PATENT DOCUMENT

Publication Number: US-8587953-B2
Application Number: US-20197508-A
Country: US
Kind Code: B2

Title: Flexible data cable

Abstract:
A multi-layered cable consisting of three or more conductive layers separated by layers of dielectric and/or adhesive material. The bottom layer and the top layer may act as return path for the transmitted signals and as a shield to prevent interference between these and external electrical signals. Located between the bottom layer and the top layer, the middle layer may transmit desired signals through the flexible cable. The material selection and specifics of each of the layers should be selected so as to achieve a balance in which the desired electrical impedance and mechanical flexibility requirements are met. The cable may also include one or more vias connecting the bottom layer to the top layer, providing shielding all the way around the flex cable. An additional conductive sock may be used to improve shielding effectiveness of the top and bottom layer and to connect to I/O connector shells and the system Faraday cage.

Claims:
The invention claimed is: 
     
       1. A data cable comprising:
 a flexible section comprising
 a bottom layer; 
 a top layer; 
 a middle layer located between the top layer and bottom layer, wherein the middle layer comprises a flexible conductive material; 
 a first dielectric layer located between the top layer and the middle layer; 
 a second dielectric layer located between the bottom layer and the middle layer; 
 at least one data transmission line located adjacent to the middle layer; and 
 at least one via, the via comprising
 a hole in the cable from the top layer to the bottom layer; and 
 a conductive filling, wherein the conductive filling electrically couples the bottom layer and the top layer; 
 
 
 a rigid section connected to the flexible section, the rigid section comprising a first end adjacent to the flexible section; and 
 a conductive sock comprising an exposed and outwardly facing conductive surface, the conductive sock surrounding the first end of the rigid section and surrounding a portion of the flexible section that is adjacent to the rigid section, the conductive sock making an electrical connection to both the flexible section and the rigid sections. 
 
     
     
       2. The data cable of  claim 1  wherein the bottom layer and the top layer provide ground planes for the flexible section of the cable, and the conductive sock connects the bottom layer and the to layer to a ground plane of the rigid section to thereby electrically interconnect the ground planes of the flexible section and the rigid section. 
     
     
       3. The data cable of  claim 1  wherein the via is located near the edge of the flexible section of the cable. 
     
     
       4. The data cable of  claim 1  further comprising:
 a first metallic pad mounted on a first side of the rigid section near the first end; 
 a second metallic pad mounted on a second side of the rigid section near the first end, the second side opposite from the first side; 
 the conductive sock further comprising
 a top piece placed above the top layer, the to piece electrically connected to the rigid section through the first metallic pad to form the electrical connection between the conductive sock and the rigid section; and 
 a bottom piece placed below the bottom layer, the bottom piece electrically connected to the rigid section through the second metallic pad to form the electrical connection between the conductive sock and the rigid section, wherein the top piece and the bottom piece are made of a conductive material. 
 
 
     
     
       5. The data cable of  claim 4  wherein the top piece of the conductive sock and the bottom piece of the conductive sock extend past the edge of the cable to surround the cable. 
     
     
       6. The data cable of  claim 4  further comprising:
 a third metal pad that surrounds the flexible section of the cable and electrically couples to the top layer and the bottom layer. 
 
     
     
       7. The data cable of  claim 6  wherein the top piece of the conductive sock and the bottom piece of the conductive sock are electrically coupled to the third metal pad to form the electrical connection between the conductive sock and the flexible section. 
     
     
       8. The data cable of  claim 1 , wherein the rigid section of the data cable further comprises a connector proximate to a second end of the rigid section of the data cable, the second end opposite from the first end. 
     
     
       9. A computer system comprising:
 a first operating component; 
 a second operating component; and 
 a data cable coupling at least the first operating component to the second operating component, the data cable comprising a flexible section, a rigid section, and a conductive sock; 
 the flexible section comprising
 a bottom layer comprised of an electrically conducting material; 
 a top layer comprised of an electrically conducting material; 
 a middle layer located between the top layer and bottom layer, wherein the middle layer comprises a flexible conductive material; 
 a first dielectric layer located between the top layer and the middle layer; 
 a second dielectric layer located between the bottom layer and the middle layer; 
 at least one data transmission line located adjacent to the middle layer; and 
 at least one via, the via comprising;
 a hole in the flexible cable from the top layer to the bottom layer; and 
 a conductive filling, wherein the conductive filling electrically couples the bottom layer and the top layer; 
 
 
 the rigid section connected to the flexible section, the rigid section comprising a first end adjacent to the flexible section; 
 the conductive sock comprising an exposed and outwardly facing conductive surface, the conductive sock surrounding the first end of the rigid section and surrounding a portion of the flexible section that is adjacent to the rigid section, the conductive sock making an electrical connection to both the flexible section and the rigid sections. 
 
     
     
       10. The computer system of  claim 9  wherein the bottom layer and the top layer of the flexible section of the data cable provide ground planes for the cable, and the conductive sock connects the bottom layer and the to layer to a ground plane of the rigid section to thereby electrically interconnect the ground planes of the flexible section and the rigid section. 
     
     
       11. The computer system of  claim 10  wherein the electrically conducting material of the bottom layer and the top layer of the flexible section of the data cable comprise at least a plurality of intersecting copper segments. 
     
