A low-inductance, high-current-sharing half-bridge power module based on flexible circuit board connection

Abstract

The present invention relates to the field of electronic technology, and more particularly to a low-inductance, high-current-sharing half-bridge power module connected via a flexible circuit board. The module comprises an upper bridge arm module, a lower bridge arm module, an electrode layer module, a substrate module, and a circuit board. The upper bridge arm module and the lower bridge arm module are respectively connected to the electrode layer module via the circuit board, and the upper bridge arm module, the lower bridge arm module, and the electrode layer module are all disposed on the substrate module. By designing the layout of copper layers, power devices, and terminals, and using a flexible circuit board to electrically connect the power circuit, the present invention achieves a symmetrical layout of multiple parallel chips, improves dynamic current sharing and junction temperature balancing of the parallel chips, achieves a smaller parasitic inductance value, and reduces shutdown overvoltage and switching oscillation.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a low-inductance and high-current-sharing half-bridge power module based on flexible circuit board connection. Background Art

[0002] With the rapid development of modern transportation, aerospace and other fields, power electronic power modules (abbreviated as power modules) have been widely used, which puts forward higher requirements on the electrical and thermal performance of power modules.

[0003] In order to improve the efficiency of the power module, it is necessary to achieve a higher switching frequency of the power module. However, the traditional power module layout structure has a high parasitic inductance, and the power chip is subjected to a high overvoltage during the switching process, which increases the risk of overvoltage breakdown of the power chip.

[0004] To improve the current flow capacity of power modules, multiple chips must be connected in parallel. However, these multiple chips can cause dynamic current imbalance due to parasitic parameters. This leads to uneven junction temperature during switching, increasing the risk of thermal runaway and reducing reliability.

[0005] In order to improve the thermal reliability of the power module, reasonable thermal design is required within the power module. The uneven junction temperature of the chips in traditional multi-chip parallel power modules causes inconsistent internal chip temperatures during operation, resulting in uneven current flow and increasing the risk of thermal runaway.

[0006] Therefore, in high-frequency, high-power applications, parasitic inductance, dynamic current sharing, and thermal resistance are difficult problems that power modules need to overcome. It is necessary to reduce parasitic inductance, achieve dynamic current sharing, and reduce thermal resistance to ensure reliable operation of the power module. Summary of the Invention

[0007] The purpose of the present invention is to provide a low-inductance, high-current-sharing half-bridge power module based on flexible circuit board connection to reduce parasitic inductance, improve dynamic current sharing and chip junction temperature balance.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] A low-inductance, high-current-sharing half-bridge power module based on flexible circuit board connection includes: an upper bridge arm module, a lower bridge arm module, an electrode layer module, a substrate module and a circuit board. The upper bridge arm module and the lower bridge arm module are respectively connected to the electrode layer module through the circuit board. The upper bridge arm module, the lower bridge arm module and the electrode layer module are all arranged on the substrate module.

[0010] Optionally, the upper bridge arm module includes: an upper bridge arm driving metal layer and a plurality of upper bridge arm chips, the upper bridge arm chip is provided with a first control terminal, a first switch terminal and a second switch terminal, and the upper bridge arm driving metal layer is connected to the first control terminal and the first switch terminal;

[0011] The lower bridge arm module includes: a lower bridge arm driving metal layer and a plurality of lower bridge arm chips, wherein the lower bridge arm chip is provided with a second control terminal, a third switch terminal and a fourth switch terminal, and the lower bridge arm driving metal layer is connected to the second control terminal and the third switch terminal;

[0012] The electrode layer module includes: a positive electrode layer, a negative electrode layer, and an AC side electrode layer, wherein the positive electrode layer is connected to the second switch terminal, the negative electrode layer is connected to the third switch terminal, and the AC side electrode layer is connected to the first control terminal and the fourth switch terminal;

[0013] The substrate module comprises: a substrate, on which the upper bridge arm driving metal layer, a plurality of upper bridge arm chips, a lower bridge arm driving metal layer, a plurality of lower bridge arm chips, a positive electrode layer, a negative electrode layer, and an AC side electrode layer are all arranged;

[0014] The circuit board includes: a flexible circuit board, which is used to realize the connection between the upper bridge arm driving metal layer and the upper bridge arm chip, the connection between the lower bridge arm driving metal layer and the lower bridge arm chip, and the connection between the positive electrode layer, the negative electrode layer, the AC side electrode layer and the upper bridge arm chip and the lower bridge arm chip.

[0015] Optionally, the lower bridge arm chip and the upper bridge arm chip are arranged along the first direction of the substrate;

[0016] The upper bridge arm chips and the lower bridge arm chips are grouped into even numbers to form parallel chips, and each group of parallel chips is symmetrically arranged along the second direction of the substrate;

[0017] The first direction is perpendicular to the second direction.

