Electronic devices

Abstract

To provide an electronic device that can suppress the occurrence of ion migration. [Solution] The electronic device 20 comprises a substrate 30, a coupling inductor 40 having a plurality of coils 42 arranged in the X direction on a core 41, and solder for joining the coils 42 to the lands 35. The coils 42 have terminals 421 and 422 located on the substrate side of the lower surface of the core 41. The terminals 421 and 422 have mounting portions 421a and 422a that overlap with the corresponding lands 35 in a plan view, and non-mounted portions 421b and 422b that are the parts excluding the mounting portions 421a and 422a and are arranged to overlap with the core 41. The substrate 30 is provided so as to overlap with a portion of the non-mounted portions 421b and 422b, and has a support portion 37 that protrudes toward the coupling inductor side relative to the lands 35 and supports the coupling inductor 40.

Description

Technical Field

[0001] The disclosure in this specification relates to an electronic device.

Background Art

[0002] Patent Document 1 discloses an electronic control device including a printed circuit board and a QFN type semiconductor package. The description of the prior art document is incorporated herein by reference as an explanation of the technical elements in this specification.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, in order to ensure the thickness of the solder connecting the terminals of the semiconductor package and the corresponding lands, a protruding portion is provided on the printed circuit board so as to contact the lower surface of the mold resin of the semiconductor package. The protruding portion is composed of a land that is electrically separated from the land connected to the terminal and a resist that covers this land.

[0005] In an inductor component in which a plurality of coils such as a coupling inductor are arranged side by side in a predetermined direction, the terminals of the coils are arranged on the substrate side rather than on the opposing surface of the core with respect to the substrate. The terminals of the coils have a mounting portion provided so as to overlap the lands and a non-mounting portion that is the portion excluding the mounting portion. The non-mounting portion is arranged directly below the core. Therefore, even if the protruding portion disclosed in Patent Document 1 is applied, the protruding portion does not contact the opposing surface of the core, and the non-mounting portion of the terminal contacts the substrate surface, which may obstruct ventilation and cause ion migration. From the above viewpoints or other viewpoints not mentioned, further improvement of the electronic device is required.

[0006] One of the purposes of this disclosure is to provide an electronic device that can suppress the occurrence of ion migration. [Means for solving the problem]

[0007] One form of disclosure is an electronic device, A substrate (30) having an insulating substrate (31) and a plurality of lands (35) arranged on one surface of the insulating substrate, An inductor component (40) having a core (41) and a plurality of coils (42) arranged on the core and aligned in a predetermined direction perpendicular to the thickness direction of the substrate, The solder (70) used to join the coil and the land, Equipped with, Each of the coils has external connection terminals (421, 422) located on the substrate side of the core, rather than on the surface facing the substrate. The terminal has mounting portions (421a, 422a) provided so as to overlap with the corresponding land in a plan view in the thickness direction of the board, and non-mounting portions (421b, 422b) which are the portions excluding the mounting portions and are arranged so as to overlap with the core in a plan view. The substrate is provided so as to overlap with a portion of the non-mounted area of ​​at least one terminal in a plan view, and has a support portion (37) that protrudes toward the inductor component side relative to the land and supports the inductor component via the non-mounted area.

[0008] According to the disclosed electronic device, the inductor component can be supported via the unmounted portion of the terminal by a support portion provided on the substrate so as to protrude toward the inductor component. Since the support portion is provided so as to overlap with a portion of the unmounted portion, a gap can be secured between the remaining portion of the unmounted portion, i.e., the portion that does not overlap with the support portion, and the substrate surface. Therefore, obstruction of ventilation can be suppressed, and consequently, ion migration can be suppressed.

[0009] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims are illustrative in their correspondence with the embodiments described later and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings. [Brief explanation of the drawing]

[0010] [Figure 1] This is a circuit diagram showing a multiphase power supply to which the electronic device according to the first embodiment is applied. [Figure 2] This figure shows an example of an ECU equipped with a multiphase power supply. [Figure 3] This is a plan view showing an example of an electronic device. [Figure 4] Figure 3 shows the view with the coupled inductor transparent. [Figure 5] This is a perspective view showing a coupled inductor. [Figure 6] This is a plan view of the coupled inductor, seen from above. [Figure 7] This is a plan view of a coupled inductor seen from the bottom. [Figure 8] This is a perspective view showing the core. [Figure 9] This is a perspective view showing a coil. [Figure 10] This is a cross-sectional view along line XX in Figure 3. [Figure 11] This is a cross-sectional view along the line XI-XI in Figure 3. [Figure 12] This is a floor plan showing an example. [Figure 13] This is a cross-sectional view along the line XIII-XIII in Figure 12. [Figure 14] This is a cross-sectional view showing another example. [Figure 15] This is a plan view showing an electronic device according to the second embodiment. [Figure 16] This is a cross-sectional view along the line XVI-XVI in Figure 15. [Figure 17] It is a plan view showing an electronic device according to the third embodiment. [Figure 18] It is a cross-sectional view taken along line XVIII-XVIII of FIG. 17. [Figure 19] In the reference example, it is a diagram showing the influence of substrate distortion. [Figure 20] It is a plan view of the coupling inductor of the electronic device according to the fourth embodiment as viewed from the bottom surface side. [Figure 21] In the reference example without providing a support portion, it is a diagram showing leakage magnetic flux. [Figure 22] It is a cross-sectional view taken along line XXII-XXII of FIG. 21. [Figure 23] It is a diagram showing the arrangement of the core gap, the coil terminals, and the support portion. [Figure 24] It is a cross-sectional view taken along line XXIV-XXIV of FIG. 23. [Figure 25] It is a plan view showing a modified example. [Figure 26] It is a plan view showing a modified example. [Figure 27] It is a plan view showing an electronic device according to the fifth embodiment. [Figure 28] It is a plan view showing a modified example.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, a plurality of embodiments will be described based on the drawings. In each embodiment, the same reference numerals may be assigned to corresponding components, and redundant explanations may be omitted. When only a part of the configuration is described in each embodiment, for the other parts of the configuration, the configurations of other embodiments described previously can be applied. Also, not only the combinations of configurations explicitly shown in the description of each embodiment, but also the configurations of multiple embodiments can be partially combined with each other as long as there is no problem with the combination, even if not explicitly shown.

[0012] (First Embodiment) The electronic device according to this embodiment includes an inductor component containing multiple coils (inductors), as described later. The inductor component is, for example, a coupled inductor. Such an electronic device can be applied to various electronic circuits, such as power supply circuits and high-frequency circuits. The electronic device can be used, for example, to reduce size and cost in a configuration using multiple inductors. An example of its application to a multiphase power supply will be described below.

[0013] <Multiphase power supply> Figure 1 is a circuit diagram showing an example of a multiphase power supply to which the electronic device according to this embodiment is applied. For convenience, some drivers are shown in a simplified manner in Figure 1.

[0014] The multiphase power supply 10 shown in Figure 1 is a step-down DC-DC converter. The multiphase power supply 10 steps down the input voltage Vin to a predetermined voltage and outputs it as an output voltage Vout. The multiphase power supply 10 includes multiple drivers 11, multiple inductors 12 corresponding to the drivers 11, and capacitors 13. The multiphase power supply 10 has multiple phases. Phases are sometimes referred to as stages or channels.

[0015] The driver 11 has switching elements 11H and 11L. The switching elements 11H and 11L are connected in series between the power line to which the input voltage Vin is input and the ground (GND) line, with switching element 11H on the high side. The switching elements 11H and 11L may be MOSFETs or IGBTs, for example. The switching elements 11H and 11L may also be bipolar transistors. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. IGBT is an abbreviation for Insulated Gate Bipolar Transistor.

[0016] One end of the inductor 12 is connected to the connection point (midpoint) of the switching elements 11H and 11L. The other end of the inductor 12 is connected to the output line. The inductor 12 is provided individually for each driver 11. The driver 11 and inductor 12 of each phase are connected in parallel with each other. Parallelization can increase the output current from the multiphase power supply 10, i.e., the load current. The number of phases is not particularly limited. The example multiphase power supply 10 has four phases.

[0017] Capacitor 13 is connected to the output line. The positive terminal of capacitor 13 is connected to the output line. The negative terminal of capacitor 13 is connected to ground. Capacitor 13 may be provided individually for each phase, or it may be provided in common for multiple phases. In the example, capacitor 13 is provided for each phase. Providing it for each phase allows the capacitor 13 to be placed closer to the inductor 12, shortening the return path from the capacitor 13. Therefore, emissions can be improved.

[0018] The multiphase power supply 10 may include a control unit (not shown). The control unit performs voltage mode control, for example, by feedback of the output voltage Vout, and controls the operation of the driver 11, i.e., the operation of the switching elements 11H and 11L. The control unit determines the pulse width (duty cycle) of the PWM signal based on the output voltage Vout and controls the output voltage Vout of the multiphase power supply 10. The control unit may perform current mode control instead of voltage mode control.

