Electronic component unit

Abstract

To reduce the number of components.SOLUTION: An electronic component unit comprises: a capacitor element 31; a cooler which has a cooling surface for cooling the capacitor element 31; a case 30 which has a fixed surface 33 facing the cooling surface, and which houses the capacitor element 31; a bonding layer for bonding the fixed surface 33 of the case 30 to the cooling surface of the cooler; a positioning part 5; and a spacer 34. The positioning part 5 has: a pin 35 formed on one of the case 30 and the cooler; and a hole part, formed on the other of the case 30 and the cooler, which engages with the pin 35 so as to position the case 30, with respect to the cooler, in a direction along the cooling surface. The spacer 34 is formed on one of the case 30 and the cooler so as to provide a distance for forming the bonding layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] This technique relates to an electronic component unit having a cooling structure. [Background technology]

[0002] Conventionally, electronic component units in which heat-generating electronic components such as capacitors and discharge resistors are housed in a resin case have been widely used. Since such electronic components generate heat when electricity is passed through them, a configuration has been developed in which the case housing the electronic components is attached to a cooler. For example, a known configuration is one in which the case housing the electronic components is attached to the cooler with bolts and adhesive (see Patent Document 1). In this configuration, a spacer that maintains a constant distance between the case housing the electronic components and the cooler maintains a constant thickness of the adhesive while ensuring insulation, allowing the electronic components to dissipate heat. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-29147 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, hybrid cars and electric cars equipped with a motor for driving the vehicle are becoming popular among vehicles such as automobiles. An inverter or the like is used as an electric drive circuit for driving such a motor for driving the vehicle. As a configuration for cooling the capacitor and discharge resistor of such an inverter, it is considered to attach a case containing these electronic components to a cooler with bolts and adhesive.

[0005] However, in the electronic component cooling structure described in Patent Document 1, the case housing the electronic components is attached to the cooler with bolts and adhesive, which results in a problem of a large number of components, and therefore there has been a demand for a reduction in the number of components.

[0006] It is therefore an object of the present invention to provide an electronic component unit that can reduce the number of components. [Means for solving the problem]

[0007] An electronic component unit which is one aspect of the present invention comprises an electronic component, a cooler having a cooling surface for cooling the electronic component, a case having a fixing surface facing the cooling surface and accommodating the electronic component, an adhesive layer bonding the fixing surface of the case to the cooling surface of the cooler, a positioning portion having an engaging portion formed on one of the case and the cooler and an engaged portion formed on the other of the case and the cooler and engaging with the engaging portion to position the case relative to the cooler in a direction along the cooling surface, and a spacer portion formed on one of the case and the cooler and providing a gap for forming the adhesive layer. Effect of the Invention

[0008] The number of parts in the electronic part unit can be reduced. [Brief description of the drawings]

[0009] [Figure 1] 1A and 1B are schematic perspective views showing an inverter according to an embodiment, in which FIG. 1A shows a state after a capacitor has been assembled, and FIG. 1B shows a state before the capacitor has been assembled. [Diagram 2] 1A and 1B are schematic perspective views showing a capacitor according to an embodiment, in which FIG. 1A is a view from above, and FIG. [Diagram 3]1A and 1B are schematic diagrams showing a capacitor according to an embodiment, in which (a) is a bottom view before the adhesive is spread, (b) is a bottom view after the adhesive has been spread, and (c) is a side view of an integrated spacer and pin according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of an electronic component unit according to the present disclosure will be described below with reference to Fig. 1 to Fig. 3. In this embodiment, a case will be described in which the electronic component unit is applied to a drive circuit (e.g., an inverter) that controls a drive motor that outputs a driving force for running a vehicle such as a hybrid vehicle or an electric vehicle.

[0011] [Inverter configuration] First, the configuration of an inverter 1 according to an embodiment will be described with reference to Figures 1(a) and 1(b). The inverter 1 has a cooler 2 and a capacitor unit 3. In this embodiment, in order to simplify the description, only the cooler 2 and the capacitor unit 3 are shown as the components of the inverter 1, but in reality, the inverter 1 is configured to include other electronic components such as a discharge resistor, an electrical board, and the like.

