Abstract:
The present invention approaches the filling efficiency problem from the perspective of the block receptor sites independent of any modification to existing manufacturing equipment or general block geometry. The present invention teaches the use of receptor site openings consisting of various shapes to increase the filling efficiency by improving the ease with which a right-side-up block can deposit into a receptor site opening while preventing improperly oriented blocks from completely entering the block receptor site and enhancing the ease with which incorrectly seated and upside down blocks can be removed from the receptor site.

Description:
[0001]     This application claims benefit and priority to provisional application 60/724,481 filed on Oct. 7, 2005. The full disclosure of the provisional application is incorporated herein in its entirety. 
     
    
     GOVERNMENT RIGHTS NOTICE  
       [0002]     This invention was made with government support with at least one of these contracts with North Dakota State University: subcontract SPP002-04, H94003-04-2-0406 (prime); subcontract 4080, DMEA90-01-C-0009 (prime); subcontract SB004-03, DMEA90-03-3-0303 (prime); and subcontract 5038, DMEA90-02-C-0224 (prime). The Government has certain rights to this invention. 
     
    
     FIELD  
       [0003]     The present invention relates generally to the field of fabricating openings in a substrate which are used for depositing block elements. In particular, the present invention relates to the shaping of the openings in a substrate which are designed to receive an element which is a block that consists of at least one functional element. More specifically, various embodiments of the present invention relate generally to the process of making Radio Frequency Identification (RFID) devices or tags.  
       BACKGROUND  
       [0004]     Many industrial and commercial electronic devices depend on integrated circuitry (IC) components for their functionalities. These electronic devices include for example, radios, audio systems, televisions, telephones, cellular phones, computer systems, computer display monitors, hand held pagers, digital video recorders, digital video disc players, radio frequency identification devices or tags (RFID) to name a few. As these electronic devices advance to become more complex or as consumers or applications demand a size reduction of these electronic devices, the demands to package smaller ICs also increase. Microstructures and ICs have been created in the form of block elements containing functional components.  
         [0005]     Many electronic devices either require a large array of functional components or are most cost effectively produced by the assembly of a large array of functional components. For instance, devices that can provide, produce, or detect electromagnetic signals or chemicals or other characteristics depend highly on a large array of functional components. An example would be an active matrix liquid crystal display which is formed by having a large array of pixels or sub-pixels which are fabricated on amorphous silicon or polysilicon substrates. Each pixel or sub-pixel is formed as part of an array of electronic elements that can function independent of each other while producing an electromagnetic signal. Another example is the manufacturing of RFID tags. Each RFID tag typically consists of a functional block element electrically connected to an antenna. In the fabrication process, functional block elements are deposited into receptor sites in a substrate, further processed and electrically coupled to antennas that are placed on the surface of a substrate. Although each RFID tag is formed from the combination of one functional block element and an antenna, the fabrication process of the RFID tag is most efficient when produced in large quantities through an array. In both of these examples, the functional block elements are manufactured and separately deposited into a substrate forming an array using methods such as fluidic self-assembly (FSA).  
         [0006]     An example of FSA is described in U.S. Pat. No. 5,545,291, which is incorporated by reference herein for all purposes. In this method, microstructures or block elements are mixed with a fluid such as water, forming a combination referred to as a slurry. The slurry is then dispensed over receptor sites in a substrate. The receptor sites are designed and sized to receive blocks with a specific range of dimensions. The receptor sites will receive a plurality of blocks and the blocks are electrically coupled to form electronic assemblies. FSA is a form of stochastic placement, and it has proven to be more efficient compared to a more deterministic approach such as pick and place, which uses a human or robot arm to pick each element and place it into a corresponding location in a different substrate. Stochastic placement is generally more effective and generates higher yield when the proper matching shape of block and receptor is used and, when compared to the pick and place methods, when applied to small and numerous elements such as those needed for large arrays. This process also gives the benefit of fabricating individual blocks, each containing a functional component, and fabricating the substrate, separately, then assembling such block functional components into the substrate through FSA.  
         [0007]     Despite its efficiency over pick and place methods, the stochastic nature of FSA presents problems that the overall process has to overcome. For example, IC functional blocks may require assembly in a specific orientation into the substrate such that the electrical circuits and layouts on the block can properly align to couple to the electrical connections that are on the surface of the substrate. A solution this problem has been described in U.S. Pat. No. 6,657,289 where functional blocks are made in a trapezoidal shape and the receptor sites receiving these functional blocks have a complementary trapezoidal shape.  
         [0008]     Shaped functional blocks align with the proper electrical connections by orienting the proper shape of the block with respect to the block receptor site. However, the improvement still does not improve the efficiency or yield of the receptor site filling process. At the end of the FSA process, many receptor sites may be left unfilled. In fact, there are often functional blocks left on the surface of the substrate without settling into receptor sites and inverted functional blocks that are partially settled into or over receptor sites. Part of the problem is due to the density ratio of the blocks relative to the receptor sites, the lubricity of the fluid and surfaces, or simply that the blocks were dislodged from the receptor sites after having been properly deposited into the receptor sites.  
         [0009]     When functional block elements are not deposited into the receptor sites or are improperly placed into the receptor sites, it prevents proper execution of subsequent manufacturing steps and leads to inefficiency of the entire process. Improperly placed blocks, excess blocks or absence of blocks in receptor sites lowers the overall production yield. Different methods have been tried to improve efficiency such as repeating the FSA process several times over the empty receptor sites. However, repeated application of the FSA process adds processing time and in some cases requires larger processing equipment or additional functional blocks, therefore it is not considered an overall cost effective solution.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention approaches the filling efficiency problem from the perspective of the block receptor sites independent of any modification to existing manufacturing equipment or general block geometry. The present invention teaches the use of receptor site openings consisting of various shapes to increase the filling efficiency by improving the ease with which a right-side-up block can deposit into a receptor site opening while preventing improperly oriented blocks from completely entering the block receptor site and enhancing the ease with which incorrectly seated and upside down blocks can be removed from the receptor site.  
         [0011]     In one embodiment, an overwide receptor site opening has a length that is at least 5% longer than a longest edge of the block but less than two times the length of a longest edge of the block and a width that is slightly longer than the length of the shortest edge of the block. When the block is properly fitted into the overwide receptor site opening, it can slide along the lengthwise direction, but cannot slide along the widthwise direction. The overall enlargement retains the receptor&#39;s ability to prevent improperly placed block from depositing into the receptor site opening and helps to increase the deposition rate of right-side-up blocks.  
         [0012]     Another embodiment of the present invention has a receptor site with oversized corners where only the corners of the receptor site opening are enlarged but the sidewalls between the corners are designed to line up in close tolerance relative to the block once the block is properly fitted into the receptor site opening. The oversized corners increase the range of rotational orientations over which right-side-up blocks can enter a receptor site, and hence fill rate is increased, while the sidewalls prevent up-side down blocks from entering the receptor site opening. Final placement precision is guaranteed by close tolerances between the sidewalls of a block and a receptor site.  
         [0013]     Yet another embodiment teaches a receptor site opening with two opposite edges of the receptor site opening that are beveled at a downward angle towards the block resulting in a space gap between the two opposite edges of the receptor site opening and the corresponding edges on the block after the block is properly fitted into the receptor site opening; at least one other edge of the receptor site opening is not beveled.  
         [0014]     Another embodiment teaches a receptor site opening formed in a substrate where edges of the opening are overwide and beveled at a curved sidewall from a top surface of the substrate to at least a point above a bottom surface of the opening.  
         [0015]     Another configuration of the present invention has a receptor site opening that is formed from a substrate with at least two corners having a beveled or stepped profile corner. In this configuration, profile of the beveled corners may be curved, linear, or vertical.  
         [0016]     These last four embodiments increase the capture cross-section for a right-side-up block to deposit into the block receptor site while still preventing inverted blocks from depositing into the opening. Hence their use results in an increase rate at which receptor sites are correctly filled by right-side-up blocks, relative to conventional receptor site geometries.  
         [0017]     Yet another embodiment of the present invention teaches a method of making a receptor site opening by punching through a substrate, laminating over the punched opening with an adhesive coated plastic or metal film on the bottom of the substrate and filling the hole formed from the punched through substrate and the laminated layer with a curable liquid polymer mixture. After the solvent evaporates and the remaining polymer is cured, the solid cured polymer forms a receptor site for the block over the metal or plastic film in the opening. This method of forming a block receptor site is an alternative to embossing or other method used to form the various previously described embodiments.  
         [0018]     The invention also teaches an embodiment where a receptor site opening consists of various depths formed from a substrate with a block receptor site of maximum depth in one part of the opening and an exit ramp immediately adjacent to the block receptor site that rises from one side of the block receptor site and extends to the opposite edge of the opening. This receptor site opening can be used in conjunction with the existing FSA process. In the process, the substrate containing receptor opening sites is oriented at an incline with the exit ramps of the receptor site openings pointing downhill and the block receptor sites in the uphill direction. During block deposition onto the substrate, the blocks that land right-side-up and slide into block receptor sites will stay and remain, while any excess blocks or inverted blocks or improperly positioned blocks will not anchor inside the block receptor sites, but slide over the receptor site and out of the receptor site opening via the exit ramp. This embodiment takes advantage of the gravitational forces acting on the blocks by the inclined angle to clear and remove excess or inverted blocks.  
         [0019]     Yet another embodiment of the present invention teaches a receptor site opening consisting of different depths formed from a substrate. In one example, there are at least two recesses of different depths located adjacently, side by side in parallel, where a deeper recess is both longer and wider than a shallower recess and forms a block receptor site at a region not bordering the shallower recess. In another example of this embodiment, there are three recesses of different depths. The shallow recess is shorter and narrower than the deeper recess which is located adjacently, side by side in parallel to the deeper recess, similar to the previous example. However, a third deepest recess, also referred to as the block receptor site, is formed at the region continuing from along the deeper recess at the end that does not share a common side wall with the shallow recess. Both of these examples may be used in combination with a clearing device mechanism to remove excess and improperly oriented blocks and move correctly seated blocks into the receptor site location. The device mechanism usually consists of a brush, static or rotating foam roller, mechanical wiper or blade. The block clearing can be accomplished in three steps after the blocks are deposited onto the substrate. First, a wiper sweeps along the widthwise direction from the deeper recess towards the shallow recess to remove any blocks that are excess or improperly placed. Second, another wiper pushes the properly seated blocks in the deeper recess along the lengthwise direction towards the block receptor site so that one block can be positioned exactly at the block receptor site. Lastly, either the first wiper or a different wiper sweeps from the shallow recess towards the deeper recess in the widthwise direction to clear any remaining properly seated but excess blocks in the deeper recess. This last step allows the wiper to take advantage of the partial depth created by the shallow recess to get partly into the receptor site opening and remove the excess blocks, while leaving exactly one block in the block receptor site.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     The present invention is illustrated by way of examples and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which:  
         [0021]      FIG. 1  shows conventional FSA process filling substrate openings with blocks.  
         [0022]      FIG. 2A  shows a cross-sectional view of a block properly seated in a block receptor site in a substrate.  
         [0023]      FIGS. 2B through 2C  show cross-sectional views of inverted blocks seated over a block receptor site.  FIG. 2B  shows an inverted block sitting directly over a block receptor site and  FIG. 2C  shows an inverted block partially seated in a block receptor site.  
         [0024]      FIGS. 3A through 3C  show a properly seated block in an overwide receptor.  FIG. 3A  shows a top view;  FIG. 3B  shows a lengthwise cross-sectional view; and  FIG. 3C  shows a widthwise cross-sectional view.  
         [0025]      FIGS. 3D through 3F  show an inverted block over an overwide block receptor site.  FIG. 3D  shows the top view of an inverted lock over an overwide block receptor site.  FIG. 3E  shows a widthwise cross-sectional view and  FIG. 3F  shows a lengthwise cross-sectional view.  
