Electronic device

Abstract

To provide an electronic device that can dissipate heat from a plurality of heat-generating electronic components while suppressing increases in manufacturing costs and weight, and that can achieve a smaller device size.SOLUTION: An electronic device 1 includes a housing 10, a partition 40 that partitions a storage space within the housing 10, and a switching element 24 that is fixed to the partition 40 and uses the partition 40 as a heat dissipation path, and the inside of a resin-sealed partition 42 partitioned by the partition 40 is resin-sealed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to electronic devices. [Background technology]

[0002] It has been proposed to attach heat-generating electronic components to a vertical wall that stands upright on the bottom surface of a housing, and to release the heat from the electronic components to the housing side via the vertical wall (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-183574 Summary of the Invention [Problem to be solved by the invention]

[0004] The method of mounting electronic components on a vertical wall erected against the bottom surface of a housing, as in Patent Document 1, can be applied to relatively small electronic components such as semiconductor devices, reducing the mounting area of the electronic components and enabling the miniaturization of the device. On the other hand, it is difficult to apply this method to relatively large electronic components such as transformers.

[0005] One method for dissipating heat from relatively large electronic components is to encapsulate them in a resin with high thermal conductivity. However, this type of resin encapsulation typically requires filling almost the entire interior space of the housing with resin, which means that some electronic components cannot be encapsulated in resin, resulting in problems such as increased costs and weight due to the increased amount of resin.

[0006] In consideration of the above, the present invention aims to provide an electronic device that can dissipate heat from multiple types of heat-generating electronic components while suppressing increases in manufacturing costs and weight, and that can achieve miniaturization of the device. [Means for solving the problem]

[0007] An electronic device according to a first aspect of the present invention comprises a housing, a partition section that partitions an accommodating space within the housing, and an electronic component that is fixed to the partition section and uses the partition section as a heat dissipation path, and the interior of the partition is sealed with resin. [Effects of the Invention]

[0008] According to the electronic device of the first aspect of the present invention, the storage space within the housing is divided by a partition, and the interior of the partition is sealed with resin. Therefore, the amount of resin filled in the housing can be reduced while allowing heat dissipation from relatively large electronic components within the partition. Furthermore, the partition is used to secure the electronic components and as a heat dissipation path for the electronic components. Therefore, by using the partition as both a mounting surface and a heat dissipation portion for relatively small electronic components, the required area of the bottom surface of the housing can be reduced. This allows for the suppression of increases in manufacturing cost and weight, and allows for heat dissipation from multiple types of heat-generating electronic components, resulting in an electronic device that can be miniaturized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a circuit configuration of an electronic device according to an embodiment of the present invention. [Figure 2] 1 is a plan view of the inside of a housing of an electronic device according to an embodiment of the present invention, viewed from above the device. [Figure 3] 3 is a partially enlarged plan view showing an area P shown in FIG. 2 in an enlarged manner. [Figure 4] 4 is a cross-sectional view of the housing taken along line IV-IV in FIG. 2. FIG. [Figure 5] FIG. 10 is a schematic view showing a first modified example of a partition section according to the present embodiment. [Figure 6] FIG. 10 is a schematic view showing a second modified example of the partition section according to the embodiment. [Figure 7] FIG. 10 is a schematic view showing a third modified example of the partition section according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] An electronic device 1 according to one embodiment of the present invention will be described below with reference to Figures 1 to 4. In this embodiment, for convenience of explanation, the directions indicated by the up / down, left / right, and front / rear arrows appropriately shown in each figure will be defined as the up / down direction, left / right direction, and front / rear direction of the electronic device 1, respectively.

[0011] Unless otherwise specified in the specification, each element is not limited to one and may be present in plural. Furthermore, in the drawings, substantially identical elements are denoted by the same reference numerals, and redundant explanations in the specification will be omitted.

[0012] (Overall configuration of electronic device) In this embodiment, as an example of an electronic device according to the present invention, an electronic device 1 will be described (see FIG. 1 ) that converts AC voltage supplied from an AC power source 7 into DC voltage and charges a battery 8 mounted on an electric vehicle (EV) or a plug-in hybrid vehicle (PHV). Such an electronic device 1 is also called an on-board charger.

