electrical equipment

Abstract

The electrical device (10) comprises: a housing (11); a circuit board (20) disposed inside the housing (11); and electronic components (30) disposed inside the housing (11) and heated by electricity. The housing (11) is filled with an insulating liquid cooling medium (40), the circuit board (20) is arranged in a horizontal position with the normal of the board surface (20A, 20B) of the circuit board (20) being horizontal, and the electronic components (30) are disposed on the lower side of the housing (11), at least a portion of the electronic components (30) being immersed in the insulating liquid cooling medium (40).

Description

Technical Field

[0001] This disclosure relates to electrical equipment. Background Technology

[0002] Conventionally, as an example of electrical equipment, there are known DC-DC converters that convert an input DC voltage into a DC voltage of a specified level for output. DC-DC converters are used in vehicles such as electric or hybrid vehicles. The electronic components used in electrical equipment such as DC-DC converters are heat-generating components that generate heat when energized, and the heat generated is relatively large. If the heat from the electronic components remains trapped inside the casing of the electrical equipment, the casing becomes very hot, and the performance of the electronic components may degrade.

[0003] Therefore, for example, Patent Document 1 discloses a cooling device for a power conversion device, which connects a heat-generating element (electronic component) to a heat-generating part via a heat sink or an insulating layer to form a component, and cools the component by circulating cooling water through a water path within the heat-generating part.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-088090 Summary of the Invention

[0007] Summary of the invention

[0008] The problem that the invention aims to solve

[0009] In recent years, there has been a desire to miniaturize the electrical equipment used in electric or hybrid vehicles. However, if the miniaturization of electronic components reduces the heat dissipation area, these components themselves are more prone to reaching high temperatures compared to the past, leading to localized temperature increases within the electrical equipment. If these localized high temperatures occur within the electrical equipment, they could potentially have thermal effects on surrounding electronic components and circuits, raising concerns about potential malfunctions.

[0010] The technology disclosed in this specification is an invention made based on the above-described situation, with the aim of providing an electrical device that suppresses localized temperature rise.

[0011] Solution for solving the problem

[0012] The electrical device disclosed herein comprises: a housing; a circuit board disposed inside the housing; and at least one electronic component disposed inside the housing, which generates heat when energized, the housing being filled with an insulating liquid cooling medium, the circuit board being disposed in an attitude in which the normal of the board surface of the circuit board is horizontal, the electronic component being disposed on the lower side of the housing, and at least a portion of the electronic component being immersed in the insulating liquid cooling medium.

[0013] Invention Effects

[0014] According to this disclosure, it is possible to provide electrical equipment that suppresses localized temperature rise. Attached Figure Description

[0015] Figure 1 It is a perspective view schematically showing the internal structure of the housing of an electrical device according to an embodiment.

[0016] Figure 2 It is a side view that schematically shows the internal structure of the housing of an electrical device.

[0017] Figure 3 This is a perspective view showing an example of the mounting configuration of electronic components. Detailed Implementation

[0018] [Description of embodiments of this disclosure]

[0019] First, let's illustrate the implementation forms of this disclosure.

[0020] (1) The electrical device disclosed herein comprises: a housing; a circuit board disposed inside the housing; and at least one electronic component disposed inside the housing, which generates heat when energized, the housing being filled with an insulating liquid cooling medium, the circuit board being disposed in a horizontal position with the normal of the board surface of the circuit board being horizontal, and the electronic component being disposed on the lower side of the housing and immersed in the insulating liquid cooling medium.

[0021] According to the structure described in (1) above, the charged part (heat-generating part) of the electronic component is directly cooled by an insulating liquid cooling medium. Heat released from the electronic component disposed on the lower side of the housing is transferred to the insulating liquid cooling medium, and the heated insulating liquid cooling medium rises along the substrate surface of the circuit board. As a result, natural convection of the insulating liquid cooling medium occurs inside the housing, dispersing heat within the housing and suppressing localized temperature rises in the electrical equipment. It should be noted that, in the above description, at least a portion of the electronic component only needs to be immersed in the insulating liquid cooling medium; in the case of multiple electronic components, only at least one electronic component needs to be disposed on the lower side of the housing.

[0022] (2) The electrical device disclosed herein preferably includes a plurality of said electronic components, which are mounted on two substrate surfaces, one of the substrate surfaces and the other of the substrate surface.

[0023] According to the structure described in (2) above, by mounting electronic components on both sides of the circuit board, the area of ​​the circuit board required to mount multiple electronic components is reduced compared to a structure where electronic components are mounted on only one side of the board. This allows for the suppression of increased mounting density of electronic components and enables the miniaturization of the circuit board and even electrical equipment.

