Inductor manufacturing method

Abstract

To provide electromagnetic devices having conductive elements, leads and the like of multiple thicknesses for devices such as an inductor.SOLUTION: In an electromagnetic device 100 having a conductive element 150 with a prescribed shape, a first curved portion C1 has a first end 152 (lead) extending adjacent to one of leads 140a, and a second end 153, where the first curved portion C1 curves around the center of the conductive element 150. A second curved portion C2 has a first end 155 extending from the other of leads 140b (lead portion), and a second end 154, where the second curved portion curves around the center of the conductive element 150 in an opposite direction from the first curved portion C1. Each curved portion forms an arc encircling part of the center of the conductive element 150. The curved portions are each formed along a circumferential path about a central area of the conductive device.SELECTED DRAWING: Figure 1A

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application was filed on June 18, 2021, and claims priority to U.S. Patent Application No. 17 / 351,782, which is incorporated herein by reference in its entirety.

[0002] This application relates to the field of electronic components, and in particular to multi-thickness electromagnetic devices such as conductive elements and leads for devices such as inductors, and to multi-thickness electromagnetic devices and electromagnetic devices formed using the multi-thickness templates described herein.

[0003] Electromagnetic devices such as inductors are generally passive two-terminal electronic components. An inductor generally consists of a conductor, such as a wire, wound into a coil. When a current flows through the coil, energy is temporarily stored in the magnetic field within the coil. When the current through the inductor changes, the time-varying magnetic field induces a voltage in the conductor according to Faraday's law of electromagnetic induction.

[0004] Some known inductors are generally formed as a core body of magnetic material with an internal conductor, such as a wound coil, sometimes formed as a wound coil. Examples of known inductors are disclosed in U.S. Patent Nos. 6,198,375 ("Inductor Coil Structure") and 6,204,744 ("High Current, Low Profile Inductor"), both of which are incorporated herein by reference.

[0005] It is often necessary to shape, set, or adjust the performance characteristics of an electromagnetic device by changing the characteristics or parameters of some element, such as a wire or coil. Many electromagnetic devices use wound coils formed from conductive materials. The characteristics of such devices can be adjusted by increasing the number of turns in the coil, i.e., by increasing the number of coil windings. Therefore, specialized machinery and careful adjustments are required.

[0006] When designing electromagnetic devices that require coils formed as laminated or folded layers, additional machining and adjustments are required. Designs that require soldering of different workpieces require additional machining and adjustments and have weaknesses.

[0007] When designing electromagnetic devices with thicker lead portions, there is a possibility that the core body surrounding the lead portions may crack when the lead portions are bent around the core body.

[0008] There is a need for simple, cost-effective methods for fabricating electromagnetic devices with consistent characteristics, such as inductors with low direct current resistance (DCR).

[0009] There is also a need to manufacture electromagnetic devices, such as inductors, in a manner that improves their performance.

[0010] Additionally, there is a need to manufacture electromagnetic devices such as inductors having conductive elements, such as coils or wires, that are of different sizes but are not wound or formed from wound pieces of wire. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] U.S. Patent No. 6,198,375 [Patent Document 2] U.S. Patent No. 6,204,744 Summary of the Invention

[0012] Disclosed herein are methods for forming or manufacturing conductive elements and leads having multiple thicknesses, and electromagnetic devices having multiple thicknesses.

[0013] As used herein, "multiple-thickness" refers to having one or more thicknesses, at least two different thicknesses, multiple thicknesses, various thicknesses, or multiple different thicknesses. In some embodiments, the thickness can be measured along the length, width, or height of the electromagnetic device or lead frame, depending on the orientation of the device. As used herein, the term "electromagnetic device having multiple thicknesses" refers to an electromagnetic device having a coil, a conductor or conductive element, and one or more leads, where the coil, conductor or conductive element, and one or more leads have various or different thicknesses, as described in more detail below. For example, the coil and the conductor or conductive element may have a first thickness, one of the leads may have a second thickness, and another of the leads may have a third thickness, where the first thickness is different from the second thickness, and the first thickness is different from the third thickness.

[0014] An electromagnetic device according to one embodiment of the present invention includes a conductive element formed from a conductive material connected to a first lead and a second lead. The conductive element has a first thickness, the first lead has a second thickness, and the second lead has a third thickness. The first thickness may be different from the second thickness, and the first thickness may be different from the third thickness and may be greater than the second thickness. The first thickness may be greater than the third thickness. The conductive element can have a variety of shapes.

[0015] One aspect of the present invention provides a method for manufacturing an electromagnetic device, comprising: providing a conductive material; and forming the conductive material into a conductive element having a first thickness, a first lead portion having a second thickness, and a second lead portion having a third thickness, wherein the first thickness is greater than the second thickness, and the first thickness is greater than the third thickness. The method can further optionally include stamping a body around the conductive element, at least a portion of the first lead, and at least a portion of the second lead.

[0016] A method for manufacturing a template for forming an electromagnetic device having multiple thicknesses according to one embodiment of the present invention includes the steps of providing a conductive material and forming the conductive material into a template having multiple thicknesses, the template having a conductive element having a first thickness, a first lead portion having a second thickness, and a second lead portion having a third thickness, the first thickness being greater than the second thickness, and the first thickness being greater than the second thickness. The template can be in the form of a lead frame.

[0017] One aspect of the present invention relates to a method for fabricating a template for a multi-thickness electromagnetic device. The method involves extruding a conductive material into a multi-thickness metal extrusion or sheet having regions of different thicknesses or heights. The extruded conductive material is a single, continuous, or integral piece of conductive material, such as a conductive metal. The thicker region, generally corresponding to a central region of the extruded conductive material, is a portion of the extruded conductive material and is thicker than the thickness of the outer, or side, regions of the central region. The multi-thickness extruded conductive material can be plated with a first layer of nickel and a second or outer layer of tin. The multi-thickness extruded conductive material is then stamped to form a multi-thickness template having a desired shape and conductive elements connected to first and second leads. The stamped multi-thickness template thus has shaped regions that can be considered coils, coil regions, or wire regions, and may be collectively referred to herein as "conductive elements." The conductive elements generally form the central or inner regions of the template within the thicker region of the template. The conductive element, the first lead, and the second lead are all formed from a single, continuous, or integral piece of conductive material.

