Coil device and power conversion device

Abstract

This coil device (20) has a coil unit (18). The coil unit (18) is provided with a winding part (11), a metal base substrate part (31), a core part (21), and a cooling part (39). The winding part (11) includes a coil pattern (37) and a coil wire (36). The coil wire (36) is electrically connected to the coil pattern (37). The coil pattern (37) is formed on the metal base substrate part (31). The core part (21) is provided with a through hole (H) through which the coil wire (36) is inserted. The cooling part (39) is disposed on the outer periphery of the core part (21). The metal base substrate part (31) includes a first metal base substrate (31a) and a second metal base substrate (31b). The first metal base substrate (31a) and the second metal base substrate (31b) are disposed so as to sandwich the core part (21) and the cooling part (39).

Description

Coil device and power conversion device

[0001] The present disclosure relates to a coil device and a power conversion device.

[0002] For example, power conversion devices such as DC-DC converters are equipped with coil devices such as transformers and smoothing reactors. The coil device mounted on the power conversion device is composed of a coil and a core. The core has a function of forming a magnetic path. The magnetic path is the path of magnetic lines of force generated by the current flowing through the coil. In the power conversion device, a direct current or an alternating voltage is applied to the coil of the coil device.

[0003] By setting the frequency of the alternating voltage to a high frequency, it is possible to reduce the size of the core and the number of turns of the coil, contributing to the miniaturization of the coil device. In recent years, in order to miniaturize the coil device and the power conversion device equipped with the coil device, as a switching element mounted on the power conversion device, for example, a switching element capable of corresponding to a high switching frequency of 1 kHz or more has been applied.

[0004] The heat generation associated with the energization of the coil device is roughly divided into Joule heat generated in the coil and heat generated in the core. Joule heat increases inversely proportional to the cross-sectional area of the wiring used as the coil. Therefore, when trying to apply wiring with a small cross-sectional area for miniaturization of the coil device, the Joule heat generated in the coil device will increase.

[0005] Also, when an alternating current flows, due to the skin effect, the current flows only near the surface of the wiring, so the electrical resistance of the coil device increases. As the frequency of the alternating current flowing through the wiring increases, the electrical resistance value will increase monotonically.

[0006] Therefore, when trying to miniaturize the coil device, the higher the frequency of the alternating voltage applied to the coil device, the higher the electrical resistance value of the wiring of the coil device due to the skin effect, and the Joule heat generated in the coil device will increase. [[ID=第十九]] [[ID=第二十]]

[0007] Therefore, in order to keep the temperature of the coil device below the allowable temperature due to Joule heating and other factors generated in the coil device, the coil device is required to have improved heat dissipation. In other words, miniaturizing the coil device also requires improving the heat dissipation of the coil device. In the coil device proposed in Patent Document 1, a method is proposed in which the heat generated from the coil in the region inside the core is dissipated via the printed circuit board and the coil.

[0008] International Publication No. 2014 / 141670

[0009] However, there is room for improvement in enhancing the heat dissipation of the coil device. This disclosure was made to solve the above-mentioned problems, and the object of this disclosure is to provide a coil device with improved heat dissipation and a power conversion device equipped with said coil device.

[0010] A coil device according to this disclosure is a coil device having a coil unit. The coil unit comprises a winding section, a metal base substrate section, a core section, and a cooling section. The winding section includes a coil pattern and coil wires. The coil wires are electrically connected to the coil pattern. The metal base substrate section has the coil pattern formed on it. The core section is provided with through holes through which the coil wires are inserted. The cooling section is arranged on the outer circumference of the core section. The metal base substrate section includes a first metal base substrate and a second metal base substrate. The first metal base substrate and the second metal base substrate are arranged to sandwich the core section and the cooling section.

[0011] A coil device according to this disclosure is a coil device having a coil unit. The coil unit comprises a winding section, a printed circuit board section, a core section, and a cooling section. The winding section includes a coil pattern and coil wires. The coil wires are electrically connected to the coil pattern. The printed circuit board section has the coil pattern formed on it. The core section is provided with through holes through which the coil wires are inserted. The cooling section is arranged on the outer circumference of the core section. The printed circuit board section includes a first printed circuit board and a second printed circuit board. The first printed circuit board and the second printed circuit board are arranged so as to sandwich the core section and the cooling section.

[0012] The power conversion device relating to this disclosure includes the above-described coil device.

[0013] According to the above, a coil device with improved heat dissipation and a power conversion device equipped with the coil device can be obtained.

[0014] This is a circuit diagram showing an example of a power conversion device to which the coil device according to each embodiment is applied. This is a perspective view showing an example of a power conversion device equipped with the coil device according to Embodiment 1. This is an exploded perspective view showing an example of a power conversion device equipped with the coil device according to Embodiment 1. This is an exploded perspective view showing the core and cooling parts in the coil device according to Embodiment 1. This is a perspective view showing the core and cooling parts in the coil device according to Embodiment 2. This is a side view showing the positional relationship between the core and cooling parts in the coil device according to Embodiment 2. This is a perspective view showing the core and cooling parts in Modification 1 of the coil device according to Embodiment 2. This is a side view showing the positional relationship between the core and cooling parts in Modification 1 of the coil device according to Embodiment 2. This is a perspective view showing how the coil wire is inserted into the top cover cooling body in Modification 1 of the coil device according to Embodiment 2. This is a partially enlarged cross-sectional view showing how the coil wire is inserted into the top cover cooling body in Modification 1 of the coil device according to Embodiment 2. This is a perspective view showing the core and cooling parts in Modification 2 of the coil device according to Embodiment 2. This is a side view showing the positional relationship between the core and cooling parts in Modification 2 of the coil device according to Embodiment 2. This is a perspective view showing how coil wires are inserted into the upper cover cooler and lower cover cooler in a modified example 2 of the coil device according to Embodiment 2. This diagram is for explaining the reason for forming a gap. This is a perspective view showing the core and cooling parts in the coil device according to Embodiment 3. This is a side view showing the positional relationship between the core and cooling parts in the coil device according to Embodiment 3. This is a perspective view showing how coil wires are inserted into the intermediate cooler in the coil device according to Embodiment 3. This is a perspective view showing the core and cooling parts in a modified example 1 of the coil device according to Embodiment 3. This is a side view showing the positional relationship between the core and cooling parts in a modified example 1 of the coil device according to Embodiment 3. This is a perspective view showing how coil wires are inserted into the intermediate cooler in a modified example 1 of the coil device according to Embodiment 3. This is an exploded perspective view showing an example of a power conversion device equipped with a coil device according to Embodiment 4. This is a perspective view showing an example of a power conversion device equipped with a coil device according to Embodiment 5. This is a perspective view showing the core and cooling parts in a modified example 1 of the coil device according to Embodiment 5.This is a side view showing the positional relationship between the core and the cooling section in a modified example 1 of the coil device according to Embodiment 5.

[0015] Embodiments of the present disclosure will be described below. Unless otherwise specified, the same or corresponding parts in the following drawings will be given the same reference numerals, and their descriptions will not be repeated.

[0016] <Circuit Diagram of Power Conversion Device> Figure 1 is a circuit diagram showing an example of a power conversion device 1 to which the coil device 20 according to each embodiment is applied. The circuit diagram of the power conversion device 1 shown in Figure 1 is a DC-DC converter. DC-DC converters are installed in electric vehicles, for example. DC-DC converters have the function of charging a lead-acid battery by converting the input voltage of a lithium-ion battery of about 100V to 300V to a voltage of 12V to 15V and outputting the converted voltage.

[0017] As shown in Figure 1, the DC-DC converter, which is a power conversion device 1, includes an inverter circuit section 2, a transformer section 3, a rectifier circuit section 4, a smoothing circuit section 5, an input terminal 6, an input capacitor 8, a control circuit section 10, and an output terminal 7.

[0018] The inverter circuit section 2 is composed of switching elements 9. Here, the inverter circuit section 2 is composed of four switching elements 9a, 9b, 9c, and 9d. As the switching elements 9, power semiconductor elements such as MOS transistors (MOSFETs: Metal Oxide Semiconductor Field Effect Transistors) or insulated-gate bipolar transistors (IGBTs: Insulated Gate Bipolar Transistors) are used. The switching operation of the four switching elements 9 is controlled by the control circuit section 10.

[0019] The transformer section 3 is composed of a transformer 20a having a winding section 11. The winding section 11 includes a primary winding section 11a and a secondary winding section 11b. The rectifier circuit section 4 is composed of rectifier elements 12. Here, the rectifier circuit section 4 is composed of four rectifier elements 12a, 12b, 12c, and 12d. As the rectifier elements 12, for example, power semiconductor elements such as diodes, MOS transistors, or thyristors are used. The smoothing circuit section 5 is composed of a smoothing reactor 13 and a smoothing capacitor 14.

[0020] The DC-DC converter, acting as a power conversion device 1, converts the DC voltage input from the input terminal 6 into an AC voltage by controlling the switching operation of each of the four switching elements 9 in the inverter circuit section 2 using the control circuit section 10.

[0021] In the transformer section 3, the AC voltage converted in the inverter circuit section 2 is converted to an arbitrary voltage by the transformer 20a. The converted voltage is determined by the winding ratio of the primary winding section 11a and the secondary winding section 11b in the transformer 20a. The transformer 20a electrically insulates the input terminal 6 and the output terminal 7.

[0022] In the rectifier circuit section 4, the AC voltage supplied from the transformer section 3 is converted back into a DC voltage by the rectifier element 12. In the smoothing circuit section 5, the DC voltage converted by the rectifier circuit section 4 is smoothed by the smoothing reactor 13 and the smoothing capacitor 14. This stabilizes the output voltage output from the output terminal 7.

