Preparation method of power module device and power module device

Abstract

This application provides a method for fabricating a power module device and the power module device itself, employing an exposure, development, and etching technique to form surface circuits and pins on components. This technique results in a smooth component surface, thereby improving soldering accuracy, reducing contact resistance, and increasing reliability of the power module device. Since the circuits and pins are on the component surface, there is no additional volume, reducing component size and increasing power module power density. Furthermore, the power module device fabricated using the method provided in this application is integrally formed, fully filling gaps between components, thereby increasing inductance and magnetic flux density, and ultimately reducing losses. Moreover, the power module device fabricated using the method provided in this application can be made very small, thus increasing power module power density and resulting in a smaller power supply size.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of power module technology, and more specifically to a method for preparing a power module device and a power module device. Prior Art

[0002] In recent years, with the advancement of data centers and artificial intelligence technologies, central processing units (CPUs), graphics processing units (GPUs), and various integrated circuits (ICs) have become increasingly faster, more integrated, and consume ever-increasing currents. This has placed increasingly stringent demands on the power density, efficiency, and dynamic response of voltage regulator modules (VRMs), the power supply modules themselves. This has posed significant challenges to VRM design. Within voltage regulator modules, efficiency, power density, and frequency are increasing, and the output inductor often accounts for the largest portion of the total volume. Furthermore, the selection of inductor value directly impacts the efficiency and dynamic performance of the entire VRM.

[0003] Among them, the inductors used in existing power modules are typically ferrite air-gap inductors with external pins or press-fit inductors with external pins. After the inductor is formed, the pins must be glued on to complete the circuit. This increases the overall volume of the inductor, and the pins are directly glued to the magnet with glue, creating a gap between them and the magnet, which increases the inductor's volume. Furthermore, the pin surface can be uneven, affecting circuit reliability and the size of the power module. Therefore, the use of glued pins in existing power modules reduces soldering reliability and power density.

[0004] Therefore, how to solve the technical problems of traditional external pin power modules, such as excessive size, low power density, and poor welding reliability, is a difficult problem that existing manufacturers urgently need to solve. Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of protection claimed.

[0006] To solve the technical problems existing in the prior art, the embodiments of the present application provide a method for preparing a power module device and a power module device, which can solve the technical problems of excessive power consumption, excessive volume, and low power density when the existing power module adopts traditional ferrite air-gap inductors.

[0007] In order to achieve the above technical effects, the embodiments of the present application adopt the following technical solutions:

[0008] One of the purposes of this application is to provide a method for preparing a power module device, the method comprising:

[0009] The soft magnetic powder and the winding are pressed into a shape to obtain an inductor green body;

[0010] The inductor green body is heated and kept warm;

[0011] Forming a circuit layer on the surface of the inductor green sheet;

[0012] The circuit layer is etched to form required circuits and pins.

[0013] As a preferred technical solution of this application, the etching process includes:

[0014] forming a photoresist layer on the circuit layer;

[0015] The circuit layer is etched with reference to the photoresist layer to form a required circuit.

[0016] As a preferred technical solution of this application, the etching process includes:

[0017] forming a photoresist layer on the circuit layer;

[0018] performing exposure and development processing on the photoresist layer with reference to the mask to form a photoresist pattern;

[0019] The circuit layer is etched with reference to the photoresist pattern to form a required circuit.

[0020] As a preferred technical solution of this application, the pressing pressure is 5~24T / cm2.

[0021] As a preferred technical solution of this application, the temperature of the heating and insulation treatment is 150~850℃.

[0022] As a preferred technical solution of the present application, a method for forming a circuit layer on the surface of the inductor green body includes laying metal on the surface of the inductor green body, heating and / or pressing the metal to form the circuit layer.

[0023] As a preferred technical solution of the present application, the preparation method further includes cleaning the inductor green body before forming the circuit layer.

[0024] As a preferred technical solution of the present application, the preparation method further includes performing a calendering treatment on the circuit layer.

[0025] As a preferred technical solution of the present application, the preparation method further includes removing the photoresist layer after the etching process.

[0026] A second object of the present application is to provide a power module device, which is prepared using the preparation method of the power module device provided in the first object, and the power module device includes an inductor green body and a circuit located on the surface of the inductor green body.

[0027] Compared with the prior art, this application has at least the following beneficial effects:

[0028] (1) The present application provides a method for preparing a power module device and a power module device. The method uses exposure, development, and etching techniques to form a circuit and a flat pin surface, thereby improving precision and reducing contact resistance of the power module device, thereby achieving the effect of reducing power module device losses.

