Coil device and power conversion device

Abstract

A coil device (20) comprises: a core (21); a first winding part (29); and a second winding part (30). Each of the first winding part (29) and the second winding part (30) is wound around the core (21) in a manner of passing through the inner region of the core (21) surrounded by the core (21). A metal base substrate (31), in which a coil pattern (37) is formed on a metal base body (33) with an insulating layer (35) interposed therebetween, is disposed in the inner region of the core (21) and the outer region of the core (21). A first cooling body (39) is thermally bonded to the side of the metal base body (33) opposite to the side where the insulating layer (35) is formed. Each of the first winding part (29) and the second winding part (30) includes the coil pattern (37).

Description

[Technical Field]

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

[0002] For example, a power conversion device such as a DC-DC converter is equipped with a coil device such as a transformer and a smoothing reactor. The coil device equipped in the power conversion device is composed of a coil and a core. The core has the function of forming a magnetic path, which is the path of magnetic lines of force generated by a current flowing through the coil. In the power conversion device, a direct current or an alternating current voltage is applied to the coil of the coil device.

[0003] By setting the frequency of the AC voltage to a high frequency, it is possible to reduce the size of the core and the number of windings (turns) of the coil, which contributes to the miniaturization of the coil device. In recent years, in order to reduce the size of coil devices and power conversion devices equipped with coil devices, switching elements that can handle high switching frequencies of, for example, 1 kHz or more have been used as switching elements to be equipped in the power conversion devices.

[0004] The heat generated by energizing a coil device can be roughly divided into Joule heat generated in the coil and heat generated in the core. Joule heat increases in inverse proportion to the cross-sectional area of ​​the wiring used as the coil. Therefore, if an attempt is made to use wiring with a small cross-sectional area in order to reduce the size of the coil device, the Joule heat generated in the coil device will increase.

[0005] Furthermore, when an AC current flows, the skin effect causes the current to flow only near the surface of the wiring, increasing the electrical resistance of the coil device. As the frequency of the AC current flowing through the wiring increases, the electrical resistance value increases monotonically.

[0006] Therefore, the higher the frequency of the AC voltage applied to the coil device is set to in an attempt to reduce its size, the higher the electrical resistance of the wiring of the coil device becomes due to the skin effect, and the more Joule heat is generated in the coil device.

[0007] For this reason, in order to suppress the temperature rise of the coil device due to Joule heat or the like generated in the coil device to an allowable temperature or below, it is required to improve the heat dissipation performance of the coil device. In other words, in order to reduce the size of the coil device, it is also required to improve the heat dissipation performance of the coil device. In the coil device proposed in Patent Document 1, a method is proposed in which heat generated from the coil in the inner region of the core is dissipated through the printed circuit board and the coil. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2014 / 141670 A1 Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, in order to reduce the size of a coil device, it is required to improve the heat dissipation performance of the coil device.

[0010] The present disclosure has been made as part of such development, and one object is to provide a coil device that can improve heat dissipation, and another object is to provide a power conversion device that applies such a coil device. [Means for solving the problem]

[0011] The coil device according to the present disclosure is a coil device having a coil unit. The coil unit includes one or more cores, a metal base substrate, a first winding portion, a second winding portion, and one or more cooling bodies. The core has a loop-shaped magnetic path. The metal base substrate is disposed in an inner region of the core surrounded by the core and an outer region of the core, and a first coil pattern and a second coil pattern are formed on the metal base body with an insulating layer interposed therebetween. The first winding portion includes the first coil pattern and is wound around the core in a manner passing through the inner region of the core. The second winding portion includes the second coil pattern and is wound around the core in a manner passing through the inner region of the core and is electrically insulated from the first winding portion. The cooling body includes a first cooling body joined to the metal base body on the side opposite the side on which the insulating layer is formed. The metal base substrate includes a first metal base substrate and a second metal base substrate. The first coil pattern is formed on the first metal base substrate. The second coil pattern is formed on the second metal base substrate. The first metal base substrate and the second metal base substrate are arranged to face each other in such a manner that an insertion portion through which the core is inserted is formed between the first metal base substrate and the second metal base substrate.

[0012] The power conversion device according to the present disclosure is a power conversion device including the above-described coil device. [Effects of the Invention]

[0013] According to the coil device of the present disclosure, heat generated in the first winding portion and the second winding portion located in the outer region of the core is dissipated to the first cooling body via the insulating layer and the metal base body. Heat generated in the first winding portion and the second winding portion located in the inner region of the core is also dissipated to the first cooling body via the insulating layer and the metal base body. This allows the heat generated in the first winding portion and the second winding portion located in the inner region of the core to be dissipated to the first cooling body to the same extent as the heat generated in the first winding portion and the second winding portion located in the outer region of the core. As a result, the heat dissipation performance of the coil device can be improved.

[0014] According to the power conversion device according to the present disclosure, the above-described coil device is provided, thereby making it possible to improve heat dissipation. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a circuit diagram showing an example of a power conversion device to which a coil device according to each embodiment is applied; [Figure 2] 1 is an exploded perspective view showing an example of a power conversion device including a coil device according to a first embodiment. [Figure 3] FIG. 2 is an enlarged exploded perspective view showing the structure of a coil device in the power conversion device according to the embodiment. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 2 in the embodiment. [Figure 5] 10A and 10B are diagrams for explaining the reason for providing slit portions in the metal base substrate in the embodiment. [Figure 6] FIG. 2 is an exploded perspective view showing a current path of the coil device in the embodiment. [Figure 7] FIG. 2 is an exploded perspective view showing an example of a variation of the power conversion device including the coil device in the embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing an example of a coil device according to a first modified example of the embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing an example of a coil device according to a second modified example of the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a coil device according to a third modified example of the embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing an example of a power conversion device including a coil device according to a second embodiment. [Figure 12] FIG. 10 is a cross-sectional view showing a coil device according to an example of a first modified example in the embodiment. [Figure 13] FIG. 10 is a cross-sectional view showing a coil device according to another example of the first modified example in the embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing a coil device according to an example of a second modified example in the embodiment. [Figure 15] FIG. 10 is a cross-sectional view showing a coil device according to another example of the second modified example in the embodiment. [Figure 16] FIG. 11 is a cross-sectional view showing an example of a power conversion device including a coil device according to a third embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing an example of a power conversion device including a coil device according to a fourth embodiment. [Figure 18] FIG. 10 is a cross-sectional view showing an example of a coil device according to a modified example of the embodiment. [Figure 19] 10 is a partial plan view showing the positional relationship between a core and a metal base substrate in a power converter including a coil device according to a fifth embodiment. FIG. [Figure 20] FIG. 10 is a partial plan view showing the positional relationship between a core and a metal base substrate in a coil device according to a first modified example of the embodiment. [Figure 21] FIG. 10 is a partial plan view showing the positional relationship between a core and a metal base substrate in a coil device according to a second modified example of the embodiment. [Figure 22] FIG. 13 is a perspective view showing an example of a power conversion device including a coil device according to a sixth embodiment. [Figure 23] FIG. 2 is a partial plan view of a power conversion device including a coil device in the embodiment. [Figure 24] FIG. 24 is a partial cross-sectional view taken along the cross-sectional line XXIV-XXIV shown in FIG. 23 in the embodiment. [Figure 25] FIG. 2 is an enlarged exploded perspective view showing the structure of a coil device in the power conversion device according to the embodiment. [Figure 26] FIG. 10 is a perspective view showing an example of a power conversion device including a coil device according to a modified example in the embodiment. [Figure 27] FIG. 2 is a partial plan view of a power conversion device including a coil device in the embodiment. [Figure 28]FIG. 28 is a partial cross-sectional view taken along the cross-sectional line XXVIII-XXVIII shown in FIG. 27 in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] First, a DC-DC converter will be described as an example of a power conversion device including a coil device. Fig. 1 shows an example of a circuit diagram of a DC-DC converter. The DC-DC converter is mounted, for example, on an electric vehicle. The DC-DC converter has the function of converting an input voltage of about 100V to 300V of a lithium-ion battery to a voltage of 12V to 15V and outputting the converted voltage to charge a lead-acid battery.

[0017] As shown in Figure 1, the DC-DC converter as 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 unit 2 is configured with switching elements 9. Here, the inverter circuit unit 2 is configured with four switching elements 9a, 9b, 9c, and 9d. As the switching elements 9, for example, 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 operations of the four switching elements 9 are controlled by a control circuit unit 10.

[0019] The transformer unit 3 is configured with a transformer 11 having a primary winding unit 11a and a secondary winding unit 11b. The rectifier circuit unit 4 is configured with a rectifier element 12. Here, the rectifier circuit unit 4 is configured with four rectifier elements 12a, 12b, 12c, and 12d. The rectifier element 12 may be, for example, a power semiconductor element such as a diode, a MOS transistor, or a thyristor. The smoothing circuit unit 5 is configured with a smoothing reactor 13 and a smoothing capacitor 14.

[0020] In the DC-DC converter serving as the power conversion device 1, the switching operation of each of the four switching elements 9 in the inverter circuit section 2 is controlled by the control circuit section 10, whereby the DC voltage input from the input terminal 6 is converted into an AC voltage.

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

[0022] In the rectifier circuit unit 4, the AC voltage supplied from the transformer unit 3 is converted back to a DC voltage by the rectifier element 12. In the smoothing circuit unit 5, the DC voltage converted by the rectifier circuit unit 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 Fig. 1, the transformer 11 and the smoothing reactor 13 are coil devices that generate a relatively large amount of heat. It is necessary to dissipate the heat generated in the transformer 11 and the smoothing reactor 13 and reduce the temperatures of the transformer 11 and the smoothing reactor 13 to an allowable temperature or lower, for example, at or below approximately 100°C to 120°C. In each embodiment, a structure for dissipating heat from a coil device made up of a coil unit will be specifically described.

[0024] Embodiment 1 In the first embodiment, a first example of a transformer as a coil device will be described. As shown in Figures 2, 3, and 4, coil device 20 is composed of one coil unit 18. Transformer 11 as coil device 20 is formed by core 21 having a loop-shaped magnetic path, and first winding portion 29 (primary winding portion 11a) and second winding portion 30 (secondary winding portion 11b) wound around core 21, respectively.

[0025] The first winding portion 29 includes a first coil pattern 37a and a first wiring main body 45a. The second winding portion 30 includes a second coil pattern 37b and a second wiring main body 45b. The first coil pattern 37a and the second coil pattern 37b are formed on a metal base substrate 31. The first wiring main body 45a and the second wiring main body 45b are formed on a wiring member 41. The first winding portion 29 and the second winding portion 30 are electrically insulated. The metal base substrate 31 is placed on a first cooling body 39a as a cooling body 39.

[0026] The structure of the coil device 20 will be described in detail. The transformer 11 includes a metal base substrate 31, a wiring member 41, a core 21, and a first cooling body 39a. First, the core 21 is composed of an E-core 23 and an I-core 25. The E-core 23 has legs 23a, 23b, and 23c. The I-core 25 comes into contact with the legs 23a, 23b, and 23c, thereby forming the core 21 with a loop-shaped magnetic path. The E-core 23 and the I-core 25 are fixed together with an adhesive (not shown).

