Abstract:
Insulated conducting devices and related methods are disclosed. An insulated conducting device for a voltage structure comprises: a conductor connected to a voltage; and multiple insulation segments enclosing the conductor, the multiple insulation segments interfacing with one another.

Description:
BACKGROUND 
   1. Technical Field 
   The disclosure relates generally to electric field stress shielding, and more particularly, to an insulated conducting device for electrically shielding a structure at a voltage. 
   2. Background Art 
   Ion implantation is a standard technique for introducing conductivity altering impurities into, or doping, semiconductor wafers. A typical ion implantation process uses an energetic ion beam to introduce impurities (ions) into semiconductor wafers. During ion implantation, a source feed material is energized to generate an ion beam, and the generated ion beam needs to be accelerated by an acceleration column at a high voltage, for example, 670 kV. A voltage structure (usually referred to as a terminal) is used to provide the high voltage. 
   A co-pending U.S. patent application Ser. No 11/527,842 filed on Sep. 27, 2006 discloses an insulated conductor used as an electrical stress shield for a voltage structure in an ion implantation device, which is herein incorporated by reference.  FIG. 1  shows a perspective view of a voltage structure  400  disclosed in Ser. No. 11/527,842. Referring to  FIG. 1 , voltage structure  400  may include a base, one or more upstanding sidewalls  404  coupled to the base, and a top  402  coupled to the one or more upstanding sidewalls  404 . One upstanding sidewall  404  may have a door  440  with a handle  442  to provide personnel access to the internal cavity of voltage structure  400 . Voltage structure  400  may have one upstanding sidewall  404  manufactured of one solid material piece or any plurality of separate pieces. Although illustrated as a solid piece, top  402  of voltage structure  400  may also be fabricated of a plurality of spaced conductors forming a type of conductor mesh to allow air to flow through the openings of the mesh. 
   One or more insulated conductors  412  may be disposed about portions of the exterior surface of voltage structure  400  that have excess electric stress. In  FIG. 1 , a top insulated conductor  412  is disposed proximate the entire periphery of a top edge  470  of voltage structure  400 , and a bottom insulated conductor  412  is disposed proximate the entire periphery of a bottom edge  472 . Although top and bottom insulated conductors  412  are positioned about an entirety of the periphery of the respective edges  470 ,  472 , alternative embodiments may have additional or alternative exterior portions where insulated conductors  412  may be positioned. These portions may include, but not be limited to, horizontal edges, vertical edges, corners, and openings or interfaces where voltage structure  400  interfaces with external parts. Some external parts may include a motor, a generator, or a utility interface. In one example, a sphere shaped insulated conductor may be positioned about a corner of voltage structure  400 . Insulated conductor  412  may include an insulator  416  with a dielectric strength greater than, for example, 75 kV/inch. 
   A plurality of brackets  422  may be coupled to voltage structure  400  and associated insulated conductors  412  to support insulated conductors  412  proximate an exterior portion of voltage structure  400 . Brackets  422  may have a length to enable insulated conductors  412  to be positioned a desired distance from voltage structure  400 . The desired distance may range from almost zero (nearly touching) to a maximum distance permitted by the surrounding air gap. In one embodiment, the desired distance is at least 1.5 inches. Bracket(s)  422  may be fabricated of either conductive or nonconductive material. Bracket  422  may also function as an electrical connection between voltage structure  400  and insulated conductor  412 . 
   As shown in  FIG. 1 , insulated conductor  412  and insulator  416  are single continuous closed structures. The large size of a single piece insulator  416  may have problems in manufacturing, installing, maintenance, cost, and reliability. 
   SUMMARY 
   A first aspect of the disclosure provides an insulated conducting device for a voltage structure, the insulated conducting device comprising: a conductor connected to a voltage; and multiple insulation segments enclosing the conductor, the multiple insulation segments interfacing with one another. 
   A second aspect of the disclosure provides an insulated conducting device for a voltage structure, the insulated conducting device comprising: multiple segments interfacing with one another, each of which includes a conductor enclosed by an insulation portion; wherein the conductor includes multiple conductor cables, one of which is connected to the voltage structure. 
   A third aspect of the disclosure provides a method of electrically shielding a voltage structure, the method comprising: providing multiple segments, each segment including a conductor encapsulated by a dielectric material; connecting each conductor to the voltage structure; and positioning the multiple segments such that two immediately adjacent conductors are in proximity such that an equi-potential line of the two immediately adjacent conductors is substantially similar to that of a continuous conductor. 
   The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which: 
       FIG. 1  shows an insulated conductor according to prior art. 
       FIG. 2  shows an embodiment of an insulated conducting device. 
       FIG. 3  shows equi-potential lines of the insulated conducting device of  FIG. 2 . 
       FIG. 4  shows another embodiment of an insulated conducting device. 
