Power module with low stray inductance

Abstract

The utility model discloses a power module with low stray inductance, which relates to the technical field of power modules and comprises a supporting substrate, an upper bridge arm unit and a lower bridge arm unit, and the upper bridge arm unit and the lower bridge arm unit are symmetrically arranged on the supporting substrate. The upper bridge arm unit comprises an upper bridge DBC substrate, the lower bridge arm unit comprises a lower bridge DBC substrate, and the upper bridge DBC substrate is electrically connected with the lower bridge DBC substrate; a positive power terminal is bonded on the upper bridge DBC substrate, a negative power terminal matched with the positive power terminal is bonded on the lower bridge DBC substrate, and the negative power terminal is adjacent to the positive power terminal and is overlapped with the positive power terminal. The power module can effectively reduce stray inductance and has high reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor power modules, in particular to a power module with low stray inductance. Background Art

[0002] A power module is a module formed by combining power electronic devices according to certain functions and then packaging them. At present, high-voltage, high-current, and high-power density power modules have been widely used in emerging industrial fields such as new energy power generation, rail transit, and smart grids.

[0003] In order to meet the ever-increasing application requirements of power modules, high-frequency silicon carbide chips have been widely used inside power modules. Since silicon carbide chips have the characteristics of small junction capacitance, low gate charge, and fast switching speed, the voltage and current change rate during the switching process is extremely large. The stray inductance in traditional power modules is very likely to produce voltage overshoot and oscillation under the extremely large current change rate, further causing the voltage stress and loss of high-frequency silicon carbide chips to increase, and bring about electromagnetic interference problems. Therefore, how to reduce the stray inductance of the module in the design of the power module and reduce the switching loss of the module is the key to exerting the performance of the power module. Utility Model Content

[0004] In response to the above problems and technical requirements, the applicant has proposed a power module with low stray inductance.

[0005] The technical solution of the utility model is as follows:

[0006] A power module with low stray inductance comprises a supporting substrate, an upper bridge arm unit and a lower bridge arm unit, wherein the upper bridge arm unit and the lower bridge arm unit are symmetrically arranged on the supporting substrate;

[0007] The upper bridge arm unit includes an upper bridge DBC substrate, the lower bridge arm unit includes a lower bridge DBC substrate, and the upper bridge DBC substrate is electrically connected to the lower bridge DBC substrate;

[0008] A positive power terminal is bonded to the upper bridge DBC substrate, and a negative power terminal adapted to the positive power terminal is bonded to the lower bridge DBC substrate. The negative power terminal is adjacent to the positive power terminal and overlaps with the positive power terminal.

[0009] A further technical solution is that the positive power terminal includes a first horizontal bonding portion, a first vertical connecting portion, a first horizontal connecting portion and a first vertical lead-out portion, wherein:

[0010] The positive power terminal is bonded to the upper bridge DBC substrate through a first horizontal bonding portion, the first horizontal bonding portion is connected to one end of the first horizontal connection portion through a first vertical connection portion, and the other end of the first horizontal connection portion is connected to the first vertical lead-out portion;

[0011] The negative power terminal includes a second horizontal bonding portion, a second vertical connecting portion, a second horizontal connecting portion and a second vertical lead-out portion, wherein:

[0012] The negative power terminal is bonded to the lower bridge DBC substrate through a second horizontal bonding portion, the second horizontal bonding portion is connected to one end of the second horizontal connection portion through a second vertical connection portion, and the other end of the second horizontal connection portion is connected to the second vertical lead-out portion.

[0013] A further technical solution thereof is that the first vertical connection portion is parallel to and overlaps with the second vertical connection portion, and the first vertical lead-out portion is parallel to and overlaps with the second vertical lead-out portion;

[0014] In the cross section of the power module, the length directions of the first vertical connection portion and the second vertical connection portion are perpendicular to the support substrate, the first vertical lead-out portion is parallel to the first vertical connection portion, and the second vertical lead-out portion is parallel to the second vertical connection portion.

[0015] A further technical solution is that the upper bridge DBC substrate includes an upper bridge first connection area and an upper bridge second connection area, and the lower bridge DBC substrate includes a lower bridge first connection area and a lower bridge second connection area;

[0016] A plurality of power units are arranged in the upper bridge first connection area, the upper bridge second connection area, the lower bridge first connection area and the lower bridge second connection area, and each power unit includes a power chip and a diode chip adapted to be connected to the power chip;

[0017] The power chip and the diode chip in the power unit are electrically connected to the corresponding DBC substrate through the connection belt.

