WO2022070282A1

WO2022070282A1 - Circuit structure

Info

Publication number: WO2022070282A1
Application number: PCT/JP2020/037030
Authority: WO
Inventors: 俊悟平谷; 雄介國井; 成治高橋
Original assignee: 住友電気工業株式会社
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2022-04-07

Abstract

A circuit structure comprising a first member having a first substrate that constitutes a first switching circuit, a second member having a second substrate that constitutes a second switching circuit, and a third member having a transformer that electrically joins the first switching circuit and the second switching circuit, the first member and the second member being stacked, and the third member being positioned in a direction intersecting the direction in which the first member and the second member are stacked.

Description

Circuit structure

This disclosure relates to a circuit structure.

Patent Document 1 discloses a DC / DC converter integrated charger including a DC / DC converter circuit unit and a housing for accommodating the DC / DC converter circuit unit inside. The DC / DC converter circuit section includes a high-voltage circuit section that converts a high-voltage DC voltage into a high-voltage AC voltage, a transformer that converts a high-voltage AC voltage into a low-voltage AC voltage, and a low-voltage AC voltage. It has a low voltage circuit unit that converts the voltage into a low voltage DC voltage. The housing is configured in the shape of a rectangular parallelepiped container, and is composed of a rectangular plate-shaped bottom portion, a rectangular frame-shaped side wall standing from the peripheral edge of the bottom portion, and a rectangular plate-shaped cover. The DC / DC converter circuit section is arranged on the upper surface of the bottom.

International Publication No. 2017/022478

The circuit structure according to the present disclosure is
The first member having the first substrate constituting the first switching circuit,
A second member having a second substrate constituting the second switching circuit,
A third member having a transformer that electromagnetically couples the first switching circuit and the second switching circuit is provided.
The first member and the second member are laminated and
The third member is arranged in a direction intersecting the stacking direction of the first member and the second member.

FIG. 1 is a cross-sectional view showing an outline of the circuit structure according to the first embodiment. FIG. 2 is a diagram showing electrical graphic symbols of a transformer provided in the circuit structure according to the first embodiment. FIG. 3 is a diagram showing electrical graphic symbols of another example of a transformer provided in the circuit structure according to the first embodiment. FIG. 4 is a diagram showing electrical graphic symbols of yet another example of the transformer provided in the circuit structure according to the first embodiment. FIG. 5 is an exploded perspective view showing an outline of a transformer provided in the circuit structure according to the first embodiment. FIG. 6 is an exploded perspective view showing an outline of another example of a transformer provided in the circuit structure according to the first embodiment. FIG. 7 is a cross-sectional view showing a state in which the circuit structure is cut along the (VII)-(VII) cutting line of FIG. FIG. 8 is a cross-sectional view showing an outline of the circuit structure according to the second embodiment. FIG. 9 is a cross-sectional view showing an outline of the circuit structure according to the third embodiment. FIG. 10 is a cross-sectional view showing an outline of the circuit structure according to the fourth embodiment. FIG. 11 is a cross-sectional view showing an outline of the circuit structure according to the fifth embodiment. FIG. 12 is a cross-sectional view showing an outline of the circuit structure according to the sixth embodiment.

[Problems to be solved by this disclosure]
By arranging the high voltage circuit section, the transformer, and the low voltage circuit section in parallel on the same plane on the upper surface of the bottom, the projected area of the DC / DC converter circuit section when viewed in plan view becomes large. ..

Therefore, one of the purposes of the present disclosure is to provide a circuit structure having a small projected area.

[Effect of this disclosure]
The circuit structure according to the present disclosure has a small projected area.

<< Explanation of Embodiments of the present disclosure >>
First, embodiments of the present disclosure will be listed and described.

(1) The circuit structure according to one aspect of the present disclosure is
The first member having the first substrate constituting the first switching circuit,
A second member having a second substrate constituting the second switching circuit,
A third member having a transformer that electromagnetically couples the first switching circuit and the second switching circuit is provided.
The first member and the second member are laminated and
The third member is arranged in a direction intersecting the stacking direction of the first member and the second member.

In the circuit structure, the first member and the second member are laminated, so that the projected area seen from the stacking direction can be easily reduced.

(2) As one form of the circuit structure,
The transformer is
With the primary coil,
With the secondary coil,
A core having a portion in which the primary coil and the secondary coil are arranged are provided.
The primary coil and the secondary coil are
An insulating substrate having a through hole through which a part of the core is inserted,
A substrate coil having a coil pattern provided around the through hole in the insulating substrate.
The substrate coil may have a direction orthogonal to the axial direction of the coil pattern along the stacking direction of the first member and the second member.

In the above form, the projected area can be reduced as compared with the case where the axial direction of the coil pattern is along the stacking direction.

(3) As one form of the circuit structure,
The transformer is
With the primary coil,
With the secondary coil,
A core having a portion in which the primary coil and the secondary coil are arranged are provided.
The primary coil and the secondary coil may be configured by winding windings.

In the above form, the number of turns of the primary coil and the secondary coil, the cross-sectional area of the winding, etc. can be easily changed, and the degree of freedom in transformer design is high.

(4) As one form of the circuit structure,
It may have a cooling member for cooling at least one selected from the group consisting of the first switching circuit, the second switching circuit, and the transformer.

The above form easily dissipates heat from at least one of the above members.

(5) As one form of the circuit structure of (4) above,
The cooling member is arranged at a position surrounded by the first member, the second member, and the third member, and has a space through which the refrigerant flows.
At least one of the first member and the cooling member has a first surface that partitions the first switching circuit and the refrigerant.
At least one of the second member and the cooling member has a second surface that partitions the second switching circuit and the refrigerant.
At least one of the third member and the cooling member may have a third surface that partitions the transformer and the refrigerant.

In the above form, since the location where the cooling member is arranged is surrounded by the first member, the second member, and the third member, the length in the stacking direction does not become excessively long, and the first member and the second member are not excessively long. It is easy to dissipate heat from the member and the third member.

(6) As one form of the circuit structure of (5) above,
One member selected from the group consisting of the first member, the second member, and the third member, and the cooling member may be an integral assembly.

The above form is excellent in assembly workability because the number of parts can be reduced as compared with the case where each of the first member, the second member, the third member, and the cooling member is composed of separate members independent of each other. ..

(7) As one form of the circuit structure of the above (5) or the above (6),
It is interposed between the first member and the cooling member, between the second member and the cooling member, and between at least one selected from the group consisting of the third member and the cooling member. It is possible to provide a heat transfer member.

In the above form, the heat transfer member makes it easy to transfer at least one heat of the first switching circuit, the second switching circuit, and the transformer to the cooling member.

(8) As one form of the circuit structure of (4) above,
The cooling member is
The first cooling member arranged on the side of the first substrate opposite to the second substrate side,
A second cooling member arranged on the side of the second substrate opposite to the first substrate side,
The transformer has the first substrate and a third cooling member arranged on the side opposite to the side of the second substrate.
The first cooling member, the second cooling member, and the third cooling member have a space through which the refrigerant flows.
At least one of the first member and the first cooling member has a first surface that partitions the first switching circuit and the refrigerant.
At least one of the second member and the second cooling member has a second surface that partitions the second switching circuit and the refrigerant.
At least one of the third member and the third cooling member may have a third surface that partitions the transformer and the refrigerant.

The above form makes it easy to dissipate heat from the first switching circuit, the second switching circuit, and the transformer while reducing the projected area.

