Power module capable of resisting driving interference

Abstract

The invention discloses an anti-driving interference power module, which comprises at least one half-bridge power module, and is characterized in that the half-bridge power module comprises a first switching device, a second switching device, a DC positive end and a DC negative end; and a filtering loop formed by the DC positive end, the first switching device, the second switching device and the DC negative end and a second driving loop of the second switching device have the same bypassing direction. Through the coupling design of the circuit bypassing direction, for devices which do not need to be switched on, driving crosstalk generated by a gate pole is restrained, and mistaken switching-on of driving is avoided; and for a device needing to be turned on, the turn-on level of gate drive is enhanced, so that the reliability of the power module is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics, and in particular relates to a power module capable of resisting driving interference. Background Art

[0002] With the continuous development of power electronics technology and power electronics devices, the application of power supplies is becoming more and more extensive, and power and frequency are constantly being provided. The demand and requirements for power modules are also getting higher and higher. As one of the core of power products, the quality of power modules directly determines the performance and stability of the product.

[0003] As the switching frequency and switching rate of power modules increase, the gate crosstalk caused by dv / dt leads to an increasing risk of false triggering of power devices in various topologies such as half-bridge, full-bridge and three-phase bridge circuits.

[0004] There are two methods to suppress driving interference in the prior art: one is to reduce the turn-on rate by increasing the size of the driving resistance in the driving circuit, but this sacrifices the performance of the switching device to a certain extent; the other is to add capacitor filtering, filtering inductors, magnetic beads, etc. in the driving circuit. On the one hand, this method will increase certain costs and space, and on the other hand, it will sacrifice certain device performance, so it is only a trade-off design.

[0005] Therefore, how to suppress driving interference as efficiently as possible while applying capacitor filtering, reduce the required cost and power space, and improve the overall performance of the device is an urgent problem to be solved. Summary of the invention

[0006] In view of this, one of the objects of the present invention is to provide a power module that is resistant to driving interference. By designing the coupling of the circuit bypass direction, for devices that do not need to be turned on, the driving crosstalk generated by the gate is suppressed to avoid erroneous turning on of the drive; and for devices that need to be turned on, the turning-on level of the gate drive is enhanced, so that the reliability of the power module is higher.

[0007] To achieve the above object, the present invention provides a power module with anti-driving interference, including at least one half-bridge power module, wherein the half-bridge power module includes a first switch device, a second switch device, a DC positive terminal, and a DC negative terminal, wherein the first switch device is electrically connected to the DC positive terminal, the second switch device is electrically connected to the DC negative terminal, the first switch device and the second switch device are connected in series to form a half-bridge arm, and the midpoint of the half-bridge arm is led out as the SW terminal.

[0008] The first switch device and the second switch device are arranged on a substrate;

[0009] The second switch device includes a second switch body, a second source terminal, and a second gate terminal;

[0010] The winding direction of the loop formed in sequence by the DC positive terminal, the first switching device, the second switching device and the DC negative terminal is the same as the winding direction of the loop formed by the second source terminal, the second switch body and the second gate terminal.

[0011] Preferably, the first switch device comprises a first switch body, a first source terminal and a first gate terminal;

[0012] The winding direction of the loop formed in sequence by the DC positive terminal, the first switching device, the second switching device and the DC negative terminal is opposite to the winding direction of the loop formed by the first source terminal, the first switch body and the first gate terminal.

[0013] Preferably, the half-bridge power module further includes a filter capacitor, and the filter capacitor is connected in parallel with the half-bridge arm.

[0014] Preferably, the filter capacitor, the second switch body and the first switch body are sequentially arranged on the substrate, the DC positive terminal and the DC negative terminal are arranged on a side of the substrate adjacent to the filter capacitor, and the SW terminal is arranged on a side of the substrate adjacent to the first switch body.

[0015] Preferably, the filter capacitor and the first switch device are electrically connected through an electrical connector that bypasses the left side of the second switch body, the first source terminal and the first gate terminal are arranged on at least one side of the first switch body, the second source terminal and the second gate terminal are arranged on the right side and the lower side of the second switch body, and the positions of the first gate terminal and the second gate terminal are closer than the positions of the first source terminal and the second source terminal.

[0016] Preferably, the filter capacitor and the first switching device are electrically connected through an electrical connector that bypasses the right side of the second switch body, the first source terminal and the first gate terminal are arranged on at least one side of the first switch body, the second source terminal and the second gate terminal are arranged on the left side and the lower side of the second switch body, and the positions of the first gate terminal and the second gate terminal are closer than the positions of the first source terminal and the second source terminal.