[0018] Optionally, the positive electrode layer includes a first positive electrode lead-out terminal and a second positive electrode lead-out terminal, and the first positive electrode lead-out terminal and the second positive electrode lead-out terminal are arranged on both sides of the upper bridge arm chip;

[0019] The negative electrode layer includes a first negative electrode lead-out terminal and a second negative electrode lead-out terminal, and the first negative electrode lead-out terminal and the second negative electrode lead-out terminal are arranged on both sides of the lower bridge arm chip;

[0020] The AC side electrode layer includes a first AC lead-out terminal and a second AC lead-out terminal, and the first AC lead-out terminal and the second AC lead-out terminal are arranged between a group of upper bridge arm chips and an adjacent group of lower bridge arm chips.

[0021] Optionally, the flexible circuit board includes an insulating layer, an upper copper layer and a lower copper layer, the insulating layer is used to isolate the upper copper layer and the lower copper layer from the external environment, the upper copper layer includes the first negative electrode layer of the flexible circuit board, the upper bridge arm driving metal layer of the flexible circuit board and the lower bridge arm driving metal layer of the flexible circuit board; the lower copper layer includes the second negative electrode layer of the flexible circuit board, the AC side electrode layer of the flexible circuit board, the first control terminal connection end of the chip of the flexible circuit board, the third negative electrode layer of the flexible circuit board, and the second control terminal connection end of the chip of the flexible circuit board.

[0022] Optionally, the upper bridge arm driving metal layer and the lower bridge arm driving metal layer each include two sub-metal layers, and the two sub-metal layers of the upper bridge arm driving metal layer are respectively connected to the first control terminal and the first switch terminal of the upper bridge arm chip through the first control terminal connection terminal of the chip of the flexible circuit board and the AC side electrode layer of the flexible circuit board;

[0023] The two sub-metal layers of the lower bridge arm driving metal layer are respectively connected to the second control terminal and the third switch terminal of the lower bridge arm chip through the second control terminal connection terminal of the flexible circuit board chip and the third negative electrode layer of the flexible circuit board.

[0024] Optionally, the power module further includes a terminal module, and the terminal module is arranged on the substrate module.

[0025] Optionally, the terminal member module includes a first terminal member, a second terminal member, a third terminal member, a fourth terminal member and a fifth terminal member; the first terminal member is connected to the positive electrode layer, the second terminal member is connected to the negative electrode layer, the third terminal member is connected to the AC side electrode layer, the fourth terminal member is connected to the upper bridge arm drive metal layer, and the fifth terminal member is connected to the lower bridge arm drive metal layer.

[0026] Optionally, the first terminal member, the second terminal member, the third terminal member, the fourth terminal member and the fifth terminal member all extend out of the outside of the substrate.

[0027] The beneficial effects of the present invention are:

[0028] The power module of the present invention is a multi-chip parallel module, with an even number of chips in a group and symmetrically distributed; a flexible circuit board is used instead of chip connectors and bonding wires to achieve electrical connection between power chips and between power chips and electrode layers, which can improve the electrical performance of the power module and improve reliability; a flexible circuit board is used instead of chip connectors and bonding wires to achieve parallel connection of power chips and electrical connection of power chips and electrode layers, which can reduce the parasitic inductance of the power module and improve current sharing and reliability; the circuit design makes the current flowing through the upper and lower copper layers of the flexible circuit board reverse, and the spacing between the copper layers in the flexible circuit board is small, which can better achieve The mutual inductance is canceled out, reducing the parasitic inductance of the power circuit; the positive electrode lead-out terminals of the positive electrode layer are arranged on both sides of the upper bridge arm chip, which can make the layout compact, reduce the commutation circuit area, and thus reduce the parasitic inductance of the power module; the AC lead-out terminals are symmetrically distributed between each group of internal chips in the upper bridge arm and between groups, which can reduce the difference between the commutation circuit areas of the two adjacent upper bridge arm chips and help to share the current between the upper bridge arm chips; the negative electrode lead-out terminals are symmetrically arranged with respect to the lower bridge arm chip, which reduces the difference between the commutation circuit areas of the two adjacent lower bridge arm chips and helps to share the current between the lower bridge arm chips.

[0029] The power module of the present invention has a highly symmetrical layout structure, which ensures that the working conditions and service life of each power chip (upper and lower bridge arm chips) remain consistent, improves the dynamic current sharing of parallel chips, and enhances the switching performance of the power module; an even number of chips inside the power module are grouped together, and the groups are symmetrically distributed, which improves the junction temperature balance of multiple chips, making the temperature of each chip close when the multiple chips are working, and improving problems such as uneven current due to differences in chip junction temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0031] Figure 1 A schematic diagram of a portion of the structure of a power module according to an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of a portion of the structure of a power module according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the flexible circuit board structure of a power module according to an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the copper layer structure on the flexible circuit board of the power module according to an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the lower copper layer structure of the flexible circuit board of the power module according to an embodiment of the present invention;

[0036] Figure 6 This is a schematic structural diagram of a first terminal component of a power module according to an embodiment of the present invention;

[0037] Figure 7 This is a schematic structural diagram of a second terminal component of a power module according to an embodiment of the present invention;

[0038] Figure 8 Schematic diagram of the structure of the third terminal of the power module according to an embodiment of the present invention;

[0039] Figure 9 Schematic diagram of the structure of the fourth terminal and the fifth terminal of the power module according to an embodiment of the present invention;