[0018] Another aspect of the present invention relates to a method for manufacturing a multi-thickness template for an electromagnetic device. The method includes providing a metal plate, sheet, or strip of conductive material starting with a uniform thickness or height. The conductive material is a single, continuous, or integral piece of conductive material. The conductive material is metal skived or cut using a cutting tool with various sized surfaces, such as a blade having a cutting surface at a first height and at least one non-cutting surface at a second, lower height, to form a multi-thickness metal sheet. The conductive material can be plated with a first layer of nickel and a second or outer layer of tin, for example. The conductive material is then stamped to form a template of the desired shape of a conductive element connected to first and second leads. The conductive element corresponding to the thicker regions of the multi-thickness template is thicker than the outer or side regions of the multi-thickness template and / or leads.

[0019] Another aspect of the present invention relates to a method for fabricating a multi-thickness template for an electromagnetic device. The method includes providing a metal plate, sheet, or strip of conductive material that begins with a uniform thickness or height. The conductive material may be a single, continuous, or integral piece of conductive material. The conductive material may be plated with a first layer of nickel and a second or outer layer of tin, for example. The conductive material is then stamped to produce a template having conductive elements with a desired shape and leads extending from the conductive material. To fabricate a multi-thickness template using conductive elements with greater thicknesses in outer or side regions of the conductive material and / or leads, the predetermined outer regions of the template, which may include the leads, are flattened by swaging, pressing, or the like. In this configuration, the thickness or height of the predetermined outer region is smaller than the thickness or height of the conductive elements.

[0020] In one embodiment of the present invention, the thickness of the conductive element is less than the thickness of the first lead and / or less than the thickness of the second lead. In this embodiment of the present invention, a manufacturing method similar to that described above can be carried out, and the thickness of the conductive element can be made smaller, and the thickness of the first lead or the second lead can be made thicker than the thickness of the conductive element.

[0021] In one aspect of the invention, the templates disclosed herein can be used to form electromagnetic devices.

[0022] In one aspect of the present invention, an electromagnetic device can be formed having only one conductive element and lead portion with different thicknesses, in which case no core body or core material is formed around the conductive element or lead portion.

[0023] An electromagnetic device according to one embodiment of the present invention may have a magnetic powder, body, or core body compressed and / or molded around a conductive element and portions of the conductive element, such as the conductive element and portions of the leads adjacent to the conductive element. In this case, the leads may be disposed around and folded around the outer surface of the body to form contact points on one outer surface of the body. Preferably, some of the leads are disposed along the bottom surface of the body to form surface-mount leads. In other embodiments, the leads are not folded in this manner.

[0024] The conductive material can be formed into a conductive element having a particular shape, such as a serpentine shape, or other shapes with bent or curved regions, such as an "S" shape, a circle, an ellipsoid, or an omega (Ω) shape. The conductive element can be generally formed into a predetermined shape, such as a beam-like rectangle, an "I" shape, an "H" shape, a "barbell" shape, or any other predetermined shape. The body of the electromagnetic device surrounds the conductive element and can be pressed around the conductive element, with leads extending from the surface(s) of the body.

[0025] It should be noted that the conductive element of the present invention is formed without the need for multiple layers of wire or coils or without winding. In some embodiments, the present invention provides a non-wirewound conductive element having a greater thickness or height region formed as a unitary piece with the attached leads by extruding, stamping, pressing, and / or cutting a sheet of metal. Preferably, there are no interruptions or breaks in the conductive element along the path from one lead along the conductive element to the other lead. The conductive element is non-wirewound, and no portion of the conductive element passes over or crosses another portion.

[0026] Also, other conductive materials known in the art, such as other materials used for coils and conductive elements, may be used without departing from the teachings of this invention. Insulation may be provided around or between portions of the conductive elements and / or leads, if desired for a particular application.

[0027] The lead portions may be aligned along a generally linear path or may lie generally along the same plane and may have a predetermined height and width.

[0028] The leads and conductive elements can be formed simultaneously during the manufacturing process, and the conductive elements do not need to be joined to the leads by welding or the like.

[0029] In accordance with the teachings of the present invention, electromagnetic devices can be formed having multiple thicknesses of conductive material within a single, continuous, or uniform piece.

[0030] Coil regions or conductive elements with greater thickness function in part to reduce the direct current resistance (DCR) of the inductor.

[0031] The thin, low thickness of the outer portion (e.g., the lead portion) facilitates lead formation. Furthermore, forming the lead portion in accordance with one or more aspects of the present invention increases the solderable surface area of ​​the lead portion, improving the mounting stability of the device and thereby improving shock and vibration resistance. Additionally, lead portions formed in accordance with the present invention improve heat transfer between the electromagnetic device and the circuit board, such as a printed circuit board (PCB), on which the device is mounted. [Brief explanation of the drawings]

[0032] The above-described aspects and many of the attendant advantages of the present invention will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0033] FIG. 1A is an isometric view of an electromagnetic device in partial transparency according to one embodiment of the present invention.

[0034] FIG. 1B is a partially transparent top view of the electromagnetic device according to one embodiment of the present invention shown in FIG. 1A.

[0035] FIG. 1C is a side view of the electromagnetic device according to one embodiment of the present invention shown in FIG. 1A, with some parts being transparent.

[0036] FIG. 2A is an isometric view of a partially transparent electromagnetic device according to one embodiment of the present invention.

[0037] FIG. 2B is a partially transparent top view of the electromagnetic device according to one embodiment of the present invention shown in FIG. 2A.

[0038] FIG. 2C is a partially transparent side view of the electromagnetic device according to one embodiment of the present invention shown in FIG. 2A.

[0039] FIG. 3 is a flow chart illustrating a method for fabricating a multi-thickness template and an electromagnetic device according to one embodiment of the present invention.

[0040] FIG. 4 illustrates a metal sheet formed from a conductive material according to several embodiments of the present invention.

[0041] FIG. 5A shows a metal sheet with multiple thicknesses according to one embodiment of the present invention.

[0042] FIG. 5B is a side view of the multi-thickness metal sheet of FIG. 5A.

[0043] FIG. 6 is a diagram illustrating a template with multiple thicknesses according to one embodiment of the present invention.

[0044] FIG. 7 illustrates a multi-thickness template according to one embodiment of the present invention, with bodies formed around multiple regions of the template.