[0019] The control unit synchronously controls the multiple drivers 11 so that they switch in different phases from each other. By using multiple phases in this way, the switching frequency can be artificially increased even if the switching frequencies of the multiple drivers 11 are the same. This makes it possible to reduce the ripple component of the output voltage Vout and improve responsiveness. The control unit switches the number of drivers 11 to be switched, i.e., the number of drive phases, according to the load current. The control unit compares the load current with the threshold current and increases and / or decreases the number of drive phases according to the comparison result.

[0020] The multiphase power supply 10 may be configured with an inductor component in which multiple inductors 12 are packaged. The example multiphase power supply 10 includes a coupled inductor 12C as the inductor component.

[0021] Figure 2 shows an example of the application of a multiphase power supply. The multiphase power supply 10 described above is applied to, for example, an ECU 15. ECU is an abbreviation for Electronic Control Unit. The ECU 15 may be mounted on, for example, a mobile device. Mobile devices include, for example, vehicles, aircraft, ships, construction machinery, agricultural machinery, etc. Mobile devices may be manned or unmanned.

[0022] The example ECU15 is installed in a vehicle. ECU15 could be, for example, an autonomous driving ECU, or an ADAS ECU that performs controls to assist the driver's driving operations. ADAS is an abbreviation for Advanced Driving Assistant System. For example, levels 3 to 5 as defined by the Society of Automotive Engineers (SAE International) correspond to autonomous driving levels, and levels 1 to 2 correspond to driver assistance levels. ECU15 could also be an infotainment system ECU or a cockpit ECU. A cockpit ECU is an ECU that controls the meter system, navigation system, air conditioning system, etc.

[0023] The ECU 15 includes a primary power supply circuit (1st DC-DC converter) 16, a multi-phase power supply 10 as a secondary power supply circuit (2nd DC-DC converter), and a processor 17. The primary power supply circuit 16 is configured to step down the input voltage to a predetermined voltage for output. The primary power supply circuit 16 is a step-down DC-DC converter. For example, the primary power supply circuit 16 generates a constant voltage (e.g., 5V) lower than the power supply voltage based on the power supplied from the battery (BATT) mounted on the vehicle. The multi-phase power supply 10 uses the voltage generated by the primary power supply circuit 16 as its input voltage Vin. The multi-phase power supply 10 steps down the input voltage Vin to a predetermined voltage (e.g., around 1V) and outputs it as the output voltage Vout.

[0024] The processor 17 is an example of a load that operates by receiving power from the multi-phase power supply 10. The processor 17 is, for example, a CPU or a GPU. CPU is an abbreviation for Central Processing Unit. GPU is an abbreviation for Graphics Processing Unit. The ECU 15 may have only one processor 17 or multiple processors 17. The ECU 15 may have multiple types of processors 17. The processor 17 performs predetermined control processing by executing a control program stored in memory (not shown). Memory is a non-transitory tangible storage medium that non-temporarily stores programs and data that can be read by a computer.

[0025] The core voltage of the processor 17 is around 1V (for example, less than 1V), and the load current is several tens of amperes or more (for example, 100A or more). To handle such low voltage and high current, the ECU 15 employs a multi-phase power supply 10 as its power supply circuit. The multi-phase power supply 10 steps down the input voltage to a voltage corresponding to the core voltage of the processor 17 and outputs it. By using the multi-phase power supply 10, it is possible to accommodate the increased performance of the processor 17 due to improvements in autonomous driving levels and advancements in infotainment functions, and in particular, to support autonomous driving level 3 and above.

[0026] In a high-performance processor 17, the current consumption fluctuates rapidly depending on the calculation process, requiring many capacitors 13 to supply a stable voltage even during sudden load changes. By using coupled inductors 12C, the magnetic fields cancel each other out between phases, reducing the effective inductance value and improving responsiveness during sudden load changes. Therefore, the number of capacitors 13 can be significantly reduced compared to a configuration using a normal single inductor. For example, the size of the ECU 15 can be reduced.

[0027] <Outline configuration of electronic device> Figure 3 is a plan view showing an example of an electronic device. Figure 3 is a magnified view of the area around a coupling inductor within the electronic device. In Figure 3, wiring covered with resist is shown with dashed lines. Figure 4 is a view of Figure 3 with the coupling inductor transparent. For convenience, the resist is omitted in Figure 4. In Figure 4, the outline of the coupling inductor is shown with a dashed line. The terminals of the coupling inductor are also shown with dashed lines.

[0028] As shown in Figures 3 and 4, the electronic device 20 comprises a substrate 30 and several components mounted on the substrate 30. These components include a coupling inductor 40, a switching device 50, and a capacitor 60. The electronic device 20 provides the multi-phase power supply 10 described above. The electronic device 20 may also provide an ECU 15. In this case, elements of the processor 17 and the primary power supply circuit 16 are also mounted on the substrate 30. The electronic device 20 may also include a housing that accommodates other components constituting the electronic device 20.

[0029] In the following, the thickness direction of the substrate is referred to as the Z direction. The direction perpendicular to the Z direction and in which multiple coils are arranged is referred to as the X direction. The direction perpendicular to both the Z and X directions is referred to as the Y direction. Unless otherwise specified, the shape viewed from the Z direction, in other words, the shape along the XY plane defined by the X and Y directions, is referred to as the planar shape. The view from the Z direction is sometimes simply referred to as the planar view.

[0030] The substrate 30 is sometimes referred to as a printed circuit board, printed wiring board, or wiring board. The substrate 30 has an insulating substrate 31, a resist 32, and a conductor 33. The insulating substrate 31 is formed using an electrical insulating material such as resin. The resist 32 is a so-called solder resist. In the Z direction, the resist 32 covers the side of the insulating substrate 31 to which components are soldered. In the example electronic device 20, the coupling inductor 40, the switching device 50, and the capacitor 60 are arranged on one side 30a of the substrate 30. The resist 32 is arranged on the insulating substrate 31 on at least one side 30a.

[0031] The conductor 33 is arranged on the insulating substrate 31. At least a portion of the conductor 33 forms a circuit together with components mounted on the substrate 30. The conductor 33 has wiring 34. The wiring 34 is formed, for example, by patterning metal foil. The wiring 34 is arranged on the surface layer on at least one side 30a. In addition to the surface layer on the one side 30a, the wiring 34 may also be arranged on the surface layer on the back side, or it may be arranged inside the insulating substrate 31. The substrate 30 may be a single-sided substrate, a double-sided substrate, or a multilayer substrate including three or more layers of wiring. The conductor 33 may have, for example, via conductors. Via conductors are formed by placing a conductor, such as plating, in through holes (vias) formed in the insulating layer constituting the insulating substrate 31. Via conductors electrically connect wiring 34 in different layers.

[0032] The example substrate 30 is a multilayer substrate. The wiring 34 includes wirings 341, 342, 343, and 344 arranged on the surface layer on one side 30a. Wiring 341 electrically connects the inductor 401 (coil 42) and the switching device 50. Wiring 341 is provided for each inductor 401. The example wiring 341 extends in the Y direction. Multiple wirings 341 are aligned in the X direction.

[0033] Wiring 342 electrically connects the inductor 401 (coil 42) and the capacitor 60. Wiring 342 is provided for each inductor 401. The example wiring 342 extends in the Y direction. Multiple wirings 342 are aligned in the X direction. Wiring 342 is located at a distance from wiring 341 in the Y direction. The coupled inductor 40 is located between wiring 342 and wiring 341 in the Y direction.

[0034] Wire 343 is a ground wire. The ground wire provides a ground potential, which is the reference potential on the substrate 30. Wire 343 is electrically connected to the inner layer ground wire, for example, via a via conductor (not shown). Wire 343 is located between adjacent wires 342. Wires 344 and 343 are arranged alternately in the X direction. Wire 34 contains three wires 343.

[0035] Wiring 344 electrically connects the inductor 401 and capacitor 60 to the output terminal of the multiphase power supply 10. Wirings 344 and 342 are aligned in the Y direction. One wire 344 is connected to multiple wires 342. Wiring 344 is a common wire for multiple wires 342. Multiple wires 342 are connected to the same wire 344.

[0036] The conductor 33 has lands 35 and 36. The lands 35 and 36 are portions of the wiring 34 that are exposed from the resist 32 so that they can be soldered to components. The lands 35 and 36 are located on the surface layer of one side 30a of the insulating substrate 31 and provide wiring functionality. The lands 35 and 36 may have an over-resist structure in which their outer edges are covered by the resist 32, or they may have a resist-normal resist structure in which their outer edges are not covered by the resist 32.

