Abstract:
A method for conserving space in a circuit or on a printed circuit board by integrating a plurality of electronic components so that the plurality of electronic components collectively take up a smaller amount of space on a substrate than the plurality of electronic components would if the plurality of electronic components were not integrated.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application No. 60/709,491, filed Aug. 19, 2005, which is hereby incorporated herein by reference in its entirety. 

   FIELD OF THE INVENTION 
   This invention relates generally to electronic components and more particularly concerns integrated electronic assemblies and methods for conserving space in a circuit or on a substrate. 
   BACKGROUND OF THE INVENTION 
   The electronics industry is continually called upon to make products smaller and more powerful. Applications such as mobile phones, portable computers, computer accessories, hand-held electronics, etc., create a large demand for smaller electronic components. These applications further drive technology to research new areas and ideas with respect to miniaturizing electronics and often require “low profile” components due to constraints in height and width. Unfortunately, the technology is often limited due to the inability to make certain circuits and components smaller, faster, or more powerful. Nowhere can this be seen more than in the struggle to manufacture smaller electronic circuits and components which take up less space on a substrate, such as a printed circuit board (“PCB”). 
   Originally, individual components had to be mounted on a PCB by inserting the leads of the component through holes in the PCB and soldering them to solder pads on the opposite side of the PCB, (called through-hole technology). This technique left half of the PCB unpopulated because one side had to be reserved for solder pads and solder and required enough space on the PCB to mount each individual component. Therefore, in order to fit more components in a particular circuit, the PCBs were made larger, or additional PCBs were required. Many times, however, these options were not available due to constraints in size for the PCBs. 
   A solution to this problem came in the form of Surface-Mount Devices (“SMD”), or Surface-Mount Technology. SMDs allow electronic devices or components to be mounted on one side of a substrate, (i.e., without having leads inserted through holes in the substrate). An SMD device has small metalized pads (solder pads, terminals or leads) connected to its body, which correspond to solder pads or lands placed on the surface of the substrate. Typically the substrate is run through a solder-paste machine, such as a screen printer, which puts a small amount of solder on the substrate lands. Then, the component is placed on the substrate, and the substrate and SMD device are sent through a re-flow oven to heat the solder paste and solder the component leads to the substrate lands (“reflow soldering”). The primary advantage to this technique is that both sides of the substrate can now be populated by electronic components. Meaning one substrate today can hold an amount of electronic components approximately equal to two substrates in the past. 
   Another solution to this problem was the development of the integrated circuit (“IC”), which allowed circuits made up of multiple electronic components to be combined into one packaged component. This allowed more components to be mounted on a substrate and reduced the amount of substrate space used (and therefore needed) by replacing multiple individual electronic components with one IC package. This also lowered manufacturing times for assembling electronics by reducing the number of components that had to be mounted to the substrate. Today, substrates continue to be populated with ICs and individual electronic components that have not been incorporated into an IC package (“discrete components”). 
   As a result of these advances in technology, current electronic circuits are mainly limited by the size and number of components needed to be used on the PCB. Meaning, if the electronic components are made smaller or fewer components are needed for a particular circuit, the circuit can be made smaller as well. Unfortunately, there are some electronic components that a circuit cannot due without and that cannot be produced any smaller than they currently are without sacrificing something, (e.g., performance, structural integrity, etc.). Usually this is because the desired parameters for the component cannot be achieved when using smaller parts. Good examples of this are coil components, such as for example, inductors, antennas, transformers, chokes and the like. Certain parameters of these components are affected by the size of the parts used. For instance, in inductors, wire gauge determines both the DC resistance and the current carrying ability of the component. In other examples, the component may be capable of being made in a smaller size, but incapable of performing comparably to the original larger version of the component, (e.g., with comparable inductance, frequency range, Q-value, self-resonant frequency, or the like). 
