A branch communication type laminated bypass busbar, a power sub-module and an integrated power module

Abstract

The application belongs to the field of power semiconductors, and particularly relates to a branch communication type laminated bypass busbar, a power sub-module and an integrated power module, which comprises an upper busbar and a lower busbar, the upper busbar is insulated from the lower busbar, and the upper busbar and the lower busbar have the same potential; the upper busbar is provided with a plurality of connection points one, the plurality of connection points one and a plurality of connection points two are combined into two columns, and the connection points one and the connection points two in each column are arranged at intervals; the bottoms of the plurality of connection points one are respectively connected with conductive columns one, the bottoms of the plurality of connection points two are respectively connected with conductive columns two, and the bottoms of the conductive columns one and the conductive columns two are respectively connected with corresponding IGBT chips; in a failure current passing condition, the circuit where the single IGBT chip is located is prevented from bearing all the current, a situation of excessive local current does not occur, and the reliability is improved; the IGBT chip has stronger anti-electromagnetic interference capability, and parallel loop PETT oscillation is effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of power semiconductors, specifically relating to a branch-connected stacked bypass busbar, a power submodule, and an integrated power module. Background Technology

[0002] With the trend towards localization of ultra-large capacity flexible DC transmission and transformation converter valve devices, more requirements are placed on the current rating and electrical characteristics of the core component, the press-fit IGBT power module. Currently, the highest power rating of the press-fit IGBT power module in mass production on the market reaches 4500V / 5000A. However, due to factors such as IGBT chip manufacturing process, the maximum current rating of a single 4500V IGBT chip can only reach about 150A. This means that the packaging of the press-fit IGBT power module requires the use of at least about 40 IGBT chips connected in parallel. The parallel connection of multiple chips brings many technical challenges, such as parallel current sharing and parallel resonant circuit PETT oscillation. In addition, due to the continuous increase in current rating, in the case of failure short circuit, the branch where a single chip is located needs to bear the entire current of the power module, which further tests the temperature resistance and durability of the entire packaging system.

[0003] The existing flexible press-fit IGBT power module has a problem with PETT oscillation in the parallel circuit of adjacent IGBT chips in the interconnected bypass busbar, and it cannot cope with the problem of failure short circuit under higher current conditions. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a branch-connected stacked bypass busbar, power submodule and integrated power module that can take into account both failure current and avoid PETT oscillation in the parallel circuit of adjacent IGBT chips.

[0005] The present invention provides a branch-connection type stacked bypass busbar, comprising: an upper busbar and a lower busbar arranged vertically, wherein the upper busbar and the lower busbar are insulated from each other, and the upper busbar and the lower busbar have the same potential; The upper busbar has multiple connection points 1, and the lower busbar has the same number of connection points 2 as the connection points 1. The multiple connection points 1 and the multiple connection points 2 are combined into two columns, and the connection points 1 and connection points 2 in each column are spaced apart. The bottom of each of the multiple connection points is connected to a conductive post 1, and the bottom of each of the multiple connection points 2 is connected to a conductive post 2. The bottoms of the conductive posts 1 and 2 are electrically connected to the corresponding IGBT chips.

[0006] Optionally, the upper busbar has a through hole one located between two connection points one, and the lower busbar has a through hole two located between two connection points two, with the through hole one and the through hole two axially overlapping.

[0007] Optionally, the first through hole is located between two connection points, and the second through hole is located between two connection points.

[0008] Optionally, a disc spring is provided on the side of the upper busbar away from the first conductive post, and a disc spring is provided on the side of the lower busbar away from the second conductive post.

[0009] Optionally, the tops of the first disc spring and the second disc spring are flush, and the bottoms of the first conductive post and the second conductive post are flush.

[0010] Optionally, the upper busbar includes a flat plate portion one and a plurality of L-shaped bend portions one, the plurality of L-shaped bend portions one being located on the outside of a plurality of connection points one; the lower busbar includes a flat plate portion two and a plurality of L-shaped bend portions two, the plurality of L-shaped bend portions two being located on the outside of a plurality of connection points two.

[0011] Optionally, the shape of the first plate section is Y-shaped, and the upper busbar has three connection points located on the three branches of the first plate section. Correspondingly, the shape of the second plate section is Y-shaped, and the lower busbar has three connection points located on the three branches of the second plate section.

