Hybrid topology power module

Abstract

The invention relates to the technical field of power semiconductor packaging and power electronic conversion, in particular to a hybrid topology power module which comprises a heat dissipation substrate, a shell, an insulating substrate, a power terminal, a silicon carbide chip and a silicon-based power chip set. The silicon carbide chip is located at the outer tube position of the bridge topology, and the high-frequency and low-loss advantages of the silicon carbide chip are exerted to improve the efficiency and the power density. The silicon-based power chip set is located at the position of the inner tube, and the advantages of large current, low conduction voltage drop and cost are utilized. The advantages of silicon carbide and silicon-based technologies are fused, the switching frequency, efficiency and power density are remarkably improved, meanwhile, the cost is effectively controlled, the contradiction that the cost of a full-silicon-carbide module is too high and the performance of an IGBT module is insufficient is solved, and comprehensive optimization of efficiency, reliability, power density and cost requirements of an energy storage system is achieved.

Description

Technical Field

[0001] This invention relates to the fields of power semiconductor packaging and power electronic conversion technology, and specifically to a hybrid topology power module. Background Technology

[0002] In the field of power electronics and energy storage, power semiconductor modules, as core components for energy conversion, have evolved technologically primarily along two directions. On one hand, all-silicon carbide (SiC) power modules, represented by silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (FETs), have brought unprecedented efficiency improvements and power density breakthroughs to systems due to their superior high-frequency switching characteristics, extremely low switching losses, and excellent thermal conductivity, making them an ideal choice for high-end applications. On the other hand, insulated-gate bipolar transistor (IGBT) power modules, based on mature silicon-based technology, have long held a dominant position in medium-to-high power applications such as industrial drives, new energy power generation, and energy storage converters due to their low on-state voltage drop under high current, excellent short-circuit withstand capability, and highly competitive cost control. These two technological approaches have each formed complete product ecosystems and broad application markets.

[0003] However, both of the aforementioned mainstream technologies exhibit their limitations when addressing the stringent requirements of energy storage systems for comprehensive indicators such as efficiency, reliability, power density, and cost. Specifically, while all-silicon carbide modules boast superior performance, their expensive semiconductor materials and complex drive and protection requirements result in a high overall module price, severely hindering their widespread application in cost-sensitive large-scale energy storage projects. Conversely, while traditional IGBT modules offer controllable costs, their relatively low switching frequency, significant switching losses, and inherent reverse recovery issues of silicon-based diodes limit further improvements in overall system efficiency and reductions in device size, making it difficult to fully meet the demands of next-generation energy storage systems for high efficiency and high power density.

[0004] The above reasons prevent existing technologies from fully balancing performance and cost in the same product. Summary of the Invention

[0005] To address the above technical problems, this invention provides a technical solution for a hybrid topology power module.

[0006] The technical problem solved by this invention can be achieved by the following technical solutions:

[0007] A hybrid topology power module, comprising:

[0008] Heat dissipation substrate;

[0009] The outer casing is fixed to the heat dissipation substrate and forms a receiving cavity with the heat dissipation substrate;

[0010] An insulating substrate is fixed to the heat dissipation substrate and located within the receiving cavity;

[0011] A power terminal having a connection portion embedded in the housing and a wiring portion exposed outside the housing, the connection portion being fixed to the conductive layer of the insulating substrate;

[0012] The silicon carbide chip is fixed on the conductive layer of the insulating substrate and is located at the outer tube position in the bridge circuit topology of the hybrid topology power module.

[0013] The silicon-based power chip assembly is fixed on the conductive layer of the insulating substrate and located in the inner tube position of the bridge circuit topology.

[0014] Preferably, the silicon-based power chipset includes an insulated gate bipolar transistor (IGBT) chip and a diode chip connected in parallel with the IGBT chip.

[0015] Preferably, the connection portion of the power terminal is fixed to the first conductive layer of the insulating substrate by ultrasonic welding.

[0016] The silicon carbide chip is fixed to the second conductive layer of the insulating substrate by a silver sintering process.

[0017] The silicon-based power chip assembly is fixed to the third conductive layer of the insulating substrate by a soldering process.

[0018] The first conductive layer, the second conductive layer, and the third conductive layer are electrically connected by a copper bridge.

[0019] Preferably, the silicon carbide chip and the silicon-based power chip assembly are electrically connected via aluminum wires.

