A silicon carbide double-sided power module suitable for multi-module parallel connection

Abstract

The application relates to the technical field of power electronic device packaging integration, in particular to a silicon carbide double-sided power module design suitable for multi-module parallel connection, the power module is a half-bridge structure, two silicon carbide power chips in parallel and completely symmetrical in layout are arranged in the upper half-bridge arm and the lower half-bridge arm, the positive and negative electrode connection nodes and the alternating current intermediate nodes are led out through power terminals, the upper and lower half-bridge driving connection points are also led out through driving terminals, and integrated driving resistors are arranged; the upper bridge arm DBC substrate and the lower bridge arm DBC substrate are connected through metal columns in hardware and electricity. The application realizes the layout design of two-chip parallel connection and complete symmetry, optimizes the power terminal layout and the driving part respectively, can realize internal parallel chip current equalization, adopts an advanced double-sided module packaging process, has high power density and heat dissipation performance, and is beneficial to expansion into multi-module parallel connection, so as to adapt to occasions with larger current in the electric vehicle application field.

Description

Technical Field

[0001] This invention relates to the field of power electronic device packaging and integration technology, specifically a silicon carbide bifacial power module suitable for multiple modules connected in parallel. Background Technology

[0002] In recent years, wide-bandgap semiconductor devices, represented by silicon carbide, have developed rapidly, demonstrating excellent characteristics in high-frequency, high-temperature, and high-voltage applications. However, due to the limitations of current semiconductor packaging technology, the superior characteristics of silicon carbide cannot be fully utilized. Especially in emerging applications such as electric vehicles, photovoltaic power generation, and rail transportation, the increasingly higher power requirements present greater challenges to the development of new packaging technologies.

[0003] Furthermore, in the long-term high-temperature operation environment of electric vehicles, the heat dissipation capacity of the power module has become crucial. The introduction of double-sided heat dissipation modules, as a new type of packaging, replaces traditional bonding wire processes with planar interconnects, achieving double-sided cooling and significantly improving the heat dissipation performance and reliability of the power module. This represents a new packaging solution for electric vehicle applications. However, with the increasing current levels in electric vehicle applications, the current capacity of single-chip silicon carbide is limited, leading to the mainstream solution of multi-chip parallel connection or even multi-module parallel connection. For multi-chip or multi-module parallel connection scenarios, there is also the problem of dynamic current unevenness caused by differences in source parasitic inductance. Uneven current distribution leads to differences in losses between different chips, reducing the overall system reliability.

[0004] However, due to the difficulty of the three-dimensional structure and manufacturing process of bifacial modules, it is not suitable to connect too many silicon carbide power chips in parallel inside a single bifacial module. This would result in a longer internal commutation circuit and a severe current imbalance caused by the impedance mismatch between the branches of the parallel chips. Therefore, developing a bifacial module with balanced internal parallel chip current and suitable for multiple modules in parallel is the solution for increasing power levels in electric vehicle applications.

[0005] Against this backdrop, a double-sided silicon carbide module with two chips connected in parallel on one bridge arm can achieve complete symmetry by optimizing the power loop layout and integrating the drive circuit inside the module, which can greatly improve the current sharing of the internal chips. Furthermore, through advanced double-sided packaging technology, the heat dissipation performance and packaging parasitic parameters of the module can be improved, maximizing the excellent characteristics of silicon carbide chips. This is the most suitable design scheme for multiple double-sided modules connected in parallel. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a silicon carbide bifacial power module suitable for multi-module parallel connection, solving the heat dissipation problem and uneven current problem caused by parasitic parameter mismatch currently faced in the electric vehicle field.

