Multi-layer PCB structure, motor controller and brushless motor
By using a multi-layer PCB structure, the signal interference and noise caused by the shared layout of power circuits and control circuits are resolved, achieving accurate control signals and high-precision acquisition of analog signals, while reducing manufacturing costs and space requirements.
Patent Information
- Application Number
- CN202522494291.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2035-11-25
AI Technical Summary
In existing PCB designs, the shared layout of power circuits and control circuits leads to problems such as transient high voltage/high current coupling, switching noise affecting the accuracy of analog signal acquisition, and increased costs.
The system employs a multi-layer PCB structure, separating the power circuit and control circuit into layers. The separation of signal ground layer, power layer, power ground layer, and power supply layer ensures the isolation between control signals and power transmission, while electrical connection is achieved through dielectric layers and conductive vias.
It effectively avoids or reduces interference from the power circuit to the control circuit, improves the acquisition accuracy of analog signals, and reduces manufacturing costs and the space occupied by the circuit board.
Smart Images
Figure CN223859327U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of power electronic wiring, in particular to a multi-layer PCB structure, a motor controller and a brushless motor. BACKGROUND
[0002] The PCB (Printed Circuit Board) design of devices such as motor controllers containing control circuits and power circuits is usually a power circuit and control circuit co-board layout, that is, the power circuit and the control circuit are arranged on the same PCB layer. This design has at least one of the following problems:
[0003] 1. The transient high voltage / current generated when the power circuit starts or stops working is easily coupled to the control circuit through parasitic capacitance, causing distortion of the control signal;
[0004] 2. The power supply plane of the power circuit and the analog signal acquisition circuit in the control circuit are in the same plane, and the switching noise of the power device is easily radiated through its power supply plane, affecting the acquisition accuracy of the low-level analog signal;
[0005] 3. The co-board design of the power circuit and the control circuit requires a large number of filtering elements to be added in the PCB, resulting in increased cost, increased area and volume of the circuit board. CONTENT OF THE INVENTION
[0006] To solve the existing technical problems, the present application provides a multi-layer PCB structure, a motor controller and a brushless motor to avoid or reduce the interference of the power circuit on the signal transmission of the control circuit.
[0007] In one aspect, the present application provides a multi-layer PCB structure, comprising a top signal layer, a signal ground layer, a power layer, a power ground layer, a power supply layer and a bottom signal layer arranged in layers;
[0008] The top signal layer and the bottom signal layer are used to arrange the control circuit;
[0009] The signal ground layer is adjacent to the top signal layer and is used to provide a reference potential for the control circuit;
[0010] The power supply layer is adjacent to the bottom signal layer and is used to power the control circuit;
[0011] The power layer is arranged between the signal ground layer and the power ground layer and is used to arrange the power device and / or power supply in the power circuit;
[0012] The power ground layer is adjacent to the power supply layer and is used to provide a closed loop for the power supply current of the power circuit; wherein the control circuit is used to control the power circuit to convert energy.
[0013] In some embodiments, the distance between the top signal layer and the power layer in the direction of the stack is greater than or equal to 0.2 mm.
[0014] In some embodiments, the signal ground layer and the power ground layer form a Faraday cage, and the power layer is located in the Faraday cage.
[0015] In some embodiments, a dielectric layer is arranged between two adjacent layers among the top signal layer, the signal ground layer, the power layer, the power ground layer, the power supply layer, and the bottom signal layer, respectively, and a first conductive via and a second conductive via are arranged in at least part of the dielectric layer, respectively.
[0016] The first conductive via is used for transmitting signals, and the second conductive via is used for transmitting power. The distance between the first conductive via and the second conductive via is greater than or equal to 1 mm, and the second conductive via is filled with a conductive material.
[0017] In some embodiments, an isolation groove with a predetermined width is arranged at the edge of the power layer, and a solder mask ink is arranged in the isolation groove.
[0018] In some embodiments, the signal ground layer is provided with a digital ground and an analog ground, and the digital ground and the analog ground are connected by a single point of resistance.
[0019] The digital ground and the power ground layer are connected by a single point of inductance.
[0020] The power supply layer is provided with a digital power supply and a reference power supply, and the digital power supply and the reference power supply are connected by a single point of magnetic beads in the power supply layer.
[0021] In some embodiments, the power circuit includes a three-phase bridge arm inverter circuit.
