Power supply module

Abstract

The invention provides a power supply module, which comprises a heat dissipation substrate, a PCB, at least one insulating ceramic substrate, at least one transformer, a plurality of high-voltage devices and a plurality of low-voltage devices, and is characterized in that the bottom surface of the heat dissipation substrate is used for exchanging heat with an external cold source, and the insulating ceramic substrate and the PCB are both mounted on the top surface of the heat dissipation substrate; the transformer comprises a transformer winding and a transformer magnetic core, and the transformer winding is arranged in the PCB and wound on the transformer magnetic core; a plurality of high-voltage devices with high heat dissipation requirements are arranged on the top surface of the insulating ceramic substrate, and other high-voltage devices are arranged on the top surface of the PCB; and the plurality of low-voltage devices are arranged on the top surface of the insulating ceramic substrate, the top surface of the PCB or / and the bottom surface of the PCB. According to the power module, the heat dissipation substrate is adopted to be connected with an external cold source for heat dissipation, electrical insulation is achieved between the PCB and the devices on the top face of the insulating ceramic substrate by coating the electrical insulation paste, compared with a traditional power module, the gap between the devices is small, and then the overall size of the power module is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a power supply module. Background Art

[0002] In the design of modular switching power supplies, in order to achieve small size and high efficiency, heat dissipation of components and safe electrical insulation between components are essential. Traditional power modules use air cooling as a whole and use air gaps to achieve safe electrical insulation between components. In order to ensure heat dissipation and electrical safety, the air gap between components needs to be large enough, which leads to a large overall size of the power module. Summary of the invention

[0003] To solve the above technical problems, the present invention provides a power module, comprising a heat dissipation substrate, a PCB board, at least one insulating ceramic substrate and a plurality of devices, wherein the plurality of devices include at least one transformer, a plurality of high-voltage devices and a plurality of low-voltage devices, the bottom surface of the heat dissipation substrate is used for heat exchange with an external cold source, and the insulating ceramic substrate and the PCB board are both mounted on the top surface of the heat dissipation substrate; the transformer comprises a transformer winding and a transformer core, the transformer winding is arranged in the PCB board and wound on the transformer core; a plurality of high-voltage devices with high heat dissipation requirements are arranged on the top surface of the insulating ceramic substrate, and other high-voltage devices are arranged on the top surface of the PCB board; the plurality of low-voltage devices are arranged on the top surface of the insulating ceramic substrate, the top surface of the PCB board or / and the bottom surface of the PCB board; the devices on the insulating ceramic substrate are electrically connected to the PCB board by wire bonding; and the PCB board and the devices on the top surface of the insulating ceramic substrate are electrically insulated by coating electrical insulating glue.

[0004] Optionally, the PCB board surrounds at least one side of the insulating ceramic substrate.

[0005] Optionally, a mounting cavity is provided on the PCB board, and the insulating ceramic substrate passes through the mounting cavity and is fixedly connected to the heat dissipation substrate.

[0006] Optionally, a cavity corresponding to the transformer core is provided on the PCB, and the transformer winding is a multi-layer copper layer structure inside the PCB board surrounding the outer periphery of the cavity.

[0007] Optionally, the transformer core passes through the cavity and is fixedly connected to the heat dissipation substrate via a thermally conductive adhesive.

[0008] Optionally, the at least one transformer includes a main transformer, a drive transformer and a galvanometer transformer, and each of the transformers corresponds to an adapted cavity.

[0009] Optionally, the top surfaces of the PCB board and the insulating ceramic substrate are both coated with electrical insulating glue to electrically insulate the devices thereon.

[0010] Optionally, the electrical insulating adhesive is silicone gel.

[0011] Optionally, thermal conductive adhesive is coated on the top surface of the heat dissipation substrate at a position corresponding to the PCB board.

[0012] Optionally, a boss is provided on the top surface of the heat dissipation substrate, and the insulating ceramic substrate is fixed on the boss by welding, silver sintering or pressure connection.

[0013] Optionally, the top surface of the heat dissipation substrate is provided with a plurality of grooves corresponding to the plurality of low-voltage components on the bottom surface of the PCB board and the transformer core, and the plurality of low-voltage components on the bottom surface of the PCB board and the transformer core are respectively installed in one of the grooves.