<< Details of Embodiments of the present disclosure >>
Details of the embodiments of the present disclosure will be described below. The same reference numerals in the figure indicate the same names.

<< Embodiment 1 >>
[Circuit structure]
The circuit structure 1 according to the first embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 corresponds to a diagram showing an outline of a state in which the circuit structure 1 is cut along a cutting line along the left-right direction of the paper surface between the input terminal 16 and the discharge port 47 shown in FIG. 7. The circuit structure 1 of the present embodiment includes a first member 10, a second member 20, and a third member 30. The first member 10 has a first substrate 11. The first substrate 11 constitutes the first switching circuit. The second member 20 has a second substrate 21. The second substrate 21 constitutes a second switching circuit. The third member 30 has a transformer 31. The transformer 31 electromagnetically couples the first switching circuit and the second switching circuit. One of the features of the circuit structure 1 of the present embodiment is that the first member 10 and the second member 20 are laminated, and the transformer 31 is arranged at a specific position with respect to the first member 10 and the second member 20. There is a point. The details will be described below.

[First member]
The first member 10 has a first substrate 11. In this embodiment, the first member 10 has a first substrate 11 and a first housing 12. The first member 10 may further include other electronic circuits of the first substrate 11.

(First board)
The first substrate 11 constitutes the first switching circuit. The first switching circuit of this embodiment includes a circuit that converts a DC voltage into an AC voltage. The first switching circuit is not limited to a circuit that converts a DC voltage into an AC voltage. A known printed circuit board (PCB) can be used as the first substrate 11.

(First housing)
The first housing 12 houses, shields, and mechanically protects the first substrate 11. The first housing 12 of the present embodiment has a bottom portion 13, a wall portion 14, and a lid portion 15. The bottom portion 13 and the wall portion 14 are configured in a series. The wall portion 14 and the lid portion 15 are made of separate members, and in this embodiment, they are fixed to each other by a tightening member such as a bolt. Unlike this embodiment, the wall portion 14 and the lid portion 15 may be fixed by an adhesive or welding.

The first substrate 11 is mounted on the bottom 13. In this embodiment, the bottom portion 13 is arranged on the second member 20 side of the first housing 12. The second member 20 side is the upper side of the paper surface in FIG. The bottom portion 13 is formed in a flat plate shape in this embodiment. The planar shape of the bottom portion 13 is rectangular in this embodiment. The planar shape means a shape seen from the stacking direction of the first member 10 and the second member 20. The bottom portion 13 of the present embodiment has a first surface 130 that partitions the first substrate 11 and the refrigerant 41 described later. The first surface 130 constitutes a surface on the bottom 13 on the second member 20 side.

The wall portion 14 surrounds the periphery of the first substrate 11. The wall portion 14 is erected from the peripheral edge of the bottom portion 13. In this embodiment, the wall portion 14 is configured in a rectangular frame shape extending from the peripheral edge of the bottom portion 13 toward the side opposite to the second member 20 side. The opposite side is the lower side of the paper in FIG. An opening is provided on the opposite side of the wall portion 14. The opening is closed by the lid 15. The wall portion 14 has a first end wall portion 141, a second end wall portion 142, a first side wall portion 143, and a second side wall portion. The illustration of the second side wall portion is omitted.

The first end wall portion 141 and the second end wall portion 142 face each other. The first side wall portion 143 and the second side wall portion face each other. The directions of the first end wall portion 141 and the second end wall portion 142 facing each other and the directions of the first side wall portion 143 and the second side wall portion facing each other are orthogonal to each other.

The first end wall portion 141 is arranged on the side opposite to the third member 30 side. The opposite side is the left side of the paper in FIG. The second end wall portion 142 is arranged on the third member 30 side. The third member 30 side is the right side of the paper in FIG. The first side wall portion 143 connects the first end portions of the first end wall portion 141 and the second end wall portion 142 to each other. The first end portion of the first end wall portion 141 and the second end wall portion 142 is the end portion on the back side of the paper surface in FIG. That is, the first side wall portion 143 is arranged on the back side of the paper surface in FIG. The second side wall portion connects the second end portions of the first end wall portion 141 and the second end wall portion 142 to each other. The second end portion of the first end wall portion 141 and the second end wall portion 142 is the end portion on the front side of the paper in FIG. That is, the second side wall portion is arranged on the front side of the paper surface in FIG.

The first end wall portion 141 is provided with an input terminal 16 connected to the first board 11. The installation location of the input terminal 16 is not limited to the first end wall portion 141. The input terminal 16 may be provided on, for example, the first side wall portion 143 or the second side wall portion.

The heights of the first end wall portion 141, the first side wall portion 143, and the second side wall portion are the same. The height is a length along the stacking direction. In this embodiment, the height of the second end wall portion 142 is lower than the height of the first end wall portion 141 over the entire width of the second end wall portion 142. Therefore, a gap is formed between the second end wall portion 142 and the lid portion 15. The width of the second end wall portion 142 is the length between the first side wall portion 143 and the second side wall portion, and in FIG. 1, it means the length in the vertical direction of the paper surface. This gap allows the wiring 90 that electrically connects the first switching circuit of the first substrate 11 and the transformer 31 of the third member 30, which will be described later, to pass through.

Unlike this embodiment, the height of the second end wall portion 142 does not have to be lower than the height of the first end wall portion 141 over the entire width of the second end wall portion 142. The height of the second end wall portion 142 is the same as that of the first end wall portion 141 except for a part of the total length of the width of the second end wall portion 142, and the height of a part thereof is the first end wall portion 141. May be lower than. That is, the second end wall portion 142 may have a portion having a height partially lower than that of the first end wall portion 141. The wiring 90 can be inserted through the gap between the partially low height portion and the lid portion 15.

Although not shown, the end faces of the first side wall portion 143 and the second side wall portion are provided with a plurality of flange portions projecting outward in the present embodiment, and bolt insertion holes are provided in each flange portion. ing. The flange portion and the insertion hole are used for fixing the wall portion 14 and the lid portion 15. Unlike this embodiment, each flange portion may be provided so as to project inward.

The lid portion 15 covers the first substrate 11. The lid portion 15 is arranged on the side opposite to the bottom portion 13 side. The lid portion 15 of the present embodiment closes the opening of the wall portion 14 of the first housing 12 and the opening of the third housing 32 of the third member 30 in a series. Unlike this embodiment, the lid portion 15 may close only the opening portion of the first housing 12. The shape of the lid portion 15 is a rectangular flat plate in this embodiment.

In this embodiment, the lid portion 15 is fixed to each end surface of the first side wall portion 143 and the second side wall portion and to the side surface of the bottom portion 33 of the third housing 32, which will be described later. Although not shown, the peripheral edge of the lid portion 15 has a plurality of flange portions corresponding to the flange portions of the first side wall portion 143 and the second side wall portion and a plurality of flange portions corresponding to the flange portions of the bottom portion 33 described later. A flange portion is provided. Bolt insertion holes are provided in each flange portion. By aligning the insertion holes of the flanges of the first side wall 143 and the second side wall, the insertion holes of the flanges of the bottom 33, and the insertion holes of each flange of the lid 15, and tightening them with bolts, the lid portion 15 is fixed to the first side wall portion 143, the second side wall portion, and the bottom portion 33 of the wall portion 14.

In this embodiment, the first housing 12 and the cooling member 40 are configured as an integral assembly. Unlike this embodiment, the first housing 12 may be composed of a separate member independent of the cooling member 40. In this embodiment, the bottom portion 13 of the first housing 12 also serves as the bottom portion 43 of the cooling member 40.

