Patent Publication Number: US-2007102486-A1

Title: Wire embedded bridge

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This utility application claims the benefit under35 U.S.C. § 119(e) of Provisional Application Ser. No. 60/729,623 filed on Oct. 24, 2005 entitled WIRE EMBEDDED BRIDGE and whose entire disclosure is incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of Invention  
      This invention is related to security tags, and in particular, to the manufacture of conductive straps often used, for example, for the integration of RFID circuits.  
      2. Description of Related Art  
      Chip bonding is costly. The two largest components of the cost of RFID tags today are the integrated circuit and the attachment of that circuit (otherwise known as silicon) to an antenna structure. While the increasing volume of the number of chips helps to drive the IC cost down, bonding is a mechanical process and does not benefit from the same technology advances or economic scale.  
      Current methods of chip bonding do not adequately address costs. A two-step approach of an intermediary chip strap achieves incremental costs improvement by relocating the costs. However, straps do not address the problem directly, as bonding is still required, but to a smaller tag. Moreover, straps add another step to bond the strap to the antenna structure. Current manufacturers, using standard bonding technology with straps, want straps to be like traditional bonding surfaces, as commonly found on circuit board technology that is, hard and inflexible. However, such straps do not lend themselves to easy integration into flexible tags (e.g., RFID tags). The standard bonding processes are all known strap-based solutions, and therefore less than ideal.  
      One related art attachment method, called Fluidic Self Assembly (FSA), provides insufficiently robust bonds. Because the chips find their own way into bonding sockets, the chips cannot use adhesives or flux, since anything sticky prevents free motion of the chips into the sockets. With the fluid self assembly process, the bond is made at a tangent between the chip bonding pad and sides of the bonding cavity. This flat-to-edge bond is different than and less reliable than traditional bonds, which are made flat-to-flat. Fluidic self assembly also places restrictions on the type of substrate that can be used. Fluidic Self Assembly (FSA) does not create the bond, it only places tags into appropriate carrier for attachment. Current FSA method being practiced uses patterned cut out polyester and laminates another film on top of the web with chips in place. The back web then is laser cut leaving a hole in direct proximity and above the chip bonding pad area. This hole is filled with conductive ink and a trace is completed on the back side perpendicular to the hole creating a strap. The FSA process is slow and uses multiple steps and requires a high degree of accuracy with known technology products available today.  
      A known wire bonding process is disclosed in U.S. Pat. No. 5,708,419 to Isaacson, et al., the contents of which are incorporated by reference herein in its entirety. Isaacson discusses the bonding of an IC to a flexible or non-rigid substrate which generally can not be subjected to high temperatures, such as the temperature required for performing soldering processes. In this wire bonding process, a chip or dye is attached to a substrate or carrier with conductive wires. The chip is attached to the substrate with the chip front-side face up. Conductive wires are bonded first to the chip, then looped and bound to the substrate. The steps of a typical wire bonding process include: 
          1. advancing web to the next bond site;     2. stopping;     3. taking a digital photograph of the bond site;     4. computing bond location;     5. picking up a chip;     6. moving the chip to the bond site;     7. using photo feedback to adjust placement to the actual site location;     8. placing or depositing chip;     9. photographing the chip to locate the bond pads;     10. moving the head to the chip bond pad;     11. pressing down, vibrating and welding conductive wire to the bond pad;     12. pulling up and moving the chip to the substrate bond pad, trailing wire back to the chip bond     13. pressing down and welding that bond;     14. pulling up and cutting off the wire; and     15. repeating steps 10-14 for each connection.        

      In contrast, the interconnection between the chip and substrate in flip-chip packaging is made through conductive connection pads or bumps of solder that are placed directly on the chip&#39;s surface. The bumped chip is then flipped over and placed face down, with the bumps electrically connecting to the substrate.  
      Flip chip bonding, a current state of the art process, is expensive because of the need to match each chip to a tiny, precision-cut bonding site. As chips get smaller, it becomes even harder to precisely cut and prepare the bonding site. However, the flip-chip bonding process is a considerable advancement over wire bonding. The steps of a typical flip-chip bonding process include: 
          1. advancing web to the next bond site;     2. stopping;     3. photographing the bond site;     4. computing the bond location;     5. picking up the chip;     6. moving the chip to the bond site;     7. using photo feedback to adjust placement at the actual site location;     8. placing the chip;     9. ultrasonically vibrating the placement head to weld chip in place; and     10. retracting the placement head.        

