Power module heat dissipation structure and power module packaging structure

Abstract

The embodiment of the application discloses a power module heat dissipation structure and a power module packaging structure. The power module heat dissipation structure is provided with a sealed space, the sealed space is used for placing N power modules, N is an integer greater than or equal to 1; a phase change insulation liquid is located in the sealed space, the sum of the volume of the phase change insulation liquid and the volume of the power module is less than the volume of the sealed space; the phase change insulation liquid is used for absorbing heat of the power module to change from a liquid state to a gaseous state, and the phase change insulation liquid is used for transferring heat out of the sealed space to change from the gaseous state to the liquid state. The above technical scheme improves the heat dissipation capacity of the power module heat dissipation structure.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a power module heat dissipation structure and a power module packaging structure. Background Technology

[0002] Existing automotive-grade IGBT or SiC MOSFET HPD (Hybrid Pack Drive Module) power modules are compact power modules designed for traction applications in hybrid and electric vehicles. They offer a scalable power range from 100kW to 250kW in 750V and 1200V ratings.

[0003] The power module heat dissipation structure adopts a single-sided direct water cooling method, which supports high-power applications. However, the single-sided direct water cooling structure has limited heat dissipation for the power module. Summary of the Invention

[0004] This invention provides a power module heat dissipation structure and a power module packaging structure to improve the heat dissipation capability of the power module heat dissipation structure.

[0005] According to one aspect of the present invention, a power module heat dissipation structure is provided, which includes a sealed space.

[0006] The sealed space is used to house N power modules, where N is an integer greater than or equal to 1.

[0007] A phase change insulating fluid is located within the sealed space. The sum of the volume of the phase change insulating fluid and the volume of the power module is less than the volume of the sealed space. The phase change insulating fluid is used to absorb heat from the power module and change from a liquid state to a gaseous state. The phase change insulating fluid is also used to transfer heat out of the sealed space and then change from a gaseous state to a liquid state.

[0008] According to another aspect of the present invention, a power module packaging structure is provided, including any of the power module heat dissipation structures described in the present invention and N power modules, wherein the value of N includes an integer greater than or equal to 1;

[0009] The power module is fixed to the power module heat dissipation structure and dissipates heat through the power module heat dissipation structure.

[0010] This invention provides a power module heat dissipation structure and a power module packaging structure. The power module heat dissipation structure has a sealed space, within which a power module is housed. A phase change insulating fluid is placed within the sealed space, achieving active heat dissipation and improving the transient heat dissipation capability of the power module heat dissipation structure, thereby enhancing the robustness and reliability of the power module. The phase change insulating fluid heat dissipation process is as follows: The heat generated during power module operation is transferred to the phase change insulating fluid in contact with the power module. After absorbing heat, the phase change insulating fluid reaches its boiling point, undergoing a liquid-to-gas phase change, transforming from a liquid to a gaseous state. The gaseous phase change insulating fluid then contacts other structures or media outside the sealed space, releasing heat out of the sealed space. Following this, the phase change insulating fluid undergoes a secondary phase change, transforming from a gaseous state back to a liquid state.

[0011] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of a power module heat dissipation structure provided in an embodiment of the present invention;

[0014] Figure 2 yes Figure 1 A partial structural diagram of the medium-power module, phase change insulating fluid, and second heat sink. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0016] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0017] To improve the heat dissipation capacity of the power module heat dissipation structure, the embodiments of the present invention provide the following technical solutions:

[0018] Figure 1 This is a schematic diagram of a power module heat dissipation structure provided in an embodiment of the present invention. Figure 2 yes Figure 1 A partial structural diagram of the medium-power module, phase change insulating fluid, and second heat sink is provided for reference. Figure 1 and combined Figure 2 The power module heat dissipation structure is equipped with a sealed space for holding N power modules 200, where N is an integer greater than or equal to 1. A phase change insulating liquid 500 is located inside the sealed space, and the sum of the volume of the phase change insulating liquid 500 and the volume of the power module 200 is less than the volume of the sealed space. The phase change insulating liquid 500 is used to absorb the heat of the power module 200 and change from liquid to gas. The phase change insulating liquid 500 is also used to transfer the heat out of the sealed space and change from gas to liquid.