[0024] (3) Preferably, the content of dust particles per unit volume of the insulating liquid cooling medium is lower than the content of dust particles per unit volume of air.

[0025] In electrical equipment, dust particles floating in the casing can cause short circuits between charged parts of electronic components, such as electronic components housed inside the casing, potentially leading to malfunctions. To avoid these malfunctions, it is necessary to set a larger spacing between electronic components (reducing installation density), which hinders the miniaturization of electrical equipment. According to the structure described above (3), compared to conventional structures without an insulating liquid cooling medium, fewer dust particles float in the casing, reducing the likelihood of short circuits caused by dust particles. As a result, compared to conventional structures, the installation density of electronic components can be increased, enabling the miniaturization of electrical equipment.

[0026] (4) The shell is preferably formed of a material containing metal.

[0027] According to the structure described in (4) above, the housing has high thermal conductivity, thus the heat transferred from the electronic components to the insulating liquid cooling medium is easily transferred from the insulating liquid cooling medium to the housing, and then to the outside. As a result, the heat dissipation of the electrical equipment is improved, and the temperature rise can be suppressed.

[0028] (5) Preferably, a flow path is formed between the housing and the electronic component, through which the insulating liquid cooling medium can flow.

[0029] According to the structure described in (5) above, the insulating liquid cooling medium flows between the housing and the electronic components, allowing for good convection within the housing and improved heat dissipation. Furthermore, the insulating liquid cooling medium flows along the housing, facilitating heat transfer from the insulating liquid cooling medium to the housing and improving heat dissipation. This helps to suppress temperature rise in the electrical equipment.

[0030] (6) Preferably, the electrical equipment of this disclosure also includes a busbar, which is formed in the shape of a plate and is made of metal, and the busbar is connected to the electronic component via a metal member made of metal.

[0031] According to the structure described in (6) above, heat from the electronic components is transferred to the busbar via a metal component with high thermal conductivity. Furthermore, the heat transferred to the busbar is transferred from the surface of the busbar, which has a large specific surface area, to the insulating liquid cooling medium in contact with it. Thus, heat from the electronic components is rapidly transferred to the insulating liquid cooling medium, improving the heat dissipation and heat dissipation of the electrical equipment.

[0032] (7) The busbar is preferably a long strip that is long in one direction and is arranged so that its length direction is along the vertical direction.

[0033] According to the structure described in (7) above, the heat transferred to the busbar is also transferred and dispersed from bottom to top inside the busbar, which has high thermal conductivity. As a result, the heat dissipation inside the electrical equipment is further improved.

[0034] (8) The busbar is preferably configured in a position where the surface of the busbar is perpendicular to the surface of the circuit board.

[0035] According to the structure described in (8) above, the insulating liquid cooling medium flows along the substrate surface of the circuit board and the board surface of the busbar, adjusting the flow of the insulating liquid cooling medium. As a result, the insulating liquid cooling medium convects more smoothly inside the housing 11, improving the heat dissipation and heat dissipation of the electrical equipment.

[0036] [Details of the embodiments of this disclosure]

[0037] The embodiments of this disclosure are described below. This invention is not limited to these examples, but is disclosed by the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0038] <Implementation Method>

[0039] Reference Figures 1-3 The following description illustrates the embodiments of this disclosure. Figure 1 and Figure 2 The upper side of the middle is the top. Figure 1 The paper in front of it Figure 2 The left side of the middle is the front. Figure 1 The inside left side of the paper in the middle Figure 2 The explanation is provided on the inside left side of the paper. It should be noted that for multiple identical components, sometimes only a portion of the components are labeled, omitting the labels of the other components.

[0040] (Electrical Equipment 10)

[0041] In this embodiment, an electrical device 10 mounted on a vehicle such as an automobile is illustrated. The electrical device 10 is a device that includes a switching type DC-DC converter (DC voltage conversion device) that converts an input DC voltage into a DC voltage of a predetermined level for output, and has a known circuit structure. The circuit structure of this embodiment is not particularly limited, and includes a first converter that converts DC voltage into AC voltage, a transformer that transforms the AC voltage, and a second converter that converts AC voltage into DC voltage. It is configured with a rectifier circuit, a resonant circuit, a smoothing circuit, etc., to adjust the output voltage. The transformer can be a voltage boosting structure or a voltage bucking structure, but the electrical device 10 of this embodiment includes a buck converter that bucks the voltage through a transformer. In the following description, the switching element of the first converter is sometimes referred to as a high-voltage side switching element, and the switching element of the second converter is sometimes referred to as a low-voltage side switching element.