[0018] A further technical solution is that the power chip includes a control electrode, and the control electrode of each power chip is connected to a protection resistor, and the protection resistor is arranged on the corresponding DBC substrate.

[0019] A further technical solution is that the upper bridge DBC substrate in the upper bridge arm unit and the lower bridge DBC substrate in the lower bridge arm unit are symmetrical about the first axis;

[0020] The upper bridge first connection area and the upper bridge second connection area in the upper bridge DBC substrate are symmetrical about the second axis, and the lower bridge first connection area and the lower bridge second connection area in the lower bridge DBC substrate are symmetrical about the second axis, and the first axis is perpendicular to the second axis.

[0021] A further technical solution is that the upper bridge DBC substrate further includes an upper bridge first source region, an upper bridge second source region and an upper bridge third source region, and the lower bridge DBC substrate further includes a lower bridge first source region, a lower bridge second source region and a lower bridge third source region;

[0022] The upper bridge first source region is electrically connected to the lower bridge first connection region and the lower bridge second connection region.

[0023] A further technical solution is that the first horizontal bonding portion of the positive power terminal includes a first positive bonding end and a second positive bonding end, the first positive bonding end is bonded to the first connection area of ​​the upper bridge, and the second positive bonding end is bonded to the second connection area of ​​the upper bridge.

[0024] A further technical solution is that the second horizontal bonding portion of the negative power terminal includes a first negative bonding end and a second negative bonding end, and the first negative bonding end and the second negative bonding end are both bonded to the first source region of the lower bridge.

[0025] A further technical solution is that a signal connection unit is also provided on the supporting substrate, and the signal connection unit includes a signal connection DBC substrate and a plurality of signal terminals provided on the signal connection DBC substrate, and the signal connection DBC substrate is electrically connected to the upper bridge DBC substrate and the lower bridge DBC substrate.

[0026] The beneficial technical effects of the utility model are:

[0027] In the utility model, the upper bridge arm unit and the lower bridge arm unit are symmetrically arranged on the supporting substrate, which can effectively reduce the thermal coupling effect in the module and improve the thermal processing capacity and stability of the power module. The positive power terminal on the upper bridge arm unit is adjacent to the negative power terminal on the lower bridge arm unit, and the positive and negative power terminals are adapted and overlapped. When the power module is working, the currents in the two power terminals flow in opposite directions, and the magnetic field distribution directions formed by the currents in the two power terminals are opposite. The magnetic fields between the positive and negative power terminals cancel each other out, effectively reducing the stray inductance in the entire power packaging module, effectively reducing the generation and output of high-power electromagnetic interference inside the module, and improving the performance of the power module.

[0028] In addition, the utility model connects the control electrode of the power chip in the module with the protection resistor, which can effectively reduce the instantaneous change of the control electrode voltage and the current mutation caused by the change of the control electrode voltage, thereby reducing the switching loss of the power module and improving the reliability of the power module. The utility model also electrically connects the chip to the DBC substrate through a connecting strip. Compared with traditional bonding wires, the connecting strip can effectively reduce the parasitic effect of the inductance, thereby further improving the stability and reliability of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a front schematic diagram of an embodiment of a power module provided by the utility model.

[0030] Figure 2 It is a cross-sectional schematic diagram of an embodiment of a power module provided by the utility model.

[0031] Figure 3 It is a front schematic diagram of the distribution of conductive areas of an upper bridge DBC substrate and a lower bridge DBC substrate in an embodiment of a power module provided by the utility model.

[0032] Reference numerals:

[0033] 10 - supporting substrate, 11 - power chip, 12 - diode chip, 13a - first output bonding terminal, 13b - second output bonding terminal, 14a - first output connection terminal, 14b - second output connection terminal, 15 - third horizontal connection part, 16 - third vertical lead-out part.

[0034] 100-upper bridge DBC substrate, 101-first upper bridge connection area, 102-second upper bridge connection area, 111a-first positive bonding end, 111b-second positive bonding end, 112a-first positive connection end, 112b-second positive connection end, 113-first horizontal connection part, 114 first vertical lead-out part, 121-first source area of ​​the upper bridge, 122-second source area of ​​the upper bridge, 123-third source area of ​​the upper bridge, 131-first gate area of ​​the upper bridge, 132-second gate area of ​​the upper bridge, 133-third gate area of ​​the upper bridge, 134-fourth gate area of ​​the upper bridge, 135-fifth gate area of ​​the upper bridge, 136-sixth gate area of ​​the upper bridge.

