Electronic device

Abstract

To provide an electronic device which can reduce inductance and variation thereof.SOLUTION: An electronic device 30 comprises a circuit board, upper arm elements 41 to 43, 51 to 53 and lower arm elements 44 to 46, 54 to 56. The upper arm elements 41 to 43, 51 to 53, and the lower arm elements 44 to 46, 54 to 56 are surface-mounted on the circuit board so that a terminal formation surface on which gate terminals, source terminals, and drain terminals are formed comes to a circuit board side. The upper arm elements 41 to 43, 51 to 53, and the lower arm elements 44 to 46, 54 to 56 constitute inverters 40, 50. Legs are provided in parallel with respective phases of motor windings 261 to 263, 271 to 273 of a plurality of phases, and at least one of the gate terminals and the source terminals of multiple switching elements to be connected in parallel with one another is connected by a solid pattern provided in an inner layer of the circuit board.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to electronic devices. [Background technology]

[0002] Conventionally, power modules have been known in which a necessary circuit is configured by mounting power semiconductor elements on a power substrate and wiring them with bonding wires. For example, Patent Document 1 uses GaN-FETs as the power semiconductor elements. In a GaN-FET, a drain electrode, a source electrode, and a gate electrode are formed on one surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-115706 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the switching elements constituting the upper arm and the switching elements constituting the lower arm are arranged so that the gates and drains are oriented in opposite directions, and a capacitor is sandwiched between the elements constituting the upper arm and the elements constituting the lower arm, thereby reducing wiring inductance. However, Patent Document 1 does not take into consideration the arrangement when there are a large number of switching elements, such as when multiple elements are connected in parallel.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an electronic device capable of reducing inductance and variations in inductance. [Means for solving the problem]

[0006] The electronic device of the present invention includes a circuit board (31) and a plurality of switching elements (41-46, 51-56, 411-414, 441-444). The switching elements are surface-mounted on the circuit board so that a terminal forming surface on which a gate terminal, a source terminal, and a drain terminal are formed faces the circuit board, and constitute inverters (40, 50) that switch the energization of motor windings (261-263, 271-273).

[0007] A leg is an element pair consisting of an upper arm element (41-43, 51-53, 411-414) which is a switching element connected to the high potential side, and a lower arm element (44-46, 54-56, 441-444) which is a switching element connected to the low potential side of the upper arm element, and multiple legs are connected in parallel to each phase of the multiple-phase motor winding.

[0008] At least one of the gate terminals and source terminals of the multiple switching elements connected in parallel is connected by a solid pattern provided on an inner layer of the circuit board. Connecting multiple parallel terminals by a solid pattern reduces inductance and also reduces variations in inductance between the multiple parallel connections. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an electric motorcycle to which a drive device according to a first embodiment is applied. [Figure 2] FIG. 1 is a perspective view of a drive device according to a first embodiment. [Figure 3] FIG. 2 is a side view of the drive device according to the first embodiment. [Figure 4] 1 is a cross-sectional view of a drive device according to a first embodiment. [Figure 5] FIG. 2 is a perspective view of the drive device according to the first embodiment with the cover removed. [Figure 6] FIG. 2 is a plan view showing a cover surface of the circuit board according to the first embodiment. [Figure 7] FIG. 2 is a plan view showing the motor surface of the circuit board according to the first embodiment. [Figure 8] 1 is a block diagram showing an electronic device according to a first embodiment; [Figure 9] 1 is a circuit diagram showing an inverter according to a first embodiment. [Figure 10] FIG. 1 is a schematic perspective view showing a switching element according to a first embodiment. [Figure 11] FIG. 2 is a schematic diagram showing a terminal arrangement of a switching element according to the first embodiment. [Figure 12] FIG. 1 is a schematic perspective view showing a switching element according to a first embodiment. [Figure 13] FIG. 2 is a schematic diagram showing a terminal arrangement of a switching element according to the first embodiment. [Figure 14] FIG. 2 is a side view showing the circuit board according to the first embodiment. [Figure 15] FIG. 2 is a schematic diagram illustrating a wiring pattern on a first layer of the circuit board according to the first embodiment. [Figure 16] FIG. 16 is an enlarged view of a portion XVI in FIG. [Figure 17] FIG. 3 is a schematic diagram illustrating a wiring pattern on a second layer of the circuit board according to the first embodiment. [Figure 18] FIG. 3 is a schematic diagram illustrating a wiring pattern on a third layer of the circuit board according to the first embodiment. [Figure 19] FIG. 10 is a plan view showing a cover surface of a circuit board according to a second embodiment. [Figure 20] FIG. 10 is a plan view showing the motor surface of a circuit board according to a second embodiment. [Figure 21] FIG. 10 is a schematic diagram illustrating an inverter arrangement according to a second embodiment. [Figure 22] FIG. 10 is a schematic diagram illustrating an inverter arrangement according to a third embodiment. [Figure 23] FIG. 10 is a schematic diagram illustrating the arrangement of inverters on the cover surface according to the fourth embodiment. [Figure 24] FIG. 10 is a schematic diagram illustrating an inverter arrangement on a motor surface according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic device according to the present invention will be described below with reference to the accompanying drawings. In the following, substantially identical components in a plurality of embodiments will be designated by the same reference numerals, and the description thereof will be omitted.

[0011] (First embodiment) The first embodiment is shown in Figures 1 to 18. The electronic device 30 is applied to, for example, an electric motorcycle 90. As shown in Figure 1, the electric motorcycle 90 is provided with a main battery 96 of, for example, 48 V, an auxiliary battery 97 of, for example, 12 V, and a drive unit 10 having the electronic device 30 (see Figure 4, etc.). The drive unit 10 is connected to the main battery 96 as a battery and is driven by the power of the main battery 96. In Figure 1, the drive unit 10 is provided on the rear wheel 92 side of the electric motorcycle 90, but the drive unit 10 may also be provided on the front wheel 91 side, or on both the front wheel 91 and the rear wheel 92.

[0012] 2 to 4, the drive device 10 includes a housing 11, a motor 20, and an electronic device 30. The drive device 10 is a so-called "mechanically and electrically integrated" type in which the electronic device 30 is provided on one axial side of the motor 20.

[0013] The housing 11 has a motor housing portion 12 that houses the motor 20, and a circuit housing portion 15 that houses the electronic device 30. The circuit housing portion 15 is formed on one axial side of the motor housing portion 12, extending to the radially outer side of the motor housing portion 12. The motor housing portion 12 and the circuit housing portion 15 are integrally formed from a metal material such as aluminum.

[0014] Heat dissipation fins 13 are formed on the cylindrical portion of the motor housing portion 12. The heat dissipation fins 13 are formed in a multi-stage annular shape that protrudes radially outward from the cylindrical portion of the motor housing portion 12. The number and shape of the heat dissipation fins 13 can be set as desired depending on the axial length of the motor 20, etc. A frame member 17 is fixed with bolts 179 to the side of the motor housing portion 12 opposite the circuit housing portion 15.

