Patent Publication Number: US-7911309-B2

Title: Conductive winding module and transformer having such conductive winding module

Description:
FIELD OF THE INVENTION 
     The present invention relates to a conductive winding module, and more particularly to a conductive winding module by continuously winding multiple loops of coils. The present invention also relates to a transformer having such a conductive winding module. 
     BACKGROUND OF THE INVENTION 
     A transformer has become an essential electronic component for voltage regulation into required voltages for various kinds of electric appliances. Referring to  FIG. 1 , a schematic exploded view of a conventional transformer disclosed in for example U.S. Pat. No. 7,091,817 is illustrated. The transformer  1  of  FIG. 1  principally includes a winding frame member  10 , a primary winding coil (not shown), multiple conductive pieces  12  and a magnetic core assembly  13 . The winding frame member  10  includes a tube structure  101 , a first partition plate  102  and a second partition plate  103 . The first partition plate  102  is parallel with second partition plate  103 . A winding section  104  is defined between the first partition plate  102 , the second partition plate  103  and the external surface of the tube structure  101 . In addition, bending pieces  105  and  106  are extended from both edges of the first partition plate  102  and the second partition plate  103 , respectively. Accordingly, two guiding slots  107  are formed on opposite sides of the winding frame member  10  for accommodating corresponding conductive pieces  12  therein. The magnetic core assembly  13  includes a first magnetic part  131  and a second magnetic part  132 . Each conductive piece  12  is a U-shaped copper piece and includes a hollow portion  121  facing the winding member  121 . After the conductive pieces  12  are received in the guiding slots  107  and fixed onto the winding frame member  10 , the conductive pieces  12  are electrically connected to a circuit board (not shown). 
     The conductive piece  12  of the transformer  1  is a one-loop structure. Although the one-loop conductive piece  12  may reduce the overall volume of the transformer  1 , there are still some drawbacks. For example, the process of winding the coil is complicated because the conductive pieces  12  need to be accommodated within the guiding slots  107 . In addition, the system board should have corresponding trace pattern for making electrical connection between these two conductive pieces  12 . As a consequence, the power loss is increased and the components of the transformer are increased. Under this circumstance, the circuitry of the system board becomes more complicated. 
     In views of the above-described disadvantages resulted from the conventional method, the applicant keeps on carving unflaggingly to develop a conductive winding module and a transformer having such a conductive winding module. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a conductive winding module by continuously winding multiple loops of coils. 
     Another object of the present invention provides a conductive winding module for increasing the power density without considerably increasing the overall volume. 
     A further object of the present invention provides a transformer having such a conductive winding module, in which the transformer is suitable for mass production. 
     In accordance with an aspect of the present invention, there is provided a conductive winding module for use in a magnetic element. The conductive winding module includes a plurality of conductive parts and at least one connecting part. Each of the conductive parts includes a conductive body, a first terminal and a second terminal. The conductive body is interconnected between the first terminal and the second terminal and having a hollow portion therein. The connecting part has a first end and a second end for interconnecting any two adjacent conductive parts. A first connecting line is defined between the first end of the connecting part and the first terminal of an adjacent conductive part. A second connecting line is defined between the second end of the connecting part and the second terminal of an adjacent conductive part. The conductive parts are folded with respect to the first connecting line and the second connecting line such that the first hollow portions of the conductive parts are aligned with each other to define a through-hole. 
     In accordance with another aspect of the present invention, there is provided a transformer. The transformer includes a winding coil, a conductive winding module and a magnetic core assembly. The conductive winding module includes a plurality of conductive parts and at least one connecting part. Each of the conductive parts includes a conductive body, a first terminal and a second terminal. The conductive body is interconnected between the first terminal and the second terminal and having a hollow portion therein. The connecting part has a first end and a second end for interconnecting any two adjacent conductive parts. A first connecting line is defined between the first end of the connecting part and the first terminal of an adjacent conductive part. A second connecting line is defined between the second end of the connecting part and the second terminal of an adjacent conductive part. The conductive parts are folded with respect to the first connecting line and the second connecting line such that the first hollow portions of the conductive parts are aligned with each other to define a through-hole. The magnetic core assembly is partially embedded into the winding coil and the through-hole of the conductive winding module. 