[0023] In the power conversion device 1 shown in Figure 1, the transformer 20a and the smoothing reactor 13 are coil devices that generate relatively high amounts of heat. It is necessary to dissipate the heat generated in the transformer 20a and the smoothing reactor 13 and lower the temperature of the transformer 20a and the smoothing reactor 13 to below an allowable temperature, for example, about 100°C to 120°C or less. In each embodiment, the structure for dissipating heat from the coil device 20, which is composed of the coil unit 18, will be described in detail.

[0024] Embodiment 1. <Configuration of the coil device> Figure 2 is a perspective view showing an example of a power conversion device 1 equipped with a coil device 20 according to Embodiment 1. Figure 3 is an exploded perspective view showing an example of a power conversion device 1 equipped with a coil device 20 according to Embodiment 1. The coil device 20 according to Embodiment 1 is an example of a transformer 20a. As shown in Figures 2 and 3, the coil device 20 has one coil unit 18. The coil unit 18 comprises a winding portion 11, a metal base substrate portion 31, a core portion 21, a cooling portion 39, and a wiring member 41.

[0025] The metal base substrate portion 31 includes a first metal base substrate 31a and a second metal base substrate 31b. The first metal base substrate 31a and the second metal base substrate 31b are arranged to sandwich the core portion 21 and the cooling portion 39.

[0026] As shown in Figures 1 and 2, the direction in which the first metal base substrate 31a and the second metal base substrate 31b are separated is defined as the Z direction. The directions perpendicular to the Z direction are defined as the X and Y directions. The Y direction is perpendicular to the X direction.

[0027] The transformer 20a, which functions as a coil device 20, is formed by a core portion 21 and a winding portion 11. The core portion 21 has a loop-shaped magnetic path. The winding portion 11 includes a first winding portion 29 (primary winding portion 11a) and a second winding portion 30 (secondary winding portion 11b). The first winding portion 29 (primary winding portion 11a) and the second winding portion 30 (secondary winding portion 11b) are wound around the core portion 21, respectively. The first winding portion 29 and the second winding portion 30 are electrically insulated from each other.

[0028] The winding section 11 includes a coil pattern 37, a wiring body 45, and a coil wire 36. The coil pattern 37 is formed on the metal base substrate 31. The wiring body 45 is formed on the wiring member 41. The coil wire 36 is inserted through a through hole H in the core section 21, which will be described later.

[0029] The coil wire 36 is electrically connected to the wiring body 45. The wiring body 45 is electrically connected to the coil pattern 37. In other words, the coil wire 36 is electrically connected to the coil pattern 37.

[0030] The coil pattern 37 includes a first coil pattern 37a and a second coil pattern 37b. The wiring body 45 includes a first wiring body 45a and a second wiring body 45b. The coil wire 36 includes a first coil wire 36a and a second coil wire 36b.

[0031] The first winding section 29 includes a first coil pattern 37a, a first wiring body 45a, and a first coil wire 36a. The second winding section 30 includes a second coil pattern 37b, a second wiring body 45b, and a second coil wire 36b.

[0032] Next, the structure of the coil device 20 will be described in detail. The transformer 20a comprises a metal base substrate 31, a wiring member 41, a core 21, and a cooling unit 39.

[0033] Figure 4 is an exploded perspective view showing the core portion 21 and the cooling portion 39 in the coil device 20 according to Embodiment 1. As shown in Figure 4, the core portion 21 is composed of a core 23 and a core 24. In a plan view along the Z direction, the shape of each of the cores 23 and 24 is E-shaped. Specifically, the core 23 has legs 23a, 23b, 23c, a bottom portion 23d, and a bottom portion 23e. The legs 23a, 23b, and 23c are spaced apart in the Y direction. The legs 23a and 23b are connected to the bottom portion 23d. The legs 23b and 23c are connected to the bottom portion 23e.

[0034] The core 24 has legs 24a, 24b, 24c, a base 24d, and a base 24e. Legs 24a, 24b, and 24c are spaced apart in the Y direction. Legs 24a and 24b are connected to the base 24d. Legs 24b and 24c are connected to the base 24e.

[0035] Legs 23a and 24a are in contact. Legs 23b and 24b are in contact. Legs 23c and 24c are in contact. In this way, a core portion 21 having a loop-shaped magnetic path is formed. Cores 23 and 24 may be connected to each other by an adhesive (not shown).

[0036] The core portion 21 is provided with through holes H. The through holes H include a first through hole H1 and a second through hole H2. The first through hole H1 is formed by legs 23a, 23b, 24a, 24b, bottom 23d and bottom 24d. The second through hole H2 is formed by legs 23b, 23c, 24b, 24c, bottom 23e and bottom 24e.

[0037] The material constituting the core portion 21 may be a ferrite core, such as a manganese-zinc (Mn-Zn) ferrite core or a nickel-zinc (Ni-Zn) ferrite core. The material constituting the core portion 21 may also be an amorphous core or an iron dust core.

[0038] In this embodiment 1, the core portion 21 has a structure that combines an E-shaped core 23 and an E-shaped core 24, but any shape of core 23 and core 24 may be combined as long as the core portion 21 has a loop-shaped magnetic path. For example, the shape of each of the cores 23 and 24 may be U-shaped, one core 23 may be E-shaped and the other core 24 may be I-shaped, or one core 23 may be T-shaped and the other core 24 may be U-shaped.

[0039] The metal base substrate portion 31 is composed of a metal base body 34, an insulating layer 35, and a coil pattern 37. In the metal base substrate portion 31, the coil pattern 37 is arranged on the metal base body 34 with the insulating layer 35 interposed between them. The thermal conductivity of the metal base body 34 may be 1.0 W / (m·K) or higher, 10.0 W / (m·K) or higher, or 100.0 W / (m·K) or higher. The material constituting the metal base body 34 may be a metallic material containing at least one of copper, iron, aluminum, iron alloy, and aluminum alloy.

[0040] The first metal base substrate 31a has a first main surface 31aa and a second main surface 31ab. The first main surface 31aa is formed by the first main surface 35a of the insulating layer 35. The second main surface 31ab is located opposite the first main surface 31aa. The second main surface 31ab is in contact with the entire surface of the first main surface 39aa of the cooling section 39.

[0041] The second metal base substrate 31b has a first main surface 31ba and a second main surface 31bb. The first main surface 31ba is formed by the first main surface 35a of the insulating layer 35. The second main surface 31bb is located opposite to the first main surface 31ba. The second main surface 31ab is in contact with the entire second main surface 39ab of the cooling part 39.

[0042] The first metal base substrate 31a is provided with an opening 32a and an opening 32b. In a plan view along the Z direction, the opening 32a is arranged so as to overlap with the first through hole H1. In a plan view along the Z direction, the opening 32b is arranged so as to overlap with the second through hole H2.

[0043] In a plan view along the Z direction, the opening area of the opening 32a may be the same as the opening area of the first through hole H1, or may be less than or equal to the opening area of the first through hole H1. In a plan view along the Z direction, the opening area of the opening 32b may be the same as the opening area of the second through hole H2, or may be less than or equal to the opening area of the second through hole H2.

[0044] The second metal base substrate 31b is provided with an opening 32c and an opening 32d. In a plan view along the Z direction, the opening 32c is arranged so as to overlap with the first through hole H1. In a plan view along the Z direction, the opening 32d is arranged so as to overlap with the second through hole H2.

[0045] In a plan view along the Z direction, the opening area of the opening 32c may be the same as the opening area of the first through hole H1, or may be less than or equal to the opening area of the first through hole H1. In a plan view along the Z direction, the opening area of the opening 32d may be the same as the opening area of the second through hole H2, or may be less than or equal to the opening area of the second through hole H2.

[0046] The insulating layer 35 has a first main surface 35a and a second main surface 35b. The second main surface 35b is located opposite to the first main surface 35a. The second main surface 35b is in contact with the entire surface of the metal base body 34. The insulating layer 35 has electrical insulation properties. The material constituting the insulating layer 35 may be, for example, epoxy resin, glass fiber reinforced epoxy resin, or polyimide resin, etc. In order to improve the thermal conductivity of the insulating layer 35, a thermal conductive filler may be added to the above materials.

[0047] As long as it is within the range that does not affect electrical insulation or manufacturability, the thickness of the insulating layer 35 in the Z direction may be thin. The thickness of the insulating layer 35 may be, for example, 1 μm or more and 2000 μm or less, or may be 1 μm or more and 200 μm or less.

[0048] A coil pattern 37 is formed on the first main surface 35a of the insulating layer 35. The first coil pattern 37a is formed on the first metal base substrate 31a. The second coil pattern 37b is formed on the second metal base substrate 31b.

[0049] The first coil pattern 37a includes a first coil pattern first part 37af and a first coil pattern second part 37as. An inverter circuit section 2 is formed on the first metal base substrate 31a. The first coil pattern first part 37af and the first coil pattern second part 37as are electrically connected to the inverter circuit section 2. In addition, wiring patterns (not shown) other than the first coil pattern 37a may be formed on the first metal base substrate 31a.

[0050] The second coil pattern 37b includes a second coil pattern first part 37bf and a second coil pattern second part 37bs. A rectifier circuit section 4 is formed on the second metal base substrate 31b. The second coil pattern first part 37bf and the second coil pattern second part 37bs are electrically connected to the rectifier circuit section 4. In addition, wiring patterns (not shown) other than the second coil pattern 37b may be formed on the second metal base substrate 31b.

[0051] The first metal base substrate 31a, on which the first coil pattern 37a and inverter circuit section 2 are formed, has an electrical primary potential. The second metal base substrate 31b, on which the second coil pattern 37b and rectifier circuit section 4 are formed, has an electrical secondary potential. The first metal base substrate 31a, which has a primary potential, and the second metal base substrate 31b, which has a secondary potential, are electrically insulated from each other.

[0052] The thickness of the coil pattern 37 in the Z direction is, for example, 1 μm or more and 2000 μm or less. The material constituting the coil pattern 37 may be a metallic material such as copper, nickel, gold, aluminum, silver, or tin. The material constituting the coil pattern 37 may also be an alloy containing the above metallic material.