[0014] Optionally, the heat dissipation substrate is made of metal or metal alloy.

[0015] Optionally, the insulating ceramic substrate is a DBC ceramic substrate or an AMB ceramic substrate.

[0016] Optionally, it includes a power supply circuit and a power supply circuit, and the several devices include devices in the topological structure of the power supply circuit and devices in the topological structure of the power supply circuit.

[0017] Optionally, the plurality of high-voltage devices include devices on a circuit connected to the high-voltage side of a main transformer in the topology of the power supply circuit, and the plurality of low-voltage devices include other devices in the topology of the power supply circuit except the high-voltage devices and the transformer, as well as devices in the topology of the power supply circuit.

[0018] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0019] The power module of the present invention adopts a heat dissipation substrate as a whole to connect to an external cold source for heat dissipation, and electrical insulation is achieved by coating electrical insulation glue between the devices on the top surface of the PCB board and the insulating ceramic substrate, and the air spacing between the components is not required to be large enough, thereby reducing the overall size of the power module. The present invention installs the insulating ceramic substrate and the PCB board on the heat dissipation substrate, and uses the high thermal conductivity and high insulation characteristics of the insulating ceramic substrate to set high-voltage devices with high heat dissipation requirements on the insulating ceramic substrate, and at the same time, the insulating ceramic substrate is used to electrically insulate these high-voltage devices from the heat dissipation substrate; and the transformer winding is integrated on the PCB board, and then the insulating ceramic substrate and the transformer core are installed in conjunction with the PCB board, and the electrical connection between the devices on the insulating ceramic substrate and the PCB board is achieved by wire bonding, so that the integration is higher, the volume is smaller, and the electrical gap is small and the power density is high.

[0020] The present invention utilizes an insulating ceramic substrate to insulate high-voltage devices that need to be insulated from a heat dissipation substrate, and other high-voltage devices are mounted on the top surface of a PCB board. Then, electrical insulating glue such as silicone gel is used on the insulating ceramic substrate and the top surface of the PCB board to achieve electrical insulation between the devices. Therefore, the electrical gap is smaller and the power density is higher.

[0021] The present invention connects the insulating ceramic substrate and the boss on the top surface of the heat dissipation substrate by welding, silver sintering or pressure connection, thereby reducing the thermal resistance from the device to the heat dissipation substrate. In addition, a groove structure matching with the bottom surface of the PCB board and the transformer core is designed on the top surface of the heat dissipation substrate, and a thermal conductive adhesive is applied, and then the top surface of the heat dissipation substrate is matched with the bottom surface of the PCB board and the transformer core and installed, and the thermal conductive adhesive is used to reduce the thermal resistance.

[0022] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A schematic diagram of the structure of a power module provided in one embodiment of the present invention;

[0025] Figure 2 A schematic structural diagram of an insulating ceramic substrate provided by an embodiment of the present invention;

[0026] Figure 3A schematic diagram of the structure of a PCB board provided in one embodiment of the present invention;

[0027] Figure 4 A schematic structural diagram of a heat dissipation substrate provided in one embodiment of the present invention;

[0028] Figure 5 A schematic diagram of the structure of a plastic package of a power module provided in one embodiment of the present invention;

[0029] Figure 6 A schematic diagram of a topological structure of a power supply circuit of a power supply module provided in an embodiment of the present invention;

[0030] Figure 7 A schematic diagram of a topological structure of a power supply circuit of a power module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The terms "on" and "above" and any variations thereof are intended to describe positional relationships and do not represent a relationship of direct contact between the described objects.

[0033] As described in the background technology, the traditional power module adopts air cooling as a whole and uses air gaps to achieve electrical insulation between components. In order to ensure the heat dissipation effect and electrical safety of air cooling, the air gap between components needs to be large enough, which leads to a large overall size of the power module.

[0034] To solve the above technical problems, please refer to Figures 1 to 5The present invention provides a power module, including a heat dissipation substrate 1, a PCB board 3, at least one insulating ceramic substrate 2 and a plurality of devices, the plurality of devices including at least one transformer 4, a plurality of high-voltage devices and a plurality of low-voltage devices, the heat dissipation substrate 1 is a double-sided board, the bottom surface of the heat dissipation substrate 1 is used for heat exchange with an external cold source, the insulating ceramic substrate 2 and the PCB board 3 are both installed on the top surface of the heat dissipation substrate 1.

