Patent Publication Number: US-2007107186-A1

Title: Method and system for high volume transfer of dies to substrates

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to the assembly of electronic devices. More particularly, the present invention relates to the transfer of dies from wafers to substrates, including substrates of radio frequency identification (RFID) tags.  
      2. Related Art  
      Pick and place techniques are often used to assemble electronic devices. Such techniques involve a manipulator, such as a robot arm, to remove integrated circuit (IC) dies from a wafer and place them into a die carrier. The dies are subsequently mounted onto a substrate with other electronic components, such as antennas, capacitors, resistors, and inductors to form an electronic device.  
      Pick and place techniques involve complex robotic components and control systems that handle only one die at a time. This has a drawback of limiting throughput volume. Furthermore, pick and place techniques have limited placement accuracy, and have a minimum die size requirement.  
      One type of electronic device that may be assembled using pick and place techniques is an RFID “tag.” An RFID tag may be affixed to an item whose presence is to be detected and/or monitored. The presence of an RFID tag, and therefore the presence of the item to which the tag is affixed, may be checked and monitored by devices known as “readers.” 
      As market demand increases for products such as RFID tags, and as die sizes shrink, high assembly throughput rates for very small die, and low production costs are crucial in providing commercially-viable products. Accordingly, what is needed is a method and apparatus for high volume assembly of electronic devices, such as RFID tags, that overcomes these limitations.  
     SUMMARY OF THE INVENTION  
      The present invention is directed to methods, systems, and apparatuses for transferring dies to respective substrates. A die application device includes a body and a die application element. The body has a channel that is configured to receive a plurality of dies. The die application element is configured to transfer dies of the plurality of dies to respective substrates. In an aspect, the die application device includes a guide coupled to the body. A combination of the guide and the body laterally surround at least a portion of the channel. In an aspect, the guide and the body are a unitary element.  
      The die application element is configured to move along a first axis. The channel is configured along a second axis. The first axis and the second axis are typically perpendicular to each other.  
      In a first example, the die application element is configured to transfer a single die at a time. In a second example, the die application element is configured to transfer multiple dies at a time.  
      The die application device includes any number of cavities and/or die application elements. In an aspect, the die application device includes a plurality of cavities, each of which is capable of receiving a plurality of dies. Each channel is associated with a respective die application element. Die application elements are actuated independently from each other or in synchronism.  
      In another aspect of the present invention, dies are loaded in a channel of the die application device. The dies are moved through the channel to align at least one die with a die pedestal of the die application element. The die application element dispenses the dies onto respective substrates. The dies may be bonded onto the respective substrates.  
      These and other advantages and features will become readily apparent in view of the following detailed description of the invention.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES  
      The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.  
       FIG. 1  shows a block diagram of an exemplary RFID tag, according to an embodiment of the present invention.  
       FIGS. 2A and 2B  show plan and side views of an exemplary die, respectively.  
       FIGS. 2C and 2D  show portions of a substrate with a die attached thereto, according to example embodiments of the present invention.  
       FIG. 3  is a flowchart illustrating a tag assembly process, according to embodiments of the present invention.  
       FIGS. 4A and 4B  are plan and side views of a wafer having multiple dies affixed to a support surface, respectively.  
       FIG. 5  is a view of a wafer having separated dies affixed to a support surface.  
       FIG. 6  shows a system diagram illustrating example options for transfer of dies from wafers to substrates, according to embodiments of the present invention.  
       FIG. 7A  shows a cross-sectional side view of a die application device, according to an embodiment of the present invention.  
       FIG. 7B  shows a front view of the die application device of  FIG. 7A , according to an embodiment of the present invention.  
       FIGS. 8A and 8B  show perspective views of an example die application device, according to embodiments of the present invention.  
       FIGS. 9A-9C  show side views of an example die application device, according to embodiments of the present invention.  
       FIGS. 10A-10C  show side views of an example die application device, according to embodiments of the present invention.  
       FIG. 11  illustrates a flowchart of a method of transferring dies to respective substrates in accordance with an embodiment of the present invention. 
    
    
      The present invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the reference number.  
     DETAILED DESCRIPTION OF THE INVENTION  
      This specification discloses one or more embodiments that incorporate the features of this invention. The embodiment(s) described, and references in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.  
