Power module, power equipment and photovoltaic power generation system

Abstract

The invention discloses a power module, power equipment and a photovoltaic power generation system. The power module comprises a substrate, a first power device, a co-fired ceramic module and a packaging body. The first power device is located on one surface of the substrate, and the first power device is electrically connected with the substrate. The co-fired ceramic module is located on the side, away from the substrate, of the first power device, and the co-fired ceramic module and the first power device are arranged in a spaced mode. The co-fired ceramic module comprises a co-fired ceramic substrate and a second power device, the second power device is embedded in the co-fired ceramic substrate, and the second power device is electrically connected with at least one of the substrate and the first power device. The packaging body wraps the substrate, the first power device and the co-fired ceramic module. By adopting the power module design scheme, the integration level and the power density of the power module are improved, the structural reliability of the power module is ensured, and the power conversion performance of the power module is improved, so that the power density of power equipment is improved, and the power generation efficiency of a photovoltaic power generation system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy, in particular to a power module, a power device and a photovoltaic power generation system. BACKGROUND

[0002] The power module is a functional module that is formed by combining power devices according to certain functions and then plastic or pot sealing as a whole. The power module is widely used in servo motors, frequency converters or inverters and other devices. Common packaging forms of the power module include housing packaging and molding packaging. The power module is mainly formed by pouring packaging materials to protect the components after the substrate, chips and pins are assembled and welded.

[0003] With the continuous development of photovoltaic technology, the integration of power circuits in power devices has become an important direction for future development. As an important component of power circuits in power devices, the integration of the power module with other power devices and the structural reliability of the integrated power module have become an important research topic for technical personnel in the field. SUMMARY

[0004] The present application provides a power module, a power device and a photovoltaic power generation system, which is used to improve the integration of the power module while ensuring the structural reliability of the power module, thereby improving the power density of the power device.

[0005] In a first aspect, the present application provides a power module, which includes a substrate, a first power device, a co-fired ceramic module and a packaging body. The first power device is arranged on one side surface of the substrate, and the first power device is electrically connected to the substrate. The co-fired ceramic module is located on the side of the first power device away from the substrate, and the co-fired ceramic module is arranged in a spaced manner with the first power device. In addition, the co-fired ceramic module includes a co-fired ceramic base and a second power device, the second power device is embedded in the co-fired ceramic base, and the second power device is electrically connected to at least one of the substrate and the first power device. The packaging body wraps the substrate, the first power device and the co-fired ceramic module. By using the co-fired ceramic technology, the present application provides a design scheme of the power module, which makes it possible to integrate more electrically interconnected power devices into a whole to improve the integration and power density of the power module. Since the co-fired ceramic structure has better structural reliability, it can be used to protect the second power device to reduce the risk of damage of the second power device caused by stress concentration, thereby improving the structural reliability of the entire power module. In addition, by embedding the second power device in the co-fired ceramic base, it is also beneficial to reduce the electromagnetic interference of external devices on the second power device, thereby improving the operation reliability of the second power device, which is beneficial to improve the power conversion performance of the power module.

[0006] In a possible implementation of the present application, the thickness of the second power device is less than or equal to half of the thickness of the co-fired ceramic base. This can improve the structural reliability of the co-fired ceramic module while improving the electromagnetic shielding effect of the co-fired ceramic base on the second power device.

[0007] In addition, the rigidity of the second power device is less than the rigidity of the co-fired ceramic base, so as to reduce the risk of damage of the second power device due to stress concentration, thereby improving the reliability of the second power device.

[0008] In a possible implementation of the present application, the projection of the co-fired ceramic base on the substrate falls within the outline of the substrate, and the projection area of the co-fired ceramic base on the substrate is less than the area of the substrate. This can facilitate increasing the difference between the size of the package and the size of the co-fired ceramic module, which is conducive to relieving the stress on the co-fired ceramic module.

[0009] In addition, the flatness of the substrate is higher than the flatness of the co-fired ceramic module. This can effectively improve the mechanical strength of the co-fired ceramic module, thereby improving the structural reliability of the entire power module.

[0010] In a possible implementation of the present application, in the direction from the co-fired ceramic module to the substrate, the projection area of the co-fired ceramic module is less than or equal to half of the projection area of the package. This increases the difference between the planar size of the package and the planar size of the co-fired ceramic module, which is conducive to relieving the stress on the co-fired ceramic module.

[0011] In the present application, the electrical impedance of the substrate is lower than the electrical impedance of the co-fired ceramic base, and the dielectric constant of the co-fired ceramic base is higher than the dielectric constant of the substrate. This can effectively reduce the electromagnetic interference between the first power device and the second power device, thereby improving the operation reliability of the power module.

[0012] In a possible implementation of the present application, the porosity of the co-fired ceramic base is lower than the porosity of the package. This can improve the moisture resistance of the co-fired ceramic base, thereby improving the reliability of the second power device.

[0013] In addition, the Young's modulus of the co-fired ceramic base is greater than the Young's modulus of the package. This can relieve the stress on the co-fired ceramic base, thereby improving the mechanical strength of the co-fired ceramic module.

[0014] In a possible implementation of the present application, the thickness of the first power device is less than the thickness of the second power device. This can facilitate reducing the influence of the first power device on the stress applied to the co-fired ceramic module, thereby improving the reliability of the co-fired ceramic module.

[0015] The power module provided in the application further comprises a bottom plate, the bottom plate comprises a first surface and a second surface arranged oppositely, and the substrate is fixed to the first surface. The projection of the co-fired ceramic module on the bottom plate falls within the contour range of the bottom plate, and the projection area of the co-fired ceramic substrate on the bottom plate is smaller than the area of the bottom plate. In this way, the heat conduction efficiency of the co-fired ceramic substrate to the bottom plate can be effectively improved, thereby improving the heat dissipation performance of the entire power module.