[0040] Among them, 1-substrate, 2-positive electrode layer, 3-negative electrode layer, 4-AC side electrode layer, 5-flexible circuit board, 6-insulating layer of flexible circuit board, 7-first negative electrode layer of flexible circuit board, 8-upper bridge arm driving metal layer of flexible circuit board, 8a-chip connection end of upper bridge arm driving metal layer of flexible circuit board, 8b-upper bridge arm driving metal layer connection end of substrate of upper bridge arm driving metal layer of flexible circuit board, 9-lower bridge arm driving metal layer of flexible circuit board, 9a-chip connection end of lower bridge arm driving metal layer of flexible circuit board, 9b-lower bridge arm driving metal layer of flexible circuit board The bridge arm driving metal layer connection end of the substrate of the flexible circuit board is 10-the second negative electrode layer of the flexible circuit board, 11-the AC side electrode layer of the flexible circuit board, 11a-the chip first switch terminal connection end of the AC side electrode layer of the flexible circuit board, 11b-the bridge arm driving metal layer connection end of the substrate of the AC side electrode layer of the flexible circuit board, 12-the chip first control terminal connection end of the flexible circuit board, 13-the third negative electrode layer of the flexible circuit board, 13a-the chip third switch terminal connection end of the third negative electrode layer of the flexible circuit board, 13b-the bridge arm driving metal layer of the substrate of the third negative electrode layer of the flexible circuit board Metal layer connection terminal, 14- flexible circuit board chip second control terminal connection terminal, 15- upper bridge arm drive metal layer, 16- lower bridge arm drive metal layer, 17- upper bridge arm chip, 18- lower bridge arm chip, 19- positive electrode lead-out terminal, 19a- first positive electrode lead-out terminal, 19b- second positive electrode lead-out terminal, 20- negative electrode lead-out terminal, 20a- first negative electrode lead-out terminal, 20b- second negative electrode lead-out terminal, 21- AC lead-out terminal, 21a- first AC lead-out terminal, 21b- second AC lead-out terminal, 22- first terminal, 221- second A mounting hole of a terminal member, 222-a groove of a first terminal member, 223-a first end of a first terminal member, 224-a second end of a first terminal member, 23-a second terminal member, 231-a mounting hole of a second terminal member, 232-a groove of a second terminal member, 233-a first end of a second terminal member, 234-a second end of a second terminal member, 24-a third terminal member, 241-a mounting hole of a third terminal member, 242-a groove of a third terminal member, 243-a first end of a third terminal member, 244-a second end of a third terminal member, 25-a fourth terminal member, 26-a fifth terminal member. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0044] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0045] This embodiment provides a low-inductance, high-current sharing half-bridge power module based on flexible circuit board connection, such as Figure 1 As shown, it includes: an upper bridge arm module, a lower bridge arm module, an electrode layer module, a substrate module and a circuit board. The upper bridge arm module and the lower bridge arm module are respectively connected to the electrode layer module through the circuit board. The upper bridge arm module, the lower bridge arm module and the electrode layer module are all arranged on the substrate module.

[0046] The upper bridge arm module includes: an upper bridge arm driving metal layer 15 and a plurality of upper bridge arm chips 17. The upper bridge arm chip 17 is provided with a first control terminal, a first switch terminal and a second switch terminal. The upper bridge arm driving metal layer 15 is connected to the first control terminal and the first switch terminal.

[0047] The lower bridge arm module includes: a lower bridge arm driving metal layer 16 and a plurality of lower bridge arm chips 18. The lower bridge arm chip 18 is provided with a second control terminal, a third switch terminal and a fourth switch terminal. The lower bridge arm driving metal layer 16 is connected to the second control terminal and the third switch terminal.

[0048] The electrode layer module includes: a positive electrode layer 2, a negative electrode layer 3, and an AC side electrode layer 4, wherein the positive electrode layer 2 is connected to the second switch terminal, the negative electrode layer 3 is connected to the third switch terminal, and the AC side electrode layer 4 is connected to the first control terminal and the fourth switch terminal;

[0049] The substrate module includes: a substrate 1, an upper bridge arm driving metal layer 15, a plurality of upper bridge arm chips 17, a lower bridge arm driving metal layer 16, a plurality of lower bridge arm chips 18, a positive electrode layer 2, a negative electrode layer 3, and an AC side electrode layer 4 are all arranged on the substrate 1;

[0050] The circuit board includes: a flexible circuit board 5, which is used to realize the connection between the upper bridge arm driving metal layer 15 and the upper bridge arm chip 17, the connection between the lower bridge arm driving metal layer 16 and the lower bridge arm chip 18, and the connection between the positive electrode layer 2, the negative electrode layer 3, the AC side electrode layer 4 and the upper bridge arm chip 17 and the lower bridge arm chip 18.

[0051] The upper bridge arm driving metal layer 15 and the lower bridge arm driving metal layer 16 are arranged on the same layer;

[0052] The lower bridge arm chip 18 and the upper bridge arm chip 17 are arranged along a first direction of the substrate 1;

[0053] The upper bridge arm chips 17 and the lower bridge arm chips 18 are grouped in even numbers to form parallel chips, and each group of parallel chips is symmetrically arranged along the second direction of the substrate 1;

[0054] The first direction is perpendicular to the second direction.