[0029] (2) The present application provides a method for preparing a power module device and a power module device, wherein the power module device is formed integrally and the gaps between the parts are fully filled, thereby increasing the inductance and magnetic flux density of the product, thereby achieving the effect of reducing losses;

[0030] (3) The present application provides a method for preparing a power module device and a power module device. The power module device is small in size, so the power density of the power module device can be improved, thereby achieving the effect of reducing power consumption and reducing size, and solving the technical problems of traditional external pin power modules such as excessive size, low power density and poor reliability.

[0031] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. Simple diagram description

[0032] Figure 1 is a schematic flow chart of a method for preparing a power module device according to an embodiment of the present application;

[0033] Figure 2 is a schematic diagram of a first sub-process of a method for preparing a power module device according to an embodiment of the present application;

[0034] Figure 3 is a schematic diagram of a second sub-process of a method for preparing a power module device according to an embodiment of the present application;

[0035] Figure 4 is a schematic diagram of a third sub-process of a method for preparing a power module device according to an embodiment of the present application;

[0036] Figure 5 is a schematic diagram of a fourth sub-process of a method for preparing a power module device according to an embodiment of the present application;

[0037] Figure 6 is a schematic diagram of a second process of a method for preparing a power module device according to an embodiment of the present application;

[0038] Figure 7 is a schematic structural diagram of a power module device according to an embodiment of the present application;

[0039] The following is a further detailed description of this application. However, the following examples are merely simplified examples of this application and do not represent or limit the scope of protection of this application. The scope of protection of this application shall be subject to the claims. Implementation Method

[0040] The following, combined with the accompanying drawings, provides a clear and complete description of the technical solutions in the embodiments of this application. Obviously, the described embodiments represent only a portion of the embodiments of this application, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of this application without further development are also within the scope of protection of this application.

[0041] In addition, the terms "first," "second," and so on in the description and claims of this application are used to distinguish different items rather than to describe a specific order. The terms "include," "include," "have," and any variations thereof are intended to cover non-exclusive inclusions.

[0042] The present invention provides a method for preparing a power module device. FIG1 is a flow chart illustrating a method for preparing a power module device according to the present invention. As shown in FIG1 , the method for preparing a power module device according to the present invention includes the following specific steps:

[0043] Step 101: Press the soft magnetic powder and the winding into a shape to obtain an inductor green body.

[0044] It should be noted that the soft magnetic powder can be one or a mixture of two or more of iron-based or iron-containing alloy metal magnetic powders such as Fe, Fe-Si, Fe-Ni, Fe-Si-Cr, Fe-Si-Al, and Fe-Ni-Mo, Fe-based amorphous magnetic powders, and nanocrystalline magnetic powders. The powder surface has an insulating layer. The insulating layer material has high resistivity and flexibility to ensure that the powders are not in full contact, thereby reducing eddy currents between the magnetic powders and improving the insulation resistance value. The insulating material also has certain bonding properties to improve the strength of the inductor green body.

[0045] Step 102: Place the inductor green body in a heat treatment furnace and heat and keep it warm.

[0046] It should be noted that the purpose of placing the inductor green body in a heat treatment furnace for heating and insulation is to release the residual stress introduced into the inductor green body by the molding process, so as to obtain a bare inductor component with the required electromagnetic properties.

[0047] Step 103: forming a circuit layer on the surface of the bare inductor.

[0048] It should be noted that the copper foil is laid on the surface of the bare inductor and tightly adhered to the bare inductor by heating or pressing, thereby forming the circuit layer. Of course, other conductive materials can also be used to form the circuit layer, and this embodiment of the application is not specifically limited here.

[0049] Step 104: Process the circuit layer to form required circuits and pins.

[0050] It should be noted that the circuit and the pins are the paths for connecting the power module device to other power module devices, that is, the pins set on the inductor in the prior art.

[0051] Please refer to FIG2 , which is a schematic diagram of the first sub-flow of a method for preparing a power module device according to an embodiment of the present application. As shown in FIG2 , step 101 includes the following specific steps:

[0052] Step 1011: Place the soft magnetic powder and windings in a mold.

[0053] Step 1012: Apply pressure to the mold to shape the soft magnetic powder and the winding to obtain an inductor green body.

