Hybrid packaging structure and power device
By designing the PCB board as a cantilever beam structure, the problems of large parasitic inductance and differences in thermal expansion coefficients in traditional packaging processes are solved, achieving high reliability and low cost power module packaging, and improving heat dissipation efficiency and switching speed.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2026-03-17
AI Technical Summary
In traditional power module packaging processes, the parasitic inductance caused by bonding wires is relatively large, which affects the switching speed and reliability of the device. Furthermore, the difference in thermal expansion coefficients between the PCB board and the DBC substrate leads to welding defects and a high risk of failure, resulting in higher costs.
The PCB board is designed as a cantilever beam structure, consisting of horizontal and vertical sections that are perpendicularly connected to each other. There is a gap between the cantilever beam and the substrate to reduce the difference in thermal expansion coefficients, avoid thermal stress concentration, increase heat dissipation area, and reduce parasitic inductance.
It reduces the risk of welding defects, improves device reliability and heat dissipation efficiency, reduces costs, and allows for faster switching speeds of power devices.
Smart Images
Figure CN224007095U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor packaging technology, and more specifically, to a hybrid packaging structure and power device. Background Technology
[0002] Traditional power module packaging processes primarily use bonding wires to interconnect the upper surfaces of electrical components. For example, multiple bonding wires are used to interconnect the chip and the DBC (Direct Bonding Copper) substrate. However, multiple bonding wires generate a changing current magnetic field, resulting in a large parasitic inductance. This large parasitic inductance can cause significant voltage overshoot during the rapid switching of the power devices contained in the power module, thereby increasing the risk of power device breakdown. Furthermore, reducing parasitic inductance requires limiting the switching speed of the power devices, thus limiting the improvement of the switching speed of the power devices.
[0003] The optimized packaging process involves directly soldering a PCB (Printed Circuit Board) onto the DBC substrate to achieve electrical interconnection on the chip's surface. However, due to the significant difference in thermal expansion coefficients between the PCB and the DBC, substantial thermal stress exists at the solder joints, leading to soldering defects and further exacerbating the high failure risk of the entire power module.
[0004] Currently, the main approach is to add a buffer layer as a transition material to minimize the difference in thermal stress caused by thermal expansion, thereby mitigating the adverse effects of the mismatch in thermal expansion coefficients between the PCB board and the DBC substrate. However, the buffer layer is relatively thin, which makes soldering more difficult and further increases the cost. Utility Model Content
[0005] This invention provides a hybrid packaging structure and power device to avoid high failure risks in power modules and reduce costs. The specific technical solution is as follows:
[0006] In a first aspect, this utility model provides a hybrid packaging structure, comprising:
[0007] A printed circuit board (PCB), at least one conductive substrate, and at least one chip;
[0008] The PCB board includes a substrate and at least one cantilever beam extending outward from the substrate. The cantilever beam includes a horizontal portion and a vertical portion that are perpendicularly connected to each other. The horizontal portion is connected to the substrate, and there is a gap between the vertical portion and the substrate.
[0009] Each conductive substrate is located on the same plane and is parallel to the PCB board;
[0010] For each chip, the upper surface of the chip is fixedly connected to the corresponding cantilever beam, and the lower surface of the chip is fixedly connected to the corresponding conductive substrate.
[0011] Optionally, the PCB board includes at least one pair of cantilever beams;
[0012] Each pair of cantilever beams is symmetrically arranged on both sides of the base.
[0013] Optionally, the above hybrid packaging structure also includes at least one metal block;
[0014] The upper surface of each metal block is fixedly connected to the substrate, and the lower surface of each metal block is fixedly connected to the corresponding conductive substrate. Each metal block is used to realize the electrical connection between the substrate and the corresponding conductive substrate.
[0015] Optionally, the above hybrid packaging structure also includes multiple passive components;
[0016] The upper surface of each passive component is fixedly connected to the substrate, and the lower surface of each passive component is fixedly connected to the corresponding conductive substrate.
[0017] Optionally, the passive components include at least one of capacitors, resistors, and inductors;
[0018] Each conductive substrate has a pattern corresponding to a passive component connected to it, and the lower surface of each passive component is fixedly connected to the position of the pattern drawn on the corresponding conductive substrate.
