Radiation-proof large-current SiC device packaging structure

Abstract

The invention discloses an anti-radiation large-current SiC device packaging structure, and belongs to the technical field of power semiconductor packaging. The module comprises at least two subunit modules, a miniature common mode inductor, an interconnection copper column and an annular flow channel radiator. Each subunit module comprises an upper half bridge arm, a lower half bridge arm and a parallel SiC MOSFET chip, a miniature common mode inductor is integrated in a driving loop, an interconnection copper column is connected with the subunit modules, and an annular flow channel radiator is filled with a heat-conducting medium and multiplexed as an irradiation shielding layer. Through the synergistic effect of external shielding and internal suppression, the problems of uneven electric heating and grid oscillation induced by irradiation are solved, large-current transmission, efficient heat dissipation and anti-irradiation performance are considered, the reliability of the device in severe environments such as aerospace and high-altitude power transmission is improved, and the device has important engineering application value.

Description

Technical Field

[0001] This invention belongs to the field of power semiconductor packaging technology, specifically relating to a radiation-resistant, high-current SiC device packaging structure. Background Technology

[0002] Power semiconductor devices are the heart of power conversion systems and key components for achieving power conversion. In applications such as high-power space electric propulsion systems, multi-electric aircraft electric drive systems, and high-altitude flexible DC transmission converter valves, the working environment is filled with radiation particles such as high-energy protons, electrons, heavy ions, gamma rays, and neutrons. This necessitates that the power semiconductor devices possess a certain degree of radiation resistance. Furthermore, the power conversion devices in these scenarios have very high power outputs, requiring the power semiconductor devices to handle large currents. In summary, radiation-resistant, high-current power semiconductor devices are a common and fundamental requirement in fields such as deep space exploration, aerospace, and high-altitude DC transmission.

[0003] Currently, the demand for radiation-resistant, high-current power devices is increasingly urgent for power electronic systems operating in harsh environments such as space radiation and high altitudes. Silicon carbide (SiC) materials, due to their wide bandgap characteristics, have superior intrinsic radiation resistance compared to silicon (Si). However, in practical high-current applications, multiple SiC MOSFET chips are typically connected in parallel to carry currents exceeding several hundred amperes. This parallel packaging structure faces two core technical challenges exacerbated by the radiation environment: First, there is the problem of irradiation-induced electrothermal inhomogeneity. When high-energy particles (such as protons, neutrons, and gamma rays) are incident on parallel-connected chips, the degree of ionization damage and transient carrier effects vary among the chips due to differences in incident angle, minute variations in shielding materials, and microscopic differences within the chips themselves. This difference directly manifests as inconsistent drift in parameters such as threshold voltage and on-resistance, leading to a severe imbalance in static and dynamic current distribution. Chips with higher currents have higher junction temperatures, and these high temperatures further exacerbate parameter drift, creating a positive feedback loop that ultimately results in localized hot spots and device burnout.

[0004] Secondly, there is the issue of gate oscillation under high-frequency switching, a problem that is more sensitive and fatal under irradiation. Parallel chips have parasitic parameters in their power circuits, generating extremely high di / dt and dv / dt during high-speed switching. These variations can intrude into the drive circuits of each chip through common-mode coupling paths (such as source parasitic inductance), interfering with the stability of the gate voltage. In the context of inconsistent chip parameters caused by irradiation, each chip responds differently to interference, easily triggering high-frequency oscillations in the gate voltage between parallel chips. Gate oscillations not only significantly increase switching losses and electromagnetic interference but can also lead to gate oxide breakdown or accidental turn-on / shoot-through, causing catastrophic failure.