[0042] like Figure 1 and Figure 2 As shown, the electrical device 10 of this embodiment includes a housing 11 and a circuit board 20 disposed inside the housing 11. Electronic components 30 are mounted on the circuit board 20, and the interior of the housing 11 is filled with an insulating liquid cooling medium 40. The electrical device 10 is... Figure 1 and Figure 2 The circuit board 20 is mounted on the vehicle in the posture shown, where the normals of the substrate surfaces 20A and 20B are horizontal.

[0043] (Shell 11)

[0044] like Figure 1 and Figure 2 As shown, the housing 11 has: a rectangular box-shaped body 11M that opens upwards; and a cover 11L that seals the opening at the top of the body 11M. The body 11M and the cover 11L are formed of a material containing metals such as aluminum or stainless steel. Even among metals, it is preferable to use a material containing a metal with high thermal conductivity, such as aluminum or an aluminum alloy. Depending on the situation, a material with copper or nickel plating on the surface of stainless steel may also be used. A copper alloy or copper plating may also be used for the cover 11L, which has a relatively small surface area, so that the cover 11L functions as a heat sink. The body 11M has a rectangular bottom wall and four side walls rising from the periphery of the bottom wall, integrally formed to a size capable of accommodating the circuit board 20. The cover 11L preferably seals the opening of the body 11M watertight.

[0045] (Circuit board 20)

[0046] like Figure 1 and Figure 2As shown, a rectangular flat circuit board 20 is housed inside the housing 11. The circuit board 20 is a flat member with a known structure in which conductive paths are formed on the mounting surface of an insulating board, for example, made of an insulating material, using printed wiring technology. The conductive paths are formed of a material containing metals such as copper. In the electrical device 10, the circuit board 20 is arranged inside the housing 11 in a horizontal position with the normals of its surface surfaces, i.e., the substrate surfaces 20A and 20B, horizontal. In other words, the circuit board 20 is housed inside the housing 11 in a so-called vertical position with the substrate surfaces 20A and 20B extending in the vertical direction.

[0047] like Figure 1 As shown, in this embodiment, gaps (flow paths) through which an insulating liquid cooling medium 40 can flow are formed between the left, right, and upper edges of the circuit board 20 housed inside the housing 11 and the inner surface of the main body 11M or the cover 11L. Figure 2 As shown, in the circuit board 20, one substrate surface 20A and the other substrate surface 20B are designated as mounting surfaces, and electronic components 30 are mounted on the two substrate surfaces 20A and 20B of the circuit board 20. Furthermore, as... Figure 1 and Figure 2 As shown, the busbar 51 is arranged vertically at the center of the left-right direction of the substrate surface 20A.

[0048] (Electronic Component 30)

[0049] like Figure 1 and Figure 2 As shown, various electronic components 30 are mounted on the substrate surfaces 20A and 20B of the circuit board 20. For example... Figure 1 and Figure 2 As shown, gaps are formed between the electronic components 30 mounted on substrate surfaces 20A and 20B and the inner surface of the main body 11M of the housing 11, allowing the flow of an insulating liquid cooling medium 40. The electronic components 30 include, for example, resistors, coils, capacitors, fuses, relays, diodes, integrated circuits (ICs), field-effect transistors (FETs), and other switching elements. More specifically, such as... Figure 1 and Figure 2 As shown, it includes a high-voltage side FET31A as a high-voltage side switching element, a low-voltage side FET31B as a low-voltage side switching element, a transformer 32, a resonant coil 33A constituting a resonant circuit, a choke coil 33B, etc.

[0050] Electronic component 30 is disposed on the lower side inside the housing 11. For example... Figure 1 and Figure 2As shown, the electrical device 10 of this embodiment has a plurality of electronic components 30, which are integrally mounted on the lower part of the substrate surfaces 20A and 20B. When the electrical device 10 has a plurality of electronic components 30, at least one electronic component 30 is located inside the housing 11, arranged such that it is positioned below 1 / 2 of its height in the vertical direction, preferably below 1 / 3 of its height, and more preferably below 1 / 4 of its height. In this way, by arranging the electronic component 30, which is a heat-generating element, on the lower side inside the housing 11, the insulating liquid cooling medium 40 at the lower position inside the housing 11 is heated and rises due to the heat generated when energized, facilitating convection of the insulating liquid cooling medium 40 and improving heat dissipation. In this embodiment, the high-voltage side FET 31A, the low-voltage side FET 31B, and the transformer 32 containing multiple coils are arranged at the lowest part inside the housing 11. It should be noted that in this embodiment, as... Figure 1 As shown, four high-voltage side FETs 31A, six low-voltage side FETs 31B, one transformer and resonant coil 33A, and two choke coils 33B are mounted on the substrate surface 20A.

