A height-adjustable 3D copper clip and silicon carbide power module

Abstract

This invention discloses a height-adjustable 3D copper clip and a silicon carbide power module, belonging to the field of silicon carbide power devices. The 3D copper clip is used in the silicon carbide power module, which includes a substrate and multiple power chips. A first copper layer and a second copper layer are provided on the substrate, and the multiple power chips are all connected to the first copper layer. The 3D copper clip includes a connector and multiple clamping bodies. The clamping bodies are respectively connected to the multiple power chips, and each clamping body is connected to the connector. The connector is connected to the second copper layer. Each clamping body includes a front top plate, a first inclined plate, a bottom plate, a second inclined plate, and a rear top plate connected in sequence. The bottom plate is mounted on the power chips, and the rear top plate is connected to the connector. The first and second inclined plates are symmetrically arranged on both sides of the bottom plate. This solves the problem of dynamic current imbalance caused by parasitic inductance differences in silicon carbide power modules.

Description

Technical Field

[0001] This invention belongs to the field of silicon carbide power device technology, specifically relating to a height-adjustable 3D copper clip and a silicon carbide power module. Background Technology

[0002] In recent years, although silicon-based devices have dominated the semiconductor market, their performance is gradually approaching the limits of the material. As a representative of third-generation wide-bandgap semiconductors, silicon carbide power devices have gradually demonstrated their advantages due to their superior electrical characteristics. However, due to the high defect density of silicon carbide materials and immature processing technology, the rated current of a single silicon carbide chip is still insufficient to meet the needs of high-power-density applications such as new energy vehicles. Therefore, in order to increase the rated current, a multi-chip parallel design must be adopted.

[0003] In traditional silicon carbide power devices, the power chip and the substrate are connected using wire bonding technology. This structure allows the power chip and substrate to be connected via metal wires (gold or aluminum wires). However, traditional silicon carbide power devices suffer from high parasitic inductance, low reliability, and are prone to thermal stress under long-term high-temperature and high-frequency operation, leading to bond detachment or breakage, further reducing device reliability. Additionally, traditional wire bonding connections can result in uneven current distribution and reduced production efficiency. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a highly adjustable 3D copper clip and silicon carbide power module. This solves the problem of dynamic current imbalance caused by parasitic inductance differences in silicon carbide power modules. The technical problem to be solved by this invention is achieved through the following technical solution: In a first aspect, the present invention provides a height-adjustable 3D copper clip for a silicon carbide power module. The silicon carbide power module includes a substrate and a plurality of power chips. A first copper layer and a second copper layer are provided on the substrate. The plurality of power chips are all connected to the first copper layer. The 3D copper clip includes a connector and a plurality of clamping bodies. The plurality of clamping bodies are respectively connected to the plurality of power chips, and the plurality of clamping bodies are all connected to the connector. The connector is connected to the second copper layer. The clamping body includes a front top plate, a first inclined plate, a bottom plate, a second inclined plate, and a rear top plate connected in sequence. The bottom plate is mounted on the power chip, and the rear top plate is connected to the connector. The first inclined plate and the second inclined plate are symmetrically arranged on both sides of the bottom plate. The first inclined plate, the bottom plate, and the second inclined plate are respectively provided with a first elongated hole, a second elongated hole, and a third elongated hole, which are connected in sequence.

[0005] In one embodiment of the present invention, the connector includes an upper connecting plate, an inclined connecting plate and a lower connecting plate connected in sequence, wherein the upper connecting plate is higher than the lower connecting plate and the lower connecting plate is connected to the second copper layer; At least one of the multiple clamping bodies is connected to the upper connecting plate, and at least one of the multiple clamping bodies is connected to the lower connecting plate.

[0006] In one embodiment of the present invention, there are three clamping bodies, and the three clamping bodies are respectively a first clamping body, a second clamping body and a third clamping body, and there are three power chips. The first clamping body, the second clamping body and the third clamping body are respectively connected to the three power chips. The first clamping body is connected to the upper connecting plate, and the second and third clamping bodies are both connected to the lower connecting plate.