[0005] Existing radiation-resistant packaging technologies mostly focus on shielding the chip itself (such as thickening the metal layer) or selecting radiation-resistant chips, lacking a holistic strategy to address the electromagnetic and thermal coupling of the packaging system. For high-current parallel structures, how to systematically suppress the initial non-uniformity introduced by radiation at the packaging level and break the vicious cycle of its coupling with switching electromagnetic interference has become a technical bottleneck restricting the application of high-reliability, high-power SiC devices in extreme environments. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a radiation-resistant high-current SiC device packaging structure to address the shortcomings of the prior art, thereby solving the technical problems of uneven electrothermal distribution and gate oscillation induced by multi-chip parallel applications under irradiation environment from the packaging system level.

[0007] The present invention adopts the following technical solution: A radiation-resistant, high-current SiC device packaging structure includes: At least two sub-unit modules, each of the sub-unit modules including an upper half-bridge arm and a lower half-bridge arm, and each sub-unit module having multiple parallel SiC MOSFET chips; Miniature common-mode inductors are integrated into the drive circuit of each parallel SiC MOSFET chip to enhance the magnetic coupling strength of each part of the drive circuit. Interconnecting copper pillars are used to connect the various sub-unit modules, serving as electrical connectors for strong current paths between sub-unit modules and providing mechanical support for the packaging structure. The annular flow channel heat sink is integrated with the device after being connected by interconnected copper pillars. It has a flow channel inside, which is filled with a thermally conductive medium to dissipate the heat generated by the SiC MOSFET chip during operation. Together with the thermally conductive medium, it forms an irradiated particle shielding layer to absorb and attenuate the energy and flux of irradiated particles.

[0008] Preferably, there are two sub-unit modules, and the two sub-unit modules are connected by interconnecting copper pillars to form a complete bridge arm circuit unit.

[0009] Preferably, each sub-unit module contains 6 SiC MOSFET chips connected in parallel, and the 6 SiC MOSFET chips are evenly distributed.

[0010] Preferably, the sub-unit module adopts a modular integrated design, with the upper half-bridge arm and the lower half-bridge arm being independently formed functional components. The upper half-bridge arm and the lower half-bridge arm are fixedly connected through internal conductive connectors to form a current path.

[0011] Preferably, the overall layout of each sub-unit module is symmetrical to ensure uniform current distribution and consistent heat dissipation.

[0012] Preferably, the connection end face of the interconnecting copper pillar and the sub-unit module is provided with a welding groove, and the connection between the interconnecting copper pillar and the sub-unit module is fixedly connected by brazing process, thereby improving the connection strength and conductivity.

[0013] Preferably, the mutual inductance value of the miniature common-mode inductor is in the microhenry level, and this mutual inductance value is greater than the stray inductance in the nanohenry level inherent in the package structure itself.

[0014] Preferably, the heat-conducting medium is a liquid medium with strong absorption capacity for neutrons and gamma rays, specifically water or ethanol.

[0015] Preferably, the flow channels in the annular flow channel heat sink correspond one-to-one with the distribution areas of the SiC MOSFET chips in the sub-unit module, so that the thermally conductive medium can specifically dissipate heat for each SiC MOSFET chip and shield irradiated particles.

[0016] Preferably, the outer shell of the sub-unit module is made of an insulating and thermally conductive material, which wraps around the upper half-bridge arm, the lower half-bridge arm, and the SiC MOSFET chip to isolate electrical signals and assist in heat dissipation.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: A radiation-resistant high-current SiC device packaging structure synergistically suppresses radiation-induced thermal unevenness and gate oscillation from two aspects: external shielding and internal suppression. On one hand, a heat sink is integrated onto the device, and its internal flow channel distribution is optimized to reuse the heat sink as a radiation particle shielding layer. This directly reduces the dose of radiation particles received by the parallel SiC MOSFET chips within the device, thereby mitigating the adverse effects of radiation particles at their source. On the other hand, a miniature common-mode inductor is integrated into the drive circuit of each parallel SiC MOSFET chip. This strengthens the coupling strength of each part of the drive circuit and suppresses interference from the power circuit to the drive circuit, thus achieving synergistic optimization of thermal unevenness and gate oscillation among the parallel SiC MOSFET chips.