[0007] A bifacial silicon carbide power module suitable for multi-module parallel connection is disclosed. The power module has a half-bridge structure, including an upper half-bridge arm, a lower half-bridge arm, an upper half-bridge arm DBC substrate, a lower half-bridge arm DBC substrate, an integrated drive resistor, a power positive terminal, a power negative terminal, an AC power terminal, and auxiliary terminals. Each of the upper and lower half-bridge arms contains two parallel silicon carbide power chips, and the two parallel silicon carbide power chips are arranged symmetrically, referred to as the upper half-bridge arm silicon carbide power chip and the lower half-bridge arm silicon carbide power chip. The upper half-bridge arm contains an upper half-bridge arm drive negative terminal and an upper half-bridge arm drive positive terminal, and the lower half-bridge arm contains a lower half-bridge arm drive negative terminal and a lower half-bridge arm drive positive terminal. An upper half-bridge arm metal pillar is disposed on the upper half-bridge arm DBC substrate, and a lower half-bridge arm metal pillar is disposed on the lower half-bridge arm DBC substrate. The power positive terminal and the power negative terminal are located on the same side, and the power positive terminal and the AC power terminal are located on opposite sides. In the upper half of the bridge arm, the drain, positive power terminal, and negative power terminal of the silicon carbide power chip in the upper bridge arm are all connected to the upper copper layer of the upper bridge arm DBC substrate. The power source is connected to the lower copper layer of the lower bridge arm DBC substrate through the metal pillar of the upper bridge arm. The drive source is connected to the drive negative terminal of the upper bridge arm, and the drive gate is connected to the drive positive terminal of the upper bridge arm. Integrated drive resistors are provided at the copper-plated areas of the drive source and gate of the upper bridge arm. In the lower half-bridge arm, the drain and AC power terminal of the silicon carbide power chip in the lower bridge arm are connected to the lower copper layer of the lower bridge arm DBC substrate, and the power source is connected to the upper copper layer of the upper bridge arm DBC substrate through the lower bridge arm metal pillar; the drive source is connected to the lower bridge arm drive negative terminal, and the drive gate is connected to the lower bridge arm drive positive terminal. Integrated drive resistors are provided at the copper-clad locations of the lower bridge arm drive source and gate. The auxiliary terminal is connected to the lower copper layer of the lower bridge arm DBC substrate, serving as the equivalent drain or source of the power chip in the upper or lower bridge arm. A supporting metal pillar is provided between the upper bridge arm DBC substrate and the lower bridge arm DBC substrate.

[0008] Preferably, the upper bridge arm silicon carbide power chip is connected to the upper bridge arm DBC substrate by welding or sintering; the lower bridge arm silicon carbide power chip is connected to the lower bridge arm DBC substrate by welding or sintering; the power positive terminal, power negative terminal, AC power terminal, integrated drive resistor, auxiliary terminal, upper bridge arm drive negative terminal, upper bridge arm drive positive terminal, lower bridge arm drive positive terminal and lower bridge arm drive negative terminal are all welded to the copper layer of their respective DBC substrates.

[0009] Preferably, the gate and source of the upper bridge arm silicon carbide power chip are connected to the copper layer of the upper bridge arm DBC substrate via bonding wires; the gate and source of the lower bridge arm silicon carbide power chip are connected to the copper layer of the lower bridge arm DBC substrate via bonding wires; the gate copper layer and source copper layer of the upper bridge arm silicon carbide power chip are connected to the positive and negative gate terminals of the upper bridge arm silicon carbide power chip via integrated drive resistors; the gate copper layer and source copper layer of the lower bridge arm silicon carbide power chip are connected to the positive and negative gate terminals of the lower bridge arm silicon carbide power chip via integrated drive resistors.

[0010] Preferably, the upper bridge arm silicon carbide power chip and the lower bridge arm silicon carbide power chip are connected to the copper layer of the corresponding DBC substrate by a sintering method of pressurized silver sintering under formic acid atmosphere.

[0011] Preferably, the positive power terminal, negative power terminal, AC power terminal, integrated drive resistor, and auxiliary terminal are connected to the copper layer of the corresponding DBC substrate by vacuum high-temperature reflow soldering solder paste.