[0007] In one embodiment of the present invention, the lower connecting plate includes a lower plate body and a bending structure, the bending structure is connected to the second copper layer, one side of the lower plate body is connected to the bending structure, and the other side of the lower plate body is connected to the inclined connecting plate. There is a gap between the lower plate, the inclined connecting plate, and the upper connecting plate and the upper surface of the second copper layer.

[0008] In one embodiment of the present invention, the bending structure includes a first bending inclined plate, a second bending inclined plate, a lower support plate, a third bending inclined plate, and a side rib connected in sequence. The first bending inclined plate is connected to the lower plate body, and the lower support plate is mounted on the second copper layer.

[0009] In one embodiment of the present invention, the distance between two adjacent clamping bodies is 6.72mm to 6.76mm, the height of the clamping body is 5.3mm to 5.7mm, and the thickness of the clamping body is 0.3mm to 0.7mm.

[0010] In one embodiment of the present invention, the height of the upper connecting plate is 4mm~4.4mm, the width of the side of the upper connecting plate connected to the inclined connecting plate is 5.35mm~5.39mm, and the width of the side of the upper connecting plate away from the inclined connecting plate is 6.11mm~6.15mm. The height of the lower connecting plate is 0.79mm~0.83mm, and the length is 13.56mm~13.6mm.

[0011] Secondly, the present invention provides a silicon carbide power module, including a substrate, multiple power chips, and a height-adjustable 3D copper clip as described above. The substrate is provided with a first copper layer, a second copper layer, and a third copper layer. There are two 3D copper clips, which are respectively the first copper clip and the second copper clip. The first copper layer and the second copper layer are connected by the first copper clip, and the first copper layer and the third copper layer are connected by the second copper clip. Power chips are mounted on both the first copper layer and the third copper layer.

[0012] In one embodiment of the present invention, aluminum bonding wires and power terminals are also included. The gate drive circuit of the power chip is connected to the first copper layer or the third copper layer through the aluminum bonding wires, and the power terminals are used to connect to external circuits.

[0013] In one embodiment of the present invention, the substrate includes an upper copper layer, a ceramic layer and a lower copper layer stacked together, wherein the upper copper layer includes a first copper layer, a second copper layer and a third copper layer; The silicon carbide power module also includes an aluminum nitride heat sink substrate, which is soldered onto the lower copper layer.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: In the above-mentioned solution of this application, firstly, the power chip and the substrate are directly connected by copper clips, which significantly reduces parasitic inductance and resistance, optimizes the switching performance of the power module, and improves the reliability of the module. Especially in high-frequency and high-power applications, it can improve the switching speed and overall efficiency of the module.

[0015] Secondly, the copper clip in this application uses a metal clip body and connector to connect the power chip and the substrate, avoiding the problem of thermal expansion coefficient mismatch in traditional wire bonding, thereby reducing the risk of bond point detachment or breakage caused by thermal stress. The copper clip provides a more stable electrical connection, effectively improving the long-term reliability of the power module in high-temperature and high-frequency operating environments.

[0016] Furthermore, the multiple power chips in this application are connected in parallel via copper clips. Compared with the traditional wire bonding connection method, this application can provide a uniform current path by adjusting the height of the copper clips, ensuring that the current distribution of each parallel chip is consistent, optimizing the parallel current sharing performance, and improving the overall efficiency and stability of the power module.

[0017] In addition, the clamp body includes a front top plate, a first inclined plate, a bottom plate, a second inclined plate, and a rear top plate connected in sequence. This structure can improve the overall reliability of the copper clamp and make the adjustment of the copper clamp height more convenient.

