Filter inductor for heavy-current application

A filter inductor for high-current applications. The filter inductor includes a magnetic core and a winding. The winding includes a shaped section having opposing ends, a pair of arm sections laterally extending from the opposing ends of the shaped section, respectively, and a pair of inductor pins, each extending perpendicular from an end of a respective arm section. The magnetic core includes a first core portion and a second core portion. The first core portion includes a recessed channel configured to receive the shaped section of the winding. The second core portion includes a pair of recessed regions configured to receive the pair of arm sections of the winding, respectively. The first core portion and the second core portion are coupled in contact to one another to secure the shaped section of the winding within the magnetic core. The filter inductor can be edge-mounted to a printed circuit board.

BACKGROUND

The present application relates generally to passive magnetic components for high-current applications, and more specifically to filter inductors for high-current applications such as power supply modules that need to satisfy requirements of compactness, high efficiency, high power density, ease of manufacture, and reduced cost.

Power supply modules such as direct current (DC)-to-DC power supply modules and others generally employ one or more filter inductors. A conventional filter inductor typically includes a magnetic core, and a coil of conductive wire wrapped around the magnetic core. Employing a magnetic core with a high permeability, as well as increasing the number of turns of the coil of conductive wire around the magnetic core, can increase an inductance of the filter inductor. Such a filter inductor can be employed in a DC-to-DC power supply module, possibly in conjunction with a filter capacitor, for removing fluctuations such as residual hums (e.g., mains hums) from a DC output.

SUMMARY

In accordance with the present application, filter inductors for high-current applications are disclosed that can avoid at least some of the drawbacks of conventional high current filter inductors, which are typically configured as large, fixed format, high profile components. Ongoing advancements in electronic packaging have called for the use of electrical and electronic circuits, components, and/or printed circuit board (PCB) assemblies that have a decreased size and weight and/or a lower profile, such as integrated circuit (IC) components and PCB assemblies employing surface mount techniques. However, the size, weight, and/or profile of passive magnetic components such as filter inductors have generally not decreased to the extent desired and/or required by the electronic packaging industry.

The disclosed filter inductors for high-current applications can avoid at least some of the drawbacks of conventional high current filter inductors by employing a compact winding-magnetic core configuration that allows a filter inductor to be mounted along an edge of a PCB, thereby lowering the profile of the filter inductor in a completed PCB assembly. The profile of the filter inductor can be further lowered by reducing a height of the magnetic core. Moreover, the winding and one or more connector pins of the filter inductor can be formed as an integrated structure, thereby decreasing the overall size of the filter inductor, as well as shortening an associated current path, reducing a power consumption of the filter inductor, and improving a thermal resistance between the filter inductor and one or more external components, devices, and/or equipment items.

In one aspect, a filter inductor for high-current applications includes a magnetic core assembly and a winding. The winding includes a shaped winding section (e.g., a C-shaped section) having opposing ends, a pair of arm sections laterally extending from the opposing ends of the C-shaped section, respectively, and a pair of inductor pins, each inductor pin extending substantially perpendicular from an end of a respective one of the pair of arm sections. The winding can further include one or more connector pins extending substantially perpendicular from at least one of the arm sections, in a direction opposite to that of the inductor pin extending from the respective arm section. The magnetic core assembly includes a first core portion and a second core portion. The first core portion includes a recessed channel configured to receive the C-shaped section of the winding. The second core portion includes a pair of recessed regions configured to receive the pair of arm sections of the winding, respectively.

In one mode of fabrication, the winding including the C-shaped section, the pair of arm sections, the pair of inductor pins, and the connector pins are formed from a sheet of copper material using any suitable sheet-metal processing technique. Further, the recessed channel is formed in the first core portion, and the recessed regions are formed in the second core portion. The C-shaped section of the winding is received in the recessed channel of the first core portion, and the arm sections of the winding are received in the recessed regions of the second core portion, respectively. The first core portion and the second core portion are coupled in contact to one another to secure at least the C-shaped section of the winding within the magnetic core assembly.