[0019] Optionally, the hybrid packaging structure described above may also include a heat sink;
[0020] The lower surface of each conductive substrate is fixedly connected to the upper surface of the heat sink.
[0021] Optionally, each cantilever beam may be fixedly connected to at least one chip.
[0022] Optionally, the conductive substrate is at least one of a ceramic substrate, a hybrid sintered substrate, a copper-clad substrate, and a flexible printed circuit board.
[0023] Optionally, the type of chip includes at least one of silicon chip, gallium arsenide chip, gallium nitride chip, and silicon carbide chip.
[0024] Secondly, the present invention provides a power device, the power device comprising a hybrid packaging structure as described in any of the first aspects.
[0025] As can be seen from the above, the hybrid packaging structure provided by this utility model embodiment includes a PCB board, at least one conductive substrate, and at least one chip. The PCB board includes a base and at least one cantilever beam extending outward from the base. The cantilever beam includes a horizontal portion and a vertical portion that are perpendicularly connected to each other. The horizontal portion is connected to the base, and there is a gap between the vertical portion and the base. Each conductive substrate is located on the same plane and is parallel to the PCB board. For each chip, the upper surface of the chip is fixedly connected to the corresponding cantilever beam, and the lower surface of the chip is fixedly connected to the corresponding conductive substrate. In this invention, the PCB board is designed to extend at least one cantilever beam, which includes a horizontal part and a vertical part that are perpendicularly connected to each other. The horizontal part is connected to the base, and there is a gap between the vertical part and the base. This allows the horizontal part to adapt to vertical deformation and the vertical part to adapt to horizontal deformation when the PCB board creeps under thermal stress, thereby releasing thermal stress, reducing the difference in thermal expansion coefficients between the PCB board and the conductive substrate, avoiding large thermal stress at the welding joint, reducing the possibility of welding defects, and further avoiding a high failure risk for the entire power module. This improves reliability, reduces welding difficulty, and lowers costs.
[0026] The innovative aspects of this utility model embodiment include:
[0027] 1. The PCB board is designed as a cantilever beam extending outwards, and the cantilever beam includes horizontal and vertical sections that are perpendicularly connected to each other. The horizontal section is connected to the base, and there is a gap between the vertical section and the base. This allows the horizontal section to adapt to vertical deformation and the vertical section to adapt to horizontal deformation when the PCB board creeps under thermal stress. This releases thermal stress, reduces the difference in thermal expansion coefficients between the PCB board and the conductive substrate, avoids large thermal stress at the solder joints, reduces the possibility of soldering defects, and further avoids situations where the entire power module faces a high risk of failure. This improves reliability, reduces soldering difficulty, and lowers costs.
[0028] 2. The addition of a PCB board allows for heat dissipation on the upper surface of the chip, and the larger PCB board area significantly increases the heat dissipation area, reduces thermal resistance, and improves heat dissipation efficiency.
[0029] 3. The addition of a PCB board eliminates the need for bonding wires, reducing parasitic inductance and preventing large voltage overshoots during the rapid switching of power devices. This reduces the risk of power device breakdown and does not limit the improvement of the switching speed of power devices.
[0030] 4. By symmetrically placing each pair of cantilever beams on both sides of the base, the balance of the base is improved.
[0031] 5. By installing heat sinks on the lower surface of each conductive substrate, heat dissipation efficiency is improved.
[0032] 6. By fixing the lower surface of each passive component to the position marked on the corresponding conductive substrate, the passive components are connected together, so that the current can be transmitted between the passive components according to the designed path.
[0033] 7. A power device is provided, the power device including a hybrid packaging structure, the hybrid packaging structure can avoid the occurrence of high failure risk of power module and reduce cost.
[0034] Of course, implementing any product or method of this utility model does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description
[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0036] Figure 1 A schematic diagram of a hybrid packaging structure provided in an embodiment of this utility model;
[0037] Figure 2 A schematic diagram of a PCB board provided in an embodiment of this utility model;
[0038] Figure 3 Another schematic diagram of the hybrid packaging structure provided in this embodiment of the utility model;
[0039] Figure 4 This is a schematic diagram of another structure of the PCB board provided in an embodiment of the present invention.
