Composite magnetic material providing high magnetic permeability

Abstract

A composite magnetic material includes a composite nonmagnetic material (MA) and a magnetic filler (MB). The magnetic filler (MB) comprises coated magnetic particles dispersed in the composite nonmagnetic material (MA). The coated magnetic particles (MB) comprise magnetic metal particles (MB1) with an insulating coating layer (MB2) on their surface. The composite magnetic material has a relative permeability of not less than 13 at a frequency not exceeding 200 MHz.

Description

Technical Field

[0001] This disclosure generally relates to electrical equipment and related materials and methods, and in particular, but not limited to, composite magnetic materials, magnetic molding compounds and related equipment and methods. Prior Technology

[0002] Power converters or power conditioners are widely used in a variety of electronic and / or electrical applications. A power converter or power conditioner typically includes at least one power switch (e.g., a semiconductor switching device or a semiconductor transistor device). In operation, the power converter or power conditioner provides stable power (e.g., stable voltage and / or current) to the load by controlling the operating state of at least one power switch. Inductive energy storage devices (e.g., inductors or transformers) typically work in conjunction with at least one power switch to perform power conversion. For example, a typical switch-mode power converter known in the art controls the power switch to perform on and off switching to convert input power into output power to supply a load. For example, when the power switch is on, the switch-mode power converter transfers energy from the input power source to the inductive energy storage device (e.g., current flows through the inductive energy storage device, and the current may gradually increase). When the power switch is off, energy is released from the inductive energy storage device to the load (e.g., the current flowing through the inductive energy storage device may gradually decrease).

[0003] With the increasing integration of electrical / electronic equipment, the demand for power supply devices or power management devices (such as power converters or power regulators) with higher power handling capabilities and smaller size is becoming increasingly prominent. High power density power supply devices or power management devices have become a trend, making reducing the size of components in these devices one of the design or development challenges. Summary of the Invention

[0004] The purpose of this application is to provide a composite magnetic material, comprising: a composite nonmagnetic material (MA); and a magnetic filler, the magnetic filler comprising coated magnetic particles (MB) dispersed in the composite nonmagnetic material (MA); wherein the coated magnetic particles (MB) comprises magnetic metal particles (MB1) with the surface coated with the insulating coating layer (MB2); the sample of the composite magnetic material has a relative permeability of not less than 13 at a frequency not exceeding 200 MHz, or a relative permeability of not less than 16 at a frequency not exceeding 100 MHz. Simple Explanation of the Diagram

[0005] To better understand the present invention, embodiments of the invention will be described with reference to the following accompanying drawings, which are for illustrative purposes only. The drawings typically show only some features of the embodiments and are not necessarily drawn to scale. [Figure 1] schematically illustrates a block diagram of a power management device 100 according to an embodiment of the present disclosure. [Figure 2A] schematically shows a top view of a packaged module 10 for power conversion according to an embodiment of the present disclosure. [Figure 2B] schematically shows a cross-sectional view of the packaging module 10 taken along section line A-A' in the top view of Figure 2A according to an embodiment of the present disclosure. [Figure 2C] schematically shows a top view of a packaged module 20 for power conversion according to an embodiment of the present disclosure. [Figure 2D] schematically shows a cross-sectional view of the packaging module 20 taken along section line A-A' in the top view of Figure 2C according to an embodiment of the present disclosure. [Figure 2E] and [Figure 2F] schematically show a cross-sectional view of the packaging module 20 taken along section line A-A' in the top view of Figure 2C according to an embodiment of the present disclosure. [Figure 2G] schematically shows a waveform diagram of the relationship between the relative permeability μr of an MMC14 and the switching frequency according to an embodiment of the present disclosure. [Figure 3A] schematically shows a top view of a packaged module 30 for power conversion according to an embodiment of the present disclosure. [Figure 3B] schematically shows a cross-sectional view of the packaging module 30 taken along section line A-A' in the top view of Figure 3A according to an embodiment of the present disclosure. [Figure 3C] schematically shows a top view of a packaged module 40 for power conversion according to an embodiment of the present disclosure. [Figure 3D] schematically shows a cross-sectional view of the packaging module 40 taken along section line A-A' in the top view of Figure 3C according to an embodiment of the present disclosure. [Figure 4A] schematically shows a top view of a packaged module 50 for power conversion according to an embodiment of the present disclosure. [Figure 4B] schematically shows a cross-sectional view of the packaging module 50 taken along section line A-A' in the top view of Figure 4A according to an embodiment of the present disclosure. [Figure 4C] schematically shows a cross-sectional view of the packaging module 50 taken along section line A-A' in the top view of FIG4A according to an embodiment of the present disclosure. [Figure 5A] schematically shows a top view of a packaged module 60 for power conversion according to an embodiment of the present disclosure. [Figure 5B] schematically shows a cross-sectional view of the packaging module 60 taken along section line A-A' in the top view of Figure 5A according to an embodiment of the present disclosure. [Figure 5C] schematically shows a cross-sectional view of the packaging module 60 taken along section line A-A' in the top view of Figure 5A according to an embodiment of the present disclosure. [Figure 6A] schematically shows a perspective top view of a package module 70 for power conversion according to an embodiment of the present disclosure. [Figure 6B] schematically shows a cross-sectional view of the packaging module 70 taken along section line A-A' in the perspective top view of Figure 6A according to an embodiment of the present disclosure. [Figure 7A] schematically shows a perspective top view of a packaged module 80 for power conversion according to an embodiment of the present disclosure. [Figure 7B] schematically shows a cross-sectional view of the packaging module 80 taken along section line A-A' in the perspective top view of Figure 7A according to an embodiment of the present disclosure. [Figure 7C] schematically shows a three-dimensional perspective view of a package module 81 for power conversion according to an alternative embodiment of the present disclosure. [Figure 7D] schematically shows a perspective side view of the package module 81 as viewed from the right side (as indicated by arrow 802) in a three-dimensional perspective view of FIG7C according to an embodiment of the present disclosure. [Figure 7E] schematically shows a perspective top view of a package module 81 for power conversion according to an embodiment of the present disclosure. [Figure 7F] schematically illustrates a three-dimensional perspective view of a package module 82 for power conversion according to an embodiment of the present disclosure. [Figure 7G] schematically shows an enlarged top view of a conductive coil 13 according to an embodiment of the present disclosure. [Figure 7H] and [Figure 7I] respectively schematically show enlarged perspective side views of a conductive coil 13 according to an embodiment of the present disclosure. [Figure 7J] and [Figure 7K] respectively schematically show enlarged perspective side views of a conductive coil 13 according to an embodiment of the present disclosure. [Figure 7L] schematically shows a perspective top view of a package module 82 for power conversion according to an embodiment of the present disclosure. [Figure 8A] schematically shows a perspective top view of a packaged module 90 for power conversion according to an embodiment of the present disclosure. [Figure 8B] schematically shows a cross-sectional view of the packaging module 90 taken along section line A-A' in the perspective top view of Figure 8A according to an embodiment of the present disclosure. [Figure 8C] schematically shows a perspective top view of a package module 91 for power conversion according to an embodiment of the present disclosure. [Figure 8D] schematically shows a cross-sectional view of the packaging module 91 taken along section line A-A' in the perspective top view of Figure 8C according to an embodiment of the present disclosure. [Figure 8E] schematically shows a perspective top view of a packaged module 92 for power conversion according to an embodiment of the present disclosure. [Figure 8F] schematically shows a cross-sectional view of the packaging module 92 taken along section line A-A' in the perspective top view of Figure 8E according to an embodiment of the present disclosure. [Figure 8G] schematically shows a perspective top view of a packaged module 94 for power conversion according to an embodiment of the present disclosure. [Figure 8H] schematically shows a cross-sectional view of the packaging module 94 taken along section line A-A' in the perspective top view of Figure 8G according to an embodiment of the present disclosure. [Figure 8I] schematically shows a perspective top view of a packaged module 96 for power conversion according to an embodiment of the present disclosure. [Figure 8J] schematically shows a cross-sectional view of the packaging module 96 taken along section line A-A' in the perspective top view of Figure 8I according to an embodiment of the present disclosure. [Figure 8K] shows a simulated waveform diagram of the relationship between the power conversion efficiency of a packaged module and the operating current of the packaged module (e.g., the load current provided at the output of the packaged module) according to an embodiment of the present disclosure. [Figure 9] shows a process flow diagram of a method 900 for manufacturing a power conversion package module according to an embodiment of the present disclosure. [Figure 10] shows a process flow diagram of a method 1000 for manufacturing a power conversion package module according to an alternative embodiment of the present disclosure. [Figure 11] shows a waveform diagram of the relative permeability μr versus switching frequency of some samples of composite magnetic materials according to some embodiments of the present disclosure. [Figure 12] shows a portion of a composite magnetic material according to some embodiments of the present disclosure, the composite magnetic material comprising island structures within a composite nonmagnetic material (MA). The same reference numerals in different schematic diagrams indicate the same or similar parts or features. Implementation

[0006] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known circuits, materials, or methods are not specifically described in order to avoid obscuring the invention.

[0007] In the specification and claims of this invention, the use of terms such as "left," "right," "inner," "outer," "upper," "lower," "above," and "below" is merely for descriptive convenience and does not indicate a necessary or permanent relative position of components / structures. Those skilled in the art should understand that such terms can be used interchangeably where appropriate, for example, so that embodiments of the invention can still operate in orientations different from those described in this specification. In the context of this invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. Furthermore, the terms "coupled" and "connected" mean a direct or indirect electrical or non-electrical connection. "One / this / that" is not used to specifically refer to the singular but may encompass the plural form. The phrases "an embodiment," "an example," "an example," and "example" appearing throughout the specification do not necessarily refer to the same embodiment or example. Those skilled in the art should understand that the various specific features, structures, parameters, steps, etc., disclosed in one or more embodiments of this invention can be combined in any suitable manner. The term “and / or” as used herein includes any and all combinations of one or more of the related listed items.

[0008] When a field-effect transistor (FET) or a bipolar junction transistor (BJT) is used as an embodiment of a transistor, the terms “gate,” “drain,” and “source” encompass “base,” “collector,” and “emitter,” respectively, and vice versa. Those skilled in the art will understand that the meanings of the above terms are not necessarily limiting, but merely illustrative examples.

[0009] Furthermore, if the present invention uses terms such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by the present invention.

[0010] For ease of explanation, this disclosure may be illustrated using specific semiconductor devices as examples, but this is not limiting. Those skilled in the art should understand that the structures and principles taught in this disclosure are also applicable to other semiconductor devices. Various embodiments will be discussed below with reference to Figures 1 to 12. The detailed descriptions given herein in conjunction with the accompanying drawings are for illustrative purposes only and should not be construed as limiting.

[0011] Figure 1 illustrates an exemplary block diagram of a power management device 100 according to an embodiment of the present disclosure. The power management device 100 can be used to supply power from a power source to a load. The power management device 100 may have an input terminal IN for receiving input power from the power source and an output terminal OUT for providing output power. The power source may include a power source such as a battery / battery pack, or other circuitry that can be used to supply power to external circuitry. In the example of Figure 1, the power source provides power in the form of an input voltage VIN, which may be a DC voltage. However, this is not a limitation, and power sources that can provide input power to the power management device 100 in other forms are also applicable.

[0012] In one embodiment, the power management device 100 may include a power switching unit 110. The power switching unit 110 may be adapted to regulate the energy or power transmitted from input IN to output OUT (or to a load) in response to a control signal (e.g., the control signal CTRL shown in the example of FIG. 1). In one embodiment, the power switching unit 110 may include at least one power switch, such as a power transistor device, which can be controlled to be turned on and off. In one embodiment, the power switching unit 110 may further include a driver 160 for driving at least one power switch in the power switching unit 110.

[0013] According to an exemplary embodiment, the power switching unit 110 can be configured to control the switching between energy storage and energy release in the inductive energy storage device 120 based on a control signal (e.g., the control signal CTRL shown in FIG. 1), thereby converting input power (e.g., in the form of input voltage VIN and / or IN in FIG. 1) into output power (e.g., in the form of output voltage VOUT and / or Io in FIG. 1). During energy storage, energy can be transferred to and stored in the inductive energy storage device 120 (e.g., current flows through the inductive energy storage device 120, and the current gradually increases). During energy release, energy can be released from and transferred out of the inductive energy storage device 120 (e.g., the current flowing through the inductive energy storage device 120 gradually decreases). Generally, the power switching unit 110 is coupled with the inductive energy storage device 120. The time period during which energy is transferred from the input terminal IN to the inductive energy storage device 120 for energy storage can be called the on-time Ton (which can also be considered as the on-time of the power switching unit 110 or the on-time of the power management device 100). The time period during which energy is transferred from the power switching unit 110 to the output terminal OUT for energy release can be called the off-time Toff (which can also be considered as the off-time of the power switching unit 110 or the off-time of the power management device 100). The sum of the on-time Ton and off-time Toff experienced by the inductive energy storage device 120 each time it completes the energy storage and energy release switch can be called one duty cycle or switching cycle Top of the power management device 100. The ratio of the on-time Ton to the sum of the on-time Ton and off-time Toff in each duty cycle Top can be called the duty cycle of the power switching unit 110 or the duty cycle of the power management device 100. Control signals (e.g., the control signal CTRL shown in Figure 1) can be used to control the power switching unit 110 to switch between energy storage and energy release of the inductive energy storage device 120, and can also be used to adjust the on-time Ton and / or off-time Toff, the duty cycle, or the switching cycle Top (or the switching frequency Fop = 1 / Top). Thus, the energy or power transmitted to the power switching unit 110 can be adjusted by regulating the power at the output terminal OUT in each switching cycle. For example, the output power can be adjusted by regulating the output voltage VOUT and / or the output current Io.

[0014] According to an exemplary embodiment, the power switching unit 110 may be configured to cooperate with the inductive energy storage device 120 to implement the power conversion topology 130. The power conversion topology 130 may include any isolated or non-isolated synchronous or asynchronous power conversion topology, including but not limited to DC-DC power conversion topology, AC-DC power conversion topology, DC-AC power conversion topology, etc. In one example, the power conversion topology 130 may include a synchronous non-isolated DC-DC power conversion topology, such as a DC-DC buck power conversion topology, a DC-DC boost power conversion topology, or a DC-DC buck-boost power conversion topology.

[0015] In one embodiment, the power management device 100 may further include a control unit 140 to provide control signals for controlling the power switching unit 110. In one embodiment, the control unit 140 may be adapted to provide control signals to the power switching unit 110 based on information indicating input voltage VIN and / or information indicating output voltage VOUT and / or information indicating output current Io, etc.