[0045] FIG. 8 is a diagram illustrating a template with multiple thicknesses according to one embodiment of the present invention.

[0046] FIG. 9 is a flowchart illustrating a method for fabricating a multi-thickness template and an electromagnetic device according to one embodiment of the present invention.

[0047] FIG. 10 shows a blade skiving a metal sheet to form sheets of multiple thicknesses.

[0048] FIG. 11 is a flow chart illustrating a method for fabricating a template and electromagnetic device with multiple thicknesses according to one embodiment of the present invention.

[0049] FIG. 12 is a diagram showing a template according to one embodiment of the present invention.

[0050] FIG. 13 is a detailed view of a multi-thickness template having planarized lead portions according to one embodiment of the present invention.

[0051] FIG. 14 is an isometric view of an electromagnetic device according to one embodiment of the present invention.

[0052] FIG. 15 is an isometric view of an electromagnetic device or template according to one embodiment of the present invention.

[0053] 16 is a diagram showing a template according to one embodiment of the present invention.

[0054] In the following description, certain terminology is used for purposes of explanation only and not limitation. The terms "right," "left," "top," and "bottom" refer to directions in the drawings to which reference is made. As used in the claims and corresponding parts of the specification, the singular terms "a," "the," "the," and "the" are defined as including one or more of the subject element, unless specifically stated to the contrary. This terminology encompasses the specifically mentioned word, its derivatives, and words of similar import. The term "at least one" preceding two or more words, such as "A, B, or C," refers not only to any one of A, B, or C, but also to any combination thereof. While some of the drawings show partially transparent portions, these are intended for explanation, illustration, and demonstration purposes only. Furthermore, these drawings do not imply that an element will be transparent in its final manufactured form.

[0055] 1A-1C illustrate an example of an electromagnetic device 100 that can be formed in accordance with an embodiment of the present invention and includes a shaped conductive element 150, sometimes referred to as a "coil" or "coil region." In the embodiment shown in FIGS. 1A-1C, conductive element 150 includes a serpentine or meandering element, which may be configured as an "S"-shaped element, "S-shaped" element, or "S-conductive element" when viewed, for example, in the orientation shown in FIGS. 1A and 1B or when viewed from above or below. A first curved portion C1 has a first end 152 (also referred to as a "lead portion") that extends adjacent to one of leads 140a, and a second end 153, and the first curved portion C1 curves around the center of conductive element 150. The second curved portion C2 has a first end 155 extending from another of the leads 140b (also referred to as the "lead portion") and a second end 154, and the second curved portion curves around the center of the conductive element 150 in the opposite direction from the first curved portion C1. Each curved portion forms an arc that surrounds a portion of the center of the conductive element 150. Each curved portion follows a circumferential path around the central region of the conductive device. A similar configuration for an electromagnetic device is described in U.S. Pat. No. 10,854,367, which is incorporated herein by reference in its entirety. A central portion 151 of the conductive element 150 crosses a generally diagonal line and extends between and connects the second end 153 and the second end 154. Preferably, the central portion can pass through the central region of the conductive element. The central portion 151 is generally straight.

[0056] The S-shaped conductive element or "S" shape is illustrative of one embodiment of the present invention. Other configurations are contemplated, including arc-shaped, Z-shaped, or N-shaped conductive elements, as well as curved or straight conductive elements, all of which are within the scope of the present invention. A conductive element configuration that extends along a serpentine path between leads, with a portion intersecting the midline or central portion of the conductive element or electromagnetic body, may be considered a "serpentine" conductive element. By way of example and not limitation, S-shaped, Z-shaped, or N-shaped conductive elements, as well as other shapes with a serpentine path from one lead to another, may all be considered "serpentine" conductive elements. The shape of conductive element 150 may be designed to optimize the path length relative to the space within the electromagnetic body while minimizing resistance and maximizing inductance. This space may be designed to maximize the ratio of used space to space within the electromagnetic body. In one embodiment of the present invention, conductive element 150 has a top surface that is preferably flat, i.e., oriented essentially in a plane. A serpentine conductive element may be considered a coil or coil region, but is distinct from a "wirewound" conductive element, which is formed from a wire or piece of conductive material wrapped around and surrounding a central portion or axis of an electromagnetic core.

[0057] As shown in FIGS. 1A-1C , the illustrated electromagnetic device 100 has a length L1 along an X1-X2 axis or X direction (where X1 is a first direction and X2 is a second direction opposite the first direction), a length L2 along a Y1-Y2 axis or Y direction (where Y1 is a third direction and Y2 is a fourth direction opposite the third direction), and a thickness H1 along a Z1-Z2 axis or Z direction (height when viewed from the side as in FIG. 1C , where Z1 is a fifth direction and Z2 is a sixth direction opposite the fifth direction). For ease of understanding, the Z1-Z2 axis will be referred to as the “thickness.” Similarly, thicker or taller regions of a conductive element may be referred to as “thicker regions.”

[0058] In one embodiment of the present invention, as shown in FIG. 1C , conductive element 150 has a thicker thickness region 159, which has a first thickness T1 along the Z1-Z2 axis as shown in FIG. 1C that is greater than the second and third thicknesses T2 and T3 of the conductive material portions of leads 140a, 140b, including lead portions 156, 157 adjacent outer side edges 174, 175 of conductive element 150. In this configuration, substantially the entire "S"-shaped conductive element 150 has thicker region 159. However, the portion of the conductive element having the thicker region can be thinner than the entire "S"-shaped conductive element. For example, a single conductive element can have thicker and thinner portions, each of which can be a thicker region. In this configuration, lead 140a has thickness T2 along substantially the entire length of lead 140a, and lead 140b has thickness T3 along substantially the entire length of lead 140a.

[0059] In one embodiment of the present invention, as shown in FIGS. 1A-1C, a finished electromagnetic device such as inductor 100 can have a body 133, also referred to as a core body, which is shown partially transparent and pressed around or otherwise encloses the conductive element 150 and at least a portion of the leads. This body can be formed as a first body portion 110 and a second body portion 120. First body portion 110 and second body portion 120 sandwich, press around, or otherwise enclose conductive element 150 and leads 140a, 140b to complete inductor 100. When compressed around the conductive element and a portion of the leads, first body portion 110 and second body portion 120 form a single, unitary, compressed body and can be referred to simply as the "body" or "core body."

