Control system and vehicle
By using prefabricated welding joint structures in welding, the high thermal conductivity of the metal layer and the precise thickness control of the metal gaskets are solved, and the reliability and heat dissipation efficiency of the welding joints are improved.
Patent Information
- Application Number
- CN202311688970.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-08
- Publication Date
- 2025-06-13
AI Technical Summary
In the existing welding technology, the high thermal resistance and uneven stress of the welding joints lead to low reliability of the welding joints, which is prone to problems such as temperature fatigue and cracking of the welding joints.
Prefabricated solder joint structures are adopted, including metal gaskets, multi-layer solder layers and metal layers. The thermal resistance of solder joints is reduced through the high thermal conductivity of the metal layer, and the thickness of the solder joints is accurately controlled through the metal gaskets to match the temperature cycle and stress distribution requirements of the weldment.
It effectively reduces the thermal resistance and stress of the solder joints, improves the reliability and heat dissipation efficiency of the solder joints, avoids the problem of cracking of the solder joints, and is suitable for a variety of welded parts products.
Smart Images
Figure CN120133803A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of welding technology, and particularly to a control system and a vehicle. Background Art
[0002] Currently, the design or integration of components such as chips, power modules, and microcontroller units is evolving towards high efficiency and high power density, requiring a reduction in thermal resistance throughout the entire link from the wafer to the system. Currently, direct soldering with solder is usually used between two existing components, resulting in a high void rate in the solder joints and relatively low reliability in temperature cycling fatigue of the solder joints. Summary of the Invention
[0003] In view of this, this application provides a control system and a vehicle to reduce the thermal resistance of solder joints, reduce solder joint stress, and improve reliability.
[0004] In a first aspect, an embodiment of this application provides a prefabricated solder joint, which includes: a metal gasket, at least two solder layers, and at least one metal layer. Along the thickness direction of the prefabricated solder joint, one of the solder layers located on one side of the prefabricated solder joint is used to be welded and connected to a first welded part, and the other solder layer located on the other side of the prefabricated solder joint is used to be welded and connected to a second welded part. The metal layer is disposed between at least two solder layers. The metal gasket is connected to the metal layer and the solder layer. At least a part of the metal gasket protrudes from the surface of the metal layer and is used to be connected to the solder layer. Wherein, the thickness of the part of the metal gasket protruding from the surface of the metal layer is H1, and the thickness of the solder layer connected to the part of the metal gasket protruding from the surface of the metal layer is H2, and H2≥H1.
[0005] In this application, by disposing a metal layer between the solder layers, the overall heat conduction ability of the prefabricated solder joint can be improved through the high heat conduction characteristic of the metal layer, the thermal resistance can be reduced, and the heat dissipation efficiency can be improved. In addition, the part of the metal gasket protruding from the surface of the metal layer can be connected to the outermost solder layer of the prefabricated solder joint, which can ensure that the thickness of the outermost solder layer is not less than the height of the part of the metal gasket protruding from the surface of the metal layer. Thus, the overall thickness of the prefabricated solder joint can be accurately limited by the metal gasket, so that the thickness of the prefabricated solder joint can accurately match the requirements of temperature cycling, stress distribution, etc. at the solder joint of the welded part product, and the welding reliability of the solder joint can be ensured for various welded part products, avoiding solder joint cracking.
[0006] In a possible design, the metal gasket is connected to the surface of the metal layer. Wherein, the metal layer can be an integrally formed structure, without the need to use a punching process to open holes in the metal sheet, and the metal gasket can be pressed on the metal layer through a cold pressing process, with a simple process. At the same time, the thickness of the prefabricated solder joint can be limited by the metal gasket to achieve precise control of the thickness and ensure the welding reliability between the welded parts.