     In accordance with a further aspect of the present invention, there is provided a transformer. The transformer includes a circuit board, a conductive winding module and a magnetic core assembly. The circuit board has a trace pattern of a primary winding coil and a first through-hole. The conductive winding module includes a plurality of conductive parts and at least one connecting part. Each of the conductive parts includes a conductive body, a first terminal and a second terminal. The conductive body is interconnected between the first terminal and the second terminal and having a hollow portion therein. The connecting part has a first end and a second end for interconnecting any two adjacent conductive parts. A first connecting line is defined between the first end of the connecting part and the first terminal of an adjacent conductive part. A second connecting line is defined between the second end of the connecting part and the second terminal of an adjacent conductive part. The conductive parts are folded with respect to the first connecting line and the second connecting line such that the first hollow portions of the conductive parts are aligned with each other to define a second through-hole. The magnetic core assembly is partially embedded into the first through-hole of the circuit board and the second through-hole of the conductive winding module. 
     The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic exploded view of a conventional transformer; 
         FIG. 2(   a ) is a schematic view illustrating a conductive winding module according to a first preferred embodiment of the present invention; 
         FIG. 2(   b ) is a schematic perspective view of the folded conductive winding module of  FIG. 2(   a ); 
         FIG. 3(   a ) is a schematic view illustrating a conductive winding module according to a second preferred embodiment of the present invention; 
         FIG. 3(   b ) is a schematic perspective view of the folded conductive winding module of  FIG. 3(   a ); 
         FIG. 4(   a ) is a schematic view illustrating a conductive winding module according to a third preferred embodiment of the present invention; 
         FIG. 4(   b ) is a schematic perspective view of the folded conductive winding module of  FIG. 4(   a ); 
         FIG. 5  is a schematic exploded view illustrating a transformer having a conductive winding module of  FIG. 2 ; 
         FIG. 6  is a schematic assembled view of the transformer of  FIG. 5 ; 
         FIG. 7  is a schematic assembled view illustrating a transformer having a conductive winding module of  FIG. 3(   b ); 
         FIG. 8  is a schematic view illustrating a variant of the conductive winding module in  FIG. 2(   a ); 
         FIG. 9  is a schematic exploded view illustrating a transformer having a conductive winding module of  FIG. 8 ; and 
         FIG. 10  is a schematic assembled view of the transformer of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. 
       FIG. 2(   a ) is a schematic view illustrating a conductive winding module according to a first preferred embodiment of the present invention. The conductive winding module  22  is a single conductive piece made of metallic material such as copper. The conductive winding module  22  principally includes a plurality of conductive parts  221 , a plurality of connecting parts  222  and pins  223 . In this embodiment, three conductive parts  221  are included in the conductive winding module  22  for illustration. Every two adjacent conductive parts  221  are interconnected by a connecting part  222 . Similarly, each pin  223  is coupled to the adjacent conductive part  221  through a connecting part  222 . 
     Every conductive part  221  principally includes a conductive body  2211 , a first terminal  2212 , a second terminal  2213 , a first surface  2216  and a second surface  2217 . In this embodiment, the conductive body  2211  is ring-shaped and has a notch  2215  between the first terminal  2212  and the second terminal  2213 . In addition, a hollow portion  2214  is formed in the center of the conductive body  2211 . The second surface  2217  is opposed to the first surface  2216  for each conductive part  221 . For example, the first surfaces  2216  of these conductive parts  221  face upwardly but the second surfaces  2217  thereof face downwardly. 
     Every connecting part  222  has a first end  2221  and a second end  2222 . A first connecting line  224  is defined between the first end  2221  of the connecting part  222  and the first terminal  2212  of the adjacent conductive part  221 . A second connecting line  225  is defined between the second end  2222  of the connecting part  222  and the second terminal  2213  of the adjacent conductive part  221 . Likewise, the first side  2223  and the second side  2224  are respectively coplanar with the first surfaces  2216  and the second surfaces  2217  of the conductive parts  221 . 