[0012] Optionally, the shape of the first plate section is wavy, and the upper busbar has 4-6 connection points located at each turning point and both ends of the first plate section. Correspondingly, the shape of the second plate section is wavy, and the lower busbar has 4-6 connection points located at each turning point and both ends of the second plate section.

[0013] This invention provides a power submodule, comprising: a side frame, a plurality of IGBT chips disposed within the side frame, a lower molybdenum plate disposed at the bottom of the plurality of IGBT chips, two gate busbars respectively disposed at both ends of the side frame, and a branch-connected stacked bypass busbar disposed within the side frame; The collectors of the multiple IGBT chips are electrically connected to the lower molybdenum plate. The multiple IGBT chips are divided into two groups. The gates of each group of IGBT chips are connected in series by bonding leads. The two groups of IGBT chips are electrically connected to two gate busbars respectively by bonding leads. The emitters of each group of IGBT chips are electrically connected to the upper and lower busbars of the branch-connected stacked bypass busbar respectively.

[0014] This invention provides an integrated power module, including a package, a frame PCB board, a cover plate, and multiple power sub-modules; Multiple power submodules and a frame PCB are disposed within a package. The frame PCB is electrically connected to the gate busbars of the multiple power submodules. The cover plate covers the top of the package and is electrically connected to the branch-connected stacked bypass busbars of the multiple power submodules.

[0015] Explanation of relevant technical terms: IGBT: A power semiconductor switching device, also known as an insulated gate bipolar transistor; its interface includes a collector metal PAD, an emitter metal PAD, and a gate metal PAD (corresponding to G as the gate, C as the collector, and E as the emitter, respectively), and its topology is shown in the diagram. Figure 9 As shown; Press-fit IGBT power sub-modules and modules: Press-fit type: This type of IGBT package eliminates the need for wire bonding and soldering, using pressure to ensure electrical and thermal connections at the interconnect interface. It features double-sided heat dissipation, failure short circuit protection, and low stray inductance. Based on structural characteristics, it is generally divided into two types: rigid press-fit and flexible press-fit. The structural feature described in this patent is flexible press-fit packaging. Power submodule: System integration of IGBT chips, packaging materials, and external electrical interfaces; components that meet the functions of heat dissipation and electrode insulation protection of IGBT chips; Integrated power module: A module with a larger power capacity composed of power sub-modules connected in parallel; PETT oscillation: like Figure 10 The IGBT chip shown exhibits PETT oscillation during turn-off. During the tailing phase of IGBT turn-off, a high concentration of holes remains in the conductivity modulation section of the neutral base region. These holes disappear through two mechanisms: 1) electron-hole recombination under high injection conditions; 2) holes traversing the space charge region and reaching the emitter. Since the injected carrier concentration is comparable to the background ionized impurity concentration when holes traverse the space charge region, the mobile carriers influence the electric field distribution in the space charge region, i.e., the space charge effect. When carriers traverse the space charge region at a finite velocity, a transit time delay occurs; when the transit time meets certain conditions, the chip's dynamic resistance becomes negative, thus causing oscillation. Failure short circuit: In a modular multi-level three-phase six-bridge arm of flexible DC transmission, when the press-fit IGBT power module fails electrically or thermally, the module is required to be in a short-circuit state to ensure the normal operation of the bridge arm. After the module is short-circuited, all the bridge arm current is borne by the failed IGBT chip branch.

[0016] The beneficial effects of this invention are that the branch-connected stacked bypass busbar provided by this invention has an upper busbar and a lower busbar serving as current bypasses. They have a height difference in their vertical spatial layout and are staggered and electrically disconnected in their horizontal arrangement. The conductive circuits of the upper and lower busbars are independent of each other. Multiple IGBT chips are arranged in two groups and electrically connected to corresponding conductive posts one and two, respectively. The structural features of the upper and lower busbars cause conductive posts one and two to be staggered. The upper and lower busbars serve as electrode interfaces for multiple parallel-connected IGBT chips, and their potentials are equal. The current paths of multiple IGBT chips corresponding to the upper and lower busbars are shared. Under the condition of failure current conduction, this avoids the circuit containing a single IGBT chip bearing all the current, and prevents excessive local current, thus improving reliability. In addition, the current paths of adjacent IGBT chips are staggered due to the upper and lower busbars, so the current path length of the parallel loop between adjacent IGBT chips increases, and the parasitic inductance increases. This inductance adjustment can make the IGBT chips have stronger anti-electromagnetic interference capability and effectively reduce the oscillation of the parallel loop PETT.