[0022] The control circuit includes a two-phase current sampling circuit, a control chip, and a driving chip arranged in the top signal layer. The two-phase current sampling circuit is used to collect the current of two phases in the three-phase bridge arm inverter circuit and send the collected current signal to the control chip. The control chip is connected with the driving chip, and the driving chip is connected with the bridge arm switch in the three-phase bridge arm inverter circuit.
[0023] The two-phase current sampling circuit includes a sampling resistor connected in series with the lower bridge arm switch in the corresponding two-phase bridge arm, and the sampling resistor is a patch alloy resistor.
[0024] In some embodiments, the two-phase current sampling circuit includes a reference voltage generating circuit that provides a reference power supply for current sampling. The reference voltage generating circuit includes a first resistor, a second resistor, a third resistor, a three-terminal adjustable parallel voltage regulator, and a first capacitor.
[0025] The first terminal of the first resistor outputs the reference voltage, and the second terminal is connected to the power supply of the reference voltage generating circuit; the first terminal of the second resistor is connected to the second terminal of the first resistor, the second terminal is connected to the first terminal of the third resistor, and is also connected to the adjustment terminal of the three-terminal adjustable parallel voltage regulator.
[0026] The second terminal of the third resistor and the anode terminal of the three-terminal adjustable parallel voltage regulator are respectively connected to analog ground; the first capacitor is connected between the power supply and the analog ground.
[0027] Secondly, embodiments of this application provide a motor controller, including a multilayer PCB board structure as described in any of the foregoing claims, wherein the power circuit is used to output energy to drive the motor to rotate.
[0028] Thirdly, this application provides a brushless motor, including a brushless motor body and a motor controller as described above. The motor controller is connected to the brushless motor body and is used to control the rotation of the brushless motor body.
[0029] The multilayer PCB structure provided in the embodiments of this application is used to arrange power circuits and control circuits. Its power layer and power ground layer are set separately from the top signal layer and signal ground layer, which can ensure the isolation between the control signal in the control circuit and the power transmission in the power circuit. This effectively avoids or reduces the interference of the power circuit to the signal in the control circuit, ensuring the accuracy of the control signal. Moreover, the switching noise of its power circuit is not easily affected by the acquisition of analog signals in the top signal layer, which can improve the acquisition accuracy of analog signals. At the same time, since the power circuit and control circuit are set separately and isolated, there is no need to set up a lot of filtering components on the board, which helps to reduce the manufacturing cost and the space occupied by the circuit board. Attached Figure Description
[0030] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0031] Figure 1 This is a schematic diagram of a multilayer PCB board structure provided according to some embodiments of this application;
[0032] Figures 2a to 2f This is a schematic diagram of the wiring of each layer of a multilayer PCB board structure provided according to some embodiments of this application. Figure 2a This is a schematic diagram of the wiring of the top-level signal layer.Figure 2b This is a schematic diagram of the signal ground layer wiring. Figure 2c This is a wiring diagram for the power layer. Figure 2d This is a schematic diagram of the wiring for the power ground layer. Figure 2e This is a schematic diagram of the power layer wiring. Figure 2f This is a schematic diagram of the wiring of the bottom signal layer;
[0033] Figure 3 This is a schematic diagram of the structure of a brushless motor provided according to some embodiments of this application;
[0034] Figure 4 This is a schematic diagram of the isolation structure between different voltage levels in a multilayer PCB board structure provided according to some embodiments of this application;
[0035] Figure 5 This is a schematic diagram of the reference voltage generation circuit for sampling in a motor controller provided according to some embodiments of this application;
[0036] Figure 6 This is a schematic diagram of the structure of a three-phase bridge arm inverter circuit in a motor controller provided according to some embodiments of this application. Detailed Implementation
[0037] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the ways in which this application may be implemented. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0039] In the description of this application, unless otherwise stated, "a plurality of" means two or more. Furthermore, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0040] In some embodiments, the multilayer PCB structure provided in this application is used to arrange power circuits and control circuits for controlling the power circuits to perform energy conversion, such as, but not limited to, a motor controller that includes power circuits and control circuits. Please refer to... Figure 1As shown, it is a structural schematic diagram of a multi-layer PCB structure provided according to some embodiments of the present application. In some embodiments, the multi-layer PCB structure provided by the present application includes a plurality of stacked conductive layers, each of which can be a patterned copper foil. The plurality of stacked conductive layers includes, from top to bottom, a top signal layer 111, a signal ground layer 112, a power layer 113, a power ground layer 114, a power supply layer 115, and a bottom signal layer 116. Among them, the top layer and the ground layer refer to the two opposite surfaces of the multi-layer PCB structure in the stacking direction. The conductive layers of each conductive layer are not directly contacted and stacked with the upper and lower layers, and it can be understood that an isolation support structure is provided between each conductive layer. The isolation structure can be but is not limited to a dielectric layer. For example, in some embodiments, a first dielectric layer 121 is provided between the top signal layer 111 and the signal ground layer 112, a second dielectric layer 122 is provided between the signal ground layer 112 and the power layer 113, a third dielectric layer 123 is provided between the power layer 113 and the power ground layer 114, a fourth dielectric layer 124 is provided between the power ground layer 114 and the power supply layer 115, and a fifth dielectric layer 125 is provided between the power supply layer 115 and the bottom signal layer 116. The number of dielectric layers provided between each conductive layer can be one or more, and the constituent materials of each dielectric layer can be the same or different. It can be understood that when each conductive layer is isolated and supported by a dielectric layer, a conductive via can be provided in each dielectric layer, and each conductive layer is electrically connected through the conductive via.