[0055] The positive electrode layer 2 includes a first positive electrode lead-out terminal 19a and a second positive electrode lead-out terminal 19b, which are arranged on both sides of the upper bridge arm chip 17;

[0056] The negative electrode layer 3 includes a first negative electrode lead-out terminal 20a and a second negative electrode lead-out terminal 20b, and the first negative electrode lead-out terminal 20a and the second negative electrode lead-out terminal 20b are arranged on both sides of the lower bridge arm chip 18;

[0057] The AC side electrode layer 4 includes a first AC lead-out terminal 21 a and a second AC lead-out terminal 21 b . The first AC lead-out terminal 21 a and the second AC lead-out terminal 21 b are disposed between a group of upper bridge arm chips 17 and an adjacent group of lower bridge arm chips 18 .

[0058] The flexible circuit board 5 includes an insulating layer 6, an upper copper layer and a lower copper layer. Figures 3 to 5 As shown, Figure 3 yes Figure 2 A schematic diagram of the overall structure of the flexible circuit board in the power module of the embodiment; Figure 4 yes Figure 2 Schematic diagram of the structure of the copper layer on the flexible circuit board in the power module of the embodiment; Figure 5 yes Figure 2Schematic diagram of the structure of the lower copper layer of the flexible circuit board in the power module of the embodiment. The insulating layer 6 is used to isolate the upper and lower copper layers from the external environment, thereby providing insulation protection for the conductive circuit. The upper copper layer includes the first negative electrode layer 7 of the flexible circuit board, the upper bridge arm driving metal layer 8 of the flexible circuit board, and the lower bridge arm driving metal layer 9 of the flexible circuit board; the lower copper layer includes the second negative electrode layer 10 of the flexible circuit board, the AC side electrode layer 11 of the flexible circuit board, the first control terminal connection terminal 12 of the chip of the flexible circuit board, the third negative electrode layer 13 of the flexible circuit board, and the second control terminal connection terminal 14 of the chip of the flexible circuit board;

[0059] The upper bridge arm driving metal layer 8 of the flexible circuit board includes a chip connection end 8a of the upper bridge arm driving metal layer of the flexible circuit board and a substrate upper bridge arm driving metal layer connection end 8b of the upper bridge arm driving metal layer of the flexible circuit board;

[0060] The lower bridge arm driving metal layer 9 of the flexible circuit board includes a chip connection end 9a of the lower bridge arm driving metal layer of the flexible circuit board and a substrate lower bridge arm driving metal layer connection end 9b of the lower bridge arm driving metal layer of the flexible circuit board;

[0061] The AC side electrode layer 11 of the flexible circuit board includes a chip first switch terminal connection terminal 11a of the AC side electrode layer of the flexible circuit board, and a bridge arm driving metal layer connection terminal 11b on the substrate of the AC side electrode layer of the flexible circuit board;

[0062] The third negative electrode layer 13 of the flexible circuit board includes a chip third switch terminal connection terminal 13a of the third negative electrode layer of the flexible circuit board and a substrate lower bridge arm driving metal layer connection terminal 13b of the third negative electrode layer of the flexible circuit board.

[0063] Multiple upper bridge arm chips 17 are connected to the AC side electrode layer 4 through the chip first switch end connection end 11a of the AC side electrode layer of the flexible circuit board; multiple lower bridge arm chips 18 are connected to the negative electrode layer 3 through the chip third switch end connection end 13a of the third negative electrode layer of the flexible circuit board, the first negative electrode layer 7 of the flexible circuit board, and the second negative electrode layer 10 of the flexible circuit board.

[0064] The above-mentioned structural setting of this embodiment constitutes a half-bridge module with a multi-chip parallel symmetrical layout, which can reduce the parasitic inductance of the commutation circuit through a compact layout and mutual inductance offset of the flexible circuit board; reduce the parasitic inductance difference between the circuits of each chip by virtue of a highly symmetrical layout, and improve the current sharing effect of the parallel chips; and utilize a symmetrical layout method of multiple parallel chips in a group of an even number to improve the junction temperature balance of the chip and improve the thermal reliability of the power module.

[0065] The commutation circuit corresponding to the power module of this embodiment is: positive electrode lead-out terminal 19-positive electrode layer 2-upper bridge arm chip 17-first switch terminal connection terminal 11a of the chip of the AC side electrode layer of the flexible circuit board-AC side electrode layer 4-lower bridge arm chip 18-third switch terminal connection terminal 13a of the chip of the third negative electrode layer of the flexible circuit board-first negative electrode layer 7 of the flexible circuit board-AC side electrode layer 10 of the flexible circuit board-negative electrode layer 3-negative electrode lead-out terminal 20 (or reverse).

