Shieled metallic powder mold inductor and manufacturing method thereof

Abstract

The invention provides a shielded metal powder mold inductor and a manufacturing method thereof. The manufacturing method of a shielded metal powder mold inductor includes: preparing a metal powder mold inductor; preparing an open metal box; and preparing a thermal conductive paste on one core of the metal powder mold inductor；the outer surface of one of the upper core body planes; and cover the open metal box to press the metal powder mold inductor.

Description

Technical Field

[0001] This invention relates to the field of inductor technology, and in particular to a shielded metal powder die-cast inductor. Prior Technology

[0002] An inductor is an electromagnetic induction element, made by winding a coil of insulated wire with a certain number of turns on a bobbin or iron core. This coil is called an inductor. According to the principle of electromagnetic induction, when the coil moves relative to a magnetic field, or when an alternating current flows through the coil to generate an alternating magnetic field, an induced voltage is generated to resist the change in the original magnetic field. This characteristic of suppressing current changes is called inductance. When the current flowing through an inductor changes, the electric and magnetic fields generated by the inductor will interfere with, disrupt, and / or reduce the performance of other electronic devices. In addition, electric fields, magnetic fields, or static charges from other electronic devices on a circuit board can also interfere with, disrupt, and / or reduce the performance of the inductor.

[0003] Inductors are crucial components in switching converters, such as those used in energy storage and power filters. Iron powder cores are made from very small, insulated high-purity iron powder particles, and the manufacturing process gives them a distributed air gap. The relative permeability of iron powder cores is approximately 10~75, with a high saturation magnetic flux density of about 15,000 Gauss. By stamping iron powder cores as the inductor core and placing a conductor or coil inside, inductors of any shape can be manufactured. Therefore, metal powder die-cast inductors are widely used in various electronic products.

[0004] To reduce electromagnetic interference (EMI) from inductors, Taiwan Patent No. 1431782, "Method, System, and Apparatus for Reducing Escaped Magnetic Fields Emitted by an Inductor," discloses encasing an inductor in a metal shell to form a magnetic shield, isolating it from external magnetic forces and preventing internal magnetic forces from affecting the external environment. While encasing the inductor in a metal shell can reduce EMI, the lack of a fixed connection between the metal shell and the inductor increases the overall size of the inductor, and the fabrication process requires considerable precision when mounting the inductor onto a circuit board. Furthermore, since the metal shell and inductor are only insulated by air, the insulation strength between them is affected, and the heat generated by the inductor cannot easily dissipate through the air between them, impacting the inductor's heat dissipation. Furthermore, in recent years, due to the rapid development of semiconductor technology, electronic products are moving towards thinner, smaller, faster, and more multifunctional designs. As a result, the high-power electronic components they use generate more and more heat, which further exacerbates the difficult problem of heat dissipation in electronic products.

[0005] To reduce the overall size and space of an inductor encased in a metal casing and to improve insulation between the two, Taiwan Patent No. 1758202B discloses a "shielded inductor". Its main technical feature is the use of a metal stamping (shielding box) to cover the inductor surface, and an insulating tape to adhere the metal stamping to the inductor surface, thereby providing both fixation and insulation between the metal stamping and the inductor.

[0006] However, the core of a powder-coated inductor is cast from iron powder. The iron powder core is made of very small, insulated, high-purity iron powder particles, and the manufacturing process creates distributed air gaps. Therefore, an air gap exists between the core of the powder-coated inductor and the metal stamping part; in other words, the core and the metal stamping part are not completely fitted together. As a result, the heat generated by the inductor during operation is restricted by this air gap and cannot be effectively dissipated.

[0007] Furthermore, an insulating tape is used to adhere the metal stamping part to the surface of the inductor, providing both fixation and insulation between the two components. However, the low thermal conductivity of the insulating tape makes heat dissipation difficult for the inductor, hindering effective heat dissipation through the metal parts. Additionally, the metal stamping process requires aligning and applying the insulating tape before stamping, making the process complex. Summary of the Invention

[0008] This invention provides a shielded metal powder cast inductor, comprising: a core, formed by casting metal powder coated with a layer of resin, including an upper core plane, a lower core plane, a first core side surface, a second core side surface, a third core side surface, and a fourth core side surface, wherein the lower core plane includes a first recess, a second recess, a third recess, and a fourth recess; a coil having a first coil end and a second coil end, mounted within the core; a first L-shaped coil lead sheet having a first lead end and a second lead end, the first lead end being adjacent to the first core side surface and electrically connected to the first coil end, and the second lead end being recessed into the first recess; and a... The second L-shaped coil lead sheet has a first lead end and a second lead end. The first lead end is adjacent to the side surface of the second core and electrically connected to the second coil end, and the second lead end is embedded in the second recess. An open metal shielding box includes an upper box plane, a first box side surface, a second box side surface, a T-shaped third box side surface, and a T-shaped fourth box side surface, wherein a middle portion of the T-shaped third box side surface is in contact with the side surface of the third core and embedded in the third recess, and a middle portion of the T-shaped fourth box side surface is in contact with the side surface of the fourth core and embedded in the fourth recess. A thermal paste is coupled to the outer surface of the upper core plane of the core and the inner surface of the upper box plane of the open metal shielding box.