Examples of the constituent material of the first housing 12 include metals such as aluminum, aluminum alloy, magnesium, and magnesium alloy. The metal has excellent electromagnetic shielding properties and also excellent thermal conductivity. Therefore, the metal easily shields the first switching circuit and the first substrate 11 electromagnetically and easily dissipates heat. Further, since the metal has excellent mechanical strength, it is easy to mechanically protect the first switching circuit and the first substrate 11. Further, since the metal is lightweight, it is easy to reduce the weight of the first housing 12, and thus the circuit structure 1.

[Second member]
The second member 20 has a second substrate 21. In this embodiment, the second member 20 has a second substrate 21 and a second housing 22. Unlike this embodiment, the second member 20 may have another electronic circuit of the second substrate 21.

The second member 20 is laminated with respect to the first member 10. That is, the first substrate 11 and the second substrate 21 are laminated. When the first substrate 11 and the second substrate 21 are laminated, the first member 10 and the second member 20 are laminated so that the front and back surfaces of the first substrate 11 and the front and back surfaces of the second substrate 21 are substantially parallel to each other. And are laminated.

(Second board)
The second substrate 21 constitutes a second switching circuit. The second switching circuit of this embodiment includes a circuit that converts an AC voltage into a DC voltage. The second switching circuit is not limited to a circuit that converts an AC voltage into a DC voltage. As for the second substrate 21, a known PCB can be used as in the case of the first substrate 11.

(Second housing)
The second housing 22 houses, shields, and mechanically protects the second substrate 21. The second housing 22 of the present embodiment has a bottom portion 23, a wall portion 24, and a lid portion 25, similarly to the first housing 12. The bottom portion 23 and the wall portion 24 are configured in a series. The wall portion 24 and the lid portion 25 are made of separate members, and in this embodiment, they are fixed to each other by a tightening member such as a bolt. Unlike this embodiment, the wall portion 24 and the lid portion 25 may be fixed by an adhesive, welding, or the like. The configuration of the bottom portion 23, the wall portion 24, and the lid portion 25 in the second housing 22 is the same as the configuration of the bottom portion 13, the wall portion 14, and the lid portion 15 in the first housing 12.

The second board 21 is mounted on the bottom 23. In this embodiment, the bottom portion 23 is arranged on the first member 10 side of the second housing 22. The first member 10 side is the lower side of the paper in FIG. The bottom 23 of the second housing 22 and the bottom 13 of the first housing 12 face each other. The shape of the bottom portion 23 is a rectangular flat plate like the bottom portion 23 of the first housing 12. The bottom portion 23 has a second surface 230 that partitions the second substrate 21 and the refrigerant 41. The second surface 230 constitutes a surface on the bottom 23 on the side of the first member 10.

The wall portion 24 surrounds the periphery of the second substrate 21. The wall portion 24 is erected from the peripheral edge of the bottom portion 23. In this embodiment, the wall portion 24 is configured in a rectangular frame shape extending from the peripheral edge of the bottom portion 23 toward the side opposite to the first member 10 side. The side opposite to the first member 10 side is the upper side of the paper surface in FIG. An opening is provided on the opposite side of the wall portion 24. The opening is closed by the lid 25. The wall portion 24 has a first end wall portion 241, a second end wall portion 242, a first side wall portion 243, and a second side wall portion. The illustration of the second side wall portion is omitted.

The positional relationship between the first end wall portion 241 and the second end wall portion 242, the first side wall portion 243, and the second side wall portion in the second housing 22 and their respective arrangement locations are the first in the first housing 12. The positional relationship between the end wall portion 141, the second end wall portion 142, the first side wall portion 143, and the second side wall portion and their respective arrangement locations are the same.

The first end wall portion 241 is provided with an output terminal 26 connected to the second board 21. The installation location of the output terminal 26 is not limited to the first end wall portion 241. The output terminal 26 may be provided on, for example, the first side wall portion 243 or the second side wall portion.

The heights of the first end wall portion 241 and the first side wall portion 243 and the second side wall portion in the second housing 22 are the same. The height of the second end wall portion 242 is lower than that of the first end wall portion 241 over the entire width of the second end wall portion 242 in this embodiment. Therefore, a gap is formed between the second end wall portion 242 and the lid portion 25. The width of the second end wall portion 242 is the length between the first side wall portion 243 and the second side wall portion, like the width of the second end wall portion 142, and is the length in the vertical direction of the paper surface in FIG. To say. This gap allows the wiring 90 that electrically connects the second switching circuit of the second substrate 21 and the transformer 31 of the third member 30, which will be described later, to pass through. Unlike this embodiment, the height of a part of the second end wall portion 242 may be lower than the height of the first end wall portion 241.

Although not shown, the end faces of the first side wall portion 243 and the second side wall portion are provided with a plurality of flange portions projecting outward in the present embodiment, and bolt insertion holes are provided in each flange portion. ing. The flange portion and the insertion hole are used for fixing the wall portion 24 and the lid portion 25. Unlike this embodiment, each flange portion may be provided so as to project inward.

The lid portion 25 covers the second substrate 21. The lid portion 25 is arranged on the side opposite to the bottom portion 23 side. The lid portion 25 of the present embodiment closes the opening of the wall portion 24 of the second housing 22 and the opening of the third housing 32 of the third member 30 in a series. Unlike this embodiment, the lid portion 25 may close only the opening portion of the second housing 22. In this embodiment, the shape of the lid portion 25 is a rectangular flat plate like the lid portion 15 of the first housing 12.

In this embodiment, the lid portion 25 is fixed to each end surface of the first side wall portion 243 and the second side wall portion and to the side surface of the bottom portion 33 of the third housing 32. Although not shown, the peripheral edge of the lid portion 25 has a plurality of flange portions corresponding to the flange portions of the first side wall portion 243 and the second side wall portion and a plurality of flange portions corresponding to the flange portions of the bottom portion 33 described later. A flange portion is provided, and each flange portion is provided with a bolt insertion hole. By aligning the insertion holes of the flanges of the first side wall portion 243 and the second side wall portion, the insertion holes of the flange portions of the bottom portion 33, and the insertion holes of each flange portion of the lid portion 25 with bolts, the lid portion is tightened. 25 is fixed to the first side wall portion 143 and the second side wall portion and the bottom portion 33 of the wall portion 24.

Unlike the first housing 12, the second housing 22 of the present embodiment is composed of a separate member independent of the cooling member 40 described later. Unlike this embodiment, the second housing 22 and the cooling member 40 may be configured as an integral assembly. For example, the bottom 23 of the second housing 22 may also serve as the bottom 43 of the cooling member 40. The bottom portion 23 of the second housing 22 of the present embodiment functions as a top portion of the cooling member 40.

Examples of the constituent material of the second housing 22 include the same metal as the constituent material of the first housing 12. The constituent material of the second housing 22 and the constituent material of the first housing 12 may be the same or different from each other.

[Third member]
The third member 30 has a transformer 31 as shown in FIGS. 1 to 7. 1 and 7 simplify the transformer 31 for convenience of explanation. In this embodiment, the third member 30 has a transformer 31 and a third housing 32, as shown in FIGS. 1 and 7. The third member 30 is arranged in a direction intersecting the stacking direction with respect to the first member 10 and the second member 20.