[0016] In one embodiment, the capacitive energy storage unit 150 may be coupled to the output terminal OUT. The capacitive energy storage unit 150 may include, for example, one or more capacitors and may be used as an output filter to smooth the output voltage VOUT at the output terminal OUT. Those skilled in the art will understand that the power management device 100 may include other active and / or passive components, which will not be elaborated further in this disclosure.

[0017] Traditionally, passive components (e.g., particularly inductive energy storage device 120) are supplied as discrete devices, which occupy a large physical volume or space and cannot be mounted on the substrate or circuit board of the application system in which the power management device 100 may be used. For example, conventional inductors are supplied as separately packaged discrete devices formed by: placing a magnetic core (e.g., a ferrite core) on a substrate (the substrate of the discrete inductor package) and arranging a conductive coil around the core; then molding the core and the corresponding coil within a conventional molding compound (e.g., plastic, epoxy compound, etc.) to create a packaged discrete inductor / magnetic device. The packaged discrete inductor / magnetic device has electrical leads extending from its substrate so that the packaged discrete inductor / magnetic device can be mounted on another substrate or circuit board of a larger system (e.g., a power converter). Examples of such packaged discrete inductor / magnetic devices are disclosed in U.S. Patent No. 5,787,569, entitled “Package for Power Magnetic Devices and Method of Manufacturing Thereof,” Lotfi et al. (“Lotfi”), issued August 4, 1998, and in U.S. Patent No. 7,462,317, entitled “Method of Manufacturing a Package for Magnetic Devices,” Lotfi et al. (“Lotfi”), issued December 9, 2008.

[0018] Furthermore, when such separately packaged discrete inductor / magnetic devices are used in power management devices (such as power converters), they may need to be packaged together with other components (such as power switching devices, capacitors, resistors, etc.) into a power converter module. This power converter module is typically packaged using conventional molding compounds (such as plastics, epoxy compounds, etc.), which greatly limits the minimum physical size of the power converter module.

[0019] To improve the integration density and / or power density of the power management device 100 and / or the application system including the device, in one embodiment, the power switching unit 110 and the inductive energy storage device 120 may be integrated into a single package module, which may be packaged using a magnetic molding compound (MMC) instead of conventional molding compounds (e.g., plastics, epoxy compounds, etc.). Compared to conventional power converter modules that use separately packaged discrete inductors / magnetic devices to implement the inductive energy storage device 120 and / or use separately packaged discrete inductors / magnetic devices and other components packaged with conventional molding compounds, the package modules according to various embodiments of this disclosure can have smaller size or physical dimensions and occupy less space when mounted on a circuit board. In one embodiment, the power switching unit 110 may be implemented and fabricated in an integrated circuit (IC) wafer. In one embodiment, the control unit 140 may be fabricated and / or integrated with the power switching unit 110 on the same IC wafer. In another embodiment, the control unit 140 may be fabricated and / or integrated with the power switching unit 110 on a different IC wafer. In another embodiment, the control unit 140 may be provided by other circuitry of the application system that includes the power management device 100. For example, a microcontroller in the application system may be configured to implement the functions of the control unit 140.

[0020] Figure 2A schematically shows a top view of a packaging module 10 according to an embodiment of the present disclosure. Figure 2B schematically shows a cross-sectional view of the packaging module 10 according to an embodiment of the present invention, taken along section line A-A' in the top view of Figure 2A. The top view in Figure 2A and the cross-sectional view in Figure 2B can be considered as shown in a three-dimensional coordinate system having mutually perpendicular x-axis, y-axis, and z-axis. It is understood that the schematic cross-sectional view can be considered as being viewed / cut from a cutting plane parallel to the xz plane defined by the x-axis and z-axis. In this disclosure, the transverse direction can refer to a direction parallel to the x-axis, while the longitudinal direction can refer to a direction parallel to the z-axis in the cross-sectional view. Length can refer to a dimension measured along a direction parallel to the x-axis, width can refer to a dimension measured along a direction parallel to the y-axis, and height, depth, and / or thickness can refer to dimensions measured along a direction parallel to the z-axis. In other words, the x-axis direction refers to the length direction of the packaging module 10, the y-axis direction refers to the width direction of the packaging module 10, and the z-axis direction refers to the height direction of the packaging module 10. The encapsulation module 10 can be described and understood by referring to Figures 2A and 2B.

[0021] The package module 10 may include a substrate 11, a power switching unit 12, and a conductive coil 13. The conductive coil 13 may be mounted on the substrate 11. The power switching unit 12 may also be disposed within the package module 10. In one embodiment, the power switching unit 12 and the conductive coil 13 may be mounted on the substrate 11 such that the power switching unit 12 and the conductive coil 13 can cooperate or coordinate with each other. For example, the power switching unit 12 may be coupled to the conductive coil 13. Other circuit components, such as capacitive energy storage devices 15 (e.g., capacitors), resistive devices 16 (e.g., resistors), and / or other components 17, may also be mounted on the substrate 11. Magnetic molding compound 14 (MMC) may be used to encapsulate the package module 10, for example, to cover or wrap the components mounted on the substrate 11 (including but not limited to the power switching unit 12 and / or the conductive coil 13). In one embodiment, the package module 10 for power conversion may be configured to implement a power management device 100 or at least a power conversion topology 130 of the power management device 100.

[0022] The power switch unit 12 can be an implementation of the power switch unit 110 as described in the example above with reference to FIG. 1. For example, the power switch unit 12 can be a semiconductor wafer or integrated circuit wafer with integrated circuitry for performing the functions of the power switch unit 110. Referring to the example shown in FIG. 2B, the power switch unit 12 may have conductive pads 121 formed on its top surface 12T (e.g., also referred to as the active surface) to electrically lead out terminals of the integrated circuitry formed inside the power switch unit 12, such that the power switch unit 12 can be directly attached to the substrate 11, for example, to the first surface 11U of the substrate 11, wherein the top surface 12T is flipped down to face the first surface 11U of the substrate 11. In one embodiment, each conductive pad 121 may be connected to a conductive post / bump 123, which may be attached to the substrate 11 and connected to a corresponding pad (e.g., see pad 112) formed on the first surface 11U via a conductive wafer adhesion material 124 (e.g., solder paste). The top surface 12T (e.g., active surface) of the power switching unit 12 can refer to the surface on which conductive pads 121 and / or conductive pillars / bumps 123 are formed or attached. The back surface 12B of the power switching unit 12 is opposite to the top surface 12T. Therefore, the power switching unit 12 in this embodiment can be referred to as a flip-chip semiconductor wafer, and its top surface 12T is suitable for attachment to the substrate 11. The underfill material 122 can be used to fill the cavities between the conductive pillars / bumps 123 and between the top surface 12T of the power switching unit 12 and the first surface 11U of the substrate 11. The underfill material 122 electrically isolates the conductive pads 121 and / or conductive pillars / bumps 123 from the MMC 14.

[0023] The conductive coil 13 may be made of a conductive material (e.g., a metal, a metal composite, or an alloy). For example, in one embodiment, the conductive coil 13 may be made of copper, aluminum, nickel, or an alloy thereof. The conductive coil 13 may be formed in various shapes such that it is suitable for use as one or more coils in an inductive energy storage device.

[0024] In one embodiment, as illustrated in the examples of Figures 2A and 2B, the conductive coil 13 may be helical and may serve as one or more multi-turn coils in an inductive energy storage device. Although the examples of Figures 2A and 2B show a multi-turn coil with its number of turns wound along the x-axis direction (i.e., along the length of the package module), it should be understood that this is merely exemplary and not limiting. Those skilled in the art will readily understand that when referring to the number of turns wound around a particular direction (e.g., the x-axis direction in Figures 2A and 2B), the number of turns is formed by winding / coiling the coil wire around or around that particular direction, for example, by unfolding the coil wire turn by turn along that particular direction. In some embodiments, the conductive coil 13 may be formed as a flat wire multi-turn coil by winding / coiling flat coil wire. In some other embodiments, the conductive coil 13 may be formed as a circular wire multi-turn coil by winding / coiling circular coil wire. In other alternative examples, the conductive coil 13 may form a greater number of turns depending on the actual application requirements, and each coil may have a single or multiple turn winding, and the number of turns need not be wound along the x-axis direction. The number of turns of each coil can be wound in other directions without departing from the spirit of this disclosure.

[0025] In the examples of Figures 2A and 2B, although the body of the conductive coil 13 (as shown by dashed box 13S, essentially comprising the turns of each coil) is shown to be spaced apart from the substrate 11 in the vertical direction, it will be understood that in other embodiments, the body of the conductive coil 13 may not be spaced apart from the substrate 11 in the vertical direction. For example, in some alternative embodiments, the body of the conductive coil 13 may be directly disposed on the substrate 11, and the bottom of the body may be substantially in contact with the substrate 11. Those skilled in the art will understand that this disclosure cannot exhaustively describe all variations, which can be obtained by studying the specification and drawings of this disclosure, and that such variations do not depart from the spirit and scope of this disclosure.

[0026] The conductive coil 13 may have coil terminals integrally formed with the conductive coil 13 (e.g., a first coil terminal 131 and a second coil terminal 132 for each coil). According to one embodiment, the coil terminals may be adapted to be directly attached to the substrate 11, such that the conductive coil 13 can be directly mounted on the substrate 11, and the inductive energy storage device can be coupled to the substrate 11. As is understood in its conventional literal sense, the term "integrated" essentially means that the coil terminals, like the body 13S, are implemented as an integral part of the conductive coil 13, without the need for connection by an additional connection method (e.g., soldering, brazing, etc.). From the perspective of "adapted to be directly attached to the substrate 11," the coil terminals are configured to be substantially coplanar with each other, such that when the conductive coil 13 is placed on the substrate 11, they can fall substantially simultaneously on the first surface 11U of the substrate 11 without significant vertical difference relative to the first surface 11U. For example, the coil terminals are substantially coplanar with each other, and the misalignment tolerance is within a predetermined range (e.g., ±5%), so that the coil terminals can be reliably connected to the substrate 11 by a conductive attachment material (e.g., solder paste). In some embodiments, each coil terminal may be integrally connected to a turn of the conductive coil 13 via a bent portion of the coil wire, depending on the predetermined direction in which the conductive coil 13 is wound. The conductive coil 13 designed according to exemplary embodiments of this disclosure is easier to mass-produce and improves the mounting yield and efficiency of mounting the conductive coil 13 onto the substrate 11 using surface mount technology (SMT), while reducing the complexity and cost of manufacturing and production. This is a long-standing problem that has been desired to be solved, as successfully and efficiently mounting the conductive coil 13 to meet the requirements of mass production is actually a serious challenge for those skilled in the art. Considering that the package module has a very small and limited size (e.g., in one embodiment, the package module size is no greater than 2mm*3mm*1.5mm to support operating currents up to 4A~6A), and the conductive coil 13 should correspondingly have a fairly small size (e.g., small enough to be accommodated in the package module) and be wound with very fine coil wires (e.g., in one embodiment, the diameter of the circular coil wire is no greater than 0.3mm, or in one embodiment, the thickness of the flat coil wire ranges from 0.03mm to 0.3mm), these coil wires are fragile and difficult to pick up, place, and connect (e.g., solder) during the mounting process. The embodiments disclosed herein advantageously overcome these challenging issues, and the conductive coil 13 is less likely to detach during reflow soldering.

[0027] Except for the coil terminals, the conductive coil 13 is conformally covered with a thin insulating layer 136. At least a portion (e.g., the bottom surface) of the coil terminals (e.g., the first coil terminal 131 and the second coil terminal 132 in this embodiment) is not covered by the thin insulating layer 136. That is, the thin insulating layer 136 covering the conductive coil 13 is peeled off at least a portion (e.g., the bottom surface) of the coil terminals (e.g., the first coil terminal 131 and the second coil terminal 132 in this embodiment), making the conductive coil 13 suitable for direct attachment to the substrate 11, and the coil terminals are configured to provide electrical connection / coupling. For example, the coil terminals (e.g., the first coil terminal 131 and the second coil terminal 132 in this embodiment) can be attached to corresponding pads (e.g., see pad 112) on the first surface 11U of the substrate 11 using a conductive attachment material 133 (e.g., solder paste). Those skilled in the art will understand that the pads 112 can be formed on the first surface 11U of the substrate 11 according to actual design and connection requirements. For the sake of brevity, the thin insulating layer 136 will not be specifically shown in the accompanying drawings of the remaining examples or embodiments provided in this disclosure, unless it is necessary to describe the thin insulating layer 136 in some embodiments.

[0028] MMC 14 offers high relative permeability (e.g., 20-50) and low core loss density. Those skilled in the art know that the permeability μ of a material is defined as the ratio of the magnetic flux density B (i.e., magnetic flux density) produced by a magnetizing field within the material to the magnetic field strength H of the magnetizing field, i.e., μ = B / H. This helps measure a material's resistance to a magnetizing field, or the extent to which a magnetizing field penetrates the material. The relative permeability of a particular medium or material, usually denoted by the symbol μr, is the ratio of the permeability of the particular medium or material to the free-space permeability μ0 (also known as the permeability in classical vacuum), i.e., μr = μ / μ0, where μ0 ≈ 4π × 10⁻⁷ H / m. Therefore, the relative permeability of MMC 14 is a dimensionless quantity, defined as the ratio of the permeability of MMC 14 to the free-space permeability μ0. In some embodiments, referring to FIG2G, a waveform diagram showing the relationship between the relative permeability μr of the MMC 14 according to embodiments of the present disclosure and the switching frequency (e.g., the switching frequency of the package module) is shown. The relative permeability of the MMC 14 is substantially in the range of 20 to 25 to support package modules according to various embodiments of the present disclosure, which can be configured to operate at switching frequencies up to 100 MHz. In some embodiments, the MMC 14 with a relative permeability substantially between 20 and 25 can support the formation of an integrated inductive energy storage device, which includes the MMC 14 and a conductive coil 13 with an inductance up to 2 μH.

[0029] In some embodiments, the MMC 14 extends upward from a first surface 11U of the substrate 11 and fills any space or volume not occupied by components mounted on the substrate 11 until it covers the tallest component mounted on the substrate 11. In one embodiment, the MMC 14 may include coated magnetic particles 142 dispersed in a non-magnetic material 141. In one embodiment, the non-magnetic material 141 may include a mixture comprising resin (or epoxy resin), a hardener, and a catalyst, but excluding silicon dioxide, meaning the non-magnetic material 141 is free of silicon dioxide. Each coated magnetic particle 142 may include a magnetic metal particle 143 and an insulating coating layer 144 surrounding or encapsulating the magnetic metal particle 143. That is, each magnetic metal particle 143 is coated and encapsulated within the insulating coating layer 144, thereby isolating it from the non-magnetic material 141 by the insulating coating layer 144. The insulating coating layer 144 may include a layer of polymer, such as silane coupling agents. The insulating coating 144 can advantageously help enhance the uniformity of the distribution of the coated magnetic particles 142 within the non-magnetic material 141 and improve the resistivity of the MMC 14. In one embodiment, each magnetic metal particle 143 may include at least 60% iron. In one embodiment, the coated magnetic particles 142 may have non-uniform size and / or may have non-uniform / different (i.e., various) shapes to reduce viscosity and increase permeability. The MMC 14 may have a much higher thermal conductivity than conventional molding compounds (e.g., plastics, epoxy compounds, etc.) because the coated magnetic particles 142 have a higher thermal conductivity than conventional molding compound particles, which can greatly enhance the thermal conductivity of the MMC 14.

