JP2018198252A - Transformer and circuit structure - Google Patents

Abstract

To provide a transformer which is excellent in heat radiation performance and a circuit structure.SOLUTION: The transformer comprises: a primary coil part; a secondary coil part; and a magnetic core in which the first coil part and the second coil part are arranged. At least one of the primary coil part and the secondary coil part constitutes a power line part on which an electronic component is mounted, and includes a thin plate coil constituted of a part of a first conductive plate installed in a heat radiation member. The primary coil part and the secondary coil part include a laminated coil part in which at least one of the thin plate coil and an individual plate coil constituted of a second conductive plate independent of the first conductive plate and a pattern coil formed on a circuit board arranged on one surface of the first conductive plate are laminated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transformer and a circuit structure.

  Patent Document 1 discloses an apparatus including a circuit configuration body that performs energization or shut-off of an in-vehicle electrical component. This apparatus includes a plurality of substrates, a case for storing these substrates, and a heat sink. Patent Document 1 includes a conductive path formed by a printed wiring technique as the substrate, a printed circuit board on which a FET (Field Effect Transistor) and a relay are mounted, and a metal plate that is press-molded, such as an FET. A bus bar mold substrate is disclosed. Electric power is supplied to the FET or the like by the bus bar mold substrate. Patent Document 1 further discloses that this apparatus is provided with a transformer (transformer), and an end portion of a coil provided in the transformer and the printed circuit board are connected by a C-shaped bus bar.

JP2013-099062A

  A transformer having excellent heat dissipation is desired as a circuit component that constitutes a device including the above-described circuit structure.

  Since the coil can generate heat when the transformer is driven, it is desirable that the heat of the coil be easily dissipated. In a transformer used as a circuit component, it is desirable to have excellent heat dissipation because a semiconductor element that easily generates heat such as an FET is disposed nearby. Patent document 1 does not mention the structure which improves the heat dissipation of a transformer more.

  Then, it is set as one of the objectives to provide the transformer and circuit structure which are excellent in heat dissipation.

The transformer of the present disclosure is
A primary coil section;
A secondary coil section;
A magnetic core on which the primary coil part and the secondary coil part are arranged,
At least one of the primary coil part and the secondary coil part is:
A power line portion on which electronic components are mounted is configured, and includes a thin coil formed of a part of a first conductive plate installed on a heat dissipation member,
The primary coil part or the secondary coil part is
At least one of the individual plate coils composed of a second conductive plate independent of the thin plate coil and the first conductive plate;
It includes a laminated coil portion in which a pattern coil formed on a circuit board disposed on one surface of the first conductive plate is laminated.

The circuit structure of the present disclosure is:
A transformer of the present disclosure as described above;
The electronic component;
The power line portion that is mounted with the electronic component and includes a portion other than the thin plate coil in the first conductive plate;
The circuit board disposed on one surface of the first conductive plate;
The power line section includes the heat radiating member installed via an insulating layer.

  Said transformer and said circuit structure are excellent in heat dissipation.

It is a schematic perspective view which shows the transformer of Embodiment 1 and its periphery. FIG. 3 is a cross-sectional view schematically showing a circuit configuration body including the transformer according to the first embodiment. FIG. 3 is an exploded perspective view showing main elements of the transformer of the first embodiment. It is sectional drawing which shows typically a circuit structure provided with the transformer of Embodiment 2. It is sectional drawing which shows typically a circuit structure provided with the transformer of Embodiment 3. It is a disassembled perspective view which shows the primary coil part and secondary coil part with which the transformer of Embodiment 3 is provided.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.
(1) A transformer according to an aspect of the present invention is
A primary coil section;
A secondary coil section;
A magnetic core on which the primary coil part and the secondary coil part are arranged,
At least one of the primary coil part and the secondary coil part is:
A power line portion on which electronic components are mounted is configured, and includes a thin coil formed of a part of a first conductive plate installed on a heat dissipation member,
The primary coil part or the secondary coil part is
At least one of the individual plate coils composed of a second conductive plate independent of the thin plate coil and the first conductive plate;
It includes a laminated coil portion in which a pattern coil formed on a circuit board disposed on one surface of the first conductive plate is laminated.
The “thin plate coil formed of a part of the first conductive plate” is a conductive plate independent of the first conductive plate, in addition to an integral coil formed integrally with a part of the conductive plate. For example, a joining coil that is made of a conductive plate of various specifications (constituent material, thickness, etc.) and that is directly connected to the first conductive plate by soldering or welding, etc., can be regarded as being substantially integrated.
Examples of the “individual plate coil made of the second conductive plate” include those that are not directly connected to the first conductive plate but are indirectly connected. For indirect connection, for example, a conductive member such as a conductive path of a circuit board or a lead wire is interposed between the first conductive plate and the individual plate coil. The second conductive plate constituting the individual plate coil may have a different specification in addition to the same specification as that of the first conductive plate.

  Since the above transformer includes a thin plate coil in at least one of the primary coil portion and the secondary coil portion, it is independent of the printed circuit board and the bus bar mold substrate as in the transformer described in Patent Document 1 described above. Compared with the case where a coil (hereinafter, sometimes referred to as an independent coil) comprising a wound winding is provided, the heat dissipation is excellent. The first conductive plate constituting the thin plate coil has a portion other than the thin plate coil as the power line portion, and this power line portion is installed in the heat radiating member, so that the heat of the thin plate coil can be transmitted to the heat radiating member and dissipated. is there.

  Furthermore, since the above transformer includes a laminated coil part in one of the primary coil part and the secondary coil part, the one coil is not a laminated coil part but only a pattern coil or only a thin coil. Compared to the case, the increase in the electrical resistance is suppressed even when the number of turns is increased as described below, and the device is small.

  For example, when the one coil is formed of only pattern coils, the number of pattern coils stacked is limited to the number of conductive paths stacked on the circuit board. In this case, in order to increase the number of turns, for example, the pattern coil provided in one layer may be a narrow spiral coil, but the electrical resistance increases by making the width narrow. If the number of turns is increased while suppressing an increase in electrical resistance when the one coil is formed of only a thin plate coil, the outer diameter of the coil increases in accordance with the number of turns, leading to an increase in size of the transformer. If a thin thin coil is used, the electrical resistance is increased.

