Inductors with pre-formed terminals, their manufacturing methods and components

Abstract

An inductor, a method of manufacturing the same, and an assembly are provided. The inductor includes a pre-formed conductive coil and an inductor body. The pre-formed conductive coil includes an intermediate portion located between first and second terminal leads. The inductor body includes a magnetic material at least surrounding the intermediate portion of the pre-formed conductive coil. At least a portion of each of the first and second terminal leads of the pre-formed conductive coil is exposed outside the inductor body. The method of manufacturing the inductor includes providing a one-piece conductive coil having a substantially curved intermediate portion and first and second terminal leads, and molding a magnetic material around at least the intermediate portion of the formed conductive coil to form an inductor body, wherein at least a portion of the first and second terminal leads of the formed one-piece conductive coil is exposed outside the inductor body.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 984,584, filed March 3, 2020, and U.S. Non-Provisional Application No. 17 / 187,161, filed February 26, 2021, which are incorporated herein by reference as if fully set forth herein. Technical Field

[0003] This application relates to the field of electronic components, and more specifically, to inductors and methods and components for manufacturing inductors. Background Technology

[0004] Inductors are typically passive, two-terminal electrical components that resist changes in the current flowing through them. An inductor consists of a conductor (such as a wire) wound into a coil. When current flows through the coil, energy is temporarily stored in the coil's magnetic field. According to Faraday's law of electromagnetic induction, when the current flowing through the inductor changes, a voltage is induced in the conductor by the time-varying magnetic field.

[0005] Some known inductors are typically formed with fine wires sandwiched between or wound around multiple molded core materials of C-shape, E-shape, toroidal, or other shapes, which can be attached by adhesive. Air gaps are common in inductor core designs where the core is made of two separate half-core materials. These air gaps negatively impact the inductor's operation and performance.

[0006] Other known inductors are formed by pressing powdered magnetic material around a conductive body. With this type of inductor, the conductive coil has some ability to move within the mold, especially during pressing. As a result, the conductive coil can move within the core, which negatively impacts the inductor's operation and performance.

[0007] Some known inductors typically require soldering conductive coils to a lead frame to hold the components together during fabrication. After the magnetic material is pressed around the conductive coil, the leads must then be formed (e.g., by cutting the lead frame and bending the leads). Post-processing steps such as cutting and bending can cause cracks in the wires or molded magnetic material, or other defects in their integrity, resulting in significant waste and additional labor.

[0008] One issue in industries related to inductors involves the inspection of lead areas suitable for soldering connections. These inspections can be performed, for example, by X-rays or by automated optical inspection (AOI). AOI systems are used to detect defects in, for example, semiconductor devices and printed circuit boards (PCBs). There is a desire to manufacture inductors with leads that allow for improved AOI, which is less expensive than X-ray inspection.

[0009] There is a need for a simple and cost-effective way to produce inductors that utilizes the smallest possible footprint while maximizing the usable core area with minimal waste. Summary of the Invention

[0010] This article discloses an inductor and its manufacturing method.

[0011] According to one aspect, the subject matter disclosed herein relates to an inductor comprising: a pre-formed conductive coil including an intermediate portion located between first and second terminal leads; and an inductor body including a magnetic material at least surrounding the intermediate portion of the pre-formed conductive coil. At least a portion of each of the first and second terminal leads of the pre-formed conductive coil is exposed outside the inductor body.

[0012] According to another aspect, the magnetic material may be magnetic particles molded around the middle portion of the conductive coil and portions of the first and second terminal leads of the conductive coil. The magnetic particles may be powdered or granular magnetic materials, or more specifically, powdered iron particles.

[0013] Alternatively, a conductive coil can be formed by bending a conductive material into a selected shape. The conductive coil can be circular, semi-circular, elliptical, or omega-shaped.

[0014] According to another aspect, the inductor body may be a package shape having a bottom side (i.e., lead side), a top side, a right side, a left side, a front side, and a rear side, and the portion of each of the first and second terminal leads exposed outside the inductor body may be positioned along the bottom side or the lead side of the inductor body. Each of the first and second terminal leads may further include a bottom having an exposed portion positioned along the bottom side of the inductor body, and a side terminating along a corresponding one of the right and left sides of the inductor body. Each of the right and left sides of the inductor body may include a cutout portion, at which the side of the corresponding one of the first and second terminal leads is positioned. The side of each of the first and second terminal leads may be pre-formed to be substantially perpendicular to the bottom.

[0015] According to another aspect, the subject matter disclosed herein relates to a method for manufacturing an inductor, the method comprising: providing a conductor having a substantially curved intermediate portion and first and second terminal leads; and molding a magnetic material around at least the intermediate portion of a formed conductive coil to form an inductor body, wherein at least a portion of the first and second terminal leads of the formed conductive coil may be exposed outside the inductor body. The formed inductor body may be an encapsulation shape having a bottom side, a top side, a right side, a left side, a front side, and a rear side, and the first and second terminal leads may be exposed along the bottom side and a corresponding one of the right and left sides of the inductor body. Molding the magnetic material may further comprise positioning the formed conductive coil in a mold assembly, introducing magnetic particles into the mold assembly, and pressing the magnetic particles around the conductive coil. Positioning the formed conductive coil may further comprise placing the first and second terminal leads of the formed conductive coil on a first shelf and a second shelf formed within a wall of the mold assembly, wherein the first shelf and the second shelf have shapes complementary to the first and second terminal leads, such that the first and second terminal leads serve as part of the wall of the mold assembly during molding. The first and second shelves may each also include a narrowed wall forming complementary cutouts in each of the right and left sides of the inductor body, and a portion of each of the first and second terminal leads may be positioned in the respective cutout.