[0030] According to exemplary embodiments, the conductive coil 13 and the MMC 14 can form an integrated inductive energy storage device, which can be used as the inductive energy storage device 120 as described above with reference to FIG. 1. Through the interaction of the MMC 14 with the conductive coil 13, various embodiments of this disclosure can eliminate the need for conventional molding compounds (e.g., plastics, epoxy compounds, etc.) and conventionally separately packaged cores of discrete inductors / magnetic devices, which occupy a large portion of the volume of conventional power converter modules. Therefore, according to various embodiments of this disclosure, on the one hand, due to the high permeability and other various properties of the MMC 14, and on the other hand, due to the design of the conductive coil 13, it is not necessary to provide a core (e.g., a ferrite core) in the conductive coil 13, which can advantageously help reduce the physical size of the integrated inductive energy storage device without reducing its energy storage capacity / efficiency. In other words, the conductive coil 13 according to various embodiments of this disclosure can be referred to as coreless (or iron-free). The integrated inductive energy storage device including an MMC 14 interacting with the conductive coil 13 according to various embodiments of this disclosure may be referred to as coreless (or coreless). On the other hand, when the conductive coil 13 is integrated into a package module, the placement of the conductive coil 13 can be more flexible. For example, in the examples of Figures 2A and 2B, the conductive coil 13 and the corresponding power switching unit 12 are shown placed side-by-side on a substrate 11 and laterally spaced from each other. The size of the package module 10 is reduced compared to conventional power converter modules, at least because the integrated inductive energy storage device replaces the conventional separately packaged discrete inductor / magnetic device. In yet another aspect, the MMC 14 can advantageously enhance inductance and reduce the direct current resistance (DCR) of the inductive energy storage device. On the other hand, since MMC 14 replaces the traditional molding compound to encapsulate the package module 10, this means that more space is saved for the inductive energy storage device in the package module 10 (i.e., the inductive energy storage device can occupy a larger proportion of the total volume of the package module 10). Therefore, a more complex structure can be used to reduce the power loss caused by the inductive energy storage device, thereby improving the power conversion efficiency of the package module 10. For example, the package module 10 can encapsulate a power management device 100. On the other hand, since the thermal conductivity of MMC 14 is much higher than that of traditional molding compounds (such as plastics, epoxy compounds, etc.), it can enhance the heat diffusion or heat dissipation of the internal components of the package module 10 (including but not limited to the power switching unit 12 and the conductive coil 13), thereby giving the package module 10 using MMC 14 encapsulation better heat dissipation performance.

[0031] Those skilled in the art will understand that although one power switch unit 12 and a corresponding conductive coil 13 are shown in the examples of Figures 2A and 2B, more power switch units 12 and corresponding conductive coils 13 can be formed in the package module 10.

[0032] The substrate 11 may include multiple conductive wiring structures 111. Some of the conductive wiring structures 111 may be used to provide interconnection or electrical coupling between the power switching unit 12 and the corresponding conductive coil 13, such that the power switching unit 12 can control the switching of energy storage and energy release in the inductive energy storage device including the corresponding conductive coil 13 and MMC 14 during operation. During energy storage, energy may be transferred to and stored in the inductive energy storage device (e.g., current will flow through the inductive energy storage device and the current may gradually increase). During energy release, energy may be released and transferred out of the inductive energy storage device (e.g., the current flowing through the inductive energy storage device may gradually decrease). Other conductive wiring structures 111 may be used to provide electrical coupling and / or electrical connections, thereby enabling electrical coupling and / or electrical connections and / or signal communication between components within the package module 10 (e.g., power switching unit 12, conductive coil 13, capacitive energy storage device 15, resistive device 16, or other components 17, etc.) and / or between components within the package module 10 and other external circuits or components outside the package module 10. The substrate 11 may have a single substrate layer, or alternatively, multiple substrate layers. A second surface 11D of the substrate 11, opposite the first surface 11U, may be configured as a pin side of the substrate 11, having multiple pins (indicated by solid black bars in the cross-sectional view of FIG. 2B; see, for example, pin 113) that connect nodes of the package module 10 to components outside the package module 10. In this embodiment, the pins may be solder pads or other means for electrically connecting nodes and components.

[0033] Figure 2C shows a top view of a package module 20 for power conversion according to an embodiment of the present invention. Figure 2D schematically shows a cross-sectional view of the package module 20 taken along section line A-A' in the top view of Figure 2C according to an embodiment of the present disclosure. Those skilled in the art will understand that the description of the package module 10 above with reference to Figures 2A and 2B largely applies to the package module 20 in the examples of Figures 2C and 2D. One difference is that in the package module 20, the conductive coil 13 can have a bridge shape, formed as a single-turn coil in the form of a conductive sheet wound along a predetermined direction (e.g., along the y-axis direction in the examples of Figures 2C and 2D), which is beneficial for further reducing the physical size and manufacturing cost of the packaged power module 20. It is readily understood that the conductive coil 13 forming the single-turn coil is not limited to a bridge shape, but can also be other suitable shapes, such as generally rectangular, generally semi-elliptical, etc., wound along a predetermined direction. For example, Figure 2E shows a conductive coil 13 comprising a single-turn coil wound in the form of a conductive sheet along a predetermined direction (e.g., along the y-axis in the example of Figure 2E), with a substantially rectangular shape. As another example, Figure 2F shows a conductive coil 13 comprising a single-turn coil wound in the form of a conductive sheet along a predetermined direction (e.g., along the y-axis in the example of Figure 2F), with a substantially semi-elliptical shape. On the other hand, the single-turn or single-coil form of the conductive coil 13 can have a lower DCR and is advantageous for supporting higher currents or higher power handling by the package module 20. The bottom surface of the body 13S of the conductive coil 13 and the bottom surfaces of the coil terminals (e.g., the first coil terminal 131 and the second coil terminal 132) are substantially flat, making it easier to mount the conductive coil 13 onto the substrate 11.

[0034] Figure 3A schematically shows a top view of a package module 30 for power conversion according to an embodiment of the present disclosure. Figure 3B schematically shows a cross-sectional view of the package module 30 taken along section line A-A' in the top view of Figure 3A according to an embodiment of the present disclosure. Those skilled in the art will understand that the above description of the package module 10 with reference to Figures 2A and 2B largely applies to the package module 30 in the examples of Figures 3A and 3B. One difference is that in the package module 30, the conductive coil 13 can be placed across the corresponding power switching unit 12 like a bridge. In the package module 30, the conductive coil 13 and the corresponding power switching unit 12 can be considered as arranged in a vertically stacked manner along the z-axis direction, but perpendicularly spaced from each other. In one embodiment, the conductive coil 13 in the package module 30 may have legs, for example, including a first leg 134 and a second leg 135, to connect the wound turns to coil terminals, such as a first coil terminal 131 and a second coil terminal 132, respectively. The first leg 134 and the second leg 135, etc., are integrally formed with the coil terminals and the winding turns of the conductive coil 13. In some embodiments, each coil terminal can be integrally connected to the coil terminal of the conductive coil 13 via a bent portion of the coil wire. The first leg 134 and the second leg 135, etc., also help support and vertically lift the body 13S of the conductive coil 13 to form a vertical space 13_V between the body 13S of the conductive coil 13 and the substrate 11, so that the corresponding power switching unit 12 can be placed in the vertical space 13_V. The packaging module 30 can advantageously further reduce the physical size, have higher package volume utilization efficiency, and higher integration density and / or power density.

[0035] Figure 3C shows a top view of a package module 40 for power conversion according to an embodiment of the present disclosure. Figure 3D schematically shows a cross-sectional view of the package module 40 taken along section line A-A' in the top view of Figure 3C according to an embodiment of the present disclosure. Those skilled in the art will understand that much of the description of the package module 30 above with reference to Figures 3A and 3B applies to the package module 40 in the examples of Figures 3C and 3D. One difference may be that in the package module 40, the conductive coil 13 can have a bridge shape, formed as a single-turn coil, placed above the corresponding power switching unit 12 like an overpass, which is beneficial for further reducing the physical size of the packaged power module 40.

[0036] Figure 4A schematically shows a top view of a package module 50 for power conversion according to an embodiment of the present disclosure. Figure 4B schematically shows a cross-sectional view of the package module 50 taken along section line A-A' in the top view of Figure 4A according to an embodiment of the present disclosure. Those skilled in the art will understand that the above description of the package module 30 with reference to Figures 3A and 3B largely applies to the package module 50 in the examples of Figures 4A and 4B. One difference is that in the package module 50, the conductive coil 13 can be spirally wound multiple turns along the z-axis direction (i.e., along the height of the package module) to form one or more coils of an inductive energy storage device, such as the inductive energy storage device 120 of the power management device 100. Although only one coil is shown in the examples of Figures 4A and 4B, it should be understood that more coils can be formed depending on the actual application requirements. In one embodiment, the conductive coil 13 and the corresponding power switching unit 12 can still be arranged in a vertically stacked manner along the z-axis dimension in the package module 50. In one embodiment, for example, the conductive coil 13 in the packaging module 50 can span the corresponding power switching unit 12 like an overpass, and can have a first leg 134 and a second leg 135 to connect the wound turns to the first coil terminal 131 and the second coil terminal 132, respectively. The first leg 134 and the second leg 135 can also help create a vertical space 13_V between the conductive coil 13 and the substrate 11, so that the corresponding power switching unit 12 can be placed in the vertical space 13_V.

[0037] Figure 4C schematically illustrates a cross-sectional view of the package module 50 taken along section line A-A' in the top view of Figure 4A according to an alternative embodiment of the present invention. In an alternative embodiment, for example, the power switching unit 12 may be disposed within a hollow space 13_M surrounded by the winding turns of the conductive coil 13 in the package module 50. That is, the conductive coil 13 in this embodiment may be placed around the corresponding power switching unit 12, for example, the winding turns of the conductive coil 13 surround the corresponding power switching unit 12. This can further contribute to improving package volume utilization efficiency, thereby further reducing the physical size of the package module 50 while increasing integration density and / or power density.

[0038] Figure 5A schematically shows a top view of a package module 60 for power conversion according to an embodiment of the present disclosure. Figure 5B schematically shows a cross-sectional view of the package module 60 taken along section line A-A' in the top view of Figure 5A according to an embodiment of the present disclosure. Figure 5C schematically shows a cross-sectional view of the package module 60 taken along section line A-A' in the top view of Figure 5A according to an alternative embodiment of the present disclosure. Those skilled in the art will understand that the above description of the package module 30 with reference to Figures 3A and 3B largely applies to the package module 60 in the examples of Figures 5A, 5B, and 5C. One difference may be that, as shown in the example of Figure 5B, a non-magnetic protective layer 41 may be formed to at least shield the back surface 12B of the power switching unit 12 in the package module 60, which is opposite to the top surface 12T of the power switching unit 12. Optionally, the non-magnetic protective layer 41 may be conformally formed on a substrate 11 and cover the components mounted on the substrate 11, as shown in the example of Figure 5C.

[0039] When each package module according to the various embodiments of this disclosure is in operation (e.g., when used in an application system), current flows through the conductive coil 13, and the inductive energy storage device including the conductive coil 13 and MMC 14 generates a certain amount of heat, which may affect the wafer junction temperature or operating wafer temperature of the power switching unit 12. For example, the heat generated by the inductive energy storage device may cause an undesirable additional increase in the wafer junction temperature of the power switching unit 12, thereby resulting in a decrease in the electrical performance of the power switching unit 12.

[0040] On the one hand, the non-magnetic protective layer 41 provides thermal isolation between the power switching unit 12 and the inductive energy storage device. On the other hand, the non-magnetic protective layer 41 can act as a buffer layer, providing thermal-mechanical compliance between the MMC 14 and the components molded therein to mitigate stress during environmental lifetime testing (e.g., temperature cycling, thermal shock, etc.), thereby improving the thermal-mechanical reliability of the packaged power module according to various examples of this disclosure. In one embodiment, the non-magnetic protective layer 41 may include a polymer layer comprising a polymer composition having high toughness and low thermal conductivity, and at least help reduce the impact of heat generated by the inductive energy storage device on the power switching unit 12. On the other hand, the MMC 14 contains magnetic metal particles 143, which may damage the semiconductor wafer (e.g., silicon wafer) of the power switching unit 12, and the non-magnetic protective layer 41 can help protect the power switching unit 12 from potential damage from the magnetic metal particles 143 in the MMC 14.

[0041] Those skilled in the art will understand that the non-magnetic protective layer 41 can be applied to other embodiments as described in this disclosure according to various examples (e.g., the examples described with reference to Figures 2A to 4C).

[0042] Figure 6A schematically shows a perspective top view of a package module 70 for power conversion according to an embodiment of the present disclosure. Figure 6B schematically shows a cross-sectional view of the package module 70 taken along section line A-A' in the perspective top view of Figure 6A according to an embodiment of the present disclosure. In the perspective top view shown in Figure 6A, the top surface of the conductive coating 51 is not shown so that relevant features of the package module 70 can be observed. Those skilled in the art will understand that the above description of the package module 60 with reference to Figures 5A and 5B largely applies to the package module 70 in the examples of Figures 6A and 6B. Compared with the package module 60 shown in the examples of Figures 5A and 5B, the package module 70 may also include a conductive coating 51 that covers and shields the outer surface of the MMC 14. The conductive coating 51 may be formed of a metal or metal alloy, such as copper, nickel, etc. The conductive coating 51 can help reduce the electromagnetic interference (EMI) of the package module 70 and enhance the heat dissipation and corrosion resistance of the package module 70.

[0043] Those skilled in the art will understand that the conductive coating 51 can be applied to other embodiments as described in the various examples in this disclosure.

