A Novel Method for Embedding Semiconductor Dies within Textile Yarn to Create Electronic Textiles

• Main Authors: Mohamad-Nour Nashed, Dorothy Anne Hardy, Theodore Hughes-Riley, Tilak Dias
• Format: Article
• Language: English
• Published: MDPI AG 2019-01-01
• Series: Fibers
• Subjects: electronics packaging; encapsulation; electronic yarns (E-yarn); textiles; electronic textiles (E-textiles); smart textiles; intelligent textiles; UV curing; polymer resin
• Online Access: https://www.mdpi.com/2079-6439/7/2/12

Electronic yarns (E-yarns) contain electronics fully incorporated into the yarn’s structure prior to textile or garment production. They consist of a conductive core made from a flexible, multi-strand copper wire onto which semiconductor dies or MEMS (microelectromechanical systems) are soldered. The device and solder joints are then encapsulated within a resin micro-pod, which is subsequently surrounded by a textile sheath, which also covers the copper wires. The encapsulation of semiconductor dies or MEMS devices within the resin polymer micro-pod is a critical component of the fabrication process, as the micro-pod protects the dies from mechanical and chemical stresses, and hermetically seals the device, which makes the E-yarn washable. The process of manufacturing E-yarns requires automation to increase production speeds and to ensure consistency of the micro-pod structure. The design and development of a semi-automated encapsulation unit used to fabricate the micro-pods is presented here. The micro-pods were made from a ultra-violet (UV) curable polymer resin. This work details the choice of machinery and methods to create a semi-automated encapsulation system in which incoming dies were detected then covered in resin micro-pods. The system detected incoming 0402 metric package dies with an accuracy of 87 to 98%.