[0016] In addition, the thermal conductivity of the bottom plate can be further higher than that of the co-fired ceramic substrate. In this way, the heat dissipation efficiency of the power module can be further improved.

[0017] In a possible implementation of the application, the power module further comprises a pin, one end of the pin is electrically connected with the substrate, and the other end of the pin penetrates through the package and extends to the outside of the power module. In this way, the interconnection between the power module and the outside can be realized through the pin.

[0018] In addition, the pin can also penetrate through the co-fired ceramic module, and the pin can be electrically connected with the second power device. In this way, the second power device can be electrically connected with the substrate through the pin, which can make the electrical connection path between the second power device and the substrate shorter, thereby being beneficial to reducing the parasitic inductance in the power circuit comprising the power module, which is beneficial to the improvement of the power density of the power module. In addition, the electrical connection port of the second power device can also be led to the outside of the power module through the pin, so as to facilitate the electrical connection between the second power device and the devices outside the power module.

[0019] In the application, the pin can be used to limit the co-fired ceramic module. Specifically, the pin comprises a limiting surface facing the co-fired ceramic module, and the surface of the co-fired ceramic module facing the substrate abuts against the limiting surface. In this way, the spacing between the co-fired ceramic module and the first power device can be limited, which can effectively prevent the co-fired ceramic module from pressing the first power device, and the current crosstalk between the first power device and the second power device can be reduced through the design of the position of the limiting surface.

[0020] In another implementation, the co-fired ceramic module can be pre-positioned by fixing the pin and the co-fired ceramic module to be assembled with the substrate as a whole, so as to limit the spacing between the co-fired ceramic module and the first power device.

[0021] In a possible implementation of the application, the co-fired ceramic module further comprises a circuit layer, at least part of the circuit layer is embedded in the co-fired ceramic substrate, and the circuit layer is electrically connected with the second power device. In this way, the second power device can be electrically connected with at least one of the substrate and the first power device through the circuit layer, which is beneficial to improving the convenience and reliability of the electrical connection between the second power device and at least one of the substrate and the first power device.

[0022] In one possible implementation of this application, the power module further includes a first conductive structure, one end of which is electrically connected to the substrate, and the other end of which is electrically connected to the second power device through a circuit layer, thereby enabling the second power device to be electrically connected to the substrate through the circuit layer.

[0023] There are various ways to connect the first conductive structure to the circuit layer. For example, the circuit layer can be exposed on the side of the co-fired ceramic substrate facing the substrate, which allows the other end of the first conductive structure to be electrically connected to the exposed part of the circuit layer, thus simplifying the electrical connection between the first conductive structure and the circuit layer.

[0024] Alternatively, if the co-fired ceramic substrate includes through-holes, the other end of the first conductive structure is inserted into the through-hole and electrically connected to the circuit layer. This can help improve the reliability of the electrical connection between the first conductive structure and the circuit layer.

[0025] This application does not limit the specific type of the first conductive structure, but its examples may include at least one of conductive pillars, conductive sheets, and bonding wires.

[0026] In one possible implementation of this application, the power module further includes a second conductive structure, one end of which is electrically connected to the first power device, and the other end of which is electrically connected to the second power device through a circuit layer, thereby enabling the second power device to be electrically connected to the first power device through the circuit layer.

[0027] There are various ways to connect the second conductive structure to the circuit layer. For example, the circuit layer can be exposed on the side of the co-fired ceramic substrate facing the substrate, which allows the other end of the second conductive structure to be electrically connected to the exposed part of the circuit layer, thus simplifying the electrical connection between the second conductive structure and the circuit layer.

[0028] Alternatively, if the co-fired ceramic substrate includes through-holes, the other end of the second conductive structure is inserted into the through-holes and electrically connected to the circuit layer. This can help improve the reliability of the electrical connection between the second conductive structure and the circuit layer.

[0029] This application does not limit the specific type of the second conductive structure, but its examples may include at least one of conductive pillars, conductive sheets, and bonding wires.

[0030] Secondly, this application also provides a power device, which includes a housing, a circuit board, and a power module. The circuit board and the power module are housed within the housing, and the power module is electrically connected to the circuit board. In the power device provided by this application, since the power module can integrate more power devices, it is beneficial to improve the integration degree of the power circuit formed by the electrical connection between the power module and the circuit board, thereby improving the integration degree and power density of the power device.

[0031] In one possible implementation of this application, the power device further includes a heat sink located within the housing. The heat sink is in thermal contact with a second surface. This allows the heat generated during the operation of the first and second power devices to be transferred through the substrate to the base plate, and then to the heat sink, thereby achieving heat dissipation for the power module. Due to the power module design provided in this application, the co-fired ceramic module and the substrate are arranged along the stacking direction, meaning the projection of the co-fired ceramic module onto the heat sink falls within the outline of the entire power module's projection onto the heat sink. This improves the integration of the power module while avoiding increasing the heat dissipation area occupied by the power module, which is beneficial for reducing the overall size of the power device. Furthermore, it increases the flexibility of power module placement within the power device while maintaining its size, thus improving the power density of the power device.

[0032] Thirdly, this application also provides a photovoltaic power generation system, which includes photovoltaic modules and a power device as described in the second aspect. The power device is used to convert the direct current output by the photovoltaic modules into alternating current. In this photovoltaic power generation system, the high power density of the power device contributes to improving the power generation efficiency of the photovoltaic power generation system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a photovoltaic power generation system provided in an embodiment of this application;

[0034] Figure 2 A schematic diagram of the structure of a power device provided in an embodiment of this application;

[0035] Figure 3a This is a schematic diagram of a power module using a housing package.