   Accordingly, it has been determined that the need exists for an improved electronic component which overcomes the aforementioned limitations and which further provides capabilities, features and functions, not available in current devices and for a method of conserving space in a circuit. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a plan view of an integrated electronic assembly according to the invention with the top of the body removed so that the second and third electronic components located within the first electronic component are visible; 
       FIG. 1B  is a side elevational view of the integrated electronic assembly of  FIG. 1 , with the first electronic component shown in cross-section so that the second and third electronic components are visible; 
       FIG. 2A  is a plan view of an alternate first electronic component for use in an integrated electronic assembly according to the invention, shown without the wire winding for purposes of clarity; 
       FIG. 2B  is a side elevational view of the first electronic component of  FIG. 2A ; 
       FIG. 2C  is a bottom view of the first electronic component of  FIG. 2A ; 
       FIG. 2D  is a cross sectional view of the first electronic component of  FIG. 2A  taken along line  2 D- 2 D in  FIG. 2A ; 
       FIG. 3A  is a plan view of an alternate first electronic component for use in an integrated electronic assembly according to the invention; 
       FIG. 3B  is a side elevational view of the first electronic component of  FIG. 3A ; 
       FIG. 3C  is a bottom view of the first electronic component of  FIG. 3A ; and 
       FIG. 3D  is a cross sectional view of the first electronic component of  FIG. 3A  taken along line  3 D- 3 D in  FIG. 3A . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   An integrated electronic assembly in accordance with the invention includes a first electronic component and at least a second electronic component wherein the first electronic component defines a receptacle, such as a recess or opening, into which at least a portion of the second electronic component is disposed. Once the second electronic component is disposed in the opening of the first electronic component, the first and second electronic components collectively form an integrated electronic assembly which may be connected to a substrate, such as a PCB, as a single component or assembly or within the footprint of a single component as will be discussed further below. 
   In a preferred form, the first electronic component has a footprint of a specified size for mounting the first electronic component to the PCB and defines a sufficient opening so that the second electronic component can be mounted to the PCB within the footprint of the first electronic component. The first electronic component may be a discrete component, such as a coil component, which defines an opening into which a second electronic component, such as an IC or, alternatively, another discrete component, is inserted. For example, in one form, the first electronic component may be a magnetic component, such as an inductor, which defines an opening for receiving at least a portion of a second discrete component, such as a capacitor. In another form, the first electronic component may consist of another discrete component which defines an opening for receiving at least a portion of an IC. In still other forms, the first electronic component may define a receptacle capable of receiving two or more additional electronic components, such as for example, both an additional discrete component and an IC. 
   Turning now to  FIGS. 1A-B , there is illustrated an integrated electronic assembly  10  embodying features of the present invention. The integrated electronic assembly  10  includes a first electronic component, such as inductor  20 , a second electronic component, such as IC  30 , and a third electronic component, such as capacitor  40 . Although the embodiment illustrated uses a discrete component as the first electronic component and both an IC and an additional discrete component as the second and third electronic components, it should be understood that any combination of discrete components and/or ICs may be used to form an integrated electronic assembly in accordance with the invention. 
   In  FIGS. 1A-B , the first electronic component  20  is an inductor having a body, such as form or core  20   a , about which a conductive element, such as wire  22 , is wound to form a coil through which current may be carried. The core  20   a  is preferably made of a high temperature plastic material or a magnetic material, such as ferrite, and defines a receptacle for receiving at least a second electronic component. For example, in the embodiment illustrated, the core  20   a  defines a first receptacle, such as first opening  20   b , for receiving the second electronic component  30  and a second receptacle, such as second opening  20   c , for receiving the third electronic component  40 . In this form, the first and second openings  20   b - c  defined by the first electronic component  20  collectively form a single opening in the first electronic component  20  for receiving at least a portion of the second and third electronic components,  30  and  40  respectively. 
   In  FIGS. 1A-B , the core  20   a  has a bobbin structure including a cylindrical center section with upper and lower flanges or flanged ends, respectively, extending from the ends of the center section. Although the core illustrated is symmetrical, it should be understood that a variety of different cores may be used, including asymmetrical cores, (e.g., cores having one flanged end that is larger in diameter than the other flanged end, etc.). 