      Steps 1 through 8 of each of the above bonding processes are substantially the same. The web must stop to locate the conductive gap in the substrate and precisely place the IC. The related art processes require that the web is stopped and measured (e.g., photographing the bond site, containing the bond location, using photo feedback to adjust placement at the actual site location) so that the chip can be accurately placed as desired adjacent the gap and bonded.  
      Retracing a path during the bonding process takes time, causes vibration, and wears mechanical linkages. These linkages also create uncertainty in absolute position. Rotating or continuous devices are preferred over reciprocating devices, in part because stopping and starting the manufacturing line always slows things down and reduces throughput. It would be beneficial to adjust tooling to operate in a process that is continuously advancing down the line at a known rate of travel.  
      When chips are placed down on an antenna structure, such as an aluminum strap to form a bridge, nearby and overlapping conductive materials can create unwanted capacitance, especially at UHF or higher frequencies. Accordingly, it would be beneficial to minimize the conductive overlap to the bonding sites between the chips and the straps, especially for higher frequency use as the greater the overlap, the greater the unwanted capacitance and the lower the frequency of the tuning. All references cited herein are incorporated herein by reference in their entireties.  
     BRIEF SUMMARY OF THE INVENTION  
      The preferred embodiments include a wire embedded strap and manufacturing approach for the creation of the strap that may be used, for example, in the formation of an RFID circuit, or for the formation of a simple dipole antenna for an RFID circuit. The preferred approach uses a flexible poly-based film as a base component of the strap. A wire is embedded into the poly at precise locations using heat and alignment aides. The embedded location of the wire allows for accurate chip placement onto the track that is reliable and inexpensive.  
      According to one of the preferred embodiments, the invention includes a manufacturing device for making a wire embedded strap. The manufacturing device includes a first rotary station, a heating station and a splitting station. The first rotary station continuously moves a sheet of poly (e.g., polyester, polyurethane, polystyrene, polypropylene, polyethylene, polyacrylate, copolymers, tripolymers and films thereof, etc.) along a machine direction. The heating station is adjacent to the first rotary station and heats a conductive strip as it continuously moves toward the first rotary station. The first rotary station embeds the heated conductive strip into the poly sheet as the conductive strip and poly sheet move about the first rotary station to form an embedded conductive strip. The splitting station separates the embedded conductive strip into portions of the conductive strip to form non-conductive gaps between consecutive portions of the conductive strip. Respective consecutive portions of the conductive strip are conductively communicatable with a respective circuit bridging the respective non-conductive gap between the respective consecutive portions and can form an antenna for the circuit. The preferred manufacturing device may also include an alignment unit adjacent the first rotary station that aligns the conductive strip with the poly sheet before the conductive strip is embedded into the poly sheet. In addition, the preferred manufacturing device may include a chip attach station that places circuits over the non-conductive gaps formed by the splitting station. The chip attach station may also bond the placed circuits to the respective portions of the conductive strip to form a bridge (e.g., by using a thermal compression process). The conductive strip may include one or more lines of wire.  
      Another preferred embodiment of the invention includes a method for making a wire embedded strap. The method includes continuously moving a poly sheet along a machine direction, heating a conductive strip continuously moving toward the poly sheet, embedding the heated conductive strip into the poly sheet as the conductive strip and the poly sheet continuously move to form an embedded conductive strip, separation the embedded conductive strip into portions of the conductive strip, and forming non-conductive gaps between consecutive portions of the conductive strip. Further, the preferred method may include aligning the heated conducted strip with the poly sheet before embedding the heated conductive strip into the poly sheet. The preferred method may also include placing respective circuits over the non-conductive gaps, and bonding the respective circuits to the consecutive portions adjacent the non-conductive gaps to form a bridge.  
      In accordance with yet another preferred embodiment, the invention includes a wire embedded strap having a poly sheet and a pair of conductive wires. The poly sheet (e.g., polystyrene, polyethylene, polyester) is adapted to continuously move along a machine direction of a rotary manufacturing device. The pair of conductive wires is embedded in the poly sheet substantially in parallel along the machine direction, with each of the pair of conductive wires separated along the machine direction into portions of the pair of conductive wires. Consecutive portions of the pair of conductive wires are longitudinally distanced along the machine direction by a non-conductive gap and conductively communicatable with a respective circuit bridging the non-conductive gap. The preferred wire embedded strap may also include the respective circuit conductively coupled to respective consecutive portions of the pair of conductive wires and conductively bridging the non-conductive gap between the respective consecutive portions. 
