PCB embedded power module and forming method thereof

Abstract

The invention provides a PCB embedded power module and a forming method thereof, the PCB embedded power module comprises a power heating unit (1), two opposite sides of the power heating unit (1) are provided with power copper layers (11), and the power copper layers (11) are provided with isolation grooves; the heat conduction insulating layer is located on at least one side of the power heating unit (1), the heat conduction insulating layer comprises a ceramic material layer (2) and a heat conduction insulating film (3) which are arranged in a stacked mode, the ceramic material layer (2) is located on one side close to the power copper layer (11), the ceramic material layer (2) is attached to the outer surface of the power copper layer (11) and the inner surface of the isolation groove, and part of the heat conduction insulating film (3) is filled in the isolation groove. The ceramic material layer is additionally arranged, so that the heat dissipation performance of the PCB embedded power module is improved; the thickness of the heat-conducting insulating film can be reduced, so that the thermal resistance of the heat-conducting insulating layer is greatly reduced, and the performance of the product is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power modules, in particular to a PCB embedded power module and a forming method thereof. BACKGROUND

[0002] In the related art, a PCB (Printed Circuit Board) embedded power module uses a heat-conducting insulating film to achieve insulating connection between a power heating unit and a heat sink. However, the heat-conducting insulating film needs to be thick (100-150 μm) to meet the requirements of insulation and filling. However, the excessive thickness increases the thermal resistance and affects the final heat dissipation performance of the product. At the same time, the thermal conductivity (heat conduction capacity per unit thickness) of the current insulating material is difficult to be greatly improved. The reason is that the insulating film material needs to ensure a high thermal conductivity while also having excellent insulation capacity. The insulation capacity is achieved by adding resin, and the thermal conductivity is achieved by adding filler. However, too high filler content will affect the flowability and filling capacity of the insulating film, and reduce the bonding capacity of the heat-conducting insulating film and the metal (because the resin content is relatively reduced). Therefore, due to the material properties, the current PCB embedded power module has the problem of insufficient heat dissipation performance. SUMMARY

[0003] The purpose of the present application is to provide a PCB embedded power module and a forming method thereof, to improve the heat dissipation performance and product performance.

[0004] To solve the above technical problems, the present application provides a PCB embedded power module, comprising: a power heating unit, the power heating unit has power copper layers on two opposite sides, the power copper layers have isolation grooves; a heat-conducting insulating layer located on at least one side of the power heating unit, the heat-conducting insulating layer includes a ceramic material layer and a heat-conducting insulating film stacked, the ceramic material layer is located on the side close to the power copper layer, the ceramic material layer is attached to the outer surface of the power copper layer and the inner surface of the isolation groove, and part of the heat-conducting insulating film is filled in the inside of the isolation groove.

[0005] The PCB embedded power module comprises ceramic material layers and a heat-conducting insulating film arranged in a stack, the ceramic material layers can be attached to the outer surface of the power copper layer and the inner surface of the isolation groove, the thermal conductivity of the ceramic material is higher than that of the traditional heat-conducting insulating film, which is more conducive to heat dissipation of the power heating unit, and greatly improves the heat dissipation performance of the PCB embedded power module; at the same time, due to the arrangement of the ceramic material layer, the heat-conducting insulating film does not need to increase the filler content in order to improve the thermal conductivity, so as to ensure that the heat-conducting insulating film has sufficient fluidity and filling capacity, so that the heat-conducting insulating film can be filled in the inside of the isolation groove to realize insulation between different voltage chip units; in addition, the ceramic material has excellent insulation performance, and the ceramic material can meet the 20kV breakdown voltage requirement above 100nm, at the same time, the voltage of the SiC chip unit is usually greater than 1.2kV, and the instantaneous voltage is usually greater than 2kV, it can be seen that the very thin ceramic material layer can meet the insulation between the power heating unit and the heat sink, therefore, the thickness of the heat-conducting insulating film can be further reduced, the total thickness of the heat-conducting insulating layer can be further reduced, and then the thermal resistance of the heat-conducting insulating layer is greatly reduced, and the performance of the product is greatly improved.