[0013] FIG. 1 is a block diagram showing the basic circuit configuration of electronic device 1. As shown in this figure, electronic device 1 includes a power conversion circuit 2 that converts AC voltage supplied from an AC power source 7 into DC voltage, and a control unit 3 that is electrically connected to power conversion circuit 2 and controls the conversion of AC to DC power. Power conversion circuit 2 includes a PFC circuit 21 and a converter circuit 22. For example, PFC circuit 21 is a single-stage PFC (Power Factor Correction) circuit equipped with a single converter. It converts AC power to DC power and improves the power factor of the power supply by shaping the output waveform. Converter circuit 22 is a known DC-DC converter that converts the DC power output from PFC circuit 21 to a level required for charging battery 8. For example, converter circuit 22 includes a transformer 22B, a converter input unit 22A arranged on the input side of transformer 22B, and a converter output unit 22C arranged on the output side of transformer 22B. The DC power output from the PFC circuit unit 21 is stepped up or stepped down through the converter input unit 22A and the transformer 22B, and is rectified and smoothed by the converter output unit 22C.

[0014] The PFC circuit unit 21 and the converter circuit unit 22 include a plurality of switching elements 24 (see FIG. 2) configured by MOSFETs, IGBTs, or the like. These switching elements 24 and the transformer 22B and the like that configure the converter circuit unit 22 are heat-generating components that generate heat during operation, and it is desirable to provide a heat dissipation means. The switching elements 24 are an example of a relatively small electronic component in the present invention, and the transformer 22B is an example of a relatively large electronic component in the present invention.

[0015] In the electronic device 1, the housing 10 that houses the power conversion circuit unit 2 is provided with a heat dissipation means via partitions 40 that partition the housing space within the housing 10. The detailed structure of the inside of the housing 10 of the electronic device 1 will be described below.

[0016] (Housing) Fig. 2 is a plan view of the housing 10 of the electronic device 1 as seen from above the device. As shown in Fig. 2, the housing 10 is formed in the shape of a rectangular box that is open at the top. The housing 10 is preferably made of a material that is both electrically conductive and highly thermally conductive, and in one example of this embodiment, it is made of die-cast aluminum.

[0017] The housing 10 has a bottom wall 14 that forms the bottom surface of the storage space within the housing 10, and side walls 16 that extend upward from the periphery of the bottom wall 14. The side walls 16 have a front wall 16A, a rear wall 16B, a left wall 16C, and a right wall 16D, and form a rectangular frame shape when viewed from above the device. Pedestals 12 that support corners of a wiring board 30 (described later) are formed integrally with the side walls 16 and bottom wall 14 at the four corners of the side walls 16.

[0018] Two through holes 18 are provided on the left side of the housing 10, penetrating the left wall portion 16C in the thickness direction. External connection connectors 19A and 19B are respectively attached to these through holes 18. In this embodiment, the input side external connection connector 19A is attached to one of the through holes 18, and the output side external connection connector 19B is attached to the other through hole 18. The external connection connectors 19A and 19B are connected to a wiring board 30 (see FIG. 4) accommodated in the upper part of the housing 10. Note that the wiring board 30 is omitted from FIG. 2 for ease of understanding.

[0019] (Partition) A partition 40 made of sheet metal and configured separately from the housing 10 is disposed in the storage space within the housing 10. The partition 40 forms a vertical wall that stands upright on the bottom surface of the housing 10, and partially partitions the storage space within the housing 10. As an example, the partition 40 is formed in the shape of a rectangular plate with the longitudinal direction being the front-to-rear direction and the plate thickness direction being the left-to-right direction.

[0020] As shown in Fig. 3, the partition 40 is supported in an upright position relative to the bottom wall 14 by inserting one and the other longitudinal ends into grooves 17 formed in the side walls 16 of the housing 10. Furthermore, within the grooves 17, the gap between the housing 10 and the side walls 16 is sealed via a sealant 26. In this embodiment, the storage space within the housing 10 is divided into left and right sections by the partition 40. The partition 40 is preferably made of a metal material with high thermal conductivity, but is not limited to this. It may also be made of a resin material with high thermal conductivity.

[0021] It should be noted that the configuration in which grooves 17 are formed in sidewalls 16 of housing 10 and the ends of partitions 40 are inserted and supported is not essential. Flanges may be formed at the ends of partitions 40 and the partitions and housing 10 may be fixed via the flanges with screws or the like, or partitions 40 may form part of a box-shaped module case, as in a first modified example described below. Furthermore, sealing material 26 may be an adhesive.

[0022] The transformer 22B is accommodated in a first accommodation space R1 on the right side of the housing 10, which is partitioned by the partition 40. The converter output section 22C and electronic components such as a plurality of capacitors 4 provided for smoothing are accommodated in a second accommodation space R2 on the left side of the housing 10, which is partitioned by the partition 40. The accommodation space on the right side is a resin-sealed compartment 42, which serves as a compartment for sealing the interior with resin. The resin-sealed compartment 42 is resin-sealed with resin 44 (see FIG. 4) mixed with a highly thermally conductive filler.

