US Patent 7229291 Flexible ring interconnection system

Multiple small conductive and flexible hollow rings, each of which is made from a pliable material, provide a flexible connection medium for use between a substrate and a microelectronic device package. Each ring is soldered to both the substrate and the device. A portion of the sidewall of each ring is not soldered thus insuring that at least part of the ring stays flexible. The rings accommodate elevation differences on a substrate and electronic device package. They also provide a vibration resistant and flexible joint.