[0012] Preferably, the upper bridge arm DBC substrate and the lower bridge arm DBC substrate have the same structure, both being a three-layer structure, with the upper and lower layers being gold-plated conductive copper layers and the middle layer being an insulating ceramic layer.

[0013] Preferably, the ceramic layer is made of AlN material and the copper layer is made of Cu material.

[0014] Preferably, the power positive terminal, power negative terminal, AC power terminal, upper bridge arm drive negative terminal, upper bridge arm drive positive terminal, lower bridge arm drive positive terminal, and lower bridge arm drive negative terminal are all made of copper.

[0015] Preferably, the upper bridge arm metal column, the lower bridge arm metal column, and the supporting metal column all adopt a Cu-Mo-Cu special laminated metal column structure.

[0016] Preferably, the internal voids of the double-sided module are filled with silicone gel.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: This invention discloses a method for a multi-module parallel silicon carbide bifacial power module. The drains and positive power terminals of two parallel upper-arm silicon carbide power chips are connected via a copper layer on the upper-arm DBC substrate. The power sources of the two parallel upper-arm silicon carbide power chips are connected to the lower-arm DBC substrate via upper-arm metal pillars and then to an AC power terminal. Similarly, the drains and AC power terminals of the lower-arm silicon carbide power chips are connected via the lower-arm DBC substrate. The power sources of the two parallel lower-arm silicon carbide power chips are connected to the upper-arm DBC substrate via lower-arm metal pillars and then to a negative power terminal. The positive and negative connection nodes and AC intermediate nodes of the module are all led out via power terminals. The drive connection points of the upper and lower half-bridges are also led out via drive terminals. The upper-arm and lower-arm DBC substrates are connected hardware and electrically via metal pillars. Auxiliary terminals are also provided as equivalent drains or sources for the power chips in the upper or lower half-bridge arm to reduce measurement errors, which is to facilitate module testing.

[0018] This invention discloses a silicon carbide bifacial power module suitable for multi-module parallel connection. Through a completely symmetrical layout design with two chips connected in parallel, and with the power terminals and AC power terminals located on opposite sides, the module's parasitic parameters can be optimized and reduced to within 8nH, meeting insulation spacing requirements and ensuring compatibility with the electrical and mechanical connection structures in most electric vehicle applications. The integrated drive resistor within the module also suppresses gate-source crosstalk caused by excessively high switching frequencies, further facilitating multi-module parallel connection. Furthermore, this invention explores a sintering silver process for interconnecting the chips and the DBC substrate, which is beneficial for operation in the increasingly demanding ambient temperatures required by electric vehicles. Finally, using Cu-Mo-Cu metal pillars instead of bonding wires to interconnect the upper and lower DBC substrates helps reduce thermo-mechanical stress, achieves double-sided heat dissipation, and thus improves the module's heat dissipation performance and reliability.

[0019] Based on this, the bifacial module solves the problem of uneven current distribution in parallel chip connections within the module, has high power density and heat dissipation performance, and is easy to expand into multiple modules in parallel to adapt to higher current applications in electric vehicles. It can bring great economic benefits to the application of semiconductor technology in the new energy industry. Attached Figure Description

[0020] Figure 1 This is the circuit schematic diagram of the silicon carbide power module corresponding to the present invention; Figure 2 This is a partial exploded view of the three-dimensional structure of the silicon carbide power module corresponding to the present invention; Figure 3 This is another partially exploded view of the three-dimensional structure of the silicon carbide power module corresponding to the present invention; Figure 4This invention relates to a first type of converter circuit for silicon carbide power modules; Figure 5 This is a schematic diagram of the second adaptation form of the silicon carbide power module according to the present invention; Figure 6 This is a structural diagram of the second power negative terminal in the second adaptation form of the silicon carbide power module according to the present invention; Figure 7 This is a structural diagram of the second positive power terminal in the second adaptation form of the silicon carbide power module according to the present invention; Figure 8 This is the second type of converter circuit adapted to the silicon carbide power module of the present invention.