[0037] Land 35 is provided corresponding to the coil 42 of the coupled inductor 40. Land 35 includes lands 351 and 352. Land 351 is provided at the end of wiring 341 on the coupled inductor 40 side. Land 352 is provided at the end of wiring 342 on the coupled inductor 40 side. Land 351 is located at a distance from land 352 in the Y direction. Terminal 421 of the coil 42 is soldered to land 351, and terminal 422 is soldered to land 352.

[0038] The example substrate 30 has a total of eight lands 35, including four lands 351 and four lands 352. The four lands 351 are aligned in the X direction. The four lands 352 are aligned in the X direction. The lands 351 and 352 that are soldered to the same coil 42 are offset in the X direction. The lands 351 and 352 are arranged alternately in the X direction. The lands 351 and 352 that are adjacent in the X direction have a small gap between them, or are arranged so that there is no gap between them.

[0039] Land 36 is provided corresponding to capacitor 60. Land 36 includes lands 361 and 362. Land 361 is provided at the X-direction end of wiring 342. Land 362 is provided at the X-direction end of wiring 343. Lands 361 and 362 are provided so as to face each other in the X-direction. The positive terminal of capacitor 60 is soldered to land 361, and the negative terminal is soldered to land 362. In the example substrate 30, the lands 36 are aligned in the X-direction. The substrate 30 has a support portion 37. The support portion 37 will be described later.

[0040] The coupled inductor 40 is located on one side 30a of the substrate 30. The coupled inductor 40 provides the coupled inductor 12C described above. The coupled inductor 40 is an inductor component comprising a core 41 and a plurality of coils 42. The exemplary coupled inductor 40 comprises four coils 42. The plurality of coils 42 are aligned in the X direction. The coupled inductor 40 comprises four inductors 401. One end of each coil 42 is soldered to a land 351, and the other end of each coil 42 is soldered to a land 352. Details of the structure of the coupled inductor 40 will be described later.

[0041] The switching device 50 provides the driver 11 described above, i.e., the switching elements 11H and 11L. The switching device 50 is provided in correspondence with the coil 42, i.e., the inductor 401. The example switching device 50 constitutes the switching elements 11H and 11L for one phase. One switching device 50 constitutes the driver 11 for one phase. The switching device 50 may also be a semiconductor package containing multiple semiconductor elements. Alternatively, a switching device 50 may be provided for each switching element 11H and 11L. Multiple switching devices 50 are arranged in the X direction. The switching devices 50 and the coupled inductor 40 are arranged in the Y direction. The switching device 50 is soldered to a land (not shown) provided at the end of the wiring 341 on the switching device 50 side.

[0042] Capacitor 60 provides the capacitor 13 described above. Capacitor 60 is, for example, a chip capacitor. In the Y direction, a coupling inductor 40 is arranged between capacitor 60 and the switching device 50. The positive terminal of capacitor 60 is soldered to land 361, and the negative terminal is soldered to land 362. Multiple example capacitors 60 are provided for each inductor 401. Multiple capacitors 60 are arranged to bridge adjacent wirings 342 and 343. Capacitors 60 corresponding to one inductor 401 are arranged in a capacitor row in the Y direction. Capacitors 60 corresponding to one inductor 401 are, for example, arranged in multiple capacitor rows. Multiple capacitor rows are arranged in the X direction.

[0043] <Coupled Inductor> Figure 5 is a perspective view of the coupled inductor. Figure 6 is a plan view of the coupled inductor seen from above. Figure 7 is a plan view of the coupled inductor seen from below. In Figure 7, the boundary between the mounted and unmounted parts is indicated by a dashed line. Figure 8 is a perspective view of the core. Figure 9 is a perspective view of the coil.

[0044] As shown in Figures 3 to 9, one coupled inductor 40 provides multiple inductors 401. The coupled inductor 40 comprises a core 41 and multiple coils 42. The multiple coils 42 are arranged on a single core 41, that is, a common core 41, and are magnetically coupled to one another. By using the coupled inductor 40, the magnetic flux between phases cancels each other out, making it possible to reduce the effective inductance.

[0045] The core 41 is formed using a magnetic material such as ferrite. The core 41 functions as a magnetic circuit. The core 41 has a plurality of core portions 411 and ends 412, 413. The coil 42 is inserted through the core 41. The core portions 411 are individually provided for the coil 42. The coil 42 is wound around the core portions 411. The core portions 411 extend in the Y direction. The plurality of core portions 411 are arranged in the X direction with predetermined intervals. The example core 41 has four core portions 411. Each core portion 411 is substantially rectangular parallelepiped in shape. The four core portions 411 have the same shape as each other. End 412 corresponds to the first end, and end 413 corresponds to the second end.

[0046] The core portion 411 has an upper surface 411a, a lower surface 411b, and side surfaces 411c and 411d. The lower surface 411b is the surface facing the substrate 30 in the Z direction. The upper surface 411a is the surface opposite to the lower surface 411b in the Z direction. The side surface 411c is the surface opposite to the side surface 411d in the X direction.

[0047] Ends 412 and 413 are positioned opposite each other in the Y direction. Ends 412 and 413 have a core portion 411 in between them. Ends 412 and 413 extend in the X direction, which is the direction in which the multiple core portions 411 are aligned. One end of the multiple core portions 411 is connected to end 412, and the other end of the multiple core portions 411 is connected to end 413. Ends 412 and 413 magnetically connect the multiple core portions 411. The example ends 412 and 413 have the same shape as each other. Ends 412 and 413 are approximately rectangular parallelepipeds with the X direction as their longitudinal direction.

[0048] End portion 412 has an upper surface 412a, a lower surface 412b, and side surfaces 412c, 412d, 412e, and 412f. End portion 413 has an upper surface 413a, a lower surface 413b, and side surfaces 413c, 413d, 413e, and 413f. The lower surfaces 412b and 413b are the surfaces facing the substrate 30 in the Z direction. The upper surfaces 412a and 413a are the surfaces opposite to the lower surfaces 412b and 413b in the Z direction. The side surfaces 412c and 413c are the surfaces opposite to the side surfaces 412d and 413d in the X direction. Side surfaces 412e and 413e are surfaces facing each other in the Y direction. Side surfaces 412f and 413f are the surfaces opposite to the side surfaces 412e and 413e in the Y direction.

[0049] In the example core 41, the lower surfaces 411b, 412b, and 413b are nearly flush. The upper surfaces 412a and 413a are further away from the substrate 30 than the upper surface 411a. The upper surfaces 411a, 412a, and 413a are also close to the substrate 30.

[0050] The coil 42 is formed using a metal material with good conductivity, such as copper. The coil 42 is formed by processing a metal sheet, not a metal wire. The metal sheet is sometimes referred to as a metal frame. Multiple coils 42 are formed from the same material and have the same shape. Multiple coils 42 have approximately equal inductance. Multiple coils 42 are arranged in the X direction with a predetermined spacing. Multiple coils 42 are arranged in the same orientation. The coils 42 are fixed to the core 41, for example, by adhesive.

[0051] The coil 42 is formed by bending a metal sheet material having a predetermined thickness. The coil 42 has terminals 421, 422, side walls 423, 424, and an upper wall 425. Terminals 421 and 422 are external connection terminals in the coil 42 and are soldered to the corresponding lands 35. Terminal 421 is soldered to land 351, and terminal 422 is soldered to land 352.

[0052] The thickness direction of terminals 421 and 422 is approximately parallel to the Z direction, and one of the surfaces of terminals 421 and 422, the bottom surface, faces one surface 30a of the substrate 30. Terminals 421 and 422 extend in the Y direction. The example terminals 421 and 422 have a planar shape that is approximately rectangular with the Y direction as the longitudinal direction. Terminals 421 and 422 are arranged in the X direction with a predetermined interval. A part of the side surface of terminal 421 and a part of the side surface of terminal 422 face each other in the X direction. Terminal 421 extends from the part facing terminal 422 in the Y direction to the side surface 412f, i.e., towards the switching device 50. Terminal 422 extends from the part facing terminal 421 in the Y direction to the side surface 413f, i.e., towards the capacitor 60. Terminals 421 and 422 are positioned offset in the Y direction such that at least a portion of the unmounted portions 421b and 422b, described later, face each other in the X direction.

[0053] Terminal 421 has a mounting portion 421a and a non-mounting portion 421b. The mounting portion 421a is the portion that overlaps with the corresponding land 351 in a plan view. The mounting portion 421a is the portion that is soldered to the land 351. The non-mounting portion 421b is the portion of terminal 421 excluding the mounting portion 421a. The non-mounting portion 421b is positioned so as to overlap with the core 41 in a plan view. In a plan view, the entire non-mounting portion 421b is located directly below the core 41. In the example coil 42, the entire terminal 421 is located directly below the core 41 in a plan view. The mounting portion 421a may include the portion located directly below the core 41 and the portion located outside the core 41.