[0020] Preferably, the outer casing is made of plastic and is fixed to the heat dissipation substrate by sealant and fasteners;

[0021] The heat dissipation substrate is a copper substrate, and the heat dissipation substrate has heat dissipation pins or heat dissipation fins.

[0022] Preferably, it further includes:

[0023] The signal needle includes a needle body and a base. The needle body is connected to the base by a plugging or forging process and extends vertically upward from the outer shell. The base is fixed to the conductive layer of the insulating substrate by a soldering process.

[0024] The thermistor is fixed to the conductive layer of the insulating substrate by soldering.

[0025] The current sensor is fixed to the housing by a mechanical connection process and is located on one side of the power terminal;

[0026] A threaded post is embedded in the first side of the housing and connected to the power terminal;

[0027] The signal terminal is embedded on the second side opposite to the first side of the housing and is fixed to the conductive layer of the insulating substrate by ultrasonic welding.

[0028] Preferably, it further includes a shielding cover, which is embedded in the housing and extends vertically outward to surround both sides of the current sensor.

[0029] Preferably, the soldering process uses one of tin-lead solder, tin-silver solder, tin-silver-copper solder, and lead-tin-silver solder, and the soldering temperature is 100° to 400°.

[0030] Preferably, both the power terminal and the signal pin are made of pure copper or copper alloy.

[0031] Preferably, it further includes a silicone gel, which fills the receiving cavity and covers the insulating substrate, the silicon carbide chip, the silicon-based power chip assembly, the connection portion of the power terminal, the signal pin, and the thermistor.

[0032] Beneficial effects: By using silicon carbide chips in the outer tube position and silicon-based power chipsets in the inner tube position in the bridge circuit topology, this invention effectively integrates the advantages of silicon carbide and silicon-based technologies. While significantly improving the overall switching frequency and efficiency of the system and reducing the size, it also greatly controls the module manufacturing cost. This successfully solves the contradiction between the high cost of traditional all-silicon carbide modules and the limited performance of traditional IGBT modules, and achieves an optimized balance of the comprehensive requirements of energy storage systems for efficiency, reliability, power density and cost. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the hybrid topology power module circuit structure of the present invention;

[0034] Figure 2 This is a schematic diagram of the overall structure of the hybrid topology power module of the present invention;

[0035] Figure 3 This is a top view schematic diagram of the hybrid topology power module of the present invention;

[0036] Figure 4 This is a bottom view schematic diagram of the hybrid topology power module of the present invention;

[0037] Figure 5 This is a cross-sectional view of the hybrid topology power module of the present invention;

[0038] Figure 6 This is a partially enlarged view of structure A in the hybrid topology power module of the present invention;

[0039] Figure 7 This is a partially enlarged view of structure B in the hybrid topology power module of the present invention;

[0040] Figure 8 This is a right-side view of the hybrid topology power module of the present invention;

[0041] Figure 9 This is a left-side view of the hybrid topology power module of the present invention.

[0042] Explanation of reference numerals in the attached drawings: 1. Heat dissipation substrate; 2. Housing; 3. Power terminal; 31. Connecting part; 32. Wiring part; 4. Insulating substrate; 5. Signal pin; 51. Pin body; 52. Base; 6. Silicon carbide chip; 7. Silicon-based power chipset; 8. Thermistor; 9. Copper bridge; 10. Shielding cover; 11. Current sensor; 12. Silicon gel; 13. Threaded post; 14. Signal terminal; 15. Screw. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0046] Reference Figure 2 The present invention provides a hybrid topology power module, comprising:

[0047] Heat dissipation substrate 1;

[0048] The outer shell 2 is fixed to the heat dissipation substrate 1 and forms a receiving cavity with the heat dissipation substrate 1;

[0049] An insulating substrate 4 (DBC, direct copper-clad ceramic substrate) is fixed to the heat dissipation substrate 1 and located within the receiving cavity;

[0050] The power terminal 3 has a connection portion 31 embedded in the housing 2 and a wiring portion 32 exposed outside the housing 2. The connection portion 31 is fixed to the conductive layer of the insulating substrate 4.

[0051] The silicon carbide chip 6 is fixed on the conductive layer of the insulating substrate 4 and is located at the outer tube position in the bridge circuit topology of the hybrid topology power module.

[0052] The silicon-based power chip assembly 7 is fixed on the conductive layer of the insulating substrate 4 and is located in the inner tube position in the bridge circuit topology.

