Power module, power device and photovoltaic power generation system

Abstract

Disclosed in the present application are a power module, a power device, and a photovoltaic power generation system. The power module comprises a substrate, a first power device, a co-fired ceramic module, and a package body. The first power device is located on a surface of the substrate and is electrically connected to the substrate. The co-fired ceramic module is located on the side of the first power device facing away from the substrate, and the co-fired ceramic module and the first power device are spaced apart. The co-fired ceramic module comprises a co-fired ceramic base and a second power device, wherein the second power device is embedded in the co-fired ceramic base and is electrically connected to at least one of the substrate and the first power device. The package body encapsulates the substrate, the first power device, and the co-fired ceramic module. By means of the design scheme of the power module, the integration level and power density of the power module are improved while ensuring the structural reliability of the power module, and improvement to the power conversion performance of the power module is also facilitated, thereby improving the power density of the power device and thus improving the power generation efficiency of the photovoltaic power generation system.

Description

Power module, power device and photovoltaic power generation system

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411091325.5, filed on August 8, 2024, and entitled "Power module, power device and photovoltaic power generation system", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of energy, and in particular to a power module, a power device and a photovoltaic power generation system. BACKGROUND

[0004] The power module is a functional module that combines power devices according to certain functions and then encapsulates or potentiates into a whole. It is widely used in servo motors, frequency converters or inverters and other devices. The common packaging forms of the power module include housing packaging and molding packaging. The main process is to assemble and weld the substrate, chip and pin, and then pour the encapsulation material to protect the above components.

[0005] 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 power modules with other power devices and the structural reliability of the integrated power modules have become an important research topic for technical personnel in the field. SUMMARY

[0006] 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 facilitating the improvement of the power density of the power device.

[0007] In a first aspect, the present application provides a power module, which comprises a substrate, a first power device, a co-fired ceramic module and a package. The first power device is arranged on one side surface of the substrate and is electrically connected to the substrate. The co-fired ceramic module is arranged on the side of the first power device away from the substrate and is spaced apart from the first power device. In addition, 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 to at least one of the substrate and the first power device. The package wraps the substrate, the first power device and the co-fired ceramic module. By using the co-fired ceramic technology, the power module provided by the present application can integrate more electrically interconnected power devices into a whole, thereby improving the integration and power density of the power module. In addition, the co-fired ceramic structure has better structural reliability, so it can be used to protect the second power device and 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 and the power conversion performance of the power module.

[0008] 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. In this way, the structural reliability of the co-fired ceramic module can be improved while the electromagnetic shielding effect of the co-fired ceramic base on the second power device is improved.

[0009] 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.

[0010] 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. In this way, it is beneficial to increase the difference between the size of the package and the co-fired ceramic module, which is beneficial to alleviate the stress on the co-fired ceramic module.

[0011] In addition, the flatness of the substrate is higher than the flatness of the co-fired ceramic module. In this way, the mechanical strength of the co-fired ceramic module can be effectively improved, thereby improving the structural reliability of the entire power module.

[0012] 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. In this way, the difference between the planar size of the package and the co-fired ceramic module is increased, which is beneficial to alleviate the stress on the co-fired ceramic module.

[0013] In the present application, the electrical impedance of the substrate is lower than that of the co-fired ceramic base, and the dielectric constant of the co-fired ceramic base is higher than that 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.

[0014] In one possible implementation of the present application, the porosity of the co-fired ceramic base is lower than that of the package. This can improve the moisture resistance of the co-fired ceramic base, thereby improving the reliability of the second power device.

[0015] In addition, the Young's modulus of the co-fired ceramic base is greater than that of the package. This can alleviate the stress on the co-fired ceramic base, thereby improving the mechanical strength of the co-fired ceramic module.

[0016] In one possible implementation of the present application, the thickness of the first power device is less than that 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.

[0017] The power module provided by the present application further includes a bottom plate, the bottom plate including 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 contour range of the bottom plate, and the projected area of the co-fired ceramic base on the bottom plate is less than the area of the bottom plate. This can effectively improve the heat conduction efficiency of the co-fired ceramic base to the bottom plate, thereby improving the heat dissipation performance of the entire power module.

[0018] In addition, the thermal conductivity of the bottom plate can be further made higher than that of the co-fired ceramic base. This can further improve the heat dissipation efficiency of the power module.

[0019] In one possible implementation of the present application, the power module further includes a pin, one end of the pin being electrically connected to the substrate, and the other end of the pin penetrating through the package and extending to the outside of the power module. This can realize the interconnection between the power module and the external device through the pin.

[0020] In addition, the pin can also penetrate through the co-fired ceramic module, and the pin can be electrically connected to the second power device. This can make the second power device realize the electrical connection with the substrate through the pin, which can make the electrical connection path between the second power device and the substrate shorter, thereby facilitating the reduction of the parasitic inductance in the power circuit including the power module, which is conducive 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 device outside the power module.

[0021] In the present application, the pin can be used to limit the co-fired ceramic module. Specifically, the pin includes 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. Thus, the spacing between the co-fired ceramic module and the first power device is 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 by designing the position of the limiting surface.