[0017] Preferably, the number of the half-bridge power modules is at least two, and the two half-bridge power modules form a full-bridge module by electrically connecting the DC positive ends.

[0018] Preferably, the number of the half-bridge power modules is at least three, and the three half-bridge power modules are electrically connected at the DC positive ends to form a three-phase bridge module.

[0019] Preferably, the number of the half-bridge power modules is at least four, and the four half-bridge power modules are electrically connected at the DC positive ends to form a four-phase bridge module, two full-bridge modules or a three-phase bridge module-half-bridge module assembly structure.

[0020] Preferably, the substrate is a copper-clad ceramic substrate.

[0021] The beneficial effects of the present invention are:

[0022] The present invention utilizes the magnetic field coupling effect of transient current and, through coupling design, suppresses the driving crosstalk generated by the gate for devices that do not need to be turned on, thereby avoiding erroneous turning on of the drive. For devices that need to be turned on, the turning-on level of the gate drive is enhanced, thereby making the power module more reliable and effectively improving the driving interference problem of high-frequency switches without increasing additional costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figures 1 to 4 is a schematic diagram of Embodiment 1 of the present invention;

[0025] Figure 5 It is a schematic diagram of the second embodiment of the present invention;

[0026] Figures 6 to 12 This is a schematic diagram of Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0027] One of the core aspects of the present invention is to provide a power module that is resistant to driving interference. By designing the coupling of the circuit bypass direction, for devices that do not need to be turned on, the driving crosstalk generated by the gate is suppressed to avoid erroneous turning on of the drive; and for devices that need to be turned on, the turning-on level of the gate drive is enhanced, making the power module more reliable.

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1

[0030] The topological structure of the power module is formed by one or more half-bridge power modules. A common half-bridge power module includes two switching devices (switching device Q1 and switching device Q2), a DC positive terminal, a DC negative terminal and a filter capacitor. The switching device Q1 is electrically connected to the DC positive terminal, and the switching device Q2 is electrically connected to the DC negative terminal. The two switching devices are connected in series to form a half-bridge arm. The filter capacitor and the half-bridge arm are connected in parallel. The half-bridge arm includes an upper arm and a lower arm. The midpoint of the half-bridge arm is led out as the SW terminal.

[0031] Figure 1 The circuit diagram of the common half-bridge power module used in this embodiment is shown, wherein Q1 and Q2 are two switching devices, DC+ and DC- represent the DC positive terminal and DC negative terminal respectively, C1 is a filter capacitor, and U is the SW terminal of the half-bridge power module; Cgd in the figure is the parasitic capacitance from the gate to the drain, and Cgs is the parasitic capacitance from the gate to the source. Due to the existence of parasitic capacitance, the gate terminal of the switching device will respond to the transient current of the surrounding circuit and generate a crosstalk voltage at the gate, changing the original signal potential, thereby interfering with the gate drive. This embodiment achieves the effect of anti-driving interference by reasonably setting the loop detour direction, thereby controlling the positive and negative directions of the induced voltage generated by the loop coupling.

[0032] Figure 2 FIG. 4 shows the layout of the half-bridge power module of this embodiment on a DBC (copper-clad ceramic substrate). Figure 2 The layout settings of each device are described in order from top to bottom according to different levels:

[0033] The first level is the DC positive terminal and the DC negative terminal, the DC positive terminal is set on the left, and the DC negative terminal is set on the right;

[0034] The second level is the filter capacitor C1. The filter capacitor C1 and the DC positive terminal and DC negative terminal form a power input loop. The filter capacitor C1 and the half-bridge arm form a filter loop. The electrical connection path from the filter capacitor C1 to the switch device Q1 bypasses the left side of the switch device Q2.

[0035] The third level is the switch device Q2 of the lower bridge arm. The driving part corresponding to the switch device Q2 is located in the outer shadow area of ​​the filter loop (the area below the switch device Q2 and the side close to the DC negative terminal), and the source terminal S is above the gate terminal G. The source terminal S, the main body of the switch device Q2, the gate terminal G and the parasitic capacitor Cgs form a second driving loop.

[0036] The fourth level is the switch device Q1 of the upper bridge arm. The driving part corresponding to the switch device Q1 is located in the outer shadow area of ​​the second loop (the area below the switch device Q1 and the area near the SW end on the side), and the gate terminal G is above the source terminal S. The source terminal S, the main body of the switch device Q1, the gate terminal G and the parasitic capacitor Cgs form a first driving loop.

[0037] The fifth level is a half-bridge bridge arm, where the midpoint of the bridge arm is led out and arranged at the SW end at the bottom side of the figure.