[0054] Similarly, terminal 422 has a mounted portion 422a and an unmounted portion 422b. The mounted portion 422a is the portion that overlaps with the corresponding land 352 in a plan view. The mounted portion 422a is soldered to the land 352. The unmounted portion 422b is the portion of terminal 422 excluding the mounted portion 422a. The unmounted portion 422b is positioned to overlap with the core 41 in a plan view. In a plan view, the entire unmounted portion 422b is located directly below the core 41. The unmounted portions 422b and 421b are arranged alternately with a predetermined interval in the X direction. In the example coil 42, the entire terminal 422 is located directly below the core 41 in a plan view. The mounted portion 422a may include the portion located directly below the core 41 and the portion located outside the core 41.

[0055] Side wall 423 is connected to the portion of terminal 421 facing terminal 422, i.e., the unmounted portion 421b. Side wall 423 is bent at an angle of approximately 90 degrees with respect to terminal 421. The thickness direction of side wall 423 is approximately parallel to the X direction. Side wall 423 has a width equal to the length of the opposing portions of terminals 421 and 422 and extends in the Z direction. Similarly, side wall 424 is connected to the portion of terminal 422 facing terminal 421, i.e., the unmounted portion 422b. Side wall 424 is bent at an angle of approximately 90 degrees with respect to terminal 422. The thickness direction of side wall 424 is approximately parallel to the X direction. Side wall 424 has a width equal to the length of the opposing portions of terminals 421 and 422 and extends in the Z direction, the same direction as side wall 423. The lower ends of the side walls 423 and 424 are connected to terminals 421 and 422.

[0056] The upper wall 425 bridges the side walls 423 and 424. The upper wall 425 extends in the X direction. One end of the upper wall 425 connects to the upper end of the side wall 423, and the other end connects to the upper end of the side wall 424. The upper wall 425 has the same width as the side walls 423 and 424. In plan view, the upper wall 425 encompasses the entire area of ​​the side walls 423 and 424, and the opposing portions of the terminals 421 and 422.

[0057] The opposing portions of terminals 421 and 422, the side walls 423 and 424, and the top wall 425 surround the core portion 411 of the core 41. The opposing portions of terminals 421 and 422, the side walls 423 and 424, and the top wall 425 are attached to and wound around the core portion 411. The portions excluding the opposing portions of terminals 421 and 422, i.e., the extended portions, are where the ends 412 and 413 of the core 41 are located. Terminals 421 and 422 include portions located closer to the substrate 30 than the lower surfaces 411b, 412b, and 413b of the core 41. The lower surfaces of terminals 421 and 422 are located closer to 30a than the lower surfaces 411b, 412b, and 413b of the core 41.

[0058] In adjacent coils 42, one side wall 423 of coil 42 faces the other side wall 424 of coil 42. In the illustrated coupled inductor 40, the outer surface of the side wall 423 located at one end of the coupled inductor 40 is offset relative to the sides 412c and 413c such that it is recessed into the sides 412c and 413c. Similarly, the outer surface of the side wall 424 located at the other end of the coupled inductor 40 is offset relative to the sides 412d and 413d such that it is recessed into the sides 412d and 413d. The upper surface of the upper wall 425 of coil 42 is offset relative to the upper surfaces 412a and 413a such that it is recessed into the upper surfaces 412a and 413a.

[0059] For example, the outer surface of the side wall 423 at one end may be made substantially flush with the sides 412c and 413c. The outer surface of the side wall 424 at the other end may be made substantially flush with the sides 412d and 413d. The upper surface of the upper wall 425 may be made substantially flush with the upper surfaces 412a and 413a.

[0060] The coupled inductor 40 may include a cover in addition to the core 41 and the plurality of coils 42. The illustrated coupled inductor 40 includes a cover 43. The cover 43 is positioned on the top surface of the core 41 and covers the core 41 and the plurality of coils 42. The cover 43 is used, for example, to suppress the adhesion of foreign matter to the coupled inductor 40. The cover 43 is used, for example, to suppress short circuits between the coils 42 due to conductive foreign matter. The cover 43 is used, for example, to improve the suction during transport when mounting the coupled inductor 40 to the substrate 30.

[0061] The constituent material of the cover 43 is not particularly limited as long as the above objective can be achieved. For example, it may be a resin or a magnetic material. The cover 43 may be made of the same material as the core 41. The cover 43 may function as part of the core 41. The illustrated cover 43 is a resin film or resin sheet. The cover 43 has a substantially rectangular shape in plan with the X direction as its longitudinal direction. The cover 43 is provided so as to enclose the core 41 and a plurality of coils 42 in plan view. The cover 43 is adhesively fixed to the upper surfaces 412a, 413a of the ends 412, 413.

[0062] <Support structure and mounting structure> Figure 10 is a cross-sectional view along line XX in Figure 3. Figure 10 shows the support structure of the coupled inductor by the support part. Figure 11 is a cross-sectional view along line XI-XI in Figure 3. Figure 11 shows the mounting structure of the coupled inductor in the state supported by the support part.

[0063] As shown in Figures 4 and 10, the substrate 30 has at least one support portion 37. The support portion 37 is provided so as to overlap with a portion of the unmounted portions 421b and 422b of the terminals 421 and 422 in a plan view. The support portion 37 protrudes toward the coupled inductor 40 relative to the land 35. On one surface 30a, the support portion 37 protrudes toward the peripheral portion of the support portion 37. The support portion 37 is a protrusion provided directly beneath the unmounted portions 421b and 422b. The support portion 37 supports the coupled inductor 40 via the unmounted portions 421b and 422b.

[0064] The illustrated electronic device 20 has only one support portion 37. The support portion 37 consists of a support conductor 371 and a resist 372. The support conductor 371 is located on the surface layer of the insulating substrate 31 on one side 30a, away from the lands 35. The resist 372 covers the support conductor 371. The resist 372 is a part of the resist 32. The support conductor 371 is electrically isolated from all the lands 35 joined to the coil 42. The support conductor 371 is a conductor 33 that does not constitute a circuit, that is, does not provide wiring functionality. The support conductor 371 is substantially rectangular in plan view. The support conductor 371 is positioned to overlap with a part of one unmounted portion 422b. The support conductor 371 is positioned to overlap with the unmounted portion 422b closest to the center of the coupled inductor 40 in the longitudinal direction (X direction). The support conductor 371 is positioned such that the center of the short-side (Y-direction) of the coupled inductor 40 and the center of the support conductor 371 substantially coincide.

[0065] The support portion 37 contacts the lower surface of the unmounted portion 422b of the terminal 422, supporting the coupled inductor 40. This ensures a ventilated gap directly below the coupled inductor 40 between the portions of the unmounted portions 421b and 422b excluding those supported by the support portion 37 and one surface 30a of the substrate 30. An even larger gap is ensured between the lower surfaces 411b, 412b, and 413b of the core 41, which is located above the lower surfaces of the terminals 421 and 422, and one surface 30a of the substrate 30. Note that the portions of the unmounted portions 421b and 422b excluding those supported by the support portion 37 include the portions of the unmounted portions 421b and 422b that the support portion 37 does not contact, and the portions of the unmounted portion 422b that the support portion 37 does contact.

[0066] As shown in Figure 11, the electronic device 20 is equipped with solder 70. The solder 70 connects the terminals 421 and 422 of the coil 42 to the corresponding lands 35. The solder 70 is interposed between the mounting portion 421a of terminal 421 and the land 351, connecting terminal 421 and land 351. The solder 70 is interposed between the mounting portion 422a of terminal 422 and land 352, connecting terminal 422 and land 352. The coupled inductor 40 is connected to the substrate 30 via the solder 70, that is, mounted on the substrate 30.

[0067] Due to the support structure using the support portion 37, the portions of terminals 421 and 422 that are not supported by the support portion 37 are located away from the surface 30a in the Z direction. A gap is secured between the mounting portions 421a and 422a of terminals 421 and 422a and the corresponding land 35, which is necessary to ensure solder life and connection reliability of the solder 70. The solder 70 has a predetermined thickness necessary to ensure solder life and connection reliability.

[0068] In the connection structure between the substrate 30 and the coupled inductor 40 described above, the current flows in the following order: wiring 341, land 351, terminal 421, side wall 423, top wall 425, side wall 424, terminal 422, land 352, and wiring 342.

[0069] <Summary of the First Embodiment> Figure 12 is a plan view showing a reference example. Figure 12 corresponds to Figure 4. In Figure 12, the coupled inductor is shown transparently. In Figure 12, the resist is omitted. In Figure 12, the outline of the coupled inductor is shown by a dashed line. The terminals of the coupled inductor are also shown by dashed lines. Figure 13 is a cross-sectional view along the line XIII-XIII in Figure 12. Figure 13 corresponds to Figure 10.