[0018] Furthermore, based on the actual needs of high-current power conversion, the corresponding connection of the two sub-modules can quickly build a complete bridge arm topology without the need for additional complex connection structures, simplifying the overall circuit layout. At the same time, the dual-module structure facilitates power expansion and, compared to single-module packaging, can more flexibly adapt to application scenarios with different power levels. The symmetrical connection ensures that the current is evenly distributed between the two modules, avoiding localized current overload and further mitigating uneven heating and cooling issues. This complements the heat dissipation function of the annular flow channel heatsink, ensuring stable operation of the device under high-current conditions.

[0019] Furthermore, each sub-unit module contains six evenly distributed SiC MOSFET chips. The parallel design of these six chips effectively distributes the high current load, reduces the current stress on individual chips, and avoids overheating damage caused by excessive current carrying capacity in a single chip, making it suitable for high-power applications. The uniform distribution ensures consistent heat dissipation paths between chips, reducing local temperature differences caused by uneven layout and helping to improve uneven electrothermal phenomena. At the same time, the symmetrical and uniform structure facilitates synchronous transmission of drive signals, provides a structural basis for the interference suppression function of the miniature common-mode inductor, ensures the consistency of the operating state of each chip, and improves the overall device's current output stability and failure resistance.

[0020] Furthermore, the sub-unit module adopts a modular integrated design. The upper and lower bridge arms are independent functional components connected by internal conductive connectors. This modular design allows each bridge arm to be individually processed, tested, and replaced, reducing production and maintenance costs. If a single bridge arm fails, there is no need to replace the entire component; only the corresponding component needs to be replaced. The independently molded components allow for precise control of processing accuracy, ensuring consistency in the connections between bridge arms. The internal conductive connectors ensure low-impedance transmission of the current path, reducing energy loss. At the same time, the modular structure facilitates adjustments to the combination of sub-unit modules according to actual needs, adapting to power conversion devices with different topologies and improving the versatility and scalability of the packaging structure.

[0021] Furthermore, the sub-unit modules adopt a symmetrical layout, ensuring consistent current transmission path lengths within the module and preventing uneven current distribution due to path differences, thus structurally mitigating the problem of uneven electrothermal distribution. The symmetrical layout also results in a more uniform heat dissipation environment, with heat dissipated evenly across the module surface by the annular flow channel heatsink, preventing localized hotspot accumulation. In addition, the symmetrical structure reduces the variability of parasitic parameters, minimizing drive signal distortion caused by inconsistencies in parasitic parameters. This provides favorable conditions for suppressing gate oscillations in miniature common-mode inductors, further enhancing the stability and reliability of the device operation.

[0022] Furthermore, the connecting end faces of the interconnecting copper pillars are provided with welding grooves and brazing is employed. These welding grooves precisely position the interconnecting copper pillars and sub-unit modules, preventing assembly misalignment and ensuring coaxiality and consistency of the connection. Brazing offers advantages such as high connection strength and excellent electrical and thermal conductivity. Compared to ordinary welding, it reduces contact resistance and thermal resistance at the connection interface, ensuring high current transmission efficiency and reducing heat loss at the connection points. Simultaneously, the high connection strength enhances the mechanical stability of the packaging structure, resisting the effects of vibration, impact, and other external forces in harsh environments, preventing circuit failures caused by loose connections, and balancing electrical performance with mechanical reliability.

[0023] Furthermore, the miniature common-mode inductor is at the microhenry level, and its mutual inductance is greater than the inherent nanohenry stray inductance of the package. This parameter design makes the magnetic coupling effect of the common-mode inductor significantly stronger than the interference effect of the stray inductor, effectively suppressing the di / dt noise generated by high-speed switching in the power circuit from entering the drive circuit through parasitic parameters. The strong magnetic coupling effect ensures the synchronization of the gate drive signals of each parallel chip, avoiding inconsistent switching actions caused by signal interference, and suppressing gate oscillation and current imbalance from the inside. The microhenry level mutual inductance meets the interference suppression requirements without significantly increasing the impedance of the drive circuit, ensuring the transmission efficiency of the drive signal, and balancing oscillation suppression and drive response speed.