[0036] Figure 3b This is a schematic diagram of a power module using molding packaging;

[0037] Figure 4 This is a schematic diagram of the structure of a power module provided in an embodiment of this application;

[0038] Figure 5 for Figure 4 A magnified view of a portion of the structure shown at point A;

[0039] Figure 6 This is another schematic diagram of the power module provided in the embodiments of this application;

[0040] Figure 7 A schematic diagram of a specific structure of the power module provided in the embodiments of this application;

[0041] Figure 8 forFigure 7 The exploded view of the power module shown;

[0042] Figure 9a A specific structural schematic diagram of the co-fired ceramic module provided in the embodiments of this application;

[0043] Figure 9b A schematic diagram of another specific structure of the co-fired ceramic module provided in an embodiment of this application;

[0044] Figure 10 This is another schematic diagram of the power module provided in the embodiments of this application;

[0045] Figure 11 This is another schematic diagram of the power module provided in the embodiments of this application;

[0046] Figure 12 This is a partial structural diagram of a power device provided in an embodiment of this application.

[0047] Figure label:

[0048] 1000 - Photovoltaic modules; 2000 - Inverters; 3000 - Transformers; 4000 - Power grid; 5000 - Loads;

[0049] 100 - Power device; 10 - Housing; 20 - Circuit board; 30 - Power module; 31 - Substrate; 311 - Ceramic substrate; 312 - First metal layer;

[0050] 313-Second metal layer; 32-Chip; 33-Casing; 34-Silicone gel; 35-Molding compound; 36-First power device; 37-Co-fired ceramic module;

[0051] 371 - Co-fired ceramic substrate; 372 - Second power device; 373 - Through-hole; 374 - Circuit layer; 375 - Metal via; 38 - Package;

[0052] 39-Pin; 391-Limit seat; 310-First conductive structure; 3101-Conductive post; 3102-Bonding wire; 320-Second conductive structure; 330-Base plate;

[0053] 3301 - First side; 3302 - Second side; 40 - Radiator. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. The terms expressing position and direction described in the embodiments of this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings of the embodiments of this application are only for illustrating relative positional relationships and do not represent actual scale.

[0055] It should be noted that specific details are set forth in the following description to facilitate understanding of this application. However, the embodiments of this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the embodiments of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0056] Power devices are widely used in photovoltaic power generation systems, energy storage systems, and powertrain systems of new energy vehicles to convert current or voltage in these systems. Power devices can include inverters and microinverters in photovoltaic power generation systems, converters in energy storage systems, and motor controllers in the powertrains of new energy vehicles.

[0057] Taking photovoltaic power generation systems as an example, Figure 1 This is a schematic diagram illustrating an application scenario of a photovoltaic power generation system provided in this application embodiment. The photovoltaic power generation system includes a photovoltaic module 1000, an inverter 2000, and a transformer 3000. The photovoltaic module 1000 is a DC power supply composed of solar cells connected in series or parallel, used to convert solar energy into DC electrical energy. The inverter 2000 is a DC-AC power device that converts the DC power output from the photovoltaic module 1000 into AC power for output to the transformer 3000. The transformer 3000 then transforms the AC power output from the inverter 2000 and connects it to the AC power grid 4000, thereby achieving grid connection of the photovoltaic power generation system. Alternatively, the AC power output from the inverter 2000 can be supplied to a load 5000 to power the load 5000.

[0058] Figure 2 This is a schematic diagram of a power device provided in an embodiment of this application. (Reference) Figure 2As shown, the power device 100 may include a housing 10 and a circuit board 20 and a power module 30 housed within the housing 10. The power module 30 is electrically connected to the circuit board 20. The circuit board 20 may be a printed circuit board (PCB), a flexible printed circuit board (FPC), or a rigid-flex PCB, etc. The power module 30 is the core component of the power device 100 that enables power conversion. The power module 30 may include multiple ports, such as input positive and negative ports, output positive and negative ports, power supply positive and negative ports, etc. These ports are electrically connected to the circuit board 20 via pins, thereby enabling the circuit board 20 to provide current or voltage input and output, as well as power supply, to the power module 30.

[0059] The power module 30 may contain various power devices such as chips, inductors, resistors, or capacitors. These power devices are connected in a certain functional combination and then packaged into a whole using packaging technology. Common packaging technologies for power modules 30 include housing packaging and molding packaging. Figure 3a A power module using a housing package was demonstrated, such as... Figure 3a As shown, housing packaging is a packaging method that uses a housing 33 to form a cavity with a substrate 31 that carries the aforementioned chips 32 and other power devices, and fills the cavity with encapsulation materials such as silicone gel 34 to protect the power devices. Figure 3b The demonstration shows a power module using a molding package, such as... Figure 3b As shown, molding packaging involves placing a substrate 31 containing various power devices such as chip 32 into a special injection mold, using softened epoxy resin or other molding compound 35 as the encapsulation material, and encapsulating and wrapping each power device under certain pressure and temperature conditions to protect the internal components.

[0060] Typically, other power devices can be installed in other locations within the circuit board 20 or the housing 10 of the power device. These power devices can be electrically connected to the power devices in the power module 30 through the circuit board 20 or other means to form a power circuit.

[0061] It is understandable that when electrically connecting power devices such as chip 32 in power module 30 to external power devices, it is necessary to pass through the packaging structure (e.g., Figure 3a Silicone gel 34 or Figure 3b If the molding compound 35 is used, its connection path is longer, which will result in a larger parasitic inductance. This will generate voltage spikes when the circuit changes rapidly, which will hinder the improvement of the power density of power devices.

[0062] Currently, to address the aforementioned issues, those skilled in the art have proposed integrating more power devices into the packaging structure of power modules to reduce power loss by shortening the connection path. However, directly integrating power devices into existing power modules can lead to damage due to high internal stress within the package.

[0063] Co-fired ceramic technology refers to the process of forming precisely thick and dense green ceramic tapes from sintered ceramic powder. Circuit patterns are then created on these tapes using processes such as laser drilling, micro-hole injection, and precision conductor paste printing. Multiple passive components (such as low-value capacitors, resistors, filters, impedance converters, and couplers) are embedded into multilayer ceramic substrates, which are then stacked and sintered together to create a high-density, three-dimensional circuit that does not interfere with each other. This technology can also be used to create three-dimensional circuit boards with built-in passive components. Furthermore, chips and active devices can be mounted on the surface to create passive / active integrated functional modules, further achieving miniaturization and high density of circuits.