[0009] The present invention also provides a method for manufacturing a shielded metal powder die-cast inductor, comprising: preparing a metal powder die-cast inductor; preparing an open metal shielding box; preparing a thermal paste on the outer surface of the upper core plane of one of the cores of the metal powder die-cast inductor; and covering the metal powder die-cast inductor with the open metal shielding box.

[0010] As previously described, the shielded metal powder die-cast inductor disclosed in this invention provides an insulating and thermally conductive paste to be placed between the metal shielding housing and the core of the metal powder die-cast inductor. In addition to providing insulation between the metal shielding housing and the core of the metal powder die-cast inductor, when the metal shielding housing and the core of the metal powder die-cast inductor are assembled, the fluidity generated by the compression of the thermally conductive paste during assembly fills the air gap between the metal shielding housing and the core of the metal powder die-cast inductor, and serves as a heat conduction path between the metal powder die-cast inductor and the metal shielding housing, thereby increasing the heat dissipation capacity of the overall structure. In addition, since the base material of the thermal paste itself is adhesive, it can not only fix the position of the metal shielding box, but also, in the process of assembling the metal shielding box and the iron core of the metal powder die-cast inductor, it is only necessary to control a certain amount of insulating thermal paste on the center of the inductor core surface. Compared with the need to align and apply insulating tape to the metal parts, then stamp the metal shielding, and then assemble the metal shielding box and the iron core of the metal powder die-cast inductor, it is relatively easier. Simple Explanation of the Diagram

[0011] Figure 1 is an external view of a metal powder die-cast inductor according to an embodiment of the present invention. Figure 2 is a bottom view of a metal powder die-cast inductor according to an embodiment of the present invention. Figure 3 is a perspective view of a metal powder die-cast inductor according to an embodiment of the present invention. Figure 4 is an external view of a metal shielding box according to an embodiment of the present invention. Figure 5 is an external view of the bottom of a metal shielding box according to an embodiment of the present invention. Figure 6 is a schematic diagram of a shielded metal powder die-cast inductor according to an embodiment of the present invention. Figure 7 shows a shielded metal powder die-cast inductor according to an embodiment of the present invention. Figure 8 is a manufacturing process diagram of a shielded metal powder die-cast inductor according to an embodiment of the present invention. Implementation

[0012] The embodiments of the present invention will be described in detail below. Although the present invention has been described and illustrated through these embodiments, it should be noted that the present invention is not limited to these embodiments. Rather, the present invention covers all alternatives, variations, and equivalents within the scope of the inventive spirit and scope defined in the appended claims. In the following detailed description of the present invention, numerous specific details are set forth in order to provide a complete understanding of the invention. However, those skilled in the art will understand that the present invention can be practiced without these specific details. In other instances, well-known schemes, processes, elements, and circuits have not been described in detail in order to highlight the spirit of the invention.

[0013] Figure 1 is an overall view of a metal powder-cast inductor 100 according to an embodiment of the present invention. For ease of explanation, please also refer to Figure 2, which shows the bottom view of the metal powder-cast inductor 100 according to an embodiment of the present invention, and Figure 3, which shows the perspective view of the metal powder-cast inductor 100 according to an embodiment of the present invention. The metal powder-cast inductor 100 includes a core 10, which is formed by casting metal powder coated with a layer of resin. It includes an upper core plane 105, a lower core plane 106, a first core side surface 101, a second core side surface 102, a third core side surface 103, and a fourth core side surface 104. The lower core plane includes a first recess 1011, a second recess 1021, a third recess 1031, and a fourth recess 1041. A coil (not shown) is installed inside the core 10.

[0014] A first L-shaped coil lead piece 1012 has a first lead end 1012-1 and a second lead end 1012-2. The first lead end 1012-1 is adjacent to the first core side surface 101 and electrically connected to a first coil end of the coil. A second L-shaped coil lead piece 1022 has a first lead end 1022-1 and a second lead end 1022-2. The first lead end 1022-1 is adjacent to the second core side surface 102 and electrically connected to a second coil end of the coil.