[0070] An inductor component having a core 41 and multiple coils 42, such as a coupled inductor 40, provides multiple inductors from a single inductor component. Such an inductor component is heavier than an inductor component that provides one (single) inductor. For this reason, in the case of an electronic device 20R1 in which the substrate 30 does not have a support portion 37, as shown in the reference example in Figures 12 and 13, the coupled inductor 40 sinks in until the terminals 421 and 422 contact the resist 32 during solder reflow 70. The unmounted portions 421b and 422b located directly below the core 41 contact the resist 32, and a space (restricting space) is formed that restricts the movement of gas in the X direction, including the adjacent unmounted portions 421b and 422b and the lower surfaces 411b, 412b, and 413b of the core 41. In this way, the unmounted portions 421b and 422b obstruct ventilation. Therefore, condensation may occur due to the temperature difference between the area directly beneath the coupling inductor 40 and the outside, potentially leading to ion migration of Sn, a component of the solder 70.

[0071] In particular, in the case of the coupled inductor 40, it is necessary to strengthen the magnetic coupling in order to enhance the effect of reducing the effective inductance value, resulting in a structure where the space between adjacent coils 42 and adjacent terminals 421 and 422 is very narrow. As a result, the degree of sealing of the regulated space described above is increased. Furthermore, in the configuration in which the coupled inductor 40 is equipped with a cover 43, the top is also closed by the cover 43, further increasing the degree of sealing of the regulated space. Therefore, ion migration is likely to occur.

[0072] Figure 14 is a cross-sectional view showing another reference example. Figure 14 corresponds to Figure 11. In the case of the electronic device 20R2 in which the support portion 37 is provided in a position that does not overlap with terminals 421 and 422, as shown in the reference example in Figure 14, terminals 421 and 422 are located on the substrate 30 side of the lower surface of the core 41. In other words, because terminals 421 and 422 protrude toward the substrate 30 side, the coupling inductor 40 cannot be supported by the support portion 37. For this reason, similar to the electronic device 20R1 described above, the unmounted portions 421b and 422b located directly below the core 41 obstruct ventilation, and there is a risk that ion migration may occur.

[0073] The electronic device 20 of this embodiment comprises a substrate 30, an inductor component, and solder 70. The inductor component has a core 41 and a plurality of coils 42 arranged on the core 41 in a predetermined direction perpendicular to the thickness direction of the substrate 30. The plurality of coils 42 each have external connection terminals 421, 422 located on the substrate 30 side of the core 41 that faces the substrate 30. The terminals 421, 422 have mounting portions 421a, 422a provided so as to overlap with the corresponding land 35 in a plan view in the thickness direction, and non-mounted portions 421b, 422b which are the portions excluding the mounting portions 421a, 422a and are arranged so as to overlap with the core 41 in a plan view. The substrate 30 is provided so as to overlap with a portion of the non-mounted portion 421b, 422b of at least one terminal 421, 422 in a plan view, and has a support portion 37 that protrudes toward the inductor component side relative to the land 35 and supports the inductor component via the non-mounted portion. In the example electronic device 20, the coupled inductor 40 corresponds to an inductor component. The Z direction corresponds to the plate thickness direction, and the X direction corresponds to a predetermined direction.

[0074] The inductor component can be supported via the unmounted portions 421b and 422b of the terminals 421 and 422 by the support portion 37 provided on the substrate 30 so as to protrude toward the inductor component. Since the support portion 37 is provided so as to overlap with a portion of the unmounted portions 421b and 422b, a gap can be secured between the remaining portion of the unmounted portions 421b and 422b, i.e., the portion that does not overlap with the support portion 37, and the substrate surface, as illustrated in Figure 10. Therefore, obstruction of ventilation can be suppressed, and consequently, ion migration can be suppressed.

[0075] The configuration of the support portion 37 is not particularly limited. As illustrated, the support portion 37 may include a support conductor 371 positioned on one surface of the insulating substrate 31, away from the land 35. This allows the support portion 37 to be formed by the substrate design, thus simplifying the substrate 30. It also simplifies the manufacturing process. For example, it can reduce costs.

[0076] As illustrated, the support portion 37 may include a resist 372 arranged to cover the support conductor 371. Since the support portion 37 including the resist 372 can be formed by the substrate design, the configuration and manufacturing process of the substrate 30 can be further simplified.

[0077] The support conductor 371 may be electrically connected to the lands 35. Alternatively, as illustrated, the support conductor 371 may be electrically isolated from all lands 35 joined to the coil 42. When the support conductor 371 is electrically connected to the lands 35, the area of ​​the lands 35 is substantially increased by the support conductor 371, which may lead to deterioration of coil characteristics due to increased parasitic inductance and deterioration of mountability due to uneven heating of the solder joints during reflow soldering. By electrically isolating the support conductor 371 from all lands 35, the deterioration of coil characteristics and deterioration of mountability described above can be suppressed. The support conductor 371 that is electrically isolated from the lands 35 may be a dummy land that does not provide wiring functionality, or a ground land that provides ground potential.

[0078] As illustrated, the inductor component may be positioned on the side of the core 41 opposite to the side facing the substrate 30, and may have a cover 43 that covers the core 41 and the multiple coils 42. Having the cover 43 helps to suppress the adhesion of foreign matter, for example. For example, it can improve adsorption during reflow transfer. Although the cover 43 creates a closed structure on the upper side of the inductor component, it helps to suppress ion migration.

[0079] <Variation> An example is shown in which the support portion 37 (support conductor 371) is provided so as to overlap with the non-mounted portion 422b closest to the center of the coupled inductor 40 in the longitudinal direction (X direction), but the example is not limited to this. The support portion 37 may also be provided so as to overlap with the non-mounted portion 421b closest to the center of the coupled inductor 40 in the longitudinal direction. In either configuration, the coupled inductor 40 can be stably supported while supporting one non-mounted portion with one support portion 37.

[0080] An example has been shown in which the support portion 37 includes a resist 372, but it is not limited to this. For example, the support portion 37 may be composed of a support conductor 371 exposed from the resist 32 and a metal piece joined to the support conductor 371. To avoid affecting the circuit operation of the coupled inductor 40, the support conductor 371 may be, for example, a dummy land that does not provide wiring functionality, or a ground land that provides ground potential.

[0081] An example of a coupled inductor 40 has been shown as an inductor component, but it is not limited to this. The inductor component is not limited to a configuration in which multiple coils 42 are arranged on a common core 41 and the multiple coils 42 are magnetically coupled. The core 41 may be provided individually for each coil 42. The inductor component may be packaged in a manner in which multiple coils 42 are arranged in a predetermined direction, for example.

[0082] While an example has been shown where one support portion 37 supports one of the terminals 421, 422, the invention is not limited to this. One support portion 37 only needs to support at least one of the terminals 421, 422. For example, one support portion 37 may support multiple terminals 421, 422.

[0083] (Second Embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, one support portion supported one terminal (non-mounted portion). Alternatively, multiple support portions may support multiple terminals.

[0084] Figure 15 is a plan view showing the electronic device according to this embodiment. Figure 15 corresponds to Figure 4. In Figure 15, the coupling inductor is shown transparently. In Figure 15, the resist is omitted. In Figure 15, the outline of the coupling inductor is shown by a dashed line. The terminals of the coupling inductor are shown by a dashed line. In Figure 15, the gas escape route between the support parts is shown by a solid arrow. Figure 16 is a cross-sectional view along the line XVI-XVI in Figure 15.

[0085] In the electronic device 20 shown in Figure 15, the substrate 30 has a plurality of support parts 37. That is, a single coupled inductor 40 is supported by a plurality of support parts 37. The plurality of support parts 37 are arranged in the X direction, which is the direction in which the coils 42 are arranged. In the example electronic device 20, the plurality of support parts 37 are spaced apart in the X direction such that terminals 421 and 422 that do not overlap with the support parts 37 are located between adjacent support parts 37.

[0086] In Figures 15 and 16, the substrate 30 has two support portions 37. One of the support portions 37 supports the unmounted portion 421b of the terminal 421 of the second coil 42 from one end in the X direction. The other support portion 37 supports the unmounted portion 422b of the terminal 422 of the third coil 42 from one end. The terminal 422 of the second coil 42 and the terminal 421 of the third coil 42 are located between the two support portions 37. In the longitudinal direction of the coupled inductor 40, one of the support portions 37 is located on one end side of the center of the coupled inductor 40, and the other support portion 37 is located on the other end side of the center. The rest of the configuration is the same as that described in the prior embodiment.