[0024] Furthermore, water or ethanol, which strongly absorbs neutrons and gamma rays, is selected as the thermal conductive medium. Liquid media have excellent fluidity and high thermal conductivity, enabling rapid dissipation of the operating heat from the SiC MOSFET chip and keeping the junction temperature within a safe range. Simultaneously, water and ethanol have strong absorption capabilities for neutrons and gamma rays commonly found in the space environment. Together with the annular flow channel heat sink, they form a highly efficient shielding layer, significantly attenuating the energy and flux of irradiated particles and reducing external radiation damage to the chip. No additional dedicated shielding structure is required, achieving integrated optimization of heat dissipation and radiation resistance functions. This reduces packaging complexity, improves adaptability to harsh environments, and the low cost and easy availability of water and ethanol facilitate large-scale applications.

[0025] Furthermore, the annular flow channels correspond one-to-one with the distribution areas of the SiC MOSFET chips, allowing the thermally conductive medium to precisely cover the heat-generating and radiation-sensitive areas of each chip, achieving point-to-point heat dissipation and shielding. This targeted flow channel distribution avoids heat dissipation blind spots, ensuring that heat from each chip is efficiently dissipated, further improving temperature uniformity between chips. Simultaneously, irradiated particles must penetrate the corresponding thermally conductive medium and heat sink before reaching the chip, making the shielding effect more targeted and preventing excessively high localized radiation doses caused by uneven flow channel distribution. This ensures that heat dissipation and radiation resistance performance are precisely matched to chip requirements, improving the overall packaging structure's performance targeting and optimization efficiency.

[0026] Furthermore, the sub-unit module's outer shell uses insulating and thermally conductive material to encase the core components. This material effectively isolates signals from various electrical components, preventing short circuits or signal crosstalk and ensuring circuit safety. Simultaneously, the material's thermal conductivity helps dissipate heat from the core components, forming a synergistic heat dissipation system with the annular flow channel heat sink, further reducing device temperature. The encapsulated design protects internal components from dust, humidity, and other external environmental factors, enhancing structural sealing and mechanical protection. Without compromising electrical performance or heat dissipation, this design improves the safety and environmental adaptability of the packaging structure, extending device lifespan.

[0027] In summary, this invention effectively suppresses the problems of uneven electrothermal distribution and gate oscillation in high-current SiC devices under irradiation conditions, and significantly improves the reliability of the devices in harsh environments.

[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the following description of the relative embodiments will be briefly introduced. Obviously, the 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.

[0030] Figure 1 This is a schematic diagram of the packaging structure of the radiation-resistant high-current SiC device of the present invention. Detailed Implementation

[0031] 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, not all, of the embodiments of the present invention. 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.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0034] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0036] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0037] This invention provides a radiation-resistant, high-current SiC device packaging structure. Through the synergistic effect of external shielding and internal suppression, it effectively solves the problems of uneven electrothermal distribution and gate oscillation in high-current SiC devices under irradiation environments. By reusing the annular flow channel heat sink as an irradiation particle shielding layer, the radiation dose received by the SiC MOSFET chip is significantly reduced, while efficiently dissipating operating heat. The miniature common-mode inductor integrated into the drive circuit enhances magnetic coupling, suppresses common-mode interference, and ensures the consistency of the gate drive signal. The modular sub-unit and interconnect copper pillar design balances high-current transmission and structural stability. The overall packaging structure achieves synergistic optimization of radiation resistance, heat dissipation, and oscillation suppression, significantly improving the reliability and lifespan of the device in harsh environments such as aerospace and high-altitude power transmission.

