Motor drive circuit board, motor, and pump device

Abstract

The present invention improves EMC performance by suppressing noise radiation from a motor drive circuit, and suppresses cost increase. In a multilayer substrate (110) provided with a motor drive circuit (150), on a second layer (112), a second conductive layer (G2) as a common ground pattern (100c) is formed over the entire substrate. On the third layer (113), a third conductive layer (G3), which is a common ground pattern (100c), is formed so as to surround the entire periphery of the power supply system circuit (170). On the fourth layer (114), a fourth conductive layer (G4), which is a common ground pattern (100c), is formed so as to surround the entire periphery of the power supply system circuit (170). The third conductive layer (G3) is provided with a noise protection part (G32) extending along the outer periphery of the power supply system circuit (170) to the outer edge of the substrate. The noise protection part (G32) is connected to the second conductive layer (G2) and the fourth conductive layer (G4) through a plurality of through holes (H1) arranged on the outer edge of the substrate so as to surround the power supply system circuit (170).

Description

Technical Field

[0001] The invention relates to a motor drive circuit substrate, a motor and a pump device. Background Art

[0002] The drive circuit of the motor includes: a signal system circuit including a control element; and a power system circuit including a switching element that outputs a drive current. In a substrate on which the drive circuit of the motor is mounted, when the signal system circuit and the power system circuit are installed on one substrate, it is necessary to arrange the circuits on the substrate at a high density. Therefore, a multilayer substrate is used in which a plurality of layers having wiring patterns and ground patterns constituting the circuit are stacked with an insulating layer therebetween. Patent document 1 describes such a multilayer substrate. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2004-363347 Summary of the invention

[0004] Technical problem to be solved by the invention In recent years, EMC (electromagnetic compatibility) is required for boards on which motor drive circuits are mounted. EMC refers to the compatibility of EMI (electromagnetic interference; radiation, the phenomenon of electromagnetic energy release) and EMS (electromagnetic susceptibility; immunity, the ability to operate without performance degradation or malfunction due to external electromagnetic energy).

[0005] As a countermeasure for EMC, especially EMI (radiation) of a motor drive circuit board, it has been proposed to add a common mode coil to the motor drive circuit. However, adding a new component will increase costs.

[0006] In Patent Document 1, as a countermeasure against EMI, a conductive shield is formed covering the end of a substrate to reduce noise radiation from the end of a multi-layer substrate to the outside. The shield connects the end of a ground layer sandwiching a signal layer, a power layer, and an insulating layer.

[0007] However, in Patent Document 1, the layer forming the circuit pattern and the ground layer are divided into completely different layers, and a shield is formed to connect the ends of the ground layer, which increases the number of layers in the multilayer substrate, and it requires steps that are not included in the conventional manufacturing process. Therefore, the cost increases compared to the conventional multilayer substrate. In addition, the drive circuit includes a signal system circuit and a power system circuit, and a large amount of noise is radiated from the power system circuit through which a large current flows, but the configuration of the signal system circuit and the power system circuit in the multilayer substrate is not considered in Patent Document 1. Therefore, the configuration of the shield cannot be said to be efficient, which is also a factor in the increase in cost.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the EMC performance and suppress the cost increase in a motor drive circuit substrate in which a signal system circuit and a power system circuit are mounted on a single substrate. Technical solutions adopted to solve technical problems

[0009] In order to solve the above-mentioned problems, the present invention provides a motor drive circuit substrate, which is provided with a motor drive circuit on a multi-layer substrate, and the motor drive circuit includes a power supply system circuit and a signal system circuit, the power supply system circuit has a switching element for outputting a driving current, and the signal system circuit has a control element for providing a signal to the switching element. In the multi-layer substrate, a ground pattern for the power supply system circuit and a ground pattern for the signal system circuit constitute a common ground pattern as an integral whole, and the multi-layer substrate includes four layers overlapped in the order of a first layer, a second layer, a third layer and a fourth layer, and the common ground pattern includes a second conductive layer provided on the second layer, a third conductive layer provided on the third layer, and a A fourth conductive layer is disposed on the fourth layer, at least the control element is installed on the first layer, and on the second layer, the second conductive layer is formed on the entire substrate, a third layer circuit including the power system circuit is formed on the third layer, and the third conductive layer is formed to surround the outer periphery of the third layer circuit on the entire circumference, a fourth layer circuit including the power system circuit is formed on the fourth layer, and the fourth conductive layer is formed to surround the outer periphery of the fourth layer circuit on the entire circumference, the third conductive layer has a noise protection portion extending along the outer periphery of the power system circuit, and the noise protection portion is connected to the second conductive layer and the fourth conductive layer through a plurality of through holes arranged to surround the power system circuit.

[0010] In the present invention, the motor drive circuit can be arranged at a high density on the multilayer substrate. In addition, the ground pattern for the signal system circuit and the power system circuit forms an integrated common ground pattern, so the common ground pattern can be arranged continuously and integrally over a wide range. The common ground pattern is arranged over a wide range, and is arranged on the entire substrate in the second layer of the multilayer substrate, surrounds the third layer circuit on the entire circumference in the third layer, and surrounds the fourth layer circuit on the entire circumference in the fourth layer. Therefore, it is possible to shield the radiation of noise from the circuits arranged in each layer to the outside. In particular, in the third layer, the periphery of the power system circuit is surrounded by a common ground pattern (noise protection part) so that there is no gap in the circumference, and the common ground pattern connected to the upper and lower layers (the second layer and the fourth layer) by a through hole configured to surround the power system circuit, so that the noise radiation from the power system circuit can be effectively suppressed. Therefore, the EMC performance is excellent. In addition, the suppression effect of noise radiation is improved by the layout of the pattern and the through hole on the substrate without adding parts, so that the cost increase can be suppressed.

[0011] In the present invention, it is preferred that, in a first region located on one side relative to the center of the multilayer substrate, a plurality of terminal holes for embedding terminals for external connection are arranged along the outer edge of the substrate, the power system circuit in the third layer circuit is arranged in a second region located on the opposite side of the first region relative to the center of the multilayer substrate, the noise protection portion extends along the outer edge of the substrate in the second region, and both ends of the noise protection portion are connected to a portion of the third conductive layer formed in the first region, and the plurality of through holes are arranged along the outer edge of the substrate in the second region. In this way, a common ground pattern can be set in a large range in the first region. In addition, in the second region, the space on the outer peripheral side of the power system circuit is narrow, so a wide common ground pattern cannot be set, but a common ground pattern can be formed in a manner of surrounding the power system loop, and can be connected to the common ground patterns of the upper and lower layers through through holes. Therefore, the radiation of noise to the outside can be effectively suppressed.

[0012] In the present invention, it is preferred that the multilayer substrate includes six layers overlapped in the order of the first layer, the second layer, the third layer, the fourth layer, the fifth layer and the sixth layer, the common ground pattern includes a fifth conductive layer provided on the fifth layer and a sixth conductive layer provided on the sixth layer, the fifth conductive layer is formed on the entire substrate on the fifth layer, the sixth layer circuit including the power system circuit is formed on the sixth layer, and the sixth conductive layer is formed to surround the outer periphery of the sixth layer circuit on the entire circumference, and the fifth conductive layer and the sixth conductive layer are connected to the second conductive layer, the third conductive layer and the fourth conductive layer through the through hole. In this way, the configuration space of the circuit can be ensured in the sixth layer, so the power system circuit can be arranged in a wider area. Therefore, a large driving current can be provided. In addition, the common ground pattern is provided on the entire substrate in the fifth layer, and surrounds the sixth layer circuit on the entire circumference in the sixth layer, so that the noise radiation from the power system circuit to the outside can be effectively shielded by the ground pattern. Therefore, it is possible to improve the EMC performance while suppressing the cost increase.

