Integrated micro-channel low-stray-inductance low-thermal-resistance power module

Abstract

The low-stray-inductance and low-thermal-resistance power module comprises a first-layer DBC structure, a second-layer DBC structure, a third-layer DBC structure and a fourth-layer DBC structure which are sequentially stacked from top to bottom and comprise the micro-channels, and chip layers are arranged between the DBC structures respectively. A heat dissipation module integrated with a micro-channel is arranged between the second-layer DBC structure and the third-layer DBC structure, and a PCB containing a decoupling capacitor is further connected between the first-layer DBC structure and the second-layer DBC structure or between the third-layer DBC structure and the fourth-layer DBC structure in an integrated mode. The power module can obviously improve the thermal performance, reduce the thermal resistance, optimize the electrical performance, reduce the loop inductance and improve the power density in unit volume; through the arrangement of the structure, the volume power density of the power module is improved by more than 35%, real three-dimensional integrated heat dissipation is realized, the system reliability is improved, and the fault-free working time is obviously prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronic device packaging, in particular to a low-inductance and low-thermal-resistance power module integrated with micro-channels, which is especially suitable for silicon carbide (SiC) or gallium nitride (GaN) power modules for high-frequency and high-power-density applications. BACKGROUND

[0002] The conventional power module heat dissipation structure adopts a single-path heat dissipation design from top to bottom, mainly dissipates heat through the bottom copper substrate, and has a large thermal resistance (typical value > 0.5K / W), which is difficult to meet the demand of high power density. The heat sink is usually externally mounted, which has an interface thermal resistance. Moreover, there is also a problem of stray inductance: the traditional bonding wire structure leads to a large loop inductance (> 10nH), and a high voltage spike is generated when a large current is switched. The decoupling capacitor is usually externally connected, which increases the module volume and parasitic parameters.

[0003] In the prior art, a double-sided heat dissipation module is also provided to improve the heat dissipation performance, but it has obvious limitations. The interlayer interconnection problem is not solved, the separately optimized DBC substrate cannot balance the heat dissipation and electrical performance, and the existing integrated heat sink design is difficult to be compatible with the multi-layer chip structure. SUMMARY

[0004] The present application aims at the problems existing in the prior art, and provides a low-inductance and low-thermal-resistance power module integrated with micro-channels.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: A low-inductance and low-thermal-resistance power module integrated with micro-channels, comprising a first layer DBC structure containing micro-channels, a second layer DBC structure, a third layer DBC structure and a fourth layer DBC structure arranged in sequence from top to bottom, wherein a chip layer is arranged between the first layer DBC structure and the second layer DBC structure, and between the third layer DBC structure and the fourth layer DBC structure, respectively; a heat dissipation module integrated with micro-channels is arranged between the second layer DBC structure and the third layer DBC structure; the first layer DBC structure, the second layer DBC structure, the third layer DBC structure, the fourth layer DBC structure and the heat dissipation module are provided with heat dissipation channels penetrating from top to bottom; and a PCB board containing a decoupling capacitor is further integrated and connected between the first layer DBC structure and the second layer DBC structure, or between the third layer DBC structure and the fourth layer DBC structure.

[0006] The low-jamming and low-thermal-resistance power module with integrated micro flow channels can obviously improve the thermal performance, reduce the thermal resistance, optimize the electrical performance, reduce the loop inductance, improve the power density per unit volume, and has a relatively simple overall structure, thereby reducing the preparation difficulty.

[0007] The four-layer DBC structure can accommodate and connect more power chips, and the application can accelerate heat transfer and dissipation by designing a micro flow channel heat dissipation structure in each layer of the DBC structure and arranging a main heat dissipation module at the middle position, thereby avoiding heat concentration in the DBC structure or near the chip, and the temperature in the chip area can be dissipated faster through the unique arrangement, so that the local temperature can be prevented from being too high, and the overall temperature distribution is more balanced. Through the arrangement of the multi-layer micro flow channel structure, the thermal resistance can be reduced by more than 40% (<0.3K / W), and the chip junction temperature can be reduced by 25-30K.