[0053] The heat generated in the coil pattern 37 is dissipated to the metal base body 34 via the insulating layer 35. By setting the thickness of the insulating layer 35 to a thin level, the heat dissipation performance of the coil device 20 is improved.

[0054] A creepage distance is maintained between the first coil pattern 37a and the metal base body 34. When the potential of the first coil pattern 37a and the potential of the metal base body 34 are different, ensuring a creepage distance prevents dielectric breakdown from occurring in the creepage between the first coil pattern 37a and the metal base body 34.

[0055] The creepage distance is set based on the potential difference between the potential of the first coil pattern 37a and the potential of the metal base body 34. The larger the potential difference, the longer the creepage distance needs to be set. From the viewpoint of preventing dielectric breakdown, the corners of the coil pattern 37 may be curved.

[0056] The second coil pattern 37b and the metal base body 34 are separated by a creepage distance. The creepage distance between the second coil pattern 37b and the metal base body 34 is set to be the same as the creepage distance between the first coil pattern 37a and the metal base body 34.

[0057] The wiring member 41 includes a first wiring member 41a and a second wiring member 41b. The first wiring member 41a and the second wiring member 41b are arranged to sandwich the cooling unit 39 and the metal base substrate 31. Specifically, the first wiring member 41a is provided on the insulating layer 35 of the first metal base substrate 31a so that the first wiring member 41a and the cooling unit 39 sandwich the first metal base substrate 31a. The second wiring member 41b is provided on the insulating layer 35 of the second metal base substrate 31b so that the second wiring member 41b and the cooling unit 39 sandwich the second metal base substrate 31b.

[0058] The first wiring member 41a includes a first insulating portion 43a, a first wiring body first portion 45aa, and a second wiring body second portion 45bb. The second wiring member 41b includes a second insulating portion 43b, a first wiring body second portion 45ab, and a second wiring body first portion 45ba. The wiring member 41 may be, for example, a printed circuit board, or, in addition to a printed circuit board, a metal busbar covered with an insulating coating.

[0059] The first wiring body 45a includes a first part 45aa and a second part 45ab. The second wiring body 45b includes a first part 45ba and a second part 45bb. The materials constituting the first wiring body 45a and the second wiring body 45b may be, for example, copper, nickel, gold, aluminum, silver, or tin. The insulating part 43 includes a first insulating part 43a and a second insulating part 43b. The first part 45aa and the second part 45bb are formed in the first insulating part 43a. The first part 45ba and the second part 45ab are formed in the second insulating part 43b.

[0060] Multiple through-hole conductive portions 47 are formed in the wiring member 41. One end of the first wiring body 45a is electrically connected to the first coil pattern first portion 37af via the through-hole conductive portion 47 and a conductive bonding member 53. The other end of the first wiring body 45a is electrically connected to the first coil pattern second portion 37as via the through-hole conductive portion 47 and a conductive bonding member 53. One end of the second wiring body 45b is electrically connected to the second coil pattern first portion 37bf via a conductive bonding member 53. The other end of the second wiring body 45b is electrically connected to the second coil pattern second portion 37bs via a conductive bonding member 53.

[0061] The joining member 53 may be, for example, a conductive adhesive or solder. The first wiring body 45a is thermally bonded to the first metal base substrate 31a via the joining member 53. The second wiring body 45b is thermally bonded to the second metal base substrate 31b via the joining member 53.

[0062] Furthermore, a heat conductive member 51 (see Figure 10) may be placed between the wiring body 45 and the coil pattern 37. In this way, the wiring body 45 is thermally bonded to the coil pattern 37 via the heat conductive member in addition to the joining member 53, enabling heat conduction. The thermal conductivity of the heat conductive member 51 may be, for example, 0.1 W / (m·K) or more, 1.0 W / (m·K) or more, or 10.0 W / (m·K) or more. The heat conductive member 51 may be, for example, a thermal conductive grease, a thermal conductive sheet, or a thermal conductive adhesive.

[0063] The insulating portion 43 has electrical insulating properties. The material constituting the insulating portion 43 may be, for example, glass fiber reinforced epoxy resin, phenolic resin, polyphenylene sulfide (PPS), or polyether ether ketone (PEEK).

[0064] The coil wire 36 includes a first coil wire 36a and a second coil wire 36b. One end of the first coil wire 36a is electrically connected to the first part 45aa of the first wiring body via a through-hole conductive portion 47 and a conductive connecting member 53. The other end of the first coil wire 36a is electrically connected to the second part 45ab of the first wiring body via a through-hole conductive portion 47 and a conductive connecting member 53. One end of the second coil wire 36b is electrically connected to the first part 45ba of the second wiring body via a through-hole conductive portion 47 and a conductive connecting member 53. The other end of the second coil wire 36b is electrically connected to the second part 45bb of the second wiring body via a through-hole conductive portion 47 and a conductive connecting member 53.

[0065] The material constituting the coil wire 36 may be any of the following: copper, nickel, gold, aluminum, silver, or tin. The material constituting the coil wire 36 may also be an alloy containing these metals.

[0066] An insulating sheath 38 may be provided on the surface of the coil wire 36 other than the end. The insulating sheath 38 covers the coil wire 36. The insulating sheath 38 has electrical insulating properties. The material constituting the insulating sheath 38 may be, for example, glass fiber reinforced epoxy resin, phenolic resin, polyphenylene sulfide, and polyether ether ketone.

[0067] A heat conduction member 51 (see Figure 10) may be placed between the insulating outer casing 38 and the core portion 21, between the insulating outer casing 38 and the metal base substrate portion 31, and between the insulating outer casing 38 and the wiring member 41. The coil wire 36 and the insulating outer casing 38 are thermally bonded to the core portion 21, the metal base substrate portion 31, and the wiring member 41 via the heat conduction member 51. The cooling section 39 is the thermal bonding point for each of the core portion 21, the metal base substrate portion 31, and the wiring member 41. Therefore, the heat generated in the coil wire 36 is conducted to the cooling section 39 via each of the core portion 21, the metal base substrate portion 31, and the wiring member 41.

[0068] The printed circuit board used as the wiring member 41 may generally be made of a material with relatively low thermal conductivity. In other words, the wiring member 41 may be a general-purpose printed circuit board. The wiring member 41 may also be a ceramic substrate such as aluminum oxide, aluminum nitride, or silicon carbide. Conductive portions (not shown) may be formed on the surface and inside of the wiring member 41.

[0069] The wiring member 41 may be, for example, a laminated busbar. The laminated busbar is formed by laminating an insulating film sheet and a metal conductor. The insulating film sheet may be, for example, a film made from polyethylene terephthalate (PET), a film made from polyimide (PI), or paper made from aramid (total aromatic polyamide) fibers. The insulating film sheet may be bonded to the metal conductor by an adhesive layer or a bonding layer. The metal conductor is the wiring body.

[0070] The metal base substrate portion 31 is placed on the cooling portion 39. The metal base substrate portion 31 is fixed to the cooling portion 39 by, for example, screws (not shown). The cooling portion 39 has a first main surface 39aa and a second main surface 39ab. The second main surface 39ab is located opposite the first main surface 39aa. The second main surface 31ab of the first metal base substrate 31a is in contact with the first main surface 39aa. The second main surface 31bb of the second metal base substrate 31b is in contact with the second main surface 39ab.

[0071] The cooling section 39 has a housing section 54 that penetrates from the first main surface 39aa to the second main surface 39ab. The core section 21 is housed in the housing section 54. In this way, the cooling section 39 is arranged on the outer circumference of the core section 21. The thickness of the core section 21 in the Z direction is less than or equal to the thickness of the housing section 54 in the Z direction. The thermal conductivity of the cooling section 39 may be, for example, 1.0 W / (m·K) or more, 10.0 W / (m·K) or more, or 100.0 W / (m·K) or more.

[0072] The material constituting the cooling section 39 may be a metallic material including, for example, copper, iron, aluminum, iron alloys, and aluminum alloys. The cooling section 39 may also be formed from, for example, a resin having high thermal conductivity. The cooling section 39 may be electrically connected to other members so that its potential is the same as the ground potential.

[0073] The metal base substrate portion 31 is in contact with the first main surface 39aa of the cooling portion 39. In this way, the cooling portion 39 and the metal base substrate portion 31 are thermally coupled to each other in a way that allows heat to be conducted between them. A heat conductive member 51 (not shown) may be interposed between the cooling portion 39 and the metal base substrate portion 31. This makes it easier for heat to be conducted from the metal base substrate portion 31 to the cooling portion 39.

[0074] Furthermore, the core portion 21 is in contact with the inner circumferential surface of the housing portion 54 of the cooling portion 39. In this way, the core portion 21 (cores 23 and 24) and the cooling portion 39 are thermally coupled to each other in a way that allows heat to be conducted between them. A heat conductive member 51 (not shown) may be interposed between the inner circumferential surface of the housing portion 54 and the core portion 21. In this way, heat is more easily conducted from the core portion 21 to the cooling portion 39.

[0075] The core portion 21 and the cooling portion 39 may be bonded together by an adhesive (not shown). The cooling portion 39 may be part of the housing of the coil device 20, or part of the housing of the power converter 1 equipped with the coil device 20. In the cooling portion 39, a surface different from the surface on which the metal base substrate portion 31 is located may be air-cooled or water-cooled. In this way, the heat generated in the core portion 21 is dissipated to the cooling portion 39. As a result, there is no need to enlarge the core portion 21. In other words, the coil device 20 and the power converter 1 equipped with the coil device 20 can be miniaturized.

[0076] <Operation of the Power Converter> Next, the operation of the power converter 1 equipped with the coil device 20 (transformer 20a) according to this embodiment will be described.

