A substrate provided with a sacrificial substrate region and a power device
By introducing a sacrificial substrate region on a metal-ceramic substrate and utilizing laser scribing and splitting processes, the problem of ceramic layer cracking during ultrasonic welding was solved, achieving a highly reliable and stable connection effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SAIJING ASIA PACIFIC SEMICON TECH (ZHEJIANG) CO LTD
- Filing Date
- 2025-08-13
- Publication Date
- 2026-07-21
AI Technical Summary
In the prior art, after removing the copper substrate, the brittle ceramic layer of the metal-ceramic substrate structure is prone to cracking during ultrasonic welding, making it difficult to guarantee a highly reliable and stable connection.
A sacrificial substrate region is introduced on the metal-ceramic substrate. The core substrate and the sacrificial substrate are separated by laser scribing to ensure that the ceramic layer edge is not cracked during ultrasonic welding. The sacrificial substrate region is removed by a splitting process to maintain the integrity of the connection.
This technology achieves the goal of preventing ceramic layer cracking without damaging the connection, improving the reliability of ultrasonic welding and connection, eliminating the limitation of welding parameters on the clamping mechanism, and ensuring that the substrate edge does not break or crack.
Smart Images
Figure CN224538410U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of power electronics technology, specifically relating to a substrate with a sacrificial substrate region and a power device. Background Technology
[0002] In modern power electronic components, a commonly used material is a thick (approximately 3 mm) copper substrate, which serves as a robust mounting base. In a typical automotive power module, terminal pins are ultrasonically welded to the copper layer on top of a cermet structure (Active Metal Brazed Board (AMB) or Direct Copper Clad Board (DBC), which is then brazed to the copper substrate. However, this thick copper substrate is expensive, heavy, and requires an additional thermal interface between it and the substrate above. Reducing the number of thermal interfaces and the types of materials used improves thermal performance and saves on the cost of expensive raw materials.
[0003] For demanding automotive applications, power modules require high reliability and robustness. External terminals for signal or control purposes (auxiliary pins) and for power transmission (power terminals) are typically made of a metal lead frame, which is connected to the upper surface of a substrate via ultrasonic welding, while the substrate is brazed to a copper substrate. Ultrasonic welding means that mechanical forces (pressures) are generated between the terminal pins and the copper upper surface of the cermet substrate. During the ultrasonic welding (USW) process, a strong mechanical force exceeding 100N is applied, and energy exceeding 20J is input to the weld joint in the form of strong mechanical oscillations. Thus, a crucial condition is that the substrate cannot undergo mechanical displacement, and since the substrate is brazed to the copper substrate, the copper substrate must also not be displaced. The copper substrate is a single solid piece of copper. Therefore, the copper substrate is typically clamped and mechanically fixed to the ultrasonic welding tool to meet the above conditions and ensure that displacement does not occur.
[0004] However, as mentioned earlier, to save costs and expensive raw material expenses, while improving the module's thermal performance, it is imperative to remove the copper substrate while retaining superior connection technology for auxiliary and power terminals—that is, to retain the ultrasonic welding (USW) process. This requirement is particularly evident in the HEEV module from SwissSEM Technologies AG in Switzerland. The problem is that after removing the copper substrate, the brittle ceramic layer in the metal-ceramic substrate structure must be mechanically clamped securely enough to ensure that the substrate does not move during the ultrasonic welding (USW) process. However, as... Figure 9 As shown, this mechanical clamping method is highly likely to cause ceramic cracks and spalling at the bottom of the metal-ceramic substrate. Figure 10 As shown, this cracking and edge cracking phenomenon is more pronounced after ultrasonic welding is completed. Utility Model Content
[0005] The technical problem solved by this utility model is to provide a substrate with a sacrificial substrate region, which avoids the cracking of the ceramic layer edge in the core substrate region by introducing the sacrificial substrate region, and at the same time ensures high reliability performance without damaging the connection between the metal ceramic substrate body and the external terminals and the integrity of the substrate ceramic layer itself.
[0006] To address the aforementioned problems, one aspect of this utility model provides a substrate with a sacrificial substrate region, comprising a metal-ceramic substrate body, the metal-ceramic substrate body including a core substrate region and a first sacrificial substrate region; the top surface of the core substrate region is provided with an upper copper layer, and the bottom surface of the core substrate region is provided with a lower copper layer, the upper copper layer being used for connection with a lead frame or other components; the first sacrificial substrate region is located on opposite outer sides of the core substrate region, and is located on the outer sides of both sides of the core substrate region for welding lead frames or other components.
[0007] Preferably, a first laser etched line is provided between the core substrate region and the first sacrificial substrate region.
