A dual inductor co-fired with copper and iron

Abstract

This invention discloses a copper-iron co-fired dual inductor, which is formed by combining a pre-formed magnetic core and two U-shaped coils. The pre-formed magnetic core is a king-shaped block with four notched slots, formed by cold pressing with powder in a single process. The two U-shaped coils are inserted and assembled parallel and spaced apart on the pre-formed magnetic core, with their bottom ends coplanar, to form an initial assembly. A secondary powder filling process using a molding die completely encapsulates the U-shaped coils, followed by high-pressure forming and high-temperature sintering to integrally encapsulate them with the pre-formed magnetic core. The ends of the two U-shaped coils are formed into four electrode pads at the bottom of the resulting package. This copper-iron co-fired dual inductor, by optimizing the pre-formed shape and combined packaging structure of the two magnetic cores and coils, achieves the integration of two inductors into a single device, effectively saving space on the PCB. It also increases the inductor charge while simultaneously reducing inductor iron losses, which is beneficial for improving the conversion efficiency of DC-DC converter circuits and promoting hardware performance development in multiple application scenarios.

Description

Technical Field

[0001] This utility model relates to an inductor device, and more particularly to a dual inductor that improves the inductance permeability and inductance value, belonging to the technical field of basic electronic components. Background Technology

[0002] Inductors are one of the most commonly used components in electronic devices, widely used in various circuits to perform functions such as filtering, energy storage, matching, and resonance. With the increasing miniaturization and portability of electronic products, and the high-density assembly of components, inductor components have developed rapidly. Furthermore, considering electromagnetic compatibility, the ability of electronic products to resist electromagnetic interference has become a basic design requirement, thus increasing the demand for and application of inductors.

[0003] Currently, DC-DC converter buck circuits are widely used in the hardware assembly of many devices. However, the large number of components and space occupied in high-density PCBs have limited the circuit design and miniaturization of functional components. In particular, the magnetic core, as a component of the inductor, is prone to iron loss, resulting in insufficient inductance in the finished product. Therefore, improving the conversion efficiency of the above circuits and enhancing the performance of dual inductors has become a pressing technical challenge for the industry. Summary of the Invention

[0004] The purpose of this invention is to propose a copper-iron co-fired dual inductor, which aims to increase the inductance of the inductor and reduce its iron loss.

[0005] The technical solution of this utility model to achieve the above-mentioned objective is: a copper-iron co-fired dual inductor, which is formed by combining a pre-formed magnetic core and two U-shaped coils. The pre-formed magnetic core is a king-shaped block with four notched slots, formed by cold pressing with powder in one step. The two U-shaped coils are inserted and assembled on the pre-formed magnetic core in parallel and spaced apart, with their bottom ends coplanar, to form an initial assembly. The U-shaped coils are completely wrapped with powder by a secondary filling of the molding mold and then encapsulated with the pre-formed magnetic core by high-pressure molding and high-temperature sintering. The ends of the two U-shaped coils are formed into four electrode pads at the bottom of the resulting encapsulation. Furthermore, the bottom surface of the inner cavity of the molding die is provided with a cross-shaped boss, and the projection of each notch on the bottom of the preformed magnetic core is located in one of the four raised areas around the cross-shaped groove formed on the bottom surface of the preformed magnetic core.

[0006] Furthermore, the outer contour of the package largely overlaps with the outer contour of the preformed magnetic core, and the recessed portion of the notch groove is filled in the secondary powder filling state.

[0007] Furthermore, the U-shaped coil is formed by cutting and continuously bending copper strip, and the ends of the U-shaped coil are ground into rounded corners to fit the bottom surface of the pre-formed magnetic core.

[0008] Furthermore, the surface of the package is covered with a fully insulating varnish, and the varnish is partially peeled off at the bottom of the package, and the exposed end portion of the U-shaped coil is electroplated to form an electrode pad.

[0009] Compared with existing technologies, the advantages of this copper-iron co-fired dual inductor are as follows: by optimizing the prefabricated shape and combined packaging structure of the two magnetic cores and coils, the dual inductors are integrated into the same device, effectively saving space on the PCB; and the initial permeability of the inductor powder can be effectively utilized, increasing the inductor charge and simultaneously reducing the inductor iron loss, which is conducive to improving the conversion efficiency of DC-DC converter circuits and promoting the development of hardware performance in application scenarios such as AI servers / data centers / HPC / supercomputing centers. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the finished structure of the copper-iron co-fired dual inductor of this utility model.

[0011] Figure 2 This is a schematic diagram showing the evolution of the external shape of the preferred embodiment of the copper-iron co-fired dual inductor of this utility model. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0013] This invention proposes a copper-iron co-fired dual inductor, which increases the inductance of the inductor and reduces its iron loss. For example... Figures 1 to 2 As shown, the basic structure of this dual inductor is formed by combining a pre-formed magnetic core 12 and two U-shaped coils 11. The pre-formed magnetic core 12 is a pre-made part based on a molding die, which is cold-pressed into a king-shaped block with four notches by a single powder feeding. The U-shaped coils are also pre-made parts, and two of them are inserted and assembled onto the pre-formed magnetic core in parallel and spaced apart, with their bottom ends coplanar, to obtain the initial assembly 13. Similarly, based on the molding die, the U-shaped coils are completely wrapped with powder after a second filling and are then encapsulated together with the pre-formed magnetic core under high pressure molding and high temperature sintering to obtain the package 14. As the basis for the inductor to be connected to the PCB, the ends of the two U-shaped coils are formed into four mutually spaced electrode pads 2 at the bottom of the package.