[0053] Specifically, in this embodiment of the invention, to address the technical contradiction between the high cost of all-silicon carbide modules and the limited performance of traditional IGBT modules, silicon carbide chips 6 are used in the key high-frequency switching path (outer tube) of the bridge topology to improve efficiency and frequency. At the same time, mature and low-cost silicon-based power chipsets 7 are used in the inner tube position that bears the main conduction current. This achieves the advantage of hybrid technology with optimal cost architecture, avoiding the shortcomings of single technology routes in terms of cost or performance, and achieving a comprehensive performance breakthrough in efficiency, power density, reliability and cost. This provides a more competitive power semiconductor solution for energy storage systems.

[0054] Specifically, refer to Figure 1 In the actual bridge circuit topology, the outer transistors T1, T4, T5, and T6 are directly connected to the output AC terminal and bear the entire output voltage. Their switching action is accompanied by a high voltage change rate, and switching losses are dominant. Therefore, using the high-frequency, low-switching-loss silicon carbide chip 6 can significantly reduce the losses here and increase the system switching frequency. On the other hand, the inner transistors T2 and T3 are connected to the DC bus. Their switching action has relatively low voltage stress, but they are in a continuous conducting state for a long time in each switching cycle, and conduction losses are dominant. Therefore, using the silicon-based power chip group 7 with low on-state voltage drop and obvious cost advantages can optimize the overall conduction performance and economy.

[0055] In a preferred embodiment of the present invention, the silicon-based power chipset 7 includes an insulated gate bipolar transistor (IGBT) chip and a diode chip connected in parallel with the IGBT chip.

[0056] Specifically, in a bridge circuit, the inner diode directly bears the freewheeling and conduction currents. Especially under inductive loads, the reverse recovery characteristics and on-state voltage drop in the freewheeling circuit are crucial. If an IGBT chip is used alone, its body diode has poor reverse recovery characteristics, easily generating large reverse recovery losses and voltage spikes, affecting efficiency and reliability. Based on this, in this embodiment of the invention, referring to… Figure 1The silicon-based power chip group 7 is constructed by connecting independent fast recovery or Schottky diode chips in parallel on a silicon-based insulated gate bipolar transistor chip to form a silicon-based power chip group with low on-state voltage drop and low reverse recovery loss.

[0057] Specifically, in such Figure 1 In the three-phase bridge topology shown, the outer transistors T1, T4, T5, and T6 all use silicon carbide chips 6. Utilizing their high-speed switching and zero reverse recovery charge characteristics, the switching losses and electromagnetic interference of the bridge arms during high-frequency switching are significantly reduced, allowing the system to operate at higher switching frequencies and thus increasing power density. Meanwhile, the inner transistors T2 and T3 use the aforementioned silicon-based power chipset 7. The IGBT chip undertakes the main conduction current, leveraging its advantage of low on-state voltage under high current. The parallel diode chips are dedicated to providing efficient and fast reverse conduction and freewheeling paths, avoiding the problems of slow recovery and high losses of the IGBT body diode itself. This further reduces the overall conduction loss and temperature rise during the inner transistor conduction and freewheeling stages.

[0058] This combination optimizes both the high-frequency switching losses of the outer tube and the conduction and freewheeling losses of the inner tube. While significantly improving system efficiency and operating frequency, the overall cost of the module is effectively controlled by using expensive silicon carbide chips only for the outer tube, while the inner tube uses a mature and low-cost silicon-based IGBT and diode combination, achieving an ideal balance between performance and cost.

[0059] In a preferred embodiment of the present invention, the connection portion 31 of the power terminal 3 is fixed to the first conductive layer of the insulating substrate 4 by ultrasonic welding process.

[0060] The silicon carbide chip 6 is fixed to the second conductive layer of the insulating substrate 4 by a silver sintering process.

[0061] The silicon-based power chip 7 is fixed to the third conductive layer of the insulating substrate 4 by a soldering process.

[0062] The first conductive layer, the second conductive layer, and the third conductive layer are electrically connected by a copper bridge 9.

