Walki Launches Service Using Lasers to Make Tag Antennas

Apr 16, 2012Finnish packaging goods firm Walki (pronounced val-i-kee) has commercially released a service that manufactures passive ultrahigh-frequency (UHF) RFID tag antennas, by means of its patented Walki-4E technology—a process that employs a laser to cut away parts of an aluminum-paper laminate in order to create a tag antenna. The company does not design antennas itself, but produces them to order, according to its customers' designs, with the antennas measuring anywhere from 6 microns to 50 microns (0.0002 inch to 0.002 inch) in thickness

The Walki-4E process is intended to enable tag manufacturing that is less expensive and more flexible than that of traditional tag antennas, which involves an etching method utilizing wet chemicals. The Walki-4E UHF Pantenna is the company's first RFID antenna-manufacturing service.

By using lamination and laser patterning on aluminum rather than traditional etching to create the antennas, the firm can offer greater flexibility in antenna designs, faster production speed (since the antennas can be produced ten times faster than traditional antennas) and lower cost, according to Sami Liponkoski, Walki Group's business line manager of 4E technology. Liponkoski described the technology at this year's RFID Journal LIVE! conference and exhibition, held in Orlando, Fla., earlier this month.

The Walki Group has been making packaging materials for several decades, including laminates, paper and packaging, for such products as frozen foods. Last month, it launched its 4E antenna-manufacturing service.

RFID antennas are typically produced using a wet chemical process that includes the etching of aluminum or copper. The etching procedure, however, can make the process slower than the Walki-4E method that uses pattern lamination and laser cutting; according to Liponkoski, it is 10 times faster than etching. Walki employs a laminate of aluminum and paper substrate, then cuts patterns into the aluminum via a laser, after which the aluminum residue is recycled.

The name 4E, Liponkoski explained, is derived from the four intended benefits of the company's antenna-making process: economy, ecology, exactness and efficiency. The antennas—which could be paired with passive UHF RFID chips to produce a variety of tags—would be less expensive than traditional tags, due to the use of materials that cost less than those required for etching, as well as a simpler design and production, since that process can be performed on a computer. In addition, the antenna's paper substrate can serve as the tag's substrate, thereby simplifying tag manufacture.

The Pantenna antennas are also more ecologically sustainable, Liponkoski said, since no chemicals are necessary to make them, and because the aluminum removed during the manufacturing process can be recycled. Referring to an expected growth in UHF tag production, Liponkoski asked the audience: "Three billion tags are made in a year. What will happen in five years?" Such tags, he suggested, could have a negative environmental impact using the existing manufacturing method.

The exactness, Liponkoski said, comes from the laser patterning, which makes it possible to cut an extremely accurate and small pattern for the antenna.

Additionally, the company can create an antenna directly onto a product, by embedding the 4E antenna into an item's packaging, such as a book's cover, or the surface of a transit ticket. The digital process, Liponkoski noted, enables the firm to make antennas to order, in a much shorter timeframe than would be needed for etched antennas.

Walki's primary customers for its Pantenna RFID antennas are manufacturers of tags, inlays and smart cards for such applications as adhesive labels, hangtags or transit tickets. Though the Pantenna process utilizes paper as the antenna's substrate, the company's customers can choose a variety of other materials, such as fabric, for the substrate. Walki then creates the antenna to order and provides it to its customer, which can then add the chip and convert it into an inlay or label.

What's more, Walki can advise customers regarding injection-molding techniques, in which an antenna or a tag could be embedded into a plastic object, such as a hard tag or tote. "We can add properties such as thermal sealing or hot stamping in the substrate," Liponkoski stated, "if it is required for embedding the antennas in a tag product."

In addition, Liponkoski said, by using a computer to design and laser-print the antennas, Walki "can offer high flexibility in antenna positioning." He added that the "improved accuracy will allow for smaller ICs used—small IC usually converts to lower IC cost."

The company—which began offering the Pantenna service last month—has a single production line in operation at the Finland facility, Liponkoski reported, with a monthly capacity of up to 10 million antennas. He said he expects his firm to increase its annual production capacity to approximately two billion tags by 2013.

Although the Pantenna antennas are intended for UHF tags, the company also plans to offer Walki-4E-based antenna-making services for high-frequency (HF) or active tags operating at up to 5.8 GHz. According to Liponkoski, the product launch for other antennas, such as those used with active tags, is expected to take place soon.