     
       12. The computer system of  claim 11  wherein the intersecting copper segments are oriented diagonally along the length of the flexible section of the data cable to form a mesh pattern. 
     
     
       13. The computer system of  claim 9  wherein the rigid section of the data cable further comprises a connector proximate to a second end of the rigid section of the data cable, the second end opposite from the first end. 
     
     
       14. The computer system of  claim 13  wherein the connector is located adjacent to a window in the top layer of the flexible section of the data cable; and
 the at least one data transmission line enters the connector through the window. 
 
     
     
       15. The computer system of  claim 9  wherein the via is located near the edge of the flexible section of the data cable. 
     
     
       16. The computer system of  claim 9  wherein the data cable further comprises:
 a first metallic pad mounted on a first side of the rigid section near the first end; 
 a second metallic pad mounted on a second side of the rigid section near the first end, the second side opposite from the first side; 
 the conductive sock comprising;
 a top piece placed above the top layer, the top piece electrically connected to the rigid section through the first metallic pad to form the electrical connection between the conductive sock and the rigid section; and 
 a bottom piece placed below the bottom layer, the bottom piece electrically connected to the rigid section through the second metallic pad to form the electrical connection between the conductive sock and the rigid section, wherein the top piece and the bottom piece are made of a conductive material. 
 
 
     
     
       17. The computer system of  claim 16  wherein the top piece of the conductive sock and the bottom piece of the conductive sock extend past the edge of the flexible section of the data cable to surround the flexible section of the data cable. 
     
     
       18. The computer system of  claim 9  wherein the top layer and the bottom layer operate to at least partially prevent electrical noise from reaching or exiting the middle layer. 
     
     
       19. The computer system of  claim 9 , further comprising
 an enclosure that contains the first operating component and not the second operating component, the enclosure containing an opening adapted to allow a portion of the flexible section of the data cable to pass there-through such that the rigid section of the data cable sits in a notch that is external to the enclosure; 
 a first gasket connected to an interior surface of the enclosure adjacent to the opening, the first gasket comprising a conductive surface; and 
 a second gasket connected the interior surface of the enclosure adjacent to the opening and opposite from the first gasket, the second gasket comprising a conductive surface; 
 wherein the conductive surface of the conductive sock contacts the conductive surfaces of the first and second gasket to thereby electrically interconnect the conductive sock and the first and second gasket. 
 
     
     
       20. A data cable comprising:
 a flexible section comprising a bottom layer, a top layer, and a middle layer located between the top layer and bottom layer, wherein the middle layer comprises a flexible conductive material; 
 a rigid section connected to the flexible section, the rigid section comprising a first end adjacent to the flexible section; and 
 a conductive sock comprising an exposed and outwardly facing conductive surface, the conductive sock surrounding the first end of the rigid section and surrounding a portion of the flexible section that is adjacent to the rigid section, the conductive sock making an electrical connection to both the flexible section and the rigid sections. 
 
     
     
       21. The data cable of  claim 20  wherein the bottom layer and the top layer provide ground planes for the flexible section of the cable, and the conductive sock connects the bottom layer and the top layer to a ground plane of the rigid section to thereby electrically interconnect the ground planes of the flexible section and the rigid section. 
     
     
       22. The data cable of  claim 20  further comprising:
 a first metallic pad mounted on a first side of the rigid section near the first end; 
 a second metallic pad mounted on a second side of the rigid section near the first end, the second side opposite from the first side; 
 the conductive sock further comprising
 a top piece placed above the top layer, the top piece electrically connected to the rigid section through the first metallic pad to form the electrical connection between the conductive sock and the rigid section; and 
 a bottom piece placed below the bottom layer, the bottom piece electrically connected to the rigid section through the second metallic pad to form the electrical connection between the conductive sock and the rigid section, wherein the top piece and the bottom piece are made of a conductive material. 
 
 
     
     
       23. The data cable of  claim 22  further comprising:
 a third metal pad that surrounds the flexible section of the cable and electrically couples to the top layer and the bottom layer; 
 wherein the top piece of the conductive sock and the bottom piece of the conductive sock are electrically coupled to the third metal pad to form the electrical connection between the conductive sock and the flexible section. 
 
     
     