[0063] Specifically, in order to achieve highly reliable, low-stress electrical interconnection of hybrid chips on insulating substrate 4, and to adapt to the material properties and process requirements of different chips, in this embodiment of the invention, reference is made to... Figure 2 and Figure 3 Different connection processes are adopted for different components. Specifically, the power terminal 3, as the channel for carrying large current, has its connection part 31 firmly connected to the first conductive layer of the insulating substrate 4 through ultrasonic welding. This process can achieve a high-strength metallurgical bond between metals at low temperature, avoid thermal damage to the insulating substrate, and ensure low resistance and high reliability of electrical contact.

[0064] For the critical high-performance silicon carbide chip 6, a silver sintering process is used to fix it onto the second conductive layer. This process uses micron or nano-sized silver powder particles to form a dense, high-melting-point, and thermally conductive bonding layer under pressure and heat. This layer can not only withstand the high heat flux density and thermal stress caused by the high-frequency switching of the silicon carbide chip, but also significantly reduce thermal resistance and improve heat dissipation and long-term reliability. The silicon-based power chip group 7 (including IGBT chips and parallel diode chips) is fixed onto the third conductive layer using a mature soldering (reflow soldering) process. This process is low-cost and has a wide process window, making it very suitable for the mass production needs of silicon-based chips.

[0065] More specifically, considering that the different conductive layers inside the module need to carry a large operating current while having low connection resistance and excellent thermomechanical reliability, copper bridge 9 is used as a key component for interlayer interconnection. It is made of thick copper material and is firmly connected between each conductive layer by welding. It not only provides a current path with low impedance and high current carrying capacity, but its solid structure also helps to alleviate the thermal stress caused by the difference in thermal expansion coefficients between the chip and the substrate materials, thereby improving the long-term reliability of the module under temperature cycling conditions.

[0066] In particular, in terms of layout, refer to Figure 2 and Figure 3 Multiple independent conductive regions are divided on the insulating substrate 4 to form different conductive layers. The silicon carbide chip 6 and the silicon-based power chip group 7 are distributed on the corresponding conductive layers. The connection part 31 of the power terminal 3 is located on the outer region of the corresponding conductive layer. The number matches the bridge arm topology. Multiple copper bridges 9 are connected between different conductive layers to form the required circuit topology, thereby realizing the electrical integration of the hybrid topology power module in a compact space.

[0067] In a preferred embodiment of the present invention, the silicon carbide chip 6 and the silicon-based power chip group 7 are electrically connected by aluminum wire.

[0068] Specifically, aluminum wire bonding technology is mature and cost-controllable. Aluminum material has good conductivity and anti-electromigration ability, which can meet the high current interconnection requirements between chips inside the module and between chips and the substrate. At the same time, its bonding process is highly flexible and can adapt to the differences in surface materials and layouts of different chips. Based on this, in this embodiment of the invention, aluminum wire made of pure aluminum or aluminum alloy is selected and reliably bonded to the insulated gate bipolar transistor chip and diode chip in the silicon carbide chip 6, the silicon-based power chip group 7, and the corresponding conductive layer of the insulating substrate 4 through ultrasonic bonding process, thereby constructing an internal interconnection network that meets the circuit topology requirements and has excellent electrical performance and process economy.

[0069] In a preferred embodiment of the present invention, the outer shell 2 is made of plastic and is fixed to the heat dissipation substrate 1 by sealant and fasteners.

[0070] Specifically, in this embodiment of the invention, since the power module generates a large amount of heat and may face a complex environment during operation, the outer shell is required to have excellent electrical insulation, high temperature resistance and reliable sealing protection. In this embodiment of the invention, PBT, PPS or nylon and other engineering plastics with good high temperature resistance and insulation properties are selected as the material of the outer shell 2, and it is firmly and sealed to the heat dissipation substrate 1 by means of sealant bonding, thereby ensuring that the internal chips and interconnection structure of the module are effectively protected during long-term operation and preventing the intrusion of contaminants such as moisture and dust.

[0071] More specifically, considering that relying solely on sealant bonding may lead to stress relaxation under extreme temperature cycles or mechanical vibrations, affecting the long-term reliability of the seal, in this embodiment of the invention, referring to... Figure 4 Screws 15 are preferably used as auxiliary mechanical fasteners to secure the outer shell 2 to the heat dissipation substrate 1 at multiple points. The continuous and stable mechanical pressing provided by the screws 15 not only strengthens the bond between the outer shell and the substrate and distributes the stress borne by the sealant, but also ensures that the joint surfaces remain tightly fitted under harsh working conditions. This significantly improves the overall structural rigidity, vibration resistance, and long-term sealing reliability of the module, providing a solid mechanical guarantee for the stable operation of the power module in industrial environments such as energy storage systems.

