There are many examples of functional blocks or components that can provide, produce, or detect electromagnetic or electronic signals or other characteristics. The functional blocks are typically objects, microstructures, or microelements with integrated circuits built therein or thereon. These functional blocks have many applications and uses. The functional components can be an array of display drivers in a display where many pixels or sub-pixels are formed with an array of electronic elements. For example, an active matrix liquid crystal display includes an array of pixels or sub-pixels which are fabricated using amorphous silicon or polysilicon circuit elements. Additionally, a billboard display or a signage display such as store displays and airport signs are also among the many electronic devices employing these functional components.
Functional components have also been used to make other electronic devices. One example of such use is that of a radio frequency (RF) identification tag (RFID tag) which contains a functional block or several blocks each having a necessary circuit element. Information is recorded into these blocks, which can be remotely communicated to a base station. Typically, in response to a coded RF signal received from the base station, the RFID tag reflects and/or modulates the incident RF carrier back to the base station thereby transferring the information. Such RFID tags are being incorporated into many commercial items for tracking and authenticating.
Systems for remote identification of objects are being used for many purposes, such as identifying items or objects in warehouses, retailer outlets, stores, dealerships, parking lots, airports, train stations and/or at any particular location. Such systems use Radio Frequency (RF) signals to communicate information between an RF reader apparatus and an RF transponder attached to the item or the object. RF transponders and readers are also sometimes referred to as RF Identification (RFID) tags and interrogators, respectively. The RF transponder includes a memory component that can store particular information, such as price, product identification, item serial number, and product information about the object or the item.
Each RFID tag has an individual code containing information related to and identifying the associated object/item. In a typical system, the RF reader sends an RF signal to the remote RFID tag. The antenna in the RFID tag receives the signal from the RF reader, backscatter-modulates the received signal with data temporarily or permanently stored in the RFID tag (such as data indicating the identity prices, (and/or contents of the object/item to which the transponder is attached), produces a sequence of signals in accordance with the transponder's individual code, and reflects this modulated signal back to the RF reader to pass the information contained in the RFID tag to the RF reader. The RF reader decodes these signals to obtain the information from the RFID tag. Likewise, the RFID tag may decode signals received from the reader and write information to the transponder's memory.
RFID tags and labels have a combination of antennas and analog and/or digital electronics, which may include for example communications electronics, data memory, and control logic. Some systems include both “read” and “write” functions; thus, the RF reader can read information previously stored in the RFID tag's memory and the RF transponder can also write new information into the memory in response to signals from the RF reader. In the passive tags, in order to retrieve the information from the chip, a base station or reader sends an excitation signal to the RFID tag or label. The excitation signal energizes the tag or label, and the RFID circuitry transmits the stored information back to the reader. The reader receives and decodes the information from the RFID tag. In general, RFID tags can retain and transmit enough information to uniquely identify individuals, packages, inventory and the like.
RFID tags and labels are widely used to associate an object with an identification code. For example, RFID tags are used in conjunction with security-locks in cars, luggage, and machine, for access control to buildings, and for tracking inventory and parcels. RFID tags are thus used in identifying or inventorying an item or object in a warehouse, retailer outlet, store, dealership, parking lot, airport, train station and/or at any particular location.
It is desirable to reduce the size of the electronics in an RFID tag to be as small as possible. In order to interconnect very small RFID chips with antennas to form RFID tags, straps (sometimes referred to as “interposers” or carriers) with the RFID chips formed therein or thereon are used to connect the RFID chips to the antennas. The straps typically include conductive leads or pads (also sometimes referred to as pad conductors) that are electrically coupled to contact pads of the chips. These pads provide a larger effective electrical contact area than the RFID chips and alleviate some stringent alignment requirement when the straps are coupled to the antennas. The larger area provided by the pads reduces the accuracy required for placement of chips during manufacture while still providing effective electrical connection. Currently, methods or structures of connecting the RFID chips to antennas still involve mechanical or physical interconnection between the straps (hence the chips) and the antennas and thus, some alignments are still required. Furthermore, it is required that the antenna assemblies and the strap assemblies be aligned to one another (strap pad conductors to antenna pads) for the completion of the RFID tags.
As demand for less expensive RFID tags increases, it is desirable to develop ways to manufacture and create RFID tags that involve simple and less expensive assembly.