       24. The data cable of  claim 20 , wherein the flexible section further comprises
 a first dielectric layer located between the top layer and the middle layer; 
 a second dielectric layer located between the bottom layer and the middle layer; 
 at least one data transmission line located adjacent to the middle layer; and 
 at least one via, the via comprising
 a hole in the cable from the top layer to the bottom layer; and 
 a conductive filling, wherein the conductive filling electrically couples the bottom layer and the top layer, and wherein the via is located near the edge of the flexible section of the cable.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 37 C.F.R. §119(e) to U.S. Provisional Patent Application No. 61/019,538, filed on Jan. 7, 2008 and entitled “Flexible Data Cable,” which is incorporated by reference herein as if fully set forth in its entirety. This application is related to 1) U.S. Provisional Patent Application No. 61/019,530, filed Jan. 7, 2008 and entitled “Input/Output Connector and Housing;” 2) U.S. Provisional Patent Application No. 61/019,540, filed Jan. 7, 2008 and entitled “I/O Connectors with Extendable Faraday Cage;” 3) U.S. Nonprovisional patent application Ser. No. 12/201,867, filed Aug. 29, 2008 and entitled “Input/Output Connector and Housing,” and 4) U.S. Nonprovisional patent application Ser. No. 12/202,038, filed Aug. 29, 2008 and entitled “I/O Connectors with Extendable Faraday Cage” all of which are incorporated by reference herein as if set forth in their entireties. 
     This application is also related to 1) U.S. Provisional Patent Application No. 61/019,278, filed Jan. 6, 2008, and entitled “MicroDVI Connector;” 2) U.S. Provisional Patent Application No. 61/019,280, filed Jan. 6, 2008, and entitled “USB Connector and Housing;” and 3) U.S. Provisional Patent Application No. 61/010,116, filed Jan. 6, 2008, and entitled “Mag Safe Connector;” 4) U.S. Nonprovisional patent application Ser. No. 12/242,784, filed Sep, 30, 2008, entitled “MicroDVI Connector;” 5) U.S. Nonprovisional patent application Ser. No. 12/242.712, filed Sep. 30, 2008, entitled “Data Port Connector and Housing:” and 6) U.S. Nonprovisional patent application Ser. No. 12/239,662, filed Sep. 26, 2008, now U.S. Pat. No. 7,762,817, entitled “System for Coupling Interfacing Parts.” 
    
    
     BACKGROUND 
     Computing devices (“computers”) have become increasingly technically complex since their inception. Computers, even those capable of being carried in a single hand (such as a mobile phone or personal digital assistant), can perform many more functions at much greater speed than the computers of the 1950s and 1960s. Many of these expanded functions rely on interconnecting a computer with an accessory, another computer or other electronic device (collectively, “peripherals”). For example, peripherals may use a variety of standards to connect to a computer, including: universal serial bus (USB); FireWire; serial; parallel; digital video interface (DVI) and so forth. Different peripherals may employ different connectors or connection standards. 
     Traditionally, input/output ports occupy a fixed, stationary position in a computer. By maintaining a static position for the input/output ports (“I/O ports”), engineering of the computer case is simplified. However, fixed I/O ports may be inconveniently placed. Further, fixed I/O ports often are susceptible to dust and/or debris entering the ports and interfering with their functions. 
     Further, I/O ports are generally contained within a Faraday cage defined by the case of the computer. The Faraday cage generally prevents electrical noise from outside the cage entering the interior and vice versa. Thus, the computer case (be it the shell of a desktop or laptop computer, the casing of a mobile telephone or PDA, or other case/cage) prevents noise or extraneous signals from exiting the computer via the I/O ports and reaching a peripheral connected to the port(s). Similarly, the computer case may also prevent noise and/or extraneous signals generated by the peripheral, or another electronic device outside the case, from entering the case via the I/O port and internal associated connector cable. In short, the computer case electrically isolates its interior from its exterior. 
     Because the I/O ports are typically located within the barrier of a Faraday cage, they are stationary; moving ports might break or exit the electrical barrier. I/O ports may be, for example, recessed within the case to place them within the cage. It may be inconvenient to access such recessed ports. 
     Because a typical I/O port and data cable would be partially outside the case&#39;s Faraday cage if used in a pivoting housing, both the interior and exterior would be vulnerable to noise originating in the other area. Accordingly, what is needed is an improved data cable that may be used with an I/O port located outside, or partially outside, a Faraday cage of a computer. 
     SUMMARY 
     One embodiment of the present invention takes the form of a cable capable of transmitting electrical signals. The exemplary cable is thin and flexible. Further, the embodiment provides an electrical shield along at least a portion of the length of the cable to prevent external electrical signals (e.g. noise) from interfering with the signals being transmitted through the cable and vice versa. In this sense, the cable may have at least some similar electrical properties as a coaxial cable, although the exemplary cable is quite different in many respects. 
     One embodiment of the present invention may take the form of a cable with three major layers. The bottom layer and the top layer may act as a return path for high speed signals carried on the middle layer of the cable. Thus, the bottom and top layers typically have a low inductance and may also act as a shield against external electrical signals. Located between the bottom layer and the top layer, the middle layer may transmit desired signals through the flexible cable. Thus, the bottom and top layers may act to surround and protect the middle layer and its associated electrical signals from external noise. The embodiment may also include one or more vias connecting the bottom layer to the top layer, creating a ground path so that the top and bottom layer potentials are the same. The vias may also be stitched regularly along the length of the cable to minimize seams and create a low-inductance electrical connection between the top and bottom layers. 
     Still another embodiment may take the form of a flexible data cable including: a bottom layer; a top layer; a middle layer located between the top layer and bottom layer; at least one data transmission line located on the middle layer; and at least one via. The via may include: a hole in the cable from the top layer to the bottom layer; and a conductive filling, wherein the conductive filling electrically couples the bottom layer and the top layer. In certain embodiments, the vias may connect the top and/or bottom layer to the middle layer, as well. 
     Yet another embodiment may be a method for forming a flexible data cable, including the operations of: providing a bottom layer; providing a top layer; placing a middle layer between the top layer and bottom layer; placing at least one data transmission line on the middle layer; forming a hole in the cable from the top layer to the bottom layer; and filling the hole with a conductive material such that the bottom layer and the top layer are electrically coupled. 
     These and other embodiments and features will be apparent to those of ordinary skill in the art upon reading this disclosure in its entirety, along with the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  depicts an exemplary computing device. 
         FIG. 2  depicts a first embodiment of the present invention, specifically a notebook computer. 
         FIG. 3  depicts a schematic view of a first portion of one embodiment of the present invention. 
         FIG. 4  depicts an exploded view of a second portion of the embodiment of  FIG. 1 , including a connector housing. 
         FIG. 5A  is an exploded view of a flexible data cable in accordance with  FIG. 4 , taken along line  5 - 5  of  FIG. 4 . 
         FIG. 5B  is a top-down, simplified plan view of the exemplary flexible data cable shown in  FIG. 5A . 
     