[0087] <Summary of the second embodiment> As illustrated, the substrate 30 may have a plurality of support portions 37 provided to support a single inductor component. In the illustrated electronic device 20, the coupled inductor 40 corresponds to the inductor component. Because the inductor component is supported by a plurality of support portions 37 arranged along the direction of the coil 42, tilting of the inductor component can be suppressed. In other words, the inductor component can be supported more stably. By suppressing tilting, the space between the inductor component and the substrate 30 becomes partially narrower, which can prevent a decrease in airflow.

[0088] As illustrated, in a configuration in which multiple support parts 37 are arranged in a predetermined direction, adjacent support parts 37 may be arranged apart in a predetermined direction such that terminals 421 and 422 that do not overlap with the support parts 37 are located between adjacent support parts 37. This makes it possible to more effectively suppress the tilting of the inductor component. In addition, since the space between the support parts 37 is widened, numerous escape routes for gas (air) from this space can be secured, as illustrated by the solid arrows in Figure 15. Therefore, even if multiple support parts 37 are provided, ventilation will not be obstructed.

[0089] <Variation> The configuration described in this embodiment can be combined with the configurations described in the prior embodiments and modified examples.

[0090] The arrangement of the multiple support parts 37 is not limited to the example described above. Support parts 37 may be provided directly below adjacent terminals 421 and 422. Considering ventilation, it is preferable to arrange the support parts 37 so that at least one terminal is located between adjacent support parts 37.

[0091] The number of support parts 37 is not limited to two. Three or more support parts 37 may be provided on the substrate 30.

[0092] (Third embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, multiple terminals were supported by multiple support parts. In addition, the effect of substrate strain acting on the solder may be suppressed.

[0093] Figure 17 is a plan view showing the electronic device according to this embodiment. Figure 17 corresponds to Figure 4. In Figure 17, the coupling inductor is shown transparently. In Figure 17, the resist is omitted. In Figure 17, the outline of the coupling inductor is shown by a dashed line. The terminals of the coupling inductor are shown by a dashed line. Figure 18 is a cross-sectional view along the line XVIII-XVIII in Figure 17.

[0094] The substrate 30 of the electronic device 20 shown in Figure 17 also has a plurality of support portions 37. The plurality of support portions 37 are arranged in the X direction, which is the direction in which the coils 42 are arranged. The exemplary substrate 30 has two support portions 37. The two support portions 37 are provided directly below the terminals 421 and 422 located at both ends. One of the support portions 37 is provided so as to overlap with a portion of the unmounted portion 421b of terminal 421 located at the end on the side surfaces 412c and 413c. The other support portion 37 is provided so as to overlap with a portion of the unmounted portion 421b of terminal 422 located at the end on the side surfaces 412d and 413d. The other configuration is the same as the configuration described in the prior embodiment.

[0095] <Summary of the third embodiment> Figure 19 shows the effect of substrate distortion in a reference example. In the electronic device 20R3 shown in Figure 19, the substrate 30 does not have a support portion 37. The coupling inductor 40 has four coils 42 (not shown) arranged in the X direction, similar to the electronic device 20. The longer the coupling inductor 40 is in the X direction, the greater the number of coils 42. For example, if substrate distortion (warping) occurs in the ZX plane such that the edges of the substrate move away from the center of the substrate, stress due to the substrate distortion acts on the solder 70. The stress acting on the solder 70 is greater the closer it is to the ends of the coupling inductor 40, that is, the ends of the multiple coils 42. Therefore, the connection reliability of the solder 70 near the ends decreases.

[0096] In this embodiment, multiple support portions 37 are provided directly below the coils 42 located at both ends in a predetermined direction. The X direction corresponds to the predetermined direction. By arranging the support portions 37 at both ends in this way, and supporting the end positions where the influence of substrate distortion is significant, the stress acting on the solder 70 joining the terminals 421, 422 at both ends to the corresponding lands 35 can be reduced. Therefore, in addition to the effects described in the prior embodiment, solder life and connection reliability can be further improved.

[0097] <Variation> The configuration described in this embodiment can be combined with the configurations described in the first embodiment and its modifications, and the configurations described in the second embodiment and its modifications.

[0098] The arrangement of the multiple support parts 37 is not limited to directly below the ends. For example, as shown in Figures 15 and 16, the multiple support parts 37 may be provided directly below a coil 42 that is positioned closer to the end of the inductor component than to the center of the inductor component in a predetermined direction (X direction). As described above, the stress acting on the solder 70 is greater the closer it is to both ends of the multiple coils 42, so by providing the support parts 37 directly below the coils 42 that are closer to the ends than to the center, the stress acting on the solder 70 can be alleviated.

[0099] (Fourth Embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, the core was not divided. Alternatively, the core may be divided into multiple parts.

[0100] Figure 20 is a plan view of the coupled inductor in the electronic device according to this embodiment, viewed from the bottom. Figure 20 corresponds to Figure 7. For convenience, the cover 43 is omitted in Figure 20. In the coupled inductor 40 of this embodiment, the core portion 411 of the core 41 is divided into multiple parts. The core portion 411 is divided into multiple parts in the opposing direction (Y direction) of the ends 412 and 413. The example core portion 411 is divided at the center position in the Y direction. The core portion 411 includes core portion 4111 and core portion 4112.

[0101] The core portion 4111 is connected to the end portion 412. The core portion 4111 extends from the side surface 412e of the end portion 412 toward the end portion 413. The core portion 4112 is connected to the end portion 413. The core portion 4112 extends from the side surface 413e of the end portion 413 toward the end portion 412. The core 41 has a gap 411g between the opposing surfaces of the core portions 4111 and 4112, where no magnetic member is placed. For example, adhesive is placed in the gap 411g to fix the core portions 4111 and 4112. The distance between the dashed lines shown in Figure 20 indicates the width of the gap 411g.

[0102] The division point is not limited to the center. A single core 411 may be connected to one of the ends 412, 413 and bonded to the other. The ends of a single core 411 may be bonded to the respective ends 412, 413. The core 411 may be divided into three or more parts.

[0103] Figure 21 shows a reference example in which the core portion 411 of the core 41 is divided and does not have a support portion 37. In Figure 21, an example is shown in which the coupled inductor 40 has two core portions 411, i.e., two coils 42. In Figure 21, only the lands 35 of the substrate 30 are shown. Also, only the terminals 421 and 422 of the core 41 and coil 42 of the coupled inductor 40 are shown. Figure 22 is a cross-sectional view along the line XXII-XXII in Figure 21. The dashed arrows shown in Figures 21 and 22 indicate leakage flux.

[0104] In Figure 21, the magnetic flux path when current flows from land 351 to 352 through one of the coils 42 in the reference example electronic device 20R4 is shown by a solid arrow. The two core portions 411 are connected to ends 412 and 413, and when current flows through one of the coils 42, a loop-shaped magnetic flux path is formed through the core portion 411 around which the other coil 42 is wound. At this time, due to the presence of a gap 411g, magnetic flux leaks from the gap 411g as shown in Figures 21 and 22. The coil 42 is wound around the core portion 411. However, there is no coil 42 (conductor) in the region between terminals 421 and 422. Therefore, magnetic flux is particularly prone to leaking from the overlapping area between the gap 411g and the region between terminals 421 and 422. Leakage flux worsens emissions.

[0105] Figure 23 shows the arrangement of the core gap, coil terminals, and support parts in the electronic device according to this embodiment. In Figure 23, only the lands 35 of the substrate 30 are shown. Also, only the core 41 and the terminals 421 and 422 of the coil 42 of the coupled inductor 40 are shown. Figure 24 is a cross-sectional view of the electronic device corresponding to line XXIV-XXIV in Figure 23.

[0106] Similar to the prior embodiment, the electronic device 20 has a support portion 37 including a support conductor 371. The support portion 37 is provided so as to overlap with at least one of the plurality of core portions 411 in a plan view. The support portion 37 is provided so as to overlap with at least a portion of the gap 411g in one of the core portions 411.

[0107] In the illustrated electronic device 20, the substrate 30 has four support conductors 371 (support portions 37). Each support portion 37 is composed of a support conductor 371 and a resist 372. A support portion 37 is provided individually for each coil 42. A support portion 37 is provided individually for each core portion 411. In each support portion 37, the support conductor 371 is positioned in the area where the gap 411g of the corresponding core portion 411 overlaps with the area between terminals 421 and 422 of the corresponding coil 42. The support conductor 371 is positioned to overlap with the entire gap 411g of the corresponding core portion 411. The support conductor 371 is positioned to overlap with the entire gap 411g in all core portions 411. Since the support conductor 371 is located directly below the gap 411g, leakage of magnetic flux from the gap 411g can be suppressed. The other configurations are the same as those described in the prior embodiment.