[0019] For example, the phase change insulating liquid 500 includes fluorinated liquid and silicone oil.

[0020] The power module heat dissipation structure provided in this embodiment of the invention includes a sealed space containing a power module 200 and a phase change insulating liquid 500. This achieves active heat dissipation, improves the transient heat dissipation capability of the power module heat dissipation structure, and enhances the robustness and reliability of the power module. The phase change heat dissipation process of the phase change insulating liquid 500 is as follows: Heat generated by the power module 200 during operation is transferred to the phase change insulating liquid 500 in contact with it. After absorbing heat, the phase change insulating liquid 500 reaches its boiling point, undergoing a liquid-to-gas phase change. The phase change insulating liquid 500 changes from a liquid to a gaseous state. Upon contact with other structures or media outside the sealed space, the gaseous phase change insulating liquid 500 releases heat out of the sealed space. Then, the phase change insulating liquid 500 undergoes a secondary phase change, changing from a gaseous state to a liquid state.

[0021] Optionally, based on the above technical solutions, such as Figure 1 and Figure 2 As shown, the sealed space is the space formed by the first radiator 100, the second radiator 300 and the sealing connection assembly 400. The sealing connection assembly 400 is located between the first radiator 100 and the second radiator 300 and surrounds the power module 200. The phase change insulating liquid 500 is used to transfer heat to the second radiator 300 and then change from a gaseous state to a liquid state.

[0022] Optionally, the sealing connection assembly 400 includes an injection-molded housing and a sealant. The injection-molded housing is a high-temperature resistant housing, and the heat generated by the power module 200 is insufficient to cause deformation of the injection-molded housing. The injection-molded housing is formed by a high-temperature injection molding process and surrounds the power module 200. The injection-molded housing has threaded holes and is threadedly connected to the first heat sink 100 and the second heat sink 300 by fasteners such as screws and the sealant, thereby achieving a sealed connection between the injection-molded housing and the first heat sink 100 and the second heat sink 300. The sealant is used to seal any gaps between the injection-molded housing and the first heat sink 100 and the second heat sink 300.

[0023] Optionally, the power module 200 is fixed to one side of the first heat sink 100 by a large-area welding or sintering process. The signal terminals of the power module 200 are bonded to the signal terminals of the injection-molded housing via copper or aluminum wire bonding, and the power terminals of the power module 200 are fixed to the power terminals of the injection-molded housing via ultrasonic bonding or laser welding.

[0024] Among them, the phase change insulating liquid 500 located in the sealed space between the sealed connection assembly 400, the power module 200 and the second heat sink 300 is an active heat dissipation structure. Active heat dissipation is achieved through the high-temperature phase change of the phase change insulating liquid 500, so as to achieve a constant and adjustable junction temperature of the power module 200 and reduce the thermal resistance of the power chip in the power module 200.

[0025] Optionally, based on the above technical solution, the first radiator 100 is provided with a first coolant channel 101, and a plurality of first heat dissipation pins 102 are provided in the first coolant channel 101; one side of the first radiator 100 is used to fix N power modules 200, and the value of N includes integers greater than or equal to 1.

[0026] Among them, the first heat dissipation pin fin 102 is a pin-fin structure, which can improve the heat dissipation effect when the coolant passes through it.

[0027] Specifically, the first radiator 100 is provided with a first coolant channel 101, and a plurality of first heat dissipation pins 102 are provided in the first coolant channel 101. During the process of the coolant flowing through the first coolant channel 101, the coolant absorbs the heat dissipated by the power module 200, and the arrangement of the plurality of first heat dissipation pins 102 further improves the heat dissipation effect of the coolant.

[0028] Optionally, based on the above technical solution, the second radiator 300 is provided with a second coolant channel 301 inside, and a plurality of second heat dissipation pins 302 are provided inside the second coolant channel 301; the second radiator 300 is located on the side of the N power modules 200 away from the first radiator 100.