[0051] Even among the various electronic components 30 included in the electrical device 10, which is a DC-DC converter, the heat generated when energized is particularly large and relatively small. Although also affected by the circuit structure of the DC-DC converter, if the heat generated by all electronic components 30 when energized is set to 100%, there are cases where the high-voltage side FET 31A (4 units) accounts for more than 25%, the low-voltage side FET 31B (6 units) accounts for more than 15%, the transformer 32 accounts for more than 15%, and the resonant coil 33A (2 units) accounts for more than 10%, with these four types of electronic components accounting for more than 70% in total. In this embodiment, the three electronic components 30 with the largest heat generation (high-voltage side FET 31A, low-voltage side FET 31B, and transformer 32) are arranged at the bottom of the housing 11, and the resonant coil 33A and choke coil 33B, which have the second largest heat generation, are arranged directly above them. As a result, within the housing 11, the heat generated from the electronic components 30 when power is supplied to the electrical equipment 10 is significantly reduced from the bottom to the top (the difference between the heat generated at the bottom and the heat generated at the top increases).

[0052] Electronic component 30 is mounted in a known form on substrate surface 20A or substrate surface 20B, which serves as the mounting surface of circuit board 20, using known methods such as soldering, and is electrically connected to conductive paths formed by a material containing metal on substrate surfaces 20A and 20B. As an example, Figure 3 The mounting configuration of FET 31, which constitutes the high-voltage side FET 31A and the low-voltage side FET 31B, is shown. Figure 3As shown, FET31 has a main body portion 31M in which components are built-in and a terminal portion 31L protruding outward from the main body portion 31M. Figure 3 The image shows a three-terminal FET 31 with three protruding terminal portions 31L, but the FET 31 is not limited to this shape. Figure 3 As shown, pads 52 are formed on a portion of the circuit distributed on substrate surfaces 20A and 20B. The protruding ends of terminal portions 31L are connected to pads 52 by soldering or the like. It should be noted that the busbar 51, described later, is electrically connected to the conductive path formed on substrate surface 20A. Electronic components 30 mounted on substrate surface 20A are connected to busbar 51 via conductive paths including pads 52, which are formed of metal.

[0053] (Insulating liquid cooling medium 40)

[0054] like Figure 1 and Figure 2 As shown, an insulating liquid cooling medium 40 is filled into the interior of the housing 11. In this embodiment, the insulating liquid cooling medium 40 fills the interior of the housing 11 in such a way that the circuit board 20 is completely submerged. The insulating liquid cooling medium 40 does not need to completely fill the interior of the housing 11; it is sufficient to immerse the electronic components 30 in the insulating liquid cooling medium 40. When multiple electronic components 30 are arranged, it is sufficient to immerse only a portion of the electronic components 30, but it is preferable to immerse at least the high-heat-generating switching elements and coils arranged in the lower part of the housing, and more preferably to immerse all the electronic components 30.

[0055] The insulating liquid coolant 40 is a non-conductive liquid coolant. Examples of suitable insulating liquid coolants 40 include perfluorocarbons, hydrofluoroethers, hydrofluoroketones, and fluorine-based inactive liquids. Specifically, examples include Novec (registered trademark) manufactured by 3M Japan, Fluorinert (registered trademark), and Galden (registered trademark) manufactured by Solvay. When considering environmental impact, the use of hydrofluoroether-based Novec is particularly preferred. By immersing the electronic component 30 in the insulating liquid coolant 40, the charged parts of the electronic component 30 are directly cooled by the insulating liquid coolant 40.

[0056] In this embodiment, the insulating liquid coolant 40 is used, which has a lower content of dust particles per unit volume than that of air. Preferably, an insulating liquid coolant 40 with a particle diameter of, for example, 100 nm or more, and more specifically 1000 nm or more, has a lower content of dust particles than air. It should be noted that, in the above description, it is assumed that the electronic component 30 is not immersed in the insulating liquid coolant 40, and air is generally considered to be present near the electronic component 30. When dust particles adhere to the charged parts of the electronic component 30, short circuits may occur due to leakage traces. By using an insulating liquid coolant 40 with a lower content of dust particles per unit volume than air, the spacing between charged parts required to avoid short circuits is reduced. Therefore, the spacing between the electronic components 30 can be reduced, thereby achieving miniaturization of the electrical device 10.