[0015] An open-type metal shielded housing 200 includes an upper housing plane 205, a first housing side surface 201, a second housing side surface 202, a T-shaped third housing side surface 203, and a T-shaped fourth housing side surface 204. A middle portion 203-1 of the T-shaped third housing side surface 203 is adjacent to and embedded in the third core side surface 103 with the third recess 1031. Similarly, a middle portion 204-1 of the T-shaped fourth housing side surface 204 is adjacent to and embedded in the fourth core side surface 104 with the fourth recess 1041. A thermal paste 301 is also included, coupling the outer surface of the upper core plane 105 of the core 10 to the inner surface of the upper housing plane 205 of the open-type metal shielded housing 200. In one embodiment, the core 10 of the shielded metal powder-cast inductor 100 may be, but is not limited to, a cube or a rectangular cube.

[0016] An open metal shielding box 200 can cover at least a portion of the core 10 to form a magnetic shield for the metal powder cast inductor 100, isolating magnetic forces entering the inductor from the outside and preventing internal magnetic forces from affecting the outside. In one embodiment, the open metal shielding box 200 includes, but is not limited to, an open square metal shielding box or an open rectangular metal shielding box. In another embodiment, the first box side 201 and the second box side 202 are a square or a rectangle.

[0017] The thermal paste 301 of this invention must not only have good thermal conductivity, but also provide insulation between the adhered materials. The base material of the thermal paste 301 must be insulating. In one embodiment, the base material of the thermal paste 301 includes, but is not limited to, any of the group consisting of silicone resin, polyurethane, and acrylate polymers, to provide insulation between the adhered materials. In another embodiment, the thermally conductive material used in the thermal paste 301 includes, but is not limited to, any of the group consisting of diamond, alumina, aluminum nitride, boron nitride, and zinc oxide, to simultaneously provide the thermal paste 301 with good thermal conductivity.

[0018] Figure 6 is a schematic diagram 600 of the shielded metal powder die-cast inductor of the present invention according to an embodiment of the present invention. Before assembling the open metal shield housing 200 and the core 10, the thermal paste 301 of the present invention is first applied to the outer surface of the upper core plane of the core 10. When the open metal shield housing 200 is pressed to cover the core 10, since the thermal paste 301 is a paste, the thermal paste 301 will be pressed and applied to the outer surface of the upper core plane of the core 10 and the inner surface of the upper housing plane of the open metal shield housing 200. In one embodiment, when the open metal shield housing 200 is pressed to cover the core 10, the T-shaped third housing side surface 203 is adjacent to the third core side surface 103, and the T-shaped fourth housing side surface 204 is adjacent to the fourth core side surface 104.

[0019] The adhesive properties of the thermal paste 301 not only provide fixation between the core 10 and the open metal shielding box 200 during assembly, but also, advantageously, because the thermal paste 301 is a paste, it can simultaneously fill the air gap between the iron core of the metal powder cast inductor and the open metal shielding box. In other words, the heat generated by the metal powder cast inductor during operation can be evenly transferred to the outside of the open metal shielding box by the thermally conductive material of the thermal paste of the present invention, and insulation can be provided between the metal powder cast inductor and the open metal shielding box.

[0020] In one embodiment, the middle portion 203-1 of the T-shaped third box side surface 203 is folded inward toward the core 10 and embedded with the third recess 1031, and the middle portion 204-1 of the T-shaped fourth box side surface 204 is folded inward toward the core 10 and embedded with the fourth recess 1041. Advantageously, this increases the tightness of the assembly between the metal powder cast inductor 100 and the open metal shielded box 200. Figure 7 shows a shielded metal powder cast inductor 700 according to an embodiment of the present invention.

[0021] Figure 8 is a flowchart 800 of the manufacturing method of a shielded metal powder die-cast inductor according to the present invention. Step 801: Prepare a metal powder die-cast inductor 100. It includes a core 10, formed by die-casting metal powder coated with a layer of resin, and includes an upper core plane 105, a lower core plane 106, a first core side surface 101, a second core side surface 102, a third core side surface 103, and a fourth core side surface 104. The lower core plane includes a first recess 1011, a second recess 1021, a third recess 1031, and a fourth recess 1041. A coil (not shown) is installed inside the core 10.

[0022] A first L-shaped coil lead piece 1012 has a first lead end 1012-1 and a second lead end 1012-2. The first lead end 1012-1 is adjacent to the first core side surface 101 and electrically connected to a first coil end of the coil. A second L-shaped coil lead piece 1022 has a first lead end 1022-1 and a second lead end 1022-2. The first lead end 1022-1 is adjacent to the second core side surface 102 and electrically connected to a second coil end of the coil.