[0007] In a possible design, a first through-hole is provided in the metal layer, the metal gasket is disposed in the first through-hole, and both ends of the metal gasket respectively protrude from the first through-hole. Wherein, by providing the first through-hole, it is convenient to install and position the metal gasket in the prefabricated solder joint. In addition, the length of the metal gasket can be greater than the depth of the first through-hole, so that both ends of the metal gasket can respectively protrude from both ends of the first through-hole, thereby the portions of the metal gasket protruding from the through-hole can be used to limit the thickness of the outermost solder layers on both sides of the prefabricated solder joint, and thus precise control of the overall thickness of the prefabricated solder joint can be achieved.
[0008] In a possible design, the metal layer, the solder layer and the metal gasket are fixedly combined by a cold pressing process. The cold pressing process can press the metal layer, the solder layer and the metal gasket into a whole at one time, with simple process and high combination reliability.
[0009] In a possible design, a barrier layer is electroplated on the metal layer, and the metal layer contacts the solder layer through the barrier layer. Wherein, the metal layer is a thin sheet structure with a certain thickness. After the metal layer is formed, it can be integrally immersed in an electroplating bath so that a layer of barrier layer is electroplated on the surface of the metal layer. This barrier layer can isolate the metal layer from the solder layer and prevent the metal layer from directly contacting the solder layer and undergoing chemical reactions.
[0010] In a possible design, the material of the barrier layer is nickel. After the nickel layer reacts with the tin-based solder layer, it will not have an adverse effect on the heat conduction performance, nor will it affect the thickness of the prefabricated solder joint, and it can ensure high reliability of the prefabricated solder joint after welding.
[0011] In a possible design, a second through-hole is provided in the metal layer, and at least part of the solder of the solder layer fills into the second through-hole. Wherein, the solder of the solder layer can not only contact the surface of the metal layer, but also contact the inner wall of the second through-hole. Thus, by providing the second through-hole, the contact area between the metal layer and the solder layer is enlarged, and the reliability of the combination between the solder layer and the metal layer is improved.
[0012] In a possible design, there are at least two layers of the metal layer, at least three layers of the solder layer, and the metal layer and the solder layer are alternately stacked. The prefabricated solder joint with a five-layer or more stack composed of more than three layers of solder layer and more than two layers of metal layer can have a larger thickness and can be applicable to the scenarios where there are large welding distance requirements between two welded parts.
[0013] In a possible design, the thickness of the prefabricated solder joint is less than or equal to 10,000 um. Among them, through the arrangement of the solder layer and the metal layer stack, and through the precise control of the overall height of the prefabricated solder joint by the metal gasket, the thickness of the prefabricated solder joint can be precisely matched according to the service life, size specifications, temperature cycle, stress distribution, cost control, heat conduction benefit, heat conduction balance, etc. of the welded part product within the range of less than or equal to 10,000 um, ensuring welding reliability in various welded parts of different types and having a wide range of applications.
[0014] In a possible design, the material of the metal layer is one of silver, copper, gold, aluminum, tungsten, and zinc. These materials have the characteristic of high heat conduction, which is beneficial to heat conduction and improves the heat dissipation effect on the aforementioned heat generating module.
[0015] In a possible design, the solder layer is a soft soldering solder preform or solder paste. These materials can be prepared into preforms with a certain thickness and can be stacked with the metal layer. Of course, they can also be combined with the metal layer into an integral structure through a cold pressing process.
[0016] In a second aspect, the present application also provides a heat dissipation system, which includes a first welded part, a second welded part, and the prefabricated solder joint provided in the first aspect of the present application. The solder layer on one side of the prefabricated solder joint is welded to the first welded part, and the solder layer on the other side of the prefabricated solder joint is welded to the second welded part. Among them, the heat dissipation system using the aforementioned prefabricated solder joint has similar technical effects to the aforementioned prefabricated solder joint and will not be elaborated here.
[0017] In a possible design, the first welded part is a radiator, and the second welded part is a heat generating module.