[0029] Among them, the second heat dissipation pin fin 302 is a pin-fin structure, which can improve the heat dissipation effect when the coolant passes through it.

[0030] Specifically, the second radiator 300 is provided with a second coolant channel 301, and multiple second heat dissipation fins 302 are provided within the second coolant channel 301. During the flow of the coolant through the second coolant channel 301, the coolant absorbs the heat dissipated by the power module 200, and the multiple heat dissipation fins 302 further improve the heat dissipation effect of the coolant. The phase change insulating fluid 500 heat dissipation process is as follows: The heat generated by the power module 200 during operation is transferred to the phase change insulating fluid 500 in contact with the power module 200. After absorbing heat, the phase change insulating fluid 500 reaches its boiling point temperature, undergoing a liquid-gas phase change, transforming from a liquid state to a gaseous state. When the gaseous phase change insulating fluid 500 comes into contact with the second radiator 300, it releases heat to the second radiator 300, undergoing a secondary phase change, transforming from a gaseous state to a liquid state. The second radiator 300 dissipates heat through the coolant and the second heat dissipation fins 302.

[0031] The power module heat dissipation structure provided in this embodiment of the invention has three heat dissipation structures: a first heat sink 100, a second heat sink 300, and a phase change insulating liquid 500 located in the sealed space between the sealed connection assembly 400, the power module 200, and the second heat sink 300. This achieves active heat dissipation and automatic uniform flow and heat distribution of the coolant, improves the transient heat dissipation capability of the power module heat dissipation structure, and enhances the robustness and reliability of the power module.

[0032] Optionally, based on the above technical solution, the power module heat dissipation structure further includes a first side coolant channel 600 and a second side coolant channel 700; the first side coolant channel 600 is used to connect the inlet of the first coolant channel 101 and the inlet of the second coolant channel 301; the second side coolant channel 700 is used to connect the outlet of the first coolant channel 101 and the outlet of the second coolant channel 301. Specifically, the above technical solution realizes that coolant flows in through the first coolant channel 101, flows through the first side coolant channel 600 and then through the second coolant channel 301, and then the coolant flows out through the confluence of the outlets of the second side coolant channel 700 and the second coolant channel 301.

[0033] Optionally, based on the above technical solution, the power module heat dissipation structure further includes a first heat sink substrate 103, a first heat sink outer shell 104, a second heat sink substrate 303, a second heat sink outer shell 304, a first side heat sink inner shell 601, a first side heat sink outer shell 602, a second side heat sink inner shell 701, and a second side heat sink outer shell 702; a first coolant channel 101 is located between the first heat sink substrate 103 and the first heat sink outer shell 104, and a first heat dissipation fin 102 is located on the surface of the first heat sink substrate 103 facing the first heat sink outer shell 104; a second coolant channel 301 is located between the second heat sink substrate 303 and the second heat sink outer shell 304, and a second heat dissipation fin 302 is located on the surface of the second heat sink substrate 303 facing the second heat sink outer shell 304; a sealing connection assembly 400 is located between the first heat sink substrate 103 and the second heat sink outer shell 304. Between the radiator substrates 303; the first side coolant channel 600 is located between the first side radiator inner shell 601 and the first side radiator outer shell 602, the first side radiator inner shell 601 is located on the side of the sealing connection assembly 400 away from the sealing space and is sealed to the first radiator substrate 103 and the second radiator substrate 303, the first side radiator outer shell 602 is sealed to the first radiator outer shell 104 and the second radiator outer shell 304; the second side coolant channel 700 is located between the second side radiator inner shell 701 and the second side radiator outer shell 702, the second side radiator inner shell 701 is located on the side of the sealing connection assembly 400 away from the sealing space and is sealed to the first radiator substrate 103 and the second radiator substrate 303, the second side radiator outer shell 702 is sealed to the first radiator outer shell 104 and the second radiator outer shell 304.