[0040] Figures 1-4 In the middle, 1 PCB board, 11 substrate, 12 cantilever beam, 121 horizontal part, 122 vertical part, 2 conductive substrate, 21 first copper plate, 22 ceramic plate, 23 second copper plate, 3 chip, 31 chip connection position, 4 metal block, 41 metal block connection position, 5 heat sink. Detailed Implementation
[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.
[0042] It should be noted that the terms "comprising" and "having," and any variations thereof, in the embodiments and drawings of this utility model are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.
[0043] This utility model discloses a hybrid packaging structure and power device, which can avoid the high failure risk of power modules and reduce costs. The following is a detailed description of this utility model embodiment.
[0044] Example 1
[0045] Figure 1 This is a schematic diagram of a hybrid packaging structure provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a PCB board provided in an embodiment of the present utility model.
[0046] See Figure 1 and Figure 2 This utility model provides a hybrid packaging structure including a PCB (Printed Circuit Board) 1, at least one conductive substrate 2, and at least one chip 3. The conductive substrate 2 can be at least one of a ceramic substrate, a hybrid sintered substrate, a copper-clad laminate, and a flexible circuit board. For example, the conductive substrate 2 is a DBC (Direct Bonding Copper) substrate, and the chip 3 can be at least one of a silicon chip, a gallium arsenide chip, a gallium nitride chip, and a silicon carbide chip.
[0047] See also Figure 2 The PCB board 1 includes a base 11 and at least one cantilever beam 12 extending outward from the base 11. The cantilever beam 12 includes a horizontal portion 121 and a vertical portion 122 that are perpendicularly connected to each other. The horizontal portion 121 is connected to the base 11, and there is a gap between the vertical portion 122 and the base 11. The number of cantilever beams 12 can be set according to the actual situation.
[0048] In one implementation, see [link to implementation details]. Figure 2 The PCB board 1 may include at least one pair of cantilever beams 12, each pair of cantilever beams 12 being symmetrically arranged on both sides of the substrate 11. For example, the PCB board 1 includes three pairs of cantilever beams 12.
[0049] Therefore, by symmetrically arranging each pair of cantilever beams 12 on both sides of the base 11, the balance of the base 11 is facilitated.
[0050] See also Figure 1 Each conductive substrate 2 is located on the same plane and is parallel to the PCB board 1. For each chip 3, the upper surface of the chip 3 is fixedly connected to the corresponding cantilever beam 12, and the lower surface of the chip 3 is fixedly connected to the corresponding conductive substrate 2. The position of the chip 3 can be designed according to the actual situation, and the fixed connection can be achieved by reflow soldering or sintering. This embodiment of the utility model does not limit the specific method of fixing the chip 3.
[0051] In summary, the hybrid packaging structure provided by this utility model embodiment includes a PCB board 1, at least one conductive substrate 2, and at least one chip 3. The PCB board 1 includes a base 11 and at least one cantilever beam 12 extending outward from the base 11. The cantilever beam 12 includes a horizontal portion 121 and a vertical portion 122 that are perpendicularly connected to each other. The horizontal portion 121 is connected to the base 11, and there is a gap between the vertical portion 122 and the base 11. Each conductive substrate 2 is located on the same plane and is parallel to the PCB board 1. For each chip 3, the upper surface of the chip 3 is fixedly connected to the corresponding cantilever beam 12, and the lower surface of the chip 3 is fixedly connected to the corresponding conductive substrate 2. In this invention, the PCB board 1 is designed to extend at least one cantilever beam 12. The cantilever beam 12 includes a horizontal portion 121 and a vertical portion 122 that are perpendicularly connected to each other. The horizontal portion 121 is connected to the base 11, and there is a gap between the vertical portion 122 and the base 11. This allows the horizontal portion 121 to adapt to vertical deformation and the vertical portion 122 to adapt to horizontal deformation when the PCB board creeps under thermal stress. This releases thermal stress, reduces the difference in thermal expansion coefficients between the PCB board 1 and the conductive substrate, avoids large thermal stress at the welding joint, reduces the possibility of welding defects, and further avoids the occurrence of a high failure risk for the entire power module. This improves reliability, reduces welding difficulty, and lowers costs.
[0052] Furthermore, the addition of PCB board 1 allows the upper surface of the chip to dissipate heat, and the larger area of PCB board 1 greatly increases the heat dissipation area, reduces thermal resistance, and improves heat dissipation efficiency.