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the silicon carbide power module in an embodiment of the present invention; Figure 2 This is a top view of the copper clip in an embodiment of the present invention; Figure 3 This is a side view of the copper clip in an embodiment of the present invention; Figure 4 This is a front view of the copper clip in an embodiment of the present invention; Figure 5This is a top view of the silicon carbide power module in an embodiment of the present invention; Figure 6 This is a side view of the silicon carbide power module in an embodiment of the present invention; Figure 7 This is a front view of the silicon carbide power module in an embodiment of the present invention.

[0020] Reference numerals: 1-substrate, 2-power chip, 3-first copper layer, 4-second copper layer, 5-third copper layer, 6-clamping body, 61-first clamping body, 62-second clamping body, 63-third clamping body, 7-connector, 71-upper connecting plate, 72-slanted connecting plate, 73-lower connecting plate, 731-lower plate, 732-bending structure. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0022] Example 1: In recent years, although silicon-based devices have dominated the semiconductor market, their performance is gradually approaching the limits of the material. As a representative of third-generation wide-bandgap semiconductors, silicon carbide power devices have gradually demonstrated their advantages due to their superior electrical characteristics. However, due to the high defect density of silicon carbide materials and immature processing technology, the rated current of a single silicon carbide chip is still insufficient to meet the needs of high-power-density applications such as new energy vehicles. Therefore, in order to increase the rated current, a multi-chip parallel design must be adopted.

[0023] In multi-chip parallel designs, ensuring uniform current distribution across each chip is crucial for improving power module efficiency and stability. However, traditional wire bonding technology, when establishing electrical connections, can easily lead to differences in current paths between parallel chips, causing problems such as uneven current distribution and heat accumulation. Furthermore, using more wire bonding points not only reduces manufacturing efficiency but also increases potential failure risks, especially under high-temperature and high-frequency operating conditions, where bonding points are prone to detachment due to thermal stress, leading to the failure of the entire device.

[0024] In existing power module designs, electrical connections primarily utilize wire bonding, a mature and widely used connection method. Wire bonding connects the chip and substrate using metal wires (such as gold or aluminum wires). However, this method has some problems in high-power applications, particularly the high parasitic inductance and resistance, leading to increased switching losses. Furthermore, differences in material thermal expansion can easily cause wire bonds to detach or break, affecting the long-term reliability of the module. Additionally, as the number of leads increases, production efficiency decreases, and each bonding point carries a potential risk.

[0025] To improve connectivity and reduce parasitic inductance, some power modules have begun to adopt aluminum or copper ribbon bonding technology. Compared to traditional wire bonding, aluminum / copper ribbon can carry higher currents and reduce resistance, making it suitable for high-power applications. However, this technology still suffers from thermal expansion mismatch, which can lead to thermal stress failure at the connection points, affecting the stability of the module. Another approach is soldering, typically used to connect chips to the substrate. It exhibits strong current carrying capacity in high-power applications, but the reliability of the solder joints is still affected by differences in thermal expansion.

[0026] In recent years, copper clip technology, as a novel electrical connection method, has been increasingly applied to power modules. By directly connecting the chip and the substrate, copper clips effectively reduce parasitic inductance and resistance, optimize the switching performance of the power module, and provide a better thermal management path, enhancing heat dissipation and thus improving module reliability. However, existing copper clip designs still have limited flexibility in height adjustment, failing to precisely adjust the current distribution path according to the needs of different parallel chips, thereby affecting current sharing performance. Therefore, an adjustable height design based on copper clips can adjust the current path according to the requirements of different chips, further improving parallel current sharing and module stability.

[0027] Therefore, traditional silicon carbide power devices have the following disadvantages: First, traditional silicon carbide power devices have large parasitic inductance and low reliability. They achieve current sharing by adjusting the length of the bonding wires. As the number of parallel chips increases, the length of the bonding wires also needs to be extended proportionally (the length increases by 30% for each additional branch), which increases the parasitic inductance and reduces the reliability of the module.