(Trance)
The transformer 31 electromagnetically couples the first switching circuit and the second switching circuit. The transformer 31 raises and lowers the AC voltage. In this embodiment, the transformer 31 includes a primary coil, a secondary coil, and a core 312 (FIGS. 5 and 6). The number of coils in each of the primary coil and the secondary coil may be one or two or more. In this embodiment, as shown in FIG. 2, the number of coils in each of the primary coil and the secondary coil is one. Unlike this embodiment, for example, as shown on the left side of the paper in FIG. 3, the number of coils in the primary coil is one, and as shown on the right side of the paper in FIG. 3, the number of coils in the secondary coil is two. But it may be. For example, as shown in FIG. 4, the number of coils in each of the primary coil and the secondary coil may be two. As the transformer 31, a known transformer can be used. The number of transformers 31 may be singular or plural. The number of transformers 31 in this embodiment is one.

The primary coil is electrically connected to the first substrate 11. The secondary coil is electrically connected to the second substrate 21. As shown in FIG. 5, the primary coil and the secondary coil are composed of the substrate coil 311. The primary coil and the secondary coil do not have to be composed of the substrate coil 311. For example, the primary coil and the secondary coil may be configured by winding the winding 310 as shown in FIG.

As shown in FIG. 5, the substrate coil 311 has an insulating substrate 311a and a coil pattern 311b provided on the insulating substrate 311a. The insulating substrate 311a has a rectangular shape in this embodiment. The insulating substrate 311a has a through hole 311c through which the leg portion of the core 312 is inserted. The number of through holes 311c corresponds to the number of legs of the core 312. FIG. 5 shows an example in which the primary coil and the secondary coil are arranged coaxially. The insulating substrate 311a is composed of a multilayer substrate, and the coil pattern of the primary coil and the coil pattern of the secondary coil are laminated on one insulating substrate 311a. Each coil pattern is composed of a metal foil such as a copper foil. In FIG. 5, each coil pattern is configured in a spiral shape. That is, the coil pattern of one layer includes a plurality of turns. It should be noted that the coil pattern of one layer may include only one turn. FIG. 6 shows a primary coil and a secondary coil configured by spirally winding the winding 310. FIG. 6 shows an example in which the primary coil and the secondary coil are arranged coaxially. The winding 310 may be a flat wire, a round wire, a bus bar, or the like. The bus bar can also be configured by hollowing out a plate in a predetermined spiral shape.

The core 312 magnetically couples the primary coil and the secondary coil. The core 312 has a central leg portion 313, a first side leg portion 314, a second side leg portion 315, a first connecting portion 316, and a second connecting portion 317. The central leg portion 313 is arranged inside the primary coil and the secondary coil. The first side leg portion 314 and the second side leg portion 315 are arranged outside the primary coil and the secondary coil. The first side leg portion 314 and the second side leg portion 315 are arranged at positions facing each other with the central leg portion 313 interposed therebetween. The first connecting portion 316 connects the first end portions of the three legs to each other. The second connecting portion 317 connects the second ends of the three legs to each other. The first end portion of each leg portion is an end portion arranged on one side in the axial direction of each leg portion. The second end of each leg is an end located on the other side of each leg in the axial direction.

The core 312 has a plurality of divided core pieces. A closed magnetic path is formed by combining a plurality of core pieces. The core 312 of the present embodiment includes two core pieces, a first core piece 312a and a second core piece 312b. The shapes of the first core piece 312a and the second core piece 312b are not particularly limited and can be appropriately selected. The core 312 of this embodiment is an EI type core. That is, the shape of the first core piece 312a is E-shaped, and the shape of the second core piece 312b is I-shaped. Unlike this embodiment, the core 312 may be an EE-shaped core in which the shapes of the first core piece 312a and the second core piece 312b are E-shaped. The other core 312 may be a U-U type core or a U-I type core. The number of legs of the core 312 may be three as in the present embodiment, or may be two as in the present embodiment.

The first core piece 312a is composed of the above-mentioned central leg portion 313, the first side leg portion 314, the second side leg portion 315, and the first connecting portion 316. The central leg portion 313, the first side leg portion 314, the second side leg portion 315, and the first connecting portion 316 are configured in a series. The central leg portion 313, the first side leg portion 314, and the second side leg portion 315 extend from the first connecting portion 316 toward the second core piece 312b side. The second core piece 312b is composed of the second connecting portion 317.

The third member 30 is relative to the first member 10 and the second member 20 so that the direction orthogonal to the axial direction of the coil pattern 311b in the substrate coil 311 is along the stacking direction of the first member 10 and the second member 20. It is preferable that they are arranged in a row. That is, it is preferable that the front and back surfaces of the substrate coil 311 follow the stacking direction. When the shape of the substrate coil 311 is rectangular as in the present embodiment, it is preferable that the creepage direction of the front and back surfaces of the substrate coil 311 is along the stacking direction. Then, the ground contact area is reduced as compared with the case where the third member 30 is arranged so that the creepage direction of the front and back surfaces of the substrate coil 311 is parallel to the planes of the first substrate 11 and the second substrate 21. easy. In this embodiment, the third member 30 is arranged with respect to the first member 10 and the second member 20 so that the creepage direction of the front and back surfaces of the substrate coil 311 is along the stacking direction.

(Third housing)
As shown in FIGS. 1 and 7, the third housing 32 houses, shields, and mechanically protects the transformer 31. In this embodiment, the third housing 32 has a bottom portion 33, a wall portion 34, and a lid portion 35. The bottom portion 33 and the wall portion 34 are configured in a series. The wall portion 34 and the lid portion 35 are made of separate members.

A transformer 31 is mounted on the bottom 33. The bottom portion 33 is arranged on the side opposite to the first substrate 11 and the second substrate 21 side. The side opposite to the side of the first substrate 11 and the second substrate 21 is the right side of the paper in FIG. The shape of the bottom portion 33 is a rectangular flat plate in this embodiment.

Although not shown, each of the side surfaces of the bottom portion 33 is provided with a plurality of flange portions protruding outward in this embodiment, and each flange portion is provided with a bolt insertion hole. Both sides constitute surfaces arranged on both sides in the stacking direction. That is, both side surfaces constitute the upper side and the lower side of the paper surface of FIG. 1 at the bottom 33. The flange portion and the insertion hole are used for fixing the lid portion 15 and the bottom portion 33 of the first housing 12 and fixing the lid portion 25 and the bottom portion 33 of the second housing 22. Unlike this embodiment, the fixing of the lid portion 15 and the bottom portion 33 and the fixing of the lid portion 25 and the bottom portion 33 may be performed by an adhesive or welding.

The wall portion 34 is erected from the peripheral edge of the bottom portion 33. In this embodiment, the wall portion 34 extends from the peripheral edge of the bottom portion 33 toward the first substrate 11 and the second substrate 21. The first substrate 11 and the second substrate 21 side are on the left side of the paper in FIG. As shown in FIG. 7, the wall portion 34 of the present embodiment has a first side wall portion 343 and a second side wall portion 344. The positional relationship between the first side wall portion 343 and the second side wall portion 344 in the third housing 32 and the respective arrangement locations thereof are the positions of the first side wall portion 343 and the second side wall portion 344 in the first housing 12. Same as the relationship and each placement location. The wall portions 34 of the present embodiment are not provided on both sides of the stacking direction, and openings are provided on both sides of the third housing 32 in the stacking direction. Each opening is closed by each of the lid portion 15 of the first housing 12 and the lid portion 25 of the second housing 22 described above. Unlike this embodiment, the wall portion 34 of the third housing 32 has a first end wall portion and a second end wall portion provided on both sides in the stacking direction in addition to the first side wall portion 343 and the second side wall portion 344. It may have a wall portion.