[0035] 200-lower bridge DBC substrate, 201-first connection area of ​​the lower bridge, 202-second connection area of ​​the lower bridge, 211a-first negative electrode bonding end, 211b-second negative electrode bonding end, 212a-first negative electrode connection end, 212b-second negative electrode connection end, 213-second horizontal connection part, 214 second vertical lead-out part, 221-first source area of ​​the lower bridge, 222-second source area of ​​the lower bridge, 223-third source area of ​​the lower bridge, 231-first gate area of ​​the lower bridge, 232-second gate area of ​​the lower bridge, 233-third gate area of ​​the lower bridge, 234-fourth gate area of ​​the lower bridge, 235-fifth gate area of ​​the lower bridge, 236-sixth gate area of ​​the lower bridge.

[0036] 300 - signal connection DBC substrate, 311 - first gate signal connection area, 312 - second gate signal connection area, 321 - first source signal connection area, 322 - second source signal connection area, 331 - first gate signal terminal, 332 - second gate signal terminal 332, 341 - first source signal terminal 341, 342 - second source signal terminal. DETAILED DESCRIPTION

[0037] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings.

[0038] The utility model provides a power module with low stray inductance, comprising a supporting substrate 10, an upper bridge arm unit and a lower bridge arm unit, wherein the upper bridge arm unit and the lower bridge arm unit are symmetrically arranged on the supporting substrate 10;

[0039] The upper bridge arm unit includes an upper bridge DBC substrate 100, and the lower bridge arm unit includes a lower bridge DBC substrate 200, and the upper bridge DBC substrate 100 is electrically connected to the lower bridge DBC substrate 200;

[0040] A positive power terminal is bonded to the upper bridge DBC substrate 100 , and a negative power terminal adapted to the positive power terminal is bonded to the lower bridge DBC substrate 200 . The negative power terminal is adjacent to the positive power terminal and overlaps with the positive power terminal.

[0041] Specifically, the support substrate 10 can be a copper substrate, which is used to provide mechanical support and heat conduction path for the upper bridge arm unit and the lower bridge arm unit. The upper bridge arm unit includes an upper bridge DBC substrate 100, and the lower bridge arm unit includes a lower bridge DBC substrate 200. DBC (copper-clad ceramic board) generally includes a top copper layer, a ceramic layer and a bottom copper layer connected in sequence from top to bottom. The top copper layer is divided into multiple different conductive areas after being patterned, and the bottom copper layer is soldered to the support substrate 10 by solder.

[0042] The upper bridge arm unit and the lower bridge arm unit are symmetrically arranged on the support substrate 10, specifically, the upper bridge DBC substrate 100 and the lower bridge DBC substrate 200 in the upper bridge arm unit are axially symmetrically arranged, the patterned conductive area formed by the top copper layer of the upper bridge DBC substrate 100 and the patterned conductive area formed by the top copper layer of the lower bridge DBC substrate 200 are also axially symmetrically arranged, and the components arranged in the conductive area are also symmetrically arranged. The specific distribution of the conductive area of ​​the top copper layer of the upper bridge DBC substrate 100 and the lower bridge DBC substrate, as well as the specific distribution of the components in the conductive area can be referred to the following description. The symmetrical arrangement of the upper bridge arm unit and the lower bridge arm unit on the support substrate 10 is conducive to reducing the thermal coupling effect in the power module, thereby improving the thermal processing capability and stability of the power module.

[0043] The above-mentioned negative power terminal is adapted to the positive power terminal, specifically, the shape of the negative power terminal and the positive power terminal are similar or the same, the negative power terminal is adjacent to the positive power terminal, and the negative power terminal and the positive power terminal have an overlapping part. When the power module is working, the positive power terminal is connected to the positive pole of the power supply, and the negative power terminal is connected to the negative pole of the power supply. The current flow direction in the two power terminals is opposite, and the current value and current distribution passing through correspond to each other. The magnetic field distribution direction formed by the current in the two power terminals is opposite, and the magnetic field between the positive and negative power terminals cancels each other, effectively reducing the stray inductance in the entire power packaging module, thereby effectively reducing the generation and output of high-power electromagnetic interference inside the module, and improving the performance of the power module. The closer the distance between the negative power terminal and the positive power terminal, the larger the overlapping area, the stronger the magnetic field coupling between the two power terminals, and the better the effect of eliminating stray inductance. Therefore, in the specific implementation, the positive and negative power terminals should be as close to each other as possible and have a larger overlapping area. The specific structure and distribution of the positive and negative power terminals can refer to the following description.