[0022] In another implementation, the co-fired ceramic module can be pre-positioned by fixing the pin and the co-fired ceramic module together and then assembling the whole with the substrate, so as to limit the spacing between the co-fired ceramic module and the first power device.

[0023] In a possible implementation of the present application, the co-fired ceramic module further includes 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.

[0024] In a possible implementation of the present application, the power module further includes a first conductive structure, one end of the first conductive structure is electrically connected with the substrate, and the other end of the first conductive structure is electrically connected with the second power device through the circuit layer, so that the second power device can be electrically connected with the substrate through the circuit layer.

[0025] The first conductive structure and the circuit layer can be connected in various ways. For example, the circuit layer is exposed from the side of the co-fired ceramic substrate facing the substrate, so that the other end of the first conductive structure is electrically connected with the exposed part of the circuit layer, so as to simplify the electrical connection between the first conductive structure and the circuit layer.

[0026] Alternatively, the co-fired ceramic substrate includes a through hole, and the other end of the first conductive structure is inserted into the through hole and electrically connected with the circuit layer. In this way, the electrical connection reliability between the first conductive structure and the circuit layer can be improved.

[0027] The present application does not limit the specific type of the first conductive structure, which can exemplarily include at least one of a conductive column, a conductive sheet and a bonding wire.

[0028] In a possible implementation of the present application, the power module further includes a second conductive structure, one end of the second conductive structure is electrically connected with the first power device, and the other end of the second conductive structure is electrically connected with the second power device through the circuit layer, so that the second power device can be electrically connected with the first power device through the circuit layer.

[0029] The second conductive structure can be connected to the circuit layer in various ways. For example, the circuit layer is exposed on the side of the co-fired ceramic substrate facing the substrate, so that the other end of the second conductive structure is electrically connected to the exposed part of the circuit layer, thereby simplifying the electrical connection between the second conductive structure and the circuit layer.

[0030] Alternatively, the co-fired ceramic substrate includes a through hole, and the other end of the second conductive structure is inserted into the through hole and electrically connected to the circuit layer. This can improve the electrical connection reliability between the second conductive structure and the circuit layer.

[0031] The present application does not limit the specific type of the second conductive structure, which can include at least one of a conductive column, a conductive sheet, and a bonding wire.

[0032] In a second aspect, the present 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 accommodated in the housing, and the power module is electrically connected to the circuit board. In the power device provided by the present application, the power module can integrate more power devices, thereby improving the integration of the power loop formed by the electrical connection between the power module and the circuit board, and improving the integration and power density of the power device.

[0033] In a possible implementation of the present application, the power device further includes a heat sink located in the housing. In addition, the heat sink is in thermal contact with the second surface. In this way, the heat generated by the first power device and the second power device during operation can be transmitted to the bottom plate through the substrate, and then transmitted to the heat sink, thereby achieving heat dissipation of the power module. Since the co-fired ceramic module and the substrate are arranged along the stacking direction according to the design scheme of the power module provided by the present application, that is, the projection of the co-fired ceramic module on the heat sink falls within the outline of the projection of the entire power module on the heat sink. In this way, the integration of the power module can be improved while avoiding an increase in the heat dissipation area occupied by the power module, which is beneficial to the reduction of the overall volume of the power device, and can improve the flexibility of the power module in the power device under the condition that the volume of the power device remains unchanged, thereby improving the power density of the power device.

[0034] In a third aspect, the present application also provides a photovoltaic power generation system, which includes a photovoltaic assembly and the power device of the second aspect, and the power device is used to convert the direct current output by the photovoltaic assembly into alternating current. In the photovoltaic power generation system, the power density of the power device is relatively high, which is beneficial to the improvement of the power generation efficiency of the photovoltaic power generation system. BRIEF DESCRIPTION OF DRAWINGS

[0035] FIG. 1 is a structural schematic diagram of a photovoltaic power generation system provided by an embodiment of the present application;

[0036] FIG. 2 is a structural schematic diagram of a power device provided by an embodiment of the present application;

[0037] Fig. 3a is a structural schematic diagram of a power module using housing packaging;

[0038] Fig. 3b is a structural schematic diagram of a power module using molding packaging;

[0039] Fig. 4 is a structural schematic diagram of a power module provided by an embodiment of the present application;

[0040] Fig. 5 is an enlarged view of a partial structure at A in the structure shown in Fig. 4;

[0041] Fig. 6 is another structural schematic diagram of a power module provided by an embodiment of the present application;

[0042] Fig. 7 is a specific structural schematic diagram of a power module provided by an embodiment of the present application;

[0043] Fig. 8 is an exploded view of the power module shown in Fig. 7;

[0044] Fig. 9a is a specific structural schematic diagram of a co-fired ceramic module provided by an embodiment of the present application;

[0045] Fig. 9b is another specific structural schematic diagram of a co-fired ceramic module provided by an embodiment of the present application;

[0046] Fig. 10 is another structural schematic diagram of a power module provided by an embodiment of the present application;

[0047] Fig. 11 is another structural schematic diagram of a power module provided by an embodiment of the present application;

[0048] Fig. 12 is a partial structural schematic diagram of a power device provided by an embodiment of the present application.