[0066] Therefore, this embodiment provides multiple AC lead-out terminals 21 on the AC-side electrode layer 4. The AC lead-out terminals 21 of the AC-side electrode layer 4 are positioned between a group of upper-arm chips 17 and an adjacent group of lower-arm chips 18. This allows the two adjacent upper-arm chips 17 to be symmetrical with respect to the AC lead-out terminals 21, reducing the difference in commutation loop area between the two adjacent upper-arm chips and facilitating current sharing between the upper-arm chips 17. The negative electrode lead-out terminals 20 are positioned on either side of the lower-arm chip 18, and their symmetrical arrangement reduces the difference in commutation loop area between the two adjacent lower-arm chips 18, facilitating current sharing between the lower-arm chips 18. The positive electrode lead-out terminals 19 are positioned on either side of the upper-arm chip 17, reducing the length of the commutation loop from the positive electrode lead-out terminal 19 to the upper-arm power chip 17, then to the lower-arm power chip 18, and finally to the negative electrode lead-out terminal 20. This results in a compact layout, reduced commutation loop area, lowered parasitic inductance, and improved switching performance of the power module.

[0067] In this example, the upper bridge arm chip 17 and the lower bridge arm chip 18 adopt Kelvin connection, which can reduce the common source inductance, decouple the drive circuit and the power circuit, and reduce the electromagnetic interference of the power circuit to the drive circuit.

[0068] The upper bridge arm chip 17 and the lower bridge arm chip 18 are divided into four groups, two groups in each upper and lower bridge arm, and each group of four chips. The parallel chips are interconnected using the first switch terminal connection terminal 11a of the chip on the AC side electrode layer of the flexible circuit board and the third switch terminal connection terminal 13a of the chip on the third negative electrode layer of the flexible circuit board. The symmetrical layout of each group of chips in the upper and lower bridge arms can reduce the parasitic inductance difference between the first switch terminal of the chip in each group of the upper bridge arm to the AC lead-out terminal 21 and the third switch terminal of the chip in each group of the lower bridge arm to the negative electrode lead-out terminal 20, thereby improving the dynamic current sharing characteristics of each power chip, so that the working condition and service life of each power chip (upper and lower bridge arm chips) remain consistent, thereby improving the switching performance of the power module;

[0069] Each group of four chips is arranged symmetrically. The distance between each group of chips and between each chip in each group is guaranteed during the layout design process, which can improve the thermal coupling between chips. At the same time, the junction temperature balance of the chips is symmetrically improved locally, thereby improving the reliability of the power module.

[0070] The flexible circuit board 5 of this embodiment is used to connect the power chips in parallel and electrically connect them to the electrode layer, reducing parasitic inductance and improving current sharing and reliability. The circuit design reverses the currents flowing through the upper and lower copper layers of the flexible circuit board. Furthermore, the close spacing between the copper layers of the flexible circuit board 5 effectively cancels out mutual inductance and reduces parasitic inductance in the power circuit.

[0071] In an application scenario, the upper bridge arm chip 17 of this embodiment may include an IGBT device, whose gate electrode serves as the first control end of the upper bridge arm chip 17 and is electrically connected to the upper bridge arm drive metal layer 15, whose source serves as the first switch end of the upper bridge arm chip and is electrically connected to the upper bridge arm drive metal layer 15 and the AC side electrode layer 4, and whose drain serves as the second switch end of the upper bridge arm chip 17 and is electrically connected to the positive electrode layer 2; the lower bridge arm chip 18 may include an IGBT device, whose gate electrode serves as the second control end of the lower bridge arm chip 16, whose source serves as the third switch end of the lower bridge arm chip 18 and is electrically connected to the lower bridge arm drive metal layer 16 and the negative electrode layer 3, and whose drain serves as the fourth switch end of the lower bridge arm chip 18 and is electrically connected to the AC side electrode layer 4.

[0072] The bridge arm chip 17 may further include a diode for protecting the bridge arm chip when a sudden change occurs in voltage or current.

[0073] Other switching tubes can also be used instead of IGBT devices, such as triodes or MOS tubes.

[0074] The power module implemented in this embodiment is a half-bridge power module, which is not limited to four chips in parallel, but can be a power module with an even number of chips in parallel, such as two chips in parallel, six chips in parallel, etc.

[0075] Specifically, the upper bridge arm chip 17 and the lower bridge arm chip 18 of the power module of this embodiment can be expanded and arranged along the second direction of the substrate 1, and multiple chips can be expanded. The lower bridge arm chip 17 and the upper bridge arm chip 18 are arranged along the first direction of the substrate 1, and the first direction is arranged perpendicular to the second direction.

[0076] In which, the AC side electrode layer 4 of this embodiment is provided with two AC lead-out terminals 21, namely a first AC lead-out terminal 21a and a second AC lead-out terminal 21b, and the first AC lead-out terminal 21a and the second AC lead-out terminal 21b are located between a group of upper bridge arm chips 18 and an adjacent group of lower bridge arm chips 17.

[0077] Specifically, the AC side electrode layer 4 is provided with a first AC lead-out terminal 21a and a second AC lead-out terminal 21b, and is arranged along the second direction of the substrate 1, the upper bridge arm chip 17 is arranged along the second direction, and the lower bridge arm chip 18 is arranged along the second direction. The first AC lead-out terminal 21a is located on the vertical line of the first group of parallel chips, and the second AC lead-out terminal 21b is located on the vertical line of the second group of parallel chips.