The lid portion 35 covers the transformer 31. The lid portion 35 is arranged on the first substrate 11 and the second substrate 21 side with respect to the transformer 31. The first substrate 11 and the second substrate 21 side are on the left side of the paper in FIGS. 1 and 7. The lid portion 35 of the present embodiment has a second end wall portion 132 of the first housing 12, a second end wall portion 232 of the second housing 22, and a second end wall portion 442 of the cooling member 40 described later. Contact. The lid portion 35 may be fixed to the above-mentioned insulating substrate 311a of the transformer 31 with bolts or the like, or has a portion overhanging to the outside of the transformer 31, and the overhanging portion is fixed to the bottom portion 33 with bolts or the like. You may. The lid portion 35 may be fixed to the insulating substrate 311a with an adhesive or the like. The overhanging portion of the lid portion 35 may be fixed to the bottom portion 33 with an adhesive, welding, or the like.

Unlike the first housing 12, the third housing 32 of this embodiment is configured independently of the cooling member 40 described later. Unlike this embodiment, the third housing 32 and the cooling member 40 may be configured as an integral assembly. For example, the lid portion 35 of the third housing 32 also serves as the second end wall portion 442 of the cooling member 40.

Examples of the constituent material of the third housing 32 include the same metal as the constituent material of the first housing 12. The constituent material of the third housing 32 and the constituent material of the first housing 12 may be the same or different from each other. The constituent material of the third housing 32 and the constituent material of the second housing 22 may be the same type or different from each other.

[Cooling member]
The circuit structure 1 preferably has a cooling member 40. The cooling member 40 cools at least one selected from the group consisting of the first switching circuit, the second switching circuit, and the transformer 31. For example, the cooling member 40 may cool both the first switching circuit and the second switching circuit without cooling the transformer 31. The cooling member 40 may cool only the transformer 31 without cooling both the first switching circuit and the second switching circuit. The cooling member 40 may cool all of the first switching circuit, the second switching circuit, and the transformer 31. In this embodiment, the cooling member 40 has a space through which the refrigerant 41 is circulated. Unlike this embodiment, the cooling member 40 may be formed of a heat pipe or the like.

The form of the refrigerant 41 includes one selected from the group consisting of a liquid, a gas, and a gas-liquid mixture. A gas-liquid mixture is a mixture of gas and liquid. When the refrigerant 41 is a liquid, the cooling target is more likely to be cooled than when the refrigerant 41 is a gas. The reason is that the thermal conductivity of the liquid is higher than the thermal conductivity of the gas, so that the liquid easily takes away the heat of the object to be cooled. Examples of the refrigerant 41 include water, antifreeze, oil, and air. If the refrigerant 41 is an antifreeze liquid, the refrigerant 41 is unlikely to freeze even in a cold region or winter, so that the cooling target can be effectively cooled even in a cold region for a long period of time. If the refrigerant 41 is water or air, the cost can be easily reduced.

In this embodiment, the cooling member 40 is arranged in a region surrounded by the first member 10, the second member 20, and the third member 30. As will be described later in Embodiment 6, the cooling member 40 may be arranged outside each of the first member 10, the second member 20, and the third member 30.

In this embodiment, the cooling member 40 and the first member 10 are an integral assembly. Therefore, the circuit structure 1 of the present embodiment has a number of parts as compared with the case where each of the first member 10, the second member 20, the third member 30, and the cooling member 40 is composed of separate members independent of each other. It is excellent in assembly workability because it can be reduced. The cooling member 40, the second member 20, and the third member 30 are composed of separate members that are independent of each other. The circuit structure 1 of the present embodiment is configured by combining an assembly, a second member 20, and a third member 30.

The cooling member 40 has a bottom portion 43, an outer wall portion 44, and an inner wall portion 45. The outer wall portion 44, the inner wall portion 45, and the bottom portion 43 are configured in a series.

The bottom portion 43 is composed of the bottom portion 13 of the first housing 12. That is, the bottom portion 43 of the cooling member 40 and the bottom portion 13 of the first housing 12 are shared. Unlike this embodiment, the bottom portion 43 of the cooling member 40 may be composed of a separate member independent of the bottom portion 13 of the first housing 12. The shape of the bottom portion 43 is a rectangular flat plate as described above. The first switching circuit of the first substrate 11 is dissipated through the bottom 43.

The outer wall portion 44 is erected from the peripheral edge of the bottom portion 43. In this embodiment, the outer wall portion 44 is configured in a rectangular frame shape extending from the peripheral edge of the bottom portion 43 toward the second member 20 side. An opening is provided on the side of the second member 20 of the outer wall portion 44, and the opening is closed by the bottom portion 23 of the second member 20. The second switching circuit of the second substrate 21 is dissipated through the bottom 23 of the second member 20.

The outer wall portion 44 has a first end wall portion 441, a second end wall portion 442, a first side wall portion 443, and a second side wall portion 444. The positional relationship between the first end wall portion 441, the second end wall portion 442, the first side wall portion 443, and the second side wall portion 444 in the outer wall portion 44 and their respective arrangement locations are the first end wall in the first member 10. The positional relationship between the portion 141, the second end wall portion 142, the first side wall portion 143, and the second side wall portion and the respective arrangement locations are the same.

The end faces of the first end wall portion 441, the second end wall portion 442, the first side wall portion 443, and the second side wall portion 444 of the outer wall portion 44, and the second surface 230 of the bottom portion 23 of the second housing 22. A sealing member is interposed between them so that the refrigerant 41 does not leak to the outside. The illustration of the seal member is omitted.

In this embodiment, the first end wall portion 441 is provided with a supply port 46 and a discharge port 47 for the refrigerant 41. The supply port 46 allows the refrigerant 41 to flow into the cooling member 40. The discharge port 47 causes the refrigerant 41 to flow out of the cooling member 40. The supply port 46 is provided on the first side wall portion 443 side of the first end wall portion 441. The discharge port 47 is provided on the second side wall portion 444 side of the first end wall portion 441. The installation location of the supply port 46 and the discharge port 47 is not limited to the first end wall portion 441. The supply port 46 and the discharge port 47 may be provided on the first side wall portion 443 or the second side wall portion 444. The supply port 46 and the discharge port 47 may be provided on the same wall portion or may be provided on different wall portions.

In this embodiment, the second end wall portion 442 has a third surface 442a that partitions the refrigerant 41 and the third member 30. The third surface 442a constitutes a surface of the second end wall portion 442 opposite to the transformer 31 side. The transformer 31 is dissipated through the third surface 442a.

The inner wall portion 45 constitutes a flow path of the refrigerant 41 inside the cooling member 40. The inner wall portion 45 of the present embodiment is a straight line from the first end wall portion 441 toward the second end wall portion 442 side between the first side wall portion 443 and the second side wall portion 444 on the first surface 130 of the bottom portion 43. It is configured to extend like a shape. The inner wall portion 45 of the present embodiment is arranged substantially in the middle between the first side wall portion 443 and the second side wall portion 444. One end of the inner wall portion 45 in the longitudinal direction is connected to the first end wall portion 441. The other end of the inner wall portion 45 in the longitudinal direction is not connected to the second end wall portion 442. That is, a gap is provided between the other end of the inner wall portion 45 and the second end wall portion 442. The shape and number of the inner wall portions 45 are not limited to the configuration shown in FIG. 7. For example, by providing a plurality of inner wall portions 45 on the first end wall portion 441 and providing a plurality of inner wall portions 45 on the second end wall portion 442, the plurality of inner wall portions 45 are arranged in a facing comb-teeth shape. A meandering flow path may be configured from the supply port 46 toward the discharge port 47.