[0034] Specifically, the above technical solution seals the first coolant channel 101, the second coolant channel 301, the first side coolant channel 600, and the second side coolant channel 700 within the power module heat dissipation structure. Optionally, the sealing connections involved in the power module heat dissipation structure can be achieved using fasteners such as screws and sealant. The housing in the power module heat dissipation structure can be made of a material with good thermal conductivity to enhance the heat dissipation effect.

[0035] Optionally, the first radiator housing 104, the second radiator housing 304, the first side radiator inner housing 601, the first side radiator housing 602, the second side radiator inner housing 701, and the second side radiator housing 702 can be made of aluminum alloy, which has good heat dissipation performance. The first radiator substrate 103, the first heat dissipation fins 102, the second radiator substrate 303, and the second heat dissipation fins 302 can be made of copper, which has good heat dissipation performance.

[0036] Optionally, based on the above technical solutions, such as Figure 1 As shown, a plurality of signal terminals 800 are provided on the side of the second heat sink 300 away from the power module 200. The signal terminals 800 are used to connect to external electrical components. The signal terminals 800 are electrically connected to the power module 200. The external electrical components are located on the side of the second heat sink 300 away from the power module 200.

[0037] Specifically, the external electrical components can be devices such as drive board transformers. While the external electrical components are electrically connected to the power module 200 via signal terminals 800, they can also be cooled by the second heat sink 300, thereby improving their electrical performance. When the external electrical component is a drive board transformer, the driving capability of the drive board transformer can be improved.

[0038] This invention also provides a power module packaging structure. For example... Figure 1 and Figure 2 As shown, the power module packaging structure includes the power module heat dissipation structure described in any embodiment of the present invention and N power modules 200, where N is an integer greater than or equal to 1; the power modules 200 are fixed to the power module heat dissipation structure and dissipate heat through the power module heat dissipation structure.

[0039] In the power module heat dissipation structure of the power module packaging structure provided in this embodiment of the invention, a power module 200 is disposed within a sealed space formed by a first heat sink, a second heat sink, and a sealed connection assembly 400. A phase change insulating liquid 500 is disposed within the sealed space, achieving active heat dissipation, improving the transient heat dissipation capability of the power module heat dissipation structure, and enhancing the robustness and reliability of the power module. The phase change heat dissipation process of the phase change insulating liquid 500 is as follows: The heat generated when the power module 200 is working is transferred to the phase change insulating liquid 500 in contact with the power module 200. After absorbing heat, the phase change insulating liquid 500 reaches its boiling point temperature, undergoing a liquid-to-gas phase change, transforming from a liquid to a gaseous state. Upon contact with the second support structure 002, the gaseous phase change insulating liquid 500 releases heat to the second support structure 002, undergoing a secondary phase change, transforming from a gaseous state to a liquid state.

[0040] Optionally, based on the above technical solution, the power module 200 includes a substrate 201, multiple power chips 202, a molding compound 203, bonding strips 204, and multiple strip bonding pins 205; the power chips 202 are located on one side of the substrate 201; the bonding strips 204 are electrically connected to the power chips 202 to realize interconnection between the multiple power chips 202; the strip bonding pins 205 are electrically connected to the bonding strips 204 and are in contact with the sealed space and the phase change insulating liquid 500; the molding compound 203 is located on the side of the power chips 202 away from the substrate 201 and covers the power chips 202 and the bonding strips 204; the power module 200 is fixed to one side of the first heat sink 100 through the substrate 201.

[0041] Optionally, the substrate 201 includes a direct-bonded copper (DBC) ceramic substrate or an active metal brazing (AMB) ceramic substrate. The electrodes or pads of the power chip 202 are fixed to one side of the substrate 201 by sintering or welding processes. The power chip 202 is then interconnected by bonding strips 204 to its pins using a clip-bonding packaging process. Clip pin-fins 205 are connected to the bonding strip 204 via a soldering process and protrude towards the sealed space. They transfer heat generated by the power chip 202 to the phase change insulating liquid 500. After absorbing heat, the phase change insulating liquid 500 reaches its boiling point, undergoing a liquid-to-gas phase change. The gaseous phase change insulating liquid 500 then contacts the second heat sink 300, releasing heat to it. A second phase change occurs, transforming the liquid from a gaseous state to a liquid state. The second heat sink 300 dissipates heat through the coolant and the second clip pin-fins 302. A molding compound 203 is located on the side of the power chip 202 furthest from the substrate 201, covering the power chip 202 and the bonding strip 204, exposing the clip pin-fins 205, thus completing the encapsulation of the power chip 202.