[0018] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0020] Figure 1 is a schematic structural diagram of the heat dissipation system provided by the embodiment of the present application;
[0021] Figure 2 is a schematic structural diagram of the prefabricated solder joint provided by the first embodiment of the present application;
[0022] Figure 3Schematic diagram of the prefabricated solder joint provided by the first embodiment of the present application in application;
[0023] Figure 4 Schematic diagram of the structure of the prefabricated solder joint provided by the second embodiment of the present application;
[0024] Figure 5 Curve graph of the thickness of the prefabricated solder joint and the change of solder joint stress provided by the embodiment of the present application;
[0025] Figure 6 Stress simulation diagram of the prefabricated solder joint provided by the embodiment of the present application in application;
[0026] Figure 7 Schematic diagram of the structure of the prefabricated solder joint provided by the third embodiment of the present application;
[0027] Figure 8 Schematic diagram of the structure of the prefabricated solder joint provided by the fourth embodiment of the present application;
[0028] Figure 9 Schematic diagram of the structure of the prefabricated solder joint provided by the fifth embodiment of the present application;
[0029] Figure 10 Schematic diagram of the second through hole opened on the metal layer provided by one embodiment of the present application;
[0030] Figure 11 Schematic diagram of the second through hole opened on the metal layer provided by another embodiment of the present application.
[0031] Reference numerals:
[0032] 100 - First welding part;
[0033] 110 - Fin;
[0034] 200 - Second welding part;
[0035] 300 - Prefabricated solder joint;
[0036] 1 - Solder layer;
[0037] 2 - Metal layer;
[0038] 21 - First through hole;
[0039] 22 - Second through hole;
[0040] 3 - Metal gasket;
[0041] 4 - Barrier layer;
[0042] Z - Thickness direction. Detailed implementation manners
[0043] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0044] It should be clear that the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.
[0045] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "the" and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0046] It should be understood that the term " / or" used herein is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, a / or b may represent: a exists alone, a and b exist simultaneously, and b exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.
[0047] In the description of this application, unless otherwise clearly specified and limited, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; unless otherwise specified or stated, the term "plural" means two or more; the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0048] Currently, transportation means such as vehicles and ships are developing towards green energy, and more and more transportation means use electric energy to power the vehicles. Exemplarily, taking vehicles as an example, for the power parameters of the vehicle's motor, the battery power control, etc., they all need to be controlled by a motor control unit (MCU). Such a control system includes various modules and components, such as a System on Chip (SOC), an Insulate-Gate Bipolar Transistor (IGBT), a power module, etc. The design or integration of these modules and components evolves towards high efficiency and high power density, requiring a reduction in thermal resistance throughout the entire link from the wafer to the system. In one embodiment, for heat-generating modules such as chips and power modules, heat sinks are generally used for heat dissipation. The front of the heat sink has fins, which can improve the heat dissipation efficiency, and the back of the heat sink is used to connect to the heat-generating module. Generally, the heat-generating module and the heat sink are welded together through a filled solder. However, with the direct welding method, the void rate of the solder joints is high. At the same time, when there is a mismatch in the coefficient of thermal expansion (CTE) between the heat-generating module and the heat sink, the thermal cycling fatigue reliability of the solder joints is low, and the welding surface cracks from the corners during the temperature cycling process, ultimately affecting the heat dissipation efficiency.
[0049] In addition, the heat sink and the heat-generating module can also be connected and fixed through the cooperation of thermal grease and screws, that is, the thermal grease material can be filled between the heat sink and the heat-generating module, and then the heat sink, the thermal grease material, and the heat-generating module are locked and fixed by screws. Among them, the thermal grease has good thermal conductivity and can conduct the heat of the heat-generating module. At the same time, the screw connection method can improve the connection reliability between the heat sink and the heat-generating module. However, using a large amount of thermal grease material and screw connectors will result in a significant increase in production costs and complex processing procedures.