[0044] Figure 7A schematically shows a perspective top view of a package module 80 for power conversion according to an embodiment of the present disclosure. Figure 7B schematically shows a cross-sectional view of the package module 80 taken along section line A-A' in the perspective top view of Figure 7A according to an embodiment of the present invention. Those skilled in the art will understand that the above description of the package module 30 with reference to Figures 3A and 3B largely applies to the package module 70 in the examples of Figures 7A and 7B. One difference may be that the power switching unit 12 can be embedded in the substrate 11 of the package module 80. Furthermore, structures for supporting the attachment of the power switching unit 12 to the substrate 11, such as conductive pillars / bumps 123, underfill material 122, and conductive wafer attachment material 124, can be omitted. By embedding the power switching unit 12 into the substrate 11, more space can be saved to form the MMC 14 and conductive coil 13 (thereby for forming an inductive energy storage device) and / or other components for placing power management devices (e.g., capacitive energy storage device 15, resistive device 16, or other components 17, etc.). With this configuration, the packaging module 80 can further improve the package volume utilization efficiency, further reduce the physical size, and increase the integration density and / or power density. In addition, it provides greater flexibility in designing the conductive coil 13, such as greater flexibility in the placement or mounting location of the conductive coil 13, the winding direction of the turns, and / or the shape of the winding turns.

[0045] For example, FIG7C schematically shows a three-dimensional perspective view of a package module 81 for power conversion according to an alternative embodiment of the present disclosure. In the three-dimensional perspective view of FIG7C, other components are not shown in detail except for the conductive coil 13 embedded in the MMC 14, so as not to obscure relevant features of the embodiment, but these components can be understood by referring to and in conjunction with the accompanying drawings of the embodiments already described above. FIG7D schematically shows a perspective side view of the package module 81 according to an embodiment of the present disclosure when viewed from the right side (as indicated by arrow 802) in the three-dimensional perspective view of FIG7C. FIG7E schematically shows a perspective top view of the package module 81 for power conversion according to an embodiment of the present disclosure.

[0046] Those skilled in the art will understand that the description of the package module 80 above with reference to Figures 7A and 7B largely applies to the package module 81 in the examples of Figures 7C to 7E. One difference may be that the conductive coil 13 in the package module 81 is exemplarily shown as comprising a multi-turn coil having turns wound along the y-axis direction (i.e., along the width direction of the package module 81). The space or volume 801 (refer to Figures 7C and 7D) surrounded by the coil of the conductive coil 13 is filled with an MMC 14. The MMC 14 also encloses the conductive coil 13 and any other components mounted to the substrate 11, as described in the examples above. By winding the conductive coil 13 along the y-axis direction (i.e., along the width direction of the package module 81) or the x-axis direction (i.e., along the length direction of the package module 81), the package module 81 and the MMC 14 can be conveniently packaged together via, for example, a pass molding process. It should be understood that in the examples of Figures 7C to 7E, the size of the space or volume 801 is related to the size of the conductive coil 13, which is one of the factors affecting the inductance of the inductive energy storage device. Embedding the power switching unit 12 in the substrate 11 and winding the conductive coil 13 along the y-axis direction (i.e., along the width direction of the package module) can advantageously increase the size of the space or volume 801 or the size of the conductive coil 13 under the condition of limited package module size, thereby helping to further increase the inductance of the inductive energy storage device and improve the efficiency of the package module under the condition of limited size.

[0047] Referring to Figures 7C and 7D, in some embodiments, the body 13S of the conductive coil 13 may not be perpendicularly spaced from the first surface 11U of the substrate 11. The bottom surface of the body 13S of the conductive coil 13 may be substantially flat, which facilitates mounting the conductive coil 13 onto the substrate 11, for example, by directly placing the body 13S on the first surface 11U of the substrate 11. The coil terminals are substantially coplanar with each other. Each coil terminal (e.g., the first coil terminal 131 and the second coil terminal 132 of each coil) is integrally formed as part of the flat portion of the winding turns of the conductive coil 13. In this case, legs such as the first leg 134 and the second leg 135 can be omitted. This will further advantageously reduce the size of the package module 81, particularly in terms of the z-axis dimension (i.e., height). This will also improve the mounting yield and efficiency of mounting the conductive coil 13 onto the substrate 11 using technologies such as surface mount technology (SMT), and further reduce the complexity and cost of manufacturing and production. This has been a long-standing problem because successfully and efficiently mounting the conductive coil 13 to meet the requirements of mass production has presented serious challenges in practice, as will be fully understood by those skilled in the art, as stated above and need not be repeated.

[0048] The conductive coil 13 is directly mounted on the substrate 11. Coil terminals (e.g., first coil terminal 131 and second coil terminal 132) are directly connected to corresponding pads (e.g., pads 112) on the first surface 11U of the substrate 11, for example, via a conductive attachment material 133 (e.g., solder paste). A thin insulating layer 136 covering the conductive coil 13 is peeled off at least at portions (e.g., on the bottom surface) of the coil terminals (e.g., the first coil terminal 131 and second coil terminal 132 in this embodiment), making the conductive coil 13 suitable for direct attachment to the substrate 11. Each coil terminal has an exposed area not covered by the thin insulating layer 136 and is configured to provide electrical connection / coupling, as can be better understood with reference to FIG. 7D. The exposed area of ​​each coil terminal can extend from the end edge P0 of each coil terminal, flexibly controlled to fall within a range from a minimum position P1 to a maximum position P2 on a flat portion integrally formed with each coil terminal. The minimum position P1 is designed based on the size of the corresponding solder pad (e.g., see solder pad 112) to which each coil terminal is to be attached, such that the exposed area of ​​each coil terminal is not less than that of the corresponding solder pad. For example, in one embodiment, the minimum position P1 is substantially located on the flat portion at a distance of 1 / 3 of the length LP from the end edge P0. The maximum position P2 is approximately located on the flat portion at a distance of the length LP from the end edge P0, i.e., the position just before the flat portion is bent to be rolled up. This approach helps to effectively control and prevent solder leakage during installation, which could lead to device damage or short circuits.

[0049] In some other embodiments, the body 13S of the conductive coil 13 may be perpendicularly spaced from the first surface 11U of the substrate 11, similar to the examples shown in Figures 7A and 7B. In the examples of Figures 7C to 7E, the conductive coil 13 is formed as a flat wire multi-turn coil. However, the conductive coil 13 may also be formed as a round wire multi-turn coil.

[0050] Referring to Figure 7E, in this example, a conductive coil 13 is mounted on the first surface 11U of the substrate 11, and a package module 81 is molded with an MMC 14. On the second surface 11D or pin side of the substrate 11, the package module 81 may include an input pin IN and a switch pin SW disposed on the first peripheral side of the package module 81. Output pins OUT (e.g., the two output pins shown in Figure 7E) are disposed on the second peripheral side opposite to the first peripheral side of the package module 81. The package module 81 may also include a bootstrap pin BST, an enable pin EN, a feedback pin FB, a signal ground pin AGND, a soft start pin SS, and a power good pin disposed on the third peripheral side of the package module 81. The package module 81 may also include an internal power output pin VCC and multiple (e.g., five) power ground pins PGND disposed on the fourth peripheral side opposite to the third peripheral side of the package module 81. The input pin IN can be configured to receive the input voltage VIN. The switch pin SW can be electrically connected to the power switch unit 12 and the conductive coil 13. The two output pins OUT are connected together inside the package module 81 and can be configured to provide the output voltage VOUT. The bootstrap pin BST can be configured with a capacitor connected between the switch pin SW and the bootstrap pin BST to form a floating power supply for, for example, a driver inside the package module 81. The enable pin EN can be configured to enable or disable the package module 81. The feedback pin FB can be configured to set the output voltage VOUT, for example, when connected to a tap of an external resistor divider connected between the output pin OUT and the power ground pin PGND. In the PCB layout, the signal ground pin AGND is electrically connected to the power ground pin PGND. The soft-start pin SS can be used to set the soft-start time of the package module 81 to avoid startup inrush current. The PG pin is an open-drain output that can be configured to provide fault protection information (such as undervoltage protection, overcurrent protection, overtemperature protection, or overvoltage conditions). Multiple (e.g., five) power ground pins PGND are electrically connected together inside the package module 81 and can be configured as a reference ground for the output voltage VOUT.

[0051] For example, FIG7F schematically shows a three-dimensional perspective view of a package module 82 for power conversion according to an alternative embodiment of the present disclosure. In the three-dimensional perspective view of FIG7F, other components are not shown in detail except for the conductive coil 13 embedded in the MMC 14, so as not to obscure the relevant features of the embodiment, but these components can be understood by referring to and in conjunction with the accompanying drawings of the embodiments already described above. FIG7G schematically shows an enlarged top view of the conductive coil 13 according to an embodiment. FIG7H and FIG7I schematically show enlarged perspective side views of the conductive coil 13 when viewed from the left side (as indicated by arrow 803) and the side opposite to the left side in the three-dimensional perspective view of FIG7F, respectively, according to an embodiment of the present disclosure. FIG7J and FIG7K schematically show enlarged perspective side views of the conductive coil 13 when viewed from the side opposite to the left side in the three-dimensional perspective view of FIG7F, respectively, according to an alternative embodiment of the present disclosure. FIG7L schematically shows a perspective top view of a package module 82 for power conversion according to an embodiment of the present disclosure.

[0052] Those skilled in the art will understand that the description of the package module 80 above with reference to Figures 7A and 7B largely applies to the package module 82 in the examples of Figures 7F to 7L. One difference may be that the conductive coil 13 in the package module 82 is exemplarily shown as comprising a multi-turn coil wound along the z-axis direction (i.e., along the height direction of the package module 82). The space or volume 804 (refer to Figures 7F to 7L) surrounded by the coil of the conductive coil 13 is filled with MMC 14. MMC 14 also encloses the conductive coil 13 and any other components mounted to the substrate 11, as described in the examples above. By winding the turns of the conductive coil 13 along the z-axis direction (i.e., along the height direction of the package module 82), the package module 82 and MMC 14 can be conveniently packaged together by, for example, a compression molding process.

[0053] Referring to FIG7F, in some embodiments, the body 13S of the conductive coil 13 may not be perpendicularly spaced from the first surface 11U of the substrate 11. The bottom side of the body 13S of the conductive coil 13 may be substantially directly disposed on the first surface 11U of the substrate 11. The initial winding (or bottom winding) 13B of the conductive coil 13, i.e., the winding that falls on the first surface 11U of the substrate 11, is generally planar, i.e., the initial winding 13B has good flatness when wound to facilitate the mounting of the conductive coil 13 onto the substrate 11. The coil terminals are substantially coplanar with each other. Each coil terminal (e.g., the first coil terminal 131 and the second coil terminal 132 of each coil) is integrally formed as part of the winding turn of the conductive coil 13 and extends outward from the winding turn beyond the body 13S on the xy plane (the width and length plane of the packaging module 82). In some embodiments, one or more coil terminals (e.g., second coil terminal 132) may be bent vertically downwards to achieve a plane substantially the same as the remaining coil terminals to enhance their coplanarity. This can be better understood with reference to the exemplary enlarged side views of Figures 7H to 7K, which show the second coil terminal 132 bent vertically downwards to achieve a plane substantially the same as the first coil terminal 131. In this case, legs such as the first leg 134 and the second leg 135 can be omitted. Advantageously, this will further reduce the size of the package module 82, particularly in the z-axis (i.e., height) dimension. This will also improve the mounting yield and efficiency of mounting the conductive coil 13 onto the substrate 11 using, for example, surface mount technology (SMT), and further reduce the complexity and cost of manufacturing and production. This is a problem that has long been desired to be solved, as successfully and efficiently mounting the conductive coil 13 to meet the requirements of mass production has presented significant challenges in practice for those skilled in the art, as stated above and will not be repeated here.

[0054] In some embodiments, the top side coil 13T (referring to the coil disposed on the top of the conductive coil 13) of the conductive coil 13 is also basically planar, that is, the top side coil 13T is wound to have good flatness, which can further facilitate the mounting of the conductive coil 13 onto the substrate 11, and in particular, make it easier to pick up the conductive coil 13.

[0055] The conductive coil 13 is directly mounted to the substrate 11. The coil terminals (e.g., first coil terminal 131 and second coil terminal 132) are directly connected to corresponding pads on the first surface 11U of the substrate 11, for example, via a conductive adhesion material 133 (e.g., solder paste). The thin insulating layer 136 covering the conductive coil 13 is peeled off at least at portions (e.g., the bottom surface) of the coil terminals (e.g., first coil terminal 131 and second coil terminal 132 in this embodiment), so that the conductive coil 13 can be adapted to be directly connected to the substrate 11. Each coil terminal has an exposed area not covered by the thin insulating layer 136 and is configured to provide electrical connection / coupling, which can be better understood with reference to FIG. 7I, where the peeled portion or exposed area is shown in light gray, and the remaining unpeeled portion (e.g., substantially including the body 13S) of the conductive coil 13 is shown in dark gray.

[0056] In some embodiments, the body 13S of the conductive coil 13 may include a multi-layered coil as seen in a plan view perpendicular to the coil winding direction. For example, in the examples of Figures 7F to 7L, the coil is wound as two layers, an inner layer 13S1 and an outer layer 13S2, when viewed from an xy-plane view in the z-axis direction perpendicular to the coil winding direction. This may become more apparent and easier to understand when referring to the enlarged top view of the conductive coil 13 exemplarily shown in Figure 7G. However, those skilled in the art will fully understand that this is merely exemplary and not intended to be limiting. In alternative examples, the number of coil turns may be wound in more than two layers, depending on the actual design and application requirements. Each layer in the multi-layered coil may include a plurality or a group of turns wound in a predetermined direction, such as the z-axis direction (i.e., along the height of the package module 82) in the examples of Figures 7F to 7L. Employing a multi-layered conductive coil 13 (e.g., 13S1, 13S2) can advantageously further increase the inductance of the inductive energy storage device, improving the efficiency of the package module within a limited size.

[0057] In some embodiments, the multiple layers (e.g., inner layer 13S1 and outer layer 13S2) are formed by winding / coiling a single coil wire, the winding / coiling starting from one end of the coil wire, the number of coil turns extending upwards to form the inner layer 13S1, and then extending downwards to form the outer layer 13S2, as shown in the examples of Figures 7H and 7I. In some alternative embodiments, the multiple layers (e.g., inner layer 13S1 and outer layer 13S2) are formed by winding / coiling a single coil wire, the winding / coiling starting simultaneously from both ends of the coil wire, the number of coil turns extending upwards from one end to form the inner layer 13S1, and the number of coil turns extending downwards from the other end to form the outer layer 13S2, as shown in the examples of Figures 7J and 7K.

[0058] In some alternative embodiments, each of the multiple layers can be made by winding / coiling a single coil wire and then connecting them to each other. For example, every two adjacent layers of the multiple layers of conductive coil 13 can be connected to each other by connection structure 13C (see exemplary illustration in FIG7G).