       FIGS. 5A-5D  show embodiments of an insulated conducting device with a group of cables. 
       FIG. 6  shows an insulated conducting device with a continuous conductor encapsulated by segmented insulation system. 
   

   It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings. 
   DETAILED DESCRIPTION 
   Referring to the drawings,  FIG. 2  shows schematically one embodiment of an insulated conducting device  10 . As shown in  FIG. 2 , a system  8  includes a voltage structure  11  and an insulated conducting device  10 . Insulated conducting device  10  is positioned between voltage structure  11  and a ground  13 , e.g., a metallic structure. And the gap between insulated conducting device  10  and ground  13  is filled with air  15 . Insulated conducting device  10  includes multiple segments  12  ( 12   a ,  12   b  shown for illustration) each including a conductor segment  14  ( 14   a ,  14   b  shown) and an insulation segment  16  ( 16   a ,  16   b  shown), respectively. Insulation segment  16  may be made of dielectric materials such as, for example, Chlorinated Poly Vinyl Chloride (CPVC), syntactic silicone foam, epoxy resin. As shown in segment  12   b  only, insulation segment  16  ( 16   b ) may include multiple layers  161 ,  162  of different materials to control the radial stress inside insulation segment  16  and in air  15  surrounding insulation segment  16 . Conductor segment  14  is enclosed/encapsulated by a respective insulation segment  16 . 
   Two immediately adjacent insulation segments  16   a ,  16   b  interface with one another. In the description herein, the term “interface” means that two insulation segments  16   a ,  16   b  are positioned close to one another, including, but is not limited to, that insulation segments  16   a ,  16   b  contact one another. According to an embodiment, an interface medium  20  may be applied between two interfacing insulation segments  16   a ,  16   b  to, inter alia, improve insulation strength in an interface area  21 . According to an embodiment, interface medium  20  extends beyond interface area  21  and partially covers insulation segments  16   a ,  16   b.    
   Although  FIG. 2  shows that conductor segments  14   a ,  14   b , are each connected separately to voltage structure  11  through respective connection vias  22   a ,  22   b  this is not necessary. For example, according to another embodiment, conductor segments  14   a ,  14   b  may be separately connected to a power supply different than voltage structure  11 , provided that the potentials of conductor segments  14   a ,  14   b  are substantially equal. For example, conductor segments  14   a ,  14   b  may be connected to a different electrical potential, e.g., 500 kV, than voltage structure  11  at, e.g., 670 kV. At 500 kV, insulated conducting device  10  would still shield voltage structure  11 , but the stress between ground  13  and insulated conducting device  10  would be reduced. 
   According to an embodiment, as shown in  FIG. 3 , conductor segments  14   a ,  14   b  are in close proximity such that an equi-potential line(s)  24  of conductor segments  14   a ,  14   b  are substantially similar to that of a continuous conductor, i.e., as if conductor segments  14   a ,  14   b  were an integrated single conductor. In addition, the equi-potential lines  24  allocate the electrical stress of voltage structure  11  mainly on the insulation material of insulation segments  16   a ,  16   b  and/or interface medium  20  instead of on air  15  around voltage structure  11 . As a consequence, an electrical breakdown may be avoided. Details of the functions of insulated conducting device  10  are provided in Ser. No. 11/527,842. 
   According to an embodiment, as shown in  FIG. 2 , interface surfaces  18   a ,  18   b  of insulation segments  16   a ,  16   b , respectively, are substantially perpendicular to an adjacent surface, e.g.,  26   a ,  26   b , respectively. An edge  27  of conductor segment  14  (shown in  14   a  only) is substantially rounded toward interface surface  18   a.    
   According to an alternative embodiment, as shown in  FIG. 4 , an interface surface  118   a  or  118   b  is substantially sloped with respect to an adjacent surface  126   a  or  126   b . In this case, interface surfaces  118   a ,  118   b  overlap one another. According to an embodiment, as shown in  FIG. 4 , an edge  128   a  of conductor segment  14   a  adjacent to interface surface  118   a  is also substantially sloped. Preferably, the sloped edge  128   a  matches the sloped interface surface  118   a , i.e., edge  128   a  and interface surface  118   a  are sloped in similar angles. According to an embodiment, as shown in  FIGS. 2 and 4 , each conductor segment  14   a ,  14   b  may be a single hollow metal pipe (detail not shown). According to another embodiment, as shown in  FIG. 5A , a conductor segment  214  may include a group of conductor cables  215 . A conductor cable  215  refers to a cable, preferably a high voltage cable, which includes a center conductor encapsulated within an insulating material. 