[0041] In some embodiments, the top signal layer 111 and the bottom signal layer 116 are used to set the control circuit. In this embodiment, the control circuit refers to the circuit on the control loop for controlling the power circuit, which can include but is not limited to a sampling circuit for sampling the current and / or voltage output by the power circuit, a driving chip for driving the power switch device in the power circuit to switch, and a control chip for energy conversion control of the power circuit, wherein the control chip can be an MCU chip. Of course, in some embodiments, the control circuit can also include sensors, communication circuits, etc. Part of the components in the control circuit are provided in the top signal layer 111, and another component in the control circuit is provided in the bottom signal layer 116. For example, in some embodiments, the control circuit is the control circuit in the motor controller, and the part of the control circuit provided in the top signal layer 111 can include a control chip, a sensor or a sensor interface, and a communication circuit, etc. The bottom signal layer 116 mainly controls the devices related to low-speed control signals in the control circuit.
[0042] The signal ground layer 112 is adjacent to the top signal layer 111, and is used to provide a reference potential for the control circuit, that is, as a return path for the power supply current of the control circuit, to provide a closed loop for the power supply current of the control circuit. The signal ground layer 112 can be a complete layer, where the complete layer refers to a continuous conductive layer (such as a copper foil layer) covering the entire planar layer of the PCB board without being divided. The power supply layer 115 is adjacent to the bottom signal layer 116, and is used to supply power to the control circuit. The power supply terminals in the top signal layer 111 can be connected to the power supply layer 115 through conductive vias of the dielectric layer.
[0043] The power layer 113 is arranged between the signal ground layer 112 and the power ground layer 114, and is used to arrange power devices and / or power supplies in the power circuit. The power devices can include, but are not limited to, power transistors, freewheeling diodes, and the switches of the power transistors are controlled by the control circuit. The power supply of the power circuit can be arranged in the power layer, or can be separately arranged in another layer. Since the power circuit needs to withstand large current, the power layer 113 can be formed by a copper foil with a thickness of 2oz. The power ground layer 114 is adjacent to the power supply layer 115, and is used to provide a closed loop for the power supply current of the power circuit.
[0044] The multi-layer PCB board structure provided by the embodiments of the present application is used to arrange the power circuit and the control circuit, and the power layer 113 and the power ground layer 114 are arranged in layers on the top signal layer 111 and the signal ground layer 112 respectively, which can ensure the isolation of the control signal in the control circuit and the power transmission in the power circuit, effectively avoid or reduce the interference of the power circuit on the signal in the control circuit, ensure the accuracy of the control signal, and the switching noise of the power circuit does not easily affect the acquisition of the analog signal in the top signal layer 111, which can improve the acquisition accuracy of the analog signal. At the same time, since the power circuit and the control circuit are arranged in layers and isolated, there is no need to arrange many filtering elements on the PCB board, which is beneficial to reduce the preparation cost and the occupied space of the circuit board.