[0028] Secondly, traditional silicon carbide power devices suffer from thermomechanical fatigue and unreliable connections. Because the materials used in wire bonding and soldering techniques have different coefficients of thermal expansion, long-term operation at high temperatures and high frequencies can easily generate thermal stress, leading to bond detachment or breakage, thus affecting the reliability of the power module. These connection methods have poor stability, especially in high power density and high-temperature environments, resulting in a higher risk of failure.

[0029] Furthermore, traditional silicon carbide power devices suffer from uneven current distribution and low production efficiency. In multi-chip parallel designs, traditional connection methods easily lead to uneven current distribution, resulting in heat accumulation and performance instability. In addition, the complexity of wire bonding and the increased number of connection points reduce production efficiency, and each bonding point has a potential failure risk, thus affecting the overall stability of the module and manufacturing costs.

[0030] Based on the above issues, please refer to Figures 1 to 7This invention provides a height-adjustable 3D copper clip for a silicon carbide power module. The silicon carbide power module includes a substrate 1 and multiple power chips 2. The substrate 1 has a first copper layer 3 and a second copper layer 4. The multiple power chips 2 are all connected to the first copper layer 3. The 3D copper clip includes a connector 7 and multiple clamping bodies 6. The multiple clamping bodies 6 are respectively connected to the multiple power chips 2, and the multiple clamping bodies 6 are all connected to the connector 7. The connector 7 is connected to the second copper layer 4. The clamping body 6 includes a front top plate, a first inclined plate, a bottom plate, a second inclined plate, and a rear top plate connected in sequence. The bottom plate is mounted on the power chips 2. The rear top plate is connected to the connector 7. The first inclined plate and the second inclined plate are symmetrically arranged on both sides of the bottom plate. The first inclined plate, the bottom plate, and the second inclined plate are respectively provided with a first elongated hole, a second elongated hole, and a third elongated hole, which are connected in sequence.

[0031] In some embodiments of this application, a plurality of power chips 2 are arranged sequentially along the width direction of the substrate 1.

[0032] In some embodiments of this application, the clamp 6 is used to connect the source of the power chip 2, and the connector 7 is used to form a circuit to eliminate mutual inductance effects.

[0033] In some embodiments of this application, by optimizing the structure and size of the copper clip, the current distribution in the power module can be significantly improved, reducing the dynamic current imbalance caused by differences in parasitic inductance, thereby improving the current sharing performance and thermal management capability of the module.

[0034] In some embodiments of this application, the upper surfaces of the front top plate and the rear top plate are located on the same horizontal plane. One end of the first inclined plate is connected to the bottom plate, and the other end is inclined toward the connecting body 7. One end of the second inclined plate is connected to the bottom plate, and the other end is inclined toward the side away from the connecting body 7. The first elongated hole, the second elongated hole and the third elongated hole are located at the middle positions of the first inclined plate, the bottom plate and the second inclined plate, respectively.

[0035] In the above-mentioned solution of this application, firstly, the power chip 2 and the substrate 1 are directly connected by copper clips, which significantly reduces parasitic inductance and resistance, optimizes the switching performance of the power module, and improves the reliability of the module. Especially in high-frequency and high-power applications, it can improve the switching speed and overall efficiency of the module.

[0036] Secondly, the copper clip in this application uses a metal clip body 6 and a connector body 7 to connect the power chip 2 and the substrate 1, avoiding the problem of thermal expansion coefficient mismatch in traditional wire bonding, thereby reducing the risk of bond point detachment or breakage caused by thermal stress. The copper clip provides a more stable electrical connection, effectively improving the long-term reliability of the power module in high-temperature and high-frequency operating environments.

[0037] Furthermore, the multiple power chips 2 in this application are connected in parallel via copper clips. Compared with the traditional wire bonding connection method, this application can provide a uniform current path by adjusting the height of the copper clips, ensuring that the current distribution of each parallel chip is consistent, optimizing the parallel current sharing performance, and improving the overall efficiency and stability of the power module.