[0060] Body 133 may be formed from a magnetic material, such as an iron-based material, and has a top surface 134 and an opposing bottom or lower surface 135, a first side 136 and an opposing second side 137, a first side 170 adjacent first lead 140a, and an opposing second side 172 adjacent second lead 140b. The body may be made of, for example, iron, a metal alloy, and / or ferrite, or a combination thereof, or other materials conventionally known and used to form such bodies. First body portion 110 and second body portion 120 may be made from iron powder or similar materials. Other acceptable materials, such as those known in the electromagnetic device art, may also be used to form the body or body portions. Magnetic molding materials containing iron powder, fillers, resins, and lubricants, such as those disclosed in U.S. Pat. No. 6,198,375 ("Electromagnetic Conductive Element Structures") and U.S. Pat. No. 6,204,744 ("High-Current, Low-Profile Inductor"), both of which are incorporated herein by reference in their entireties, can be used for the body. Body 133 can be formed from magnetic materials containing one or more of iron, iron alloys, and / or ferrites, and / or combinations thereof. For example, body 133 can be formed from iron, iron alloys, or ferrites, combinations thereof, or other materials known in the inductor art and used to form such bodies. Materials such as those described in U.S. Pat. Nos. 6,198,375 and 6,204,744, combinations thereof, and other equivalents known in the art can be used, and are generally referred to as "core material(s)." It should be noted that although the first body portion 110 and the second body portion 120 are formed from the same core material using the same forming method, the first body portion 110 and the second body portion 120 may be formed from different core materials using different processes as known in the art.

[0061] The regions of conductive material between the thicker region T1 of body 133 and outer sides 170, 172 may be considered the beginning or portion of leads 140a and 140b, or may be considered transition portions of conductive element 150 of lesser thickness or height extending between the thicker regions to sides 170, 172, respectively. For convenience, these regions are referred to as first inner lead portion 156 and second inner lead portion 157. As described below, these portions will be contained within or otherwise surrounded by body 133.

[0062] When first body portion 110 and second body portion 120 surround the conductive element and a portion of the leads and are pressed or overmolded around conductive element 150, a portion of leads 140a, 140b is initially exposed until folded under first body portion 110, as can be seen in the final state shown in the partially transparent embodiment of FIGS. 1 and 2. In the completed electromagnetic device or "portion," a portion of each lead 140a, 140b extends along a side or lateral surface of first body portion 110, as shown in FIGS. 1A-1C. First lead 140a may terminate in surface mount contact portion 130a, and second lead 140b may terminate in surface mount contact portion 130b, each folded under bottom surface 135 of body 133, which may be first body portion 110, as shown in FIGS. 1A-1C.

[0063] It should be noted that electromagnetic devices according to embodiments of the present invention can be formed without a core body. The leads can be bent to form surface-mount terminations. One example is shown in FIG. 14. FIG. 15 shows an electromagnetic device according to embodiments of the present invention that can be formed without a core body, with the leads straight, i.e., unbent, and extending either linearly or at an angle upward from the conductive element. FIGS. 14 and 15 illustrate examples of completed electromagnetic devices that can be constructed with conductive elements and leads having multiple thicknesses and that do not use core material or a core body surrounding these elements. The electromagnetic device 100′ can be constructed with a serpentine-shaped conductive element 150′. A first curved portion C1′ has a first end 152′ and a second end 153′ that extend along one of the leads 140a′ (also referred to as the “lead portion”), and the first curved portion C1′ curves around the center of the conductive element 150′. The second curved portion C2' has a first end 155' and a second end 154' extending from the other end of the lead 140b' (also referred to as the "lead portion"). This second curved portion is opposite the first curved portion C1' and curves around the center of the conductive element 150'. Each curved portion forms an arc surrounding the center of the conductive element 150'. The curved portions may extend along a circumferential path around the central region of the device. The central portion 151' of the conductive element 150' crosses a generally diagonal direction, connects the second end 153' to the second end 154', and preferably passes through the central region of the conductive element. The central portion 151' is generally straight. The first inner lead portion 156' is adjacent to the first end 152', and the second inner lead portion 157' is adjacent to the second end 155'. The conductive element 150' has a thicker region 159'. As shown in Figure 15, leads 140a', 140b' extend linearly outward from conductive element 150'. As shown in Figure 14, leads 140a', 140b' are bent to form surface mount lead portions 130a', 130b'. As shown in Figure 15, conductive element 150' has a thicker region, which includes a first thickness portion TH1B that is thicker than a second thickness portion TH2B adjacent outer end 174', and a third thickness portion TH3B adjacent outer end 175'.

[0064] Leads 140a, 140b may have the same uniform thickness, or substantially the same uniform thickness, along the entire length of each lead.

[0065] 2A-2C, illustrating another embodiment of the present invention, illustrate an example of an electromagnetic device 200 that can be formed in accordance with an embodiment of the present invention, including a shaped conductive element 250. In the device illustrated in FIGS. 2A-2C, conductive element 250 may be a substantially linear conductive element configured as an "I" or "H" shaped conductive element, or may be a "barbell" shaped conductive element when viewed from above, as shown in FIG. 2B. Such a conductive element may also be considered or referred to as a coil. In this configuration, a central portion 252 of conductive element 250 has a width W1 along the Y1-Y2 axis or Y direction when viewed in FIGS. 2A-2C, a first side 253 has an outer width W2 that is greater than width W1 along the Y1-Y2 axis or Y direction when viewed in FIGS. 2A-2C, and a second side 254 opposite first side 253 of device 200, having a width W3 that is greater than width W1 along the Y1-Y2 axis or Y direction when viewed in FIG. 3. W3 may be the same as W2. Conductive element 250 may be generally rectangular between first side 253 and second side 254.

[0066] 2A-2C show an embodiment of a conductive element 250 of the present invention, in which the conductive element 250 has a thicker region 259 having a first thickness T1′ that is greater than the second thickness T2′ and the third thickness T3′ of other portions of the conductive material, such as the lead portions, including the first and second inner lead portions 255 and 257, adjacent the outer ends 274, 275 of the conductive element 250 along the Z1-Z2 axis or direction, as shown in FIG. 2C. In this configuration, substantially the entire "barbell"-shaped conductive element can have the thicker first thickness T1′. The thicker portion of the conductive element can be smaller than the entire "barbell"-shaped conductive element, and the conductive element 250 is not wrapped around an axis.