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
      The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements, and wherein:  
       FIG. 1  is a sectional side view of an in-mold chip attach manufacturing device in accordance with the preferred embodiments of the invention;  
       FIG. 2  is a top view of an embedded wire and chip attach approach in accordance with the preferred embodiments;  
       FIG. 2A  is a perspective view of a chip strap (poly sheet omitted) made in accordance with the approach of  FIG. 2 ;  
       FIG. 3  is an exploded side view partially in section of a chip strap in accordance with the preferred embodiments;  
       FIG. 4  is a sectional view of the chip strap shown in  FIG. 3 ;  
       FIG. 5  is a side sectional view illustrating a first preferred approach for creating a non-conductive gap at a first time;  
       FIG. 6  is a side sectional view illustrating the first preferred approach for creating a non-conductive gap at a second time;  
       FIG. 7  is a side sectional view illustrating a second preferred approach for creating a non-conductive gap;  
       FIG. 8  is a side view partially in section illustrating a third preferred approach for creating a non-conductive gap at a first time; and  
       FIG. 9  is a side sectional view illustrating the third preferred approach for creating a non-conductive gap at a second time. 
    
    
      DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION  
      According to the preferred embodiments of the invention, a heated wire (e.g., aluminum, gold, silver, copper, and/or combinations thereof) is embedded into a poly (e.g., polystyrene, polyethylene, polyester, polypropylene, polyethylene, polyacrylate, copolymers, tripolymers and films thereof) at precise locations for alignment with subsequently placed chips and for conductive communication with the wire. The wire has dimensional stability and is preferably in the area of 2 mils in diameter, or commonly known as 40 to 50 American Wire Gauge (AWG). In a preferred embodiment, two independent lines of wire are embedded into the poly and transversely spaced to align with connection points (e.g., conductive contact bumps) of a subsequently placed chip. The embedded wire is cut and longitudinally separated to form gaps that are non-conductive between the separated wires. The non-conductive gaps in the wire are formed preferably to use as an antenna for a coupled chip and/or to prevent an electrical short that may otherwise occur if the chip (e.g., RFID chip, transponder) is placed adjacent the gap and in conductive communication with separated portions of the embedded wire.  
      An exemplary preferred embodiment for a wire embedded strap and approach for making a wire embedded strap is shown in  FIGS. 1-4 . As can best be seen in  FIG. 1 , a manufacturing device  10  for making a wire embedded strap includes a rotary station  12  having two rollers  14  and  16  that continuously move a poly sheet  18  along a machine direction  20 . The manufacturing device  10  also includes a heating station  22  that heats the conductive strip (e.g., wire  24 , rod, coil) to a temperature that softens the poly sheet  18  and allows the roller  14  to embed the conductive strip into the malleable poly sheet  18  by pushing the conductive strip into the poly sheet. In particular, the heated wire  24  deforms the poly sheet  18  at their intersection, which allows the roller  14  to push the wire into the poly sheet, thereby embedding the wire. Preferably, the manufacturing device  10  includes an alignment unit  26  that aligns the wire  24  in a predetermined position to help control its lateral or transverse placement in the poly sheet  18 . While not being limited to a particular theory, the manufacturing device  10  also includes a splitting station  28  that longitudinally separates the wire along the machine direction into wire strips  30  with non-conductive gaps  32  between consecutive wire strips, as will be described in greater detail below. The non-conductive gaps  32  may subsequently be bridged by a chip to form a chip strap as will also be described in greater detail below.  
      Still referring to  FIG. 1 , the poly sheet  18  moves in a machine direction along the manufacturing device  10 . While not being limited to a particular theory, the poly sheet  18  preferably continuously moves along the manufacturing device  10  with the aid of rollers such as the roller  16  and the roller  14  (also referred to as the embedding roller  14 ). The rollers are preferably formed of a hard rubber or metal capable of gripping the poly sheet to continuously advance the sheet. The embedding roller  14  is preferably made of a material or composition that is hard enough to push the wire  24  into the poly sheet  18  and is temperature resistant so as to not deform or otherwise be adversely affected by the temperature of the heated wire. Therefore, the shapes of the embedding roller  14  and the roller  16  are not compromised by the temperature of the heated wire  24 , which is high enough to melt or soften the poly sheet  18  and allow its deformation to accept the wire. The poly sheet  18  becomes a protective carrier for the wire  24 , and thus prevents unwanted damage to the wire after it is embedded into the poly sheet.  