[0038] In addition, the clamp body 6 includes a front top plate, a first inclined plate, a bottom plate, a second inclined plate, and a rear top plate connected in sequence. This structure can improve the overall reliability of the copper clamp and make the adjustment of the copper clamp height more convenient.

[0039] In some embodiments of this application, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the connector 7 includes an upper connecting plate 71, an inclined connecting plate 72, and a lower connecting plate 73 connected in sequence. The upper connecting plate 71 is higher than the lower connecting plate 73, and the lower connecting plate 73 is connected to the second copper layer 4. At least one of the multiple clamping bodies 6 is connected to the upper connecting plate 71, and at least one of the multiple clamping bodies 6 is connected to the lower connecting plate 73. This structure allows different clamping bodies 6 to be connected in a hierarchical manner through the upper connecting plate 71 and the lower connecting plate 73, thereby creating a height difference within the module. This helps to balance the differences in current paths and provides a suitable electrical circuit for parallel chips. This hierarchical connection method facilitates the adjustment of the electrical length corresponding to each chip, helps to suppress uneven mutual inductance caused by asymmetrical layout, and supports a more uniform distribution of current among parallel branches.

[0040] In some embodiments of this application, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, there are three clamping units 6, namely the first clamping unit 61, the second clamping unit 62, and the third clamping unit 63. There are three power chips 2. The first clamping unit 61, the second clamping unit 62, and the third clamping unit 63 are connected to the three power chips 2 respectively. The first clamping unit 61 is connected to the upper connecting plate 71, and the second clamping unit 62 and the third clamping unit 63 are both connected to the lower connecting plate 73. With this structure, the first clamping unit 61 is connected to the higher upper connecting plate 71, while the second and third clamping units 63 are connected to the lower lower connecting plate 73, forming a one-high-two-low connection layout. This layout naturally introduces a difference in the length of the current path between the three parallel chips, which can compensate for the differences in parasitic parameters caused by different positions. By adjusting this high-low connection relationship, it is possible to adapt to the different circuit characteristics of the middle chip and the two side chips, thereby making the dynamic impedance of the three parallel branches more balanced and improving the current balance during the turn-on and turn-off processes.

[0041] In some embodiments of this application, such as Figure 1 , Figure 2 and Figure 4 As shown, the lower connecting plate 73 includes a lower plate body 731 and a bent structure 732. The bent structure 732 is connected to the second copper layer 4. One side of the lower plate body 731 is connected to the bent structure 732, and the other side of the lower plate body 731 is connected to the inclined connecting plate 72. There is a gap between the lower plate body 731, the inclined connecting plate 72, and the upper connecting plate 71 and the upper surface of the second copper layer 4. This structure allows the lower plate body 731, the inclined connecting plate 72, and the upper connecting plate 71 to be suspended above the upper surface of the second copper layer 4. This is equivalent to constructing an overhead structure between the connector 7 and the substrate 1. This structure utilizes the bent structure 732 to achieve welding and fixation to the substrate 1, while simultaneously providing a suspended conductor for current to flow from the chip to the upper connecting plate 71, expanding the adjustable range of the current path. The existence of this gap allows the current loop to be partially detached from the copper layer wiring of the substrate 1, helping to reduce the influence of the substrate 1's parasitic parameters on the loop and providing more possibilities for adjusting the loop inductance through three-dimensional spatial shape.

[0042] In some embodiments of this application, the bending structure 732 includes a first bending ramp, a second bending ramp, a lower support plate, a third bending ramp, and side ribs connected in sequence. The first bending ramp is connected to the lower plate 731, and the lower support plate is mounted on the second copper layer 4. With this structure, the bending structure 732 extends and transitions in both the vertical and horizontal directions through the combination of its multiple ramps and support plates. This multi-segment bending shape can absorb and disperse thermal stress caused by temperature changes, preventing stress concentration that could lead to cracking at the connection point. The side ribs increase the local rigidity and contact area of ​​the welding area between the lower support plate and the substrate 1, improving the mechanical strength of the welded connection. Simultaneously, the connection method between the first bending ramp and the lower plate 731 allows for a smooth transition of the current path from the lower plate 731 to the substrate 1, helping to maintain the stability of the inductance characteristics of this conductor segment and preventing changes due to deformation.