The flow of the refrigerant 41 of this embodiment is as follows. The arrow of the alternate long and short dash line in FIG. 7 indicates the flow of the refrigerant 41. The refrigerant 41 that has flowed in from the supply port 46 of the first end wall portion 441 flows from the first end wall portion 441 toward the second end wall portion 442 side on the first side wall portion 443 side. The refrigerant 41 flows from the first side wall portion 443 side to the second side wall portion 444 side on the second end wall portion 442 side. The refrigerant 41 flows from the second end wall portion 442 side toward the first end wall portion 441 side on the second side wall portion 444 side. The refrigerant 41 that has flowed to the first end wall portion 441 side is discharged to the outside from the discharge port 47 of the first end wall portion 441.

Unlike this embodiment, the cooling member 40 may have a top portion facing the bottom portion 43 in addition to the bottom portion 43, the outer wall portion 44, and the inner wall portion 45.

[Use]
The circuit structure 1 of this embodiment can be suitably used for an in-vehicle power conversion device such as a charger for an electric vehicle or a DC / DC converter. In addition, the circuit structure 1 of this embodiment can be suitably used for an AC / DC converter, an AC / AC converter, and the like.

[Action effect]
The circuit structure 1 of the present embodiment has a small projected area when viewed from the stacking direction. In particular, in the circuit structure 1 of the present embodiment, the third member 30 is arranged with respect to the first member 10 and the second member 20 so that the direction orthogonal to the axial direction of the substrate coil 311 is along the stacking direction. Therefore, the projected area is even smaller. Moreover, the circuit structure 1 of the present embodiment can dissipate heat from each of the first switching circuit, the second switching circuit, and the transformer 31. In particular, in the circuit structure 1 of the present embodiment, the cooling member 40 is arranged at a position surrounded by the first member 10, the second member 20, and the third member 30, so that the length in the stacking direction is excessive. Each of the first switching circuit, the second switching circuit, and the transformer 31 can dissipate heat without becoming too long.

<< Embodiment 2 >>
[Circuit structure]
The circuit structure 1 according to the second embodiment will be described with reference to FIG. The circuit structure 1 of the present embodiment mainly has a point that the outer wall portion 44 of the cooling member 40 does not have the second end wall portion 442 (see FIGS. 1 and 7) and the lid portion 35 of the third housing 32. Is different from the first embodiment in that it has a third surface 350 that partitions between the refrigerant 41 and the transformer 31. The following explanation will focus on the differences. The description of the same configuration will be omitted. These points are the same in the third and subsequent embodiments described later.

Each of the first side wall portion 143 and the second side wall portion of the first housing 12, each of the first side wall portion 243 and the second side wall portion of the second housing 22, and the first side wall portion 443 and the cooling member 40. Each of the second side wall portions 444 extends to a portion facing each side surface of the lid portion 35 of the third housing 32. The third surface 350 constitutes a surface on the side of the first substrate 11 and the second substrate 21 in the lid portion 35 of the third housing 32. The third surface 350 faces each of the second end wall portion 142 of the first housing 12 and the second end wall portion 242 of the second housing 22.

Between the above-mentioned facing portions in each of the first side wall portion 143 and the second side wall portion of the first housing 12 and each side surface of the lid portion 35 of the third housing 32, and the first side wall portion of the second housing 22. The facing portion of each of the 243 and the second side wall portion and the side surface of the lid portion 35 of the third housing 32, and the facing portion of each of the first side wall portion 443 and the second side wall portion 444 of the cooling member 40. Between the location and each side of the lid 35 of the third housing 32, between the third surface 350 and the second end wall 142 of the first housing 12, the third surface 350 and the second housing. A sealing member is interposed between the second end wall portion 242 of 22. The sealing member prevents the refrigerant 41 from leaking to the outside from between them. The illustration of the seal member is omitted.

[Action effect]
Since the circuit structure 1 of the present embodiment has fewer components of the cooling member 40 as compared with the first embodiment, the weight can be reduced. Moreover, since the circuit structure 1 of the present embodiment has fewer members interposed between the refrigerant 41 and the transformer 31 as compared with the first embodiment, the transformer 31 can effectively dissipate heat.

<< Embodiment 3 >>
[Circuit structure]
The circuit structure 1 according to the third embodiment will be described with reference to FIG. The circuit structure 1 of the present embodiment is different from the first embodiment in that it includes a heat transfer member 50 interposed between the specific members.

[Heat transfer member]
The heat transfer member 50 is at least selected from the group consisting of between the first member 10 and the cooling member 40, between the second member 20 and the cooling member 40, and between the third member 30 and the cooling member 40. Intervened between one. In this embodiment, the heat transfer member 50 is interposed between the lid portion 35 of the third housing 32 of the third member 30 and the cooling member 40. The heat transfer member 50 of the present embodiment includes the second end wall portion 142 of the first housing 12 of the first member 10, the second end wall portion 442 of the cooling member 40, and the second housing 22 of the second member 20. It is in contact with the second end wall portion 242 of the above.

The heat transfer member 50 is made of a material having excellent deformation performance that can fill the gaps caused by minute irregularities at the contact interface between adjacent members. The heat transfer member 50 may be made of, for example, a heat radiating grease, a heat radiating sheet, or a heat radiating adhesive. Examples of the material of the heat transfer member 50 include silicone resin, epoxy resin, and unsaturated polyester resin. It is preferable that the heat transfer member 50 contains a filler. Specific examples of the filler include alumina filler. Thermal paste, heat dissipation sheet, and heat dissipation adhesive are relatively soft. Therefore, the thermal paste, the heat dissipation sheet, and the heat dissipation adhesive can easily fill the gap between at least one of the above.

[Action effect]
Since the circuit structure 1 of the present embodiment can fill the gap between the cooling member 40 and the third member 30 by the heat transfer member 50, it is easy to effectively dissipate heat from the transformer 31.

<< Embodiment 4 >>
[Circuit structure]
The circuit structure 1 according to the fourth embodiment will be described with reference to FIG. The circuit structure 1 of the present embodiment is different from the circuit structure 1 of the first embodiment in that the bottom portion 13 of the first housing 12 is formed not in the shape of a flat plate but in the shape of a bent plate. That is, the bottom 43 of the cooling member 40 is not a flat plate but a bent plate.

[Cooling member]
The first surface 130 of the bottom 13 of the first housing 12 has a concave surface 131 provided on the third member 30 side. The concave surface 131 is recessed on the side opposite to the second member 20 side. The longer the depth of the concave surface 131, the longer the height of the second end wall portion 442. The depth of the concave surface 131 means the length of the first member 10 and the second member 20 along the stacking direction. As described above, the height means the length along the stacking direction. That is, the contact area between the second end wall portion 442 and the lid portion 35 of the third member 30 becomes large. Therefore, the refrigerant 41 easily dissipates heat from the transformer 31 via the second end wall portion 442 and the lid portion 35 of the third member 30. The inner wall portion 45 of the present embodiment may be provided from the first end wall portion 441 to the edge of the concave surface 131 on the first end wall portion 441 side. Then, the refrigerant 41 easily flows to the concave surface 131.

[Action effect]
Since the circuit structure 1 of the present embodiment can increase the area of the transformer 31 facing the refrigerant 41 as compared with the first embodiment, it is easy to effectively dissipate the heat of the transformer 31.