[0015] The circuit housing portion 15 is provided with an opening on the side opposite the motor housing portion 12, and houses the electronic device 30 inside. A cover 18 that covers the opening is provided on the side of the circuit housing portion 15 opposite the motor housing portion 12. A connector 69 is provided on the circuit housing portion 15 at a location that extends radially outward from the motor housing portion 12. The connector 69 is provided so that a harness (not shown) can be inserted and removed from the output end 258 side. The arrangement, shape, number, number of openings, etc. of the connectors 69 are arbitrary.

[0016] The motor 20 is, for example, a three-phase brushless motor, and the driving force is transmitted to the rear wheel 92 via a reducer or the like (not shown). The electric motorcycle 90 runs using the driving force of the motor 20, and the motor 20 is a driving motor (a so-called main motor) and may also be a so-called motor generator.

[0017] 4, the motor 20 includes a stator 23, a rotor 24, a shaft 25, and winding sets 26 and 27. The stator 23 is fixed to the housing 11. The rotor 24 is disposed radially inside the stator 23 and is rotatable relative to the stator 23.

[0018] The shaft 25 is fitted into the rotor 24 and rotates integrally with the rotor 24. The shaft 25 is rotatably supported by bearings 251 and 252. One end of the shaft 25 is exposed from the motor housing portion 12 toward the electronic device 30, and is provided with a magnet 255. The other end of the shaft 25 is an output end 258, which is exposed from the housing 11 on the side opposite the electronic device 30. The output end 258 is connected to the rear wheel 92 via a reducer or the like (not shown). As a result, the rear wheel 92 is driven by the driving force of the motor 20.

[0019] The winding sets 26 and 27 are respectively made up of three-phase motor windings 261-263 and 271-273 (see FIG. 9). The motor windings 261-263 and 271-273 are wound around the stator 23, and one end thereof is taken out to the electronic device 30 side and connected to the circuit board 31.

[0020] 5 to 9, the electronic device 30 has a circuit board 31, various electronic components mounted on the circuit board 31, and a connector 69 (see FIG. 2, etc.). The circuit board 31 is fixed to the circuit housing part 15. Hereinafter, the surface of the circuit board 31 facing the cover 18 will be referred to as a cover surface 311, and the surface facing the motor will be referred to as a motor surface 312.

[0021] On the circuit board 31, the area within the projection of the motor 20 in the axial direction is the motor area, and the area extending outside the motor area is the extended area. The tip side of the extended area (the right side of the paper in FIGS. 6 and 7) is the extended end side, and the side opposite the motor area to the extended area (the left side of the paper in FIGS. 6 and 7) is the base end side.

[0022] A power supply terminal connection portion 313 connected to a power supply terminal of the connector 69 and a ground terminal connection portion 314 connected to a ground terminal of the connector 69 are formed on the extending end side of the circuit board 31. Furthermore, a motor line connection portion 315 connected to the motor windings 261-263, 271-273 is formed on the extending area side of the circuit board 31 within the motor area. In the motor line connection portion 315, six connection portions are provided so as to be aligned in the same straight line. Details will be described in the second embodiment.

[0023] The electronic device 30 has, as electronic components, a power supply filter 32, a DC-DC converter 33, an internal power supply circuit 34, current sensors 351, 352, motor rotation angle sensors 361, 362, motor voltage monitor circuits 371, 372, pre-drivers 381, 382, ​​inverters 40, 50, a microcomputer 60, and an interface circuit 61, and these components are mounted on a circuit board 31. Fig. 5 shows a state in which the cover 18 and connector 69 are removed, and Figs. 5 to 7 schematically show the areas where the components are mounted.

[0024] The cover surface 311 of the circuit board 31 is mounted with the inverters 40 and 50, current sensors 351 and 352, and an ASIC 65. The ASIC 65 includes the power supply filter 32, the internal power supply circuit 34, motor voltage monitor circuits 371 and 372, and an interface circuit 61. In FIGS. 5 and 6, the inverter regions where the inverters 40 and 50 are mounted are designated INV1 and INV2, the current sensor regions where the current sensors 351 and 352 are mounted are designated IS1 and IS2, and the pre-driver regions where the pre-drivers 381 and 382 are mounted are designated DR1 and DR2. The inverter regions INV1 and INV2 do not necessarily correspond to the systems. The same applies to the current sensor regions IS1 and IS2 and the pre-driver regions DR1 and DR2.

[0025] The inverter regions INV1 and INV2 are generally symmetrical with respect to the motor line connection portion 315. The current sensor regions IS1 and IS2 are provided on the motor line connection portion 315 side of the inverter regions INV1 and INV2, and are generally symmetrical with respect to the motor line connection portion 315. The ASIC 65 is mounted in the motor region on the base end side of the pre-driver 381.

[0026] Fig. 7 is a diagram illustrating the component arrangement on the motor side 312 of the circuit board 31, and is a perspective view from the cover 18 side. Fig. 24 is similar. On the motor side 312 of the circuit board 31, a power supply filter 32, a DC-DC converter 33, motor rotation angle sensors 361 and 362, pre-drivers 381 and 382, ​​and a microcomputer 60 are mounted.

[0027] The pre-driver areas DR1 and DR2 are provided behind the inverter areas INV1 and INV2. The power supply filter 32 includes an inductor and a capacitor and is provided in an area adjacent to the power supply terminal connection part 313 and the ground terminal connection part 314. The motor rotation angle sensors 361 and 362 are provided in the motor area, facing the shaft 25, and detect the motor rotation angle by detecting changes in the magnetic field of the magnet 255 that accompany the rotation of the motor 20. The DC-DC converter 33 and the microcomputer 60 are provided in the motor area.

[0028] As shown in Fig. 8, motor voltage monitor circuits 371, 372 are provided for each system and detect the motor terminal voltage. Power is supplied to the microcomputer 60 from the internal power supply circuit 34. The microcomputer 60 obtains detected values ​​from current sensors 351, 352, motor rotation angle sensors 361, 362, and motor voltage monitor circuits 371, 372. The microcomputer 60 also obtains signals from sensors such as an accelerator position sensor and switches (not shown) via the interface circuit 61.

[0029] Based on the acquired various signals and detection values, the microcomputer 60 generates drive commands to drive the inverters 40 and 50 and outputs them to the pre-drivers 381 and 382, ​​thereby controlling the drive of the motor 20. The microcomputer 60 also outputs control signals via the interface circuit 61 to control the display of the meter display, the illumination of lights, etc.

[0030] 9, the first inverter 40 is connected to the first winding set 26, and the second inverter 50 is connected to the second winding set 27. Hereinafter, the combination of the configurations of the inverters 40, 50 corresponding to the respective winding sets 26, 27 will be referred to as a "system," the combination of the configurations related to the energization control of the first winding set 26 will be referred to as the first system, and the combination of the configurations related to the energization control of the second winding set 27 will be referred to as the second system. In addition, the U phase of the first system will be referred to as U1, the V phase will be referred to as V1, and the W phase will be referred to as W1, and the U phase of the second system will be referred to as U2, the V phase will be referred to as V2, and the W phase will be referred to as W2.