[0023] 2 and 4, a switching element 24 that uses the partition 40 as a heat dissipation path is fixed to the partition 40. The switching element 24 is fixed to a first side surface 40A of the partition 40 that faces the inside of the resin-sealed partition 42 via a presser 50.

[0024] The presser 50 is configured as a plate curved in a generally crank shape in a side view, and includes a fixing portion 51 provided in contact with the first side surface 40A and a pressing portion 52 provided spaced apart from the first side surface 40A. The fixing portion 51 is fixed to the first side surface 40A using a fastener such as a screw 62. A sheet-like insulating member 54 is disposed between the fixing portion 51 and the first side surface 40A. The pressing portion 52 is configured to hold the switching element 24 inserted between the fixing portion 52 and the first side surface 40A by pressing the switching element 24 toward the first side surface 40A. In this embodiment, an open end of the pressing portion 52 opens toward the top of the housing 10. A lead wire 241 of the switching element 24 (the lead wire 241 extending from the switching element 24 fixed to the partition 40) serving as a connecting member extends upward from the resin-sealed partition 42.

[0025] The tips of the lead wires 241 extend toward a board accommodating section 46 provided within the housing 10 and are connected to the wiring board 30. The board accommodating section 46 is provided corresponding to the partition section 40 and faces the resin-sealed section 42. In this embodiment, the board accommodating section 46 is formed above the partition section 40, in the upper part of the accommodation space within the housing 10. The tips of the lead wires 241 of the switching element 24 fixed to the partition section 40, protruding from the resin-sealed section 42, are connected to the wiring board 30 arranged in the board accommodating section 46. The wiring board 30 is arranged approximately parallel to the bottom wall 14 of the housing 10, with the thickness direction being the up-down direction. The four corners of the wiring board 30 are fixed to pedestals 12 erected from the four corners of the bottom wall 14 of the housing 10 using fastening members such as screws.

[0026] As described above, by forming a resin-sealed compartment 42 at the bottom of the storage space within the housing 10 and making the top of the storage space the substrate storage section 46, the work of installing the compartment 40 in the housing 10, the work of filling with resin 44, and the work of connecting the electronic components to the wiring board 30 can be performed in one direction in order.

[0027] In the above, it is not essential that the switching element 24 be fixed to the partition 40 via the presser 50. The switching element 24 may be fixed directly to the partition 40 using a fastening member such as a screw or an adhesive. Also, it is not essential that the switching element 24 be fixed to the first side surface 40A facing the inside of the resin-sealed partition 42. The switching element 24 may be fixed to the second side surface 40B (see FIG. 4) of the partition 40 facing the second housing space R2 that is not sealed with the resin 44.

[0028] (Action and effect) In the electronic device 1 according to this embodiment, the storage space within the housing 10 is divided by the partition 40, and the interior of the partition (resin-sealed partition 42) is sealed with resin. Therefore, the amount of resin filled in the housing 10 can be reduced while the interior of the partition can efficiently dissipate heat from a relatively large electronic component, such as the transformer 22B. Furthermore, the partition 40 is used as a heat dissipation path for a relatively small electronic component, such as the switching element 24, and is used as a mounting surface and heat dissipation section for the relatively small electronic component. Therefore, by using the partition 40 as both a mounting surface and a heat dissipation section for the relatively small electronic component, the required area of the bottom surface of the housing 10 can be reduced. This makes it possible to obtain an electronic device that can minimize manufacturing costs and weight, dissipate heat from multiple types of heat-generating electronic components, and achieve a compact device.

[0029] Furthermore, in this embodiment, the partition 40 is configured as a separate body from the housing 10. Therefore, electronic components can be fixed to the partition 40 outside the housing 10, and the structure of the electronic device 1 can be made to be excellent in assembly workability.

[0030] In this embodiment, the switching element 24 fixed to the partition 40 is fixed to the first side surface 40A of the partition 40, which is the side to be sealed with resin. Therefore, the switching element 24 fixed to the partition 40 can use both the partition 40 and the resin 44 filled in the resin-sealed partition 42 as heat dissipation paths.

[0031] In the present embodiment, the compartments to be resin-sealed are formed by the partitions 40 in the housing space of the housing 10, and a board accommodating section 46 corresponding to the partitions 40 is also formed. Furthermore, lead wires 241 extending from the switching element 24 fixed to the partitions 40 are connected to the wiring board 30 placed in the board accommodating section 46. Therefore, within the housing 10, the lead wires 241 of the switching element 24 are arranged to extend from the partitions 40 toward the board accommodating section 46. This makes it easy to connect the switching element 24 fixed to the partitions 40 and the wiring board 30 in the process of accommodating the wiring board 30 in the board accommodating section 46 inside the housing 10 after one compartment within the housing 10 has been resin-sealed.