[0038] In actual operation, the upper and lower arms of the half-bridge are turned on in an alternating and complementary manner. Figure 3 and Figure 4 The effect produced by the circuit coupling between the second driving circuit and the first driving circuit of the switching device Q2 in operation of this embodiment is shown.

[0039] At time T0, the PWM signal switches the switch device Q2 from the on state to the off state;

[0040] The interval from T0 to T1 is the dead zone interval;

[0041] At time T1, the PWM signal turns on the switching device Q1, and the transient current direction of the filter circuit (capacitor discharge direction) is C1→Q1→Q2. Due to the presence of parasitic capacitors Cgd and Cgs, the transient current will interfere with the gate, causing the gate of the switching device Q2 to generate an inflow current, generating crosstalk of a positive voltage spike. It should be noted that the positive voltage spike mentioned here refers to the first peak of the oscillation attenuation signal in the actual application scenario. Since the amplitude of subsequent oscillation signals other than the first peak will attenuate and be less than the amplitude of the first peak, its impact is negligible compared to the first peak.

[0042] After the circuit coupling direction of this embodiment is set, the transient current of the filter circuit generates a coupling voltage from the source to the gate for the second drive circuit, which has the effect of offsetting and suppressing the forward voltage spike of the switching device Q2, and generates a coupling voltage from the gate to the source for the first drive circuit, which has the effect of positively enhancing the opening of the switching device Q1.

[0043] At time T2, the PWM signal turns off the switch device Q1. Also due to the presence of parasitic capacitances Cgd and Cgs, the transient current will interfere with the gate, causing the gate of the switch device Q2 to generate an outflow current, resulting in crosstalk of negative voltage spikes.

[0044] After the circuit coupling direction of this embodiment is set, the transient current of the filter circuit generates a coupling voltage from the gate to the source for the second drive circuit, which has the effect of offsetting and suppressing the negative voltage spike of the switching device Q2, and generates a coupling voltage from the source to the gate for the first drive circuit, which has the effect of strengthening the shutdown of the switching device Q1.

[0045] The half cycle of the switch device Q2 from being turned on to being turned off is similar to the half cycle of the switch device Q1 and will not be described in detail here.

[0046] Embodiment 2

[0047] The difference between this embodiment and the first embodiment is that the layout of the half-bridge power module on the DBC (copper-clad ceramic substrate) is arranged in a mirror-symmetrical manner on the left and right sides. Figure 5 As shown, specifically:

[0048] The DC positive terminal is set on the right, and the DC negative terminal is set on the left;

[0049] The electrical connection path from the filter capacitor C1 to the switch device Q1 is routed around the right side of the switch device Q2;

[0050] The driving parts corresponding to the switch devices Q2 and Q1 are respectively located in the outer shadow area of ​​the filter loop, and the outer shadow area in this embodiment faces left.

[0051] Due to the mirror-symmetrical setting, the winding direction of each loop in this embodiment is opposite to that of the first embodiment, so the coupling effect between the first drive loop and the filter loop, and the coupling effect between the second drive loop and the filter loop is still the same. This embodiment has the same technical effect as the first embodiment, which will not be repeated here.

[0052] Embodiment 3

[0053] A half-bridge power module in the first embodiment is called module A, and a half-bridge power module in the second embodiment is called module B. Module A and module B can form a full-bridge, three-phase bridge or other power modules including more half-bridge power modules by combining the same modules or different modules.

[0054] Figure 6 and Figure 7 The structure of a full-bridge power module is shown, and the full-bridge power module consists of an A module and a B module. Figure 6 is a circuit diagram, wherein the portion enclosed by a dotted line represents a circuit of a half-bridge power module, and module A and module B are electrically connected to form a common DC positive terminal. Figure 7Schematic diagram of the layout, Q1 and Q2 are two switch devices of module A, Q3 and Q4 are two switch devices of module B, C1 and C2 are filter capacitors of module A and module B respectively, SW1 and SW2 are SW terminals of module A and module B respectively. The DC positive terminals of the two modules are arranged adjacent to each other for electrical connection. In a preferred embodiment, the two DC negative terminals of the full-bridge power module are independently arranged internally, and are electrically connected through other circuits outside the full-bridge power module (such as circuits on the system mainboard) to realize its complete function.