  On the other hand, the laminated coil portion provided in the transformer can have a total number of turns of the thin plate coil or the individual plate coil and the pattern coil, and the pattern coil and the thin plate coil are excessively narrow as described above. Without increasing the number of turns, the increase in electrical resistance can be suppressed. And since a laminated coil part contains a pattern coil, it is easy to make the total thickness of a laminated coil part thin even if it increases more turns. Therefore, it is easy to make the laminated coil portion a small coil as compared with the case where the one coil is only a thin plate coil. Typically, the thickness of the pattern coil is very thin compared to the thickness of the conductive plate forming a thin plate coil or individual plate coil, for example, 1/2 or less of the thickness of the conductive plate, and further 1/3 or less, It is 1/4 or less, and it is easy to reduce the total thickness.

  In addition, the above-described transformer can eliminate the need for parts independent of the circuit board such as the independent coil and the like, and can reduce the manufacturing cost as compared with the case where the independent coil is provided.

(2) As one form of the above transformer,
Each of the primary coil portion and the secondary coil portion includes the thin plate coil,
The said primary coil part is a form provided with the said laminated coil part containing the said thin plate coil.
In the said form, the electric power line part which comprises the electroconductive board which produces the thin plate coil contained in a primary coil part and the electroconductive board which produces the thin plate coil contained in a secondary coil part comprises. It can be set as the form which the heat radiating member which installs these electric power line parts is common, or another form.

  Since both the primary coil part and the secondary coil part contain a thin-plate coil, the said form can dissipate the heat | fever of each thin-plate coil from the power line part connected to each thin-plate coil to a heat radiating member, and is excellent in heat dissipation. Moreover, since the primary coil part utilized as a high voltage | pressure side coil is equipped with a laminated coil part typically, the said form is easy to increase the number of turns of a primary coil part, and also increases an electrical resistance as mentioned above. Can be suppressed. Furthermore, since the secondary coil portion in the above embodiment typically does not include a pattern coil, and consists essentially of a thin plate coil, the total thickness of the primary coil portion and the secondary coil portion can be reduced. As described above, it is easy to reduce the size.

(3) As one form of the transformer of (2) above,
The primary coil portion and the secondary coil portion are laminated coaxially on the magnetic core,
The thin plate coil included in the primary coil portion and the thin plate coil included in the secondary coil portion may be positioned at both ends in the stacking direction.

  Since the thin coil included in the primary coil portion and the secondary coil portion is positioned at both ends in the stacking direction, the above form is easy to dissipate heat and is excellent in heat dissipation, and both the coil portions are stacked coaxially. From the point that the installation area by the coil part can be further reduced, it is easy to reduce the size.

(4) As one form of the above transformer,
The laminated coil section includes the thin plate coil and the individual plate coil, and the pattern coil is sandwiched between the thin plate coil and the individual plate coil.

  The said form can increase more turns of a laminated coil part. If the primary coil portion and the secondary coil portion are arranged in a stacked manner as in (3) above, it is easy to reduce the size because the installation area can be easily reduced even if the number of turns is larger.

(5) A circuit structure according to an aspect of the present invention is:
The transformer according to any one of (1) to (4) above;
The electronic component;
The power line portion that is mounted with the electronic component and includes a portion other than the thin plate coil in the first conductive plate;
The circuit board disposed on one surface of the first conductive plate;
The power line section includes the heat radiating member installed via an insulating layer.

  According to said circuit structure, the thin plate coil which consists of a part of electrically-conductive board which comprises the electronic component mounted in a power line part and a power line part can radiate | emit heat to a heat radiating member via a power line part. For this reason, the circuit structure is excellent in heat dissipation as compared with the case where the electronic component is mounted only on the printed circuit board or the case where the coil of the transformer is not installed on the heat dissipation member. Since the conductive plate constituting the power line portion is typically made of a metal having excellent conductivity and thermal conductivity, such as copper or copper alloy, the above circuit structure is excellent in heat dissipation. In particular, even if the electronic component is a semiconductor element that easily generates heat when driving an FET or the like, the semiconductor element can dissipate heat to the heat dissipation member via the power line portion as described above, and thus has excellent heat dissipation.

  In addition, since the above-described circuit structure includes a laminated coil portion in one coil of the primary coil portion and the secondary coil portion as described above, only the pattern coil or only the thin plate coil is included in the one coil. Compared to the case, the increase in electrical resistance is suppressed even if the number of turns is increased, and the size is reduced.

  Furthermore, the heat radiating member is typically made of a metal having excellent thermal conductivity such as aluminum or an aluminum alloy. Even when both the heat dissipating member and the power line portion are made of metal as described above, the circuit structure is excellent in electrical insulation because an insulating layer is interposed between the both.

  In addition, the circuit configuration body described above can eliminate the need for parts independent of the power line section, the circuit board, and the like, as compared with the case where the independent coil is provided as described above, and can reduce the manufacturing cost.

(6) As an example of the above circuit structure,
The said heat radiating member has a form provided with the recessed part which accommodates a part of said magnetic core.

  In addition to the above-described effects, the above form easily transfers the heat of the magnetic core housed in the recess of the heat dissipation member to the heat dissipation member, and is excellent in heat dissipation. Moreover, the said form is easy to make it more compact from the point which is easy to make low the protrusion height of the magnetic core from a heat radiating member.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same reference numerals in the figure indicate the same names. 1, FIG. 2, FIG. 4 and FIG. 5 show the vicinity of the transformer 1 of the embodiment. In FIG. 1, the heat radiating member 8 is omitted. 2, 4, and 5 are cross-sectional views of the transformer 1 of the embodiment and the circuit configuration body 10 of the embodiment cut along a plane orthogonal to the stacking direction of components (vertical direction in the figure). The part where the layered state of is easy to understand is cut. Each component is schematically shown for easy understanding, and its size (thickness, length, etc.) may differ from the actual magnitude relationship.

[Embodiment]
(Overview)
The transformer 1 of the embodiment is used for circuit components provided in an electrical connection box such as a power supply unit, and constructs a part of the circuit configuration body 10 of the embodiment. The transformer 1 includes a primary coil portion 2 on the high voltage side (see also FIG. 3 and the like), a secondary coil portion 3 on the low voltage side, and a magnetic core 4 on which the primary coil portion 2 and the secondary coil portion 3 are arranged. With. Here, the case where the magnetic core 4 is an EI type core (same as above), and the primary coil portion 2 and the secondary coil portion 3 are coaxially laminated on the middle leg portion 40 of the magnetic core 4 is illustrated. The circuit structure 10 is provided on one surface of the transformer 1, the electronic component 6, the power line unit 5 on which the electronic component 6 is mounted, and a conductive plate (first conductive plate) constituting the power line unit 5. The circuit board 7 to be disposed and the heat radiation member 8 (FIG. 2) on which the power line portion 5 is installed via the insulating layer 85 (FIG. 2) are provided. Here, the primary side power line part 52, the electronic components 62a to 62c, and the primary side circuit board 72 are provided on the primary coil part 2 side, and the secondary side power line part 53 and the electronic parts 63a to 63d are provided on the secondary coil part 3 side. The case where the secondary side circuit board 73 is provided and one power radiating member 8 is shared by both power line parts 52 and 53 is illustrated (refer also to FIG. 2).

