Patent ID: 6025649
Filing Date: 2000-02-15
Classification: H01L,H05K,Y02P

Abstract:
A solder structure in the form of a column which, when used to bond a first and second electronic substrates together, forms an enhanced fatigue resistant solder bond the solder column structure comprising a solder comprising less than about 3% by weight tin, the balance lead, the column having at one end the solder forming the column and at the other free end thereof a layer of metal thereon which metal forms a single phase ternary alloy with the solder when the solder column is reflowed, the solder column being attached at the solder end to one of a plurality of pads or other bonding sites on the first electronic substrate to be joined, and, when the solder column structure is to be reflowed to join the solder column to the second substrate to be joined, the metal layer free end portion of the solder column is positioned proximate the corresponding pad or other bonding site on the second substrate with the proviso that the ratio of lead to tin in the ternary alloy is about the same as in the solder.