[0013] In the present invention, it is preferred that, in a first region located on one side relative to the center of the multilayer substrate, a plurality of terminal holes for embedding terminals for external connection are arranged along the outer edge of the substrate, and the power system circuits of the third layer circuit, the fourth layer circuit, and the sixth layer circuit are arranged in a second region located on the opposite side of the first region relative to the center of the multilayer substrate, in the third layer, the noise protection portion extends along the outer edge of the substrate in the second region, and both ends of the noise protection portion are connected to the portion of the third conductive layer formed in the first region, in the fourth layer, the portion of the fourth conductive layer overlapping with the noise protection portion extends along the outer edge of the substrate in the second region, in the sixth layer, the portion of the sixth conductive layer overlapping with the noise protection portion extends along the outer edge of the substrate in the second region, and the plurality of through holes are arranged along the outer edge of the substrate in the second region. In this way, in each layer where the circuit is formed, a common ground pattern can be provided over a large area in the first region. In addition, in the second region, the space on the outer peripheral side of the power system circuit is narrow, so a wide common ground pattern cannot be provided, but a common ground pattern can be formed in a manner of surrounding the power system circuit, and can be connected to the common ground pattern of the upper and lower layers by using through holes. Therefore, it is possible to effectively suppress the radiation of noise to the outside.

[0014] In the present invention, it is preferred that the motor drive circuit has a noise countermeasure electronic component, the noise countermeasure electronic component includes an inductor, and the common ground pattern is formed in each layer of the multilayer substrate except for the region overlapping with the inductor. In this way, the generation of stray capacitance between the inductor and the common ground pattern can be suppressed. Therefore, the generation of magnetic lines of force due to the current flowing through the inductor can be suppressed, thereby suppressing the eddy current generated by the magnetic lines of force passing through the conductor constituting the motor drive circuit, and the circuit operation problems and noise caused by the eddy current can be suppressed.

[0015] In the present invention, it is preferred that the noise countermeasure electronic component includes a first capacitor and a second capacitor, and the first capacitor and the second capacitor connect the driving voltage line connected in series with the inductor to the common ground pattern at two locations on the power supply side and the switching element side relative to the inductor. In this way, the inductor and the two capacitors arranged before and after the inductor act as a π-type low-pass filter, thereby filtering out high-frequency noise from the power supply side.

[0016] In the present invention, it is preferred that the noise countermeasure electronic component includes a third capacitor with a smaller capacity than the first capacitor, the first capacitor is configured on the power supply side relative to the inductor, and the third capacitor connects the drive voltage line to the common ground pattern on the power supply side relative to the first capacitor. In this way, at a position closer to the power supply side than the first capacitor, the third capacitor can be used to first reduce high-frequency noise (e.g., MHz-level noise) that is higher in frequency than the noise that can be reduced by the first capacitor (e.g., KHz-level noise). Generally speaking, the overall noise can be reduced by reducing the high-frequency noise first, so this configuration can enhance the noise reduction effect when noise is generated on the power supply side.

[0017] In the present invention, it is preferred that the noise countermeasure electronic component includes a fourth capacitor with a smaller capacity than the second capacitor, the second capacitor is configured on the switching element side relative to the inductor, and the fourth capacitor connects the drive voltage line to the common ground pattern on the switching element side relative to the second capacitor. In this way, at a position closer to the switching element side than the second capacitor, the fourth capacitor can be used to first reduce high-frequency noise (e.g., MHz-level noise) that is higher in frequency than the noise (e.g., KHz-level noise) that can be reduced by the second capacitor. Generally speaking, the overall noise can be reduced by reducing the high-frequency noise first, so this configuration can enhance the noise reduction effect when noise is generated on the switching element side.

[0018] In the present invention, it is preferred that a fixing portion and a terminal soldering portion are provided at the outer edge of the multilayer substrate, a fixing component for fixing the multilayer substrate is arranged at the fixing portion, a terminal for external connection is soldered to the terminal soldering portion, and a connector through hole for plugging and unplugging a connector pin is provided between the fixing portion and the terminal soldering portion in the outer edge of the multilayer substrate. In this way, by using the through hole as a hole for plugging and unplugging the connector pin, the connector can be connected from either the front or back side of the substrate. Therefore, in a state where the multilayer substrate is fixed to the motor housing, the connector can be connected to the substrate to write a program, etc. In addition, by providing a connector through hole between the position where the terminal is soldered and the position where the housing is screwed (i.e., the position where the substrate is fixed), the deformation of the substrate can be suppressed when the connector is plugged and unplugged. Therefore, the stress applied to the solder can be alleviated, so that the occurrence of solder cracks can be suppressed, and poor conduction can be suppressed.

[0019] Next, when the motor driving circuit substrate of the present invention is applied to a motor, the motor includes: the motor driving circuit substrate described above; and a coil to which a driving current output from the motor driving circuit substrate is supplied.

[0020] Next, when the motor of the present invention is applied to a pump device, the pump device has an impeller driven to rotate by the motor. Effects of the Invention

[0021] In the present invention, the motor drive circuit can be arranged at a high density on the multilayer substrate. In addition, the ground pattern for the signal system circuit and the ground pattern for the power system circuit form an integrated common ground pattern, so the common ground pattern can be arranged continuously and integrally over a wide range. The common ground pattern is arranged over a wide range, and is arranged on the entire substrate in the second layer of the multilayer substrate, surrounds the third layer circuit on the entire circumference in the third layer, and surrounds the fourth layer circuit on the entire circumference in the fourth layer. Therefore, it is possible to shield the radiation of noise from the circuits arranged in each layer to the outside. In particular, in the third layer, the periphery of the power system circuit is surrounded by a common ground pattern (noise protection part) so that there is no gap in the circumference, and the common ground pattern connected to the upper and lower layers (the second layer and the fourth layer) by a through hole configured to surround the power system circuit, so that the noise radiation from the power system circuit can be effectively suppressed. Therefore, the EMC performance is excellent. In addition, the suppression effect of noise radiation is improved by the layout of the pattern and the through hole on the substrate without adding parts, so that the cost increase can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a perspective view of a pump device including a motor to which the present invention is applied. Figure 2 yes Figure 1 A cross-sectional view of the pump assembly is shown. Figure 3 It is shown from Figure 1 The pump device shown is an exploded perspective view with the cover removed. Figure 4 This is an explanatory diagram of the motor drive circuit mounted on the motor drive circuit substrate of the first embodiment. Figure 5 It is a top view of the motor drive circuit substrate according to the first embodiment. Figure 6 It is an explanatory diagram of a common ground pattern formed on the motor drive circuit substrate according to the first embodiment. Figure 7 It is a plan view of the first surface and the second surface of the motor drive circuit substrate according to the second embodiment. Figure 8 This is an explanatory diagram of a motor drive circuit mounted on a motor drive circuit substrate according to a second embodiment. Fig. 9 It is an explanatory diagram of a common ground pattern formed on a motor drive circuit substrate according to the second embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the motor drive circuit substrate, the motor, and the pump device to which the present invention is applied will be described with reference to the accompanying drawings. In the following description, the axial direction refers to the direction in which the rotation axis L of the motor extends, and the radial direction in the radial inner side and the radial outer side refers to the radial direction centered on the rotation axis L. The circumferential direction refers to the rotation direction centered on the rotation axis L. In addition, when the direction along the rotation axis L is defined as the axial direction, one side of the axial direction is defined as L1, and the other side of the axial direction is defined as L2.

[0024] [Implementation Method 1] (Overall structure of the pump device) Figure 1 It is a perspective view of a pump device 1 including a motor 10 to which the present invention is applied. Figure 2 yes Figure 1 A cross-sectional view of the pump device 1 is shown. Figure 1 and Figure 2 As shown, the pump device 1 includes: a housing 2 having a suction pipe 21 and a discharge pipe 22; a motor 10 disposed on one side L1 of the housing 2 in the axial direction; and an impeller 25 disposed in a chamber 20 inside the housing 2. The impeller 25 is driven by the motor 10 to rotate around the rotation axis L.