[0064] In view of this, the power module provided in this application, by utilizing co-fired ceramic technology, makes it possible to integrate more electrically interconnected power devices into a single unit, thereby improving the integration level of the power module while ensuring its structural reliability. To facilitate understanding of the solution provided in this application, a detailed description will follow with reference to specific embodiments.

[0065] Figure 4 This is a schematic diagram of a power module provided in an embodiment of this application. The power module 30 may include a substrate 31, a first power device 36, a co-fired ceramic module 37, and a package 38. The first power device 36 is disposed on one side surface of the substrate 31 and is electrically connected to the substrate 31. In this application, the first power device 36 may be a chip 32. This application does not limit the number of chips 32, but it is exemplarily possible to have one or more chips 32 mounted on one side surface of the substrate 31. In addition, the chip 32 may include an integrated circuit (IC) chip, an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or a power transistor, etc.

[0066] In this application, the substrate 31 may include a ceramic substrate 311 and a metal layer, the metal layer being fixed to the surface of the ceramic substrate 311. For example, as shown... Figure 5 As shown,Figure 5 for Figure 4 The diagram shows a partial enlarged view of the structure at point A. The substrate 31 may include two metal layers, which are respectively fixed to opposite surfaces of the ceramic substrate 311. For ease of explanation, in this embodiment, the two metal layers are referred to as the first metal layer 312 and the second metal layer 313. The first metal layer 312 can be used to mount the chip 32. The chip 32 can be electrically connected to the first metal layer 312 via bonding wires made of aluminum, copper, silver, or their alloys, or via a clip soldering process based on metals such as aluminum, copper, silver, or their alloys, or by other possible methods, which will not be listed here.

[0067] In addition, the first power device 36 can also be an inductor, resistor or capacitor, etc., and the first metal layer 312 can also be used to mount inductors, resistors or capacitors. The chip 32 and these devices can be fixed to the surface of the first metal layer 312 by processes such as reflow soldering, or the chip 32 and these devices can be pre-packaged using ball grid array package (BGA), quad flat non-leaded package (QFN), small out-line package (SOP), transistor outline (TO) or any other packaging form and then fixed to the surface of the first metal layer 312.

[0068] In one embodiment, the ceramic substrate 311 can be made of relatively low-cost materials such as alumina or aluminum nitride to reduce the overall cost of the power module 30. The first metal layer 312 and the second metal layer 313 can each be copper layers, in which case the substrate 31 is a direct-bonded copper (DBC) ceramic substrate. In other embodiments, the first metal layer 312 and the second metal layer 313 can also be aluminum layers, in which case the substrate 31 is a direct-bonded aluminum (DBA) ceramic substrate. In other possible embodiments of this application, the substrate 31 can also be an active metal bonding (AMB) copper substrate, an insulated metal substrate (IMS), or a printed circuit board (PCB), etc., and is not limited thereto.

[0069] You can continue to refer to Figure 4The co-fired ceramic module 37 includes a co-fired ceramic substrate 371 and a second power device 372, which is embedded in the co-fired ceramic substrate 371. The co-fired ceramic module 37 is located on the side of the first power device 36 opposite to the substrate 31, and the co-fired ceramic module 37 and the first power device 36 are spaced apart. The second power device 372 is electrically connected to at least one of the substrate 31 and the first power device 36.

[0070] In this application, the type of co-fired ceramic substrate 371 is not limited, but it can be exemplarily a low-temperature co-fired ceramic (LTCC), a medium-temperature co-fired ceramic (HTCC), or a high-temperature co-fired ceramic (HTCC). Furthermore, the second power device 372 can be an active device such as an IC, IGBT, MOSFET, or diode, or a passive device such as a low-capacitance capacitor, resistor, impedance converter, filter, or coupler.

[0071] It is worth mentioning that in the co-fired ceramic module 37, the thickness of the second power device 372 is less than or equal to half the thickness of the co-fired ceramic substrate 371. This improves the structural reliability of the co-fired ceramic module 37 while enhancing the electromagnetic shielding effect of the co-fired ceramic substrate 371 on the second power device 372.

[0072] In addition, the stiffness of the second power device 372 is less than that of the co-fired ceramic substrate 371, so as to reduce the risk of damage to the second power device 372 due to stress concentration, thereby improving the reliability of the second power device 372.

[0073] Since the first power device 36 can normally be electrically connected to the second power device 372 via the substrate 31, in this application, the resistivity of the substrate 31 can be lower than that of the co-fired ceramic substrate 371, and the dielectric constant of the co-fired ceramic substrate 371 can be higher than that of the substrate 31. This effectively reduces electromagnetic interference between the first power device 36 and the second power device 372, thereby improving the operational reliability of the power module 30.

[0074] In addition, the direction of current flow in the plane in the substrate 31 can be made perpendicular to the direction of current flow in the plane in the second power device 372, so as to further reduce the electromagnetic interference between the first power device 36 and the second power device 372.

[0075] You can continue to refer to Figure 4The package 38 encapsulates the substrate 31, the first power device 36, and the co-fired ceramic module 37, thereby encapsulating the substrate 31, the first power device 36, and the co-fired ceramic module 37 into a single unit. In this application, the package 38 may be, but is not limited to, the aforementioned silicone gel 34 or molding compound 35, as long as it can provide encapsulation and protection for the various devices in the power module 30.

[0076] In practical applications, along the direction from the co-fired ceramic module 37 to the substrate 31, the projected area of ​​the co-fired ceramic module 37 is less than or equal to half the projected area of ​​the package 38. This increases the difference in planar dimensions between the package 38 and the co-fired ceramic module 37, which helps to alleviate the stress on the co-fired ceramic module 37.