<< Embodiment 5 >>
[Circuit structure]
The circuit structure 1 according to the fifth embodiment will be described with reference to FIG. The circuit structure 1 of the present embodiment mainly has a point that the outer wall portion 44 of the cooling member 40 does not have the second end wall portion 442 (see FIGS. 1 and 7) and the lid portion 35 of the third housing 32. Is different from the fourth embodiment in that it has a third surface 350 that partitions between the refrigerant 41 and the transformer 31.

Each of the first side wall portion 143 and the second side wall portion of the first housing 12, each of the first side wall portion 243 and the second side wall portion of the second housing 22, and the first side wall portion 443 and the cooling member 40. Each of the second side wall portions 444 extends to a portion facing each side surface of the lid portion 35 of the third housing 32. The third surface 350 constitutes a surface on the side of the first substrate 11 and the second substrate 21 in the lid portion 35 of the third housing 32. The third surface 350 faces each of the end surface of the bottom 43 of the cooling member 40 and the second end wall portion 242 of the second housing 22.

Between the above-mentioned facing portions in each of the first side wall portion 143 and the second side wall portion of the first housing 12 and each side surface of the lid portion 35 of the third housing 32, and the first side wall portion of the second housing 22. The facing portion of each of the 243 and the second side wall portion and the side surface of the lid portion 35 of the third housing 32, and the facing portion of each of the first side wall portion 443 and the second side wall portion 444 of the cooling member 40. Between the location and each side of the lid 35 of the third housing 32, between the third surface 350 and the end face of the bottom 13 of the first housing 12, and between the third surface 350 and the second housing 22. A sealing member is interposed between the second end wall portion 242 and the second end wall portion 242. The sealing member prevents the refrigerant 41 from leaking to the outside from between them. The illustration of the seal member is omitted.

[Action effect]
Since the circuit structure 1 of the present embodiment has fewer components of the cooling member 40 as compared with the fourth embodiment, the weight can be reduced. Moreover, since the circuit structure 1 of the present embodiment has fewer members interposed between the refrigerant 41 and the transformer 31 as compared with the fourth embodiment, the transformer 31 can effectively dissipate heat.

<< Embodiment 6 >>
[Circuit structure]
The circuit structure 1 according to the sixth embodiment will be described with reference to FIG. The circuit structure 1 of the present embodiment mainly differs from the first embodiment in the configuration of the cooling member 40.

[First member, second member, third member]
The first member 10 of the present embodiment roughly corresponds to the first member 10 of the first embodiment inverted upside down. That is, the bottom portion 13 of the first housing 12 of the first member 10 is arranged on the side opposite to the second member 20 side, and the lid portion 15 is arranged on the second member 20 side. The second member 20 of the present embodiment roughly corresponds to the second member 20 of the first embodiment inverted upside down. That is, the bottom portion 23 of the second housing 22 of the second member 20 is arranged on the side opposite to the first member 10 side, and the lid portion 25 is arranged on the first member 10 side. The lid portion 15 of the first housing 12 and the lid portion 25 of the second housing 22 face each other. The lid portion 15 of the first housing 12 covers only the opening of the wall portion 14 of the first housing 12. The lid portion 25 of the second housing 22 covers only the opening of the wall portion 24 of the second housing 22. The lid portion 15 of the first housing 12 and the lid portion 25 of the second housing 22 may be spaced apart from each other or may be in contact with each other. The lid portion 15 and the lid portion 25 may be shared by a single plate material.

[Cooling member]
The cooling member 40 has a first cooling member 401, a second cooling member 402, and a third cooling member 403. The first cooling member 401, the second cooling member 402, and the third cooling member 403 are configured as separate members independent of each other and are combined with each other. The first cooling member 401, the second cooling member 402, and the third cooling member 403 are configured in the shape of a rectangular parallelepiped container.

The first cooling member 401 is arranged on the side of the first substrate 11 opposite to the second substrate 21 side. The side opposite to the second substrate 21 side is the lower side of the paper in FIG. The bottom 13 of the first housing 12 is fixed to the first cooling member 401. The first cooling member 401 is in contact with the entire surface of the bottom 13. The first cooling member 401 is provided with a supply port 46 for the refrigerant 41 and a connection port for connecting the third cooling member 403. The supply port 46 of the refrigerant 41 is provided on the side of the first cooling member 401 opposite to the third cooling member 403 side. The connecting port is provided on the third cooling member 403 side of the first cooling member 401.

The second cooling member 402 is arranged on the side of the second substrate 21 opposite to the first substrate 11 side. The side opposite to the first substrate 11 side is the upper side of the paper surface in FIG. The bottom 23 of the second housing 22 is fixed to the second cooling member 402. The second cooling member 402 is in contact with the entire surface of the bottom portion 23. The second cooling member 402 is provided with a discharge port 47 for the refrigerant 41 and a connection port for connecting the third cooling member 403. The discharge port 47 of the refrigerant 41 is provided on the side of the second cooling member 402 opposite to the third cooling member 403 side. The connecting port of the second cooling member 402 is provided on the third cooling member 403 side of the second cooling member 402. The supply port 46 may be provided in the second cooling member 402, and the discharge port 47 may be provided in the first cooling member 401.

The third cooling member 403 is arranged on the side opposite to the side of the first substrate 11 and the second substrate 21 in the transformer 31. The side opposite to the side of the first substrate 11 and the second substrate 21 is the right side of the paper in FIG. The bottom 33 of the third housing 32 is fixed to the third cooling member 403. The third cooling member 403 is in contact with the entire surface of the bottom 33. The third cooling member 403 is provided with a connection port with the first cooling member 401 and a connection port with the second cooling member 402.

The first cooling member 401 and the third cooling member 403 are connected to each other so that their internal spaces communicate with each other. The second cooling member 402 and the third cooling member 403 communicate with each other by connecting the connecting ports to each other. A sealing member is interposed at the boundary between the connection ports of the first cooling member 401 and the third cooling member 403 so that the refrigerant 41 does not leak to the outside. Similarly, a sealing member is interposed at the boundary between the connecting ports of the second cooling member 402 and the third cooling member 403 so that the refrigerant 41 does not leak to the outside. Illustration of any of the sealing members is omitted.

Unlike this embodiment, the first cooling member 401 and the third cooling member 403 do not have to communicate with each other in their internal spaces. The second cooling member 402 and the third cooling member 403 do not have to communicate with each other in their internal spaces. That is, the internal spaces of the first cooling member 401, the second cooling member 402, and the third cooling member 403 may be independent of each other. In that case, each of the first cooling member 401, the second cooling member 402, and the third cooling member 403 has a supply port and a discharge port for the refrigerant 41.

Unlike this embodiment, each of the first cooling member 401, the second cooling member 402, and the third cooling member 403 does not have to be configured in a container shape. Each of the first cooling member 401, the second cooling member 402, and the third cooling member 403 may be composed of, for example, an integral body in which a flat plate-shaped member and fins are integrally formed. The fin is composed of a plurality of protrusions protruding from one surface of the flat plate-shaped member. In that case, the refrigerant 41 may be a gas that is blown toward the plurality of protrusions.

[Action effect]
The circuit structure 1 of the present embodiment has a projected area as small as that of the first embodiment, and can dissipate heat from each of the first switching circuit, the second switching circuit, and the transformer 31. In particular, in the circuit structure 1 of the present embodiment, since the third cooling member 403 is in contact with the entire bottom portion 33 of the third member 30, the transformer 31 can effectively dissipate heat as compared with the first embodiment.