By providing a filter inductor that includes at least a winding having a shaped winding section, a pair of arm sections laterally extending from opposing ends of the shaped winding section, respectively, and a pair of inductor pins, in which each inductor pin extends substantially perpendicular from an end of a respective one of the pair of arm sections, the filter inductor can be mounted along an edge of a PCB, thereby lowering the profile of the filter inductor in a completed PCB assembly. Moreover, by forming the winding and at least one connector pin as an integrated structure, in which the connector pin extends substantially perpendicular from one of the arm sections in a direction opposite to that of the inductor pin extending from the respective arm section, the overall size of the filter inductor can be decreased, while shortening an associated current path, reducing a power consumption of the filter inductor, and improving a thermal resistance between the filter inductor and one or more external components, devices, and/or equipment items.

Other features, functions, and aspects of the invention will be evident from the Detailed Description that follows.

DETAILED DESCRIPTION

The disclosure of U.S. Provisional Patent Application No. 62/325,258 filed Apr. 20, 2016 entitled FILTER INDUCTOR FOR HEAVY-CURRENT APPLICATION is hereby incorporated herein by reference in its entirety.

Filter inductors for high-current applications are disclosed that employ a compact winding-magnetic core configuration that allows a filter inductor to be mounted along an edge of a printed circuit board (PCB), thereby lowering the profile of the filter inductor in a completed PCB assembly. The filter inductor can include a winding and one or more connector pins formed as an integrated structure, which can decrease the overall size of the filter inductor, as well as shorten an associated current path, reduce a power consumption of the filter inductor, and improve a thermal resistance between the filter inductor and one or more external components, devices, and/or equipment items.

FIG. 1adepicts an exploded view of an illustrative embodiment of an exemplary filter inductor100for high-current applications, in accordance with the present application. The filter inductor100includes a magnetic core assembly102(seeFIG. 1b) and a winding104. The magnetic core assembly102includes a first core portion102.1and a second core portion102.2. The first core portion102.1includes a recessed channel106configured to receive a shaped winding section (seeFIG. 2, reference numeral202) of the winding104. The second core portion102.2includes a pair of recessed regions108.1,108.2configured to receive a pair of arm sections (seeFIG. 2, reference numerals204.1,204.2) of the winding104, respectively.FIG. 1bdepicts a perspective view of the filter inductor100, including the magnetic core assembly102, the first core portion102.1, the second core portion102.2, and the winding104, in an assembled configuration.

FIG. 2depicts a perspective view of the winding104included in the filter inductor100ofFIGS. 1aand1b.As shown inFIG. 2, the winding104includes the shaped winding section202having opposing ends210.1,210.2, a pair of arm sections204.1,204.2extending laterally from the opposing ends210.1,210.2of the shaped winding section202, respectively, and a pair of inductor pins206, each inductor pin206extending substantially perpendicular from an end (not numbered) of a respective one of the pair of arm sections204.1,204.2. For example, the shaped winding section202can be a C-shaped section or any other suitably shaped section. Further, the arm section204.1can be longer than the arm section204.2(as illustrated inFIG. 2), the arm section204.2can be longer than the arm section204.1, or the arm sections204.1,204.2can have substantially the same length. The winding104can further include one or more connector pins208extending substantially perpendicular from at least one of the arm sections204.1,204.2, in a direction opposite to that of the inductor pin206extending from the respective arm section204.1or204.2.

In an exemplary mode of fabrication, the winding104of the filter inductor100including the C-shaped section202, the pair of arm sections204.1,204.2, the pair of inductor pins206, and the connector pins208are formed from a sheet of copper material using any suitable sheet-metal processing technique. Further, the recessed channel106is formed in the first core portion102.1of the magnetic core assembly102, and the recessed regions108.1,108.2are formed in the second core portion102.2of the magnetic core assembly102. The C-shaped section202of the winding104is received in the recessed channel106of the first core portion102.1, and the arm sections204.1,204.2of the winding104are received in the recessed regions108.1,108.2of the second core portion102.2, respectively. The first core portion102.1and the second core portion102.2are coupled in contact to one another to secure at least the C-shaped section202of the winding104within the magnetic core assembly102.