[0049] Fig. 12 is a partial structural schematic diagram of a power device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the purposes, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein. The same reference numerals in the drawings represent the same or similar structures, and thus repeated description thereof will be omitted. The words expressing position and direction described in the embodiments of the present application are described with reference to the drawings, but can be changed as needed, and the changes made are included in the scope of protection of the present application. The drawings of the embodiments of the present application are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0051] It should be noted that specific details are set forth in the following description in order to facilitate understanding of the present application. However, the example embodiments can be implemented in various other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotations of the embodiments of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0052] Power devices are widely used in photovoltaic power generation systems, energy storage systems, or powertrain systems of new energy vehicles, etc. for power conversion of current or voltage in the application system. The power device can include an inverter, a micro-inverter in a photovoltaic power generation system, or a current converter in an energy storage system, or a motor controller in a powertrain of a new energy vehicle, etc.

[0053] Taking a photovoltaic power generation system as an example, FIG. 1 is a schematic diagram of an application scenario of a photovoltaic power generation system provided by an embodiment of the present application. The photovoltaic power generation system includes a photovoltaic module 1000, an inverter 2000, and a transformer 3000. The photovoltaic module 1000 is a direct current power supply composed of series or parallel encapsulation of solar cell pieces, and is used to convert the energy of sunlight into direct current electrical energy. The inverter 2000 is a direct current- alternating current power device, which can be used to convert the direct current output by the photovoltaic module 1000 into alternating current and output to the transformer 3000. The transformer 3000 is used to transform the alternating current output by the inverter 2000 and then input into an alternating current grid 4000, thereby realizing grid connection of the photovoltaic power generation system. Alternatively, the alternating current output by the inverter 2000 can be output to a load 5000 to supply power to the load 5000.

[0054] Fig. 2 is a structural schematic diagram of a power device according to an embodiment of the present application. Referring to Fig. 2, the power device 100 can include a housing 10, a circuit board 20 and a power module 30 accommodated in the housing 10, and the power module 30 is electrically connected with the circuit board 20. The circuit board 20 can be a printed circuit board (PCB), a flexible printed circuit (FPC), or a rigid-flex printed circuit board, etc. The power module 30 is a core component of the power device 100 for realizing power conversion function. The power module 30 can include a plurality of ports, such as input positive and negative electrode ports, output positive and negative electrode ports, power supply positive and negative electrode ports, etc. These ports are respectively electrically connected with the circuit board 20 through pins, so as to provide the power module 30 with functions of input and output of current or voltage, power supply, etc. by the circuit board 20.

[0055] The power module 30 can include chips, inductors, resistors, capacitors and other power devices. These power devices are connected according to certain function combinations and then encapsulated as a whole through an encapsulation process. Common encapsulation processes of the power module 30 include housing encapsulation and molding encapsulation, etc. Fig. 3a shows a power module using housing encapsulation. As shown in Fig. 3a, the housing encapsulation is a kind of encapsulation mode which forms an accommodating cavity by using a shell 33 and a substrate 31 carrying the above-mentioned chips 32 and other power devices, and pours encapsulation material such as silica gel 34 into the accommodating cavity to protect the power devices. Fig. 3b shows a power module using molding encapsulation. As shown in Fig. 3b, the molding encapsulation is a kind of encapsulation mode which puts the substrate 31 carrying the chips 32 and other power devices into a special injection mold, uses softened epoxy resin 35 as encapsulation material, and encapsulates and wraps the power devices under certain pressure and temperature conditions to protect the internal devices.

[0056] Generally, other power devices can also be arranged in the circuit board 20 or other positions in the housing 10 of the power device. These power devices can be electrically connected with the power devices in the power module 30 through the circuit board 20 or other ways to form a power circuit.

[0057] It can be understood that when the chips 32 and other power devices in the power module 30 are electrically connected with external power devices, the connection path is relatively long because it needs to pass through the encapsulation structure (such as the silica gel 34 in Fig. 3a or the plastic encapsulation material 35 in Fig. 3b), so as to cause relatively large parasitic inductance, which can generate voltage spikes when the circuit is rapidly converted, and hinder the improvement of power density of the power device.

[0058] At present, for the above problems, the person skilled in the art proposes a scheme of integrating more power devices in the packaging structure of the power module to reduce power loss by shortening the connection path. However, if the power devices are directly integrated in the existing power module, there is a problem of damage to the power devices due to large internal stress of the package.

[0059] The co-fired ceramic technology refers to the following process: sintering ceramic powder into a green ceramic tape with accurate thickness and density, using laser drilling, micro-hole grouting, and precise conductor paste printing process to make the required circuit pattern on the green ceramic tape, and embedding multiple passive components (such as low-capacitance capacitors, resistors, filters, impedance converters, couplers, etc.) in the multilayer ceramic substrate, then stacking and sintering to make a high-density circuit in three-dimensional space without interference, which can also be made into a three-dimensional circuit substrate with built-in passive components. In addition, chips and active devices can be attached to the surface to make a passive / active integrated functional module to further realize the miniaturization and high density of the circuit.