         [0026]      FIGS. 3G through 3I  show an inverted block partially seated in an overwide block receptor site.  FIG. 3G  shows the top view;  FIG. 3H  shows the lengthwise cross-sectional view and  FIG. 3I  shows the widthwise cross-sectional view.  
         [0027]      FIGS. 4A through 4E  show a properly seated block in a receptor with overwide corners.  FIG. 4A  shows a top view;  FIGS. 4B through 4E  show cross-sectional views of different corner profiles of overwide corner block receptor sites.  FIGS. 4B and 4D  show a cross-sectional view with an oversizing of each edge of the receptor corner uniformly extending to full depth of the opening with a stepped and curved profile respectively.  FIGS. 4C and 4E  show a cross-sectional view with an oversizing of each edge of the receptor corner extending only to limited depth of the opening with a stepped and curved profile respectively.  
         [0028]      FIGS. 4F through 4G  show a cross-sectional view of blocks between sidewalls of a block receptor site.  FIG. 4F  shows a cross-sectional view of a properly seated block between sidewalls of a block receptor site and  FIG. 4G  shows a cross-sectional view of an inverted block between sidewalls of a block receptor site.  
         [0029]      FIG. 4H  shows a top view of a block receptor site with overwide corners where blocks of different rotational orientation are overlaid on top of the block receptor site.  
         [0030]      FIG. 5A  shows a top view of a block receptor site with beveled edges on only two sides.  
         [0031]      FIGS. 5B and 5C  show the side views of a block properly seated in the block receptor site with beveled edges on only two sides.  FIG. 5B  shows a cross-sectional view of a block seated between two beveled edges and  FIG. 5C  shows a cross-sectional view of a block between two non-beveled edges.  
         [0032]      FIG. 5D  shows a top view of two blocks with different rotational orientation over a block receptor site with only two beveled edges.  
         [0033]      FIGS. 5E and 5F  show cross-sectional views of an inverted block seated in the block receptor site with only two beveled edges.  FIG. 5E  shows an inverted block between two beveled edges and  FIG. 5F  shows an inverted block between two non-beveled edges.  
         [0034]      FIGS. 6A through 6C  shows a block receptor site with curved beveled edges on all sides.  FIG. 6A  shows a top view and  FIGS. 6B and 6C  show cross-sectional views of a block in block receptor site with different curved beveled edge profiles.  FIG. 6B  shows a continuous curved beveled edge profile extending from the substrate top surface to the block receptor site bottom.  FIG. 6C  shows a curved beveled edge profile extending from the substrate top surface to a point from the bottom of the receptor which extends into a sloped straight edge that continues to the bottom of the receptor site.  
         [0035]      FIGS. 6D and 6E  show cross-sectional views of two different inverted blocks, one directly above and another partially seated in block receptor sites with curved beveled edges.  
         [0036]      FIGS. 7A through 7E  show a block receptor site with beveled corners.  FIG. 7A  shows the top view of one embodiment of a block receptor site with beveled corners with a properly seated block;  FIG. 7B  shows the diagonal cross-sectional view of the block receptor site with a properly seated block;  FIG. 7C  shows the widthwise or lengthwise cross-sectional view of the block receptor site with a properly seated block;  FIG. 7D  shows the three-dimensional view of a block receptor site with the particular beveled corner configuration as illustrated in  FIGS. 7A through 7C .  
         [0037]      FIGS. 8A through 8D  show a block receptor site with stepped corner profile.  FIG. 8A  shows the top view of the block receptor with a properly seated block;  FIG. 8B  shows the diagonal cross-section of the block receptor site with a properly seated block;  FIG. 8C  shows the widthwise or lengthwise cross-section of the block receptor site with a properly seated block; and  FIG. 8D  shows the three-dimensional view of the block receptor site with stepped corner profile as illustrated in  FIGS. 8A through 8C .  
         [0038]      FIGS. 9A through 9D  show the various stages of forming a block receptor site by filling a hole with a curable liquid polymer mixture and evaporating any solvent and curing or cross-linking the remaining polymer.  FIG. 9A  shows a punched through substrate with a laminated layer.  FIG. 9B  shows a punched through substrate with a laminated layer filled with curable liquid polymer mixture.  FIG. 9C  shows a punched through substrate with a sidewall formed after evaporation of solvent and curing of the curable polymer mixture.  FIG. 9D  shows a block seated properly in a curable polymer mixture block receptor site with sidewalls formed after evaporation of solvent and curing or cross-linking of the curable polymer mixture.  
         [0039]      FIGS. 10A through 10D  show a block receptor site with an exit ramp.  FIG. 10A  shows the top view of a block receptor with an exit ramp.  FIGS. 10B through 10E  shows different block receptor cross-sectional views having exit ramps with a flat region and a sloped region, two sloped regions, one continuous linear slope, and one continuous curved region, respectively.  
         [0040]      FIG. 11  shows an array of block receptor sites with exit ramps in a substrate with the exit ramps oriented downhill on an incline.  
         [0041]      FIG. 12  shows a flowchart describing a general method of removing excess and inverted blocks using a receptor site with an exit ramp when used in combination with a FSA process.  
         [0042]      FIGS. 13A through 13C  show a receptor site opening with a shallow recess and a deeper recess.  FIG. 13A  shows a top view of the receptor site opening.  FIG. 13B  shows a widthwise cross-sectional view of the deeper recess that is also the block receptor site.  FIG. 13C  shows a widthwise cross-sectional view of the portion of the receptor site opening where the shallow recess is adjacent to the deeper recess.  
         [0043]      FIGS. 14A through 14E  shows a variation of the above receptor site opening with a shallow recess and a deeper recess where the block receptor site depth is deeper than the deeper recess.  FIG. 14A  shows a top view of the receptor site opening.  FIG. 14B  shows a lengthwise cross-sectional view of the block receptor site and the deeper recess.  FIG. 14C  shows a widthwise cross-sectional view of the block receptor site.  FIG. 14D  shows a widthwise cross-sectional view of the portion of the deeper recess that does not share a bordering sidewall with the shallow recess.  FIG. 14E  shows a widthwise cross-sectional view of the shallow recess adjacent to the deeper recess.  
         [0044]      FIGS. 15A and 15B  show a clearing method where excess blocks are removed.  FIG. 15A  shows a flowchart describing the multiple steps in clearing and removing excess and inverted blocks from a receptor site opening with a block receptor and a deeper recess bordering a shallow recess and  FIG. 15B  shows the directions in which a device mechanism clears away excess blocks from the receptor site opening.  
     
    
     DETAILED DESCRIPTION  
       [0045]     The present invention relates to apparatuses and methods for shaping receptor openings to improve the efficiency of depositing functional elements into an array of receptor sites in a receiving substrate, or a long web of repeated substrate elements, via a FSA process. The following descriptions and drawings are illustrative of the invention by example and are not to be construed as limiting the invention. Numerous details are described to provide a thorough understanding of the present invention. In certain instances, well-known or conventional details are not described in order to not unnecessarily obscure the present invention in detail.  
         [0046]     The present invention relates generally to the field of shaping openings in a receiving substrate and to apparatuses having these openings. The present invention may be used to shape openings for different types of arrays. Generally an element in an array includes a functional component that may include an electrical component, a chemical component, a micro electromechanical component or a micro mechanical component. The various methods of the present invention are illustrated in certain detailed examples with regard to the manufacturing of Radio Frequency Identification (RFID) tags, but it should be recognized that the invention has wider applicability. In one instance, the invention may be used with electromagnetic signal detectors (e.g. antennas), or solar cells or chemical sensors. In another example, the invention may be applied to the manufacturing of an active matrix liquid crystal display, specifically directed to the fabrication of an electronic array to deliver precise voltages for the control of liquid crystal cells to create a liquid crystal display.  
         [0047]     In the fabrication of RFID tags or other integrated circuit (IC) elements, it is advantageous to first form the IC elements in a densely packed array then transfer them to another substrate, where the spacing and density of the IC elements in the final configuration may vary differently depending on its application.  
         [0048]     As an example, a Fluidic Self-Assembly (FSA) process is used to place functional elements such as these IC elements in receptor openings in a substrate. When FSA is employed in depositing functional elements into receptor sites, the functional elements are often referred to as blocks or NanoBlock® ICs. Each individual functional element in each receptor opening is capable of functioning independently of other elements in other receptor openings. In an alternative embodiment, functional elements in two or more receptor openings can operate in concert. That is to say, some devices may need two or more functional blocks. In the case of RFID tags, each functional element is typically the control element of the RFID tag and must be electrically connected to an antenna (e.g., a monopole antenna, dipole antenna, folded dipole antenna, double dipole antenna or the like) that is much larger than the functional element. In one embodiment, each functional element is less than 1 mm on a side, while an antenna is several square centimeters in area. FSA is one method to deposit a large number of functional elements into a large number of receptor openings in a substrate, while a separate process forms the antenna and attaches the functional element to the antenna on the web. Although FSA has the advantage of depositing a large number of functional elements into a large number of receptor sites, the method&#39;s inexact and random nature often results in improperly placed functional elements, therefore resulting in a less efficient process which becomes the rate-limited process step of the manufacturing process.  
         [0049]     The invention in its various embodiments illustrated in this application is to modify the configuration of the receptor site openings to promote efficient fitting and placement of the functional blocks that are randomly deposited onto the web from the FSA dispenser. Some blocks used in combination with the block receptor sites are functional block elements containing electrical circuitry and may contain metal and dielectric stack and contact pads or bumps on top of the block. Often, an inverted block with a metal and dielectric stack can become trapped in the receptor sites thus preventing right-side-up blocks from entering, thus resulting in a less than optimum yield. The finite capture cross-section of inverted devices stems from several sources including receptor site width being too wide, undersized blocks, and the metal and dielectric stack on the top of a device.  
         [0050]      FIG. 1  illustrates a conventional FSA process described in U.S. Pat. No. 5,545,291. In a typical FSA process, functional block elements  100  are placed into a FSA fluid such as water or another type of fluid. The combination of the blocks and the fluid, referred to as a slurry, is dispensed from a FSA dispenser  130  over a web consisting of receptor site openings  110  in a substrate  120 . The methods for forming receptor site openings in a substrate and the methods for creating assemblies with these openings are further described in U.S. Pat. No. 6,479,395, which is hereby incorporated by reference for all purposes.  
         [0051]     In all of the embodiments to be discussed below, the functional block element has a top surface where at least one circuit element is situated. The circuit element on the top surface of the functional block may be an ordinary IC for any particular function. In the case of a passive RFID tag, an IC may be designed to receive power from another circuit for operation (e.g., an antenna having power incident thereon). Whereas in a semi-passive or an active RFID tag, an IC may be designed to receive power from an energy source such as a battery for operation. Details regarding the method of making the functional blocks can be found in the method described in U.S. Pat. No. 6,291,896, which is hereby incorporated by reference. Alternatively, the functional block element can be a NanoBlock IC made by Alien Technology Corporation, Morgan Hill, Calif.  
         [0052]      FIGS. 2A through 2C  show a conventional block and block receptor site combination.  FIG. 2A  illustrates a block  200  with a flat, parallel top and bottom surface that is properly fitted and seated into a receptor site opening  210  in a flexible substrate  220 . Note that this specific combination of block and block receptor site consists of a block with a truncated pyramidal geometry that closely resembles the dimensions of the block receptor site. At the same time, the top surface of the block may be flush with the top of the substrate. It should be noted that the receptor site is a close fit to the block, especially at the bottom or base of the receptor site and along the edges of the sidewalls of the block receptor site bordering the blocks. Embodiments according to the present invention and described later in this application do not necessarily have the same degree of fit between the functional block element and the block receptor site along all sidewall edges of the block.  