[0008] By integrating the PCB board between the DBC structures and the DBC structures and configuring the decoupling capacitor, the circuit inductance and impedance can be optimized, the interference can be reduced, the high-frequency interference signals can be filtered out, and the overall performance of the power module can be improved.

[0009] Further, each of the chip layers comprises a plurality of power chips arranged in parallel, and the plurality of power chips in each layer are arranged with a spacing of less than 3mm to reduce current imbalance, and the power chips in the upper and lower layers are arranged one-to-one.

[0010] Further, the power chip is a SiC MOSFET or GaN HEMT power device, and the power chip is interconnected with the first layer of DBC structure and the second layer of DBC structure, the third layer of DBC structure and the fourth layer of DBC structure by silver sintering or transient liquid phase connection.

[0011] Further, the PCB board is a high-frequency multilayer board comprising at least one ground layer and one power layer; the PCB board is connected at the edge between the one layer of DBC structure and the second layer of DBC structure or between the third layer of DBC structure and the fourth layer of DBC structure; the decoupling capacitor is a low-ESL SMD ceramic capacitor, the capacitance of the decoupling capacitor is 0.1-10uF, and the decoupling capacitor is installed on the PCB board at a position less than 5mm from the power chip in the chip layer.

[0012] Further, the first layer DBC structure, the second layer DBC structure, the third layer DBC structure and the fourth layer DBC structure each include a pair of DBC copper layers, and a ceramic heat dissipation layer arranged between the pair of DBC copper layers, and a micro flow channel is arranged in the ceramic heat dissipation layer.

[0013] Further, the thickness of the DBC copper layer is 0.2-0.5mm, the thickness of the ceramic heat dissipation layer is 0.3-0.8mm, and the surface of the copper layer is further provided with a nickel-copper alloy or silver plating layer; the area of the DBC copper layer is not greater than the area of the ceramic heat dissipation layer, and the edges of the pair of DBC copper layers are further provided with connecting pieces.

[0014] Further, the thickness of the heat dissipation module is greater than the thickness of the first layer DBC structure, the second layer DBC structure, the third layer DBC structure or the fourth layer DBC structure, and the thickness of the chip layer, and the heat dissipation module is provided with a micro flow channel penetrating from top to bottom.

[0015] Further, the micro flow channel includes a main flow channel in communication with the heat dissipation channel, a plurality of branch flow channels are arranged on both sides of the main flow channel, and dense heat dissipation flow channels are arranged in the middle of the main flow channel and the branch flow channels, respectively, the dense heat dissipation flow channels are arranged corresponding to the power chips in the chip layer, respectively, and the coverage area of the dense heat dissipation flow channels is not less than the coverage area of the power chips.

[0016] Further, the width of the micro flow channel is 0.2-1mm, and the depth is 0.3-1mm, and the shape of the dense heat dissipation flow channel is serpentine, spiral or net-like distribution.

[0017] Further, a plurality of copper connecting columns are arranged in the heat dissipation module, staggered with the micro flow channel, and the copper connecting columns connect the second layer DBC structure and the third layer DBC structure.