[0067] While the finished electromagnetic device of the present invention can be formed without a core body as shown in Figures 2A-2C, in one embodiment of the present invention, the finished electromagnetic device 200, such as an inductor, has a body 233, shown partially transparent, or, for a core body, can be pressed onto or otherwise encase or surround at least a portion of the conductive element 250 and leads 140a, 240b. A body 233 may be formed having a top surface 234, an opposing lower or bottom surface 235, a first side 236 and an opposing second side 237, and a first side 270 adjacent to first lead 240a (or "lead portion") and an opposing second side 272 adjacent to second lead 240b (or "lead portion"). The body may be formed as first body portion 210 and second body portion 220. First body portion 210 and second body portion 220 sandwich and press around or otherwise contain conductive element 150 and portions of leads 240a and 240b to complete inductor 200. When compressed around the conductive element and portions of the leads, first body portion 210 and second body portion 220 may be considered a single, unitary compressed body from the core material(s).

[0068] Body portion 210 and second body portion 220 surround the conductive element and a portion of the leads and may be pressed or overmolded around conductive element 250, initially leaving exposed portions of leads 240a and 240b until they are folded under first body portion 210 as shown in the final state of the partially transparent embodiment in FIGS. 2A-2C. In the completed electromagnetic device or "part," each lead 240a and 240b may extend along side portions 270, 272 of first body portion 210 as shown in FIGS. 2A-2C. First lead 240a may terminate in a first contact portion 230a, and second lead 240b may terminate in a second contact portion 230b. Each contact portion is folded under the underside 235 of a body 233, such as first body portion 210, as shown in FIGS. 2A-2C.

[0069] The following describes a method for fabricating an electromagnetic device as illustrated in Figures 1A-2C or 14-16, or a similar electromagnetic device having a multi-thickness element or a multi-thickness template that can be used to form the electromagnetic device shown in Figures 1A-2C or 14-16, or a similar electromagnetic device. In some embodiments, the template can be formed as a lead frame.

[0070] In one embodiment of the present invention, a method for manufacturing an electromagnetic device is illustrated by the flow chart in FIG.

[0071] In step 1010, a conductive material is provided. This conductive material may be heated to form a molten conductive material that may be formed as disclosed herein. Examples of conductive materials include, but are not limited to, copper, steel, aluminum, zinc, bronze, and combinations or alloys thereof. Further examples of conductive materials that may be used include conductive materials in wire form, such as copper wire, aluminum wire, and platinum wire.

[0072] In step 1012, the conductive material is extruded using a metal extrusion process to form a sheet of multiple thicknesses. For example, a heated or molten conductive material is extruded through a shaped opening. The extrusion process involves forcing a near-molten or heated conductive material, such as a metal, through a die having the desired profile or shape. Figures 5A and 5B show a sheet of multiple thicknesses 310. The sheet has a central region 312 having a thickened region 314 with a first thickness TH1, a first outer portion 316 adjacent to a first side 318 of the thickened region 314 with a second thickness TH2 that is less than TH1, and a second outer portion 320 adjacent to a second side 329 of the thickened region 314 with a third thickness TH3 that is less than TH1. As shown, the first outer portion 316 and the second outer portion 320 may be located on opposite sides of the thickened region 314. As described below, multiple thickness sheets 310 are used to form a template.

[0073] Electroplating or a similar process may be used to plate the multiple thicknesses of sheet 310 with a first layer of nickel and a second layer of tin over the nickel in step 1014. Known plating methods may be used to form the nickel and tin layers, which improve solderability.

[0074] In step 1016, the multi-thickness sheet 310 is stamped or otherwise machined or formed to form a multi-thickness template 322 for use in an electromagnetic device such as that shown in FIGS. 1A-1C. FIG. 6 illustrates the multi-thickness template 322 with conductive elements 150 according to the configuration shown in FIGS. 1A-1C. It should be noted that various shapes of conductive elements can be formed without departing from the teachings herein. When stamped or otherwise machined, the template 322 has thicker regions that correspond to the thicker regions 314 of the multi-thickness sheet 310 used to form the template 322, which have a greater thickness TH1. The conductive elements 150 may be located in a central or interior region of the template.

[0075] 6 illustrates one or more conductive elements, the template can also be provided with a single conductive element. Additionally, the template can be provided with any number of conductive elements greater than or equal to two.

[0076] It should be noted that steps 1014 and 1016 can be performed in any order. For example, multi-thickness sheet 310 may be formed into multi-thickness sheet 322 according to step 1016 and then plated according to step 1014.

[0077] As shown in FIG. 6, the template 322 includes leads 140a and 140b connected to the conductive element 150. The area where the leads 140a and 140b are formed corresponds to a first outer portion 316 having a thickness TH2 and a second outer portion 320a having a third thickness TH3. Therefore, the thickness of each of the leads 140a and 140b is less than the greater thickness TH1 of the conductive element 150. The presence of the first inner lead portion 156 and the second inner lead portion 157 adjacent to the conductive element 150 facilitates lead formation, such as by bending. The small lead thickness facilitates bending and facilitates the formation of surface-mount leads without cracking or bursting. As shown in FIGS. 1B and 6, the leads 140a and 140b have a width along the Y1-Y2 axis, or Y direction, which may be smaller than the width of the conductive element 150.

[0078] For example, as illustrated in Figures 1A-1C and 6, the first inner lead portion 156 of the first lead 140a and the second inner portion 157 of the second lead 140b have a width (along the Y1-Y2 axis or direction) that may be narrower or smaller than the widths of other portions of the leads 140a, 140b, such as the first surface mount contact portion 130a and the second surface mount contact portion 130b.

[0079] The upper surface of the conductive element 150 can be formed to lie substantially in or along a plane. The lower surface of the conductive element 150 can be formed to lie substantially in or along a plane. The upper or lower surface of the conductive element can be generally flat.

[0080] The leads 140a, 140b can be formed with upper or lower surfaces that lie substantially in or along a plane. The upper or lower surfaces of the leads 140a, 140b can also be generally flat.