FIG. 3depicts a perspective view of an exemplary completed PCB assembly300that includes the filter inductor100ofFIGS. 1aand1b.As shown inFIG. 3, the PCB assembly300further includes a PCB302, an integrated circuit (IC) component303mounted on one side the PCB302, and a plurality of PCB pins304coupled to and extending from an opposite side of the PCB302. The plurality of PCB pins304can provide electrical and/or mechanical connections to the PCB assembly300. As further shown inFIG. 3, the compact winding-magnetic core configuration of the filter inductor100allows it to be mounted along an edge (such as an edge306; seeFIG. 3) of the PCB302.

In the PCB assembly300, a pair of holes (not numbered) can be drilled or otherwise formed through the PCB302at locations suitable to receive the pair of inductor pins206of the filter inductor100, respectively. Further, a surface of the second core portion102.2can be positioned against the edge306of the PCB302so as to align the inductor pins206with the respective drilled holes. The filter inductor100can then be slid along the edge306to insert the inductor pins206through the respective drilled holes until portions of the inductor pins206protrude from a surface of the PCB302, thereby providing points of electrical connection to the winding104of the filter inductor100. In one embodiment, each respective inductor pin206can be formed with one or more stops110(seeFIG. 1b), and the inductor pins206can be inserted through the respective drilled holes until the PCB302impinges against the stops110.

Once the inductor pins206are inserted through the respective holes in the PCB302, the inductor pins206can be soldered to establish the points of electrical connection to the winding104of the filter inductor100. In the completed PCB assembly300, the profile of the filter inductor100is lowered by about one quarter or more compared to that of a conventional filter inductor. Moreover, the connector pins208of the filter inductor100provide further mechanical connections to the PCB assembly300, as well as provide further points of electrical connection to the winding104of the filter inductor100.

An exemplary method of fabricating the filter inductor100ofFIGS. 1aand 1bis described herein with reference toFIG. 4, as well asFIGS. 1a,1b,and2. As depicted in block402(seeFIG. 4), the winding104(seeFIGS. 1aand 1b) of the filter inductor100including the C-shaped section202(seeFIG. 2), the pair of arm sections204.1,204.2, the pair of inductor pins206, and the connector pins208are formed as an integrated structure from a sheet of copper material using a suitable sheet-metal processing technique. As depicted in block404, the magnetic core assembly102is provided, including the first core portion102.1and the second core portion102.2. As depicted in block406, the recessed channel106is formed in the first core portion102.1to conform to a shape of the C-shaped section202of the winding104. As depicted in block408, the recessed regions108.1,108.2are formed in the second core portion102.2to conform to cross-sections of the respective arm sections204.1,204.2of the winding104. As depicted in block410, the C-shaped section202of the winding104is received in the recessed channel106of the first core portion102.1. As depicted in block412, the arm sections204.1,204.2of the winding104are received in the recessed regions108.1,108.2of the second core portion102.2. As depicted in block414, the first core portion102.1and the second core portion102.2are coupled in contact to one another to secure at least the C-shaped section202of the winding104within the magnetic core assembly102.

Having described the foregoing illustrative embodiment of the filter inductor100, other alternative embodiments and/or variations can be made. For example, it was described herein that the profile of the filter inductor100in a PCB assembly could be lowered by mounting the filter inductor100along an edge of a PCB. In an alternative embodiment, the profile of the filter inductor100can be further lowered by reducing a height of the magnetic core assembly102. In another alternative embodiment, the filter inductor100can be mounted along more than one edge of a PCB, such as within a cutout region of the PCB302(seeFIG. 3). In this way, uniform dimensions in length and/or width of the PCB302can be maintained while lowering the profile of the filter inductor100within the completed PCB assembly300. It was further described herein that the disclosed compact winding-magnetic core configuration is implemented in a filter inductor. In an alternative embodiment, one or more features of the disclosed compact winding-magnetic core configuration can be implemented in a power inductor, a transformer, or any other suitable passive magnetic component or device.