[0057] Furthermore, in this embodiment, an insulating liquid coolant 40 with a higher withstand voltage than air is used as the insulating liquid coolant 40. For example, the withstand voltage of air is approximately 3 kV / mm, while that of Novec is approximately 16 kV / mm. By using an insulating liquid coolant 40 with a higher withstand voltage than air, the spacing between charged parts required to avoid short circuits is reduced. As a result, the creepage distance between electronic components 30 can be reduced, i.e., the mounting density of electronic components 30 on the circuit board 20 can be increased, thereby achieving miniaturization of the electrical device 10.

[0058] (Mother row 51)

[0059] like Figure 1 and Figure 2 As shown, a busbar 51 is disposed on the substrate surface 20A of the circuit board 20. The busbar 51 is a conductive member formed into an elongated flat strip in one direction by stamping or forming a metal sheet. In this embodiment, a busbar 51 formed of a copper-containing material with very high thermal conductivity is used. Figure 1 and Figure 2 As shown, the busbar 51 is arranged on the substrate surface 20A in a manner that is consistent in the vertical direction along its length and perpendicular to the substrate surface 20A, and is electrically connected to the conductive path formed on the substrate surface 20A. Thus, as described above, the busbar 51 is connected to the electronic component 30 via a metal component such as a conductive path including pads 52. It should be noted that, as... Figure 2 As shown, when disposed on the substrate surface 20A, a gap is formed between the front edge of the busbar 51 and the inner surface of the front wall of the main body 11M of the housing 11, through which the insulating liquid cooling medium 40 can flow.

[0060] like Figure 1As shown, in this embodiment, the busbar 51 is positioned at the center of the substrate surface 20A in the left-right direction, located between the high-voltage side FET 31A and choke coil 33B mounted on the substrate surface 20A and the low-voltage side FET 31B, transformer 32 and resonant coil 33A. Thus, multiple electronic components 30 that generate particularly large amounts of heat are arranged on the substrate surface 20A in a state of separation on the left and right sides of the busbar 51.

[0061] (Heat dissipation and heat dissipation in electrical equipment 10)

[0062] Next, an example of heat dissipation and heat dissipation in the electrical equipment 10 of this embodiment will be described.

[0063] When power is supplied to the electrical device 10, the electronic components 30, which are immersed in the insulating liquid cooling medium 40 within the housing 11, generate heat. For example... Figure 1 and Figure 2 As shown, particularly large amounts of heat are generated in the high-voltage side FET 31A, low-voltage side FET 31B, and transformer 32 located at the bottom of the housing 11. The heat generated by these electronic components 30 is transferred to the insulating liquid coolant 40, which is in contact with charged parts. The temperature of the insulating liquid coolant 40 rises and its specific gravity decreases as heat is transferred, so it rises as indicated by arrow F1. The insulating liquid coolant 40 rises further along the busbar 51 as indicated by arrows F2 and F3. As the insulating liquid coolant 40 rises and draws in the surrounding insulating liquid coolant 40 to create an upward flow, it moves along the liquid surface (the lower surface of the cover 11L in this embodiment) towards the left and right ends of the housing 11 as indicated by arrows F4 and F5 when it reaches the vicinity of the uppermost liquid surface (the lower surface of the cover 11L in this embodiment).

[0064] The heat from the insulating liquid coolant 40 reaching the lower surface of the cover 11L is transferred to the cover 11L, which is made of a metallic material with high thermal conductivity, and released from the upper surface of the cover 11L to the outside of the shell 11. As a result, the temperature of the insulating liquid coolant 40 decreases and its specific gravity increases, causing the insulating liquid coolant 40 to descend along the sidewall of the body 11M of the shell 11, as indicated by arrows F6 and F7. The descending insulating liquid coolant 40 draws in surrounding insulating liquid coolant 40, creating a downward flow. The body 11M, also made of a metallic material with high thermal conductivity, transfers the heat from the insulating liquid coolant 40 to the sidewall of the body 11M, and releases it from the outer surface of the sidewall to the outside of the shell 11. This further reduces the temperature of the insulating liquid coolant 40.

[0065] The insulating liquid coolant 40, moving along the bottom wall of the main body 11M as indicated by arrow F8, flows into the vicinity of the electronic components 30. The insulating liquid coolant 40 flowing into the vicinity of the high-voltage side FET 31A, low-voltage side FET 31B, and transformer 32 located at the bottom releases heat to the outside of the housing 11 via the cover 11L, the side walls of the main body 11M, etc., thus lowering its temperature. The cooled insulating liquid coolant 40 then comes into contact with the high-heat-generating electronic components 30, such as the high-voltage side FET 31A, low-voltage side FET 31B, and transformer 32, thereby transferring heat from them back to the insulating liquid coolant 40. The insulating liquid coolant 40, having transferred heat from the electronic components 30, rises again as indicated by arrow F1. It should be noted that convection of the insulating liquid coolant 40 also occurs on the substrate surface 20B side due to heat generation from the electronic components 30.