[0027] The core 21 (E-shaped core 23 and I-shaped core 25) is, for example, a ferrite core such as a manganese-zinc (Mn-Zn) ferrite core or a nickel-zinc (Ni-Zn) ferrite core. Alternatively, the core 21 may be an amorphous core or an iron dust core.

[0028] Although the core 21 has a structure in which the E-shaped core 23 and the I-shaped core 25 are combined, the core 21 is not limited to the E-shaped core 23 and the I-shaped core 25 as long as the combination can form the core 21 having a loop-shaped magnetic path. For example, it may be a core in which two U-shaped cores are combined. It may also be a core in which two E-shaped cores are combined. It may also be a core in which a T-shaped core and a U-shaped core are combined.

[0029] The metal base substrate 31 is composed of a metal base body 34, an insulating layer 35, and a coil pattern 37. In the metal base substrate 31, the coil pattern 37 is disposed on the metal base body 34 with the insulating layer 35 interposed therebetween. The metal base body 34 has a thermal conductivity of 1.0 W / (m·K) or more, preferably 10.0 W / (m·K) or more, and more preferably 100.0 W / (m·K) or more. The metal base body 34 is formed from a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy.

[0030] The metal base substrate 31 includes a first metal base substrate 31a and a second metal base substrate 31b. The first metal base substrate 31a includes a first extension portion 33a extending from an outer region of the core 21 to an inner region of the core 21. The second metal base substrate 31b includes a second extension portion 33b extending from the outer region of the core 21 to an inner region of the core 21.

[0031] The first metal base substrate 31a and the second metal base substrate 31b are arranged such that the first extending portion 33a and the second extending portion 33b face each other, with an insertion portion 32 formed between the first metal base substrate 31a and the second metal base substrate 31b, through which the legs 23a to 23c of the core 21 are inserted. The insertion portion 32 includes an insertion portion 32a through which the leg 23a is inserted, an insertion portion 32b through which the leg 23b is inserted, and an insertion portion 32c through which the leg 23c is inserted.

[0032] The metal base substrate 31 has a slit portion 27 formed therein to prevent a loop-shaped induced current from flowing in the portion surrounding the core 21. The slit portion 27 is formed in the inner region of the core 21. The slit portion 27 is formed in a manner to be connected to the insertion portion 32. The first extension portion 33a (first metal base substrate 31a) and the second extension portion 33b (second metal base substrate 31b) are arranged with a length SL corresponding to the slit portion 27 between them.

[0033] The portions of the first metal base substrate 31a and the second metal base substrate 31b surrounding the leg portion 23a are physically and electrically separated by the slit portion 27. The slit portion 27 has the function of preventing the formation of a short coil in the metal base main body 34, as will be described later.

[0034] The insulating layer 35 has a first main surface 35a and a second main surface 35b. The second main surface 35b is in contact with almost the entire surface of the metal base body 33. The insulating layer 35 has electrical insulation properties. The insulating layer 35 is made of, for example, epoxy resin, glass fiber reinforced epoxy resin, polyimide resin, or the like. Furthermore, a thermally conductive filler may be mixed into the epoxy resin, etc., to improve thermal conductivity.

[0035] The thickness of the insulating layer 35 is preferably as thin as possible within a range that does not affect electrical insulation or manufacturability. The thickness of the insulating layer 35 is set, for example, to about 1 μm or more and 2000 μm or less. More preferably, the thickness of the insulating layer 35 is set to about 1 μm or more and 200 μm or less. The insulating layer 35 is formed with an insertion portion 32a through which the leg portion 23a of the E-shaped core 23 is inserted, an insertion portion 32b through which the leg portion 23b is inserted, and an insertion portion 32c through which the leg portion 23c is inserted.

[0036] A coil pattern 37 is formed on a first main surface 35a of the insulating layer 35. 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.

[0037] The first coil pattern 37a includes a first coil pattern first portion 37af and a first coil pattern second portion 37as. The inverter circuit portion 2 is formed on the first metal base substrate 31a. The first coil pattern first portion 37af and the first coil pattern second portion 37as are electrically connected to the inverter circuit portion 2. Note that a wiring pattern (not shown) other than the first coil pattern 37a may be formed on the first metal base substrate 31a.

[0038] The second coil pattern 37b includes a second coil pattern first portion 37bf and a second coil pattern second portion 37bs. The rectifier circuit portion 4 is formed on the second metal base substrate 31b. The second coil pattern first portion 37bf and the second coil pattern second portion 37bs are electrically connected to the rectifier circuit portion 4. Note that a wiring pattern (not shown) other than the second coil pattern 37b may be formed on the second metal base substrate 31b.

[0039] The first metal base substrate 31a on which the first coil pattern 37a and the 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 the rectifier circuit section 4 are formed has an electrical secondary potential. The first metal base substrate 31a having the primary potential and the second metal base substrate 31b having the secondary potential are electrically insulated from each other.

[0040] The thickness of the first coil pattern 37a and the second coil pattern 37b (coil pattern 37) is, for example, about 1 μm or more and 2000 μm or less. The first coil pattern 37a and the second coil pattern 37b are made of, for example, copper, nickel, gold, aluminum, silver, tin, or the like. The coil pattern 37 may also be made of an alloy containing these metals.

[0041] Heat generated in the coil pattern 37 is dissipated to the metal base body 34 through the insulating layer 35 that is in contact with almost the entire surface of the metal base body 34. By setting the thickness of the insulating layer 35 as thin as possible without affecting both electrical insulation and manufacturability, the heat dissipation performance of the heat dissipation path can be improved.

[0042] The first coil pattern 37a and the metal base body 34 are separated by a creepage distance CR1. When the potential of the first coil pattern 37a and the potential of the metal base body 34 are different, ensuring the creepage distance CR1 can prevent dielectric breakdown from occurring on the creepage between the first coil pattern 37a and the metal base body 34.

[0043] The creepage distance CR1 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 CR1 needs to be set. From the viewpoint of preventing dielectric breakdown, it is preferable that the first coil pattern 37a be arranged with rounded corners and other edges to avoid sharp edges. The second coil pattern 37b and the metal base body 34 are separated by a creepage distance CR2. The creepage distance CR2 is set in the same manner as the creepage distance CR1.

[0044] The wiring member 41 is disposed so as to straddle the first metal base substrate 31a and the second metal base substrate 31b, which face each other with the slit portion 27 interposed therebetween. The wiring member 41 includes an insulating portion 43 and a wiring main body 45. The wiring member 41 is formed with an insertion portion 42. The insertion portion 42 includes an insertion portion 42a through which the leg portion 23a of the E-shaped core 23 is inserted, an insertion portion 42b through which the leg portion 23b is inserted, and an insertion portion 42c through which the leg portion 23c is inserted. A printed wiring board is used as the wiring member 41. In addition to a printed circuit board, for example, a metal bus bar covered with an insulating coating may also be used as the wiring member 41.

[0045] The insulating portion 43 has a first main surface 43a and a second main surface 43b. The wiring body 45 includes a first wiring body 45a and a second wiring body 45b. The first wiring body 45a and the second wiring body 45b are formed of, for example, copper, nickel, gold, aluminum, silver, or tin. The first wiring body 45a is formed on the first main surface 43a of the insulating portion 43. The first wiring body 45a is disposed so as to surround the insertion portion 42a. The second wiring body 45b is formed on the second main surface 43b of the insulating portion 43. The second wiring body 45b is disposed so as to surround the insertion portion 42a.

[0046] One end of the first wiring body 45a is connected to the first wiring body 45b via the through-hole conductive portion 47 and the conductive joining member 53. coil The other end of the first wiring main body 45a is electrically connected to the first pattern first portion 37af via the through-hole conductive portion 47 and the conductive bonding member 53. coil One end of the second wiring main body 45b is electrically connected to the second pattern portion 37as via a conductive bonding member 53. coil The other end of the second wiring main body 45b is electrically connected to the second pattern first portion 37bf via a conductive bonding member 53. coil It is electrically connected to the second pattern portion 37bs.

[0047] For example, a conductive adhesive or solder can be used as the joining member 53. The first wiring body 45a is thermally joined to the first metal base substrate 31a via the joining member 53 so as to be thermally conductive. The second wiring body 45b is thermally joined to the second metal base substrate 31b via the joining member 53 so as to be thermally conductive.

[0048] Furthermore, a thermally conductive member (not shown) may be interposed between the wiring body 45 and the coil pattern 37. The wiring body 45 and the coil pattern 37 are thermally bonded to each other via the thermally conductive member in addition to the bonding member 53, allowing for thermal conductivity. The thermal conductivity of the thermally conductive member is preferably 0.1 W / (m·K) or more, more preferably 1.0 W / (m·K) or more, and even more preferably 10.0 W / (m·K) or more. For example, thermally conductive grease, a thermally conductive sheet, or a thermally conductive adhesive may be used as the thermally conductive member.

[0049] The insulating portion 43 has electrical insulating properties and is made of, for example, glass fiber reinforced epoxy resin, phenol resin, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or the like.

[0050] In this way, the printed circuit board used as the wiring member 41 may generally be made of a material that is considered to have a relatively low thermal conductivity. In other words, the printed circuit board used as the wiring member 41 may be a general-purpose printed circuit board. Alternatively, a ceramic substrate such as aluminum oxide, aluminum nitride, or silicon carbide may be used as the printed circuit board used as the wiring member 41. Note that a conductive portion (not shown) may be formed on the surface or inside of the wiring member 41.

[0051] Alternatively, the wiring member 41 may be a laminated bus bar formed by laminating an insulating film sheet and a metal conductor. The insulating film sheet may be, for example, a film made of polyethylene terephthalate (PET), a film made of polyimide (PI), or a paper made of aramid (wholly aromatic polyamide) fiber. The insulating film sheet may be adhered to the metal conductor, which is the wiring body, by an adhesive layer or a pressure-sensitive adhesive layer.

[0052] The metal base substrate 31, on which the coil pattern 37 and the like are formed, is placed on the first cooling body 39a. The metal base substrate 31 is fixed to the first cooling body 39a, for example, with screws (not shown). A groove 40 for accommodating the E-core 23 is formed in a main surface 39aa of the first cooling body 39a. The thermal conductivity of the first cooling body 39a is preferably 1.0 W / (m·K) or more, more preferably 10.0 W / (m·K) or more, and even more preferably 100.0 W / (m·K) or more.

[0053] First cooling body 39a is made of a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy. First cooling body 39a may also be made of a resin with high thermal conductivity. First cooling body 39a may be electrically connected to another member so that it has the same potential as the ground potential.

[0054] The metal base substrate 31 is in contact with the main surface 39aa of the first cooling body 39a, so that the first cooling body 39a and the metal base substrate 31 are thermally coupled to each other in a manner that allows heat conduction. By interposing a heat conductive member (not shown) between the main surface 39aa of the first cooling body 39a and the metal base substrate 31, heat conduction becomes even easier.