[0016] According to another aspect, the subject matter disclosed herein relates to an assembly for forming an inductor. The assembly includes: a pre-formed conductive coil including an intermediate portion located between first and second terminal leads; a die section having a placement channel defined therethrough and a wall surrounding the placement channel, the wall including first and second shelves configured to receive the first and second terminal leads of the pre-formed conductive coil; and at least one punch configured to press magnetic particles around the conductive coil when the conductive coil is positioned within the die. The first and second shelves have shapes complementary to the first and second terminal leads, such that the first and second terminal leads contact the wall of the die when the magnetic particles are pressed around the conductive coil. Attached Figure Description

[0017] Figure 1A This is an isometric view of the lead side of an inductor according to an exemplary embodiment of the present invention.

[0018] Figure 1B yes Figure 1A A partial transparent view of the inductor body, showing the conductive coil.

[0019] Figure 1C yes Figure 1A An isometric view of the right front side of the inductor.

[0020] Figure 1D yes Figure 1C A partial transparent view of the inductor body, showing the conductive coil.

[0021] Figure 1E yes Figure 1A Plan view of the front side of the inductor.

[0022] Figure 1F yes Figure 1E A partial transparent view of the inductor body, showing the conductive coil.

[0023] Figure 1G yes Figure 1A Plan view of the right side of the inductor. Figure 1A The left side of the inductor is preferably Figure 1G The mirror image on the right side depicted in the image.

[0024] Figure 1H yes Figure 1G A partial transparent view of the inductor body, showing the conductive coil.

[0025] Figure 2A This is the invention Figure 1A-1B An isometric view of the front side of an exemplary embodiment of a conductive coil.

[0026] Figure 2B yes Figure 2A An isometric view of the top side of the conductive coil.

[0027] Figure 2C yes Figure 2A An isometric view of the bottom side of the conductive coil.

[0028] Figure 2D yes Figure 2A Plan view of the right side of the conductive coil. Figure 2A The left side of the conductive coil is preferably Figure 2D The mirror image on the right side depicted in the image.

[0029] Figure 3 This is a flowchart of an exemplary method for forming an inductor with pre-formed terminals according to the present invention.

[0030] Figure 4A This is a plan view of an exemplary mold section for forming an inductor with pre-formed terminals according to the present invention.

[0031] Figure 4B and Figure 4C yes Figure 4A A perspective view of the mold section.

[0032] Figure 5A and Figure 5B yes Figure 4AA perspective view of the mold section, in which the conductive coil is placed in the placement channel.

[0033] Figure 6A This is a perspective view of a mold assembly for forming an inductor with pre-formed terminals according to the present invention.

[0034] Figure 6B yes Figure 6A A cross-sectional view of the mold assembly, showing the conductive coil disposed within the mold assembly.

[0035] Figure 6C yes Figure 6A A cross-sectional view of a mold assembly, showing an inductor with pre-formed terminals according to the invention formed within the mold assembly.

[0036] Figure 7 yes Figure 4A A perspective view of the mold section, showing an inductor formed according to the invention disposed within a placement channel.

[0037] Figure 8A This is a partial transparent view of another exemplary embodiment of an inductor according to the present invention, showing a conductive coil.

[0038] Figure 8B yes Figure 8A An isometric view of a conductive coil.

[0039] Figure 8C yes Figure 8B Plan view of the right side of the conductive coil. Figure 8B The left side of the conductive coil is preferably Figure 8C The mirror image on the right side depicted in the image.

[0040] Figure 9A This is a partial transparent view of another exemplary embodiment of an inductor according to the present invention, showing a conductive coil.

[0041] Figure 9B yes Figure 9B A plan view of the conductive coil. Detailed Implementation

[0042] This article describes an inductor with pre-formed terminals and a method for manufacturing the inductor using a die assembly.

[0043] The use of certain terms in the following description is for convenience only and not for limitation. The words “right,” “left,” “top,” and “bottom” indicate orientation in the referenced figures. Unless otherwise expressly stated, the words “a” and “an,” as used in the corresponding portions of the claims and specification, are defined to include one or more of the referenced items. This term includes the words specifically mentioned above, their derivatives, and words with similar meanings. The phrase “at least one” followed by a list of two or more items, such as “A, B, or C,” refers to any single one of A, B, or C, and any combination thereof. It may be noted that some figures are shown in a partially transparent manner for purposes of explanation, illustration, and demonstration only, and are not intended to indicate that the elements themselves are transparent in their final manufactured form.

[0044] The description provided herein is intended to enable those skilled in the art to make and use the described embodiments. However, various modifications, equivalents, variations, combinations, and alternatives will be apparent to those skilled in the art. Any and all such modifications, variations, equivalents, combinations, and alternatives are intended to fall within the spirit and scope of the invention as defined by the claims.

[0045] Figure 1A-1H An inductor 100 according to an exemplary embodiment described herein is illustrated. The inductor 100 preferably includes an inductor body 110 partially surrounding a pre-formed conductive coil 200. The inductor body 110 is preferably formed of a magnetic material molded around the conductive coil 200. In one embodiment, the inductor body 110 may be formed of an ferrous material. In one embodiment, the inductor body 110 may include, for example, iron, a metal alloy, ferrite, a combination of the foregoing, or other materials known in the field of inductors and used to form such a body. In one embodiment, the inductor body 110 may be formed of magnetic particles such as powdered or granular magnetic particles. In one embodiment, the magnetic particles may be powdered iron particles. In a non-limiting example, the magnetic material may be used for an inductor body consisting of powdered iron particles, fillers, resins, and lubricants, as described in U.S. Patents Nos. 6,198,375 (“Inductor Coil Structure”) and 6,204,744 (“High Current, Thin Inductor”), both of which are incorporated herein by reference as if fully set forth herein.