      1.0 Overview  
      The present invention provides improved processes and systems for assembling electronic devices, including RFID tags. The present invention provides improvements over current processes. Conventional techniques include vision-based systems that pick and place dies one at a time onto substrates. The present invention can transfer multiple dies simultaneously or consecutively. Vision-based systems are limited as far as the size of dies that may be handled, such as being limited to dies larger than 600 microns square. The present invention is applicable to dies 100 microns square and even smaller. Furthermore, yield is poor in conventional systems, where two or more dies may be accidentally picked up at a time, causing losses of additional dies. The present invention allows for improved yield values.  
      The present invention provides an advantage of simplicity. Conventional die transfer tape mechanisms may be used by the present invention. Furthermore, much higher fabrication rates are possible. Furthermore, because the present invention allows for flip-chip die attachment techniques, wire bonds are not necessary. Elements of the embodiments described herein may be combined in any manner.  
      1.1 Example Electronic Device  
      The present invention is directed to techniques for producing electronic devices, such as RFID tags. For illustrative purposes, the description herein primarily relates to the production of RFID tags. However, the description is also adaptable to the production of further electronic device types, as would be understood by persons skilled in the relevant art(s) from the teachings herein.  
       FIG. 1  shows a block diagram of an exemplary RFID tag  100 , according to an embodiment of the present invention. As shown in  FIG. 1 , RFID tag  100  includes a die  104  and related electronics  106  located on a tag substrate  116 . Related electronics  106  includes an antenna  114  in the present example. Die  104  can be mounted onto antenna  114  of related electronics  106 . As is further described elsewhere herein, die  104  may be mounted in either a pads up or pads down orientation.  
      RFID tag  100  may be located in an area having a large number, population, or pool of RFID tags present. RFID tag  100  receives interrogation signals transmitted by one or more tag readers. According to interrogation protocols, RFID tag  100  responds to these signals. Each response includes information that identifies the corresponding RFID tag  100  of the potential pool of RFID tags present. Upon reception of a response, the tag reader determines the identity of the responding tag, thereby ascertaining the existence of the tag within a coverage area defined by the tag reader.  
      RFID tag  100  may be used in various applications, such as inventory control, airport baggage monitoring, as well as security and surveillance applications. Thus, RFID tag  100  can be affixed to items such as airline baggage, retail inventory, warehouse inventory, automobiles, compact discs (CDs), digital video discs (DVDs), video tapes, and other objects. RFID tag  100  enables location monitoring and real time tracking of such items.  
      In the present embodiment, die  104  is an integrated circuit that performs RFID operations, such as communicating with one or more tag readers (not shown) according to various interrogation protocols. Exemplary interrogation protocols are described in U.S. Pat. No. 6,002,344 issued Dec. 14, 1999 to Bandy et al. entitled System and Method for Electronic Inventory, and U.S. patent application Ser. No. 10/072,885 filed Feb. 12, 2002 entitled Method, System, and Apparatus for Binary Traversal of a Tag Population. Die  104  includes a plurality of contact pads that each provide an electrical connection with related electronics  106 .  
      Related electronics  106  are connected to die  104  through a plurality of contact pads of IC die  104 . In embodiments, related electronics  106  provide one or more capabilities, including RF reception and transmission capabilities, sensor functionality, power reception and storage functionality, as well as additional capabilities. The components of related electronics  106  can be printed onto a tag substrate  116  with materials, such as conductive inks. Examples of conductive inks include silver conductors 5000, 5021, and 5025, produced by DuPont Electronic Materials of Research Triangle Park, N.C. Other materials or means suitable for printing related electronics  106  onto tag substrate  116  include polymeric dielectric composition 5018 and carbon-based PTC resistor paste 7282, which are also produced by DuPont Electronic Materials of Research Triangle Park, N.C. Other materials or means that may be used to deposit the component material onto the substrate would be apparent to persons skilled in the relevant art(s) from the teachings herein.  
      As shown in  FIG. 1 , tag substrate  116  has a first surface that accommodates die  104 , related electronics  106 , as well as further components of tag  100 . Tag substrate  116  also has a second surface that is opposite the first surface. An adhesive material or backing can be included on the second surface. When present, the adhesive backing enables tag  100  to be attached to objects, such as books and consumer products. Tag substrate  116  is made from a material, such as polyester, paper, plastic, fabrics such as cloth, and/or other materials such as commercially available Tyvec®.  