[0042] Furthermore, in the above technical solution, the molding layer 203 completes the first layer of encapsulation structure of the power module 200; the sealing connection component 400, located between the first heat sink 100 and the second heat sink 300, is used to seal and connect the first heat sink 100 and the second heat sink 300, thus completing the second layer of encapsulation structure of the power module 200; the above two-layer encapsulation structure allows the power chip 202 to be in a double-sealed environment, isolating it from external moisture, salt spray, etc., reducing the impact of extreme conditions on the power chip 202, and improving the robustness and reliability of the power module 200.

[0043] In summary, the power chip 202 inside the power module 200 (which includes components such as substrate 201, multiple power chips 202, molding compound 203, bonding strips 204, and multiple strip bonding pins 205, which are interconnected by welding or sintering) is interconnected on the upper surface by the strip bonding pins 205. After molding, the strip bonding pins 205 are partially immersed in the phase change insulating liquid 500 in the upper sealed space. By selecting a phase change insulating liquid with a suitable boiling point, heat is rapidly transferred by using endothermic phase change instead of traditional heat conduction. The second heat sink 300 is responsible for re-liquefying the vaporized phase change insulating liquid 500 by condensation, forming a liquid-gas-liquid loop. This makes the junction temperature of the power module 200 constant and adjustable, and reduces the thermal resistance of the power chip 202 inside the power module 200.

[0044] Optionally, based on the above technical solution, the power chip 202 includes a metal-oxide-semiconductor field-effect transistor power chip (MOSFET power chip) or an insulated-gate bipolar transistor power chip (IGBT power chip).

[0045] Optionally, based on the above technical solutions, the metal-oxide-semiconductor field-effect transistor power chip includes a silicon carbide metal-oxide-semiconductor field-effect transistor power chip (SiC MOSFET power chip) or a gallium nitride metal-oxide-semiconductor field-effect transistor power chip (GaN MOSFET power chip).

[0046] Optionally, based on the above technical solutions, the insulated gate bipolar transistor power chip includes a silicon carbide insulated gate bipolar transistor power chip (SiC IGBT power chip) or a gallium nitride insulated gate bipolar transistor power chip (GaNIGBT power chip).

[0047] For example, the pads connecting the MOSFET power chip to the drain are fixed to one side of the substrate 201 by sintering or welding processes, the pads connecting the MOSFET power chip to the source are welded to the strip bonding pins 205, and then the power chip 202 is encapsulated by the molding compound 203.

[0048] Specifically, the power chip 202 includes any one of SiC MOSFET power chips, GaN MOSFET power chips, SiC IGBT power chips, and GaN IGBT power chips, which has the advantages of high withstand voltage, low on-resistance, and high frequency, thus enhancing the electrical performance of the power chip 202.

[0049] Optionally, based on the above technical solution, the power module 200 includes a half-bridge power module, where N is 3, and the three power modules constitute a three-phase full-bridge power module.

[0050] The three power modules 200 include a U-phase half-bridge power module, a V-phase half-bridge power module, and a W-phase half-bridge power module.