[0081] 6, the template 322 is formed as a lead frame, and has at least first and second carrier strips 324, 326 on opposing outer sides of the lead frame 322. The carrier strips 324, 326 may have progressive holes 328 used for alignment when connecting to a manufacturing device. Therefore, the carrier strips 324, 326 may be considered as members to be used as needed.

[0082] It should be noted that conductive element 150, leads 140a, 140b, and, if used, carrier strips 324, 326, are all formed from a single piece of conductive material. This piece of conductive material is pre-formed to a thickness greater than the thickness of leads 140a, 140b. Conductive element 150 is formed to a predetermined shape and does not require wrapping or bending of metal strip or wire. No portion of conductive element 150 crosses over or under another portion of conductive element 150. The inductance of an electromagnetic device fabricated as described herein can be adjusted, for example, by changing the thickness, width, shape, or other dimensions of the conductive element; by changing the core material; by increasing or decreasing the thickness of the core material; by changing the density of the core material, such as by hot or cold pressing; and / or by changing the position of the conductive element within the core body.

[0083] 15 can also be seen as a representation of a template for an electromagnetic device by, for example, trimming or bending leads 140a', 140b'. In this example, the template would be formed by stamping multiple thicknesses of conductive material into the shapes shown in FIG.

[0084] In step 1018, if the device has a core body, one or more core materials, preferably iron and / or ferrite powder, are pressed around conductive element 150 and a portion of leads 140a, 140b, including first and second inner lead portions 156, 157, to form body 133. To form body 133, a plated template 322 is inserted into a compression press, and one or more core materials are pressed into the coil portion of a lead frame of the desired shape, such as a generally rectangular shape. As shown, the shape may have rounded corners or edges. FIG. 7 illustrates template 322 with body 133, with the body 133 partially transparent, showing the body formed around conductive element 150 and a portion of leads 140a, 140b. Note that step 1018 is optional if the electromagnetic device is formed without a core body.

[0085] In step 1020, portions of the template adjacent the leads are trimmed to size and applied around body 133 to form surface mount leads, as desired for current circuit board assembly processes. At least a portion of each of leads 140a, 140b is applied along the side of body 133, and at least end portions 130 of leads 140a, 140b are bent under and applied along bottom surface 135 of body 133. As previously discussed, an example of a completed electromagnetic device 100 is shown in FIG. 1A.

[0086] Figure 8 illustrates a template 330 formed according to the process illustrated in Figure 3 and corresponding to an electromagnetic device having conductive elements 250 as shown in Figures 2A-2C. As shown in Figure 8, the conductive elements 250 of template 330 have linear conductive elements, such as "I" or "H" shaped conductive elements, or "barbell" shaped conductive elements when viewed from above. The template may be formed according to the process outlined in Figure 3 and described above. In step 1016, conductive elements 250 have the predetermined shape shown in Figures 2A-2C.

[0087] As shown in FIG. 8 , the template 330 includes not only the conductive element 250 but also the leads 240a and 240b. When the template 330 is formed as a lead frame, for example, carrier strips 332 and 334 may be provided. The conductive element 250 and the leads 240a and 240b are both formed from the same single piece of conductive material. The carrier strips 332 and 334 may include progressive holes 336 for alignment during connection to manufacturing equipment. The conductive element 250 may include a thicker region 280 having a thickness TH1a. The first lead 240a has a thickness TH2a, and the second lead 240b has a thickness TH3a. Therefore, the thickness of each of the leads 240a and 240b is thinner than the thicker thickness TH1a of the conductive element 150. The thinner thickness of the first inner lead portion 255 and the second inner lead portion 257 adjacent to the conductive element 150 facilitates forming the leads, for example by bending them. Because the leads have a thinner thickness, these regions can bend more easily to form surface mount leads without cracking or breaking. 2B and 8, the width (along the Y1-Y2 axis or Y direction) of first inner lead portion 255 and second inner lead portion 257 may be narrower or smaller than the width of other portions of leads 240a, 240b, such as first surface mount contact portion 230a or second surface mount contact portion 230b.

[0088] Skiving or cutting processes can also be used to manufacture electromagnetic devices according to aspects of the present invention. Skiving uses a cutting blade to skim off material.

[0089] A method for manufacturing an electromagnetic device according to one embodiment of the present invention is described with reference to the flowchart of FIG. 9. In step 2010, a sheet of conductive material is used as a starting material, which can be formed from the conductive material by rolling, pressing, or the like. FIG. 4 illustrates a sheet 300 formed from a conductive material. The term "sheet" as used herein encompasses the concepts of a sheet, plate, or strip of conductive material pieces used as starting materials to form the templates of the present invention. The sheet 300 of conductive material is preferably a metal sheet, such as copper. Examples of conductive materials that can be used to form the sheet 300 include, but are not limited to, copper, steel, aluminum, zinc, bronze, and combinations or alloys thereof. The thickness of the metal sheet may be selected to correspond to the thickness of the thicker regions of the conductive element to be formed from the sheet. Additionally, the conductive material can be formed or provided as, or can start from, a rod, wire, or the like, which can be processed or formed in accordance with the teachings herein without departing from the scope of the present invention. Thus, although a sheet is illustrated, other conductive materials having other shapes can be used to form the electromagnetic devices shown and disclosed herein.

[0090] In step 2012, skiving is performed to form a sheet using a blade to form a sheet 410 with multiple thicknesses.

[0091] FIG. 10 shows a cutting blade 437 having a convex central cut portion 439 in the process of cutting a sheet of conductive material to form a multi-thickness sheet 410. The resulting multi-thickness sheet 410 has a central region 412 as a thicker region, a first outer portion 416 adjacent a first side 418 of the thicker region 414 having a second thickness less than the thickness of the central region 412, and a second outer portion 420 adjacent a second side 422 of the thicker region 414 having a third thickness less than the thickness of the central region but which may be equal to the thickness of the first outer portion 416. As shown, the first outer portion 416 and the second outer portion 420 may be on opposite sides of the thicker region 414. This multi-thickness sheet 410 is used to form a template as described below.

[0092] In step 2014, electroplating or a similar process is used to plate the multiple thickness sheets with a first layer of nickel and a second layer of tin over the nickel.