[0031] Inverter 40 has a U-phase upper arm element 41, a V-phase upper arm element 42, a W-phase upper arm element 43, a U-phase lower arm element 44, a V-phase lower arm element 45, and a W-phase lower arm element 46. Inverter 50 has a U-phase upper arm element 51, a V-phase upper arm element 52, a W-phase upper arm element 53, a U-phase lower arm element 54, a V-phase lower arm element 55, and a W-phase lower arm element 56.

[0032] Power is supplied to inverters 40, 50 from battery 96 via power supply filter 32. Furthermore, the on / off operation of upper arm elements 41-43 and lower arm elements 44-46 is controlled by a drive signal from pre-driver 381, and the on / off operation of upper arm elements 51-53 and lower arm elements 54-56 is controlled by a drive signal from pre-driver 382.

[0033] The upper arm elements 41-43 and 51-53 are switching elements connected to the high potential side, and the lower arm elements 44-46 and 54-56 are switching elements connected to the low potential side of the paired upper arm elements. A current sensor 351 is provided on the low potential side of the lower arm elements 44-46, and a current sensor 352 is provided on the low potential side of the lower arm elements 54-56. In this embodiment, the current sensors 351 and 352 are shunt resistors, but they may also be Hall elements or the like. The current sensors 351 and 352 may also be provided at any locations where they can detect the phase current.

[0034] The connection point between the upper arm element 41 and the lower arm element 44 of the first system is connected to a U-phase motor winding 261, the connection point between the upper arm element 42 and the lower arm element 45 is connected to a V-phase motor winding 262, and the connection point between the upper arm element 43 and the lower arm element 46 is connected to a W-phase motor winding 263.

[0035] The connection point between upper arm element 51 and lower arm element 54 of the second system is connected to a U-phase motor winding 271, the connection point between upper arm element 52 and lower arm element 55 is connected to a V-phase motor winding 272, and the connection point between upper arm element 53 and lower arm element 56 is connected to a W-phase motor winding 273.

[0036] If a pair of upper arm element and lower arm element is defined as a leg, in this embodiment, a plurality of legs are provided in parallel to each of the motor windings 261 to 263, 271 to 273. In Fig. 9, for space reasons, the number of parallel connections is shown as two, but it may be three or more.

[0037] In this embodiment, GaN-FETs are used as the elements 41 to 46 and 51 to 56, but elements other than GaN-FETs may also be used. By using GaN-FETs, high-speed switching can be achieved.

[0038] Here, when the current flowing through inductance L changes, a counter electromotive force is generated in a direction that opposes the change in current. The generated voltage is expressed by equation (1). From equation (1), inductance L becomes the cause of the surge. The longer the wiring length, the larger inductance L becomes. Furthermore, when GaN-FETs are used as elements 41 to 46 and 51 to 56 and high-speed switching is performed, dv / dt becomes large, making it more likely that overshoot and noise will occur.

[0039] V = -L × (di / dt) (1)

[0040] For this reason, it is desirable to minimize the inductance L by shortening the paths between the power supply parallel connection and the upper arm element, between the upper arm element and the motor winding connection, between the motor winding connection and the lower arm element, and between the lower arm element and the parallel connection on the upstream side of the current sensor. It is also desirable to reduce the variation in inductance L between multiple legs or multiple systems. In Figure 9, the inductance between the power supply and the upper arm element is L1, the inductance between the inverter and the motor midpoint is L2, and the inductance between the inverter and the lower arm element is L3, which are represented by the dashed lines in the W phase on the first system side.

[0041] 10 to 13, unlike MOS-FETs etc., a GaN-FET has a drain terminal D, a source terminal S, and a gate terminal G formed on the same side of a package. In Figs. 10 to 13, upper arm element 41 will be described as an example.

[0042] As shown in Figures 10 and 11, solder balls H that form each terminal are provided on one side of the package of upper arm element 41. To avoid complexity, one solder ball is numbered "H" as a representative. In the example of Figure 11, the solder balls are arranged in a 5x5 grid, and from the top row on the page, they alternately form source terminal S, drain terminal D, source terminal S, and drain terminal D. In the bottom row, the middle solder ball H is not provided, and two solder balls H on one side are used as gate terminal G, and the remaining two solder balls H are used as source terminals S.

[0043] 12 and 13, the drain terminal D may be formed along one side, and the source terminal S and gate terminal G may be formed along the other side. The central drain terminal D functions as a heat dissipation surface. In this embodiment, the upper arm element 41 is surface-mounted on the circuit board 31 with its terminal-forming surface facing the circuit board 31. Each terminal of the upper arm element 41 is directly connected to a wiring pattern formed on the mounting surface of the circuit board 31. This minimizes the distance from the upper arm element 41 to the circuit board 31, and reduces the inductance L compared to, for example, connecting each terminal to the circuit board 31 by wire bonding.

[0044] 14, upper arm elements 41-43, 51-53 and lower arm elements 44-46, 54-56 are mounted on cover surface 311 of circuit board 31, and pre-drivers 381, 382 are mounted on motor surface 312 of circuit board 31. In FIG. 14, a portion of circuit board 31 is shown in a simplified manner, with switching elements indicated as "SW" and pre-drivers indicated as "DR."

[0045] 15 to 18, the element arrangement and wiring pattern on circuit board 31 will be described using the U-phase of the first system as an example. Here, an example of a four-parallel arrangement will be described in which four switching elements 411 to 414 are provided in parallel as upper arm element 41, and four switching elements 441 to 444 are provided in parallel as lower arm element 44.

[0046] In this embodiment, the switching elements 411-414, 441-444 are of the BGA (ball grid array) type shown in FIG. 11. The solder balls H are not limited to being spherical, and may be formed as a single oval array of balls of the same potential. Hereinafter, the terminal row comprising the drain terminals D will be referred to as the drain terminal row, and the terminal row comprising the source terminals S will be referred to as the source terminal row. Furthermore, the terminal row consisting of the gate terminals G and the source terminals S will be referred to as the signal terminal row.

[0047] The circuit board 31 of this embodiment is a four-layer board, and is made up of a first layer WL1 to a fourth layer WL4 from the cover surface 311 side. That is, in the circuit board 31, the wiring pattern on the cover surface 311 side is the first layer WL1, the second layer WL2 and the third layer WL3 are internal wiring patterns, and the wiring pattern on the motor surface 312 side is the fourth layer WL4.

[0048] As shown in Fig. 15, on the cover surface 311 of the circuit board 31, a relatively wide power supply voltage pattern P10, a motor voltage pattern P20, and a ground pattern P30 are formed substantially parallel to each other as wiring patterns on the first layer WL1, and comb-like protrusions are formed on one or both sides. Details of the protrusions will be described later. Hereinafter, in the patterns P10, P20, and P30, the portions extending in the left-right direction of the paper surface of Fig. 15 will be referred to as "bases" or simply as patterns P10, P20, and P30, as appropriate. In addition, the projection area where the pre-driver 381 is mounted and the area extending from the projection area to the power supply voltage pattern P10 and ground pattern P30 (described later) are referred to as a pre-driver area DRu.

[0049] The power supply voltage pattern P10 is the power supply voltage, and the ground pattern P30 is the ground potential. The motor voltage pattern P20 is connected to the motor winding 261. The patterns P10, P20, and P30 are all formed to extend in a planar shape, so-called "solid patterns."