[0051] The heat dissipation structure of the three-phase full-bridge power module includes a first radiator 100 with a first heat dissipation fin 102 and a second radiator 300 with a second heat dissipation fin 302. The inverter cooling circulation channel leads to the coolant channels of the first radiator 100 and the second radiator 300 respectively. The inverter coolant is diverted through the first radiator 100 and the second radiator 300, circulating continuously to carry away the heat generated by the power module 200. When the three-phase full-bridge power module is operating normally (current < 250A, 55℃ < Tj < 120℃), the inverter coolant flow rate is 8L / min, the flow rate diverted to the first radiator 100 is 7L / min, and the flow rate diverted to the second radiator 300 is 1L / min. At this time, the heat dissipation path of the three-phase full-bridge power module mainly relies on the first radiator 100. When the three-phase full-bridge power module operates under peak conditions (current > 400A, 175℃ > Tj > 150℃), the inverter coolant flow rate increases to 10L / min. The flow rate to the first heat sink 100 is 8L / min, and the flow rate to the second heat sink 300 is 2L / min. The heat dissipation path is through built-in insulating liquid phase change and double-sided coolant circulation, significantly reducing the high heat generated under short-term high-current peak conditions. The junction temperature is the actual operating temperature of the power module 200.

[0052] The power module packaging structure provided in this invention achieves active heat dissipation, automatic flow and heat equalization of the coolant, and bi-lateral heat dissipation through the power module heat dissipation structure. This improves the transient heat dissipation capability of the power module heat dissipation structure, reduces transient thermal resistance, and enhances the robustness and reliability of the power module. Furthermore, this power module heat dissipation structure also has the following beneficial effects: A phase-change insulating fluid is injected between the power module side frame and the second heat sink. Heat transfer is achieved through the transient and rapid absorption of heat during the phase change at the constant boiling point of the coolant, realizing active heat dissipation. This stabilizes the junction temperature of the power module and reduces the thermal resistance of the power module or power devices under high-loss conditions; active heat dissipation also enables automatic flow and heat equalization of the power module.

[0053] The heat dissipation structure on the top of the power module can cool the driver board transformer and driver.

[0054] By increasing or decreasing the number of power chips inside the power module, a wider current range can be covered to meet the application needs of customers in different power segments. Compared with existing power modules, while maintaining the same output current capacity, the number of chips used is reduced, product costs are lowered, module package size is reduced, and power density is increased. The transient loss heat dissipation capacity is improved, which can reduce the junction temperature rise caused by the high heat generated by the power module or power device under short-term high current peak conditions, and improve the short-circuit capability of the power module or power device. The power chip is double-sealed to reduce the impact of extreme conditions on the power chip and improve the tolerance of the high temperature and high humidity bias test system (H3TRB), high voltage high temperature and high humidity bias test system (HV-H3TRB), and low voltage high temperature and high humidity bias test system (LV-H3TRB). The defects of uneven distribution of conduction resistance (Rdson) are compensated by the active heat dissipation and automatic heat equalization function of the power module or power device. The copper bus terminals adopt laser welding technology, which has high production efficiency, flexible assembly, and high reliability. The pin-to-pin interface is replaced with HPD water circuit interface, and IGBT is currently used. Customers of HPD and SiCHPD modules can directly replace them; the double-sealed structure isolates external moisture and salt spray, providing salt spray, moisture, and water resistance; suitable for high power density and high-performance applications, helping to improve the application efficiency of clients; signal and high current transmission through copper busbars reduces the parasitic inductance of power modules or power devices, shrinking their size and lowering product costs; the power chip operates at high frequencies, reducing switching losses and energy loss, thereby increasing current density and enhancing system reliability and lifespan.

[0055] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0056] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A heat dissipation structure for a power module, characterized in that, A sealed space is provided for accommodating N power modules, wherein the value of N includes integers greater than or equal to 1; A phase change insulating fluid is located within the sealed space. The sum of the volume of the phase change insulating fluid and the volume of the power module is less than the volume of the sealed space. The phase change insulating fluid is used to absorb heat from the power module and change from a liquid state to a gaseous state. The phase change insulating fluid is also used to transfer heat out of the sealed space and then change from a gaseous state to a liquid state. The sealed space is a space formed by a first heat sink, a second heat sink, and a sealing connection assembly. The sealing connection assembly is located between the first heat sink and the second heat sink, and is used to seal and connect the first heat sink and the second heat sink, and is arranged to surround the power module. The phase change insulating liquid is used to transfer heat to the second radiator and then change from a gaseous state to a liquid state. The first radiator has a first coolant channel inside, through which coolant flows to absorb the heat emitted by the power module. The first coolant channel has a plurality of first heat dissipation fins inside. One side of the first radiator is used to fix N power modules. The second radiator has a second coolant channel inside, through which coolant flows to absorb the heat transferred to the second radiator by the phase change insulating liquid. The second coolant channel has multiple second heat dissipation fins inside. The second radiator is located on the side of the N power modules away from the first radiator.