[0093] In step 2016, the multi-thickness sheet 410 is stamped or otherwise machined to form a multi-thickness template for use in an electromagnetic device such as that shown in Figures 1A-1C. This step results in the multi-thickness template shown in Figure 6.

[0094] In step 2018, one or more core materials, preferably comprising iron powder and / or ferrite powder, are pressed around the conductive elements and the portion of the leads comprising the first and second inner lead portions to form a body. In this step, body 133 is formed around a portion of the template, as described with reference to Figure 7. Step 2018 may be performed optionally if a core body is not desired.

[0095] In step 2020, portions of the template adjacent the leads are trimmed to size and applied around the body to form surface mount leads, as desired for current circuit board assembly processes. At least a portion of each lead is applied along the side of the body, and at least an end portion of the lead is bent under and along the bottom surface of the body. As previously discussed, an example of a completed electromagnetic device 100 is shown in FIG. 1A.

[0096] Skiving can also be used to form electromagnetic designs having the configurations shown in Figures 2A-2C. The skiving process can also be used to form conductive elements having various shapes, sizes, orientations, and / or configurations.

[0097] Swaging and / or pressing and / or flattening processes may also be used to form electromagnetic devices according to embodiments of the present invention.

[0098] A method for manufacturing an electromagnetic device according to one embodiment of the present invention is described according to the flow chart in Figure 11. A sheet of conductive material is used as a starting material in step 3010. Sheet 300 shown in Figure 4 is an exemplary sheet of conductive material.

[0099] In step 3012, the sheet is plated using electroplating or a similar process to form a first layer of nickel and a second layer of tin over the nickel. At this plating stage, the sheet has a uniform thickness, which will be greater than the thickness of the conductive elements, as described below.

[0100] In step 3014, stamping or other machining is performed to form a template of uniform thickness.

[0101] 12 shows the template 500 in the process of being formed. The template has a shaped conductive element 520, a first lead 530a, and a second lead 530b, all formed from a unitary piece of the same conductive material forming a sheet. If the template 500 is formed as a lead frame, it may have carrier strips 540, 542. The carrier strips 540, 542 may have progressive holes 544 for alignment when connecting to manufacturing equipment.

[0102] To obtain a template with multiple thicknesses in step 3016, first lead 530a and second lead 530b, or portions of each, are flattened by swaging, pressing, or the like.

[0103] 13 is a detailed view of a portion of template 500. First lead 530a and second lead 530b are flattened or compressed, thereby giving them a thickness that is less than the thickness of conductive element 520. Different processes can be used to form the reduced thickness portions, such as stamping, coining, roll forming, or milling.

[0104] Upon planarization of the first lead 530a and the second lead 530b, the template 500 has a conductive element 520 with a central region 512 formed as a thicker region 514 having the thickness of the original sheet, the first lead 530a having a thickness less than that of the central region 512, and the second lead 530b having a minor thickness less than that of the central region 512 but which may be the same thickness as the first lead 530a. If these regions are not planarized, the carrier strips 540, 542 may be the same thickness as the conductive element 520.

[0105] In step 3018, one or more core materials, preferably comprising iron powder and / or ferrite powder, are pressed around conductive element 520 and a portion of leads 530a, 530b to form body 546. To form body 546, plated template 500 is inserted into a compression press and the one or more core materials are pressed into the coil portion of a lead frame of the desired shape, such as a generally rectangular shape. At this stage, the lead body and frame are configured similarly to FIG. 7, as described above. If a core body is not desired, step 3018 is optional.

[0106] In step 3020, portions of the template adjacent the leads are trimmed to size and placed around the periphery of body 546 to form surface mount leads, as desired for current circuit board assembly processes. At least a portion of each of leads 530a, 530b is placed along the side of body 133, and at least end portions of leads 530a, 530b are bent under and placed along a portion of the bottom surface of body 546.

[0107] In addition, the process shown in Figure 11 can be used to form a template having conductive elements with linear conductive elements that are "I" or "H" shaped, or conductive elements that are "barbell" shaped when viewed from above, as shown in Figures 2A to 2C, etc.

[0108] Additionally, to form conductive elements with thicker regions, a template with a generally uniform thickness, as shown in FIG. 12, can be started and plated onto conductive element 520. For example, copper can be plated onto the entire conductive element until a consistent thickness is achieved. This "build-up" process can be accomplished, for example, by 3D printing a plating material or by depositing metal onto conductive element 520 using methods known in the metalworking art (e.g., sputtering).

[0109] Additionally, the methods disclosed herein can be used to form electromagnetic devices having shaped conductive elements that are smaller than the thickness of one or more leads. For example, with reference to FIG. 3, in step 1012, a sheet can be extruded having multiple thicknesses, with a thinner center portion of the sheet and thicker outer portions of the sheet. Continuing with reference to FIG. 9, in step 2012, a sheet can be skived having multiple thicknesses, with a thinner center portion of the sheet and thicker outer portions of the sheet. Continuing with reference to FIG. 11, in step 3016, the conductive elements, rather than the leads, can be flattened to form conductive elements that are thinner than the leads.

[0110] Thus, as illustrated in FIG. 16, template 700 is stamped from a piece of conductive material of uniform thickness, such as the sheet shown in FIG. 4. Conductive element 750, which may be a serpentine conductive element, first lead 740a, and second lead 740b, all formed from the same piece of conductive material, is stamped or otherwise formed. In this embodiment, conductive element 750 is stamped, pressed, swaged, or skived to form an electromagnetic device having a thinner thickness of conductive material than leads 740a, 740b. Conductive element 750 may have a serpentine, barbell, or other predetermined shape, and may be generally flat with one or more surfaces lying in or along a plane. Leads 740a, 740b may be folded or trimmed as known or described herein. A core body may be formed around conductive element 750 and portions of the leads.

[0111] The conductive material or sheet of conductive material may be formed so that the area used to form the conductive element has a different hardness than the area used to form the first and second lead portions. For example, the first portion of the conductive material may have a first hardness (e.g., semi-hard) and the second portion of the conductive material may have a second hardness (e.g., annealed softness). Alternatively, the first portion of the conductive material may have a first hardness (Vickers hardness 100 HV10) and the second portion of the conductive material may have a second hardness (Vickers hardness 30 HV10).