[0017] The power submodule provided by this invention forms parallel current branches with the IGBT chip, lower molybdenum plate and upper molybdenum sheet through the upper and lower busbars, disc spring assemblies (disc spring assembly one and disc spring assembly two) and conductive pillars (conductive pillar one and conductive pillar two) in the bypass busbar. The parallel branches of adjacent IGBT chips are independent and unconnected, which improves the anti-electromagnetic interference capability and effectively avoids PETT oscillation of the parallel resonant circuit of adjacent IGBT chips. Attached Figure Description

[0018] Figure 1 This is a top view of the branch-connected stacked bypass busbar structure of the present invention; Figure 2 for Figure 1 AA section view in the middle; Figure 3 This is a top view of the second type of branch-connected stacked bypass busbar of the present invention; Figure 4 This is a top view of the third type of branch-connected stacked bypass busbar of the present invention; Figure 5 This is an exploded view of the branch-connected stacked bypass busbar of the present invention; Figure 6 This is a schematic diagram of the structure of the IGBT power submodule of the present invention; Figure 7 This is an exploded view of the IGBT power submodule of the present invention; Figure 8 This is an exploded view of the integrated power module of the present invention; Figure 9 IGBT topology diagram; Figure 10 This is a schematic diagram illustrating the oscillation phenomenon of the IGBT chip when it is turned off.

[0019] In the diagram: 100, Branch-connecting stacked bypass busbar; 110, Upper busbar; 111, Flat plate section one; 1111, Connection point one; 1112, Through hole one; 112, L-shaped bend one; 120, Lower busbar; 121, Flat plate section two; 1211, Connection point two; 1212, Through hole two; 122, L-shaped bend two; 130, Conductive post one; 140, Conductive post two; 150, Disc spring one; 160, Disc spring two; 200, Side frame; 300, IGBT chip; 400, Lower molybdenum plate; 500, Gate busbar; 600, Upper molybdenum sheet; 700, Bonding wire; 1000, Power submodule; 2000, Package box; 3000, Frame PCB board; 4000, Cover plate. Detailed Implementation

[0020] like Figure 1-3 As shown, the present invention provides a branch-connection type stacked bypass busbar, including an upper busbar 110 and a lower busbar 120 arranged vertically. The upper busbar 110 and the lower busbar 120 are insulated from each other and have the same potential. The upper busbar 110 has a plurality of connection points 1111, and the lower busbar 120 has the same number of connection points 1211 as the connection points 1111. The plurality of connection points 1111 and the plurality of connection points 1211 are combined into two columns, and the connection points 1111 and the connection points 1211 in each column are spaced apart. The bottom of the plurality of connection points 1111 is connected to a conductive post 130, and the bottom of the plurality of connection points 1211 is connected to a conductive post 140. The bottom of the conductive post 130 and the conductive post 140 are electrically connected to the corresponding IGBT chip 300.

[0021] Compared with the prior art, the branch-connected stacked bypass busbar 100 provided by the present invention has an upper busbar 110 and a lower busbar 120 serving as current bypasses. These two busbars have a height difference in their vertical spatial layout and are staggered and electrically disconnected in their horizontal arrangement. The conductive circuits of the upper busbar 110 and the lower busbar 120 are independent of each other. Multiple IGBT chips 300 are arranged in two groups and electrically connected to corresponding conductive posts 130 and 140, respectively. The structural features of the upper busbar 110 and the lower busbar 120 result in an alternating distribution of conductive posts 130 and 140. The upper busbar 110 and the lower busbar 120 serve as electrode interfaces for multiple parallel-connected IGBT chips 300. With equal potential, the current paths of multiple IGBT chips 300 corresponding to the upper busbar 110 and the lower busbar 120 are shared. Under the condition of failure current conduction, the circuit where a single IGBT chip 300 is located is prevented from bearing all the current, and the local current is not too large, thus improving reliability. In addition, the current paths of adjacent IGBT chips 300 are staggered due to the upper busbar 110 and the lower busbar 120. Therefore, the current path length of the parallel loop between adjacent IGBT chips 300 is increased, and the parasitic inductance is increased. This inductance adjustment can make the IGBT chips 300 have stronger anti-electromagnetic interference capability and effectively reduce the oscillation of the parallel loop PETT.

