Aliens land in Paris
20 Dec 2001
Last month, at the 'Cartes Show' in Paris, the German-based Giesecke & Devrient (G&D) demonstrated smart cards with built in flexible plastic displays.
The cards can show the monetary value stored in the card as well as the last 15 transactions that have been carried out. To the consumer, the card simply looks like standard smart card with the addition of a display, pushbutton and internal battery.
The technology behind the new card was developed by Alien Technology, a company which has developed, and holds exclusive patent rights to, 'Fluidic Self-Assembly' (FSA), a technique that permits the efficient assembly of ICs into a variety of substrates, from glass to flexible plastic.
The Fluidic Self Assembly (FSA) technique can solve many problems that designers have faced when attempting to integrate displays onto smart cards. Not the least is that it can be used to integrate the display itself with the electronic assembly containing the controller and driver ICs.
In the FSA process, specifically shaped semiconductor devices ranging in size from 10 microns to several hundred microns are suspended in liquid and flowed over a surface, which has correspondingly shaped 'holes' or receptors on it and into which the devices settle.
The shape of the devices and the holes are designed so that the devices fall easily into place and self-align. Alien has demonstrated the assembly of tens of thousands of devices in a single process step.
Because the FSA process can also be used with roll-to-roll 'continuous Web' manufacturing, displays can be produced on continuous rolls in a facility costing one-tenth as much as that of a similar batch processing line.
That has the added benefit that displays produced on an FSA/web process typically costs less than half than those produced in conventional glass LCD factories.