[0025] like Figure 2 As shown, the pump chamber 20 is provided between the housing 2 and the casing 6. The housing 2 includes a wall surface 23 on the other side L2 of the axial direction of the pump chamber 20 and a side wall 29 extending in the circumferential direction. The motor 10 includes: a cylindrical stator 3; a rotor 4 provided inside the stator 3; a casing 6 made of resin covering the stator 3; and a support shaft 5 supporting the rotor 4 so as to be rotatable.

[0026] In the motor 10, the stator 3 has: a stator core 31; insulators 32 and 33 held by the stator core 31; and a coil 35 wound around the stator core 31 via the insulators 32 and 33. The stator core 31 has: an annular portion 311 centered on the rotation axis L; and a plurality of salient poles 312 protruding radially inward from the annular portion 311. The insulators 32 and 33 overlap the stator core 31 from both sides in the axial direction and cover each of the plurality of salient poles 312. The coil 35 is wound around the salient poles 312 via the insulators 32 and 33. The motor 10 is a three-phase motor.

[0027] The rotor 4 includes a cylindrical portion 40 extending in the axial direction, and a cylindrical magnet 47 is held on the outer peripheral surface of the cylindrical portion 40 so as to face the stator 3 on the radial inner side. A disc-shaped flange portion 45 is formed at the end of the cylindrical portion 40 on the other side L2 in the axial direction, and the disc 26 is connected to the flange portion 45 from the other side L2 in the axial direction. A plurality of blades 261 are formed at equal angles on the surface of the disc 26 facing the flange portion 45, and the disc 26 is fixed to the flange portion 45 via the blades 261. Therefore, the flange portion 45 and the disc 26 constitute the impeller 25 connected to the cylindrical portion 40 of the rotor 4.

[0028] In the rotor 4, a cylindrical radial bearing 11 is held radially inside the cylindrical portion 40. The rotor 4 is rotatably supported by the support shaft 5 via the radial bearing 11. The end portion of the support shaft 5 on one side L1 in the axial direction is held non-rotatably by the bottom wall 63 of the housing 6. The housing 2 includes: a cylindrical portion 28 disposed at the radial center of the pump chamber 20; and a support portion 27 that supports the cylindrical portion 28, and the end portion of the support shaft 5 on the other side L2 in the axial direction is supported by the cylindrical portion 28 of the housing 2 via the thrust bearing 12.

[0029] The housing 6 is a resin sealing member 60 that covers the stator 3 from both radial sides (i.e., the inner circumference and the outer circumference) and both axial sides. Therefore, the housing 6 includes: a first partition wall 61 that constitutes a part of the wall surface of the pump chamber 20; a second partition wall 62 that is interposed between the stator 3 and the magnet 47; and a cylindrical body portion 66 that covers the stator 3 from the radial outer side.

[0030] (Motor drive circuit board) Figure 3 It is shown from Figure 1 The pump device 1 shown in FIG. 1 is an exploded perspective view of a state where the cover 18 is removed. Figure 3 The axis direction is Figure 1 and Figure 2 The upper and lower sides are opposite, and one side L1 in the axial direction is the upper side in the figure.

[0031] like Figure 2 and Figure 3As shown, the cover 18 is fixed to the end 64 of the one side L1 of the axial direction of the housing 6 from the one side L1 in the axial direction. A motor drive circuit substrate 19 is provided between the cover 18 and the bottom wall 63 of the housing 6, and is provided with a circuit for controlling the power supply to the coil 35, etc. A straight portion 196 cut out in a straight line is provided on the outer periphery of the motor drive circuit substrate 19, and two notches 197 as a fixing portion fixed to the housing 6 are provided on both sides of the circumferential direction of the straight portion 196. The motor drive circuit substrate 19 is fixed to the housing 6 by screws 91, and the screws 91 are self-tapping screws passing through the two notches 197 (fixing portions). In addition, the motor drive circuit substrate 19 is positioned in the circumferential direction by fitting the protrusion 645 of the housing 6 into the three notches 199 provided on the opposite side of the straight portion 196 in the radial direction.

[0032] A plurality of terminal holes 190 are provided on the motor drive circuit substrate 19, and the metal winding terminal 71 that penetrates the bottom wall 63 of the housing 6 from the stator 3 and protrudes toward one side L1 in the axial direction is soldered in a state of being embedded in the terminal hole 190. The terminal hole 190 is provided in a region on the radially opposite side of the straight portion 196 of the outer peripheral edge of the motor drive circuit substrate 19. In Embodiment 1, a total of four winding terminals 71 protrude from the four terminal holes 190. Three of the four winding terminals 71 are respectively connected to one end of the winding constituting the three coils 35 connected in series. The remaining one winding terminal 71 is a common (C) terminal, and is electrically connected to the other end of the winding.

[0033] The motor drive circuit substrate 19 is provided with a plurality of terminal holes 195, and the metal connector terminals 75 held by the housing 6 are soldered in a state of being inserted into the terminal holes 195. The terminal holes 195 are arranged in a straight line along the straight portion 196 of the motor drive circuit substrate 19. The motor drive circuit 150 (see FIG. 1 ) is formed on the motor drive circuit substrate 19. Figure 4 ) wiring electrically connected to the winding terminal 71 and the connector terminal 75, etc.

[0034] The housing 6 is formed with a cylindrical connector housing 69 protruding toward the outer peripheral side, and the end of the connector terminal 75 is located inside the connector housing 69. Therefore, when the connector is connected to the connector housing 69 and a signal is provided, the signal is input to the motor drive circuit 150 via the connector terminal 75, and the drive current generated by the motor drive circuit 150 is provided to each coil 35 via the winding terminal 71. As a result, the rotor 4 rotates around the rotation axis L. As a result, the impeller 25 rotates in the pump chamber 20, and the inside of the pump chamber 20 becomes negative pressure, so that the fluid is sucked into the pump chamber 20 from the suction pipe 21 and discharged from the discharge pipe 22.

[0035] (Motor drive circuit) Figure 4This is an explanatory diagram of the motor drive circuit 150 mounted on the motor drive circuit substrate 19 according to the first embodiment. Figure 4 1 shows a schematic structure of the motor drive circuit 150. As described above, the motor 10 is a three-phase motor. In the following description, the three-phase coil 35 is sometimes described by marking U, V, and W indicating each phase, but when it is not necessary to specify the phase, the coil 35 is described without marking U, V, and W indicating each phase.

[0036] The motor drive circuit substrate 19 is Figure 4 The motor drive circuit 150 is shown mounted on the multi-layer substrate 110 (see Figure 5 and Figure 6 ) on the substrate. Figure 4 As shown, the motor drive circuit 150 includes: a signal system circuit 160, which includes a motor control unit 161 that controls the rotation of the motor 10 using a PWM signal; a power system circuit 170, which includes an inverter that supplies a drive current to the three-phase coil 35 based on an output signal from the motor control unit 161; a drive voltage line 135 that supplies a drive voltage to the power system circuit 170; and a common line 140 that is connected to a neutral point 165 of the three-phase coils 35U, 35V, and 35W. The drive voltage line 135 supplies a rated voltage of 12V to the motor control unit 161 and the power system circuit 170.

[0037] The motor drive circuit 150 further includes a control signal line 133 for inputting a PWM signal from an external device to the motor control unit 161 , and an FG output line 134 for transmitting a rotation speed signal corresponding to the rotation speed of the motor 10 to the external device.

[0038] The motor drive circuit substrate 19 has four connector terminals 75, which include a constant voltage terminal 751, a first signal terminal 752, a second signal terminal 753, and a ground terminal 754, which will be described below. The constant voltage terminal 751 is electrically connected to the drive voltage line 135, the first signal terminal 752 is electrically connected to the control signal line 133, and the second signal terminal 753 is electrically connected to the FG output line 134. The ground terminal 754 is electrically connected to the ground pattern 100 of the motor drive circuit substrate 19.

[0039] The driving voltage line 135 is branched into a first line 136 and a second line 137, and power is supplied to the motor control unit 161 via the first line 136 and the second line 137. The second line 137 is electrically connected to the motor control unit 161 via the resistor R32. The capacitors 122 and 123 are electrically connected in series between the driving voltage line 135 and the ground pattern 100. The common line 140 is electrically connected between the capacitors 122 and 123. The ground terminal 754 to which the ground potential is applied is electrically connected between the capacitor 123 and the ground pattern 100.