[0022] It should be noted that both the upper busbar 110 and the lower busbar 120 can be integrally stamped and formed from annealed oxygen-free copper, which has good plasticity and ductility. After structural pressure transmission, it can adaptively compensate for contact gaps caused by processing errors. Both have an insulating layer on their surfaces, which can be formed by subsequent resin potting or a pre-coated resin layer. The bypass busbar is formed as a whole using injection molding, serving as the outer shell and frame of the IGBT chip 300 packaging submodule.

[0023] In one embodiment, the upper busbar 110 has a through-hole 1112 located between two connection points 1111, and the lower busbar 120 has a through-hole 1212 located between two connection points 1211. The through-holes 1112 and 1212 are axially aligned. It is understood that the through-holes 1112 and 1212 serve as filling windows for the internal insulating potting material (e.g., silicone gel) of the submodule, ensuring high-voltage insulation characteristics. After the busbars (upper busbar 110 and lower busbar 120) have openings (through-hole 1112 and through-hole 1212), a narrower current path is formed at the connection points on both sides of the opening. This can further increase the parasitic inductance of the resonant circuit, forming a narrow current path region, which can further increase the parasitic inductance and series resistance of the parallel resonant circuit, helping to suppress the PETT oscillation of the IGBT chip 300 parallel circuit. Preferably, both through hole one 1112 and through hole two 1212 are round holes, but they can also be square holes or elliptical holes.

[0024] Furthermore, via 1112 is located between two connection points 1111, and via 1212 is located between two connection points 1211. It is understandable that via 1112 and via 1212 coincide on the center line of the entire branch-connected multilayer bypass busbar 100, with openings at two symmetrical geometric centers corresponding to the IGBT submodules. The overlap of via 1112 and via 1212 ensures that the silicone gel flows more uniformly and fills all locations of the IGBT chips 300 within the submodule, guaranteeing the uniformity of the internal electric field distribution.

[0025] In one embodiment, a disc spring 150 is provided on the side of the upper busbar 110 away from the conductive post 130, and a disc spring 160 is provided on the side of the lower busbar 120 away from the conductive post 140. It is understood that, due to the variable stiffness pressure-stroke characteristics of the disc springs 150 and 160, their function is to compensate for the material accumulation tolerance in the height direction of different IGBT chip 300 branches, and to regulate the uniformity of pressure distribution on the IGBT chip 300.

[0026] In one embodiment, the tops of disc spring 150 and disc spring 160 are flush, and the bottoms of conductive post 130 and conductive post 140 are flush, so that the upper and lower interfaces of the branch-connected stacked bypass busbar 100 are flush, ensuring internal force balance.

[0027] In one embodiment, the upper busbar 110 includes a flat section 111 and a plurality of L-shaped bends 112, with the L-shaped bends 112 located outside the plurality of connection points 1111. The lower busbar 120 includes a flat section 121 and a plurality of L-shaped bends 122, with the L-shaped bends 122 located outside the plurality of connection points 1211. It is understood that the L-shaped bends 112 and 122 serve as external connection ports for the upper busbar 110 and lower busbar 120, respectively. The L-shaped bends 112 and 122 are staggered on both sides of the branch-connected stacked bypass busbar 100, thus extending the current path of each branch, which helps to further increase parasitic inductance, improve electromagnetic interference immunity, and further reduce PETT oscillation in the parallel circuit.

[0028] In one embodiment, the first plate section 111 is Y-shaped, with three connection points 1111 on the upper busbar 110 located on three branches of the first plate section 111. Similarly, the second plate section 121 is Y-shaped, with three connection points 1211 on the lower busbar 120 located on three branches of the second plate section 121. Specifically, the first plate section 111 and the second plate section 121 are symmetrically intersecting. The three connection points 1111 on the upper busbar 110 are located at the three vertices of an isosceles triangle, and the three connection points 1211 on the lower busbar 120 are also located at the three vertices of an isosceles triangle. The six connected IGBT chips 300 are divided into two columns of three, spaced apart between the first plate section 111 and the second plate section 121. This results in a more compact branch-connected stacked bypass busbar 100 structure, allowing for the installation of more power semiconductors within a given volume.

[0029] It should be noted that the spacing of the 6 IGBT chips (300mm) determines the spacing between connection point 1111 and connection point 2 (1211).

[0030] In one embodiment, the shape of the first plate section 111 is wavy, and the upper busbar 110 has 4-6 connection points 1111 located at each turning point and both ends of the first plate section 111. The corresponding shape of the second plate section 121 is wavy, and the lower busbar 120 has 4-6 connection points 1211 located at each turning point and both ends of the second plate section 121.