[0035] In the technical field of power modules, the power module includes a power circuit and a power supply circuit. Therefore, the devices in the power module provided by the present invention are devices in the topological structure of the power circuit and devices in the topological structure of the power supply circuit. The plurality of high-voltage devices include devices on the circuit connected to the high-voltage side of the main transformer in the topological structure of the power circuit, and the plurality of low-voltage devices include other devices in the topological structure of the power circuit except the high-voltage devices and the transformer and devices in the topological structure of the power supply circuit.

[0036] The power module of the present invention adopts a heat dissipation substrate as a whole to connect to an external cold source for heat dissipation, and electrical insulation is achieved by coating electrical insulating glue between the components on the top surface of the PCB board and the insulating ceramic substrate. There is no need for the air spacing between the components to be sufficiently large, thereby reducing the overall size of the power module.

[0037] The present invention dissipates heat by connecting an external cold source through a heat dissipation substrate. Compared with the air-cooling heat dissipation form of the traditional power module, the thermal resistance is smaller and the heat dissipation problem of high heat flux density in a smaller size can be solved. The external cold source is not limited and can be, for example, a liquid cooling plate, an evaporator, etc.

[0038] The transformer 4 includes a transformer winding 401 and a transformer core, wherein the transformer winding 401 is disposed in the PCB board 3 and wound around the transformer core. In the present invention, the transformer winding 401 is disposed in the PCB board 3, so that the overall size of the power module can be further reduced.

[0039] The present invention arranges a number of high-voltage devices with high heat dissipation requirements (devices with large heat generation and high heat dissipation requirements) on the top surface of the insulating ceramic substrate 2, and other high-voltage devices (i.e., high-voltage devices with low heat generation and low or no heat dissipation requirements) on the top surface of the PCB board 3; a number of low-voltage devices are arranged on the top surface of the insulating ceramic substrate 2, the top surface of the PCB board 3, or / and the bottom surface of the PCB board 3; the devices on the insulating ceramic substrate 2 are electrically connected to the PCB board 3 by wire bonding. The present invention utilizes the high thermal conductivity and high insulation characteristics of the insulating ceramic substrate 2 to arrange high-voltage devices with high heat dissipation requirements on the insulating ceramic substrate 2, and electrically insulates these high-voltage devices from the heat dissipation substrate 1 by the insulating ceramic substrate 2. The present invention integrates the transformer winding 401 on the PCB board 3, then cooperates and installs the insulating ceramic substrate 2 and the transformer core with the PCB board 3, and realizes the electrical connection between the devices on the insulating ceramic substrate 2 and the PCB board 3 by wire bonding, so that the integration is higher and the volume is smaller. At the same time, the electrical gap is smaller and the power density is higher.

[0040] Since the insulating ceramic substrate 2 needs to be connected to the PCB through wire bonding, at least one side of the insulating ceramic substrate 2 needs to be surrounded by the PCB.

[0041] Furthermore, the PCB board 3 is provided with a mounting cavity 301, and the insulating ceramic substrate 2 penetrates the mounting cavity 301 and is fixedly connected to the heat dissipation substrate 1. To ensure good thermal conductivity between the heat dissipation substrate 1 and the insulating ceramic substrate 2, the two are generally connected by welding, silver sintering or pressure connection.

[0042] In order to facilitate wiring and reduce the module height, the insulating ceramic substrate 2 and the PCB board are installed on the same plane as much as possible, so the top surface of the heat dissipation substrate 1 is provided with a boss 101, and the insulating ceramic substrate 2 is fixed on the boss 101, so that the insulating ceramic substrate 2 is flush with the top surface of the PCB board.

[0043] In order to reduce the installation space of the transformer 4, the present invention integrates the transformer winding 401 in the PCB board 3. The PCB board 3 is provided with a cavity 302 corresponding to the transformer core. The transformer winding 401 is a multi-layer copper layer structure inside the PCB board 3 surrounding the outer periphery of the cavity 302. When installing, it is sufficient to install the transformer core in the corresponding cavity 302. In order to further reduce the installation space of the transformer, a first groove 102 is reserved on the heat dissipation substrate 1 corresponding to the installation position of the transformer 4. The transformer core passes through the cavity 302 and is fixedly connected to the first groove 102.