  The transformer 1 of the embodiment includes a thin plate coil formed of a part of a conductive plate (first conductive plate) constituting the power line unit 5 in at least one of the primary coil unit 2 and the secondary coil unit 3. 2 and 5 show a case where the thin coil 21 and 31 are provided in both the primary coil portion 2 and the secondary coil portion 3. FIG. 4 shows a case where the primary coil portion 2 is not provided with a thin plate coil, and the secondary coil portion 3 is provided with a thin plate coil 31. Moreover, the transformer 1 of the embodiment includes an individual plate coil 23 formed of a second conductive plate independent of the thin plate coil 21 and the first conductive plate in the primary coil portion 2 or the secondary coil portion 3 (FIGS. 5 and 5). 6) and a laminated coil portion 20 in which the pattern coil 22 formed on the circuit board 7 is laminated (FIG. 2 and the like). The transformer 1 is excellent in heat dissipation since the thin plate coils 21 and 31 can radiate heat to the heat radiating member 8 via the power line portion 5. In addition, since the transformer 1 includes the laminated coil portion 20 in one of the high-voltage side coil and the low-voltage side coil, the number of turns compared to the case where the one coil consists of only a pattern coil or only a thin plate coil. Even if it increases, it is small, suppressing the increase in electrical resistance.

As a more specific configuration of the transformer 1 of the embodiment, for example, the following may be mentioned.
In the transformer 1 </ b> A of the first embodiment shown in FIG. 2, the primary coil unit 2 and the secondary coil unit 3 include thin plate coils 21 and 31, respectively, and the primary coil unit 2 includes a laminated coil unit 20 </ b> A including the thin plate coil 21. In the transformer 1A of this example, the primary coil part 2 and the secondary coil part 3 are coaxially stacked on the middle leg part 40 of the magnetic core 4, and the thin coil 21 and the secondary coil part 3 included in the primary coil part 2 The thin coil 31 to be included is located at both ends in the stacking direction. The circuit configuration body 10A of the first embodiment includes the transformer 1A, and the thin coil 21 of the primary coil portion 2 is disposed on the heat radiating member 8 side.

  In the transformer 1B of Embodiment 2 shown in FIG. 4, the primary coil unit 2 does not include a thin plate coil, includes a laminated coil unit 20B including an individual plate coil 23, and the secondary coil unit 3 includes a thin plate coil 31. The circuit configuration body 10B of the second embodiment includes the transformer 1B, and the thin coil 31 of the secondary coil unit 3 is disposed on the heat radiating member 8 side.

  In the transformer 1C of Embodiment 3 shown in FIG. 5, the primary coil part 2 and the secondary coil part 3 include thin plate coils 21 and 31, respectively, and the primary coil part 2 includes a laminated coil part 20C. The laminated coil portion 20 </ b> C includes a thin plate coil 21 and an individual plate coil 23, and sandwiches the pattern coil 22 between the thin plate coil 21 and the individual plate coil 23. The circuit configuration body 10C of the third embodiment includes the transformer 1C.

  Hereinafter, with reference mainly to FIGS. 1 to 3, each component of the circuit configuration body 10 of the embodiment will be described, and then the transformer 1 of the embodiment will be described in detail.

[Embodiment 1]
(Circuit structure)
《Electronic parts》
The electronic component 6 is provided according to the application of the circuit component 10, and includes a semiconductor element such as a semiconductor relay, a switching element such as an FET or a transistor, a capacitor (C), a current transformer (CT), and the like. Can be mentioned. As the electronic component 6, a known product such as a commercially available product can be used. In particular, an FET or the like can be suitably used in a power supply unit application of a large current power circuit. The electronic components 62a to 62c and 63a to 63d in this example are all semiconductor elements such as FETs.

<Power line section>
The power line unit 5 is a circuit component on which the electronic component 6 is mounted and supplies power to the electronic component 6. From this application, the power line portion 5 is a plate-like member formed by molding a conductive plate made of a material having excellent conductivity, typically a metal such as copper or copper alloy, into a predetermined shape. The power line portion 5 is formed, for example, by stamping or bending a flat plate made of the above-mentioned metal as a material (hereinafter also referred to as a material plate) into a predetermined shape by press molding or the like. A known method such as Patent Document 1 can be referred to for the method of manufacturing the power line portion 5. In the transformer 1 and the circuit structure 10 of the embodiment, a part of the conductive plate is a thin plate coil 21 and the like, and a part other than the thin plate coil 21 is a power line portion 5, and at least a region where the power line portion 5 is formed is a heat radiating member 8. Installed.

  The power line part 5 is excellent in heat dissipation by being made of metal as described above. In particular, copper and copper alloys have high thermal conductivity and are excellent in heat dissipation. For this reason, the power line portion 5 made of copper or the like functions as a heat dissipation path from the mounted electronic component 6, particularly a semiconductor element that easily generates heat when driving an FET or the like, to the heat dissipation member 8. The circuit structure 10 provided with such a power line part 5 is excellent in heat dissipation.

  As for the thickness of the electrically conductive board which comprises the power line part 5 and the thin-plate coils 21 and 31, 0.3 mm or more and 2.0 mm or less are mentioned, for example. If the said thickness is 0.3 mm or more, it will be easy to ensure large cross-sectional area of the thin-plate coils 21 and 31, and it will be easy to reduce an electrical resistance. From the viewpoint of reducing electrical resistance, the thickness can be set to 0.4 mm or more, and further to 0.5 mm or more. If the said thickness is 2.0 mm or less, the thin coil 21 and 31 can be made thin. When the thickness is 1.9 mm or less, further 1.8 mm or less, 1.5 mm or less, 1.2 mm or less, or 1.0 mm or less, the thin coils 21 and 31 can be made thinner, and the transformer 1 can be made smaller. easy.

