ITEC brings semiconductor manufacturing to RFID tag production
Martijn Zwegers, product director, joined ITEC at the end of 2022 to take on responsibility for the company’s high tech die-attach machines, including the Tagliner for RFID inlays. He has worked in the semiconductor industry for nearly 20 years, holding positions with major manufacturers of equipment for the back-end semiconductor industry.
Industry forecasters, such as IDTechEx, are predicting double-digit year-on-year growth for RFID tags and labels. Barcodes are virtually free, though. So why are people moving to RFID as an alternative? There must be commercial benefits. Like barcodes, RFID tags identify objects for tracking by transmitting data to a reader. RFID tags normally hold data like date and item and batch references.
“RFID tags … don’t need to be within line of sight of a reader and don’t need people to physically scan the items.”
RFID tags have unique benefits. They don’t need to be within line of sight of a reader and don’t need people to physically scan the items. Although barcode readers are easy to set up, and very reliable, RFID readers can scan 100 or more items simultaneously. The data on RFID tags are more durable and secure than barcodes, with data encryption also possible. They are also more versatile, and for example can be embedded into cards.
Compared to other semiconductors, though, RFID tag manufacturing is still at an infant stage. To compete with barcodes, the tags must be produced more cost effectively than now.
Slow glue curing processes limit traditional die bonder throughput
There’s a lot of interest in RFID from the paper conversion industry, where traditional RFID die bonders dominate. These are relatively slow, largely because of the low-temperature glue curing process used in the industry. It is strong enough, but takes more than a second to cure.
That needs a massively parallel operation (> 100 thermodes) for any sort of throughput. It in turn means many more moving parts, which particularly reduces throughput for short product runs if the thermodes need adjusting. It also affects reliability, and demands more frequent maintenance because there is much more to go wrong.
And, traditional die bonders don’t have the accuracy and repeatability you need for reliable > 99.5% yields with small dies and small feature sizes.
Bringing semiconductor manufacturing benefits to RFID Tag Making
Some years ago, we had a request to develop a die bonder to bring down production costs. We were interested because RFID tags are fundamentally a semiconductor technology and we have over 30 years’ semiconductor experience. We have installed thousands of similar high-volume chip-attach systems in other markets.
Process control in the semiconductor industry is much more advanced, with years of quality and productivity improvements. Transferring this to the RFID industry is a breakthrough, and Tagliner is the market’s most advanced machine.
“Ease of operation and short set-up time, high capacity and precise positioning of the chip attachment are the key features we value in the Tagliner.”
- ITEC customer
It’s performance is unique within the industry. The Tagliner machine produces 48,000 units per hour with positional and rotational accuracies an unrivaled <9 microns and 0.67º at 1 sigma. That is three times faster and 30% more accurate than anything else on the market. It already accurately places dies down to 200 microns, and will in future go smaller. Tagliner is more versatile, easier to use, adjust and maintain than traditional RFID die bonders. A lot of features are mandatory in the semiconductor industry, so are natural to ITEC but are a huge step up for other manufacturers.
The Tagliner can handle 8 and 12 inch wafers and features automatic wafer change as standard. That means you can load 10 wafers into the cassette, with each wafer carrying typically more than 250,000 dies. At 48,000 units per hour, that takes five hours to consume, and the machine automatically changes the wafer when empty.
Simple single-track design makes for easy operation. Rather than 100+ thermodes there are just two. High-speed servo-controlled thermo compression curing gives precise control of impact, force and height, with a curing time of just 65 milliseconds – a fraction of that needed by traditional machines – resulting in industry-leading throughput times.
Fast and easy setup reduces conversion times to change the product line, which is critical for short product runs and contract manufacture. And our transport system maintains its throughput independent of the pitch between labels. For traditional machines it quickly drops when the pitch between labels gets bigger, down to 20% for large-pitch labels.
Cameras inspect every stage of the process
Semiconductor chips for automotive and other equally demanding industries cannot tolerate failing devices. We sell into those markets and so use camera inspection before and after each process step. These are placed in such a way that the Tagliner can work with transparent substrates like PET and also opaque materials such as paper.
We continually collect statistics on accuracy and other key parameters, so we know exactly how every die is placed, and its position and rotation. Rotational accuracy is especially important. A slight rotation of the die on the antenna can mean that none of the contacts are good and you could be producing a whole series of dead tags. That will get more critical as the dies get smaller.
There’s corrective feedback when the camera detects that the dies are about to go out of alignment or limit, to realign or reject a part if necessary. We can filter out visual defects, and even detect difficult microscopic defects and cracks.
“Tagliner has the industry’s lowest Total Cost of Ownership, which is key in an extremely price sensitive market.”
Our yields are consistently above 99.5% when using good quality materials. The process is fully qualified for major chip suppliers at the industry’s tightest temperature, humidity and mechanical reliability requirements. Tagliner has by a considerable margin the industry’s lowest Total Cost of Ownership, which is key in an extremely price sensitive market.
We have found companies to be particularly receptive to the new machine, which brings a lot of benefits from the semiconductor industry. We have won some impressive machine placements already including tags for a major retailer’s products, metro tickets, and luggage labels for major airlines. Others are evaluating the machine for automotive labels, access control, shipping containers and more.
We have impressive demo machines assembling tags in Nijmegen and the Technology Park in Hong Kong. We run samples for customers there or invite them to run the samples with us and experience the machine.
Figure 1: Substrate material with aluminum foil is etched (subtractive) or a foil is printed (additive) to form the antenna. The RF semiconductor die from the chip maker is then glued to the substrate.
A semiconductor roadmap
Because Tagliner is modular we can also offer in-situ lifetime machine upgrades, so machines do not become obsolete. That future-proofs investment. And talking of the future, we plan to upgrade to higher machine throughputs, for example, and to accommodate smaller chip sizes – while traditional equipment suppliers are already struggling with 200 microns. Advances like these will help us to match the Tagliner’s productivity to the peaks of the semiconductor market.
Marketing Communication Manager