[0038] Example 1 Please see Figure 1This invention discloses a radiation-resistant high-current SiC device packaging structure, comprising: a sub-unit module consisting of upper and lower half-bridge arms, interconnecting copper pillars, and an annular heat sink; the two sub-unit modules are connected by welding through the interconnecting copper pillars; in each sub-unit module, a miniature common-mode inductor is integrated in the drive circuit of each parallel SiC MOSFET chip; the annular heat sink is integrally integrated with the welded device, and has annularly distributed flow channels inside, which are filled with a thermally conductive medium that has the ability to absorb irradiated particles.

[0039] The sub-units employ a modular design and integration, constructing the upper and lower half-bridge arms as two independent sub-unit modules. Each sub-unit module contains six parallel SiC MOSFET chips, and the entire module layout is symmetrical. The two sub-unit modules are soldered together via interconnecting copper pillars. These interconnecting copper pillars not only serve as electrical connections for strong current paths between the sub-units but also provide crucial mechanical support for the entire package structure.

[0040] Optionally, two sub-unit modules are used, each consisting of an upper half-bridge arm and a lower half-bridge arm. The upper and lower half-bridge arms are independently molded ceramic-based copper-clad laminate assemblies, which are fixedly connected by bolts through copper busbars (internal conductive connectors) to form a low-impedance current path. Each sub-unit module contains six evenly distributed SiC MOSFET chips (model C2M0080120D). The chips are fixed to the ceramic-based copper-clad laminate by silver paste sintering, with a chip spacing of 5mm. The overall module dimensions are 80mm × 60mm × 10mm, and the layout is symmetrical to ensure consistent current transmission path length.

[0041] The interconnecting copper pillars are made of high-conductivity oxygen-free copper, with a diameter of 8mm and a length of 15mm. The connecting end faces have welding grooves with a depth of 2mm and a diameter of 10mm. Two sub-unit modules are connected correspondingly via four interconnecting copper pillars. One end of each interconnecting copper pillar is embedded into the welding point of the sub-unit module, and the modules are fixed using silver-based brazing at 850℃. The contact resistance at the welding interface is less than 5mΩ, ensuring high current transmission efficiency and providing stable mechanical support for the packaging structure.

[0042] Integrated miniature common-mode inductor to suppress internal interference and oscillation. A miniature common-mode inductor is directly integrated into the drive circuit (gate circuit) of each parallel SiC MOSFET chip. The mutual inductance of this miniature common-mode inductor is designed to be in the microhenry (μH) range, significantly larger than the inherent stray inductance of the package itself (typically in the nanohenry range). By significantly enhancing the magnetic coupling strength of each part of the drive circuit, common-mode interference caused by di / dt noise generated by high-speed switching in the power circuit through parasitic parameters is effectively suppressed. This ensures the consistency of the gate drive signals of each parallel chip, thereby internally and collaboratively suppressing current imbalance (thermal imbalance) and gate oscillation caused by irradiation or uneven switching.

[0043] The miniature common-mode inductor selected is the ACM7060-101M, with a mutual inductance of 10μH and a rated current of 5A. It is integrated into the gate drive circuit of each SiC MOSFET chip. The inductor's input terminal is connected to the output terminal of the drive chip, and the output terminal is connected to the gate of the SiC MOSFET chip. This inductor's mutual inductance is much greater than the inherent stray inductance of the package (approximately 2nH), which can significantly enhance the magnetic coupling strength of the drive circuit.

[0044] Reusing the heat sink as an irradiation shielding layer This invention integrates a customized annular flow channel heat sink with a pre-welded device. The heat sink has annularly distributed cooling channels inside. These channels are filled with a liquid heat-conducting medium, such as water or ethanol, that has a strong absorption capacity for irradiated particles (e.g., neutrons, gamma rays). This achieves the following functions: Firstly, it has a heat dissipation function: the flow of the thermally conductive medium can efficiently dissipate the heat generated by the SiC chip during operation, ensuring that the junction temperature is always within a safe range.