[0054] It should be noted that this embodiment adopts compression molding, and the pressure is 5-24 T / cm2, for example, 5 T / cm2, 6 T / cm2, 7 T / cm2, 8 T / cm2, 9 T / cm2, 10 T / cm2, 11 T / cm2, 12 T / cm2, 13 T / cm2, 14 T / cm2, 15 T / cm2, 16 T / cm2, 17 T / cm2, 18 T / cm2, 19 T / cm2, 20 T / cm2, 21 T / cm2, 22 T / cm2, 23 T / cm2 or 24 T / cm2, and any value between any two end points. It should be noted that appropriately increasing the pressure can increase the density of the magnetic part and increase the magnetic permeability, but excessive pressure has the risk of reducing the inductance insulation properties, especially for spiral coils with more than 1 turns. In addition, after the pressure increases to a certain level, the density of the magnetic part tends to stabilize and will not continue to increase. Excessive pressure will damage economic benefits; too low pressure may lead to poor inductance strength, low magnetic permeability, and electromagnetic properties cannot meet the requirements.

[0055] Compression molding causes elastic and plastic deformation of soft magnetic powders, necessitating annealing of the green inductor to remove internal stress. Annealing also eliminates internal defects introduced during the powder preparation process. Therefore, annealing can improve the initial magnetic permeability of the magnetic portion, reduce iron loss, and enhance the mechanical strength of the inductor component. Depending on the type of soft magnetic powder, the heating and holding temperature is generally between 150°C and 850°C, including, for example, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, or 850°C, as well as any value between these two endpoints. Excessively low annealing temperatures will not sufficiently release internal residual stress, resulting in low permeability and high losses. Excessively high annealing temperatures can damage the insulating layer on the powder surface, reducing initial permeability and increasing eddy current losses.

[0056] Please refer to FIG3 , which is a schematic diagram of a second sub-flow diagram of a method for preparing a power module device according to an embodiment of the present application. As shown in FIG3 , step 104 includes the following specific steps:

[0057] Step 1041 : forming a photoresist pattern on the circuit layer.

[0058] Step 1042: Using the photoresist pattern as a reference, perform etching on the circuit layer to form a desired circuit.

[0059] It should be noted that during the etching process, the etching solution will corrode the circuit layer, but since the photoresist pattern will not be corroded, the circuit layer located below the photoresist pattern will be retained during the etching process, while the circuit layer located in other parts will be corroded, thus forming a circuit consistent with the photoresist pattern.

[0060] Please refer to FIG4 , which is a schematic diagram of a third sub-flow of a method for preparing a power module device according to an embodiment of the present application. As shown in FIG4 , step 1041 includes the following specific steps:

[0061] Step 10411: forming a photoresist layer on the circuit layer.

[0062] It should be noted that the photoresist layer is formed by attaching the entire photoresist to the surface of the circuit layer.

[0063] It should be noted that the material of the photoresist layer is positive photoresist or negative photoresist. The specific material selection of the photoresist layer is determined by the mask used in the exposure and development technology.

[0064] Step 10412: Expose and develop the photoresist layer with the mask as a reference to form a photoresist pattern.

[0065] Please refer to FIG5 , which is a schematic diagram of a fourth sub-process of a method for preparing a power module device according to an embodiment of the present application. As shown in FIG5 , step 104 includes the following specific steps:

[0066] Step 1041: forming a photoresist pattern on the circuit layer.

[0067] Step 1042: Using the photoresist pattern as a reference, perform etching on the circuit layer to form a desired circuit.

[0068] Step 1043: remove the photoresist pattern.

[0069] It should be noted that since the photoresist pattern is provided to form the required circuit diagram, it will affect the performance of the power module device. Therefore, it is necessary to remove the photoresist pattern after forming the required circuit to avoid affecting the performance of the power module device.

[0070] Please refer to Figure 6, which is a second flow chart of a method for preparing a power module device according to an embodiment of the present application. As shown in Figure 6, the method for preparing a power module device according to an embodiment of the present application includes the following specific steps:

[0071] Step 101: Press the soft magnetic powder and the winding into a shape to obtain an inductor green body.

[0072] Step 102: Place the inductor green body in a heat treatment furnace and heat and keep it warm.

[0073] Step 105: Clean the bare inductor.

[0074] It should be noted that if impurities are present on the surface of the inductor green sheet, the circuit layer formed in the subsequent manufacturing process will be uneven, which will affect the power consumption of the power module. Therefore, cleaning the inductor green sheet can remove impurities such as grease and dirt on the surface of the inductor green sheet, thereby preventing the uneven circuit layer formed in the subsequent manufacturing process from increasing the power consumption of the power module.