[0008] Preferably, the metal-ceramic substrate body further includes a second sacrificial substrate region, which is located on two opposite outer sides of the core substrate region perpendicular to the first sacrificial substrate region; the upper copper layer is surrounded by the first sacrificial substrate region and the second sacrificial substrate region.
[0009] Preferably, a second laser etched line is provided between the core substrate region and the second sacrificial substrate region.
[0010] Preferably, the top surface of the first sacrificial substrate region is provided with a first sacrificial substrate upper copper layer; the bottom surface of the first sacrificial substrate region is provided with a first sacrificial substrate lower copper layer.
[0011] Preferably, the top surface of the second sacrificial substrate region is provided with an upper copper layer of the second sacrificial substrate; the bottom surface of the second sacrificial substrate region is provided with a lower copper layer of the second sacrificial substrate.
[0012] Preferably, the length of the first sacrificial substrate region is the same as the length of the side of the adjacent core substrate region.
[0013] Preferably, the width of the first sacrificial substrate region is 3-10 mm.
[0014] Preferably, the length of the second sacrificial substrate region is the sum of the length of the side of the adjacent core substrate region and twice the width of the first sacrificial substrate region; the width of the second sacrificial substrate region is 3-10 mm.
[0015] Another aspect of this invention provides a power device including the aforementioned substrate having a sacrificial substrate region.
[0016] Compared with the prior art, this utility model has the following advantages:
[0017] This invention discloses a substrate with a sacrificial substrate region. By introducing this sacrificial substrate region, the chipping of the ceramic edge in the core substrate region can be avoided, while ensuring high reliability without compromising the connection between the substrate and external terminals or the integrity of the ceramic layer of the metal-ceramic substrate itself. Adding the sacrificial substrate region eliminates all constraints imposed by the clamping mechanism, which previously limited the "parameter space" (force, power, and input energy during ultrasonic welding). Therefore, a trade-off is eliminated; the ultrasonic welding parameters are no longer limited by the clamping capacity, thus ensuring that the substrate edge will not break or chip. This results in a superior ultrasonic welding connection, thereby improving the reliability of the connection between the lead frame and the substrate. Regardless of the degree of chipping at the substrate edge, it can be eliminated by removing the sacrificial substrate region. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the substrate with a sacrificial substrate region as described in Embodiment 1 of this utility model; Figure 1 In the diagram, 'a' is a top view of the substrate. Figure 1 In the diagram, b is a cross-sectional view of the substrate;
[0019] Figure 2 This is a schematic diagram of the structure of the substrate with a sacrificial substrate region as described in Embodiment 2 of this utility model;
[0020] Figure 3 This is a schematic diagram of the structure of the substrate after the sacrificial substrate area is removed in embodiments 1 and 2 of this utility model; Figure 3 In the diagram, 'a' is the top view. Figure 3 In the diagram, b is a cross-sectional view;
[0021] Figure 4 This is a schematic diagram of the structure of the substrate with a sacrificial substrate region as described in Embodiment 3 of this utility model; Figure 4 In the diagram, 'a' is a top view of the substrate. Figure 4 In the diagram, b is a cross-sectional view of the substrate;
[0022] Figure 5 This is a schematic diagram of the structure of the substrate with a sacrificial substrate region as described in Embodiment 4 of this utility model;
[0023] Figure 6 These are schematic diagrams of the substrate structure after the sacrificial substrate region is removed in embodiments 3 and 4 of this utility model; Figure 6 In the diagram, 'a' is the top view. Figure 6 In the diagram, b is a cross-sectional view;
[0024] Figure 7 This is a schematic diagram of the structure during the welding of the lead frame in Embodiment 3 of this utility model; Figure 7 In the diagram, 'a' is the top view. Figure 7 In the diagram, b is a cross-sectional view;
[0025] Figure 8 This is a schematic diagram of the operation when splitting and removing the sacrificial substrate area in Embodiment 3 of this utility model; Figure 8 In step a, the sacrificial substrate region is removed by applying a thrust to the lead frame to split and remove it. Figure 8 In step b, the sacrificial substrate area is removed by splitting it through a tensile force applied to the lead frame. Figure 8 In step c, the sacrificial substrate region is split and removed by applying a thrust to the sacrificial substrate region.
[0026] Figure 9 These are photos of the HEEV metal substrate after a mechanical clamping test performed without the welding process, showing the edge of the substrate cracking.
[0027] Figure 10 These are photos showing cracks at the edges of the HEEV substrate and chipping at the ceramic edges after ultrasonic welding.