[0050] The embodiment of the present application provides a control system, which can be applied in a vehicle. Exemplarily, the control system can be an MCU in the vehicle. In this control system, it can include a first welded part, a second welding, and a prefabricated solder joint. The prefabricated solder joint can be used for welding the first welded part and the second welded part to ensure the connection reliability of the two welded parts. Exemplarily, when at least one of the two welded parts has a heat dissipation requirement, the prefabricated solder joint also has excellent thermal conductivity, and efficient heat dissipation can be achieved through the prefabricated solder joint, which is beneficial to improving the heat dissipation efficiency of the heat-generating module.
[0051] In one embodiment, the prefabricated solder joint 300 can be applied to two welded parts with connection and heat dissipation requirements. Figure 1 The structural schematic diagram of the heat dissipation system provided by the embodiment of the present application is referred toFigure 1 , as described above, the control system may include a first welded part 100 and a second welded part 200. Among them, one of the first welded part 100 and the second welded part 200 can generate heat and has a heat dissipation requirement, and the other has a heat dissipation function. The first welded part 100 and the second welded part 200 can be welded and fixed through the prefabricated solder joint 300. Through the prefabricated solder joint 300, the reliability of the connection between the first welded part 100 and the second welded part 200 can be ensured, and the heat generated by the welded part with the heat dissipation requirement can be efficiently conducted to the welded part with the heat dissipation function to achieve efficient heat dissipation.
[0052] In one embodiment, Figure 1 exemplarily shows that the heat dissipation system includes a radiator and a heat generating module. Specifically, referring to Figure 1 , the first welded part 100 can be a radiator, and the second welded part 200 can be a heat generating module. Exemplarily, the heat generating module can include a SOC chip, a power module, an insulated gate bipolar transistor (IGBT), etc. The front of the radiator has fins 110, and the back of the radiator can be welded and connected to the heat generating module through the prefabricated solder joint provided in this embodiment. The heat generated by the heat generating module can be conducted to the radiator through the prefabricated solder joint, and the radiator can dissipate the heat to the external environment through the fins 110.
[0053] Figure 2 is a schematic structural diagram of the prefabricated solder joint provided by the embodiment of the present application. Referring to Figure 2 , the aforementioned prefabricated solder joint provided in this embodiment includes a metal gasket 3, at least two solder layers 1 and at least one metal layer 2. Among them, the metal sheet is made of a metal material. Exemplarily, the metal sheet can be made of one of silver, copper, gold, aluminum, tungsten, and zinc. These materials have the characteristics of high heat conduction, which is beneficial to conducting heat and improving the heat dissipation effect on the aforementioned heat generating module. Of course, in some other embodiments, the material of the metal sheet can also be other metal materials with high heat conduction characteristics.
[0054] The solder layer 1 has good solderability and can be reliably combined with the aforementioned welded parts. In one embodiment, the solder layer 1 can be a prefabricated soft soldering solder sheet. This soft soldering solder can be a low-temperature tin-bismuth-silver alloy, a tin-bismuth alloy, etc. These materials can be prepared into prefabricated sheets with a certain thickness and can be stacked with the metal layer 2. Of course, they can also be combined with the metal layer 2 into an integral structure through a cold pressing process. In addition, the solder layer 1 can also be a normal-temperature solder, such as a tin-lead alloy or SAC305 solder paste, etc. Among them, SAC305 solder paste is composed of three parts: tin Sn, silver Ag, and copper Cu according to a certain percentage content, and has good physical and mechanical properties in terms of heat conduction and connection reliability between welded parts.
[0055] The metal gasket 3 can play a role in restricting the overall height of the prefabricated solder joint, enabling precise control of the height of the prefabricated solder joint. Specifically, it can be reflected in the control of the laminated thickness of the solder layer 1 and the metal layer 2, so that the performance of the prefabricated solder joint can match the conditional requirements of the welded part product, such as the service life, size specifications, etc. of the welded part product. Among them, the material used for the metal gasket 3 can be the same as that of the metal layer 2. It can jointly play the function of heat conduction with the metal sheet, improving the heat dissipation effect. At the same time, it can play a role in strengthening the structure of the prefabricated solder joint, reducing the risk of solder joint cracking. In one embodiment, the metal gasket 3 can be in a cylindrical structure, and its cross-sectional shape can be circular, rhombic, square, trapezoidal, triangular or irregular, and it can be discretely distributed at various positions of the metal layer 2 or can be arrayed according to a certain rule.
