Thermosonic-Adhesive (TS-A) Integration of Flexible Integrated Circuits on Flexible Plastic Substrates

The integration of flexible integrated circuits (FlexICs) on flexible plastic substrates to deliver smart flexible electronic solutions has enormous potential across a range of consumer markets, including wearable devices, healthcare devices and smart labels. At present, reliable FlexIC integration for hybrid flexible electronic circuits is mainly based on conductive adhesive packaging which is too slow and/or expensive to address the highest volume products envisioned for consumer markets. In this research we have investigated low-cost bonding processes for FlexICs based on non-conductive adhesive (NCA) and thermosonic-adhesive (TS-A) bonding. Four-wire resistance tests, shear tests and bending tests were used for evaluation during process development. The results confirmed that NCA and TS-A bonding were feasible for FlexIC packaging, and the evaluation tests showed encouraging electrical and mechanical performance. This research is bringing novel bonding techniques that will significantly advance the development of low-cost manufacturing of smart flexible electronics to drive mass market adoption in consumer markets.