While the "age of the bar code" required close partnerships among retailers, consumer product goods (CPGs) manufacturers and their label suppliers, the "age of EPC Gen 2" requires an even greater level of collaboration with EPC technology suppliers to reap the rewards from Gen 2 deployments.
By examining the design and manufacturing processes behind Gen 2 tag technology, retailers and CPGs can leverage the insight and experience of major RFID players to achieve greater efficiencies in their own supply chain management to bring Gen 2 technology to prime time.
EPC Gen 2 Production Cycles
A Gen 2 smart label consists of several components:
- Semiconductor wafer processed into chips with enough data storage capacity to meet EPC code requirements
- Antenna made of a conductive material that enables the chip to receive and send data to and from an RFID reader
- Substrate on which the antenna can be printed, and to which the chip can be adhered
- Label face stock which covers the RFID inlay and provides a readable print area
Release liner that serves as the bottom "sandwich" layer for the inlay
- Adhesive that attaches the inlay to the face stock, as well as the release liner to the inlay and face stock
The first three components make up the RFID inlay which can require 10-14 weeks to produce. They are delivered in reel form to the label converter who in turn completes steps four through six which can require an additional one to three weeks. These steps mean the production and delivery process can take 15 to 17 weeks. In addition, adjusting production to respond to large increases in demand can take months and may lead to unplanned stock-outs. So, in short, being familiar with the Gen 2 RFID chip, inlay, and label manufacturing processes can help better manage manufacturing and delivery lead times.
The Semiconductor Manufacturing Process
The entire processing flow for the integrated circuit (IC) consists of 20 to 30 patterning steps to define the transistors, interconnects, and overall modules. The Gen 2-compliant IC is manufactured in TI's state-of-art clean room facilities using leading-edge 130 nanometer (nm) process node technologies, which enables smaller, more robust and more power efficient chips in high volumes faster than with older process node technologies.
Once the ICs are ready, the inlay assembly process begins with alignment of the chip bumps, typically 60-100um in diameter, with the printed landing pads on the inlay configuration. Each bump provides a physical electrical connection to the analog and digital circuitry that make up the Gen 2-compliant IC. The bump is mechanically secured with a high-strength epoxy to ensure a good conductive electrical connection.
Products shipped to retailers with EPC Gen 2 tags come in a range of sizes, shapes, materials, and density. These product variations result in corresponding variations in radio frequency properties which can greatly affect the performance of Gen 2 smart labels for products or cartons.
Designing, building, and testing a Gen 2 antenna involves significant time to create an optimal implementation.
To address the variables in the Gen 2 smart label supply chain, inlay providers will likely offer three or more inlays. Technology providers including TI may have to build specific inlay and antenna designs to meet customers' requirements.
The steps involved in manufacturing a wafer of Gen 2 chips and perfecting various antenna designs are complex. The more accurate the information that semiconductor manufacturers and label converters have from end-users about their requirements and forecasts, the better their ability to plan according to market demand.
Inlay Reel and Packaging Design
The next step in the Gen 2 smart label supply chain is the delivery of inlays in reel form to the label converter. It is important that the label converter's existing insertion equipment be configured to receive product in a reel format. Carefully winding the inlays on reels to avoid damage is a critical process in the final steps of inlay production. The quantity per reel must also be precisely calculated so that the weight of the outer inlays does not damage the chips on the inner part of the reel.
To create a final RFID label, a label converter takes a flexible RFID inlay containing an IC and an etched metal or printed RFID antenna, and inserts it between the face sheet and liner of a label. After testing, inlays are then attached to the adhesive that covers the back side of the pressure sensitive face sheet. After inserting the inlay, the liner is reunited with the face sheet, and die cut to the desired label dimensions.
The final stage in the Gen 2 smart label supply chain is the appropriate placement of the inlay in the label. This is important because it will determine what type of printer the end customer will need to print their labels. Because CPGs and other manufacturers have a variety of products to tag, they will likely require different types of labels.
The ordering, manufacturing, and inventory of Gen 2 smart labels are more complex than for standard, bar code-printable adhesive labels. Label converters make a wide variety of labels available across a diverse customer base, and the challenge is to efficiently manage in-stock supplies. Today, many label converters provide testing facilities and services to ensure that EPC labels will be appropriately matched for use with product stock keeping units (SKUs).
With the level of variation and complexity in the Gen 2 smart label supply chain, the supply chain requires intentional, informed, and innovative process development among all its members. The more that the semiconductor manufacturer, the label converter, and the end customer can communicate true demand, the more successful each player can be in their quest to meet customers' needs cost-effectively and efficiently.