      The heating station  22  and alignment unit  26  prepare the wire for accurate and consistent placement in the poly sheet  18 . The heating station  22  heats the wire  24  as readily understood by a skilled artisan, for example by applying heat, radiation, or other energy to the wire and causing the temperature of the wire to increase to a temperature sufficient to melt or soften the poly sheet  18  and allow the poly sheet to accept the wire as the wire is pushed into the poly sheet by the embedding roller  14 . The alignment unit  26  includes grooves (e.g., spacers, openings  27 ) that allow the wire  24  to pass through the alignment unit at the grooves or openings so that the wire  24  is aligned as desired to be embedded into the poly sheet at a precise location. Preferably, the aligned location of the wire  24  is set corresponding with connection pads  40  (e.g., contact points, conductive bumps) of circuits that may be attached to the wire at a subsequent time. While not being limited to a particular theory, the alignment unit  26  is preferably located between the heating station  22  and the embedding roller  14  and as close to the embedding roller as needed to prevent the wire  26  from wandering off of its aligned position before being embedded into the poly sheet  18 . However, it is understood that the location of the alignment unit  26  is not limited thereto, as the alignment unit may be attached to the heating station  22  or may be part of the rotary station  12 , as long as the alignment unit  26  provides for the alignment of the wire that is embedded into the poly sheet  18 .  
      Still referring to  FIG. 1 , the wire  24  is shown as a wound conductive strip that unwinds to dispose the wire toward the poly sheet  18 . It is understood that the manner of the wires origin is not critical to the invention, as the spool of wire is simply an example of where the wire  24  preferably comes from. Accordingly, the wire  24  may arrive at the heating station  22  in other manners, as would readily be understood by a skilled artisan.  
      After the wire  24  is embedded into the poly sheet  18 , the wire is cut into wire strips  30 . In particular, a splitting station  28  cuts the embedded wire  24  as it moves with the poly sheet  18  at intervals determined to provide wire strips  30  of sufficient length for its intended use (e.g., antenna, connector, chip strap, bridge). Preferably, the splitting station  28  also separates the cut wire straps  30 , leaving a gap in conductivity between consecutive wire straps. While not being limited to a particular theory, there are several approaches for forming the non-conductive gaps between the consecutive wire straps, with the preferred approaches described in greater detail below.  
      As is well known in the art, a chip or circuit having multiple conductive connection pads attached to a single conductive strip may become shorted if there is no conductive gap in the strip between the connection pads of the chip. Accordingly, in a preferred embodiment, non-conductive gaps  32  are formed between consecutive wire strips  30 . The gaps are large enough to prevent direct conductive communication between the consecutive wire strips  30 , yet small enough to allow attachment of a chip or circuit to the consecutive wire strips over the gaps, for example, as shown in  FIGS. 1-3 . The wire strips  30  can then be used as an antenna for the chip.  
      In operation, the rollers  14  and  16  continuously urge and move the poly sheet  18  along the machine direction  20 . The wire  24  preferably moves continuously from its spooled starting location  34  toward the poly sheet  18  and, after it is embedded, along the machine direction  20  with the poly sheet  18 . The heater  22  heats the wire  24  to a temperature that melts or softens the poly sheet  18  that contacts the heated wire. As one skilled in the art would readily understand, preferred temperatures for the heated wire can be determined at least in part by the poly sheet material, the size of the wire, and the speed of the poly sheet  18  through the rollers  14 ,  16 . The speed is limited only in the ability to maintain tension in the webs and control product formation. In the where chips are not to be attached in line to the wire  24 , one could assume a running web speed of about 300 to 400 feet per minute. This rate will not likely be achieved when attaching chips in line as described in greater detail below, yet the speed of the poly sheet  18  through the rollers is still several times faster than the current technology. The current output standard that most manufacturers are trying to achieve is about 20,000 units (e.g., chip straps) per hour. This equates to a web speed rate of 2 to 3 feet per minute for a 0.040 inch chip under the current technology.  