[0056] Refer to Figure 2 , at least two layers of solder layer 1 and at least one layer of metal layer 2 can be laminated, and the metal layer 2 is arranged between at least two layers of solder layer 1. In one embodiment, the solder layer 1 has two layers and the metal layer 2 has one layer. The metal layer 2 is arranged between the two layers of solder layer 1. That is to say, one layer of solder layer 1, one layer of metal layer 2 and another layer of solder layer 1 are laminated in sequence to form a prefabricated solder joint. Among them, Figure 3 is a schematic diagram of the prefabricated solder joint provided by the first embodiment of the present application in application. Refer to Figure 3 , the two layers of solder layer 1 are respectively the outermost layers on both sides of the prefabricated solder joint, and these two layers of solder layer 1 can be respectively welded to the first welded part 100 and the second welded part 200 in the aforementioned heat dissipation system. In one embodiment, the solder layer 1 has at least three layers and the metal layer 2 has at least two layers. Exemplarily, Figure 4 is a schematic structural diagram of the prefabricated solder joint provided by the second embodiment of the present application. Refer to Figure 4 , the solder layer 1 has three layers and the metal layer 2 has two layers. Each solder layer 1 and metal layer 2 are laminated alternately. That is to say, there is one layer of metal layer 2 between adjacent two layers of solder layer 1, and there is one layer of solder layer 1 between adjacent two layers of metal layer 2. The outermost layers on both sides of the prefabricated solder joint with this laminated structure are also solder layer 1. This prefabricated solder joint can be welded to the corresponding first welded part and the second welded part 200 through the outermost solder layer 1. The prefabricated solder joint with a five-layer lamination composed of three layers of solder layer 1 and two layers of metal layer 2 can have a larger thickness and can be applicable to scenarios where there are greater welding distance requirements between two welded parts. In some other embodiments, the prefabricated solder joint can also be a seven-layer lamination structure, specifically including four layers of solder layer 1 and three layers of metal layer 2. The four layers of solder layer 1 and the three layers of metal layer 2 are still alternately distributed, so that the outermost layers on both sides of the prefabricated solder joint are both solder layer 1 to achieve welding connection with the corresponding first welded part 100 and the second welded part 200. Thus, through the selection and combination of multiple solder layer 1 and metal layer 2, it can be applicable to more welding scenarios.
[0057] Among them, the thermal conductivity of the metal layer 2 is generally higher than that of the solder layer 1. For example, the thermal conductivity of the metal layer 2 prepared from copper Cu is much higher than that of the solder layer 1 prepared from tin Sn. Therefore, by arranging the metal layer 2 between the solder layers 1, the overall thermal conductivity of the prefabricated solder joints can be improved through the high thermal conductivity characteristics of the metal layer 2, the thermal resistance can be reduced, and the heat dissipation efficiency can be improved.