[0046] like Figure 1A-1H As shown, in an exemplary embodiment, the inductor body 110 is preferably a package shape having a bottom or lead side 120, a top side 130, a right side 140, a left side 150, a front side 160, and a rear side 170. Non-limiting examples of package shapes include box shapes, cuboid shapes, and rectangular prisms, any of which include rounded corners (see [link to documentation]). Figure 8AOne or more irregular surfaces, etc. Those skilled in the art will recognize that other inductor shapes can be employed without departing from the spirit of the invention. For example, an inductor 100 with pre-formed terminals formed according to the invention may have mismatched mold sections formed together in a mold assembly. The inductor body 110 is preferably formed around the conductive coil 200 such that the right and left leads 210, 220 of the conductive coil 200 are exposed outside the inductor body 110 along the lead side 120 of the inductor body 110.

[0047] Figure 2A-2C A conductive coil 200 according to an exemplary embodiment described herein is illustrated. The conductive coil 200 is preferably a pre-formed component made of a conductive material such as a metal plate, sheet, or strip. Acceptable metals for forming the conductive coil 200 may be copper, aluminum, platinum, or other metals known in the art for use as inductor coils. In one exemplary embodiment, the conductive coil can be formed into a pre-formed component by bending the conductive material into a selected shape. Non-limiting examples of wires that can be used to form the conductive coil 200 include flat wires, square or rectangular wires, and round wires. Those skilled in the art will recognize that other wire shapes can be used within the scope of the invention. The conductive coil 200 may have a uniform thickness (e.g., as shown in the image). Figure 2A-2C (as depicted in the text), or may have varying thicknesses (e.g., as shown in the text). Figures 8A-8C and Figures 9A-9B (As shown). In one embodiment, the conductive coil 200 may be a single, one-piece component. In another embodiment, the conductive coil 200 may consist of multiple parts connected together (e.g., by welding), provided that the conductive coil 200 is fully formed during the molding process before the inductor body is formed around the conductive coil.

[0048] The conductive coil 200 is preferably configured to provide improved efficiency and performance in a small volume, be simple to manufacture, and generate minimal or no waste. The shape of the conductive coil 200 is designed to optimize the path length to fit the available space within the inductor body 110, while minimizing resistance and maximizing inductance.

[0049] As in the exemplary embodiment Figure 2A-2C As shown, the conductive coil 200 preferably has a right end and a left end forming right and left leads 210, 220, as well as a middle portion 230. The right and left leads 210, 220 are preferably formed in an L-shape or a U-shape. Those skilled in the art will recognize that when the right and left leads 210, 220 are formed in an L-shape or a U-shape, this L-shape or U-shape can be formed by substantially right-angled segments (e.g., such as...). Figure 2A-2C (as shown) or substantially rounded sections (e.g., such as Figures 8A-8C(As discussed herein) constitutes the structure. The middle portion 230 is preferably formed as a circle or a semicircle; however, other shapes may be used based on the desired inductor characteristics. In one embodiment, the middle portion 230 is preferably a single semicircular shape (e.g., as shown). Figure 2A-2C (as shown) or elliptical shape (e.g., as shown) Figures 9A-9B (As shown in the diagram, discussed herein). Furthermore, the intermediate portion 230 may include one or more wound circular segments or stacked coils. (As illustrated in the diagram). Figure 2A-2C As shown in the preferred embodiment, the conductive coil 200 may be an omega-shaped flat conductor having L-shaped right and left leads 210, 220 and a semi-circular middle portion 230. Those skilled in the art will recognize that, within the scope of the invention, the right and left leads 210, 220 and the middle portion 230 may be formed in other shapes suitable for performing the desired inductive characteristics.

[0050] like Figure 2A-2C As shown in an exemplary embodiment, the conductive coil 200 has a bottom side 240, a top side 250, a right side 260, a left side 270, a front side 280, and a rear side 290 forming right and left leads 210, 220. In one embodiment, the rear side 290 is preferably a mirror image of the front side 280, and the left side 270 is preferably a mirror image of the right side 260. In an exemplary embodiment, the middle portion 230 has a right extension leg and a left extension leg 232, 234 respectively adjacent to the right and left leads 210, 220. Each of the right and left leads 210, 220 preferably includes a bottom 212, 222 and a side 214, 224. The bottom 212, 222 of each lead 210, 220 is preferably positioned between a corresponding right extension leg and left extension leg 232, 234 and a side 212, 222. Side portions 214, 224 preferably form the terminal ends of each lead 210, 220. Side portions 214, 224 are pre-formed to be substantially perpendicular to the bottom portions 212, 222 of each lead 210, 220. Although leads 210, 220 are illustrated with sides 214, 224, those skilled in the art will recognize that sides 214, 224 can be omitted, and leads 210, 220 can terminate at bottom portions 212, 222.

[0051] Return to reference Figure 1A-1HEach lead 210, 220 has a terminal preferably exposed outside the inductor body 110 and pre-formed such that at least a portion of the bottom 212, 222 of each lead 210, 220 is exposed along the lead side 120 of the inductor body 110, and the sides 214, 224 of each lead 210, 220 are exposed along the respective right and left sides 140, 150 of the inductor body 110. In one embodiment, the leads 210, 220 are L-shaped and positioned along the lead side 120 and the left and right sides 140, 150 of the inductor body 110. As used herein, "L-shaped" or "L-shaped" includes two leg sections connected at an angle or by a bending member. For example, the bottom 212, 222 may extend to the sides 214, 224 of each lead 210, 220 by a bending section or an acute angle.