   Referring to  FIGS. 5A and 5B , collectively, segments  212  ( 212   a ,  212   b  shown for illustration in  FIGS. 5A and 5B , respectively) each includes a conductor segment  214  including a group of conductor cables  215  (shown on left side of  FIG. 5A  only for clarity). According to an embodiment, the group of conductor cables  215  includes multiple conductor cables, for example four conductor cables  215 ( 1 ),  215 ( 2 ),  215 ( 3 ), and  215 ( 4 ). One of the four conductor cables  215 , here conductor cable  215 ( 4 ), is electrically connected to voltage structure  11  through connection via  222 . Connection via  222  may be an integrated part of connector cable  215 ( 4 ). 
   Conductor segment  214  may also include a shielding conductor portion  236  ( 236   a ,  236   b  shown for segments  212   a ,  212   b , respectively) adjacent to interface surface  218  ( 218   a ,  218   b  shown). Shielding conductor portion  236  extends toward interface surface  218  further than the group of conductor cables  215 . The group of cables  215  are electrically connected to shielding conductor portion  236  by extending into an opening  238  ( 238   a ,  238   b  shown) of shielding conductor portion  236 . 
   According to an embodiment, shielding conductor portion  236  is substantially U-shaped, as shown by shielding conductor portion  236   a  in a cross-sectional view in  FIG. 5A , with a connecting edge  240  of the U-shape facing interface surface  218   a . Connecting edge  240  is rounded toward interface surface  218   a . According to an embodiment, an end  242  adjacent to opening  238   a  of the U-shape is also rounded. 
   According to another embodiment, shielding conductor portion  236  is substantially H-shaped, as shown by shielding conductor portion  236   b  in a cross-sectional view in  FIG. 5B , with an opening  244  of the H-shape facing interface surface  218   b . An end  246  adjacent to opening  244  is rounded toward interface surface  218   b . According to an embodiment, an end  248  adjacent to opening  238   b  of the H-shape is also rounded 
   Other physical configurations of shielding conductor portion  236  are also possible and included. 
   With continuing reference to  FIGS. 5A and 5B , segment  212  may include an insulation segment  216  (shown only in  FIG. 5A  for brevity) which includes a pipe-shaped portion  230  and a connection mold portion  232 . According to an embodiment, connection mold portion  232  may include interface surface  218 . Pipe-shaped portion  230  may include a Chlorinated Poly Vinyl Chloride (CPVC) pipe. Pipe-shaped portion  230  may include a single pipe, as shown in  FIGS. 5A and 5B , or may include multiple nested pipes  231 ,  233 , as shown in  FIG. 5C , to divide the insulation region into separate/different cavities  235 ,  237 , where different cavities  235 ,  237  may further include different insulation materials (not shown). 
   Conductor cables  215  may be substantially straight lines, as shown in  FIGS. 5A and 5B , or may be coiled inside pipe-shaped portion  230 , as shown in  FIG. 5D , to further reduce the electrical stresses. In addition, two conductor cables  215  may be transposed with respect to the respective positions, e.g., may change the relation positions thereof, or may be twisted together inside pipe-shaped portion  230 . 
   Returning to  FIG. 5A , connection mold portion  232  is adjacent to interface surface  218  of segment  212 . A portion  234  of connection mold portion  232  may be received by/extend into pipe-shaped portion  230  such that connection mold portion  232  and pipe-shaped portion  230  are coupled. Connection mold portion  232  substantially encapsulates shielding conductor portion  236  except a portion  248  thereof connected to cables  215 . Connection mold portion  232  may be a substantially solid non-conductive material, e.g., epoxy resin (plastic). 
   According to an embodiment, preferably, as shown in  FIG. 5A , connection mold portion  232  may include a hollow portion  250  which extends to portion  248  of shielding conductor portion  236 . Group of conductor cables  215  may go through hollow portion  250  to connect to shielding conductor portion  236 . 
   According to another embodiment, as shown in  FIG. 6 , insulated conductor device  312  includes a continuous conductor  314  and multiple insulation segments  316  ( 316   a ,  316   b  shown). Continuous conductor  314  may include multiple conductor cables  315 , one of which may be connected to voltage structure  11 . Insulation segments  316  interface with one another and collectively enclose continuous conductor  314 . According to an embodiment, insulation segments  316  may include insulation pipes  338  of, e.g., Chlorinated Poly Vinyl Chloride (CPVC). Another insulation layer  340  of, e.g., pressurized air, SF6, syntactic silicone foam, or epoxy resin, may be positioned between continuous conductor  314  and insulation pipes  338 . 
   According to another embodiment, the disclosure also includes a method for electrically shielding a voltage structure, e.g., voltage structure  11 , by providing the insulated conducting devices of FIGS.  2  and  4 - 6 , and coupling (positioning) the insulated conducting device to the voltage structure. 
   It is apparent that there have been provided with this disclosure structures of insulated conducting devices with insulation segments and related method of producing the same. While the disclosure has been particularly shown and described in conjunction with a preferred embodiment thereof, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the disclosure.