[0053] Furthermore, the addition of PCB board 1 eliminates the need for bonding wires, reducing parasitic inductance and preventing large voltage overshoots during the rapid switching of power devices. This reduces the risk of power device breakdown and does not limit the improvement of the switching speed of power devices.
[0054] Figure 3 This is another schematic diagram of the hybrid packaging structure provided in an embodiment of the present invention. Figure 4 Another structural schematic diagram of the PCB board provided in this embodiment of the utility model is shown below. Figure 3 The hybrid packaging structure provided in this embodiment of the present invention further includes at least one metal block 4, the upper surface of each metal block 4 being fixedly connected to the substrate 11, and the lower surface of each metal block 4 being fixedly connected to the corresponding conductive substrate 2. See also Figure 4 The base 11 is provided with a metal block connection position 41 for fixing and connecting the metal block 4.
[0055] Each metal block 4 is used to realize the electrical connection between the substrate 11 and the corresponding conductive substrate 2. That is, the function of the metal block 4 is to realize the electrical connection between the conductive substrate 2 and the PCB board 1. The position and number of the metal blocks 4 can be designed according to the actual situation. This utility model embodiment does not make any limitation in this regard, as long as the electrical connection between the conductive substrate 2 and the PCB board 1 can be realized.
[0056] For example, the metal block 4 can be fixedly connected to the substrate 11 and the conductive substrate 2 by welding, and the connecting material used for welding can be solder paste, silver film or solder sheet.
[0057] For example, metal block 4 is a copper block.
[0058] See also Figure 4 Each cantilever beam 12 is fixedly connected to at least one chip 3.
[0059] In other words, each cantilever beam 12 can be fixedly connected to one chip 3 or multiple chips 3, and the number of chips 3 can be designed according to the actual situation. Figure 4 In the case where only one chip 3 is fixedly connected to each cantilever beam 12, each cantilever beam 12 is provided with a chip connection position 31.
[0060] In one implementation, the hybrid packaging structure provided by this utility model embodiment further includes multiple passive components, the upper surface of each passive component is fixedly connected to the substrate 11, and the lower surface of each passive component is fixedly connected to the corresponding conductive substrate 2.
[0061] Each conductive substrate 2 has a pattern corresponding to a passive component connected to it. The position of each passive component is related to the pattern on the conductive substrate 2, and can be designed according to the actual situation. That is, each passive component should be installed at the position where the pattern is drawn on the corresponding conductive substrate 2. The pattern can serve as a conductive line to connect different components, so that current can be transmitted between the components according to the designed path. The fixed connection can be fixed by reflow soldering or sintering. This utility model embodiment does not limit this in any way. For example, the types of passive components include at least one of capacitors, resistors and inductors.
[0062] Electronic components are the basic parts that enable electronic devices to function, and can broadly refer to all structural parts that make up electronic devices. Based on whether they require electrical energy, they can be divided into active components and passive components. Chips are active components, while capacitors, resistors, etc., are passive components.
[0063] Thus, by fixing the lower surface of each passive component to the position where the pattern is drawn on the corresponding conductive substrate 2, the passive components are connected together, so that the current can be transmitted between the passive components according to the designed path.
[0064] See also Figure 3 The hybrid packaging structure provided in this embodiment of the present invention also includes a heat sink 5, with the lower surface of each conductive substrate 2 fixedly connected to the upper surface of the heat sink 5. The fixed connection can be achieved by soldering.
[0065] For example, Figure 3 The conductive substrate 2 is a ceramic substrate, and a first copper plate 21, a ceramic plate 22, and a second copper plate 23 are fixedly connected from top to bottom. The fixed connection method can be welding.
[0066] Therefore, by providing heat sinks 5 on the lower surface of each conductive substrate 2, heat dissipation efficiency is improved.