<Circuit board>
The circuit board 7 typically constitutes a predetermined circuit such as a signal circuit, a part of a power circuit, a current or voltage detection circuit, and is provided with at least one foil-like conductive path made of copper or the like. (PCB). The primary circuit board 72 in this example is an insulating substrate 724 and two-layer conductive paths 720 formed on the front and back surfaces (upper and lower surfaces in FIG. 2) of the insulating substrate 724 (only those formed on the upper surface in FIG. 2). And insulating films 722 and 722 that cover and protect each conductive path 720. The basic configuration of the secondary circuit board 73 is the same as that of the primary circuit board 72, and includes an insulating substrate 734, two layers of conductive paths 730 (same as above), and two layers of insulating films 732 and 732. The conductive path can be formed by a known printed wiring technique. The thickness of the conductive path is, for example, about 20 μm to 200 μm, and further about 50 μm to 200 μm. When the total thickness of the circuit board 7 is about 300 μm or more and 1000 μm or less, the difference in height between the circuit board 7 and the conductive plate forming the power line portion 5 is small, and soldering or the like is easily performed. A known configuration can be referred to for the basic configuration of the circuit board 7.

  In the circuit structure 10, the power line unit 5 and the circuit board 7 are typically stacked and bonded by an adhesive layer 55. As a constituent material of the adhesive layer 55, an appropriate adhesive can be used. In particular, if the insulating layer is excellent, the insulating property between the power line portion 5 and the conductive paths 720 and 730 of the circuit board 7 can be improved as compared with the case where only the insulating films 722 and 732 are provided.

  When the electronic component 6 is a semiconductor element such as an FET and includes a plurality of terminals such as a drain terminal D, a source terminal S, and a gate terminal G, the drain terminal D and the source terminal S are mounted on the power line unit 5; The gate terminal G may be electrically connected to the conductive paths 720 and 730 of the circuit board 7 via solder or the like. The above-mentioned “mounting the electronic component 6 on the power line portion 5” means placing the electronic component 6 package on the power line portion 5 as shown in FIG. It means to make an electrical connection. Here, when some of the plurality of terminals included in the electronic component 6 are directly connected to the power line unit 5 via solder or the like, “the electronic component is mounted on the power line unit”. To do. In the figure, the arrangement positions of the terminals D, S, and G are examples.

《Heat dissipation member》
The heat radiating member 8 is a member that radiates the heat of the power line unit 5 itself and the heat from the electronic component 6 mounted on the power line unit 5 to the outside to suppress the temperature rise. The heat radiating member 8 typically has one surface as a mounting surface (the upper surface in FIG. 2) of the power line portion 5. In FIG. 2, the case where a mounting surface consists of a flat plane which has a magnitude | size which can mount all the one surface among the front and back of the power line part 5 is illustrated. For example, if the heat radiating member 8 includes fins (not shown) at locations not covered by the power line portion 5, the surface area can be increased and the heat dissipation can be further improved. In this example, both the primary side power line unit 52 and the secondary side power line unit 53 share one heat radiating member 8, but the primary side power line unit 52 and the secondary side power line unit 53 have different heat dissipation. It can also be installed on a member.

  The heat radiating member 8 of this example includes a recess 84 that houses a part of the magnetic core 4. The concave portion 84 in this example opens toward the mounting surface described above, and is provided toward the side facing the mounting surface (the lower side in FIG. 2). In addition, the shape of the recess 84 in this example corresponds to the shape of a portion (hereinafter sometimes referred to as a storage location) stored in the recess 84 in the magnetic core 4. Since the storage location of the magnetic core 4 is the ribbon-shaped connecting portion 42 as shown in FIG. 3, the concave portion 84 is also a ribbon-shaped recess. If the shape of the recess 84 is a shape along the storage location of the magnetic core 4, the gap between the recess 84 and the storage location can be easily reduced. Therefore, the heat of the thin coil 21 can be easily transmitted to the heat radiating member 8 through the magnetic core 4, and the heat dissipation is excellent.

  The inner dimension of the recess 84 may be adjusted according to the size of the storage location. If the inner size is slightly larger than the outer size of the storage location, the storage location can be easily inserted into the recess 84. The deeper the recess 84, the smaller the protrusion height of the magnetic core 4 from the placement surface. Moreover, the proximity | contact location with the heat radiating member 8 in the magnetic core 4 can be increased, and it is easy to transmit the heat | fever of the magnetic core 4 to the heat radiating member 8, and is excellent in heat dissipation. It is possible to make the transformer 1 and the circuit structure 10 that are easy to make smaller in terms of the small protruding height and also excellent in heat dissipation. The depth of the recess 84 in this example is approximately the same as the height of the one connecting portion 42 (the size in the vertical direction in FIG. 2). Therefore, when the magnetic core 4 is housed in the recess 84, the inner surface of the one connecting portion 42 is substantially flush with the mounting surface (FIG. 2). Accordingly, the installation position of the coil of the transformer 1 with respect to the heat radiating member 8 (for example, the thin plate coil 21 of the primary coil portion 2 in the first and third embodiments, the thin plate coil 31 of the secondary coil portion 3 in the second embodiment), and the power line portion 5. (For example, in the first and third embodiments, the primary power line portion 52, and in the second embodiment, the secondary power line portion 53) can be provided on substantially the same plane. In this case, there is no step in the coil portion, and it is easy to perform a planar mounting operation. The concave portion 84 can be formed by an appropriate method such as casting, cutting, or plastic processing using a punch.

  Examples of the constituent material of the heat radiating member 8 include materials having excellent thermal conductivity, such as metals such as aluminum and aluminum alloys. An insulating layer 85 is interposed between the heat radiating member 8 and the power line portion 5 disposed on the mounting surface. Examples of the constituent material of the insulating layer 85 include resins and ceramics having excellent insulating properties. The insulating layer 85 made of an insulating adhesive may be used, and the power line portion 5 and the metal heat radiating member 8 may be joined. When the insulating layer 85 is made of an insulating adhesive containing a filler and having excellent thermal conductivity, the heat dissipation from the power line portion 5 to the heat radiating member 8 can be further enhanced. As shown in FIG. 2, when the constituent material of the insulating layer 85 is interposed between the turns of the thin plate coil 21, the insulation between the turns is increased, and further, the heat dissipation of the thin plate coil 21 is increased. Can do.