         [0053]      FIGS. 2B and 2C  illustrate an inverted block  205  partially seated in the receptor site  210 .  FIG. 2B  shows an inverted block lying flat over the block receptor site with a large gap between the top surface  207  of the block and the bottom surface  217  of the block receptor site.  FIG. 2C  shows an inverted block lying slanted with one edge of its top surface in contact with the bottom of the block receptor site where the geometry of the block and the block receptor site will not allow the top surface  207  of the block to be in contact with the bottom surface  217  of the block receptor site. During the FSA process, blocks are deposited as part of a slurry onto the substrate surface and randomly dropped onto the receptor block sites. Inverted blocks that are dropped into the receptor sites will often result in one of the two configurations illustrated. Since the top surface is larger than the bottom surface of the block, it can only properly fit into the block receptor site if it is right side up and will not fit if inverted because of mismatch geometry between top of the block and the bottom of the receptor site.  
         [0054]     Conventional receptor sites are designed to exclude or strictly limit the possibility that upside down or otherwise incorrectly oriented blocks can enter the receptor sites. While this does ensure only correctly oriented and seated blocks will populate the finished assembly, it is unnecessarily restrictive and results in an FSA receptor site fill rate that is much slower than is attainable by receptor sites of the current invention.  
         [0055]     Distinguishing from the above conventional block and block receptor site combination, in certain embodiments of the current invention, a properly fitted block is expected to have significant gap clearance between the block and the sidewall of the receptor in certain locations of the receptor site opening, but not everywhere. Despite the significant gap distances at certain locations, the blocks are still precisely positioned. Overall, the receptor site opening size increases at strategic locations enhancing filling efficiency while the receptor site opening retains the ability to prevent improperly oriented or upside down blocks from fully seating into the receptor site openings. Embodiments of the current invention have significantly enhanced FSA fill rates that shift the stringency burden from key-in-lock, tight geometric fit between block and receptor site, to block removal processes, which are very efficient and rapid. Hence, the FSA process shifts from one dominated by receptor site filling time to a more rapid and efficient cyclic process balanced between receptor site filling and removal of incorrectly seated blocks.  
         [0056]     In the application of a RFID tag, there are at least two electrical connections required between the functional block element and the antenna (e.g., two, three, four or more connections). In the example of two electrical connections, these electrical connections are usually made from contact pads on two diagonal corners generally located on the top surface of the functional block element. The contact pads connect a dielectric stack through to the IC circuitry below or on the surface of the block. If there are two pairs of these connectors, each pair corresponding to a diagonal pair of corners on the top surface of the block, the rotational orientation of the block is not an issue if the block has a square geometry. If the block has a rectangular geometry, the block only needs to align its longest edge with the longest edge of the receptor site for proper fitting.  
         [0057]     A functional RFID tag can be assembled by the following simplified method:  
         [0058]     (i) form a substrate with an array of RFID block receptor sites and use an FSA process to deposit RFID blocks into these receptor sites,  
         [0059]     (ii) laminate an adhesive coated dielectric film, such as a hot-melt adhesive coated polyimide film, over the substrate, thus encapsulating the RFID blocks,  
         [0060]     (iii) laser-drill vias through the laminate to the contact pads on the RFID blocks,  
         [0061]     (iv) screen print conducting ink onto regions of the substrate to form the antennas and make connections to the pads on the blocks, and  
         [0062]     (v) singulate the individual RFID tags.  
         [0063]     In an alternative method, a functional RFID tag or RFID label (i.e., a tag with an adhesive and release liner) can be assembled using a strap assembly as generally described in U.S. Pat. No. 6,606,247, entitled “Multi-Feature-Size Electronic Structures,” and U.S. Patent Application Publication No. 2004/0183182, entitled “Apparatus Incorporating Small-Feature-Size and Large-Feature-Size Components and Method for Making Same,” both of which are hereby incorporated by reference for all purposes. According to embodiments of the present invention, a strap assembly or methods for making same can include one or more of the features described herein.  
         [0064]     The various embodiments disclosed in this invention will promote two aspects of the FSA process. First is to improve the ease of the blocks to slide into the receptor site when the block is not at an exact angle required for the block to drop into the site, second is to improve the ease for any device mechanism to clear away improperly fitted or excess blocks in the receptor site.  
         [0065]      FIGS. 3A  to  3 C illustrate one embodiment of the present invention, an over-wide block receptor site.  FIG. 3A  shows a top view of a block properly seated in an over-wide block receptor site. The block  300  is properly fitted into a block receptor site  310  with electrical connections  303  to be connected to the antenna. In this embodiment, the width  301  and the length  302  can each measure as much as 3000 μm or more. While they often range from about 20 μm to about 1500 μm, it is preferred to be in the range of about 200 μm to about 1000 μm. In this example, the block has a rectangular geometry with a width  301  less than 850 μm and a length  302  more than 850 μm.  
         [0066]     In one embodiment of the present invention, an over-wide block receptor site can be stretched in the direction of the longest edge of the block with a rectangular geometry. Alternatively, either edge of the block receptor site  310  can be stretched if the block has a square geometry. In any example, including the gap clearance between the block sidewall and the block receptor site sidewall, the stretched length of the block receptor site edge  312  can range from 105% to 200% of the distance of the longest edge of the block. In other words, the recommended limit of the stretch is no more than twice the distance of the longest edge of the block. In order to ensure that an inverted block cannot completely slide into the block receptor site to render the removal or clearing process difficult, it is important that only edges of the block receptor site that are parallel to the longest edge of the block be stretched. The shorter edges of the receptor site that are parallel to the shorter edge of the block are not stretched. The selective stretching allows sliding of properly seated blocks along the lengthwise direction while imposing a size limit in the widthwise direction to prevent an improperly oriented block to fit into the block receptor site.  
         [0067]     Still referring to  FIG. 3A , sidewalls  321  and  322  of the block receptor site  310  are sloped at an angle where it maintains a constant gap between the block sidewalls from the bottom of the block receptor site to the top surface of the block. Where the block has an inverted truncated pyramidal geometry, it will have the same angle on all four sides of the block, thus the sidewalls  321  and  322  will have the same angle. However, if adjacent sidewalls of the block do not have the same slope, receptor site sidewalls  321  and  322  will have different angles with respect to each other.  
         [0068]      FIGS. 3B and 3C  illustrates the cross-sectional view of a block properly fitted into the block receptor site.  FIG. 3B , a lengthwise cross-sectional view shows the block seated on one side of the receptor with space for the block to slide along the lengthwise direction of the receptor site, while  FIG. 3C  shows a widthwise cross-sectional view of the block seated in the receptor site. In the latter view, the block has only a nominal clearance between its sidewalls and the receptor site sidewalls and thus minimal block movement is permitted by the tight fit. Similarly, the depth of the block receptor site is within 100% to 130% of the thickness of the block for which it is designed to ensure that the block is securely situated in the block receptor site and cannot easily slide out of the receptor site from translation of the block within the block receptor site. For example, a receptor site opening designed for an 80 μm thick block could range from 80 μm to 104 μm in depth.  
         [0069]      FIGS. 3D and 3G  illustrate the top views of two different configurations where an inverted block is seated in the block receptor site. In  FIG. 3D , an inverted block is seated flat over the block receptor with its bottom surface facing up and the block fully protruded into mid-air.  FIGS. 3E and 3F  show the corresponding widthwise and lengthwise cross-sectional views where the inverted block is directly over the block receptor site and not engaging the interior of the block receptor site sidewalls. In  FIG. 3G , the block is slanted and partially seated inside the block receptor site. The block&#39;s side walls are neither aligned nor engaged to the block receptor site sidewalls as illustrated in the widthwise cross-sectional view in  FIG. 3H  and the lengthwise view in  FIG. 3I . Whether the removal mechanism is a mechanical device like a wiper, a blade, a brush, or a sponge roller sweeping across the surface of the substrate, or moving the substrate up an incline in using gravity to naturally remove an improperly seated block, or a jet of fluid moving tangentially over the surface of the substrate, or any other means, an inverted block that protrudes outside the block receptor site and not fully engaged with the block receptor site sidewalls is much easier to remove than a fitted block that is seated properly inside a block receptor site anchored by the sidewalls of the block receptor site.  
         [0070]     The next embodiment involves a receptor site opening where only the corners of the block receptor site are oversized.  FIG. 4A  shows the top view of a receptor with over-wide corners. The essence of this embodiment is that only the corners  401  of the block receptor site are enlarged without altering the sidewalls  407  and  408  in the block receptor site between the corners. Enlargement of the corners is measured by the edge distances  405  and  406 , and the expansion distances  403  and  404 . If the block has a square geometry, the edge distances  405  and  406 , as well as the expansion distances  403  and  404  will be the same relative to each other. However, if the block has a rectangular geometry, each pair of the edge distances  405  and  406  and the expansion distances  403  and  404  can be made different relative to each other to capture the maximum angle for a rotated rectangular block to slide into the block receptor site. The over-wide corner receptor design allows for a larger range of rotational angles over which a right side up block can begin to enter the receptor site, thus increasing the block capture cross-section and FSA fill rate.  
         [0071]     Still referring to  FIG. 4A , there is no maximum for the length of the sidewalls  407  and  408  but there must be a minimum. A functional range of the block receptor site sidewall length is approximately between about 5% to about 60% of edge length of that block sidewall. The reason for a minimum is that the sidewall serves as an upper limit dimension measured along the lengthwise and widthwise axes of the block receptor site to prevent an inverted block from completely seating into the block receptor site thus rendering the removal process difficult. The sidewalls  407  and  408  and gap between these sidewalls and a correctly seated block determine the ultimate placement tolerance to which the block can be localized on the substrate. On the contrary, the block receptor sidewall length can be minimized to maximize the range of rotational angles over which a right side up block can enter into the block receptor site by increasing the area of the oversized corners.  
         [0072]      FIGS. 4B through 4E  shows the implementation of multiple different corner sidewall profiles.  FIGS. 4B-4E  illustrate the cross sectional views AA and BB from  FIG. 4A , showing different corner profiles. In the present example, it is assumed that the block receptor is of a square geometry, therefore, the cross-sectional views AA and BB are the same and all corners are assumed to have the same enlargement. Each of the unique profiles from  FIG. 4B through 4E  can be implemented effectively in accomplishing the objective of the invention.  FIG. 4B  shows one embodiment where the block receptor site corner sidewall  411  drops straight from the substrate top surface  499  to the bottom  412  of the block receptor site with a gap  413 . This configuration gives the largest gap at the corners with the block receptor site sidewalls being the only physical structure that engages and secures the block to the block receptor site.  FIG. 4C  shows a corner profile where the block receptor site corner sidewall  421  drops to approximately half depth of the block receptor site where the bottom half of the block receptor site corner sidewall  424  is sloped to the block receptor bottom  422  such that it engages the block sidewall and helps the block receptor site sidewall to secure the placement of a properly fitted block. The gap  423  is smaller and shallower compared to the gap  413  in the previous configuration. Variations of the embodiments in  FIG. 4B  and  FIG. 4C  are shown in  FIGS. 4D and 4E  respectively. Instead of a straight drop like a step from the surface of the substrate,  FIG. 4D  shows a block receptor site corner sidewall with one curve  433  that extends straight to the bottom  422  of the block receptor site, while  FIG. 4E  shows a block receptor site corner sidewall with a half curve  443  to half-depth of the block receptor site before joining a sloped corner sidewall  444  that corresponds to the block sidewall profile. The various profiles of the block receptor site corner profile are not only limited to a step or a curve but can be extended to any other configurations that satisfy the functional objective of the invention in enlarging only the corners of a block receptor site thereby increasing the angle to which a right-side-up block can rotate and fit into the block receptor site.  
         [0073]      FIGS. 4F and 4G  illustrate the cross-sectional views CC and DD from  FIG. 4A  of the block receptor site sidewall profiles.  FIG. 4F  illustrates a block  400  properly placed inside a block receptor site  410  between the sidewalls of the receptor site. Note the tight tolerance between the block and the block receptor site sidewall as compared to the large gaps in the oversized corners. Similarly, because of the tight tolerance, the size limitation of the block receptor site sidewalls limits any inverted blocks from dropping into the site.  FIG. 4G  shows a cross-sectional sidewall view of an inverted block  400  directly over the block receptor site  410 . As discussed above, the block receptor site sidewall acts to restrict the orientation of any block to be deposited into the block receptor site while the oversized corners maximizes the range of rotational orientations of a right-side-up block to enter into the block receptor site.  