[0112] It should be noted that the surfaces of the conductive elements and / or leads disclosed herein may be slightly rounded, arcuate, or curved, and the side edges may be rounded, arcuate, or curved, depending on the processing method used to form the conductive elements. Acceptable metals used to form the conductive elements and leads include copper, aluminum, platinum, and other metals used in electromagnetic conductive elements as known in the art. As used herein, "flat" means "generally flat," i.e., within normal manufacturing tolerances. It should be noted that the surfaces of the conductive elements and / or leads disclosed herein may be slightly rounded, arcuate, curved, or corrugated, depending on the processing method used, and the side edges may be slightly rounded, arcuate, curved, or corrugated, and all may be considered "flat."

[0113] The thickened portions or regions of the conductive elements described herein act to reduce the direct current resistance (DCR) of an electromagnetic device, such as an inductor, that includes such conductive elements.

[0114] The templates described herein provide multiple thicknesses in a single, integral piece. The templates described herein can also be formed by 3D printing techniques.

[0115] The leads or lead portions of the template have areas of reduced thickness, which facilitates forming the leads, for example, by molding and / or bending. Additionally, the thinner and wider lead portions not only improve heat transfer when mounted to a circuit board, but also improve mounting strength and resistance to shock and vibration due to the width of the surface mount leads or terminations.

[0116] The foregoing description is illustrative only and is not intended to be limiting, and changes and modifications may be made to the described embodiments without departing from the spirit and scope of the invention. While the present invention has been described in detail, those skilled in the art will readily appreciate that many physical variations, only a few of which are described in the detailed description, can be made without altering the inventive concepts and principles of the described embodiments. Numerous other variations, including only a few of the preferred embodiments, are possible, none of which alter the inventive concepts and principles of those embodiments. The construction of the embodiments of the present invention and the configurations that may be employed are intended in all respects to be illustrative and not restrictive. The scope of the invention is defined by the appended claims, rather than the foregoing description, and all alternative embodiments and modifications thereto that come within the meaning and scope of this scope are intended to be embraced by the present invention.

Claims

1. providing a conductive material; forming the conductive material into a sheet of uniform thickness; forming a first portion of the sheet into a coil area, a second portion of the sheet into a first lead portion adjacent a first side of the coil area, a third portion of the sheet into a second lead portion adjacent a second side of the coil area, the first lead portion having a thickness less than a thickness of the coil area, and the second lead portion having a thickness less than a thickness of the coil area, and forming the sheet into a template; trimming the first lead portion to separate it from the template; trimming the second lead portion to separate it from the template; A method for manufacturing an inductor comprising:

2. moreover, 2. The method of claim 1, further comprising forming a core body around a portion of the first lead portion, a portion of the second lead portion, and the coil region before trimming each of the first lead portion and the second lead portion, leaving an exposed portion of the first lead portion and an exposed portion of the second lead portion, respectively.

3. The method of claim 2 , wherein a portion of the exposed portion of the first lead portion extends along the outer surface of the core body, and a portion of the exposed portion of the second lead portion extends along the outer surface of the core body.

4. 2. The method of claim 1, wherein the step of reducing the thickness of the first lead portion comprises flattening or compressing a portion of the first lead portion.

5. 2. The method of claim 1, wherein the step of reducing the thickness of the second lead portion comprises flattening or compressing a portion of the second lead portion.

6. The method of claim 1 , wherein the sheet has a thickness and the coil region has a thickness equal to the thickness of the sheet.

7. The method of claim 1 , wherein at least a portion of the template is formed by stamping the sheet.

8. 10. The method of claim 1, wherein the coil region has a serpentine, rectangular, I-shaped, H-shaped, or barbell shape.

9. 10. The method of claim 1, wherein the coil region, the first lead portion, and the second lead portion are formed from a continuous piece of unwound conductive material.

10. providing a conductive material; forming the conductive material into a sheet of uniform thickness; forming a template from the sheet by forming a first portion of the sheet into a coil region, a second portion of the sheet into a first lead portion adjacent a first side of the coil region, and a third portion of the sheet into a second lead portion adjacent a second side of the coil region, the thickness of the coil region being less than the thickness of each of the first and second lead portions; In one portion of the template, the width of the first lead portion adjacent to the coil region is less than the width of the coil region measured at the widest position of the coil region, and the width of the second lead portion adjacent to the coil region is less than the width of the coil region measured at the widest position of the coil region. forming a core body including a magnetic material around a portion of the first lead portion and a portion of the second lead portion and a magnetic material around the coil region before trimming each of the first lead portion and the second lead portion, and leaving an exposed portion of each of the first lead portion and the second lead portion; trimming the first lead portion to separate it from the template; trimming the second lead portion to separate it from the template; A method for manufacturing an inductor comprising:

11. The method of claim 10 , wherein a portion of the exposed portion of the first lead portion extends along the outer surface of the core body, and a portion of the exposed portion of the second lead portion extends along the outer surface of the core body.

12. 11. The method of claim 10, wherein reducing the thickness of the coil region comprises flattening or compressing a portion of the first lead portion.

13. 11. The method of claim 10, wherein the sheet has a thickness, and the first lead portion and the second lead portion have the same thickness as the thickness of the sheet.

14. The method of claim 10 , wherein at least a portion of the template is formed by stamping the sheet.

15. 11. The method of claim 10, wherein the coil region has a serpentine, rectangular, I-shaped, H-shaped, or barbell shape.

16. The method of claim 10 , wherein the coil region, the first lead portion, and the second lead portion are formed from a continuous piece of unwound conductive material.

17. providing a conductive material; and forming a first portion of the sheet into a coil area, a second portion of the sheet into a first lead portion adjacent a first side of the coil area, and a third portion of the sheet into a second lead portion adjacent a second side of the coil area; and forming the conductive material into the sheet and the sheet into a template. and and a stacking process method for making the thickness of the coil region thicker than the thicknesses of the first lead portion and the second lead portion includes plating, 3D printing, and sputtering; The method for manufacturing an inductor further comprises trimming the first lead portion to separate the first lead portion from the template, and trimming the second lead portion to separate the second lead portion from the template.

18. moreover, 18. The method of claim 17, further comprising forming a core body around a portion of the first lead portion, a portion of the second lead portion, and the coil region before trimming each of the first lead portion and the second lead portion, leaving an exposed portion of each of the first lead portion and the second lead portion.

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