[0077] In addition, in this application, the mechanical strength of the co-fired ceramic module 37 can be improved by making the flatness of the substrate 31 higher than that of the co-fired ceramic module 37, thereby improving the structural reliability of the entire power module 30.

[0078] In this application, flatness refers to the difference between the uneven parts of an object's surface and an absolutely flat reference surface. The smaller this difference is, the higher the flatness of the object.

[0079] Since the package 38 simultaneously encapsulates both the substrate 31 and the co-fired ceramic module 37, in this application, the projection of the co-fired ceramic substrate 371 onto the substrate 31 can fall within the projection range of the substrate 31, and the projected area of ​​the co-fired ceramic substrate 371 onto the substrate 31 is smaller than the area of ​​the substrate 31. This helps to increase the size difference between the package 38 and the co-fired ceramic module 37, which helps to alleviate the stress on the co-fired ceramic module 37.

[0080] In the power module 30 provided in this application, the porosity of the co-fired ceramic substrate 371 can be lower than that of the package 38. This improves the moisture resistance of the co-fired ceramic substrate 371, thereby enhancing the reliability of the second power device 372.

[0081] In addition, the Young's modulus of the co-fired ceramic substrate 371 is greater than that of the package 38. This can alleviate the stress on the co-fired ceramic substrate 371, thereby improving the mechanical strength of the co-fired ceramic module 37.

[0082] In addition, the thickness of the first power device 36 can be made smaller than the thickness of the second power device 372. This can effectively reduce the stress effect of the first power device 36 on the second power device 372, thereby improving the reliability of the co-fired ceramic module 37.

[0083] Understandably, in this application, the stiffness of the first power device 36 is greater than the stiffness of the co-fired ceramic substrate 371. This can effectively alleviate the stress applied to the co-fired ceramic module, thereby improving the reliability of the co-fired ceramic module 37.

[0084] By adopting the power module 30 design scheme provided in this application, the second power device 372 embedded in the co-fired ceramic substrate 371 is integrated into the power module 30 using co-fired ceramic technology, thereby improving the integration and power density of the power module 30. Furthermore, since the co-fired ceramic structure has better structural reliability, it can be used to protect the second power device 372, reducing the risk of damage to the second power device 372 due to stress concentration, thus improving the overall structural reliability of the power module 30.

[0085] It is understandable that embedding the second power device 372 in the co-fired ceramic substrate 371 can also help reduce electromagnetic interference from external devices to the second power device 372, thereby improving the operational reliability of the second power device 372 and improving the power conversion performance of the power module.

[0086] After understanding the design principle of the power module 30 provided in this application, the following section will introduce several possible configuration methods of the power module 30 in practical applications.

[0087] Figure 6 This is another structural schematic diagram of the power module provided in the embodiments of this application. As can be seen from the above description of the power module, the power module also includes a pin 39. One end of the pin 39 is electrically connected to the substrate 31, and the other end of the pin 39 extends through the package 38 to the outside of the power module 30 to realize the interconnection between the power module 30 and external devices.

[0088] This application does not limit the number of pins 39 of the power module 30, which can be designed according to the specific connection requirements between the power module 30 and external devices.

[0089] Furthermore, since the co-fired ceramic module 37 is located on the side of the first power device 36 facing away from the substrate 31, therefore, as Figure 6As shown, in this embodiment, pin 39 can penetrate the co-fired ceramic module 37 and is electrically connected to the second power device 372. This allows for electrical connection between the second power device 372 and the substrate 31, while also leading the electrical connection port of the second power device 372 to the outside of the power module 30 via pin 39, facilitating electrical connection between the second power device 372 and external devices of the power module 30. Additionally, the first power device 36 can be electrically connected to the second power device 372 via the substrate 31 and pin 39. This solution can improve the integration of the power module 30 and reduce its design complexity, thereby reducing the design cost of the power module 30.

[0090] In addition, Figure 6 In the embodiment shown, the second power device 372 is electrically connected to the substrate 31 through pin 39, which can make the electrical connection path between the second power device 372 and the substrate 31 shorter. This is beneficial to reduce the parasitic inductance in the power circuit including the power module 30, thereby improving the power density of the power module 30.

[0091] For ease of use Figure 6 To understand the structure of the power module shown, please refer to... Figure 7 , Figure 7 This is a schematic diagram of a specific structure of a power module provided in an embodiment of this application. Figure 7 In the power module shown, multiple pins 39 extend through the package 38 to the outside of the power module 30.

[0092] As described above regarding the structure of the power module 30 provided in this application, the co-fired ceramic module 37 and the first power device 36 are spaced apart. The spacing between the co-fired ceramic module 37 and the first power device 36 can be adjusted according to actual design requirements to avoid the co-fired ceramic module 37 crowding the first power device 36, while also reducing current crosstalk between the first power device 36 and the second power device 372, and avoiding a significant increase in the size of the power module.

[0093] In this application, there are multiple methods for limiting the position of the co-fired ceramic module 37. For example, see [link to example]. Figure 8 , Figure 8 for Figure 7The exploded view of the power module is shown. Pin 39 includes a limiting seat 391, through which pin 39 is fixedly connected to substrate 31. The co-fired ceramic module 37 includes a through hole 373, wherein the maximum cross-sectional dimension of the limiting seat 391 is larger than the maximum cross-sectional dimension of the through hole 373, so that the co-fired ceramic module 37 abuts against the limiting surface of the limiting seat 391 facing the co-fired ceramic module 37, thereby limiting the distance between the co-fired ceramic module 37 and the first power device 36 through the limiting seat 391.

[0094] It is worth mentioning that, in this application, the cross-sectional area of ​​the pins 39 is smaller than the area of ​​the co-fired ceramic module 37, so as to facilitate the limiting of the co-fired ceramic module 37 by multiple pins 39, thereby improving the limiting reliability of the co-fired ceramic module 37 by the pins 39. In addition, the stiffness of the pins 39 is less than the stiffness of the co-fired ceramic substrate 371, so that the stress applied to the co-fired ceramic module 37 can be absorbed by the deformation of the pins 39, thereby improving the structural reliability of the co-fired ceramic module 37.

