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Printed Intelligent NFC Game cards and packaging

Periodic Reporting for period 1 - PING (Printed Intelligent NFC Game cards and packaging)

Reporting period: 2015-01-01 to 2016-06-30

The emerging technology breakthrough of the Internet-of-Things is expected to offer promising solutions for packaging and interactive entertainment. The PING project anticipates on this evolution and aims to develop flexible, fully integrated metal-oxide Near Field Communication (NFC) tags seamlessly embedded in folded carton packaging and game cards. This will introduce NFC technology at lower cost and without substantial changes to product dimensions and mechanical characteristics. Moreover, one-time programmable memory (PROM) will enable additional functionality. More specifically the objectives of the PING project are as follows:
• Development of a Process Design Kit (PDK) for automated design of complex integrated circuits in scalable metal-oxide technology and compatible with standard simulation tools
• Advancing the design of complex NFC circuitry with enhanced performance and functionality using the developed PDK
• Implementation of scalable manufacturing processes to realize flexible, metal-oxide NFC circuitry
• Evaluation of suitable antenna manufacturing processes and chip bonding technologies
• Demonstration of flexible, fully integrated metal-oxide NFC tags in the existing products of two end-users scalable to high-volume markets
During the first period of the project, significant progress has been made in the development of the design platform and the design of NFC building blocks as well as in antenna printing technology, memory processes, singulation and chip bonding technology and product integration.
Early in the project, application, system and technology specifications were defined. Focusing on the market needs and exploitation of CM and VGP, 5 priority use cases were defined. These were used as basis to define the requirements for system and protocols as well as technology. Each variant is anticipated to include a Tag Talks Only (TTO) tag operating at 13.56MHz with a pre-programmed individual identification code.
A 'Process Design Kit' based on PP’s metal-oxide TFT technology was successfully created. Device models, a Design Rule Manual and a Design Rule Check file were developed. Using this PDK a first mask-set has been designed, including digital test blocks (inverters, NAND gates, NOR gates) as well as the test structures for the relevant analog building blocks (rectifiers, load modulators and clock recovery) necessary for each of the final circuit demonstrators.
Complete PING12 digital blocks, along with successful operation of all analog front end blocks has been demonstrated. This includes the successful clock division of a 13.56MHz carrier signal to 3.39MHz (divide by 4) in a flexIC. This proof assuages one of the key risk factors in the project, proving that the required performance level is achievable in this technology. A first version of a complete NFC circuit is completed. This prototype has been demonstrated on-wafer to be functional in initial tests at PP, providing the correct code output via load modulation of a 13.56MHz carrier signal.
In addition, different memory process technologies as well as different memory design variations have been evaluated during the first period of the project. Laser ablation has been selected as the preferred approach to program the memory. Using this technology, first state-of-the-art PROM memory elements based on unipolar n-type IGZO technology have been realized. Two different implementations were evaluated: a 3-bit NOR gate based on diode-load topologies and an 8-bit NOR gate based on pseudo-CMOS topologies. Both cases are functional and promising for the 128-bit arrays, which have been designed and will be realized in the coming period.
Prototypes of printed antennas were designed and realized. Additionally, effort was spent in evaluating conductive inks and certified papers with focus on their possible use within the PING project. A comparison of additive technologies with etching and laser cut technologies has demonstrated the benefit of printed antennas within PING. Initial performance, environmental and reliability tests have been performed with good results.
During the first period of the project, also quite some work has already been done towards system integration. An inventory of technical options for dicing and foil release has been explored and the preferred methods have been identified. Investigation of the chip to the antenna bonding has been started. Based on technical inputs of the flex-IC, several antennas layouts have been designed. So far 3 to 9 Ω joint resistance was measured. Further optimizations are needed and are foreseen in the first half of the second period. Development work towards integration into finished products is done on two parallel tracks to cover a broad range of options. A first track focuses on thin paper substrates, more adapted to card products, whereas a second track focuses on thick paper/cardboard substrates, used for packaging products.
The concept of integrating an electronic layer between pre-printed paper layers is completely new in the industry of paper cards and boxes. The potential impact in the printing industry is huge. It merges all the possibilities of different printing techniques (offset, screen, digital …) with electronics, without interfering with the core manufacturing processes. This means large quantities (offset) , very small quantities (digital), unique products (digital), specialty printed products (screenprint) can be foreseen with NFC inside, in a very cost effective way because the inlay gets inside late in the process, avoiding expensive electronics got wasted during print make-readies. Although we are still early stage with respect to the integration of the electronics inside the finished products, manual tests have already proven feasibility of embedding thin film electronics inside pre-printed paper layers. Achieved Thickness, stiffness, look and feel, materials are beyond state of the art.
With respect to circuitry, a state-of-the-art PDK for TFT logic on plastic foil and a state-of-the-art 12-bit metal-oxide RFID chip on flexible film have been realized. The published chip advances state-of-the-art in power x delay, as the obtained state-of-the-art data rates are 5.5x improved compared to previous publications while maintaining similar power figures. The data rates are now proven to be compatible to all NFC standards, from ISO 15693, to Sony FeliCa and ISO 14443, which is a big advancement in the field of metal-oxide RFID/NFC tags.
It is however not sufficient to reach the data rate levels, in contrary, it is necessary to generate the exact data rate of 106kb/s for ISO 14443 to enable true smartphone readout and compatibility. This implies the necessity of on-chip direct clock recovery circuits from 13.56MHz carrier to 106kHz. Successful division by four in the technology of PP has been demonstrated. This is truly an advancement beyond state-of-the-art. It will result in a true game changer for the field when, in next period, the full division circuit can be used as clock in the RFID/NFC tags. As such, smartphones will become the reader device for low-cost metal-oxide NFC tags. This will pave the way for other use cases beyond the PING project.
The PING flexIC will provides at least three basic improvements with regard to the state of the art. The chip will have a thickness < 25 µm, whereas the currently available silicon chips have an average thickness between 75 µm and 120 µm. Embedding of a passe-partout will be disregarded, resulting in a simplified manufacturing process. The flexibility of the chip additionally supports the mechanical characteristics like bending properties of a playing card.

First additive antenna structures printed on paper and initial test runs to integrated inlays between two paper sheets were successfully demonstrated. Using silver inks including nanoparticles, low-cost manufacturing of printed antenna structures has been enabled. This provides potential new applications which have not been feasible to date.