[0052] As in Figure 1E and Figure 1F As best shown, notches or cutouts 142, 152 can be formed in each of the right and left sides 140, 150 of the inductor body 110. The inductor body 110 has a smaller width W3 at the cutouts 142, 152 compared to the maximum width W2 of the inductor body 110. The exposed sides 214, 224 of each lead 210, 220 are positioned along the corresponding cutouts 142, 152 to minimize the influence of the leads 210, 220 in the width direction. In particular, by positioning the exposed sides 214, 224 of each lead 210, 220 along the corresponding cutouts 142, 152, the maximum width W1 of the conductive coil 200 between the leads 210, 220 can be substantially the same as the maximum width W2 of the inductor body 110. Therefore, the exposed sides 214, 224 of each lead 210, 220 are substantially aligned (in the same plane) with the corresponding right and left sides 140, 150 of the inductor body 110, which allows the overall size of the inductor 100 to be minimized. It should be understood that cutouts 142, 152 are not required in all cases, and the sides 214, 224 of the leads 210, 220 can be formed along the right and left sides 140, 150 of the inductor body 110 without cutouts 142, 152.

[0053] Figure 1B , Figure 1D , Figure 1F and Figure 1HAn exemplary embodiment of the inductor body 110 is shown in a partially transparent manner to allow observation of the conductive coil 200 inside the inductor body 110. The finished inductor 100 according to the invention preferably comprises an inductor body 110 molded, formed, or pressed around the conductive coil 200. At least portions of the leads 110, 120 are exposed outside the inductor body 110 on the lead side 120 and the lower portions of the right and left sides 140 of the inductor body 110. The leads 110, 120 form a considerable portion of the bottom side or lead side 120 of the inductor 100.

[0054] The length, width, and height of the conductive coil 200 and the inductor body 110 can vary depending on the inductor application. The dimensions of the conductive coil 200 can be designed to increase the ratio of the space used to the available space in the inductor body 110.

[0055] like Figure 1F As shown, in one embodiment, the vertical height H1 of the conductive coil 200 (from the bottom side 240 to the top side 250) is substantially equal to or less than the vertical height H2 of the inductor body 110 (from the lead side 120 to the top side 130). Since at least a portion of the leads 210, 220 of the conductive coil 200 are located outside the inductor body 110 in the formed inductor 100, at least the middle portion 230 of the conductive coil 200 can be fully embedded within the inductor body 110 when the conductive coil 200 and the inductor body have substantially the same vertical height. Alternatively, the vertical height H1 of the conductive coil 200 can be >99%, >98%, >95%, >90%, >85%, >75%, >60%, or >50% of the vertical height H2 of the inductor body 110.

[0056] Or as Figure 1E As shown, the maximum width W1 of the conductive coil 200 is substantially equal to the maximum width W2 of the inductor body 110. Those skilled in the art will recognize that the maximum width W1 of the conductive coil 200 or the maximum width W2 of the inductor body may differ slightly without departing from the spirit of the invention.

[0057] like Figure 1H As shown, the depth D1 of the conductive coil 200 is preferably less than the depth D2 of the inductor body 110. For example, the conductive coil 200 may be centered within the inductor body 110 along the depth direction and have a depth D1 that is approximately 50% of the depth D2 of the inductor body 110. Those skilled in the art will recognize that, without departing from the spirit of the invention, the maximum width W1 of the conductive coil 200 or the depth D1 of the inductor body may be greater than or less than 50% of the depth D2 of the inductor body 110.

[0058] In a non-limiting example, the maximum dimensions of the finished inductor may be approximately 10 mm (vertical height (H3)) x 10 mm (width (W2)) x 6 mm (depth (D2)). In this embodiment, the vertical height H1 of the conductive coil 200 is approximately 9 mm, and the maximum vertical height H3 of the inductor 100 is approximately 10 mm. The maximum width W1 of the conductive coil 200 and the maximum width W2 of the inductor body 110 are both approximately 10 mm. The depth D1 of the conductive coil 200 is approximately 3 mm, and the depth D2 of the inductor body 110 is approximately 6 mm. In a preferred embodiment, the inductor can achieve a resistance of less than 0.15 mΩ and an inductance of more than 100 nH, while achieving a rated current of more than 100 A, resulting in a temperature rise of 40°C or lower. In one embodiment, the current handling capability can be in the range of 100-125 A, producing a temperature rise of 40°C or lower.

[0059] Those skilled in the art will recognize that, within the scope of this disclosure, the length, width, and height of the conductive coil 200 and the inductor body 110 can vary considerably. Other non-limiting examples of inductor dimensions according to this disclosure include: 10 mm (H3) x 10 mm (W2) x 5 mm (D2); 12 mm (H3) x 10 mm (W2) x 5 mm (D2); 7 mm (H3) x 10 mm (W2) x 5 mm (D2); and 5 mm (H3) x 8 mm (W2) x 4 mm (D2).

[0060] In one embodiment, the resistance can range from 0.01 mΩ to 5.0 mΩ and the inductance can range from 10 nH to 1000 nH. Those skilled in the art will recognize that resistance typically increases with increasing inductance. However, as the size of the inductor body 110 increases, the inductance can increase without increasing the resistance.