[0050] Switching elements 411 to 414, which are upper arm elements, are arranged between the power supply voltage pattern P10 and the motor voltage pattern P20, and switching elements 441 to 444, which are lower arm elements, are arranged between the motor voltage pattern P20 and the ground pattern P30.

[0051] Between the power supply voltage pattern P10 and the motor voltage pattern P20, switching elements 411 and 412 are arranged adjacent to each other on one side of the pre-driver area DRu so that their terminal rows are on the same straight line, and switching elements 413 and 414 are arranged adjacent to each other on the other side so that their terminal rows are on the same straight line. Furthermore, the switching elements 411 and 413 are arranged on the power supply voltage pattern P10 side, and the switching elements 412 and 414 are arranged on the motor voltage pattern P20 side. The switching elements 411 to 414 are arranged with their signal terminal rows facing the pre-driver area DRu side.

[0052] Between the motor voltage pattern P20 and the ground pattern P30, switching elements 441 and 442 are arranged adjacent to each other on one side of the pre-driver area DRu so that their terminal rows are on the same straight line, and switching elements 443 and 444 are arranged adjacent to each other on the other side so that their terminal rows are on the same straight line. Furthermore, the switching elements 441 and 443 are arranged on the motor voltage pattern P20 side, and the switching elements 442 and 444 are arranged on the ground pattern P30 side. The switching elements 441 to 444 are arranged with their signal terminal rows facing the pre-driver area DRu side.

[0053] On one side of the pre-driver region DRu, the switching elements 411 and 412, the motor voltage pattern P20, the switching elements 441 and 442, and the ground pattern P30 are arranged in this order from the power supply voltage pattern P10 side. The switching elements 441 and 442 are arranged offset by one terminal row from the switching elements 411 and 412 on the side away from the pre-driver region DRu. This causes the source terminal row of the upper arm element and the drain terminal row of the lower arm element to be on the same straight line.

[0054] On the other side of the pre-driver region DRu, the switching elements 413 and 414, the motor voltage pattern P20, the switching elements 443 and 444, and the ground pattern P30 are arranged in this order from the power supply voltage pattern P10 side. The switching elements 443 and 444 are arranged offset by one terminal row toward the side away from the pre-driver region DRu with respect to the switching elements 413 and 414. This causes the source terminal row of the upper arm element and the drain terminal row of the lower arm element to be on the same straight line.

[0055] The power supply voltage pattern P10 has protrusions P11 to P16 that protrude toward the motor voltage pattern P20. The protrusion P11 is provided on the opposite side of the pre-driver region DRu of the switching elements 411 and 412, and the protrusion P16 is provided on the opposite side of the pre-driver region DRu of the switching elements 413 and 414. Capacitors 48 are provided on the opposite sides of the protrusions P11 and P16 to the pre-driver region DRu, respectively. The capacitors 48 in this embodiment are ceramic capacitors.

[0056] The protrusions P12 and P13 are formed on one side of the pre-driver region DRu in correspondence with the drain terminal rows of the switching elements 411 and 412. The drain terminal rows of the switching elements 411 and 412 are connected to the protrusions P12 and P13 by the BGA. Furthermore, the protrusions P14 and P15 are formed on the other side of the pre-driver region DRu in correspondence with the drain terminal rows of the switching elements 413 and 414. The drain terminal rows of the switching elements 413 and 414 are connected to the protrusions P14 and P15 by the BGA.

[0057] The motor voltage pattern P20 has protrusions P21-P24 that protrude toward the power supply voltage pattern P10 and protrusions P25-P28 that protrude toward the ground pattern P30. The protrusions P21 and P25 are formed on the same line with the base of the motor voltage pattern P20 in between. Similarly, the protrusions P22-P24 and the corresponding P26-P28 are formed on the same line with the motor voltage pattern P20 in between.

[0058] The protrusions P21 and P22 are formed between the protrusions P11 to P13 on one side of the pre-driver region DRu, and the protrusions P11 to P13 and the protrusions P21 and P22 are alternately arranged in the order of P11, P21, P12, P22, and P13 from the opposite side of the pre-driver region DRu. The protrusions P23 and P24 are formed between the protrusions P14 to P16 on the other side of the pre-driver region DRu, and the protrusions P14 to P16 and the protrusions P23 and P24 are alternately arranged in the order of P14, P23, P15, P24, and P26 from the pre-driver region DRu side.

[0059] The protrusions P21 and P22 are formed corresponding to the source terminal rows of the switching elements 411 and 412. The source terminal rows of the switching elements 411 and 412 are connected to the protrusions P21 and P22 by the BGA. The protrusions P23 and P24 are formed corresponding to the source terminal rows of the switching elements 413 and 414. The source terminal rows of the switching elements 413 and 414 are connected to the protrusions P23 and P24 by the BGA.

[0060] The protrusions P25 and P26 are formed corresponding to the drain terminal rows of the switching elements 441 and 442. The drain terminal rows of the switching elements 441 and 442 are connected to the protrusions P25 and P26 by the BGA. Furthermore, the protrusions P27 and P28 are formed corresponding to the drain terminal rows of the switching elements 443 and 444. The drain terminal rows of the switching elements 443 and 444 are connected to the protrusions P27 and P28 by the BGA.

[0061] The ground pattern P30 has protrusions P31 to P34 that protrude toward the motor voltage pattern P20. The protrusions P32 and P33 are formed on the same straight line as the protrusions P12 and P15 of the power supply voltage pattern P10, sandwiching the motor voltage pattern P20 therebetween.

[0062] The protrusions P31 and P32 are formed between the protrusions P25 and P26 on one side of the pre-driver region DRu, and the protrusions P31 and P32 and the protrusions P25 and P26 are alternately arranged in the order P31, P25, P32, P26 from the opposite side of the pre-driver region DRu. The protrusions P33 and P34 are formed between the protrusions P27 and P28 on the other side of the pre-driver region DRu, and the protrusions P27 and P28 and the protrusions P33 and P34 are alternately arranged in the order P27, P33, P28, P34 from the pre-driver region DRu side. A capacitor 48 is provided on the opposite side of the protrusions P31 and P34 from the pre-driver region DRu.

[0063] The protrusions P31 and P32 are formed corresponding to the source terminal rows of the switching elements 441 and 442. The source terminal rows of the switching elements 441 and 442 are connected to the protrusions P31 and P32 by the BGA. The protrusions P33 and P34 are formed corresponding to the source terminal rows of the switching elements 443 and 444. The source terminal rows of the switching elements 443 and 444 are connected to the protrusions P33 and P34 by the BGA.

[0064] This allows the drains of the upper arm switching elements 411 to 414 to be connected to the power supply voltage pattern P10, the sources of the switching elements 411 to 414 to be connected to the motor voltage pattern P20, the drains of the lower arm switching elements 441 to 444 to be connected to the motor voltage pattern P20, and the sources of the switching elements 441 to 444 to the ground pattern P30 to be connected in the shortest distance, thereby reducing inductance and reducing variations in inductance between parallel connections.