      The wire  24  is configured to be embedded at a precise transverse location of the poly sheet  18  by the alignment unit  26 . As the heated and aligned wire  24  reaches the embedding roller  14 , the heated wire is pushed through a first side  78  of the poly sheet  18  by the roller  14 . The roller  16  is located at a second side  76  of the poly sheet  18  opposite the embedding roller  14  to support the poly sheet against the wire being pushed into the poly sheet by the embedding roller. The embedding roller  14  pushes the wire  24  into the softened poly sheet  18 , preferably to a depth where an exposed portion of the embedded wire is substantially coplanar with the first side  78  of the poly sheet. An example of the preferred depth of the embedded wire  24  into the poly sheet is shown at  FIG. 4 , which is discussed in greater detail below.  
      After the heated wire  24  is embedded into the poly sheet  18 , the wire and poly sheet continue along the machine direction  20  in a continuous motion. The continuously moving poly sheet  18  and embedded wire  24  advance through the splitting station  28 , which separates the wire into wire strips  30 . Then, for chip attach, the poly sheet  18  and wire strips  30  continue through a chip attach station  36 , which attaches a chip  38  to consecutive wire strips  30  to form a conductive bridge over a respective non-conductive gap  32 . The chips  38  are attached to the consecutive wire strips  30  in a known manner such as a flip chip process where the chips  38  have conductive connection pads  40  (e.g., contact points, conductive bumps) placed on the wire strips, and the placed chip  38  is compressed and heated to bond the connection pads  40  to the embedded wire  24  and create a chip strap  42  as shown for example in  FIGS. 1-4 .  
       FIG. 2  is a partial top view of the poly sheet  18 , wire  24 , embedding roller  14  and chips  38  of the preferred embodiment shown in  FIG. 1 . While not being limited to a particular theory, the exemplary embodiment shown in  FIG. 2  illustrates two lines of wire  24  distanced from each other and embedded side by side into the poly sheet  18 . The two lines of wire  24  are simultaneously embedded substantially in parallel by the embedding roller  14  into the poly sheet  18  as the poly sheet moves continuously in the machine direction  20 . As can be seen in  FIGS. 1 and 2 , after the lines of heated wire  24  are embedded by the embedding roller  14 , both lines of wire  24  are cut by the splitting station  28 , which forms gaps  32  between consecutive wire strips in each line. The chip attach station  36  then places chips  38  over the gaps  32  for conductive communication with the wire strips  30  via the connection pads  40  that are attached to the wire strips.  
      It should be noted that the size of the chips  38  and the number of connection pads  40  of the chips are not critical to the invention, and are merely shown as an example of the preferred embodiment. It is understood that the size of the chips  38  and the number or placement of the connection pads  40  are configured to allow the connection pads to align with the conductive strip or strips of wire  24  over a corresponding gap between the wire strips  30  that are attached to the connection pads of the chip  38 . For example, a chip  38  having two connection pads  40  could be attached to consecutive wire strips  30  from a single line of wire  24 . Moreover, a chip  38  having four connection pads  40  may preferably be attached to consecutive wire strips  30  separated and originating from two lines of wire  24 , as shown in  FIG. 2 . In other words, the number of lines of wire embedded into the poly sheet  18  should correspond with the number and configuration of connection pads on the chips  38  that are to be attached to the wire  24 , as would readily be understood by a skilled artisan. In addition, the wire preferably does not surpass the connection pad on the chip.  
      The chip attached station  36  ( FIG. 1 ) places the chips  38  or circuits onto wire strips  30  separated by non-conductive gaps  32  to form chip straps  42  having a wire embedded bridge. The wire embedded bridge of the preferred embodiments includes consecutive wire strips  30  embedded and formed in the poly sheet  18  in a continuous process. The wire embedded bridge is configured to attach to a chip  38  or circuit to form a chip strap with its wires embedded into the poly sheet for protection. The wire embedded bridge may also form a dipole antenna that may be used with the chips  38 .  
      Preferably the chips  38  are also pressed firmly into the poly sheet  18  to backfill the underside of the chip to add stability to the strap and chip as it is allowed to flex in downstream processes and during ultimate product use. Examples of chip straps and/or wire embedded bridges are shown in  FIGS. 2A-4  in accordance with the preferred embodiment. For example,  FIG. 3  is an exploded side view partially in section of an exemplary chip strap  42  shown in  FIG. 1 . In  FIG. 3  the poly sheet  18  encapsulates the wire  30  and therefore the wire is at a similar level in the plain as the poly sheet. There is preferably no gap in the poly sheet  18 , since it is not melted away or cut away; preferably only the wire is cut.  