[0021] The attached figures are labeled as follows: 1. Power positive terminal; 2. Power negative terminal; 3. AC power terminal; 4. Lower bridge arm drive positive terminal; 5. Lower bridge arm drive negative terminal; 6. Upper bridge arm drive negative terminal; 7. Upper bridge arm drive positive terminal; 8. Integrated drive resistor; 9. Auxiliary terminal; 10. Upper bridge arm DBC substrate; 11. Lower bridge arm DBC substrate; 12. Lower bridge arm silicon carbide power chip; 13. Lower bridge arm metal pillar; 14. Upper bridge arm silicon carbide power chip; 15. Upper bridge arm metal pillar; 16. Support metal pillar; 17. Second power positive terminal; 18. Second power negative terminal. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention discloses a silicon carbide bifacial power module suitable for multi-module parallel connection, with reference to... Figure 1 , 23, 4. The power module is a half-bridge structure, including an upper half-bridge arm, a lower half-bridge arm, an upper half-bridge arm DBC substrate 10, a lower half-bridge arm DBC substrate 11, an integrated drive resistor 8, a power positive terminal 1, a power negative terminal 2, an AC power terminal 3, and an auxiliary terminal 9. Both the upper and lower half-bridge arms are provided with two parallel silicon carbide power chips, and the two parallel silicon carbide power chips are arranged symmetrically, referred to as upper half-bridge arm silicon carbide power chip 14 and lower half-bridge arm silicon carbide power chip 12. The upper half-bridge arm is provided with an upper half-bridge arm drive negative terminal 6 and an upper half-bridge arm drive positive terminal 7. The upper half-bridge arm DBC substrate 10 is provided with an upper half-bridge arm metal pillar 15. The power positive terminal 1 and the power negative terminal 2 are located on the same side, and the power positive terminal 1 and the AC power terminal 3 are located on opposite sides. In this embodiment, the positive power terminal 1, negative power terminal 2, AC power terminal 3, integrated drive resistor 8, auxiliary terminal 9, upper bridge arm drive negative terminal 6, upper bridge arm drive positive terminal 7, lower bridge arm drive positive terminal 4, and lower bridge arm drive negative terminal 5 are all made of copper and are all soldered to the copper layer of their respective DBC substrates. The positive power terminal 1, negative power terminal 2, AC power terminal 3, integrated drive resistor 8, and auxiliary terminal 9 are connected to the copper layer of their respective DBC substrates by vacuum high-temperature reflow soldering solder paste.

[0024] In the upper half of the bridge arm, an upper bridge arm metal pillar 15 is provided on the upper bridge arm DBC substrate 10. The drains of the two parallel upper bridge arm silicon carbide power chips 14 are connected to the positive power terminal 1 through the copper layer on the upper bridge arm DBC substrate 10. The power sources of the two parallel upper bridge arm silicon carbide power chips 14 are connected to the lower copper layer of the lower bridge arm DBC substrate 11 through the upper bridge arm metal pillar 15 and are connected to the AC power terminal 3. The driving sources and driving gates of the two parallel upper bridge arm silicon carbide power chips 14 are respectively connected to the upper bridge arm driving negative terminal 6 and the upper bridge arm driving positive terminal 7. Integrated driving resistors 8 are provided at the copper-clad locations of the upper bridge arm driving sources and gates. In this embodiment, the upper bridge arm parallel silicon carbide power chip 14 is connected to the upper bridge arm DBC substrate 10 by welding or sintering. The gate and source of the upper bridge arm silicon carbide power chip 14 are connected to the copper layer of the upper bridge arm DBC substrate 10 by bonding wires. The gate copper layer and source copper layer of the upper bridge arm silicon carbide power chip 14 are connected to the positive and negative terminals of the gate of the upper bridge arm silicon carbide power chip 14 by integrated drive resistor 8. The upper bridge arm silicon carbide power chip 14 is connected to the copper layer of the upper bridge arm DBC substrate 10 by a sintering method of pressing silver under formic acid atmosphere.