[0045] In some embodiments, the distance between the top signal layer 111 and the power layer 113 in the stacking direction of the plurality of conductive layers is greater than or equal to 0.2mm, to ensure the physical isolation between the top signal layer 111 and the power layer 113, to block the electromagnetic interference of the power layer 113 on the top signal layer 111 in a physical isolation manner, and to ensure the accuracy of signal transmission. The isolation between the power layer 113 and the top signal layer 111 can be realized by a glass fiber base material, that is, the thickness of the first dielectric layer 121 and the second dielectric layer 122 between the top signal layer 111 and the power layer 113 in the stacking direction is greater than or equal to 0.2mm, and the constituting materials of the first dielectric layer 121 and the second dielectric layer 122 can be glass fibers respectively.
[0046] In some embodiments, the distance between the signal ground layer 112 and the power layer 113 in the stacking direction can also be set to be greater than or equal to 0.2 mm, i.e., the thickness of the second dielectric layer 122 in the stacking direction is greater than or equal to 0.2 mm, to ensure the physical isolation effect between signal transmission and power transmission.
[0047] In some embodiments, the signal ground layer 112 and the power ground layer 114 arranged on both sides of the power layer 113 are respectively set as complete layers, and a Faraday cage is formed by the two, so that the power layer 113 is located in the Faraday cage, thereby effectively avoiding the electromagnetic interference phenomenon caused by the power layer 113 to the signal layer.
[0048] In some embodiments, the wiring schematic diagram of each layer of the multi-layer PCB structure can be but is not limited to as shown in Figures 2a to 2f , wherein, Figure 2a is the wiring schematic diagram of the top signal layer 111, Figure 2b is the wiring schematic diagram of the signal ground layer 112, Figure 2c is the wiring schematic diagram of the power layer 113, Figure 2d is the wiring schematic diagram of the power ground layer 114, Figure 2e is the wiring schematic diagram of the power supply layer 115, and Figure 2f is the wiring schematic diagram of the bottom signal layer 116. The multi-layer PCB structure provided in the embodiment realizes the physical isolation of signal transmission and power transmission through multi-layer wiring, which is beneficial to improve the performance of the device.
[0049] Please continue to refer to Figure 1 , in some embodiments, at least part of the dielectric layers of the multi-layer PCB structure are respectively provided with first conductive vias 131 and second conductive vias 132. Wherein, the first conductive via 131 is used for signal transmission, and the second conductive via 132 is used for power transmission. That is, the first conductive via is used for electrically connecting the control circuit and the signal connection terminal between the control circuit and the power circuit, and the second conductive via 132 is used for connecting the power supply of the power layer 113 and the power supply terminal. In some embodiments, the distance between the first conductive via 131 and the second conductive via 132 is greater than or equal to 1 mm, to ensure the safety distance between signal transmission and power transmission. In some embodiments, the second conductive via 132 is filled with conductive material to increase its power transmission capacity.
[0050] In some embodiments, the edge of the power layer 113 is provided with an isolation groove with a predetermined width, and the isolation groove is filled with solder resist ink to prevent creepage. Wherein, the predetermined width here can be but is not limited to 2 mm. The isolation groove filled with solder resist ink surrounds the edge of the power layer 113 to form a creepage isolation band.
[0051] Please refer to Figure 3As shown, it is a structural schematic diagram of a brushless motor provided by some embodiments of the present application. The multi-layer PCB structure provided by any embodiments of the present application can be applied to the brushless motor provided by the embodiments of the present application. The brushless motor provided by the embodiments of the present application includes a motor controller 31 and a brushless motor body 32 provided by some embodiments of the present application. The motor controller 31 is connected with the brushless motor body 32, and is used to control the brushless motor body 32 to rotate at a set speed and direction.
[0052] The motor controller 31 provided by some embodiments of the present application includes a control circuit 311 and a power circuit 312. The control circuit 311 is used to control the power circuit 312 to perform energy conversion, so that the power circuit 312 outputs energy to drive the brushless motor body 32 to rotate.
[0053] Specifically, the control circuit 311 can control the current output of the power circuit 312 by collecting the phase current of the brushless motor body 32. The control circuit 311 can but not limited to include a control chip 3111, a driving chip 3112 and a sampling circuit 3113. The control chip 3111 is used to realize the processing of signals and the output of control signals, and is connected with the driving chip 3112, and is used to control the driving chip 3112 to drive the power circuit 312. The sampling circuit 3113 can be a two-phase current sampling circuit, which is used to collect the two-phase driving current of the brushless motor body 32. It can collect the current of the current input end of the brushless motor body 32 or the current of the output end of the power circuit 312, and feedback to the driving chip 3112, so that the driving chip 3112 controls the switching driving signal of the power switch in the power circuit 312 according to the control signal output by the control chip 3111 and the current collected by the sampling circuit 3113.
