Power module and electronic device
Patent Information
- Application Number
- CN202521598640.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-29
- Publication Date
- 2026-08-18
- Estimated Expiration
- 2035-07-29
AI Technical Summary
[0005]本申请实施例提供了一种功率模块和电子设备，以至少解决相关技术中的功率模块不满足大电流承载能力的技术问题
[0015] In this embodiment, the power module includes a power chip, multiple substrates, and a copper bridge structure. Each substrate has multiple lead frames, including drain and source lead frames, each with pins for external communication. A first copper bridge in the copper bridge structure connects the port of the power chip to a corresponding lead frame on the substrate. A second copper bridge in the copper bridge structure connects the source lead frames on the first substrate to the source lead frames on the second substrate, and connects the drain lead frames on the first substrate to the source lead frames on the second substrate. The first substrate and the second substrate are adjacent to each other. The copper bridge is smaller than the second copper bridge. Replacing the previous aluminum wire with a copper bridge solution solves the technical problem of power modules not meeting the high current carrying capacity in related technologies due to the stronger current carrying capacity of copper materials. The copper bridge also makes the heat distribution in the device more uniform, avoiding local overheating in the dense aluminum wire area. It also eliminates the need for a larger aluminum wire area to conduct high current (which would make local overheating more severe). In addition, the current carrying capacity of a single power chip is relatively small, so a smaller first copper bridge is selected between the chip and the substrate. However, each substrate has multiple power chips, meaning the current carrying capacity between substrates is relatively large. Therefore, a larger second copper bridge is selected between the substrates. This satisfies the differentiated current carrying capacity and also saves materials.
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Figure CN224654004U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power electronics, and more specifically, to a power module and an electronic device. Background Technology
[0002] The demand for high power density, high current carrying capacity and low switching loss in current power electronic equipment is increasing. EconoDUAL 3 (ED3) package has become one of the mainstream packaging forms for medium and high power IGBT modules due to its standardized interface and mature process. The typical solution in the industry is based on silicon-based IGBT (insulated gate bipolar transistor) and FRD (fast recovery diode) technology, and the output pin definition conforms to the ED3 package specification.
[0003] In the existing power module solutions mentioned above, aluminum wire bonding technology is used. However, aluminum wires have high resistivity, low current carrying capacity, occupy too much chip pad area, and generate more heat, which is not suitable for the current high-current substrate layout requirements.
[0004] There is currently no effective solution to the above problems. Utility Model Content
[0005] This application provides a power module and an electronic device to at least solve the technical problem in the related art that power modules do not meet the requirements for high current carrying capacity.
[0006] According to one aspect of the embodiments of this application, a power module is provided, including: a power chip, a plurality of substrates, and a copper bridge structure. Each substrate is provided with a plurality of lead frames, the plurality of lead frames including drain lead frames and source lead frames, and the lead frames have pins communicating with the outside. A first copper bridge in the copper bridge structure is used to connect the port of the power chip to the corresponding lead frame on the substrate. A second copper bridge in the copper bridge structure is used to connect the source lead frame on the first substrate and the source lead frame on the second substrate, and to connect the drain lead frame on the first substrate and the source lead frame on the second substrate. The first substrate and the second substrate are adjacent to each other, and the first copper bridge is smaller than the second copper bridge.
[0007] Optionally, the first copper bridge is used to connect the source port of the power chip to the source lead frame on the substrate.
[0008] Optionally, the thickness of the first copper bridge is 0.2 to 0.3 mm, and the thickness of the second copper bridge is 0.5 mm.
[0009] Optionally, the first copper bridge is located above the power chip, and the second copper bridge laterally spans the edges of the first and second substrates.
[0010] Optionally, a stress relief hole is provided at the top of the copper bridge structure.
[0011] Optionally, the height difference between the top of the copper bridge structure and the pin is 1.5 to 2 mm.
[0012] Optionally, the first copper bridge is connected to the power chip and the substrate by soldering.
[0013] Optionally, the second copper bridge is connected to the backing plate by soldering.
[0014] According to another aspect of the embodiments of this application, an electronic device is also provided, including the power module described above.
[0015] In this embodiment, the power module includes a power chip, multiple substrates, and a copper bridge structure. Each substrate has multiple lead frames, including drain and source lead frames, each with pins for external communication. A first copper bridge in the copper bridge structure connects the port of the power chip to a corresponding lead frame on the substrate. A second copper bridge in the copper bridge structure connects the source lead frames on the first substrate to the source lead frames on the second substrate, and connects the drain lead frames on the first substrate to the source lead frames on the second substrate. The first substrate and the second substrate are adjacent to each other. The copper bridge is smaller than the second copper bridge. Replacing the previous aluminum wire with a copper bridge solution solves the technical problem of power modules not meeting the high current carrying capacity in related technologies due to the stronger current carrying capacity of copper materials. The copper bridge also makes the heat distribution in the device more uniform, avoiding local overheating in the dense aluminum wire area. It also eliminates the need for a larger aluminum wire area to conduct high current (which would make local overheating more severe). In addition, the current carrying capacity of a single power chip is relatively small, so a smaller first copper bridge is selected between the chip and the substrate. However, each substrate has multiple power chips, meaning the current carrying capacity between substrates is relatively large. Therefore, a larger second copper bridge is selected between the substrates. This satisfies the differentiated current carrying capacity and also saves materials. Attached Figure Description
[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.
