Bonding of flip-chip i.c. dies to a substrate

摘要

An integrated circuit die 2 has exposed regions on its upper surface of aluminium on which forms an oxide layer 13. The oxide layer 13 is etched away to form windows 12 onto the underlying aluminium regions 10. A conductive, protective layer 14 of titanium nitride is sputtered on the upper surface of the die; pads 7 of a conductive thermoplastic 15 are then deposited over the windows 12. The titanium nitride layer 14 is subsequently removed by etching, except where it is protected by the pads 7. The die 2 can then be flipped over and joined to a substrate 1 by making electrical connection between the pads 7 and conductive regions 8 on the substrate. $$