      As can be seen in  FIG. 3 , the chip  38  is placed over a gap  32  between consecutive wire strips  30  such that the chips&#39; connection pads  40  are in conductive contact with the wire strips. In this manner, the chip  38  bridges that gap  32 , and is conductively coupled to the wire strips  30 .  FIG. 4  is a side sectional view of the chip strap  42  shown in  FIG. 3 . As such,  FIG. 4  shows the wire strips  30  embedded in the poly sheet  18  and coupled to the connection pads  40  of the chip  38 . To help secure the attachment of the chip  38  to the embedded wire strips  30 , the chip can be bonded to the wire preferably using compression and heat as is well known in the flip chip bonding technology. Such a process provides both a conductive and mechanical bond for enhanced security and reliability.  
       FIG. 2A  is a perspective view of a chip strap (with the poly sheet  18  omitted) as provided by the manufacturing device  10  and process described in conjunction with  FIGS. 1, 2 ,  3  and  4 . As can best be seen in  FIGS. 2 and 2 A, the wire strips are transversely separated by the alignment unit  26  to a distance predetermined for alignment with the connection pads  40  of the chips  38 . While not being limited to a particular theory, the connection pads  40  of the chips  38  (e.g., flip chip) are shown in  FIGS. 2A-4  inwardly offset from the periphery of a chip. However, the connection pads  40  may be located at other locations of the chip (e.g., at the periphery, adjacent the periphery) and the alignment unit  26  would offset the strips of wire  24  to align with the locations of the connection pads, for example by increasing or decreasing the distance between the lines of wire.  
      As noted above, the manufacturing device  10  includes a splitting station  28  that cuts the wire  24  into wire strips  30  and separates the wire strips with a non-conductive gap  32 . The gap  32  is formed between consecutive wire strips  30  and the poly refills the gap as needed to prevent electrical problems, for example shorting of a chip coupled to the consecutive wire strips during use. The gaps  32  may be formed by numerous approaches and the invention is not limited to any one approach. Some exemplary approaches for creating the non-conductive gaps are described below in conjunction with  FIGS. 5-9 .  
       FIGS. 5 and 6  illustrate a first preferred approach for creating non-conductive gaps  32  between consecutive wire strips  30 . In this embodiment, the splitting station  28  includes a cutting station having rollers  44  and  46 , and a gap forming station having rollers  48 ,  50 ,  52  and  54 . All of the rollers  44 ,  46 ,  48 ,  50 ,  52  and  54  are at least in partial contact with the embedded wires  24  and/or the poly sheet  18  and rotating such that the rollers help advance the embedded wire/poly sheet in the machine direction  20 . For example, the view shown in  FIGS. 5 and 6 , the rollers  44 ,  48  and  52  rotate counter-clockwise as indicated by rotational arrow  56 , and rollers  46 ,  50  and  54  rotate clockwise as indicated by rotational arrow  58 . While not being limited to a particular theory, and unless otherwise noted below, the rollers are preferably formed of rubber, plastic or metal that permits the rollers to roll with and/or urge the embedded wire and poly sheet in the machine direction  20 .  
      Still referring to  FIGS. 5 and 6 , roller  44  includes a mechanical cutter, for example a blade  60  that extends outwardly from the perimeter of the roller to a sharp edge  62 . The blade  60  is adapted to rotate with the roller  44  and engage with and cut through the embedded wire  24  as the wire moves with the poly sheet  18  continuously along the machine direction  20 . Preferably, the blade extends from the periphery of the roller  44  to a length that allows the blade to cut through the wire  24 , but not through the poly sheet  18  surrounding the wire so that the integrity of the poly sheet is not compromised. The roller  46  is located on the side or surface  76  of the poly sheet  18  opposite the roller  44  and provides a support or backing for the poly sheet as the blade  60  cuts the wire  24 . Accordingly, the roller  44  aided by the roller  46  cuts the embedded wire  24  into the wire strips  30 .  
