Packaging and wired interconnections for insertion of miniaturized chips in smart fabrics

Electronic devices are currently used in a complete system including mobile phone, television etc... Now, more and more applications need functionality as close as possible to the final system for in situ measurement and control (smart textile, automotive or medical applications) or for security. The components concerned are sensors, light emitting diodes or RFID for example. Concerning microsystem, being integrated in a material means several key properties, including a packaging form adapted to the material manufacturing process, autonomy in terms of energy means for being powered, neutrality versus the initial material properties and resilience, as materials usually get post-processed once manufactured. A particularly attractive support for such integration is the textile way, since textile or textile-like materials are often part of composite materials and are extremely common in the design of complex objects. The "Diabolo" process aims at a direct connection from a chip assembly to external wires without using the traditional bonding / packaging stage. Through a very limited set of wafer scale operations, one or several chip dies can be assembled and connected to conductive wires directly from the chip surface. The result of a fully processed Diabolo assembly is a spool of chips connected to a flexible wire that can be used for incorporation into materials through taping, weaving, knitting, extrusion or more generally inclusion in a liquid phase before curing. The process is still in its early stage of development but our current studies make us confident that assembly throughput as high as 10 k UPH (Unit per Hour) can be reached with a relatively simple equipment.