[0044] The positive power terminal includes a first horizontal bonding portion, a first vertical connection portion, a first horizontal connection portion 113 and a first vertical lead-out portion 114, wherein:

[0045] The positive power terminal is bonded to the upper bridge DBC substrate 100 through a first horizontal bonding portion, the first horizontal bonding portion is connected to one end of the first horizontal connection portion 113 through a first vertical connection portion, and the other end of the first horizontal connection portion 113 is connected to the first vertical lead-out portion 114;

[0046] The negative power terminal includes a second horizontal bonding portion, a second vertical connecting portion, a second horizontal connecting portion 213 and a second vertical lead-out portion 214, wherein:

[0047] The negative power terminal is bonded to the lower bridge DBC substrate 200 via a second horizontal bonding portion, the second horizontal bonding portion is connected to one end of a second horizontal connection portion 213 via a second vertical connection portion, and the other end of the second horizontal connection portion 213 is connected to a second vertical lead-out portion 214 .

[0048] Specifically, the first vertical connection portion is parallel to and overlaps with the second vertical connection portion, and the first vertical lead-out portion 114 is parallel to and overlaps with the second vertical lead-out portion 214 . Figure 2 A cross-sectional schematic diagram of an embodiment of a power module provided by the utility model is shown in FIG. Figure 2As shown, in the cross section of the power module, the positive power terminal and the negative power terminal have similar shapes, and the length direction of the first vertical connection portion and the second vertical connection portion is perpendicular to the support substrate 10, the first vertical lead-out portion 114 is parallel to the first vertical connection portion, and the second vertical lead-out portion 214 is parallel to the second vertical connection portion. The length direction of the first horizontal bonding portion and the second horizontal bonding portion is perpendicular to the length direction of the first vertical connection portion and the second vertical connection portion, the first horizontal bonding portion and the second horizontal bonding portion are parallel and located in the same plane, and the first horizontal connection portion 113 and the second horizontal connection portion 213 are parallel and located in the same plane.

[0049] Figure 1 A front view schematic diagram of an embodiment of a power module provided by the utility model, such as Figure 1 As shown, in this embodiment, the area of ​​the negative power terminal is greater than that of the positive power terminal, the first horizontal bonding portion of the positive power terminal includes a first positive bonding end 111a and a second positive bonding end 111b, the first vertical connection portion includes a first positive connection end 112a and a second positive connection end 112b, and the first positive bonding end 111a is connected to the first horizontal connection portion 113 through the first positive connection end 112a. The first positive bonding end 111a and the second positive bonding end 111b have the same shape, and the first positive connection end 112a and the second positive connection end 112b have the same shape.

[0050] The second horizontal bonding portion of the negative power terminal includes a first negative bonding end 211a and a second negative bonding end 211b, and the second vertical connection portion includes a first negative connection end 212a and a second negative connection end 212b, and the first negative bonding end 211a is connected to the second horizontal connection portion 213 through the first negative connection end 212a. The first negative bonding end 211a and the second negative bonding end 211b have the same shape, and the first negative connection end 212a and the second negative connection end 212b have the same shape.

[0051] Furthermore, the patterned conductive area formed by the top copper layer of each DBC substrate includes two connection areas. The upper bridge DBC substrate 100 includes an upper bridge first connection area 101 and an upper bridge second connection area 102, and the lower bridge DBC substrate includes a lower bridge first connection area 201 and a lower bridge second connection area 202.

[0052] Preferably, the upper bridge DBC substrate 100 in the upper bridge arm unit and the lower bridge DBC substrate 200 in the lower bridge arm unit are symmetrical about the first axis. The upper bridge first connection area 101 and the upper bridge second connection area 102 in the upper bridge DBC substrate 100 are symmetrical about the second axis, and the lower bridge first connection area 201 and the lower bridge second connection area 202 in the lower bridge DBC substrate 200 are symmetrical about the second axis, and the first axis is perpendicular to the second axis.