[0012] The cooler 2 is, for example, in the form of an aluminum plate, and is of a water-cooled type in which cooling water circulates inside. The cooler 2 has a cooling surface 20. The cooler 2 is provided to cool the entire heat generating parts, such as the condenser unit 3 and the electrical board. Here, as the cooling water, for example, a long-life coolant (LLC) containing ethylene glycol, propylene glycol, or the like can be used. In addition, in this embodiment, cooling water is applied, but the present invention is not limited thereto, and a refrigerant used in a refrigeration cycle may be applied. In this case, as the refrigerant, for example, hydrofluorocarbon (HFC) or hydrofluoroolefin (HFO) may be applied. In addition, in this embodiment, the cooler 2 is of a water-cooled type, but the present invention is not limited thereto, and an air-cooled type in which air circulates inside may be applied.

[0013] As shown in FIGS. 2(a) and 2(b), the capacitor unit 3 includes a resin case 30, a capacitor element 31 housed in the case 30, and a bus bar 32 connected to the capacitor element 31. In this embodiment, six capacitor elements 31 are housed in the case 30. The capacitor element 31 is an example of an electronic component, and has electrodes on the top and bottom sides of the case 30, each of which is connected to a bus bar 32, and the ends of the bus bar 32 protrude to the outside of the case 30. The inside of the case 30 is filled with an insulating epoxy resin as a sealant. In this embodiment, a capacitor is used as the electronic component housed in the case 30, but this is not limiting, and other electronic components such as a discharge resistor may be housed.

[0014] 1(b), the case 30 has a fixing surface 33 facing the cooling surface 20. As a result, the cooling surface 20 cools the capacitor element 31. In the present embodiment, the case 30 is made of resin, but the present invention is not limited to this. For example, a metal case may be used to improve cooling performance. As for the epoxy resin used as the sealant, an epoxy resin with high thermal conductivity may be used to improve cooling performance.

[0015] Between the fixing surface 33 of the case 30 and the cooling surface 20 of the cooler 2, an adhesive layer 4 is provided to bond the fixing surface 33 and the cooling surface 20. The adhesive layer 4 is formed of an adhesive. When the condenser unit 3 is assembled to the cooler 2, as shown in FIG. 3(a), an adhesive 40 (shown by hatching) is applied to the center of the fixing surface 33, and the condenser unit 3 is pressed against the cooling surface 20 to spread the adhesive 40, and as shown in FIG. 3(b), the adhesive 40 is spread over almost the entire surface of the fixing surface 33. This adhesive 40 becomes the adhesive layer 4. The material of the adhesive 40 is not particularly limited, but if the material has high thermal conductivity, the cooling efficiency of the condenser unit 3 can be improved. In addition, the case where the adhesive 40 is applied to the fixing surface 33 is described here, but the present invention is not limited thereto, and the adhesive 40 may be applied to the cooling surface 20 or to both the fixing surface 33 and the cooling surface 20.

[0016] As shown in FIG. 1(a), the case 30 and the cooler 2 are fixed by an adhesive layer 4, and positioned by a spacer 34 and a positioning portion 5, which will be described later. Therefore, the case 30 and the cooler 2 are fixed without using bolts, and the number of parts can be reduced compared to when bolts are used. Furthermore, by not using bolts, the inverter 1 can be made more compact. Furthermore, by not using bolts, the fixing position can be prevented from becoming unstable, since the positioning is performed by the spacer 34 and the positioning portion 5.

[0017] As shown in FIG. 2(b), a spacer 34 and a pin 35 are formed on the fixing surface 33 of the case 30. The spacer 34 is an example of a spacer portion, and is provided to provide a space for forming the adhesive layer 4 on the cooler 2. In this embodiment, the spacers 34 are provided at four locations on the fixing surface 33, two locations near both ends of a long side of the fixing surface 33, and two locations sandwiching the center of another long side different from the long side. However, the number and arrangement positions of the spacers 34 are not limited to this.