    
    
     DETAILED DESCRIPTION 
     One embodiment of the present invention takes the form of a cable capable of transmitting electrical signals. The exemplary cable is thin and flexible. Further, the embodiment provides an electrical shield along the length of the cable to prevent external electrical signals (e.g. noise) from interfering with the signals being transmitted through the cable. In this sense, the cable may have at least some similar electrical properties as a coaxial cable, although the exemplary cable is quite different in many respects. 
     One embodiment of the present invention may take the form of a cable with three layers. The bottom layer and the top layer may act as a shield against external electrical signals. Located between the bottom layer and the top layer, the middle layer may transmit desired signals through the flexible cable. Thus, the bottom and top layers may act to surround and protect the middle layer and its associated electrical signals from external noise. The embodiment may also include one or more vias connecting the bottom layer to the top layer, creating a low-inductance electrical connection, completing the shield around the signals on the middle layer. 
       FIG. 1  shows an exemplary computing device, in this case a notebook or laptop computer  100 . The notebook computer  100  includes one or more I/O ports  102  which facilitate communication between the computer  100  (or its constituent elements) and a peripheral, as generally previously described. The I/O ports  102  are held within an I/O housing  104 . As shown in  FIG. 1 , the I/O housing  104  of the computer  100  occupies a fixed position; therefore, the I/O ports  102  are likewise fixed. The ports are thus constantly accessible to a user or device outside the computer itself. 
     It should be noted that the computer  100  shown in  FIG. 1  is depicted as a notebook computer purely for convenience. The computer could be any form of computing device having one or more I/O ports, such as a desktop computer, mainframe, miniframe, network server, handheld computing device, personal digital assistant, mobile telephone, music or audio player (such as an MP3 player), and so on. Accordingly, a “computer,” as used generally herein, encompasses all such devices and any other computing device having an I/O port. 
       FIG. 2  depicts a first embodiment of the present invention, specifically a notebook computer  200 . As with the computer  100  of  FIG. 1 , the embodiment  200  includes one or more I/O ports  202  within an I/O housing  204 . In this embodiment, however, the housing  204  may pivot between an open and closed position. In the open position, as shown in  FIG. 2 , the I/O ports  202  are exposed and can be accessed from outside the embodiment  200 . When the housing is in a closed position, the I/O ports are covered and cannot be externally accessed. 
     One embodiment of the present invention may be a data cable that connects from the computer  200  to the I/O ports  202 . The embodiment would permit the computer  200  to interface with external components. 
       FIG. 3  depicts a schematic view of a segment of one embodiment of the present invention. This embodiment may take the form of a flexible, thin cable  300  that includes electrical shielding layers to insulate any signals transmitted through the cable  300 . It should be appreciated, however, that the cable  300  may be any shape or size and may be either flexible or inflexible. 
     The cable  300  depicted in  FIG. 3  may be composed of three major layers arranged in a stacked fashion. Additional layers, such as insulating layers, may be positioned atop, beneath or between the three major layers; the use of the term “major layers” is for convenience only and should not be interpreted to preclude additional layers or assign particular importance to any or all of the major layers. The major layers include a top layer, middle layer and bottom layer. The bottom layer  302  may be constructed of a noise-insulating material to prevent extraneous noise from entering a signal layer, such as the middle layer  304 . In the present embodiment, the bottom layer  302  may be made of an electrically conducting material, such as copper or a copper mesh. Accordingly, it should be appreciated that any conductive material may be used in constructing the bottom layer  302 . 
     A middle layer  304  is located above the bottom layer  302 . The middle layer  304  is typically formed of a flexible conductive material, such as copper. One or more signal traces or lines  308  may be formed on the conductive substance of the middle layer. Such traces may be formed, for example, by etching away portions of the copper on the middle layer. Alternatively or additionally, copper or any other conductive metal or material may be deposited on, or bonded to, the surface of the middle layer  304  to form the signal lines  308 . Further, the signal lines  308  may be formed within the middle layer  304  instead of on a surface thereof. 
     Generally, these lines  308  run substantially the length of the embodiment. For example, the signal line or lines may begin at or near one end of the flex cable and be electrically connected to an internal connector of a type suitable for the function of the cable. That is, the internal connector may mate with a storage device, a signal bus, a memory device, a processor, interface and so forth, depending on the intended operation of the flex cable. The signal line(s)  308  may extend to an external connector  314  located at or near an opposing end of the flex cable, as described in more detail below. Generally, the signal lines  308  permit transmission of data along the flex cable and between any two devices or components connected thereby. 
     A top layer  306  may be placed above the middle layer  304 . Similar to the bottom layer  302 , the top layer  306  may be made of any suitable electrically conductive noise-insulating material. In this embodiment, the top layer  306  may be made of copper or another electrically conductive metal. Such metal, as with the bottom and middle layers, generally is flexible and/or ductile to permit flexing and motion of the cable. 
     A dielectric layer  315  may be placed between the top layer  306  and middle layer  304 . Each dielectric layer  315  may electrically insulate the top and/or bottom layers from the middle layer. Such dielectric layers  315  may be formed from any suitable electrically insulating material, such as polyester, polyimide or any suitable resin or polymer. 