[0059] In some other embodiments, the body 13S of the conductive coil 13 may be perpendicularly spaced from the first surface 11U of the substrate 11, similar to the examples shown in Figures 7A and 7B. In the examples of Figures 7F to 7J, the conductive coil 13 is formed as a round wire multi-turn coil. However, the conductive coil 13 may also be formed as a flat wire multi-turn coil.

[0060] The description of the package module 81 now referring to FIG7L and FIG7E applies to the example package module 82 in FIG7L, and therefore will not be repeated here.

[0061] Those skilled in the art will understand that, for other embodiments of the present invention, such as those described with reference to FIG2A to FIG6B, the power switching unit 12 may also be embedded in the substrate 11, similar to the examples described with reference to FIG7A to FIG7L.

[0062] Figure 8A schematically shows a perspective top view of a package module 90 for power conversion according to an embodiment of the present invention. Figure 8B schematically shows a cross-sectional view of the package module 90 taken along section line A-A' in the perspective top view of Figure 8A according to an embodiment of the present invention. Those skilled in the art will understand that the above description of the package module 30 with reference to Figures 3A and 3B largely applies to the package module 90 in the examples of Figures 8A and 8B. In this example, the substrate 11 is exemplarily shown as comprising multiple substrate layers, for example, four substrate layers 115 to 118 are shown. One difference compared to the package module 30 is that, in the package module 90, an inductive energy storage device including a conductive coil 13 and an MMC 14 encapsulating the conductive coil 13 can be embedded in the substrate 11. For example, the conductive coil 13 and the MMC 14 can be formed in a second substrate layer 116 and a third substrate layer 117 sandwiched between a first substrate layer 115 and a fourth substrate layer 118. By embedding an inductive energy storage device, including a conductive coil 13 and an MMC 14, into the substrate 11, the package module 90 can further improve the package volume utilization efficiency, further reduce the physical size, and at the same time improve the integration density and / or power density.

[0063] Figure 8C schematically shows a perspective top view of a package module 91 for power conversion according to an embodiment of the present disclosure. Figure 8D schematically shows a cross-sectional view of the package module 91 taken along section line A-A' in the perspective top view of Figure 8C according to an embodiment of the present invention. Those skilled in the art will understand that the package module 91 can be considered an alternative embodiment of an inductive energy storage device including a conductive coil 13 and an MMC 14 embedded in a substrate 11; this example can be considered a variant of the package module 90. One difference from the package module 90 is that the conductive coil 13 in the package module 91 can be formed around the MMC 14. That is, the conductive coil 13 can be wound around the MMC 14 several times. In this example, the turns of the conductive coil 13 can be continuously wound on the MMC 14, thereby interconnecting each other.

[0064] Figure 8E schematically shows a perspective top view of a package module 92 for power conversion according to an embodiment of the present disclosure. Figure 8F schematically shows a cross-sectional view of the package module 92 taken along section line A-A' in the perspective top view of Figure 8E according to an embodiment of the present disclosure. Those skilled in the art will understand that the package module 92 can be considered as an alternative embodiment of an inductive energy storage device including a conductive coil 13 and an MMC 14 embedded in a substrate 11; for example, this example can be considered a variant of the package module 91. One difference from the package module 91 is that the conductive coil 13 in the package module 92 can be wound on the MMC 14 with a discontinuous number of turns. In this example, the turns of the conductive coil 13 can be connected together via coil connection portions 138.

[0065] Figure 8G schematically shows a perspective top view of a package module 94 for power conversion according to an embodiment of the present disclosure. Figure 8H schematically shows a cross-sectional view of the package module 94 taken along section line A-A' in the perspective top view of Figure 8G according to an embodiment of the present disclosure. Those skilled in the art will understand that the package module 94 can be considered as an alternative embodiment of an inductive energy storage device including a conductive coil 13 and an MMC 14 embedded in a substrate 11; for example, this example can be considered a variant of the package module 92. One difference from the package module 92 is that the discontinuously wound turns of the conductive coil 13 in the package module 94 can be connected together by a connection structure 139 similar to the conductive wiring structure 111 formed in the substrate 11. For example, in the example of Figure 8H, a connection structure 139 formed in the first substrate layer 115 is shown for connecting the turns of the conductive coil 13 together.

[0066] Figure 8I schematically shows a perspective top view of a package module 96 for power conversion according to an embodiment of the present disclosure. Figure 8J schematically shows a cross-sectional view of the package module 96 taken along section line A-A' in the perspective top view of Figure 8I according to an embodiment of the present disclosure. Those skilled in the art will understand that the package module 96 can be considered an alternative embodiment in which the power switching unit 12 and the inductive energy storage device (including the conductive coil 13 and MMC 14) are both embedded in the substrate 11; for example, this example can be considered a variant of the package module 92. One difference from the package module 92 is that the power switching unit 12 in the package module 96 can also be embedded in the substrate 11. For example, in the example shown in Figure 8J, the power switching unit 12 is shown embedded in a second substrate layer 116 of the substrate 11.

[0067] Compared to conventional power converter modules with substantially the same functionality and / or given specifications, the packaged modules according to various embodiments of the present disclosure can result in a 10% to 50% reduction in the physical size and / or footprint of the packaged module. This can improve the power conversion efficiency and current density of the packaged module. On the other hand, the cost of the packaged power modules according to various embodiments of the present disclosure can be lower than that of conventional power conversion modules.

[0068] For example, the packaged modules according to various embodiments of this disclosure can support operating currents from 1A to 4A (e.g., the load current provided at the output terminal OUT of the packaged module), and their physical dimensions are substantially in the range of width × length from 2mm × 2mm to 2mm × 3mm and height from 1.0mm to 1.5mm, or substantially in the range of width × length from 2mm × 2mm to 2mm × 2.2mm and height from 1.0mm to 1.2mm. Compared to conventional power converter modules supporting the same operating current range, their size is significantly reduced. Those skilled in the art will understand that the design of the physical dimensions of these packaged modules is crucial, and any reduction in size by even 0.1mm is a result of the inventive effort of the embodiments of this invention. For example, the packaged module 82 described with reference to Figures 7F to 7L can be configured to support operating currents from 1A to 4A, wherein the conductive coil 13 can be wound with circular coil wire with a diameter not greater than 0.3mm to form a generally cylindrical coil with a cylindrical diameter not greater than 1.6mm. According to various embodiments of this disclosure, the peak power conversion efficiency of the power conversion package module supporting operating currents from 1A to 4A can be higher than 88% or even higher than 90%. According to various embodiments of this disclosure, the integrated inductive energy storage device includes an MMC 14 and a conductive coil 13 integrated in the package module to support operating currents from 1A to 4A, with an inductance up to 2μH. This significantly reduces the DCR of the integrated inductive energy storage device, which is highly advantageous for low-current applications (e.g., below 4A).

[0069] For example, the packaged modules according to various embodiments of this disclosure can support operating currents from 4A to 10A (e.g., the load current provided at the output terminal OUT of the packaged module), with physical dimensions that are substantially in the range of width x length from 2mm x 3mm to 3mm x 4mm and height from 1.0mm to 2mm, or substantially in the range of width x length from 2mm x 3mm to 2mm x 4mm and height from 1.0mm to 1.5mm. This represents a significant reduction in size compared to conventional power converter modules supporting the same operating current range. For instance, the packaged module 81 described with reference to Figures 7C to 7E can be configured to support operating currents in the range of 4A to 10A, wherein the conductive coil 13 can be wound with flat coil wire having a wire thickness in the range of 0.03mm to 0.3mm and wound into a coil that is substantially cuboid in shape, with a height in the range of 0.85mm to 1.85mm. For example, the package module 82 described with reference to Figures 7F to 7L can be configured to support operating currents ranging from 4A to 10A. The conductive coil 13 can be wound with circular coil wire having a diameter no greater than 0.4mm to form a generally cylindrical coil with a cylindrical diameter ranging from 1.6mm to 2.6mm. Alternatively, the conductive coil 13 can be wound with circular coil wire having a diameter substantially 0.23mm ± 0.05mm to form a generally cylindrical coil with a cylindrical diameter ranging from 1.6mm to 1.8mm. Package modules for power conversion according to various embodiments of this disclosure support operating currents from 4A to 10A, and their peak power conversion efficiency can be higher than 88% or even higher than 90%. According to various embodiments of this disclosure, the integrated inductive energy storage device includes an MMC 14 and a conductive coil 13 integrated in a package module to support operating currents of 4A to 10A, with an inductance value up to 1μH. This facilitates a good balance between inductance value and DCR specifications, which is highly advantageous for medium current (e.g., 4A to 10A) applications.

[0070] For example, the packaged modules according to various embodiments of this disclosure can support operating currents from 6A to 20A (e.g., the load current provided at the output terminal OUT of the packaged module), with physical dimensions of approximately 2mm x 3mm to 5mm x 6mm (width x length) and approximately 1.2mm to 3mm (height), or approximately 2mm x 3mm to 4mm x 4mm (width x length) and approximately 1.2mm to 2.5mm (height). Compared to conventional power converter modules supporting the same operating current range, their size is significantly reduced. The power conversion packaged modules according to various embodiments of this disclosure support operating currents from 6A to 20A, and their peak power conversion efficiency can be higher than 85%, or even higher. The integrated inductive energy storage device, comprising an MMC 14 and a conductive coil 13, is integrated into the packaged modules according to various embodiments of this disclosure. It supports operating currents up to 20A and has an inductance value up to 1μH, which facilitates a good balance between inductance value and DCR specifications, which is particularly important for relatively high current (e.g., 6A to 20A) applications.

[0071] For example, Figure 8K shows a waveform graph of the power conversion efficiency versus the operating current (e.g., the load current provided at the output of the package module) of the package module according to an embodiment of the present disclosure. This embodiment tests or simulates the package modules shown in Figures 7F to 7L, with example parameters of VIN = 3.3V and VOUT = 1V. As can be seen from Figure 8K, the peak power conversion efficiency of this package module is higher than 88%, reaching a maximum of over 90%.

[0072] Figure 9 shows a process flow diagram of a method 900 for manufacturing a power conversion package module according to an embodiment of the present disclosure.

[0073] In step 901, a substrate panel suitable for large-scale or batch production of packaged module arrays according to various embodiments of the present disclosure can be prepared and provided. The substrate panel can be adapted to be individualized in subsequent manufacturing steps to form the substrate of each individual packaged module of the packaged module array to be manufactured (such as substrate 11 described above according to various embodiments). In some embodiments, various structures suitable for each packaged module (such as interconnect structures and / or conductive wiring structures 111) can be pre-formed or embedded in the substrate panel. In some embodiments, some elements suitable for each individual packaged module (such as power switching units 12 and / or inductive energy storage devices, etc.) can be pre-formed or embedded in the substrate panel. For example, for an embodiment in which power switching units 12 are embedded in substrate 11, an array of power switching units 12 and corresponding conductive wiring structures 111 can be pre-embedded in the substrate panel provided in step 901. As another example, for an embodiment in which inductive energy storage devices are embedded in substrate 11, such as the example structures of Figures 8A to 8J, an array of conductive coils 13 respectively packaged with MMC 14 and corresponding conductive wiring structures 111 can be pre-embedded in the substrate panel provided in step 901.

[0074] In step 902, a semiconductor wafer array is attached to a substrate. At least one power switch unit 12 can be fabricated within each semiconductor wafer in the array. For example, each semiconductor wafer having a power switch unit 12 can be attached to a substrate panel using a conductive wafer attachment material 124, wherein conductive pads 121 and / or conductive pillars / bumps 123 are formed on the top surface of the semiconductor wafer, with the top surface facing downwards towards the substrate panel. Those skilled in the art will understand that for embodiments where the power switch unit 12 is embedded in the substrate 11, the wafer mounting in step 902 can be omitted.

[0075] In step 903, other components of each individual package module to be manufactured (e.g., passive components including but not limited to capacitive energy storage device 15, resistive device 16, or other components 17, etc.) can be attached to the substrate panel.

[0076] In step 904, the underfill material 122 can be used to fill the cavity between the power switch unit 12 and the substrate panel to provide insulation and / or thermal-mechanical compliance. In one example, for each individual package module to be manufactured, an embodiment may also include a non-magnetic protective layer 41, and a conformal encapsulation process for covering or depositing the non-magnetic protective layer 41 on the component mounted on the substrate panel may optionally be performed in step 904.

[0077] In step 905, a conductive coil 13 corresponding to each semiconductor wafer in which at least one power switching unit 12 is manufactured can be attached to the substrate panel. The placement of the conductive coil 13 can be flexibly designed as illustrated in the examples described with reference to Figures 2A to 8B. Those skilled in the art will understand that for embodiments where an inductive energy storage device is embedded in the substrate 11, the attachment of the conductive coil 13 in step 905 can be omitted.

[0078] In step 906, a magnetic powder processing process for the magnetic metal particles 143 can be performed. During this process, the magnetic metal particles 143 are processed such that an insulating coating layer 144 coats and encapsulates each magnetic metal particle 143 to form a coated magnetic particle 142.

[0079] In step 907, the components of MMC 14 can be mixed to form a magnetic material mixture. The components may include non-magnetic material 141 and coated magnetic particles 142. In one embodiment, during this process, the coated magnetic particles 142 may be dispersed throughout the non-magnetic material 141, and the magnetic material mixture may be in a fluid or gel-like state. In other words, after the component processing in step 907, a fluid or gel-like composite magnetic material can be obtained.

[0080] In step 908, a drying process can be performed to dry the mixture of magnetic materials.

[0081] In steps 909 and 910, the dried magnetic material mixture may be pulverized or granulated to form a powdered or granular magnetic molding compound MMC 14 that is compatible with molding processes such as transfer molding or compression molding.

[0082] In step 911, a molding process may be performed to encapsulate the substrate panel and / or components to be molded using magnetic molding compound 14. Those skilled in the art will understand that the molding process or method is not limited to the examples given herein. Those skilled in the art will also understand that, for embodiments in which an inductive energy storage device is embedded in the substrate 11, the molding process may also be performed in step 901 of preparing the substrate panel.

[0083] In step 912, the demolding process is performed after the molding process.

[0084] In step 913, a post-curing process can be performed after the demolding process to fully cure MMC 14, thereby improving thermal stability and reducing moisture absorption.

[0085] In step 914, a marking process can be performed on the molded substrate panel.

[0086] In step 915, the tethered panel on which components are mounted and / or embedded can be individualized according to the markings made in step 914, and individualized packaged modules can be obtained according to various embodiments such as those described with reference to Figures 2A to 8K.

[0087] Figure 10 shows a process flow diagram of a method 1000 for manufacturing a power conversion package module according to an alternative embodiment of the present disclosure.

[0088] Steps 1001 to 1005 can correspond to steps 901 to 905 respectively. That is to say, the descriptions of steps 901 to 905 are applicable to steps 1001 to 1005 respectively, so they will not be repeated here.