[0061] Figures 8A-8C An inductor 800 according to an alternative embodiment described herein is shown. Inductor 800 is generally associated with... Figure 1A-1H The inductor 100 shown is formed of the same material. For example... Figure 8A As shown, inductor 800 preferably includes an inductor body 810 that partially surrounds a pre-formed conductive coil 820. Inductor 800 and Figure 1A-1H The inductor 100 shown and Figure 2A-2C The difference in the conductive coil 200 shown is that the inductor 800 has a conductive coil 820 with an intermediate section 830 of a different size compared to the right and left ends forming the right and left leads 840, 850. For example... Figure 8A and Figure 8BAs shown in the preferred embodiment, the conductive coil 820 is preferably a flat wire with an omega shape, the omega shape having L-shaped right and left leads 840, 850 and a semi-circular middle portion 830. The middle portion 830 of the conductive coil 820 preferably has a greater thickness than the right and left leads 840, 850. The thickness of the wire gradually tapers from the middle portion 830 along the right and left extension legs 860 and 870. As a result, the right and left leads 840, 850 preferably have a flatter and wider cross-sectional area than the cross-sectional area of ​​the middle portion 830, such as... Figure 8C As shown.

[0062] Figures 8A-8C The advantages of the inductor 800 depicted in the diagram are: the flatter and wider leads 840, 850 allow for greater stability, especially when manufacturing larger inductors. It also allows for greater stability in the depth direction (…). Figure 1H Manufacturing inductors with a wider inductor body in the direction of reference (D) results in additional core material and increased inductance.

[0063] Furthermore, increasing the width of the inductor's lead terminals (e.g., inductor 800) allows for thinner lead terminals with the same cross-sectional area. As a result, the resistance of the lead terminals can remain substantially the same, while freeing up additional space for the core material in the same effective area. Because the size of an inductor is typically determined by the amount of space it will occupy on a circuit board, the inductor according to this embodiment (such as inductor 800) can utilize available circuit board space more efficiently. Moreover, inductors with wider lead terminals (such as inductor 800) allow for mounting a larger lead surface area onto the circuit board, which provides a more secure attachment to the board.

[0064] Wider lead terminals (such as in inductor 800) also improve the inductor's shock and vibration handling capabilities and enhance heat transfer between the inductor and the circuit board. Furthermore, thinner, wider lead terminals (such as in inductor 800) are easier to form or bend.

[0065] Furthermore, those skilled in the art will recognize that inductors with the opposite configuration, consisting of a flatter, wider central portion and thicker, narrower leads, are also available within the spirit and scope of the subject matter of this application. Inductors with a flatter, wider central portion and narrower leads can be used to match existing circuit board footprints. This is advantageous, for example, in circuit boards with a fixed design or layout to accommodate inductors of a specific size.

[0066] Figures 9A-9B An inductor 900 according to another alternative embodiment described herein is shown. The inductor 900 is generally associated with... Figure 1A-1H The inductor 100 shown and Figures 8A-8C The inductor 800 shown is formed from the same material. For example... Figure 9A As shown, the inductor 900 preferably includes an inductor body 910 that partially surrounds a pre-formed conductive coil 920. The inductor 900 preferably has a conductive coil 920, which is preferably formed of a flat wire having an omega shape, the omega shape having a middle section 930 and L-shaped right and left leads 940, 950. Similar to... Figures 8A-8C In the inductor 800 shown, the middle portion 930 of the conductive coil 920 preferably has a greater thickness than the right and left leads 940 and 950, and the thickness of the conductor gradually tapers from the middle portion 930 toward the right and left leads 940 and 950, making the right and left leads 940 and 950 preferably flatter than the middle portion 930. Figures 9A-9B As shown. Inductor 900 and Figures 8A-8C The difference in the inductor 800 shown is that the middle portion 930 of the conductive coil 920 is elliptical instead of semi-circular, and the height of the inductor body 910 is greater than its width. For example, but not limited to, the aspect ratio can be approximately 1.5:1 or 2:1. Alternatively, according to another embodiment (not shown), the middle portion of the conductive coil can be elliptical, such that it has a smaller height relative to its width.

[0067] Figures 9A-9B The advantage of the inductor 900 depicted is that the inductor body 910 can have various heights and widths to allow for a wider range of applications. Inductors such as inductor 900 facilitate customization of inductor dimensions to more effectively utilize available space on the circuit board. This is useful, for example, in applications where board footprint is limited but height is more flexible. Similarly, this is useful in applications where inductor height is a limiting factor, but the width or length of the inductor offers greater flexibility.

[0068] Figure 3 An exemplary method 300 for manufacturing an inductor according to the present invention is described. In one embodiment, the inductor body 110 can be formed by pressing a magnetic material around a pre-formed conductive coil 200. Those skilled in the art will understand that Figure 3 The method of manufacturing inductors described herein and the mold assembly depicted with reference to inductor 100 in Figures 4-7 are for illustrative purposes only. Those skilled in the art will understand that inductors using pre-formed conductive coils of different sizes and shapes, and inductor bodies of different sizes and shapes, are used in... Figure 3-7 The methods and mold components described herein are within the scope and spirit of this document.

[0069] At step 310, the pre-formed conductive coil 200 (such as in...) is... Figure 2A-2CThe (as depicted) is preferably disposed in the mold assembly 400. An exemplary mold assembly 400 is in... Figures 6A-6C The drawing depicts an upper mold section 410 and a lower mold section 411. Those skilled in the art will recognize that the terms "lower" and "upper" are used as reference points in the drawings, and that the lower mold section 410 may be located on the top side of the mold assembly 400, and the upper mold section 411 may be located on the bottom side of the mold assembly 400. Those skilled in the art will also understand that, within the scope of the invention, a single mold section or multiple mold sections may be used.