[0006] Optionally, the ceramic material layer is attached to the outer surface of the power copper layer and the inner surface of the isolation groove by a vacuum plating process or a SOG process.

[0007] Optionally, the thickness of the ceramic material layer ranges from 0.02μm to 5μm.

[0008] Optionally, the thickness of the heat-conducting insulating film ranges from 50μm to 100μm.

[0009] Optionally, the ceramic material layer is made of aluminum nitride, silicon nitride, aluminum oxide or silicon dioxide material.

[0010] Optionally, the heat-conducting insulating layer further comprises an adhesion enhancer layer connected between the ceramic material layer and the heat-conducting insulating film.

[0011] Optionally, the adhesion enhancer layer is made of a material containing silane coupling agent component or polyimide component.

[0012] Optionally, the adhesion enhancer layer is attached to the surface of the ceramic material layer facing the heat-conducting insulating film by an impregnation process, a spraying process, a CVD process or a printing process.

[0013] Optionally, the surface of the ceramic material layer facing the heat-conducting insulating film has a roughened treatment surface.

[0014] The application further provides a forming method of a PCB embedded power module, which is used for forming the aforementioned PCB embedded power module, and comprises the following steps: Step S1: attaching a ceramic material layer to the outer surface of at least one side power copper layer of the power heating unit and the inner surface of the isolation groove; Step S2: connecting a heat-conducting insulation film to the side of the ceramic material layer away from the power copper layer, and allowing part of the heat-conducting insulation film to fill in the inside of the isolation groove.

[0015] The forming method of the PCB embedded power module of the present application is used for forming the aforementioned PCB embedded power module, and thus has the same technical effects as the aforementioned PCB embedded power module, which will not be described here again.

[0016] Optionally, between the step S1 and the step S2, the following step is further included: Step S01: connecting an adhesion enhancer layer to the side of the ceramic material layer away from the power copper layer.

[0017] Optionally, between the step S1 and the step S2, the following step is further included: Step S02: performing surface roughening treatment on the surface of the ceramic material layer away from the power copper layer, so that the surface of the ceramic material layer facing the heat-conducting insulation film has a roughened surface. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A partial sectional view in the thickness direction of a specific embodiment of the PCB embedded power module provided by the present application; Figure 2 A partial sectional view in the thickness direction of a specific embodiment of the PCB embedded power module provided by the present application; Figure 1 A structural schematic diagram of a chip unit in the PCB embedded power module; Figure 3 A partial sectional view in the thickness direction of a specific embodiment of the PCB embedded power module provided by the present application; Figure 1 A partial sectional view in the thickness direction of a specific embodiment of the PCB embedded power module provided by the present application; Figure 4 A partial sectional view in the thickness direction of a specific embodiment of the PCB embedded power module provided by the present application; Figure 1 A structural schematic diagram of a first state in the forming process of the PCB embedded power module; Figure 5 A structural schematic diagram of a second state in the forming process of the PCB embedded power module; Figure 1 A structural schematic diagram of a second state in the forming process of the PCB embedded power module; Figure 6 A structural schematic diagram of a third state in the forming process of the PCB embedded power module; Figure 1 A structural schematic diagram of a third state in the forming process of the PCB embedded power module; Wherein, Figures 1-6 The reference signs in the drawings are as follows: 1-power heating unit; 11-power copper layer; 11a-isolation groove; 12-chip unit; 121-power chip; 122-copper block; 13-chip board; 2-ceramic material layer; 3- Thermally conductive insulating film; 4-Adhesion enhancer layer; 5-Connecting metal layer; 6-Radiator; 01-Carrier membrane. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Please refer to Figure 1 , Figure 1 This is a partial cross-sectional view along the thickness direction of a specific embodiment of the PCB embedded power module provided in this application.