      As noted above, the gap forming station of the splitting station  28  includes the rollers  48 ,  50 ,  52  and  54 . The rollers  48 ,  50  are located on opposite sides of the embedded wire/poly sheet, and are adapted to grip and advance the embedded wire and poly sheet continuously at a consistent speed. In particular, the roller  48  grips at least the embedded wire  24  and preferably the first side  78  of the poly sheet  18  adjacent the roller  48 , and the roller  50  grips the second side  76  of the poly sheet adjacent the roller  50 . The roller  54  is substantially similar to the rollers  46  and  50  in that the roller  54  remains in contact with and urges the second side  76  of the poly sheet adjacent the roller  54  at a consistent speed in the machine direction  20 . However, the roller  52  rotates faster than roller  48  so that its surface moves faster than the belt speed of the poly sheet  18 . In other words, rollers  48  and  50  are essential a mechanical nip point which drives the web (e.g., poly sheet  18 ) at a particular speed which matches that of the cutting roller  44 . However, the roller  52  is a servo control roller that is overdriven and acts to stretch the web slightly at the location that the wire  24  was cut, by nipping the web and, due to higher speed, pulling the poly sheet  18  forward faster than the prior nip point of rollers  56  and  58 .  
      The roller  52  includes a gripping member  64  radially extending outwardly from the periphery of the roller  52  preferably as a ridge extending longitudinally along the length of the roller. Preferably, the gripping member  64  is the only portion of the roller  52  that comes into contact with the first side  78  or surface of the poly sheet  18  and the embedded wire strips  30 . In other words, in this preferred approach, the roller  52  grabs the wire strips  30  with the gripping member  64 ; otherwise, the roller  52  does not touch the wire or poly sheet. With the roller  52  spinning at a rate faster than the other rollers, and in particular, the roller  48 , the gripping member  64  contacts and grips the first side  78  of the poly sheet  18  and the embedded wire strips  30 , and tugs or urges the wire and first side  78  at a speed faster than the next wire strip  30  moving at the continuous speed of the rollers  48  and  50 . The tugging by the gripping member  64  moves the wire strip  30  away from the next wire strip that is still in contact with the roller  48 . The separation creates a non-conductive gap  32  between the wire strips  30  between the rollers  48  and  52 . As this process continues, the gripping member  64  separates each cut wire strip  30  from the next wire strip by gripping and moving the respective wire strip at a pace faster than the pace of the next wire strip, creating a gap  32  between consecutive wire strips  30  embedded in the poly sheet  18 .  
       FIG. 5  shows a cut  66  in the embedded wire  24  made by the blade  60 . At this time, t 0 , the wire strip  68  is not attached to the wire  24  as the cut  66  has separated the two. At a subsequent time, t 1 , as exemplified in  FIG. 6 , the roller  44  continues its rotation, causing the blade  60  to cut through the embedded wire  24  and form a cut  70  and a wire strip  72 . Still referring to  FIG. 6 , the roller  52  continues its rotation, causing the gripping member  64  to grab and pull wire strip  68  away from wire strip  72 , creating a non-conductive gap  32  there between. This process continues to create non-conductive gaps between the consecutive wire strips  30  advancing in the machine direction  20 .  
      It should be noted that all of the rollers described herein illustrates an example of a rotary station, as a whole or in part. That is, a rotary station may include at lest one of the rollers (e.g., the roller  44 , the roller  48 , the roller  52 ), a pair of the rollers oppositely arranged on the poly sheet  18  (e.g., the pair of rollers  44  and  46 , the pair of rollers  48  and  50 , the pair of rollers  52  and  54 ), or any equivalent elements as understood by a skilled artisan that affect the continuously moving poly sheet and/or wire  24  as described by example via the rollers herein.  
      A second preferred example of the splitting station  28  is exemplified in  FIG. 7 . In particular, the splitting station  28  illustrated in  FIG. 7  includes a laser device  74  that periodically emits an intense monochromatic beam of light at the continuously moving wire  24  embedded in the poly sheet  18 . This laser beam separates the wire to create non-conductive gaps  32  between consecutive wire strips  30 . That is, the laser device  74  emits a laser beam that cuts through the wire  24  to form the wire strips  30 , and that ablates the wire exposed to the laser to create the non-conductive gaps  32 .  