[0018] The four spacers 34 have uniform heights, and their tip surfaces are arranged on the same plane to form a reference surface, and the four spacers 34 come into contact with the cooling surface 20, so that the fixing surface 33 is arranged at equal intervals from the cooling surface 20. As a result, even if the fixing surface 33 is not highly flat, the adhesive 40 will have a uniform thickness when it is pressed and spread between the fixing surface 33 and the cooling surface 20, and the adhesive layer 4 will have a uniform thickness.

[0019] In this embodiment, the spacers 34 are provided on the fixing surface 33, but the present invention is not limited thereto and the spacers 34 may be provided on the cooling surface 20. In addition, among the plurality of spacers 34, some may be provided on the fixing surface 33 and the other may be provided on the cooling surface 20. That is, the spacers 34 are formed on one of the case 30 and the cooler 2, and a gap is provided for forming the adhesive layer 4.

[0020] The cooling surface 20 is formed with holes 21 (see FIG. 1(b)) into which the pins 35 engage. Here, the pins 35 are an example of an engaging portion, the holes 21 are an example of an engaged portion, and the pins 35 and the holes 21 form a positioning portion 5. The positioning portion 5 positions the position of the case 30 relative to the cooler 2 in a direction along the surface of the cooling surface 20 by the pins 35 engaging with the holes 21. In this embodiment, the pins 35 are provided on the fixing surface 33 at two locations sandwiching the center of the long side on both ends of which the spacers 34 are arranged, and the holes 21 are arranged at positions opposite to the pins 35 and the holes 21. However, the number and arrangement positions of the pins 35 and the holes 21 are not limited to this.

[0021] In the present embodiment, the pin 35 is provided on the fixing surface 33, and the hole 21 is provided on the cooling surface 20. However, the present embodiment is not limited to this, and the pin 35 may be provided on the cooling surface 20, and the hole 21 may be provided on the fixing surface 33. Also, some of the multiple pins 35 may be provided on the fixing surface 33, and the other may be provided on the cooling surface 20. That is, the pin 35 is formed on one of the case 30 and the cooler 2, and the hole 21 is formed on the other of the case 30 and the cooler 2. Also, in the present embodiment, the spacer 34 and the pin 35 are both formed on the fixing surface 33. However, the present embodiment is not limited to this, and one may be formed on the fixing surface 33, and the other may be provided on the cooling surface 20.

[0022] In this embodiment, both the spacer 34 and the positioning portion 5 are provided between the fixing surface 33 and the cooling surface 20, so that the inverter 1 can be made compact. Note that, in this embodiment, the case where both the spacer 34 and the positioning portion 5 are provided between the fixing surface 33 and the cooling surface 20 has been described, but this is not limiting. For example, the spacer 34 and the positioning portion 5 may be disposed outside the fixing surface 33 and the cooling surface 20, and the spacing between the case 30 and the cooler 2 and the positioning in the direction along the surface may be determined.

[0023] [Spacer and positioning part placement] In recent years, there has been a demand for a smaller inverter 1, and it is also desirable to reduce the size of the capacitor unit 3 used in the inverter 1. The demand for a smaller capacitor unit 3 has led to a reduction in the size of the case 30, thereby increasing the density of the capacitor elements 31 inside the case 30. However, if the spacer 34 and the positioning portion 5 overlap the capacitor elements 31 when viewed from a direction perpendicular to the cooling surface 20, this will hinder heat dissipation.

[0024] 3(a), in this embodiment, the spacer 34 and the positioning portion 5 are arranged at positions that overlap the cooling surface 20 but do not overlap the capacitor element 31 when viewed in a direction perpendicular to the cooling surface 20. That is, in this embodiment, the spacer 34 and the positioning portion 5 are formed on the fixing surface 33, so that they overlap the cooling surface 20. Also, the spacer 34 and the positioning portion 5 are each arranged near the long side of the fixing surface 33, so that they do not overlap the capacitor element 31. As a result, heat generated in the capacitor element 31 is conducted to the cooling surface 20 via the fixing surface 33 and the adhesive layer 4, and is cooled.