[0058] In addition, as described above, if only solder is used to fill the gap between two workpieces for welding, the problem of solder joint voids will occur, and in the case of CTE mismatch between the two workpieces, large stress is likely to be generated at the corners of the solder joints, resulting in solder joint cracking. In this application, on the one hand, by arranging metal sheets in the prefabricated solder joints, the structural strength of the prefabricated solder joints can be improved, and the risk of prefabricated solder joint cracking can be reduced. On the other hand, since the smaller the thickness of the prefabricated solder joint, the greater the solder joint stress, and the easier it is to cause solder joint cracking. For the traditional welding method of directly filling solder between two workpieces, the thickness of the solder joint cannot be controlled. When the overall thickness of the solder joint is small or the local thickness is small, the solder joint is likely to crack at the corners or at the positions with relatively small thickness. Referring to Figure 2 , a metal gasket 3 is provided in the prefabricated solder joints provided in this application. The metal gasket 3 is connected to the metal layer 2 and the solder layer 1, and at least part of the metal gasket 3 protrudes from the surface of the metal layer 2 for connection with the solder layer 1. In one embodiment, the metal gasket 3 is arranged on the surface of the metal layer 2 and connected to the solder layer 1. That is to say, the metal gasket 3 is entirely located outside the metal layer 2, and one end of the metal gasket 3 can be connected to the surface of the metal layer. In one embodiment, at least part of the metal gasket 3 is embedded inside the metal layer 2, and at least part of the metal gasket 3 protrudes from the surface of the metal layer 2, and the part of the metal gasket 3 protruding from the surface of the metal layer 2 can be connected to the solder layer 1.
[0059] Among them, the distance between the end of the metal gasket 3 and the adjacent metal layer 2 is H1, and the thickness of the outermost solder layer 1 of the prefabricated solder joint is H2, and H2≥H1. Therefore, the part of the metal gasket 3 protruding from the surface of the metal layer 2 can be connected to the outermost solder layer 1 of the prefabricated solder joint, which can ensure that the thickness of the outermost solder layer 1 is not less than the height of the part of the metal gasket 3 protruding from the surface of the metal layer 2. Thus, the overall thickness of the prefabricated solder joint can be accurately limited by the metal gasket 3, so that the thickness of the prefabricated solder joint can accurately match the requirements of temperature cycle, stress distribution, etc. at the solder joint of the workpiece product, and the welding reliability of the solder joint can be ensured for various workpiece products, avoiding solder joint cracking. In addition, when using traditional solder paste welding, the content of flux is high and the solder joint voids are large. After changing to the prefabricated solder joint provided in this application, the content of flux is less, so the void ratio is reduced.
[0060] In one embodiment, by laminating the solder layer 1 and the metal layer 2, and precisely controlling the overall height of the prefabricated solder joint through the metal gasket 3, the thickness of the prefabricated solder joint can be precisely matched according to the requirements of conditions such as the service life, size specifications, temperature cycle, stress distribution, cost control, heat conduction benefit, and heat conduction balance of the welded part product within a range less than or equal to 10,000 μm, ensuring welding reliability in various different welded parts and having a wide range of applications. Exemplarily, in a heat dissipation system including a radiator and a heat generating device, the thickness of the prefabricated solder joint between the radiator and the heat generating device can be in the range of 200 μm to 550 μm, specifically, it can be 200 μm, 350 μm, 450 μm, 550 μm, etc.
[0061] Figure 5 The graph shows the relationship between the thickness of the prefabricated solder joint provided by the embodiment of the present application and the change in solder joint stress. Refer to Figure 5 As the thickness of the prefabricated solder joint gradually increases, the corresponding solder joint stress gradually decreases. Figure 6 The stress simulation diagram of the prefabricated solder joint provided by the embodiment of the present application in application. Refer to Figure 6 From top to bottom, there are five groups of simulation results, and the thickness of the prefabricated solder joint gradually increases in sequence, which are 160 μm, 200 μm, 250 μm, 490 μm, and 550 μm respectively. The corresponding stresses of the prefabricated solder joint are 231.3 MPa, 216.8 MPa, 197.4 MPa, 183.3 MPa, and 177.4 Mpa respectively. It can be seen that as the thickness of the prefabricated solder joint gradually increases, the stress of the prefabricated solder joint gradually decreases. For Figure 5 the simulation result shown at the bottom in