[0031] like Figure 4 As shown, the present invention provides a second type of branch-connected stacked bypass busbar, which can integrate and connect 8 IGBT chips 300.

[0032] like Figure 5As shown, the present invention provides a third type of branch-connected stacked bypass busbar, which can integrate and connect 10 IGBT chips 300.

[0033] It should be noted that, theoretically, the present invention can be further extended to include the structure of the branch-connected stacked bypass busbar, integrating more IGBT chips 300.

[0034] like Figure 6 and Figure 7 As shown, the present invention provides a power submodule 1000, including: a side frame 200, a plurality of IGBT chips 300 disposed within the side frame 200, a lower molybdenum plate 400 disposed at the bottom of the plurality of IGBT chips 300, two gate busbars 500 respectively disposed at both ends of the side frame 200, and a branch-connected stacked bypass busbar 100 disposed within the side frame 200; the collectors of the plurality of IGBT chips 300 are all electrically connected to the lower molybdenum plate 400, the plurality of IGBT chips 300 are divided into two groups, the gates of each group of IGBT chips 300 are connected in series by bonding leads 700, the two groups of IGBT chips 300 are electrically connected to the two gate busbars 500 respectively by bonding leads 700, and the emitters of each group of IGBT chips 300 are electrically connected to the upper busbar 110 and the lower busbar 120 of the branch-connected stacked bypass busbar 100 respectively.

[0035] Through the upper busbar 110 and lower busbar 120, disc spring assemblies (disc spring assembly one and disc spring assembly two) and conductive posts (conductive post one 130 and conductive post two 140) in the bypass busbar, corresponding current branches are formed in parallel with the IGBT chip 300, lower molybdenum plate 400 and upper molybdenum sheet 600. The parallel branches of adjacent IGBT chips 300 are independent and unconnected to each other, which improves the anti-electromagnetic interference capability and effectively avoids PETT oscillation of the parallel resonant circuit of adjacent IGBT chips 300.

[0036] It should be noted that the IGBT chip 300 in this embodiment is a press-fit IGBT.

[0037] like Figure 8 As shown, this invention provides an integrated power module, including a package 2000, a frame PCB board 3000, a cover plate 4000, and multiple power sub-modules 1000. The multiple power sub-modules 1000 and the frame PCB board 3000 are disposed within the package 2000. The frame PCB board 3000 is electrically connected to the gate busbars 500 of the multiple power sub-modules 1000. The cover plate 4000 covers the top of the package 2000 and is electrically connected to the branch-connected stacked bypass busbars 100 of the multiple power sub-modules 1000. Through the parallel connection of multiple power sub-modules 1000, the integrated power module has high electromagnetic interference immunity and low PETT oscillation in the parallel resonant circuit.

[0038] PETT oscillation control principle: Plasma evacuation transit frequency (f PETT This refers to the pulse tail current generated during the turn-off process of a bipolar semiconductor due to the penetration of some minority carriers (holes) into the space charge region; it is related to the natural frequency (f) of the parallel resonant circuit. res The "common frequency resonance" occurs when the resonant circuit exhibits a "negative resistance region"; Therefore, the approach to suppressing PETT oscillation is as follows: Increasing the parasitic resistance of the circuit can reduce or even eliminate the amplitude (damping characteristics), but this will increase the line loss. Adjusting the PETT oscillation frequency (f PETT ) and the natural frequency of the resonant circuit (f res The control methods are to adjust the resistivity of the 300 single crystal IGBT chip and the parasitic inductance of the resonant circuit, respectively. The formula for calculating its frequency is: ; ; In the formula: f PETT It is only negatively correlated with the single-crystal resistivity ρ; f res With loop stray inductance L res Junction capacitance C dep Negative correlation.

[0039] Therefore, the invention increases the parasitic inductance and the natural frequency of the resonant circuit, thereby weakening or even eliminating PETT oscillations.

[0040] Increase the natural frequency (f) of the parasitic inductance resonant circuit res The principle of ) For parallel circuits with connected busbars, the current path only passes through the busbars. However, for circuits with unconnected busbars, the current path must flow completely through one side of the busbar, then to the top electrode, and then completely through the other side of the busbar. Combined with the busbar inductance design, the parasitic inductance can be increased by up to 400%. The specific control target depends on the chip parameters.