(Trance)
<Magnetic core>
The magnetic core 4 is a member that magnetically couples the primary coil portion 2 and the secondary coil portion 3. As shown in FIG. 3, the magnetic core 4 of this example is an EI type core that forms a closed magnetic circuit by combining a plurality of divided core pieces. The magnetic core 4 is disposed along the axial direction of the middle leg portion 40 in which the primary coil portion 2 and the secondary coil portion 3 are coaxially stacked, and sandwiches the middle leg portion 40 therebetween. A pair of side leg portions 41, 41 opposed to each other, and a pair of flat plate-like connecting portions 42, 42 arranged so as to sandwich these three leg portions arranged in parallel. One (upper in FIG. 3) core piece is an E-type core including one connecting portion 42 and the three leg portions standing on the inner surface thereof. The other (lower side) core piece is a flat I-shaped core. In this example, the middle leg portion 40 has a columnar shape and the connecting portion 42 has a ribbon shape in plan view, but the shape of the magnetic core 4 can be changed as appropriate. When the other core piece is an I-type core as in this example, there is no middle leg portion 40, so that the mounting surface of the heat radiating member 8 can be made flat, and the power line portion 5 and circuit connected to the coil of the transformer 1 It is easy to stack the substrates 7 and the like and is excellent in workability. The shape of the magnetic core 4 is an example and can be changed as appropriate. For example, it can be an EE type core or a core that is O-shaped when combined.

  The magnetic core 4 (core piece) includes, for example, a sintered body such as a ferrite core, a compacted body formed by compression molding a soft magnetic material powder, and a composite material molded body including a soft magnetic material powder and a resin. In addition, a laminated body in which soft magnetic materials such as electromagnetic steel sheets are laminated can be used. The magnetic core 4 (core piece) can be made of a known material and shape. In addition, the magnetic core 4 can be provided with a magnetic gap (not shown) as needed.

"coil"
The primary coil unit 2 and the secondary coil unit 3 included in the transformer 1 have different specifications as described above. In this example, the primary coil portion 2 is composed of a laminated coil portion 20, and the secondary coil portion 3 is composed of a thin plate coil 31.

<Primary coil section>
The laminated coil part 20 constituting the primary coil part 2 is formed by laminating at least one of the thin plate coil 21 and the individual plate coil 23 and the pattern coil 22 formed on the circuit board 7.

  The laminated coil portion 20A forming the primary coil portion 2 in the transformer 1A of the first embodiment is a single thin plate coil in which a part of the conductive plate forming the primary power line portion 52 is spirally formed as shown in FIG. 21 and two pattern coils 220 and 221 formed on the primary side circuit board 72.

  The thin plate coil 21 of this example is formed integrally with a part of the conductive plate constituting the primary power line portion 52. One end portion of the thin plate coil 21 (the end portion of the turn located on the outermost periphery in FIG. 3) is a portion continuous with the formation region of the primary power line portion 52 in the conductive plate. Here, the input of the primary coil portion 2 Make the end. The other end portion of the thin coil 21 (the end portion of the turn located in the innermost periphery in FIG. 3) is an electrical connection location with the pattern coil 22. In this example, the electrical connection location is a section having a certain large area, and the bonding area with the pattern coil 22 is increased. By doing so, the reliability of the connection point can be increased. The number of turns of the thin coil 21 is an example, and in FIG. 3, it is 5 turns, but can be changed as appropriate (see the thin coil 21 in FIG. 6). If the number of turns of the thin coil 21 that forms the high voltage side coil is increased, the total number of turns of the primary coil portion 2 can be increased.

  Since the thin coil 21 in this example is an integral part of the primary power line section 52, the primary power line section 52 having a predetermined shape is manufactured by subjecting the material plate to press molding (including punching). If the thin coil 21 is formed at the same time, the number of steps can be reduced and the productivity is excellent. The molding conditions may be adjusted so that the number of turns, the width of one turn, the gap between turns, and the like have predetermined values. If the width of one turn and the gap between turns are narrowed like the thin coil 21 shown in FIG. 3, the number of turns can be easily increased. If the width of one turn is increased to some extent (see the thin coil 21 in FIG. 6), the cross-sectional area can be increased and the electric resistance can be easily reduced. If the gap between turns is widened to some extent (same as above), it is easy to punch and excellent manufacturability.

  The pattern coils 220 and 221 in this example are formed of a part of the plurality of conductive paths 720 formed on the primary circuit board 72 that are respectively formed on the front and back surfaces of the insulating substrate 724. One end of one pattern coil 220 is an electrical connection location with the other end of the thin plate coil 21, and the other end is an electrical connection location with the other pattern coil 221. For joining the thin coil 21 and the pattern coil 22, for example, solder or the like is used or welding is performed. In FIG. 2, the joining part 9 by solder etc. is illustrated. One end of the other pattern coil 221 is an electrical connection location with the other end of the one pattern coil 220, and the other end is an electrical connection location with the primary power line portion 52. Here, It forms the output end of the primary coil section 2. At least one (here, a plurality) via holes 26 are provided at the electrical connection locations between the pattern coils 220 and 221 (see also FIG. 2). Each pattern coil 220, 221 has one turn. However, if the pattern coils 220 and 221 are connected via the via hole 26, a coil having a total of two turns can be obtained. The other pattern coil 221 and the primary power line portion 52 are electrically connected through a joint 9 such as solder. In this example, as shown in FIG. 2, there is a step corresponding to the thickness of the primary side circuit board 72 between the other pattern coil 221 and the primary side power line portion 52. A step absorbing member 27 made of a conductive material such as copper is interposed. In the figure, the member with cross-hatching illustrates a joint 9 such as solder.

  Here, one end portion of the thin plate coil 21 is described as an input end portion, and one end portion of the pattern coil 221 is described as an output end portion. However, input and output can be reversed. The matters regarding the input / output are the same in the second and third embodiments described later.

  Here, it is considered practical that the circuit board 7 includes a coil having a number of turns equal to or less than the number of layers, unless the number of conductive paths is locally changed. For example, if a narrow spiral coil is used to form a pattern coil having a large number of turns in a conductive path located in the lower layer of the circuit board 7, the electrical resistance is more than doubled. On the other hand, in the transformer 1, one coil (here, the primary coil portion 2) is the laminated coil portion 20 including both the thin plate coil 21 and the individual plate coil 23 and the pattern coil 22. , 22 total turns. The primary coil portion 2 in this example includes a laminated coil portion 20A having a total of 7 turns, which is a 5-turn thin plate coil 21 and pattern coils 220 and 221 each having 1 turn, and the number of turns is large, but the electrical resistance is increased. Can be suppressed.

  In addition, in this example, the planar outer shape of each of the thin plate coil 21 and the pattern coil 22 is a circular shape, but a rectangular shape or the like can be appropriately used.

<Secondary coil section>
The thin coil 31 constituting the secondary coil portion 3 in this example is formed from a conductive plate having the same specifications as the conductive plate constituting the secondary power line portion 53, and the secondary coil 31 is connected to the secondary coil via a joint 9 such as solder. It is electrically connected to the side power line portion 53 (FIG. 2).

  The thin plate coil 31 is obtained by preparing a material plate and punching it into a predetermined shape by press molding or bending it. The basic manufacturing method of the thin plate coil 31 can refer to the thin plate coil 21 provided in the laminated coil unit 20 described above.