[0028] Wherein: 1-Metal-ceramic substrate body; 11-Core substrate area; 12-First sacrificial substrate area; 13-First laser etched line; 14-Second sacrificial substrate area; 15-Second laser etched line; 2-Upper copper layer; 3-Lower copper layer; 4-Lead frame; 5-Upper copper layer of the first sacrificial substrate; 6-Lower copper layer of the first sacrificial substrate; 7-Upper copper layer of the second sacrificial substrate; 9-Clamping device. Detailed Implementation
[0029] 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 some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0030] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", 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 utility model 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 utility model.
[0031] Example 1
[0032] like Figure 1 As shown, a substrate with a sacrificial substrate region in this embodiment includes a metal-ceramic substrate body 1, which includes a core substrate region 11 and a first sacrificial substrate region 12. The top surface of the core substrate region 11 has an upper copper layer 2, and the bottom surface of the core substrate region 11 has a lower copper layer 3. The upper copper layer 2 is used for connection with a lead frame 4 or other components. The first sacrificial substrate region 12 is located on both opposite outer sides of the core substrate region 11, and is located on the outer sides of the solder lead frame or other components of the core substrate region 11. A first laser etched line 13 is provided between the core substrate region 11 and the first sacrificial substrate region 12.
[0033] Other components refer to pins or pin housings.
[0034] The first laser scriber can be laser-processed directly on the metal-ceramic substrate raw material at the substrate supplier, or it can be processed by the power module manufacturer after ultrasonic welding. This first laser scriber is used to separate the sacrificial substrate from the core substrate after ultrasonic welding using a process that is easy to automate (bending along the edge = applying shear force).
[0035] The first sacrificial substrate region 12 must be located on the outer side of the welding lead frame or other components of the core substrate region 11, i.e., arranged along the welding direction, because this direction usually bears the strongest force.
[0036] In this embodiment, the length of the first sacrificial substrate region 12 is the same as the side length of the adjacent core substrate region. The width of the first sacrificial substrate region is 5 mm.
[0037] In this embodiment, a substrate with a sacrificial substrate region is used for ultrasonic welding of a lead frame. The operation involves mechanically clamping the first sacrificial substrate regions on opposite sides of the cermet substrate body sufficiently firmly using a clamping device to ensure the substrate does not move during ultrasonic welding. Then, a lead frame or other components are ultrasonically welded onto the upper copper layer. After ultrasonic welding, the first sacrificial substrate region (e.g., [missing information]) is removed using a splitting process. Figure 3The diagram shows the structure of the substrate after the first sacrificial substrate region has been split (as shown). This process is the same as the process typically used by suppliers to separate individual substrates from the motherboard. The sacrificial substrate can be split and removed by applying tension or pushing force to the lead frame. Alternatively, the sacrificial substrate region can be split and removed by applying tension or pushing force. If the clamping operation damages the outer edge of the cermet substrate body during clamping or ultrasonic welding, such damage will be eliminated after splitting and removing the sacrificial substrate region. From a reliability perspective, the ceramic portion of the substrate remains intact.
[0038] This embodiment provides a substrate with a sacrificial substrate region. By introducing this region, chipping of the ceramic edge in the core substrate region can be avoided, while ensuring high reliability without compromising the connection between the substrate and external terminals or the integrity of the ceramic layer of the metal-ceramic substrate itself. Adding the sacrificial substrate region eliminates all constraints imposed by the clamping mechanism, which previously limited the "parameter space" (force, power, and input energy during ultrasonic welding). Therefore, a trade-off is eliminated; the ultrasonic welding parameters are no longer limited by the clamping capacity, ensuring that the substrate edge will not break or chip. This results in a superior ultrasonic welding connection, thereby improving the reliability of the lead frame-substrate connection. Regardless of the degree of chipping at the substrate edge, it can be eliminated by removing the sacrificial substrate region.
[0039] Example 2
[0040] like Figure 2 As shown, this embodiment of the substrate includes a sacrificial substrate region. The remaining structure is the same as in Embodiment 1, except that the metal-ceramic substrate body 1 further includes a second sacrificial substrate region 14, located on the two opposite outer sides of the core substrate region 11 perpendicular to the first sacrificial substrate region 12. The upper copper layer 2 is surrounded by the first sacrificial substrate region 12 and the second sacrificial substrate region 14. A second laser-etched line 15 is provided between the core substrate region 11 and the second sacrificial substrate region 14. After ultrasonic welding, the first and second sacrificial substrate regions are removed using a splitting process. The length of the second sacrificial substrate region is the sum of the length of the adjacent side of the core substrate region and twice the width of the first sacrificial substrate region. The width of the second sacrificial substrate region is 5 mm.