[0025] The lower half-bridge arm is provided with a lower bridge arm drive negative terminal 5 and a lower bridge arm drive positive terminal 4, and a lower bridge arm metal pillar 13 is provided on the lower bridge arm DBC substrate 11. The drain of the lower bridge arm silicon carbide power chip 12 is connected to the AC power terminal 3 through the lower copper layer of the lower bridge arm DBC substrate 11. The power sources of the two parallel lower bridge arm silicon carbide power chips 12 are connected to the copper layer of the lower bridge arm DBC substrate 10 through the lower bridge arm metal pillar 13 and are connected to the power negative terminal 2. The drive sources and drive gates of the two parallel lower bridge arm silicon carbide power chips 12 are respectively connected to the lower bridge arm drive negative terminal 5 and the lower bridge arm drive positive terminal 4. Integrated drive resistors 8 are provided at the copper-clad areas of the lower bridge arm drive sources and gates. In this embodiment, the two parallel silicon carbide power chips 12 of the lower bridge arm are connected to the lower bridge arm DBC substrate 11 by welding or sintering. The gate and source of the lower bridge arm silicon carbide power chip 12 are connected to the copper layer of the lower bridge arm DBC substrate 11 by bonding wires. The gate copper layer and source copper layer of the lower bridge arm silicon carbide power chip 12 are connected to the positive and negative terminals of the gate of the lower bridge arm silicon carbide power chip 12 by integrated drive resistor 8. The lower bridge arm silicon carbide power chip 12 is connected to the copper layer of the lower bridge arm DBC substrate 11 by a sintering method of pressing silver under formic acid atmosphere.

[0026] To facilitate module testing, auxiliary terminal 9 serves as the equivalent drain or source of the upper bridge arm silicon carbide power chip 14 or the lower bridge arm silicon carbide power chip to reduce measurement errors.

[0027] A supporting metal pillar 16 is provided between the upper bridge arm DBC substrate 10 and the lower bridge arm DBC substrate 11. In this embodiment, the upper bridge arm metal pillar 15, the lower bridge arm metal pillar 13 and the supporting metal pillar 16 all adopt a Cu-Mo-Cu special stacked metal pillar structure.

[0028] refer to Figure 2 As shown, the upper bridge arm DBC substrate 10 and the lower bridge arm DBC substrate 11 have the same structure, both being three-layer structures. The upper and lower layers are gold-plated conductive copper layers, and the middle layer is an insulating ceramic layer. The ceramic layer of the DBC substrate used in this example is made of AlN with a thickness of 0.635mm. The copper layer is gold-plated to reduce the stress between the chip, terminals, and DBC and improve reliability, with a copper layer thickness of 0.3mm. The metal pillars are made of Cu-Mo-Cu material, which can also reduce the thermo-mechanical stress in the double-sided module. The chip and DBC are made of sintered silver material, which is more suitable for high-temperature working environments. To ensure high power density, the overall module size is designed to be 52mm×30mm×5.8mm (excluding the power terminals and drive terminals). At the same time, in order to adapt to more application scenarios, the design of this module also takes into account the compatibility of power terminal connections. Both terminal forms can achieve good parallel current sharing. The optimization of the internally integrated drive terminals and the parasitic inductance of the drive circuit can increase the gate-source stability and is also more conducive to applications after multiple modules are connected in parallel.

[0029] Reference Figure 1 The power terminal arrangement was optimized. The first method involves a power terminal consisting of a positive power terminal 1 and two negative power terminals 2, all located on the same side. This allows for complete structural symmetry between the two negative power terminals. (Refer to...) Figure 5 , 6 7. If, due to application limitations, two negative power terminals cannot be brought out, the second method can be used to adjust the relative positions between the positive and negative terminals and optimize the parasitic parameter distribution to achieve parallel current sharing. If only one positive power terminal and one negative power terminal are needed, the relative positions of the positive and negative power terminals can be adjusted, and parasitic parameters can be extracted and iteratively optimized through ANSYS Q3D simulation to achieve parallel current sharing of the two chips. The positive and negative power terminals can be adjusted as follows: Figure 6 , 7 The second power positive terminal 17 and the second power negative terminal 18.