[0053] To clearly show the patterned conductive area formed by the top copper layer in the DBC substrate, Figure 3 FIG. 4 shows a front view of a power module in which no connection terminals are provided on the DBC substrate. Figure 3 As shown, the support substrate 10 in this embodiment is a rounded rectangle, with the long side center axis A-A' of the support substrate 10 as the first axis, and the short side center axis BB' of the support substrate 10 as the second axis. The upper bridge first connection area 101 and the lower bridge first connection area 201 are symmetrical about the center axis A-A', and the upper bridge second connection area 102 and the lower bridge second connection area 202 are symmetrical about the center axis A-A'. The upper bridge first connection area 101 and the upper bridge second connection area 102 in the upper bridge DBC substrate 100 are symmetrical about the center axis BB', and the lower bridge first connection area 201 and the lower bridge second connection area 202 in the lower bridge DBC substrate 200 are symmetrical about the center axis BB'.

[0054] like Figure 3 As shown, the conductive area in the upper bridge DBC substrate 100 in this embodiment also includes the upper bridge first source region 121, the upper bridge second source region 122, the upper bridge third source region 123, the upper bridge first gate region 131, the upper bridge second gate region 132, the upper bridge third gate region 133, the upper bridge fourth gate region 134, the upper bridge fifth gate region 135 and the upper bridge sixth gate region 136; symmetrically with the upper bridge DBC substrate 100, the lower bridge DBC substrate also includes the lower bridge first source region 221, the lower bridge second source region 222, the lower bridge third source region 223, the lower bridge first gate region 231, the lower bridge second gate region 232, the lower bridge third gate region 233, the lower bridge fourth gate region 234, the lower bridge fifth gate region 235 and the lower bridge sixth gate region 236. In specific implementation, the distribution of the conductive area of ​​the copper layer on the DBC substrate can be set according to actual needs.

[0055] The upper bridge first gate region 131 is connected to the lower bridge first gate region 231 through a bonding wire, the upper bridge second source region 122 is connected to the lower bridge second source region 222 through a bonding wire, the lower bridge second gate region 232 is connected to the lower bridge first gate region 231 through a bonding wire, and the lower bridge third source region 223 is connected to the lower bridge second source region 222 through a bonding wire.

[0056] The first positive bonding end 112a of the positive power terminal is bonded to the upper bridge first connection area 101; the second positive bonding end 112b is bonded to the upper bridge second connection area 102. The first negative bonding end 211a and the second negative bonding end 211b of the negative power terminal are both bonded to the lower bridge first source area 221.

[0057] Furthermore, the lower bridge DBC substrate 200 is also provided with an output terminal;

[0058] Specifically, the output terminal includes a third horizontal bonding portion, a third vertical connection portion, a third horizontal connection portion 15 and a third vertical lead-out portion 16, wherein the third horizontal bonding portion includes a first output bonding end 13a and a second output bonding end 13b, the first output bonding end 13a is bonded to the second connection area 202 of the lower bridge, and the second output bonding end 13b is bonded to the first connection area 201 of the lower bridge. The first output bonding end 13a is connected to one end of the third horizontal connection portion 15 through the first output connection end 14a, the second output bonding end 13b is connected to one end of the third horizontal connection portion 15 through the second output connection end 14b, and the other end of the third horizontal connection portion 15 is connected to the third vertical lead-out portion 16. In this embodiment, the third horizontal bonding portion is parallel to the third horizontal connection portion 15, the third vertical connection portion is parallel to the third vertical lead-out portion 16, the first vertical connection portion, the second vertical connection portion and the third vertical connection portion are parallel, and the first vertical lead-out portion 114, the second vertical lead-out portion 214 and the third vertical lead-out portion 16 are parallel. The first horizontal bonding portion, the second horizontal bonding portion and the third horizontal bonding portion are parallel and in the same plane, and the first horizontal connection portion 113, the second horizontal connection portion 213 and the third horizontal connection portion 15 are parallel and in the same plane. In specific implementation, the shape of the output terminal can be set according to actual needs.

[0059] Furthermore, a plurality of power units are disposed in the upper bridge first connection area 101, the upper bridge second connection area 102, the lower bridge first connection area 201 and the lower bridge second connection area 202, and each power unit includes a power chip 11 and a diode chip 12 adapted to be connected to the power chip 11;

[0060] The power chip 11 and the diode chip 12 in the power unit are electrically connected to the corresponding DBC substrate via a connecting strip;

[0061] The power chip 11 includes a control electrode, and the control electrode of each power chip 11 is connected to a protection resistor, and the protection resistor is arranged on the corresponding DBC substrate. Connecting the control electrode with the protection resistor can effectively reduce the instantaneous change of the control electrode voltage, reduce the current mutation caused by the change of the control electrode voltage, reduce the control electrode charging peak current, prevent current oscillation, thereby reducing the switching loss of the power module and improving the reliability of the power module.