         [0074]      FIG. 4H  shows the top view of multiple blocks each with a different rotational orientation. In this view, there are three blocks directly overlaid on top of each other with the solid lines representing the outline of the top surface of the block while the dotted lines represent the outline of the bottom surface of the block. Two of the three blocks are rotated at an angle over the block receptor site, while one block is properly placed and fitted. It can be appreciated that blocks with different rotational angles can take advantage of the oversized corners and slide into the block receptor site easier simply because the smaller area on the bottom of the block can rotate and still be directly over and within the opening of the receptor site. On the other hand, an inverted block will be impossible to slide in because of the size limitations placed by the non-oversized sidewalls of the receptor site opening.  
         [0075]      FIGS. 5A through 5E  illustrate another embodiment of a block receptor site with beveled edges on only two sides of the receptor site.  FIG. 5A  illustrates a top view of the block receptor site having two opposite sloped sidewalls  510  with the same angle from the substrate top surface  530  to the bottom surface  550  of the block receptor site, and two opposite beveled sidewalls  520  each has two different sloped sections  521  and  522 . The bottom section  522  has the same angle profile as block receptor site sidewall  510  that corresponds to the angle of the block sidewall profile  505  to allow for a snug fit of the block into the block receptor site. The top section  521  generally has a shallower angle compared to the bottom section  522  or sidewalls  510 . The sidewall angle profiles are further illustrated in cross-sectional views in  FIGS. 5B and 5C .  FIG. 5B  illustrates the cross-sectional view of the beveled sidewalls. A block  500  is fitted inside the block receptor site between the two bottom sections  522  of the block receptor side sidewalls. Comparing to bottom sections  522 , the top sections  521  are shallower.  FIG. 5C  shows a cross-sectional view of the single-sloped block receptor site sidewall where the block  500  is fitted snugly between the block receptor site sidewalls  510 . The height of the functional block element may be within a distance of 0% to 30% of the thickness of the block relative to the substrate top surface  530 . For example, for an 80 μm thick block, there may be a gap of 0 μm to 24 μm from the top of the block to the top surface of the substrate.  
         [0076]     Referring back to  FIG. 5B , the gap distance  523  between the edge of the block and the edge of the bevel may be approximately as large as about 100% the thickness of the block, often seen approximately between the range of about 10% to about 80% thickness of the block and preferably in the approximate range of about 30% to about 50% of thickness of the block, while the depth of the gap  524  from the bottom surface  550  of the substrate to the top edge of the bottom section  522  may be approximately in the range of about 0% to about 80% of block thickness, often in the approximate range of about 15% to about 75% of block thickness and preferably within the approximate range of about 25% to about 60% of block thickness. The beveled edges serve to allow misaligned blocks that are right-side-up to slide into the block receptor site easily while allowing easy removal of an inverted block to slide out of the block receptor site. For example,  FIG. 5D  shows a top view of two right-side-up blocks  501  and  502  rotated at off-angles overlaid on top of each other and not directly aligned to the block receptor site. The solid lines represent the outlines of the top surfaces of the two overlaid blocks, while the dotted lines represent the outlines of the bottom surfaces of the two overlaid blocks. The beveled edges will allow the block to seat partially within the block receptor site, re-orient, rotate and slide into place. Therefore, generally the gap distance  523  is important for increasing the ease of a misaligned block to slide into the block receptor site while the depth  524  helps to maintain a block correctly seated within the receptor site. Note that where the length  524  is zero, so that surface  521  extends from the top of the substrate to the bottom of the receptor site, the angle of the sidewall  521  is limited to approximately 30 degrees or steeper. If the sidewall angle is too shallow, then blocks tend to rest part way up the sidewall, not fully seated with the bottom of the block parallel to the bottom of the receptor site.  
         [0077]      FIGS. 5E and 5F  show two cross-sectional views of an inverted block seated up-side-down over the block receptor site with the top surface of the block facing the bottom surface of the receptor site.  FIG. 5E  shows the cross-sectional view of an inverted block over the block receptor site opening of the beveled edges while  FIG. 5F  shows the cross-sectional view of an inverted block over the non-beveled edges. While two edges of the top surface of the block are touching the two shallow sloped sections  521  of the beveled edge in  FIG. 5E , the top surface does not touch the bottom surface of the block receptor site. Consequently, the block will be able to slide along the shallow beveled sections and removed from the site by sliding or by a block clearing device mechanism because the inverted block protrudes far above the block receptor site.  
         [0078]     Referring back to  FIG. 5B  and  FIG. 5C , the shallower top section  521  of the beveled edges may take on a preferred profile of a linear slope, but it may also consist of multiple sections with various slopes or take on the profile of a convex curve. Note that for the block receptor with only two beveled edges, each of the two beveled edges should consist of at least two sections, one section  522  that matches the slope of the block sidewall, and another section that is shallower.  
         [0079]      FIGS. 6A  to  6 E illustrate another embodiment of the present invention where the block receptor site has two, three, or four overwide and curved sidewalls from the substrate top surface  640  to at least one point above the bottom surface of the receptor site.  FIG. 6A  illustrates the top view of a block receptor site  610  with over-wide and curved sidewalls  630  extending from all four of the edges  641  of the receptor site.  FIG. 6B  illustrates a block  600  sitting right side up in a block receptor site with a continuous curve  627  extending from the substrate top surface  640  to the block receptor site bottom  650 . Alternatively, another example of the present embodiment can be seen in  FIG. 6C  which illustrates a block  600  sitting right side up in a block receptor site where the sidewall profile consists of two sections, a convex curve  623  which transitions at a point  625  from the bottom of the receptor into a vertical or sloped straight edge  624  that continues to the bottom of the receptor site. The convex curvature  623  can be arbitrary while the edge  624  may have an angle that matches the angle of the block sidewall profile  605  to secured the block in the block receptor site or simply extends vertically from point  625  directly to the bottom  650  of the receptor site opening. The depth  622  from the substrate bottom surface  650  to the point of transition  625  should approximately be no deeper than three quarters the thickness of the block. Similar to the previous embodiment, a block receptor site with only two beveled edges, the gap distance is important for increasing the ease of a misaligned block to slide into the block receptor site while the gap depth is important to elevate an inverted block above the substrate top surface for easy removal.  
         [0080]     With the overwide and curved sidewalls of the receptors, regardless of how much a right-side up block is rotated, the curved sidewalls will facilitate easy rotation for the block to turn into the proper orientation and slide into the receptor site. Conversely, when the block is inverted, the curved sidewalls can also facilitate easy removal of the blocks when the top edges of the block are resting against a curve that makes sliding easier. For example in  FIG. 6D , an inverted block sits flush over the block receptor site while in  FIG. 6E  part of the inverted block sits inside the receptor site opening. In neither case does the top surface of the block  660  touch the bottom surface  650  of the receptor site. Nevertheless, the curved sidewall in both cases will help facilitate the inverted block to slide out of the receptor site because of the smoothness of the curved sidewall profile.  
         [0081]      FIGS. 7A through 7E  illustrate a block receptor site with beveled corners.  FIG. 7A  illustrates a block  700  properly seated in a block receptor site  710 . The block receptor site has four beveled corners  720 , each formed from a triangular bevel  725  with edges  722  that extends from the substrate top surface  705  to the bottom surface  750  of the receptor site. The overall opening of the block receptor site has length  716  and width  715 . In the case of a square block and a square block receptor as illustrated in this example, all length and width measurements on the block and the block receptor site are the same. The surface  720  of the triangular bevels are closely approximated to the corners formed by the edges  701  and  702 , and  703  and  704  respectively, of the block. When the block is properly fitted into the block receptor site, the corners of the blocks will rest closely along the beveled profile  720  of the beveled corners. Also, the block length  714  and block width  713  on the bottom surface of the block receptor site, formed by the distances between the center points on the bottom edge  723  of the beveled corners, will closely approximate the length  704  and width  703  on the bottom surface of the block. The dimensions  715  and  716  of the block receptor site opening should be less than the distance between two diagonal corners on the top surface of the block. The dimensions  715  and  716  of the block receptor site opening along with the beveled corners  720  will allow only the properly seated blocks into the block receptor site.  
         [0082]     Consequent of the configuration of the block receptor site, there is a gap  719  between the block sidewall and the block receptor site sidewall. Only the slanted edges between block sidewalls are in close proximity to the beveled corners of the block receptor site as later illustrated in  FIG. 7B . Furthermore, there is a top gap distance  727  or  717  between the corresponding edges  712  and  711  of the block receptor site with respect to the edges  702  and  701  on the top surface of the block. There exist bottom gap distances  719  and  729  between the bottom edge of the block receptor sidewall and the edges along the bottom of the block. This distance is also arbitrary, dependent on the dimensions of the block receptor site as mentioned above and the bottom dimensions of the block. The essence of this embodiment is to use the facet of the triangular bevel to prevent any upside down blocks from falling into the receptor site, while the square or rectangular top opening to the receptor site determines the placement precision, in x-y and angular rotation, of the block in the receptor site.  
         [0083]      FIGS. 7B and 7C  show the diagonal and widthwise cross-sectional views of the block receptor.  FIG. 7B  shows the diagonal cross-sectional views AA or BB of a block  700  properly seated in the block receptor site with its corners resting in near the beveled corner surface or profile  720 . The block receptor site depth  731 , as described in previous embodiments, should be approximately in the range of about 100% to about 130% the nominal thickness of the block for which it is designed. While the beveled corner originates along the top surface of the substrate, it slopes down toward the bottom surface of the block receptor site with edges  722 . The distance  732  in which the corner advances in toward the center of the block receptor site is dependent on the angle  733  of the block while maintaining a constant gap distance of  734 , usually seen in the approximate range of about 0 μm to about 50 μm, practically implemented approximately between about 2 μm to about 20 μm, and preferred to be approximately between about 5 μm to 10 μm, along the entire distance of the beveled corner profile  720 .  FIG. 7C  shows the widthwise cross-sectional view CC of the block receptor site with a properly seated block. The block has a large gap  718  between the block sidewall  736  and the vertical block receptor site sidewall  735 , while top gap distance  727 , between edge  712  along the block receptor top and the edge  702  on the top surface of the block, is smaller and defines the minimum uncertainty in block placement, i.e. the achievable placement tolerance, similar to gap distance  734  as previously defined in  FIG. 7B . Section CC essentially determines the placement precision and rotational orientation precision of the block while sections AA and BB prevents the upside down blocks from entering the receptor site opening.  
         [0084]      FIG. 7D  shows a three dimensional view of the block receptor site as described in  FIGS. 7A through 7C . The block receptor site with triangular beveled corners has outside edges  712  and  711  with beveled corners  725  sloping down and in towards the center of the block receptor site. Each beveled corner has a top corner  721 , two side edges  722  running from the top corner  721  to the bottom surface of the receptor site opening, a surface  720  bordering the corner edges of the block, and a bottom edge  723  on the bottom of the receptor site opening.  
         [0085]      FIGS. 8A through 8D  illustrate a block receptor site with stepped corners.  FIG. 8A  shows a top view of a block receptor site with block  800  properly seated inside a block receptor site  810  with stepped corners  820  inside the block receptor. For illustration purposes, both the block and the block receptor site in this example take on a square geometry and therefore all length and width measurements are symmetrical and identical. The block receptor site has top edges  805  and  806  corresponding to the top edges  803  and  804  along the top surface of the block. The length  815  and width  816  of the block is measured slightly less than the corresponding length  817  and the width  818  of the block receptor site. Similar to the previous embodiment of a block receptor site with beveled corners, the length  817  and width  818  of the block receptor site should be less than the distance between any two diagonal corners on the top surface of the block. In fact, the small gap  811  and  812  between the top edges of the block and the block receptor site along the lengthwise direction or widthwise direction should ensure that this requirement is met. Typically, gaps  811  and  812  can be in the approximate range of about 0 μm to about 50 μm, or approximately between about 2 μm to about 20 μm, or approximately between about 5 μm to about 10 μm.  