[0077] First, in the power conversion device 1 equipped with the coil device 20 (transformer 20a) according to this embodiment, the AC voltage converted by the inverter circuit 2 is converted to an arbitrary voltage by the transformer 20a. At this time, the AC voltage converted by the inverter circuit 2 flows through the current path PT1 shown in Figure 3. The current path PT1 is a first winding section 29 including a first coil pattern 37a, a first coil wire 36a, and a first wiring body 45a. The first winding section 29 becomes the primary winding section 11a of the transformer 20a.

[0078] The AC voltage converted to an arbitrary voltage by the transformer 20a flows through the current path PT2. The current path PT2 is a second winding section 30, which includes a second coil pattern 37b, a second coil wire 36b, and a second wiring body 45b. The second winding section 30 becomes the secondary winding section 11b of the transformer 20a. The AC voltage that has flowed through the current path PT2 is converted to a DC voltage in the rectifier circuit section 4. The primary winding section 11a generates heat when the AC voltage flows through it. The secondary winding section 11b also generates heat when the AC voltage flows through it.

[0079] In the coil device 20 according to this embodiment 1, heat generated in the portion of the primary winding 11a located outside the internal region of the through-hole H of the core 21 is dissipated to the cooling unit 39 via the insulating layer 35 and the metal base body 34. A portion of the heat generated in the portion of the primary winding 11a located inside the internal region of the through-hole H of the core 21 is dissipated from the insulating outer casing 38 to the cooling unit 39 via the heat conductive member 51 and the metal base body 34. The remaining heat generated in the portion of the primary winding 11a located inside the internal region of the through-hole H of the core 21 is transferred to the portion of the primary winding 11a located outside the internal region of the through-hole H of the core 21. The heat transferred to the portion of the primary winding 11a located outside the internal region of the through-hole H is dissipated to the cooling unit 39 via the insulating layer 35 and the metal base body 34.

[0080] In this way, heat generated in the primary winding section 11a located in the internal region of the through-hole H of the core section 21 is dissipated to the cooling section 39 to a degree equivalent to the heat generated in the primary winding section 11a located in the external region of the core section 21 (excluding the internal region of the through-hole H).

[0081] Heat generated in the portion of the secondary winding 11b located outside the internal region of the through-hole H of the core 21 is dissipated to the cooling section 39 via the insulating layer 35 and the metal base body 34. A portion of the heat generated in the portion of the secondary winding 11b located inside the internal region of the through-hole H of the core 21 is dissipated to the cooling section 39 via the insulating outer casing 38, the heat conductive member 51 and the metal base body 34. The remaining heat generated in the portion of the secondary winding 11b located inside the internal region of the through-hole H of the core 21 is transferred to the portion of the secondary winding 11b located outside the internal region of the through-hole H of the core 21. The heat transferred to the portion of the secondary winding 11b located outside the internal region of the through-hole H is dissipated to the cooling section 39 via the insulating layer 35 and the metal base body 34.

[0082] In this way, heat generated in the secondary winding section 11b located in the internal region of the through-hole H of the core section 21 is dissipated to the cooling section 39 to a degree equivalent to the heat generated in the secondary winding section 11b located in the external region of the core section 21 (excluding the internal region of the through-hole H).

[0083] In this way, the heat dissipation of the coil device 20 is improved. As a result, there is no need to enlarge the coil pattern 37 (first coil pattern 37a and second coil pattern 37b). In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0084] Furthermore, the metal base substrate portion 31 includes a first metal base substrate 31a and a second metal base substrate 31b. In other words, the first metal base substrate 31a and the second metal base substrate 31b are separate metal base substrates, not a single integrated metal base substrate. The area of ​​the separate metal base substrates is smaller than the area of ​​the integrated metal base substrate. By doing so, the coil device 20 according to this embodiment 1 can be made smaller compared to a coil device using an integrated metal base substrate. As a result, warping of the metal base substrate portion 31 that occurs when manufacturing the coil device 20 can be suppressed. In addition, the number of metal base bodies 34 taken from the sheet-like metal base body can be optimized. In other words, the manufacturing cost of the metal base substrate portion 31 can be reduced.

[0085] In this embodiment 1, the power converter 1 described is in a case where the first wiring body 45a of the first winding section 29 is placed in the first insulating section 43a of the wiring member 41, and the second wiring body 45b of the second winding section 30 is placed in the second insulating section 43b. For example, if the voltage of the first winding section 29 is higher than the voltage of the second winding section 30, the current flowing through the second winding section 30 will be greater than the current flowing through the first winding section 29. As a result, the amount of heat generated in the second winding section 30 will be greater than the amount of heat generated in the first winding section 29.

[0086] For this reason, the second winding portion 30 may be placed on the back surface of the second insulating portion 43b (the surface facing the second metal base substrate 31b), and the first winding portion 29 may be placed on the front surface of the first insulating portion 43a (the surface opposite to the surface facing the first metal base substrate 31a). By doing so, the first winding portion 29, which has a relatively higher voltage than the second winding portion 30, can be reliably insulated.

[0087] Furthermore, in the power conversion device 1 according to this embodiment 1, the coil device 20 has a structure in which, as an example, the first winding section 29 and the second winding section 30 are each wound twice around the legs 23b and 24b of the core section 21 (number of turns is 2). The first wiring member 41a and the second wiring member 41b on which the first wiring body 45a and the second wiring body 45b are arranged are each made of a single printed circuit board.

[0088] The number of turns in the first winding section 29 and the second winding section 30 may be two or more, depending on the specifications. When increasing the number of turns, the wiring member 41 (each of the first wiring member 41a and the second wiring member 41b) may be constructed by stacking two or more printed circuit boards. When stacking two or more printed circuit boards, each printed circuit board may be electrically connected by a conductive bonding member. The wiring member 41 may be a multilayer printed circuit board in which the wiring body 45 and the insulating section 43 are stacked alternately.

[0089] In this way, when increasing the number of turns in the first winding section 29 and the second winding section 30, multiple printed circuit boards may be stacked. This prevents the first metal base substrate 31a and the second metal base substrate 31b from becoming larger. As a result, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0090] <Effects> The coil device 20 according to this disclosure is a coil device 20 having a coil unit 18. The coil unit 18 comprises a winding portion 11, a metal base substrate portion 31, a core portion 21, and a cooling portion 39. The winding portion 11 includes a coil pattern 37 and coil wires 36. The coil wires 36 are electrically connected to the coil pattern 37. The metal base substrate portion 31 has the coil pattern 37 formed on it. The core portion 21 is provided with through holes H through which the coil wires 36 are inserted. The cooling portion 39 is arranged on the outer circumference of the core portion 21. The metal base substrate portion 31 includes a first metal base substrate 31a and a second metal base substrate 31b. The first metal base substrate 31a and the second metal base substrate 31b are arranged to sandwich the core portion 21 and the cooling portion 39.

[0091] In this way, the first metal base substrate 31a and the second metal base substrate 31b sandwich the core portion 21 and the cooling portion 39, so that the heat generated in the portion of the winding portion 11 located outside the internal region of the through-hole H of the core portion 21 is dissipated to the cooling portion 39 via the insulating layer 35 and the metal base body 34. A portion of the heat generated in the portion of the primary winding portion 11a located inside the internal region of the through-hole H of the core portion 21 is dissipated to the cooling portion 39 via the metal base body 34. The remaining heat generated in the portion of the winding portion 11 located inside the internal region of the through-hole H of the core portion 21 is transferred to the portion of the winding portion 11 located outside the internal region of the through-hole H of the core portion 21. The heat transferred to the portion of the winding portion 11 located outside the internal region of the through-hole H is dissipated to the cooling portion 39 via the insulating layer 35 and the metal base body 34. As a result, the heat dissipation performance of the coil device 20 is improved.

[0092] The power converter 1 according to this disclosure includes the coil device 20. In this way, a power converter 1 equipped with a coil device 20 with improved heat dissipation can be obtained.

[0093] The power conversion device 1 described above comprises an inverter circuit section 2 and a rectifier circuit section 4. The inverter circuit section 2 is located on a first metal base substrate 31a. The rectifier circuit section 4 is located on a second metal base substrate 31b. The coil pattern 37 includes a first coil pattern 37a and a second coil pattern 37b. The first coil pattern 37a is formed on the first metal base substrate 31a. The second coil pattern 37b is formed on the second metal base substrate 31b. The inverter circuit section 2 is electrically connected to the first coil pattern 37a. The rectifier circuit section 4 is electrically connected to the second coil pattern 37b.

[0094] In this way, the AC voltage converted by the inverter circuit 2 is converted back to a DC voltage by the rectifier circuit 4.

[0095] Embodiment 2. <Configuration of the Coil Device> Figure 5 is a perspective view showing the core portion 21 and the cooling portion 39 in the coil device 20 according to Embodiment 2. Figure 6 is a side view showing the positional relationship between the core portion 21 and the cooling portion 39 in the coil device 20 according to Embodiment 2. The coil device 20 shown in Figures 5 and 6 basically has the same configuration as the coil device 20 shown in Figures 2 to 4 and can obtain the same effects, but differs in that the cooling portion 39 includes a main body portion 39a, an upper cover cooling body 39b, and a lower cover cooling body 39c.

[0096] The storage section 54 is formed in the main body section 39a. The core section 21, the upper cover cooler 39b, and the lower cover cooler 39c are housed in the internal area of ​​the storage section 54. Within the internal area of ​​the storage section 54, the upper cover cooler 39b and the lower cover cooler 39c are arranged to sandwich the core section 21 in the Z direction.

[0097] In a plan view along the Z direction, the upper cover cooler 39b and the lower cover cooler 39c are positioned to overlap the core portion 21. The area of ​​each of the upper cover cooler 39b and the lower cover cooler 39c is larger than the area of ​​the core portion 21. From a different perspective, as shown in Figure 6, the width of each of the upper cover cooler 39b and the lower cover cooler 39c in the Y direction is larger than the width of the core portion 21 in the Y direction. The width of each of the upper cover cooler 39b and the lower cover cooler 39c in the X direction is larger than the width of the core portion 21 in the X direction.

