Fraunhofer Institute for Reliability and Microintegration IZM
Fraunhofer Institute for Reliability and Microintegration IZM

Process and Product Development

NCA-Bonding interconnection process for E-Textiles

© Fraunhofer IZM
Electronic textiles technologies
© Fraunhofer IZM

Interconnecting textiles and electronics: A new approach

Many E-Textile applications – like systems to monitor vital signs or log ergonomic data, heating pads, lighting, or innovative human-machine-interfaces – require sensors and electronic components integrated into the fabric itself. This combination of electrical components and soft textile materials and the resulting requirements concerning comfort, washability, design, reliability, or signal stability makes the integration process a complex challenge. Interconnecting electronic modules is especially demanding. When it comes to dynamic mechanical stability, reliable contact resistance, or sufficient washability, conventional e-textile contacting methods – snap fasteners, crimping, soldering, embroidering, conductive adhesive, or sewing – often do not lead to satisfying results. The E-Textile bonding technology developed at Fraunhofer IZM solves these issues by contacting electronic modules to textile circuits mechanically and electrically in one single step. The resulting interconnections exhibit outstanding reliability under cyclical temperature and humidity strains as well as excellent washability.

E-Textile Bonding: A universal interconnection technology

Using E-Textile bonding, you can:

  • Achieve mechanical and electrical interconnections in one single step
  • Contact directly onto insulated wires
  • Contact PCB, flexible PCBs, and even SCBs
  • Contact modules onto a wide range of textile circuits, including woven, knitted, embroidered, printed, and textile-based circuits
  • Achieve high I/O counts in one step

Compared to other established technologies, E-Textile bonding:

  • Needs no flux or underfiller
  • Needs no conductive adhesives or particles
  • Uses only inexpensive adhesives
  • Allows for recycling and repair due to the use of thermoplastic adhesives
  • Achieves higher mechanical stability by contact pads located on the bottom side of the modules, avoiding peel forces

E-Textile Bonder

Developed at the Fraunhofer IZM for the practical application of its bonding process, the E-Textile bonder is capable of processing a wide range of fabrics at sizes of up to one square meter and bonding electronic modules of up to 50 mm by 50 mm. An optical alignment system and proprietary software allow high precision assembly. The bonder’s compatibility with standard machine embroidery hoops makes it easy to incorporate e-textile bonding into textile processing chains. The upper and lower bonding heads can be controlled individually, and the bonding pressure and temperature can be programmed in ramps according to the requirements of the bonded materials.  

Service offer

  • Assembly of electronic modules on textiles
  • Demonstrator and prototype development
  • Custom miniaturized electronics solutions (rigid / flex / stretch)
  • E-textiles circuits development (embroidery, knitting, ribbons, stretchable TPU foils)
  • Reliability testing and failure analysis tailored to e-textiles
  • Joint development of new e-textile machinery
  • Licensing and technology transfer