[0075] It should be noted that the inductor green body can be placed in a cleaning machine for cleaning, or other methods can be used to clean the inductor green body, and this embodiment of the present application does not make specific limitations here.

[0076] Step 103: forming a circuit layer on the surface of the bare inductor.

[0077] Step 106: performing calendering treatment on the circuit layer.

[0078] Among them, it should be noted that the use of a calender to calender the circuit layer can ensure that the circuit layer is flat and free of bubbles, thereby helping to improve the flatness of the circuit pattern formed in the subsequent process and improve the reliability of the power module device.

[0079] Step 104: Process the circuit layer to form required circuits and pins.

[0080] In a method for preparing a power module device provided in an embodiment of the present application, a circuit pattern is formed using exposure, development, and etching techniques. This results in a smooth component surface, thereby improving precision and reducing the contact resistance of the power module device, thereby reducing losses in the power module device. Furthermore, the power module device prepared using the method for preparing a power module device provided in an embodiment of the present application is integrally formed, fully filling gaps between components. This can increase the inductance and magnetic flux density of the product, thereby reducing losses. Furthermore, the power module device prepared using the method for preparing a power module device provided in an embodiment of the present application can be very small, thereby increasing the power density of the power module and making the power supply smaller.

[0081] The present invention also provides a power module device. See Figure 7, which is a schematic diagram of the structure of a power module device provided in the present invention. As shown in Figure 7, the power module device 200 provided in the present invention includes a bare inductor 201 and a circuit pattern 202 located on the surface of the bare inductor 201. The power module device 200 is manufactured using the power module device manufacturing method described above. The manufacturing method of the power module device can be found in the above description and will not be further elaborated here.

[0082] In a method for preparing a power module device and a power module device provided in an embodiment of the present application, exposure, development, and etching techniques are used to form a circuit, allowing the inductor to be tightly integrated with the circuit and the circuit pins, thereby reducing the size. The component surface is flat, thereby improving precision and reducing the contact resistance of the power module device, thereby achieving the effect of reducing the power module device's losses. In addition, the power module device prepared using the method for preparing a power module device provided in an embodiment of the present application is formed into an integral part, fully filling the gaps between each part, thereby increasing the inductance and magnetic flux density of the product, thereby achieving the effect of reducing losses. Moreover, the power module device prepared using the method for preparing a power module device provided in an embodiment of the present application can be made into a very small volume, thereby increasing the power density of the power module and making the power supply volume smaller.

[0083] The above is a detailed introduction to a preparation method of a power module device and a power module device provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present application.

[0084] 101~106: Steps 1011~1012: Steps 1041~1043: Steps 10411~10412: Steps 200: Power module device 201: Bare inductor 202: Circuit pattern

Claims

1. A method for manufacturing a power module device, comprising: The soft magnetic powder and winding are pressed into shape to obtain an inductor green blank; the inductor green blank is then subjected to heating and heat preservation treatment. A circuit layer is formed on the surface of the inductor blank; the circuit layer is etched to form the required circuit and pins.

2. The preparation method according to claim 1, wherein, The etching process includes: forming a photoresist layer on the circuit layer; and etching the circuit layer with the photoresist layer as a reference to form the desired circuit.

3. The preparation method according to claim 2, wherein, The etching process includes: forming a photoresist layer on the circuit layer; exposing and developing the photoresist layer with a mask as a reference to form a photoresist pattern; and etching the circuit layer with the photoresist pattern as a reference to form the desired circuit.

4. The preparation method according to claim 1, wherein, The pressure for pressing and molding is 5~24T / cm2.

5. The preparation method according to claim 1, wherein, The temperature for the heating and heat preservation treatment is 150~850℃.

6. The preparation method according to claim 1, wherein, A method for forming a circuit layer on the surface of the inductor preform includes laying metal on the surface of the inductor preform, heating and / or pressing the metal to form the circuit layer.

7. The preparation method according to claim 1, wherein, The preparation method further includes cleaning the inductor preform before forming the circuit layer.

8. The preparation method according to claim 1, wherein, The preparation method further includes performing a photopolymerization process on the circuit layer.

9. The preparation method according to claim 2, wherein, The preparation method further includes removing the photoresist layer after the etching process.

10. A power module device, which is prepared by the method of preparing a power module device as described in any one of claims 1-9, the power module device comprising an inductor blank and circuitry located on the surface of the inductor blank.

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