[0098] Each of the upper lid cooler 39b and the lower lid cooler 39c is provided with a lid opening 40a and a lid opening 40b. Multiple coil wires 36 are inserted through the lid openings 40a and 40b. In a plan view along the Z direction, the lid opening 40a is positioned to overlap the first through hole H1. In a plan view along the Z direction, the lid opening 40b is positioned to overlap the second through hole H2.

[0099] In a plan view along the Z direction, the opening area of ​​the lid opening 40a may be the same as the opening area of ​​the first through hole H1, or it may be less than or equal to the opening area of ​​the first through hole H1. In a plan view along the Z direction, the opening area of ​​the lid opening 40b may be the same as the opening area of ​​the second through hole H2, or it may be less than or equal to the opening area of ​​the second through hole H2. From a different viewpoint, as shown in Figure 6, the opening width of each of the lid openings 40a and 40b in the Y direction is less than or equal to the opening width of the through hole H (each of the first through hole H1 and the second through hole H2) in the Y direction. The opening width of each of the lid openings 40a and 40b in the X direction is less than or equal to the opening width of the through hole H (each of the first through hole H1 and the second through hole H2) in the X direction.

[0100] The thermal conductivity of the upper lid cooler 39b and the lower lid cooler 39c may be, for example, 1.0 W / (m·K) or more, 10.0 W / (m·K) or more, or 100.0 W / (m·K) or more. The material constituting each of the upper lid cooler 39b and the lower lid cooler 39c may be a metallic material containing at least one of the following: copper, iron, aluminum, iron alloy, and aluminum alloy.

[0101] In the coil device 20 according to this second embodiment, the heat generated in the core portion 21 is dissipated to the main body portion 39a of the cooling unit 39 via the upper cover cooler 39b or the lower cover cooler 39c. As a result, there is no need to enlarge the core portion 21. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0102] The cooling section 39 may include a plurality of screw members 57. The screw members 57 are positioned at the four corners of the upper cover cooling body 39b or the lower cover cooling body 39c. The upper cover cooling body 39b and the lower cover cooling body 39c are fixed to the main body 39a using the screw members 57. In this way, the vibration resistance of the coil device 20 is improved. Furthermore, the vibration resistance of the power conversion device 1 equipped with the coil device 20 is improved.

[0103] <Effects and Effects> According to the coil device 20 described above, the cooling section 39 includes an upper cover cooling body 39b and a lower cover cooling body 39c. The direction in which the first metal base substrate 31a and the second metal base substrate 31b are separated is defined as the Z direction. The upper cover cooling body 39b and the lower cover cooling body 39c are arranged to sandwich the core portion 21 in the Z direction. In a plan view along the Z direction, the area of ​​each of the upper cover cooling body 39b and the lower cover cooling body 39c is larger than the area of ​​the core portion 21. Each of the upper cover cooling body 39b and the lower cover cooling body 39c is provided with lid openings 40a and 40b through which the coil wire 36 is inserted. The opening width of the lid openings 40a and 40b is less than or equal to the opening width of the through hole H.

[0104] In this way, the heat generated in the core 21 is dissipated to the main body 39a of the cooling unit 39 via the upper cover cooler 39b or the lower cover cooler 39c. As a result, there is no need to enlarge the core 21. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0105] <Configuration of Modified Coil Device 1> Figure 7 is a perspective view showing the core portion 21 and the cooling portion 39 in Modified Coil Device 20 1 according to Embodiment 2. Figure 7 corresponds to Figure 5. Figure 8 is a side view showing the positional relationship between the core portion 21 and the cooling portion 39 in Modified Coil Device 20 1 according to Embodiment 2. Figure 8 corresponds to Figure 6. Figure 9 is a perspective view showing how the coil wire 36 is inserted through the upper cover cooling body 39b in Modified Coil Device 20 1 according to Embodiment 2. Figure 10 is a partially enlarged cross-sectional view showing how the coil wire 36 is inserted through the upper cover cooling body 39b in Modified Coil Device 20 1 according to Embodiment 2. Figure 10 is a cross-sectional view of the coil hole 50 viewed along the Z direction.

[0106] The coil device 20 shown in Figures 7 to 10 basically has the same configuration as the coil device 20 shown in Figures 5 and 6 and can achieve the same effect, but differs in that the upper lid cooler 39b and the lower lid cooler 39c are each provided with multiple coil holes 50 through which the coil wire 36 is inserted, instead of lid openings 40a and 40b.

[0107] As shown in Figure 9, one coil wire 36 and an insulating sheath 38 provided on the surface of the coil wire 36 are inserted through each of the coil holes 50. Therefore, the number of coil holes 50 corresponds to the number of coil wires 36. In Modification 1 of the coil device 20 according to this embodiment 1, as shown in Figures 7 and 9, eight coil holes 50 are provided in each of the upper cover cooler 39b and the lower cover cooler 39c.

[0108] As shown in Figure 10, a heat conductive member 51 is positioned between the insulating outer casing 38 and the inner circumferential surface of the coil hole 50. In other words, the upper cover cooler 39b and the lower cover cooler 39c are thermally bonded to the coil wire 36 via the heat conductive member 51 and the insulating outer casing 38.

[0109] In this way, the heat generated in the coil wire 36 can be conducted to the upper cover cooler 39b or the lower cover cooler 39c. As a result, the heat conducted to the upper cover cooler 39b or the lower cover cooler 39c is dissipated to the main body 39a. Consequently, there is no need to enlarge the core 21. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0110] Furthermore, by providing coil holes 50 in the upper cover cooling body 39b and the lower cover cooling body 39c, the insulating casing 38 and the coil wire 36 are fixed to the cooling section 39. In this way, the vibration resistance of the coil device 20 is improved. In addition, the vibration resistance of the power conversion device 1 equipped with the coil device 20 is improved.

[0111] <Effects> The coil device 20 is equipped with an insulating casing 38. The insulating casing 38 is provided on the surface of the coil wire 36. The direction in which the first metal base substrate 31a and the second metal base substrate 31b are separated is defined as the Z direction. The cooling section 39 includes an upper cover cooling body 39b and a lower cover cooling body 39c. The upper cover cooling body 39b and the lower cover cooling body 39c are arranged to sandwich the core section 21 at s. Each of the upper cover cooling body 39b and the lower cover cooling body 39c is provided with a plurality of coil holes 50 through which the coil wire 36 and the insulating casing 38 are inserted.

[0112] In this way, the heat generated in the coil wire 36 can be conducted to the upper cover cooler 39b or the lower cover cooler 39c. As a result, the heat conducted to the upper cover cooler 39b or the lower cover cooler 39c is dissipated to the main body 39a. Consequently, there is no need to enlarge the core 21. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0113] <Configuration of Modified Coil Device 2> Figure 11 is a perspective view showing the core portion 21 and the cooling portion 39 in Modified Coil Device 20 according to Embodiment 2. Figure 11 corresponds to Figure 7. Figure 12 is a side view showing the positional relationship between the core portion 21 and the cooling portion 39 in Modified Coil Device 20 according to Embodiment 2. Figure 12 corresponds to Figure 8. Figure 13 is a perspective view showing how the coil wire 36 is inserted through the upper cover cooling body 39b and the lower cover cooling body 39c in Modified Coil Device 20 according to Embodiment 2. Figure 13 corresponds to Figure 9.

[0114] The coil device 20 shown in Figures 11 to 13 has basically the same configuration as the coil device 20 shown in Figures 7 to 10 and can achieve the same effects, but differs in that the cooling section 39 includes a first extension section 33a and a second extension section 33b. Specifically, the first extension section 33a is provided to protrude from the upper lid cooling body 39b. The first extension section 33a extends from the upper lid cooling body 39b into the through hole H. The second extension section 33b is provided to protrude from the lower lid cooling body 39c. The second extension section 33b extends from the lower lid cooling body 39c into the through hole H.

[0115] As shown in Figure 13, each of the first extended portion 33a and the second extended portion 33b is provided with a plurality of coil holes 50. The first extended portion 33a and the second extended portion 33b are arranged to face each other in the Z direction.

[0116] As shown in Figure 12, a gap 52a is formed between the first extended portion 33a and the second extended portion 33b. Specifically, the gap 52a is formed by the first extended portion 33a and the second extended portion 33b being spaced apart in the Z direction. In other words, the gap 52a is formed in the internal region of the through hole H of the core portion 21. In this way, the gap 52a prevents a loop-shaped induced current from flowing in the portion surrounding the core portion 21.

[0117] The formation of the gap 52a physically and electrically separates the upper lid cooler 39b and the lower lid cooler 39c surrounding the leg portions 23b and 24b. In other words, the gap 52a has the function of preventing the formation of a short coil through the upper lid cooler 39b and the lower lid cooler 39c.

[0118] Figure 14 is a diagram illustrating the reason for forming the gap 52a. As shown in the left diagram of Figure 14, if a gap 52a is not provided between the upper cover cooler 39b and the lower cover cooler 39c, the parts of the upper cover cooler 39b and the lower cover cooler 39c that surround the legs 23b and 24b around which the coil pattern 37 is wound will be physically and electrically connected. Therefore, when current flows between terminals TA and TB in the first winding section 29, an induced current RP will flow in a loop through the upper cover cooler 39b and the lower cover cooler 39c.

[0119] As shown in the right-hand figure of Figure 14, the induced current RP forms a short coil that is magnetically coupled with the coil wire 36 in the upper cover cooler 39b and the lower cover cooler 39c. As a result, the coil device 20 (transformer 20a) is unable to perform as intended.

[0120] On the other hand, as in Modification 2 of the coil device 20 according to this embodiment 2, the flow of induced current RP is blocked by providing a gap 52a between the upper cover cooler 39b and the lower cover cooler 39c. As a result, the coil device 20 exhibits the desired performance as a transformer 20a.