[0078] The arrangement of the AC lead-out terminal 21 can improve the parasitic inductance from the first switch end of each group of four chips in the upper bridge arm chip 17 and the second switch end of each group of four chips in the lower bridge arm chip 18 to the AC lead-out terminal, thereby improving the dynamic current sharing characteristics of the parallel chips.

[0079] The negative electrode layer 3, the positive electrode layer 2, and the AC-side electrode layer 4 are arranged adjacent to each other in the first direction of the substrate 1, so that the upper-arm drive metal layer 15 and the lower-arm drive metal layer 16 are located on the same side of the substrate 1. This can isolate the drive circuit from the main power circuit, preventing the main power circuit signal from generating electromagnetic interference with the drive circuit signal, which could cause problems such as misconduct.

[0080] In this embodiment, multiple upper-arm chips 17 are disposed on the side of the positive electrode layer 2 facing away from the substrate 1, with four chips arranged in groups along the second direction. Positive electrode lead terminals 19, including a first positive electrode lead terminal 19a and a second positive electrode lead terminal 19b, are provided on the positive electrode layer 2 on both sides of each group of chips. These terminals 19a and 19b are symmetrically arranged, shortening the circulation path, minimizing differences in commutation loop area between groups of chips, and reducing parasitic inductance.

[0081] The negative electrode layer 3 and the AC-side electrode layer 4 are arranged along a first direction on the substrate 1. Multiple lower-arm chips 18 are positioned on the side of the AC-side electrode layer 4 facing away from the substrate 1 and arranged along a second direction. The negative electrode layer 3 is positioned away from the multiple lower-arm chips 17, allowing the negative electrode layer 7 of the flexible circuit board to cover more of the module's power circuit, canceling out mutual inductance and reducing parasitic inductance. A first negative electrode lead-out terminal 20a and a second negative electrode lead-out terminal 20b are provided on the negative electrode layer 3 on either side of each chip group. The symmetrical arrangement of the negative electrode lead-out terminals minimizes differences in the commutation loop areas of adjacent lower-arm chips 18, facilitating current sharing among the lower-arm chips.

[0082] In this embodiment, the upper-arm drive metal layer 15 comprises two insulated sub-metal layers, electrically connected to the first control terminal and first switch terminal of the upper-arm chip 9 via the upper-arm drive metal layer 8 of the flexible circuit board, the chip first control terminal connection terminal 12 of the flexible circuit board, and the upper-arm drive metal layer connection terminal 11b of the substrate of the AC-side electrode layer of the flexible circuit board, respectively, providing drive signals to the first control terminal and first switch terminal of the upper-arm chip 17. The lower-arm drive metal layer 16 comprises two insulated sub-metal layers, electrically connected to the second control terminal and third switch terminal of the lower-arm chip 18 via the lower-arm drive metal layer 9 of the flexible circuit board, the chip second control terminal connection terminal 14 of the flexible circuit board, and the lower-arm drive metal layer connection terminal 13b of the substrate of the third negative electrode layer of the flexible circuit board, respectively, providing drive signals to the second control terminal and third switch terminal of the lower-arm chip 18. The first control terminal and first switch terminal of multiple upper-arm parallel chips are connected to the same metal layer, which improves the consistency of the drive signals and the parallel effect.

[0083] The upper bridge arm driving metal layer 15 and the lower bridge arm driving metal layer 16 may be a copper-aluminum alloy layer or a copper layer, etc., which can improve the conductive performance.

[0084] The power module provided in this embodiment further includes a terminal module, which is arranged on the substrate module. Figures 6 to 9 As shown, Figure 6 yes Figure 2 A schematic structural diagram of a first terminal element in a power module according to an embodiment; Figure 7 yes Figure 2 A schematic structural diagram of a second terminal member in a power module according to an embodiment; Figure 8 yes Figure 2 A schematic structural diagram of a third terminal member in a power module according to an embodiment; Figure 9 yes Figure 2 Schematic diagram of the structure of the fourth terminal member and the fifth terminal member in the power module of the embodiment.

[0085] The terminal member module specifically includes: a first terminal member 22, a second terminal member 23, a third terminal member 24, a fourth terminal member 25 and a fifth terminal member 26; wherein, the first end 223 of the first terminal member 22 and the second end 224 of the first terminal member 22 are electrically connected to the first positive electrode lead-out terminal 19a and the second positive electrode lead-out terminal 19b respectively, and the other end of the first terminal member 22 extends out of the outside of the substrate 1, and the other end of the first terminal member 22 is provided with a mounting hole 221 for fixing the positive voltage power line.

[0086] The first end 233 of the second terminal 23 and the second section 234 of the second terminal 23 are electrically connected to the first negative electrode lead-out terminal 20a and the second negative electrode lead-out terminal 20b, respectively. The other end of the second terminal 23 extends out of the outside of the substrate 1 to enable the introduction of an external negative electrode. The other end of the second terminal 23 is provided with a mounting hole 231 for fixing the negative voltage power line.

[0087] The first end 243 of the third terminal 24 and the second end 244 of the third terminal 24 are electrically connected to the first AC lead-out terminal 21a and the second AC lead-out terminal 21b respectively. The other end of the third terminal 24 extends out of the outside of the substrate 1. The other end of the third terminal 24 is provided with a mounting hole 241 for fixing the power line of the AC side voltage.