[0055] Furthermore, the E-shaped core 23 is in contact with the bottom surface of the groove 40 of the first cooling body 39a, so that the core 21 (E-shaped core 23) and the first cooling body 39a are thermally coupled to each other so that heat can be conducted between them. By providing a heat conducting member (not shown) between the bottom surface of the groove 40 and the E-shaped core 23, heat conduction becomes even easier.

[0056] The E-shaped core 23 and the first cooling body 39a may be bonded together with an adhesive (not shown) or the like. The first cooling body 39a may form part of the housing of the coil device 20. The first cooling body 39a may form part of the housing of the power conversion device 1 including the coil device 20. Furthermore, a surface of the first cooling body 39a other than the surface on which the metal base substrate 31 is arranged may be air-cooled or water-cooled. The coil device 20 (power conversion device 1) according to the first embodiment is configured as described above.

[0057] Next, the operation of the above-mentioned power conversion device (coil device 20, transformer 11) will be briefly described. First, it has been mentioned that the slit portion 27 in the coil device 20 (transformer 11) has the function of preventing the formation of a short coil in the metal base body 34. This will be described.

[0058] 5, if no slits are provided in the metal base body 34, the portion of the metal base body 34 that surrounds the leg portion 23a around which the coil pattern 37 is wound will be physically and electrically connected. Therefore, when a current flows between the terminals TA and TB in the coil pattern 37, an induced current RP will flow in a loop in that portion of the metal base body 34.

[0059] 5, the induced current RP becomes a short coil magnetically coupled with the coil pattern 37 in the metal base body 34. As a result, the coil device 20 (transformer 11) is unable to exhibit the desired performance. Therefore, by providing the slit portion 27 in the metal base body 34, the flow of the induced current RP is blocked, allowing the transformer 11 to exhibit the desired performance.

[0060] In the power conversion device 1 including the coil device 20 (transformer 11), the AC voltage converted in the inverter circuit unit 2 is converted to an arbitrary voltage by the transformer 11. At this time, as shown in FIG. 6 , the AC voltage converted by the inverter circuit unit 2 flows through a current path PT1. The current path PT1 is a first winding portion 29 including a first coil pattern 37a and a first wiring main body 45a. The first winding portion 29 becomes a primary winding portion 11a of the transformer 11.

[0061] The AC voltage converted to an arbitrary voltage by the transformer 11 flows through a current path PT2. The current path PT2 is the second winding portion 30 including the second coil pattern 37b and the second wiring main body 45b. The second winding portion 30 becomes the secondary winding portion 11b of the transformer 11. The AC voltage that flows through the current path PT2 is converted to a DC voltage in the rectifier circuit portion 4. During this operation of the coil device 20 (transformer 11), the AC voltage flows through the primary winding portion 11a, causing the primary winding portion 11a to generate heat. Furthermore, the AC voltage flows through the secondary winding portion 11b, causing the secondary winding portion 11b to generate heat.

[0062] In the coil device 20 described above, heat generated in a portion of the first winding portion 29 located in the outer region of the core 21 is dissipated to the first cooling body 39a via the insulating layer 35 and the metal base body 34. Heat generated in a portion of the first winding portion 29 located in the inner region of the core 21 is also dissipated to the first cooling body 39a via the insulating layer 35 and the metal base body 34.

[0063] This allows the heat generated in the part of the first winding portion 29 located in the inner region of the core 21 to be dissipated to the first cooling body 39a to the same extent as the heat generated in the part of the first winding portion 29 located in the outer region of the core 21.

[0064] Similarly to the primary winding portion 11a, the heat generated in the portion of the secondary winding portion 11b located outside the core 21 is dissipated to the first cooling body 39a via the insulating layer 35 and the metal base body 34. The heat generated in the portion of the secondary winding portion 11b located inside the core 21 is also dissipated to the first cooling body 39a via the insulating layer 35 and the metal base body 34.

[0065] This allows heat generated in the portion of secondary winding portion 11b located in the inner region of core 21 to be dissipated to first cooling body 39a to the same extent as heat generated in the portion of secondary winding portion 11b located in the outer region of core 21. As a result, the heat dissipation performance of coil device 20 can be improved. Furthermore, there is no need to increase the size of first coil pattern 37a, second coil pattern 37b, etc. for heat dissipation, which can contribute to the miniaturization of coil device 20 and, ultimately, the miniaturization of power conversion device 1.

[0066] Furthermore, in the coil device 20 described above, the metal base substrate 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 not an integrated metal base substrate but are separate metal base substrates. Therefore, compared to when the first metal base substrate 31a and the second metal base substrate 31b are formed from a single integrated metal base substrate, the area per metal base substrate can be made smaller.

[0067] This reduces warping of the metal base substrate 31, which is expected to occur during the manufacture of the coil device 20. Also, it is possible to optimize the number of metal base bodies that can be taken out from a sheet-shaped metal base body, which contributes to reducing the manufacturing cost of the metal base substrate.

[0068] Furthermore, by forming the first metal base substrate 31a and the second metal base substrate 31b as separate metal base substrates, it is possible to standardize the metal base substrate 31 even when the input voltages to the input terminals 6 in the power conversion device 1 are different. This will be described below.

[0069] First, if the magnetic flux density of the core 21 (leg 23a) shown in Figure 2 is Bm, the period during which the switching element 9 of the inverter circuit section 2 is on is Ton, the input voltage to the input terminal 6 is Vin, the number of turns of the first winding section 29 (primary winding section 11a) in the coil device 20 (transformer 11) is N, and the cross-sectional area of ​​the leg 23a in the core 21 (E-shaped core 23) is Ae, then the following relationship holds: Vin × Ton = Bm × N × Ae.

[0070] Here, the magnetic flux density Bm affects the heat generation of the core 21. Therefore, when the input voltage Vin increases, it is preferable that the magnetic flux density Bm is also approximately the same if the heat dissipation structure of the core 21 is the same. Assume that the input voltage Vin input to the input terminal 6 of the power conversion device 1 increases, for example, three times.

[0071] In this case, based on the above relational expression, it is necessary to select one of the following values: the period Ton during which switching element 9 is on is multiplied by 1 / 3, the number of turns N of first winding 29 is multiplied by 3, or the cross-sectional area Ae of leg 23a is multiplied by 3. In addition, it is necessary to satisfy the above relational expression by combining increases and decreases in the values ​​of period Ton, number of turns N, and cross-sectional area Ae.

[0072] Note that, if the period Ton during which the switching element 9 is on is reduced, the amount of heat generated by both the switching element 9 in the inverter circuit unit 2 and the rectifying element 12 in the rectifying circuit unit 4 will increase. For this reason, if the heat dissipation structure of the switching element 9 and the heat dissipation structure of the rectifying element 12 are the same, it is preferable that the period Ton during which the switching element 9 is on is also the same.

[0073] When increasing the number of turns N of the first winding portion 29 (primary winding portion 11a) in the wiring member 41, it is only necessary to change the wiring member 41, without needing to change the first metal base substrate 31a and the second metal base substrate 31b of the metal base substrate 31. In this case, the metal base substrate 31 may be formed of a single metal base substrate.

[0074] When the cross-sectional area Ae of the leg 23a is increased, the first metal base substrate 31a and the second metal base substrate 31b need not be modified, but the spacing (length SL) between the first metal base substrate 31a and the second metal base substrate 31b should be secured so that insertion portions 32a (32) through which the leg 23a of the E-shaped core 23 is inserted are formed. Also, the wiring member 41 should be modified so that insertion portions 42a (42) through which the leg 23a of the E-shaped core 23 is inserted are formed in the wiring member 41.

[0075] The design range for the number of turns N of the first winding portion 29 (primary winding portion 11a) in the wiring member 41 is limited by constraints on the insulation distance and the wiring width. Therefore, by using the first metal base substrate 31a and the second metal base substrate 31b as the metal base substrate 31, the cross-sectional area Ae of the leg portion 23a of the E-shaped core 23 can be changed, and the design range can be expanded by combining the number of turns N and the cross-sectional area Ae.

[0076] Fig. 7 shows an example of the structure of the power converter 1 (coil device 20) when it is assumed that the input voltage Vin input to the input terminal 6 of the power converter 1 is tripled. In the power converter 1 shown in Fig. 7, a first metal base substrate 31a and a second metal base substrate 31b are used as the metal base substrate 31, and the insertion portion 42 of the wiring member 41 and the cross-sectional area Ae of the E-shaped core 23 are changed.

[0077] In the power converter 1 shown in FIG. 7, the cross-sectional area Ae (3·CD×CW) of the E-shaped core 23 is three times larger than that of the power converter 1 shown in FIG. 2. The first metal base substrate 31a and the second metal base substrate 31b are arranged apart by a length SL so as to form an insertion portion 32 through which the E-shaped core 23, whose cross-sectional area Ae has been increased three times, can be inserted. In addition, the area of ​​the insertion portion 42 of the wiring member 41 is increased three times. When the input voltage Vin increases three times, the cross-sectional area Ae is increased three times, and therefore the above relational expression is established.

[0078] In this way, when changing the electrical specifications of the power conversion device 1, such as increasing the input voltage Vin, it is possible to change the dimensions of the wiring member 41 while leaving the dimensions of the first metal base board 31a and the second metal base board 31b unchanged, and to use the first metal base board 31a and the second metal base board 31b before the change. tree This allows the first metal base substrate 31a and the second metal base substrate 31b to be standardized in response to changes in electrical specifications, which contributes to reducing the manufacturing cost of the metal base substrate 31.

[0079] In the above-described power conversion device 1, the first wiring main body 45a of the first winding portion 29 is disposed on the first main surface 43a of the insulating portion 43 of the wiring member 41, and the second wiring main body 45b of the second winding portion 30 is disposed on the second main surface 43b of the insulating portion 43. For example, when the voltage of the first winding portion 29 is higher than the voltage of the second winding portion 30, the current flowing through the second winding portion 30 becomes greater than the current flowing through the first winding portion 29, and the amount of heat generated by the second winding portion 30 becomes greater than the amount of heat generated by the first winding portion 29.

[0080] For this reason, it is preferable to arrange the second winding portion 30 on the second main surface 43b of the insulating portion 43, which is closer to the second metal base substrate 31b, and to arrange the first winding portion 29, which has a relatively high voltage, on the first main surface 43a of the insulating portion 43 in order to more reliably provide electrical insulation.

[0081] Furthermore, in the coil device 20 of the power conversion device 1 described above, the first winding portion 29 and the second winding portion 30 are each wound once (one winding (one turn)) around the leg portion 23a of the E-shaped core 23. Furthermore, a single printed circuit board has been used as an example of the wiring member 41 on which the first wiring main body 45a and the second wiring main body 45b are arranged.

[0082] The number of turns of each of the first winding portion 29 and the second winding portion 30 may be two or more depending on the specifications. To increase the number of turns, two or more printed circuit boards may be stacked as the wiring member 41. When two or more printed circuit boards are stacked, one printed circuit board may be electrically connected to the other printed circuit boards by a conductive joining member. Also, for example, a multilayer printed circuit board may be used in which wiring bodies and insulating portions are alternately stacked.