[0044] The present invention does not limit the number and type of transformers 4, which can be set according to actual use requirements. As an embodiment, the power module has three types of transformers, namely the main transformer, the drive transformer and the galvanometer transformer, and each of the transformers corresponds to an adapted cavity. The main transformer refers to a transformer that performs high-voltage and low-voltage AC conversion in the topological structure of the power module. The drive transformer refers to a transformer that converts the voltage output by the driver chip to provide voltage for the GS end of the active switch MOS tube, wherein the driver chip belongs to the device in the topological structure of the power supply circuit, is a low-voltage device, and can be set on the top surface of the insulating ceramic substrate 2, the top surface of the PCB board 3 or the bottom surface of the PCB board 3; the active switch MOS tube belongs to the device in the topological structure of the power supply circuit, is a high-voltage device with high heat dissipation requirements, and is set on the insulating ceramic substrate 2. The galvanometer transformer refers to a transformer in the galvanometer used to detect the current on the high-voltage side of the main transformer. The windings of all transformers are integrated inside the PCB board 3 in the form of multiple copper layers, located at the cavity position on the PCB board 3 that matches the shape of the transformer core.

[0045] In the present invention, the high-voltage device is a device on a circuit connected to the high-voltage side of the transformer in the topological structure of the power supply circuit, and the low-voltage device includes other devices in the topological structure of the power supply circuit except the high-voltage device and the transformer and the devices in the topological structure of the power supply circuit. Since the high-voltage device has high requirements for electrical insulation, the electrical insulation requirements of the high-voltage device cannot be met between the heat dissipation substrate 1 and the PCB board 3, and therefore, the high-voltage device cannot be arranged on the bottom surface of the PCB board 3. Since the low-voltage device has low requirements for electrical insulation, the low-voltage device can be arranged on the bottom surface of the PCB board 3, and considering the heat dissipation design, the high-loss device in the low-voltage device can be preferentially arranged on the bottom surface of the PCB board 3. A thermal conductive adhesive is applied to the top surface of the heat dissipation substrate 1 at a position corresponding to the PCB board 3. The thermal conductive adhesive has insulation and good thermal conductivity. The thermal conductive adhesive is used to realize electrical insulation between the low-voltage devices on the bottom surface of the PCB board 3 and the heat dissipation substrate 1 on the one hand, and to reduce the thermal resistance from the low-voltage devices on the bottom surface of the PCB board 3 to the heat dissipation substrate 1 on the other hand.

[0046] On the one hand, in order to make the PCB board 3 and the insulating ceramic substrate 2 at the same height after installation to facilitate wiring, and on the other hand, in order to provide better heat dissipation conditions for the devices on the bottom surface of the PCB board 3, the top surface of the heat dissipation substrate 1 is provided with a plurality of second grooves 103 corresponding to the low-voltage devices on the bottom surface of the PCB board 3, and the plurality of low-voltage devices on the bottom surface of the PCB board 3 are respectively installed in the plurality of second grooves 103.

[0047] Since the problem of electrical insulation needs to be considered for high-voltage devices, the high-voltage devices are respectively mounted on the top surfaces of the PCB board 3 and the insulating ceramic substrate 2, and electrical insulation between the devices is achieved by coating the top surfaces of the PCB board 3 and the insulating ceramic substrate 2 with electrical insulation glue. Since the electrical insulation material glue is a conventional material in this field, the present invention does not limit the specific type of the electrical insulation material glue, such as silicone gel. The present invention coats silicone gel on the top surfaces of the PCB board 3 and the insulating ceramic substrate 2, and uses silicone gel as a medium to achieve electrical insulation between the high-voltage devices. Since the bottom surface of the PCB board 3 cannot be installed with high-voltage devices, only low-voltage devices can be installed, so the devices on the bottom surface of the PCB board 3 do not need to be electrically insulated using silicone gel.