[0060] Therefore, the power module provided by the embodiments of the present application makes it possible to integrate more electrically interconnected power devices into one whole by using the co-fired ceramic technology, so as to improve the integration of the power module while ensuring the structural reliability of the power module. In order to facilitate the understanding of the scheme provided by the present application, the following will be described in detail in combination with specific embodiments.

[0061] FIG. 4 is a structural schematic diagram of a power module provided by an embodiment of the present application. The power module 30 can 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 arranged on one side surface of the substrate 31 and is electrically connected to the substrate 31. In the present application, the first power device 36 can be a chip 32, and the present application does not limit the number of the chip 32, which can be one or more, and the one or more chips 32 are mounted on one side surface of the substrate 31. In addition, the chip 32 can 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.

[0062] In the present application, the substrate 31 can include a ceramic substrate 311 and metal layers fixed on surfaces of the ceramic substrate 311. For example, as shown in FIG. 5, which is an enlarged view of a partial structure at position A of the structure shown in FIG. 4, the substrate 31 can include two metal layers fixed on two opposite surfaces of the ceramic substrate 311. For ease of description, the two metal layers are referred to as a first metal layer 312 and a second metal layer 313 in the present embodiment. The first metal layer 312 can be used to mount the chip 32, which can be electrically connected to the first metal layer 312 by bonding wires made of aluminum, copper, silver, alloys thereof, or the like, or can be electrically connected to the first metal layer 312 by a clip welding process based on aluminum, copper, silver, alloys thereof, or the like, or can be electrically connected to the first metal layer 312 by other possible manners, which are not listed here.

[0063] In addition, the first power device 36 can also be an inductor, a resistor, or a capacitor, and the first metal layer 312 can also be used to mount the inductor, the resistor, or the capacitor. The chip 32 and these devices can be fixed on the surface of the first metal layer 312 by reflow soldering or the like, or can be fixed on the surface of the first metal layer 312 by forming a pre-packaging body by using a ball grid array package (BGA), a quad flat non-leaded package (QFN), a small out-line package (SOP), a transistor outline (TO), or any other packaging form.

[0064] In an embodiment, the ceramic substrate 311 can be made of alumina or aluminum nitride, which are relatively low in cost, to reduce the overall cost of the power module 30. The first metal layer 312 and the second metal layer 313 can be copper layers, and the substrate 31 is a direct bonding copper (DBC) substrate. In other embodiments, the first metal layer 312 and the second metal layer 313 can be aluminum layers, and the substrate 31 is a direct bonded aluminum (DBA) substrate. In other possible embodiments of the present application, the substrate 31 can also be an active metal bonding (AMB) substrate, an insulated metal substrate (IMS), a printed circuit board (PCB), or any other form of substrate, which are not limited here.

[0065] Continuing to refer to FIG. 4, the co-fired ceramic module 37 includes a co-fired ceramic substrate 371 and a second power device 372 embedded in the co-fired ceramic substrate 371. The co-fired ceramic module 37 is located on a side of the first power device 36 facing away from the substrate 31, and is spaced apart from the first power device 36, and the second power device 372 is electrically connected to at least one of the substrate 31 and the first power device 36.

[0066] In the present application, the type of the co-fired ceramic substrate 371 is not limited, and exemplary can be low temperature co-fired ceramic (LTCC), medium temperature co-fired ceramic (HTCC) or high temperature co-fired ceramic (HTCC). In addition, the second power device 372 can be an active device such as IC, IGBT, MOSFET or diode, or a passive device such as low capacitance capacitor, resistor, impedance converter, filter or coupler.

[0067] 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 of the thickness of the co-fired ceramic substrate 371. In this way, the structural reliability of the co-fired ceramic module 37 can be improved, and the electromagnetic shielding effect of the co-fired ceramic substrate 371 on the second power device 372 can be improved.

[0068] In addition, the rigidity of the second power device 372 is less than the rigidity of the co-fired ceramic substrate 371, so as to reduce the risk of damage of the second power device 372 due to stress concentration, thereby improving the reliability of the second power device 372.

[0069] Since the first power device 36 can be electrically connected to the second power device 372 through the substrate 31 in general, in the present application, the electrical impedance of the substrate 31 is lower than the electrical impedance of the co-fired ceramic substrate 371, and the dielectric constant of the co-fired ceramic substrate 371 is higher than the dielectric constant of the substrate 31. In this way, the electromagnetic interference between the first power device 36 and the second power device 372 can be effectively reduced, so as to improve the operation reliability of the power module 30.

[0070] In addition, the flow direction of the current in the substrate 31 in the plane can be perpendicular to the flow direction of the current in the second power device 372 in the plane, so as to further reduce the electromagnetic interference between the first power device 36 and the second power device 372.

[0071] Continuing to refer to FIG. 4, the encapsulant 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 as a whole. In the present application, the encapsulant 38 can be, but is not limited to, the silicone gel 34 or the plastic encapsulant 35 described above, as long as it can play a role of encapsulating and protecting the devices in the power module 30.

[0072] In actual applications, the projected area of the co-fired ceramic module 37 in the direction from the co-fired ceramic module 37 to the substrate 31 is less than or equal to half of the projected area of the encapsulant 38. Increasing the difference between the planar size of the encapsulant 38 and the co-fired ceramic module 37 can help to relieve the stress on the co-fired ceramic module 37.