   In the embodiment illustrated, metalized pads, such as solder pads  24   a - b , are connected to the body  20   a  and provide terminals by which the first electronic component  20  may be connected into a circuit. The metalized pads  24   a - b  are made of a conductive material and are preferably fused or bonded to the body  20   a  so that the first electronic component  20  may be electrically and mechanically attached to corresponding lands located on the PCB via solder. More particularly, the metalized pads  24   a - b  provide an electrically conductive surface to which the solder paste printed on the PCB can bond once the first electronic component  20  and PCB are passed through a reflow oven. As is depicted in  FIG. 1 , the metalized pads  24   a - b  are preferably located on the bottom of the body  20   a . It should be understood, however, that metalized pads of different shapes and sizes may alternatively be used and that the metalized pads  24   a - b  may be placed in alternate locations about the body  20   a  if desired. For example, the metalized pads  24   a - b  may alternately be L-shaped or U-shaped pads that wrap around the sides of the body  20   a  of first electronic component  20 . In yet other forms, the metalized pads  24   a - b  may be provided as clips which are connected to the first electronic component  20  rather than being pads fused or bonded onto the body  20   a  thereof. 
   In a preferred embodiment, the wire  22  is an insulated wire such as a forty-two gauge (42 AWG) copper wire having ends  22   a  and  22   b  connected to the bottom of the metalized pads  16 . It should be understood, however, that any conductive material may be used for the wire and that the wire size may be selected from a variety of wire gauges. For example, a preferred component may use wire ranging from thirty-two gauge wire to forty-eight gauge wire (32-48 AWG), while alternate components use wires of different wire gauges. 
   The ends of the wire  22   a - b  are preferably flattened (not shown) and bonded to the metalized pads  24   a - b  in order to minimize the amount of space between the lower surface of the metalized pads  24   a - b  and the upper surface of the corresponding substrate lands. This helps maintain the low profile of the assembly  10  and also helps ensure that the component will remain co-planar when positioned on the substrate so that the pads  24   a - b  and wire ends  22   a - b  will make sufficient contact with the solder on the substrate and make solid electrical and mechanical connections to the circuit on the substrate. 
   In alternate embodiments, the wire ends  22   a - b  may be connected to the inner or outer side surfaces of L-shaped, U-shaped or clip-type metalized pads, in order to avoid disrupting the flat bottom surface of pads  24   a - b  and in order to avoid increasing the height of the assembly  10  and/or creating a gap between any portion of the pads  24   a - b  and the corresponding substrate lands. In yet other embodiments, notches or dimples may be present in the lower surfaces of the body  20   a  and/or pads  24   a - b  in order to provide a designated location for the wire ends  22   a - b  to be bonded to the pads  24   a - b  without raising the height of the assembly  10  or creating a gap between the pads  24   a - b  and corresponding substrate lands. 
   In the embodiment illustrated, a single wire  22  is wound about the center section of the core  20   a . It should be understood however, that in alternate embodiments, multiple wires may be used depending on the type of component the first electronic component is. For example, in an alternate embodiment wherein the first electronic component  20  is a transformer, multiple wires may be used and wrapped around the body  20   a . In such embodiments, the component  20  will also include more than two metalized pads for the ends of the wire  22  to be connected to. 
   In  FIGS. 1A-B , the second electronic component  30  is shown as an IC and the third electronic component  40  is shown as another discrete electronic component, such as a capacitor. The IC  30  may contain any number of active and/or passive components which are constructed on a substrate, such as semiconductor wafers (e.g., silicon, gallium arsenide or the like), glass substrates, insulative substrates or any other conventional IC material, and both the IC  30  and capacitor  40  may be of a variety of different sizes and shapes. In the form illustrated, both the IC  30  and capacitor  40  have metalized pads,  32  and  42  respectively, for electrically connecting the second and third components  30  and  40  into the substrate circuit. For example, the metalized pads or pins  32  of IC  30  may be aligned with and soldered to corresponding lands on the substrate in order to connect the IC  30  to the circuit on the substrate. Similarly, the metalized pads  42  of capacitor  40  may be aligned with and soldered to corresponding lands on the substrate in order to connect the capacitor  40  into the circuit on the substrate. 