      Yet another preferred example of the splitting system  28  is shown in  FIGS. 8 and 9 . In this approach, the splitting station  28  includes a cutting station  80  located adjacent the first side  78  of the poly sheet  18 , and a support member, for example a roller  82  located at the second side  76  of the poly sheet opposite the cutting station  80 . The cutting station  80  includes a blade, laser or cutting member adapted to cut the wire  24  extending above the first side  78  of the poly sheet  18  as described in greater detail below.  FIG. 8  also illustrates the roller  16  shown in  FIG. 1  and a roller  14 A. The roller  14 A is an alternative rolling member to the roller  14  shown in  FIG. 1  and is somewhat similar to the roller  14  in its purpose and material. The roller  14 A includes a curved portion  86  that embeds the wire  24 , as described above for roller  14 . However, the roller  14 A also includes a flat portion  84  that does not extend radially to the periphery of the curved portion  86  of the roller  14 A. In operation, as the roller  14 A turns in the direction of the rotational arrow  88 , the curved portion  86  embeds the heated wire  24  into the poly sheet  18  by pushing the wire into the poly sheet. However, the flat section does not push the wire into the poly sheet. Instead, as can best be seen in  FIG. 9 , the wire  24  remains above the poly sheet while the flat section  84  of the roller  14 A faces the poly sheet  18 . The wire  24  that is not embedded remains above the poly sheet  18  as exposed wire sections  90 . As the roller  14 A continues its rotation, the curved portion  86  again embeds the wire  24  adjacent the now downstream wire section  90  by pushing it into the poly sheet.  
      Referring to  FIG. 8 , the cutting station  80  cuts the exposed wire sections  90  above the first side  78  of the poly sheet  18  as the poly sheet advances in the machine direction  20  to create the non-conductive gaps  32  and the embedded wire strips  30 . Alternately the exposed wire section  90  can be etched away from the embedded wire strips  30 , with the wire that is completely embedded being protected from being etched. While not being limited to a particular theory, the cutting station  80  preferably includes a blade, laser, or other cutting member located adjacent the first side  78  of the poly sheet  18  to cut the exposed wire sections  90  as readily understood by a skilled artisan. The inventors have discovered that the edges of the wire strips  30  that have been cut by the cutting station  80  are preferably left turned upwards out of the poly sheet  18  for reliable attachment with the connection pads  40  of a subsequently placed chip  38 .  
      While not being limited to a particular theory, the preferred embodiments of the invention provide wire strips at least partially embedded into a poly sheet in a continuous motion. The inventors have discovered that connecting the connection pads of chips to independent lines of wire, as shown for example in  FIG. 2A , minimizes unwanted parasitic capacitance between the chip circuit and its antenna structure, especially over chips attached to single antenna bands. The parasitic capacitance becomes more relevant as the chip is used with higher frequencies (e.g., UHF or higher). When coupling a chip to an antenna structure, any nearby conductive material matters as it can create unwanted capacitance, lowering the frequency of the tuning. Accordingly, in the preferred embodiments, the wire does not surpass the respective connection pad on the chip. The chip strap  42  made by the manufacturing device and method described herein provides an additional benefit of minimizing parasitic capacitance by minimizing conductive overlap around the bonding sites between the chip and the antenna structure. In fact, the preferred diameter of the wire  24  is less than the diameter of the connection pads  40  of the chip  38  to further minimize conductive overlap.  
      While not being limited to a particular theory, the preferred depth of the poly sheet  18  is 50 to 75 microns and the preferred diameter of the wire  24  is 25 to 50 microns. However, it is understood that measurements of the poly sheet and wire are not critical to the invention as other measurements may be used and are considered within the scope of the invention. Preferably, the depth of the poly sheet  18  is greater than the diameter of the wire  24 , which is preferably not insulated and formed of a conductive material (e.g., gold, aluminum, copper).  
      It is understood that the in-mold chip attach method and apparatus, and the wire embedded strap described and shown are exemplary indications of preferred embodiments of the invention, and are given by way of illustration only. In other words, the concept of the present invention may be readily applied to a variety of preferred embodiments, including those disclosed herein. While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. For example, the gripping member  64  shown in  FIGS. 5 and 6  could be at least one extending bump, instead of a ridge, with each bump aligned with a line of wire  24  to move the wire strips  30  forward at a speed faster than the bolt speed of the poly sheet  18  and create the non-conductive gaps  32 . Without further elaboration, the foregoing will so fully illustrate the invention that others may, by applying current or future knowledge, readily adapt the same for use under various conditions of service.