[0062] In one embodiment, refer to Figure 2 The metal gasket 3 can be connected to the surface of the metal layer 2. That is to say, the metal gasket 3 does not embed into the metal layer 2, but can be fixedly combined with the surface of the metal layer 2. Exemplarily, the metal gasket 3, the metal layer 2, and the solder layer 1 can be pressed into a whole through a cold pressing process. Through the limitation of the metal gasket in the thickness direction Z, the thickness of the outermost solder layer 1 can be made consistent with the height of the metal gasket 3, thereby realizing precise control of the thickness of the prefabricated solder joint through the metal gasket 3. In one embodiment, refer to Figure 2, for the design with only one metal layer 2, metal gaskets 3 are provided on both sides of the metal layer 2 in the thickness direction Z. Thus, the thicknesses of the solder layers 1 located on both sides of the metal layer 2 can be respectively restricted by the metal gaskets 3 on both sides of the metal layer 2, so that precise control of the overall thickness of the prefabricated solder joints can be achieved. In another embodiment, referring to Figure 4 , for the design with two or more metal layers 2, metal gaskets 3 are provided on the two metal layers 2 adjacent to the outermost side of the prefabricated solder joints, and the metal gaskets 3 are respectively arranged on the surfaces of the two metal layers 2 facing away from each other. Thus, the thicknesses of the outermost solder layers 1 on both sides of the prefabricated solder joints can be respectively restricted, so that precise control of the thickness of the prefabricated solder joints can also be achieved. Among them, metal gaskets 3 may not be provided on the surfaces between the two outermost metal layers 2 or other metal layers 2, and of course, metal gaskets 3 may also be provided. This embodiment does not make any restrictions on this.
[0063] In one embodiment, Figure 7 is a schematic structural diagram of the prefabricated solder joints provided by the third embodiment of the present application. Referring to Figure 7 , a first through hole 21 is provided on the metal layer 2, and the metal gasket 3 is arranged in the first through hole 21, and both ends of the metal gasket 3 respectively extend out of the through hole. The shape of the first through hole 21 can be consistent with the cross-sectional shape of the metal gasket 3, so as to obtain a better match with the metal gasket 3. The length of the metal gasket 3 can be greater than the depth of the first through hole 21, so that both ends of the metal gasket 3 can respectively extend out of both ends of the first through hole 21. Thus, the parts of the metal gasket 3 extending out of the through hole can be used to restrict the thicknesses of the outermost solder layers 1 on both sides of the prefabricated solder joints, so that precise control of the overall thickness of the prefabricated solder joints can be achieved.
[0064] Among them, whether the metal gasket 3 is arranged on the surface of the metal layer 2 or the metal gasket 3 penetrates through the metal layer 2, the metal gasket 3, the metal layer 2 and the solder layer 1 can be combined and fixed into a whole through a cold pressing process to form a prefabricated part of the prefabricated solder joints, so that the prefabricated solder joints can be integrally placed between two weldments for welding, which is convenient for operation. In addition, in some other embodiments, the metal gasket 3, the metal layer 2 and the solder layer 1 may not be pre-combined and fixed by a cold pressing process, but the solder layer 1, the metal layer 2 and the metal gasket 3 can be sequentially placed between two weldments in a certain order, and then the combination and fixation of each layer can be achieved during the welding process.
[0065] If the metal layer 2 and the solder layer 1 are in direct contact, during the welding process, certain chemical reactions will occur between some materials of the metal layer 2 and the solder layer 1, and another new component will be generated. This new component is usually not conducive to heat conduction, and at the same time, it will also affect the overall thickness of the prefabricated solder joints, and it is easy to cause inaccurate control of the thickness of the prefabricated solder joints. For this reason, in one embodiment, Figure 8The structural schematic diagram of the prefabricated solder joint provided by the fourth embodiment of the present application is referred to Figure 8 , a barrier layer 4 is electroplated on the metal layer 2, and the metal layer 2 is in contact with the solder layer 1 through the barrier layer 4. Among them, the metal layer 2 is a thin sheet structure with a certain thickness. After the metal layer 2 is formed, it can be integrally immersed in an electroplating bath so that a layer of barrier layer 4 is electroplated on the surface of the metal layer 2. The barrier layer 4 can isolate the metal layer 2 from the solder layer 1 and prevent the metal layer 2 from directly contacting the solder layer 1 and undergoing a chemical reaction.