[0025] In contrast, when the spacer 34 and the positioning portion 5 overlap the capacitor element 31, the heat generated in the capacitor element 31 is conducted to the cooling surface 20 via the spacer 34 and the positioning portion 5, and is cooled. Comparing the case where the heat generated in the capacitor element 31 is conducted to the cooling surface 20 via the fixing surface 33 and the adhesive layer 4 with the case where the heat is conducted to the cooling surface 20 via the spacer 34 and the positioning portion 5, the case where the heat is conducted to the cooling surface 20 via the fixing surface 33 and the adhesive layer 4 has a smaller thermal resistance, and therefore the cooling efficiency is higher. Therefore, according to this embodiment, the cooling efficiency of cooling the capacitor element 31 can be improved.

[0026] In this embodiment, the spacer 34 and the positioning portion 5 are described as being arranged at positions that do not overlap the capacitor element 31, but this is not limited to the above. For example, if it is not possible to prevent the spacer 34 and the pin 35 from overlapping the capacitor element 31 due to space limitations, at least one of the spacer 34 and the pin 35 may be arranged so that at least a portion of the spacer 34 and the pin 35 overlaps the capacitor element 31. Even in this case, the case 30 and the cooler 2 are fixed together without using bolts, so that the number of parts can be reduced compared to when bolts are used.

[0027] 3(a), the spacers 34 and the positioning parts 5 are disposed between the outer edge of the fixing surface 33 and the capacitor element 31 when viewed in a direction perpendicular to the cooling surface 20. In this embodiment, two of the spacers 34 are disposed at two locations on either side of the center of the long side of the fixing surface 33, but these are disposed in the rounded portions between the corners of adjacent capacitor elements 31 so as not to overlap with the capacitor elements 31.

[0028] Here, when the adhesive 40 is applied to the center of the fixing surface 33 and spread, the adhesive 40 spreads radially outward (as shown by the arrows in FIG. 3(a)). At this time, in the spreading direction of the adhesive 40, the adhesive 40 does not easily reach the rear side of the spacer 34 and the positioning portion 5, and air may remain and form an air layer. For this reason, if the spacer 34 and the positioning portion 5 are positioned in the center of the fixing surface 33, an air layer may be formed around them, and the cooling efficiency may be reduced by the air layer having a lower heat transfer rate than the adhesive 40. Therefore, in this embodiment, the spacer 34 and the positioning portion 5 are positioned outside the capacitor element 31, so that even if an air layer is formed behind the spacer 34 and the positioning portion 5, they are not overlapped with the capacitor element 31, thereby reducing the effect of the reduction in cooling efficiency.

[0029] In this embodiment, the case where the spacer 34 and the positioning portion 5 are disposed between the outer edge of the fixing surface 33 and the capacitor element 31 has been described, but the present invention is not limited to this. For example, the spacer 34 or the positioning portion 5 may be disposed at a position in the center of the fixing surface 33 that does not overlap the capacitor element 31. In this case, for example, the adhesive 40 may be applied so as to surround the outer periphery of the spacer 34 or the positioning portion 5 provided in the center of the fixing surface 33, and then the adhesive 40 may be pushed out, thereby preventing the formation of an air layer.

[0030] As described above, the inverter 1 of this embodiment has the adhesive layer 4 that bonds the fixing surface 33 and the cooling surface 20, the positioning portion 5, and the spacer 34. Therefore, the capacitor unit 3 can be fixed to the cooler 2 without using bolts, so the number of parts can be reduced compared to when bolts are used. By not using bolts, the inverter 1 can be made more compact. Furthermore, the capacitor unit 3 is positioned relative to the cooler 2 by the positioning portion 5 and the spacer 34, so the fixing position of the capacitor unit 3 can be set to a set position without using bolts.