[0023] Step 602: Prepare an open metal shielding box 200. This includes an upper box plane 205, a first box side surface 201, a second box side surface 202, a T-shaped third box side surface 203, and a T-shaped fourth box side surface 204. A middle portion 203-1 of the T-shaped third box side surface 203 is adjacent to and embedded in the third core side surface 103 with the third recess 1031. Similarly, a middle portion 204-1 of the T-shaped fourth box side surface 204 is adjacent to and embedded in the fourth core side surface 104 with the fourth recess 1041. A thermal paste 301 is also provided, coupling the outer surface of the upper core plane 105 of the core 10 to the inner surface of the upper box plane 205 of the open metal shielding box 200. In one embodiment, the core 10 of the shielded metal powder cast inductor 100 may be, but is not limited to, a cube or a rectangular cube.

[0024] The open metal shielding box 200 may cover at least a portion of the core 10. In another embodiment, the open metal shielding box 200 may include, but is not limited to, an open square metal shielding box or an open rectangular metal shielding box.

[0025] Step 603: Prepare a thermal paste. The base material of the thermal paste is any one of the group consisting of silicone resin, polyurethane and acrylate polymer, and the thermally conductive material of the thermal paste is any one of the group consisting of diamond, alumina, aluminum nitride, boron nitride and zinc oxide.

[0026] Step 604: Thermal paste 301 is applied to the outer surface of the upper core plane 105 of the core 10.

[0027] Step 605: Press the open metal shielding box 200 to cover the metal powder cast inductor 100. Since the thermal paste 301 is a paste, it will be pressed and applied to the outer surface of the upper core plane 105 of the core 10 and the inner surface of the upper box plane 205 of the open metal shielding box 200. In one embodiment, the second pin end 1012-2 of the first L-shaped coil pin sheet 1012 is folded inward along the first core plane 101 of the core 10 down to the core plane 106 and embedded in the first recess 1011, and the second pin end 1022-2 of the second L-shaped coil pin sheet 1022 is folded inward along the second core plane 102 of the core 10 down to the core plane 106 and embedded in the second recess 1021. This increases the tightness and fixation between the metal powder cast inductor 100 and the open metal shielding box 200 when they are assembled.

[0028] As previously described, this invention discloses a shielded metal powder die-cast inductor, which provides a thermal paste to be placed between the metal shielding housing and the core of the metal powder die-cast inductor. In addition to providing insulation between the metal shielding housing and the core of the metal powder die-cast inductor, the thermal paste, through the fluidity generated by the compression of the metal shielding housing and the core of the metal powder die-cast inductor, fills the air gap between the metal shielding housing and the core of the metal powder die-cast inductor, thereby increasing the heat conduction path between the metal shielding housing and the core of the metal powder die-cast inductor, and thus increasing the heat dissipation capacity of the shielded metal powder die-cast inductor.

[0029] Furthermore, due to the adhesive nature of the thermal paste's base material, it not only serves to fix the position of the metal shielding box and the metal powder-coated inductor core, but also, during the assembly process of the metal shielding box and the metal powder-coated inductor core, only a fixed amount of thermal paste needs to be controlled at the center of the inductor core surface. Compared to the previous method of applying insulating tape to the metal parts for alignment, stamping the metal shielding box, and then assembling the metal powder-coated inductor core, this method is relatively easier.

[0030] The wording and expressions used herein are illustrative and not limiting, and their use does not exclude any equivalents (or partial equivalents) of the features illustrated and described herein from the scope of the invention. Various modifications, variations, and substitutions may exist within the scope of the claims. Therefore, the scope of the claims is intended to cover all such equivalents.

[0031] 100: Metal powder die-cast inductor according to an embodiment of the present invention 10: Core 101: First core edge 102: Second core edge 103: Third core edge 104: Fourth Core Edge 105: Upper core plane 106: Lower core plane 1011: First concave part 1021: Second concave part 1031: The third concave part 1041: The fourth concave part 1012: First L-shaped coil lead sheet 1012-1: First L-shaped coil lead piece, first lead end 1012-2: Second pin end of one of the first L-shaped coil lead pieces 1022: Second L-shaped coil lead sheet 1022-1: One of the lead pieces for the second L-shaped coil, first lead end 1022-2: One of the second L-shaped coil lead pieces, second lead end 200: Open-ended metal shielding box 205: Upper box plane 201: First box of side dishes 202: Second box edge 203: T-shaped third box side 204: T-shaped fourth box side 203-1: Middle of one of the sides of the third box of the T-type 204-1: Middle part of one of the sides of the fourth box of type T 301: Thermal paste 700: Shielded metal powder die-cast inductor according to an embodiment of the present invention 800: Flowchart of the manufacturing method of the shielded metal powder die-cast inductor according to the present invention 801, 802, 803, 804, 805: Steps