[0083] In this way, when increasing the number of turns of each of the first winding portion 29 and the second winding portion 30, it is only necessary to stack the printed circuit boards, and there is no need to increase the size of the first metal base substrate 31a and the second metal base substrate 31b. As a result, this can contribute to the miniaturization of the coil device 20, and ultimately the miniaturization of the power conversion device 1.

[0084] (First Modification) A coil device 20 (power conversion device 1) according to a first modified example will be described. As shown in Fig. 8, in the coil device 20, a sealing member 55 is filled between the metal base substrate 31 and the wiring member 41. In addition, a sealing member 55 is filled between the core 21 (E-shaped core 23) and the first cooling body 39a (groove portion 40). Note that the rest of the configuration is similar to that of the coil device 20 shown in Fig. 4, so the same members are given the same reference numerals, and their description will not be repeated unless necessary.

[0085] The sealing member 55 is preferably formed from a material having a thermal conductivity of about 0.1 W / (m·K) or more, preferably about 1.0 W / (m·K). The sealing member 55 has electrical insulation properties. The sealing member 55 may have a Young's modulus of 1 MPa or more. The sealing member 55 may be formed from an elastic resin material. The sealing member 55 may be formed from an epoxy resin containing a thermally conductive filler. The sealing member 55 may be formed from a rubber material such as silicone or urethane.

[0086] By filling the space with such sealing member 55, the heat generated in the metal base substrate 31 and the heat generated in the wiring member 41 can be dissipated to the first cooling body 39a via the sealing member 55. As a result, it is no longer necessary to increase the size of the metal base substrate 31 etc. in order to dissipate heat from the metal base substrate 31 and the wiring member 41, which can further contribute to the miniaturization of the coil device 20 and, in turn, the miniaturization of the power conversion device 1.

[0087] In general, between conductive materials with different potentials, a certain creepage distance or more is required to prevent dielectric breakdown between one conductive material and the other. If it is anticipated that the creepage between the one conductive material and the other conductive material may be contaminated by electrically conductive substances, a longer creepage distance must be ensured.

[0088] In the coil device 20 according to the first modified example described above, a sealing member 55 is filled between the metal base substrate 31 and the wiring member 41, including between the first metal base substrate 31a and the second metal base substrate 31b. This prevents the surface of the metal base substrate 31 from being contaminated with electrically conductive substances. As a result, it is possible to reduce both the creepage distance between the first coil pattern 37a and the metal base main body 34 and the creepage distance between the second coil pattern 37b and the metal base main body 34, which contributes to the miniaturization of the coil device 20 and, ultimately, the miniaturization of the power conversion device 1.

[0089] Furthermore, with the E-shaped core 23 housed in the groove 40 provided in the first cooling body 39a, a sealing member 55 is filled between the groove 40 and the E-shaped core 23. This allows heat generated in the core 21 to be dissipated to the first cooling body 39a via the sealing member 55. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the power conversion device 1.

[0090] Furthermore, the wiring member 41 is fixed to the metal base substrate 31, and the core 21 (E-shaped core 23) is fixed to the first cooling body 39a by the sealing member 55. As a result, the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1, can be improved.

[0091] (Second Modification) A coil device 20 (power conversion device 1) according to a second modified example will now be described. As shown in Fig. 9, in the coil device 20, an elastic member 57 such as a spring serving as a biasing member is interposed between the metal base substrate 31 and the E-shaped core 23. Note that other configurations are similar to those of the coil device 20 shown in Fig. 4, and therefore the same members are given the same reference numerals, and their description will not be repeated unless necessary.

[0092] In the coil device 20 according to the second modified example described above, an elastic member 57 is interposed between the metal base substrate 31 and the E-shaped core 23. As a result, heat generated in the E-shaped core 23 (core 21) is efficiently conducted to the metal base substrate 31 (first metal base substrate 31a and second metal base substrate 31b) via the elastic member 57, such as a spring, and the heat conducted to the metal base substrate 31 (metal base main body 34) is dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the miniaturization of the power conversion device 1.

[0093] Furthermore, the E-shaped core 23 (core 21) is biased toward the first cooling body 39a by the elastic member 57 interposed between the metal base substrate 31 and the E-shaped core 23. As a result, the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1, can be improved.

[0094] (Third Modification) A coil device 20 (power conversion device 1) according to a third modified example will be described. As shown in Fig. 10, in the coil device 20, a metal base substrate 31 is formed with an uneven portion 59 as a biasing member. The uneven portion 59 is interposed between the metal base substrate 31 and the E-shaped core 23. Burrs generated when processing the metal base substrate 31 are used as the uneven portion 59. Pressing is an example of processing the outer shape of the metal base substrate 31 (metal base main body 34).

[0095] In the press working, a mold is used to apply pressure to the metal base substrate 31 (metal base main body 34), thereby processing the metal base substrate 31. During this press working, burrs are generated on the metal base main body 34. The burrs are generated so as to protrude from the surface of the metal base substrate 31. For example, the burrs are generated so that convex portions and concave portions are alternately connected.

[0096] In this coil device 20, burrs generated by press working are interposed between the metal base substrate 31 and the E-shaped core 23 (core 21) as uneven portions 59. Note that other configurations are similar to those of the coil device 20 shown in Fig. 4, and therefore the same members are given the same reference numerals, and their description will not be repeated unless necessary.

[0097] In the coil device 20 according to the third modified example described above, burrs generated on the metal base substrate 31 due to press working are formed as uneven portions 59 and are interposed between the metal base substrate 31 and the E-shaped core 23. Therefore, the uneven portions 59 interposed between the metal base substrate 31 and the E-shaped core 23 urge the E-shaped core 23 (core 21) toward the first cooling body 39a.

[0098] Moreover, the protrusions of the uneven portion 59 acting as burrs have a pointed shape. This restricts the movement of the E-shaped core 23 (21) in a direction intersecting the direction in which the E-shaped core 23 (core 21) is biased toward the first cooling body 39a. As a result, the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1, can be further improved.

[0099] Furthermore, the concave-convex portion 59 biases the E-shaped core 23 (core 21) toward the first cooling body 39a, thereby allowing the heat generated in the core 21 to be efficiently dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, in turn, the miniaturization of the power conversion device 1.

[0100] Embodiment 2 In the second embodiment, a second example of a transformer as a coil device will be described. As shown in Fig. 11, a metal base substrate 31 is formed with a stepped portion 61a and a stepped portion 61b as sandwiching portions that sandwich an E-shaped core 23 (core 21).

[0101] The first extension portion 33a of the first metal base substrate 31a and the second extension portion 33b of the second metal base substrate 31b face each other across the slit portion 27. The step portion 61a is formed in the first extension portion 33a of the first extension portion 33a and the second extension portion 33b facing each other. The step portion 61b is formed in the second extension portion 33b of the first extension portion 33a and the second extension portion 33b facing each other.

[0102] One end of the E-shaped core 23 is received in the step portion 61a, and the other end of the E-shaped core 23 is received in the step portion 61b, so that the E-shaped core 23 is sandwiched between the step portion 61a (first extension portion 33a) and the step portion 61b (second extension portion 33b) and is biased against the first cooling body 39a. Note that the rest of the configuration is the same as the configuration of the coil device 20 shown in Figure 4, so the same members are given the same reference numerals and their description will not be repeated unless necessary.

[0103] In the coil device 20 described above, the E-shaped core 23 is sandwiched between the step portion 61a of the first extension portion 33a and the step portion 61b of the second extension portion 33b, and is biased by the first cooling body 39a. This restricts the movement of the E-shaped core 23. As a result, the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1, can be improved.

[0104] Furthermore, since the E-shaped core 23 is received in the step portion 61a, the contact area between the E-shaped core 23 and the first metal base substrate 31a (first extension portion 33a) increases. Since the E-shaped core 23 is received in the step portion 61b, the contact area between the E-shaped core 23 and the second metal base substrate 31b (second extension portion 33b) increases.

[0105] As a result, heat generated in the E-shaped core 23 (core 21) is efficiently conducted to the metal base substrate 31 (first metal base substrate 31a and second metal base substrate 31b), and the heat conducted to the metal base substrate 31 (metal base main body 34) is dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the power conversion device 1.

[0106] (First Modification) A coil device 20 (power conversion device 1) according to a first modified example will be described. As shown in Fig. 12, a first extension 33a in a first metal base substrate 31a has an upwardly curved portion 63a that curves upward from the E-shaped core 23 toward the wiring member 41. A second extension 33b in a second metal base substrate 31b has an upwardly curved portion 63b that curves upward from the E-shaped core 23 toward the wiring member 41.

[0107] The thickness of the E-shaped core 23 is set to a thickness equal to or greater than the thickness corresponding to the depth of the groove 40, and the upwardly curved portion 63a and the upwardly curved portion 63b are configured to abut against the E-shaped core 23. Note that other configurations are similar to those of the coil device 20 shown in Fig. 4, and therefore the same members are denoted by the same reference numerals, and their description will not be repeated unless necessary.

[0108] In the coil device 20 according to the first modified example described above, the E-shaped core 23 is sandwiched between the first metal base substrate 31a (the cambered portion 63a) and the first cooling body 39a, and the E-shaped core 23 is sandwiched between the second metal base substrate 31b (the cambered portion 63b) and the first cooling body 39a. At this time, the cambered portions 63a and 63b urge the E-shaped core 23 toward the first cooling body 39a, fixing the E-shaped core 23 (core 21) to the first cooling body 39a. This eliminates the need for a fixing member to fix the E-shaped core 23 (core 21) to the first cooling body 39a, which contributes to reducing manufacturing costs.

[0109] Moreover, the upward cambered portions 63a and 63b urge the E-shaped core 23 toward the first cooling body 39a, thereby improving the vibration resistance of the coil device 20 and, ultimately, the vibration resistance of the power conversion device 1. Furthermore, the upward cambered portions 63a and 63b urge the E-shaped core 23 toward the first cooling body 39a, thereby enabling heat generated in the E-shaped core 23 (core 21) to be efficiently dissipated to the first cooling body 39a.

[0110] 13, inclined portions 24 may be provided along the cambered portions 63a and 63b at the portions of the E-shaped core 23 where the cambered portions 63a and 63b abut, respectively. By providing the inclined portions 24 on the E-shaped core 23, the contact areas between the E-shaped core 23 and the first metal base substrate 31a and the second metal base substrate 31b can be increased.

[0111] This allows the heat generated in the E-shaped core 23 (core 21) to be efficiently conducted to the metal base substrate 31, and the heat conducted to the metal base substrate 31 to be dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the miniaturization of the power conversion device 1.

[0112] (Second Modification) A coil device 20 (power conversion device 1) according to a second modified example will be described. As shown in Fig. 14, a downwardly curved portion 65a that curves downward from the first cooling body 39a toward the E-core 23 is formed in the first extension portion 33a of the first metal base substrate 31a. A downwardly curved portion 65b that curves downward from the first cooling body 39a toward the E-core 23 is formed in the second extension portion 33b of the second metal base substrate 31b.