[0018] Compared with the prior art, the low-stray inductance and low-thermal-resistance power module with integrated micro-flow channels has the following advantages: 1. The low-stray inductance and low-thermal-resistance power module with integrated micro-flow channels can significantly improve the thermal performance, reduce the thermal resistance, optimize the electrical performance, reduce the loop inductance, and improve the power density per unit volume by improving the layered structure, heat dissipation structure and stacking mode. Moreover, the overall structure is relatively simple, and the preparation difficulty is reduced; 2. The power module can stack and array multiple power chips through the arrangement of multiple chip layers, so that the power module has higher management control efficiency and realizes efficient electric energy transmission and conversion. At the same time, the multi-layer DBC structure is provided, which not only makes the whole structure more stable and reliable, but also has the functions of excellent heat dissipation, insulation and circuit interconnection, can make the multi-layer chip layers mutual inductance, combined with the micro-flow channels arranged inside, and the heat dissipation module with integrated micro-flow channels specially arranged between the multi-layer DBC structures, the heat dissipation capacity of the whole power module can be greatly improved, so that the temperature is controlled within a reasonable range, and the safety and stability are higher; 3. Through the arrangement of the above structure, the volume power density of the power module is increased by more than 35%, the real three-dimensional integrated heat dissipation is realized, the system reliability is improved, and the MTBF is obviously increased; 4. By arranging the decoupling capacitor on the PCB connected with the DBC structure and controlling the distance between the decoupling capacitor and the power chip, the electrical performance can be optimized, the high-frequency impedance in the loop can be effectively reduced, the loop inductance can be controlled to be less than 3nH, which is reduced by more than 60% compared with the traditional power module structure; 5. By designing the micro-flow channel heat dissipation structure in each DBC structure and arranging the main heat dissipation module at the middle position, the heat transfer and dissipation can be accelerated, and the heat can be prevented from being concentrated in the DBC structure or near the chip. The temperature in the chip area can be dissipated faster through the dense micro-flow channels arranged corresponding to the power chip, so that the local temperature is prevented from being too high, the overall temperature distribution is more balanced, the thermal resistance is reduced by more than 40% (<0.3K / W), and the chip junction temperature is reduced by 25-30K; 6. By integrating the PCB between the DBC structures and the DBC structures and configuring the decoupling capacitor, the circuit inductance and impedance can be optimized, the interference can be reduced, the high-frequency interference signals can be filtered out, and the overall performance of the power module can be improved; 7. The power module is designed in cooperation with the multi-layer DBC substrate and the integrated micro-flow channel radiator, which can realize efficient heat dissipation while reducing the stray inductance, so that it can be applied to application scenarios with voltage level ≥1200V and current ≥200A, such as electric vehicle driving, industrial frequency conversion, new energy power generation and other high-frequency high-power density application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the low-stray inductance and low-thermal-resistance power module with integrated micro-flow channels. Figure 2 It is an exploded structural schematic diagram of the low-stray inductance and low-thermal-resistance power module with integrated micro-flow channels. Figure 3 A schematic diagram of a transverse section of a low inductance and low thermal resistance power module with integrated micro flow channels according to the present application; Figure 4 A schematic diagram of a longitudinal section of a low inductance and low thermal resistance power module with integrated micro flow channels according to the present application; Figure 5 A schematic diagram of a DBC structure according to the present application; Figure 6 A schematic diagram of an exploded view of a DBC structure according to the present application; Figure 7 A schematic diagram of a structure of a heat dissipation module according to the present application; Figure 8 A schematic diagram of a structure of a micro flow channel according to the present application; Figure: 1, the first layer of DBC structure; 2, the second layer of DBC structure; 3, the third layer of DBC structure; 4, the fourth layer of DBC structure; 5, power chip; 6, heat dissipation module; 7, PCB board; 8, decoupling capacitor; 9, micro flow channel; 901, main flow channel; 902, branch flow channel; 903, dense heat dissipation flow channel; 10, heat dissipation channel; 11, connecting hole; 12, copper connecting column; 13, DBC copper layer; 14, ceramic heat dissipation layer. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] In the description of the present application, it should be noted that the terms "intermediate", "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0022] As Figures 1-8As shown, a low-inductance and low-thermal-resistance power module integrated with micro flow channels comprises a first layer of DBC structure 1 containing micro flow channels, a second layer of DBC structure 2, a third layer of DBC structure 3, and a fourth layer of DBC structure 4 arranged in a stack from top to bottom, a chip layer is arranged between the first layer of DBC structure 1 and the second layer of DBC structure 2, and between the third layer of DBC structure 3 and the fourth layer of DBC structure 4, a heat dissipation module 6 integrated with micro flow channels is arranged between the second layer of DBC structure 2 and the third layer of DBC structure 3, and a heat dissipation channel 10 penetrating from top to bottom is arranged on the first layer of DBC structure 1, the second layer of DBC structure 2, the third layer of DBC structure 3, the fourth layer of DBC structure 4, and the heat dissipation module 6; and a PCB board 7 containing a decoupling capacitor is further integrated and connected between the first layer of DBC structure 1 and the second layer of DBC structure 2, or between the third layer of DBC structure 3 and the fourth layer of DBC structure 4.