[0021] This embodiment provides a PCB embedded power module, including: Power heating unit 1, power copper layer 11 on both opposite sides of power heating unit 1, power copper layer 11 has isolation groove; A thermally conductive insulating layer is located on one side of the power heating unit 1. The thermally conductive insulating layer includes a ceramic material layer 2 and a thermally conductive insulating film 3 stacked together. The ceramic material layer 2 is located on the side close to the power copper layer 11. Part of the ceramic material layer 2 is attached to the outer surface of the power copper layer 11 and the inner surface of the isolation groove, and part of the thermally conductive insulating film 3 is filled inside the isolation groove.

[0022] Combination Figure 1 Understanding is that the power heating unit 1 includes multiple chip units 12 arranged in an array. Figure 1 (Only one chip unit 12 is shown) Chip units 12 with different voltages need to be insulated from each other. Therefore, the power copper layer 11 needs to be provided with an isolation groove. The isolation groove penetrates the power copper layer 11 along the thickness direction. The thermally conductive insulating layer needs to be filled inside the isolation groove to isolate the chip units 12 with different voltages.

[0023] It is understandable that the thermally conductive insulating film in the relevant technology is a thin film structure. The thermally conductive insulating film can only be connected to the power copper layer 11 of the power heating unit 1 through a lamination process. Therefore, if the filler content in the thermally conductive insulating film is too high and the resin content is too low in order to improve the thermal conductivity of the thermally conductive insulating film, the bonding ability between the thermally conductive insulating film and the power copper layer 11 will be reduced, and the fluidity of the thermally conductive insulating film will decrease. As a result, the thermally conductive insulating film cannot flow sufficiently into the isolation groove, which affects the filling capacity of the thermally conductive insulating film and the insulation performance between different voltage chip units 12. Therefore, in order to ensure the insulation performance between different voltage chip units 12, the filler content in the thermally conductive insulating film in the relevant technology is limited. This is the reason why the thermal conductivity of the thermally conductive insulating film in the relevant technology is low and it does not utilize the heat dissipation of the power heating unit 1.

[0024] The PCB embedded power module of the embodiment includes the ceramic material layer 2 and the heat-conducting insulation film 3 arranged in a stack. The ceramic material layer 2 can be attached to the outer surface of the power copper layer 11 and the inner surface of the isolation groove by a special process other than the lamination process (to be described in detail later). The thermal conductivity of the ceramic material is higher than that of the conventional heat-conducting insulation film, which is more conducive to heat dissipation of the power heating unit 1. At the same time, due to the arrangement of the ceramic material layer 2, the heat-conducting insulation film 3 does not need to increase the filler content to improve the thermal conductivity, ensuring that the heat-conducting insulation film 3 has sufficient fluidity and filling capacity, so that the heat-conducting insulation film 3 can be filled in the inside of the isolation groove to realize the insulation between different voltage chip units 12. In addition, the ceramic material has excellent insulation performance. The ceramic material can meet the 20kV breakdown voltage requirement at more than 100nm. At the same time, the voltage of the SiC chip unit is usually greater than 1.2kV, and the instantaneous voltage is usually greater than 2kV. It can be seen that the very thin ceramic material layer 2 can meet the insulation between the power heating unit 1 and the heat sink 6. Therefore, the thickness of the heat-conducting insulation film 3 can be reduced, the total thickness of the heat-conducting insulation layer can be reduced, and the thermal resistance of the heat-conducting insulation layer is greatly reduced, which greatly improves the heat dissipation performance of the PCB embedded power module of the embodiment, and the performance of the product is greatly improved. Through simulation, the maximum current-carrying capacity per unit area of the PCB embedded power module of the embodiment is greater than 110A / (25mm 2 ) at 200℃ junction temperature, so that the performance of the SiC chip unit can be fully utilized.

[0025] By Figure 1 It can be seen that in the embodiment, the number of the heat-conducting insulation layer is one, and the heat-conducting insulation layer can be located on the upper side or the lower side of the power heating unit 1. The number of the heat sink 6 is one, and the heat sink 6 is also located on the upper side or the lower side of the power heating unit 1.