[0089] Steps 1006 and 1007 can be correlated with steps 906 and 907, respectively. That is, the descriptions of steps 906 to 907 apply to steps 1006 to 1007, respectively, and will not be described in detail here.

[0090] In step 1008, a vacuum process may be performed to eliminate air bubbles in the magnetic material fluid mixture obtained in step 1007.

[0091] In step 1009, a molding process such as gel injection molding can be performed to fill or infuse a mixture of magnetic materials in a fluid or gel state, thereby using the composite magnetic material in fluid or gel form as the magnetic molding compound 14 and filling it into the encapsulation module according to various embodiments of the invention. Those skilled in the art will understand that, for embodiments in which an inductive energy storage device is embedded in the substrate 11, the molding process can be performed in step 1001 of preparing the substrate panel.

[0092] In steps 1010 and 1011, a vacuuming process and a shaking process are performed to eliminate air bubbles in the fluid or gel-like magnetic molding compound 14 and obtain a smooth top surface.

[0093] In steps 1012 and 1013, a curing process (e.g., a heat curing process) and a demolding process may be performed.

[0094] In step 1014, a marking process can be performed on the molded substrate panel.

[0095] In step 1015, the substrate panel on which the components are mounted and / or embedded can be divided according to the markings made in step 1014, and a segmented package module according to various embodiments such as those described with reference to Figures 2A to 8K can be obtained.

[0096] The methods for manufacturing power conversion package modules according to various embodiments of this disclosure can be implemented without requiring special equipment different from the equipment used to manufacture conventional power conversion modules, thereby saving a significant amount of effort and cost in process and assembly verification.

[0097] According to an exemplary embodiment, a composite magnetic material is further disclosed. In one embodiment, the composite magnetic material includes a composite nonmagnetic material (MA) and coated magnetic particles (MB) dispersed in the composite nonmagnetic material (MA). The coated magnetic particles (MB) may also be referred to as magnetic fillers dispersed in the composite nonmagnetic material (MA), and the composite nonmagnetic material (MA) may also be referred to as a nonmagnetic polymer matrix. In one embodiment, the composite magnetic material can provide a high relative permeability and a relatively low core loss. For example, according to some embodiments of this disclosure, the relative permeability of the composite magnetic material sample at a frequency not greater than 100 MHz may be not less than 16. As another example, the composite magnetic material sample according to some embodiments of this disclosure may have a low core loss of 15 kW / m³ to 60 kW / m³ at 5 mT, where mT represents the magnetic unit millitalas.

[0098] Therefore, the composite magnetic materials according to the embodiments of this disclosure can provide good relative permeability for applications requiring high energy / power efficiency, low power loss, and small size, such as data centers, cloud computing, artificial intelligence (AI), automated test equipment (ATE), medical, and industrial applications. These applications all require high integration or high power density, thus necessitating power supplies or power management devices with high power efficiency and small size, such as power modules / converter modules according to the embodiments of this disclosure. Furthermore, according to the various embodiments of this disclosure, composite magnetic materials in which coated magnetic particles (MB) are dispersed within a composite nonmagnetic material (MA) can improve their insulation resistance and / or withstand voltage. Therefore, when used as magnetic molding materials, they can be directly combined with other components (such as conductive coils like the conductive coil 13 described above) without complex insulation treatment. This simplifies the structure and reduces the size and cost of the encapsulation module, for example, the encapsulation module includes an energy storage device with conductive coils interacting with the composite magnetic material.

[0099] In some embodiments, referring to FIG11, a waveform diagram of the relative permeability μr of some samples of composite magnetic materials according to some embodiments of the present disclosure versus a switching frequency is shown. According to some embodiments, the composite magnetic material samples have a relative permeability of not less than 6.5 at frequencies substantially between 800 MHz and 1000 MHz. According to some embodiments, the composite magnetic material samples have a relative permeability of not less than 8 at frequencies substantially between 450 MHz and 750 MHz. According to some embodiments, the composite magnetic material samples have a relative permeability of not less than 10 at frequencies not exceeding 450 MHz. According to some embodiments, the composite magnetic material samples have a relative permeability of not less than 13 at frequencies not exceeding 200 MHz. According to some embodiments, the composite magnetic material samples have a relative permeability of not less than 16 at frequencies not exceeding 100 MHz.

[0100] Conversely, while conventional molding compounds (such as plastics, epoxy compounds, etc.) are non-magnetic, existing magnetic molding compounds cannot provide sufficient relative permeability for applications requiring high energy / power efficiency, low power loss, and small size (such as data centers, cloud computing, artificial intelligence (AI), automated test equipment (ATE), medical, and industrial applications). These applications all demand high integration or high power density, thus requiring power supplies or power management devices with high energy efficiency and small size, such as power modules / converter modules according to various embodiments of this disclosure. Existing magnetic molding compounds typically have a relative permeability of less than 10 at frequencies not exceeding 200 MHz and exhibit high core losses. Therefore, even when using existing magnetic molding compounds to mold coils, a core (e.g., a ferrite core) is required, which limits the increase in inductance of inductive components and the reduction in direct current resistance (DCR), especially in meeting the aforementioned application requirements, such as providing efficient inductive energy storage devices for power modules.

[0101] On the one hand, it is necessary to improve the relative permeability of existing magnetic molding compounds. On the other hand, it is necessary to further optimize the proportion and / or formulation of resin components to improve the performance and properties of existing magnetic molding compounds. Furthermore, it is necessary to improve the composition and / or concentration or proportion of magnetic metal particle fillers (such as iron, Fe) in existing magnetic molding compounds to obtain better or higher relative permeability and lower core losses. Moreover, while improving the relative permeability of existing magnetic molding compounds, it is desirable that other properties of the magnetic molding compounds are also improved or at least not reduced, such as thermal conductivity and / or resistivity and / or flowability and / or mechanical strength. In addition, the existing manufacturing processes of magnetic molding compounds and their integration with power module inductors need to be further improved to ensure consistency in quality, performance, and cost-effectiveness.

[0102] According to an exemplary embodiment of this disclosure, the coated magnetic particles (MB) of the composite magnetic material may include magnetic metal particles (MB1) and an insulating coating layer (MB2) surrounding or encapsulating the magnetic metal particles (MB1). In some embodiments, the insulating coating layer (MB2) comprises elements such as silicon (Si), carbon (C), and oxygen (O). In some embodiments, the insulating coating layer (MB2) comprises elements such as silicon (Si), carbon (C), and oxygen (O), as well as other elements such as sulfur (S). In some embodiments, the insulating coating layer (MB2) may include a polymer layer comprising molecules containing elements such as silicon (Si), carbon (C), and oxygen (O). In some embodiments, the insulating coating layer (MB2) may include a polymer layer comprising molecules containing elements such as silicon (Si), carbon (C), and oxygen (O), as well as other elements such as sulfur (S). Those skilled in the art will understand that "element" or "factor" here refers to a chemical element / factor. For example, the insulating overlay (MB2) may include a polymer comprising silane coupling agents, such as γ-aminopropyltriethoxysilane (KH550), whose chemical structure includes structural units represented by general formula (1); γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560), whose chemical structure includes structural units represented by general formula (2); γ-methacryloxypropyltrimethoxysilane (KH570), whose chemical structure includes structural units represented by general formula (3); or dopamine (DA), whose chemical structure includes structural units represented by general formula (4), etc. In some embodiments, the insulating overlay (MB2) may include only one silane coupling agent. In some embodiments, the insulating coating (MB2) may comprise two or more types of silane coupling agents. Those skilled in the art will understand that many known compounds can be used as the insulating coating (MB2) as long as they demonstrate the effects of the present invention, and this disclosure does not impose any particular limitation on this.

[0103] The insulating coating layer (MB2) can advantageously help eliminate or at least reduce the aggregation of coated magnetic particles (MB) and improve the uniformity of the distribution of coated magnetic particles (MB) within the composite nonmagnetic material (MA), which is beneficial for improving the relative permeability and resistivity of the composite magnetic material. The insulating coating layer (MB2) containing Si, C, and O can further help the magnetic filler connect to the composite nonmagnetic material (MA) through hydrogen bonds (e.g., bonds between H and O) to promote heat transfer, which is beneficial for improving the thermal conductivity of the composite magnetic material.

[0104] According to some embodiments, the composite magnetic material may include an insulating coating layer (MB2) of coated magnetic particles (MB) having a mass percentage (or weight percentage) substantially between 0.08% and 3.2% of the composite magnetic material. According to some embodiments, the insulating coating layer (MB2) of the coated magnetic particles (MB) may contain silicon (Si) element, with a mass percentage (or weight percentage) of silicon (Si) element between 0.52% and 2.93% of the composite magnetic material, and a predetermined tolerance range of ±20% is allowed. In other words, the amount of silicon (Si) contained in the molecules of the insulating coating layer (MB2) of the coated magnetic particles (MB), calculated as a mass percentage (or weight percentage), may be between 0.52% × (1 ± 20%) and 2.93% × (1 ± 20%) of the composite magnetic material. According to some embodiments, the insulating coating layer (MB2) of the coated magnetic particles (MB) may contain silicon (Si) element, with a mass percentage (or weight percentage) of 0.63% to 1.82% of the composite magnetic material, and an allowable predetermined tolerance range of ±20%. In other words, the amount of silicon (Si) contained in the molecules of the insulating coating layer (MB2) of the coated magnetic particles (MB), calculated by mass percentage (or weight percentage), may be from 0.63% × (1 ± 20%) to 1.82% × (1 ± 20%) of the composite magnetic material. According to some embodiments, the thickness of the insulating coating layer (MB2) may not exceed 1 µm. According to some embodiments, the thickness of the insulating coating layer (MB2) may not exceed 200 nm.

[0105] In one embodiment, the composite magnetic material includes coated magnetic particles (MB) comprising 68.3% to 99% of the composite magnetic material by mass percentage (or weight percentage). In one embodiment, each magnetic metal particle (MB1) may include other elements such as iron (Fe), silicon (Si), and / or aluminum (Al). In one embodiment, the coated magnetic particles (MB) may include iron (Fe) comprising at least 48% of the coated magnetic particles (MB) by mass percentage (or weight percentage). In one example, the iron (Fe) content in the coated magnetic particles (MB) accounts for 48.6% to 90.7% of the mass percentage of the coated magnetic particles (MB). In one embodiment, the iron (Fe) in the magnetic metal particles (MB1) accounts for at least 48% by mass (or weight percentage) of the magnetic metal particles (MB1). In one example, the magnetic metal particles (MB1) may include iron comprising 48.6% to 90.7% by mass percentage (or weight percentage) of the magnetic metal particles (MB1).

[0106] In one embodiment, the coated magnetic particles (MBs) may have non-uniform size and / or non-uniform or non-identical (i.e., various) shapes to reduce viscosity and improve the relative permeability of the composite magnetic material. In one embodiment, the coated magnetic particles (MBs) may be spherical, elliptical, or other particle shapes without sharp corners. In one embodiment, the size (e.g., median diameter) of the coated magnetic particles (MBs) may range from 0.3 µm to 54.8 µm. In one embodiment, the size (e.g., median diameter) of the coated magnetic particles (MBs) may range from 0.8 µm to 51.8 µm.

[0107] In one embodiment, the coated magnetic particles (MB) or magnetic filler may include large-sized particles with dimensions (e.g., median diameter) substantially between 33.6 µm and 54.8 µm, or in one example between 33.6 µm and 51.8 µm. In one embodiment, the coated magnetic particles (MB) or magnetic filler may further include small-sized and / or medium-sized particles. The dimensions (e.g., median diameter) of the small-sized particles are substantially between 0.3 µm and 8.6 µm, or in one example between 0.8 µm and 8.6 µm. The dimensions (e.g., median diameter) of the medium-sized particles are substantially between 8.7 µm and 33.4 µm.

[0108] In one embodiment, the coated magnetic particles (MB) may include large-sized particles, with a mass percentage (or weight percentage) of not less than 48.6% or approximately 48.6% to 79.3% based on the coated magnetic particles (MB). In one embodiment, the coated magnetic particles (MB) may include small-sized particles, with a mass percentage (or weight percentage) of not more than 28.7% or approximately 7.2% to 28.7% based on the coated magnetic particles (MB). In one embodiment, the coated magnetic particles (MB) may include medium-sized particles, with a mass percentage (or weight percentage) of not more than 38.4% or approximately 11.3% to 38.4% based on the coated magnetic particles (MB).

[0109] In one embodiment, the encapsulated magnetic particles (MBs) may include large-sized particles (e.g., with a median diameter substantially between 33.6 µm and 54.8 µm or between 33.6 µm and 51.8 µm), for example, when viewed in a cross-sectional view of the molded composite magnetic material, whose percentage of number is not less than 33.8% × (1 ± 20%) of the number of encapsulated magnetic particles (MBs), or whose percentage of number is between 33.8% and 76.3%, with a predetermined tolerance range of ±20%. In other words, for example, when viewed in a cross-section of the molded composite magnetic material, the percentage of number of large-sized particles contained in the encapsulated magnetic particles (MBs) may be not less than 33.8% × (1 ± 20%) of the number of encapsulated magnetic particles (MBs), or may be between 33.8% × (1 ± 20%) and 76.3% × (1 ± 20%).

[0110] In one embodiment, the coated magnetic particles (MBs) may include large-sized particles (e.g., with a median diameter of substantially 33.6 µm to 54.8 µm or 33.6 µm to 51.8 µm), for example, whose cross-sectional area percentage is not less than 48.6% of the total cross-sectional area of ​​the coated magnetic particles (MBs) when viewed from a cross-sectional view of the molded composite magnetic material, or whose cross-sectional area percentage is substantially 48.6% to 79.3% of the total cross-sectional area of ​​the coated magnetic particles (MBs).

[0111] In one embodiment, the coated magnetic particles (MB) may include small-sized particles (e.g., with a median diameter of substantially 0.3 µm to 8.6 µm or 0.8 µm to 8.6 µm) and medium-sized particles (e.g., with a median diameter of substantially 8.7 µm to 33.4 µm) comprising 22.3% to 62.2% of the total number of coated magnetic particles (MB), with a predetermined tolerance range of ±20%, for example, when viewed in a cross-section of the molded composite magnetic material. In other words, the percentage of small-sized and medium-sized particles contained in the coated magnetic particles (MB) may be 22.3% × (1 ± 20%) to 62.2% × (1 ± 20%) of the total number of coated magnetic particles (MB), for example, when viewed in a cross-sectional view of the molded composite magnetic material.