[0041] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0042] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A branch-connected stacked bypass busbar, characterized in that, include: An upper busbar (110) and a lower busbar (120) are arranged vertically, the upper busbar (110) and the lower busbar (120) are insulated from each other, and the upper busbar (110) and the lower busbar (120) have the same potential; The upper busbar (110) has multiple connection points one (1111), and the lower busbar (120) has the same number of connection points two (1211) as the connection points one (1111). The multiple connection points one (1111) and the multiple connection points two (1211) are combined into two columns, and the connection points one (1111) and connection points two (1211) in each column are arranged at intervals. The bottom of each of the multiple connection points (1111) is connected to a conductive post (130), and the bottom of each of the multiple connection points (1211) is connected to a conductive post (140). The bottoms of the conductive posts (130) and (140) are electrically connected to the corresponding IGBT chips (300).

2. The branch-connected stacked bypass busbar according to claim 1, characterized in that, The upper busbar (110) has a through hole 1 (1112) and the through hole 1 (1112) is located between two connection points 1 (1111). The lower busbar (120) has a through hole 2 (1212) and the through hole 2 (1212) is located between two connection points 2 (1211). The through hole 1 (1112) and the through hole 2 (1212) are axially coincident.

3. The branch-connection type stacked bypass busbar according to claim 2, characterized in that, The first through hole (1112) is located between the two connection points (1111), and the second through hole (1212) is located between the two connection points (1211).

4. The branch-connected stacked bypass busbar according to claim 1, characterized in that, The upper busbar (110) is provided with a disc spring (150) on the side away from the first conductive post (130), and the lower busbar (120) is provided with a disc spring (160) on the side away from the second conductive post (140).

5. The branch-connected stacked bypass busbar according to claim 4, characterized in that, The tops of the first disc spring (150) and the second disc spring (160) are flush, and the bottoms of the first conductive post (130) and the second conductive post (140) are flush.

6. The branch-connection type stacked bypass busbar according to any one of claims 1-5, characterized in that, The upper busbar (110) includes a flat section (111) and a plurality of L-shaped bends (112), the plurality of L-shaped bends (112) being located outside the plurality of connection points (1111); the lower busbar (120) includes a flat section (121) and a plurality of L-shaped bends (122), the plurality of L-shaped bends (122) being located outside the plurality of connection points (1211).

7. The branch-connected stacked bypass busbar according to claim 6, characterized in that, The shape of the first plate section (111) is Y-shaped, and the upper busbar (110) has three connection points (1111) located on the three branches of the first plate section (111). The corresponding shape of the second plate section (121) is Y-shaped, and the lower busbar (120) has three connection points (1211) located on the three branches of the second plate section (121).

8. The branch-connection type stacked bypass busbar according to claim 6, characterized in that, The shape of the first plate section (111) is wavy, and the upper busbar (110) has 4-6 connection points (1111) located at each turning point and both ends of the first plate section (111). The corresponding shape of the second plate section (121) is wavy, and the lower busbar (120) has 4-6 connection points (1211) located at each turning point and both ends of the second plate section (121).

9. A power submodule, characterized in that, include: Side frame (200), multiple IGBT chips (300) disposed within the side frame (200), a lower molybdenum plate (400) disposed at the bottom of the multiple IGBT chips (300), two gate busbars (500) respectively disposed at both ends of the side frame (200), and a branch-connected stacked bypass busbar (100) as described in any one of claims 1-8 disposed within the side frame (200); The collectors of the multiple IGBT chips (300) are electrically connected to the lower molybdenum plate (400). The multiple IGBT chips (300) are divided into two groups. The gates of each group of IGBT chips (300) are connected in series through bonding leads (700). The two groups of IGBT chips (300) are electrically connected to two gate busbars (500) respectively through bonding leads (700). The emitters of each group of IGBT chips (300) are electrically connected to the upper busbar (110) and the lower busbar (120) of the branch-connected stacked bypass busbar (100).

10. An integrated power module, characterized in that, It includes a package box (2000), a frame PCB board (3000), a cover plate (4000), and multiple power sub-modules (1000) as described in claim 9. Multiple power submodules (1000) and frame PCBs (3000) are disposed within a package (2000). The frame PCBs (3000) are electrically connected to the gate busbars (500) of the multiple power submodules (1000). A cover plate (4000) covers the top of the package (2000) and is electrically connected to the branch-connected stacked bypass busbars (100) of the multiple power submodules (1000).

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