   In  FIGS. 1A-B , the inductor  20 , IC  30  and capacitor  40  make up a portion of a power supply circuit. Thus, in this form, some or all of the power supply components are capable of being disposed or housed inside the inductor  20 , which is typically the largest component in a low power switching regulator. In other embodiments, the assembly  10  may be designed so that all or most of the other power supply components are placed inside the first electronic component  20 . Thus, this configuration may be used to reduce the size of switching power supplies while allowing the switching power supplies to provide higher power density. 
   As mentioned above, the assembly  10  may be provided as a single module with the first, second and third electronic components,  20 ,  30  and  40  respectively, already connected to one another (i.e., a pre-connected configuration). The connection between the components,  20 ,  30  and  40 , may either be a simple mechanical one wherein the components are held together but are not electrically connected, or may be an electromechanical one wherein the components are held together and are electrically connected to one another to create a circuit. With a mechanical connection, the components may be mechanically connected to one another via an adhesive or other conventional method for connecting electronic components or their parts. With an electromechanical connection, the components may be wired together in addition to being secured into position via an adhesive or the components may be connected to their own substrate having traces electrically connecting the components into a circuit. Regardless of which type of pre-connection configuration is used, however, the assembly  10  will be capable of being placed as a single module or part rather than requiring the placement of the individual components. 
   Alternatively, the components  20 ,  30  and  40  may simply be provided apart from one another (i.e., an unconnected configuration) and assembled by the circuit manufacturer into the integrated electronic assembly  10  by placing one component after the other until the assembly  10  is complete. In a preferred form, however, the assembly  10  will be provided in a pre-connected configuration wherein the components are mechanically connected to one another, but not electrically connected to one another. This configuration provides the circuit designer with flexibility in deciding how to interconnect the components of the assembly  10  and eliminates or greatly reduces the volume, cost and reduced reliability of using an additional or duplicate substrate to electro-mechanically connect the components. This configuration also reduces the number of components that must be placed on the substrate in order to complete the circuit and, thus, should result in faster more efficient manufacturing. For example, an electronic device manufacturer&#39;s PCB may be designed to provide lands and traces that correspond to the metalized pads of the electronic components  20 ,  30  and  40 , so that the assembly can simply be picked and placed on the substrate as a single module and electrically connected to the circuit via reflow soldering. This configuration also conserves space on the overall circuit by mounting multiple electronic components within the footprint of a single component. 
   If the assembly  10  is to be provided in either the mechanically connected configuration or the electromechanical configuration, the components  20 ,  30  and  40  will be assembled by aligning the components in their proper x, y and z axis to ensure correct location/positioning and to ensure co-planarity of their respective metalized pads  22   a - b ,  32  and  42 . Then, in a preferred form, the components will be connected or secured to one another using materials suitable for maintaining component alignment before, during and after reflow soldering. The assembly  10  may then be inspected and tested to ensure proper operation and construction, if desired. 
   If the assembly  10  is to be provided in an unconnected configuration, the components  20 ,  30  and  40  will be assembled via conventional pick-and-place equipment and the components will be electrically connected to one another via the corresponding lands and traces of the substrate. In a preferred form, the electronic components located within the receptacle of the first electronic component will be mounted on the substrate first and then the first electronic component will be mounted to the substrate. Although this configuration does not reduce the number of components that are placed on the substrate, it does conserve space in the substrate circuit by mounting multiple electronic components within the footprint of one single component. 