[0030] This invention discloses a silicon carbide bifacial power module suitable for multi-module parallel connection, which has excellent characteristics such as small parasitic parameters, strong heat dissipation performance, high reliability, and good parallel current sharing characteristics. It is also very suitable for multi-module parallel application of bifacial modules in the field of electric vehicle applications. Its preparation process is as follows: The first step is to ultrasonically clean the prepared DBC substrate, fixture, terminals, and metal pillars. Then, using a pre-cut stencil, apply an appropriate amount of sintering silver paste to the chip location on the DBC substrate. The thickness of the stencil needs to be selected appropriately, and the sintering silver paste is preheated and cured at 150°C for 1 hour.

[0031] The second step involves fixing the chip in place using a pre-designed graphite fixture, and then performing pressure sintering in a vacuum sintering furnace using a pre-set sintering curve.

[0032] The third step is to take out the sintered chip, apply solder to the pre-cut stencil on the metal pillar positions, power terminal positions, drive terminal positions and integrated drive resistor positions on the DBC substrate, fix it with graphite clamps and place it in a vacuum welding furnace to complete the welding.

[0033] The fourth step is to remove the DBC substrate that has been soldered in the previous step, place it in an ultrasonic cleaning device to remove the residue, and then use an ultrasonic bonding machine to interconnect the gate and source on the power chip with the corresponding DBC copper layer.

[0034] Fifth, apply solder to the chip surface and the metal pillar connection of the DBC substrate again with a stencil, shape it with a graphite jig, and place it in a vacuum soldering machine to complete the soldering. Note that the solder selected in this step needs to be one temperature gradient lower than the solder in the third step.

[0035] The sixth step is to remove the welded double-sided module and clean it in an ultrasonic cleaning device in order to meet the higher insulation withstand voltage requirements. Then, silicone gel is used to fill it to achieve mechanical support and improve insulation strength.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A silicon carbide bifacial power module suitable for multi-module parallel connection, characterized in that, The power module has a half-bridge structure, including an upper half-bridge arm, a lower half-bridge arm, an upper half-bridge arm DBC substrate (10), a lower half-bridge arm DBC substrate (11), an integrated drive resistor (8), a power positive terminal (1), a power negative terminal (2), an AC power terminal (3), and an auxiliary terminal (9). Both the upper and lower half-bridge arms are provided with two parallel silicon carbide power chips, and the two parallel silicon carbide power chips are arranged symmetrically, referred to as the upper half-bridge arm silicon carbide power chip (14) and the lower half-bridge arm silicon carbide power chip. (12); The upper half of the bridge arm is provided with an upper bridge arm drive negative terminal (6) and an upper bridge arm drive positive terminal (7), and the lower half of the bridge arm is provided with a lower bridge arm drive negative terminal (5) and a lower bridge arm drive positive terminal (4); The upper bridge arm DBC substrate (10) is provided with an upper bridge arm metal pillar (15), and the lower bridge arm DBC substrate (11) is provided with a lower bridge arm metal pillar (13); The power positive terminal (1) and the power negative terminal (2) are located on the same side, and the power positive terminal (1) and the AC power terminal (3) are located on opposite sides; In the upper half of the bridge arm, the drain, positive power terminal (1) and negative power terminal (2) of the upper bridge arm silicon carbide power chip (14) are all connected to the upper copper layer of the upper bridge arm DBC substrate (10). The power source is connected to the lower copper layer of the lower bridge arm DBC substrate (11) through the upper bridge arm metal pillar (15). The drive source is connected to the upper bridge arm drive negative terminal (6). The drive gate is connected to the upper bridge arm drive positive terminal (7). The integrated drive resistor (8) is set at the copper plating of the drive source and gate of the upper bridge arm. In the lower half-bridge arm, the drain of the silicon carbide power chip (12) and the AC power terminal (3) are both connected to the lower copper layer of the lower bridge arm DBC substrate (11). The power source is connected to the upper copper layer of the upper bridge arm DBC substrate (10) through the lower bridge arm metal pillar (13). The drive source is connected to the lower bridge arm drive negative terminal (5), the drive gate is connected to the lower bridge arm drive positive terminal (4), and the integrated drive resistor (8) is set at the copper-clad area between the lower bridge arm drive source and the gate. The auxiliary terminal (9) is connected to the lower copper layer of the lower bridge arm DBC substrate (11) and serves as the equivalent drain or source of the upper or lower bridge arm power chip. A supporting metal pillar (16) is provided between the upper bridge arm DBC substrate (10) and the lower bridge arm DBC substrate (11).

2. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 1, characterized in that, The upper arm silicon carbide power chip (14) is connected to the upper arm DBC substrate (10) by welding or sintering; the lower arm silicon carbide power chip (12) is connected to the lower arm DBC substrate (11) by welding or sintering; the power positive terminal (1), power negative terminal (2), AC power terminal (3), integrated drive resistor (8), auxiliary terminal (9), upper arm drive negative terminal (6), upper arm drive positive terminal (7), lower arm drive positive terminal (4) and lower arm drive negative terminal (5) are all welded to the copper layer of their respective DBC substrates.

3. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 2, characterized in that, The gate and source of the upper bridge arm silicon carbide power chip (14) are connected to the copper layer of the upper bridge arm DBC substrate (10) through bonding wires; the gate and source of the lower bridge arm silicon carbide power chip (12) are connected to the copper layer of the lower bridge arm DBC substrate (11) through bonding wires; the gate copper layer and source copper layer of the upper bridge arm silicon carbide power chip (14) are connected to the positive and negative gate terminals of the upper bridge arm silicon carbide power chip (14) through integrated drive resistors (8); the gate copper layer and source copper layer of the lower bridge arm silicon carbide power chip (12) are connected to the positive and negative gate terminals of the lower bridge arm silicon carbide power chip (12) through integrated drive resistors (8).

4. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 2, characterized in that, The upper arm silicon carbide power chip (14) and the lower arm silicon carbide power chip (12) are connected to the copper layer of the corresponding DBC substrate by a sintering method of pressurized silver sintering under formic acid atmosphere.

5. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 2, characterized in that, The positive power terminal (1), negative power terminal (2), AC power terminal (3), integrated drive resistor (8), and auxiliary terminal (9) are connected to the copper layer of the corresponding DBC substrate by vacuum high-temperature reflow soldering solder paste.

6. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 1, characterized in that, The upper bridge arm DBC substrate (10) and the lower bridge arm DBC substrate (11) have the same structure, both being three-layer structures. The upper and lower layers are gold-plated conductive copper layers, and the middle layer is an insulating ceramic layer.

7. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 6, characterized in that, The ceramic layer is made of AlN material, and the copper layer is made of Cu material.

8. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 1, characterized in that, The power positive terminal (1), power negative terminal (2), AC power terminal (3), upper bridge arm drive negative terminal (6), upper bridge arm drive positive terminal (7), lower bridge arm drive positive terminal (4) and lower bridge arm drive negative terminal (5) are all made of copper.

9. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 1, characterized in that, The upper bridge arm metal column (15), the lower bridge arm metal column (13), and the supporting metal column (16) all adopt a Cu-Mo-Cu special laminated metal column structure.

10. The silicon carbide bifacial power module suitable for multi-module parallel connection according to claim 1, characterized in that, The internal voids of the bifacial power module are encapsulated with silicone gel.

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