         [0086]     Still referring to  FIG. 8A , each stepped corner extends in toward the center of the block receptor site with edges  821  and  822 , resulting in the distances of  823  and  824  between the stepped corners in the lengthwise and widthwise direction respectively. While the step has a linear and vertical profile, the edges  801  and  802  along the bottom surface of the block will not be near any of the stepped corners or the block receptor sidewalls because they are measured shorter comparing to the corresponding edges on the top surface of the block.  
         [0087]      FIG. 8B  illustrates the diagonal cross-sectional profile of the block receptor site with a properly seated block  800 . The block receptor site has stepped corners  820  that are measured with a depth  832  from the substrate top surface  809 . The gap between the corner  829  of the stepped corner and the block&#39;s corner edge  807  should be within the described ranges for gap  811  and  812  in  FIG. 8A . Similar to previously described embodiments, the depth of the block receptor site  831  measured from the substrate top surface  809  to the bottom surface  808  of the block receptor site should be approximately in the range of about 100% to about 130% of the nominal block thickness. Furthermore, there exist two gaps  805  and  806  between the block&#39;s corner edge above and below the stepped corner as oppose to one big gap between the block and the block receptor site sidewall as illustrated in  FIG. 8C .  
         [0088]      FIG. 8C  illustrates the widthwise cross-sectional view of the block receptor site with a properly placed block  800 . The block receptor site sidewall  835  has a vertical profile extending straight down from the substrate top surface  809  to the bottom  808  of the block receptor site. The profile of the vertical block receptor site sidewall  835  and the downward sloping block sidewall  836  results in one large gap  837  between block and block receptor site sidewalls in the widthwise cross-sectional view, as compared to the diagonal cross-sectional view.  FIG. 8D  shows the three dimensional view of a block receptor site with stepped corners illustrating characteristics such as stepped corner depths  821  and  822 , vertical depths  832  and  831  of the stepped corners and the block receptor site respectively, as well as lengthwise distance  823  and widthwise distance  824  along the block receptor site sidewall between adjacent stepped corners.  
         [0089]      FIGS. 9A through 9D  illustrate an embodiment of the current invention that is formed by punching, lamination, and filling.  FIG. 9A  illustrates a cross-sectional view of a substrate  910  with a hole  911  that has been punched through entirely and laminated with an adhesive coated metal or plastic film to form the bottom surface  912  of the substrate. In this illustration, the substrate sidewalls  913  of the aperture opening are vertical and not sloped. The lamination process can be performed by a hot roller laminator where the adhesive coating can be a pressure sensitive adhesive, or hot melt, thermoplastic, or thermo set adhesive.  FIG. 9B  illustrates the aperture opening  911  being filled with a curable liquid polymer mixture  920  after the lamination process. Curable liquid polymer mixture can be deposited into the aperture  911  by dispensing over the entire substrate and removing excess with a squeegee or spreader bar, by screen print deposition into aperture  911  only, or by ink-jet dispensing into the aperture. The curable liquid polymer is used to form a base mold for the block receptor site after any volatile solvent has evaporated and the remaining polymer has been cured or cross-linked.  FIG. 9C  illustrates the resulting cross-sectional profile of the block receptor after any volatile solvent has evaporated and the remaining polymer cured. After evaporation, the residual cured solid polymer forms a sidewall  921  and a base  922  of the final block receptor site. Consequent of the nature of polymer drying and cross-linking and molecular adhesive forces, more curable liquid polymer accumulates at the bottom corners  914  where the substrate sidewall meets the laminated layer, resulting in a thicker layer of cured solid polymer  923  and thus a sloped or concavely curved sidewall  924  near the bottom of the receptor site.  FIG. 9D  illustrates a block  900  fitted inside the block receptor site  940 . Like previous embodiments, the gap distance  932  between the top surface of the block and the top surface of the substrate can usually be seen in the approximate range of about 0 μm to 50 μm, or approximately between about 2 μm to 20 μm, or approximately between about 5 μm to 10 μm. Since the sidewalls result from drying of the curable liquid polymer, it may not exactly match the profile of the block&#39;s sidewalls and thus result in gaps  930  that can be different from the range as described above.  
         [0090]     This process may be used as an alternative to the typical processes used to form receptors such as embossing. This process has several significant advantages over standard embossing processes, including the ease and speed with which substrate can be fabricated. It also facilitates use of materials that do not emboss well, or at all. In addition, this process can be a low temperature process, much lower than required for efficient embossing, and hence thermal stress induced substrate deformations can be avoided. Hence, polyethylene terephthalate (PET), polystyrene (PS), polyimide (PI), Teflon (PTFE), liquid crystal polymers and other low cost or high performance plastics can be used to make substrates with precise dimensional control.  
         [0091]      FIGS. 10A-10E  illustrate a substrate opening consisting of a block receptor site with an exit ramp with sufficient depth such that the top of an inverted device cannot contact the receptor site sidewall from which the ramp extends.  FIG. 10A  shows the top view of the block receptor site  1010  surrounded by sidewalls  1011 ,  1012 , and  1013  where all sidewalls sloped down and in toward the bottom  1015  of the block receptor site. The angle of the block receptor site sidewalls corresponds to the angle of the sidewalls of the blocks. Block receptor site sidewalls  1011  and  1012  are of full height and extend from the substrate top surface  1002  to the block receptor site bottom surface  1015 , while block receptor site sidewall  1013  extends from one end of the exit ramp  1014  to the block receptor site bottom surface  1015 . The block receptor site width  1022 , measured slightly wider than the block, is uniform along the entire opening from one end of the block receptor site  1010  to the end of the exit ramp  1014 . There would be a gap clearance between the block and the block receptor site walls, this clearance as described previously can be in the range of about zero to about 50 μm, or in the range of about 2 μm to about 20 μm, but targeted to be within the range of about 5 μm to about 10 μm. Thus, if the block has a square geometry, the block receptor site width  1022  would measure exactly the same as the block receptor site length  1021 ; but if the block has a rectangular geometry, the block receptor site length  1021  will be longer than the block receptor site width  1022 . The length of the exit ramp  1020  can be in the approximate range of about 10% to about 200% of the length  1021 , often seen in the approximate range of about 15% to about 110% of length  1021 , but expected to be most effective within the approximate range of about 25% to about 50% of length  1021 . The larger opening created by the exit ramp leads to an increased surface area to accommodate blocks, yet it also helps to facilitate the removal of improperly seated or inverted blocks.  
         [0092]     The exit ramp  1020  illustrated by  FIG. 10A  can take on different configurations and profile, and they are illustrated in  FIGS. 10B-10E . In all different configurations, the depth of the block receptor site  1031  can be in the range of about 100% to about 130% the nominal block thickness. The configuration in  FIG. 10B  illustrates a lengthwise cross-sectional view of an exit ramp consisting of two portions, a flat region  1041  with a length  1023  and a sloped region  1042  with a horizontal length of  1024 . Alternatively,  FIG. 10C  shows a lengthwise cross-sectional view of an exit ramp consisting of two sloped portions  1043  and  1044 . The incline angles of  1043  and  1044  would vary where  1043  is shallower than  1044  or vice versa. The selection of which sloped region is steeper is a matter of manufacturing preference but the objective is simply to prevent any inverted blocks from catching on the sidewall bordering the block receptor site and the exit ramp. One example is to have  1043  steeper than  1044  to elevate the inverted block as much as possible for easy removal. In other simpler cases, the exit ramp can consist only of one linear continuous slope  1045  as shown in  FIG. 10D  or a continuous curve as in  FIG. 10E . The sloped or curved ramp is used to facilitate the sliding of blocks into the receptor site as well as removal of improperly seated blocks. Thus, the depth of the exit ramp  1032 , indicated in  FIG. 10B , measuring from the top surface of the substrate to the highest point of the shortest receptor block site sidewall  1013 , cannot be too deep, rendering removal of inverted blocks difficult. Typically, the depth  1032  of the exit ramp can be in the approximate range of about 10% to about 50% of receptor depth  1031 , and often seen in the range of about 15% to about 25% of receptor depth  1031 .  
         [0093]     Despite the various depth constraints, the distances  1023  and  1024  of the exit ramp is only limited by the density of the receptor site openings in the substrate as long as the exit ramp depth requirement is met and the top surface of an inverted block does not contact the receptor site sidewall from which the ramp extends. A combination of the appropriate exit ramp depth  1032  and exit ramp length  1023  and  1024  will maximize filling efficiency as well as removal efficiency.  
         [0094]      FIG. 11  illustrates one manner in which a part of the FSA process is arranged to achieve optimal fill rate with this block receptor site configuration.  FIG. 11  shows a continuous sheet of substrate  1151  incorporating a web of block receptor sites  1152  each containing an exit ramp  1153  oriented at an incline angle during the FSA fill process, where the exit ramp is on the downhill direction  1154  of its receptor site. Furthermore, the continuous sheet of substrate is rolled into a big roll  1156  and oriented in the uphill direction  1157 . As the blocks  1155  are dispensed as a slurry from a block dispenser and flow downhill over the substrate, any inverted blocks or excess blocks entering a receptor site will simply flow over the exit ramp and out of the receptor site opening because the exit ramp prevents inverted blocks from catching on the downhill sidewall of the block receptor site bordering the exit ramp.  
         [0095]      FIG. 12  is a flow chart outlining the steps to implement the above block receptor site in an FSA process. In  1210 , a substrate filled with block receptor sites is oriented where the exit ramp is on the downhill direction relative to the block receptor site. While the substrate is often rolled up into a big roll as shown in  FIG. 11 , this may be accomplished by having the roll of substrate with empty block receptor sites at a downhill location while connected to a mechanism that rolls the substrate with filled block receptor sites located on the uphill direction. In  1220 , blocks are released from a FSA dispenser and allowed to fill the block receptor sites while the web of block receptor sites in the substrate is continuously rolled and moved in an uphill direction. Consequently, the blocks are allowed to fill the block receptor site openings in the substrate. In  1230 , inverted blocks, blocks improperly positioned, or excess blocks that are situated in the block receptor site opening will be pulled by gravity and flow out of the openings over the exit ramp, leaving only the right-side up blocks in the block receptor site.  
         [0096]     In this arrangement, the angle of the incline slope is critical in affecting the FSA fill rate. If the angle is too steep, too many blocks may slide out and over the openings, but if the angle is too shallow, gravity may not be strong enough to pull the inverted blocks or improperly seated blocks out of the block receptor sites. The angle of this inclined slope depends on the size of the block. For example, for a 350 um×350 um×62 um thick block a slope approximately in the range of about 12.5 to about 15.0 degrees works well, whereas for a 850 um×850 um×80 um thick block a slope approximately in the range of about 9.0 to about 11.0 degrees is superior. In further facilitating this process, two additional features may be added. For instance, small but constant vibrations may be applied to the substrate during its continuous movement to help fill the receptor sites or to remove blocks. Typically, vibrations in the plane of the substrate can be used, where the vibration frequency is approximately in the range of about 175 Hz to about 300 Hz, approximately targeted to about 190 Hz to about 260 Hz, and acceleration amplitude is approximately in the range of about 0.1 g-rms to about 1.5 g-rms, and approximately targeted to about 0.2 g-rms to about 0.8 g-rms. Further, the exit ramp surface can be coated with a lubricious material to assist sliding of the improperly seated or inverted blocks outside of the block receptor site opening, while the receptor site surface can be coated with an adhesive or high friction material to promote block retention.  
