Radio frequency identification (RFID) tags are poised to replace barcodes as the tags of choice, but the replacement has been slow because of the inability to bring tag cost down to 5 cent (US). While silicon die costs have been lowered via die reduction, assembly cost for small dies need to be lowered concomitantly. Although large-scale low cost tag assembly solutions have been developed, they are not suited for adoption by conventional packaging house because of their high capital investment. In this thesis, a low cost hybrid self-alignment die assembly method suited for evolutionary migration was developed. In this approach, small dies are firstly placed onto the substrate using low cost robotic pick and place and fine self-align to nanometer accuracy using low surface tension adhesi...[ Read more ]

Radio frequency identification (RFID) tags are poised to replace barcodes as the tags of choice, but the replacement has been slow because of the inability to bring tag cost down to 5 cent (US). While silicon die costs have been lowered via die reduction, assembly cost for small dies need to be lowered concomitantly. Although large-scale low cost tag assembly solutions have been developed, they are not suited for adoption by conventional packaging house because of their high capital investment. In this thesis, a low cost hybrid self-alignment die assembly method suited for evolutionary migration was developed. In this approach, small dies are firstly placed onto the substrate using low cost robotic pick and place and fine self-align to nanometer accuracy using low surface tension adhesive. Design guidelines on the usage of adhesive liquid volume and oversized binding sites were developed. Tag antenna manufacturing is another major cost factor. Coil antennas fabricated by printing conductive ink on plastic substrates are recognized to be lower in assembly cost, but are lower in tag readability and read range reproducibility. The effects of material, antenna line geometry, and tag configuration on read range were examined in this study. Tag design and selection criteria that can compensate for bent tag on cylindrical bottles or soft packages were developed. Experimental characterization of the tag behavior revealed the presence of an antenna geometry-independent read range plateau. Tags designed to function in the plateau regime enable the use of low precision high volume printing techniques as fabrication processes to lower tag fabrication cost, without sacrificing read range consistency. Tag performance can be further increased using thick-lined printed antennas and line compaction to reduce line resistance. Tags fabricated using these new developed design and fabrication methods were shown to have read ranges comparable to tags with metal wire antennas.

Innovations on self-alignment die assembly and printed coil design made the production scaling to high volume and low cost possible. The die assembly cost can potentially be brought down to 0.25 cent (US) using hybrid self-alignment at high volume. The printed antenna cost, with the compaction process, can be reduced down to 1 cent (US). Using this new compacted printed antenna designed according to the developed design guidelines and the demonstrated hybrid die assembly technique developed in this thesis, the total manufacturing cost of a tag is estimated to be 2.49 cent (US). The tag cost is below the 5 cent (US) threshold tag cost such that the developed technologies can be adopted as a low cost foundation for wide adoption of RFID in the marketplace.