[0095] However, the positioning method of the co-fired ceramic module 37 is not limited to this. For example, the co-fired ceramic module 37 can also be pre-positioned by fixing the pin 39 to it and assembling it as a whole with the substrate 31. Alternatively, the distance between the co-fired ceramic module 37 and the first power device 36 can be limited by the package 38 when forming the package. Of course, any other possible methods can be used to limit the positioning of the co-fired ceramic module 37, which will not be listed here, but all of them should be understood to fall within the protection scope of this application.

[0096] Figure 9a This is a schematic diagram of a specific structure of the co-fired ceramic module provided in an embodiment of this application. Figure 9a The co-fired ceramic matrix is ​​omitted. For example... Figure 9a As shown, the co-fired ceramic module 37 also includes a circuit layer 374, wherein the circuit layer 374 may be a conductive layer such as a metal layer including circuit patterns, and at least a portion of the circuit layer 374 is embedded in the co-fired ceramic substrate 371. Figure 9a Not shown in the image, please refer to the image below. Figure 6 This allows the co-fired ceramic substrate 371 to support the circuit layer 374, thereby ensuring the structural reliability of the circuit layer 374.

[0097] like Figure 9a As shown, the second power device 372 is electrically connected to the circuit layer 374. This allows for the following as described above. Figure 8 The pin 39 shown extends through and is electrically connected to the line layer 374 to enable the electrical connection between the pin 39 and the second power device 372.

[0098] It is understood that this application does not limit the specific configuration of line layer 374. For example, in... Figure 9a In the illustrated embodiment, the co-fired ceramic module 37 includes two circuit layers 374 disposed on the same layer, and the second power device 372 is located between the two circuit layers 374 and electrically connected to the two circuit layers 374. For example, in... Figure 9b In the co-fired ceramic module 37 shown, the co-fired ceramic module 37 includes two stacked circuit layers 374, and the second power device 372 is still located between the two circuit layers 374 and is electrically connected to the two circuit layers 374. Additionally, in Figure 9b In the embodiment shown, the two circuit layers 374 can be electrically connected through a metal via 375, and the second power device 372 can also be electrically connected to the circuit layer 374 through a metal via 375.

[0099] Figure 9b The electrical connection between the second power device 372 and pin 39 in the co-fired ceramic module 37 shown can be referred to Figure 9a The introduction in the text is omitted here.

[0100] It is worth mentioning that the configuration of the circuit layer 374 of the co-fired ceramic module 37 can be designed according to the usage requirements of the actual application scenario and the type of the second power device 372, for example, in Figure 9a In the illustrated embodiment, the second power device 372 can be a passive device. For example, in... Figure 9b In the illustrated embodiment, the second power device 372 can be an active device. Of course, in some other embodiments, it can also be... Figure 9a The second power device 372 in the co-fired ceramic module 37 shown is an active device, which makes... Figure 9b The second power device 372 in the co-fired ceramic module 37 shown is a passive device.

[0101] In the above Figure 8 The power module 30 shown only depicts one co-fired ceramic module 37 to illustrate its specific structure. In other possible embodiments, the number of co-fired ceramic modules 37 can be selected according to actual design needs. It is understood that when the power module includes multiple co-fired ceramic modules 37, its design can be set with reference to the co-fired ceramic module 37 in any of the above embodiments, and will not be described in detail here.

[0102] It is understood that, in this application, the second power device 372 can be electrically connected to the substrate 31 and the first power device 36 in other ways. For example, see [reference to...] Figure 10 , Figure 10 This is another structural schematic diagram of the power module provided in an embodiment of this application. Figure 10In the illustrated embodiment, the power module 30 further includes a first conductive structure 310, which may be a conductive pillar 3101. The conductive pillar 3101 may be, but is not limited to, a metal pillar structure with good conductivity, such as a copper pillar. The second power device 372 embedded in the co-fired ceramic substrate 371 can then be electrically connected to the substrate 31 via the conductive pillar 3101. One end of the conductive pillar 3101 is electrically connected to the substrate 31, and the other end of the conductive pillar 3101 is electrically connected to the second power device 372.

[0103] In a specific implementation, one end of the conductive post 3101 can be fixedly connected to the substrate 31 by welding or bonding, and electrical connection can be achieved simultaneously. In addition, when electrically connecting the other end of the conductive post 3101 to the second power device 372, a through hole can be opened in the co-fired ceramic substrate 371 so that the other end of the conductive post 3101 can be inserted into the through hole and electrically connected to the second power device 372.

[0104] From the above Figure 9a and Figure 9b As can be understood from the description of the co-fired ceramic module 37, the other end of the conductive post 3101 is inserted into the through hole and can be electrically connected to the circuit layer 374 of the co-fired ceramic module 37, thereby enabling the conductive post 3101 to be electrically connected to the second power device 372 through the circuit layer 374.

[0105] In other embodiments of this application, the circuit layer 374 of the co-fired ceramic module 37 may be exposed on the side of the co-fired ceramic substrate 371 facing the substrate 31. This allows the other end of the conductive post 3101 to be directly fixed to the exposed portion of the circuit layer 374 of the co-fired ceramic module 37 to achieve electrical connection, thereby achieving electrical connection with the second power device 372. Alternatively, a conductive layer may be provided on the side of the co-fired ceramic substrate 371 facing the substrate 31, and this conductive layer may be electrically connected to the circuit layer 374 of the co-fired ceramic module 37 through a metal via or the like, thereby achieving electrical connection between the conductive layer and the second power device 372. This allows the other end of the conductive post 3101 to be directly fixed to this conductive layer to achieve electrical connection, thereby achieving electrical connection with the second power device 372.