[0048] Figure 6 The power circuit topology structure of an embodiment of the power module is a DC-DC power module topology structure. In the buck mode, the high voltage side is a phase-shifted full bridge, and the low voltage side is a full-wave rectifier. In the boost mode, the low voltage side is a push-pull, and the high voltage side is a full-bridge rectifier. The components included in the high voltage side are: active switch MOS tubes S1-S4, input filter capacitor Cin, current sensing resistor CS1, resonant inductor Lr, etc. The components included in the low voltage side are: synchronous rectifier MOS tubes S5-S6, clamping MOS tubes Sc1-Sc2, clamping capacitor Cc, secondary inductor Lo, secondary capacitor Co, current sensing resistor Cs2, Oring MOS tube So, etc.

[0049] Figure 7 The power supply circuit topology structure of an embodiment of the power supply module is provided by a 9-16V low-voltage power supply through a driver chip LDO (LDO is a low voltage difference linear regulator, which is an electronic component used to convert a higher voltage into a lower voltage), Buck (Buck converter, also known as a step-down converter, is a single-tube non-isolated DC converter with an output voltage less than the input voltage), Boost (Boost is a DC boost converter, also known as a DC boost converter or a DC boost chopper. Its main function is to convert the input DC voltage into a higher output voltage, that is, the output voltage is higher than the input voltage), etc., and after the power supply transformer converts the voltage, the active switch MOS tubes S1-S4, the synchronous rectifier MOS tubes S5-S6, the Oring MOS tube So, and the control chip and other devices are powered. The devices in the power supply circuit topology structure are all low-voltage devices.

[0050] In this embodiment, the active switch MOS tube 5 has large losses and high heat dissipation requirements, so it is installed on the insulating ceramic substrate 2 with good thermal conductivity. The active switch MOS tube 5 is installed on the insulating ceramic substrate 2 in the form of an unpackaged bare chip, which has a smaller volume and lower thermal resistance. The electrical insulation between the active switch MOS tube 5 and the heat dissipation substrate 1 is achieved by the insulating ceramic substrate 2. The high-voltage input pin 6 is also installed on the insulating ceramic substrate 2. The electrical insulation between the devices on the insulating ceramic substrate 2 is achieved by silicone gel. Unpackaged bare chips cannot be installed on the PCB board 3. The traditional power module is to install the chip with the package on an additional single-sided aluminum substrate, and then connect the external cold source to the single-sided aluminum substrate for heat dissipation. The disadvantage is that the module volume is large. Alternatively, the chip with the package is installed on the PCB board 3, and then other heat dissipation structures are used to dissipate the heat of the chip. The chip with the package is large in volume, and other additional heat dissipation structures will also cause the module volume to be large.

[0051] Components are installed on the top and bottom surfaces of the PCB board 3, and the components installed on the top surface include the input filter capacitor, current sensing resistor, and resonant inductor on the high-voltage side. The high-voltage side components in the power circuit topology are installed on the insulating ceramic substrate and the top surface of the PCB board 3 respectively. The low-voltage side components in the power circuit topology and the components in the power supply circuit topology are installed on the top and bottom surfaces of the PCB board 3.

[0052] There is also a plastic shell on the power module, that is, a shell 7 is also provided on the heat dissipation substrate 1. The plastic shell is formed by a plastic sealing process. The shell 7 and the heat dissipation substrate 1 form an accommodating space for accommodating the PCB board 3, the insulating ceramic substrate 2 and various components, which plays a physical protection role for each component and electrically insulates each conductive component from the outside world.

[0053] In summary, the power module of the present invention adopts a heat dissipation substrate to connect an external cold source for heat dissipation, and does not require a sufficiently large air gap between components, thereby reducing the overall size of the power module. The present invention installs an insulating ceramic substrate and a PCB board on a heat dissipation substrate, and uses the high thermal conductivity and high insulation properties of the insulating ceramic substrate to set high-voltage components with high heat dissipation requirements on the insulating ceramic substrate, and electrically insulates these high-voltage components from the heat dissipation substrate through the insulating ceramic substrate; and integrates the transformer winding on the PCB board, and then the insulating ceramic substrate and the transformer core are installed in conjunction with the PCB board, and the electrical connection between the components on the insulating ceramic substrate and the PCB board is achieved by wire bonding, so that the integration is higher, the volume is smaller, and the electrical gap is small and the power density is high.