[0088] The first terminal 22 is provided with a groove 222, which can reduce the mechanical stress in the middle part of the first terminal 22; similarly, the second terminal 23 and the third terminal 24 are also provided with grooves 232 and 242, which can reduce the mechanical stress in the middle part of the second terminal 223 and the third terminal 24.

[0089] The first terminal 22, the second terminal 23, and the third terminal 24 can be led out from a parallel surface along the substrate 1 or from a perpendicular surface along the substrate 1. The first terminal 22, the second terminal 23, and the third terminal 24 are stacked to reduce the parasitic inductance introduced by the terminals by utilizing the mutual inductance cancellation principle.

[0090] The fourth terminal 25 and the fifth terminal 26 are electrically connected to the upper bridge arm driving metal layer 15 and the lower bridge arm driving metal layer 16 respectively. The other ends of the fourth terminal 25 and the fifth terminal 26 are led out along the vertical direction of the substrate 1 .

[0091] Specifically, the fourth terminal 25 and the fifth terminal 26 each include two insulated terminal columns, which are electrically connected to the two sub-metal layers of the upper bridge arm driving metal layer 15 and the lower bridge arm driving metal layer 16, respectively, and are used to provide the driving signal of the first control end of the upper bridge arm chip 17 and the driving signal of the first switch end and the driving signal of the second control end of the lower bridge arm chip 18 and the driving signal of the third switch end.

[0092] All of the above-mentioned terminal members in this embodiment can be led out along the parallel surface of the substrate 1, which facilitates the connection between the power module and the circuit board carrying the power module and shortens the connection path between the two. In other embodiments, based on other electrical properties, the above-mentioned terminal members can be led out in a perpendicular direction of the substrate or from other sides of the substrate.

[0093] Different from the existing technology, the power module includes: multiple upper bridge arm chips, each of which is provided with a first control terminal, a first input terminal, and a first output terminal; an upper bridge arm drive metal layer electrically connected to the first control terminal and the first output terminal; a positive electrode layer connected to the first input terminal; multiple lower bridge arm chips, each of which is provided with a second control terminal, a second input terminal, and a second output terminal; a lower bridge arm drive metal layer electrically connected to the second control terminal and the second input terminal; a negative electrode layer connected to the second output terminal; and an AC side electrode layer connected to the first output terminal and the second input terminal. The upper bridge arm chips, upper bridge arm drive metal layer, positive electrode layer, lower bridge arm chips, lower arm drive metal layer, and negative electrode layer are all arranged on a substrate; the multiple chips are grouped into groups of four, and each group of parallel chips is connected via a flexible circuit board and then electrically connected to the negative electrode layer and the AC side electrode layer.

[0094] Using flexible circuit boards (FPCBs) instead of chip connectors and bonding wires enables parallel connection of power chips and electrical connection between the power chips and electrode layers, reducing the parasitic inductance of the power module and improving current sharing and reliability. Circuit design reverses the currents flowing through the upper and lower copper layers of the FPCB. The FPCB's closely spaced copper layers better offset mutual inductance, reducing parasitic inductance in the power circuit.

[0095] The positive electrode lead terminals are located on both sides of the upper bridge arm chip, which can reduce the size of the layout and the parasitic inductance of the commutation circuit. The negative electrode layer lead terminals are arranged symmetrically on both sides of the chip, achieving a highly symmetrical layout structure, which can improve the current sharing effect of the parallel chips in the lower bridge arm.

[0096] The AC lead-out terminal of the AC side electrode layer is located between a group of upper bridge arm chips and an adjacent group of lower bridge arm chips, so that each group of chips is symmetrical about the AC lead-out point and adjacent groups of chips are symmetrical about the AC lead-out point, which can reduce the parasitic inductance difference from the parallel chips in each group to the AC lead-out terminal, and at the same time improve the current sharing effect of the upper bridge arm parallel chips.

[0097] The symmetrical layout of multiple parallel chips in an even number of groups improves the junction temperature balance problem when multiple chips are connected in parallel. Compared with the traditional layout, this structure makes the junction temperature of each chip closer, improving the thermal reliability of the power module.