[0072] In a preferred embodiment of the present invention, the heat dissipation substrate 1 is a copper substrate, and the heat dissipation substrate 1 has heat dissipation pins or heat dissipation fins.

[0073] Specifically, since the hybrid topology power module integrates both a high-frequency switching silicon carbide chip 6 and a continuously conducting silicon-based power chip group 7, its overall heat dissipation density is high and unevenly distributed, which places stringent requirements on the thermal conductivity and thermal uniformity of the heat dissipation substrate 1. Based on this, in this embodiment of the invention, the heat dissipation substrate 1 is preferably made of copper substrate. Copper material has an extremely high thermal conductivity, which can quickly and uniformly diffuse the heat generated by the chip laterally to the entire substrate surface, effectively avoiding the formation of local hot spots, and providing a stable low-temperature working environment for each chip inside the module, thereby ensuring its full performance and long-term reliability.

[0074] More specifically, considering that the heat dissipation substrate 1 must not only possess excellent lateral thermal conductivity but also an efficient external heat dissipation interface to ultimately transfer heat to the external cooling medium, in this embodiment of the invention, heat dissipation pins or fins are provided on the heat dissipation substrate 1, and an extended heat dissipation surface with a significantly increased surface area is constructed through welding or integral molding processes. When air cooling is used, the heat dissipation fins or pin structures can effectively disturb the air and enhance convective heat transfer; when water cooling is used, these structures can be embedded in the cold plate channels, greatly improving the heat exchange efficiency with the coolant. This design allows the heat dissipation substrate 1 to flexibly adapt to different cooling schemes, achieving reliable dissipation of high heat flux density within a compact space, thereby supporting the continuous and stable operation of hybrid topology power modules at high power and high frequency.

[0075] As a preferred embodiment of the present invention, it further includes:

[0076] The signal needle 5 includes a needle body 51 and a base 52. The needle body 51 is connected to the base 52 by a plug-in or forging process and extends vertically upward from the outer shell 2. The base 52 is fixed to the conductive layer of the insulating substrate 4 by a soldering process.

[0077] The thermistor 8 is fixed to the conductive layer of the insulating substrate 4 by soldering.

[0078] The current sensor 11 is fixed to the housing 2 by a mechanical connection process and is located on one side of the power terminal 3;

[0079] A threaded post 13 is embedded in the first side of the housing 2 and connected to the power terminal 3;

[0080] Signal terminal 14 is embedded on the second side opposite to the first side of the housing 2 and is fixed to the conductive layer of the insulating substrate 4 by ultrasonic welding process.

[0081] Specifically, considering that the hybrid topology power module needs to integrate multiple auxiliary functions such as drive signal acquisition, temperature monitoring, current detection and external electrical connection to achieve intelligent and reliable system control, in this embodiment of the invention, a fully functional and compact modular unit is constructed through the coordinated layout and integration of various components.

[0082] Specifically, firstly, considering that the drive signal needs to be transmitted to the chip gate with low inductance and reliability, while also facilitating external connection, based on this, referring to Figure 5 and Figure 7The signal pin 5 is preferably used as the vertical interconnect interface. Its pin body 51 is integrated with the base 52 by plugging or forging, and extends vertically upward from the outer shell 2 to facilitate plugging and connecting with the external printed circuit board (PCB). The base 52 is soldered to the conductive layer of the insulating substrate 4 to realize a low impedance and high reliability transmission path for the drive signal from the internal circuit of the substrate to the external controller.

[0083] Secondly, since accurate monitoring of the junction temperature of the chips inside the module is crucial for over-temperature protection and lifespan prediction, based on this, referring to Figure 2 and Figure 3 Preferably, a thermistor 8 is placed directly near the center of the power chip area. The thermistor 8 is directly fixed to the conductive layer of the critical temperature rise area (such as the middle position of the silicon-based power chip group 7 or silicon carbide chip 6) of the insulating substrate 4 by soldering, so that it can quickly and accurately sense the local temperature changes of the substrate, thereby providing real-time feedback for thermal management.