     By using the first connecting line  224  and the second connecting line  225  as bending lines, the first ends  2221  of the connecting parts  222  are bent in the direction A and the second ends  2222  of the connecting parts  222  are bent in the direction B. Then, these conductive parts  221  are folded with respect to the first connecting line  224  and the second connecting line  225  such that small acute angles are formed between the first side  2223  of a connecting part  222  and the first surface  2216  of an adjacent conductive part  221  and between the second side  2224  of a connecting part  222  and the second surface  2217  of an adjacent conductive part  221 . The resulting structure of the folded conductive winding module is schematically shown in  FIG. 2(   b ). Meanwhile, every two adjacent conductive parts  221  are parallel with each other. That is, the first surfaces  2216  of these conductive parts  221  face toward the same direction X. After the folding process, the hollow portions  2214  of these conductive parts  221  are aligned with each other to define a through-hole  2218 . Due to the inherent rigidity and ductility of the conductive piece, there is a gap distance “h” between any two adjacent conductive parts  221 . 
       FIG. 3(   a ) is a schematic view illustrating a conductive winding module according to a second preferred embodiment of the present invention. The conductive winding module  32  is also a single conductive piece made of metallic material such as copper. The conductive winding module  32  principally includes a first winding unit  328  and at least an extension part  326 . The first winding unit  328  may be used as the secondary winding coil of a transformer for example. The first winding unit  328  includes a plurality of conductive parts  321  and a plurality of connecting parts  322 . Every two adjacent conductive parts  321  are interconnected by a connecting part  322 . By using the similar folding process as described in  FIGS. 2(   a ) and  2 ( b ), the resulting structure of the folded first winding unit  328  is illustrated in  FIG. 3(   b ). 
     In addition, two extension parts  326  are respectively coupled to a first side  3212  and a second side  3213  of the first winding unit  328 . Each of the extension parts  326  has several holes  3261  and several pins  3262 . In some embodiments, an electronic component such as a transistor may be fixed on the extension part  326  such that the extension part  326  functions as a heat sink. By penetrating for example screws (not shown) through the holes  3261  and then coupled with corresponding nuts (not shown), the electronic component may be fixed on the extension part  326 . The pins  3262  may be bonded on a system board (not shown). 
     Please refer to  FIG. 3(   a ) again. The conductive winding module  32  further includes a second winding unit  327 . A terminal  3213  of the second winding unit  327  is coupled to one of the extension parts  326  and used as a winding coil of an inductor for example. The second winding unit  327  principally includes a plurality of conductive parts  321 , a plurality of connecting parts  322  and a pin  323 . Every two adjacent conductive parts  321  are interconnected by a connecting part  322 . By using the similar folding process as described in  FIGS. 2(   a ) and  2 ( b ), the resulting structure of the folded second winding unit  327  is illustrated in  FIG. 3(   b ). Similarly, the pins  323  may be bonded on a system board (not shown). 
       FIG. 3(   b ) is a schematic perspective view illustrating arrangement of the conductive winding module of  FIG. 3(   a ) after the folding process. Please refer to  FIGS. 3(   a ) and  3 ( b ). The first surfaces  3216  of the conductive parts  321  and the first surfaces  3263  of the extension parts  326  face toward the same direction Y. In addition, the hollow portions  3214  of these conductive parts  321  are aligned with each other to define a first through-hole  3218 . Likewise, the hollow portions  3214  of the conductive parts  321  of the second winding unit  327  are aligned with each other to define a second through-hole  3219 . 
     It is noted that, however, those skilled in the art will readily observe that numerous modifications and alterations may be made while retaining the teachings of the invention. For example, the conductive winding module of the present invention may be an unbroken conductive piece having more than three loops. In addition, the conductive body of the conductive part of the conductive winding module may have an arbitrary shape such as a rectangular shape or a polygonal shape. 
       FIG. 4(   a ) is a schematic view illustrating a conductive winding module according to a second preferred embodiment of the present invention. The conductive winding module  32  is also a single conductive piece made of metallic material such as copper. The conductive winding module  32  principally includes a first winding unit  328 , an extension part  326  and a pin  323 . The first winding unit  328  may be used as the secondary winding coil of a transformer for example. The first winding unit  328  includes a plurality of conductive parts  321  and a plurality of connecting parts  322 . Every two adjacent conductive parts  321  are interconnected by a connecting part  322 . By using the similar folding process as described in  FIGS. 2(   a ) and  2 ( b ), the resulting structure of the folded first winding unit  328  is illustrated in  FIG. 4(   b ). 
