(A) study on Flex-on-Fabric (FOF) Interconnection Using Anisotropic Conductive Films (ACFs) and Ultrasonic Bonding Method

Abstract

As wearable electronics for health care become important topic, a lot of researchers have tried to combine electronics with clothing. Accordingly, advanced interconnection methods between conductive fabric and flexible substrate are required as well. Anisotropic conductive film (ACF) is the electrical interconnection adhesive film which consists of polymer adhesive resins and conductive particles. However, interconnection between conductive fabric and flexible substrate using ACFs has lots of difficulties because of some fabrics’ unique properties. First, fabric is porous material that makes resins flow into pores. It reduces adhesion between fabric and flexible substrate. Secondly, fabric can be damaged under the high temperature and pressure for bonding. Thirdly, fabric can shrink after the reliability test. Above these factors, there are lots of other factors that affect durability of interconnection. In this paper, we propose suitable interconnection methods using diverse ACFs for 2 different types of conductive fabrics respectively. There are several variations that affect property of ACFs. For example, resin viscosity, structure of Flex-on-Fabric (FOF), and so on. We analyzed characteristics of 2 different fabrics and optimized ACFs for each fabric. This paper establishes guidelines for various Flex-on-Fabric (FOF) interconnections.