[0040] The motor drive circuit 150 includes a plurality of noise countermeasure electronic components 180 electrically connected to the drive voltage line 135 after the capacitors 122 and 123. The noise countermeasure electronic components 180 of the first embodiment include: an inductor 181 connected in series to the drive voltage line 135; a diode 182 electrically connected between the drive voltage line 135 and the ground pattern 100 before the inductor 181; and a plurality of capacitors electrically connected between the drive voltage line 135 and the ground pattern 100 before and after the inductor 181. In the first embodiment, four capacitors are included: a first capacitor C1 and a second capacitor C2 which are electrolytic capacitors; and a third capacitor C3 and a fourth capacitor C4. The diode 182 protects the components in the motor drive circuit 150 from the influence of surge voltage.

[0041] In addition, the noise countermeasure electronic component 180 is not limited to these components, and other components may be used. For example, ferrite beads may also be used. In addition, the number and arrangement of capacitors may be changed.

[0042] The inductor 181 is, for example, a choke coil. The first capacitor C1 is arranged immediately before the inductor 181. The second capacitor C2 is arranged immediately after the inductor 181. The three elements of the inductor 181, the first capacitor C1 and the second capacitor C2 are used as a π-type low-pass filter. The diode 182 is arranged before the first capacitor C1, and the third capacitor C3 is arranged before the diode 182. The capacity of the third capacitor C3 is smaller than the capacity of the first capacitor C1. The fourth capacitor C4 is arranged after the second capacitor C2. The capacity of the fourth capacitor C4 is smaller than the capacity of the second capacitor C2. In addition, after the fourth capacitor C4, the capacitor 128 as an electrolytic capacitor is electrically connected between the first line 136 and the ground pattern 100.

[0043] The control signal line 133 transmits a PWM signal from an external device to the motor control section 161. The resistor R3 is electrically connected in series with the control signal line 133. The portion of the control signal line 133 between the resistor R3 and the motor control section 161 is electrically connected to the ground pattern 100 via the capacitor 124. Sometimes the portion of the control signal line 133 between the first signal terminal 752 and the resistor R3 is electrically connected to the ground pattern 100 via the capacitor 126, in which case the portion between the connection position of the capacitor 126 and the resistor R3 is electrically connected to the first line 136 via the third line 138. The resistor R2 is electrically connected to the third line 138 in series.

[0044] The FG output line 134 transmits the speed signal of the motor 10 output from the motor control unit 161 to an external device. The capacitor 125, the resistor R1, and the NOT gate Q7 are connected to the FG output line 134. The capacitor 125 is electrically connected between the FG output line 134 and the ground pattern 100. The resistor R1 is electrically connected to the FG output line 134 in series between the connection position of the capacitor 125 and the motor control unit 161. The NOT gate Q7 is electrically connected to the FG output line 134 in series between the resistor R1 and the motor control unit 161.

[0045] The motor control unit 161 is composed of a control element such as an IC chip mounted on the motor drive circuit substrate 19. The motor control unit 161 outputs an output signal for controlling the power system circuit 170 based on a PWM signal input from an external device. In addition, the motor control unit 161 outputs a speed signal corresponding to the speed of the rotor 4 to the external device. The external device outputs a PWM signal to the motor control unit 161 so as to set the motor 10 to a desired speed based on the speed signal.

[0046] The power system circuit 170 includes: switching elements Q1 and Q2 for the U-phase coil; switching elements Q3 and Q4 for the V-phase coil; and switching elements Q5 and Q6 for the W-phase coil. For example, MOS-type FETs are used as the switching elements Q1 to Q6. The drains of the switching elements Q1, Q3, and Q5 are connected to the drive voltage line 135, and the sources of the switching elements Q2, Q4, and Q6 are connected to the ground pattern 100 via the shunt resistor Rs. Both ends of the shunt resistor Rs are connected to the motor control unit 161 via the output lines 131 and 132. Resistors R33 and R34 are electrically connected in series to the output lines 131 and 132.

[0047] The source of the switching element Q1 and the drain of the switching element Q2 are connected to a capacitor 151, the source of the switching element Q3 and the drain of the switching element Q4 are connected to a capacitor 152, and the source of the switching element Q5 and the drain of the switching element Q6 are connected to a capacitor 153. The capacitors 151 to 153 are used as charging / discharging capacitors of the bootstrap circuit. Bootstrap diodes D31 to D33 are connected between the capacitors 151 to 153 and the motor control unit 161, respectively. The diodes D31 to D33 are connected to the motor control unit 161 via the resistor R31.

[0048] Resistors R11 to R16 are connected between the gate and source of each switching element Q1 to Q6. Resistors R21 to R26 are connected between the gate of each switching element Q1 to Q6 and the motor control unit 161. Filters 141 to 146 are connected between the drain and source of each switching element Q1 to Q6. Filters 141 to 146 are composed of resistors and capacitors connected in series.

[0049] In the power system circuit 170 , the switching elements Q1 to Q6 are switched based on the output signal output by the motor control unit 161 , and a three-phase AC driving current is supplied to the coil 35 .

[0050] (Multilayer substrate) Figure 5 It is a top view of the motor drive circuit board 19 according to the first embodiment. Figure 6 1 is an explanatory diagram of a common ground pattern 100c formed on a motor drive circuit substrate 19 of Embodiment 1. The motor drive circuit substrate 19 is a multilayer substrate 110 having multiple layers. In the multilayer substrate 110, multiple insulating layers stacked on a substrate body constitute multiple layers in which conductive layers such as wiring and electrodes are arranged, and the conductive layers formed in different layers are electrically connected through contact holes penetrating the insulating layers. The conductive layers such as wiring and electrodes are composed of copper layers.

[0051] like Figure 5 As shown, in the first area 101 located on one side relative to the center O of the multilayer substrate 110, a plurality of terminal holes 195 for the connector terminals 75 to fit into are provided. The plurality of terminal holes 195 are arranged in a straight line along a straight line portion 196 of the outer edge of the substrate. The plurality of terminal holes 195 include a first terminal hole 191, a second terminal hole 192, a third terminal hole 193, and a fourth terminal hole 194, which are respectively provided for the connector terminals 75 to fit into. Figure 4 The constant voltage terminal 751, the first signal terminal 752, the second signal terminal 753 and the ground terminal 754 are shown embedded. Therefore, among the plurality of terminal holes 195, the two terminal holes (the first terminal hole 191 and the fourth terminal hole 194) located at both ends correspond to the constant voltage. The wiring extending from the first terminal hole 191 and the fourth terminal hole 194 corresponding to the constant voltage can be used as a shielding wiring.

[0052] like Figure 5 As shown, the switching elements Q1 to Q6 are mounted in the second region 102 located on the opposite side of the first region 101 with respect to the center O of the multilayer substrate 110. When two regions located on both sides of the direction intersecting with the imaginary line P extending straight through the first region 101, the center O, and the second region 102 are defined as the third region 103 and the fourth region 104, the motor control unit 161 is arranged at a position closer to the third region 103 than the center O. In addition, the inductor 181 is arranged in the fourth region 104. By arranging the inductor 181 near the terminal hole 195 (the first terminal hole 191 or the fourth terminal hole 194) corresponding to the constant voltage, the EMC performance can be particularly improved.

[0053] Here, if Figure 4As shown, when the circuit including the motor control unit 161 is set as a relatively low voltage signal system circuit 160, and the circuit including the switching elements Q1 to Q6 that output the driving current is set as a relatively high voltage power system circuit 170, as shown in FIG. Figure 6 As shown, the ground pattern 100 includes a common ground pattern 100c electrically connected to both the signal system circuit 160 and the power system circuit 170. The common ground pattern 100c serves as both the ground pattern 100 of the signal system circuit 160 and the ground pattern 100 of the power system circuit 170.