         [0097]     Application of an enlarged opening for a block receptor site, such as one where the receptor opening is longer than longest edge of the block, has been demonstrated to greatly increase the yield of the FSA fill rates relative to a receptor opening with a standard nominal length about 1× the longest edge of the block. Block receptors have generally in past experiments been limited to less than two times the maximum distance of the longest edge of the block to prevent multiple blocks from depositing in a given block receptor site. In the present embodiment, specific design features of a block receptor site and FSA process steps allow the application of sites with lengths greater than two times the maximum distance of the longest edge of the block, yet the final output of the FSA process is a single block per receptor.  
         [0098]      FIGS. 13A-13C  illustrate a receptor site opening with two recesses of different depths and different lengths where the deeper and longer recess has an end portion designed as the block receptor site.  FIG. 13A  is a top view of the entire receptor site opening  1300 . The receptor site opening  1300  has two recesses relative to the substrate top surface  1301 . The deeper recess  1310 , and a shallower recess  1320 . The deeper recess  1310  is longer than the shallower recess  1320 . Furthermore, the portion of the deeper recess that does not share a sidewall with the shallow recess is the block receptor site. The deeper recess has sidewalls  1311 ,  1312 ,  1313 ,  1314  and  1315 , all with a same downward slope angle. The angle of the deeper recess sidewalls corresponds to the block sidewall angle so the block can fit snugly into the block receptor site. When a block is properly seated into the block receptor site  1302 , it will be seated between walls  1311 ,  1312  and  1313  with a gap clearance, but can slide in a lengthwise direction. This gap clearance as described in previous embodiments can be approximately in the range of about zero to about 50 μm, often seen in the range of about 2 μm to about 20 μm, but targeted to be within the range of about 5 μm to about 10 μm. While the block receptor site sidewalls  1311 ,  1312 ,  1313  and  1314  extend fully from the flat bottom  1319  of the deeper recess  1310  to the substrate top surface  1301 , the sidewall portion  1315 , an extension of sidewall  1313  with the same angle, only extends from the flat bottom  1319  of the block receptor site  1302  to the edge  1324  of the shallower recess.  
         [0099]     Still referring to  FIG. 13A , the shallower recess  1320  is seated immediately adjacent to the deeper receptor site  1310  just above the block receptor site sidewall  1315 . The shallower recess  1320  has sidewalls  1321 ,  1322  and  1323  which are sloped downward from the substrate top surface  1301  to the bottom  1329  of the shallower recess  1320 . The angle of the shallower recess sidewalls can be the same as the angle of the block receptor site sidewalls, steeper, or shallower. Alternately, the bottom surface  1329  and sidewall  1322  can be combined as one continuous sloped plane intercepting the sidewall  1315  and substrate surface  1301 .  
         [0100]     The length  1332  of the block receptor site  1302  with cross-section AA can have a range of about half to just under two times the distance of the longest edge of the block, implemented in a range from slightly less than one to slightly less than two times the distance of the longest edge of the block, but with a preferred range of about zero to about 50 μm greater than the distance of the longest edge of the block. The length  1331  of the deeper recess  1310  with cross section BB has a range approximately half the distance of the longest edge of the block to a maximum of up to ten times the length of the distance of the longest edge of the block limited only by the practical placement of the number of receptor sites on the substrate. Nevertheless, the distance  1331  can be practically implemented in a range approximately between about one times to four times the distance of the longest edge of the block, and preferred to be between about two to three times the distance of the longest edge of the block.  
         [0101]     Similarly, the width of the block receptor site and the deeper recess section  1333  is designed to be slightly greater than the distance of the shorter edge of the block with a gap clearance between the block and the block receptor site sidewalls  1311 ,  1312  and  1313  as defined above. The width  1334  of the shallow recess approximately ranges from a about tenth to about one times distance of the short edge of the block, practically implemented approximately within a range of about a quarter to slightly less than one times distance of the short edge of the block, but preferred to be within a range of approximately one half to three quarters distance of the short edge of the block.  
         [0102]      FIGS. 13B and 13C  illustrate the different cross sections AA and BB of the opening receptor site.  FIG. 13B  shows the cross section AA of the block receptor site with a depth  1341 , extending from the bottom  1319  of the block receptor site to the top of the substrate surface  1301 . The depth measures similar to previously described embodiments in this application to accommodate for the metal and dielectric stack that may reside on the top of some functional block elements.  FIG. 13C  illustrates the cross section BB of the receptor site opening consisting of the deeper recess adjacent to the shallow recess. The depth  1341  of the deeper recess is the same as the depth of the block receptor site. The depth  1351  of the shallow recess, measured from the bottom  1329  of the shallow recess to the top of the substrate surface  1301 , ranges approximately between about a tenth to slightly less than one times the thickest portion of the block with a metal or dielectric stack, practically implemented approximately within a range between less than a third to more than three-quarters the thickest portion of the block with a metal or dielectric stack but preferred to be approximately between about twenty to about thirty percent of the thickest portion of the block with a metal or dielectric stack. The shallow recess  1320  is designed to improve removal of inverted or excess blocks by creating a gap between the surface of the substrate  1301  and any excess or inverted blocks in the deeper recess so a mechanical removal mechanism can get at the sidewall of the block through the shallow recess and push the block outside of the deeper recess.  
         [0103]      FIGS. 14A-14D  show an extension of the concept presented in the embodiment described in  FIGS. 13A-13C . This configuration is different from the previously described embodiment in that a properly seated block will be securely situated in a block receptor site which is deeper than the deeper recess and will not slide in the lengthwise or widthwise direction. This configuration may further allow blocks of different thickness be deposited into the receptor site opening in sequence and increase the utility of the receptor site opening and the FSA processing.  FIG. 14A  refers to an opening receptor site  1400  with three different depths where recess  1460  is the deepest which is also the block receptor site, while recess  1410  is less deep compared to recess  1460  and recess  1420  is the shallowest of the three. Similar to the previous embodiment, block receptor site sidewalls  1461 ,  1462 ,  1463  and  1464  have the same angle corresponding to the block sidewalls, all extending from the block receptor site bottom  1469  in a straight, linear slope upwards towards the substrate top surface  1401 . When a block is properly seated in the block receptor site  1460 , the gap clearance between each of the block sidewalls and each of the block receptor site sidewalls  1461 ,  1462 ,  1463 , and  1464  is described as in the previous embodiments, approximately ranges from about zero to about 50 μm, often seen approximately between about 2 μm to about 20 μm, and preferred to be approximately between about 5 μm to about 10 μm.  
         [0104]     The block receptor site sidewall  1464  borders the block receptor site and the deeper recess  1410 .  1464  has the same angle as block receptor site sidewalls  1461 ,  1462  and  1463  and extends from the bottom surface  1469  of the block receptor site to the bottom surface  1419  of the deeper recess, while  1462  and  1463  extend to become sidewalls  1412  and  1413  of the deeper recess respectively.  1462 ,  1463 ,  1412 , and  1413  will typically share the same sidewall angle; however, if different blocks with different thickness are used,  1412  and  1413  can have a different sidewall angle as compared to  1462  and  1463  to accommodate different block configurations. Deeper recess sidewall  1414  has the same sidewall angle as deeper recess sidewalls  1412  and  1413 , but both  1414  and  1412  are taller than sidewall  1413  which borders the shallow recess and extends from the bottom  1419  of the deeper recess to the bottom  1429  of the shallow recess. The shallow recess has lengthwise sidewall  1422  and widthwise sidewalls  1421  and  1423 , all having the same angle and same height while  1423  extends to become a part of sidewall  1414  for the deeper recess.  
         [0105]     Referring still to  FIG. 14A , the deepest recess or the block receptor site  1460  is located lengthwise at one end of the deeper recess, shorter in length comparing to the deeper recess  1410  and the shallow recess  1420 . The shallow recess  1420  can be as long as the deeper recess  1410  in length, but is usually shorter than the deeper recess. Similar to the previously described embodiment, the length  1432  of the block receptor site  1460  with cross-section AA can have an approximate range of about slightly less than one to two times the distance of the longest edge of the block, implemented in a range from one to slightly less than two times the distance of the longest edge of the block, but with a preferred range of about zero to about 50 μm greater than the distance of the longest edge of the block. The length  1431  of the deeper recess can have a range of approximately half the distance of the longest edge of the block to a maximum of up to ten times the length of the longest edge of the block or defined only by the size feasible to be implemented on the substrate. However, the length  1431  is more practically implemented in a range between about one times to about four times the distance of the longest edge of the block, and preferred to be between about two to about three times the distance of the longest edge of the block. As described above, length of the shallow recess  1435  can be as long as the length of the deeper recess, often implemented at a length ranging from about a half to about one times block distance shorter than the length of the deeper recess.  
         [0106]      FIGS. 14B  to  14 D, illustrate the different cross-sections of the opening receptor site.  FIG. 14B  shows the lengthwise cross-section DD of the block receptor site and the deeper recess. The block receptor site, similar to previous descriptions, can have a depth  1471  approximately ranging from about 100% to about 130% of the nominal block thickness, often seen between about 1 um to about 6 um thicker than the nominal block thickness, and preferred to between about 2 um to about 4 um thicker than the nominal block thickness. The deeper recess on the other hand is shallower than the block receptor site so that any excess blocks or inverted blocks landing on the deeper receptor will protrude above the top surface of the substrate  1401  and can be removed easily. Typically, the depth  1441  of the deeper recess can approximately range from about 30% to about 110% of the nominal block thickness, often seen between about 70% to about 105% of the nominal block thickness, and preferred to between about 90% to about 100% of the nominal block thickness relative to the top of the substrate surface  1401 . Furthermore, the design of the block receptor and the deeper recess is such that the top surface of any inverted block will not be in contact with the bottom surface of the block receptor site or the block receptor sidewall  1464 . Any excess block or inverted block will protrude above the top surface  1401  of the substrate for easy removal.  
         [0107]      FIG. 14C  refers to the width-wise cross-section AA of the block receptor only, having a depth  1471  as described above.  FIG. 14D  refers to the short section of the deeper recess between the block receptor site and the shallower recess, in a width-wise cross-section BB, with a depth of  1441 , as described above, which is shallower than block receptor site depth  1471 , but deeper than the shallower recess depth  1451  to be described below.  FIG. 14E  refers to the width-wise cross-section CC of the deeper recess and the shallow recess, showing the shallow recess and the deeper recess adjacent to each other, with a deeper recess depth  1441  and a shallow recess depth  1451 . The depth  1451  of the shallow recess, measured from the bottom surface  1429  of the shallow recess to the top of the substrate surface  1401 , approximately ranges between about a tenth to slightly less than one times the thickest portion of the block with a metal or dielectric stack, practically implemented within a range approximately between less than a third to more than three-quarters the thickest portion of the block with a metal or dielectric stack but preferred to be between about twenty to thirty percent of the thickest portion of the block with a metal or dielectric stack but is never as deep or deeper than the deeper recess depth  1441  to ensure easy removal of inverted blocks or excess blocks.  