     In some embodiments, an adhesive may bond one or both of the top and bottom layers  302 ,  306  to the middle layer  304  or the intervening dielectric layers  315 ). The optional adhesive may be an insulating adhesive to provide additional insulation of any signals carried on the signal traces  308  from the top and bottom layers. It should be noted that the adhesive is entirely optional; several embodiments omit any adhesive of this nature. 
     Thus, one exemplary embodiment may have the following layers, going from top to bottom: the top layer  302 , a first dielectric layer  315 , a first adhesive layer, the middle layer  304 , a second adhesive layer, a second dielectric layer  315  and the bottom layer  302 . Alternative embodiments may omit one or more of these layers or may add additional layers (for example, additional dielectric  315  or adhesive layers). 
     Still with reference to  FIG. 3 , the bottom layer  302  and the top layer  306  of the cable provide a protective shield for the signals being sent on the middle layer  304  from external electrical signals. That is, the bottom and top layers, in conjunction, may at least partially isolate any signals transmitted along the signal lines  308  from extraneous noise. 
     In some embodiments, as shown in  FIG. 3 , the top, middle and bottom layers  306 ,  304 ,  302  extend laterally approximately the same distance such that all three layers terminate at an edge of the cable  300 . In alternative embodiments, the top and bottom layers may extend laterally further than the middle layer, thus “sandwiching” the middle layer to some extent. 
     External electrical fields (e.g., noise) can disrupt the electrical signals within a conducting material and may cause the signals to be degraded or canceled. Shielding is typically utilized in cables to prevent interference of the electrical signals being transmitted through the cable by external noise, as well as to reduce or minimize interference to external devices resulting from the signal(s) transmitted along the cable. A typical example of a shielded cable is a coaxial cable. In a coaxial cable, the conducting material on which the electrical signals are being transmitted is surrounded by a hollow, flexible conductor. The outside flexible conductor acts as a shield and prevents external noise from corrupting the electrical signals being sent through the coaxial cable. In many coaxial cables, the outside conductor is connected to ground. By connecting the outside conductor of the cable to ground, any external electrical fields that may interfere with the electrical signals being sent on the interior conductor are collected by the outside conductor and bled to ground to prevent corruption of the interior signal and vice versa. The theory and purpose of shielded cables are well known in the art. 
     The top layer  306  and bottom layer  302  may be made of an electrically conductive material to prevent noise from reaching or exiting the middle layer. Since current induced by outside noise sources flows on the outside surfaces of the top layer  306  and bottom layer  302 , the signals on the middle layer are isolated from the noise and interference is minimized. Conversely, the top and bottom layer may prevent energy radiating from the signals on the middle layer, preventing interference with external devices. The top and bottom layers may be electrically connected to the system Faraday cage and/or I/O connector shells to complete the shield interface to the host computer. 
     Certain embodiments may connect the bottom layer  302  to the top layer  306  with one or more vias  312 . The vias  312  may be constructed by drilling, punching or otherwise forming holes through the bottom layer  302  and the top layer  306  (and, in the event the top and bottom layers do not extend outward further than the middle layer  304 , the middle layer  304  as well). The holes may then be filled with copper to provide an electrical connection between the bottom layer  302  and the top layer  306 . In the event the via runs through the middle layer  304 , it typically does not extend through any signal line  308 , but may extend through a ground line formed on or in the middle layer. In embodiments where the via extends through a ground line on the outer edges of the middle layer, the middle layer is effectively connected to one or more ground planes. This, in turn effectively provides shielding all the way around the flex cable  400  for signals carried thereon. 
     In certain alternative embodiments, the vias  312  may be any device or construct capable of providing an electrical connection between the bottom layer  302  and the top layer  306 . For example, the vias may be a wire (or other conductor) electrically connected to the bottom layer  302  and the top layer  306  and passing outside the cable  300 . Another example may be a metal foil or strip that surrounds at least a portion of the cable  300  and electrically connects the bottom layer  302  to the top layer  306 . A series of metal foils or strip may be used to provide multiple connections. 
     In the present embodiment, the vias  312  are located near the outside edge of the cable  300 . The placement of the vias  312  near the outer edge of the cable  300  allows the vias  312  to connect the bottom layer  302  with the top layer  306  without the vias  312  passing through any signal lines  308 . However, in alternative embodiments, the present invention allows for the vias  312  to be located anywhere along the cable  300  between the bottom layer  302  and the top layer  306 . Again, by stitching the top, middle and bottom layers together with a via, 360 degree electrical shielding may be achieved. 
     The placement of the vias  312  in the present embodiment near the outer edge of the cable may also facilitate shielding the electrical signals being transmitted on the conductive lines  308  of the middle layer  304  of the cable  300 . Together with the bottom layer  302  and the top layer  306 , the vias  312  may provide some shielding on the sides of the cable  300 . By placing shielding structures on the sides as well as the top and bottom of the cable  300 , the present embodiment may more effectively prevent the internal electrical signals from being degraded by external noise or vice versa. 