[0054] The multi-layer substrate 110 has four layers: Figure 6 The first layer 111, the second layer 112, the third layer 113 and the fourth layer 114 are shown. Among the four layers of the multi-layer substrate 110, the top first layer 111 is formed with a pad or the like (not shown), on which components constituting the Figure 4 The electronic components of the motor driving circuit 150 shown in the figure. Conductive layers used as the common ground pattern 100c are formed on the first layer 111, the second layer 112, the third layer 113 and the fourth layer 114, respectively. The common ground pattern 100c includes a first conductive layer G1 formed on the first layer 111, a second conductive layer G2 formed on the second layer 112, a third conductive layer G3 formed on the third layer 113, and a fourth conductive layer G4 formed on the fourth layer 114. Figure 6 In FIG. 1 , regions where these conductive layers are formed are shown as shaded regions.

[0055] like Figure 6 As shown, Figure 4 The motor driving circuit 150 shown includes a first layer circuit 111C disposed in the first layer 111, a third layer circuit 113C disposed in the third layer, and a fourth layer circuit 114C disposed in the fourth layer. Here, Figure 6 The shapes of the circuits and conductive layers of each layer shown show the approximate arrangement areas of the electronic components, wiring, conductive layers, etc. constituting the circuits, and detailed wiring, contact holes, etc. are not shown. For example, the wiring arrangement area extending from the first layer circuit 111C to the terminal hole 195 at the outer edge of the substrate is not shown. The conductive layer is not formed around the contact holes and wiring.

[0056] The first layer circuit 111C, the third layer circuit 113C, and the fourth layer circuit 114C respectively include a portion of the signal system circuit 160 and a portion of the power system circuit 170. Figure 6As shown, the first layer circuit 111C includes: a signal system circuit 160, which is arranged centered on the central area of ​​the substrate; and a power system circuit 170, which is arranged in an area centered on the second area 102 and extending to the third area 103 and the fourth area 104. The first conductive layer G1 is formed centered on the first area 101 and extends to a portion of the third area 103 and the fourth area 104.

[0057] In the second layer 112, the second conductive layer G2 is formed on the entire substrate and extends to the outer edge of the substrate. In the third layer 113, the third conductive layer G3 is formed to surround the outer periphery of the third layer circuit 113C on the entire circumference. In addition, in the fourth layer 114, the fourth conductive layer G4 is formed to surround the outer periphery of the fourth layer circuit 114C on the entire circumference.

[0058] like Figure 6 As shown, the third layer circuit 113C includes: a signal system circuit 160 arranged in the central area of ​​the substrate; and a power system circuit 170 arranged in an area extending from the second area 102 to the third area 103 and the fourth area 104. The power system circuit 170 extends to the vicinity of the outer edge of the substrate and extends to the four terminal holes 190 to which the winding terminals 71 are soldered. The third conductive layer G3 includes: a third conductive layer body G31, which is formed to surround the third layer circuit 113C from the first area 101, the third area 103 and the fourth area 104 side; and a noise protection part G32, which extends along the outer edge of the substrate in the second area 102 to surround the outer periphery of the power system circuit 170. The noise protection part G32 extends in an arc shape, and the two ends in the circumferential direction extend to the third area 103 and the fourth area 104, and is connected to the third conductive layer body G31.

[0059] The fourth layer circuit 114C includes a signal system circuit 160 configured in the central area of ​​the substrate and a power system circuit 170 configured in the second area 102. The configuration area of ​​the fourth layer circuit 114C is narrower than the configuration area of ​​the third layer circuit 113C as a whole. The fourth conductive layer G4 includes a portion extending along the outer edge of the substrate in the second area 102 and overlapping with the noise protection portion G32 of the third conductive layer G3.

[0060] In addition, one or both of the third layer circuit 113C and the fourth layer circuit 114C may include the power system circuit 170 instead of the signal system circuit 160 .

[0061] The common ground pattern 100c is not formed in a portion of each layer of the multilayer substrate 110 that overlaps with the inductor 181 mounted on the first layer 111. Figure 6 As shown, each of the second conductive layer G2 , the third conductive layer G3 , and the fourth conductive layer G4 has a shape in which a portion overlapping the inductor 181 is hollowed out.

[0062] like Figure 5 and Figure 6 As shown, the multilayer substrate 110 is provided with a plurality of through holes H1 arranged along the outer edge of the substrate in the second region 102. The multilayer substrate 110 is also provided with a plurality of through holes H2 for connectors, which are arranged along the outer edge of the substrate between the notch 197 (fixed portion with the housing 6) and the terminal hole 195 arranged in the third region 103. The through holes H1 arranged at the outer edge of the substrate in the second region 102 are arranged in a manner to surround the outer periphery of the power system circuit 170 of the third layer circuit 113C. The through holes H1 are formed in the region of the noise protection portion G32 of the third conductive layer G3. The noise protection portion G32, the second conductive layer G2, and the fourth conductive layer G4 are electrically connected through the through holes H1.

[0063] In Embodiment 1, most of the power system circuit 170 is concentrated in a layer (third layer 113) between two layers (second layer 112 and fourth layer 114), wherein the two layers (second layer 112 and fourth layer 114) are provided with a common ground pattern 100c in a large range. Therefore, in the third layer circuit 113C, the configuration area of ​​the power system circuit 170 is ensured by extending the configuration area for the power system circuit 170 to the vicinity of the outer edge of the substrate. As a result, the space for forming the noise protection portion G32 is narrowed. The noise protection portion G32 has a pattern width of about 0.5 mm at its thinnest portion. Since the inner diameter of the through hole H1 configured in the noise protection portion G32 is about 0.3 mm, the pattern width of the noise protection portion G32 is greater than the inner diameter of the through hole H1. Even if the noise protection part G32 is very thin, it can continuously surround the periphery of the power system circuit 170 of the third layer 113, and be connected to the common ground pattern 100c (second conductive layer G2, fourth conductive layer G2) of the upper and lower layers through the through hole H1, thereby reducing the noise radiation from the power system circuit 170 concentrated in the third layer 113 to the outside of the substrate.

[0064] (Main Effects of Embodiment 1) As described above, the pump device 1 of the first embodiment includes the motor 10 and the impeller 25 driven to rotate by the motor 10. The motor 10 includes the motor drive circuit substrate 19, which is provided with the motor drive circuit 150 on the multilayer substrate 110. The motor drive circuit 150 includes: a power system circuit 170, which includes switching elements Q1 to Q6 that output drive current; and a signal system circuit 160, which includes a motor control unit 161 (control element) that provides a control signal to the switching elements Q1 to Q6. In the multilayer substrate 110, the ground pattern 100 for the power system circuit 170 and the ground pattern 100 for the signal system circuit 160 form an integrated common ground pattern 100c. The multilayer substrate 110 includes four layers stacked in sequence: a first layer 111, a second layer 112, a third layer 113, and a fourth layer 114. The common ground pattern 100c includes: a second conductive layer G2 provided on the second layer 112; a third conductive layer G3 provided on the third layer 113; and a fourth conductive layer G4 provided on the fourth layer 114. The motor control unit 161 and the switching elements Q1 to Q6 are mounted on the first layer 111. In the second layer 112, the second conductive layer G2 is formed on the entire substrate. A third layer circuit 113C including a power system circuit 170 is formed on the third layer 113, and the third conductive layer G3 is formed to surround the outer periphery of the third layer circuit 113C over the entire circumference. A fourth layer circuit 114C including a power system circuit 170 is formed on the fourth layer 114, and the fourth conductive layer G4 is formed to surround the outer periphery of the fourth layer circuit 114C over the entire circumference. The third conductive layer G3 has a noise protection portion G32 extending along the outer periphery of the power system circuit 170. The noise protection portion G32 is connected to the second conductive layer G2 and the fourth conductive layer G4 through a plurality of vias H1 arranged to surround the power system circuit 170 .