[0065] The connection of the gate terminals G and source terminals S of the signal terminal array will be described with reference to Figs. 16 to 18. Figs. 16 to 18 are diagrams showing the wiring patterns of the area surrounded by the two-dot chain line XVI in Fig. 15, with Fig. 16 showing the wiring pattern of the first layer WL1, Fig. 17 showing the wiring pattern of the second layer WL2, and Fig. 18 showing the wiring pattern of the third layer WL3. Figs. 16 to 18 will explain the wiring pattern of the pre-driver area DRu on the upper arm side. Note that the wiring pattern on the lower arm side is similar, so its explanation will be omitted.

[0066] As shown in FIG. 16, the gate terminals G of the signal terminal array of the switching elements 411-414 are connected to the gate lands GL1-GL4 via BGA, and the source terminals S are connected to the source lands SL1-SL4 via BGA. Through holes 321-324 are formed in the gate lands GL1-GL4 connected to the switching elements 411-414, and through holes 331-334 are formed in the source lands SL1-SL4. Through holes 325 and 335 are formed in the central region, which is approximately equidistant from the four switching elements 411-414. The through holes 325 and 335 do not need to be located exactly in the center of the four elements, as long as they are within an allowable range for the influence of differences in wiring inductance via the solid pattern. Although the through holes 325 and 335 are arranged horizontally on the page in FIG. 16, they may also be arranged vertically or diagonally on the page, for example.

[0067] Through holes 321 to 325 and 331 to 335 are through-holes that penetrate all layers to ensure electrical continuity between layers. In Figures 16 to 18, through holes for gate potential are shown with a matte finish, and through holes for source potential are shown with hatching, with conductive areas indicated by a single outline and non-conductive areas indicated by a double outline.

[0068] 17, a gate potential pattern PG1 is formed on the second layer WL2. The gate potential pattern PG1 is a solid pattern and is electrically connected to the gate lands GL1 to GL4 of the first layer WL1 via through holes 321 to 324. The gate potential pattern PG1 is not electrically connected to the through holes 331 to 335.

[0069] The gate solid pattern is also electrically connected to a gate signal line pattern PG2 formed on the fourth layer WL4 via a through-hole 325. The gate signal line pattern PG2 is connected to a pre-driver 381. As a result, gate signals are transmitted from the pre-driver 381 to the switching elements 411 to 414 via the gate potential pattern PG1, as schematically indicated by the dashed arrows. In detail, gate signals output from the pre-driver 381 are transmitted to the gate terminals of the switching elements 411 to 414 via the gate signal line pattern PG2, the through-hole 325, the gate potential pattern PG1, and the through-holes 321 to 324.

[0070] 18, a reference potential pattern PS1 is formed on the third layer WL3. The reference potential pattern PS1 is a solid pattern and is electrically connected to the source lands SL1 to SL4 of the first layer WL1 via through holes 331 to 334. The reference potential pattern PS1 is not electrically connected to the through holes 321 to 324.

[0071] Furthermore, the reference potential pattern PS1 is electrically connected to a reference potential signal line pattern PS2 formed on the fourth layer WL4 via a through-hole 335. The reference potential signal line pattern PS2 is connected to the pre-driver 381. As a result, a reference potential signal is output from the pre-driver 381 to the switching elements 411 to 414 via the reference potential pattern PS1, as schematically indicated by the dashed arrows. In detail, the reference potential signal output from the pre-driver 381 is transmitted to the source terminals of the switching elements 411 to 414 via the reference potential signal line pattern PS2, the through-hole 335, the reference potential pattern PS1, and the through-holes 331 to 334.

[0072] In this embodiment, at least a portion of the wiring connecting the parallel-connected switching elements 411-414 to other components is configured as a solid pattern on the circuit board 21, thereby reducing variations in the parallel-connected inductance L. In particular, the gate potential pattern PG1 and the reference potential pattern PS1 are formed as solid patterns on an inner layer of the circuit board 31, and the gates and sources of the multiple (four in this embodiment) parallel-connected switching elements 411-414 are connected via through holes 321-324, 331-334. This makes it possible to keep the gate-source inductance as small as possible and reduce variations in inductance among the four parallel-connected elements.

[0073] Furthermore, by forming a through-hole 325 in the center of the gate potential pattern PG1 and connecting it to the pre-driver 381, it is possible to equalize the gate signal paths to the four switching elements 411 to 414. Similarly, by forming a through-hole 335 in the center of the reference potential pattern PS1 and connecting it to the pre-driver 381, it is possible to equalize the reference potential signal paths to the four switching elements 411 to 414.

[0074] As described above, electronic device 30 includes circuit board 31 and a plurality of switching elements, namely upper arm elements 41-43, 51-53 and lower arm elements 44-46, 54-56. Gate terminals G, source terminals S, and drain terminals D of upper arm elements 41-43, 51-53 and lower arm elements 44-46, 54-56 are formed on the same surface, and are surface-mounted on circuit board 31 such that the terminal formation surface on which gate terminals G, source terminals S, and drain terminals D are formed faces the circuit board 31. Upper arm elements 41-43, 51-53 and lower arm elements 44-46, 54-56 constitute inverters 40, 50 that switch the energization of motor windings 261-263, 271-273.

[0075] In the electronic device 30, a pair of elements is defined as a leg, consisting of upper arm elements 41-43, 51-53, which are switching elements connected to the high potential side, and lower arm elements 44-46, 54-56, which are switching elements connected to the low potential side of the upper arm elements 41-43, 51-53, and multiple legs are provided in parallel for each phase of the multiple-phase motor windings 261-263, 271-273.

[0076] Taking the upper arm of U1 as an example, at least one of the gate terminals G and source terminals S of the multiple switching elements 411 to 414 connected in parallel is connected by a solid pattern provided on an inner layer of the circuit board 31. In this embodiment, both the gate terminals G and the source terminals S are connected by an inner layer solid pattern.

[0077] By connecting the gate terminals G of multiple switching elements connected in parallel with a solid pattern, it is possible to minimize the inductance of the gate wiring while reducing the inductance variation between parallel gate wirings. Similarly, by connecting the source terminals S of multiple switching elements connected in parallel with a solid pattern, it is possible to minimize the inductance of the source wiring while reducing the inductance variation between parallel source wirings. This makes it possible to suppress gate oscillation due to inductance variation.

[0078] The gate potential pattern PG1, which is a solid pattern connected to the gate terminal G, and the reference potential pattern PS1, which is a solid pattern connected to the source terminal S, are formed on different inner layers of the circuit board 31. In this embodiment, the gate potential pattern PG1 is formed on the second layer WL2, and the reference potential pattern PS1 is formed on the third layer WL3.

[0079] The gate potential pattern PG1 is connected to a plurality of gate lands GL1 to GL4, which are formed on the surface of the circuit board 31 on which the switching elements 411 to 414 are mounted and connected to the gate terminals G, via through holes 321 to 324 provided for each of the gate lands GL1 to GL4. This makes it possible to minimize the wiring distance between the gate terminals of the switching elements 411 to 414 and the gate potential pattern PG1.