[0055] Figures 8 to 11 The structure of a three-phase bridge module is shown. The three-phase bridge module can be composed of three A modules or three B modules or a mixture of A modules and B modules. Figure 8 : is a circuit diagram, in which the dotted-line framed portion represents a circuit of a half-bridge power module, and the three half-bridge power modules are electrically connected to form a common DC positive terminal, and the SW terminals of the three half-bridge power modules are the three-phase U, V, and W terminals in the figure. In a preferred embodiment, the three DC negative terminals of the three-phase bridge module are independently set internally, and are electrically connected through other circuits outside the three-phase bridge module (such as circuits on the system mainboard) to realize its complete function. Figures 9 to 11 Figure 1 is a layout diagram. C1-Q1-Q2, C2-Q3-Q4, and C3-Q5-Q6 are the device groups of each half-bridge power module. Fig. 9 It is composed of three A modules. Fig.10 It is composed of three B modules. Fig.11 The three modules are combined in the form of BAB. In some other embodiments, they can also be combined in other forms, which will not be described here.

[0056] In a preferred embodiment, according to the actual layout requirements, the layout positions of the driving parts corresponding to the switching devices of the same half-bridge power module can be respectively located on the left and right sides of the half-bridge power module, that is, the layout position of the driving part of the first switching device is adjusted so that the overall layout leaves a layout space in the lower left corner that can be used to set other functional areas. Fig.12 The circuit board layout design of this embodiment is shown, in which other functional areas are used to set the thermal sensor (NTC). On the other hand, the B module and the A module adjacent to the DC positive terminal can share the copper foil (electrical connection from the DC positive terminal to the first switching device Q3 / Q5).

[0057] In a preferred embodiment, the embodiment includes four half-bridge power modules, which can work independently of each other, or form a four-phase bridge module, two full-bridge modules or a three-phase bridge module-half-bridge module assembly structure by electrically connecting the DC positive ends.

[0058] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0059] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power module with anti-driving interference, comprising at least one half-bridge power module, wherein the half-bridge power module comprises a first switch device, a second switch device, a DC positive terminal, and a DC negative terminal, wherein the first switch device is electrically connected to the DC positive terminal, the second switch device is electrically connected to the DC negative terminal, the first switch device and the second switch device are connected in series to form a half-bridge arm, and the midpoint of the half-bridge arm is led out as the SW terminal, characterized in that: The first switch device and the second switch device are arranged on a substrate; The second switch device includes a second switch body, a second source terminal, and a second gate terminal; The winding direction of the loop formed in sequence by the DC positive terminal, the first switching device, the second switching device and the DC negative terminal is the same as the winding direction of the loop formed by the second source terminal, the second switch body and the second gate terminal.

2. The power module according to claim 1, characterized in that: The first switch device includes a first switch body, a first source terminal and a first gate terminal; The winding direction of the loop formed in sequence by the DC positive terminal, the first switching device, the second switching device and the DC negative terminal is opposite to the winding direction of the loop formed by the first source terminal, the first switch body and the first gate terminal.

3. The power module according to claim 1, characterized in that: The half-bridge power module further includes a filter capacitor, which is connected in parallel with the half-bridge arm.

4. The power module according to claim 3, characterized in that: The filter capacitor, the second switch body and the first switch body are sequentially arranged on the substrate, the DC positive terminal and the DC negative terminal are arranged on a side of the substrate adjacent to the filter capacitor, and the SW terminal is arranged on a side of the substrate adjacent to the first switch body.

5. The power module according to claim 4, characterized in that: The filter capacitor and the first switch device are electrically connected through an electrical connector that bypasses the left side of the second switch body. The first source terminal and the first gate terminal are arranged on at least one side of the first switch body, and the second source terminal and the second gate terminal are arranged on the right side and the lower side of the second switch body. The positions of the first gate terminal and the second gate terminal are closer than the positions of the first source terminal and the second source terminal.

6. The power module according to claim 4, characterized in that: The filter capacitor and the first switch device are electrically connected through an electrical connector that bypasses the right side of the second switch body. The first source terminal and the first gate terminal are arranged on at least one side of the first switch body, and the second source terminal and the second gate terminal are arranged on the left side and the lower side of the second switch body. The positions of the first gate terminal and the second gate terminal are closer than the positions of the first source terminal and the second source terminal.

7. The power module according to any one of claims 1 to 6, characterized in that: The number of the half-bridge power modules is at least two, and the two half-bridge power modules form a full-bridge module by electrically connecting the DC positive ends.

8. The power module according to any one of claims 1 to 6, characterized in that: The number of the half-bridge power modules is at least three, and the three half-bridge power modules form a three-phase bridge module by electrically connecting the DC positive ends.

9. The power module according to any one of claims 1 to 6, characterized in that: The number of the half-bridge power modules is at least four, and the four half-bridge power modules are electrically connected at the DC positive ends to form a four-phase bridge module, two full-bridge modules or a three-phase bridge module-half-bridge module assembly structure.

10. The power module according to claim 1, characterized in that: The substrate is a copper-clad ceramic substrate.

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