[0065] In Embodiment 1, since the multilayer substrate 110 is used as the motor drive circuit substrate 19, the motor drive circuit 150 can be mounted at a high density. In addition, the common ground pattern 100c can be provided continuously and integrally over a wide range. The common ground pattern 100c is provided over a wide range: it is provided over the entire substrate in the second layer 112 of the multilayer substrate 110, surrounds the third layer circuit 113C over the entire circumference in the third layer 113, and surrounds the fourth layer circuit 114C over the entire circumference in the fourth layer 114. Therefore, it is possible to shield the noise radiated to the outside from the power system circuit 170 provided in each layer. In particular, in the third layer 113, the outer periphery of the power system circuit 170 is surrounded by the noise protection portion G32 so that no gap is generated in the circumferential direction, and is connected to the common ground pattern 100c of the upper and lower layers (the second layer 112 and the fourth layer 114) through the through hole H1 configured to surround the power system circuit 170, so that the noise radiation from the power system circuit 170 can be effectively suppressed. Therefore, the EMC performance is excellent. Furthermore, since the effect of suppressing noise radiation is enhanced by the pattern on the substrate and the layout of the through hole H1 without adding any components, an increase in cost can be suppressed.

[0066] In Embodiment 1, in the first region 101 located on one side relative to the center of the multilayer substrate 110, a plurality of terminal holes 195 are arranged along the outer edge of the substrate. The power system circuit 170 of the third layer 113 is arranged in the second region 102 located on the opposite side of the first region 101 relative to the center of the multilayer substrate 110. The noise protection portion G32 extends along the outer edge of the substrate in the second region 102, and both ends of the noise protection portion G32 are connected to a portion of the third conductive layer G3 (third conductive layer body G31) formed in the first region 101. A plurality of through holes H1 are arranged along the outer edge of the substrate in the second region 102.

[0067] With such a pattern configuration, in Embodiment 1, the common ground pattern 100c (third conductive layer body G31) can be widely provided in the first region 101 of the third layer 113, and the power system circuit 170 can be widely provided in the second region 102. When the power system circuit 170 is widely provided in the second region 102 (for example, when the power system circuit 170 is concentrated in the third layer 113), the space on the outer peripheral side of the power system circuit 170 becomes narrow, and therefore, the noise protection portion G32 cannot be made wider, however, in Embodiment 1, the noise protection portion G32 is formed to surround the power system circuit 170 over the entire circumference, and is connected to the common ground pattern 100c of the upper and lower layers through the through hole H1, and therefore, the noise radiation to the outside can be suppressed.

[0068] In Embodiment 1, the motor drive circuit 150 is provided with the noise countermeasure electronic component 180 in addition to the common ground pattern 100c, and therefore has excellent EMC performance. The noise countermeasure electronic component 180 includes an inductor 181, and the common ground pattern 100c is formed in a region of each layer of the multilayer substrate 110 except for a region overlapping with the inductor 181. In this way, by configuring the pattern so that the inductor 181 and the common ground pattern 100c are not opposite, it is possible to suppress the occurrence of stray capacitance between the inductor 181 and the common ground pattern 100c. Therefore, it is possible to suppress the generation of magnetic lines of force caused by the current flowing through the inductor 181, and therefore it is possible to suppress the eddy current caused by the magnetic lines of force passing through the conductor constituting the motor drive circuit 150, and it is possible to suppress the failure and noise of the circuit operation caused by the eddy current.

[0069] In Embodiment 1, the noise countermeasure electronic component 180 includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 and the second capacitor C2 connect the driving voltage line 135 connected in series with the inductor 181 to the common ground pattern 100c at two locations on the power supply side and the switching element Q1 to Q6 side relative to the inductor 181. Thus, the inductor 181 and the two capacitors arranged before and after the inductor 181 function as a π-type low-pass filter, thereby filtering out high-frequency noise from the power supply side.

[0070] In Embodiment 1, the noise countermeasure electronic component 180 includes a third capacitor C3 having a capacitance smaller than that of the first capacitor C1. The first capacitor C1 is arranged on the power supply side relative to the inductor 181, and the third capacitor C3 connects the drive voltage line 135 to the common ground pattern 100c on the power supply side relative to the first capacitor C1. In other words, the capacitance of the capacitors connected to the drive voltage line 135 is arranged in the order of increasing capacitance from the power supply side to the inductor 181 side. Thus, at a position closer to the power supply side than the first capacitor C1, the third capacitor C3 can be used to first reduce high-frequency noise (e.g., MHz-level noise) that is higher in frequency than the noise (e.g., KHz-level noise) that can be reduced by the first capacitor C1. Generally speaking, reducing the high-frequency noise first can reduce the overall noise, so this arrangement order can enhance the noise reduction effect when noise is emitted from the power supply side.

[0071] In Embodiment 1, the noise countermeasure electronic component 180 includes a fourth capacitor C4 having a smaller capacitance than the second capacitor C2. The second capacitor C2 is arranged on the switching element Q1-Q6 side relative to the inductor 181, and the fourth capacitor C4 connects the drive voltage line 135 to the common ground pattern 100c on the switching element Q1-Q6 side relative to the second capacitor C2. In other words, the capacitance of the capacitor connected to the drive voltage line 135 is arranged in the order of increasing capacitance from the switching element side to the inductor 181 side. Thus, at a position closer to the switching element Q1-Q6 side than the second capacitor C2, the fourth capacitor C4 can be used to first reduce high-frequency noise (e.g., MHz-level noise) with a frequency higher than the noise (e.g., KHz-level noise) that can be reduced by the second capacitor C2. Generally speaking, reducing the high-frequency noise first can reduce the overall noise, so through this configuration, the noise reduction effect when noise is emitted from the switching element Q1-Q6 side can be enhanced.

[0072] In Embodiment 1, the outer edge of the multilayer substrate 110 is provided with a notch 197 and a terminal hole 195, the notch 197 is a fixing portion provided with a fixing member (e.g., a screw) for fixing the multilayer substrate 110, and the terminal hole 195 is a terminal soldering portion for soldering a terminal for external connection. In the outer edge of the multilayer substrate 110, a connector through hole H2 for plugging and unplugging a connector pin is provided between the notch 197 as a screw fixing portion and the terminal soldering portion (terminal hole 195). In this way, by using the through hole H1 as a hole for plugging and unplugging the connector pin, the connector can be connected from the front or back side of the multilayer substrate 110. Therefore, when the motor drive circuit substrate 19 (multilayer substrate 110) is connected as Figure 3 In the state shown in which the motor 10 is fixed to the housing 6 of the motor 10, a program or the like can be written by connecting the connector to the connector through hole H2 without removing the motor drive circuit substrate 19 from the housing 6. In addition, by providing the connector through hole H2 between the terminal soldering portion (terminal hole 195) and the screw fixing portion (notch 197) of the motor drive circuit substrate 19, the stress applied to the motor drive circuit substrate 19 can be alleviated when the connector is plugged in and out. Therefore, it is possible to suppress the occurrence of solder cracks due to stress, and to suppress poor conduction. In addition, the fixing portion for fixing the motor drive circuit substrate 19 to the housing 6 may not be in the shape of a notch but a through hole. In addition, the fixing component may also be a component other than a screw. For example, it may be a hook or a rivet portion formed integrally with the housing.

[0073] [Example 2] Figure 7 It is a plan view of the first surface S1 and the second surface S2 of the motor drive circuit board 19A according to the second embodiment. Figure 8 This is an explanatory diagram of the motor drive circuit 150 mounted on the motor drive circuit substrate 19A according to the second embodiment. Fig. 9 This is an explanatory diagram of a common ground pattern 100c formed on a motor drive circuit board 19A according to Embodiment 2. Since the basic structure of Embodiment 2 is the same as that of Embodiment 1, the same reference numerals are given to the common parts and their description is omitted.

[0074] The motor drive circuit substrate 19 of the first embodiment is a multi-layer single-sided substrate, while the motor drive circuit substrate 19A of the second embodiment is a double-sided mounting substrate. Figure 7 As shown in (a), on the first surface S1 of the motor drive circuit substrate 19A, an inductor 181 is mounted on the third region 103 side, and a motor control unit 161 is mounted at a position located on the first region 101 side and the fourth region 104 side relative to the center O. Figure 7 As shown in FIG. 2( b ), switching elements Q1 to Q6 are mounted in a second region 102 on a second surface S2 on the opposite side of the first surface S1 of the motor drive circuit substrate 19A.