[0112] In one embodiment, the coated magnetic particles (MBs) may comprise small-sized particles (e.g., with a median diameter substantially from 0.3 µm to 8.6 µm or 0.8 µm to 8.6 µm), comprising no more than 34.6% of the total number of coated magnetic particles (MBs), for example, when viewed in a cross-sectional view of the molded composite magnetic material. In another embodiment, the coated magnetic particles (MBs) may comprise medium-sized particles (e.g., with a median diameter substantially from 8.7 µm to 33.4 µm), comprising no more than 34.6% of the total number of coated magnetic particles (MBs), for example, when viewed in a cross-sectional view of the molded composite magnetic material.

[0113] In one embodiment, the coated magnetic particles (MB) may comprise small-sized particles (e.g., with a median diameter of substantially 0.3 µm to 8.6 µm or 0.8 µm to 8.6 µm) whose cross-sectional area percentage does not exceed 28.7% or substantially 7.2% to 28.7% of the total cross-sectional area of ​​the coated magnetic particles (MB), for example when viewed from a cross-sectional view of a molded composite magnetic material.

[0114] In one embodiment, the coated magnetic particles (MB) may comprise medium-sized particles (e.g., with a median diameter of substantially 8.7 µm to 33.4 µm), for example, when viewed from a cross-sectional view of the molded composite magnetic material, having a cross-sectional area percentage of no more than 38.4% of the total cross-sectional area of ​​the coated magnetic particles (MB), or 11.3% to 38.4% of the total cross-sectional area of ​​the coated magnetic particles (MB).

[0115] In one embodiment, the coated magnetic particles (MB) may include particles with a median diameter not exceeding 20 µm, and the mass percentage or weight percentage of the coated magnetic particles (MB) does not exceed 40.8%, or the number percentage does not exceed 47.2%, or the cross-sectional area percentage of the coated magnetic particles (MB) does not exceed 40.8%, for example, when viewed from a cross-sectional view of the composite magnetic material.

[0116] By using coated magnetic particles (MBs) with multiple particle size ranges (i.e., large, small, and / or medium particle sizes), and by carefully designing and / or adjusting the content of small-size particles, and / or medium-size particles, and / or large-size particles according to embodiments of this disclosure, it is helpful to improve composite magnetic materials to achieve higher relative permeability while improving other properties or performance, such as fluidity and / or thermal conductivity, or at least without reducing or sacrificing other properties or performance of the composite magnetic material, such as fluidity and / or thermal conductivity. For example, according to some embodiments of this disclosure, the composite magnetic material has a thermal conductivity ranging from 1.6 W / mK to 4 W / mK, while having a sufficiently high relative permeability, for example, not less than 16 at frequencies not exceeding 100 MHz.

[0117] For example, in one embodiment, by designing the coated magnetic particles (MB) to contain a large number of particles with a median diameter substantially between 33.6 µm and 54.8 µm (or alternatively between 33.6 µm and 51.8 µm), for example, based on coated magnetic particles (MB) with a number percentage of not less than 33.8% × (1 ± 20%) (or alternatively not less than 37.8% × (1 ± 20%)), or a mass percentage or cross-sectional area percentage of not less than 48.6%, the relative permeability of the composite magnetic material can be improved without affecting its flowability. Conversely, using coated magnetic particles (MB) with a median diameter greater than 55 µm in the majority may impair the flowability of the composite magnetic material. Using coated magnetic particles (MB) containing a median diameter not exceeding 20 µm, with a mass percentage or cross-sectional area percentage greater than 40.8%, or a number percentage greater than 47.2%, may impair the relative permeability and thermal conductivity of the composite magnetic material.

[0118] On another front, for example, by cleverly designing and / or adjusting the median diameter to substantially 33.6 µm to 54.8 µm (or alternatively 33.6 µm to 51.8 µm), it is possible to further reduce the overall interface between the coated magnetic particles (MB) and the composite nonmagnetic material (MA), which is beneficial for improving the relative permeability and / or thermal conductivity of the composite magnetic material.

[0119] In another aspect, for example, in one embodiment, the coated magnetic particles (MB) are designed to contain small-sized particles (e.g., median diameter substantially from 0.3 µm to 8.6 µm or 0.8 µm to 8.6 µm) or medium-sized particles (e.g., median diameter substantially from 8.7 µm to 33.4 µm) or particles with a median diameter not exceeding 20 µm, the content of which does not exceed the respective values ​​as described above, and the number percentage, mass percentage or cross-sectional area percentage of the coated magnetic particles (MB) is not less than 10%, which helps to reduce viscosity and thus improve flowability without reducing the thermal conductivity and / or relative permeability of the composite magnetic material.

[0120] According to an exemplary embodiment, the composite nonmagnetic material (MA) or nonmagnetic polymer matrix (MA) may comprise a thermoset cross-linkable polymer resin (MA1), which may be in a cured or uncured state. In some embodiments, a sample of the composite nonmagnetic material (MA) or nonmagnetic polymer matrix (MA) may comprise an uncured form of the thermoset cross-linkable polymer resin (MA1) and a polymer curing agent (MA2). In some embodiments, a sample of the composite nonmagnetic material (MA) or nonmagnetic polymer matrix (MA) may comprise a cured form of the thermoset cross-linkable polymer resin (MA1) cured by the polymer curing agent (MA2).

[0121] According to an exemplary embodiment, the thermoset cross-linkable polymeric resin (MA1) may include a resin containing epoxy functional groups (A11) and a resin containing different functional groups (A12), which is different from the resin containing epoxy functional groups (A11). The resin containing epoxy functional groups may have a chemical structure comprising structural units represented by general formula (5).

[0122] In one embodiment, the epoxy-functionalized resin (A11) may include bisphenol-type epoxy resins, such as bisphenol A type resin having a chemical structure comprising a structural unit represented by general formula (6), bisphenol F type resin having a chemical structure comprising a structural unit represented by general formula (7), or biphenyl-type epoxy resin, etc., the above being merely an example. In one embodiment, the epoxy-functionalized resin (A11) may comprise only one type of epoxy resin, or it may comprise two or more types of epoxy resin. Those skilled in the art will understand that many known compounds can be used as epoxy-functionalized resins (A11) as long as the effects of this disclosure are achieved, and this disclosure does not limit this.

[0123] In one embodiment, the resin of different functional groups or units (A12) may contain one or more compounds selected from naphthalene, dicyclopentadiene, amino triazine, and ester. For example, in some embodiments, the chemical structure of naphthalene may contain structural units represented by general formula (8). In some embodiments, dicyclopentadiene may have a chemical structure containing structural units represented by general formula (9). In some embodiments, amino triazine may have a chemical structure containing structural units represented by general formula (10). In some embodiments, ester may have a chemical structure containing structural units represented by general formula (11).

[0124] According to an exemplary embodiment, the polymer curing agent (MA2) may include phenol, cresol, or amine groups. The polymer curing agent (MA2) facilitates the opening of the epoxy ring, thereby promoting the crosslinking reaction between the thermosetting crosslinked polymer resin (MA1) and the polymer curing agent (MA2).

[0125] In one embodiment, the mass ratio (or weight ratio) of the thermosetting crosslinked polymer resin (MA1) to the polymer curing agent (MA2) based on the composite magnetic material can be set between 0.99 and 3.72. By appropriately adjusting the mass ratio of the thermosetting crosslinked polymer resin (MA1) to the polymer curing agent (MA2) according to the embodiments of this disclosure, an improved crosslinking network can be formed between the thermosetting crosslinked polymer resin (MA1) and the polymer curing agent (MA2), which helps to improve mechanical strength and / or thermal stability, and / or the coefficient of thermal expansion (CTE) of the overall nonmagnetic composite material (MA), or in other words, the coefficient of thermal expansion (CTE) of the nonmagnetic polymer matrix (MA).

[0126] According to an exemplary embodiment, the composite nonmagnetic material (MA) or the nonmagnetic polymer matrix (MA) may further comprise other additives (MA3). For example, other additives selected from one or more materials such as catalysts, coupling agents, flame retardants, and releasing agents may be added to the composite nonmagnetic material (MA) according to application requirements to impart specific additional properties to the composite nonmagnetic material (MA). For example, other additives such as catalysts may be added to accelerate the reaction between the thermosetting crosslinked polymer resin (MA1) and the polymer curing agent (MA2). In one embodiment, one or more catalysts selected from imidazole, phosphate, and metal ion compounds may be added as additives to the composite nonmagnetic material (MA). The composite nonmagnetic material (MA) or the nonmagnetic polymer matrix (MA) does not contain silicon dioxide.

[0127] According to an exemplary embodiment, the composite magnetic material may further include a modulus reducing filler (MC) comprising modulus reducing particles. The modulus reducing filler (MC) or modulus reducing particles may be embedded or dispersed within the composite nonmagnetic material (MA), for example, in a substantially uniform manner. In one embodiment, the modulus reducing filler (MC) or modulus reducing particles may comprise fillers having -OH or -COOH functional groups. In some embodiments, the modulus reducing filler (MC) or modulus reducing particles may comprise rubber particles. For example, the modulus reducing particles or rubber particles may comprise structures having -OH or -COOH functional groups. The modulus reducing filler (MC) may react with an epoxy-functionalized resin (A11) in a thermosetting crosslinked polymer resin (MA1) to form a connection or bond between the modulus reducing particles (MC) and the composite nonmagnetic material (MA), for example, a connection or bond between the modulus reducing particles (MC) and the epoxy-functionalized resin (A11). Falling mass fillers (MCs) can form island-like structures within composite nonmagnetic materials (MA), as shown in Figure 12, which exemplarily illustrates a portion of a composite magnetic material containing island-like structures within the composite nonmagnetic material (MA). Therefore, falling mass fillers (MCs) help reduce the modulus of composite magnetic materials while maintaining sufficient mechanical strength. This helps eliminate or at least reduce the likelihood of cracking or delamination during molding, for example, when the composite magnetic material is used as a molding material, molding compound, or molding encapsulation material to manufacture or mold components, such as encapsulation modules manufactured according to various embodiments of this disclosure, and inductive components manufactured according to various embodiments of this disclosure.

[0128] In one embodiment, the composite magnetic material comprises falling film filler (MC) or falling film particles (MC) at a mass percentage (or weight percentage) of about 0.8% to 17.3% of the composite magnetic material. In one example, the composite magnetic material comprises falling film filler (MC) or falling film particles (MC) at a mass percentage (or weight percentage) of about 0.8% to 15.3% of the composite magnetic material.

[0129] By using magnetic fillers (e.g., coated magnetic particles (MB)) and falling film fillers (e.g., falling film particles (MC)), composite magnetic materials prepared according to various embodiments of the present disclosure can have high relative permeability, while possessing low modulus performance comparable to existing or conventional molded compounds (whether conventional non-magnetic or magnetic materials) and improved flowability.

[0130] In this disclosure, the term "non-magnetic polymer matrix" refers to the composite non-magnetic material (MA) in a composite magnetic material, whether it is in a cured or uncured state. In this disclosure, "resin" or "thermosetting crosslinked polymer resin (MA1)" may be in a cured or uncured state. When a polymer curing agent (MA2) is required to induce the curing of the resin (e.g., thermosetting crosslinked polymer resin), the term "resin" refers to the main component of the non-magnetic polymer matrix, excluding the polymer curing agent (MA2). In other words, "non-magnetic polymer matrix" refers to a composite non-magnetic material (MA) containing a thermosetting crosslinked polymer resin (MA1), which may be in a cured or uncured state. The polymer curing agent (MA2) may be added to the thermosetting crosslinked polymer resin (MA1) before or after the addition of magnetic filler (MB) and / or other additives (MA3) and / or falling film filler (MC).

[0131] According to one embodiment of this disclosure, the composite magnetic material described with reference to exemplary embodiments can be used to implement the MMC 14 mentioned or described in various embodiments of this disclosure. For example, the packaging module of various embodiments shown in Figures 2A to 8K may include the MMC 14, which may be implemented using the composite magnetic material described in various embodiments of this disclosure.

[0132] For example, in an exemplary embodiment of the method for manufacturing a power conversion packaging module as shown in FIG9 or FIG10, the MMC 14 may be implemented using the composite magnetic material described in various embodiments of this disclosure. In this case, those skilled in the art will readily understand that the detailed description of the method for manufacturing the packaging module shown in FIG9 or FIG10 still applies when implementing the MMC 14 using the composite magnetic material described in various embodiments of this disclosure. The following explanations only cover certain steps to aid better understanding. Even without these explanations, those skilled in the art can readily understand the method for manufacturing the packaging module when implementing the MMC 14 using the composite magnetic material described in various embodiments of this disclosure by referring to FIG9 or FIG10.

[0133] In step 906 or 1006, a magnetic particle processing procedure may be performed. During this process, the magnetic metal particle 143 may be implemented as a magnetic metal particle (MB1), and the insulating coating layer 144 may be implemented as an insulating coating layer (MB2), thus forming a coated magnetic particle 142 that includes the coated magnetic particle (MB) in this example. In one embodiment, the magnetic particle processing procedure may include a coating process, i.e., coating and encapsulating each magnetic metal particle (MB1) with the coating layer of the insulating coating layer (MB2) to form a coated magnetic particle (MB). In one embodiment, the coating process may use a polymer, for example, containing elements such as Si, C, and O, to surface treat the magnetic metal particle (MB1) to form an insulating coating layer (MB2) that encapsulates each magnetic metal particle (MB1). In one embodiment, the coating process may use a polymer, for example, containing silane coupling agents, to surface treat the magnetic metal particle (MB1) to form an insulating coating layer (MB2) that encapsulates each magnetic metal particle (MB1). For more details on the insulating coating layer (MB2) formed during the processing of magnetic particles, please refer to the above description related to composite magnetic materials, which will not be repeated here.

[0134] In step 907 or 1007, a raw material processing procedure may be performed. For example, raw materials suitable for preparing or using as a composite magnetic material in MMC 14 may be mixed to form a magnetic material mixture. The raw materials may include a composite nonmagnetic material (MA) that can be used as a nonmagnetic material 141, and coated magnetic particles (MB) that can be used as coated magnetic particles 142. In an exemplary embodiment, the raw materials may also include falling film filler (MC). During this process, the coated magnetic particles (MB) or coated magnetic particles 142 may be dispersed in the composite nonmagnetic material (MA) or nonmagnetic material 141. The magnetic material mixture may be in a fluid or gel state. In other words, after the component processing procedure of 907 or 1007, a fluid or gel-like composite magnetic material can be obtained.

[0135] In step 909, the dried mixture of magnetic materials can be pulverized. After the pulverization process is completed, a powdered composite magnetic material is obtained. This powdered composite magnetic material can be used as a powdered magnetic molding compound (MMC) compatible with molding processes such as compression molding.