[0098] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A low-inductance, high-current sharing half-bridge power module based on flexible circuit board connection, characterized in that: include: An upper bridge arm module, a lower bridge arm module, an electrode layer module, a substrate module and a circuit board, wherein the upper bridge arm module and the lower bridge arm module are respectively connected to the electrode layer module through the circuit board, and the upper bridge arm module, the lower bridge arm module and the electrode layer module are all arranged on the substrate module; The upper bridge arm module comprises: an upper bridge arm driving metal layer (15) and a plurality of upper bridge arm chips (17), wherein the upper bridge arm chip (17) is provided with a first control end, a first switch end and a second switch end, and the upper bridge arm driving metal layer (15) is connected to the first control end and the first switch end; The lower bridge arm module comprises: a lower bridge arm driving metal layer (16) and a plurality of lower bridge arm chips (18), wherein the lower bridge arm chip (18) is provided with a second control end, a third switch end and a fourth switch end, and the lower bridge arm driving metal layer (16) is connected to the second control end and the third switch end; The electrode layer module comprises: a positive electrode layer (2), a negative electrode layer (3), and an AC side electrode layer (4); the positive electrode layer (2) is connected to the second switch end, the negative electrode layer (3) is connected to the third switch end, and the AC side electrode layer (4) is connected to the first control end and the fourth switch end; The substrate module comprises: a substrate (1), an upper bridge arm driving metal layer (15), a plurality of upper bridge arm chips (17), a lower bridge arm driving metal layer (16), a plurality of lower bridge arm chips (18), a positive electrode layer (2), a negative electrode layer (3), and an AC side electrode layer (4) all being arranged on the substrate (1); The circuit board comprises: a flexible circuit board (5), the flexible circuit board (5) being used to realize the connection between the upper bridge arm driving metal layer (15) and the upper bridge arm chip (17), the connection between the lower bridge arm driving metal layer (16) and the lower bridge arm chip (18), and the connection between the positive electrode layer (2), the negative electrode layer (3), the AC side electrode layer (4) and the upper bridge arm chip (17), and the lower bridge arm chip (18); The lower bridge arm chip (18) and the upper bridge arm chip (17) are arranged along a first direction of the substrate (1); The upper bridge arm chips (17) and the lower bridge arm chips (18) are grouped in even numbers to form parallel chips, and each group of parallel chips is symmetrically arranged along the second direction of the substrate (1); The first direction is arranged perpendicular to the second direction; The positive electrode layer (2) comprises a first positive electrode lead-out terminal (19a) and a second positive electrode lead-out terminal (19b), wherein the first positive electrode lead-out terminal (19a) and the second positive electrode lead-out terminal (19b) are arranged on both sides of the upper bridge arm chip (17); The negative electrode layer (3) comprises a first negative electrode lead-out terminal (20a) and a second negative electrode lead-out terminal (20b), wherein the first negative electrode lead-out terminal (20a) and the second negative electrode lead-out terminal (20b) are arranged on both sides of the lower bridge arm chip (18); The AC side electrode layer (4) comprises a first AC lead-out terminal (21a) and a second AC lead-out terminal (21b), wherein the first AC lead-out terminal (21a) and the second AC lead-out terminal (21b) are arranged between a group of upper bridge arm chips (17) and an adjacent group of lower bridge arm chips (18).

2. The low-inductance, high-current-sharing half-bridge power module based on flexible circuit board connection according to claim 1 is characterized in that: The flexible circuit board (5) comprises an insulating layer, an upper copper layer and a lower copper layer, wherein the insulating layer is used to isolate the upper copper layer and the lower copper layer from the external environment, the upper copper layer comprises a first negative electrode layer (7) of the flexible circuit board, an upper bridge arm driving metal layer (8) of the flexible circuit board and a lower bridge arm driving metal layer (9) of the flexible circuit board; and the lower copper layer comprises a second negative electrode layer (10) of the flexible circuit board, an AC side electrode layer (11) of the flexible circuit board, a first control terminal connection end (12) of the chip of the flexible circuit board, a third negative electrode layer (13) of the flexible circuit board and a second control terminal connection end (14) of the chip of the flexible circuit board.

3. The low-inductance, high-current-sharing half-bridge power module based on flexible circuit board connection according to claim 2, characterized in that: The upper bridge arm driving metal layer (15) and the lower bridge arm driving metal layer (16) respectively include two sub-metal layers, and the two sub-metal layers of the upper bridge arm driving metal layer (15) are respectively connected to the first control terminal and the first switch terminal of the upper bridge arm chip (17) through the first control terminal connection terminal (12) of the flexible circuit board chip and the AC side electrode layer (11) of the flexible circuit board; The two sub-metal layers of the lower bridge arm driving metal layer (16) are respectively connected to the second control terminal and the third switch terminal of the lower bridge arm chip (18) through the second control terminal connection terminal (14) of the flexible circuit board chip and the third negative electrode layer (13) of the flexible circuit board.

4. The low-inductance, high-current sharing half-bridge power module based on flexible circuit board connection according to any one of claims 1 to 3, characterized in that: The power module further includes a terminal module, and the terminal module is disposed on the substrate module.

5. The low-inductance, high-current sharing half-bridge power module based on flexible circuit board connection according to claim 4 is characterized in that: The terminal module comprises a first terminal (22), a second terminal (23), a third terminal (24), a fourth terminal (25) and a fifth terminal (26); the first terminal (22) is connected to the positive electrode layer (2), the second terminal (23) is connected to the negative electrode layer (3), the third terminal (24) is connected to the AC side electrode layer (4), the fourth terminal (25) is connected to the upper bridge arm drive metal layer (15), and the fifth terminal (26) is connected to the lower bridge arm drive metal layer (16).

6. The low-inductance, high-current-sharing half-bridge power module based on flexible circuit board connection according to claim 5, characterized in that: The first terminal member (22), the second terminal member (23), the third terminal member (24), the fourth terminal member (25) and the fifth terminal member (26) all extend outside the substrate (1).

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