[0045] Secondly, it provides a shielding function: the heat sink and the thermally conductive medium within it together form an adjustable radiation particle shielding layer. Before high-energy particles reach the sensitive SiC chip, they must first penetrate this shielding layer. Their energy and flux are absorbed and attenuated by the medium, thereby directly reducing the actual radiation dose received by each chip.

[0046] The internal flow channel geometry parameters and distribution location, as well as the flow velocity of the heat transfer medium, are comprehensively designed. By comprehensively designing and optimizing the geometric parameters (such as channel cross-sectional shape, width, and depth), spatial distribution (relative to chip layout), and flow rate of the thermally conductive medium of the annular flow channel, this integrated design allows for active control of the spatial concentration and energy spectrum distribution of irradiated particles as they enter the device, maximizing the shielding effect. Simultaneously, the optimized flow channel design also ensures heat dissipation efficiency, achieving synergistic optimization of thermal management and radiation resistance performance.

[0047] Optionally, the annular flow channel heatsink is made of 6061 aluminum alloy, with overall dimensions of 120mm × 100mm × 20mm. It features an internal annular flow channel with a rectangular cross-section, 8mm wide and 6mm deep. The center of the flow channel is 5mm from the surface of the sub-unit module, and the channel distribution corresponds one-to-one with the positions of the six SiC MOSFET chips. The flow channel is filled with deionized water (thermal conductive medium), and the flow rate is controlled at 0.8m / s by a micro-circulation pump. The heatsink is fixed to the soldered components with bolts, and thermal grease is applied to the contact surfaces, resulting in a thermal resistance of less than 0.1℃ / W.

[0048] The assembly process is as follows: First, SiC MOSFET chips are sintered onto the ceramic-based copper-clad laminate of the sub-unit module, and internal conductive connectors are soldered to form upper and lower half-bridge arm paths. Then, miniature common-mode inductors are soldered to the gate circuit of each chip. Subsequently, the two sub-unit modules are connected by interconnecting copper pillars. Finally, an annular flow channel heat sink is assembled, thermally conductive medium is injected, and the package is sealed to complete the overall encapsulation.

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0050] Example 2 The difference between this embodiment and the main embodiment is that: there are 3 sub-unit modules, and each module contains 8 SiCMOSFET chips connected in parallel, with the chip model being AON6998 and a spacing of 4mm; the heat-conducting medium is a 50% volume fraction ethanol-water solution, and the flow rate is adjusted to 1.0m / s; the interconnecting copper pillars are connected using ultrasonic welding at a welding temperature of 200℃, with a contact resistance of less than 8mΩ. The remaining structure is consistent with the main embodiment. This solution is suitable for high-altitude flexible DC transmission converter valves with higher power ratings.

[0051] Example 3 The difference between this embodiment and the main embodiment is as follows: the miniature common-mode inductor used is product B82790-A5101-K, with a mutual inductance of 5μH; the flow channel cross-section of the annular flow channel heat sink is circular with a diameter of 8mm, and the flow channels are distributed in a double-ring pattern; the sub-unit module shell is made of aluminum nitride ceramic (insulating and thermally conductive material) with a thickness of 2mm. The rest of the structure is the same as the main embodiment. This solution is suitable for multi-electric aircraft electric drive devices with higher requirements for structural compactness.

[0052] III. Simulation Data Verification To verify the technical effects of this invention, a simulation model was built using simulation software. The existing conventional packaging structure (without common-mode inductor, and separation of heat sink and shielding layer) served as the control group, while the main embodiment of this invention served as the experimental group. The simulation conditions were: an irradiation environment containing 1 MeV neutrons and a flux of 1 × 10⁻⁶. 12 n / cm 2 The device operates at a current of 800A for 2 hours. The simulation results are as follows:

[0053] Simulation results show that, through the synergistic effect of its core technical features, this invention significantly reduces radiation dose, suppresses grid oscillation and electrothermal unevenness, while improving heat dissipation efficiency and operational reliability, fully meeting the application requirements in harsh environments.