[0067] For ease of understanding, the following describes the installation steps of a hybrid packaging structure provided by this utility model through a specific embodiment, assuming that the conductive substrate 2 is a DBC substrate and the metal block 4 is a copper block:
[0068] 1. Mount each chip 3 and each passive component to the corresponding position, and select appropriate connection materials to connect them to the DBC substrate by reflow soldering or sintering;
[0069] 2. Fix copper blocks on the surface of a suitable DBC substrate using a spot application of solder paste or solder pads process, and apply solder paste or place solder pads on the copper blocks for connection to PCB board 1;
[0070] 3. For each chip 3, the chip 3 is assigned to the chip soldering position of the corresponding cantilever beam on the PCB board 1. The PCB board 1 is then placed upside down on the DBC substrate, ensuring that the copper block and the PCB board are in contact through solder paste and connected by reflow soldering. This achieves electrical interconnection between the upper surface of the chip 3 and the DBC substrate through the copper block.
[0071] Example 2
[0072] This utility model provides a power device, which includes any of the hybrid packaging structures provided in Embodiment 1.
[0073] Therefore, this utility model embodiment provides a power device, which includes any of the hybrid packaging structures provided in Embodiment 1. The hybrid packaging structure designs the PCB board as a cantilever beam extending outwards, and the cantilever beam includes a horizontal part and a vertical part that are perpendicularly connected to each other. The horizontal part is connected to the substrate, and there is a gap between the vertical part and the substrate. This allows the horizontal part to adapt to the vertical deformation and the vertical part to adapt to the horizontal deformation when the PCB board creeps under thermal stress. This releases thermal stress, reduces the difference in thermal expansion coefficients between the PCB board and the conductive substrate, avoids large thermal stress at the welding joint, reduces the possibility of welding defects, and further avoids the occurrence of a high failure risk for the entire power module, improving reliability. Moreover, it is easier to weld and reduces costs.
[0074] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this utility model.
[0075] Those skilled in the art will understand that the modules in the apparatus of the embodiments can be distributed in the apparatus of the embodiments as described in the embodiments, or they can be located in one or more devices different from this embodiment with corresponding changes. The modules of the above embodiments can be combined into one module, or they can be further divided into multiple sub-modules.
[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A hybrid package structure, characterized by, The application relates to a hybrid packaging structure. The hybrid packaging structure comprises a printed circuit board (PCB), at least one conductive substrate and at least one chip. The PCB comprises a base and at least one cantilever beam extending outward from the base, the cantilever beam comprises a horizontal part and a vertical part connected perpendicularly to each other, the horizontal part is connected to the base, and a gap exists between the vertical part and the base. Each conductive substrate is located on the same plane and parallel to the PCB. For each chip, the upper surface of the chip is fixedly connected to the corresponding cantilever beam, and the lower surface of the chip is fixedly connected to the corresponding conductive substrate.
2. The hybrid package structure of claim 1, wherein, The PCB comprises at least one pair of cantilever beams. Each pair of cantilever beams is symmetrically arranged on the two sides of the base.
3. The hybrid package structure of claim 1 or 2, wherein, The hybrid packaging structure further comprises at least one metal block. The upper surface of each metal block is fixedly connected to the base, and the lower surface of each metal block is fixedly connected to the corresponding conductive substrate, wherein each metal block is used to realize the electrical connection between the base and the corresponding conductive substrate.
4. The hybrid package structure of claim 1, wherein, The hybrid packaging structure further comprises a plurality of passive components. The upper surface of each passive component is fixedly connected to the base, and the lower surface of each passive component is fixedly connected to the corresponding conductive substrate.
5. The hybrid package structure of claim 4, wherein, The types of the passive components include at least one of a capacitor, a resistor and an inductor. A pattern corresponding to the passive component is drawn on each conductive substrate, and the lower surface of each passive component is fixedly connected to the position where the pattern is drawn on the corresponding conductive substrate.
6. The hybrid package structure of claim 1 or 2, wherein, The hybrid packaging structure further comprises a heat sink. The lower surface of each conductive substrate is fixedly connected to the upper surface of the heat sink.
7. The hybrid package structure of claim 1, wherein, Each cantilever beam is fixedly connected to at least one chip.
8. The hybrid package structure of claim 1, wherein, The types of the conductive substrate include at least one of a ceramic substrate, a mixed sintering substrate, a copper-clad substrate and a soft substrate.
9. The hybrid package structure of claim 1, wherein, The types of the chip include at least one of a silicon chip, a gallium arsenide chip, a gallium nitride chip and a silicon carbide chip.
10. A power device, characterized by The power device comprises the hybrid packaging structure as claimed in any one of claims 1-9.