[0023] The integrated micro flow channel low-inductance and low-thermal-resistance power module can significantly improve thermal performance, reduce thermal resistance, optimize electrical performance, reduce circuit inductance, and improve power density per unit volume by improving its layered structure, heat dissipation structure, and stacking method.

[0024] The power module can stack and array multiple power chips through the arrangement of multiple chip layers, which has higher management and control efficiency, and realizes efficient electrical energy transmission and conversion. At the same time, the multiple layers of DBC structures not only make the entire structure more stable and reliable, but also have excellent heat dissipation, insulation, and circuit interconnection functions, which can reduce the mutual inductance of multiple chip layers, and the micro flow channels inside and the heat dissipation module integrated with micro flow channels specially arranged between the multiple layers of DBC structures can greatly improve the heat dissipation capacity of the entire power module, control the temperature within a reasonable range, and have higher safety and stability. Through the above structure, the volume power density of the power module is increased by more than 35%, realizing true three-dimensional integrated heat dissipation, improving system reliability, and significantly increasing MTBF (mean time between failures).

[0025] The four-layer DBC structure can accommodate and connect more power chips, and by designing micro flow channel heat dissipation structures in each layer of DBC structure and arranging a main heat dissipation module in the middle position, it can accelerate heat transfer and dissipation, avoid heat concentration in the DBC structure or near the chip, and through the unique arrangement, the temperature in the chip area can be dissipated faster, avoiding local high temperature and achieving more balanced overall temperature distribution. Through the arrangement of multiple micro flow channel structures, the thermal resistance can be reduced by more than 40% (<0.3K / W), and the chip junction temperature can be reduced by 25-30K.

[0026] By integrating PCB boards between DBC structures and configuring decoupling capacitors, the circuit inductance and impedance can be optimized, interference can be reduced, and high-frequency interference signals can be filtered out, which is conducive to improving the overall performance of the power module.

[0027] The power module is designed in cooperation with the multi-layer DBC substrate and the integrated micro-channel radiator, which can realize efficient heat dissipation while reducing stray inductance, so that it can be applied to application scenarios with voltage level ≥1200V and current ≥200A, such as electric vehicle driving, industrial frequency conversion, new energy power generation, and other high-frequency high-power density application scenarios.

[0028] Further, each layer of the chip layer includes a plurality of power chips 5 arranged in parallel, and the plurality of power chips 5 in each layer are arranged in parallel with a spacing of less than 3mm, which can reduce current imbalance, and the power chips 5 in the upper and lower layers are arranged one-to-one.

[0029] In the embodiment, two chip layers are provided, and three power chips 5 are arranged at equal intervals in each chip layer. Through the design of the multi-layer structure and the composite, a plurality of power chips 5 can be stacked and arranged. The multi-layer stacking not only increases the number of chips, but also takes into account heat dissipation and electrical performance. The area where the multi-layer power chips 5 are stacked corresponds to the area where the micro-channel is arranged, so that the upper power chip and the lower power chip can be effectively cooled.

[0030] Further, the power chip 5 is a SiC MOSFET or GaN HEMT power device, the upper power chip 5 is interconnected with the copper layer in the first layer DBC structure 1 and the second layer DBC structure 2 by silver sintering or transient liquid phase connection, and the upper power chip 5 is interconnected with the copper layer in the third layer DBC structure 3 and the fourth layer DBC structure 4 by silver sintering or transient liquid phase connection, realizing vertical current conduction.