      In some implementations of tags  100 , tag substrate  116  can include an indentation, “cavity,” or “cell” (not shown in  FIG. 1 ) that accommodates die  104 . An example of such an implementation is included in a “pads up” orientation of die  104 .  
       FIGS. 2A and 2B  show plan and side views of an example die  104 . Die  104  includes four contact pads  204   a - d  that provide electrical connections between related electronics  106  and internal circuitry of die  104 . Note that although four contact pads  204   a - d  are shown, any number of contact pads may be used, depending on a particular application. Contact pads  204  are made of an electrically conductive material during fabrication of the die. Contact pads  204  can be further built up if required by the assembly process, by the deposition of additional and/or other materials, such as gold and solder flux. Such post processing, or “bumping,” will be known to persons skilled in the relevant art(s).  
       FIG. 2C  shows a portion of a substrate  116  with die  104  attached thereto, according to an example embodiment of the present invention. As shown in  FIG. 2C , contact pads  204   a - d  of die  104  are coupled to respective contact areas  210   a - d  of substrate  116 . Contact areas  210   a - d  provide electrical connections to related electronics  106 . The arrangement of contact pads  204   a - d  in a rectangular (e.g., square) shape allows for flexibility in attachment of die  104  to substrate  116 , and good mechanical connection. This arrangement allows for a range of tolerance for imperfect placement of IC die  104  on substrate  116 , while still achieving acceptable electrical coupling between contact pads  204   a - d  and contact areas  210   a - d.  For example,  FIG. 2D  shows an imperfect placement of IC die  104  on substrate  116 . However, even though IC die  104  has been improperly placed, acceptable electrical coupling is achieved between contact pads  204   a - d  and contact areas  210   a - d.    
      Note that although  FIGS. 2A-2D  show the layout of four contact pads  204   a - d  collectively forming a rectangular shape, greater or lesser numbers of contact pads  204  may be used. Furthermore, contact pads  204   a - d  may be laid out in other shapes in embodiments of the present invention.  
      1.2 Device Assembly  
      The present invention is directed to continuous-roll assembly techniques and other techniques for assembling tags, such as RFID tag  100 . Such techniques involve a continuous web (or roll) of the material of the tag antenna substrate  116  that is capable of being separated into a plurality of tags. Alternatively, separate sheets of the material can be used as discrete substrate webs that can be separated into a plurality of tags. As described herein, the manufactured one or more tags can then be post processed for individual use. For illustrative purposes, the techniques described herein are made with reference to assembly of RFID tag  100 . However, these techniques can be applied to other tag implementations and other suitable devices, as would be apparent to persons skilled in the relevant art(s) from the teachings herein.  
      The present invention advantageously eliminates the restriction of assembling electronic devices, such as RFID tags, one at a time, allowing multiple electronic devices to be assembled in parallel. The present invention provides a continuous-roll technique that is scalable and provides much higher throughput assembly rates than conventional pick and place techniques.  
       FIG. 3  shows a flowchart  300  with example steps relating to continuous-roll production of RFID tags  100 , according to example embodiments of the present invention.  FIG. 3  shows a flowchart illustrating a process  300  for assembling tags  100 . Process  300  begins with a step  302 . In step  302 , a wafer  400  having a plurality of dies  104  is produced.  FIG. 4A  illustrates a plan view of an exemplary wafer  400 . As illustrated in  FIG. 4A , a plurality of dies  104  are arranged in a plurality of rows  402   a - n.    
      In a step  304 , wafer  400  is optionally applied to a support structure or surface  404 . Support surface  404  includes an adhesive material to provide adhesiveness. For example support surface  404  may be an adhesive tape that holds wafer  400  in place for subsequent processing.  FIG. 4B  shows an example view of wafer  400  in contact with an example support surface  404 . In some embodiments, wafer  400  does not need to be attached to a support surface, and can be operated on directly.  
      In a step  306 , the plurality of dies  104  on wafer  400  are separated. For example, step  306  may include scribing wafer  400  according to a process, such as laser etching.  FIG. 5  shows a view of wafer  400  having example separated dies  104  that are in contact with support surface  404 .  FIG. 5  shows a plurality of scribe lines  502   a - l  that indicate locations where dies  104  are separated. In an embodiment, wafer  400  is only scribed in one direction, so that separated strips (e.g., rows or columns) of dies are formed.  