[0106] It is understood that when a conductive layer is provided on the side of the co-fired ceramic substrate 371 facing the substrate 31, the surface of the conductive layer can be subjected to anti-oxidation treatment to improve the reliability of the electrical connection between the co-fired ceramic module 37 and the first conductive structure 310. Furthermore, the electrical connection between the other end of the conductive post 3101 and the second power device 372 is not limited to this, and will not be listed here, but all should be understood to fall within the scope of protection of this application.

[0107] You can continue to refer to Figure 10The power module 30 also includes a second conductive structure 320, which in this embodiment can be a conductive sheet. The second conductive structure 320 is located between the first power device 36 and the co-fired ceramic module 37. The first power device 36 can be electrically connected to the second power device 372 via the second conductive structure 320. The second conductive structure 320 and the side of the first power device 36 facing the co-fired ceramic module 37 are fixedly connected by welding or bonding, thus achieving electrical connection between the second conductive structure 320 and the first power device 36. Furthermore, the second conductive structure 320 is electrically connected to the second power device 372. Since the electrical connection method between the second conductive structure 320 and the second power device 372 is similar to the electrical connection method between the first conductive structure 310 and the second power device 372 described above, it will not be elaborated further here.

[0108] It is worth mentioning that, Figure 10 Other structures of the power module 30 shown can be configured with reference to any of the above embodiments, and will not be described in detail here.

[0109] Figure 11 This is another structural schematic diagram of the power module provided in an embodiment of this application. Figure 11 In the illustrated embodiment, the first conductive structure 310 includes conductive posts 3101 and bonding wires 3102. The second power device 372 can be electrically connected to the substrate 31 via the conductive posts 3101 and bonding wires 3102. This can be understood as the co-fired ceramic module 37 including multiple second power devices 372, with at least one second power device 372 electrically connected to the substrate 31 via the conductive posts 3101 and at least one second power device 372 electrically connected to the substrate 31 via the bonding wires 3102. Alternatively, it can be understood that a second power device 372 can be electrically connected to different functional portions of the substrate 31 via the conductive posts 3101 and bonding wires 3102. For example, the second power device 372 can be electrically connected to the substrate 31 via the conductive posts 3101 and bonding wires 3102 to achieve electrical connection between the second power device 372 and different types of first power devices 36 mounted on the substrate 31.

[0110] It is worth mentioning that, such as Figure 11 As shown, when the bonding wire 3102 is electrically connected to the second power device 372 via the side of the co-fired ceramic module 37 away from the substrate 31, a conductive layer can be formed on the surface of the co-fired ceramic substrate 371 away from the substrate 31, and this conductive layer can be subjected to anti-oxidation treatment, so that one end of the bonding wire 3102 is electrically connected to the conductive layer and the other end is electrically connected to the substrate 31, thereby realizing the electrical connection between the second power device 372 and the substrate 31. Additionally, Figure 11 Other structures of the power module 30 shown can be configured with reference to any of the above embodiments, and will not be described in detail here.

[0111] This application does not limit the specific materials of the first conductive structure 310 and the second conductive structure 320. For example, when the bonding wire 3102 is selected as the conductive structure, its material can be aluminum wire to reduce its influence on the stress on the co-fired ceramic module 37.

[0112] The above Figure 8 , Figure 10 and Figure 11 The illustrated embodiments are merely exemplary descriptions of the interconnection between the substrate 31, the first power device 36, and the second power device 372 in the power module 30. Based on this, a series of modifications can be made according to the specific application requirements. For example, the first conductive structure 310 may include at least one of conductive pillars 3101, bonding wires 3102, and conductive sheets, so that the second power device 372 can be electrically connected to the substrate 31 through the first conductive structure 310 in at least one of the above-described configurations. Similarly, the second conductive structure 320 may also include at least one of conductive pillars 3101, bonding wires 3102, and conductive sheets, so that the first power device 36 can be electrically connected to the second power device 372 through the second conductive structure 320 in at least one of the above-described configurations. Furthermore, in Figure 10 and Figure 11 Based on the power module 30 shown, pin 39 can also be electrically connected to the second power device 372. The specific implementation method can be found above. Figure 8 The illustrated embodiment will not be described in detail here. In addition, other reasonable designs can be adopted to achieve the electrical connection between the substrate 31, the first power device 36 and the second power device 372. They will not be listed one by one here, but they should all be understood to fall within the protection scope of this application.

[0113] It is worth mentioning that in the above embodiments of this application, the power module 30 may include one substrate 31 or multiple substrates 31. When it includes multiple substrates 31, the arrangement of the multiple substrates 31 is similar, so it will not be described in detail.

[0114] The above only introduced some key parts of the power module 30. For more details, please refer to [link / reference needed]. Figure 10 or Figure 11The power module 30 may also include a base plate 330. The base plate 330 includes a first surface 3301 and a second surface 3302 disposed opposite to each other, and a substrate 31 is fixed to the first surface 3301 of the base plate 330. The heat generated by the first power device 36 and the second power device 372 during operation can be transferred through the substrate 31 to the first surface 3301 of the base plate 330, and then to the second surface 3302 of the base plate 330, and dissipated to the outside through the base plate 330, thereby achieving heat dissipation of the power module 30.

[0115] You can continue to refer to Figure 10 or Figure 11 In this application, the projection of the substrate 31 onto the first surface 3301 of the base plate 330 is located within the outline of the first surface 3301 of the base plate 330, or it can be understood that the edge of the base plate 330 extends beyond the edge of the substrate 31. This is beneficial for increasing the heat dissipation area of ​​the substrate 31, thereby improving the heat dissipation performance of the power module 30. It is understood that the base plate 330 can be made of a metal material with good thermal conductivity, for example, the base plate 330 can be a copper substrate or an aluminum substrate.

[0116] In addition, such as Figure 10 or Figure 11 As shown, the projected area of ​​the co-fired ceramic substrate 371 on the base plate 330 is smaller than the area of ​​the base plate 330. This effectively improves the heat transfer efficiency of the co-fired ceramic module 37 to the base plate 330, thereby improving the heat dissipation performance of the entire power module 30.