     As described above, the cable  300  permits electrical signals to be transmitted along the conductive lines  308  extending substantially the length of the cable  300 . In one embodiment, a connector  314  may mate the conductive lines  308  to another component. For example, the connector  314  may allow the cable to interface with external components. The connectors  314  of the embodiment may be any device or construct capable of receiving electrical signals from a cable. Exemplary connectors include FireWire ports, USB ports, RCA-type ports, VGA ports, DB25 ports, S-Video ports, SDI ports, BNC ports, DVI ports, DisplayPort ports, audio ports and so on. In the embodiment shown in  FIG. 3 , the cable  300  may terminate at or adjacent connector  314  such that the signal lines  308  are in electrical contact with the connector. 
     It should be noted the signal lines  308  may electrically contact the connector  314  in many different ways. For example, in one embodiment, the conductive lines  308  of the cable  300  may be soldered or otherwise connected directly to a circuit board. In another embodiment, a through hole or surface mount pin may provide a connection between the signal lines  308  and connector  314 . In yet another embodiment, the cable  300  may directly interface with a second cable. It should be appreciated the there exists many varied ways in which the cable  300  and conductive lines  308  may terminate. 
     As shown in  FIG. 3 , the cable  300  may terminate at a connector  314  on either end of the cable  300 . In this embodiment, the connector  314  may mount on top of the cable  300 . In such an embodiment, a window  316  may be located in the top of the cable  300  and extend roughly the width of the connector  314  across the width of the cable. Depending on the nature of the connector, the window may extend substantially less than the width of the connector. The window  316  in the cable may extend through the top layer  302 , thus exposing the middle layer  304  of the cable  300 . Below the window  316 , the conductive lines  308  of the middle layer  304  may extend vertically. The conductive lines  308  may thus exit the cable  300  through the window  316  and mate with the connector  314 . It should be appreciated that the conductive lines may exit the cable  300  in a variety of ways. For example, in one embodiment, the window  316  may be cut in the bottom of the cable  300  through the bottom layer  302 . Alternatively, the connector  314  may mount on the end of the cable  300 . In such an embodiment, a window may be provided at the end of the cable, permitting the conductive lines  308  to pass out of the cable  300  without bending. Those skilled in the art will appreciate the many ways at which the cable  300  may terminate into a connector  314 . 
     Still with respect to  FIG. 3 , in the present embodiment the conductive lines  308  exit the cable through the window  316  and interface with the connector  314 . The construction of the connector  314  is well known to those of ordinary skill in the art. As such, the operation and construction of the connector  314  will not be described further. 
       FIG. 4  depicts an exploded view of one embodiment of the present invention having a cable  400  terminating at a connector housing  420 . In this embodiment, the cable may contain a rigid section  422  near one or both ends of the cable  400 . A connector housing  420  may be mounted on the rigid section  422 . As described above, the conductive lines may run through the middle layer of the cable and up into or adjacent the connector housing  420 . The conductive lines may terminate within or adjacent the connector, thereby providing an interface through which the cable may transmit or receive electrical signals from an external device communicating with the connector  414 . Accordingly, the cable  400  may provide an interface for internal components of the computer to a device external the computer. 
     As further shown in  FIG. 4 , the cable  400  may include a conductive sock  432  that surrounds the cable  400  at the point where the conductive lines enter the rigid section  422  of the cable  400 . In one embodiment, the conductive sock may include a top piece  424  and a bottom piece  426 . Both the top piece  424  and the bottom piece  426  may be of a conductive material. In the present embodiment, the top piece  424  and the bottom piece  426  are constructed of a metallic foil. However, it should be appreciated that the top piece  424  and the bottom piece  426  may be constructed of any conductive material. Certain applications of the cable may require that the sock  432  have a minimum flexibility, which should be kept in mind when choosing the conductive material used to form the sock. Generally, the top piece  424  overlies at least a portion of the top layer  306  of the cable  400  and the bottom piece  426  of the sock overlies at least a portion of the cable&#39;s bottom layer  302 . 
     In one embodiment, the conductive sock  432  may be adhered or soldered to the cable and/or a rigid section  422  near the end of the cable  400 . As shown in  FIG. 4 , a metallic pad  428  may be mounted on the rigid section  422  of the cable  400  near the point where the flex cable  400  and the rigid section  422  mate. A second metallic pad may also be mounted on the opposite side of the rigid section  422  of the cable  400  at or near the same position. A third metallic pad  430  may also be provided on the flex cable. The third metallic pad  430  may surround the cable  400  at a point away from the connector housing  420 . To connect the conductive sock  432  to the cable assembly, the top sock  424  may be soldered or adhered to the first metallic pad  428  and the top section of the third metallic pad  430 . Similarly, the bottom sock  426  may be soldered or adhered to the second metallic pad and the bottom section of the third metallic pad  430 . The top sock  424  and the bottom sock  426  may also extend past the edge of the flex cable  400  and join together, thus providing a sock  432  that surrounds the cable  400  when the top  424  and bottom piece  426  are brought together. It should be noted that a dielectric layer may be placed between the bottom sock  426  and the bottom layer  302  of the flex cable  400 . Likewise, another dielectric layer may separate the top sock  424  from the top layer  306 . The dielectric layer may be placed above or below any adhesive layers. 