<< Embodiment 7 >>
Although not shown, as the circuit structure according to the seventh embodiment, in the circuit structure 1 of the sixth embodiment, the cooling member is further added to the first member 10, the second member 20, and the third member 30 shown in FIG. It is possible to have an inner cooling member arranged between and.

The inner cooling member is configured in the shape of a rectangular parallelepiped container, for example, and is interposed between the lid portion 15 and the lid portion 25 shown in FIG. A refrigerant similar to the refrigerant 41 shown in FIG. 12 is circulated inside the inner cooling member. Even if the supply port of the inner cooling member and the discharge port 47 of the second cooling member 402 shown in FIG. 12 are connected so that the refrigerant 41 flowing through the second cooling member 402 flows into the inside of the inner cooling member. good. The discharge port of the inner cooling member and the supply port 46 of the first cooling member 401 shown in FIG. 12 are connected so that the refrigerant flowing inside the inner cooling member flows into the inside of the first cooling member 401. May be good. The supply port and the discharge port of the inner cooling member may be independent of the supply port 46 of the first cooling member 401 and the discharge port 47 of the second cooling member 402 shown in FIG.

In this embodiment, a substrate different from the first substrate 11 is provided on the inner surface of the lid portion 15, and a substrate different from the second substrate 21 is provided on the inner surface of the lid portion 25. Each of the other substrates has, for example, a circuit electrically connected to the first substrate 11 and the second substrate 21. The substrate provided on the inner surface of the lid portion 15 and the substrate provided on the inner surface of the lid portion 25 are dissipated by the refrigerant flowing inside the inner cooling member. As in the sixth embodiment, each of the first substrate 11 and the second substrate 21 is dissipated by the refrigerant flowing through the first cooling member 401 and the refrigerant flowing through the second cooling member 402. The lid portion 15 and the lid portion 25 may also serve as a bottom portion and a top portion of the inner cooling member.

[Action effect]
The circuit structure of this embodiment can efficiently dissipate heat from a total of four boards even when each of the first board and the second board is composed of two boards. Moreover, the circuit structure of the present embodiment can be miniaturized by stacking four substrates even when the total area of the substrates is large.

The present invention is not limited to these examples, but is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

As described above, the number of switching circuits provided in the circuit structure is not limited to two, that is, the first switching circuit and the second switching circuit, and may be three or more. For example, the circuit structure may include a third switching circuit and a fourth switching circuit in addition to the first switching circuit and the second switching circuit. The third switching circuit may be configured on the first substrate, or may be configured on a substrate different from the first substrate and the second substrate. The fourth switching may be configured on the second substrate, or may be configured on the first substrate and a substrate different from the second substrate.

In the circuit structure 1 shown in FIG. 10 or 11, the second surface 230 of the bottom 23 of the second housing 22 may also be provided with a concave surface corresponding to the concave surface 131, or the second housing 22 may be provided with a concave surface. The two-end wall portion 242 may also be provided with a groove portion or a notch portion. The concave surface of the second surface 230 is provided on the third member 30 side of the bottom portion 23. The concave surface of the second surface 230 is recessed on the side opposite to the first member 10 side. The groove portion is provided so as to open on the surface of the second end wall portion 242 on the first member 10 side. The cutout portion may be provided on the surface of the second end wall portion 242 on the third member 30 side from the surface on the first member 10 side toward the second member 20 side. Since the concave surface of the second surface 230 and the groove portion and the notch portion of the second end wall portion 242 are provided, the area of the transformer 31 facing the refrigerant 41 becomes even larger than the case where only the concave surface 131 is provided. The transformer 31 is likely to be effectively cooled.

1 Circuit structure 10 1st member 11 1st board 12 1st housing 13 Bottom 130 1st surface 131 Concave 14 Wall 141 1st end wall 142 2nd end wall 143 1st side wall 15 Lid 16 Input Terminal 20 Second member 21 Second board 22 Second housing 23 Bottom 230 Second surface 24 Wall 241 First end wall 242 Second end wall 243 First side wall 25 Lid 26 Output terminal 30 Third member 31 Transformer 310 Winding 311 Board Coil

311a Insulated Board

311b Coil Pattern 311c Through Hole 312 Core 312a First Core Piece 312b Second Core Piece 313 Central Leg 314 First Side Leg 315 Second Side Leg 316 First Connection 317 Second connecting part 32 Third housing 33 Bottom 34 Wall 343 First side wall 344 Second side wall 35 Lid 350 Third side 40 Cooling member 41 Refrigerator 43 Bottom 44 Outer wall 441 First end wall 442 First Two-end wall part 442a Third surface 443 First side wall part 444 Second side wall part 45 Inner wall part 46 Supply port 47 Discharge port 401 First cooling member 402 Second cooling member 403 Third cooling member 50 Heat transfer member 90 Wiring

Claims

The first member having the first substrate constituting the first switching circuit,
A second member having a second substrate constituting the second switching circuit,
A third member having a transformer that electromagnetically couples the first switching circuit and the second switching circuit is provided.
The first member and the second member are laminated and
The third member is arranged in a direction intersecting the stacking direction of the first member and the second member.
Circuit structure.
The transformer is
With the primary coil,
With the secondary coil,
A core having a portion in which the primary coil and the secondary coil are arranged are provided.
The primary coil and the secondary coil are
An insulating substrate having a through hole through which a part of the core is inserted,
A substrate coil having a coil pattern provided around the through hole in the insulating substrate.
The circuit structure according to claim 1, wherein the substrate coil has a direction orthogonal to the axial direction of the coil pattern along the stacking direction of the first member and the second member.
The transformer is
With the primary coil,
With the secondary coil,
A core having a portion in which the primary coil and the secondary coil are arranged are provided.
The circuit structure according to claim 1, wherein the primary coil and the secondary coil are configured by winding windings.
The circuit structure according to any one of claims 1 to 3, further comprising a cooling member for cooling at least one selected from the group consisting of the first switching circuit, the second switching circuit, and the transformer. ..
The cooling member is arranged at a position surrounded by the first member, the second member, and the third member, and has a space through which the refrigerant flows.
At least one of the first member and the cooling member has a first surface that partitions the first switching circuit and the refrigerant.
At least one of the second member and the cooling member has a second surface that partitions the second switching circuit and the refrigerant.
The circuit structure according to claim 4, wherein at least one of the third member and the cooling member has a third surface that partitions the transformer and the refrigerant.
The circuit structure according to claim 5, wherein one member selected from the group consisting of the first member, the second member, and the third member and the cooling member are an integral assembly.
Intervened between the first member and the cooling member, between the second member and the cooling member, and at least one selected from the group consisting of the third member and the cooling member. The circuit structure according to claim 5 or 6, further comprising a heat transfer member.
The cooling member is
The first cooling member arranged on the side of the first substrate opposite to the second substrate side,
A second cooling member arranged on the side of the second substrate opposite to the first substrate side,
The transformer has the first substrate and a third cooling member arranged on the side opposite to the side of the second substrate.
The first cooling member, the second cooling member, and the third cooling member have a space through which the refrigerant flows.
At least one of the first member and the first cooling member has a first surface that partitions the first switching circuit and the refrigerant.
At least one of the second member and the second cooling member has a second surface that partitions the second switching circuit and the refrigerant.
The circuit structure according to claim 4, wherein at least one of the third member and the third cooling member has a third surface that partitions the transformer and the refrigerant.