[0062] Specifically, in this embodiment, two power units are arranged in each connection area, and the power units in the two connection areas on the same DBC substrate are symmetrically arranged, and the two power units in each connection area are also symmetrically arranged to further reduce the thermal coupling effect. The power chip 11 in any power unit can be an IGBT chip or a MOSFET chip, and the power chip 11 can be a chip of Si substrate or a chip of SiC substrate, and the diode chip 12 can be an FRD chip. The chip usually includes a front side and a back side corresponding to the front side. For MOSFET chips, the control pole is the gate, the front side of the chip is provided with a gate pad and a source pad, and the back side of the chip is provided with a drain pad; for IGBT chips, the control pole is the gate, the front side of the chip is provided with a gate pad and an emitter pad, and the back side of the chip is provided with a collector pad. For FRD chips, a cathode pad is provided on the back side of the chip, and an anode pad is provided on the front side of the chip. The specific arrangement forms of the pads of the IGBT chip, MOSFET chip and FRD chip are consistent with the prior art. When the chip is packaged on the DBC substrate, the pad on the back of the chip is generally soldered to the upper copper layer of the DBC substrate. In specific implementation, the number, type and connection method of the power chip 11 and the diode chip 12 can be set according to the specific circuit topology of the power module.

[0063] The power module in this embodiment includes eight power units connected in parallel with each other, and any power unit includes a SiC-MOSFET chip and an FRD chip connected in reverse parallel with the SiC-MOSFET chip, and the gate of each SiC-MOSFET chip is connected to a protection resistor. In any power unit, the source pad of the SiC-MOSFET chip is connected to the anode pad of the FRD chip and the first source region of the corresponding DBC substrate through a connecting tape. At the same time, the first source region 121 of the upper bridge in this embodiment is connected to the first connection region 201 of the lower bridge and the second connection region 202 of the lower bridge through several connecting tapes. The material of the connecting tape can be copper or aluminum. Compared with the bonding wire, the connecting tape has higher reliability and can reduce the parasitic effect of the inductance. The wider the width of the connecting tape, the smaller its self-inductance value and the lower the stray inductance. If the space of the DBC substrate allows, the conductive areas of the above-mentioned DBC substrate can also be electrically connected using connecting tapes instead of bonding wires to further reduce the stray inductance of the power module.

[0064] To form the above circuit topology, Figure 1 As shown, in the lower bridge DBC substrate 200, the lower bridge first connection area 201 is welded with SiC-MOSFET chip M1, SiC-MOSFET chip M2, FRD chip F1 and FRD chip F2 in parallel, wherein SiC-MOSFET chip M1 and SiC-MOSFET chip M2 are symmetrically arranged, and FRD chip F1 and FRD chip F2 are symmetrically arranged.

[0065] The source pad of the SiC-MOSFET chip M1 and the anode pad of the FRD chip F1 are connected to the first source region 221 of the lower bridge through a connecting strip, and the source pad of the SiC-MOSFET chip M1 is also connected to the third source region 223 of the lower bridge through a bonding wire; the source pad of the SiC-MOSFET chip M2 and the anode pad of the FRD chip F2 are also connected to the first source region 221 of the lower bridge through a connecting strip, and the source pad of the SiC-MOSFET chip M2 is also connected to the third source region 223 of the lower bridge through a bonding wire.

[0066] like Figure 1 As shown, four protection resistors are correspondingly arranged on the lower bridge DBC substrate 200, namely, resistor R1, resistor R2, resistor R3 and resistor R4, wherein one end of the resistor R1 is welded to the lower bridge second gate area 232, and the other end of the resistor R1 is welded to the lower bridge third gate area 233, and the lower bridge third gate area 233 is connected to the gate pad of the SiC-MOSFET chip M1 through a bonding wire; one end of the resistor R2 is welded to the lower bridge second gate area 232, and the other end of the resistor R2 is welded to the lower bridge fourth gate area 234, and the lower bridge fourth gate area 234 is connected to the gate pad of the SiC-MOSFET chip M2 through a bonding wire.

