b. The refrigerant flows in the Y-axis direction in the figure. In the laminated unit 2, the through holes of adjacent coolers communicate with each other, and the refrigerant is distributed to all the coolers through one through hole 34a (see FIG. 1). Further, the refrigerant that has passed through the flow path Ps of each cooler gathers through the other through-hole 34b and is discharged from the discharge pipe 92 (see FIG. 1).

  The plurality of fins 14a and 14b extend along the flow direction of the refrigerant. The refrigerant absorbs heat of the power card through the fins while flowing between the flat surfaces of the fins in the flow path Ps. A notch 15 is provided in each of the plurality of fins 14a. All of the plurality of fins 14a have notches having the same shape at the same position, and these notches form a space extending in the fin arrangement direction. The rib 31 mentioned later passes through the space. Similarly, a notch 15 is provided in each of the plurality of fins 14b.

  Ribs 31 are provided in the flow path Ps of the main body 30. The rib 31 extends in the Z-axis direction in the drawing. That is, the rib 31 extends in parallel to the pair of metal plates 13a and 13b and extends in a direction intersecting the refrigerant flow direction (Y-axis direction). The rib 31 is provided so as to connect a pair of parallel main body inner surfaces 37 and 38 facing the flow path Ps. The elastic member 33a is fitted to the edge of the rib 31 on the refrigerant upstream side, and the elastic member 33b is fitted to the edge on the refrigerant downstream side. The elastic member 33a has a length that reaches from one of a pair of parallel main body inner surfaces 37, 38 facing the flow path Ps to the other. In other words, the elastic members 33a and 33b have a length that crosses the flow path Ps. The elastic members 33a and 33b are made of the same material as the gaskets 12a and 12b. The elastic members 33a and 33b and the gaskets 12a and 12b are made of, for example, silicon rubber.

  The relationship between the rib 31, the elastic members 33a and 33b, and the fins 14a and 14b will be described. FIG. 4 is a cross-sectional view of the cooler 3b cut along the XY plane at the center in the Z-axis direction. Since the cooler 3b is a target with respect to the Z axis centering on the rib 31, a part of the left side of the rib 31 is not shown in FIG.

  The rib 31 is located at the center of the flow path Ps in the stacking direction (X-axis direction). The rib 31 is located at the center of the main body 30 also in the refrigerant flow direction (Y-axis direction). As is well shown in FIG. 4, the rib 31 passes through the notches 15 provided in the fins 14a and 14b. The elastic member 33a covers the upstream edge of the rib 31 in the refrigerant flow direction. The elastic member 33b covers the downstream edge of the rib 31 in the refrigerant flow direction. Each of the elastic members 33a and 33b is sandwiched between the rib 31 and the fins 14a and 14b at the notch 15.

  The tips of the fins 14a of one metal plate 13a and the tips of the fins 14b of the other metal plate 13b face each other in the flow path Ps. Here, the “tip of the fin” means the tip of the fin in the normal direction of the metal plate (X-axis direction in the drawing). A gap G exists between the tip of the fin 14a and the tip of the fin 14b. This gap G is difficult to be zero for the following reason. The metal plate 13a is in contact with one side surface of the main body 30 through the gasket 12a, and the metal plate 13b is in contact with the other side surface of the main body 30 through the gasket 12b. As described above, the stacking unit 2 is pressurized in the stacking direction (that is, the X-axis direction in FIG. 4), and each of the pair of metal plates 13a and 13b causes the respective openings 32a, 32b is sealed. The amount of deformation of the gaskets 12a and 12b due to pressurization varies with each cooler. Also, if the tip of the fin 14a and the tip of the fin 14b come into contact before the gasket 12a, 12b is deformed enough to seal the openings 32a, 32b, the metal plates 13a, 13b will be more than that. There is a possibility that the gap between the two cannot be narrowed and the sealing of the openings 32a and 32b is incomplete. In order to allow variation in the deformation amount of the gaskets 12a and 12b due to pressurization, the gap G cannot be made zero.

  On the other hand, since the refrigerant flowing through the gap G does not come into contact with the flat surface of the fin, waste in cooling performance occurs. That is, the loss on cooling efficiency increases. The rib 31 and the elastic members 33a and 33b fill the gap G with a part of the refrigerant flow direction. Accordingly, as indicated by arrows F1 and F2 in FIG. 4, the refrigerant is guided from the gap G to the space between the flat surfaces of the fins. As a result, all the refrigerant passing through the flow path Ps comes into contact with at least a part of the flat surface of the fin, and the cooling effect is enhanced. That is, a loss in cooling efficiency is suppressed. Even if the tips of the fins 14a and 14b abut against the elastic members 33a and 33b at the notch 15, the elastic members 33a and 33b are deformed, and deformation of the fins 14a and 14b is suppressed. The coolers 3c and 3d have the same structure as the cooler 3b.

  The laminated unit 2 of the embodiment has the following characteristics. Each of the plurality of power cards 5 accommodates a semiconductor element. The plurality of power cards 5 and the plurality of coolers 3a-3e are alternately stacked one by one. A cooler is in contact with both sides of each power card 5. Each of the coolers (3b-3d) excluding the coolers (coolers 3a and 3e) at both ends in the stacking direction of the stacking unit 2 has the structure shown in FIG.

  Points to be noted regarding the technology described in the embodiments will be described. The cooler 3 b of the embodiment has one rib 31 at the center of the main body 30 in the refrigerant flow direction. The main body of the cooler may have a plurality of ribs. The elastic members 33a and 33b may be formed directly on the main body 30 by injection molding together with the gaskets 12a and 12b.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

3a-3e; Cooler 2: Laminating unit 5: Power cards 12a, 12b; Gaskets 13a, 13b; Metal plates 14a, 14b; Fins 15: Notches 30; Main body 31: Ribs 32a, 32b; Openings 33a, 33b; 34a, 34b; through-holes 35a, 35b; cylindrical portions 37, 38; main body inner surface 80; housing 81; capacitor element 82; strut 83; leaf spring 84; reactor 100; power converter G;

Claims (2)

A plurality of power cards containing a semiconductor element and a plurality of coolers are stacked, and a stacked unit in which the power cards are in contact with both sides of at least one cooler,
The at least one cooler is
A main body in which a flow path through which the refrigerant flows in a direction crossing the stacking direction is formed, and an opening communicating with the flow path is provided at a position facing each of the power cards on both sides,
Each opening of the main body is closed with a gasket, a plurality of fins extending along the flow direction of the refrigerant are provided on the flow path side surface, and the opposite surface is in contact with the power card. A pair of metal plates,
With
The opening on both sides of the main body is sealed with the pair of metal plates by being pressed in the stacking direction of the stacking unit,
At least one rib extending in the flow path in a direction parallel to the pair of metal plates and intersecting the flow direction of the refrigerant, and extending from one of the opposed inner surfaces of the flow path to the other. Provided,
The plurality of fins included in each of the pair of metal plates are opposed to each other in the flow path, and the plurality of fins of each metal plate are provided with notches through which the ribs pass,
An elastic member is sandwiched between the rib and the plurality of fins at the notch,
A laminated unit characterized by that.   The laminated unit according to claim 1, wherein the main body is made of resin.

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