[0136] In one embodiment, step 910 may optionally be performed after step 909. In step 910, a granulation process may be performed to further granulate the powdered composite magnetic material (e.g., to form granules, such as small or micro cylindrical, spherical, or elliptical shapes), thereby forming a granular composite magnetic material. The granulated composite magnetic material obtained through the granulation process can be used as a granulated magnetic molding compound 14 (MMC) compatible with molding processes such as transfer molding.

[0137] In step 911, a composite magnetic material can be used as a molding material in a molding process (e.g., to achieve magnetic molding compound 14), for example, to wrap or cover components that need to be molded (e.g., components attached / mounted to a substrate panel in some embodiments, such as conductive coil 13, power switch unit 12, and other components). This composite magnetic material can directly replace conventional molding compounds in the molding process. For example, the powdered composite magnetic material obtained in step 909 is suitable as magnetic molding compound 14 and directly replaces conventional molding compounds in compression molding. The granular composite magnetic material obtained in step 910 is suitable as magnetic molding compound 14 and directly replaces conventional molding compounds in transfer molding.

[0138] In some embodiments, after the raw material processing in step 1007, the magnetic material mixture in a fluid or gel state, or the composite magnetic material in a fluid or gel state, can be adapted to realize or be used as a fluid or gel-like magnetic molding compound 14 (MMC) compatible with molding processes such as gel casting molding. Therefore, in step 1009, a molding process such as gel casting molding can be performed to fill or infuse the magnetic material mixture in a fluid or gel state, such that the composite magnetic material in a fluid or gel state serves as the magnetic molding compound 14, and is filled into the packaging module according to various embodiments of the invention.

[0139] Those skilled in the art will understand that the molding process or method is by no means limited to the examples given herein. They will also understand that, for embodiments in which an inductive energy storage device is embedded in the substrate 11, the molding process may also be performed in step 901 or 1001 of preparing the substrate panel.

[0140] According to some embodiments of this disclosure, the composite magnetic material described in various embodiments can be used to manufacture or form inductive elements, including but not limited to discrete inductive components or integrated inductive components. For example, an integrated inductive component as described in various embodiments of this disclosure, such as an inductive energy storage device 120 including a conductive coil 13 and an MMC 14, can be formed by using a composite magnetic material for the MMC 14. Another example is that discrete inductive elements, such as molded inductors or molded transformers, can be fabricated, wherein the conductive coil is encapsulated or molded in a composite magnetic material. Those skilled in the art will understand that the examples herein are not intended to be limiting. According to various embodiments of this disclosure, the composite magnetic material can be used to manufacture any other components that require magnetism and that require the properties or performance of the composite magnetic material as described above.

[0141] According to some embodiments of this disclosure, composite magnetic materials can be used as molding materials in the manufacturing process of electronic devices, apparatuses, components, etc., such as powder molding materials suitable for or compatible with compression molding processes, granular molding materials suitable for or compatible with transfer molding processes, or paste or gel molding materials suitable for or compatible with gel casting molding processes.

[0142] In some embodiments, the method of forming a magnetic molding compound (e.g., in a fluid or gel form) may include providing or forming a magnetic filler comprising coated magnetic particles (MBs), for example, steps 906 or 1006 as described in the relevant paragraphs above with reference to FIG9 or FIG10, which need not be repeated here. The method of forming a magnetic molding compound (e.g., in a gel form) may also include mixing raw materials of a composite magnetic material through a raw material processing process to form a composite magnetic material in a fluid or gel form, for example, steps 907 or 1007 as described in the relevant paragraphs above with reference to FIG9 or FIG10, which will not be elaborated here.

[0143] In some embodiments, a molding method using the composite magnetic material described in the various embodiments of this disclosure may include: providing or preparing a magnetic molding material (e.g., in gel form), which can be obtained by the method for preparing magnetic molding materials described in this disclosure, and using the composite magnetic material (e.g., in gel form) as a molding material to perform a molding process, for example including step 1009 as described with reference to FIG10 in the relevant paragraphs above, which will not be repeated here. A vacuum treatment process as described in step 1008 may be performed prior to the molding process.

[0144] In some embodiments, a method for preparing a magnetic molding material (e.g., in powder form) may include: providing or preparing a magnetic filler comprising coated magnetic particles (MB), for example including step 906; forming a composite magnetic material (e.g., fluid or gel) through a raw material processing process, for example including step 907; a drying process, for example as described in step 908; and a pulverizing process to form a powdered composite magnetic material, for example including step 909; as described in the relevant paragraphs above in conjunction with Figure 9, further details are omitted here.

[0145] In some embodiments, a molding method using the composite magnetic material involved in the various embodiments described in this disclosure may include: providing or preparing a magnetic molding material (e.g., in powder form), which can be obtained by the method for preparing magnetic molding materials described in this disclosure; and using the composite magnetic material (e.g., in powder form) as a molding material to perform a molding process, such as including step 911 as described with reference to FIG9 in the relevant paragraph above, which will not be repeated here.

[0146] In some embodiments, a method for preparing a magnetic molding material (e.g., granular) may include: providing or preparing a magnetic filler comprising coated magnetic particles (MB), for example, step 906; preparing a composite magnetic material (e.g., fluid or gel) through a raw material processing process, for example, step 907; a drying process, for example, as described in step 908; a pulverizing process to form a powdered composite magnetic material, for example, step 909; and a granulation process to convert the powdered composite magnetic material into a granular composite magnetic material, for example, step 910; as described in the relevant paragraphs above in conjunction with Figure 9, further details are omitted here.

[0147] In some embodiments, a molding method using the composite magnetic material in the various embodiments described in this disclosure may include: providing or preparing a magnetic molding material (e.g., in particulate form), which can be obtained by the method for preparing magnetic molding materials described in this disclosure; and using the composite magnetic material (e.g., in particulate form) as a molding material to perform a molding process, such as including step 911 as described with reference to FIG9 in the relevant paragraphs above, which will not be repeated here.

[0148] The advantages of the various embodiments of the present invention are not limited to those described above. These and other advantages of the various embodiments of the present invention will become clearer by reading the detailed description of the invention and studying the various illustrations in the accompanying drawings.

[0149] As can be seen from the foregoing, some specific embodiments of the present invention have been described herein for illustrative purposes, but various modifications can be made without departing from the technology involved in the present invention. Many elements in one embodiment can be used in combination with elements in other embodiments, or can replace elements in other embodiments.

[0150] 10: Packaging Module 11:Substrate 12: Power Switching Unit 13: Conductive coil 14: Magnetic Molding Compound (MMC) 15: Capacitive energy storage devices 16: Resistive devices 17: Other components 20: Packaging Module 30: Packaging Module 40: Packaging Module 41: Non-magnetic protective layer 50: Packaging Module 51: Conductive coating 60: Packaging Module 70: Packaging Module 80: Packaging Module 81: Packaging Module 82: Packaging Module 90: Packaging Module 91: Packaging Module 92: Packaging Module 94: Packaging Module 96: Packaging Module 100: Power Management Device 110: Power Switching Unit 111: Conductive wiring structure 112: Solder pad 113: Foot Connection 115: Substrate layer / First substrate layer 116: Substrate layer / Second substrate layer 117: Substrate layer / Third substrate layer 118: Substrate layer / Fourth substrate layer 120: Inductive energy storage device 121: Conductive solder pad 122: Bottom filling material 123: Conductive pillars / bumps 124: Conductive wafer attachment material 130: Power Conversion Topology 131: First coil terminal 132: Second coil terminal 133: Conductive adhesion materials 134: First leg 135: Second leg 136: Thin insulating layer 138: Coil connection part 139: Connection Structure 140: Control Unit 141: Non-magnetic materials 142: Coated magnetic metal particles 143: Magnetic metal particles 144: Insulation coating layer 150: Capacitive energy storage unit 160: Driver 801: Space or volume 802: Arrow 803: Arrow 804: Space or volume 900: Method 901: Steps 902: Steps 903: Steps 904: Steps 905: Steps 906: Steps 907: Steps 908: Steps 909: Steps 910: Steps 911: Steps 912: Steps 913: Steps 914: Steps 915: Steps 1000: Method 1001: Steps 1002: Steps 1003: Steps 1004: Steps 1005: Steps 1006: Steps 1007: Steps 1008: Steps 1009: Steps 1010: Steps 1011: Steps 1012: Steps 1013: Steps 1014: Steps 1015: Steps 11D: Second Surface 11U: First Surface 12B: Back 12T: Top surface 13B: Initial winding coil 13C: Connection Structure 13S: Main Body 13S1: Inner layer 13S2: Outer layer 13T: Top Side Line Turn 13_V: Vertical Space 13_M: Hollow Space IN: Input terminal / Input pin OUT: Output terminal / output pin VIN: Input voltage CTRL: Control Signal Ton: On-time Toff: Shutdown time Top: Working cycle / Switching cycle VOUT: Output voltage Io: Output current SW: Switch pin BST: Self-supporting foot EN: Enabling connector FB: Feedback and support AGND: Signal ground pin SS: Soft start pin PG:PG foot VCC: Internal power output pin PGND: Power ground pin P0: End edge P1: Minimum position P2: Maximum position LP: Length

Claims

1. A composite magnetic material, comprising: A composite nonmagnetic material (MA); and a magnetic filler comprising coated magnetic particles (MB) dispersed in the composite nonmagnetic material (MA); wherein the coated magnetic particles (MB) comprise magnetic metal particles (MB1) with the surface coated with the insulating coating layer (MB2); the sample of the composite magnetic material has a relative permeability of not less than 13 at a frequency not exceeding 200 MHz, or a relative permeability of not less than 16 at a frequency not exceeding 100 MHz; wherein the coated magnetic particles (MB) have non-uniform size and / or non-uniform shape, or the median diameter of the coated magnetic particles (MB) is in the range of 0.3 µm to 54.8 µm.

2. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) include large-sized particles with a median diameter ranging from 33.6 µm to 54.8 µm.

3. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) include small-sized particles with a median diameter ranging from 0.3 µm to 8.6 µm, and / or medium-sized particles with a median diameter ranging from 8.7 µm to 33.4 µm.

4. The composite magnetic material according to claim 1, wherein the sample of the composite magnetic material has a relative permeability of not less than 6.5 in the frequency range of 800 MHz to 1000 MHz, or a relative permeability of not less than 8 in the frequency range of 450 MHz to 750 MHz, or a relative permeability of not less than 10 in the frequency range not exceeding 450 MHz.

5. The composite magnetic material according to claim 1, wherein, The sample of this composite magnetic material has low core loss, which is substantially between 15 kW / m³ and 60 kW / m³ at 5 mT.

6. The composite magnetic material according to claim 1, wherein, The mass percentage of the coated magnetic particles (MB) in the composite magnetic material is between 68.3% and 99%.

7. The composite magnetic material according to claim 1, wherein, Each of the magnetic metal particles (MB1) comprises iron (Fe) and silicon (Si), or comprises iron (Fe) in a mass percentage of 48.6% to 90.7%.

8. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) include particles with a median diameter not exceeding 20 µm, whose mass percentage or cross-sectional area percentage does not exceed 40.8%, or whose number percentage does not exceed 47.2%.

9. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) include large-sized particles with a median diameter ranging from 33.6µm to 54.8µm, comprising a number percentage of not less than 33.8% × (1 ± 20%), or a number percentage between 33.8% and 76.3% with a predetermined tolerance range of ± 20%, or a cross-sectional area percentage of not less than 48.6%, or a cross-sectional area percentage between 48.6% and 79.3%, or a mass percentage of not less than 48.6%, or a mass percentage between 48.6% and 79.3%.

10. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) comprise small particles with a median diameter ranging from 0.3µm to 8.6µm, comprising no more than 34.6% of the number of particles, no more than 28.7% of the cross-sectional area of ​​particles, or between 7.2% and 28.7% of the cross-sectional area of ​​particles, or no more than 28.7% of the mass of particles, or between 7.2% and 28.7% of the mass of particles.

11. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) comprise medium-sized particles with a median diameter ranging from 8.7 µm to 33.4 µm, comprising no more than 34.6% of the number, no more than 38.4% of the cross-sectional area, or between 11.3% and 38.4% of the cross-sectional area, or no more than 38.4% of the mass, or between 11.3% and 38.4% of the mass.

12. The composite magnetic material according to claim 1, wherein, The coated magnetic particles (MB) comprise small particles with a median diameter between 0.3µm and 8.6µm and medium particles with a median diameter between 8.7µm and 33.4µm, comprising a percentage between 22.3% and 62.2%, with a predetermined tolerance range of ±20%.

13. The composite magnetic material according to claim 1, wherein, The thermal conductivity of the composite magnetic material samples ranges from 1.6 W / mK to 4 W / mK.

14. The composite magnetic material according to claim 1, wherein, The insulating cladding layer (MB2) contains silicon (Si), carbon (C) and oxygen (O) elements.

15. The composite magnetic material according to claim 1, wherein, The content of element Si in the insulating cladding layer (MB2) is measured as a mass percentage in the composite magnetic material and is between 0.52% and 2.93%, with a predetermined tolerance range of ±20%.

16. The composite magnetic material according to claim 1, wherein, The insulating overlay (MB2) comprises a polymer layer containing a silane coupling agent, or comprises one or more types of silane coupling agents selected from KH550, KH560, KH570 and DA.

17. The composite magnetic material according to claim 1, wherein, The thickness of the insulating covering layer (MB2) is no greater than 1µm or no greater than 200nm.

18. The composite magnetic material according to claim 1, wherein, The composite nonmagnetic material (MA) includes thermosetting cross-linked polymer resin (MA1) in cured or uncured form.

19. The composite magnetic material according to claim 18, wherein, The thermosetting cross-linked polymer resin (MA1) is in an uncured state, and the composite non-magnetic material (MA) also includes a polymer curing agent (MA2).

20. The composite magnetic material according to claim 1, wherein, The composite nonmagnetic material (MA) includes an epoxy functional group-containing resin (A11).

21. The composite magnetic material according to claim 20, wherein, The composite nonmagnetic material (MA) further includes a resin (A12) containing different functional groups, which is different from the epoxy functional group-containing resin (A11).

22. The composite magnetic material according to claim 1 further comprises: Falling film mass fillers (MC) include falling film mass particles or rubber particles, or fillers having -OH or -COOH functional groups.

23. The composite magnetic material according to claim 22, wherein, The composite nonmagnetic material (MA) forms a connection with the falling film filler (MC), the falling film particles, or the rubber particles.

24. The composite magnetic material according to claim 22, wherein, The falling film filler (MC), the falling film particles, or the rubber particles form an island-like structure within the composite nonmagnetic material (MA).

25. The composite magnetic material according to claim 22, wherein, The composite magnetic material contains 0.8% to 17.3% by mass of the falling film filler (MC).

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