[0113] The thickness of the E-shaped core 23 is set to a thickness equal to or less than the thickness corresponding to the depth of the groove 40, and the downwardly curved portion 65a and the downwardly curved portion 65b are configured to abut against the E-shaped core 23. Note that other configurations are similar to those of the coil device 20 shown in Fig. 4, so the same members are denoted by the same reference numerals, and their description will not be repeated unless necessary.

[0114] In the coil device 20 according to the second modified example described above, the E-shaped core 23 is sandwiched between the first metal base substrate 31a (the downwardly curved portion 65a) and the first cooling body 39a, and the E-shaped core 23 is sandwiched between the second metal base substrate 31b (the downwardly curved portion 65b) and the first cooling body 39a. At this time, the downwardly curved portions 65a and 65b urge the E-shaped core 23 toward the first cooling body 39a, and the E-shaped core 23 (core 21) is fixed to the first cooling body 39a. This eliminates the need for a fixing member to fix the E-shaped core 23 (core 21) to the first cooling body 39a, which can contribute to reducing manufacturing costs.

[0115] Moreover, the downwardly curved portions 65a and 65b urge the E-shaped core 23 toward the first cooling body 39a, thereby improving the vibration resistance of the coil device 20 and, ultimately, the vibration resistance of the power conversion device 1. Furthermore, the downwardly curved portions 65a and 65b urge the E-shaped core 23 toward the first cooling body 39a, thereby enabling heat generated in the E-shaped core 23 (core 21) to be efficiently dissipated to the first cooling body 39a.

[0116] 15, inclined portions 24 may be provided along the downwardly curved portions 65a and 65b at the portions of the E-shaped core 23 where the downwardly curved portions 65a and 65b abut, respectively. By providing the inclined portions 24 on the E-shaped core 23, the contact areas between the E-shaped core 23 and the first metal base substrate 31a and the second metal base substrate 31b can be increased.

[0117] This allows the heat generated in the E-shaped core 23 (core 21) to be efficiently conducted to the metal base substrate 31, and the heat conducted to the metal base substrate 31 to be dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the miniaturization of the power conversion device 1.

[0118] Embodiment 3 In the third embodiment, a third example of a transformer as a coil device will be described. As shown in Fig. 16, a convex portion 67 that protrudes toward the slit portion 27 is formed on the E-shaped core 23. The convex portion 67 is sandwiched between the first extension portion 33a (first metal base substrate 31a) and the second extension portion 33b (second metal base substrate 31b). Note that the rest of the configuration is the same as that of the coil device 20 shown in Fig. 4, so the same members are given the same reference numerals, and their description will not be repeated unless necessary.

[0119] In the coil device 20 described above, the E-shaped core 23 is formed with a protrusion 67 that protrudes toward the slit portion 27. This allows the E-shaped core 23 to be pressed against the first cooling body 39a while the core 21 (E-shaped core 23) is sandwiched between the first metal base substrate 31a and the second metal base substrate 31b. This improves the vibration resistance of the coil device 20, and ultimately the vibration resistance of the power conversion device 1.

[0120] Furthermore, since the convex portion 67 provided on the E-shaped core 23 is sandwiched between the first metal base substrate 31a and the second metal base substrate 31b, the contact area between each of the first metal base substrate 31a and the second metal base substrate 31b and the E-shaped core 23 can be increased.

[0121] This allows the heat generated in the E-shaped core 23 (core 21) to be efficiently conducted to the metal base substrate 31, and the heat conducted to the metal base substrate 31 to be dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the miniaturization of the power conversion device 1.

[0122] Embodiment 4 In the fourth embodiment, a fourth example of a transformer as a coil device will be described. As shown in Fig. 17, a screw member 69 is attached as a first fixing member, penetrating the first extension portion 33a (first metal base substrate 31a) and the E-shaped core 23 to reach the first cooling body 39a. A screw member 69 is attached as a first fixing member, penetrating the second extension portion 33b (second metal base substrate 31b) and the E-shaped core 23 to reach the first cooling body 39a. Note that the rest of the configuration is similar to that of the coil device 20 shown in Fig. 4, so the same members are designated by the same reference numerals, and description thereof will not be repeated unless necessary.

[0123] In the coil device 20 described above, the first metal base substrate 31a, the second metal base substrate 31b, and the E-shaped core 23 are fixed to the first cooling body 39a by the screw members 69. This improves the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1.

[0124] Furthermore, heat generated in the core 21 (E-shaped core 23) is efficiently conducted to the first metal base substrate 31a and the second metal base substrate 31b (metal base substrate 31) via the screw members 69, and the heat conducted to the metal base substrate 31 is dissipated to the first cooling body 39a. As a result, there is no need to increase the size of the core 21 for heat dissipation, which can further contribute to the miniaturization of the coil device 20 and, ultimately, the power conversion device 1.

[0125] (Variation) A coil device 20 (power conversion device) according to a modified example will be described. As shown in Fig. 18, an insulating member 71 is filled between the first metal base substrate 31a (first extension portion 33a) and the second metal base substrate 31b (second extension portion 33b). A screw member 73 is attached as a second fixing member, penetrating the insulating member 71 and the E-shaped core 23 to reach the first cooling body 39a. Note that the rest of the configuration is similar to that of the coil device 20 shown in Fig. 4, so the same members are given the same reference numerals, and their description will not be repeated unless necessary.

[0126] In the coil device 20 according to the above-described modified example, the insulating member 71 and the E-shaped core 23 interposed between the first extension portion 33a and the second extension portion 33b are fixed to the first cooling body 39a by the screw member 73. This improves the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1. Furthermore, by pressing the E-shaped core 23 against the first cooling body 39a, heat generated in the core 21 can be efficiently dissipated to the first cooling body 39a.

[0127] The insulating member 71 may be made of any electrically insulating material, which can more effectively prevent dielectric breakdown in the region between the first metal base substrate 31a and the second metal base substrate 31b.

[0128] Embodiment 5. In the fifth embodiment, a fifth example of a transformer as a coil device will be described. As shown in Fig. 19, the first extension 33a (first metal base substrate 31a) is formed so that its width gradually narrows from the outer region of the core 21 toward the inner region of the core 21. The second extension 33b (second metal base substrate 31b) is formed so that its width gradually narrows from the outer region of the core 21 toward the inner region of the core 21. Note that the rest of the configuration is similar to that of the coil device 20 shown in Fig. 4, so the same members are given the same reference numerals, and their description will not be repeated unless necessary.

[0129] In the coil device 20 described above, the portions (root portions) of each of the first extension portion 33a and the second extension portion 33b located in the outer region of the core 21 have a width WA. The tip portions (inner region of the core 21) of each of the first extension portion 33a and the second extension portion 33b have a width WB. In the E-shaped core 23, the distance between the adjacent leg portion 23a and leg portion 23b (or leg portion 23c) is the distance DL. The width WA is set wider than the distance DL. The width WB is set narrower than the distance DL.

[0130] As a result, one first extending portion 33a abuts against the corners 22a of both leg portion 23a and leg portion 23b. The other first extending portion 33a abuts against the corners 22a of both leg portion 23a and leg portion 23c. Furthermore, one second extending portion 33b abuts against the corners 22b of both leg portion 23a and leg portion 23b. The other second extending portion 33b abuts against the corners 22b of both leg portion 23a and leg portion 23c.

[0131] The first extension 33a abuts against the corner 22a of the E-shaped core 23, and the second extension 33b abuts against the corner 22a of the E-shaped core 23. 23 When the core 21 (E-shaped core 23) comes into contact with the corner 22b of the coil device 20, the core 21 (E-shaped core 23) is sandwiched between the first extension portion 33a and the second extension portion 33b. As a result, the vibration resistance of the coil device 20, and therefore the vibration resistance of the power conversion device 1, can be improved.

[0132] (First Modification) A first modification will be described. As shown in Fig. 20, the first extension portion 33a has a length EFL extending from the outer region toward the inner region of the core 21. The second extension portion 33b has a length ESL extending from the outer region toward the inner region of the core 21. The length EFL of each of the two first extension portions 33a is shorter than the length ESL of each of the two second extension portions 33b. The two second extension portions 33b, each having the length ESL, are located beyond the center portion CP (extension direction) of the core 21 and in the inner region of the core 21.

[0133] In the coil device 20 according to the first modification, the two second extension portions 33b of the second metal base substrate 31b are positioned beyond the center portion CP of the core 21. This allows the heat generated in the core 21 near the center portion CP, where the amount of heat generated is the highest, to be efficiently conducted to the second metal base substrate 31b via the two second extension portions 33b. The heat conducted to the second metal base substrate 31b is dissipated to the first cooling body 39a.

[0134] The two first extensions 33a of the first metal base substrate 31a may be positioned beyond the center portion CP of the core 21. In this case, heat generated near the center portion CP, where the amount of heat generated in the core 21 is the highest, is efficiently conducted to the first metal base substrate 31a via the two first extensions 33a. The heat conducted to the first metal base substrate 31a is dissipated to the first cooling body 39a.

[0135] (Second Modification) A coil device 20 (power conversion device) according to a second modification will be described. As shown in FIG. 21 , the first extension portion 33a has a length EFL extending from the outer region toward the inner region of the core 21. The second extension portion 33b has a length ESL extending from the outer region toward the inner region of the core 21. The length EFL of one first extension portion 33a is longer than the length ESL of one second extension portion 33b. The length EFL of the other first extension portion 33a is shorter than the length ESL of the other second extension portion 33b. One first extension portion 33a having the length EFL is located in an inner region of the core 21 beyond the center portion CP (extension direction) of the core 21. The other second extension portion 33b having the length ESL is located in an inner region of the core 21 beyond the center portion CP (extension direction) of the core 21.

[0136] In the coil device 20 according to the second modification, one first extension portion 33a of the first metal base substrate 31a is positioned beyond the center portion CP of the core 21. In addition, the other second extension portion 33b of the second metal base substrate 31b is positioned beyond the center portion CP of the core 21. As a result, heat generated in the core 21 near the center portion CP, where the amount of heat generation is the highest, is efficiently conducted to the first metal base substrate 31a via one first extension portion 33a, and is also efficiently conducted to the second metal base substrate 31b via the other second extension portion 33b. The heat conducted to the first metal base substrate 31a and the second metal base substrate 31b is dissipated to the first cooling body 39a.

[0137] Embodiment 6 In the sixth embodiment, a sixth example of a transformer as a coil device will be described. Here, the XYZ Cartesian coordinate system will be used as needed. Furthermore, the same components as those in the coil device 20 shown in FIG. 4 and other figures will be given the same reference numerals, and their description will not be repeated unless necessary.