Claims

1. A shielded metal powder die-cast inductor, comprising: A core, formed by casting metal powder coated with a layer of resin, includes an upper core plane, a lower core plane, a first core side surface, a second core side surface, a third core side surface, and a fourth core side surface. The lower core plane includes a first recess, a second recess, a third recess, and a fourth recess. A coil, having a first coil end and a second coil end, is mounted within the core. A first L-shaped coil lead piece has a first lead end and a second lead end. The first lead end of the first L-shaped coil lead piece is adjacent to the first core side surface and electrically connected to the first coil end, and the second lead end of the first L-shaped coil lead piece is embedded in the first recess. A second L-shaped coil lead piece has... The second L-shaped coil lead sheet has a first lead end and a second lead end, the first lead end of the second L-shaped coil lead sheet being adjacent to the side surface of the second core and electrically connected to the second coil end, and the second lead end of the second L-shaped coil lead sheet being recessed into the second recess; an open metal shielding box includes an upper box plane, a first box side surface, a second box side surface, a T-shaped third box side surface, and a T-shaped fourth box side surface, wherein a middle portion of the T-shaped third box side surface is in contact with the side surface of the third core and recessed into the third recess, and a middle portion of the T-shaped fourth box side surface is in contact with the side surface of the fourth core and recessed into the fourth recess; and a thermal paste, coupled to the outer surface of the upper core plane of the core and the inner surface of the upper box plane of the open metal shielding box. The thermal grease further couples the outer surface of the first core side of the core to the inner surface of the first box side of the open metal shielding box, the outer surface of the second core side of the core to the inner surface of the second box side of the open metal shielding box, the outer surface of the third core side of the core to the inner surface of the third box side of the open metal shielding box, and the outer surface of the fourth core side of the core to the inner surface of the fourth box side of the open metal shielding box.

2. As in claim 1, the shielded metal powder die-cast inductor, wherein, The core is a regular cube or a rectangular cube.

3. As in claim 1, the shielded metal powder die-cast inductor, wherein, The open metal shielding box can be a square metal shielding box or a rectangular metal shielding box.

4. As in claim 1, the shielded metal powder die-cast inductor, wherein, The base material of the thermal paste is any one of the group consisting of silicone resin, polyurethane and acrylate polymer.

5. As in claim 1, a shielded metal powder-cast die-cast inductor, wherein, The thermally conductive material of this thermal paste is any one of the group consisting of diamond, aluminum oxide, aluminum nitride, boron nitride, and zinc oxide.

6. As in claim 1, a shielded metal powder-cast die-cast inductor, wherein, The first box and the second box have a rectangular side surface.

7. A method for manufacturing a shielded metal powder die-cast inductor, comprising: Prepare a metal powder die-cast inductor; Prepare an open metal shielded box; A thermal paste is applied to the outer surface of the upper core plane of one core of the metal powder-coated inductor; and an open metal shielding box is used to cover the metal powder-coated inductor. The open metal shielding box further includes: an upper box plane, a first box side surface, a second box side surface, a T-shaped third box side surface, and a T-shaped fourth box side surface; the metal powder-coated inductor further includes: an upper core plane, a lower core plane, a first core side surface, a second core side surface, a third core side surface, and a fourth core side surface, and the lower core plane includes a first recess, a second recess, a third recess, and a fourth recess; and a middle portion of one of the T-shaped third box side surfaces is in contact with and embedded in the third core side surface of the inductor, and a middle portion of one of the T-shaped fourth box side surfaces is in contact with and embedded in the fourth core side surface of the inductor. Furthermore, the thermal paste is further coupled between the upper core plane of the core and the upper box plane of the open metal shielding box, and between the first core side surface of the core and the first box side surface of the open metal shielding box, the second core side surface of the core and the second box side surface of the open metal shielding box, the third core side surface of the core and the third box side surface of the open metal shielding box, and the fourth core side surface of the core and the fourth box side surface of the open metal shielding box.

8. The method for manufacturing a shielded metal powder die-cast inductor according to claim 7, wherein, The base material of the thermal paste is any one of the group consisting of silicone resin, polyurethane and acrylate polymer, and the thermally conductive material of the thermal paste is any one of the group consisting of diamond, alumina, aluminum nitride, boron nitride and zinc oxide.

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