[0108] <Summary of the fourth embodiment> As illustrated, the core portion 411 of the core 41 of the coupled inductor 40 may be divided into multiple parts, and the core portion 411 may have gaps 411g. The support portion 37 may be arranged so as to overlap at least a part of the gaps 411g in a plan view. In this case, the support portion 37, which is positioned opposite the gaps 411g, can suppress magnetic flux leakage from the gaps 411g. By providing the support portion 37, magnetic flux leakage can be suppressed compared to a configuration without the support portion 37, i.e., a configuration in which air is present. In particular, the effect can be enhanced by arranging the support conductor 371 so as to face the gaps 411g.

[0109] As illustrated, the support portion 37 may be positioned in the portion of the gap 411g that overlaps with the area between the first and second terminals of the coil 42 in a plan view. In the illustrated electronic device 20, one of the terminals 421 and 422 corresponds to the first terminal, and the other terminal 421 and 422 corresponds to the second terminal. The conductor constituting the coil 42 is wound around the core portion 411. However, the first and second terminals are positioned with a predetermined distance between them. Therefore, magnetic flux is prone to leaking from the portion of the gap 411g that overlaps with the area between the first and second terminals. By positioning the support portion 37 in the portion of the gap 411g that overlaps with the area between the first and second terminals, magnetic flux leakage can be effectively suppressed.

[0110] As illustrated, the support portion 37 may be positioned to overlap the entire gap 411g in one core portion 411. By positioning the support portion 37 to face the entire area of ​​the gap 411g, magnetic flux leakage can be suppressed more reliably.

[0111] As illustrated, the support portion 37 may be positioned to overlap with at least a portion of each of the gaps 411g between the multiple core portions 411. By positioning the support portion 37 opposite to all of the multiple gaps 411g, leakage flux can be suppressed across the entire coupled inductor 40.

[0112] <Variation> The configuration described in this embodiment can be combined with the configuration described in the first embodiment and its modified form, the configuration described in the second embodiment and its modified form, and the configuration described in the third embodiment and its modified form.

[0113] The arrangement of the support portion 37 (support conductor 371) is not limited to the example described above. The support portion 37 may be provided for one of the multiple core portions 411. As shown in Figure 25, the support portion 37 may be provided for two of the four core portions 411. Although not shown, the support portion 37 may be provided for three of the four core portions 411.

[0114] The support portion 37 should be positioned so as to overlap at least a part of the gap 411g in a plan view. The support portion 37 may also be positioned in a part of the gap 411g that does not overlap with the area between the first terminal and the second terminal. As shown in Figure 25, the support portion 37 may also be positioned opposite a part of the gap 411g, including the part of the gap 411g that overlaps with the area between the first terminal and the second terminal.

[0115] An example has been shown in which one support portion 37 (support conductor 371) is provided for one core portion 411, but the invention is not limited to this. For example, as shown in Figure 26, one support portion 37 may be arranged for four core portions 411. In Figure 26, one support portion 37 (support conductor 371) is arranged so as to overlap all of the gaps 411g between the four core portions 411. The support conductor 371, like the coupled inductor 40, has a roughly rectangular shape in plan with the X direction, which is the direction in which the coils 42 are arranged, as its longitudinal direction.

[0116] (Fifth embodiment) This embodiment is a modification based on the prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, a support conductor was provided separately from the wiring that electrically connects the capacitor and the switching device. Alternatively, the support conductor may be provided as part of the wiring that electrically connects the capacitor and the switching device.

[0117] Figure 27 is a plan view showing the electronic device according to this embodiment. Figure 27 corresponds to Figure 4. In Figure 27, the coupling inductor is shown transparently. In Figure 27, the resist is omitted. In Figure 27, the outline of the coupling inductor is shown by a dashed line. The terminals of the coupling inductor are shown by a dashed line.

[0118] The substrate 30 includes wiring 343 arranged on the surface layer of one side 30a of the insulating substrate 31. The wiring 343 extends generally in the Y direction. The wiring 343 electrically connects the ground terminal of the capacitor 60 to a ground terminal (not shown) of the switching device 50. The wiring 343 is a ground wire. The wiring 343 crosses the coupled inductor 40 in the Y direction. In a plan view, the wiring 343 is positioned to overlap with at least one of the unmounted portions 421b, 422b of the terminals 421, 422. The portion of the wiring 343 that overlaps with the unmounted portions 421b, 422b of the terminals 421, 422 functions as a support conductor 371. The support portion 37 is composed of, for example, a support conductor 371 and a resist 372. The capacitor 60 is connected near one end of the wiring 343, and the switching device 50 is connected near the other end.

[0119] The illustrated substrate 30 has three wirings 343. All three wirings 343 cross the coupled inductor 40. A support conductor 371, which is part of the wiring 343, is positioned to overlap with two terminals 421 and 422 that are adjacent to each other in a plan view. The substrate 30 has three support conductors 371 (support portions 37). One support conductor 371 includes a portion that extends in the X direction so as to overlap one unmounted portion 421b of terminal 421 and one unmounted portion 422b of terminal 422. The other configurations are the same as those described in the prior embodiment.

[0120] <Summary of the Fifth Embodiment> As illustrated, an inductor component may be placed between the switching device 50 and the capacitor 60 in an orthogonal direction perpendicular to both the plate thickness direction and the predetermined direction. In this arrangement, the ground wiring that electrically connects the capacitor 60 and the switching device 50 may be used as the support conductor 371. In the illustrated electronic device 20, the Z direction corresponds to the plate thickness direction, the X direction corresponds to the predetermined direction, and the Y direction corresponds to the orthogonal direction. The coupled inductor 40 corresponds to the inductor component, and the wiring 343 corresponds to the ground wiring.

[0121] In this configuration, the ground wiring is placed directly beneath the inductor component, and a portion of the ground wiring is used as a support conductor 371. This shortens the return path from the capacitor 60 to the switching device 50, thereby reducing emissions. Thus, emissions can be reduced while suppressing ion migration. In particular, in the configuration shown in Figure 27, the capacitor 60 and the switching device 50 are electrically connected only by wiring 343 located on the surface layer of one side 30a, further shortening the return path and effectively reducing emissions.

[0122] <Variation> The configuration in which a portion of the ground wiring electrically connecting the capacitor 60 and the switching device 50 is supported by a support conductor 371 is not limited to the example described above. The inner layer wiring disposed inside the insulating substrate 31 may also be included as part of the ground wiring electrically connecting the capacitor 60 and the switching device 50. The inner layer wiring is connected to the surface layer wiring via via conductors. Of the ground wiring electrically connecting the capacitor 60 and the switching device 50, for example, only the island-shaped wiring 343 and the support conductor 371 illustrated in Figure 4 may be surface layer wiring, and the remaining portion may be inner layer wiring.

[0123] As shown in Figure 28, the wiring 342 may have a connecting portion 342F that connects multiple wirings 342 between land 352 and land 361. By connecting the wiring 342 between phases with the connecting portion 342F, the capacitor 60 can be utilized across phases. This makes it possible to reduce the number of capacitors 60 while placing them near the coupled inductor 40. In Figure 28, in order to avoid the connecting portion 342F, a portion of the wiring 343 shown in Figure 27 is replaced with wiring 345 located in the inner layer. This shortens the turn path and reduces emissions.

[0124] (Other embodiments) The disclosures in this specification and drawings are not limited to the exemplary embodiments. The disclosures include the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to combinations of parts and / or elements shown in the embodiments. The disclosures are implementable in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures include those in which parts and / or elements of the embodiments have been omitted. The disclosures include substitutions or combinations of parts and / or elements between one embodiment and another. The scope of the disclosed technical areas is not limited to the descriptions of the embodiments. Some of the scope of the disclosed technical areas are indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.

[0125] The disclosures in the specification and drawings are not limited by the claims. The disclosures in the specification and drawings encompass the technical ideas described in the claims and extend to a wider and more diverse range of technical ideas than those described in the claims. Therefore, a variety of technical ideas can be extracted from the disclosures in the specification and drawings without being bound by the claims.

[0126] When an element or layer is referred to as “on top of,” “connected to,” “linked to,” or “joined,” it may be directly on top of, connected to, or joined to another element or layer, and there may also be an intervening element or layer. In contrast, when an element is referred to as “directly on top of,” “directly connected to,” “directly linked to,” or “directly joined to” another element or layer, there is no intervening element or layer. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used in this specification, the term “and / or” includes any combination and all combinations relating to one or more of the enumerated items relating to each other. That is, the statement A and / or B means at least one of A and B.

[0127] Spatially relative terms such as "inside," "outside," "back," "below," "low," "above," and "high" are used here to facilitate descriptions of the relationship between one element or feature and other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned upside down, an element described as "below" or "directly below" another element or feature will be oriented "above" the other element or feature. Thus, the term "below" can encompass both up and down orientations. The device may also be oriented in other directions (it may be rotated 90 degrees or in other directions), and the spatially relative descriptors used in this specification will be interpreted accordingly.