   Although the embodiment illustrated in  FIGS. 1A-B  and discussed above shows the assembly  10  made up of three separate components, it should be understood that the assembly  10  may alternately be made up of two components or, in yet other embodiments, may be made up of more than three components if desired. In addition, although the application discussed above is for a power supply component (e.g., a power switching regulator), it should be understood that the concept of an integrated electronic assembly in accordance with the invention may be used in any application where space is critical, such as for example, in portable electronics, hand-held electronics, cell phones, digital cameras, music and video players, laptops, LED flashlights, and the like. 
   Turning now to  FIGS. 2A-D , there is illustrated an alternate embodiment of the first electronic component  20  of integrated electronic assembly  10 . In this embodiment, an outer body or base is used in connection with the first electronic component  20 , with the outer body or base defining (at least in part) the receptacle into which any additional electronic components are disposed. For convenience, features of alternate embodiments illustrated in  FIGS. 2A-D  that correspond to features already discussed with respect to  FIGS. 1A-B  are identified using the same reference numeral in combination with an apostrophe or prime notation (′) merely to distinguish one embodiment from the other, but otherwise such features are similar. 
   In the alternate embodiment of electronic component  20  illustrated, (hereinafter component  20 ′), the first electronic component  20 ′ includes an outer body or base  26  which is made of an insulating material, such as a non-conductive plastic or ceramic. In the form illustrated the base  26  has a polygonal shape and has smooth planer top  26   a  and bottom  26   b  surfaces. The base  26  further defines an opening or recess  26   c  for receiving at least a portion of core  20   a ′ and defines a receptacle  26   d  for receiving any additional electronic components such as second and third electronic components  30  and  40 . In the form illustrated, the recess or opening  26   c  and receptacle  26   d  are formed by the aperture through the base  26 . Thus, both the core  20   a ′ and base  26  define the boundary of receptacle  26   d . However, it should be understood that in alternate embodiments the base  26  may be provided with a separate and distinct recess  26   c  and receptacle  26   d , if desired. For example, in an alternate embodiment, a wall or partition may be used to separate the recess  26   c  and receptacle  26   d  from one another. It should also be understood that in alternate embodiments the base  26  may be provided in a different shape, such as for example in a generally rectangular shape or in a generally round or circular shape. 
   In the embodiment illustrated in  FIGS. 2A-D , the side wall of base  26  that defines recess  26   c  has a radius of curvature and diameter which corresponds to or compliments the radius of curvature and diameter of the flanged ends of core  20   a ′. In a preferred form, the flanged ends of core  22   a ′ fit loosely within the recess  26   c  so that space is provided between the outer edge of the flanged ends and the inner side wall of base  26 , which allows the core  22   a ′ to be installed into the base  26  more easily. In addition, the core  22   a ′ is positioned such that the top of the core&#39;s upper flanged end is about even, or coplanar, with the top surface  26   a  of base  26 , which helps provide a generally flat upper surface with which the component  20  may be picked up and placed on a substrate circuit. 
   In the form shown, the pieces of the first electronic component  20 ′, such as the base  26  and core  22   a ′, are held together via a film layer, such as adhesive tape  28 , which may be positioned over the top of base  26   a  and core  20   a ′. The film  28  serves as a structural member of the component and, in a preferred embodiment, comprises a flexible member having an adhesive layer on the bottom and a printable layer on the top. Thus, in addition to keeping the pieces of the first electronic component  20 ′ together, the film  28  provides the component manufacturer with a surface for printing indicia, such as product numbers, trademarks, and other desirable information. The film  28  also establishes a generally planar top surface with which the assembly  10  or first electronic component  20 ′, depending on how the assembly is configured (i.e., connected or unconnected configurations), may be picked from conventional tape and reel packaging and placed on a substrate using industry standard vacuum pick-and-place machinery. In a preferred embodiment, film  28  may be a polyimide film, a polyetheretherketone (PEEK) film, a liquid crystal polymer (LCP) film or the like. These and other details regarding film  28  may be found in U.S. Pat. No. 6,914,506 issued Jul. 5, 2005, which is hereby incorporated herein by reference in its entirety. 