2. The power module heat dissipation structure according to claim 1, characterized in that, The power module heat dissipation structure also includes a first side coolant channel and a second side coolant channel; The first side coolant passage is used to connect the inlet of the first coolant passage and the inlet of the second coolant passage; The second side coolant channel is used to connect the outlet of the first coolant channel and the outlet of the second coolant channel.

3. The power module heat dissipation structure according to claim 2, characterized in that, The power module heat dissipation structure further includes a first heat sink substrate, a first heat sink outer shell, a second heat sink substrate, a second heat sink outer shell, a first side heat sink inner shell, a first side heat sink outer shell, a second side heat sink inner shell, and a second side heat sink outer shell. The first coolant channel is located between the first radiator base plate and the first radiator housing, and the first heat dissipation pin is located on the surface of the first radiator base plate facing the first radiator housing. The second coolant channel is located between the second radiator base plate and the second radiator housing, and the second heat dissipation pins are located on the surface of the second radiator base plate facing the second radiator housing; The sealing connection assembly is located between the first heat sink substrate and the second heat sink substrate; The first side coolant channel is located between the inner shell of the first side radiator and the outer shell of the first side radiator. The inner shell of the first side radiator is located on the side of the sealing connection assembly away from the sealing space and is sealed to the first radiator base plate and the second radiator base plate. The outer shell of the first side radiator is sealed to the first radiator outer shell and the second radiator outer shell. The second side coolant channel is located between the inner shell of the second side radiator and the outer shell of the second side radiator. The inner shell of the second side radiator is located on the side of the sealing connection assembly away from the sealing space and is sealed to the first radiator substrate and the second radiator substrate. The outer shell of the second side radiator is sealed to the first radiator outer shell and the second radiator outer shell.

4. The power module heat dissipation structure according to claim 1, characterized in that, The second heat sink has multiple signal terminals on the side away from the power module. These signal terminals are used to connect to external electrical components and are electrically connected to the power module. The external electrical components are located on the side of the second heat sink away from the power module.

5. A power module packaging structure, characterized in that, It includes the power module heat dissipation structure as described in any one of claims 1-4 and N power modules, wherein the value of N includes an integer greater than or equal to 1; The power module is fixed to the power module heat dissipation structure and dissipates heat through the power module heat dissipation structure.

6. The power module packaging structure according to claim 5, characterized in that, The power module includes a substrate, multiple power chips, a molding layer, bonding strips, and multiple strip bonding pins. The power chip is located on one side of the substrate; The bonding strip is electrically connected to the power chip to enable interconnection between multiple power chips. The strip bonding needle fin is connected to the bonding strip and is oriented to contact the phase change insulating liquid; The molding layer is located on the side of the power chip away from the substrate and covers the power chip and the bonding strip; The power module is fixed to one side of the first heat sink via the substrate.

7. The power module packaging structure according to claim 6, characterized in that, The power chip includes a metal-oxide-semiconductor field-effect transistor power chip or an insulated-gate bipolar transistor power chip.

8. The power module packaging structure according to claim 7, characterized in that, The metal-oxide-semiconductor field-effect transistor power chip includes a silicon carbide metal-oxide-semiconductor field-effect transistor power chip or a gallium nitride metal-oxide-semiconductor field-effect transistor power chip.

9. The power module packaging structure according to claim 8, characterized in that, The insulated gate bipolar transistor (IGBT) power chip includes a silicon carbide IGBT power chip or a gallium nitride IGBT power chip.

10. The power module packaging structure according to claim 5, characterized in that, The power module includes a half-bridge power module, and the value of N is 3. Three of the power modules constitute a three-phase full-bridge power module.

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