[0073] In addition, in the present application, the flatness of the substrate 31 can be higher than that of the co-fired ceramic module 37 to improve the mechanical strength of the co-fired ceramic module 37 and thus the structural reliability of the entire power module 30.

[0074] In the present application, the flatness refers to the difference between the uneven part of the surface of an object and the reference surface that is absolutely flat, and the smaller the difference, the higher the flatness of the object.

[0075] Since the encapsulant 38 encapsulates both the substrate 31 and the co-fired ceramic module 37, in the present application, the projection of the co-fired ceramic matrix 371 on the substrate 31 falls within the projection range of the substrate 31, and the projected area of the co-fired ceramic matrix 371 on the substrate 31 is less than the area of the substrate 31. This can help to increase the difference between the size of the encapsulant 38 and the co-fired ceramic module 37, which can help to relieve the stress on the co-fired ceramic module 37.

[0076] In the power module 30 provided in the present application, the porosity of the co-fired ceramic matrix 371 can be lower than that of the encapsulant 38. This can improve the moisture resistance of the co-fired ceramic matrix 371 and thus the reliability of the second power device 372.

[0077] In addition, the Young's modulus of the co-fired ceramic matrix 371 is greater than that of the encapsulant 38. This can relieve the stress on the co-fired ceramic matrix 371 and thus improve the mechanical strength of the co-fired ceramic module 37.

[0078] In addition, the thickness of the first power device 36 can be less than that of the second power device 372. This can effectively reduce the influence of the first power device 36 on the stress on the second power device 372 and thus improve the reliability of the co-fired ceramic module 37.

[0079] It can be understood that, in the present application, the rigidity of the first power device 36 is greater than the rigidity of the co-fired ceramic base 371. It can also effectively alleviate the stress applied to the co-fired ceramic module, so as to improve the reliability of the co-fired ceramic module 37.

[0080] By using the design scheme of the power module 30 provided in the present application, the second power device 372 embedded in the co-fired ceramic base 371 is integrated in the power module 30 by using the co-fired ceramic technology, so as to improve the integration and power density of the power module 30. Since the co-fired ceramic structure has better structural reliability, it can be used to protect the second power device 372, so as to reduce the risk of damage of the second power device 372 caused by stress concentration, thereby improving the structural reliability of the entire power module 30.

[0081] It can be understood that, embedding the second power device 372 in the co-fired ceramic base 371 is also conducive to reducing the electromagnetic interference of external devices on the second power device 372, thereby improving the operation reliability of the second power device 372, which is conducive to improving the power conversion performance of the power module.

[0082] After understanding the design principle of the power module 30 provided in the present application, the following describes several possible setting modes of the power module 30 in actual application.

[0083] FIG. 6 is another structural schematic view of a power module provided in an embodiment of the present application. As can be known from the above description of the power module, the power module further includes a pin 39, one end of the pin 39 is electrically connected with the substrate 31, and the other end of the pin 39 penetrates the package 38 to the outside of the power module 30, so as to realize the interconnection between the power module 30 and external devices.

[0084] The present application does not limit the number of the pin 39 of the power module 30, which can be designed according to the specific connection requirement between the power module 30 and external devices.

[0085] Since the co-fired ceramic module 37 is located on the side of the first power device 36 away from the substrate 31, as shown in FIG. 6, in this embodiment, the pin 39 can penetrate the co-fired ceramic module 37, and the pin 39 is electrically connected with the second power device 372. In this way, the electrical connection between the second power device 372 and the substrate 31 can be realized, and the electrical connection port of the second power device 372 can be led to the outside of the power module 30 through the pin 39, so as to facilitate the electrical connection between the second power device 372 and devices outside the power module 30. In addition, the first power device 36 can be electrically connected with the second power device 372 through the substrate 31 and the pin 39. This scheme can be conducive to improving the integration of the power module 30 and reducing the design difficulty of the power module 30, thereby being conducive to reducing the design cost of the power module 30.

[0086] In addition, in the embodiment shown in FIG. 6, the second power device 372 is electrically connected to the substrate 31 through the pin 39, which can shorten the electrical connection path between the second power device 372 and the substrate 31, thereby reducing the parasitic inductance in the power circuit including the power module 30, and thus improving the power density of the power module 30.

[0087] To facilitate the understanding of the structure of the power module shown in FIG. 6, reference can be made to FIG. 7, which is a schematic diagram of a specific structure of a power module according to an embodiment of the present application. In the power module shown in FIG. 7, a plurality of pins 39 extend through the package 38 to the outside of the power module 30.

[0088] As can be known from the above introduction of the structure of the power module 30 provided by the present application, the co-fired ceramic module 37 is spaced apart from the first power device 36. The spacing between the co-fired ceramic module 37 and the first power device 36 can be adjusted according to actual design requirements, so as to avoid the co-fired ceramic module 37 pressing the first power device 36, reduce the current crosstalk between the first power device 36 and the second power device 372, and avoid significantly increasing the size of the power module.

