| abstract |
(E. G., A ceramic or plastic ball grid array module) to a circuit board with solder. A lead-free solder ball is soldered to the module without using a bonding solder. The solder balls include tin-antimony alloys containing about 3 to about 15 weight percent antimony. The solder balls are soldered to the circuit board using lead-free solder. The bonding solder essentially consists of a tin-silver-copper alloy essentially consisting of about 95.5-96.0 wt% tin, about 3.5-4.0 wt% silver, and about 0.5-1.0 wt% copper. The resulting solder connection between the module and the circuit board has a fatigue life of at least 90% of the fatigue life of the reference structure. The reference structure is a 90Pb / 10Sn solder ball bonded to the module and circuit card by 63Sn / 37Pb solder solder. |