[0026] In some other embodiments of the application, the number of the heat-conducting insulation layer is two, and the heat-conducting insulation layer is located on the opposite sides of the power heating unit 1. The number of the heat sink 6 is also two, and the heat sink 6 is also located on the opposite sides of the power heating unit 1. In this way, the heat dissipation performance of the PCB embedded power module of the embodiment can be further improved.

[0027] In some embodiments of the application, the ceramic material layer 2 is attached to the outer surface of the power copper layer 11 by a vacuum plating process.

[0028] The vacuum coating process is a process method for depositing a thin film on a surface under vacuum conditions. The material is heated to an evaporation temperature to form a gaseous substance, and then the gaseous substance is deposited on the surface of the substrate to form a thin film. In this embodiment, the ceramic material layer 2 is attached to the outer surface of the power copper layer 11 by the vacuum coating process, which can solve the problem of low bonding ability of the ceramic material and the metal in the lamination process, effectively improve the bonding strength of the ceramic material layer 2 and the power copper layer 11, and have better adhesion performance. At the same time, the vacuum coating process can make the thickness of the ceramic material layer 2 reach microns, and the thickness of the ceramic material layer 2 is relatively thin, which can improve the thermal conductivity and insulation performance of the thermal insulation layer without affecting the total thickness of the thermal insulation layer.

[0029] The ceramic material layer 2 can be attached to the outer surface of the power copper layer 11 and the inner surface of the isolation groove by CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), PECVD (Plasma Enhance Chemical Vapour Deposition), Plasma Sputtering, etc.

[0030] In some embodiments of the present application, the ceramic material layer 2 is attached to the outer surface of the power copper layer 11 and the inner surface of the isolation groove by the SOG (Spin on glass) process.

[0031] The SOG process is a coating process that relies on the centrifugal force generated by the rotation of the workpiece and the action of gravity to spread the coating liquid droplets on the workpiece surface. It has the advantages of easy to obtain a coating with high density, uniform thickness, etc.

[0032] In this embodiment, the ceramic material layer 2 is made of aluminum nitride (AlN), silicon nitride (Si3N4), aluminum oxide (Al2O3), silicon dioxide (SiO2), etc.

[0033] The thermal conductivity of aluminum nitride is 150 W / mK, the thermal conductivity of silicon nitride is 90 W / mK, the thermal conductivity of aluminum oxide is 32 W / mK, and the thermal conductivity of silicon dioxide is 27 W / mK. It can be seen that the thermal conductivity of the related art thermal insulation film at room temperature is greatly improved, which improves the heat dissipation performance of the PCB embedded power module of the present embodiment.

[0034] In some other embodiments of the present application, when the ceramic material layer 2 is formed by a vacuum plating process, the ceramic material layer 2 can also be made of hafnium dioxide (HfO2), zirconium dioxide (ZrO2), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), etc.

[0035] In the present embodiment, the thickness of the ceramic material layer 2 ranges from 0.02 μm to 5 μm.

[0036] In practice, the thickness of the ceramic material layer 2 can be 0.02 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, etc. Since the thermal expansion coefficient of the ceramic material (3 ppm / K-8 ppm / K) is lower than that of copper (17 ppm / K), i.e., the deformation of the ceramic material layer 2 is smaller than that of copper when the temperature rises, and since the ceramic material layer 2 is brittle, if the thickness of the ceramic material layer 2 is too thin, the ceramic material layer 2 may be broken due to the tensile force of the power copper layer 11, affecting the insulation capability of the ceramic material layer 2; if the thickness of the ceramic material layer 2 is too thick, it needs to be realized by multiple processes, reducing the forming efficiency of the ceramic material layer 2. Therefore, the ceramic material layer 2 in the present embodiment has the above thickness range, which improves the forming efficiency on the premise of ensuring the structural reliability of the ceramic material layer 2 and the insulation capability of the ceramic material layer 2.

[0037] In practice, according to the characteristics of different forming processes, when the thickness of the ceramic material layer 2 is low, such as 0.02 μm, the ALD process is preferred; when the thickness of the ceramic material layer 2 is thick, such as 5 μm, the CVD process is preferred.