[0066] like Figure 1 and Figure 2 As shown, inside the housing 11, gaps are formed between the left, right, and upper edges of the circuit board 20 and the inner surface of the main body 11M or the cover 11L, allowing the insulating liquid cooling medium 40 to flow. Furthermore, gaps are also formed between the electronic components 30 mounted on the substrate surfaces 20A and 20B and the inner surface of the main body 11M of the housing 11, allowing the insulating liquid cooling medium 40 to flow. Additionally, when disposed on the substrate surface 20A, gaps are also formed between the front edge of the busbar 51 and the inner surface of the front wall of the main body 11M of the housing 11, allowing the insulating liquid cooling medium 40 to flow. Thus, in addition to the general flow described above, the insulating liquid cooling medium 40 also flows relatively freely throughout the housing 11, including the area between the substrate surface 20A and the substrate surface 20B.

[0067] In this way, the insulating liquid cooling medium 40 directly cools the charged parts of the electronic components 30 while convection inside the housing 11. As a result, heat is dispersed inside the electrical equipment 10 and released to the outside of the housing 11 through the cover 11L, the side walls of the main body 11M, etc.

[0068] Furthermore, in this embodiment, heat generated from the electronic component 30 is also dispersed via paths through highly thermally conductive metal components, such as conductive pathways containing pads 52, which are formed of a metal-containing material. Figure 3 As shown by the double-dot arrow H1, heat generated in, for example, FET31 is transferred from terminal portion 31L to pad 52. Furthermore, it is transferred to the conductive path formed on substrate surface 20A, including pad 52, and then to busbar 51 connected to the conductive path. Figure 1 and Figure 2As shown by the double-dot arrow H2, the heat transferred to the busbar 51 moves upward inside the busbar 51. The busbar 51, formed as a flat plate, has a large specific surface area, and an insulating liquid coolant 40 is attached to its surface. Therefore, heat inside the busbar 51 moves upward along its length while being transferred from the surface of the busbar 51 to the insulating liquid coolant 40. The insulating liquid coolant 40, having received heat from the busbar 51 and experiencing a temperature increase and decrease in specific gravity, rises along the busbar 51 as indicated by arrows F1, F2, and F3. This generates convection within the insulating liquid coolant 40, similar to the aforementioned phenomenon, dispersing heat within the electrical equipment 10. Furthermore, the heat from the insulating liquid coolant 40 is released to the outside of the housing 11 via the cover 11L, the side walls of the main body 11M, and the like.

[0069] As described above, electrical equipment 10 has a simple structure and excellent heat dissipation and heat dissipation.

[0070] (Effects of the implementation method)

[0071] The effects of this implementation method will be explained again.

[0072] The electrical device 10 of this embodiment includes a housing 11, a circuit board 20 disposed inside the housing 11, and at least one electronic component 30 disposed inside the housing 11 and heated by electricity. The housing 11 is filled with an insulating liquid cooling medium 40. The circuit board 20 is arranged in a horizontal position with the normals of the board surface 20A and 20B of the circuit board 20 being horizontal. The electronic component 30 is disposed on the lower side of the housing 11 and is immersed in the insulating liquid cooling medium 40.

[0073] According to the structure of this embodiment, the charged parts of the electronic components 30 can be directly cooled by the insulating liquid cooling medium 40. Heat released from the electronic components 30 disposed on the lower side of the housing 11 is transferred to the insulating liquid cooling medium 40, and the heated insulating liquid cooling medium 40 rises along the substrate surfaces 20A and 20B of the circuit board 20. As a result, natural convection of the insulating liquid cooling medium 40 is generated inside the housing 11, and heat is dispersed within the housing 11, suppressing localized temperature rises in the electrical device 10. Consequently, the mounting spacing of the electronic components 30 can be reduced, achieving miniaturization of the electrical device 10. It should be noted that the aforementioned electronic components 30 include semiconductor switching elements such as FETs 31. Furthermore, the aforementioned electronic components 30 include elements such as transformers 32 with coils and coils 33. Semiconductor switching elements such as FETs 31, transformers 32, and coils 33 are among the electronic components 30 used in the electrical device 10 that generate significant heat. By immersing these electronic components 30 in an insulating liquid coolant 40 and arranging them together on the lower side inside the housing 11, natural convection of the insulating liquid coolant 40 is easily generated inside the housing 11, which can improve heat dissipation and effectively suppress local temperature rise.