[0054] The present invention utilizes an insulating ceramic substrate to insulate high-voltage devices that need to be insulated from a heat dissipation substrate, and other high-voltage devices are mounted on the top surface of a PCB board. Then, electrical insulating glue such as silicone gel is used on the insulating ceramic substrate and the top surface of the PCB board to achieve electrical insulation between the devices. Therefore, the electrical gap is smaller and the power density is higher.

[0055] The present invention connects the insulating ceramic substrate and the boss on the top surface of the heat dissipation substrate by welding, silver sintering or pressure connection, thereby reducing the thermal resistance from the device to the heat dissipation substrate. In addition, a groove structure matching with the bottom surface of the PCB board and the transformer core is designed on the top surface of the heat dissipation substrate, and a thermal conductive adhesive is applied, and then the top surface of the heat dissipation substrate is matched with the bottom surface of the PCB board and the transformer core and installed, and the thermal conductive adhesive is used to reduce the thermal resistance.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power module, characterized in that: The invention comprises a heat dissipation substrate, a PCB board, at least one insulating ceramic substrate and several devices, wherein the several devices comprise at least one transformer, several high-voltage devices and several low-voltage devices, the bottom surface of the heat dissipation substrate is used for heat exchange with an external cold source, and the insulating ceramic substrate and the PCB board are both mounted on the top surface of the heat dissipation substrate; the transformer comprises a transformer winding and a transformer core, and the transformer winding is arranged in the PCB board and wound on the transformer core; several high-voltage devices with high heat dissipation requirements are arranged on the top surface of the insulating ceramic substrate, and other high-voltage devices are arranged on the top surface of the PCB board; the several low-voltage devices are arranged on the top surface of the insulating ceramic substrate, the top surface of the PCB board or / and the bottom surface of the PCB board; the devices on the insulating ceramic substrate are electrically connected to the PCB board by wire bonding; and the PCB board and the devices on the top surface of the insulating ceramic substrate are electrically insulated by coating electrical insulating glue.

2. The power module according to claim 1, characterized in that: The PCB board surrounds at least one side of the insulating ceramic substrate.

3. The power module according to claim 2, characterized in that: The PCB board is provided with a mounting cavity, and the insulating ceramic substrate passes through the mounting cavity and is fixedly connected to the heat dissipation substrate.

4. The power module according to claim 1, characterized in that: The PCB is provided with a cavity corresponding to the transformer core, and the transformer winding is a multi-layer copper layer structure inside the PCB board surrounding the outer periphery of the cavity.

5. The power module according to claim 4, characterized in that: The transformer core passes through the cavity and is connected to the heat dissipation substrate through a thermally conductive adhesive.

6. The power module according to claim 4, characterized in that: The at least one transformer comprises a main transformer, a driving transformer and a galvanometer transformer, and each of the transformers corresponds to an adapted cavity.

7. The power module according to claim 1, characterized in that: The electrical insulating glue is silicone gel.

8. The power module according to claim 1, characterized in that: The top surface of the heat dissipation substrate is coated with thermal conductive glue at a position corresponding to the PCB board.

9. The power module according to claim 1, characterized in that: A boss is provided on the top surface of the heat dissipation substrate, and the insulating ceramic substrate is fixed on the boss by welding, silver sintering or pressure connection.

10. The power module according to claim 1, characterized in that: The top surface of the heat dissipation substrate is provided with a plurality of grooves corresponding to the plurality of low-voltage components on the bottom surface of the PCB board and the transformer core. The plurality of low-voltage components on the bottom surface of the PCB board and the transformer core are respectively installed in one of the grooves.

11. The power module according to claim 1, characterized in that: The material of the heat dissipation substrate is metal or metal alloy.

12. The power module according to claim 1, characterized in that: The insulating ceramic substrate is a DBC ceramic substrate or an AMB ceramic substrate.

13. The power module according to any one of claims 1 to 12, characterized in that: It comprises a power supply circuit and a power supply circuit, and the plurality of devices comprise devices in the topological structure of the power supply circuit and devices in the topological structure of the power supply circuit.

14. The power module according to claim 13, characterized in that: The plurality of high-voltage devices include devices on the circuit connected to the high-voltage side of the main transformer in the topological structure of the power supply circuit, and the plurality of low-voltage devices include other devices in the topological structure of the power supply circuit except the high-voltage devices and the transformer, as well as devices in the topological structure of the power supply circuit.

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