[0070] like Figures 4A-4C As shown, the lower mold section 410 is preferably a block shape having a top side 412, a bottom side 414, a right side 416, a left side 418, a front side 420, and a rear side 422. Those skilled in the art will recognize that the lower mold section 410 can have other shapes without departing from the scope of the invention. The lower mold section 410 preferably has one or more placement channels 424. Figures 4A-4C In the illustrated exemplary embodiment, the lower mold section 410 has a single placement channel 424; however, those skilled in the art will recognize that, within the scope of the invention, the lower mold section 410 may have multiple placement channels to improve production efficiency. The placement channel 424 preferably extends from the top side 412 through the lower mold section 410 to the bottom side 414, and is preferably open on both the top side 412 and the bottom side 414. However, in one embodiment, the placement channel 424 may be closed on one side. The lower mold section 410 may include alignment holes (not shown) to align the lower mold section 410 with the upper mold section 411 during the molding process.

[0071] like Figures 4A-4C As shown, the placement channel 424 is defined by channel wall 426. Right shelf 430 and left shelf 432 are preferably formed in channel wall 426 and positioned to receive the right and left leads 210, 220 of the conductive coil 200. Right shelf 430 and left shelf 432 preferably have shapes complementary to the shapes of leads 210, 220. In one embodiment, right shelf 430 and left shelf 432 are L-shaped to accommodate L-shaped leads 210, 220 of the conductive coil 200. A central protrusion 434 is formed in channel wall 426 and is preferably positioned between right and left shelves 430, 432. The central protrusion 434 serves to form a segment of the lead side 110 of the inductor body 110 positioned between leads 210 and 220 in the formed inductor (see...). Figure 1A The placement channel 424 preferably has a right narrowing wall and a left narrowing wall 436, 438 formed in the channel wall 426, which form a right cutout and a left cutout 142, 152 in the inductor body 110.

[0072] like Figure 5A and Figure 5B As shown, the conductive coil 200 is preferably positioned in the mounting channel 424 such that the right and left leads 210, 220 are positioned within the right and left shelves 430, 432 of the mounting channel 424 and contact the channel wall 426. The right and left shelves 430, 432, the right and left narrowing walls 436, 438, the intermediate protrusion 434, and the channel wall 426 preferably work together to restrict movement of the conductive coil 200 during molding. Furthermore, the intermediate protrusion 434 and the right and left leads 210, 220 are preferably used to form the lead side 120 of the inductor body 110.

[0073] Figures 6A-6C An exemplary embodiment of a mold assembly 400 is shown, which includes a lower mold section 410, an upper mold section 411, a lower punch 500, and an upper punch 502. In one embodiment, the upper mold section 411 is preferably block-shaped. Those skilled in the art will recognize that the upper mold section 411 may have other shapes without departing from the scope of the invention. The upper mold section 411 preferably has a receiving channel 464. Those skilled in the art will recognize that the upper mold section 411 may have a plurality of receiving channels 464 to correspond to the number of placement channels 424 in the lower mold section 410. The receiving channel 464 preferably extends from the top side to the bottom side of the upper mold section 411, and preferably is open on both the top and bottom sides. The upper mold section 411 may include alignment holes (not shown) for alignment with the lower mold section 410 during molding.

[0074] Return to reference Figure 3 At step 320, magnetic material 504 may be introduced into molding assembly 400. Magnetic material 504 is preferably magnetic particles, more preferably powdered or granular magnetic material, and even more preferably powdered iron material. Magnetic material 504 is preferably poured into mold assembly 400 around conductive coil 200. In one embodiment, a portion of magnetic material 504 may be pre-compressed or pre-pressed together with conductive coil 200 and added to mold assembly 400. An initial pressing step may be performed on the pre-compressed or pre-pressed magnetic material, and then additional loose magnetic material 504 may be added to mold assembly 400 during a final pressing step.

[0075] In step 330, magnetic material 504 is molded around conductive coil 200 within mold assembly 400. Magnetic material 504 is preferably pressed by lower and upper punches 500, 502 into an inductor body 110 encapsulating conductive coil 200, except for the exposed portions of the right and left leads 210, 220. Figures 6A-6CIn the exemplary embodiment shown, the lower punch 500 is inserted from the bottom side 414 of the lower mold section 410 through the placement channel 424, and the upper punch 502 is inserted from the top side of the upper mold section 411 through the receiving channel 464 to press powdered magnetic material around the conductive coil 200. Figure 6B A mold assembly 400 without magnetic material inserted around the conductive coil 200 is shown. Figure 6C A mold assembly 400 is shown having a magnetic material 504 inserted and pressed around a conductive coil 200. Those skilled in the art will recognize that other forms of molding of powdered magnetic materials can be employed without departing from the scope of the method 300, including but not limited to pressure molding, injection molding, etc.

[0076] Figure 7 An inductor 100 formed within a lower mold section 411 after a molding step is shown. After the molding step, a magnetic material 504 is formed as a composite material surrounding a conductive coil 200.

[0077] Return to reference Figure 3 After the inductor 100 is formed by the molding process in step 330, in step 340, the formed inductor 100 is cured, such as by heating in an oven. This curing process bonds the powdered magnetic material forming the inductor body together. Those skilled in the art will recognize that other forms of curing can be used without departing from the scope of the invention.

[0078] At step 350, the formed inductor 100 may optionally be inspected, such as by visual inspection and / or electrical characteristic inspection. The unique arrangement of leads 210, 220 allows for stronger solder joint connections between the inductor and the circuit board, and also allows for improved visibility during overhead inspections such as AOI or X-ray inspections.