[0074] The electrical device 10 of this embodiment includes a plurality of electronic components 30, which are mounted on two substrate surfaces 20A and 20B, one substrate surface 20A and the other substrate surface 20B.

[0075] According to the structure of this embodiment, by mounting electronic components on both sides of the two surfaces of the circuit board 20, the area of ​​the circuit board 20 required to mount multiple electronic components 30 is reduced compared to a structure where electronic components are mounted on only one side of the board. This allows for suppression of the increase in the mounting density of the electronic components 30 and enables miniaturization of the circuit board 20 and even the electrical device 10.

[0076] In the electrical equipment 10 of this embodiment, the content of dust particles per unit volume of the insulating liquid cooling medium 40 is lower than the content of dust particles per unit volume of air.

[0077] According to the structure of this embodiment, compared with conventional electrical devices that are not filled with insulating liquid cooling medium 40, the number of dust particles floating in the housing 11 is reduced, and the possibility of short circuits due to dust particles is decreased. As a result, compared with conventional structures, the mounting density of electronic components 30 can be increased, and the electrical device 10 can be miniaturized.

[0078] In the electrical device 10 of this embodiment, the housing 11 is formed of a material containing metal.

[0079] According to the structure of this embodiment, the housing 11 has high thermal conductivity, thereby allowing heat transferred from the electronic component 30 to the insulating liquid cooling medium 40 to easily transfer from the insulating liquid cooling medium 40 to the housing 11, and then to the outside. As a result, the heat dissipation of the electrical device 10 is improved, and the temperature rise of the electrical device 10 can be suppressed.

[0080] In the electrical device 10 of this embodiment, an insulating liquid cooling medium 40 is formed between the housing 11 and the electronic component 30, allowing the flow path of the medium to flow.

[0081] According to the structure of this embodiment, the insulating liquid coolant 40 flows between the housing 11 and the electronic component 30, thereby ensuring good convection of the insulating liquid coolant 40 within the housing 11 and improving heat dissipation. Furthermore, the insulating liquid coolant 40 flows along the housing 11, thereby facilitating heat transfer from the insulating liquid coolant 40 to the housing 11 and improving heat dissipation. This helps to suppress the temperature rise of the electrical equipment 10.

[0082] The electrical device 10 of this embodiment also includes a busbar 51 formed in the shape of a flat plate containing metal, and the busbar 51 is connected to the electronic component 30 via a metal member formed in the shape of a metal containing metal.

[0083] According to the structure of this embodiment, heat from the electronic component 30 is transferred to the busbar 51 via a metal component with high thermal conductivity, such as a conductive path including the pad 52. Furthermore, the heat transferred to the busbar 51 is transferred from the surface of the busbar 51, which has high thermal conductivity and a large specific surface area, to the insulating liquid cooling medium 40. As a result, the heat generated by the electronic component 30 is rapidly transferred to the insulating liquid cooling medium 40, improving the heat dissipation and heat dissipation of the electrical device 10.

[0084] In the electrical equipment 10 of this embodiment, the busbar 51 is a long strip that extends in one direction and is arranged so that its length direction is along the vertical direction.

[0085] According to the structure of this embodiment, the heat transferred to the busbar 51 is also transferred and dispersed from bottom to top inside the busbar 51, which has high thermal conductivity. As a result, the heat dissipation inside the electrical equipment is further improved.

[0086] In the electrical device 10 of this embodiment, the busbar 51 is configured in a position where the plate surface of the busbar 51 is perpendicular to the substrate surface 20A of the circuit board 20.

[0087] According to the structure of this embodiment, the insulating liquid cooling medium 40 is guided by the substrate surface 20A of the circuit board 20 and the plate surface of the busbar 51 while flowing, and the flow of the insulating liquid cooling medium 40 is adjusted. As a result, the insulating liquid cooling medium 40 convects more smoothly inside the housing 11, and the heat dissipation and heat dissipation of the electrical equipment 10 are improved.

[0088] <Other Implementation Methods>

[0089] This disclosure is not limited to the embodiments described above and the accompanying drawings. For example, the embodiments described below are also included in the technical scope of the technology disclosed in this specification.

[0090] (1) The electronic component 30 is not limited to the structure described above. The size, shape, number, and arrangement of each electronic component 30 described in the above embodiments are just examples.

