May 06, 2014For end users and solution providers of radio frequency identification, the price per tag for passive EPC Gen 2 ultrahigh-frequency (UHF) RFID labels can be key to making a project affordable. Two companies releasing new products to enable the production of lower-cost tags are German adhesives firm DELO Industrial Adhesives (which provides the glue that affixes an antenna and a chip to an inlay during the application, bonding and curing processes) and Mühlbauer (which makes the machinery to manufacture those tags, including the adhesive's injection into the inlay). DELO showcased its latest adhesives product at the RFID Journal LIVE! 2014 conference and exhibition, held last month in Orlando, Fla.
DELO and Mühlbauer work closely with tag manufacturers, enabling them to produce cost-efficient labels, on demand, with equipment that can produce those tags, using adhesives that enable such production. DELO has the largest share of the RFID label adhesives market, and has been modifying its product so that tags can be made more inexpensively.
"Most of our changes have been around enabling a lower-cost tag," says Jens Amarell, DELO's RFID product manager. Tags need to have less material and be produced faster, he explains, and the chips themselves are smaller. Thus, he says, bonding to an antenna—and still providing conductivity for electrical signals—becomes even more challenging.
"In terms of adhesives, it's been quite a task for us," Amarell says. "The chips have become so small that they are only 400 by 400 micrometers [0.016 inch by 0.016 inch]. That's basically nothing, but they need to be bonded to the antenna reliably and still need to conduct the electrical signals."
In addition, the tags must be produced quickly. When a thermode (currently the curing instrument of choice for mass production) is used, the adhesive takes eight seconds at 180 degrees Celsius (356 degrees Fahrenheit) to cure, or to reach full strength. This represents a considerable reduction in time, Amarell says, compared with earlier adhesives, which typically required a few minutes under heat to reach full strength.
DELO offers a jetting system for the application of adhesives that makes the dispensing process fast and accurate. The first tag-production machines that enabled the jetting of adhesives entered the market approximately five years ago. Since then, Amarell says , jetting has become more important, with more than two-thirds of all new machines currently using this process.
Jetting offers several advantages, Amarell reports: It is faster and more precise, and smaller amounts of adhesive can be dispensed. By enabling miniaturization and higher production speeds, he explains, jetting helps to reduce costs.
"We developed our first jettable adhesive back in 2008," Amarell states. "We have been continuously improving our products ever since." The latest product, the DELOMONOPOX AC245, was released ahead of LIVE! 2014. According to Amarell, it combines the highest level of jetting performance of all DELO products to date, with high reliability in all 85 tests in which the tags are exposed to 85 degrees Celsius (185 degrees Fahrenheit) and 85 percent humidity for 1,000 hours.
Chips are now bonded to antenna substrates at a rate of 20,000 per hour, Amarell says—the fastest rate yet achieved by the most sophisticated machines. "One vision… is a capacity of 100,000 labels per hour in the long-term," he adds, "Obviously, this volume requires the development of complete new concepts, new material and new processes."
DELO has also continued improving the adhesive material itself, in order to achieve high reliability and jetting capabilities, though Amarell says the details are proprietary. "As chips are becoming ever smaller and various substrates are used," he states, "we think that our focus on epoxy-based adhesives was the right one, as it allowed us to quickly adapt to these changes." Epoxies, he notes, adhere to a broad range of substrates, from paper to high-end plastics—such as polyimide—and can withstand humidity and cure quickly.
Another trend affecting the adhesives market, Amarell says, is the need for more flexible RFID labels. With the shrinkage of chips in terms of both footprint and thickness, the chips have become more fragile. This becomes an issue when converting RFID inlays to labels, he says, but can also be a problem throughout the lifetime of a tag that might be bended or folded by end users. "Our current R&D efforts focus on adhesives that find answers to these upcoming challenges," he reports.
Mühlbauer, which manufactures machines that can produce inlays and labels at such high speeds, has also innovated with its equipment to ensure that the products it provides can offer fast tag production using changing materials in often very small sizes. Mühlbauer and DELO frequently work together to provide the solution that their customers, such as inlay manufacturer Smartrac, use to produce their own products.
Continuously reducing production costs without impacting production quality is the greatest challenge facing Mühlbauer and its equipment portfolio, according to Thomas Betz, a member of the company's management board. There is a demand to constantly strive for the lowest rate of non-working tags (the standard for Mühlbauer's equipment is that at least 99.5 percent of all tags produced must be capable of being read properly), and daily outputs in mass-production are as high as the equipment can produce the tags.
To reduce tag-manufacturing costs and shorten the lead time required to create specially ordered inlays and labels, Mühlbauer has developed completely new systems in recent years. For instance, the company's Antenna Production System enables customers to print tag antennas in-house. This, Betz explains, allows a tag manufacture to provide "an unmatched print-on-demand flexibility with fastest possible customer service."
As another low-cost solution for new entries and startups in the RFID market, Mühlbauer has released what it calls the Light Series. These lower-volume machines cost less than the high-volume versions, the company reports, and are designed for quick changeover times for short label runs, thereby enabling users to react quickly to market demands.
In addition, Mühlbauer brings to market a new inlay-production system that employs a new technology known as Direct Die Attach (DDA), which Mühlbauer developed and has already submitted for patent. The DDA is designed to dramatically reduce an RFID inlay's production cost, by producing up to 20,000 units per hour, thereby drastically lowering the cost of a produced RFID inlay.
This spring, Mühlbauer plans to release two new Personalization Systems—known as PL 30000 and PL 60000—as well as a single-tag handling system known as PL Light. The PL 30000 version works with all common chip types available on the market, providing what it claims is the highest flexibility in the production of personalized RFID labels. A special feature in PL equipment involves the removal of labels and tags that failed read tests during production. The PL 30000 and PL 60000 solutions provide chip encoding and print personalization, while the PL 60000 also incorporates Impinj's STP Source Tagging platform (see Impinj Launches Products to Speed Item-Level Encoding).