[0089] In the present application, there are various ways to limit the co-fired ceramic module 37. For example, reference can be made to FIG. 8, which is an exploded view of the power module shown in FIG. 7. The pin 39 includes a limiting seat 391, and the pin 39 can be fixedly connected to the substrate 31 through the limiting seat 391. The co-fired ceramic module 37 includes a through hole 373, wherein the maximum size of the cross section of the limiting seat 391 is greater than the maximum size of the cross section of the through hole 373, so that the co-fired ceramic module 37 and the limiting surface of the limiting seat 391 facing the co-fired ceramic module 37 abut each other, thereby limiting the spacing between the co-fired ceramic module 37 and the first power device 36 through the limiting seat 391.

[0090] It is worth mentioning that in the present application, the cross-sectional area of the pin 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 the plurality of pins 39, thereby improving the limiting reliability of the co-fired ceramic module 37 by the pin 39. In addition, the rigidity of the pin 39 is smaller than the rigidity of the co-fired ceramic substrate 371, so as to absorb the stress applied to the co-fired ceramic module 37 through the deformation of the pin 39, thereby improving the structural reliability of the co-fired ceramic module 37.

[0091] But the limiting mode of the co-fired ceramic module 37 is not limited to this, for example, the pin 39 can be fixedly connected with the co-fired ceramic module 37, and then the co-fired ceramic module 37 and the substrate 31 are assembled as a whole, so that the co-fired ceramic module 37 can be positioned. Alternatively, the spacing between the co-fired ceramic module 37 and the first power device 36 can be limited by the package 38 when the package 38 is formed. Of course, other any possible way can be used to limit the co-fired ceramic module 37, which is not listed one by one, but it should be understood as falling within the protection scope of the present application.

[0092] Fig. 9a is a specific structural schematic diagram of the co-fired ceramic module provided by the embodiment of the present application, in which the co-fired ceramic substrate is omitted. As shown in Fig. 9a, the co-fired ceramic module 37 further comprises a circuit layer 374, wherein the circuit layer 374 can be a conductive layer such as a metal layer including circuit patterns, and at least part of the circuit layer 374 is embedded in the co-fired ceramic substrate 371 (not shown in Fig. 9a, which can be referred to Fig. 6), so that the co-fired ceramic substrate 371 can support the circuit layer 374, thereby ensuring the structural reliability of the circuit layer 374.

[0093] As shown in Fig. 9a, the second power device 372 is electrically connected with the circuit layer 374. In this way, the pin 39 as shown in Fig. 8 above can penetrate the circuit layer 374 and be electrically connected with the circuit layer 374, so as to realize the electrical connection between the pin 39 and the second power device 372.

[0094] It can be understood that the specific arrangement mode of the circuit layer 374 is not limited by the present application. For example, in the embodiment shown in Fig. 9a, the co-fired ceramic module 37 comprises two circuit layers 374 arranged in the same layer, the second power device 372 is located between the two circuit layers 374 and is electrically connected with the two circuit layers 374. For example, in the co-fired ceramic module 37 shown in Fig. 9b, the co-fired ceramic module 37 comprises two circuit layers 374 arranged in layers, the second power device 372 is still located between the two circuit layers 374 and is electrically connected with the two circuit layers 374. In addition, in the embodiment shown in Fig. 9b, the two circuit layers 374 can be electrically connected through a metal via 375, and the second power device 372 and the circuit layer 374 can also be electrically connected through the metal via 375.

[0095] The electrical connection mode between the second power device 372 and the pin 39 in the co-fired ceramic module 37 shown in Fig. 9b can be referred to the introduction in Fig. 9a, which is not described herein.

[0096] It is worth mentioning that the arrangement of the circuit layer 374 of the co-fired ceramic module 37 can be designed according to the use requirement in the actual application scene and the type of the second power device 372, and for example, in the embodiment shown in FIG. 9a, the second power device 372 can be a passive device. For example, in the embodiment shown in FIG. 9b, the second power device 372 can be an active device. Of course, in other embodiments, the second power device 372 in the co-fired ceramic module 37 shown in FIG. 9a can be an active device, and the second power device 372 in the co-fired ceramic module 37 shown in FIG. 9b can be a passive device.

[0097] In the power module 30 shown in FIG. 8, only one co-fired ceramic module 37 is shown for illustrating the specific structure of the co-fired ceramic module 37. In other possible embodiments, the number of co-fired ceramic modules 37 can be selected according to the actual design requirement. It can be understood that when the power module includes multiple co-fired ceramic modules 37, the design manner of the co-fired ceramic modules 37 can be set according to the co-fired ceramic module 37 in any of the above-mentioned embodiments, which will not be described herein.

[0098] It can be understood that in the present application, the second power device 372 and the substrate 31 and the first power device 36 can also be electrically connected in other manners. For example, referring to FIG. 10, FIG. 10 is another structural schematic view of a power module provided by an embodiment of the present application. In the embodiment shown in FIG. 10, the power module 30 further includes a first conductive structure 310, which can be a conductive column 3101, which can be but is not limited to a metal columnar structure with good conductive performance such as a copper column. The second power device 372 embedded in the co-fired ceramic base 371 can be electrically connected to the substrate 31 through the conductive column 3101. One end of the conductive column 3101 is electrically connected to the substrate 31, and the other end of the conductive column 3101 is electrically connected to the second power device 372.