[0032] Although the electronic device 1 according to the present embodiment has been described above, the present invention is not limited to this. Modifications of the above embodiment are listed below. Each modification basically follows the configuration of the electronic device according to the above embodiment, and therefore can achieve the same functions and effects.

[0033] (First Modification) As shown in FIG. 5, the partition 40 according to the above embodiment may be a partition 70 that constitutes at least a part of a module case 72 that forms an independent storage space within the housing 10. For ease of understanding, FIG. 5 omits illustration of electronic components housed within the housing 10. In this first modified example, the storage space within the box-shaped module case 72 serves as the resin-sealed compartment 42. As an example, the module case 72 is formed in the shape of a rectangular box that opens upward, and has a bottom wall 74 that forms the bottom surface of the storage space within the housing 10, and a side wall 76 that extends upward from the periphery of the bottom wall 74. The partition 70 is constituted by the side wall 76 of the module case 72.

[0034] According to the first modification, the partition 70 constitutes at least a part of a module case 72 that forms an independent storage space within the housing 10, and the storage space within the module case 72 is the resin-sealed partition 42. Therefore, in the manufacturing process, electronic components that require resin sealing can be modularized and assembled into the housing 10.

[0035] (Second Modification) The partition 40 according to the above embodiment may be formed of a heat dissipation substrate 82, as shown in Fig. 6. The partition 80 according to the second modification is formed of a heat dissipation substrate 82 in which wiring (not shown) is provided on a metal base substrate 84 having high thermal conductivity via an insulating layer 86. At least some of the switching elements 24 included in the PFC circuit unit 21 and the converter circuit unit 22 housed in the housing 10 are mounted on the heat dissipation substrate 82. At least some of the wiring constituting the PFC circuit unit 21 and the converter circuit unit 22 is formed on the heat dissipation substrate 82. A plurality of terminals 66 are connected to the upper end of the heat dissipation substrate 82. The plurality of terminals 66 extend toward the substrate housing portion 46 in the housing 10 and are connected to the wiring substrate 30.

[0036] According to the second modification, the partition 80 is a member that partitions the storage space within the housing 10, and also constitutes at least a part of the wiring board, thereby reducing the number of components and costs.

[0037] (Third Modification) Although not shown, the partition section 40 according to the above embodiment may be configured as a printed wiring board in which conductive wiring is formed on a substrate made of an insulating material such as resin.

[0038] (Fourth Modification) Furthermore, although the partition 40 according to the above embodiment is formed in a rectangular plate shape, this is not limiting. The shape can be modified as appropriate to partially partition the storage space within the housing 10. For example, as shown in FIG. 7 , the partition 40 may be configured as a plate-shaped partition 90 bent into an L-shape. The partition 90 partitions the storage space within the housing 10 by two sides formed by the side wall 16 of the housing 10 and two sides of the partition 90. The storage space within the partition 90 is the resin-sealed partition 42.

[0039] In addition, in the above embodiment and each modified example, the partition is configured as a separate body from the housing 10, but the present invention is not limited to this. The housing 10 may be made of a die-cast material, so that the partition is formed integrally with the housing 10. Furthermore, in the above embodiment and each modified example, the figures show the case without a lid, but it is also possible to have a lid. The lid and the case may also be fixed by means of screws, adhesive, or the like. [Explanation of symbols]

[0040] 1 Electronic equipment 10. Cabinet 24 Switching elements (electronic components) 30 Wiring board 40 Compartment 42 Resin sealing section 44 Resin 46 Substrate storage section 70 Compartment 72 Module Case 80 Compartment 82 Heat dissipation board 90 Compartment 241 Lead wire (connecting member)

Claims

1. The housing and a partition portion that partitions an accommodation space within the housing; an electronic component fixed to the partition and using the partition as a heat dissipation path, wherein the interior of the partition is sealed with resin.

2. The electronic device according to claim 1 , wherein the partition is configured as a separate body from the housing.

3. The electronic device according to claim 1 or 2, wherein the electronic component is fixed to the resin-sealed side of the partition.

4. 3. The electronic device according to claim 1, wherein the partition constitutes at least a part of a module case that forms an independent storage space within the housing, and the storage space within the module case is the compartment to be sealed with resin.

5. 3. The electronic device according to claim 1, wherein the partition section is a heat dissipation substrate having wiring provided on a base substrate via an insulating layer, and the electronic component is mounted on the heat dissipation substrate.

6. 3. The electronic device according to claim 1, wherein the partition section forms the resin-sealed compartment in the housing storage space, and a board storage section corresponding to the partition section is formed, and a connecting member extending from an electronic component fixed to the partition section is connected to a wiring board arranged in the board storage section.

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