[0054] In some embodiments, the control circuit 311 further includes a position sensor 3114. The position sensor 3114 collects the physical position information of the rotor of the brushless motor body 32, and feeds back to the control chip 3111, so that the control chip 3111 outputs corresponding control signals based on the position of the rotor of the brushless motor body 32. The control chip 3111 can be an MCU chip.
[0055] In the multi-layer PCB structure provided by some embodiments of the present application, the signal ground layer 112 is provided with a digital ground GND and an analog ground AGND, and the power supply layer 115 is provided with a digital power supply VDDA and a reference power supply Vref. Please refer to Figure 4As shown, it is the isolation structure schematic diagram between each level in the multi-layer PCB structure, the digital ground GND and the analog ground AGND can be connected by the resistor R41; the digital ground GND and the power ground PGND in the power ground layer 113 are connected by the inductor L41; the digital power VDDA and the reference power Vref are connected by the magnetic bead I41 in the power supply layer 115, so as to avoid the pollution of the signal ground layer 112 and the power supply layer 115. The resistance of the resistor R41 can be 0Ω, the inductance of the inductor L41 can be 1uh, and the resistance of the magnetic bead I41 can be 0Ω.
[0056] In some embodiments, the sampling circuit 3113 in the control circuit 311 is a two-phase current sampling circuit, which includes a reference voltage generating circuit for providing a reference power Vref for current sampling. Please refer to Figure 5 As shown, the reference voltage generating circuit includes a first resistor R51, a second resistor R52, a third resistor R53, a three-terminal adjustable shunt regulator U51 and a first capacitor C51. The first end of the first resistor R51 outputs a reference voltage (i.e. as the output end of the reference power Vref), and the second end is connected with the power supply (i.e. the digital power VDDA) of the reference voltage generating circuit; the first end of the second resistor R52 is connected with the second end of the first resistor R51, the second end is connected with the first end of the third resistor R53, and is connected with the adjusting end of the three-terminal adjustable shunt regulator U51. The second end of the third resistor R53 and the anode end of the three-terminal adjustable shunt regulator U51 are respectively connected with the analog ground AGND; the first capacitor C51 is connected between the power supply and the analog ground AGND. The motor controller 31 provided by the embodiment of the application is beneficial to the reference sampling of the current through the reference voltage generating circuit provided by the embodiment, so as to realize the reference control of the driving current of the brushless motor body 32.
[0057] Please refer to Figure 6 As shown, in some embodiments, the power circuit 312 includes a three-phase bridge arm inverter circuit, which is used to convert the direct current P_VBUS into three-phase alternating current output to the brushless motor body 32 according to the control of the driving chip 3112, so as to provide driving current for the brushless motor body 32. The three-phase bridge arm inverter circuit includes three bridge arms, which are respectively a U-phase bridge arm composed of a first upper bridge arm switch Q61 and a first lower bridge arm switch Q62, a V-phase bridge arm composed of a second upper bridge arm switch Q63 and a second lower bridge arm switch Q64, and a W-phase bridge arm composed of a third upper bridge arm switch Q63 and a third lower bridge arm switch Q63. Each bridge arm switch in the three-phase bridge arm inverter circuit can be a power transistor, such as a MOSFET. The gate of each bridge arm switch is respectively connected with a corresponding gate drive resistor. The connection relationship of each gate drive resistor and the corresponding bridge arm switch can be referred to Figure 5 As shown.
[0058] The two-phase current sampling circuit in the control circuit 311 is used to collect the current of two phases in the three-phase bridge arm inverter circuit, such as the current of U phase and V phase. Specifically, the sampling circuit 3113 includes a sampling resistor connected in series with the lower arm switch in the corresponding two-phase bridge arm, for example, the first sampling resistor R67 connected in series with the first lower arm switch Q62 in the U phase bridge arm, the first sampling resistor R67 connected in series with the first lower arm switch Q64 in the V phase bridge arm, and no sampling resistor between the third lower arm switch Q66 in the W phase bridge arm and the power ground PGND. The sampling circuit 3113 sends the collected current signal to the control chip 311, the control chip 3111 is connected with the drive chip 3112, and the drive chip 3112 is connected with each bridge arm switch in the three-phase bridge arm inverter circuit.
[0059] In some embodiments, at least one of the first sampling resistor R67 and the second sampling resistor R68 is a patch alloy resistor, so that the degree of interference of current sampling can be reduced, and the sampling accuracy can be improved.