[0043] In some embodiments of this application, the distance between two adjacent clamp bodies 6 is 6.72mm~6.76mm, preferably 6.74mm; the height of the clamp body is 5.3mm~5.7mm, preferably 5.5mm; and the thickness of the clamp body 6 is 0.3mm~0.7mm, preferably 0.5mm. Thus, by precisely controlling the height and thickness of the copper clamps, the current paths between the chips are ensured to be as consistent as possible, thereby optimizing current sharing. Specifically, in this embodiment, the distance between the clamp bodies 6 is controlled to be slightly larger than the chip spacing, so that after the current flows out of the chip, it needs to pass through a section of copper clamp in the horizontal direction before entering the parallel clamp body 6. This extension section can be equivalent to a small inductor, which can fine-tune the mutual inductance difference between adjacent chips. Setting the height and thickness within the above range ensures that the clamp body 6 has sufficient mechanical strength while its vertical thermal expansion can be accommodated within its own elastic deformation range, avoiding excessive vertical stress on the chips. The preferred dimensions are the balance point obtained after calculation and experimental verification, which can better balance the flow uniformity effect and structural reliability within the actual manufacturing tolerance.

[0044] In some embodiments of this application, the height of the upper connecting plate 71 is 4mm~4.4mm, preferably 4.2mm; the width of the side of the upper connecting plate 71 connected to the inclined connecting plate 72 is 5.35mm~5.39mm, preferably 5.37mm; and the width of the side of the upper connecting plate 71 away from the inclined connecting plate 72 is 6.11mm~6.15mm, preferably 6.13mm. The height of the lower connecting plate 73 is 0.79mm~0.83mm, preferably 0.81mm, and the length is 13.56mm~13.6mm, preferably 13.58mm. This further optimizes the uniform distribution of current and reduces the impact of mutual inductance.

[0045] Understandably, this application effectively solves the common problems of current unevenness and thermal imbalance in multi-chip parallel power modules, and significantly improves the dynamic current balancing capability of the power module. The precise size design and symmetrical layout of the copper clips effectively reduce the impact of parasitic inductance on current distribution, improving the module's operating efficiency, stability, and lifespan, making it particularly suitable for high power density and high frequency applications.

[0046] Example 2: Please see Figure 5 , Figure 6 and Figure 7This invention provides a silicon carbide power module, including a substrate 1, multiple power chips 2, and height-adjustable 3D copper clips as described above. The substrate 1 has a first copper layer 3, a second copper layer 4, and a third copper layer 5. There are two 3D copper clips, which are the first copper clip and the second copper clip, respectively. The first copper layer 3 and the second copper layer 4 are connected by the first copper clip, and the first copper layer 3 and the third copper layer 5 are connected by the second copper clip. Power chips 2 are mounted on both the first copper layer 3 and the third copper layer 5.

[0047] The beneficial effects of Embodiment 2 and its various implementations of the present invention can be found in the analysis of the beneficial effects of Embodiment 1 and its various implementations, and will not be repeated here.

[0048] In some embodiments of this application, the silicon carbide power module further includes aluminum bonding wires and power terminals. The gate drive circuit of the power chip 2 is connected to the first copper layer 3 or the third copper layer 5 via the aluminum bonding wires, and the power terminals are used to connect to external circuits. With this structure, the gate drive circuit of the power chip 2 is independently connected via aluminum bonding wires, enabling Kelvin source connection. This connection method physically separates the drive circuit from the main power circuit, preventing voltage drop fluctuations generated by high-power current on the source copper layer from being coupled into the gate drive signal, thereby improving the stability of the gate drive voltage and helping to ensure the consistency and reliability of chip switching operations. The power terminals provide a low-impedance, high-current-carrying path for the main current to connect to external circuits and bear the heat generated by the module during operation, facilitating heat conduction outwards.