  The number of turns of the thin coil 31 is an example, and here it is 1 turn, but it can be changed as appropriate. The thin coil 31 constituting the low voltage side coil can typically have fewer turns than the high voltage side coil. Each end 33 of the thin coil 31 in this example forms an input end and an output end, and is an electrical connection location with the secondary power line portion 53. In this example, as shown in FIG. 2, there is a step corresponding to the thickness of the primary circuit board 72 between the thin coil 31 and the secondary power line portion 53, so that the above-described electrical connection is possible. Thus, each end 33 is appropriately bent according to the step. Since the thin coil 31 of this example can be manufactured independently of the secondary power line portion 53, even such a stepped shape can be accurately formed. Each end portion 33 is joined to a predetermined position of the secondary power line portion 53 via the joint portion 9 described above.

  For the number of turns and the width of the turn of the thin coil 31 that forms the secondary coil part 3, the term of the thin coil 21 provided in the laminated coil part 20 may be referred to. The thin plate coil 31 of this example has a wider width than the thin plate coil 21 of the primary coil portion 2 and can easily reduce the electric resistance. The number of turns of the secondary coil unit 3 can be made larger than that of the primary coil unit 2.

  The thin coil 31 can be formed integrally with a conductive plate constituting the secondary power line section 53 (see FIG. 5), similarly to the primary thin coil 21.

<Assembly state>
As shown in FIG. 3, the transformer 1A according to the first embodiment includes a secondary coil portion 3 made of a thin plate coil 31 coaxially laminated on a primary coil portion 2 made of a laminated coil portion 20A. The middle leg portion 40 of the magnetic core 4 is inserted and arranged around the circumference. In the laminated coil portion 20A of this example, the thin plate coil 21 included in the primary coil portion 2 and the thin plate coil 31 forming the secondary coil portion 3 are located at both ends in the lamination direction. Therefore, each thin plate coil 21 and 31 is easy to radiate | emit heat to the heat radiating member 8 and the exterior, and is excellent in heat dissipation. As in this example, the heat radiation sheet 35 can be interposed between the primary circuit board 72 (insulating film 722) and the thin coil 31 of the secondary coil portion 3 (FIG. 2). In this case, the heat of the primary circuit board 72 can be transmitted to the secondary power line portion 53 through the thin coil 31 and further transmitted to the heat radiating member 8 through the secondary power line portion 53. Can be further enhanced. As the constituent material of the heat radiating sheet 35, a material having excellent heat radiating property, for example, a material made of a resin containing the above-described filler can be used. Further, it is preferable that the heat dissipating sheet 35 is relatively low in hardness and excellent in flexibility so that it can be in close contact with the thin coil 31. Between the primary circuit board 72 (insulating film 722) and the secondary coil section 3 (thin plate coil 31), instead of the heat radiating sheet 35 or in addition to the heat radiating sheet 35, the above-described adhesive having excellent heat radiating properties is used. An adhesive layer or the like may be provided.

  Further, in this example, as shown in FIG. 2, an adhesive layer 55 and an insulating film 722 are interposed between the thin plate coil 21 forming the laminated coil portion 20A and one pattern coil 220. An insulating substrate 724 is interposed between the pattern coils 220 and 221. An insulating film 722 is interposed between the other pattern coil 221 and the thin plate coil 31 forming the secondary coil portion 3. For these reasons, the transformer 1A is also excellent in insulation. When the above-described heat radiating sheet 35 is made of a material having excellent insulating properties such as a resin, the insulating property between the other pattern coil 221 and the thin plate coil 31 can be further enhanced.

  As illustrated in FIG. 2, the circuit configuration body 10 </ b> A according to the first embodiment includes an insulating layer 85, a “primary side power line portion 52 and a secondary side power line portion 53”, an adhesive layer 55, The primary side circuit board 72 and the secondary side circuit board 73 "are laminated. The primary side power line portion 52 and the secondary side power line portion 53 are disposed at positions where the height from the mounting surface of the heat radiating member 8 is substantially equal, and the primary side circuit board 72 and the secondary side circuit board 73 are also included. It is the same. An electronic component 6 is mounted on each of the power line portions 52 and 53. In the vicinity of the transformer 1A provided in the circuit structure 10A, the primary coil portion 2 disposed in the same position as the (radiating member 42 connecting portion 42), the insulating layer 85, and the primary side power line portion 52 in this order from the heat radiating member 8 side. The thin coil 21, the adhesive layer 55, the pattern coil 22 provided on the primary circuit board 72, the heat radiation sheet 35, and the thin coil 31 of the secondary coil unit 3 are laminated.

  In addition, an insulating intermediate portion (not shown) can be provided between the thin coil 31 and the magnetic core 4. In this case, the insulation between both can be improved. Examples of the constituent material of the insulating interposition part include a material having excellent insulating properties such as a resin, a resin containing a filler or the like and excellent heat dissipation, and an adhesive having excellent insulating properties and heat dissipation.

<Production method>
The transformer 1 according to the embodiment and the circuit structure 10 according to the embodiment including the transformer 1 include, for example, a step of preparing the above-described components and laminating them in the order described above, a step of appropriately joining them by soldering or welding, and the like. Can be manufactured by performing the process of assembling the magnetic core 4 at the position. By constructing the circuit structure 10, the transformer 1 can be constructed in a part thereof. Specific steps for manufacturing the transformer 1A and the circuit structure 10A in this example include, for example, the following. The following are examples and can be changed as appropriate. For example, some of the joints at the plurality of locations in (5) may be performed in other steps.

(1) A primary power line portion 52 integrally including the thin coil 21, a primary circuit board 72 formed with the pattern coil 22, the magnetic core 4, the heat radiation member 8 including the recess 84, the thin coil 31, and the secondary power A line portion 53, a secondary circuit board 73, and an electronic component 6 are prepared. In this example, an insulating layer 85 (material), an adhesive layer 55 (material), a heat radiation sheet 35, and the like are also prepared.
(2) The I-type core (connecting portion 42) of the magnetic core 4 is housed in the recess 84.
(3) The insulating layer 85, “primary side power line portion 52 and secondary side power line portion 53”, adhesive layer 55, “primary side circuit board 72 and secondary side circuit board 73” are laminated on the heat radiating member 8. .
(4) The heat radiating sheet 35 and the thin plate coil 31 are laminated on the location where the pattern coil 22 is formed on the primary circuit board 72.
(5) A predetermined portion of the power line portion 5 is joined to the electronic component 6, one end of the step absorbing member 27, and the end portion 33 of the thin coil 31 by the joint portion 9. In addition, a predetermined portion of the circuit board 7, an appropriate terminal of the electronic component 6, and the other end of the step absorbing member 27 are joined by the joining portion 9 or the like. The pattern coil 220 is joined to the thin plate coil 21 of the primary power line portion 52.
(6) The middle leg portion 40 of the E-type core of the magnetic core 4 is inserted into the inner periphery of the thin plate coil 31, the pattern coil 22, and the thin plate coil 21, and is assembled to the I-type core. The I-type core and the E-type core can be fixed with an adhesive or the like, or the contact state can be maintained using a leaf spring or the like.
Through the above steps, the transformer 1A and the circuit structure 10A can be constructed.