      In a step  308 , the plurality of dies  104  is transferred to a substrate. For example, dies  104  can be transferred from support surface  404  to tag substrates  116 . Alternatively, dies  104  can be directly transferred from wafer  400  to substrates  116 . In an embodiment, step  308  may allow for “pads down” transfer. Alternatively, step  308  may allow for “pads up” transfer. As used herein the terms “pads up” and “pads down” denote alternative implementations of tags  100 . In particular, these terms designate the orientation of connection pads  204  in relation to tag substrate  116 . In a “pads up” orientation for tag  100 , die  104  is transferred to tag substrate  116  with pads  204   a - 204   d  facing away from tag substrate  116 . In a “pads down” orientation for tag  100 , die  104  is transferred to tag substrate  116  with pads  204   a - 204   d  facing toward (and in contact with) tag substrate  116 . In an embodiment, as described below, dies are transferred using a die application device that holds the strips of dies formed in step  306 .  
      Note that step  308  may include multiple die transfer iterations. For example, in step  308 , dies  104  may be directly transferred from a wafer  400  to substrates  116 . Alternatively, dies  104  may be transferred to an intermediate structure, and subsequently transferred to substrates  116 .  
      Note that steps  306  and  308  can be performed simultaneously in some embodiments. This is indicated in  FIG. 3  by step  320 , which includes both of steps  306  and  308 . In a step  310 , post processing is performed. During step  310 , assembly of RFID tag(s)  100  is completed.  
      2.0 Die Transfer Embodiments  
      Step  308  shown in  FIG. 3 , and discussed above, relates to transferring dies to a tag substrate. The dies can be attached to a support surface (e.g., as shown in  FIG. 5 ), or can be transferred directly from the wafer, and can be transferred to the tag substrate by a variety of techniques. Conventionally, the transfer is accomplished using a pick and place tool. The pick and place tool uses a vacuum die collet controlled by a robotic mechanism that picks up the die from the support structure by a suction action, and holds the die securely in the die collet. The pick and place tool deposits the die into a die carrier or transfer surface. For example, a suitable transfer surface is a “punch tape” manufactured by Mulbauer, Germany. A disadvantage of the present pick and place approach is that only one die at a time may be transferred. Hence, the present pick and place approach does not scale well for very high throughput rates.  
      The present invention allows for the transfer of more than one die at a time from a support surface to a transfer surface. In fact, the present invention allows for the transfer of more than one die between any two surfaces, including transferring dies from a wafer or support surface to an intermediate surface, transferring dies between multiple intermediate surfaces, transferring dies between an intermediate surface and the final substrate surface, and transferring dies directly from a wafer or support surface to the final substrate surface.  
       FIG. 6  shows a high-level system diagram  600  that provides a representation of the different modes or paths of transfer of dies from wafers to substrates.  FIG. 6  shows a wafer  400 , a web of substrates  606 , and a transfer surface  608 . Two paths are shown in  FIG. 6  for transferring dies, a first path  602 , which is a direct path, and a second path  604 , which is a path having intermediate steps. For example, as shown in  FIG. 6 , first path  602  leads directly from wafer  400  to web  606 . In other words, dies can be transferred from wafer  400  to substrates of web  606  directly, without the dies having first to be transferred from wafer  400  to another surface or storage structure. However, according to path  604 , at least two steps are required, path  604 A and path  604 B. For path  604 A, dies are first transferred from wafer  400  to an intermediate transfer surface  608 . The dies then are transferred from transfer surface  608  via path  604 B to the substrates of web  606 . Paths  602  and  604  each have their advantages. For example, path  602  can have fewer steps, but can have issues of die registration, and other difficulties. Path  604  typically has a larger number of steps than path  602 , but transfer of dies from wafer  400  to a transfer surface  608  can make die transfer to the substrates of web  606  easier, as die registration may be easier.  
      According to embodiments of the present invention, a die application tool or device is used to transfer dies to surfaces, such as substrates, including substrates of a web.  
       FIG. 7A  shows a cross-sectional side view of a die application device  700 , according to an example embodiment of the present invention.  FIG. 7B  shows a front view of die application device  700 , according to an embodiment of the present invention. Die application device  700  is used to transfer dies  104  to surfaces, such as substrates  116 . As shown in  FIGS. 7A and 7B , die application device  700  includes a body  710 . Body  710  has length  702  shown in  FIG. 7A , and a width  704  shown in  FIG. 7B . Body  710  has a channel  706  formed in a top surface  708  along length  702 . Channel  706  is a groove or slot in top surface  708  configured to hold a row or column of integrated circuit chips or dies during operation of die application device  700 .  