[0079] The inductor 100 made with pre-formed conductive coil 200 according to any embodiment discussed herein eliminates the need for post-processing cutting of leads to solder wires to a lead frame, resulting in solder joints and the lead frame, which improves inductor performance. The inductor 100 made with pre-formed conductive coil 200 according to any embodiment discussed herein also eliminates the need for post-printed lead processing (such as forming and / or bending leads around the inductor body).

[0080] As described above, the leads 210, 220 of the conductive coil 200 serve as a significant portion of the walls of the mounting channels 424, 426 during molding. This allows the inductor 100 to have a minimal usable footprint while maximizing the usable core area within the inductor body 110. Furthermore, the arrangement of the conductive coil 200 within the mounting channels 466 of the mold assembly 200 of the present invention restricts the movement of the conductive coil 200 during molding, which allows the conductive coil 200 to be consistently positioned within the inductor body 110, and preferably at the center of the inductor body 110.

[0081] like Figure 1A , Figure 1B , Figure 1G and Figure 1H As shown, the exposed portions of the right and left leads 210 and 220 constitute a significant portion of the lead side 120 of the inductor body 110, which maximizes the strength of the solder joint and makes the inductor ideal for surface mount applications. Furthermore, the sides 214 and 224 provide additional shock and vibration stability to the finished inductor 100.

[0082] Inductors according to any embodiment discussed herein can be used in electronic applications with relatively small footprints, surface mount, and / or high form factor requirements, such as server applications or other applications including DC / DC converters for servers, ultrabooks, laptops, automotive BLDC motors, and solar inverters. Furthermore, inductors according to any embodiment discussed herein preferably achieve one or more of the following: low DC resistance (DCR) below 0.15 mΩ; inductance above 100 nH; DC handling capability in the range of 100-125 A while generating a temperature rise of 40°C or lower; low profile and high current; efficiency where circuits and / or similar products cannot meet current requirements.

[0083] The inductor 100 described herein provides a simple and cost-effective way to produce consistent inductors with minimal waste. Almost all the materials used to manufacture the inductor 100 are used in the finished product. Compared to competing products with waste components such as lead frames and wires, and additional labor requirements due to post-processing finishing and forming, the inductor 100 described herein achieves significant component and labor costs.

[0084] It should be understood that the foregoing is presented by way of illustration only and not by way of limitation. Various substitutions and modifications to the described embodiments are conceivable without departing from the spirit and scope of the invention. Having described the invention in such detail, it will be understood and apparent to those skilled in the art that many physical changes can be made without altering the inventive concepts and principles embodied therein (of which only a few are exemplified in the detailed description of the invention). It should also be understood that multiple embodiments are possible in conjunction with only a portion of the preferred embodiments, for which the inventive concepts and principles embodied are not altered. Therefore, these embodiments and optional configurations are to be considered exemplary and / or illustrative rather than restrictive in all respects, the scope of the invention is indicated by the appended claims rather than by the foregoing description, and all alternative embodiments and modifications thereof falling within the equivalent meaning and scope of the claims should therefore be included therein.

Claims

1. An inductor comprising: A pre-formed conductive coil includes a middle portion comprising a single curved turn positioned between a first extension leg and a second extension leg, the first extension leg and the second extension leg extending from corresponding first and second symmetrical terminal leads. as well as A monolithic inductor body comprising magnetic material molded around a portion of a pre-formed conductive coil, the monolithic inductor body comprising a front surface and an opposite rear surface, a top surface and an opposite bottom surface, and a first side surface and an opposite second side surface, the height of the monolithic inductor body extending between the top surface and the bottom surface, the width of the monolithic inductor body extending between the first side surface and the second side surface, the depth of the monolithic inductor body extending between the front surface and the rear surface, the height of the monolithic inductor body being greater than the depth of the monolithic inductor body, and the bottom surface being configured to face the surface on which the inductor is mounted; Wherein, at least a portion of each of the first symmetrical terminal leads and the second symmetrical terminal leads of the pre-formed conductive coil is exposed outside the monolithic inductor body along the bottom surface of the monolithic inductor body, and The first and second extension legs extend from the bottom surface of the monolithic inductor body along the height direction, and the single curved turn of the middle portion extends from the first and second extension legs toward the top surface of the monolithic inductor body. The single curved turn of the middle portion of the pre-formed conductive coil has a first portion and a second portion, the first portion bending outward from the first extension leg toward the first side surface, and the second portion bending outward from the second extension leg toward the second side surface.

2. The inductor of claim 1, wherein, The magnetic material is molded around the middle portion of the conductive coil and portions of the first symmetrical terminal lead and the second symmetrical terminal lead.

3. The inductor of claim 1, wherein, The middle portion can be circular, semi-circular, or elliptical.

4. The inductor according to claim 1, wherein, The conductive coil is omega-shaped.

5. The inductor according to claim 1, wherein, The single-piece inductor body is in a package shape.

6. The inductor according to claim 1, wherein, The first symmetrical terminal lead is a mirror image of the second symmetrical terminal lead.

7. The inductor according to claim 5, wherein: Each of the first symmetrical terminal lead and the second symmetrical terminal lead further includes: The bottom has an exposed portion positioned along the bottom surface of the monolithic inductor body; and The side portion terminates along a corresponding one of the first side surface and the second side surface of the monolithic inductor body.

8. The inductor according to claim 7, wherein, Each of the first and second side surfaces of the monolithic inductor body includes a cutout portion, and the side portion of a corresponding one of the first and second symmetrical terminal leads is positioned within the cutout portion. The maximum width of the conductive coil between the corresponding sides of the first symmetrical terminal lead and the second symmetrical terminal lead is substantially the same as the maximum width of the monolithic inductor body.