[0038] Further, in the present embodiment, the thickness of the heat-conducting insulation film 3 ranges from 30 μm to 200 μm.

[0039] In practice, the thickness of the heat-conducting insulation film 3 can be 30 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 180 μm, 200 μm, etc. Since the surface of the power heat-generating unit 1 (the outer surface of the power copper layer 11) is not an absolute plane, the heat-conducting insulation film 3 also has the effect of offsetting the warping of the power heat-generating unit 1 to improve the heat transfer efficiency; at the same time, as mentioned above, part of the heat-conducting insulation film 3 needs to be filled in the isolation groove, if the thickness of the heat-conducting insulation film 3 is too small, the heat-conducting insulation film 3 may not be able to offset the warping of the power heat-generating unit 1, and the heat-conducting insulation film 3 may not be able to completely fill the isolation groove, affecting the insulation performance between different voltage chip units 12; if the thickness of the heat-conducting insulation film 3 is too large, the total thickness of the heat-conducting insulation layer is too large, and the thermal resistance is too large, which is not conducive to improving the heat dissipation capability of the PCB embedded power module.

[0040] Based on this, the heat-conducting insulating film 3 has the thickness range as above, so that the heat-conducting insulating film 3 can offset the warping of the power heating unit 1, and the heat-conducting insulating film 3 can completely fill the isolation groove, guarantee the insulation performance between different voltage chip units 12, and compared with the related art PCB embedded power module, the total thickness of the heat-conducting insulating layer is reduced, the thermal resistance is reduced, and the heat dissipation performance of the PCB embedded power module is improved.

[0041] In the embodiment, the heat-conducting insulating film 3 can be made of a heat-conducting glue with good insulation performance, such as a resin material containing part of ceramic fillers; or the heat-conducting insulating film 3 can also be made of a silicone glue material such as AB glue.

[0042] Please continue to refer to Figure 1 In the embodiment, the heat-conducting insulating layer further includes an adhesion enhancer layer 4 connected between the ceramic material layer 2 and the heat-conducting insulating film 3.

[0043] Since the heat-conducting insulating film 3 is usually connected to one side of the ceramic material layer 2 by a lamination process, and the ceramic material has poor combination ability with organic matters, the embodiment adds the adhesion enhancer layer 4 to improve the combination strength of the ceramic material layer 2 and the heat-conducting insulating film 3.

[0044] The adhesion enhancer layer 4 can be made of a material containing a silane coupling agent component or a polyimide component, and both the silane coupling agent and the polyimide can play a role in improving the combination ability of the resin material with the ceramic material.

[0045] In the embodiment, the adhesion enhancer layer 4 can be attached to the surface of the ceramic material layer 2 facing the heat-conducting insulating film 3 by an impregnation process, a spraying process, a CVD process or a printing process, and the above processes can guarantee the uniformity of the adhesion enhancer layer 4, so that the adhesion enhancer layer 4 can better play a connecting role.

[0046] In some other embodiments of the application, it is also feasible not to set the adhesion enhancer layer 4, and in this case, the surface of the ceramic material layer 2 facing the heat-conducting insulating film 3 can be subjected to surface roughening treatment, so that the surface of the ceramic material layer 2 facing the heat-conducting insulating film 3 has a roughened surface, the adhesion of the surface of the ceramic material layer 2 facing the heat-conducting insulating film 3 is improved, and the combination strength of the ceramic material layer 2 and the heat-conducting insulating film 3 is improved.

[0047] Please continue to refer to Figure 1 In the embodiment, the PCB embedded power module further includes a connecting metal layer 5 and a heat sink 6, the connecting metal layer 5 is connected to the side of the heat-conducting insulating film 3 away from the ceramic material layer 2, and the connecting metal layer 5 connects the heat sink 6.