[0066] In one embodiment, the material of the barrier layer 4 can be nickel Ni. After the nickel layer reacts with the tin-based solder layer 1, it will not have an adverse impact on the thermal conduction performance, nor will it affect the thickness of the prefabricated solder joint, and can ensure high reliability of the prefabricated solder joint after welding.
[0067] In one embodiment, Figure 9 The structural schematic diagram of the prefabricated solder joint provided by the fifth embodiment of the present application is referred to Figure 9 , a second through hole 22 is provided on the metal layer 2, and at least part of the solder in the solder layer 1 fills into the second through hole 22. The solder in the solder layer 1 can not only contact the surface of the metal layer 2, but also contact the inner wall of the second through hole 22. Thus, by providing the second through hole 22, the contact area between the metal layer 2 and the solder layer 1 is enlarged, and the reliability of the combination of the solder layer 1 and the metal layer 2 is improved. Among them, the shape of the second through hole 22 can be circular, diamond-shaped, square, trapezoidal, triangular or irregular, and this embodiment does not limit this. Figure 10 The schematic diagram of the second through hole 22 opened on the metal layer 2 provided by the embodiment of the present application is Figure 10 , in which the shape of the second through hole 22 is exemplarily shown as circular. Figure 11 The schematic diagram of the second through hole 22 opened on the metal layer 2 provided by another embodiment of the present application is Figure 11 , in which the shape of the second through hole 22 is exemplarily shown as diamond-shaped.
[0068] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A control system, characterized in that, it includes a first welded part, a second welded part and a prefabricated solder joint; The prefabricated solder joint includes: At least two solder layers. Along the thickness direction of the prefabricated solder joint, one solder layer located on one side of the prefabricated solder joint is used for welding connection with the first welded part, and the other solder layer located on the other side of the prefabricated solder joint is used for welding connection with the second welded part; At least one metal layer, and the metal layer is arranged between at least two solder layers; A metal gasket, the metal gasket is arranged on the surface of the metal layer and is connected to the solder layer; or, the metal gasket is embedded in the metal layer, and at least part of the metal gasket protrudes from the surface of the metal layer for connection with the solder layer.
2. The control system according to claim 1, characterized in that, the distance between the end of the metal gasket and the adjacent metal layer is H1, and the thickness of the solder layer on the outermost layer of the prefabricated solder joint is H2, and H2≥H1.
3. The control system according to claim 1 or 2, characterized in that, a first through hole is provided on the metal layer, the metal gasket is arranged in the first through hole, and both ends of the metal gasket extend out of the first through hole respectively.
4. The control system according to claim 2 or 3, characterized in that, the metal layer, the solder layer and the metal gasket are combined and fixed by a cold pressing process.
5. The control system according to any one of claims 1-4, characterized in that, a barrier layer is electroplated on the metal layer, and the metal layer contacts the solder layer through the barrier layer.
6. The control system according to claim 5, characterized in that, the material of the barrier layer is nickel.
7. The control system according to any one of claims 1-6, characterized in that, a second through hole is provided on the metal layer, and the solder of at least part of the solder layer fills into the second through hole.
8. The control system according to any one of claims 1-7, characterized in that, at least two metal layers are provided, at least three solder layers are provided, and the metal layers and the solder layers are stacked alternately.
9. The control system according to any one of claims 1-8, characterized in that, the thickness of the prefabricated solder joint is less than or equal to 10000um.
10. The control system according to any one of claims 1-9, characterized in that, the material of the metal layer is one of silver, copper, gold, aluminum, tungsten, zinc.
11. The control system according to any one of claims 1-10, characterized in that, the solder layer is a soft soldering solder preform or solder paste.
12. The control system according to any one of claims 1-10, characterized in that, the first welded part is a radiator, and the second welded part is a heat generating module.
13. A vehicle, characterized in that, it includes the control system according to any one of claims 1-12.