         [0108]      FIGS. 15A and 15B  show a clearing method where excess blocks are removed.  FIG. 15A  is a simplified flow chart referring to a method or a series of steps whereby excess or inverted blocks are removed from the receptor site opening and  FIG. 15B  shows the directions in which a device mechanism clears away excess blocks over the receptor site opening.  1510  illustrates that in the FSA process, blocks are continuously deposited onto the substrate, filling the receptor openings, while the substrate is continuously moving in one direction.  1520  shows that as the long web, of substrate with receptor site openings, moves, a device mechanism that can be a mechanical wiper, brush, foam roller or similar device, clears excess or inverted blocks by moving in the direction along the width of the opening from deeper recess towards the shallower recess, as shown in direction  1560  in  FIG. 15B . This step removes all excess devices from the surface of the substrate and all up-side-down and incorrectly seated devices from the receptors, leaving only correctly-seated right-side-up blocks in the receptor sites.  1530  shows the sliding of any remaining right-side-up blocks correctly seated in the deeper recess into the block receptor site at the far side of the deeper recess that does not share a common sidewall or bordering with the shallower recess. Sliding can be accomplished by gravity such as moving the substrate up an incline with the block receptor site in the downhill direction where the block slides downhill into the block receptor site. Enhancements can be made to facilitate sliding by gravity such as increasing lubricity of the bottom surface of the deeper recess, or increasing the inclination angle. Furthermore, sliding can be accomplished by the use of a device mechanism or mechanical device such as a wiper, a blade, a brush or a foam roller as described in step  1520 . This mechanical wiper will simply push the blocks in a length-wise direction along the deeper recess toward the block receptor site without removing the correctly seated right-side-up blocks, as illustrated by direction  1570  in  FIG. 15B . Lastly,  1540  shows the removal of all but one of any remaining correctly seated right-side-up blocks seated in the receptor site opening with a clearing mechanism such as the one described above. The clearing mechanism such as a clearing blade, a brush, a wiper, or a foam roller will move in a width-wise direction from the shallow recess towards the deeper recess so the wiper can engage any excess blocks in the deeper recess. The removal of excess blocks from the site is accomplished by the receptor site opening&#39;s geometry utilizing the partial depth step of the shallow recess, as illustrated by direction  1580  in  FIG. 15B . Since the block is located in the block receptor site at the end of the deeper recess not bordering the shallow recess, it is not susceptible to removal by a wiper or blade that can go below the substrate top surface via a partial depth of a shallow recess, and therefore will remain in the block receptor site.  
         [0109]     Certain embodiments are described below in the context of claim language including the following claims:  
         [0110]     A receptor site for a block comprising: an opening formed in a substrate, the opening having a longest edge ranging from about 5% to about 200% of a length defined by a longest edge of the functional block, and the opening being sized to preclude seating more than one functional block. The receptor site fits a block that is a NanoBlock or functional block element containing at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. This receptor site described in the previous sentence fits a block that has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the block is larger than the bottom surface of the block. This receptor site described in the previous sentence is such that top surface of the substrate is approximately within a range of about 0% to 30% thickness of the block from a top surface of a fitted block. The receptor site is configured so that all sidewalls of the opening are linearly sloped downward and inward from top to bottom of the opening and a tolerance between a block sidewall and a receptor site sidewall is approximately within a range of about 0 μm to 50 μm. The receptor has the opening configured to allow a properly fitted block to slide inside the opening along the longest edge of the opening and an inverted block to partially protruded above a top surface of the substrate for easy removal.  
         [0111]     A receptor site for a block comprising: a plurality of recesses in the substrate configured to seat a plurality of blocks, each recess defined by sidewalls and oversized corners, the sidewalls being configured to be in relative closer proximity to a seated block than the oversized corners. The receptor site as described wherein the block is a NanoBlock or functional block element containing at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The receptor as described in the previous sentence wherein the block to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the block is larger than the bottom surface of the block. The receptor site as described in the previous sentence wherein top surface of the substrate is approximately within a range of about 0% to 30% thickness of the block from a top surface of a fitted block. The receptor site&#39;s opening is configured to allow a properly fitted block to slide inside the opening and an inverted block to partially protruded above a top surface of the substrate for easy removal. The receptor site&#39;s opening has a square or rectangular geometry and the oversized corners of the opening increase a range of rotational angles for which the block element can be positioned in a specific orientation alignment to enter the opening for proper fitting. The receptor site as described in the previous sentence wherein oversizing of each edge of the receptor corner occurs for less than half distance along the sidewalls between corners. The receptor site as described in the previous sentence wherein the oversizing of each edge of the receptor corner uniformly extends to limited or full depth of the opening or gradually decrease from a top surface of the substrate to limited or full depth of the opening. The receptor site&#39;s center portions of the sidewalls are angled downward towards middle of the opening from a top surface of the substrate with a tolerance within a range of about 0 μm to about 50 μm between each block sidewall and the center portions of the sidewall.  
         [0112]     A receptor site for a block comprising: an opening formed in a substrate where two opposite edges of the opening are beveled at a downward angle towards the block resulting in a space gap between the two opposite edges of the opening corresponding to two opposite edges of the block while at least one other edge of the opening is not beveled. The receptor wherein the block is a NanoBlock or functional block element containing at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The receptor site as described in the previous sentence wherein the block to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the block is larger than the bottom surface of the block. The receptor site as described in the previous sentence wherein top surface of the substrate is approximately within a range of about 0% to 30% thickness of the block from a top surface of a fitted block. The receptor site has its opening configured to allow a properly fitted block to slide inside the opening and an inverted block to partially protruded above a top surface of the substrate for easy removal. The receptor site has its dimensions of four edges of a bottom surface of the opening are measured similar to corresponding four edges of a bottom surface of the block. The receptor site as described in the previous sentence wherein the downward angle of the two opposite edges of the opening forms a linear straight slope or a varying stepped profile and may vary at different depths of the opening. The receptor site as described two sentences ago wherein remaining two opposite opening sidewalls each has a same continuous sloping angle from a top surface of the substrate to a bottom surface of the opening as the block sidewall with a gap approximately ranging from about 0 μm to about 50 μm between block sidewall and the remaining two opening sidewalls.  
         [0113]     A receptor site for a block comprising: an opening formed in a substrate where an edge of the opening is overwide and beveled at a curved sidewall from a top surface of the substrate to at least a point above a bottom surface of the opening. The receptor site fits the block that is a NanoBlock or functional block element containing at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The receptor site as described in the previous sentence wherein the block to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the block is larger than the bottom surface of the block. The receptor site as described in the previous sentence wherein top surface of the substrate is approximately within a range of about 0% to 30% thickness of the block from a top surface of a fitted block. The receptor site wherein the opening is configured to allow a properly fitted block to slide inside the opening and an inverted block to partially protruded above a top surface of the substrate for easy removal. The receptor site wherein the opening is square or rectangular shaped and all four edges of the opening are overwide relative to a properly fitted block such that a same gap distance lies between each top edge of the block and a corresponding edge of the opening. The receptor site wherein dimensions of four edges of a bottom surface of the opening are measured similar to corresponding four edges of a bottom surface of the block. The receptor as in the previously described sentence wherein each sidewall curves continuously from a corresponding top edge of the opening to the bottom surface or curves continuously to a point above the bottom surface and then transition into a vertical or straight edge that continues to the bottom surface. The receptor site as described two sentences ago wherein a downward angle of two opposite curved sidewalls of the receptor site opening varies at different depths.  
         [0114]     A receptor site for a block comprising an opening formed in a substrate with at least two corners having a beveled or stepped profile. The block to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the block is larger than the bottom surface of the block. A specific orientation alignment of the block relative to the opening is required for proper fitting. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the block from a top surface of the block. This block, when inverted, remains partially exposed and protrudes above a top surface of the substrate for easy removal. The receptor site as described above can have stepped profile at the corners each extends from vertical sidewalls into middle of the opening while maintaining an approximate top gap distance of about 0 μm to about 50 μm between an edge of the top surface of the block and the opening sidewall. In this configuration, the stepped profile at the corners each rise to any height where an approximate gap distance between the corner and each edge between sidewalls of the block is about 0 μm to about 50 μm. Alternatively, the receptor site as described above has a beveled profile at the corners that slides downwards from a top surface to a bottom surface of the opening. The beveled profile at the corners each extends from the vertical sidewalls into middle of the opening while maintaining an approximate top gap distance of about 0 μm to about 50 μm between an edge of the top surface of the block and the opening sidewall. Also, the beveled profile at the corners slides downward from the top surface of the opening to a point between mid-height and the bottom surface of the opening.  
         [0115]     An assembly comprising, a functional block element and, a receptor site opening formed in a substrate with at least two corners having a beveled or stepped profile. The functional block element contains an electrical circuitry for radio frequency identification tag. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the functional block element. A specific orientation alignment of the functional block element relative to the opening is required for proper fitting. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the functional block element from a top surface of the block. This functional block element, when inverted, remains partially exposed and protrudes above a top surface of the substrate for easy removal. The assembly as described above can have a stepped profile at the corners each extending from the vertical sidewalls into middle of the receptor site opening while maintaining an approximate top gap distance of about 0 μm to about 50 μm between an edge of a top surface of the functional block element and the receptor opening sidewall. In this configuration, the stepped profile at the corners may each rise to any height where an approximate gap distance between the corner and an edge between sidewalls of the functional block element sidewall is approximately about 0 μm to about 50 μm. Alternatively, the assembly described above can have beveled profile at the corners that slides downwards from a top surface to a bottom surface of the receptor site opening. In this configuration, the beveled profile at the corners each extends from the vertical sidewalls into middle of the receptor site opening while maintaining an approximate top gap distance of about 0 μm to about 50 μm between an edge of a top surface of the functional block element and the receptor side wall. Also, the beveled profile at the corners slides downward from a top surface of the receptor site opening to a point between mid height and a bottom surface of the receptor site opening.  
         [0116]     A receptor site for a block comprising an opening created by a punched through substrate where one side of the substrate is laminated with an adhesive coated film and the opening is filled with a curable liquid polymer mixture over the adhesive coated film which forms a bottom surface and sidewalls in the opening upon evaporating solvent components and curing or cross-linking remainder of the curable liquid polymer. The block to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the block is larger than the bottom surface of the block. A specific orientation alignment of the block relative to the opening is required for proper fitting. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the block from a top surface of the block. This block, when inverted, remains partially exposed and protrudes above a top surface of the substrate for easy removal. The curable liquid polymer mixture, in the receptor site described above, includes a thermoplastic polymer in a suitable volatile solvent or mixture of volatile solvents, and cross-linkable polymer and cross-linking agent mixture and suitable volatile solvent. Also in the receptor site described above, the adhesive coated film consists of a thin plastic or metal layer and an attached adhesive layer which may include a thermoplastic, hot-melt, UV curing, thermoset, or pressure sensitive adhesive material. Moreover, in the receptor site described above, the sidewalls formed after evaporation of the solvent components and curing or cross-linking of the curable liquid polymer are thicker near the bottom surface of the opening compared to near a top surface of the opening.  
         [0117]     An assembly comprising, a functional block element and, a receptor site opening created by a punched through substrate where one side of the substrate is laminated with an adhesive coated film and the receptor site opening is filled with a curable liquid polymer mixture over the adhesive coated film which forms a bottom surface and sidewalls in the receptor site opening upon evaporating solvent components and curing or cross-linking remainder of the curable liquid polymer. The functional block element contains an electrical circuitry for radio frequency identification tag. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the functional block element. A specific orientation alignment of the functional block element relative to the opening is required for proper fitting. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the functional block element from a top surface of the functional block element. This functional block element, when inverted, remains partially exposed and protrudes above a top surface of the substrate for easy removal. The curable liquid polymer mixture, in the receptor site described above, includes a thermoplastic polymer in a suitable volatile solvent or mixture of volatile solvents, and cross-linkable polymer and cross-linking agent mixture and suitable volatile solvent. Also in the receptor site described above, the adhesive coated film consists of a thin plastic or metal layer and an attached adhesive layer which may include a thermoplastic, hot-melt, UV curing, thermoset, or pressure sensitive adhesive material. Moreover, in the receptor site described above, the sidewalls formed after evaporation of the solvent components and curing or cross-linking of the curable liquid polymer are thicker near the bottom surface of the opening compared to near a top surface of the opening.  