[0014] The structural features and assembly distribution of the aforementioned components will be detailed below. For the design considerations of dual inductors and mass production, the aforementioned U-shaped coils can be prefabricated and reused in batches. Based on the overview of this technical solution and the illustrations of preferred embodiments, the detailed features of each functional component of this inductor also include: the bottom surface of the forming mold of the aforementioned pre-formed magnetic core 12 is provided with a cross-shaped boss, thereby forming a cross-shaped groove on the bottom surface of the pre-formed magnetic core obtained by cold pressing, accompanied by four raised areas distributed around it. In a particularly illustrated embodiment, the bottom edge is also rounded; based on this, the projection of each notch groove on the bottom of the pre-formed magnetic core corresponds to each raised area, creating conditions for the separation of the final formed electrode pads.

[0015] The outer contour of the aforementioned package largely overlaps with the outer contour of the pre-formed magnetic core. Furthermore, during the secondary powder filling process of the molding die, the recessed portion facing the notch is simultaneously filled, resulting in smooth sidewalls around the package. The aforementioned U-shaped coil 11 is formed by cutting and continuously bending copper strip, and the ends of the U-shaped coil are ground into rounded corners to fit the bottom surface of the pre-formed magnetic core, eliminating any sharp, protruding edges at the bottom of the package and facilitating the formation of smooth, rounded electrode pads. Specifically, to ensure component independence when the inductor is mounted and used on a PCB, the surface of the aforementioned package is covered with a full layer of insulating varnish, and partial varnish stripping is performed at the bottom of the package, with the exposed ends of the U-shaped coil electroplated to form electrode pads.

[0016] like Figure 2 As shown in the schematic diagram of the complete manufacturing process of the preferred embodiment of the dual inductor: first, U-shaped coils are prefabricated in batches; then, powder is fed into a molding die and low-pressure is applied to obtain a pre-formed magnetic core, and the notch slot is partially demolded to leave space for the assembly of the U-shaped coils. Then, the two U-shaped coils are inserted into the notch slots with their free ends facing down (step A in the diagram), with most of them protruding from the surface of the pre-formed magnetic core, resulting in a preliminary assembly 13. Further powder filling is performed based on the above molding die (i.e., the preliminary assembly does not need to be moved), completely encapsulating the U-shaped coils, and cold-pressing is carried out under a high pressure of 20T / cm², followed by sintering at a high temperature of 600-700℃ under nitrogen protection (step B in the diagram) to obtain a package 14. The package is then transferred to a roller spraying workshop, and step C is performed to obtain a primary semi-finished product 15 fully encapsulated with insulating varnish. Step D is then performed to partially laser-strip the varnish from the raised areas at the bottom, exposing the metal surface layer 111 at the ends of the U-shaped coils. Finally, step E is performed to electroplate the forming electrode pads 2, after which the finished product is ready for shipment. Subsequent routine steps such as external testing are omitted.

[0017] In summary, the preferred embodiment of the copper-iron co-fired dual inductor of this utility model shows that, compared with the prior art, its technical effects are as follows: by optimizing the prefabricated shape and combined packaging structure of the two magnetic cores and coils, the dual inductors are integrated into the same device, effectively saving space on the PCB; and it can effectively utilize the initial permeability of the inductor powder, increasing the inductor charge and simultaneously reducing the inductor iron loss, which is conducive to improving the conversion efficiency of DC-DC converter circuits and promoting the development of hardware performance in application scenarios such as AI servers / data centers / HPC / supercomputing centers.

[0018] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A copper-iron co-fired dual inductor, characterized by: The inductor is formed by a preformed magnetic core and two U-shaped coils, wherein the preformed magnetic core is a king-shaped block with four notched slots formed by cold powder pressing, the two U-shaped coils are parallel and spaced apart and are inserted and assembled on the preformed magnetic core with the bottom ends coplanar to form an initial assembly, the U-shaped coils are completely wrapped by secondary powder filling based on a forming die, and the preformed magnetic core is integrally packaged by high-pressure forming and high-temperature sintering, and the end portions of the two U-shaped coils are formed into four electrode pads at the bottom of the obtained packaging body.

2. The co-fired dual inductor of claim 1, wherein: The bottom surface of the inner cavity of the forming die is provided with a cross-shaped boss, and each notched slot is projected on the bottom of the preformed magnetic core and located in the four protruding areas around the cross-shaped recess formed on the bottom surface of the preformed magnetic core.

3. The co-fired dual inductor of claim 1, wherein: The outer contour of the packaging body is mostly coincident with the outer contour of the preformed magnetic core, and the recessed part of the notched slot is filled in the secondary powder filling state.

4. The co-fired dual inductor of claim 1, wherein: The U-shaped coil is cut from a copper strip and continuously bent to form, and the end portion of the U-shaped coil is ground to form a round angle suitable for the bottom surface of the preformed magnetic core.

5. The co-fired dual inductor of claim 1, wherein: The surface of the packaging body is provided with an all-over insulating paint, the insulating paint is partially stripped at the bottom of the packaging body, and the exposed part of the end portion of the U-shaped coil is electroplated to form an electrode pad.

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