[0031] Furthermore, according to inverter 1 of this embodiment, positioning portion 5 and spacer 34 are arranged at positions that overlap cooling surface 20 but do not overlap capacitor element 31 when viewed in a direction perpendicular to cooling surface 20. Therefore, since positioning portion 5 and spacer 34 overlap cooling surface 20, it is possible to achieve a smaller size compared to a case where they do not overlap. Furthermore, since positioning portion 5 and spacer 34 are arranged at positions that do not overlap capacitor element 31, it is possible to improve the cooling efficiency of capacitor element 31.

[0032] Furthermore, according to the inverter 1 of this embodiment, the positioning portion 5 and the spacer 34 are disposed between the outer edge of the fixing surface 33 and the capacitor element 31 when viewed in a direction perpendicular to the cooling surface 20. Therefore, even if an air layer is formed behind the spacer 34 and the positioning portion 5 when the adhesive 40 is pushed and spread from the center of the fixing surface 33, the air layer will not overlap with the capacitor element 31, so that a decrease in cooling efficiency can be suppressed.

[0033] Furthermore, according to this embodiment, the electronic component unit is used in the inverter 1, which is a drive circuit that controls the drive motor that outputs the driving force for the vehicle, so that it is possible to reduce the number of components in such an inverter 1 by reducing the voltage.

[0034] In the above embodiment, the spacer 34 and the positioning portion 5 are provided at different positions, but the present invention is not limited to this, and the spacer and the positioning portion may be provided at the same position. For example, as shown in FIG. 3(c), the positioning portion 105 has a pin 135 provided on the fixing surface 33 and a hole portion 121 provided on the cooling surface 20. The pin 135 is provided coaxially with the spacer 134 provided on the fixing surface 33. That is, the positioning portion 105 is arranged so as to overlap with the spacer 134 when viewed in a direction perpendicular to the cooling surface 20. In this case, the total area of ​​the spacer 34 and the positioning portion 105 can be reduced, thereby achieving further miniaturization and improved cooling efficiency.

[0035] In addition, in the above-described embodiment, the electronic component unit is applied to the inverter 1 that controls a drive motor that outputs driving force for a vehicle such as a hybrid vehicle or an electric vehicle. However, the present invention is not limited to this, and can be applied to any configuration for cooling a capacitor unit having a capacitor element. [Explanation of symbols]

[0036] 1... inverter (electronic component unit), 2... cooler, 4... adhesive layer, 5... positioning portion, 20... cooling surface, 21... hole portion (engaged portion), 30... case, 31... capacitor element (electronic component), 33... fastening surface, 34... spacer (spacer portion), 35... pin (engagement portion), 105... positioning portion, 121... hole portion (engaged portion), 135... pin (engagement portion)

Claims

1. Electronic components, a cooler having a cooling surface for cooling the electronic component; a case having a fixing surface facing the cooling surface and housing the electronic component; an adhesive layer that bonds the fixing surface of the case and the cooling surface of the cooler; a positioning portion having an engaging portion formed on one of the case and the cooler, and an engaged portion formed on the other of the case and the cooler, the positioning portion engaging with the engaging portion to position the case relative to the cooler in a direction along the cooling surface; a spacer portion formed on one of the case and the cooler and providing a gap for forming the adhesive layer; Electronic component unit.

2. the positioning portion and the spacer portion are disposed at positions that overlap the cooling surface but do not overlap the electronic component when viewed in a direction perpendicular to the cooling surface. The electronic component unit according to claim 1 .

3. the positioning portion and the spacer portion are disposed between an outer edge of the fixing surface and the electronic component when viewed in a direction perpendicular to the cooling surface. The electronic component unit according to claim 1 .

4. The positioning portion is disposed so as to overlap the spacer portion when viewed in a direction perpendicular to the cooling surface. The electronic component unit according to claim 1 .

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