[0080] Furthermore, the reference potential pattern PS1 is connected to a plurality of source lands SL1 to SL4, which are formed on the surface of the circuit board 31 on which the switching elements 411 to 414 are mounted and connected to the source terminals S, via through holes 331 to 334 provided for each of the source lands SL1 to SL4. This shortens the wiring distance between the source terminals of the switching elements 411 to 414 and the reference potential pattern PS1, thereby reducing inductance.

[0081] The electronic device 30 includes a pre-driver 381 mounted on the surface of the circuit board 31 opposite to the surface on which the switching elements 411-414 are mounted, and which outputs gate signals and reference potential signals to the switching elements 411-414. The signal line patterns and solid patterns formed on the surface on which the pre-driver 381 is mounted are connected by through-holes. More specifically, the gate signal line pattern PG2 and the gate potential pattern PG1, which is a solid pattern, are connected by through-hole 325. Furthermore, the reference potential signal line pattern PS2 and the reference potential pattern PS1, which is a solid pattern, are connected by through-hole 335. This shortens the wiring distance between the pre-driver 381 and the gate potential pattern PG1 and the reference potential pattern PS1, thereby reducing inductance.

[0082] Switching elements 411 to 414 connected in parallel are arranged so as to be equidistant from through holes 325 and 335. Here, "arranged so as to be equidistant from the through holes" means that deviations are allowed to the extent that the inductance between parallel elements can be considered equal, and for example, the arrangement in Fig. 16 is considered to be "arranged so as to be equidistant." This makes it possible to reduce variations in inductance between parallel elements.

[0083] The source terminals and drain terminals are arranged alternately in rows. The switching elements 411-414, 441-444 are arranged on one side of a motor voltage pattern P20, which is a wiring pattern connected to the motor winding 261, so that the row of source terminals of the switching elements 411-414, which are upper arm elements, and the row of drain terminals of the switching elements 441-444, which are lower arm elements, are on the same straight line. This simplifies the wiring pattern connecting the switching elements 411-414, 441-444 to the motor winding 261, and reduces inductance.

[0084] (Second embodiment) The second embodiment is shown in Figures 19 to 21. As shown in Figure 19, pre-drivers 381 and 382, ​​inverters 40 and 50, current sensors 351 and 352, and an ASIC 65 are mounted on a cover surface 311 of a circuit board 31. As shown in Figure 20, a power supply filter 32, a DC-DC converter 33, motor rotation angle sensors 361 and 362, and a microcomputer 60 are mounted on a motor surface 312 of the circuit board 31.

[0085] 19, on the cover surface 311 of the circuit board 31, the current sensor area IS1, inverter area INV1, and pre-driver area DR1 are arranged on the motor area side in this order from the motor line connection portion 315 side. The current sensor area IS2, inverter area INV2, and pre-driver area DR2 are arranged on the extension area side in this order from the motor line connection portion 315 side. The inverter areas INV1 and INV2 are roughly symmetrical with the motor line connection portion 315 in between. Similarly, the current sensor areas IS1 and IS2 are roughly symmetrical with the motor line connection portion 315 in between, and the pre-driver areas DR1 and DR2 are roughly symmetrical with the motor line connection portion 315 in between. The ASIC 65 is mounted in the motor area on the base end side of the pre-driver area DR1.

[0086] 21 is a diagram for explaining the arrangement of inverter regions INV1, INV2 and motor line connection portion 315, and omits the illustration of parts such as current sensors and part of circuit board 31. This is also the case for the drawings relating to the embodiments described later. Also, the order of phase, system, and arm is shown, such as "U1-up" for the region where U-phase upper arm element 41 of the first system is mounted.

[0087] As shown in Fig. 21, in the motor wire connection unit 315, the connection points of the six (3 phases x 2 systems) motor windings 261-263, 271-273 are arranged on an imaginary line C1. The connection points of the motor windings 261-263, 271-273 are arranged in the order of U-phase, V-phase, and W-phase from one end, with the U-phase motor windings 261, 271 adjacent to each other, the V-phase motor windings 262, 272 adjacent to each other, and the W-phase motor windings 263, 273 adjacent to each other. That is, in the motor wire connection unit 315, the windings are arranged in the order of U1, U2, V1, V2, W1, and W2 from one end. In Fig. 21 and other figures, the motor wires connected to each connection point are numbered as appropriate.

[0088] Furthermore, a power supply voltage pattern P18 is provided on one end side (U1 side in FIG. 21) of the motor line connection portion 315, and a ground pattern P38 is provided on the other end side (W2 side in FIG. 21). The power supply voltage pattern P18 is electrically connected to the power supply terminal connection portion 313 (not shown in FIG. 21) by a wiring pattern, and the ground pattern P38 is electrically connected to the ground terminal connection portion 314 (not shown in FIG. 21) by a wiring pattern.

[0089] The inverter regions INV1 and INV2 are provided on both sides of the motor line connection portion 315. The regions in which the switching elements of each phase are mounted are arranged line-symmetrically with the motor line of the connected phase in between. Note that the phase regions only need to be arranged symmetrically as regions, and the elements themselves do not need to be arranged perfectly symmetrically depending on the routing of the wiring pattern, etc. The same applies to the descriptions regarding the arrangement of other regions.

[0090] In each inverter domain INV1, INV2, the switching elements are arranged in the order of U-phase, V-phase, and W-phase from one end, similar to the phase arrangement of the motor line connection unit 315. Specifically, U-phase switching elements are mounted on both sides of the U-phase motor winding connection unit, V-phase switching elements are mounted on both sides of the V-phase motor winding connection unit, and W-phase switching elements are mounted on both sides of the W-phase winding. Furthermore, for each phase, an upper arm element is disposed on one end where the power supply voltage pattern P18 is provided, and a lower arm element is disposed on the other end where the ground pattern P38 is provided. This allows the lengths of the current paths in the first and second systems to be equalized when current is applied to one phase (e.g., the U-phase). This reduces variations in inductance between the systems.

[0091] In this embodiment, the inverter domain INV1 has switching elements for the U phase of the first system, the V phase of the second system, and the W phase of the first system, while the inverter domain INV2 has switching elements for the U phase of the second system, the V phase of the first system, and the W phase of the second system. That is, in each of the inverter domains INV1 and INV2, the V phase located in the middle and the U phase and W phase located on both ends belong to different systems.

[0092] In Figure 21, the current path of the first system is shown by a thick line, and the current path of the second system is shown by a thin line. The line type is changed here simply to distinguish between the systems, and there is no correlation between the line thickness and the amount of current flow.

[0093] As shown by the solid lines, when current is applied to the UV phase, that is, when current is applied from the U-phase upper arm to the V-phase lower arm via the U-phase coil and V-phase coil, in the first system, current flows from the first inverter region INV1 to the second inverter region INV2 (from left to right on the page), and in the second system, current flows from the second inverter region INV2 to the first inverter region INV1 (from right to left on the page), with the current path being reversed.

[0094] Furthermore, when current is applied to the VW phase, that is, when current is applied from the V-phase upper arm to the W-phase lower arm via the V-phase coil and W-phase coil, in the first system, current flows from the second inverter region INV2 to the first inverter region INV1 (from right to left on the page), and in the second system, current flows from the first inverter region INV1 to the second inverter region INV2 (from left to right on the page), reversing the current path. This makes it possible to cancel magnetic field noise.