[0099] In specific implementation, one end of the conductive column 3101 can be fixedly connected to the substrate 31 by welding or bonding, and at the same time, the electrical connection is realized. In addition, when the other end of the conductive column 3101 is electrically connected to the second power device 372, a through hole can be formed on the co-fired ceramic base 371, so that the other end of the conductive column 3101 can be inserted into the through hole and electrically connected to the second power device 372.

[0100] As can be understood from the above description of the co-fired ceramic module 37 in FIGS. 9a and 9b, the other end of the conductive column 3101 can be electrically connected to the circuit layer 374 of the co-fired ceramic module 37 after being inserted into the through hole, so that the conductive column 3101 realizes electrical connection with the second power device 372 through the circuit layer 374.

[0101] In some other embodiments of the present application, the circuit layer 374 of the co-fired ceramic module 37 can be exposed on the side of the co-fired ceramic base 371 facing the substrate 31, so that the other end of the conductive pillar 3101 can be directly fixed to the exposed part of the circuit layer 374 of the co-fired ceramic module 37 to achieve electrical connection, and further achieve electrical connection with the second power device 372. Alternatively, a conductive layer can be arranged on the side of the co-fired ceramic base 371 facing the substrate 31, and the conductive layer can be electrically connected to the circuit layer 374 of the co-fired ceramic module 37 through a metal via or the like to achieve electrical connection between the conductive layer and the second power device 372, so that the other end of the conductive pillar 3101 can be directly fixed to the conductive layer to achieve electrical connection, and further achieve electrical connection with the second power device 372.

[0102] It can be understood that when the conductive layer is arranged on the side of the co-fired ceramic base 371 facing the substrate 31, the surface of the conductive layer can be subjected to oxidation prevention treatment to improve the electrical connection reliability between the co-fired ceramic module 37 and the first conductive structure 310. In addition, the electrical connection between the other end of the conductive pillar 3101 and the second power device 372 is not limited to this, and is not listed one by one here, but it should be understood as falling within the protection scope of the present application.

[0103] Referring back to FIG. 10, the power module 30 further comprises a second conductive structure 320, which in this embodiment can be a conductive sheet. The second conductive structure 320 is arranged between the first power device 36 and the co-fired ceramic module 37, so that the first power device 36 can be electrically connected to the second power device 372 through the second conductive structure 320. The side of the second conductive structure 320 facing the co-fired ceramic module 37 is fixedly connected to the first power device 36 by welding or bonding, and the electrical connection between the second conductive structure 320 and the first power device 36 is achieved at the same time. In addition, the second conductive structure 320 is electrically connected to the second power device 372. Since the electrical connection between the second conductive structure 320 and the second power device 372 is similar to the electrical connection between the first conductive structure 310 and the second power device 372, it is not described here.

[0104] It is worth mentioning that the other structures of the power module 30 shown in FIG. 10 can be arranged according to any of the above embodiments, and are not described here.

[0105] Fig. 11 is another structural schematic diagram of the power module provided by the embodiment of the present application. In the embodiment shown in Fig. 11, the first conductive structure 310 includes the conductive column 3101 and the bonding wire 3102, and the second power device 372 can be electrically connected to the substrate 31 through the conductive column 3101 and the bonding wire 3102. It can be understood that the co-fired ceramic module 37 includes a plurality of second power devices 372, at least one second power device 372 is electrically connected to the substrate 31 through the conductive column 3101, and at least one second power device 372 is electrically connected to the substrate 31 through the bonding wire 3102. Alternatively, it can be understood that one second power device 372 is electrically connected to the substrate 31 through the conductive column 3101 and the bonding wire 3102, respectively, for realizing different functions on the substrate 31, for example, the second power device 372 is electrically connected to the substrate 31 through the conductive column 3101 and the bonding wire 3102, respectively, to realize the electrical connection between the second power device 372 and the first power device 36 of different types mounted on the substrate 31.

[0106] It is worth mentioning that, as shown in Fig. 11, when the bonding wire 3102 is electrically connected to the second power device 372 through the side of the co-fired ceramic module 37 away from the substrate 31, a conductive layer can be arranged on the surface of the co-fired ceramic base 371 away from the substrate 31, and the conductive layer is subjected to an oxidation prevention 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, to realize the electrical connection between the second power device 372 and the substrate 31. In addition, the other structures of the power module 30 shown in Fig. 11 can be arranged according to any of the above embodiments, and will not be described here.

[0107] For the specific material of the first conductive structure 310 and the second conductive structure 320, the present application is not limited, for example, when the bonding wire 3102 is selected as the conductive structure, the material thereof can be an aluminum wire, so as to reduce the influence of the stress on the co-fired ceramic module 37.