[0084] Next, in order to achieve accurate sampling of the output current and reduce the interference of strong power magnetic fields, refer to Figure 2 and Figure 3 Preferably, a current sensor 11 is arranged above the outlet side of the power terminal 3. The current sensor 11 is fixedly installed on the side of the power terminal 3 on the housing 2 by means of mechanical connection such as clips or screws, so that its sensing surface is directly aligned with the current path of the power busbar. At the same time, this position is usually within the coverage of the electromagnetic shielding structure inside the module, which effectively suppresses the impact of switching noise on sampling accuracy.

[0085] Furthermore, to facilitate low-inductance and stable connection of high-current devices such as external DC support capacitors, refer to Figure 2 and Figure 8 Preferably, threaded post 13 is used as a high current connection terminal. The threaded post 13 is embedded in the first side of the housing 2 (usually the output side) through injection molding and is electrically and mechanically integrated with the internal power terminal 3 by welding or integral casting, thereby providing a standardized bolt interface with high current carrying capacity and high mechanical strength for external copper busbar or capacitor connection.

[0086] Then, in order to meet the connection requirements of multiple low-voltage signals (such as fault feedback, enable signals, etc.) between the module and the external controller, refer to Figure 9Signal terminal 14 is preferably used as the control signal interface. Signal terminal 14 is embedded in the second side (usually the control side) opposite to the threaded post 13 of the housing 2 through injection molding insert process, and is fixed to the corresponding conductive layer of the insulating substrate 4 through ultrasonic welding process, forming a set of robust and reliable weak current signal interfaces. This realizes the physical separation of strong and weak current interfaces on both sides of the module, which is beneficial to system wiring and electromagnetic compatibility design.

[0087] As a preferred embodiment of the present invention, it further includes a shielding cover 10, which is embedded in the outer shell 2 and extends vertically outward to surround both sides of the current sensor 11.

[0088] Specifically, considering that the power terminal area where the current sensor 11 is located has a high-intensity, high-frequency switching electromagnetic field, which can easily interfere with sensitive elements such as Hall sensors and affect the current sampling accuracy, based on this, in this embodiment of the invention, referring to... Figure 2 , Figure 3 , Figure 5 as well as Figure 6 A shielding cover 10, made of silicon steel or other high-permeability metal material, is integrally molded and fitted into the housing 2 using an injection molding process. The shielding cover 10 has a U-shaped or door-frame structure, is embedded in a specific position inside the housing 2, and extends vertically upwards to surround both sides of the power terminal 3 outlet area, thereby shielding the current sensor 11 (such as...) Figure 2 , Figure 3 (As shown) is placed within the semi-enclosed shielding space it forms.

[0089] This design utilizes the absorption and guidance of the alternating magnetic field by the shielding cover to effectively attenuate the electromagnetic noise radiated by the external power circuit, providing a clean electromagnetic environment for the current sensor and significantly improving the accuracy and anti-interference capability of the current detection signal.

[0090] In particular, the shape, size and relative position of the shielding cover 10 to the power terminal 3 can be adapted to the specific model and installation position of the current sensor 11 to achieve the optimal local shielding effect.

[0091] For some applications with relatively low requirements for electromagnetic compatibility performance or for cost considerations, this shield 10 can be omitted to simplify the structure and reduce the overall cost of the module.

[0092] This modular, optional shielding design allows this hybrid topology power module to flexibly adapt to the diverse needs of different customers and applications, achieving the best balance between performance and cost while ensuring core functionality.

[0093] In a preferred embodiment of the present invention, the soldering process employs one of tin-lead (SnPb) solder, tin-silver (SnAg) solder, tin-silver-copper (SnAgCu) solder, and lead-tin-silver (PbSnAg) solder, and the soldering temperature is 100° to 400°.

[0094] Specifically, since different solder alloys differ in melting point, mechanical strength, electrical and thermal conductivity, and long-term reliability (such as resistance to thermal fatigue and creep), targeted selection is required based on chip type, interconnection location, and reliability requirements. In this embodiment of the invention, the aforementioned mature and proven tin-containing solder system is preferred. For example, for soldering silicon-based power chipsets 7 with high thermal stress requirements, high-strength, fatigue-resistant SnAgCu lead-free solder can be used; for soldering auxiliary components requiring low melting points to reduce thermal shock, traditional SnPb solder can be selected. Through matched solder selection, the thermomechanical reliability of the solder interface is optimized while ensuring the mechanical strength and electrical conductivity of the solder joint.