[0031] The interconnection mode of the high-power density integrated power chip and the copper layer material is silver sintering (sintering temperature 200-300°C, pressure 5-20MPa), transient liquid phase connection (TLP) (using Ag-Sn, Cu-Sn alloy system), or copper-copper direct bonding (realized by hot pressing or surface activation bonding).

[0032] Further, the PCB board 7 is a high-frequency multilayer board, comprising at least one ground layer and one power supply layer; the PCB board 7 is connected at the edge between the one DBC structure 1 and the second DBC structure 2; the decoupling capacitor 8 is a SMD ceramic capacitor with low ESL (equivalent series inductance), the capacitance of the decoupling capacitor 8 is 0.1-10 μF, and the decoupling capacitor 8 is installed on the PCB board 7 at a position less than 5 mm away from the power chip 5 in the chip layer.

[0033] By arranging the decoupling capacitor on the PCB board connected with the DBC structure and controlling the distance between the decoupling capacitor and the power chip, the electrical performance can be optimized, the high-frequency impedance in the loop can be effectively reduced, and the loop inductance can be controlled to be less than 3 nH, which is reduced by more than 60% compared with the traditional power module structure.

[0034] In the embodiment, the number of the decoupling capacitors is the same as the number of the power chips arranged in the layer, and the decoupling capacitors are arranged close to the edge of the DBC structure.

[0035] Further, as shown in Figure 5 and Figure 6 The first DBC structure 1, the second DBC structure 2, the third DBC structure 3 and the fourth DBC structure 4 each comprise a pair of DBC copper layers 13 and a ceramic heat dissipation layer 14 arranged between the pair of DBC copper layers 13, and the ceramic heat dissipation layer 14 is provided with a micro channel 9.

[0036] The DBC copper layer 13 can conduct current, and can also be provided with a circuit pattern to reduce the loop inductance. The ceramic heat dissipation layer 14 can play an insulating role to avoid direct contact between the upper and lower DBC copper layers, can also avoid breakdown of the layer structure, and can itself play a heat dissipation role. By arranging the micro channel in the ceramic heat dissipation layer 14, cooling medium can be introduced to effectively cool the DBC structure and the power chip in real time, further improving the efficiency and effect of heat dissipation and cooling.

[0037] Further, the thickness of the DBC copper layer 13 is 0.2-0.5 mm, and the surface of the DBC copper layer 13 is further provided with a nickel-copper alloy or silver plating layer to connect with the power chip; the material of the ceramic heat dissipation layer 14 can be AlN or Si3N4, and the thickness of the ceramic heat dissipation layer 14 is 0.3-0.8 mm; the area of the DBC copper layer 13 is not greater than the area of the ceramic heat dissipation layer 14, so that the ceramic heat dissipation layer 14 can fully cover the DBC copper layer 13 to fully cool the DBC copper layer 13 and improve the uniformity of heat dissipation; the edge of the pair of DBC copper layers 13 is further provided with a connecting piece.

[0038] Further, as shown in Figure 7As shown, the thickness of the heat dissipation module 6 is greater than the thickness of the first layer DBC structure 1, the second layer DBC structure 2, the third layer DBC structure 3 or the fourth layer DBC structure 4, and the thickness of the chip layer, and the micro flow channel 9 is arranged in the heat dissipation module 6.

[0039] The thickness of the heat dissipation module 6 is greater than the thickness of the other layers, which is arranged in the middle of the entire power module and can play a main heat dissipation component and also play a connecting role. The shape of the micro flow channel arranged therein is similar to that of the ceramic heat dissipation layer, but the thickness is much larger, which can accommodate more cooling medium and the heat exchange effect is more obvious.