[0117] In this application, the thermal conductivity of the base plate 330 can be further made higher than that of the co-fired ceramic substrate 371 to further improve the heat dissipation efficiency of the power module 30.

[0118] Understandably, the thickness of the base plate 330 can be greater than the thickness of the co-fired ceramic module 37 to reduce the stress applied to the co-fired ceramic module 37 and improve the structural reliability of the entire power module 30. Furthermore, the flatness of the base plate 330 can be greater than the flatness of the co-fired ceramic module 37 to further alleviate the stress applied to the co-fired ceramic module 37 and improve its reliability.

[0119] When the power module 30 provided in this application is applied to power devices, it can be referred to Figure 12 , Figure 12 This is a partial structural schematic diagram of a power device provided in an embodiment of this application. Figure 12 It can be seen that the power module 30 can also make thermal contact with the heat sink 40 in the power device. In specific implementation, the surface of the heat sink 40 is attached to the second surface 3302 of the base plate 330 so that the heat transferred to the base plate 330 can be transferred to the heat sink 40, thereby achieving efficient heat dissipation of the power module 30.

[0120] You can continue to refer to Figure 12 Because of the design scheme of the power module 30 provided in this application, the co-fired ceramic module 37 and the substrate 31 are arranged along the stacking direction. That is to say, the projection of the co-fired ceramic module 37 on the heat sink 40 falls within the outline of the projection of the entire power module 30 on the heat sink 40. This can improve the integration of the power module 30 while avoiding increasing the heat dissipation area occupied by the power module 30. This is conducive to reducing the overall size of the power device, and can improve the placement flexibility of the power module 30 in the power device without changing the size of the power device, thereby improving the power density of the power device.

[0121] It is worth mentioning that, Figure 12 This description only uses the power module 30 of one embodiment provided in this application as an example to illustrate the arrangement between the power module 30 and the heat sink 40. The arrangement between the power module 30 and the heat sink 40 in other embodiments is similar and will not be described in detail here.

[0122] It is understood that the integrated design scheme of the power module 30 provided in this application is not limited to its specific packaging method. That is to say, the scheme is applicable to power modules 30 with various packaging forms, and therefore has a wide range of applications. In addition, the integrated design scheme is not only applicable to the power module 30, but also to other modules with similar integration requirements, such as automotive-grade modules or some small and medium power modules. The specific settings can be referred to the above embodiments, and will not be elaborated here.

[0123] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power module, characterized by The power module comprises a substrate, a first power device, a co-fired ceramic module and a package body, wherein: the first power device is arranged on one side surface of the substrate, and the first power device is electrically connected with the substrate; the co-fired ceramic module is arranged on the side of the first power device away from the substrate, and the co-fired ceramic module is arranged spaced apart from the first power device; the co-fired ceramic module comprises a co-fired ceramic base and a second power device, the second power device is embedded in the co-fired ceramic base, and the second power device is electrically connected with at least one of the substrate and the first power device; the package body wraps the substrate, the first power device and the co-fired ceramic module.

2. The power module of claim 1, wherein, The thickness of the second power device is less than or equal to half of the thickness of the co-fired ceramic base.

3. The power module of claim 1 or 2, wherein, The rigidity of the second power device is less than the rigidity of the co-fired ceramic base.

4. The power module of any one of claims 1 to 3, wherein, The projection of the co-fired ceramic base on the substrate falls within the outline range of the substrate, and the projection area of the co-fired ceramic base on the substrate is less than the area of the substrate.

5. The power module of any one of claims 1 to 4, wherein, The flatness of the substrate is higher than the flatness of the co-fired ceramic module.

6. The power module of any one of claims 1 to 5, wherein, The projection area of the co-fired ceramic module is less than or equal to half of the projection area of the package body in the direction from the co-fired ceramic module to the substrate.

7. The power module of any one of claims 1 to 6, wherein, The electrical impedance of the substrate is lower than the electrical impedance of the co-fired ceramic base, and the dielectric constant of the co-fired ceramic base is higher than the dielectric constant of the substrate.

8. The power module of any one of claims 1 to 7, wherein, The porosity of the co-fired ceramic base is lower than the porosity of the package body.

9. The power module of any one of claims 1 to 8, wherein, The Young's modulus of the co-fired ceramic base is greater than the Young's modulus of the package body.

10. The power module of any one of claims 1 to 9, wherein, The thickness of the first power device is less than the thickness of the second power device.

11. The power module of any one of claims 1 to 10, wherein, The power module further comprises a bottom plate, the bottom plate comprises a first surface and a second surface arranged opposite to each other, and the substrate is fixed to the first surface; the projection of the co-fired ceramic module on the bottom plate falls within the outline range of the bottom plate, and the projection area of the co-fired ceramic base on the bottom plate is less than the area of the bottom plate.

12. The power module of claim 11, wherein, The thermal conductivity of the bottom plate is higher than the thermal conductivity of the co-fired ceramic base.

13. The power module of any one of claims 1 to 12, wherein, The power module further comprises a pin, the pin penetrates through the package body and extends to the outside of the power module; the pin is electrically connected with the substrate, and the pin penetrates through the co-fired ceramic module and is electrically connected with the second power device.

14. The power module of claim 13, wherein, The pin comprises a limiting surface facing the co-fired ceramic module, and the surface of the co-fired ceramic module facing the substrate abuts against the limiting surface.

15. A power device, characterized by The power device comprises a shell, a circuit board and the power module as claimed in any one of claims 1-14, the circuit board and the power module are accommodated in the shell, and the power module is electrically connected with the circuit board.

16. A photovoltaic power system, characterized by The power device comprises a photovoltaic assembly and the power module as claimed in claim 15, wherein the power device is used for converting direct current output by the photovoltaic assembly into alternating current.

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