[0138] As shown in Figures 22, 23, 24, and 25, transformer 11 as coil device 20 includes cores 21, which are first core 21a, second core 21b, third core 21c, and fourth core 21d. Cooling bodies 39 include, in addition to first cooling body 39a, second cooling body 39b, third cooling body 39c, fourth cooling body 39d, fifth cooling body 39e, and sixth cooling body 39f. Second cooling body 39b, third cooling body 39c, fourth cooling body 39d, fifth cooling body 39e, and sixth cooling body 39f are each placed on first cooling body 39a. Second cooling body 39b to sixth cooling body 39f are thermally bonded to first cooling body 39a.

[0139] The first wiring main body 45a includes a first wiring main body first portion 45aa and a first wiring main body second portion 45ab. The first wiring main body first portion 45aa and the first wiring main body second portion 45ab each include a portion extending along the X-axis, which is the first direction. The second wiring main body 45b includes a second wiring main body first portion 45ba and a second wiring main body second portion 45bb. The second wiring main body first portion 45ba and the second wiring main body second portion 45bb each include a portion extending along the X-axis. The first wiring main body first portion 45aa and the second wiring main body first portion 45ba, and the first wiring main body second portion 45ab and the second wiring main body second portion 45bb are arranged at a distance in the Y-axis direction, which is the second direction.

[0140] The second core 21b is arranged at a distance in the X-axis direction from the first core 21a. The third core 21c is arranged at a distance in the Y-axis direction from the first core 21a. The fourth core 21d is arranged at a distance in the X-axis direction from the third core 21c and at a distance in the Y-axis direction from the second core 21b. The four cores, the first core 21a to the fourth core 21d, are arranged in a matrix (2×2).

[0141] The second cooling body 39b is disposed between the first core 21a and the second core 21b. The second cooling body 39b is disposed with a gap between it and the first core 21a and the second core 21b. The third cooling body 39c is disposed between the first core 21a and the third core 21c, and also between the second core 21b and the fourth core 21d.

[0142] Fourth cooling body 39d is disposed on the opposite side of first core 21a from the side on which third cooling body 39c is disposed, with first core 21a sandwiched between fourth cooling body 39d and third cooling body 39c. Furthermore, fourth cooling body 39d is disposed on the opposite side of second core 21b from the side on which third cooling body 39c is disposed, with second core 21b sandwiched between fourth cooling body 39d and third cooling body 39c.

[0143] The fifth cooling body 39e is disposed on the opposite side of the third core 21c from the side on which the third cooling body 39c is disposed, with the third core 21c sandwiched between the fifth cooling body 39e and the third cooling body 39c. The fifth cooling body 39e is disposed on the opposite side of the fourth core 21d from the side on which the third cooling body 39c is disposed, with the fourth core 21d sandwiched between the fifth cooling body 39e and the third cooling body 39c. The sixth cooling body 39f is disposed between the third cooling body 39c and the fourth cooling body 39d. The sixth cooling body 39f is disposed with a gap between it and the third cooling body 39c and the fourth cooling body 39d.

[0144] Third cooling body 39c is in contact with each of first core 21a, second core 21b, third core 21c, and fourth core 21d, and is thermally bonded to each of first core 21a, second core 21b, third core 21c, and fourth core 21d.

[0145] The fourth cooling body 39d is in contact with each of the first core 21a and the second core 21b. The fourth cooling body 39d is thermally bonded to each of the first core 21a and the second core 21b. The fifth cooling body 39e is in contact with each of the third core 21c and the fourth core 21d. The fifth cooling body 39e is thermally bonded to each of the third core 21c and the fourth core 21d. As a result, the core 21 (first core 21a to fourth core 21d) is thermally bonded to the first cooling body 39a via each of the third cooling body 39c, the fourth cooling body 39d, and the fifth cooling body 39e.

[0146] Each of second cooling body 39b and sixth cooling body 39f includes E-type cooling body 38a as the first part of the second cooling body and I-type cooling body 38b as the second part of the second cooling body. E-type cooling body 38a is disposed on first cooling body 39a. I-type cooling body 38b is disposed opposite E-type cooling body 38a. E-type cooling body 38a has legs 38aa, 38ab, and 38ac. I-type cooling body 38b is disposed in contact with legs 38aa, 38ab, and 38ac, respectively.

[0147] E-type cooling body 38a and I-type cooling body 38b are arranged with wiring member 41 sandwiched between them, from the side where first cooling body 39a is arranged and the side opposite to the side where first cooling body 39a is arranged. E-type cooling body 38a is thermally joined to wiring member 41 via heat conduction member 75. I-type cooling body 38b is thermally joined to wiring member 41 via heat conduction member 76. As a result, wiring member 41 is thermally joined to first cooling body 39a via second cooling body 39b and sixth cooling body 39f.

[0148] Although second cooling body 39b and sixth cooling body 39f are configured by combining E-type cooling body 38a and I-type cooling body 38b, the configuration is not limited to E-type cooling body 38a and I-type cooling body 38b as long as the combination can sandwich wiring member 41. For example, a configuration in which two E-type cooling bodies are combined may also be used.

[0149] The thermal conductivity of each of second cooling body 39b to sixth cooling body 39f is preferably 1.0 W / (m·K) or more, more preferably 10.0 W / (m·K) or more, and even more preferably 100.0 W / (m·K) or more. Each of second cooling body 39b to sixth cooling body 39f is formed from a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy.

[0150] Furthermore, each of second cooling body 39b to sixth cooling body 39f may be made of, for example, a resin with high thermal conductivity. Each of second cooling body 39b to sixth cooling body 39f may be electrically connected to another member so that the potential is the same as the ground potential.

[0151] The wiring member 41 has insertion portions 42a, 42b, 42c, 42d, and 42e formed as insertion portions 42. Legs 23c (see FIG. 2) of core 21 (first core 21a and second core 21b), legs 23b (see FIG. 2) of core 21 (third core 21c and fourth core 21d), third cooling body 39c, legs 38ac of E-type cooling body 38a (second cooling body 39b), and legs 38ab of E-type cooling body 38a (sixth cooling body 39f) are inserted into insertion portion 42a.

[0152] Legs 23a (see FIG. 2) of core 21 (first core 21a and second core 21b) and leg 38aa of E-type cooling body 38a (second cooling body 39b) are inserted through insertion portion 42b. Legs 23a (see FIG. 2) of core 21 (third core 21c and fourth core 21d) and leg 38aa of E-type cooling body 38a (sixth cooling body 39f) are inserted through insertion portion 42c.

[0153] Legs 23b (see FIG. 2) of core 21 (first core 21a and second core 21b), legs 38ab of E-type cooling body 38a (second cooling body 39b), and fourth cooling body 39d are inserted through insertion portion 42d. Legs 23c (see FIG. 2) of core 21 (third core 21c and fourth core 21d), legs 38ac of E-type cooling body 38a (sixth cooling body 39f), and fifth cooling body 39e are inserted through insertion portion 42e.

[0154] The first wiring main body first portion 45aa and the second wiring main body first portion 45ba are wound around the first core 21a and the second core 21b with the second cooling body 39b interposed between them. The first wiring main body second portion 45ab and the second wiring main body second portion 45bb are wound around the third core 21c and the fourth core 21d with the sixth cooling body 39f interposed between them.

[0155] In the coil device 20 described above, second cooling body 39b and sixth cooling body 39f are thermally joined to wiring member 41 via heat conduction member 75 or heat conduction member 76. This allows heat generated in wiring member 41 to be dissipated to first cooling body 39a via second cooling body 39b and sixth cooling body 39f. As a result, there is no need to increase the size of wiring member 41 for heat dissipation, which can contribute to the miniaturization of coil device 20 and, ultimately, the miniaturization of power conversion device 1.

[0156] Additionally, third cooling body 39c is thermally bonded to each of first core 21a, second core 21b, third core 21c, and fourth core 21d. Fourth cooling body 39d is thermally bonded to each of first core 21a and second core 21b. Fifth cooling body 39e is thermally bonded to each of third core 21c and fourth core 21d.

[0157] This allows the heat generated in core 21 (first core 21a to fourth core 21d) to be efficiently conducted to third cooling body 39c, fourth cooling body 39d, and fifth cooling body 39e, respectively, and further allows the heat conducted to third cooling body 39c, fourth cooling body 39d, and fifth cooling body 39e, respectively, to be dissipated to first cooling body 39a. As a result, there is no need to increase the size of core 21 for heat dissipation, which can contribute to the miniaturization of coil device 20 and, ultimately, the miniaturization of power conversion device 1.

[0158] Furthermore, in the coil device 20 described above, the case where the core 21 is arranged with a gap between it and each of the second cooling body 39b and the sixth cooling body 39f has been exemplified, but the core 21 may be arranged so as to be in contact with each of the second cooling body 39b and the sixth cooling body 39f. That is, the first core 21a and the second core 21b may be arranged so as to be in contact with the second cooling body 39b, and the third core 21c and the fourth core 21d may be arranged so as to be in contact with the sixth cooling body 39f.

[0159] By bringing core 21 into contact with second cooling body 39b and sixth cooling body 39f, the heat generated in core 21 can be conducted to second cooling body 39b and sixth cooling body 39f and dissipated to first cooling body 39a, and the heat generated in core 21 can be effectively dissipated to first cooling body 39a. As a result, there is no need to increase the size of core 21 for heat dissipation, which can further contribute to the miniaturization of coil device 20 and, ultimately, the miniaturization of power conversion device 1.

[0160] (Variation) A coil device 20 (power conversion device 1) according to a modified example will be described. As shown in Figures 26, 27, and 28, coil device 20 includes first cooling body 39a to sixth cooling body 39f and lid cooling body 39g as cooling bodies 39. Lid cooling body 39g is arranged to cover cores 21 (first core 21a to fourth core 21d) and second cooling body 39b to sixth cooling body 39f.

[0161] A heat conduction member 77 is interposed between lid cooling body 39g and core 21 and second cooling body 39b to sixth cooling body 39f. Lid cooling body 39g is fixed to second cooling body 39b to sixth cooling body 39f with screw members 74. Note that the rest of the configuration is similar to the configuration of coil device 20 shown in Figures 22 to 24 or 4, etc., so the same members are designated by the same reference numerals, and their description will not be repeated unless necessary.

[0162] The thermal conductivity of lid cooling body 39g is preferably 1.0 W / (m·K) or more, more preferably 10.0 W / (m·K) or more, and even more preferably 100.0 W / (m·K) or more. Lid cooling body 39g is made of a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy.

[0163] Furthermore, lid cooling body 39g may be formed from, for example, a resin with high thermal conductivity. Note that lid cooling body 39g may be electrically connected to another member so that the potential of lid cooling body 39g is the same as the ground potential.

[0164] In the coil device 20 described above, a heat conductive member 77 is interposed between the lid cooling body 39g and the core 21 and the second cooling body 39b to the sixth cooling body 39f. The lid cooling body 39g is thermally joined to the core 21 and the second cooling body 39b to the sixth cooling body 39f via the heat conductive member 77. The second cooling body 39b to the sixth cooling body 39f are also thermally joined to the first cooling body 39a.