      As shown in  FIGS. 7A and 7B , body  710  further includes a guide chamber  712 , which is open at a side surface  714  of body  710 , and also at top surface  708 , where top surface  708  intersects with side surface  714 . Guide chamber  712  has a rectangular shape, and is configured to contain and guide a die application element  730  during operation of die application device  700 . As shown in  FIGS. 7A and 7B , die application element  730  resides in guide chamber  712 , and is moveable along an axis  716 .  
      Die application element  730  has a die pedestal  718 . During operation of die application device  700 , a die in channel  706  is moved from channel  706  onto die pedestal  718 . The position of the die relative to die pedestal  718  is maintained by any of a variety of means, such as a vacuum. Die application element  730  is actuated in a first direction (shown as an upward direction in  FIGS. 7A and 7B ) along axis  716  through guide chamber  712  to move the die in the first direction. The die is thereby made accessible from die application device  700 , and can be applied to a subsequent surface or otherwise utilized.  
      For instance,  FIGS. 8A-8B  show example operation of die application device  700 .  FIGS. 8A-8B  show perspective views of die application device  700  during operation, according to embodiments of the present invention. As shown in  FIG. 8A , a row of dies  104  are present in channel  706 . Furthermore, dies  104  in channel  706  have been incremented such that a first die  104   a  is positioned on die pedestal  718  of die application element  730 . As shown in  FIG. 8B , die application element  730  has been actuated, to move upward along axis  716 . Die  104   a  can be transferred from die pedestal  718  to a subsequent surface. In  FIGS. 8A-8B , a cover plate  802  is coupled to top surface  708  for illustrative purposes. Cover plate  802  encloses channel  706 , thereby securing dies  104  that are moved along channel  706  toward die pedestal  718 .  
      3.0 Other Embodiments  
      Die application device  700  is capable of being operated in any orientation. For instance,  FIGS. 9A-9C  show perspective views of die application device  700  oriented to transfer dies  104  downward onto surfaces, such as substrates. In  FIG. 9A , channel  706  is open at a bottom surface  908  of body  710 . Die application device  700  includes a guide  902  coupled to bottom surface  908  of body  710  to provide structural support for dies  104  that are moved through channel  706  toward die pedestal  718 .  
      Referring to  FIG. 9A , the combination of guide  902  and body  710  laterally surrounds at least a portion of channel  706 . The term “laterally surround” as used herein means to “define a perimeter of”. The laterally surrounded portion of channel  706  is referred to as being enclosed, though not all sides of channel  706  need to be surrounded or covered. For example, channel  706  may have a cylindrical shape with one or both ends being uncovered. In this example, the enclosed portion is the entire channel  706 . According to an embodiment, body  710  and guide  902  are a unitary element.  
      Channel  706  may be configured to receive dies in any of a variety of arrangements. In a first aspect, channel  706  is configured to receive a linear array of dies. The linear array includes a single row or column of dies or multiple rows or columns of dies. In a second aspect, channel  706  is configured to receive a random or pseudo-random arrangement of dies. For instance, dies  104  may be moved to a corner or a relatively narrow portion of channel  706  to orient at least one of the dies  104  relative to die application element  730 .  
      Channel  706  is provided between walls of body  710 . In a first embodiment, the walls are substantially parallel. In a second embodiment, the distance between the walls decreases toward die application element  730 . Channel  706  has a proximal end and a distal end with respect to die application element  730 . In the second embodiment, the walls are closer to each other at the proximal end than at the distal end.  
      As shown in  FIG. 9B , dies  104  are moved through channel  706  in a direction indicated by arrow  940 . In  FIG. 9B , dies  104  are moved substantially parallel with bottom surface  908  of body  710 , though the scope of the present invention is not limited in this respect. Dies  104  are moved through channel  706  in any of a variety of ways. According to a first embodiment, air is used to push and/or a vacuum is used to pull dies  104  along guide  902 . In a second embodiment, vibration is used to facilitate moving dies  104 . According to a third embodiment, body  710  and guide  902  are not necessarily fixably attached to each other. In an aspect, guide  902  moves with reference to body  710  in the direction indicated by arrow  940  until guide  902  reaches a threshold or an obstacle. The obstacle may be coupled to body  710  along surface  908 , for instance. In another aspect, dies  104  rest upon guide  902  as guide  902  moves along surface  908  of body  710 . In a fourth embodiment, a lever, an arm, and/or a spring is used to move dies  104  in the direction indicated by arrow  940 . The lever, arm, and/or spring is coupled to body  710  or guide  902 . According to a fifth embodiment, a brush is used to move dies  104  through channel  706 . The brush is moved in the direction indicated by arrow  940 , such that the brush is placed in contact with one or more dies  104 , thereby moving one or more dies  104  along guide  902 .  