[0121] In this way, the heat generated in the coil wire 36 is conducted to the upper cover cooler 39b or the lower cover cooler 39c. As a result, the heat conducted to the upper cover cooler 39b or the lower cover cooler 39c is dissipated to the main body 39a of the cooling unit 39. Consequently, there is no need to enlarge the core unit 21 and the coil wire 36. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0122] By providing coil holes 50 in the first extended portion 33a and the second extended portion 33b, the insulating casing 38 and the coil wire 36 are fixed to the cooling portion 39. In this way, the vibration resistance of the coil device 20 is improved. Furthermore, the vibration resistance of the power conversion device 1 equipped with the coil device 20 is also improved.

[0123] <Effects and Effects> According to the coil device 20 described above, the cooling section 39 includes a first extended section 33a and a second extended section 33b. The first extended section 33a extends from the upper lid cooling body 39b into the interior of the through hole H. The second extended section 33b extends from the lower lid cooling body 39c into the interior of the through hole H. The first extended section 33a and the second extended section 33b are arranged to face each other in the Z direction. Each of the first extended section 33a and the second extended section 33b is provided with a plurality of coil holes 50.

[0124] In this way, the heat generated in the coil wire 36 is conducted to the upper cover cooler 39b or the lower cover cooler 39c. As a result, the heat conducted to the upper cover cooler 39b or the lower cover cooler 39c is dissipated to the main body 39a of the cooling unit 39. Consequently, there is no need to enlarge the core 21 and the coil wire 36. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized. Furthermore, by arranging the first extended portion 33a and the second extended portion 33b apart from each other, a gap 52a is formed. As a result, the upper cover cooler 39b and the lower cover cooler 39c surrounding the leg portions 23b and 24b are physically and electrically separated. In this way, the occurrence of short coils using the upper cover cooler 39b and the lower cover cooler 39c as pathways is suppressed.

[0125] Embodiment 3. <Configuration of the Coil Device> Figure 15 is a perspective view showing the core portion 21 and the cooling portion 39 in the coil device 20 according to Embodiment 3. Figure 16 is a side view showing the positional relationship between the core portion 21 and the cooling portion 39 in the coil device 20 according to Embodiment 3. Figure 17 is a perspective view showing how the coil wire 36 is inserted into the intermediate cooler 39d in the coil device 20 according to Embodiment 3.

[0126] The coil device 20 shown in Figures 15 to 17 basically has the same configuration as the coil device 20 shown in Figures 2 to 4 and can achieve the same effects, but differs in that the cooling section 39 includes a main body 39a and an intermediate cooler 39d.

[0127] The storage section 54 is formed in the main body section 39a. The core section 21 and the intermediate cooler 39d are housed in the internal region of the storage section 54. The core section 21 includes a first core 21a and a second core 21b. Within the internal region of the storage section 54, the intermediate cooler 39d is positioned between the first core 21a and the second core 21b. In other words, the second core 21b is spaced apart from the first core 21a in the Z direction.

[0128] As shown in Figure 17, the intermediate cooler 39d is provided with a plurality of coil holes 50. One coil wire 36 and an insulating sheath 38 provided on the surface of the coil wire 36 are inserted through each coil hole 50. Therefore, the number of coil holes 50 corresponds to the number of coil wires 36. In the coil device 20 according to this third embodiment, as shown in Figure 17, the intermediate cooler 39d is provided with eight coil holes 50.

[0129] A heat conductive member 51 is positioned between the insulating outer casing 38 and the inner circumferential surface of the coil hole 50. In other words, the intermediate cooler 39d is thermally bonded to the coil wire 36 via the heat conductive member 51 and the insulating outer casing 38.

[0130] The thermal conductivity of the intermediate cooler 39d may be, for example, 1.0 W / (m·K) or more, 10.0 W / (m·K) or more, or 100.0 W / (m·K) or more. The material constituting the intermediate cooler 39d may be a metallic material containing, for example, copper, iron, aluminum, an iron alloy, or an aluminum alloy.

[0131] In this way, the heat generated in the coil wire 36 can be conducted to the intermediate cooler 39d. As a result, the heat conducted to the intermediate cooler 39d is dissipated to the main body 39a. Consequently, there is no need to enlarge the core 21 and the coil wire 36. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0132] Furthermore, by providing coil holes 50 in the intermediate cooler 39d, the insulating casing 38 and coil wire 36 are fixed to the cooling section 39. In this way, the vibration resistance of the coil device 20 is improved. In addition, the vibration resistance of the power converter 1 equipped with the coil device 20 is improved.

[0133] <Effects and Effects> The coil device 20 is equipped with an insulating casing 38. The insulating casing 38 is provided on the surface of the coil wire 36. The direction in which the first metal base substrate 31a and the second metal base substrate 31b are separated is defined as the Z direction. The core portion 21 includes a first core 21a and a second core 21b. The second core 21b is spaced apart from the first core 21a in the Z direction. The cooling portion 39 includes an intermediate cooler 39d. The intermediate cooler 39d is positioned between the first core 21a and the second core 21b. The intermediate cooler 39d is provided with a plurality of coil holes 50 through which the coil wire 36 and the insulating casing 38 are inserted.

[0134] In this way, the heat generated in the coil wire 36 can be conducted to the intermediate cooler 39d. As a result, the heat conducted to the intermediate cooler 39d is dissipated to the main body 39a. Consequently, there is no need to enlarge the core 21 and the coil wire 36. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0135] <Configuration of Modified Coil Device 1> Figure 18 is a perspective view showing the core portion 21 and the cooling portion 39 in Modified Coil Device 20 1 according to Embodiment 3. Figure 18 corresponds to Figure 15. Figure 19 is a side view showing the positional relationship between the core portion 21 and the cooling portion 39 in Modified Coil Device 20 1 according to Embodiment 3. Figure 19 corresponds to Figure 16. Figure 20 is a perspective view showing how the coil wire 36 is inserted into the intermediate cooler 39d in Modified Coil Device 20 1 according to Embodiment 3. Figure 20 corresponds to Figure 17.

[0136] The coil device 20 shown in Figures 18 to 20 has basically the same configuration as the coil device 20 shown in Figures 15 to 17 and can achieve the same effects, but differs in that the cooling section 39 includes a third extension section 33c and a fourth extension section 33d. Specifically, the third extension section 33c is provided to protrude from the intermediate cooler 39d. The third extension section 33c extends from the intermediate cooler 39d toward the first metal base substrate 31a. The fourth extension section 33d is provided to protrude from the intermediate cooler 39d. The fourth extension section 33d extends from the intermediate cooler 39d toward the second metal base substrate 31b.

[0137] As shown in Figure 20, each of the third extension portion 33c and the fourth extension portion 33d is provided with a plurality of coil holes 50. The third extension portion 33c and the fourth extension portion 33d are arranged to sandwich the intermediate cooler 39d.

[0138] As shown in Figure 19, gaps 52b and 52c are formed in the internal region of the through-hole H. Specifically, gap 52b is formed when the third extending portion 33c is positioned spaced apart in the Z direction from the first metal base substrate 31a. Gap 52c is formed when the fourth extending portion 33d is positioned spaced apart in the Z direction from the second metal base substrate 31b. In this way, gaps 52c and 52c prevent loop-shaped induced current from flowing in the portion surrounding the core portion 21. In other words, gaps 52b and 52c have the function of preventing the formation of a short coil with the intermediate cooler 39d and the metal base body 34 as the path.

[0139] The heat generated in the coil wire 36 is conducted to the intermediate cooler 39d. As a result, the heat conducted to the intermediate cooler 39d is dissipated to the main body 39a of the cooling unit 39. Consequently, there is no need to enlarge the core unit 21 and the coil wire 36. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0140] By providing coil holes 50 in the third extension portion 33c and the fourth extension portion 33d, the insulating casing 38 and the coil wire 36 are fixed to the cooling portion 39. In this way, the vibration resistance of the coil device 20 is improved. Furthermore, the vibration resistance of the power conversion device 1 equipped with the coil device 20 is also improved.

[0141] <Effects> According to the coil device 20 described above, the cooling section 39 includes a third extension section 33c and a fourth extension section 33d. The third extension section 33c extends from the intermediate cooler 39d toward the first metal base substrate 31a. The fourth extension section 33d extends from the intermediate cooler 39d toward the second metal base substrate 31b. Each of the third extension section 33c and the fourth extension section 33d is provided with a plurality of coil holes 50.

[0142] In this way, the heat generated in the coil wire 36 is conducted to the intermediate cooler 39d. As a result, the heat conducted to the intermediate cooler 39d is dissipated to the main body 39a of the cooling unit 39. Consequently, there is no need to enlarge the core unit 21 and the coil wire 36. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0143] Embodiment 4. <Configuration of the coil device> Figure 21 is an exploded perspective view showing an example of a power conversion device 1 equipped with a coil device 20 according to Embodiment 4. Figure 21 corresponds to Figure 3. The coil device 20 shown in Figure 21 basically has the same configuration as the coil devices 20 shown in Figures 2 to 4 and can obtain the same effects, but differs in that the coil unit 18 does not have a wiring member 41.

[0144] In other words, the first wiring member 41a is not provided on the insulating layer 35 of the first metal base substrate 31a. The second wiring member 41b is not provided on the insulating layer 35 of the second metal base substrate 31b.

[0145] The coil wire 36 is connected to the coil pattern 37 without going through the wiring body 45. The coil wire 36 is inserted through openings 32a and 32b provided in the first metal base substrate 31a, through hole H provided in the core portion 21, and openings 32c and 32d provided in the second metal base substrate 31b.

[0146] Embodiment 5. <Configuration of the coil device> Figure 22 is a perspective view showing an example of a power conversion device 1 equipped with a coil device 20 according to Embodiment 5. Figure 22 corresponds to Figure 2.

[0147] The coil device 20 shown in Figure 22 basically has the same configuration as the coil devices 20 shown in Figures 2 to 4 and can achieve the same effects, but differs in that the coil unit 18 includes a printed circuit board portion 60 and a heat conductive member 61 instead of a metal base substrate 31.