(Use)
The transformer 1 and the circuit structure 10 of the embodiment can be used for an electrical junction box, particularly an automobile electrical junction box that is desired to be small. More specifically, the transformer 1 and the circuit configuration body 10 can be used for various voltage conversion devices such as a DC / DC converter, an AC / DC converter, and a DC / AC inverter, in particular, a component of an in-vehicle device.

[effect]
Since the transformer 1 of the embodiment includes the thin plate coils 21 and 31 in at least one of the primary coil portion 2 and the secondary coil portion 3, the heat of the coil can be dissipated to the heat radiating member 8 and is excellent in heat dissipation. Moreover, since the transformer 1 of the embodiment includes the laminated coil portion 20 in one of the primary coil portion 2 and the secondary coil portion 3, the case where only one of the coils is a pattern coil or only a thin plate coil is used. Compared to the case, the number of turns can be increased, while an increase in electrical resistance can be suppressed, and the size is small.

  The circuit structure 10 of the embodiment can dissipate not only the electronic component 6 but also the thin plate coil 21 to the heat dissipating member 8 through the power line portion 5, and is excellent in heat dissipation. In addition, since the circuit configuration body 10 of the embodiment includes the transformer 1 of the embodiment, even if the number of turns of the coil included in the transformer 1 is increased as described above, the increase in electric resistance can be suppressed and the size is small. Furthermore, since the circuit configuration body 10 of the embodiment includes the insulating layer 85 between the metal power line portion 5 and the metal heat dissipation member 8 excellent in thermal conductivity, the circuit structure 10 is excellent in heat dissipation and insulative. Also excellent.

The transformer 1A of the first embodiment of this example further exhibits the following effects.
(A) Since the primary coil portion 2 includes the laminated coil portion 20A, the number of turns of the high-voltage side coil that is desired to have a relatively large number of turns can be increased.
(B) The secondary coil portion 3 is a thin plate coil 31, and the laminated coil portion 20A and the thin plate coil 31 are coaxially laminated, so that the lamination height can be easily reduced, and in this respect, the size is smaller. .
(C) Since both the primary coil part 2 and the secondary coil part 3 are equipped with the thin-plate coils 21 and 31, it is more excellent in heat dissipation.

  In this example, the circuit structure 10A according to the first embodiment is further improved in heat dissipation by including a recess 84 in the heat dissipation member 8 and housing a part of the magnetic core 4, and further including the magnetic core 4. It is easy to reduce the height of the entire 10A, and it is smaller in this respect.

[Embodiment 2]
The basic configuration of the transformer 1B of the second embodiment shown in FIG. 4 and the circuit configuration body 10B of the second embodiment is the same as that of the first embodiment. The transformer 1B includes the laminated coil portion 20B in the primary coil portion 2, The secondary coil part 3 is provided with a thin plate coil 31, and these coils are coaxially stacked. In the second embodiment, the laminated coil portion 20B includes the individual plate coil 23 made of the second conductive plate independent of the first conductive plate, and the thin plate coil 31 forms the secondary power line portion 53. The main difference from the first embodiment is that the primary coil portion 2 and the secondary coil portion 3 are reversely stacked in order. The thin plate coil 31 of the secondary coil unit 3, the pattern coils 220 and 221 of the primary coil unit 2, and the individual plate coil 23 are arranged in order from the side close to the heat radiating member 8.

  The individual plate coil 23 may be an appropriate conductive plate, for example, a conductive plate having the same specifications (component materials, thickness, etc.) as the conductive plate constituting the primary power line section 52. Such an individual plate coil 23 can be manufactured by preparing a material plate and forming it appropriately as in the case of the thin plate coil 31 provided in the first embodiment. The details of the individual plate coil 23 may be referred to the thin plate coil 21 of the first embodiment.

  In this example, the primary power line section 52 and the conductive path 720 formed on the primary circuit board 72 are electrically connected via the step absorbing member 27 as in the first embodiment. The pattern coil 220 is electrically connected to the conductive path 720 through the via hole 26. The pattern coil 220 is electrically connected to the pattern coil 221 through another via hole 26. The pattern coil 221 and one end portion of the individual plate coil 23 (the end portion of the turn located at the innermost periphery in FIG. 4) are connected via a joint 9 such as solder. The other end of the individual plate coil 23 (the end of the turn located on the outermost periphery in FIG. 4) is connected to the conductive path 720 via a joint 9 such as solder. That is, in this example, one end of the pattern coil 220 is used as an input end, and the other end of the individual plate coil 23 is used as an output end.

  The transformer 1B and the circuit configuration body 10B according to the second embodiment are different from the first embodiment in that the stacking order of the primary coil portion 2 and the secondary coil portion 3 is reversed, but the secondary coil portion 3 including the thin plate coil 31 is used. Is installed on the heat radiating member 8 through the insulating layer 85, and thus has excellent heat dissipation. In particular, the transformer 1B and the circuit configuration body 10B of the second embodiment are located on the side where the electrical connection portion between the individual plate coil 23 and the pattern coil 221 of the primary circuit board 72 is away from the heat radiating member 8 (upper side in FIG. 4). Therefore, it is easy to perform a joining operation with solder or the like. In addition, the transformer 1B and the circuit configuration body 10B of the second embodiment have the same effects as those of the first embodiment such that the increase in the electrical resistance described above can be suppressed and the size can be reduced.

[Embodiment 3]
The basic configuration of the transformer 1C of the third embodiment shown in FIG. 5 and the circuit configuration body 10C of the third embodiment is the same as that of the first embodiment. The transformer 1C includes the laminated coil unit 20C in the primary coil unit 2, The secondary coil part 3 is provided with a thin plate coil 31, and these coils are coaxially stacked. In the third embodiment, the laminated coil portion 20 </ b> C includes the thin plate coil 21 and the individual plate coil 23, and the thin plate coil 31 is integrally formed on a part of the conductive plate constituting the secondary power line portion 53. Is the main difference from the first embodiment. The details of the individual plate coil 23 may be referred to the individual plate coil 23 of the second embodiment.