[0067] Symmetrically with the first connection area 201 of the lower bridge, the second connection area 202 of the lower bridge is welded with SiC-MOSFET chip M3, SiC-MOSFET chip M3, FRD chip F3 and FRD chip F4 in parallel, wherein SiC-MOSFET chip M3 and SiC-MOSFET chip M4 are symmetrically arranged, and FRD chip F3 and FRD chip F4 are symmetrically arranged. At the same time, SiC-MOSFET chip M1 and SiC-MOSFET chip M4, SiC-MOSFET chip M2 and SiC-MOSFET chip M3, FRD chip F1 and FRD chip F4, and FRD chip F2 and FRD chip F3 are all about Figure 3 The center axis BB' is shown symmetrically.

[0068] The source pad of the SiC-MOSFET chip M3 and the anode pad of the FRD chip F3 are connected to the first source region 221 of the lower bridge through a connecting strip, and the source pad of the SiC-MOSFET chip M3 is also connected to the third source region 223 of the lower bridge through a bonding wire; the source pad of the SiC-MOSFET chip M4 and the anode pad of the FRD chip F4 are also connected to the first source region 221 of the lower bridge through a connecting strip, and the source pad of the SiC-MOSFET chip M4 is also connected to the third source region 223 of the lower bridge through a bonding wire. One end of the resistor R3 is welded to the second gate region 232 of the lower bridge, and the other end of the resistor R1 is welded to the fifth gate region 235 of the lower bridge, and the fifth gate region 235 of the lower bridge is connected to the gate pad of the SiC-MOSFET chip M3 through a bonding wire; one end of the resistor R4 is welded to the second gate region 232 of the lower bridge, and the other end of the resistor R2 is welded to the sixth gate region 236 of the lower bridge, and the sixth gate region 236 of the lower bridge is connected to the gate pad of the SiC-MOSFET chip M4 through a bonding wire.

[0069] Symmetrically with the lower bridge DBC substrate 200, the upper bridge DBC substrate 100 is provided with SiC-MOSFET chip M5, SiC-MOSFET chip M6, SiC-MOSFET chip M7, SiC-MOSFET chip M8, FRD chip F5, FRD chip F6, FRD chip F7, FRD chip F8, resistor R5, resistor R6, resistor R7 and resistor R8, wherein the connection method of each component in the upper bridge DBC substrate 100 is consistent with the connection method of each component in the lower bridge DBC substrate 200, and please refer to the above description for details, which will not be repeated here.

[0070] Furthermore, a signal connection unit is also provided on the support substrate 10, and the signal connection unit includes a signal connection DBC substrate 300 and a plurality of signal terminals provided on the signal connection DBC substrate 300, and the signal connection DBC substrate 300 is electrically connected to the upper bridge DBC substrate 100 and the lower bridge DBC substrate 200.

[0071] Specifically, the signal connection DBC substrate 300 is disposed on the side of the upper bridge DBC substrate 100 away from the lower bridge DBC substrate 200. The upper copper layer of the signal connection DBC substrate 300 is also patterned to form a conductive area. In this embodiment, the signal connection DBC substrate 300 includes a first gate signal connection area 311, a second gate signal connection area 312, a first source signal connection area 321 and a second source signal connection area 322. Figure 3As shown, the first gate signal connection area 311 and the second gate signal connection area 312 are symmetrical about the central axis BB', and the first source signal connection area 321 and the second source signal connection area 322 are also symmetrical about the central axis BB' to further eliminate the thermal coupling effect. The first gate signal connection area 311 is connected to the first gate area 131 of the upper bridge through a bonding wire and / or a connection belt, the first source signal connection area 321 is connected to the second source area 122 of the upper bridge through a bonding wire and / or a connection belt, the second gate signal connection area 312 is connected to the second gate area 132 of the upper bridge through a bonding wire and / or a connection belt, and the second source signal connection area 322 is connected to the third source area 123 of the upper bridge through a bonding wire and / or a connection belt.

[0072] The first gate signal connection area 311 is bonded with a first gate signal terminal 331, and the second gate signal connection area 312 is bonded with a second gate signal terminal 332. The first source signal connection area 321 is bonded with a first source signal terminal 341, and the second source signal connection area 322 is bonded with a second source signal terminal 342.