     In addition, a first side  3212  and a second side  3213  of the first winding unit  328  is coupled to the pin  323  and the extension parts  326 , respectively. In some embodiments, an electronic component such as a transistor may be fixed on the extension part  326  such that the extension part  326  functions as a heat sink. By penetrating for example screws (not shown) through the holes  3261  and then coupled with corresponding nuts (not shown), the electronic component may be fixed on the extension part  326 . The pins  3262  may be bonded on a system board (not shown). 
       FIG. 4(   b ) is a schematic perspective view illustrating arrangement of the conductive winding module of  FIG. 4(   a ) after the folding process. Please refer to  FIGS. 4(   a ) and  4 ( b ). The first surfaces  3216  of the conductive parts  321  and the first surfaces  3263  of the extension parts  326  face toward the same direction Z. In addition, the hollow portions  3214  of these conductive parts  321  are aligned with each other to define a first through-hole  3218 . 
       FIG. 5  is a schematic exploded view illustrating a transformer having a conductive winding module of  FIG. 2 .  FIG. 6  is a schematic assembled view of the transformer of  FIG. 5 . As shown in  FIGS. 5 and 6 , the transformer  2  principally includes a winding coil  20 , a bobbin  21 , a conductive winding module  22  and a magnetic core assembly  23 . In an embodiment, the winding coil  20  is a primary winding coil and the conductive winding module  22  is used as a secondary winding coil. The bobbin  21  includes a main body  211 , a first channel  213 , one or more winding sections  214  and one or more receiving portions  215 . The first channel  213  is communicated with the receiving portions  215 . The magnetic core assembly  23  includes a first magnetic part  231  and a second magnetic part  232 . In this embodiment, the first magnetic part  231  and the second magnetic part  232  of the magnetic core assembly  23  are cooperatively formed as an EE-type core assembly. The middle portions of the first magnetic part  231  and the second magnetic part  232  are partially embedded into the first channel  213  of the bobbin  21  and communicated with the receiving portions  215 . Each receiving portion  215  has an entrance  2151 . The cross-sectional length of the entrance  2151  is substantially greater than the diameter of the corresponding conductive part  221  of the conductive winding module  22  such that the conductive part  221  may be inserted into the receiving portion  215  through the entrance  2151 . In this embodiment, the conductive parts  221  at the bilateral sides of the conductive winding module  22  may be directly attached on bilateral sides of the bobbin  21  without embedding into the receiving portion  215 . Moreover, the gap distance “h” between any two adjacent conductive parts  221  is greater than or equal to the width of each winding section  214 . The primary winding coil  20  is wound on the winding sections  214 . The diameter of the hollow portion  2214  of the conductive part  221  is substantially identical to that of the first channel  213  of the bobbin  21 . After the conductive parts  221  are inserted into the corresponding receiving portions  215  through the entrances  2151 , the hollow portion  2214  is communicated with the first channel  213 . After the middle portions of the first magnetic part  231  and the second magnetic part  232  are embedded into the first channel  213  of the bobbin  21  and the hollow portions  2214 , the transformer  2  is assembled. As a result, the primary winding coil  20  and the secondary winding coil (i.e. the conductive winding module  22 ) interact with the magnetic core assembly  23  to achieve the purpose of voltage regulation. In addition, by soldering the pins  223  on a system board (not shown), the transformer  2  is mounted on the system board. 
     In the above embodiments, the conductive winding module of the present invention may be applied to a magnetic element such as a transformer. Since the conductive winding module is an unbroken multi-loop conductive piece, the overall volume of the conductive winding module is reduced. As the loop number of the conductive winding module is increased, the power density is increased. 
       FIG. 7  is a schematic assembled view illustrating a transformer having a conductive winding module of  FIG. 3(   b ). As shown in  FIG. 7 , the transformer  3  principally includes a winding coil  30 , a bobbin  31 , a conductive winding module  32 , a first magnetic core assembly  33  and a second magnetic core assembly  34 . In an embodiment, the winding coil  30  is a primary winding coil and the first winding unit  328  of the conductive winding module  32  is used as a secondary winding coil. In addition, the second winding unit  327  is used as an inductor. The procedures of assembling the first winding unit  328  of the conductive winding module  32 , the primary winding coil  30  and the first magnetic core assembly  33  are similar to those described in  FIGS. 5 and 6 , and are not redundantly described herein. 