     The construction of the sock surrounding the cable  400  may aid in maintaining a Faraday cage for the computer. Generally, a Faraday cage is an enclosure formed by conducting material that blocks out external electrical fields. External electrical fields, or noise, can disrupt the electrical signals within a conducting material and may cause the signals to be degraded or canceled. Faraday cages are typically utilized in cables to prevent the electrical signals being sent through the cable from being interfered with by external noise or vice versa. The theory and purpose of Faraday cages are well known in the art and, therefore, will not be described further. 
     In one embodiment, the Faraday cage of the computer may be partially composed of the computer body, including the top, bottom, and sides of the body. However, the inclusion of an I/O port may require a notch or slot in one side of the computer body. To complete the Faraday cage, the cage may extend into the notch and past the I/O connectors to a top and bottom gasket that are electrically connected to the conductive sock. Thus, the top, bottom, and sides of the I/O port housing, combined with the top gasket, the conductive sock placed about a portion of the flex cable, and the bottom gasket may form the portions of the Faraday cage within the notch of the computer body. Generally, the body connects to both the top and bottom gaskets. The gaskets are in turn electrically connected to one another by the conductive sock. It should be noted that the electrical connection between the sock and gaskets persists regardless of any motion of the I/O housing. The Faraday cage structure is described in greater detail in a separate U.S. Provisional Patent Application filed with attorney docket no. 189921/US (P6148US1), entitled “I/O Connectors with Extendable Faraday Cage” and filed concurrently with this application and is incorporated by reference herein. 
     The flex cable  400  may connect to one or more I/O ports mounted to the I/O port housing. In particular and as shown in the schematic view of  FIG. 5 , the I/O port housing  500  may define an I/O connector shell  502 . One or more I/O connectors  504  within the shell  502  may be electrically connected to the middle layer  304  of the flex cable  400 . Likewise, a ground pin  506  within the I/O shell  502  may electrically connect to either the top layer  306  or bottom layer  304  of the flex cable  400 . In this manner, the ground potential of the I/O connector shell may be matched to that of the flex cable (or, at a minimum, the top and/or bottom layer of the cable). 
     In addition, the aforementioned conductive sock  432  may be electrically connected to both the flex cable  400  as described above and also to a printed circuit board on which the I/O connector shell  502  rests. The sock may be electrically connected to the printed circuit board via the aforementioned metallic pad  428 , for example. Typically, the printed circuit board is also electrically connected to the I/O shell  502 ; therefore, the top sock  424  may be grounded to the chassis and shell through one end and to the top layer  306  of the flex cable  400  at another end. Likewise, the bottom sock  426  may be grounded to the printed circuit board at a first end and the bottom layer  302  of the flex cable at its second end. In this manner, the sock may continue the Faraday cage structure previously mentioned. It can also be seen that this Faraday cage may surround the I/O connectors insofar as the I/O connector shells form a portion of the cage. 
     Certain alternative embodiments may vary the construction of the flex cable without departing from the spirit or scope of the disclosure contained herein. For example, one embodiment may include one or more nonconductive materials that surrounding and/or separate the bottom layer  302 , middle layer  304 , and the top layer  306 . The nonconductive material  310  may be any nonconductive device or entity sufficient to prevent the electrical charges contained on the three layers from interfering with each other. Exemplary nonconductive material  310  include polyester or polyimide. In this particular embodiment, the nonconductive material  310  surrounds and separates all three layers of the cable  300 . Alternatively, the nonconductive material  310  may be located between the bottom layer  302  and the middle layer  304  and the top layer  306  and the middle layer  304 . In such an embodiment, the outer surfaces of the bottom layer  302  and the middle layer  304  are exposed. 
     The nonconductive material  310  may also be provided to fill the space between the conductive lines  308  of the middle layer  304 . As stated above, electrical signals may be transmitted along the length of the conductive lines  308  of the middle layer  304 . The nonconductive material  310  may be provided between the conductive lines  308  to prevent the lines from becoming electrically connected. Thus, the nonconductive material  310  may isolate and separate the conductive lines  308  such that the electrical signals being transmitted on the lines  308  do not create interference with the other conductive lines  308 . 
       FIG. 5A  is a simplified exploded view of the flex cable  400  of  FIG. 3 , taken along line  5 - 5  of  FIG. 3 . As shown to best effect in  FIG. 5A , the top layer  306  may be formed from a copper mesh  500  generally consisting of intersecting copper segments  502 ,  504 . In the present embodiment, the segments  502 ,  504  run diagonally up and down along the length of the top layer  306  to form the mesh  500 . Thus, when viewed from above looking along the length of the top layer  306 , the traces form a diamond pattern rather than a square pattern. By forming the top layer  306  from a mesh  500  instead of a contiguous strip, the overall flexibility and ductility of the middle layer (and thus the entire cable) may be increased. The bottom layer  302  is formed from a diamond mesh in a manner similar to the top layer. Traces  508  provide a path for electrical signals and may be formed above or below the plane of the copper segments  502 ,  504 . The cross-hatching pattern formed by the mesh generally is sufficiently dense to operate as an electrical filter to prevent noise leakage out of or into the middle layer  304 . The conductive sock  432  may be used to cover the section of the cable past the gaskets to compensate for any reduction in shielding effectiveness of top layer  306  and bottom layer  302  due to openings in the cross-hatching pattern. 