[0095] By swapping the V-phase system located in the middle and arranging the upper arm elements 41-43, 51-53 and the lower arm elements 44-46, 54-46 in a triangular shape that crosses the virtual line C1, it is possible to cancel out magnetic field noise caused by the motor current when current is applied to the first and second systems in the same phase.

[0096] The electronic device 30 of this embodiment has a two-system configuration in which inverters 40, 50 are provided for two winding sets 26, 27, each of which is formed by connecting multiple-phase motor windings 261-263, 271-273. Motor wire connection sections 315, which connect the motor windings 261-263, 271-273 to the circuit board 31, are arranged in a row overall so that the same phases of different systems are adjacent to each other. Specifically, the U-phase motor windings 261, 271 are adjacent to each other, the V-phase motor windings 262, 272 are adjacent to each other, and the W-phase motor windings 273, 283 are adjacent to each other, and from one end, the motor windings 261, 271, 262, 272, 263, 273 are arranged on the imaginary line C1 in this order.

[0097] The switching elements are mounted on the circuit board 31 in the first inverter region INV1, which is one side of the motor line connection portion 315, and in the second inverter region INV2, which is the other side of the motor line connection portion 315, in a phase arrangement that is the same as the phase arrangement of the motor line connection portion 315. Preferably, the switching elements are arranged symmetrically and equidistantly with respect to the motor windings of each phase. Note that "symmetrically and equidistantly" means that some deviation is allowed, depending on, for example, the wiring layout, etc., so that the inductance between the motor windings 261-263, 271-273 and the inverters 40, 50 can be equalized in the two systems.

[0098] In the first inverter domain INV1 and the second inverter domain INV2, at least one phase is equipped with a switching element that constitutes an inverter of a system different from that of the other phases. In this embodiment, in each inverter domain INV1 and INV2, the V phase located in the middle is equipped with a switching element that constitutes an inverter of a system different from that of the other phases (U phase, W phase), resulting in a cross arrangement. By using the cross arrangement, when current is applied to two phases including the cross-arranged phase without a phase difference, the current flows in opposite directions in the first system and the second system, thereby canceling magnetic field noise.

[0099] The electronic device 30 includes pre-drivers 381 and 382 and current sensors 351 and 352. The pre-drivers 381 and 382 output drive signals to the switching elements. The drive signals include gate signals and reference potential signals. The current sensors 351 and 352 are mounted on the circuit board 31 and detect the currents flowing through the motor windings 261-263 and 271-273. On the same side of the circuit board 31, the current sensors 351 and 352, the inverters 100 and 200, and the pre-drivers 381 and 382 are arranged in this order from the motor line connection portion 315 side, which is the connection portion between the motor windings 261-263 and 271-273 and the circuit board 31. This shortens the wiring, thereby reducing inductance. This also provides the same effects as the above-described embodiment.

[0100] (Third embodiment) The third embodiment is shown in Fig. 22. As shown in Fig. 22, in the third embodiment, a power supply voltage pattern P18 and a ground pattern P38 are provided between inverter regions INV1 and INV2. In this embodiment, a first-system inverter 100 is arranged in the inverter region INV1, and a second-system inverter 200 is arranged in the inverter region INV2. In this embodiment, the first inverter region INV1 and the second inverter region INV2 are arranged symmetrically with respect to a virtual line C2 that passes through the power supply voltage pattern P18 and the ground pattern P38.

[0101] The motor wire connection part 316 connected to the motor windings 261-263 of the first system is connected to the circuit board 31 on the side opposite the virtual line C2 in the inverter area INV1. The motor wire connection part 317 connected to the motor windings 271-273 of the second system is connected to the circuit board 31 on the side opposite the virtual line C2 in the inverter area INV2. The motor windings 261-263, 271-273 are arranged in the order of U-phase, V-phase, and W-phase from one side. Furthermore, in the inverter areas INV1 and INV2, the switching elements are arranged so that the mounting areas are in the order of U-phase, V-phase, and W-phase from one side, corresponding to the phase arrangement of the motor windings 261-263, 271-273.

[0102] In this embodiment, on the circuit board 31, a power supply voltage pattern P18 connected to a power supply terminal of the connector 69 and a ground pattern P38 connected to a ground terminal are formed adjacent to each other.

[0103] Switching elements of one system (first system in this embodiment) are mounted in a first inverter area INV1, which is on one side of a virtual line C2 passing through the power supply voltage pattern P18 and the ground pattern P38, and switching elements of the other system (second system in this embodiment) are mounted in a second inverter area INV2, which is on the other side of the virtual line C2. The switching elements are mounted on the circuit board 31 with the same phase arrangement in the first inverter area INV1 and the second inverter area INV2. The virtual line C2 passes through the centers of the power supply voltage pattern P18 and the ground pattern P38, but may not be exactly at the center depending on the pattern shape.

[0104] In this embodiment, by providing inverter regions INV1 and INV2 on both sides of the power supply voltage pattern P18 and the ground pattern P38, the distance between the power supply and the inverter and the distance between the inverter and the ground can be made as short as possible. This reduces wiring inductance. Furthermore, by arranging the inverter regions INV1 and INV2 symmetrically with respect to the virtual line C2, the inductance between the power supply and the inverter and between the inverter and the ground can be equalized. This also provides the same effects as the above-mentioned embodiment.

[0105] (Fourth embodiment) The fourth embodiment is shown in Figures 23 and 24. Both Figures 23 and 24 show the arrangement as viewed from the cover side. In this embodiment, an inverter area INV1 is provided on the cover surface 311 of the circuit board 31, and an inverter area INV2 is provided on the motor surface 312. The inverter 100 of the first system is provided in the inverter area INV1, and the inverter 200 of the second system is provided in the inverter area INV2. That is, in this embodiment, the inverter 200 is provided on the back surface of the inverter 100. It should be noted that the terms "front and back" merely distinguish between one surface and the other surface of the circuit board 31.

[0106] A power supply voltage pattern P18 is formed on one side of the inverter regions INV1 and INV2, and a ground pattern P38 is formed on the other side. The power supply voltage pattern P18 on the cover surface 311 and the power supply voltage pattern P18 on the motor surface 312 are electrically connected by vias or the like. The same applies to the ground pattern P38.

[0107] In inverters 100, 200, the mounting regions are in the order of U-phase, V-phase, and W-phase from the power supply voltage pattern P18 side, and upper arm elements 41-43, 51-53 and lower arm elements 44-46, 54-46 are arranged so that the back side of the U-phase region of first inverter 100 is the U-phase region of second inverter 200, the back side of the V-phase region of first inverter 100 is the V-phase region of second inverter 200, and the back side of the W-phase region of first inverter 100 is the W-phase region of second inverter 200. Note that in inverters 100, 200, the mounting positions of each element do not need to strictly match as long as they are arranged so that corresponding phases are on the back side.