     Please refer to  FIG. 7  again. Two extension part  326  are opposed to each other. Two electronic components  329  such as transistors are fixed on the extension parts  326  by fasting fastening elements  3264  (e.g. screw/nut assemblies) in the holes  3261 . Generally, the extension parts  326  of the conductive winding module  32  may facilitate dissipating heat of the electronic components  329  and increasing space utilization. In addition, the pins  3262  of the extension parts  326  may be bonded on a system board (not shown). 
       FIG. 8  is a schematic view illustrating a variant of the conductive winding module in  FIG. 2(   a ). The structures, the connecting means and the folding means of the conductive parts  221  and the connecting parts  222  are identical to those described in  FIG. 2(   a ), and are not redundantly described herein. In this embodiment, the tip portions  2231  of the pins  223  are substantially perpendicular to the connecting parts  222 . 
       FIG. 9  is a schematic exploded view illustrating a transformer having a conductive winding module of  FIG. 8 .  FIG. 10  is a schematic assembled view of the transformer of  FIG. 9 . As shown in  FIGS. 9 and 10 , the transformer  4  principally includes a circuit board  41 , at least one conductive winding module  22  and a magnetic core assembly  43 . The circuit board  41  is mainly a ring-shaped structure having a through-hole  413  in the center thereof. In addition, the circuit board  41  has a protrusion  416  extended from a side thereof. A primary winding coil  411  is formed as a trace pattern within the circuit board  41 , and both terminals of the primary winding coil  411  are connected to power contacts  414 . The power contacts  414  are further electrically connected to a power source (not shown) through wires  44  so as to transmit the input power to the circuit board  41 . Moreover, the circuit board  41  has a signal connecting interface  412  (e.g. an edge connector). The signal connecting interface  412  is electrically connected to signal contacts  415  through specified trace pattern (not shown). The signal connecting interface  412  may be inserted into a corresponding slot of a system board (not shown) so that the control signals may be transmitted to the control circuit of the system board through the signal wires  45 , the signal contacts  415  and the signal connecting interface  412 . It is preferred that the power contacts  414  and the signal contacts  415  are arranged on the protrusion  416  of the circuit board  41  in order to provide a desired electrical safety distance. 
     Please refer to  FIGS. 9 and 10  again. After the folding process, the hollow portions  2214  of these conductive parts  221  are aligned with each other to define a through-hole  2218 . For assembling the transformer  4 , the conductive winding module  22  is placed on the circuit board  21  such that the through-hole  413  of the circuit board  41  is aligned with the through-hole  2218  and the pins  223  of the conductive winding module  22  are extended in the same direction as the signal connecting interface  412 . The magnetic core assembly  43  includes a first magnetic part  431  and a second magnetic part  432 . The first magnetic part  431  and the second magnetic part  432  of the magnetic core assembly  43  are cooperatively formed as an EE-type core assembly. The middle portions  431   a  and  432   a  of the first magnetic part  431  and the second magnetic part  432  are partially embedded into the through-hole  2218  of the conductive winding module  22  and the through-hole  413  of the circuit board  41 . As a result, the primary winding coil  411  of the circuit board  41  and the secondary winding coil (i.e. the conductive winding module  22 ) interact with the magnetic core assembly  43  to achieve the purpose of voltage regulation. In some embodiments, the magnetic core assembly  43  has an aperture  433  for the protrusion  416  of the circuit board  41  to penetrate therethrough, thereby providing a desired electrical safety distance. 
     For facilitating securely assembling the transformer  4 , the inner surfaces of the first magnetic part  431  and the second magnetic part  432  are bonded onto the conductive winding module  22  via adhesives  46 . Similarly, the conductive winding modules  22  are bonded onto the circuit board  41  via adhesives  47 . 
     From the above description, the conductive winding module of the present invention may be used as the secondary winding coil of the transformer. Since the conductive winding module is an unbroken multi-loop conductive piece, the overall volume of the conductive winding module is reduced and the power loss is decreased. Since the process of assembling the conductive winding module is very simple, the transformer is suitable for mass production. Moreover, the extension parts of the conductive winding module may facilitate dissipating heat of electronic components and increasing space utilization. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.