[0048] As arranged above, the connecting metal layer 5 plays a role of connecting the heat sink 6, and the connecting metal layer 5 and the heat sink 6 are connected through a welding process or a sintering process, so as to ensure the reliable connection of the connecting metal layer 5 and the heat sink 6.

[0049] In the forming process of the PCB embedded power module, the connecting metal layer 5 and the heat-conducting insulating film 3 can be simultaneously connected to the ceramic material layer 2 through a lamination process.

[0050] In some embodiments of the present application, the connecting metal layer 5 is made of copper material, which has good heat conduction performance and improves the heat dissipation performance of the PCB embedded power module.

[0051] In some other embodiments of the present application, the connecting metal layer 5 is made of aluminum material, which reduces the cost.

[0052] Please continue to refer to Figures 1-6 , Figure 2 for Figure 1 the structure diagram of the chip unit in the PCB embedded power module; Figure 3 for Figure 1 the partial sectional view of the core plate in the PCB embedded power module; Figure 4 for Figure 1 the structure diagram of the first state in the forming process of the PCB embedded power module; Figure 5 for Figure 1 the structure diagram of the second state in the forming process of the PCB embedded power module; Figure 6 for Figure 1 the structure diagram of the third state in the forming process of the PCB embedded power module.

[0053] In the present embodiment, the chip unit 12 includes a power chip 121 and a copper block 122, the copper block 122 has a sink, and the power chip 121 is embedded in the sink. The power chip 121 and the copper block 122 can be connected through diffusion welding or silver film sintering process. The thickness of the copper block 122 is usually 0.8mm-1.5mm, so as to ensure the heat dissipation angle of the chip unit 12.

[0054] Further, the power heating unit 1 further includes a core plate 13, the core plate 13 has a plurality of chip grooves 13a arranged in an array. In the forming process, a bearing film 01 is first pasted on the bottom of the core plate 13, then the chip unit 12 is placed in the corresponding chip groove 13a, and then a resin sheet is stacked above the core plate 13 and lamination is completed under high temperature, high pressure and vacuum conditions. After lamination, a power copper layer 11 above the chip unit 12 is made through a conventional PCB process such as laser drilling-copper plating-exposure development etching, and the power copper layer 11 is directly connected to the power chip 121, as shown in Figure 4 . Then, the carrier film 01 is torn off, and the same procedure is used to make the power copper layer 11 at the lower end of the power heat generating unit 1, which is the positive electrode copper layer of the power heat generating unit 1, the positive electrode copper layer is connected with the positive electrode of the power chip 121, and laser drilling is performed on the positive electrode copper layer to form the isolation groove 11a, as shown in Figure 5 The same procedure is also used to make the power copper layer 11 at the upper end of the power heat generating unit 1, which is separated into the negative electrode copper layer and the switch copper layer after laser drilling, the negative electrode copper layer is connected with the negative electrode of the power chip 121, and the switch copper layer is connected with the switch electrode of the power chip 121, as shown in Figure 6

[0055] The embodiment also provides a forming method of the PCB embedded power module, which is used to form the PCB embedded power module as described above, and includes the following steps. Step S1: The ceramic material layer 2 is attached to the outer surface of the at least one side power copper layer 11 of the power heat generating unit 1 and the inner surface of the isolation groove. Step S2: The heat-conducting insulating film 3 is connected to the side of the ceramic material layer 2 away from the power copper layer 11, and part of the heat-conducting insulating film 3 is filled in the inside of the isolation groove.

[0056] The forming method of the PCB embedded power module of the embodiment is used to form the PCB embedded power module as described above, and thus has the same technical effects as the PCB embedded power module as described above, which will not be described here.

[0057] Further, the following step is also included between step S2: Step S01: The adhesion enhancer layer 4 is connected to the side of the ceramic material layer 2 away from the power copper layer 11.

[0058] In this way, the ceramic material layer 2 and the heat-conducting insulating film 3 are connected through the adhesion enhancer layer 4, and the bonding strength of the ceramic material layer 2 and the heat-conducting insulating film 3 is improved.