[0040] Further, in combination with Figure 8 As shown, the micro flow channel 9 includes a main flow channel 901 in communication with the heat dissipation channel 10, a plurality of branch flow channels 902 are arranged on both sides of the main flow channel 901, and a dense heat dissipation flow channel 903 is arranged in the middle of the main flow channel 901 and the branch flow channel 902. The dense heat dissipation flow channel 903 is arranged corresponding to the power chip 5 in the chip layer, and the coverage area of the dense heat dissipation flow channel 903 is not less than the coverage area of the power chip 5.

[0041] The heat dissipation channel 10 can introduce cooling medium into the micro flow channel of each layer, and the arrangement of the main flow channel 901 and the branch flow channel 902 can increase the heat exchange area of the cooling medium to carry away more heat. The arrangement of the dense heat dissipation flow channel 903 can greatly improve the local heat exchange capacity by arranging more micro flow channels, and can purposefully dissipate heat for the power chip corresponding to the position of the power chip.

[0042] Generally, only these main flow channels and branch flow channels can achieve the effect of heat dissipation, but for the power module, a plurality of stacked chips are arranged inside, and the chip is the main heat source. Although the entire multi-layer stacked structure can be cooled, the temperature at the chip is higher and the temperature is more concentrated. By arranging the dense heat dissipation flow channel on each flow channel, the power chip area can be further efficiently cooled, the temperature at the power chip can be reduced more quickly, and the temperature difference with the surrounding temperature is reduced, so that the temperature and heat distribution of the entire multi-layer stacked chip structure is more uniform after cooling, and the safety is higher, and the performance of the power module is more stable.

[0043] Further, the width of the micro flow channel 9 is 0.2-2mm, and the depth is 0.3-4mm, and the shape of the dense heat dissipation flow channel 903 is serpentine, spiral or net distribution. For the heat dissipation module 6, the depth of the micro flow channel can reach 4mm, and the width is about 1.6mm, and the small flow channel in the dense heat dissipation flow channel is more dense, and the width can be as low as 0.6mm or less, and the diameter or side length of the area covered by the dense heat dissipation flow channel is about 10mm.

[0044] The cooling medium entering the micro flow channel can be selected from high-boiling point dielectric liquids such as deionized water, hydrocarbon cooling liquid or fluorinated liquid, and the liquid flow rate is 0.5-5m / s.

[0045] In the embodiment, the dense heat dissipation flow channel 903 is a circular area, and a plurality of concentric rings are arranged therein, and a break is arranged on each concentric ring to allow the liquid to pass through, and the positions of the breaks on each concentric ring are on the same radial line. This can form a network-shaped heat dissipation structure, contain a large number of heat exchange flow channels, and improve the heat exchange area and the cooling medium flow time of the area, and greatly improve the heat dissipation effect of the area.

[0046] Further, a plurality of connecting holes 11 are arranged in the heat dissipation module 6 and staggered with the micro flow channel 9, a plurality of copper connecting columns 12 are arranged in the connecting holes 11, the copper connecting columns 12 connect the DBC copper layer in the second layer DBC structure 2 and the third layer DBC structure 3, and the arrangement of the copper connecting columns 12 can play a limiting and positioning role, and also play an electrical connection role between the upper and lower layers. When needed, heat-conducting sealant or heat-conducting silicone grease or the like can also be arranged between the layers where the micro flow channel is arranged, so as to reduce the interface thermal resistance and play a certain connecting role.

[0047] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An integrated microchannel low inductance low thermal resistance power module, characterized by, The application relates to a multi-layer DBC structure, which comprises, from top to bottom, a first layer of DBC structure containing micro flow channels, a second layer of DBC structure, a third layer of DBC structure and a fourth layer of DBC structure, wherein a chip layer is arranged between the first layer of DBC structure and the second layer of DBC structure and between the third layer of DBC structure and the fourth layer of DBC structure, a heat dissipation module integrated with micro flow channels is arranged between the second layer of DBC structure and the third layer of DBC structure, and a heat dissipation channel penetrating through the first layer of DBC structure, the second layer of DBC structure, the third layer of DBC structure, the fourth layer of DBC structure and the heat dissipation module is arranged on the first layer of DBC structure, the second layer of DBC structure, the third layer of DBC structure, the fourth layer of DBC structure and the heat dissipation module; and a PCB board containing a decoupling capacitor is further integrated and connected between the first layer of DBC structure and the second layer of DBC structure or between the third layer of DBC structure and the fourth layer of DBC structure.