   In the embodiment illustrated in  FIGS. 2A-D , the first electronic component  20 ′ has a height of 1 mm, a length and width of 3 mm each, and a receptacle  26   d  that is 0.72 mm high with an annular inner wall radius of 1.2 mm. Unlike the first electronic component illustrated in  FIGS. 1A-B , component  20 ′ has metalized pads  22   a ′- b ′ which are connected to the bottom surfaces  26   b  of base  26 . The base  26  of first electronic component  20 ′ also defines ventilation openings  26   e - f  which allow air to circulate through the assembly  10  and over any additional electronic components disposed within receptacle  26   d . In the form illustrated, the ventilation openings  26   e - f  are formed by leg members extending down from the base  26  and bounded by the bottom surfaces of base  26  and its leg members. 
   In  FIGS. 3A-D , there is illustrated yet another embodiment of the first electronic component  20  of assembly  10  embodying features in accordance with the present invention. In this embodiment, like the embodiment illustrated in  FIGS. 2A-D , an outer body or base is used in connection with the electronic component  20 , with the outer body or base defining (at least in part) the receptacle into which any additional electronic components are disposed. Unlike the embodiment illustrated in  FIGS. 2A-D , however, the core illustrated in the electronic component of  FIGS. 3A-D  is much larger leaving a smaller sized receptacle into which the additional electronics can be inserted. For convenience, features of alternate embodiments illustrated in  FIGS. 3A-D  that correspond to features already discussed with respect to  FIGS. 1A-B  and  FIGS. 2A-D  are identified using the same reference numeral in combination with an a quotation mark or double prime notation (″) merely to distinguish one embodiment form the other, but otherwise such features are similar. 
   In the embodiment illustrated in  FIGS. 3A-D  (hereinafter  20 ″), the electronic component  20 ″ includes a similar structure to that of component  20 ′ in  FIGS. 2A-D . For example, component  20 ″ has a base  26 ″ defining an opening or recess  26   c ″ into which at least a portion of core  20   a ″ is disposed and ventilation openings  26   e ″- f ″. The base  26 ″ further includes metalized pads  22   a ″- b ″ and has a wire (not shown) wound about the reduced diameter center portion of core  20   a ″ and having first and second wire ends which are connected to their respective metalized pads  22   a ″- b ″. The base  26 ″ and core  20   a ″ are connected or secured to one another via an adhesive film layer, such as tape  28 ″, which provides a generally flat upper surface for conventional pick-and-place equipment to pick up and place component  20 ″ and preferably provides a surface for providing indicia. Unlike the component  20 ′ of  FIGS. 2A-D , however, the core  20   a ″ is much larger, thereby, leaving a smaller sized receptacle for receiving additional electronic components, such as second and third electronic components  30  and  40 . For example, in the form illustrated in  FIGS. 3A-D , the core  20   a ″ has a height of 0.78 mm as compared to the 0.28 mm height of the core  20   a ′ in  FIGS. 2A-D . Thus, with this configuration, the receptacle  26   d ″ of  FIGS. 3A-D  has a height of 0.22 mm and an annular inner wall radius of 1.2 mm and will only be able to house smaller additional electronic components than component  20 ′. 
   An advantage to the structures of  FIGS. 2A-D  and  FIGS. 3A-D  over that of  FIGS. 1A-B  is that the base  28  or  28 ″ can be made of any height desired in order to adjust the size of the receptacle in the first electronic component. Whereas, in the bobbin configuration illustrated in  FIGS. 1A-B , the core  20   a  actually has to be bored out in order to provide the desired receptacle size. Thus, in the embodiments of  FIGS. 2A-D  and  3 A-D, existing core structures may be used rather than requiring special core structures to be built. 
   It should be understood that the assembly  10 , including any of its components, may be made in a variety of shapes and sizes and used to conserve space in a circuit. Thus, in accordance with the present invention, an integrated electronic assembly and method of conserving space in a circuit are provided that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.