[0075] like Figure 8 As shown, the motor drive circuit 150A of the second embodiment is different from the first embodiment in that it further includes a fifth capacitor C5, which is an electrolytic capacitor, as the noise countermeasure electronic component 180 in addition to the first capacitor C1 to the fourth capacitor C4. The fifth capacitor C5 is arranged between the second capacitor C2 and the fourth capacitor C4. The second capacitor C2, the fifth capacitor C5, and the fourth capacitor C4 are arranged in the order of increasing capacitance from the switching element side to the inductor 181 side.

[0076] like Fig. 9 As shown, the motor drive circuit substrate 19A is a multi-layer substrate 110A, which has six layers stacked in sequence: a first layer 111, a second layer 112, a third layer 113, a fourth layer 114, a fifth layer 115, and a sixth layer 116. A conductive layer used as a common ground pattern 100c is formed in each layer. The common ground pattern 100c includes: a first conductive layer G1 formed on the first layer 111; a second conductive layer G2 formed on the second layer 112; a third conductive layer G3 formed on the third layer 113; a fourth conductive layer G4 formed on the fourth layer 114; a fifth conductive layer G5 formed on the fifth layer 115; and a sixth conductive layer G6 formed on the sixth layer 116. Fig. 9 In FIG. 1 , regions where these conductive layers are formed are shown as shaded regions.

[0077] The motor driving circuit 150A includes: a first layer circuit 111C provided in the first layer 111; a third layer circuit 113C provided in the third layer; a fourth layer circuit 114C provided in the fourth layer; and a sixth layer circuit 116C formed in the sixth layer.

[0078] In the second embodiment, the first layer circuit 111C and the sixth layer circuit 116C respectively include a part of the signal system circuit 160 and a part of the power system circuit 170. On the other hand, the third layer circuit 113C and the fourth layer circuit 114C do not include the signal system circuit 160 but include a part of the power system circuit 170. The power system circuit 170 is mainly arranged in the second region 102 of each layer.

[0079] As in the first embodiment, the common ground pattern 100c is not formed in a portion overlapping with the inductor 181 mounted on the first layer 111. Fig. 9 As shown, each of the second conductive layer G2 , the third conductive layer G3 , the fourth conductive layer G4 , the fifth conductive layer G5 , and the sixth conductive layer G6 has a shape in which a portion overlapping the inductor 181 is hollowed out.

[0080] like Fig. 9 As shown, the first conductive layer G1 is formed along the outer edges of the substrates of the first region 101, the fourth region 104, and the second region 102. The portion of the second region 102 extending along the outer edge of the substrate is a noise protection portion G12 surrounding the periphery of the power system circuit 170. In the second layer 112 and the fifth layer 115, the second conductive layer G2 and the fifth conductive layer G5 are respectively formed on the entire substrate.

[0081] In the third layer 113 and the fourth layer 114, the third conductive layer G3 and the fourth conductive layer are formed to surround the periphery of the power system circuit 170 constituting the third layer circuit 113C and the fourth layer circuit 114C, respectively, over the entire periphery. The third conductive layer G3 includes: a third conductive layer body G31, which is arranged on the first region 101 side, the third region 103 side, and the fourth region 104 side relative to the power system circuit 170; and a noise protection portion G32, which extends along the outer edge of the substrate in the second region 102 to surround the outer periphery of the power system circuit 170. The fourth conductive layer G4 includes a noise protection portion G42 overlapping with the noise protection portion G32 of the third conductive layer G3. The noise protection portion G42 extends along the outer edge of the substrate in the second region 102 in the fourth layer 114 to surround the outer periphery of the power system circuit 170.

[0082] The multilayer substrate 110A of the second embodiment is provided with a plurality of through holes H1 arranged along the outer edge of the substrate of the second region 102. The noise protection part G32 of the third layer 113 and the noise protection part G42 of the fourth layer 114 are electrically connected through the through holes H1. In addition, the noise protection part G32 is electrically connected to the second conductive layer G2 through the through holes H1, and the noise protection part G42 is electrically connected to the fifth conductive layer G5. In the multilayer substrate 110A of the second embodiment, the through holes H1 penetrate the region where the common ground pattern 100c is formed in each of the first layer 111, the second layer 112, the third layer 113, the fourth layer 114, the fifth layer 115, and the sixth layer 116.

[0083] (Main effects of Example 2) As described above, in Embodiment 2, the multilayer substrate 110A includes six layers overlapped in sequence: the first layer 111, the second layer 112, the third layer 113, the fourth layer 114, the fifth layer 115, and the sixth layer 116. As in Embodiment 1, the common ground pattern 100c includes the first conductive layer G1, the second conductive layer G2, the third conductive layer G3, and the fourth conductive layer, and further includes the fifth conductive layer G5 disposed in the fifth layer 115 and the sixth conductive layer G6 disposed in the sixth layer 116. In the fifth layer 115, the fifth conductive layer G5 is formed on the entire substrate. In the sixth layer 116, the sixth layer circuit 116C including the power system circuit 170 is formed, and the sixth conductive layer G6 is formed to surround the outer periphery of the sixth layer circuit 116C. The fifth conductive layer G5 and the sixth conductive layer G6 are connected to the second conductive layer G2, the third conductive layer G3, and the fourth conductive layer G4 through the through hole H1.

[0084] In this way, the multilayer substrate 110A of the second embodiment has more layers than the first embodiment, and the circuit configuration space in the sixth layer 116 can be ensured. Therefore, the motor drive circuit 150A can be mounted at a high density, and the power system circuit 170 can be set in a large range, so that a large drive current can be provided. In addition, the common ground pattern 100c is provided on the entire substrate in the fifth layer 115, and surrounds the power system circuit 170 in the entire circumference in the fourth layer 114 and the sixth layer 116, so that the radiation of noise from the power system circuit 170 to the outside can be effectively shielded. Therefore, it is possible to improve the EMC performance while suppressing the cost increase.

[0085] In Embodiment 2, the power system circuit 170 included in each of the third layer circuit 113C, the fourth layer circuit 114C, and the sixth layer circuit 116C is arranged in the second region 102 of the multilayer substrate 110. In the third layer 113, as in Embodiment 1, the noise protection part G32 extends along the outer edge of the substrate in the second region 102, and both ends of the noise protection part G32 are connected to the third conductive layer G3 portion (third conductive layer body G31) formed in the first region 101. In the fourth layer 114 and the sixth layer 116, the noise protection part G42 of the fourth conductive layer G4 and the noise protection part G62 of the sixth conductive layer G6 extend along the outer edge of the substrate in the second region 102 at a position overlapping with the noise protection part G32. In addition, a plurality of through holes H1 arranged along the outer edge of the substrate in the second region 102 are provided.

[0086] By such a pattern configuration, in each layer (first layer 111, third layer 113, fourth layer 114, sixth layer 116) where the motor drive circuit 150A is formed, the common ground pattern 100c can be provided in a wide range in the first region 101. In addition, in the second region 102, the space on the outer periphery of the power system circuit 170 is narrow, so a wide common ground pattern 100c cannot be provided, but the common ground pattern 100c is formed to surround the power system circuit 170 on the entire periphery and is connected to the common ground pattern 100c of the upper and lower layers through the through hole H1. Therefore, it is possible to effectively suppress the radiation of noise to the outside.