[0060] In some embodiments, each bridge arm switch can select a MOSFET with low resistance, and the wiring of the three-phase bridge arm inverter circuit and the sampling resistor can be performed by using the Kelvin wiring method to reduce the influence of interference. In addition, in some embodiments, the gate drive resistor connected with each bridge arm switch can select a resistor with a small resistance value to ensure the switching response speed of the bridge arm switch.
[0061] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A multi-layer PCB board structure, characterized by, The top layer signal layer, the signal ground layer, the power layer, the power ground layer, the power supply layer and the bottom layer signal layer are arranged in a stack; The top layer signal layer and the bottom layer signal layer are used to arrange control circuits; The signal ground layer is adjacent to the top layer signal layer and is used to provide a reference potential for the control circuits; The power supply layer is adjacent to the bottom layer signal layer and is used to supply power to the control circuits; The power layer is arranged between the signal ground layer and the power ground layer and is used to arrange power devices and / or power supplies in the power circuit; The power ground layer is adjacent to the power supply layer and is used to provide a closed loop for the power supply current of the power circuit; wherein the control circuit is used to control the power circuit to perform energy conversion.
2. The multi-layer PCB board structure of claim 1, wherein, The distance between the top layer signal layer and the power layer in the direction of the stack is greater than or equal to 0.2mm.
3. The multi-layer PCB board structure of claim 1, wherein, The signal ground layer and the power ground layer form a Faraday cage, and the power layer is located in the Faraday cage.
4. The multi-layer PCB board structure of claim 1, wherein, Adjacent two layers among the top layer signal layer, the signal ground layer, the power layer, the power ground layer, the power supply layer and the bottom layer signal layer are respectively provided with a dielectric layer, and at least part of the dielectric layer is respectively provided with a first conductive via and a second conductive via; The first conductive via is used to transmit signals, and the second conductive via is used to transmit power. The distance between the first conductive via and the second conductive via is greater than or equal to 1mm, and the second conductive via is filled with conductive material.
5. The multi-layer PCB board structure of claim 1, wherein, The edge of the power layer is provided with an isolation groove with a predetermined width, and the isolation groove is provided with solder mask ink.
6. The multi-layer PCB board structure of claim 1, wherein, The signal ground layer is provided with digital ground and analog ground, and the digital ground and the analog ground are connected by a single point of resistance; The digital ground and the power ground layer are connected by a single point of inductance; The power supply layer is provided with a digital power supply and a reference power supply, and the digital power supply and the reference power supply are connected by a single point of magnetic beads in the power supply layer.
7. The multi-layer PCB board structure according to any one of claims 1 to 6, characterized in that, The power circuit includes a three-phase bridge arm inverter circuit; The control circuit includes a two-phase current sampling circuit arranged in the top layer signal layer, a control chip and a driving chip. The two-phase current sampling circuit is used to collect the current of two phases in the three-phase bridge arm inverter circuit and send the collected current signal to the control chip. The control chip is connected with the driving chip, and the driving chip is connected with the bridge arm switch in the three-phase bridge arm inverter circuit. The two-phase current sampling circuit includes a sampling resistor connected in series with the lower bridge arm switch in the corresponding two-phase bridge arm. The sampling resistor is a patch alloy resistor.
8. The multi-layer PCB board structure of claim 7, wherein, The two-phase current sampling circuit includes a reference voltage generating circuit for providing a reference power supply for current sampling. The reference voltage generating circuit includes a first resistor, a second resistor, a third resistor, a three-terminal adjustable shunt regulator and a first capacitor. The first end of the first resistor outputs the reference voltage, and the second end is connected with the power supply of the reference voltage generating circuit. The first end of the second resistor is connected with the second end of the first resistor, the second end is connected with the first end of the third resistor, and the second end is connected with the adjustment end of the three-terminal adjustable shunt regulator. The second end of the third resistor and the anode end of the three-terminal adjustable shunt regulator are respectively connected to an analog ground; and the first capacitor is connected between the power supply and the analog ground.
9. An electric machine controller characterized by The multi-layer PCB structure as claimed in any one of claims 1 to 8, wherein the power circuit is configured to output energy for driving the motor to rotate.
10. A brushless electric motor characterized by comprising: The motor controller as claimed in claim 9, wherein the motor controller is connected to the brushless motor body and configured to control the brushless motor body to rotate.