[0128] (Disclosure of technical ideas) This specification discloses several technical concepts, as listed in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, referring to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical concepts.

[0129] <Technical philosophy 1> A substrate (30) having an insulating substrate (31) and a plurality of lands (35) arranged on one surface of the insulating substrate, An inductor component (40) having a core (41) and a plurality of coils (42) arranged on the core and aligned in a predetermined direction perpendicular to the thickness direction of the substrate, A solder (70) that joins the coil and the land, Equipped with, Each of the coils has external connection terminals (421, 422) located on the substrate side of the core that faces the substrate, The terminal has a mounting portion (421a, 422a) provided so as to overlap with the corresponding land in a plan view in the thickness direction of the plate, and a non-mounting portion (421b, 422b) which is the portion excluding the mounting portion and is arranged so as to overlap with the core in a plan view. The substrate is provided so as to overlap with a portion of the non-mounted portion of at least one of the terminals in the plan view, and has a support portion (37) that protrudes toward the inductor component side relative to the land and supports the inductor component via the non-mounted portion, in an electronic device.

[0130] <Technical philosophy 2> The electronic device according to technical concept 1, wherein the support portion includes a support conductor (371) positioned on one surface at a location separate from the land.

[0131] <Technical philosophy 3> The electronic device according to technical concept 2, wherein the support portion includes a resist (372) arranged to cover the support conductor.

[0132] <Technical philosophy 4> The electronic device according to technical idea 2 or technical idea 3, wherein the support conductor is electrically isolated from all of the lands joined to the coil.

[0133] <Technical philosophy 5> The electronic device according to any one of technical concepts 1 to 4, wherein the substrate has a plurality of support portions provided to support one of the inductor components.

[0134] <Technical philosophy 6> The multiple support parts are arranged in the predetermined direction, The electronic device according to technical concept 5, wherein adjacent support portions are arranged apart in the predetermined direction such that the terminals that do not overlap with the support portions are located between adjacent support portions.

[0135] <Technical philosophy 7> The electronic device according to technical concept 5, wherein the plurality of support portions are provided directly below the coil, which is positioned closer to the end of the inductor component than to the center of the inductor component in the predetermined direction.

[0136] <Technical philosophy 8> The electronic device according to technical concept 7, wherein the plurality of support parts are provided directly below the coils located at both ends in the predetermined direction.

[0137] <Technical philosophy 9> The core has a plurality of core portions (411) individually provided with respect to the coil and on which the corresponding coil is wound, a first end portion (412) to which one end of the plurality of core portions is connected, and a second end portion (413) arranged between the first end portion and the plurality of core portions in an orthogonal direction perpendicular to both the thickness direction and the predetermined direction, to which the other ends of the plurality of core portions are connected. The core portion is divided into multiple parts in the orthogonal direction and has gaps (411g) between them. The support portion is arranged to overlap with at least a portion of the gap in the plan view, as described in any one of the technical concepts 1 to 3.

[0138] <Technical Thought 10> Each of the coils has, as terminals, a first terminal (421) and a second terminal (422) that is spaced apart from the first terminal and aligned in the predetermined direction. The support portion is located in the portion of the gap that overlaps with the region between the first terminal and the second terminal in the plan view, as described in technical concept 9 of the electronic device.

[0139] <Technical Thought 11> The electronic device according to technical concept 10, wherein the support portion is arranged to overlap with all of the gaps in one of the core portions.

[0140] <Technical Thought 12> The support portion is arranged to overlap with at least a portion of each of the gaps between the multiple core portions, according to any one of the technical ideas 9 to 11.

[0141] <Technical Thought 13> The board is mounted and includes a switching device (50) and a capacitor (60) that, together with the inductor component, constitute a multiphase power supply. In an orthogonal direction perpendicular to both the plate thickness direction and the predetermined direction, the inductor component is arranged between the switching device and the capacitor. The electronic device according to technical concept 2 or technical concept 3, wherein the support conductor is a ground wire that electrically connects the capacitor and the switching device.

[0142] <Technical Thought 14> The inductor component is arranged on the surface of the core opposite to the surface facing the substrate, and the electronic device has a cover (43) that covers the core and the plurality of coils, according to any one of technical ideas 1 to 13. [Explanation of Symbols]

[0143] 10…Multiphase power supply, 11…Driver, 11H,11L…Switching element, 12…Inductor, 12C…Coupled inductor, 13…Capacitor, 15…ECU, 16…Primary power supply circuit, 17…Processor, 20…Electronic device, 30…Substrate, 30a…One side, 31…Insulating substrate, 32…Resist, 33…Conductor, 34, 341, 342, 343, 344, 345…Wiring, 342F…Connecting part, 35, 351, 352, 36, 361, 362…Land, 37…Support part, 371…Support conductor, 372…Resist, 40…Coupled inductor, 401… Inductor, 41...core, 411, 4111, 4112...core, 411g...gap, 412, 413...end, 411a, 412a, 413a...top, 411b, 412b, 413b...bottom, 411c, 411d, 412c, 412d, 412e, 412f, 413c, 413d, 413e, 413f...side, 42...coil, 421, 422...terminal, 421a, 422a...mounted part, 421b, 422b...non-mounted part, 423, 424...side wall, 425...top wall, 43...cover, 50...switching device, 60...capacitor, 70...solder

Claims

1. A substrate (30) having an insulating substrate (31) and a plurality of lands (35) arranged on one surface of the insulating substrate, An inductor component (40) having a core (41) and a plurality of coils (42) arranged on the core and aligned in a predetermined direction perpendicular to the thickness direction of the substrate, A solder (70) that joins the coil and the land, Equipped with, Each of the coils has external connection terminals (421, 422) located on the substrate side of the core that faces the substrate, The terminal has a mounting portion (421a, 422a) provided so as to overlap with the corresponding land in a plan view in the thickness direction of the plate, and a non-mounting portion (421b, 422b) which is the portion excluding the mounting portion and is arranged so as to overlap with the core in a plan view. The substrate is provided so as to overlap with a portion of the non-mounted portion of at least one of the terminals in the plan view, and has a support portion (37) that protrudes toward the inductor component side relative to the land and supports the inductor component via the non-mounted portion, in an electronic device.

2. The electronic device according to claim 1, wherein the support portion includes a support conductor (371) positioned on one surface at a location separate from the land.

3. The electronic device according to claim 2, wherein the support portion includes a resist (372) arranged to cover the support conductor.

4. The electronic device according to claim 3, wherein the support conductor is electrically isolated from all of the lands joined to the coil.

5. The electronic device according to claim 1, wherein the substrate has a plurality of support portions provided to support one of the inductor components.

6. The multiple support parts are arranged in the predetermined direction, The electronic device according to claim 5, wherein adjacent support portions are arranged apart in the predetermined direction such that the terminals that do not overlap with the support portions are located between adjacent support portions.

7. The electronic device according to claim 5, wherein the plurality of support portions are provided directly below the coil, which is positioned closer to the end of the inductor component than to the center of the inductor component in the predetermined direction.

8. The electronic device according to claim 7, wherein the plurality of support portions are provided directly below the coils located at both ends in the predetermined direction.

9. The core has a plurality of core portions (411) individually provided with respect to the coil and on which the corresponding coil is wound, a first end portion (412) to which one end of the plurality of core portions is connected, and a second end portion (413) arranged between the first end portion and the plurality of core portions in an orthogonal direction perpendicular to both the thickness direction and the predetermined direction, to which the other ends of the plurality of core portions are connected. The core portion is divided into multiple parts in the orthogonal direction and has gaps (411g) between them. The electronic device according to any one of claims 1 to 3, wherein the support portion is arranged to overlap with at least a portion of the gap in the plan view.

10. Each of the coils has, as terminals, a first terminal (421) and a second terminal (422) that is spaced apart from the first terminal and aligned in the predetermined direction. The electronic device according to claim 9, wherein the support portion is arranged in the portion of the gap that overlaps with the region between the first terminal and the second terminal in the plan view.

11. The electronic device according to claim 10, wherein the support portion is arranged to overlap with all of the gaps in one of the core portions.

12. The electronic device according to claim 9, wherein the support portion is arranged to overlap with at least a portion of each of the gaps between the plurality of core portions.

13. The circuit board is mounted and includes a switching device (50) and a capacitor (60) that, together with the inductor component, constitute a multiphase power supply. In an orthogonal direction perpendicular to both the plate thickness direction and the predetermined direction, the inductor component is arranged between the switching device and the capacitor. The electronic device according to claim 2, wherein the support conductor is a ground wire that electrically connects the capacitor and the switching device.

14. The electronic device according to claim 1, wherein the inductor component is arranged on the surface of the core opposite to the surface facing the substrate, and has a cover (43) that covers the core and the plurality of coils.

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