2. The integrated microfluidic low-junction, low-thermal-resistance power module of claim 1, wherein, Each chip layer comprises a plurality of power chips arranged in parallel, and the power chips in each layer are arranged at a spacing of less than 3 mm, and the power chips in the upper and lower layers are arranged one-to-one.

3. The integrated microfluidic low-junction low-thermal-resistance power module of claim 2, wherein, The power chips are SiC MOSFET or GaN HEMT power devices, and the power chips are interconnected with the first layer of DBC structure and the second layer of DBC structure, the third layer of DBC structure and the fourth layer of DBC structure by silver sintering or transient liquid phase connection.

4. The integrated microfluidic low-junction low-thermal-resistance power module of claim 1, wherein, The PCB board is a high-frequency multilayer board, which comprises at least one ground layer and one power layer; the PCB board is connected at the edge between the first layer of DBC structure and the second layer of DBC structure or between the third layer of DBC structure and the fourth layer of DBC structure; the decoupling capacitor is a low-ESL SMD ceramic capacitor, the capacitance of the decoupling capacitor is 0.1-10 mu F, and the decoupling capacitor is installed on the PCB board at a position with a distance of less than 5 mm from the power chip in the chip layer.

5. The integrated microfluidic low-junction low-thermal-resistance power module of claim 1, wherein, The first layer of DBC structure, the second layer of DBC structure, the third layer of DBC structure and the fourth layer of DBC structure each comprise a pair of DBC copper layers and a ceramic heat dissipation layer arranged between the pair of DBC copper layers, and micro flow channels are arranged in the ceramic heat dissipation layer.

6. The integrated microfluidic low-junction low-thermal-resistance power module of claim 5, wherein, The thickness of the DBC copper layer is 0.2-0.5 mm, the thickness of the ceramic heat dissipation layer is 0.3-0.8 mm, and the surface of the copper layer is further provided with a nickel-copper alloy or silver plating layer; the area of the DBC copper layer is not greater than the area of the ceramic heat dissipation layer, and the edges of the pair of DBC copper layers are further provided with connecting pieces.

7. The integrated microfluidic low-junction low-thermal-resistance power module of claim 1, wherein, The thickness of the heat dissipation module is greater than the thickness of the first layer of DBC structure, the second layer of DBC structure, the third layer of DBC structure or the fourth layer of DBC structure and the thickness of the chip layer, and the heat dissipation module is provided with micro flow channels penetrating through the top and bottom.

8. The integrated microchannel low inductance low thermal resistance power module of claim 1, wherein, The micro flow channel comprises a main flow channel communicated with the heat dissipation channel, a plurality of branch flow channels are arranged on both sides of the main flow channel, dense heat dissipation flow channels are arranged in the middle of the main flow channel and the branch flow channels respectively, the dense heat dissipation flow channels are arranged correspondingly to the power chips in the chip layer respectively, and the coverage area of the dense heat dissipation flow channels is not less than the coverage area of the power chips.

9. The integrated microfluidic low-junction low-thermal-resistance power module of claim 8, wherein, The width of the micro flow channel is 0.2-1 mm, the depth is 0.3-1 mm, and the shape of the dense heat dissipation flow channel is serpentine, spiral or net distribution.

10. The integrated microfluidic low-junction low-thermal-resistance power module of claim 1, wherein, A plurality of copper connecting columns are arranged in the heat dissipation module and staggered with the micro flow channel, and the copper connecting columns connect the second layer DBC structure and the third layer DBC structure.

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