[0095] More specifically, since the welding temperature directly affects the melting, flow, wetting of the solder, and the formation of the final solder joint's microstructure, excessively low temperatures can lead to cold solder joints or incomplete soldering, while excessively high temperatures may damage the chip or substrate materials. In this embodiment of the invention, the peak temperature of the welding process (such as reflow soldering) is strictly controlled within a wide and precise range of 100°C to 400°C. This temperature window can be precisely set according to the specific melting point of the selected solder (e.g., SnPb eutectic is approximately 183°C, SnAgCu is approximately 217°C-227°C), ensuring that the solder fully melts and effectively wets the surface to be welded, forming a metallurgical bond. At the same time, it avoids thermal damage to heat-sensitive components (such as the internal structure of the chip and the ceramic layer of the insulating substrate) due to overheating, thereby achieving a high yield and high reliability of the welded connection.

[0096] In a preferred embodiment of the present invention, both the power terminal 3 and the signal pin 5 are made of pure copper or copper alloy.

[0097] Specifically, considering that the power terminal 3 needs to carry a continuous operating current of up to several hundred amperes, while the signal pin 5 needs to ensure low-loss and low-inductive-resistance transmission of the drive signal, both place extremely high demands on the conductivity, current-carrying capacity, and mechanical strength of the materials. Therefore, in this embodiment of the invention, pure copper or copper alloys (such as brass or beryllium copper) are preferred as the substrate for the power terminal 3 and the signal pin 5. Pure copper has excellent conductivity, making it an ideal choice for achieving low conduction loss; copper alloys, while maintaining good conductivity, provide higher mechanical strength and formability, which is beneficial for the processing of complex terminal structures and the reliability of long-term use. By selectively electroplating the surface of the substrate with metals such as gold, nickel, and tin, which have excellent solderability and corrosion resistance, not only is the interface quality of the terminal soldered or plugged into the external circuit ensured, but its oxidation and corrosion resistance in harsh environments is also improved, thereby comprehensively ensuring the long-term stability of the electrical performance of the power and signal transmission paths.

[0098] In a preferred embodiment of the present invention, a silicone gel 12 is further included, which fills the cavity and covers the insulating substrate 4, the silicon carbide chip 6, the silicon-based power chip group 7, the connection portion 31 of the power terminal 3, the signal pin 5 and the thermistor 8.

[0099] Specifically, in order to effectively improve the insulation withstand voltage between conductors at different potentials within the module (such as between chips, between chips and substrates, and between bonding wires), and to protect sensitive components from environmental humidity, dust, chemical corrosion, and mechanical stress, in this embodiment of the invention, reference is made to... Figure 6 After all chip soldering, bonding, and internal interconnection are completed, a silicone gel 12 with excellent insulation, high flexibility, and good thermal conductivity is potted and filled into the entire cavity formed by the outer shell 2 and the heat dissipation substrate 1. The silicone gel 12 fully wets and covers all conductive components and connection points on the insulating substrate 4, forming a gapless, integrated insulating protective layer. This insulating protective layer not only significantly improves the creepage distance and clearance between components inside the module, ensuring long-term insulation reliability under high voltage, but its elastic properties can also absorb thermal stress caused by temperature cycling and buffer external vibration and shock, thereby comprehensively improving the environmental adaptability and long-term operating life of the hybrid topology power module under harsh operating conditions.

[0100] In summary, this invention provides a novel hybrid topology power module that integrates the advantages of silicon carbide chips and silicon-based power chipsets within a single semiconductor package through innovative structural design and process integration.

[0101] Compared with the prior art, the present invention has the following advantages:

[0102] Structural reliability and advanced technology: The design of partially wrapping the power terminal 3 with an injection-molded shell, combined with the direct ultrasonic welding of the power terminal 3 and the insulating substrate 4, significantly improves the power terminal's ability to resist thermal stress and external installation stress, eliminates the fatigue defects of traditional welding, and achieves a highly reliable connection.

[0103] High integration and size optimization: By directly soldering auxiliary interfaces such as signal pin 5 onto the conductive layer of insulating substrate 4, the module size is effectively reduced and the overall integration is improved while ensuring current capability.

[0104] Superior heat dissipation and current capability: The silicon carbide chip 6 is connected using a silver sintering process, which greatly enhances the chip's heat dissipation capability; the heat dissipation substrate 1 integrates optimized heat dissipation pins (or heat sinks), and its size and spacing are optimized based on thermal resistance simulation, which together improve the module's heat dissipation performance and continuous output current capability.