[0148] The printed circuit board section 60 includes a first printed circuit board 60a and a second printed circuit board 60b. The first printed circuit board 60a and the second printed circuit board 60b are arranged so as to sandwich the core section 21, the cooling section 39, and the heat conductive member 61.

[0149] The heat conduction member 61 includes a first heat conduction member 61a and a second heat conduction member 61b. The first heat conduction member 61a and the second heat conduction member 61b are arranged to sandwich the core portion 21 and the cooling portion 39. From a different perspective, the first heat conduction member 61a is arranged between the first printed circuit board 60a and the cooling portion 39. The second heat conduction member 61b is arranged between the second printed circuit board 60b and the cooling portion 39.

[0150] The material constituting the heat conduction member 61 may be, for example, a material having a thermal conductivity of 0.1 W / (m·K) or higher, or a material having a thermal conductivity of 1.0 W / (m·K) or higher. The heat conduction member 61 may also have electrical insulating properties. The Young's modulus of the heat conduction member 61 may be 1 MPa or higher. The material constituting the heat conduction member 61 may be an elastic resin material. The material constituting the heat conduction member 61 may be an epoxy resin containing a thermally conductive filler, silicone, or a rubber material such as urethane.

[0151] The material constituting the printed circuit board portion 60 is a material with relatively lower thermal conductivity compared to the metal base substrate 31. In other words, the printed circuit board portion 60 may be a general-purpose printed circuit board. The material constituting the printed circuit board portion 60 may also be a ceramic substrate such as aluminum oxide, aluminum nitride, or silicon carbide. Conductive portions (not shown) may be formed on the surface and inside of the printed circuit board portion 60.

[0152] The first printed circuit board 60a has a first main surface 31aa and a second main surface 31ab. The second main surface 31ab is located opposite the first main surface 31aa. The second main surface 31ab is in contact with the entire surface of the first heat conductive member 61a.

[0153] The second printed circuit board 60b has a first main surface 31ba and a second main surface 31bb. The second main surface 31bb is located opposite the first main surface 31ba. The second main surface 31ab is in contact with the entire surface of the second heat conductive member 61b.

[0154] The first printed circuit board 60a is provided with openings 32a and 32b (not shown). In a plan view along the Z direction, opening 32a is positioned to overlap the first through hole H1. In a plan view along the Z direction, opening 32b is positioned to overlap the second through hole H2.

[0155] The second printed circuit board 60b is provided with openings 32c and 32d (not shown). In a plan view along the Z direction, opening 32c is positioned to overlap the first through hole H1. In a plan view along the Z direction, opening 32d is positioned to overlap the second through hole H2.

[0156] A coil pattern 37 is formed on the printed circuit board portion 60. The first coil pattern 37a is formed on the first printed circuit board 60a. The second coil pattern 37b is formed on the second printed circuit board 60b.

[0157] An inverter circuit section 2 is formed on the first printed circuit board 60a. The first coil pattern first section 37af and the first coil pattern second section 37as are electrically connected to the inverter circuit section 2. Note that wiring patterns other than the first coil pattern 37a (not shown) may be formed on the first printed circuit board 60a.

[0158] A rectifier circuit section 4 is formed on the second printed circuit board 60b. The first part 37bf of the second coil pattern and the second part 37bs of the second coil pattern are electrically connected to the rectifier circuit section 4. Note that wiring patterns other than the second coil pattern 37b (not shown) may be formed on the second metal base substrate 31b.

[0159] The first printed circuit board 60a, on which the first coil pattern 37a and inverter circuit section 2 are formed, has an electrical primary potential. The second printed circuit board 60b, on which the second coil pattern 37b and rectifier circuit section 4 are formed, has an electrical secondary potential. The first printed circuit board 60a, which has a primary potential, and the second printed circuit board 60b, which has a secondary potential, are electrically insulated from each other.

[0160] In the coil device 20 according to Embodiment 5, heat generated in the portion of the primary winding 11a located outside the internal region of the through-hole H of the core 21 is dissipated to the cooling unit 39 via the first printed circuit board 60a and the first heat conductive member 61a. A portion of the heat generated in the portion of the primary winding 11a located inside the internal region of the through-hole H of the core 21 is dissipated from the insulating outer casing 38 to the cooling unit 39 via the heat conductive member 51 and the first heat conductive member 61a. The remaining heat generated in the portion of the primary winding 11a located inside the internal region of the through-hole H of the core 21 is transferred to the portion of the primary winding 11a located outside the internal region of the through-hole H of the core 21. The heat transferred to the portion of the primary winding 11a located outside the internal region of the through-hole H is dissipated to the cooling unit 39 via the first printed circuit board 60a and the first heat conductive member 61a.

[0161] In this way, heat generated in the primary winding section 11a located in the internal region of the through-hole H of the core section 21 is dissipated to the cooling section 39 to a degree equivalent to the heat generated in the primary winding section 11a located in the external region of the core section 21 (excluding the internal region of the through-hole H).

[0162] Heat generated in the portion of the secondary winding 11b located outside the internal region of the through-hole H of the core 21 is dissipated to the cooling section 39 via the second printed circuit board 60b and the second heat conductive member 61b. A portion of the heat generated in the portion of the secondary winding 11b located inside the internal region of the through-hole H of the core 21 is dissipated from the insulating outer casing 38 to the cooling section 39 via the heat conductive member 51 and the second heat conductive member 61b. The remaining heat generated in the portion of the secondary winding 11b located inside the internal region of the through-hole H of the core 21 is transferred to the portion of the secondary winding 11b located outside the internal region of the through-hole H of the core 21. The heat transferred to the portion of the secondary winding 11b located outside the internal region of the through-hole H is dissipated to the cooling section 39 via the second printed circuit board 60b and the second heat conductive member 61b.

[0163] In this way, heat generated in the secondary winding section 11b located in the internal region of the through-hole H of the core section 21 is dissipated to the cooling section 39 to a degree equivalent to the heat generated in the secondary winding section 11b located in the external region of the core section 21 (excluding the internal region of the through-hole H).

[0164] In this way, the heat dissipation of the coil device 20 is improved. As a result, there is no need to enlarge the coil pattern 37 (first coil pattern 37a and second coil pattern 37b). In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0165] <Effects> The coil device 20 according to this disclosure is a coil device 20 having a coil unit 18. The coil unit 18 comprises a winding section 11, a printed circuit board section 60, a core section 21, and a cooling section 39. The winding section 11 includes a coil pattern 37 and coil wires 36. The coil wires 36 are electrically connected to the coil pattern 37. The printed circuit board section 60 has the coil pattern 37 formed on it. The core section 21 is provided with through holes H through which the coil wires 36 are inserted. The cooling section 39 is arranged on the outer circumference of the core section 21. The printed circuit board section 60 includes a first printed circuit board 60a and a second printed circuit board 60b. The first printed circuit board 60a and the second printed circuit board 60b are arranged to sandwich the core section 21 and the cooling section 39.

[0166] In this way, the first printed circuit board 60a and the second printed circuit board 60b sandwich the core portion 21 and the cooling portion 39, so that the heat generated in the winding portion 11 is dissipated to the cooling portion 39 via the printed circuit board portion 60. As a result, the heat dissipation performance of the coil device 20 is improved.

[0167] The coil device 20 described above includes a heat conductive member 61. The heat conductive member 61 is positioned between the printed circuit board portion 60 and the cooling portion 39.

[0168] In this way, the heat generated in the winding section 11 is further dissipated to the cooling section 39 via the heat conductive member 61. As a result, the heat dissipation performance of the coil device 20 is further improved.

[0169] <Configuration of Modified Coil Device 1> Figure 23 is a perspective view showing the core portion 21 and the cooling portion 39 in Modified Coil Device 20 1 according to Embodiment 5. Figure 23 corresponds to Figure 5. Figure 24 is a side view showing the positional relationship between the core portion 21 and the cooling portion 39 in Modified Coil Device 20 1 according to Embodiment 5. Figure 24 corresponds to Figure 6.

[0170] The coil device 20 shown in Figures 23 and 24 has basically the same configuration as the coil device 20 shown in Figure 22 and can achieve the same effect, but differs in that the cooling section 39 includes the main body 39a, the upper cover cooling element 39b, and the lower cover cooling element 39c.

[0171] The storage section 54 is formed in the main body section 39a. The core section 21, the upper cover cooler 39b, and the lower cover cooler 39c are housed in the internal area of ​​the storage section 54. Within the internal area of ​​the storage section 54, the upper cover cooler 39b and the lower cover cooler 39c are arranged to sandwich the core section 21 in the Z direction.

[0172] In a plan view along the Z direction, the upper cover cooler 39b and the lower cover cooler 39c are positioned to overlap the core portion 21. The area of ​​each of the upper cover cooler 39b and the lower cover cooler 39c is larger than the area of ​​the core portion 21. From a different perspective, as shown in Figure 24, the width of each of the upper cover cooler 39b and the lower cover cooler 39c in the Y direction is larger than the width of the core portion 21 in the Y direction. The width of each of the upper cover cooler 39b and the lower cover cooler 39c in the X direction is larger than the width of the core portion 21 in the X direction.

[0173] Each of the upper lid cooler 39b and the lower lid cooler 39c is provided with a lid opening 40a and a lid opening 40b. Multiple coil wires 36 are inserted through the lid openings 40a and 40b. In a plan view along the Z direction, the lid opening 40a is positioned to overlap the first through hole H1. In a plan view along the Z direction, the lid opening 40b is positioned to overlap the second through hole H2.