[0054] In summary, this invention provides a radiation-resistant high-current SiC device packaging structure that effectively addresses the core challenges of parallel applications of high-current SiC MOSFETs under irradiation through a systematic approach combining external shielding and internal suppression. Externally, it innovatively reuses a ring-shaped heatsink as a controllable irradiation particle shielding layer. A special thermally conductive medium filled within the heatsink directly absorbs and attenuates high-energy particles, fundamentally reducing the difference in irradiation dose received by each parallel chip and mitigating the initial current imbalance caused by uneven irradiation. Internally, a miniature common-mode inductor is integrated into the drive circuit of each chip, significantly enhancing the intrinsic magnetic coupling strength of the drive circuit. This strongly suppresses common-mode interference of power circuit switching noise on the drive signal, ensuring the synchronization and stability of the gate drive signals of each parallel chip, and fundamentally curbing the vicious cycle of uneven electrothermal distribution and gate oscillation. The synergistic effect of the two significantly improves the electrothermal uniformity, switching reliability, and long-term operational stability of the device under strong radiation and high current conditions, providing key hardware support for power electronic systems in extreme environments such as aerospace and high-energy physics.

[0055] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A radiation-resistant, high-current SiC device packaging structure, characterized in that, include: At least two sub-unit modules, each of the sub-unit modules including an upper half-bridge arm and a lower half-bridge arm, and each sub-unit module having multiple parallel SiC MOSFET chips; Miniature common-mode inductors are integrated into the drive circuit of each parallel SiC MOSFET chip to enhance the magnetic coupling strength of each part of the drive circuit. Interconnecting copper pillars are used to connect the various sub-unit modules, serving as electrical connectors for strong current paths between sub-unit modules and providing mechanical support for the packaging structure. The annular flow channel heat sink is integrated with the device after being connected by interconnected copper pillars. It has a flow channel inside, which is filled with a thermally conductive medium to dissipate the heat generated by the SiC MOSFET chip during operation. Together with the thermally conductive medium, it forms an irradiated particle shielding layer to absorb and attenuate the energy and flux of irradiated particles.

2. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The number of sub-unit modules is two, and the two sub-unit modules are connected by interconnecting copper pillars to form a complete bridge arm circuit unit.

3. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The number of SiC MOSFET chips connected in parallel within each sub-unit module is 6, and the 6 SiC MOSFET chips are evenly distributed.

4. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The sub-unit module adopts a modular integrated design. The upper half-bridge arm and the lower half-bridge arm are independently formed functional components. The upper half-bridge arm and the lower half-bridge arm are fixedly connected through internal conductive connectors to form a current path.

5. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The overall layout of each sub-unit module is symmetrical, ensuring uniform current distribution and consistent heat dissipation.

6. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The connection end face of the interconnecting copper pillar and the sub-unit module is provided with a welding groove. The connection between the interconnecting copper pillar and the sub-unit module is fixedly connected by brazing process, which improves the connection strength and conductivity.

7. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The mutual inductance of the miniature common-mode inductor is in the microhenry level, and this mutual inductance is greater than the stray inductance in the nanohenry level inherent in the package structure itself.

8. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The heat-conducting medium is a liquid medium with strong absorption capacity for neutrons and gamma rays, specifically water or ethanol.

9. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The flow channels within the annular flow channel heat sink correspond one-to-one with the distribution areas of the SiC MOSFET chips in the sub-unit module, enabling the thermally conductive medium to specifically dissipate heat for each SiC MOSFET chip and shield against irradiated particles.

10. The radiation-resistant high-current SiC device packaging structure according to claim 1, characterized in that, The outer shell of the sub-unit module is made of insulating and thermally conductive material. The insulating and thermally conductive material is wrapped around the upper half-bridge arm, the lower half-bridge arm, and the SiCMOSFET chip to isolate electrical signals and assist in heat dissipation.

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