[0108] The embodiments shown in FIG. 8, FIG. 10 and FIG. 11 are only some exemplary descriptions of the implementation of the interconnection between the substrate 31, the first power device 36 and the second power device 372 in the power module 30. On this basis, a series of modifications can be made according to the use requirements in specific application scenarios, for example, the first conductive structure 310 can include at least one of the conductive column 3101, the bonding wire 3102 and the conductive sheet, so that the second power device 372 can be electrically connected to the substrate 31 through the first conductive structure 310 in the above-mentioned at least one setting form; similarly, the second conductive structure 320 can also include at least one of the conductive column 3101, the bonding wire 3102 and the conductive sheet, so that the first power device 36 is electrically connected to the second power device 372 through the second conductive structure 320 in the above-mentioned at least one setting form. In addition, on the basis of the power module 30 with the structure shown in FIG. 10 and FIG. 11, the pin 39 can also be electrically connected to the second power device 372, and the specific implementation manner can refer to the embodiment shown in FIG. 8, which will not be described here. In addition, other reasonable designs can also be used to realize the electrical connection between the substrate 31, the first power device 36 and the second power device 372, which will not be listed one by one here, but it should be understood that they all fall within the protection scope of the present application.

[0109] It is worth mentioning that in the above-mentioned embodiments of the present application, the power module 30 can include one substrate 31 or a plurality of substrates 31, and when it includes a plurality of substrates 31, the setting manner of the plurality of substrates 31 is similar, so it will not be described here.

[0110] The above only introduces some key parts in the power module 30, in addition, referring to FIG. 10 or FIG. 11, the power module 30 can also include a bottom plate 330. The bottom plate 330 includes a first surface 3301 and a second surface 3302 arranged opposite to each other, and the substrate 31 is fixed to the first surface 3301 of the bottom plate 330. The heat generated by the first power device 36 and the second power device 372 during work can be transmitted to the first surface 3301 of the bottom plate 330 through the substrate 31, and then transmitted to the second surface 3302 of the bottom plate 330, and dissipated to the outside through the bottom plate 330, thereby realizing the heat dissipation of the power module 30.

[0111] Referring to FIG. 10 or FIG. 11, in the present application, the projection of the substrate 31 on the first surface 3301 of the bottom plate 330 is within the contour range of the first surface 3301 of the bottom plate 330, or it can be understood that the edge of the bottom plate 330 exceeds the edge of the substrate 31. This is helpful to increase the heat dissipation area of the substrate 31, thereby improving the heat dissipation performance of the power module 30. It can be understood that the bottom plate 330 can be made of a metal material with good heat conduction performance, for example, the bottom plate 330 can be a copper substrate or an aluminum substrate.

[0112] In addition, as shown in FIG. 10 or FIG. 11, the projection area of the co-fired ceramic substrate 371 on the bottom plate 330 is less than the area of the bottom plate 330. In this way, the heat conduction efficiency of the co-fired ceramic module 37 to the bottom plate 330 can be effectively improved, so as to improve the heat dissipation performance of the entire power module 30.

[0113] In the present application, the thermal conductivity of the bottom plate 330 can be further higher than that of the co-fired ceramic substrate 371. In this way, the heat dissipation efficiency of the power module 30 can be further improved.

[0114] It can be understood that the thickness of the bottom plate 330 can be greater than that of the co-fired ceramic module 37, so as to facilitate the reduction of the stress applied to the co-fired ceramic module 37, and improve the structural reliability of the entire power module 30. In addition, the flatness of the bottom plate 330 can be greater than that of the co-fired ceramic module 37, so as to further alleviate the stress applied to the co-fired ceramic module 37, and improve the reliability of the co-fired ceramic module 37.

[0115] The power module 30 provided by the present application can be applied to a power device. Referring to FIG. 12, FIG. 12 is a schematic view of a partial structure of a power device according to an embodiment of the present application. As shown in FIG. 12, the power module 30 can also be in thermal contact with a heat sink 40 in the power device. In a specific implementation, the surface of the heat sink 40 is attached to the second surface 3302 of the bottom plate 330, so that the heat transferred to the bottom plate 330 can be transferred to the heat sink 40, thereby achieving efficient heat dissipation of the power module 30.

[0116] Continuing to refer to FIG. 12, since the design scheme of the power module 30 provided by the present application is adopted, the co-fired ceramic module 37 and the substrate 31 are arranged along the stacking direction, that is, the projection of the co-fired ceramic module 37 on the heat sink 40 falls within the contour range of the projection of the entire power module 30 on the heat sink 40. In this way, the integration of the power module 30 can be improved while avoiding increasing the heat dissipation area occupied by the power module 30, which is beneficial to reducing the overall volume of the power device, and can improve the setting flexibility of the power module 30 in the power device under the condition that the volume of the power device remains unchanged, thereby improving the power density of the power device.

[0117] It is worth mentioning that FIG. 12 only takes the power module 30 according to an embodiment of the present application as an example to introduce the setting mode between the power module 30 and the heat sink 40, and the setting mode between the power module 30 and the heat sink 40 in other embodiments is similar, which will not be described here.

[0118] It can be understood that the integrated design scheme of the power module 30 provided by the present application is not limited to the specific packaging manner, that is, the scheme is applicable to the power module 30 in 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 applicable to other modules with similar integration requirements, such as vehicle modules or some small and medium-sized power modules, and the specific setting manner can be referred to the above embodiments, which will not be described here.

[0119] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection 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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