[0174] In a plan view along the Z direction, the opening area of ​​the lid opening 40a may be the same as the opening area of ​​the first through hole H1, or it may be less than or equal to the opening area of ​​the first through hole H1. In a plan view along the Z direction, the opening area of ​​the lid opening 40b may be the same as the opening area of ​​the second through hole H2, or it may be less than or equal to the opening area of ​​the second through hole H2. From a different viewpoint, as shown in Figure 6, the opening width of each of the lid openings 40a and 40b in the Y direction is less than or equal to the opening width of the through hole H (each of the first through hole H1 and the second through hole H2) in the Y direction. The opening width of each of the lid openings 40a and 40b in the X direction is less than or equal to the opening width of the through hole H (each of the first through hole H1 and the second through hole H2) in the X direction.

[0175] The thermal conductivity of the upper lid cooler 39b and the lower lid cooler 39c may be, for example, 1.0 W / (m·K) or more, 10.0 W / (m·K) or more, or 100.0 W / (m·K) or more. The material constituting each of the upper lid cooler 39b and the lower lid cooler 39c may be a metallic material containing at least one of the following: copper, iron, aluminum, iron alloy, and aluminum alloy.

[0176] In the coil device 20 according to Embodiment 5, the heat generated in the core portion 21 is dissipated to the main body portion 39a of the cooling unit 39 via the upper cover cooler 39b or the lower cover cooler 39c. As a result, there is no need to enlarge the core portion 21. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0177] The cooling section 39 may include a plurality of screw members 57. The screw members 57 are positioned at the four corners of the upper cover cooling body 39b or the lower cover cooling body 39c. The upper cover cooling body 39b and the lower cover cooling body 39c are fixed to the main body 39a using the screw members 57. In this way, the vibration resistance of the coil device 20 is improved. Furthermore, the vibration resistance of the power conversion device 1 equipped with the coil device 20 is improved.

[0178] <Effects and Effects> According to the coil device 20 described above, the cooling section 39 includes an upper cover cooling body 39b and a lower cover cooling body 39c. The direction in which the first printed circuit board 60a and the second printed circuit board 60b are separated is defined as the Z direction. The upper cover cooling body 39b and the lower cover cooling body 39c are arranged to sandwich the core portion 21 in the Z direction. In a plan view along the Z direction, the area of ​​each of the upper cover cooling body 39b and the lower cover cooling body 39c is larger than the area of ​​the core portion 21. Each of the upper cover cooling body 39b and the lower cover cooling body 39c is provided with lid openings 40a and 40b through which the coil wire 36 is inserted. The opening width of the lid openings 40a and 40b is less than or equal to the opening width of the through hole H.

[0179] In this way, the heat generated in the core 21 is dissipated to the main body 39a of the cooling unit 39 via the upper cover cooler 39b or the lower cover cooler 39c. As a result, there is no need to enlarge the core 21. In other words, the coil device 20 and the power conversion device 1 equipped with the coil device 20 can be miniaturized.

[0180] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The basic scope of this disclosure is indicated by the claims rather than the foregoing description and is intended to include all modifications within the meaning and scope of the claims equivalents.

[0181] 1 Power converter, 2 Inverter circuit section, 3 Voltage transformer section, 4 Rectifier circuit section, 5 Smoothing circuit section, 6 Input terminal, 7 Output terminal, 8 Input capacitor, 9 Switching element, 9a Switching element, 9b Switching element, 9c Switching element, 9d Switching element, 10 Control circuit section, 11 Winding section, 11a Primary winding section, 11b Secondary winding section, 12 Rectifier element, 12a Rectifier element, 12b Rectifier element, 12c Rectifier element, 12d Rectifier element, 13 Smoothing reactor, 14 Smoothing capacitor, 18 Coil unit, 20 Coil device, 20a Transformer, 21 Core section, 21a First core, 21b Second core, 23 Core, 23a Legs, 23b Legs, 23c Legs, 23d Bottom, 23e Bottom, 24 Core, 24a Legs, 24b Legs, 24c Legs, 24d Bottom, 24e Bottom, 29 First winding section, 30 Second winding section, 31 Metal base substrate section, 31a First metal base substrate, 31aa First main surface, 31ab Second main surface, 31b Second metal base substrate, 31ba First main surface, 31bb Second main surface, 32a Opening, 32b Opening, 32c Opening, 32d Opening, 33a First extension section, 33b Second extension section, 33c Third extension section, 33d Fourth extension section, 34 Metal base body, 35 Insulating layer, 35a First main surface, 35b Second main surface, 36 Coil wire, 36a First coil wire, 36b Second coil wire, 37 Coil pattern, 37a First coil pattern, 37af 37as First coil pattern, first part; 37b First coil pattern, second part; 37bf Second coil pattern, first part; 37bs Second coil pattern, second part; 38 Insulating casing; 39a Cooling section; 39a Main body; 39aa First main surface; 39ab Second main surface; 39b Top cover cooling body; 39c Bottom cover cooling body; 39d Intermediate cooling body; 40a Cover opening; 40b Cover opening; 41 Wiring member; 41a First wiring member; 41b Second wiring member; 43 Insulation section; 43a First insulation section; 43b Second insulation section; 45a First wiring body; 45aa First wiring body; 45ab First wiring body, second part; 45b Second wiring body; 45ba Second wiring body, first part; 45bb Second wiring body, second part; 47 Through-hole conductive part, 50 coil hole, 51 heat conductive member, 52a gap, 52b gap, 52c gap,53 Joining member, 54 Storage section, 57 Screw member, 60 Printed circuit board section, 60a First printed circuit board, 60b Second printed circuit board, 61 Heat conductive member, 61a First heat conductive member, 61b Second heat conductive member, H Through hole, H1 First through hole, H2 Second through hole, PT1 Current path, PT2 Current path, RP Induction current, TA Terminal, TB Terminal.

Claims

1. A coil device having a coil unit, wherein the coil unit comprises a winding portion including a coil pattern and coil wires electrically connected to the coil pattern, a metal base substrate portion on which the coil pattern is formed, a core portion having through holes through which the coil wires are inserted, and a cooling portion disposed on the outer circumference of the core portion, and the metal base substrate portion includes a first metal base substrate and a second metal base substrate disposed so as to sandwich the core portion and the cooling portion.

2. The coil device according to claim 1, wherein, with respect to the direction in which the first metal base substrate and the second metal base substrate are separated, the cooling section includes an upper cover cooling body and a lower cover cooling body arranged to sandwich the core portion in the Z direction, and in a plan view along the Z direction, the area of ​​each of the upper cover cooling body and the lower cover cooling body is larger than the area of ​​the core portion, each of the upper cover cooling body and the lower cover cooling body is provided with a cover opening through which the coil wire is inserted, and the opening width of the cover opening is less than or equal to the opening width of the through hole.

3. The coil device according to claim 1 or 2, comprising an insulating outer covering provided on the surface of the coil wire, wherein, with the direction in which the first metal base substrate and the second metal base substrate are separated being the Z direction, the cooling section includes an upper cover cooling body and a lower cover cooling body arranged to sandwich the core section in the Z direction, and each of the upper cover cooling body and the lower cover cooling body is provided with a plurality of coil holes through which the coil wire and the insulating outer covering are inserted.

4. The coil device according to claim 3, wherein the cooling section includes a first extending section extending from the upper lid cooling body into the through hole and a second extending section extending from the lower lid cooling body into the through hole, the first extending section and the second extending section are arranged to face each other in the Z direction, and each of the first extending section and the second extending section is provided with a plurality of coil holes.

5. The coil device according to any one of claims 1 to 4, comprising an insulating sheath provided on the surface of the coil wire, wherein, with the direction in which the first metal base substrate and the second metal base substrate are separated from each other being the Z direction, the core portion includes a first core and a second core spaced apart from the first core in the Z direction, the cooling portion includes an intermediate cooler disposed between the first core and the second core, and the intermediate cooler is provided with a plurality of coil holes through which the coil wire and the insulating sheath are inserted.

6. The coil device according to claim 5, wherein the cooling section includes a third extending section extending from the intermediate cooler toward the first metal base substrate and a fourth extending section extending from the intermediate cooler toward the second metal base substrate, and each of the third extending section and the fourth extending section is provided with a plurality of coil holes.

7. A coil device having a coil unit, wherein the coil unit comprises a winding portion including a coil pattern and coil wires electrically connected to the coil pattern, a printed circuit board portion on which the coil pattern is formed, a core portion having through holes through which the coil wires are inserted, and a cooling portion disposed on the outer circumference of the core portion, and the printed circuit board portion includes a first printed circuit board and a second printed circuit board disposed so as to sandwich the core portion and the cooling portion.

8. The coil device according to claim 7, further comprising a heat conductive member disposed between the printed circuit board portion and the cooling portion.

9. The coil device according to claim 7 or 8, wherein, with respect to the direction in which the first printed circuit board and the second printed circuit board are separated, the cooling section includes an upper cover cooling body and a lower cover cooling body arranged to sandwich the core portion in the Z direction, and in a plan view along the Z direction, the area of ​​each of the upper cover cooling body and the lower cover cooling body is larger than the area of ​​the core portion, each of the upper cover cooling body and the lower cover cooling body is provided with a cover opening through which the coil wire is inserted, and the opening width of the cover opening is less than or equal to the opening width of the through hole.

10. A power conversion device comprising a coil device according to any one of claims 1 to 6.

11. The power conversion device according to claim 10, comprising an inverter circuit section disposed on a first metal base substrate and a rectifier circuit section disposed on a second metal base substrate, wherein the coil pattern includes a first coil pattern formed on the first metal base substrate and a second coil pattern formed on the second metal base substrate, the inverter circuit section is electrically connected to the first coil pattern, and the rectifier circuit section is electrically connected to the second coil pattern.

12. A power conversion device comprising a coil device according to any one of claims 7 to 9.

13. The power conversion device according to claim 12, comprising an inverter circuit section arranged on the first printed circuit board and a rectifier circuit section arranged on the second printed circuit board, wherein the coil pattern includes a first coil pattern formed on the first printed circuit board and a second coil pattern formed on the second printed circuit board, the inverter circuit section is electrically connected to the first coil pattern, and the rectifier circuit section is electrically connected to the second coil pattern.

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