      Referring to  FIG. 9B , die  104   a  is aligned with die pedestal  718  for transfer to a respective substrate. In  FIG. 9B , one die  104   a  at a time is aligned with pedestal  718  for illustrative purposes. Any number of dies  104  may be aligned with pedestal  718  of die application element  730 . As shown in  FIG. 9C , die application element  730  is actuated in a direction indicated by arrow  950 , thereby making die  104   a  accessible from die application device  700 . Die application element  730  is actuated by any of a variety of means, such as an electromechanical solenoid or a servo-controlled linear drive.  
      Upon transferring die  104   a  to a substrate, die application element  730  moves in a direction opposite that indicated by arrow  950 . Dies  104  that remain in channel  706  are incremented in a direction indicated by arrow  940  of  FIG. 9B  to align the next successive die with die pedestal  718  of die application element  730 . Die application element  730  is again actuated in the direction indicated by arrow  950 , such that the die that is aligned with die pedestal  718  is transferred to a respective substrate. This process can be repeated for any number of dies  104 .In  FIGS. 10A-10C , die application device  700  is configured to transfer more than one die  104  at a time from channel  706 . For example, in  FIG. 10A , die application device  730  is capable of transferring five dies  104  at a time  FIG. 10B , dies  104  are moved in the direction indicated by arrow  940 , so that dies  104   a - e  are aligned with die pedestal  718  of die application element  730 . Five dies  104   a - e  are aligned with surface  735  for illustrative purposes. Any number of dies may be aligned with die pedestal  718 . In  FIG. 10C , die application element  730  is moved in the direction indicated by arrow  750 , thereby transferring dies  104   a - e  from channel  706 .  
       FIG. 11  illustrates a flowchart  1100  of a method of transferring dies to respective substrates in accordance with an embodiment of the present invention. The invention, however, is not limited to the description provided by the flowchart  1100 . Rather, it will be apparent to persons skilled in the relevant art(s) from the teachings provided herein that other functional flows are within the scope and spirit of the present invention.  
      Flowchart  1100  will be described with continued reference to example die application device  700  described above in reference to  FIGS. 7A-10C , though the method is not limited to those embodiments.  
      Referring now to  FIG. 11 , a plurality of dies  104  is loaded in a channel  706  of a die application device  700  at block  1110 . According to an embodiment, a wafer includes a plurality of rows, each row having a plurality of dies. A row of the wafer is loaded in channel  706  of die application device  700 .  
      The plurality of dies  104  are moved through channel  706  to align at least one die of the plurality of dies  104  with a die pedestal  718  of die application device  700 . The plurality of dies  104  may be moved by pushing or pulling the dies  104  using air, by vibrating the dies  104 , or by any other means. In an aspect, the dies  104  are moved using a mechanical means, such as a spring, a brush, or a guide  902  that can move independently from a body  710  of die application device  700 . For example, guide  902  carries the dies  104  toward die application element  730  for dispensing.  
      Die application device  700  dispenses the dies  104  onto respective substrates  116  at block  1120 . In a first embodiment, die application device  700  independently dispenses each die of the plurality of dies  104 . In a second embodiment, die application device  700  dispenses multiple dies at a time.  
      Die application device  700  includes any number of channels  706  and/or die application elements  730 . According to an embodiment, die application device  700  includes a plurality of channels  706 , each of which is capable of receiving a plurality of dies  104 . Dies in each channel  706  are moved as described above with respect to  FIGS. 7A-10C . Each channel  706  is associated with a respective die application element  730 . A first die is aligned with a first surface of a first die application element, a second die is aligned with a second surface of a second die application element, and so on. The die application elements are actuated independently from each other or in synchronism.  
      4.0 Conclusion  
      While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant arts that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.