[0105] Electrical performance optimization: Directly connecting the threaded post 13 to the DC-side power terminal 3 effectively reduces the parasitic inductance on the DC side of the module, which is beneficial to improving the dynamic response and efficiency of the system.

[0106] Overall performance and cost balance: The core hybrid topology design (silicon carbide chip 6 for the outer tube and silicon-based power chipset 7 for the inner tube) optimizes the loss distribution at the system level. While giving full play to the advantages of silicon carbide in high frequency and low loss to improve efficiency and power density, it uses mature silicon-based technology to control the overall cost, and successfully achieves the best balance between efficiency, power density, reliability and cost.

[0107] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A hybrid topology power module, characterized in that, include: Heat dissipation substrate (1); The outer shell (2) is fixed on the heat dissipation substrate (1) and forms a receiving cavity with the heat dissipation substrate (1); An insulating substrate (4) is fixed to the heat dissipation substrate (1) and located within the receiving cavity; Power terminal (3), the power terminal (3) has a connection part (31) embedded in the housing (2) and a wiring part (32) exposed outside the housing (2), the connection part (31) is fixed to the conductive layer of the insulating substrate (4); The silicon carbide chip (6) is fixed on the conductive layer of the insulating substrate (4) and is located at the outer tube position in the bridge circuit topology of the hybrid topology power module. The silicon-based power chip assembly (7) is fixed on the conductive layer of the insulating substrate (4) and located in the inner tube position in the bridge circuit topology.

2. A hybrid topology power module according to claim 1, characterized in that, The silicon-based power chip set (7) includes an insulated gate bipolar transistor chip and a diode chip connected in parallel with the insulated gate bipolar transistor chip.

3. A hybrid topology power module according to claim 1, characterized in that, The connection part (31) of the power terminal (3) is fixed to the first conductive layer of the insulating substrate (4) by ultrasonic welding process. The silicon carbide chip (6) is fixed to the second conductive layer of the insulating substrate (4) by a silver sintering process; The silicon-based power chip assembly (7) is fixed to the third conductive layer of the insulating substrate (4) by a soldering process. The first conductive layer, the second conductive layer and the third conductive layer are electrically connected by a copper bridge (9).

4. A hybrid topology power module according to claim 1, characterized in that, The silicon carbide chip (6) and the silicon-based power chip group (7) are electrically connected by aluminum wires.

5. A hybrid topology power module according to claim 1, characterized in that, The outer shell (2) is made of plastic and is fixed to the heat dissipation base plate (1) by sealant and fasteners; The heat dissipation substrate (1) is a copper substrate, and the heat dissipation substrate (1) has heat dissipation pins or heat dissipation fins.

6. A hybrid topology power module according to claim 1, characterized in that, Also includes: The signal needle (5) includes a needle body (51) and a base (52). The needle body (51) is connected to the base (52) by a plug-in or forging process and extends vertically upward from the outer shell (2). The base (52) is fixed to the conductive layer of the insulating substrate (4) by a soldering process. The thermistor (8) is fixed to the conductive layer of the insulating substrate (4) by soldering. The current sensor (11) is fixed to the housing (2) by a mechanical connection process and is located on one side of the power terminal (3); A threaded post (13) is embedded in the first side of the housing (2) and connected to the power terminal (3); The signal terminal (14) is embedded on the second side opposite to the first side of the housing (2) and fixed to the conductive layer of the insulating substrate (4) by ultrasonic welding process.

7. A hybrid topology power module according to claim 6, characterized in that, It also includes a shield (10), which is embedded in the housing (2) and extends vertically outward to surround both sides of the current sensor (11).

8. A hybrid topology power module according to claim 3 or 6, characterized in that, The soldering process uses one of the following: tin-lead solder, tin-silver solder, tin-silver-copper solder, and lead-tin-silver solder, with a soldering temperature of 100° to 400°.

9. A hybrid topology power module according to claim 6, characterized in that, Both the power terminal (3) and the signal pin (5) are made of pure copper or copper alloy.

10. A hybrid topology power module according to claim 6, characterized in that, It also includes a silicone gel (12), which fills the cavity and covers the insulating substrate (4), the silicon carbide chip (6), the silicon-based power chip assembly (7), the connection portion (31) of the power terminal (3), the signal pin (5), and the thermistor (8).

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