US Patent 7125789 Composite metal column for mounting semiconductor device

An integrated circuit chip 903, which has a plurality of pads 903b and non-reflowable contact members 1201 to be connected by reflow attachment to external parts. Each of these contact members 1201 has a height-to-diameter ratio and uniform diameter favorable for absorbing strain under thermo-mechanical stress. The members have a solderable surface 1202 on each end and a layer of reflowable material on each end. Each member is solder-attached (1204) at one end to a chip contact pad 903b, while the other end (1203) of each member is operable for reflow attachment to external parts.