[0059] Alternatively, the following step is also included between step S2: Step S02: The surface of the ceramic material layer 2 away from the power copper layer 11 is subjected to surface roughening treatment, so that the surface of the ceramic material layer 2 facing the heat-conducting insulating film 3 has a roughened surface.

[0060] In this way, the adhesion of the surface of the ceramic material layer 2 facing the heat-conducting insulating film 3 is improved, and the bonding strength of the ceramic material layer 2 and the heat-conducting insulating film 3 is improved.

[0061] It can be understood that in practice, only one of step S01 and step S02 is performed.

[0062] ​​The above merely preferred embodiments of the present application, it should be noted that for those of ordinary skill in the art, without departing from the principles of the present application, can make several improvements and refinements, these improvements and refinements should also be considered as the scope of protection of the present application.

Claims

1. A PCB-embedded power module, characterized by, The application relates to a power heating unit (1) comprising: a power copper layer (11) provided on two opposite sides of the power heating unit (1), the power copper layer (11) having an isolation groove; a heat-conducting insulation layer provided on at least one side of the power heating unit (1), the heat-conducting insulation layer comprising a ceramic material layer (2) and a heat-conducting insulation film (3) arranged in a stack, the ceramic material layer (2) being provided on a side close to the power copper layer (11), the ceramic material layer (2) being attached to an outer surface of the power copper layer (11) and an inner surface of the isolation groove, and part of the heat-conducting insulation film (3) being filled in the isolation groove.

2. The PCB-embedded power module of claim 1, wherein, The ceramic material layer (2) is attached to the outer surface of the power copper layer (11) and the inner surface of the isolation groove by a vacuum coating process or a SOG process.

3. The PCB-embedded power module of claim 1, wherein, The thickness of the ceramic material layer (2) ranges from 0.02 micrometers to 5 micrometers.

4. The PCB-embedded power module of claim 1, wherein, The thickness of the heat-conducting insulation film (3) ranges from 30 micrometers to 200 micrometers.

5. The PCB-embedded power module of claim 1, wherein, The ceramic material layer (2) is made of aluminum nitride, silicon nitride, aluminum oxide or silicon dioxide.

6. The PCB-embedded power module of any of claims 1-5, wherein, The heat-conducting insulation layer further comprises an adhesion enhancer layer (4) connected between the ceramic material layer (2) and the heat-conducting insulation film (3).

7. The PCB-embedded power module of claim 6, wherein, The adhesion enhancer layer (4) is made of a material containing a silane coupling agent component or a polyimide component.

8. The PCB-embedded power module of claim 6, wherein, The adhesion enhancer layer (4) is attached to a surface of the ceramic material layer (2) facing the heat-conducting insulation film (3) by an impregnation process, a spraying process, a CVD process or a printing process.

9. The PCB-embedded power module of any of claims 1-5, wherein, The surface of the ceramic material layer (2) facing the heat-conducting insulation film (3) has a roughened surface.

10. A method of forming a PCB-embedded power module for forming the PCB-embedded power module of any one of claims 1-9, wherein, The application further relates to a method for manufacturing the power heating unit (1), comprising the following steps: Step S1: attaching a ceramic material layer (2) to an outer surface of a power copper layer (11) and an inner surface of an isolation groove of a power heating unit (1) on at least one side of the power heating unit (1); Step S2: connecting a heat-conducting insulation film (3) to a side of the ceramic material layer (2) away from the power copper layer (11) and allowing part of the heat-conducting insulation film (3) to be filled in the isolation groove.

11. The method of claim 10, wherein the PCB-embedded power module is formed by, The method further comprises the following step between the step S1 and the step S2: Step S01: attaching an adhesion enhancer layer (4) to the side of the ceramic material layer (2) away from the power copper layer (11).

12. The method of claim 10, wherein the PCB-embedded power module is formed by, The method further comprises the following step between the step S1 and the step S2: Step S02: roughening a surface of the ceramic material layer (2) away from the power copper layer (11) to form a roughened surface of a surface of the ceramic material layer (2) facing the heat-conducting insulation film (3).

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