[0165] This allows heat generated in core 21 to be conducted to lid cooling body 39g, and the heat conducted to lid cooling body 39g can then be dissipated to first cooling body 39a via second cooling body 39b to sixth cooling body 39f. As a result, there is no need to increase the size of core 21 for heat dissipation, which can further contribute to the miniaturization of coil device 20 and, ultimately, the miniaturization of power conversion device 1.

[0166] Furthermore, core 21 and second to sixth cooling bodies 39b to 39f, together with lid cooling body 39g, are fixed to first cooling body 39a by screw member 74. This improves the vibration resistance of coil device 20, and ultimately the vibration resistance of power conversion device 1.

[0167] In the coil device 20 described above, the four cores 21, the first core 21a to the fourth core 21d, are arranged in a matrix (2×2) as an example of the cores 21. The number and arrangement of the cores 21 are not limited to this.

[0168] In addition, although the coil device described in each of the above-mentioned embodiments has been described using an example of a coil device consisting of one coil unit, the coil device can also be applied to a coil device consisting of two or more coil units.

[0169] The coil device 20 (power conversion device 1) explained in each embodiment can be variously combined as needed.

[0170] The embodiments disclosed herein are examples and are not intended to be limiting. The scope of the present disclosure is defined by the scope of the claims, not the scope described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

[0171] The present disclosure includes the following aspects. [Appendix 1] A coil device having a coil unit, The coil unit includes: one or more cores having a loop-shaped magnetic path; a metal base substrate disposed in an inner region of the core and an outer region of the core, the metal base substrate having a first coil pattern and a second coil pattern formed on a metal base body with an insulating layer interposed therebetween; a first winding portion including the first coil pattern and wound around the core in a manner passing through the inner region of the core; a second winding portion including the second coil pattern, wound around the core in a manner passing through the inner region of the core, and electrically insulated from the first winding portion; one or more cooling bodies including a first cooling body joined to the metal base body on the side opposite to the side on which the insulating layer is formed; Equipped with The metal base substrate is a first metal base substrate on which the first coil pattern is formed; a second metal base substrate on which the second coil pattern is formed; and Including, A coil device in which the first metal base substrate and the second metal base substrate are arranged facing each other in a manner that an insertion portion through which the core is inserted is formed between the first metal base substrate and the second metal base substrate.

[0172] [Appendix 2] a slit portion that prevents a loop-shaped induced current from flowing in a portion surrounding the core is formed in the metal base substrate in a manner that the slit portion is connected to the insertion portion; 2. The coil device according to claim 1, wherein the first metal base substrate and the second metal base substrate are arranged at a distance corresponding to the slit portion.

[0173] [Appendix 3] a wiring member including a wiring main body wound around the core, The first coil pattern is a first coil pattern first portion; 1st coil pattern 2nd part and Including, The second coil pattern is a first portion of a second coil pattern; Second coil pattern part 2 and Including, The wiring body is a first wiring body that electrically connects the first coil pattern first portion and the first coil pattern second portion; a second wiring main body that electrically connects the second coil pattern first portion and the second coil pattern second portion; Including, the first winding portion includes the first wiring main body, 3. The coil device according to claim 1, wherein the second winding portion includes the second wiring body.

[0174] [Appendix 4] the wiring member is a printed circuit board, 4. The coil device according to claim 3, wherein the wiring body is disposed on the printed circuit board.

[0175] [Appendix 5] the wiring member is located in the inner region of the core and the outer region of the core, surrounded by the core, and is disposed on the opposite side of the metal base substrate from the side where the first cooling body is disposed; a receiving groove for receiving the core is formed in the first cooling body; 5. The coil device according to claim 3, wherein a sealing material is filled between the wiring member and the metal base substrate, and between the receiving groove and the core.

[0176] [Appendix 6] A coil device described in any one of Appendices 1 to 5, wherein a biasing member is interposed between the metal base substrate and the core, biasing the portion of the core located between the metal base substrate and the first cooling body toward the first cooling body.

[0177] [Appendix 7] the first metal base substrate includes a first extension portion extending from the outer region of the core to the inner region of the core; the second metal base substrate includes a second extension portion extending from the outer region of the core to the inner region of the core; 7. The coil device according to any one of claims 1 to 6, wherein the first metal base substrate and the second metal base substrate are arranged such that the first extension portion and the second extension portion face each other.

[0178] [Appendix 8] A coil device as described in Appendix 7, wherein the first extension portion and the second extension portion are formed with a clamping portion that sandwiches the portion of the core located between the metal base substrate and the first cooling body between the first extension portion and the second extension portion.

[0179] [Appendix 9] A coil device as described in Appendix 7, wherein the first extension portion and the second extension portion have a warped portion that sandwiches the portion of the core located between the metal base substrate and the first cooling body between the metal base substrate and the first cooling body and urges the core toward the first cooling body.

[0180] [Appendix 10] A coil device as described in Appendix 7, wherein the core has a protrusion formed thereon that protrudes from a portion of the core located between the metal base substrate and the first cooling body toward the space between the first extension portion and the second extension portion.

[0181] [Appendix 11] The core is a first leg portion around which the first winding portion and the second winding portion are wound; a second leg portion positioned at a first distance from the first leg portion; Including, the first extension portion and the second extension portion are positioned between the first leg portion and the second leg portion so as to face each other, the first extension portion is formed so that its width narrows from a first width wider than the first interval to a second width narrower than the first interval toward a tip of the first extension portion, the second extension portion is formed so that its width narrows from a third width wider than the first interval to a fourth width narrower than the first interval toward a tip of the second extension portion, A coil device as described in Appendix 7, wherein the metal base substrate is arranged to sandwich the core, with the first extension portion abutting against the first leg portion and the second leg portion, and the second extension portion abutting against the first leg portion and the second leg portion.

[0182] [Appendix 12] A coil device as described in Appendix 7, wherein a first fixing member is attached from each of the first extension portion and the second extension portion, passing through a portion of the core located between the metal base substrate and the first cooling body and reaching the first cooling body.

[0183] [Appendix 13] an insulating member is filled between the first extension portion and the second extension portion; 8. The coil device according to claim 7, further comprising a second fixing member attached thereto, the second fixing member passing through the insulating member and reaching the first cooling body.

[0184] [Appendix 14] the first extension portion has a first extension length extending from the outer region of the core to the inner region of the core; the second extension portion has a second extension length extending from the outer region of the core to the inner region of the core; 8. The coil device according to claim 7, wherein the first extension length is set to either a first length that is longer than the second extension length or a second length that is shorter than the second extension length.

[0185] [Appendix 15] the cores include a first core and a second core arranged at a distance from each other in a first direction; the cooling body includes a second cooling body disposed between the first core and the second core and thermally joined to the first cooling body; The coil device according to any one of appendixes 3 to 5, wherein the first wiring body and the second wiring body are wound around the first core and the second core, respectively, with the second cooling body interposed between the first core and the second core.

[0186] [Appendix 16] The second cooling body is a second cooling body first part disposed on the first cooling body; a second cooling body second part disposed so as to face the second cooling body first part; Including, A coil device as described in Appendix 15, wherein the second cooling body first part and the second cooling body second part are arranged to sandwich the wiring member from the side where the first cooling body is arranged and the side opposite to the side where the first cooling body is arranged.

[0187] [Appendix 17] 17. The coil device according to claim 16, wherein a heat conductive member is interposed between the second cooling body first part and the wiring member, and between the second cooling body and the wiring member.

[0188] [Appendix 18] 18. The coil device according to any one of appendixes 15 to 17, wherein the second cooling body is arranged so as to be in contact with both the first core and the second core.

[0189] [Appendix 19] the first wiring body includes a first wiring body first part and a first wiring body second part connected in series, the second wiring main body includes a second wiring main body first part and a second wiring main body second part connected in series, each of the first wiring body first portion, the first wiring body second portion, the second wiring body first portion, and the second wiring body second portion includes a portion extending in a first direction; the first wiring main body first portion and the first wiring main body second portion, and the second wiring main body first portion and the second wiring main body second portion are disposed at a distance in a second direction intersecting the first direction, the cores include a first core and a third core that are spaced apart from each other in the second direction, the cooling bodies include a third cooling body, a fourth cooling body, and a fifth cooling body, each thermally joined to the first cooling body; the third cooling body is disposed between the first core and the third core in a manner to be in contact with each of the first core and the third core; the fourth cooling body is disposed on the opposite side of the first core from the side on which the third cooling body is disposed, in a manner in which the first core is sandwiched between the fourth cooling body and the third cooling body; the fifth cooling body is disposed on the opposite side of the third core from the side on which the third cooling body is disposed, in a manner in which the third core is sandwiched between the fifth cooling body and the third cooling body; the first wiring main body first portion and the second wiring main body first portion are each wound around the first core; 6. The coil device according to any one of claims 3 to 5, wherein the first wiring main body second portion and the second wiring main body second portion are each wound around the third core.

[0190] [Appendix 20] the first wiring body includes a first wiring body first part and a first wiring body second part connected in series, the second wiring main body includes a second wiring main body first part and a second wiring main body second part connected in series, each of the first wiring body first portion, the first wiring body second portion, the second wiring body first portion, and the second wiring body second portion includes a portion extending in a first direction; the first wiring main body first portion and the first wiring main body second portion, and the second wiring main body first portion and the second wiring main body second portion are disposed at a distance in a second direction intersecting the first direction, The core is A first core; a second core disposed at a distance from the first core in the first direction; a third core disposed at a distance from the first core in the second direction; a fourth core that is spaced apart from the third core in the first direction and spaced apart from the second core in the second direction; Including, the first wiring main body first portion and the second wiring main body first portion are wound around the first core and the second core, respectively; the first wiring main body second portion and the second wiring main body second portion are wound around the third core and the fourth core, respectively; the cooling body includes a lid cooling body thermally joined to the first cooling body and arranged to cover the first core, the second core, the third core, and the fourth core; 6. The coil device according to any one of claims 3 to 5, wherein the lid cooling body is thermally bonded to the first core, the second core, the third core, and the fourth core.

[0191] [Appendix 21] the cooling bodies include a second cooling body, a third cooling body, a fourth cooling body, a fifth cooling body, and a sixth cooling body, each thermally joined to the first cooling body; the second cooling body is disposed between the first core and the second core, the third cooling body is disposed between the first core and the third core so as to be in contact with each of the first core and the third core, and is disposed between the second core and the fourth core so as to be in contact with each of the second core and the fourth core, the fourth cooling body is disposed on an opposite side of the first core and the second core from a side on which the third cooling body is disposed, with the first core and the second core sandwiched between the fourth cooling body and the third cooling body; the fifth cooling body is disposed on the opposite side of the third core from the side on which the third cooling body is disposed, in a manner in which the third core and the fourth core are sandwiched between the fifth cooling body and the third cooling body; 21. The coil device according to claim 20, wherein the sixth cooling body is disposed between the third core and the fourth core.

[0192] [Appendix 22] 22. The coil device according to claim 20, wherein a heat conductive member is interposed between the lid cooling body and the first core, the second core, the third core, and the fourth core.

[0193] [Appendix 23] A power conversion device comprising the coil device according to any one of appendices 1 to 22.