[0087] [Other embodiments] In the above-described embodiments, the motor 10 used in the pump device 1 is exemplified, but the present invention can also be applied to motors mounted on other devices. Explanation of symbols

[0088] 1... pump device, 2... housing, 3... stator, 4... rotor, 5... support shaft, 6... housing, 10... motor, 11... radial bearing, 12... thrust bearing, 18... cover, 19, 19A... motor drive circuit board, 20... pump chamber, 21... suction pipe, 22... discharge pipe, 23... wall surface, 25... impeller, 26... disk, 27... support part, 28... cylinder part, 29... side wall, 31... stator core, 32, 33... insulator, 35... coil, 40... cylinder part, 45... flange part, 47... magnet, 60... resin sealing component, 61... first part Partition wall, 62...Second partition wall, 63...Bottom wall, 64...End portion, 66...Main body, 69...Connector housing, 71...Winding terminal, 75...Connector terminal, 100...Ground pattern, 100c...Common ground pattern, 101...First region, 102...Second region, 103...Third region, 104...Fourth region, 110, 110A...Multilayer substrate, 111...First layer, 111C...First layer circuit, 112...Second layer, 113...Third layer, 113C...Third layer circuit, 114...Fourth layer, 114C...Fourth layer circuit, 115...Fifth layer, 116 ...sixth layer, 116C...sixth layer circuit, 122-126, 128...capacitors, 131, 132...output line, 133...control signal line, 134...FG output line, 135...drive voltage line, 136...first line, 137...second line, 138...third line, 140...common line, 141-146...filter, 150, 150A...motor drive circuit, 151-153...capacitors, 160...signal system circuit, 161...motor control unit, 165...neutral point, 170...power supply system circuit, 180...noise countermeasure electronic component, 181...inductor, 18 2... diode, 190... terminal hole, 191... first terminal hole, 192... second terminal hole, 193... third terminal hole, 194... fourth terminal hole, 195... terminal hole, 196... straight portion, 197... notch (screw fixing portion), 199... notch, 261... blade portion, 311... annular portion, 312... salient pole, 645... protrusion, 751... constant voltage terminal, 752... first signal terminal, 753... second signal terminal, 754... ground terminal, C1... first capacitor, C2... second capacitor, C3... third capacitor, C4... fourth capacitor, C5...The fifth capacitor, D31 to D33 ... diodes, G1 ... first conductive layer, G12 ... noise protection part, G2 ... second conductive layer, G3 ... third conductive layer, G31 ... third conductive layer body, G32 ... noise protection part, G4 ... fourth conductive layer, G42 ... noise protection part, G5 ... fifth conductive layer, G6 ... sixth conductive layer, G62 ... noise protection part, H1 ... through hole, H2 ... through hole for connector, L ... rotation axis, L1 ... one side in the axial direction, L2 ... the other side in the axial direction, O ... the center of the multilayer substrate, P ... imaginary line, Q1 ... Q6 ... switch element, Q7 ... NOT gate, R1, R2, R3 ... resistors, R11 ... R16, R21 ... R26, R31 ... R34 ... resistors, Rs ... shunt resistor, S1 ... first surface, S2 ... second surface. .

Claims

1. A motor drive circuit substrate, wherein a motor drive circuit is provided on a multi-layer substrate, the motor drive circuit comprising a power system circuit and a signal system circuit, the power system circuit having a switch element for outputting a drive current, the signal system circuit having a control element for providing a signal to the switch element, characterized in that: In the multilayer substrate, the ground pattern for the power system circuit and the ground pattern for the signal system circuit are formed as an integrated common ground pattern. The multi-layer substrate includes four layers stacked in the order of a first layer, a second layer, a third layer and a fourth layer, The common ground pattern includes a second conductive layer disposed on the second layer, a third conductive layer disposed on the third layer, and a fourth conductive layer disposed on the fourth layer, at least the control element is mounted on the first layer, On the second layer, the second conductive layer is formed on the entire substrate, A third layer circuit including the power system circuit is formed on the third layer, and the third conductive layer is formed to surround the outer periphery of the third layer circuit over the entire periphery. A fourth layer circuit including the power system circuit is formed on the fourth layer, and the fourth conductive layer is formed to surround the outer periphery of the fourth layer circuit over the entire circumference. The third conductive layer includes a noise protection portion extending along the outer periphery of the power system circuit. The noise protection portion is connected to the second conductive layer and the fourth conductive layer through a plurality of through holes arranged to surround the power system circuit.

2. The motor drive circuit substrate according to claim 1, characterized in that: In a first region located on one side relative to the center of the multilayer substrate, a plurality of terminal holes for embedding terminals for external connection are arranged along the outer edge of the substrate, The power system circuit in the third layer circuit is arranged in a second region located on the opposite side of the first region with respect to the center of the multilayer substrate. The noise protection portion extends along the outer edge of the substrate in the second region, and both ends of the noise protection portion are connected to a portion of the third conductive layer formed in the first region. The plurality of through holes are arranged along an outer edge of the substrate in the second region.

3. The motor drive circuit substrate according to claim 1, characterized in that: The multi-layer substrate includes six layers stacked in the order of the first layer, the second layer, the third layer, the fourth layer, the fifth layer and the sixth layer, The common ground pattern includes a fifth conductive layer disposed on the fifth layer and a sixth conductive layer disposed on the sixth layer, On the fifth layer, the fifth conductive layer is formed on the entire substrate, A sixth layer circuit including the power system circuit is formed on the sixth layer, and the sixth conductive layer is formed to surround the outer periphery of the sixth layer circuit over the entire periphery. The fifth conductive layer and the sixth conductive layer are connected to the second conductive layer, the third conductive layer, and the fourth conductive layer through the through-holes.

4. The motor drive circuit substrate according to claim 3, characterized in that: In a first region located on one side relative to the center of the multilayer substrate, a plurality of terminal holes for embedding terminals for external connection are arranged along the outer edge of the substrate, The power system circuits of the third layer circuit, the fourth layer circuit, and the sixth layer circuit are respectively arranged in a second region located on the opposite side of the first region with respect to the center of the multilayer substrate. In the third layer, the noise protection portion extends along the outer edge of the substrate in the second region, and both ends of the noise protection portion are connected to a portion of the third conductive layer formed in the first region. In the fourth layer, a portion of the fourth conductive layer overlapping the noise protection portion extends along an outer edge of the substrate in the second region. In the sixth layer, a portion of the sixth conductive layer overlapping the noise protection portion extends along an outer edge of the substrate in the second region. The plurality of through holes are arranged along an outer edge of the substrate in the second region.

5. The motor drive circuit substrate according to claim 1, characterized in that: The motor drive circuit includes a noise countermeasure electronic component. The noise countermeasure electronic component includes an inductor, The common ground pattern is formed in a region other than a region overlapping with the inductor in each layer of the multilayer substrate.

6. The motor drive circuit substrate according to claim 5, characterized in that: The noise countermeasure electronic component includes a first capacitor and a second capacitor, The first capacitor and the second capacitor connect a driving voltage line connected in series with the inductor to the common ground pattern at two locations on the power supply side and the switching element side with respect to the inductor.

7. The motor drive circuit substrate according to claim 6, characterized in that: The noise countermeasure electronic component includes a third capacitor having a smaller capacitance than the first capacitor, The first capacitor is arranged on the power supply side relative to the inductor, The third capacitor connects the driving voltage line to the common ground pattern at the power supply side relative to the first capacitor.

8. The motor drive circuit substrate according to claim 6, characterized in that: The noise countermeasure electronic component includes a fourth capacitor having a smaller capacitance than the second capacitor, The second capacitor is arranged on the switching element side relative to the inductor. The fourth capacitor connects the driving voltage line to the common ground pattern on the switching element side relative to the second capacitor.

9. The motor drive circuit substrate according to claim 1, characterized in that: A fixing portion and a terminal soldering portion are provided at the outer edge of the multi-layer substrate, a fixing member for fixing the multi-layer substrate is arranged at the fixing portion, and a terminal for external connection is soldered to the terminal soldering portion. A connector through hole for inserting and removing a connector pin is provided at an outer edge of the multilayer substrate between the fixing portion and the terminal soldering portion.

10. A motor, characterized in that: have: The motor drive circuit substrate according to any one of claims 1 to 9; as well as A coil to which a driving current output from the motor driving circuit substrate is supplied.

11. A pump device comprising the motor according to claim 10, characterized in that: An impeller is provided which is driven to rotate by the motor.

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