         [0118]     A method of forming a receptor site for a functional block element comprising: punching a hole forming an opening through a template substrate; laminating one side of substrate with an adhesive coated film; filling the opening with a curable liquid polymer mixture with volatile solvent components that will evaporate; and evaporating the volatile solvent components and curing or cross-linking remainder of the curable liquid polymer and formation of a base over the adhesive layer and sidewalls within the opening. The functional block element contains an electrical circuitry for radio frequency identification tag. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the block. A specific orientation alignment of the block relative to the opening is required for proper fitting. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the block from a top surface of the functional block element. This functional block element, when inverted, remains partially exposed and protrudes above a top surface of the substrate for easy removal. In this method, the template substrate includes at least one of polysulfone (PSF), polycarbonate (PC), ply(Ethylene terephthalate) (PET), polystyrene (PS), aluminum foil, copper foil, and other plastic film and metal foils. The adhesive coated film, in this method, includes at least one of polyimide (PI), poly(etherimide)(PEI), polysulfone (PSF), polycarbonate (PC), poly(ethylene terephthalate) (PET), polystyrene (PS), aluminum foil, copper foil, and other plastic film and metal foils coated with an layer of adhesive material which may include a thermoplastic, hot-melt, UV curing, thermoset, and pressure sensitive adhesive. Also in this method, the curable liquid polymer mixture includes at least one of wax in toluene or other volatile non-polar solvent, polystyrene in acetone, UV or heat cross-linking epoxy with acetone, UV or heat cross-linking adhesives such as Norland Optical Adhesive (NOA61), cyanoacrylate based adhesives, polyvinylalcohol PVA with water as volatile solvent, and other liquid polymer and solvent mixtures which shrink by at least 10% in volume upon evaporation of the solvent components and curing or cross-linking remainder of the curable liquid polymer. The method, as described, will result in sidewalls that are thicker near a bottom surface of the opening as compared to near a top surface of the opening.  
         [0119]     A receptor site for a block comprising: an opening with varying depths formed from a substrate with a block receptor site of maximum depth in one part of the opening and an exit ramp in another part immediately adjacent to the block receptor site that rises and extends from one edge of the block receptor site to the opposite edge of the opening. The block is a NanoBlock or functional block element which contains at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the functional block element. A specific orientation alignment of the functional block element relative to the opening is required for proper fitting, and when inverted, this functional block element remains partially exposed and protrudes above a top surface of the substrate for easy removal. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the functional block element from a top surface of the functional block element. In the receptor site as described, the block receptor site has at least one sidewall which angles down and toward the middle of the block receptor site and a sidewall bordering the block receptor site and the exit ramp that is shorter than other sidewalls of the block receptor site. In this receptor site, the exit ramp is recessed sufficiently deep, with a maximum depth of the exit ramp no more than 50% of maximum depth of the receptor site, such that a top surface of an inverted block cannot contact the block receptor site sidewall from which the exit ramp extends. Further, the exit ramp rises gradually in at least two sections with different rising angles from the edge bordering the block receptor site to a top surface of the opposite edge of the opening. Alternatively, the exit ramp rises gradually in one continuous slope or curve from the edge bordering the block receptor site to a top surface of the substrate at the opposite edge of the opening.  
         [0120]     A method for improving filling process of mating blocks to a substrate comprising: moving the substrate with an opening containing a block receptor site and an exit ramp in one direction and traveling up an incline; orienting the exit ramp on the downhill side of the substrate relative to the block receptor site; filling the block receptor sites with the blocks as the substrate is moving; flowing any blocks improperly positioned in the block receptor site over the exit ramp by way of gravity while leaving properly positioned blocks in the block receptor site. The blocks in this method are NanoBlocks or functional block elements each containing at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the functional block element. A specific orientation alignment of the functional block element relative to the opening is required for proper fitting, and when inverted, this functional block element remains partially exposed and protrudes above a top surface of the substrate for easy removal. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the functional block element from a top surface of the functional block element. The filling process in this method is an FSA filling process. In this method, moving the substrate comprises continuous moving the by rolling of the substrate into a roll with assistance of rollers. Also, the substrate in this method can be made of polysulfone (PSF), plycarboneate (PC) or other thermoplastic film. In this method, the opening has varying depths with the block receptor site of maximum depth in one part of the opening and the exit ramp, which is a sliding region, adjacent to the block receptor site rising and extending from one side of the block receptor site to a substrate surface at opposite edge of the opening. Furthermore, the opening can be formed by embossing, molding, and casting of the substrate. This block receptor site has at least one sidewall that angles down and toward the middle of the block receptor site and a sidewall bordering the block receptor site and the exit ramp is shorter than other sidewalls of the block receptor site. Also, the exit ramp is recessed sufficiently deep, with a maximum depth of the exit ramp is no more than 50% of maximum depth of the receptor site, such that a top surface of an inverted block cannot contact the block receptor site sidewall from which the exit ramp extends. Further, the exit ramp can rise gradually in at least two sections with different rising angles from the edge bordering the block receptor site to a top surface of the opposite edge of the opening. Or, alternatively, the exit ramp can rise gradually in one continuous slope or curve from the edge bordering the block receptor site to a top surface of the substrate at the opposite edge of the opening.  
         [0121]     A receptor site for a block comprising: an opening with different depths formed from a substrate with at least tow recesses of different depths locate adjacently side by side in parallel, where a deeper recess is both longer and wider than a shallower recess and forms a block receptor site at a region not bordering the shallower recess. The block is a NanoBlock or functional block element which contains at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the functional block element. A specific orientation alignment of the functional block element relative to the opening is required for proper fitting, and when inverted, this functional block element remains partially exposed and protrudes above a top surface of the substrate for easy removal. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the functional block element from a top surface of the functional block element. In the receptor site as described, all sidewalls of the deeper recess are sloped down and in toward middle of the deeper recess with one sidewall between the deeper recess and the shallower recess shorter than all other sidewalls of the deeper recess. In this configuration, both the shallower recess and the deeper recess each has a different but uniform width along lengthwise of the opening. Further, the shallower recess has a width approximately ranging from at least one-tenth shortest top edge of the block to just shorter than a longest top edge of the block. Also, the deeper recess and the block receptor site both share a common width that approximately ranges between nearly shortest top edge of the block and nearly two times shortest top edge of the block. Still further, the shallower recess has a different but constant depth compared to the same depth shared by the deeper recess and the block receptor site. For another configuration, in the receptor site opening as described above, the shallower recess has one constant depth and the deeper recess has at least two different depths. Here, the deeper recess has two different depths with a deepest recessed region forming a block receptor site on one end of the deeper recess beyond a length of the shallower recess and does not share a common sidewall with the shallower recess. The width of the block receptor site is same as the deeper recess but wider than the shallower recess. In this case where the width of the deeper recess and the block receptor site is the same but wider than the shallower recess, the block receptor site has a depth allowing the block to be flush or within a distance of about 0% to about 30% of thickness of the block from a top surface of the substrate. Also in this similar case, the depth of the deeper recess is less than a depth of the block receptor site but deeper than the depth of the shallower recess. Further still, when the width is the same between the deeper recess and the block receptor site and block receptor site is deeper than the deeper recess which is deeper than the shallower recess, the depths and widths of the block receptor site, the deeper recess, and the shallower recess are each constant along its own length. Back to the limitation when the width of the deeper recess and the block receptor site are the same but wider than the shallower recess, all sidewalls of the block receptor site slope down and in toward a middle of the block receptor site with a sidewall between the block receptor site and the deeper recess that is shorter than other sidewalls of the block receptor site. Further in this case, length of the block receptor site length approximately ranges from about one times to about two times length of longest edge of the block. Also in this case, the length of the shallower recess is approximately between one times to nine times length of longest edge of the block but less than length of the deeper recess. Still further in this case, the length of the deeper recess ranges approximately between two times to ten times length of longest edge of the block.  
         [0122]     A method for improving filling process of mating blocks to a substrate comprising: depositing the blocks using a filling process into the substrate with an opening containing at least two recesses of different depths located adjacently side by side in parallel, where a deeper recess forming a block receptor site is both longer and wider than a shallower recess; removing excess or improperly positioned blocks from the substrate surface and the block receptor site by a device mechanism; sliding remaining blocks lengthwise to a far side of the block receptor site not bordering the shallower recess; removing the remaining blocks from the block receptor site by a device mechanism leaving one block properly positioned in the block receptor site. In this method, the filling process comprises an FSA filling process. Also in this method, the substrate materials may include at least one of polysulfone (PSF), polycarbonate (PC), and other thermoplastic film. Still in this method, the opening of the substrate may be formed by at least one of embossing, molding, and casting of the substrate. The blocks in this method are NanoBlocks or functional block elements each containing at least one of an electrical circuitry for radio frequency identification tag and a functional integrated circuit with a dielectric stack on top. The functional block element to be fitted into the receptor site has a truncated pyramid geometry with parallel top and bottom surfaces that are square or rectangular shaped and where the top surface of the functional block element is larger than the bottom surface of the functional block element. A specific orientation alignment of the functional block element relative to the opening is required for proper fitting, and when inverted, this functional block element remains partially exposed and protrudes above a top surface of the substrate for easy removal. A properly fitted receptor site will have a top surface of the substrate to be approximately within a distance of about 0% to about 30% thickness of the functional block element from a top surface of the functional block element. Returning to the described method, all sidewalls of the deeper recess are sloped down and in toward middle of the deeper recess with one sidewall between the deeper recess and the shallower recess shorter than other sidewalls of the deeper recess. Further, both the shallower recess and the deeper recess each has a different but uniform width along lengthwise of the opening. In this configuration, the shallower recess has a width ranging from one-tenth shortest top edge of the block to just shorter than a longest top edge of the block. Also in this configuration, the deeper recess has a width that ranges approximately between nearly shortest top edge of the block and two times shortest top edge of the block. Still in this configuration, both the shallower recess and the deeper recess each has a different but constant depth. Further still in this configuration, the deeper recess has a depth allowing the block to be flush or within a distance of about 0% to about 30% thickness of the block from a top surface of the substrate. Returning to the described method, the shallower recess has one constant depth and the deeper recess has at least two different depths. Further, the deeper recess has two different depths with a deepest recessed region forming a block receptor site on one end of the deeper recess beyond a length of the shallower recess and does not share a common sidewall with the shallower recess. Still further, all sidewalls of the block receptor site slope downward and in toward middle of the block receptor site with a sidewall between the block receptor site and the deeper recess that is shorter than other sidewalls of the block receptor site. In this configuration, the block receptor site has a depth allowing the block to be flush or within a distance of about 0% to about 30% thickness of the block from a top surface of the substrate. Also in this configuration, width of the block receptor site is same as the deeper recess but wider than the shallower recess. In this case where the width of the deeper recess and the block receptor is the same but wider than the shallower recess, the block receptor site length approximately ranges from about one times to about two times length of longest edge of the block. Further in this case, the length of the shallower recess is approximately between one times to nine times length of longest edge of the block but less than length of deeper recess. Still further in this case, a length of the deeper recess ranges approximately between about two times to about ten times length of longest edge of the block. Back to the configuration referred above, depth and width of the block receptor site, the deeper recess, and the shallower recess are each constant along its length. Further in this new configuration, the depth of the shallowest region of the deeper recess is less than the block receptor site but deeper than a depth of the shallower recess. Back to the described method, the device mechanism comprises at least one of a clearing blade or wiper, a brush, a static or rotating foam roller and any other mechanical clearing device. Similarly in the described method, the removing excess of improperly positioned blocks comprises moving the device mechanism in a direction from the deeper recess to the shallower recess perpendicular to length of the opening. Also in the described method, the sliding remaining blocks comprises using a clearing blade, wiper mechanism, a brush, a static or rotating foam roller, and any other mechanical device along lengthwise direction of the opening from an end where the shallower recess borders the deeper recess to an end occupied only by the block receptor site. Still in the described method, the sliding remaining blocks comprises tilting the substrate at an angle placing the receptor site not bordering the shallower recess downhill using gravity to slide blocks along lengthwise toward the block receptor site from an end where the shallower recess borders the deeper recess. Still further in the described method, the removing excess positioned blocks comprises moving the device mechanism in direction from the shallower recess to the deeper recess perpendicular to length of the opening.  
         [0123]     While exemplary embodiments have been described and shown in the accompanying drawings, it should be noted that such embodiments are merely illustrative in nature and not restrictive of the current invention. It is understood that this invention is not restricted to the specific constructions and arrangements shown and described since modifications may be made by persons ordinarily skilled in the art.