[0041] Example 3
[0042] like Figure 4As shown, this embodiment has a substrate with a sacrificial substrate region. The rest of the structure is the same as that of embodiment 1, except that: the top surface of the first sacrificial substrate region 12 is provided with a first sacrificial substrate upper copper layer 5; the bottom surface of the first sacrificial substrate region 12 is provided with a first sacrificial substrate lower copper layer 6. The same copper layer is provided on the upper and lower surfaces of the ceramic layer of the sacrificial substrate region, which can improve mechanical stability or uniformity.
[0043] The substrate with a sacrificial substrate region in this embodiment is used for ultrasonic welding of the lead frame as follows: Figure 7 As shown, the clamping device 9 mechanically clamps the first sacrificial substrate areas on opposite sides of the metal-ceramic substrate body securely enough to ensure that the substrate does not move during ultrasonic welding. Figure 8 Figures a and b illustrate the operation of splitting and removing the sacrificial substrate area by applying a pushing or pulling force to the lead frame after soldering. Figure 8 As shown in Figure c, this is a schematic diagram illustrating the operation of splitting and removing the sacrificial substrate region by applying a pushing force to the sacrificial substrate region after welding. Figure 6 The diagram shown is a schematic representation of the substrate structure after splitting the first sacrificial substrate region and the second sacrificial substrate region.
[0044] Example 4
[0045] like Figure 5 As shown, this embodiment of the substrate has a sacrificial substrate region, and the rest of the structure is the same as that of embodiment 3, except that: the metal-ceramic substrate body 1 also includes a second sacrificial substrate region 14, which is located on the two opposite outer sides of the core substrate region 11 perpendicular to the first sacrificial substrate region 12; the upper copper layer 2 is surrounded by the first sacrificial substrate region 12 and the second sacrificial substrate region 14. The top surface of the second sacrificial substrate region 14 is provided with a second sacrificial substrate upper copper layer 7; the bottom surface of the second sacrificial substrate region 14 is provided with a second sacrificial substrate lower copper layer.
[0046] The substrates with sacrificial substrate regions in the above embodiments are applicable not only to scenarios where the substrate is soldered to the lead frame, but also to scenarios where the substrate is soldered to the pins or pin housings.
[0047] Example 5
[0048] One power device of this embodiment includes any one of the substrates provided with a sacrificial substrate region in embodiments 1-4.
[0049] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A substrate having a sacrificial substrate region, characterized in that: The device includes a metal-ceramic substrate body, which includes a core substrate region and a first sacrificial substrate region. The top surface of the core substrate region is provided with an upper copper layer, and the bottom surface of the core substrate region is provided with a lower copper layer. The upper copper layer is used to connect with a lead frame or other components. The first sacrificial substrate region is located on both opposite sides of the core substrate region and is located on the outer sides of the two sides of the core substrate region where the lead frame or other components are soldered.
2. The substrate with a sacrificial substrate region according to claim 1, characterized in that: A first laser etched line is provided between the core substrate region and the first sacrificial substrate region.
3. The substrate with a sacrificial substrate region according to claim 1, characterized in that: The metal-ceramic substrate body also includes a second sacrificial substrate region, which is located on the two opposite outer sides of the core substrate region perpendicular to the first sacrificial substrate region; the upper copper layer is surrounded by the first sacrificial substrate region and the second sacrificial substrate region.
4. The substrate with a sacrificial substrate region according to claim 3, characterized in that: A second laser etched line is provided between the core substrate region and the second sacrificial substrate region.
5. The substrate with a sacrificial substrate region according to claim 1, characterized in that: The top surface of the first sacrificial substrate region is provided with an upper copper layer of the first sacrificial substrate; the bottom surface of the first sacrificial substrate region is provided with a lower copper layer of the first sacrificial substrate.
6. The substrate with a sacrificial substrate region according to claim 3, characterized in that: The top surface of the second sacrificial substrate region is provided with an upper copper layer of the second sacrificial substrate; the bottom surface of the second sacrificial substrate region is provided with a lower copper layer of the second sacrificial substrate.
7. The substrate with a sacrificial substrate region according to claim 1, characterized in that: The length of the first sacrificial substrate region is the same as the length of the side of the adjacent core substrate region.
8. The substrate with a sacrificial substrate region according to claim 1, characterized in that: The width of the first sacrificial substrate region is 3-10 mm.
9. The substrate with a sacrificial substrate region according to claim 3, characterized in that: The length of the second sacrificial substrate region is the sum of the length of the side of the adjacent core substrate region and twice the width of the first sacrificial substrate region; the width of the second sacrificial substrate region is 3-10 mm.
10. A power device, characterized in that, The substrate includes a sacrificial substrate region as described in any one of claims 1-9.