[0049] In some embodiments of this application, substrate 1 is a direct copper-clad ceramic substrate, abbreviated as DBC substrate.

[0050] In some embodiments of this application, the silicon carbide chip is soldered to the copper layer of the DBC substrate using a high-temperature solder capable of withstanding temperatures up to 250°C. To achieve Kelvin source connection, the gate drive circuit is bonded to the chip via a 6-mil diameter aluminum wire bond between the chip and the solder joint. Electrical signals are connected to external circuitry via three terminals, thereby enabling signal transmission between the module and external devices.

[0051] In some embodiments of this application, substrate 1 includes an upper copper layer, a ceramic layer, and a lower copper layer stacked together. The upper copper layer includes a first copper layer 3, a second copper layer 4, and a third copper layer 5. The silicon carbide power module also includes an aluminum nitride heat dissipation substrate, which is soldered onto the lower copper layer. With this structure, substrate 1 is formed by stacking an upper copper layer, a ceramic layer, and a lower copper layer. The ceramic layer provides electrical insulation between the upper and lower copper layers. The upper copper layer is divided into isolated first, second, and third copper layers 5 to achieve power connections at different potentials. The lower copper layer, as a continuous metal layer at the bottom of the module, provides mechanical support and a unified heat dissipation substrate for the entire module. The aluminum nitride heat dissipation substrate is soldered onto the lower copper layer, utilizing the high thermal conductivity of aluminum nitride to quickly conduct and dissipate the heat generated by the chip and copper clips downwards through the lower copper layer, preventing heat accumulation inside the module.

[0052] In some embodiments of this application, the DBC substrate consists of an upper copper layer, a ceramic layer, and a lower copper layer, arranged sequentially between the layers to ensure stable operation of the module under high power and high temperature environments. The AIN heat dissipation substrate is connected to the lower copper layer of the DBC substrate through a high-temperature solder layer, effectively improving heat conduction and thus enhancing the heat dissipation performance of the power module.

[0053] In some embodiments of this application, the copper clips are welded using a vacuum reflow soldering process during assembly to ensure high reliability of the connection. The upper and lower structures of the module are completely symmetrical to optimize heat distribution and current balance. In a specific implementation, this invention uses three silicon carbide chips connected in parallel to form a power module, and the copper clips connect the source and drain terminals of these chips to the substrate 1. By constructing a copper clip circuit in the air, the module can effectively eliminate the mutual inductance effect on the substrate 1, thereby improving the stability of the electrical connection and the overall performance of the power module.

[0054] Understandably, the adjustable height of the copper clip in this application allows for precise adjustment of the current path lengths of the source and drain of each silicon carbide chip. By flexibly adjusting the connection height between the copper clip and the DBC substrate, the current imbalance caused by mutual inductance can be eliminated, and the influence of parasitic inductance can be balanced and optimized, thereby effectively solving the dynamic current imbalance problem in parallel chips. This significantly improves the dynamic current sharing performance of the power module and reduces heat accumulation and module overheating problems caused by current imbalance.

[0055] Furthermore, through this precise adjustment and optimization of the current path design, the reliability of silicon carbide power modules has been significantly improved, which helps to fully leverage the performance advantages of silicon carbide semiconductor chips and further enhance the module's application capabilities and long-term stability in high-frequency, high-power-density, and high-temperature environments.

