Demonstration of silver micro-joints for flip-chip interconnect

► Silver micro-joints for flip-chip interconnect are formed between silicon chips and copper substrates by solid state bonding. ► No flux is used during bonding. ► Bonding temperature is compatible with typical reflow temperature of lead-free solders used in industries. ► Solid state bonding occurs when silver and copper atoms are brought within atomic distance so as to share electrons. ► Silver joints do not contain intermetallic compound, avoiding reliability issues associated with its growth.