[0108] 21 and 22 indicate UW-phase current flow, i.e., current flow when current flows from the U-phase upper arm to the W-phase lower arm via the U-phase coil and W-phase coil. In UW-phase current flow, the current flows in opposite directions on the cover surface 311 side and the motor surface 312 side for the U and W phases. This allows magnetic field noise caused by the motor current to be canceled out on both sides.

[0109] In this embodiment, the switching elements are mounted on the circuit board 31 so that elements of the same phase in different systems are on the front and back of the same area of ​​the circuit board 31. This results in opposite current directions on the front and back, making it possible to cancel magnetic field noise caused by the motor current. In addition, the same effects as those of the above embodiment are achieved.

[0110] In the embodiment, the upper arm elements 41 to 43, 51 to 53 and the lower arm elements 44 to 46, 54 to 56 correspond to "switching elements," the pre-drivers 381 and 382 correspond to "driver components," the through holes 321 to 324 correspond to "gate through holes," the through holes 331 to 334 correspond to "source through holes," and the through holes 325 and 335 correspond to "driver through holes." In addition, the gate potential pattern PG1 and the reference potential pattern PS1 correspond to "solid patterns," the gate signal line pattern PG2 and the reference potential signal line pattern PS2 correspond to "signal line patterns," the first inverter region INV1 corresponds to "first region," and the second inverter region INV2 corresponds to "second region."

[0111] (Other embodiments) In the above embodiment, a two-system configuration is provided, with two motor windings and two inverters. In other embodiments, the number of systems may be one or three or more. Also, in the above embodiment, each phase has multiple legs (for example, two or four). In other embodiments, each phase may have one leg, or three or five or more legs.

[0112] In the above embodiment, the switching element has a plurality of gate terminals, source terminals, and drain terminals, each of which is provided together. In other embodiments, there may be only one gate terminal, source terminal, and drain terminal, and the arrangement and shape may differ from those in the above embodiment. In the above embodiment, the electronic device is applied to an electric motorcycle. In other embodiments, the electronic device may be applied to any device other than an electric motorcycle, such as a small mobility vehicle or agricultural or construction machinery.

[0113] The present disclosure may be modified to "an electronic device according to any one of items 1 to 5, wherein the source terminals and the drain terminals are arranged alternately in rows, and the upper arm elements are arranged on one side of a motor voltage pattern, which is a wiring pattern connected to the motor windings, and the lower arm elements are arranged on the other side of the motor voltage pattern, so that the source terminal row of the upper arm elements and the drain terminal row of the lower arm elements are on the same straight line."

[0114] As described above, the present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0115] 10. Drive unit 20 Motor 26, 27 Winding set 261~263, 271~273 Motor windings 30...electronic equipment 31 Circuit board 315···Motor wire connection (connection) 40... Inverter 41 to 43: Upper arm element (switching element) 44 to 46: Lower arm element (switching element) 411 to 414, 441 to 444... Switching elements

Claims

1. A circuit board (31); a plurality of switching elements (41-46, 51-56, 411-414, 441-444) that are surface-mounted on the circuit board such that a terminal forming surface on which gate terminals, source terminals, and drain terminals are formed faces the circuit board, and that constitute an inverter (40, 50) that switches current flow through motor windings (261-263, 271-273); Equipped with a leg is an element pair made up of an upper arm element (41-43, 51-53, 411-414) which is the switching element connected to a high potential side, and a lower arm element (44-46, 54-56, 441-444) which is the switching element connected to a low potential side of the upper arm element, and a plurality of the legs are provided in parallel for each phase of the motor windings having a plurality of phases; At least one of the gate terminals and the source terminals of the plurality of switching elements connected in parallel is connected by solid patterns (PG1, PS1) provided on an inner layer of the circuit board.

2. 2. The electronic device according to claim 1, wherein the gate potential pattern (PG1), which is the solid pattern connected to the gate terminal, and the reference potential pattern (PS1), which is the solid pattern connected to the source terminal, are formed on different inner layers of the circuit board.

3. the gate potential pattern is connected to a plurality of gate lands (GL1 to GL4) formed on a surface of the circuit board on which the switching elements are mounted and connected to the gate terminals, and to gate through holes (321 to 324) provided for each of the gate lands; The electronic device according to claim 2, wherein the reference potential pattern is connected to a plurality of source lands (SL1 to SL4) formed on the surface of the circuit board on which the switching elements are mounted and connected to the source terminals, and to source through holes (331 to 334) provided for each of the source lands.

4. driver components (381, 382) mounted on a surface of the circuit board opposite to the surface on which the switching elements are mounted, for outputting gate signals and reference potential signals to the switching elements; An electronic device according to any one of claims 1 to 3, wherein a signal line pattern (PG2, PS2) formed on the surface on which the driver component is mounted and the solid pattern are connected by a driver through hole (325, 335).

5. 5. The electronic device according to claim 4, wherein the switching elements connected in parallel are arranged at equal distances from the driver through-hole.

6. the source terminals and the drain terminals are arranged in alternating rows; The electronic device according to any one of claims 1 to 3, wherein the upper arm elements are arranged on one side of a motor voltage pattern (P20), which is a wiring pattern connected to the motor windings, and the lower arm elements are arranged on the other side of the motor voltage pattern, so that the source terminal row of the upper arm elements and the drain terminal row of the lower arm elements are on the same straight line.

7. a two-system configuration in which the inverter is provided for each of two winding sets (26, 27) formed by connecting the motor windings of a plurality of phases, The connection portions between the motor windings and the circuit board are arranged so that the same phases of different systems are adjacent to each other, 2. The electronic device according to claim 1, wherein the switching elements are mounted on the circuit board in a first region on one side of the connection portion and in a second region on the other side of the connection portion in a phase arrangement that is the same as the phase arrangement of the connection portion.

8. The electronic device according to claim 7 , wherein the first region and the second region are provided with the switching elements that constitute the inverter for at least one phase, the switching elements being of a different system from the inverters for the other phases.

9. driver components (381, 382) mounted on the circuit board and outputting drive signals to the switching elements; current sensors (351, 352) mounted on the circuit board to detect current flowing through the motor windings; Furthermore, On the same side of the circuit board, 9. The electronic device according to claim 1, wherein the current sensor, the inverter, and the driver components are arranged in this order from the connection portion (315) between the motor winding and the circuit board.

10. a two-system configuration in which the inverter is provided for each of two winding sets (26, 27) formed by connecting the motor windings of a plurality of phases, A power supply voltage pattern (P19) connected to a power supply terminal of the connector (69) and a ground pattern (P38) connected to a ground terminal are formed adjacent to each other on the circuit board, the switching elements of one system are mounted in a first region that is one side of a virtual line (C2) that passes through the power supply voltage pattern and the ground pattern, and the switching elements of the other system are mounted in a second region that is the other side of the virtual line; The electronic device according to claim 1 , wherein the switching elements are mounted on the circuit board in the same phase arrangement in the first region and the second region.

11. a two-system configuration in which the inverter is provided for each of two winding sets (26, 27) formed by connecting the motor windings of a plurality of phases, 2. The electronic device according to claim 1, wherein the switching elements are mounted on the circuit board so that elements of the same phase in different systems are on the front and back of the same region of the circuit board.

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