     Further, by forming the top and bottom layers  302 ,  306  from a mesh, the density of the copper (or other conductive material) forming the top and bottom layers  306 ,  302  is reduced. (“Density” here refers to the amount of copper per square millimeter or other measurement of area, not volume). This, in turn raises the impedance of the signals that may reference to the ground planes formed by the top and bottom layers. 
     As also shown in  FIG. 5A , one or more signal paths  506  may be formed on the middle layer  304 . The signal paths  506  underlie the first and second copper traces  502 ,  504  and several other traces. It should be noted that the signal paths generally define a first signal transmission route extending in one direction along the flexible cable  400  while the aforementioned return signal paths of the top and bottom layers  302 ,  306  form a second signal transmission route extending in an opposing direction. Thus, return signals may be routed across the second signal transmission route. It should be noted that the cross-hatching pattern may also increase inductance of the second signal transmission route. 
     Because the ground planes have a lower density than a solid ground plane, the signal paths  506  and  508  on the middle layer may be routed so as to minimize or maximize the effective impedance of signals referencing to that plane. For example and as shown in  FIG. 5B , the signal paths  506  may be routed such that they underlie the intersection  510  of each of the copper segments  502 . In this manner, the effective impedance of the signal trace that reference to this plane  506  is increased to meet the impedance requirements specific to the application. Alternatively, the signal trace could be routed relative to ground mesh such that the impedance of the signal trace is lowered. Yet another alternative is to change the orientation of the ground mesh to align it with the signal traces. 
     In one embodiment of the invention a thin dielectric material may be used to achieve improved mechanical flexibility. With a thin dielectric between impedance controlled traces and the reference plane, the impedance of those traces is effectively lowered. To compensate for that lower impedance, selective dielectric materials, including a mix of adhesives or polyimides or other insulators, may be chosen to meet the requirements of the application. A balance may be achieved between mechanical flexibility and electrical requirements (such as trace impedance and loss) by adjusting trace widths, dielectric materials, dielectric thickness, copper density on the signal layer, copper/area of the ground reference plane and the alignment of the signal traces to the mesh reference plane. 
     It should be noted that certain embodiments of the present flex cable may separate certain signal lines to prevent cross-interference between signals carried on such lines. For example, in an embodiment carrying both analog and digital signals, the ground planes to which the analog and digital signal lines reference may be spatially separated on each layer of the cable. Such separation may prevent return currents for the digital signal(s) from coupling to the analog signals. In some embodiments, analog audio signals and digital video or data signals may thus be carried on a single flex cable. 
     As one example thereof, a sample flex cable may carry analog audio signals, DVI signals, video graphics array (VGA) signals and universal serial bus (USB) signals each on a unique signal path. The VGA signals may be single-ended signals while the USB and DVI signals maybe differential signals. In certain embodiments, at least the DVI interface may achieve a data throughput of approximately 4.95 gigabits per second or higher by employing a flex cable as described herein. Further, the VGA signals may be routed along the cable as a 50 ohm impedance signal with resistive termination to impedance match the VGA signal to a typical 75 ohm connector. 
     To further separate different types of signals, a ground trace may be routed between them. This ground trace may be connected to the top layer  306  and bottom layer  302  with multiple vias along its length. This approximates a structure similar to coaxial cable in which different types of signals are electrically isolated from each other. 
     The foregoing merely illustrates certain principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles disclosed in this document and are thus within the spirit and scope of the present invention. From the above description and drawings, it will be understood by those of ordinary skill in the art that the particular embodiments shown and described are for purposes of illustration only and are not intended to limit the scope of the present invention. References to details of particular embodiments are not intended to limit the scope of the invention.

Metadata:
Filing Date: 20080829
Publication Date: 20131119
Grant Date: 20131119
Priority Date: 20080107
Inventors: BROCK JOHN
DEGNER BRETT WILLIAM
MATHEW DINESH
WILSON, JR. THOMAS W.
LIGTENBERG CHRIS
HENDREN KEITH
KEIPER STEVEN
KIM EUGENE
Assignee: APPLE INC
CPC Classifications: [{"code": "H01R12/592", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K1/0218", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/5213", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09618", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0224", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R12/62", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0393", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09681", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R12/592", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01B13/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01B11/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/5313", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/5313", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49117", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49117", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/5213", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R12/62", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0224", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09681", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0218", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/09618", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0393", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 40843677