9. The inductor according to claim 7, wherein, The side of each of the first symmetrical terminal lead and the second symmetrical terminal lead is pre-formed to be substantially perpendicular to the bottom of each of the first symmetrical terminal lead and the second symmetrical terminal lead.

10. The inductor according to claim 5, wherein, Each of the first symmetrical terminal lead and the second symmetrical terminal lead is substantially L-shaped or U-shaped, wherein a first portion of the L or U is positioned along the bottom surface of the monolithic inductor body, and a second portion of the L or U is positioned along a corresponding one of the first side surface and the second side surface of the monolithic inductor body.

11. The inductor according to claim 1, wherein, Each of the first symmetrical terminal lead and the second symmetrical terminal lead of the conductive coil has a flatter and wider cross-sectional area than the cross-sectional area of ​​the middle portion of the conductive coil.

12. The inductor according to claim 1, wherein, The magnetic material is a powdered magnetic material.

13. The inductor according to claim 1, wherein, The magnetic material is powdered iron particles.

14. The inductor according to claim 1, wherein, The magnetic material surrounds at least the entire middle portion of the conductive coil without any gaps.

15. The inductor according to claim 1, wherein, The pre-formed conductive coil is formed as a planar component without any stacked coil turns.

16. The inductor according to claim 4, wherein, Each of the first and second symmetrical terminal leads of the pre-formed conductive coil is exposed outside the monolithic inductor body along a common plane.

17. The inductor according to claim 1, wherein, A centerline is defined in the height direction between the first side surface (140) and the second side surface (150), and the first extension leg (232) and the second extension leg (234) are positioned closer to the centerline than the first and second portions of the single curved turn of the intermediate portion (230).

18. The inductor according to claim 1, wherein, A center line is defined along the height direction between the first side surface (140) and the second side surface (150), and The single curved turn of the middle portion of the pre-formed conductive coil extends in a continuous path in the height direction, the continuous path extending outward from each of the first extension leg (232) and the second extension leg (234) toward the corresponding first side surface (140) and second side surface (150), and then extending inward toward and across the centerline near the top surface (130) of the monolithic inductor body (110).

19. The inductor according to claim 1, wherein, Each of the first symmetrical terminal lead (210) and the second symmetrical terminal lead (220) further includes a bottom having an exposed portion positioned along the bottom surface of the monolithic inductor body; and the combined width of the exposed portions of the first symmetrical terminal lead (210) and the second symmetrical terminal lead (220) extends in the width direction along most of the bottom surface (120) of the monolithic inductor body (110).

20. A method for manufacturing an inductor, comprising: A conductive coil is provided having an intermediate portion including a single curved turn positioned between a first extension leg and a second extension leg, the first extension leg and the second extension leg extending from a first symmetrical terminal lead and a second symmetrical terminal lead, the conductive coil having a top side and a bottom side in a height direction and a first side and a second side in a width direction, the first extension leg and the second extension leg extending from the bottom side of the conductive coil along the height direction, the single curved turn extending from the first extension leg and the second extension leg toward the top side of the conductive coil, the single curved turn having a first portion and a second portion, the first portion bending outward from the first extension leg toward the first side, and the second portion bending outward from the second extension leg toward the second side; as well as Magnetic material is molded around at least the middle portion of the formed conductive coil to form a monolithic inductor body, wherein at least a portion of the first symmetrical terminal lead and the second symmetrical terminal lead of the formed conductive coil are exposed to the outside of the monolithic inductor body.

21. The method according to claim 20, wherein, The monolithic inductor body is essentially a package shape having a bottom surface, a top surface, a first side surface, a second side surface, a front surface, and a rear surface, and the first symmetrical terminal lead and the second symmetrical terminal lead are exposed along the bottom surface of the monolithic inductor body and a corresponding one of the first side surface and the second side surface.

22. The method according to claim 21, wherein, Molding the magnetic material further includes: Position the formed conductive coil in the mold assembly; Introducing the magnetic material into the mold assembly; and The magnetic material is pressed around the formed conductive coil.

23. The method according to claim 22, wherein, Positioning the formed conductive coil within the mold assembly further includes: The first and second symmetrical terminal leads of the formed conductive coil are placed on the first and second shelves within the wall of the mounting channel formed in the mold assembly. The first shelf and the second shelf have shapes complementary to the first symmetrical terminal lead and the second symmetrical terminal lead, such that the first symmetrical terminal lead and the second symmetrical terminal lead serve as part of the wall of the mold assembly during molding.

24. The method of claim 23, wherein, The first symmetrical terminal lead and the second symmetrical terminal lead are L-shaped or U-shaped.

25. The method according to claim 24, wherein, The first shelf and the second shelf each further include a narrowing wall, the narrowing wall forming complementary cutouts in each of the first side surface and the second side surface of the monolithic inductor body, and A portion of each of the first symmetrical terminal lead and the second symmetrical terminal lead is positioned in a corresponding cutout.

26. An assembly for forming an inductor having a pre-formed conductive coil, the pre-formed conductive coil including an intermediate portion located between a first terminal lead and a second terminal lead, the assembly comprising: A mold section having a placement channel defined therethrough and a wall surrounding the placement channel, the wall including a first shelf and a second shelf configured to receive a first terminal lead and a second terminal lead of the pre-formed conductive coil; as well as At least one punch, the at least one punch being configured to press magnetic particles around the conductive coil when the conductive coil is positioned within the mold section. The first shelf and the second shelf have shapes complementary to the first terminal lead and the second terminal lead of the conductive coil, such that when the magnetic particles are pressed around the conductive coil, the first terminal lead and the second terminal lead can contact the wall of the mold section.

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