[0056] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A height adjustable 3D copper clip for silicon carbide power modules, characterized by, The silicon carbide power module comprises a substrate and a plurality of power chips, the substrate is provided with a first copper layer and a second copper layer, the plurality of power chips are connected to the first copper layer, the 3D copper clip comprises a connecting body and a plurality of clip details, the plurality of clip details are connected to the plurality of power chips respectively, and the plurality of clip details are connected to the connecting body. The clip detail comprises a front top plate, a first inclined plate, a bottom plate, a second inclined plate and a rear top plate connected in sequence, the bottom plate is installed on the power chip, the rear top plate is connected to the connecting body, the first inclined plate and the second inclined plate are symmetrically arranged on both sides of the bottom plate, and the first inclined plate, the bottom plate and the second inclined plate are respectively provided with a first long hole, a second long hole and a third long hole, and the first long hole, the second long hole and the third long hole are sequentially communicated.

2. The height adjustable 3D copper clamp of claim 1, wherein, The connecting body comprises an upper connecting plate, an inclined connecting plate and a lower connecting plate connected in sequence, the upper connecting plate is higher than the lower connecting plate, and the lower connecting plate is connected to the second copper layer. At least one of the plurality of clip details is connected to the upper connecting plate, and at least one of the plurality of clip details is connected to the lower connecting plate.

3. The height adjustable 3D copper clamp of claim 2, wherein, The clip detail is provided with three first clip details, second clip details and third clip details, and the power chip is provided with three first clip details, second clip details and third clip details. The first clip detail is connected to the upper connecting plate, and the second clip detail and the third clip detail are connected to the lower connecting plate.

4. The height adjustable 3D copper clamp of claim 2, wherein, The lower connecting plate comprises a lower plate body and a bending structure, the bending structure is connected to the second copper layer, one side of the lower plate body is connected to the bending structure, and the other side of the lower plate body is connected to the inclined connecting plate. The lower plate body, the inclined connecting plate and the upper connecting plate are spaced apart from the upper surface of the second copper layer.

5. The height adjustable 3D copper clamp of claim 4, wherein, The bending structure comprises a first bending inclined plate, a second bending inclined plate, a lower supporting plate, a third bending inclined plate and an edge rib connected in sequence, the first bending inclined plate is connected to the lower plate body, and the lower supporting plate is installed on the second copper layer.

6. The height adjustable 3D copper clamp of claim 2, wherein, The distance between adjacent two clip details is 6.72mm~6.76mm, the height of the clip detail is 5.3mm~5.7mm, and the thickness of the clip detail is 0.3mm~0.7mm.

7. The height adjustable 3D copper clamp of claim 6, wherein, The height of the upper connecting plate is 4mm~4.4mm, the width of the side of the upper connecting plate connected to the inclined connecting plate is 5.35mm~5.39mm, and the width of the side of the upper connecting plate away from the inclined connecting plate is 6.11mm~6.15mm. The height of the lower connecting plate is 0.79mm~0.83mm, and the length of the lower connecting plate is 13.56mm~13.6mm.

8. A silicon carbide power module, characterized by, The power module comprises a substrate, a plurality of power chips, and a height-adjustable 3D copper clip as claimed in any one of claims 1 to 7, the substrate is provided with a first copper layer, a second copper layer, and a third copper layer, the 3D copper clip is provided with two, and the two 3D copper clips are respectively a first copper clip and a second copper clip, the first copper layer and the second copper layer are connected through the first copper clip, and the first copper layer and the third copper layer are connected through the second copper clip. The first copper layer and the third copper layer are both provided with the power chip.

9. The silicon carbide power module of Claim 8, wherein, The power module further comprises an aluminum bonding wire and a power terminal, a gate drive circuit of the power chip is connected with the first copper layer or the third copper layer through the aluminum bonding wire, and the power terminal is used for being connected with an external circuit.

10. The silicon carbide power module of Claim 8, wherein, The substrate comprises an upper copper layer, a ceramic layer, and a lower copper layer which are stacked, and the upper copper layer comprises the first copper layer, the second copper layer, and the third copper layer. The silicon carbide power module further comprises an aluminum nitride heat dissipation substrate which is welded on the lower copper layer.

Images