[0073] It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the above description refer to directions in the drawings of the present application specification, and the words "front" and "back", "inner" and "outer" refer to directions toward or away from a specific component, respectively. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0074] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A power module with low stray inductance, characterized in that: It includes a supporting substrate, an upper bridge arm unit and a lower bridge arm unit, wherein the upper bridge arm unit and the lower bridge arm unit are symmetrically arranged on the supporting substrate; The upper bridge arm unit includes an upper bridge DBC substrate, the lower bridge arm unit includes a lower bridge DBC substrate, and the upper bridge DBC substrate is electrically connected to the lower bridge DBC substrate; A positive power terminal is bonded to the upper bridge DBC substrate, and a negative power terminal adapted to the positive power terminal is bonded to the lower bridge DBC substrate. The negative power terminal is adjacent to the positive power terminal and overlaps with the positive power terminal.

2. The stray inductance power module according to claim 1, characterized in that: The positive power terminal includes a first horizontal bonding portion, a first vertical connecting portion, a first horizontal connecting portion and a first vertical lead-out portion, wherein: The positive power terminal is bonded to the upper bridge DBC substrate through a first horizontal bonding portion, the first horizontal bonding portion is connected to one end of the first horizontal connection portion through a first vertical connection portion, and the other end of the first horizontal connection portion is connected to the first vertical lead-out portion; The negative power terminal includes a second horizontal bonding portion, a second vertical connecting portion, a second horizontal connecting portion and a second vertical lead-out portion, wherein: The negative power terminal is bonded to the lower bridge DBC substrate through a second horizontal bonding portion, the second horizontal bonding portion is connected to one end of the second horizontal connection portion through a second vertical connection portion, and the other end of the second horizontal connection portion is connected to the second vertical lead-out portion.

3. The stray inductance power module according to claim 2, characterized in that: The first vertical connection portion is parallel to and overlaps with the second vertical connection portion, and the first vertical lead-out portion is parallel to and overlaps with the second vertical lead-out portion; In the cross section of the power module, the length directions of the first vertical connection portion and the second vertical connection portion are perpendicular to the support substrate, the first vertical lead-out portion is parallel to the first vertical connection portion, and the second vertical lead-out portion is parallel to the second vertical connection portion.

4. The stray inductance power module according to claim 2, characterized in that: The upper bridge DBC substrate includes an upper bridge first connection area and an upper bridge second connection area, and the lower bridge DBC substrate includes a lower bridge first connection area and a lower bridge second connection area; A plurality of power units are arranged in the upper bridge first connection area, the upper bridge second connection area, the lower bridge first connection area and the lower bridge second connection area, and each power unit includes a power chip and a diode chip adapted to be connected to the power chip; The power chip and the diode chip in the power unit are electrically connected to the corresponding DBC substrate through the connection belt.

5. The stray inductance power module according to claim 4, characterized in that: The power chip includes a control electrode. The control electrode of each power chip is connected to a protection resistor, and the protection resistor is arranged on the corresponding DBC substrate.

6. The stray inductance power module according to claim 4, characterized in that: The upper bridge DBC substrate in the upper bridge arm unit and the lower bridge DBC substrate in the lower bridge arm unit are symmetrical about the first axis; The upper bridge first connection area and the upper bridge second connection area in the upper bridge DBC substrate are symmetrical about the second axis, and the lower bridge first connection area and the lower bridge second connection area in the lower bridge DBC substrate are symmetrical about the second axis, and the first axis is perpendicular to the second axis.

7. The stray inductance power module according to claim 4, characterized in that: The upper bridge DBC substrate further includes an upper bridge first source region, an upper bridge second source region and an upper bridge third source region, and the lower bridge DBC substrate further includes a lower bridge first source region, a lower bridge second source region and a lower bridge third source region; The upper bridge first source region is electrically connected to the lower bridge first connection region and the lower bridge second connection region.

8. The stray inductance power module according to claim 7, characterized in that: The first horizontal bonding portion of the positive power terminal includes a first positive bonding end and a second positive bonding end, wherein the first positive bonding end is bonded to the first connection area of ​​the upper bridge, and the second positive bonding end is bonded to the second connection area of ​​the upper bridge.

9. The stray inductance power module according to claim 7, characterized in that: The second horizontal bonding portion of the negative power terminal includes a first negative bonding end and a second negative bonding end, and the first negative bonding end and the second negative bonding end are both bonded to the first source region of the lower bridge.

10. The power module with stray inductance according to any one of claims 1 to 9, characterized in that: A signal connection unit is also provided on the support substrate. The signal connection unit includes a signal connection DBC substrate and a plurality of signal terminals provided on the signal connection DBC substrate. The signal connection DBC substrate is electrically connected to the upper bridge DBC substrate and the lower bridge DBC substrate.

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