[0091] (2) The circuit board 20 is not limited to the configuration described above. In the above embodiment, the circuit board 20 is positioned rearward in the front-rear direction of the housing 11, and the electronic components 30 that generate a large amount of heat are mounted on the front side of the circuit board 20, i.e., the substrate surface 20A. For example, the circuit board may also be positioned in the center of the front-rear direction within the housing, so that the electronic components 30 that generate a large amount of heat are distributed on one substrate surface and the other substrate surface.

[0092] (3) The circuit board 20 and the housing 11 are not limited to the size and shape described above. In the above embodiment, the circuit board 20 and the housing 11 are described as having a vertically elongated shape with a height dimension larger than a width dimension larger than a width dimension larger than a height ... smaller than a height dimension larger than a height dimension larger than a height dimension smaller than a height dimension smaller than a height dimension larger than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a height dimension smaller than a

[0093] (4) The shape, number, and arrangement of the busbars 51 are not limited to the situations described above. For example, multiple busbars can be arranged on both one substrate surface and the other substrate surface of the circuit board. Furthermore, multiple busbars can be arranged in parallel side by side, spaced apart in the left-right direction on one substrate surface or on both substrate surfaces of the circuit board, and extending in the vertical direction. In this way, the flow of the insulating liquid cooling medium can be further adjusted.

[0094] (5) Electrical equipment 10 is not limited to cases that include DC-DC converters. For example, this technology can also be applied to AC-DC converters, electrical connection boxes, distribution boxes, ECUs, etc.

[0095] Label Explanation

[0096] 10: Electrical equipment (DC-DC converter)

[0097] 11: Shell

[0098] 11L: Cover

[0099] 11M: Main Body

[0100] 20: Circuit board

[0101] 20A, 20B: Substrate surface

[0102] 30: Electronic components

[0103] 31: FET

[0104] 31A: High-voltage side FET

[0105] 31B: Low-side FET

[0106] 31L: Terminal section

[0107] 31M: Main body

[0108] 32: Transformer

[0109] 33: Coil

[0110] 33A: Resonant coil

[0111] 33B: Choke coil

[0112] 40: Insulating liquid cooling medium

[0113] 51: Mother row

[0114] 52: Solder pad.

Claims

1. An electrical device comprising: The housing has a rectangular box-shaped body that opens upwards and a cover that seals the opening at the top of the body. The body and the cover are made of a metal material with high thermal conductivity. The body has a rectangular bottom wall and four side walls that stand up from the periphery of the bottom wall. It is integrally formed to a size that can accommodate a circuit board. The cover can watertightly seal the opening of the body. The circuit board is disposed inside the housing; and Multiple electronic components are disposed inside the housing, and the heat generated by these multiple electronic components when powered on is different from that of each other. The interior of the housing is filled with an insulating liquid cooling medium. The circuit board is configured with its surface, i.e., the normal to the surface of the board, in a horizontal position. The plurality of said electronic components are arranged inside the housing in such a manner that the heat generated from the plurality of said electronic components decreases from the bottom to the top when energized, and are immersed in the insulating liquid cooling medium. A gap is formed between the electronic component and the inner surface of the main body of the housing, allowing the insulating liquid cooling medium to flow through. The insulating liquid cooling medium releases heat to the outside of the housing through the side walls of the cover and the main body. The electrical equipment also includes a busbar, which is formed into a flat plate shape and is made of metal. The busbar is connected to the electronic components via a metal member made of metal. The busbar is a long strip that extends in one direction, and is arranged so that its length direction is along the vertical direction. The busbar is arranged in an orientation in which the surface of the busbar is perpendicular to the surface of the circuit board. A flow path of the insulating liquid cooling medium extending in a vertical direction is formed along the substrate surface of the circuit board and the plate surface of the busbar. The electrical equipment includes a plurality of said electronic components, and the busbar is arranged extending vertically among the plurality of said electronic components. If the normal direction of the substrate surface of the circuit board is taken as the height direction, then the height of the busbar is higher than the height of the plurality of electronic components in this height direction.

2. The electrical equipment according to claim 1, wherein, The electrical equipment includes multiple of the aforementioned electronic components. The electronic components are mounted on two substrate surfaces, one on one substrate surface and the other on the substrate surface.

3. The electrical equipment according to claim 1 or 2, wherein, The insulating liquid cooling medium has a lower dust particle content per unit volume than air.

4. The electrical equipment according to claim 1 or 2, wherein, The plurality of said electronic components are arranged inside the housing in such a manner that the total heat generated from said electronic components arranged at a height of less than 1 / 2 in the vertical direction accounts for more than 70% of the total heat generated from all said electronic components when energized.

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