[0019] Figure 1 This is a schematic diagram of an optional power module in related technologies;
[0020] Figure 2 This is a schematic diagram of an optional power module according to an embodiment of this application;
[0021] Figure 3 This is a schematic diagram of an optional copper bridge according to an embodiment of this application;
[0022] Figure 4 This is a schematic diagram of an optional copper bridge according to an embodiment of this application;
[0023] Figure 5 This is a schematic diagram of an optional copper bridge bonding according to an embodiment of this application;
[0024] Figure 6 This is a schematic diagram of an optional aluminum wire bonding method in related technologies. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0026] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0028] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0029] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0031] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0032] like Figure 1 The power module shown uses aluminum wire (as shown in area A). However, aluminum wire has a weak current carrying capacity and occupies a large area of the pad, which cannot meet the high current conduction requirements of the current environment. In addition, aluminum has a high resistivity and generates a lot of heat, making it unsuitable for the layout of high current substrates.
[0033] Based on this, this application provides a power module that uses a copper bridge solution instead of an aluminum wire solution, such as... Figure 2 As shown, it includes:
[0034] The power chip 1, multiple substrates 2 and copper bridge structure 3 are provided. Each substrate is provided with multiple lead frames, including at least a drain lead frame and a source lead frame. Each lead frame has a pin that communicates with the outside. The height difference between the top of the copper bridge structure and the pin is 1.5 to 2 mm.
[0035] The first copper bridge 31 in the copper bridge structure connects the port of the power chip to the corresponding lead frame on the substrate (such as connecting the source port of the power chip to the source lead frame on the substrate and connecting the drain port of the power chip to the drain lead frame on the substrate). The first copper bridge is located directly above the power chip and is connected to the power chip and the substrate by soldering.
[0036] The second copper bridge 32 in the copper bridge structure (which is larger than the first copper bridge and can be called the large copper bridge, while the first copper bridge is called the small copper bridge) is used to connect adjacent first and second liner plates among the plurality of liners. Specifically, the source lead frame on the first liner plate among the plurality of liners can be connected to the source lead frame on the second liner plate among the plurality of liners, and the drain lead frame on the first liner plate and the source lead frame on the second liner plate can be connected. The second copper bridge is laterally spanned across the edges of the first liner plate and the second liner plate, and the edges of the two liners are connected by soldering.
[0037] The technical solution of this application replaces the previous aluminum wire with a copper bridge. Since copper material has a stronger current carrying capacity, it can solve the technical problem that the power module in the related technology does not meet the high current carrying capacity. In addition, the copper bridge can make the heat distribution in the device more uniform, avoiding local overheating in the dense area of the original aluminum wire. It also eliminates the need to lay out a larger aluminum wire area to conduct high current (which would make local overheating more serious). In addition, the current carrying capacity of a single power chip is relatively small, so a smaller first copper bridge is selected between the chip and the substrate. However, there are multiple power chips on each substrate, that is, the current carrying demand between substrates is large. Therefore, a larger second copper bridge is selected between the substrates. This can meet the differentiated current carrying requirements and save materials.
[0038] In an optional embodiment, since the current carrying capacity requirement for a single chip is relatively lower, while the current carrying capacity requirement between substrates (each substrate contains multiple chips) is relatively higher, the first copper bridge is smaller than the second copper bridge. Here, "smaller" refers to a smaller shape (e.g., a smaller upper surface area, a smaller thickness, or at least one of several shape features). Based on the size relationship, the first copper bridge can be referred to as the smaller copper bridge (e.g., ...). Figure 3 As shown), the second bronze bridge is referred to as the Great Bronze Bridge (as shown). Figure 4(as shown); In addition, the thickness of the first copper bridge can also be smaller (less than the thickness of the second copper bridge). For example, the thickness of the first copper bridge is 0.2 to 0.3 mm, and the thickness of the second copper bridge is 0.5 mm, so as to save materials as much as possible while meeting the flow capacity, thereby reducing costs.
[0039] In another optional embodiment, in order to further save copper material, a through hole, i.e. a stress relief hole, can be opened at the top of the copper bridge structure. This can provide a certain buffer space for the expansion and contraction of the copper bridge under temperature changes, and avoid the connection between the copper bridge and other components becoming loose or damaged due to stress concentration.