[0194] [Appendix 24] an inverter circuit section electrically connected to the first coil pattern and disposed on the first metal base substrate; a rectifier circuit unit electrically connected to the second coil pattern and disposed on the second metal base substrate; 24. The power conversion device of claim 23, comprising: [Industrial Applicability]

[0195] INDUSTRIAL APPLICABILITY The present disclosure is effectively applied to a coil device in which a first winding portion and a second winding portion are wound around a core, and a power conversion device including the coil device. [Explanation of symbols]

[0196] REFERENCE SIGNS LIST 1 power conversion device, 2 inverter circuit section, 3 transformer section, 4 rectifier circuit section, 5 smoothing circuit section, 6 input terminal, 7 output terminal, 8 input capacitor, 9, 9a, 9b, 9c, 9d switching element, 10 control circuit section, 11 transformer, 11a primary winding section, 11b secondary winding section, 12, 12a, 12b, 12c, 12d rectifier element, 13 smoothing reactor, 14 smoothing capacitor, 18 coil unit, 20 coil device, 21 core, 21a first core, 21b second core, 21c third core, 21d fourth core, 22a, 22b corner portion, 23 E-shaped core, 23a, 23b, 23c leg portion, 24 inclined portion, 25 I-shaped core, 27 slit portion, 29 first winding portion, 30 second winding portion, 31 Metal base substrate, 31a first metal base substrate, 31b second metal base substrate, 32, 32a, 32b, 32c insertion portion, 33a first extension portion, 33b second extension portion, 34 metal base body, 34a first main surface, 34b second main surface, 35 insulating layer, 35a first main surface, 35b second main surface, 37 coil pattern, 37a first coil pattern, 37af first coil pattern first part, 37as first coil pattern second part, 37b second coil pattern, 37bf second coil pattern first part, 37bs second coil pattern second part, 38a E-type cooling body, 38b I-type cooling body, 38aa, 38ab, 38ac leg portion, 39 cooling body, 39a first cooling body, 39b second cooling body, 39c third cooling body, 39d fourth cooling body, 39e Fifth cooling element, 39f sixth cooling element, 39g lid cooling element, 39aa main surface, 40 groove portion, 41 wiring member, 42, 42a, 42b, 42c, 42d, 42e insertion portion, 43 insulating portion, 43a first main surface, 43b second main surface, 45 wiring body, 45a first wiring body, 45aa first wiring body first portion, 45ab first wiring body second portion, 45b second wiring body, 45ba second wiring body first portion, 45bb second wiring body second portion, 47 through-hole conductive portion, 53 joining member, 55 sealing member, 57 elastic member, 59 uneven portion, 61a, 61b step portion, 63a, 63b upwardly curved portion, 65a, 65b downwardly curved portion, 67 convex portion, 69, 73, 74 Screw member, 71 Insulating member, 75, 76, 77 Heat conducting member, RP Induced current, TA, TB Terminal, CR Creepage distance, SL, CW, CD Length, TA, TBTerminal, WA, WB width, DL spacing, CP center, EFL, ESL length, PT1 current path, PT2 current path.

Claims

1. A coil device having a coil unit, The coil unit includes: one or more cores having a looped magnetic path; a metal base substrate disposed in an inner region of the core and an outer region of the core, the metal base substrate having a first coil pattern formed on a metal base body with an insulating layer interposed therebetween; a first winding portion including the first coil pattern and wound around the core in a manner passing through the inner region of the core; Equipped with The metal base substrate is a first metal base substrate on which the first coil pattern is formed; a second metal base substrate; Including, A coil device in which the first metal base substrate and the second metal base substrate are arranged facing each other, with an insertion portion through which the core is inserted formed between the first metal base substrate and the second metal base substrate.

2. A second coil pattern is formed on the second metal base substrate with the insulating layer interposed between the metal base body, a second winding portion including the second coil pattern, wound around the core in a manner passing through the inner region of the core, and electrically insulated from the first winding portion; one or more cooling bodies including a first cooling body joined to the metal base body on the side opposite to the side on which the insulating layer is formed; The coil device of claim 1 , further comprising:

3. a slit portion that prevents a loop-shaped induced current from flowing in a portion surrounding the core is formed in the metal base substrate in a manner that the slit portion is connected to the insertion portion; 2. The coil device according to claim 1, wherein the first metal base substrate and the second metal base substrate are arranged at a distance corresponding to the slit portion.

4. a wiring member including a wiring main body wound around the core, The first coil pattern is a first coil pattern first portion; First coil pattern second part Including, The second coil pattern is a first portion of a second coil pattern; a second coil pattern second part; Including, The wiring body is a first wiring main body electrically connecting the first coil pattern first portion and the first coil pattern second portion; a second wiring main body that electrically connects the second coil pattern first portion and the second coil pattern second portion; Including, the first winding portion includes the first wiring main body, The coil device according to claim 2 , wherein the second winding portion includes the second wiring body.

5. the wiring member is a printed circuit board, The coil device according to claim 4 , wherein the wiring body is disposed on the printed circuit board.

6. the wiring member is located in the inner region of the core and the outer region of the core, surrounded by the core, on the opposite side of the metal base substrate from the side where the first cooling body is located, a receiving groove portion for receiving the core is formed in the first cooling body; 5. The coil device according to claim 4, wherein a sealing material is filled between the wiring member and the metal base substrate and between the receiving groove and the core.

7. 3. The coil device according to claim 2, wherein a biasing member is interposed between said metal base substrate and said core.

8. the first metal base substrate includes a first extension portion extending from the outer region of the core to the inner region of the core; the second metal base substrate includes a second extension portion extending from the outer region of the core to the inner region of the core; 3. The coil device according to claim 2, wherein the first metal base substrate and the second metal base substrate are arranged such that the first extending portion and the second extending portion face each other.

9. The coil device of claim 8, wherein the first extension portion and the second extension portion have a clamping portion formed thereon that sandwiches the portion of the core located between the metal base substrate and the first cooling body between the first extension portion and the second extension portion.

10. The coil device of claim 8, wherein the first extension portion and the second extension portion have a warped portion that sandwiches the portion of the core located between the metal base substrate and the first cooling body between the metal base substrate and the first cooling body and urges the portion toward the first cooling body.

11. The coil device according to claim 8, wherein the core has a protrusion formed thereon that protrudes from a portion of the core located between the metal base substrate and the first cooling body toward a portion between the first extension portion and the second extension portion.

12. The core is a first leg portion around which the first winding portion and the second winding portion are wound; a second leg portion positioned at a first distance from the first leg portion; Including, the first extension portion and the second extension portion are located between the first leg portion and the second leg portion so as to face each other, the first extension portion is formed so that its width narrows from a first width wider than the first interval to a second width narrower than the first interval toward a tip of the first extension portion, the second extension portion is formed so that its width narrows from a third width wider than the first interval to a fourth width narrower than the first interval toward a tip of the second extension portion, The coil device of claim 8, wherein the metal base substrate is arranged to sandwich the core, with the first extension portion abutting against the first leg portion and the second leg portion, and the second extension portion abutting against the first leg portion and the second leg portion.

13. The coil device of claim 8, wherein a first fixing member is attached from each of the first extension portion and the second extension portion, passing through a portion of the core located between the metal base substrate and the first cooling body and reaching the first cooling body.

14. an insulating member is provided between the first extension portion and the second extension portion; 9. The coil device according to claim 8, further comprising a second fixing member attached to the insulating member and extending to the first cooling body.

15. the first extension portion has a first extension length extending from the outer region of the core to the inner region of the core; the second extension portion has a second extension length extending from the outer region of the core to the inner region of the core; The coil device according to claim 8 , wherein the first extension length is set to either a first length longer than the second extension length or a second length shorter than the second extension length.

16. The core includes a first core and a second core arranged at a distance from each other in a first direction, the cooling body includes a second cooling body disposed between the first core and the second core and thermally joined to the first cooling body; 5. The coil device according to claim 4, wherein the first wiring body and the second wiring body are wound around the first core and the second core, respectively, with the second cooling body interposed between the first core and the second core.

17. The second cooling body is a second cooling body first portion disposed on the first cooling body; a second cooling body second part disposed so as to face the second cooling body first part; Including, The coil device of claim 16, wherein the second cooling body first part and the second cooling body second part are arranged to sandwich the wiring member from the side where the first cooling body is arranged and the side opposite to the side where the first cooling body is arranged.

18. the first wiring main body includes a first wiring main body first portion and a first wiring main body second portion connected in series, the second wiring main body includes a second wiring main body first portion and a second wiring main body second portion connected in series, each of the first wiring body first portion, the first wiring body second portion, the second wiring body first portion, and the second wiring body second portion includes a portion extending in a first direction; the first wiring body first portion and the first wiring body second portion, and the second wiring body first portion and the second wiring body second portion are arranged at a distance in a second direction intersecting the first direction, the cores include a first core and a third core that are spaced apart from each other in the second direction, the cooling bodies include a third cooling body, a fourth cooling body, and a fifth cooling body, each thermally joined to the first cooling body; the third cooling body is disposed between the first core and the third core in a manner of contacting each of the first core and the third core, the fourth cooling body is disposed on an opposite side of the first core from a side on which the third cooling body is disposed, in a manner in which the first core is sandwiched between the fourth cooling body and the third cooling body, the fifth cooling body is disposed on an opposite side of the third core from a side on which the third cooling body is disposed, with the third core sandwiched between the fifth cooling body and the third cooling body; the first wiring main body first portion and the second wiring main body first portion are each wound around the first core; The coil device according to claim 4 , wherein the first wiring main body second portion and the second wiring main body second portion are each wound around the third core.

19. the first wiring main body includes a first wiring main body first portion and a first wiring main body second portion connected in series, the second wiring main body includes a second wiring main body first portion and a second wiring main body second portion connected in series, each of the first wiring body first portion, the first wiring body second portion, the second wiring body first portion, and the second wiring body second portion includes a portion extending in a first direction; the first wiring body first portion and the first wiring body second portion, and the second wiring body first portion and the second wiring body second portion are arranged at a distance in a second direction intersecting the first direction, The core is A first core; a second core disposed at a distance from the first core in the first direction; a third core disposed at a distance from the first core in the second direction; a fourth core that is spaced apart from the third core in the first direction and spaced apart from the second core in the second direction; Including, the first wiring main body first portion and the second wiring main body first portion are wound around the first core and the second core, respectively; the first wiring main body second portion and the second wiring main body second portion are wound around the third core and the fourth core, respectively; the cooling body includes a lid cooling body thermally joined to the first cooling body and arranged to cover the first core, the second core, the third core, and the fourth core; The coil device according to claim 4 , wherein the lid cooling body is thermally bonded to the first core, the second core, the third core, and the fourth core.

20. A power conversion device comprising the coil device according to any one of claims 1 to 19.

21. an inverter circuit section electrically connected to the first coil pattern and disposed on the first metal base substrate; a rectifier circuit unit disposed on the second metal base substrate; 21. The power converter of claim 20, comprising:

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