  In this example, the thin plate coil 21 and the individual plate coil 23 are arranged so as to sandwich the pattern coils 220 and 221. Moreover, in this example, the thin plate coil 21 included in the primary coil portion 2 and the thin plate coil 31 included in the secondary coil portion 3 are arranged so as to be positioned at both ends in the stacking direction. As shown in FIG. 5, the thin plate coil 21 of the primary coil portion 2, the pattern coils 220 and 221, the individual plate coil 23, and the thin plate coil 31 of the secondary coil portion 3 are arranged in order from the side closer to the heat radiating member 8. In this way, the laminated coil portion 20 can be formed by laminating both the thin plate coil 21 and the pattern coil 22.

  In this example, as shown in FIG. 6, the thin plate coil 21 has 3 turns and the individual plate coil 23 has 2 turns. Therefore, the primary coil part 2 is provided with a laminated coil part 20C having a total of 7 turns including a 3-turn thin coil 21, 1-turn pattern coils 220 and 221, and a 2-turn individual plate coil 23. The number of turns is the same as that of the laminated coil portion 20A described in the first embodiment, but the thin plate coil 21 and the individual plate coil 23 each have a width of one turn larger than the five-turn thin plate coil 21 described in the first embodiment. Therefore, it is easy to reduce electrical resistance.

  Of the laminated coil portion 20C constituting the primary coil portion 2, the electrical connection of the thin plate coil 21 and the pattern coil 22 is the same as in the first embodiment. The electrical connection between the pattern coil 221 and the individual plate coil 23 is as follows. The pattern coil 221 and one end portion of the individual plate coil 23 (the end portion of the turn located in the innermost periphery in FIG. 6, the portion closer to the middle leg portion 40 in FIG. 5) are connected via the joint portion 9 such as solder. Connected. The other end portion of the individual plate coil 23 (the end portion of the turn located on the outermost periphery in FIG. 6, the portion closer to the step absorbing member 27 in FIG. 5) is connected to the conductive path 720 via the joint portion 9 such as solder. Connected. The conductive path 720 and the primary power line portion 52 are electrically connected via the step absorbing member 27. That is, in this example, one end of the thin plate coil 21 is used as an input end, and the other end of the individual plate coil 23 is used as an output end.

  In this example, a heat radiating sheet 35 is interposed between the individual plate coil 23 of the primary coil part 2 and the thin plate coil 31 of the secondary coil part 3 arranged on the side away from the heat radiating member 8, but it should be omitted. You can also.

  The transformer 1C and the circuit configuration body 10C according to the third embodiment are excellent in heat dissipation because both the primary coil portion 2 and the secondary coil portion 3 include the thin plate coils 21 and 31 as in the first embodiment. In this example, the thin coil 31 on the secondary side is formed integrally with the conductive plate constituting the secondary power line portion 53, the joint 9 is not interposed, and the heat dissipation sheet 35 is further interposed. In addition, the heat of the thin coil 31 can be easily dissipated to the heat radiating member 8, and the heat dissipation is excellent. Moreover, in Embodiment 3, since the primary coil part 2 which is a high voltage | pressure side is made into the laminated coil part 20C, and both the thin plate coil 21 and the individual plate coil 23 are provided, it is easy to increase the number of turns. Even if the number of turns is larger, in this example, the primary coil portion 2 and the secondary coil portion 3 are coaxially stacked and arranged, and the installation area can be easily reduced. Furthermore, in this example, if the thin coil 31 is formed at the same time as the formation of the secondary power line section 53, the number of steps can be reduced and the productivity is excellent. Moreover, the joining process by the junction part 9 can also be made unnecessary. In addition, the transformer 1 </ b> C and the circuit configuration body 10 </ b> C of the third embodiment have the same effects as those of the first embodiment such that the increase in the electrical resistance described above can be suppressed and the size can be reduced.

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

1, 1A, 1B, 1C Transformer 10, 10A, 10B, 10C Circuit component 2 Primary coil part 20, 20A, 20B, 20C Laminated coil part 21 Thin plate coil 22, 220, 221 Pattern coil 23 Individual plate coil 26 Via hole 27 Step Absorbing member 3 Secondary coil portion 31 Thin coil 33 End portion 35 Heat radiation sheet 4 Magnetic core 40 Middle leg portion 41 Side leg portion 42 Connection portion 5 Power line portion 52 Primary side power line portion 53 Secondary side power line portion 55 Adhesive layer 6, 62a, 62b, 62c, 63a, 63b, 63c, 63d Electronic component 7 Circuit board 72 Primary side circuit board 73 Secondary side circuit board 720, 730 Conductive path 722, 732 Insulating film 724, 734 Insulating board 8 Heat radiation member 84 Recess 85 Insulating layer 9 Junction D Drain terminal S Source terminal G Gate terminal

Claims (6)

A primary coil section;
A secondary coil section;
A magnetic core on which the primary coil part and the secondary coil part are arranged,
At least one of the primary coil part and the secondary coil part is:
A power line portion on which electronic components are mounted is configured, and includes a thin coil formed of a part of a first conductive plate installed on a heat dissipation member,
The primary coil part or the secondary coil part is
At least one of the individual plate coils composed of a second conductive plate independent of the thin plate coil and the first conductive plate;
A transformer including a laminated coil portion in which a pattern coil formed on a circuit board disposed on one surface of the first conductive plate is laminated. Each of the primary coil portion and the secondary coil portion includes the thin plate coil,
The transformer according to claim 1, wherein the primary coil unit includes the laminated coil unit including the thin plate coil. The primary coil portion and the secondary coil portion are laminated coaxially on the magnetic core,
The transformer according to claim 2, wherein the thin plate coil included in the primary coil portion and the thin plate coil included in the secondary coil portion are located at both ends in the stacking direction.   The transformer according to any one of claims 1 to 3, wherein the laminated coil unit includes the thin plate coil and the individual plate coil, and the pattern coil is sandwiched between the thin plate coil and the individual plate coil. The transformer according to any one of claims 1 to 4,
The electronic component;
The power line portion that is mounted with the electronic component and includes a portion other than the thin plate coil in the first conductive plate;
The circuit board disposed on one surface of the first conductive plate;
A circuit structure provided with the heat dissipation member in which the power line part is installed via an insulating layer.   The circuit structure according to claim 5, wherein the heat dissipating member includes a recess that houses a part of the magnetic core.

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