[0040] To address the issue of high voltage spikes during device switching caused by low output current and low switching frequency in existing solutions, this application replaces the Si-based solution with a SiC-based (silicon carbide) MOS (metal oxide semiconductor field-effect transistor) and, in conjunction with a copper bridge design, increases the module's current rating to 1000A, thereby reducing voltage spikes and switching losses and improving product performance.
[0041] As an optional embodiment, the technical solution of this application is further described in detail below with reference to specific embodiments:
[0042] like Figure 1 As shown, this power module uses an 8-chip parallel design, bonded with 15mil diameter aluminum wire. This design suffers from insufficient space for wire bonding and places high demands on the precision of the bonding process. Figure 2 As shown, the improved solution provided in this application uses large and small copper bridges to replace the 15mil aluminum lines, optimizing the layout space and improving the current flow capacity between the chip and the substrate, and between substrates. In the technical solution of this application:
[0043] 1) Chip soldering and bonding
[0044] like Figure 2 The product's internal structure, as shown, features two substrates (e.g., the left substrate is the first substrate, and the right substrate is the second substrate) each containing eight power chips (SiC MOS chips). These SiC MOS chips are soldered to the substrates using silver sintering or other welding processes. A copper bridge is then soldered between the SiC MOS chips and the substrates using a soldering process, connecting the chip's source (the centrally facing area of the chip is the source, and the externally facing area is the drain) to the source lead frame. (See [reference needed]). Figure 5 It is different from Figure 6 The 15mil aluminum wire bonding scheme has poor current carrying capacity in the relevant technologies.
[0045] 2) Module bonding
[0046] Soldering large copper bridges is performed between the substrates to connect the source lead frame and the drain lead frame. The outer casing busbar electrodes are ultrasonically welded to connect the busbar and the substrate, completing the circuit connection of the entire module product.
[0047] 3) Potting and curing
[0048] The potting compound is injected into the product and then cured.
[0049] This solution uses two copper bridges to complete the conduction between the chip and the substrate, and between substrates. The resistivity of copper is about 1.7 μΩ / cm, and the resistivity of aluminum is about 3.1 μΩ / cm. Using copper bridges can reduce RC delay. When transmitting the same current, copper bridges generate less heat (see Table 1), have lower power loss, and can improve the efficiency of power devices.
[0050] Table 1
[0051]
[0052] In the technical solution of this application, a copper bridge design is proposed, which uses the minimum amount of copper while ensuring performance. A hole is made at the top of the copper bridge to provide a buffer space for expansion and contraction due to temperature changes, preventing loosening or damage to the connection between the copper bridge and other components due to stress concentration. Considering the module's operating environment and compression costs, a smaller copper bridge is selected for the chip area, while a larger copper bridge is selected for the substrate area. The difference between the top height and the pin height is between 1.5 and 2 mm.
[0053] According to another aspect of the embodiments of this application, an electronic device is also provided, including the power module described above. The electronic device can be a household appliance, a new energy vehicle, an industrial power supply, an industrial motor, or other equipment.
[0054] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of feature combinations. However, those skilled in the art should understand that this application is not limited to the described feature order, as some features can be replaced by other features according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the features involved are not necessarily essential to this application.
[0055] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A power module, characterized in that, include: The chip comprises a power chip, multiple substrates, and a copper bridge structure. Each substrate is provided with multiple lead frames, each lead frame having pins that communicate with the outside. The multiple lead frames include a drain lead frame and a source lead frame. The first copper bridge in the copper bridge structure is used to connect the port of the power chip to the corresponding lead frame on the substrate. The second copper bridge in the copper bridge structure is used to connect the source lead frame on the first liner and the source lead frame on the second liner, and to connect the drain lead frame on the first liner and the source lead frame on the second liner. The first liner and the second liner are adjacent to each other, and the first copper bridge is smaller than the second copper bridge.
2. The power module according to claim 1, characterized in that, The thickness of the first copper bridge is less than the thickness of the second copper bridge.
3. The power module according to claim 2, characterized in that, The thickness of the first copper bridge is 0.2-0.3 mm, and the thickness of the second copper bridge is 0.5 mm.
4. The power module according to claim 1, characterized in that, The first copper bridge is used to connect the source port of the power chip to the source lead frame on the substrate.
5. The power module according to any one of claims 1 to 4, characterized in that, The first copper bridge is located above the power chip, and the second copper bridge is laterally connected across the edges of the first and second substrates.
6. The power module according to any one of claims 1 to 4, characterized in that, The copper bridge structure has stress relief holes at its top.
7. The power module according to any one of claims 1 to 4, characterized in that, The height difference between the top of the copper bridge structure and the pin is 1.5 to 2 mm.
8. The power module according to any one of claims 1 to 4, characterized in that, The first copper bridge is connected to the power chip and the substrate by soldering.
9. The power module according to any one of claims 1 to 4, characterized in that, The second copper bridge is connected to the backing plate by soldering.
10. An electronic device, characterized in that, Includes the power module as described in any one of claims 1-9.